@article{
 title = {Achieving over 15% Efficiency in Solution-Processed Cu (In, Ga)(S, Se) 2 Thin-Film Solar Cells via a Heterogeneous-Formation-Induced Benign p–n Junction Interface},
 type = {article},
 year = {2021},
 publisher = {ACS Publications},
 id = {a5c5460f-0461-356e-b458-4851b0570c31},
 created = {2021-03-23T08:16:18.445Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-03-23T08:50:12.383Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 bibtype = {article},
 author = {Kim, Da-Seul and Park, Gi Soon and Kim, Byungwoo and Bae, Soohyun and Park, Sang Yeun and Oh, Hyung-Suk and Lee, Ung and Ko, Doo-Hyun and Kim, Jihyun and Min, Byoung Koun},
 journal = {ACS Applied Materials & Interfaces}
}

@article{
 title = {Learning the properties of a water-lean amine solvent from carbon capture pilot experiments},
 type = {article},
 year = {2021},
 pages = {116213},
 volume = {283},
 publisher = {Elsevier},
 id = {9331e987-1c5f-3b91-92bf-a2e3fa5d081e},
 created = {2021-03-23T08:16:18.510Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-03-23T08:50:11.542Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 bibtype = {article},
 author = {Kim, Jeongnam and Na, Jonggeol and Kim, Kyeongsu and Bak, Ji Hyun and Lee, Hyunjoo and Lee, Ung},
 journal = {Applied Energy}
}

@article{
 title = {Highly selective and stackable electrode design for gaseous CO2 electroreduction to ethylene in a zero-gap configuration},
 type = {article},
 year = {2021},
 keywords = {CO2 reduction reaction (CO2RR),Ethylene,KOH incorporated Cu,Scaling and stacking up system,Zero-gap electrolyzer},
 pages = {105859},
 volume = {84},
 publisher = {Elsevier},
 id = {e4ebaa7e-089f-3f56-b49e-5a511d9dd785},
 created = {2021-03-23T08:23:13.443Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-03-23T08:50:12.130Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 abstract = {The electrochemical reduction of CO2 to ethylene has the potential to reduce greenhouse gas emissions while producing commodity chemicals for plastics; however, a scalable and feasible system for this remains a challenge. Herein, we report an efficient and stackable electrode design for the electrolysis of CO2 to ethylene. Using KOH-incorporated Cu nanoparticle (Cu-KOH) as the cathode in a zero-gap electrolyzer, Faradaic efficiency of 78.7% for C2 products was achieved at a current density of 281 mA cm–2. Among C2 products, ethylene with a 54.5% FE was dominant product. For mass production, three membrane electrode assemblies (MEAs) were stacked and operated. Operando X-ray absorption spectroscopy under the zero-gap electrolyzer suggested mainly metallic Cu state with some persistent oxide-derived Cu species in Cu-KOH, including Cu2O and Cu(OH)2, which expected a synergistic effect for the conversion of CO2 to C2H4. Our findings provide a new strategy for converting CO2 to C2H4, which is expected to accelerate the commercialization of high-value chemical production through electrochemical CO2 reduction.},
 bibtype = {article},
 author = {Lee, Woong Hee and Lim, Chulwan and Lee, Si Young and Chae, Keun Hwa and Choi, Chang Hyuck and Lee, Ung and Min, Byoung Koun and Hwang, Yun Jeong and Oh, Hyung Suk},
 doi = {10.1016/j.nanoen.2021.105859},
 journal = {Nano Energy}
}

The electrochemical reduction of CO2 to ethylene has the potential to reduce greenhouse gas emissions while producing commodity chemicals for plastics; however, a scalable and feasible system for this remains a challenge. Herein, we report an efficient and stackable electrode design for the electrolysis of CO2 to ethylene. Using KOH-incorporated Cu nanoparticle (Cu-KOH) as the cathode in a zero-gap electrolyzer, Faradaic efficiency of 78.7% for C2 products was achieved at a current density of 281 mA cm–2. Among C2 products, ethylene with a 54.5% FE was dominant product. For mass production, three membrane electrode assemblies (MEAs) were stacked and operated. Operando X-ray absorption spectroscopy under the zero-gap electrolyzer suggested mainly metallic Cu state with some persistent oxide-derived Cu species in Cu-KOH, including Cu2O and Cu(OH)2, which expected a synergistic effect for the conversion of CO2 to C2H4. Our findings provide a new strategy for converting CO2 to C2H4, which is expected to accelerate the commercialization of high-value chemical production through electrochemical CO2 reduction.

@article{
 title = {Amine blending optimization for maximizing CO2 absorption capacity in a diisopropanolamine – methyldiethanolamine – H2O system using the electrolyte UNIQUAC model},
 type = {article},
 year = {2021},
 keywords = {Blended amine,CO2 solubility,Cyclic capacity,Diisopropanolamine (DIPA),Electrolyte universal quasi-chemical (electrolyte,Methyldiethanolamine (MDEA)},
 volume = {419},
 month = {9},
 publisher = {Elsevier B.V.},
 day = {1},
 id = {ceb36285-f823-3b18-80a3-a4a9375396c3},
 created = {2021-07-26T15:08:37.630Z},
 file_attached = {true},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-08-11T17:58:34.799Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {Experimental data on CO2 solubility in diisopropanolamine (DIPA) and methyldiethanolamine (MDEA) blended aqueous solutions were measured at different amine blending ratios and working temperatures. The successive (iterative) substitution method was implemented to calculate the molar fractions of all chemical species, including molecules and electrolytes, from equilibrium along with four material balances and one electroneutrality equation. The electrolyte universal quasi-chemical (electrolyte UNIQUAC) model was used to consider the nonideality in the liquid phase. The partial pressures of CO2 in the gas phase and molar fractions of all components in the liquid phase were recalculated using thermodynamic models. In addition, the effect of the blending ratio of DIPA, MDEA, and H2O was investigated and expressed using the newly applied triangular diagrams of pH, heat of absorption, and cyclic capacity of CO2 according to the absorption and stripping conditions.},
 bibtype = {article},
 author = {Choi, Bong Ken and Kim, Seung Mo and Kim, Kyung Min and Lee, Ung and Choi, Jeong Ho and Lee, Jong Seop and Baek, Il Hyun and Nam, Sung Chang and Moon, Jong Ho},
 doi = {10.1016/j.cej.2021.129517},
 journal = {Chemical Engineering Journal}
}

Experimental data on CO2 solubility in diisopropanolamine (DIPA) and methyldiethanolamine (MDEA) blended aqueous solutions were measured at different amine blending ratios and working temperatures. The successive (iterative) substitution method was implemented to calculate the molar fractions of all chemical species, including molecules and electrolytes, from equilibrium along with four material balances and one electroneutrality equation. The electrolyte universal quasi-chemical (electrolyte UNIQUAC) model was used to consider the nonideality in the liquid phase. The partial pressures of CO2 in the gas phase and molar fractions of all components in the liquid phase were recalculated using thermodynamic models. In addition, the effect of the blending ratio of DIPA, MDEA, and H2O was investigated and expressed using the newly applied triangular diagrams of pH, heat of absorption, and cyclic capacity of CO2 according to the absorption and stripping conditions.

@article{
 title = {Condensation of furans for the production of diesel precursors: A study on the effects of surface acid sites of sulfonated carbon catalysts},
 type = {article},
 year = {2021},
 pages = {155-163},
 volume = {375},
 publisher = {Elsevier},
 id = {2cd34336-752a-3edd-af8d-babed2130ad3},
 created = {2021-08-11T16:56:20.514Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-08-11T17:58:34.829Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 bibtype = {article},
 author = {Yang, Hyemin and Joh, Han-Ik and Choo, Hyunah and Choi, Jae-wook and Suh, Dong Jin and Lee, Ung and Choi, Jungkyu and Ha, Jeong-Myeong},
 journal = {Catalysis Today}
}

@article{
 title = {Bayesian optimization of industrial-scale toluene diisocyanate liquid-phase jet reactor with 3-D computational fluid dynamics model},
 type = {article},
 year = {2021},
 pages = {327-339},
 volume = {98},
 publisher = {Elsevier},
 id = {53e4ea5f-abaf-3d0d-b5aa-50e3468346d3},
 created = {2021-08-11T16:56:20.561Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-08-11T17:58:34.250Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 bibtype = {article},
 author = {Park, Seongho and Atwair, Mohamed and Kim, Kyeongsu and Lee, Ung and Na, Jonggeol and Zahid, Umer and Lee, Chul-Jin},
 journal = {Journal of Industrial and Engineering Chemistry}
}

@article{
 title = {New strategies for economically feasible CO 2 electroreduction using a porous membrane in zero-gap configuration},
 type = {article},
 year = {2021},
 publisher = {Royal Society of Chemistry},
 id = {0683c75d-449a-32c8-9057-b73f85b8d20c},
 created = {2021-08-11T17:03:53.843Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-08-11T17:58:34.849Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 bibtype = {article},
 author = {Lee, Woong Hee and Kim, Kyeongsu and Lim, Chulwan and Ko, Young-Jin and Hwang, Yun Jeong and Min, Byoung Koun and Lee, Ung and Oh, Hyung-Suk},
 journal = {Journal of Materials Chemistry A}
}

@article{
 title = {Design methodology for mass transfer-enhanced large-scale electrochemical reactor for CO2 reduction},
 type = {article},
 year = {2021},
 keywords = {CFD,CO2 reduction,Electrolyzer,Mass transfer},
 volume = {424},
 month = {8},
 publisher = {Elsevier B.V.},
 id = {2d184c14-15f1-3a5d-b931-bba71912cd7c},
 created = {2021-08-11T17:03:53.843Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-08-11T17:58:34.254Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 abstract = {The electrochemical conversion of CO2 using a continuous flow membrane reactor is a promising technology. This is because the membrane reactor can achieve high productivity and selectivity by enhancing the mass transfer of CO2. In an industrial-scale reactor, the extrinsic properties that facilitate the mass transfer rate are crucial because the uniform flow distribution and high production rate can only be achieved when the interface and flow patterns are properly designed. Herein, we experimentally measured the production rate of CO in a large-scale electrochemical CO2 reduction reactor by varying the pH, interface, and flow pattern. The result indicated that optimization of the flow pattern alone can improve the production rate of CO by 28% indicating that a high convection rate through gas diffusion electrode (GDE) results in a high production rate. A three-dimensional computational fluid dynamic model was developed to quantify the effect of the new flow pattern on the mass transfer. From the model, the Peclet number increased by 28%, which is consistent with the CO partial current increment. This result indicates that the convective mass transfer improves the production rate. Additionally, we proposed a general guideline for the flow pattern design for a large-scale electrochemical CO2 reduction reactor that maximizes convective mass transfer through a GDE.},
 bibtype = {article},
 author = {Jung, Byungchan and Park, Seongho and Lim, Chulwan and Lee, Woong Hee and Lim, Youngsub and Na, Jonggeol and Lee, Chul Jin and Oh, Hyung Suk and Lee, Ung},
 doi = {10.1016/j.cej.2021.130265},
 journal = {Chemical Engineering Journal}
}

The electrochemical conversion of CO2 using a continuous flow membrane reactor is a promising technology. This is because the membrane reactor can achieve high productivity and selectivity by enhancing the mass transfer of CO2. In an industrial-scale reactor, the extrinsic properties that facilitate the mass transfer rate are crucial because the uniform flow distribution and high production rate can only be achieved when the interface and flow patterns are properly designed. Herein, we experimentally measured the production rate of CO in a large-scale electrochemical CO2 reduction reactor by varying the pH, interface, and flow pattern. The result indicated that optimization of the flow pattern alone can improve the production rate of CO by 28% indicating that a high convection rate through gas diffusion electrode (GDE) results in a high production rate. A three-dimensional computational fluid dynamic model was developed to quantify the effect of the new flow pattern on the mass transfer. From the model, the Peclet number increased by 28%, which is consistent with the CO partial current increment. This result indicates that the convective mass transfer improves the production rate. Additionally, we proposed a general guideline for the flow pattern design for a large-scale electrochemical CO2 reduction reactor that maximizes convective mass transfer through a GDE.

@article{
 title = {A perspective on practical solar to carbon monoxide production devices with economic evaluation},
 type = {article},
 year = {2020},
 websites = {https://doi.org/10.1039/C9SE00647H},
 id = {d05ad1ed-5832-3eaf-8fc4-f62df2e4e361},
 created = {2020-05-07T10:51:38.311Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2020-05-07T10:51:38.311Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 bibtype = {article},
 author = {Chae, Sang Youn and Lee, Si Young and Han, Sung Gyu and Kim, Honggon and Ko, Jongwon and Park, Sejin and Joo, Oh-Shim and Kim, Donghwan and Kang, Yoonmook and Lee, Ung and Hwang, Yun Jeong and Min, Byoung Koun},
 doi = {10.1039/C9SE00647H},
 journal = {Sustainable Energy & Fuels}
}

@article{
 title = {Continuous-flow production of petroleum-replacing fuels from highly viscous Kraft lignin pyrolysis oil using its hydrocracked oil as a solvent},
 type = {article},
 year = {2020},
 keywords = {CoMo/Hβ,Hydrocracking,Hydrodeoxygenation,Lignin pyrolysis oil,Viscosity},
 volume = {213},
 month = {6},
 publisher = {Elsevier Ltd},
 day = {1},
 id = {bbf02c9a-94ec-3074-86e5-8490c04f6301},
 created = {2020-05-07T10:53:07.310Z},
 file_attached = {true},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2020-05-07T10:53:10.194Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {The development of solvent-free lignin pyrolysis processes is highly desirable, because these processes would allow the depolymerized product to be used directly as a renewable energy source and chemical feedstock, without removal of solvnets. However, this product is typically highly viscous and cannot be used in continuous-flow reaction systems. In this study, lignin pyrolysis oil was prepared from Kraft lignin using bench-scale fixed-bed batch pyrolysis and then hydrocracked to produce less-viscous liquid products. Oligomers were degraded into smaller molecules via reactions involving hydrogen (hydrocracking) using CoMo/Hβ and CoMo/Al2O3 as catalysts. A low viscosity of 21 cP, a liquid yield of 76.6%, and a low coke yield of 1.6% were successfully attained using a reaction temperature of 400 °C, a reaction time of 60 min, and the CoMo/Hβ catalyst. Thus, these conditions were selected to achieve the highest liquid yield with sufficient fluidity, although the lowest viscosity of 3.2 cP was achieved after 240 min. When 30 wt% of the resulting hydrocracked oil was used, it dissolved sticky raw lignin pyrolysis oil, significantly reducing its viscosity from 751 cP to 111 cP, which is sufficient to ensure flow in a typical petroleum pipeline. Using the hydrocracked/raw lignin pyrolysis oil mixture, the proposed continuous-flow hydrodeoxygenation successfully produced petroleum-replacing deoxygenated fuels.},
 bibtype = {article},
 author = {Kim, Yoonsoo and Shim, Jingi and Choi, Jae Wook and Jin Suh, Dong and Park, Young Kwon and Lee, Ung and Choi, Jungkyu and Ha, Jeong Myeong},
 doi = {10.1016/j.enconman.2020.112728},
 journal = {Energy Conversion and Management}
}

The development of solvent-free lignin pyrolysis processes is highly desirable, because these processes would allow the depolymerized product to be used directly as a renewable energy source and chemical feedstock, without removal of solvnets. However, this product is typically highly viscous and cannot be used in continuous-flow reaction systems. In this study, lignin pyrolysis oil was prepared from Kraft lignin using bench-scale fixed-bed batch pyrolysis and then hydrocracked to produce less-viscous liquid products. Oligomers were degraded into smaller molecules via reactions involving hydrogen (hydrocracking) using CoMo/Hβ and CoMo/Al2O3 as catalysts. A low viscosity of 21 cP, a liquid yield of 76.6%, and a low coke yield of 1.6% were successfully attained using a reaction temperature of 400 °C, a reaction time of 60 min, and the CoMo/Hβ catalyst. Thus, these conditions were selected to achieve the highest liquid yield with sufficient fluidity, although the lowest viscosity of 3.2 cP was achieved after 240 min. When 30 wt% of the resulting hydrocracked oil was used, it dissolved sticky raw lignin pyrolysis oil, significantly reducing its viscosity from 751 cP to 111 cP, which is sufficient to ensure flow in a typical petroleum pipeline. Using the hydrocracked/raw lignin pyrolysis oil mixture, the proposed continuous-flow hydrodeoxygenation successfully produced petroleum-replacing deoxygenated fuels.

@article{
 title = {Mass Transport Control by Surface Graphene Oxide for Selective CO Production from Electrochemical CO2 Reduction},
 type = {article},
 year = {2020},
 keywords = {Zn-based catalyst,computational fluid dynamics simulation,electrochemical CO2 reduction,reduced graphene oxide,suppression of H2 evolution},
 pages = {3222-3231},
 volume = {10},
 month = {3},
 publisher = {American Chemical Society},
 day = {6},
 id = {c0a14b4d-9f43-349d-bcc3-f164e2364c94},
 created = {2020-05-07T10:54:36.972Z},
 file_attached = {true},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2020-05-07T10:54:39.876Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {Electrochemical CO2 reduction is always accompanied by a competitive hydrogen evolution reaction as water is used as a hydrogen source. In addition to intrinsic activity control, geometrical factors of electrocatalysts such as their porous structure have been demonstrated to affect the reaction selectivity, but understanding its origin is still important. Herein, we demonstrate that reduced graphene oxide layers can effectively control the Faradaic efficiency for CO production of porous zinc nanoparticle electrocatalysts. Simply tuning the coverage of graphene oxide dramatically varies Faradaic efficiency for CO production from 66 to 94% even in the bicarbonate electrolyte at the same biased potential, in which the hydrogen evolution rate was notably suppressed without sacrificing CO2 reduction to CO production rate unlike many Zn-based electrocatalysts. The graphene oxide layers are revealed to play roles in providing geometric barriers for the mass transport channels of reactants rather than changing the chemical states of the Zn-based electrocatalysts according to in situ X-ray absorption spectroscopic analysis and electrochemical reaction kinetic studies. In addition, computational fluid dynamics simulation studies estimate the Faradaic efficiency dependence on the surface coverage and suggest that the selective suppression of H2 evolution is associated with the larger increment in local pH compared to that in local pCO2 at the porous electrocatalyst surfaces. Decoupling between these reactant concentrations is originated from the higher consumption rate and lower bulk concentration of proton compared to those of CO2, and the surface coating with graphene oxide can be an effective way to control mass transport channel.},
 bibtype = {article},
 author = {Nguyen, Dang Le Tri and Lee, Chan Woo and Na, Jonggeol and Kim, Min Cheol and Tu, Nguyen Dien Kha and Lee, Si Young and Sa, Young Jin and Won, Da Hye and Oh, Hyung Suk and Kim, Heesuk and Min, Byoung Koun and Han, Sang Soo and Lee, Ung and Hwang, Yun Jeong},
 doi = {10.1021/acscatal.9b05096},
 journal = {ACS Catalysis},
 number = {5}
}

Electrochemical CO2 reduction is always accompanied by a competitive hydrogen evolution reaction as water is used as a hydrogen source. In addition to intrinsic activity control, geometrical factors of electrocatalysts such as their porous structure have been demonstrated to affect the reaction selectivity, but understanding its origin is still important. Herein, we demonstrate that reduced graphene oxide layers can effectively control the Faradaic efficiency for CO production of porous zinc nanoparticle electrocatalysts. Simply tuning the coverage of graphene oxide dramatically varies Faradaic efficiency for CO production from 66 to 94% even in the bicarbonate electrolyte at the same biased potential, in which the hydrogen evolution rate was notably suppressed without sacrificing CO2 reduction to CO production rate unlike many Zn-based electrocatalysts. The graphene oxide layers are revealed to play roles in providing geometric barriers for the mass transport channels of reactants rather than changing the chemical states of the Zn-based electrocatalysts according to in situ X-ray absorption spectroscopic analysis and electrochemical reaction kinetic studies. In addition, computational fluid dynamics simulation studies estimate the Faradaic efficiency dependence on the surface coverage and suggest that the selective suppression of H2 evolution is associated with the larger increment in local pH compared to that in local pCO2 at the porous electrocatalyst surfaces. Decoupling between these reactant concentrations is originated from the higher consumption rate and lower bulk concentration of proton compared to those of CO2, and the surface coating with graphene oxide can be an effective way to control mass transport channel.

@article{
 title = {Low-temperature oxidative coupling of methane using alkaline earth metal oxide-supported perovskites},
 type = {article},
 year = {2020},
 keywords = {Alkaline-earth metal oxide,Barium oxide,Low temperature,Methane,Oxidative coupling,Perovskite},
 publisher = {Elsevier B.V.},
 id = {f98267b6-8dbf-3f0b-bce9-7c05ed05b06b},
 created = {2020-05-07T10:56:45.109Z},
 file_attached = {true},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2020-05-07T10:56:48.570Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {Perovskite-supported alkaline-earth metal oxide catalysts were prepared for application in the oxidative coupling of methane (OCM). The selective production of C2+ compounds, including ethane, ethylene, acetylene, propane, and propylene, was observed at reaction temperatures < 700 °C. This lower reaction temperature was not achieved with pure perovskites but only with the combination of alkaline-earth metal oxides and perovskite supports. The formation of complex mixed oxides, such as Ba-Ca-Ti-Ox, Ba-Sr-Ti-Ox, and Ba2TiO4, was also observed for these catalysts. This contributed to the improved C2+ yield at the lower reaction temperature. The strong basicity, which contributes to the improved OCM activity, was also observed for these catalysts.},
 bibtype = {article},
 author = {Lim, Seoyeon and Choi, Jae Wook and Jin Suh, Dong and Lee, Ung and Song, Kwang Ho and Ha, Jeong Myeong},
 doi = {10.1016/j.cattod.2019.11.014},
 journal = {Catalysis Today}
}

Perovskite-supported alkaline-earth metal oxide catalysts were prepared for application in the oxidative coupling of methane (OCM). The selective production of C2+ compounds, including ethane, ethylene, acetylene, propane, and propylene, was observed at reaction temperatures < 700 °C. This lower reaction temperature was not achieved with pure perovskites but only with the combination of alkaline-earth metal oxides and perovskite supports. The formation of complex mixed oxides, such as Ba-Ca-Ti-Ox, Ba-Sr-Ti-Ox, and Ba2TiO4, was also observed for these catalysts. This contributed to the improved C2+ yield at the lower reaction temperature. The strong basicity, which contributes to the improved OCM activity, was also observed for these catalysts.

@article{
 title = {Facile one-pot synthesis of ZnBr2 immobilized ion exchange resin for the coupling reaction of CO2 with propylene oxide},
 type = {article},
 year = {2020},
 pages = {101324},
 volume = {42},
 publisher = {Elsevier},
 id = {dc687d30-2c6f-3563-a043-c4ec9977eae9},
 created = {2021-03-23T08:16:18.567Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-03-23T08:50:13.406Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 bibtype = {article},
 author = {Cho, Shin Hye and Dahnum, Deliana and Cheong, Seok-Hyeon and Lee, Hee Won and Lee, Ung and Ha, Jeong-Myeong and Lee, Hyunjoo},
 journal = {Journal of CO2 Utilization}
}

@article{
 title = {Condensation of furans for the production of diesel precursors: A study on the effects of surface acid sites of sulfonated carbon catalysts},
 type = {article},
 year = {2020},
 publisher = {Elsevier},
 id = {e9508853-bbe2-370b-a443-30dfb0b6d4cb},
 created = {2021-03-23T08:16:18.677Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-03-23T08:50:12.486Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 bibtype = {article},
 author = {Yang, Hyemin and Joh, Han-Ik and Choo, Hyunah and Choi, Jae-wook and Suh, Dong Jin and Lee, Ung and Choi, Jungkyu and Ha, Jeong-Myeong},
 journal = {Catalysis Today}
}

@article{
 title = {Catalyst–electrolyte interface chemistry for electrochemical CO 2 reduction},
 type = {article},
 year = {2020},
 pages = {6632-6665},
 volume = {49},
 publisher = {Royal Society of Chemistry},
 id = {45e41000-eaac-3527-9121-2c8903a2d8b5},
 created = {2021-03-23T08:16:18.683Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-03-23T08:50:12.145Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 bibtype = {article},
 author = {Sa, Young Jin and Lee, Chan Woo and Lee, Si Young and Na, Jonggeol and Lee, Ung and Hwang, Yun Jeong},
 journal = {Chemical Society Reviews},
 number = {18}
}

@article{
 title = {Data-driven pilot optimization for electrochemical CO mass production},
 type = {article},
 year = {2020},
 pages = {16943-16950},
 volume = {8},
 publisher = {Royal Society of Chemistry},
 id = {3b2d64a9-7961-329f-a7c9-e813c69a8a34},
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 starred = {false},
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 bibtype = {article},
 author = {Kim, Kyeongsu and Lee, Woong Hee and Na, Jonggeol and Hwang, YunJeong and Oh, Hyung-Suk and Lee, Ung},
 journal = {Journal of Materials Chemistry A},
 number = {33}
}

@article{
 title = {Toward the practical application of direct CO2 hydrogenation technology for methanol production},
 type = {article},
 year = {2020},
 pages = {8781-8798},
 volume = {44},
 publisher = {Wiley Online Library},
 id = {02b42275-34de-37f5-a427-e301860426fd},
 created = {2021-03-23T08:23:13.194Z},
 file_attached = {false},
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 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 bibtype = {article},
 author = {Lee, Hee W and Kim, Kyeongsu and An, JinJoo and Na, Jonggeol and Kim, Honggon and Lee, Hyunjoo and Lee, Ung},
 journal = {International Journal of Energy Research},
 number = {11}
}

@article{
 title = {Low-temperature oxidative coupling of methane using alkaline earth metal oxide-supported perovskites},
 type = {article},
 year = {2020},
 pages = {127-133},
 volume = {352},
 publisher = {Elsevier},
 id = {8e3007db-6657-379d-bdd5-e3b19509cecc},
 created = {2021-03-23T08:23:13.255Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-03-23T08:50:13.931Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 bibtype = {article},
 author = {Lim, Seoyeon and Choi, Jae-Wook and Suh, Dong Jin and Lee, Ung and Song, Kwang Ho and Ha, Jeong-Myeong},
 journal = {Catalysis Today}
}

@article{
 title = {Electrochemical oxidation of toluene with controlled selectivity: The effect of carbon anode},
 type = {article},
 year = {2020},
 pages = {147517},
 volume = {534},
 publisher = {Elsevier},
 id = {c06f9b21-3802-3b9c-94b2-60d660780ebb},
 created = {2021-03-23T08:23:13.321Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-03-23T08:50:12.290Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 bibtype = {article},
 author = {Seo, Bora and Lee, Woong Hee and Sa, Young Jin and Lee, Ung and Oh, Hyung-Suk and Lee, Hyunjoo},
 journal = {Applied Surface Science}
}

@article{
 title = {A perspective on practical solar to carbon monoxide production devices with economic evaluation},
 type = {article},
 year = {2020},
 websites = {https://doi.org/10.1039/C9SE00647H},
 id = {5902f854-cd3b-351a-973a-d0863a468621},
 created = {2021-03-23T08:23:13.571Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-03-23T08:50:12.749Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 bibtype = {article},
 author = {Chae, Sang Youn and Lee, Si Young and Han, Sung Gyu and Kim, Honggon and Ko, Jongwon and Park, Sejin and Joo, Oh-Shim and Kim, Donghwan and Kang, Yoonmook and Lee, Ung and Hwang, Yun Jeong and Min, Byoung Koun},
 doi = {10.1039/C9SE00647H},
 journal = {Sustainable Energy & Fuels}
}

@article{
 title = {An experimental based optimization of a novel water lean amine solvent for post combustion CO2 capture process},
 type = {article},
 year = {2019},
 keywords = {CO2 capture,Gaussian process Bayesian optimization,Pilot-scale testing,Water-lean amine solvent},
 pages = {174-184},
 volume = {248},
 month = {8},
 publisher = {Elsevier Ltd},
 day = {15},
 id = {401c6451-0592-3592-83a0-c1813b547b23},
 created = {2020-05-07T10:41:41.952Z},
 file_attached = {true},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2020-05-07T10:41:44.243Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {The development of new amine solvents without the major drawbacks of conventional amines is crucial to industrial applications of CO2 capture. This paper presents a water-lean CO2 capture solvent having a low regeneration energy and low degradation. The water-lean solvent, K2Sol, is a sterically hindered diamine; because of the hindered amine site, K2Sol easily forms bicarbonate, resulting in a high absorption capacity. The minimum solvent regeneration energy is obtained using Gaussian process Bayesian optimization (GPBO) and bench-scale pilot plant experiments. GPBO finds the optimal solution using the input and output relationship of experiments; thus, expensive first-principle model construction can be avoided. According to the pilot plant experiment, the optimal regeneration energies of monoethanolamine (MEA) and K2Sol are 4.3 and 2.8 GJ/t CO2, respectively, indicating that K2Sol requires only 65% of the regeneration energy of MEA. Fewer than 30 experiments are required to find the optimal pilot plant operation for both the MEA and K2Sol experiments. We also describe the superior properties of K2Sol in terms of the CO2 loading, cyclic capacity, regeneration temperature, and degradation.},
 bibtype = {article},
 author = {Hwang, Junhyeok and Kim, Jeongnam and Lee, Hee Won and Na, Jonggeol and Ahn, Byoung Sung and Lee, Sang Deuk and Kim, Hoon Sik and Lee, Hyunjoo and Lee, Ung},
 doi = {10.1016/j.apenergy.2019.04.135},
 journal = {Applied Energy}
}

The development of new amine solvents without the major drawbacks of conventional amines is crucial to industrial applications of CO2 capture. This paper presents a water-lean CO2 capture solvent having a low regeneration energy and low degradation. The water-lean solvent, K2Sol, is a sterically hindered diamine; because of the hindered amine site, K2Sol easily forms bicarbonate, resulting in a high absorption capacity. The minimum solvent regeneration energy is obtained using Gaussian process Bayesian optimization (GPBO) and bench-scale pilot plant experiments. GPBO finds the optimal solution using the input and output relationship of experiments; thus, expensive first-principle model construction can be avoided. According to the pilot plant experiment, the optimal regeneration energies of monoethanolamine (MEA) and K2Sol are 4.3 and 2.8 GJ/t CO2, respectively, indicating that K2Sol requires only 65% of the regeneration energy of MEA. Fewer than 30 experiments are required to find the optimal pilot plant operation for both the MEA and K2Sol experiments. We also describe the superior properties of K2Sol in terms of the CO2 loading, cyclic capacity, regeneration temperature, and degradation.

@article{
 title = {General technoeconomic analysis for electrochemical coproduction coupling carbon dioxide reduction with organic oxidation},
 type = {article},
 year = {2019},
 volume = {10},
 month = {12},
 publisher = {Nature Research},
 day = {1},
 id = {30d16b91-e57d-30c8-b6c0-5e754238a03e},
 created = {2020-05-07T10:43:17.080Z},
 file_attached = {true},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2020-05-07T10:43:18.342Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {Electrochemical processes coupling carbon dioxide reduction reactions with organic oxidation reactions are promising techniques for producing clean chemicals and utilizing renewable energy. However, assessments of the economics of the coupling technology remain questionable due to diverse product combinations and significant process design variability. Here, we report a technoeconomic analysis of electrochemical carbon dioxide reduction reaction–organic oxidation reaction coproduction via conceptual process design and thereby propose potential economic combinations. We first develop a fully automated process synthesis framework to guide process simulations, which are then employed to predict the levelized costs of chemicals. We then identify the global sensitivity of current density, Faraday efficiency, and overpotential across 295 electrochemical coproduction processes to both understand and predict the levelized costs of chemicals at various technology levels. The analysis highlights the promise that coupling the carbon dioxide reduction reaction with the value-added organic oxidation reaction can secure significant economic feasibility.},
 bibtype = {article},
 author = {Na, Jonggeol and Seo, Bora and Kim, Jeongnam and Lee, Chan Woo and Lee, Hyunjoo and Hwang, Yun Jeong and Min, Byoung Koun and Lee, Dong Ki and Oh, Hyung Suk and Lee, Ung},
 doi = {10.1038/s41467-019-12744-y},
 journal = {Nature Communications},
 number = {1}
}

Electrochemical processes coupling carbon dioxide reduction reactions with organic oxidation reactions are promising techniques for producing clean chemicals and utilizing renewable energy. However, assessments of the economics of the coupling technology remain questionable due to diverse product combinations and significant process design variability. Here, we report a technoeconomic analysis of electrochemical carbon dioxide reduction reaction–organic oxidation reaction coproduction via conceptual process design and thereby propose potential economic combinations. We first develop a fully automated process synthesis framework to guide process simulations, which are then employed to predict the levelized costs of chemicals. We then identify the global sensitivity of current density, Faraday efficiency, and overpotential across 295 electrochemical coproduction processes to both understand and predict the levelized costs of chemicals at various technology levels. The analysis highlights the promise that coupling the carbon dioxide reduction reaction with the value-added organic oxidation reaction can secure significant economic feasibility.

@article{
 title = {Pt black catalyzed methane oxidation to methyl bisulfate in H2SO4-SO3},
 type = {article},
 year = {2019},
 websites = {https://doi.org/10.1016/j.jcat.2019.04.042},
 month = {6},
 id = {61e2b5a4-ee02-35aa-a4b6-df8faa54cbb5},
 created = {2020-05-07T10:51:38.248Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2020-05-07T10:51:38.248Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 bibtype = {article},
 author = {Lee, Hee Won and Dang, Huyen Tran and Kim, Honggon and Lee, Ung and Ha, Jeong-Myeong and Jae, Jungho and Cheong, Minserk and Lee, Hyunjoo},
 doi = {10.1016/j.jcat.2019.04.042},
 journal = {Journal of Catalysis}
}

@article{
 title = {Formation of defect site on ZIF-7 and its effect on the methoxycarbonylation of aniline with dimethyl carbonate},
 type = {article},
 year = {2019},
 keywords = {Aniline,Aromatic carbamate,DMC,Defect site,Methoxycarbonylation,ZIF-7},
 pages = {297-306},
 volume = {380},
 month = {12},
 publisher = {Academic Press Inc.},
 day = {1},
 id = {aed2c712-ecba-3a01-8f69-cf14287b7957},
 created = {2020-05-07T10:55:36.759Z},
 file_attached = {true},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2020-05-07T10:55:39.140Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {The Zeolitic Imidazole Framework ZIF-7, (Zn(benzimidazole)2), is known to exhibit a unique gate-opening property depending on the temperature and pressure in the presence of guest molecules, making it useful for H2, CO2, and paraffine separation technology. Besides this distinctive gas adsorption property, ZIF-7 can be used as a catalyst because it contains a Lewis acid site on Zn, and a Lewis basic site on the benzimidazole. In this study, for the first time, we demonstrate that ZIF-7 is a very promising material as a catalyst for the methoxycarbonylation of aniline with dimethyl carbonate (DMC) to produce methyl phenyl carbamate (MPC), an isocyanate precursor. Fresh ZIF-7 showed a high aniline conversion of over 95% at 190 °C for 2 h, and the yield MPC was 60–70% due to the formation of methylated side products, such as N-methyl aniline and N,N′-dimethylaniline. However, interestingly, when the ZIF-7 was reused, the yield of MPC gradually increased and reached over 94.7% by the catalyst's 6th run. SEM and TEM images revealed the crystalline structure of ZIF-7 collapsed during the reaction due to the leaching of benzimidazole from the ZIF-7, which created defect sites on the Lewis acidic zinc center. Based on 1H NMR and XPS studies, it can be assumed that the DMC binds to the Zn defect sites on the ZIF-7, activating the carbonyl groups on DMC, resulting in the increased selectivity to methoxycarbonylation compared to methylation. Pretreating ZIF-7 with DMC at 190 °C for 6 h could directly activated the ZIF-7 for this methoxycarbonylation reaction. The activated ZIF-7 showed 91.0% MPC yield and the catalyst was reusable.},
 bibtype = {article},
 author = {Dahnum, Deliana and Seo, Bora and Cheong, Seok Hyeon and Lee, Ung and Ha, Jeong Myeong and Lee, Hyunjoo},
 doi = {10.1016/j.jcat.2019.09.039},
 journal = {Journal of Catalysis}
}

The Zeolitic Imidazole Framework ZIF-7, (Zn(benzimidazole)2), is known to exhibit a unique gate-opening property depending on the temperature and pressure in the presence of guest molecules, making it useful for H2, CO2, and paraffine separation technology. Besides this distinctive gas adsorption property, ZIF-7 can be used as a catalyst because it contains a Lewis acid site on Zn, and a Lewis basic site on the benzimidazole. In this study, for the first time, we demonstrate that ZIF-7 is a very promising material as a catalyst for the methoxycarbonylation of aniline with dimethyl carbonate (DMC) to produce methyl phenyl carbamate (MPC), an isocyanate precursor. Fresh ZIF-7 showed a high aniline conversion of over 95% at 190 °C for 2 h, and the yield MPC was 60–70% due to the formation of methylated side products, such as N-methyl aniline and N,N′-dimethylaniline. However, interestingly, when the ZIF-7 was reused, the yield of MPC gradually increased and reached over 94.7% by the catalyst's 6th run. SEM and TEM images revealed the crystalline structure of ZIF-7 collapsed during the reaction due to the leaching of benzimidazole from the ZIF-7, which created defect sites on the Lewis acidic zinc center. Based on 1H NMR and XPS studies, it can be assumed that the DMC binds to the Zn defect sites on the ZIF-7, activating the carbonyl groups on DMC, resulting in the increased selectivity to methoxycarbonylation compared to methylation. Pretreating ZIF-7 with DMC at 190 °C for 6 h could directly activated the ZIF-7 for this methoxycarbonylation reaction. The activated ZIF-7 showed 91.0% MPC yield and the catalyst was reusable.

@article{
 title = {Turning Harmful Deposition of Metal Impurities into Activation of Nitrogen-Doped Carbon Catalyst toward Durable Electrochemical CO2 Reduction},
 type = {article},
 year = {2019},
 pages = {2343-2350},
 volume = {4},
 month = {9},
 publisher = {American Chemical Society},
 day = {13},
 id = {25e654d2-6af6-3ceb-9670-30ecf8edf31d},
 created = {2020-05-07T10:58:35.888Z},
 file_attached = {true},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2020-05-07T10:58:38.289Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {Electrochemical CO2 reduction is typically operated under highly refined electrolyte conditions. However, trace amounts of metal impurities exist even in ultrapure electrolyte solutions, causing a fatal deactivation of the catalysts. To address this issue, various efforts have been made to prevent the harmful deposition of metal impurities on the catalyst. Herein, we designed a new system where metal impurities are utilized as activators. We demonstrated "self-activation" of the N-doped carbon catalyst in the presence of Fe impurity with remarkable stability for 120 h. The origin of the self-activation was the selective adsorption of Fe impurity forming highly dispersed Fe sites through Fe-N interactions. The correlations between the self-activation and number of N sites and their moieties were investigated and further generalized into other metals, such as Ni, Zn, and Cu. This novel general strategy has enormous impact on design of durable catalysts for various electrochemical reactions suffering from deactivation by metal impurities.},
 bibtype = {article},
 author = {Kim, Chanyeon and Choe, Yoong Kee and Won, Da Hye and Lee, Ung and Oh, Hyung Suk and Lee, Dong Ki and Choi, Chang Hyuck and Yoon, Sungho and Kim, Woong and Hwang, Yun Jeong and Min, Byoung Koun},
 doi = {10.1021/acsenergylett.9b01581},
 journal = {ACS Energy Letters},
 number = {9}
}

Electrochemical CO2 reduction is typically operated under highly refined electrolyte conditions. However, trace amounts of metal impurities exist even in ultrapure electrolyte solutions, causing a fatal deactivation of the catalysts. To address this issue, various efforts have been made to prevent the harmful deposition of metal impurities on the catalyst. Herein, we designed a new system where metal impurities are utilized as activators. We demonstrated "self-activation" of the N-doped carbon catalyst in the presence of Fe impurity with remarkable stability for 120 h. The origin of the self-activation was the selective adsorption of Fe impurity forming highly dispersed Fe sites through Fe-N interactions. The correlations between the self-activation and number of N sites and their moieties were investigated and further generalized into other metals, such as Ni, Zn, and Cu. This novel general strategy has enormous impact on design of durable catalysts for various electrochemical reactions suffering from deactivation by metal impurities.

@article{
 title = {Reversible absorption of SO<inf>2</inf> with alkyl-anilines: The effects of alkyl group on aniline and water},
 type = {article},
 year = {2019},
 keywords = {Absorbent,Acid-base salt,Aniline,Charge transfer complex,Reversibility,SO 2},
 volume = {69},
 id = {592efc60-ca61-315d-9da6-8734876bbfee},
 created = {2018-10-17T23:59:00.000Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2020-10-15T22:50:02.678Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2018 The Korean Society of Industrial and Engineering Chemistry SO2 absorption behaviours of N,N-dimethylaniline (DMA), N,N-diethylaniline (DEA), N,N-dibutylaniline (DBA), and N-methyldiphenylamine (MDPA) — were investigated in dry and wet conditions. DMA showed the highest SO2 absorption capacity of 1.5 molSO2 molAbsorbent−1 in dry condition, while DBA showed the highest capacity of 1.75 molSO2 molAbsorbent−1 in wet condition. Raman analyses revealed that anilines captured SO2 by forming charge transfer complexes in dry condition and the interaction between SO2 and aniline decreased as the steric hindrance of alkyl aniline increased. In contrast, bisulfite-based acid-base salt was formed in the presence of water, and the capacity increased with an increasing basicity of the alkyl aniline.},
 bibtype = {article},
 author = {Vo, H.T. and Cho, S.H. and Lee, U. and Jae, J. and Kim, H. and Lee, H.},
 doi = {10.1016/j.jiec.2018.09.033},
 journal = {Journal of Industrial and Engineering Chemistry}
}

© 2018 The Korean Society of Industrial and Engineering Chemistry SO2 absorption behaviours of N,N-dimethylaniline (DMA), N,N-diethylaniline (DEA), N,N-dibutylaniline (DBA), and N-methyldiphenylamine (MDPA) — were investigated in dry and wet conditions. DMA showed the highest SO2 absorption capacity of 1.5 molSO2 molAbsorbent−1 in dry condition, while DBA showed the highest capacity of 1.75 molSO2 molAbsorbent−1 in wet condition. Raman analyses revealed that anilines captured SO2 by forming charge transfer complexes in dry condition and the interaction between SO2 and aniline decreased as the steric hindrance of alkyl aniline increased. In contrast, bisulfite-based acid-base salt was formed in the presence of water, and the capacity increased with an increasing basicity of the alkyl aniline.

@article{
 title = {Bayesian Inference of Aqueous Mineral Carbonation Kinetics for Carbon Capture and Utilization},
 type = {article},
 year = {2019},
 volume = {58},
 id = {4ad306ed-e76b-3195-98a7-a8ab22527762},
 created = {2019-05-28T23:59:00.000Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2020-12-23T06:56:40.910Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2019 American Chemical Society. We develop a rigorous mathematical model of aqueous mineral carbonation kinetics for carbon capture and utilization (CCU) and estimate the parameter posterior distribution using Bayesian parameter estimation framework and lab-scale experiments. We conduct 16 experiments according to the orthogonal array design and an additional one experiment for the model test. The model considers the gas-liquid mass transfer, solid dissolution, ionic reactions, precipitations, and discrete events in the form of differential algebraic equations (DAEs). The Bayesian parameter estimation framework, which we distribute as a toolbox (https://github.com/jihyunbak/BayesChemEng), involves surrogate models, Markov chain Monte Carlo (MCMC) with tempering, global optimization, and various analysis tools. The obtained parameter distributions reflect the uncertain or multimodal natures of the parameters due to the incompleteness of the model and the experiments. They are used to earn stochastic model responses which show good fits with the experimental results. The fitting errors of all the 16 data sets and the unseen test set are measured to be comparable or lower than when deterministic optimization methods are used. The developed model is then applied to find out the operating conditions which increase the duration of high CO2 removal rate and the carbonate production rate. They have highly nonlinear relationships with design variables such as the amounts of CaCO3 and NaOH, flue gas flow rate, and CO2 inlet concentration.},
 bibtype = {article},
 author = {Na, J. and Park, S. and Bak, J.H. and Kim, M. and Lee, D. and Yoo, Y. and Kim, I. and Park, J. and Lee, U. and Lee, J.M.},
 doi = {10.1021/acs.iecr.9b01062},
 journal = {Industrial and Engineering Chemistry Research},
 number = {19}
}

© 2019 American Chemical Society. We develop a rigorous mathematical model of aqueous mineral carbonation kinetics for carbon capture and utilization (CCU) and estimate the parameter posterior distribution using Bayesian parameter estimation framework and lab-scale experiments. We conduct 16 experiments according to the orthogonal array design and an additional one experiment for the model test. The model considers the gas-liquid mass transfer, solid dissolution, ionic reactions, precipitations, and discrete events in the form of differential algebraic equations (DAEs). The Bayesian parameter estimation framework, which we distribute as a toolbox (https://github.com/jihyunbak/BayesChemEng), involves surrogate models, Markov chain Monte Carlo (MCMC) with tempering, global optimization, and various analysis tools. The obtained parameter distributions reflect the uncertain or multimodal natures of the parameters due to the incompleteness of the model and the experiments. They are used to earn stochastic model responses which show good fits with the experimental results. The fitting errors of all the 16 data sets and the unseen test set are measured to be comparable or lower than when deterministic optimization methods are used. The developed model is then applied to find out the operating conditions which increase the duration of high CO2 removal rate and the carbonate production rate. They have highly nonlinear relationships with design variables such as the amounts of CaCO3 and NaOH, flue gas flow rate, and CO2 inlet concentration.

@article{
 title = {Formation of defect site on ZIF-7 and its effect on the methoxycarbonylation of aniline with dimethyl carbonate},
 type = {article},
 year = {2019},
 keywords = {Aniline,Aromatic carbamate,DMC,Defect site,Methoxycarbonylation,ZIF-7},
 pages = {297-306},
 volume = {380},
 month = {3},
 publisher = {Academic Press Inc.},
 id = {e9e52086-1d67-362e-a898-fc2e42be2297},
 created = {2021-03-23T08:23:13.505Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-03-23T08:50:14.419Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 abstract = {The Zeolitic Imidazole Framework ZIF-7, (Zn(benzimidazole)2), is known to exhibit a unique gate-opening property depending on the temperature and pressure in the presence of guest molecules, making it useful for H2, CO2, and paraffine separation technology. Besides this distinctive gas adsorption property, ZIF-7 can be used as a catalyst because it contains a Lewis acid site on Zn, and a Lewis basic site on the benzimidazole. In this study, for the first time, we demonstrate that ZIF-7 is a very promising material as a catalyst for the methoxycarbonylation of aniline with dimethyl carbonate (DMC) to produce methyl phenyl carbamate (MPC), an isocyanate precursor. Fresh ZIF-7 showed a high aniline conversion of over 95% at 190 °C for 2 h, and the yield MPC was 60–70% due to the formation of methylated side products, such as N-methyl aniline and N,N′-dimethylaniline. However, interestingly, when the ZIF-7 was reused, the yield of MPC gradually increased and reached over 94.7% by the catalyst's 6th run. SEM and TEM images revealed the crystalline structure of ZIF-7 collapsed during the reaction due to the leaching of benzimidazole from the ZIF-7, which created defect sites on the Lewis acidic zinc center. Based on 1H NMR and XPS studies, it can be assumed that the DMC binds to the Zn defect sites on the ZIF-7, activating the carbonyl groups on DMC, resulting in the increased selectivity to methoxycarbonylation compared to methylation. Pretreating ZIF-7 with DMC at 190 °C for 6 h could directly activated the ZIF-7 for this methoxycarbonylation reaction. The activated ZIF-7 showed 91.0% MPC yield and the catalyst was reusable.},
 bibtype = {article},
 author = {Dahnum, Deliana and Seo, Bora and Cheong, Seok Hyeon and Lee, Ung and Ha, Jeong Myeong and Lee, Hyunjoo},
 doi = {10.1016/j.jcat.2019.09.039},
 journal = {Journal of Catalysis}
}

The Zeolitic Imidazole Framework ZIF-7, (Zn(benzimidazole)2), is known to exhibit a unique gate-opening property depending on the temperature and pressure in the presence of guest molecules, making it useful for H2, CO2, and paraffine separation technology. Besides this distinctive gas adsorption property, ZIF-7 can be used as a catalyst because it contains a Lewis acid site on Zn, and a Lewis basic site on the benzimidazole. In this study, for the first time, we demonstrate that ZIF-7 is a very promising material as a catalyst for the methoxycarbonylation of aniline with dimethyl carbonate (DMC) to produce methyl phenyl carbamate (MPC), an isocyanate precursor. Fresh ZIF-7 showed a high aniline conversion of over 95% at 190 °C for 2 h, and the yield MPC was 60–70% due to the formation of methylated side products, such as N-methyl aniline and N,N′-dimethylaniline. However, interestingly, when the ZIF-7 was reused, the yield of MPC gradually increased and reached over 94.7% by the catalyst's 6th run. SEM and TEM images revealed the crystalline structure of ZIF-7 collapsed during the reaction due to the leaching of benzimidazole from the ZIF-7, which created defect sites on the Lewis acidic zinc center. Based on 1H NMR and XPS studies, it can be assumed that the DMC binds to the Zn defect sites on the ZIF-7, activating the carbonyl groups on DMC, resulting in the increased selectivity to methoxycarbonylation compared to methylation. Pretreating ZIF-7 with DMC at 190 °C for 6 h could directly activated the ZIF-7 for this methoxycarbonylation reaction. The activated ZIF-7 showed 91.0% MPC yield and the catalyst was reusable.

@article{
 title = {Pt black catalyzed methane oxidation to methyl bisulfate in H2SO4-SO3},
 type = {article},
 year = {2019},
 websites = {https://doi.org/10.1016/j.jcat.2019.04.042},
 month = {3},
 id = {168a8d8b-bdae-3df1-b43c-f887c0102b1f},
 created = {2021-03-23T08:23:13.591Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-03-23T08:50:13.100Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 bibtype = {article},
 author = {Lee, Hee Won and Dang, Huyen Tran and Kim, Honggon and Lee, Ung and Ha, Jeong-Myeong and Jae, Jungho and Cheong, Minserk and Lee, Hyunjoo},
 doi = {10.1016/j.jcat.2019.04.042},
 journal = {Journal of Catalysis}
}

@article{
 title = {An experimental based optimization of a novel water lean amine solvent for post combustion CO2 capture process},
 type = {article},
 year = {2019},
 keywords = {CO2 capture,Gaussian process Bayesian optimization,Pilot-scale testing,Water-lean amine solvent},
 pages = {174-184},
 volume = {248},
 month = {3},
 publisher = {Elsevier Ltd},
 id = {b6d8ba76-9cf3-33b8-abd3-82b53f68b71b},
 created = {2021-03-23T08:23:13.676Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-03-23T08:50:13.801Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 abstract = {The development of new amine solvents without the major drawbacks of conventional amines is crucial to industrial applications of CO2 capture. This paper presents a water-lean CO2 capture solvent having a low regeneration energy and low degradation. The water-lean solvent, K2Sol, is a sterically hindered diamine; because of the hindered amine site, K2Sol easily forms bicarbonate, resulting in a high absorption capacity. The minimum solvent regeneration energy is obtained using Gaussian process Bayesian optimization (GPBO) and bench-scale pilot plant experiments. GPBO finds the optimal solution using the input and output relationship of experiments; thus, expensive first-principle model construction can be avoided. According to the pilot plant experiment, the optimal regeneration energies of monoethanolamine (MEA) and K2Sol are 4.3 and 2.8 GJ/t CO2, respectively, indicating that K2Sol requires only 65% of the regeneration energy of MEA. Fewer than 30 experiments are required to find the optimal pilot plant operation for both the MEA and K2Sol experiments. We also describe the superior properties of K2Sol in terms of the CO2 loading, cyclic capacity, regeneration temperature, and degradation.},
 bibtype = {article},
 author = {Hwang, Junhyeok and Kim, Jeongnam and Lee, Hee Won and Na, Jonggeol and Ahn, Byoung Sung and Lee, Sang Deuk and Kim, Hoon Sik and Lee, Hyunjoo and Lee, Ung},
 doi = {10.1016/j.apenergy.2019.04.135},
 journal = {Applied Energy}
}

The development of new amine solvents without the major drawbacks of conventional amines is crucial to industrial applications of CO2 capture. This paper presents a water-lean CO2 capture solvent having a low regeneration energy and low degradation. The water-lean solvent, K2Sol, is a sterically hindered diamine; because of the hindered amine site, K2Sol easily forms bicarbonate, resulting in a high absorption capacity. The minimum solvent regeneration energy is obtained using Gaussian process Bayesian optimization (GPBO) and bench-scale pilot plant experiments. GPBO finds the optimal solution using the input and output relationship of experiments; thus, expensive first-principle model construction can be avoided. According to the pilot plant experiment, the optimal regeneration energies of monoethanolamine (MEA) and K2Sol are 4.3 and 2.8 GJ/t CO2, respectively, indicating that K2Sol requires only 65% of the regeneration energy of MEA. Fewer than 30 experiments are required to find the optimal pilot plant operation for both the MEA and K2Sol experiments. We also describe the superior properties of K2Sol in terms of the CO2 loading, cyclic capacity, regeneration temperature, and degradation.

@article{
 title = {Design of carbon dioxide dehydration process using derivative-free superstructure optimization},
 type = {article},
 year = {2018},
 keywords = {CO  dehydration 2,Genetic algorithm,Process design,Superstructure optimization,TEG absorption,Techno-economic optimization},
 volume = {129},
 id = {f10a0dff-4fd2-3ba7-bb5d-60afe565f607},
 created = {2019-02-13T12:19:07.370Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.370Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2017 Institution of Chemical Engineers A comprehensive optimal design for the CO2 dehydration process created by decomposition-based superstructure optimization is proposed. To reach the most economical process configuration, the superstructure model has been developed including binary interaction parameter regression of the NRTL-RK thermodynamic model, unit operation modeling, and identification of the connectivity of each of the unit operations in the superstructure. The superstructure imbeds 30,720 possible process alternatives and unit operation options. To simplify the optimization problem, the process simulation was explicitly carried out in a sequential process simulator, and the constrained optimization problem was solved externally using a genetic algorithm and an Aspen Plus-MATLAB interface. The optimal process includes a five-stage contactor, a nine-stage still column (with the feed stream entering at the seventh stage), a lean/rich solvent heat exchanger, and a cold rich solvent split flow fed to the first stage of still column. The total annualized cost of the optimum process is 6.70 M$/year, which corresponds to the specific annualized cost of 1.88 $/t CO2. As part of the process optimization, a Monte Carlo simulation was performed to analyze the sensitivity of utility cost volatility; the refrigerant and steam present the most influential utility costs.},
 bibtype = {article},
 author = {An, J. and Na, J. and Lee, U. and Han, C.},
 doi = {10.1016/j.cherd.2017.11.028},
 journal = {Chemical Engineering Research and Design}
}

© 2017 Institution of Chemical Engineers A comprehensive optimal design for the CO2 dehydration process created by decomposition-based superstructure optimization is proposed. To reach the most economical process configuration, the superstructure model has been developed including binary interaction parameter regression of the NRTL-RK thermodynamic model, unit operation modeling, and identification of the connectivity of each of the unit operations in the superstructure. The superstructure imbeds 30,720 possible process alternatives and unit operation options. To simplify the optimization problem, the process simulation was explicitly carried out in a sequential process simulator, and the constrained optimization problem was solved externally using a genetic algorithm and an Aspen Plus-MATLAB interface. The optimal process includes a five-stage contactor, a nine-stage still column (with the feed stream entering at the seventh stage), a lean/rich solvent heat exchanger, and a cold rich solvent split flow fed to the first stage of still column. The total annualized cost of the optimum process is 6.70 M$/year, which corresponds to the specific annualized cost of 1.88 $/t CO2. As part of the process optimization, a Monte Carlo simulation was performed to analyze the sensitivity of utility cost volatility; the refrigerant and steam present the most influential utility costs.

@article{
 title = {Optimal design and operation of Fischer-Tropsch microchannel reactor for pilot-scale compact Gas-to-Liquid process},
 type = {article},
 year = {2018},
 keywords = {Computer-aided,Fischer-Tropsch,Gas-to-Liquid,Microchannel,Pilot plant,Reactor design},
 volume = {128},
 id = {73dc1416-b274-3b36-b114-5c93dc361c81},
 created = {2019-02-13T12:19:08.118Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:08.118Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2018 Elsevier B.V. Design and operation of pilot-scale (1.0 BDP) compact GTL process comprising of reforming section, CO2separating section, and Fischer-Tropsch (FT) synthesis section is presented. Detailed systematic computer-aided design procedure adopted to design a modular 0.5 BPD pilot-scale microchannel reactor used in the pilot plant operation is also presented. The modular microchannel FT reactor block design consists of 528 process channels and numerous coolant channels arranged in cross-cocurrent-cross configuration for adequate heat removal. On average 98.27% CH4conversion to syngas in reforming section comprising of a pre-reformer unit and a tri-reformer unit, and CO2separation rate of 36.75% along with CO/H2reduction from 2.67 to 2.08 in CO2membrane separation section were achieved from the entire pilot plant operation duration of 450 h. Parallel operation of FT microchannel reactor and multitubular fixed-bed type FT reactor for comparison showed that multitubular fixed-bed type reactor undergoes reaction runaway for the applied process conditions, while microchannel reactor showed adequate temperature control. Overall CO conversion of 83% and adequate temperature control at three different applied operating temperatures of 220 °C, 230 °C, and 240 °C subsequently during the 139 h FT reactor operation demonstrated the appreciable performance of the present microchannel FT reactor designed.},
 bibtype = {article},
 author = {Na, J. and Kshetrimayum, K.S. and Jung, I. and Park, S. and Lee, Y. and Kwon, O. and Mo, Y. and Chung, J. and Yi, J. and Lee, U. and Han, C.},
 doi = {10.1016/j.cep.2018.04.013},
 journal = {Chemical Engineering and Processing - Process Intensification}
}

© 2018 Elsevier B.V. Design and operation of pilot-scale (1.0 BDP) compact GTL process comprising of reforming section, CO2separating section, and Fischer-Tropsch (FT) synthesis section is presented. Detailed systematic computer-aided design procedure adopted to design a modular 0.5 BPD pilot-scale microchannel reactor used in the pilot plant operation is also presented. The modular microchannel FT reactor block design consists of 528 process channels and numerous coolant channels arranged in cross-cocurrent-cross configuration for adequate heat removal. On average 98.27% CH4conversion to syngas in reforming section comprising of a pre-reformer unit and a tri-reformer unit, and CO2separation rate of 36.75% along with CO/H2reduction from 2.67 to 2.08 in CO2membrane separation section were achieved from the entire pilot plant operation duration of 450 h. Parallel operation of FT microchannel reactor and multitubular fixed-bed type FT reactor for comparison showed that multitubular fixed-bed type reactor undergoes reaction runaway for the applied process conditions, while microchannel reactor showed adequate temperature control. Overall CO conversion of 83% and adequate temperature control at three different applied operating temperatures of 220 °C, 230 °C, and 240 °C subsequently during the 139 h FT reactor operation demonstrated the appreciable performance of the present microchannel FT reactor designed.

@article{
 title = {Design of carbon dioxide dehydration process using derivative-free superstructure optimization},
 type = {article},
 year = {2018},
 keywords = {CO  dehydration 2,Genetic algorithm,Process design,Superstructure optimization,TEG absorption,Techno-economic optimization},
 volume = {129},
 id = {248dcdbb-dadb-309d-9e72-abac70f00dca},
 created = {2021-03-23T08:23:14.436Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-03-23T08:50:11.750Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 abstract = {© 2017 Institution of Chemical Engineers A comprehensive optimal design for the CO2 dehydration process created by decomposition-based superstructure optimization is proposed. To reach the most economical process configuration, the superstructure model has been developed including binary interaction parameter regression of the NRTL-RK thermodynamic model, unit operation modeling, and identification of the connectivity of each of the unit operations in the superstructure. The superstructure imbeds 30,720 possible process alternatives and unit operation options. To simplify the optimization problem, the process simulation was explicitly carried out in a sequential process simulator, and the constrained optimization problem was solved externally using a genetic algorithm and an Aspen Plus-MATLAB interface. The optimal process includes a five-stage contactor, a nine-stage still column (with the feed stream entering at the seventh stage), a lean/rich solvent heat exchanger, and a cold rich solvent split flow fed to the first stage of still column. The total annualized cost of the optimum process is 6.70 M/year, which corresponds to the specific annualized cost of 1.88 /t CO2. As part of the process optimization, a Monte Carlo simulation was performed to analyze the sensitivity of utility cost volatility; the refrigerant and steam present the most influential utility costs.},
 bibtype = {article},
 author = {An, J and Na, J and Lee, U and Han, C},
 doi = {10.1016/j.cherd.2017.11.028},
 journal = {Chemical Engineering Research and Design}
}

© 2017 Institution of Chemical Engineers A comprehensive optimal design for the CO2 dehydration process created by decomposition-based superstructure optimization is proposed. To reach the most economical process configuration, the superstructure model has been developed including binary interaction parameter regression of the NRTL-RK thermodynamic model, unit operation modeling, and identification of the connectivity of each of the unit operations in the superstructure. The superstructure imbeds 30,720 possible process alternatives and unit operation options. To simplify the optimization problem, the process simulation was explicitly carried out in a sequential process simulator, and the constrained optimization problem was solved externally using a genetic algorithm and an Aspen Plus-MATLAB interface. The optimal process includes a five-stage contactor, a nine-stage still column (with the feed stream entering at the seventh stage), a lean/rich solvent heat exchanger, and a cold rich solvent split flow fed to the first stage of still column. The total annualized cost of the optimum process is 6.70 M/year, which corresponds to the specific annualized cost of 1.88 /t CO2. As part of the process optimization, a Monte Carlo simulation was performed to analyze the sensitivity of utility cost volatility; the refrigerant and steam present the most influential utility costs.

@article{
 title = {Optimal multicomponent working fluid of organic Rankine cycle for exergy transfer from liquefied natural gas regasification},
 type = {article},
 year = {2017},
 keywords = {Gglobal optimization,Liquefied natural gas,Mmulticomponent working fluid,Organic Rankine cycle,Wwaste heat recovery},
 volume = {127},
 id = {24b5506c-da75-3913-b869-fac3561d3bc5},
 created = {2019-02-13T12:19:07.306Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.306Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2017 Elsevier Ltd A hybrid optimization methodology is proposed for the working fluid selection of an organic Rankine cycle (ORC). First, a stochastic global solver is used to select the chemical species of the working fluid; then, a deterministic global solver is used to optimize the composition. The first step is a mixed integer nonlinear programing (MINLP) and the second a nonlinear program (NLP). The methodology is applied to the recovery of cryogenic energy during the evaporation of liquefied natural gas (LNG), which is a promising way to produce electricity with relatively high efficiency from the large amount of otherwise wasted heat. Seawater or low-grade heat sources can be used as heat source. Multicomponent working fluids have advantages compared to pure fluids because of the nonisothermal evaporation of LNG. Herein, a ternary mixture is considered. A mixture of CF4, CHF3, n-pentane is identified as an optimum ternary working fluid. It produces about 1.1 MJ/kmol LNG with a simple organic Rankine cycle using seawater as heat source. The optimization results are quantitatively compared with the literature in terms of power generation and are shown to have substantially higher electricity generation.},
 bibtype = {article},
 author = {Lee, U. and Mitsos, A.},
 doi = {10.1016/j.energy.2017.03.126},
 journal = {Energy}
}

© 2017 Elsevier Ltd A hybrid optimization methodology is proposed for the working fluid selection of an organic Rankine cycle (ORC). First, a stochastic global solver is used to select the chemical species of the working fluid; then, a deterministic global solver is used to optimize the composition. The first step is a mixed integer nonlinear programing (MINLP) and the second a nonlinear program (NLP). The methodology is applied to the recovery of cryogenic energy during the evaporation of liquefied natural gas (LNG), which is a promising way to produce electricity with relatively high efficiency from the large amount of otherwise wasted heat. Seawater or low-grade heat sources can be used as heat source. Multicomponent working fluids have advantages compared to pure fluids because of the nonisothermal evaporation of LNG. Herein, a ternary mixture is considered. A mixture of CF4, CHF3, n-pentane is identified as an optimum ternary working fluid. It produces about 1.1 MJ/kmol LNG with a simple organic Rankine cycle using seawater as heat source. The optimization results are quantitatively compared with the literature in terms of power generation and are shown to have substantially higher electricity generation.

@article{
 title = {Multi-objective optimization of microchannel reactor for Fischer-Tropsch synthesis using computational fluid dynamics and genetic algorithm},
 type = {article},
 year = {2017},
 keywords = {Catalyst packing,Computational fluid dynamics,Fischer-Tropsch,Microchannel reactor,Multi-objective optimization,Stochastic optimization},
 volume = {313},
 id = {a1d7749c-b740-3cc5-bc32-767153b741fd},
 created = {2019-02-13T12:19:07.372Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.372Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2016 We propose a multi-objective optimization methodology using a stochastic optimization algorithm, a genetic algorithm (GA) with ε-constraint method, and a 2D axisymmetric computational fluid dynamics (CFD)-based Fischer-Tropsch microchannel reactor model, validated by experimental data of CO conversion and CH4selectivity, for simultaneously maximizing C5+productivity and minimizing the temperature rise of a Fischer-Tropsch microchannel reactor. The main mixed integer nonlinear programming (MINLP) optimization problem is decomposed into an external CFD reactor model function and internal optimization constraints. The methodology is applied to the catalyst packing zone division, which is divided and packed with a different dilution ratio to distribute the heat of reaction evenly. The best solutions of the proposed optimizer are reproducible with different crossover fractions and are more efficient than other traditional non-convex constraint local solvers. Based on the Pareto optimal solution of the final optimizer with 4 zones, discrete dilution increases C5+productivity to 22% and decreases ΔTmaxto 63.2% compared to the single zone catalyst packing case. Finally, several Pareto optimal solutions and sub-optimal solutions are compared and the results are documented in terms of C5+productivity and maximum temperature increase.},
 bibtype = {article},
 author = {Na, J. and Kshetrimayum, K.S. and Lee, U. and Han, C.},
 doi = {10.1016/j.cej.2016.11.040},
 journal = {Chemical Engineering Journal}
}

© 2016 We propose a multi-objective optimization methodology using a stochastic optimization algorithm, a genetic algorithm (GA) with ε-constraint method, and a 2D axisymmetric computational fluid dynamics (CFD)-based Fischer-Tropsch microchannel reactor model, validated by experimental data of CO conversion and CH4selectivity, for simultaneously maximizing C5+productivity and minimizing the temperature rise of a Fischer-Tropsch microchannel reactor. The main mixed integer nonlinear programming (MINLP) optimization problem is decomposed into an external CFD reactor model function and internal optimization constraints. The methodology is applied to the catalyst packing zone division, which is divided and packed with a different dilution ratio to distribute the heat of reaction evenly. The best solutions of the proposed optimizer are reproducible with different crossover fractions and are more efficient than other traditional non-convex constraint local solvers. Based on the Pareto optimal solution of the final optimizer with 4 zones, discrete dilution increases C5+productivity to 22% and decreases ΔTmaxto 63.2% compared to the single zone catalyst packing case. Finally, several Pareto optimal solutions and sub-optimal solutions are compared and the results are documented in terms of C5+productivity and maximum temperature increase.

@article{
 title = {Techno-economic feasibility study of membrane based propane/propylene separation process},
 type = {article},
 year = {2017},
 keywords = {Economic evaluation,Facilitated transport membranes,Optimization,Propylene propane separation,Vapor recompression distillation},
 volume = {119},
 id = {56a8f615-3336-3f8c-a3ab-e76163951d01},
 created = {2019-02-13T12:19:07.435Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.435Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2017 One of the most important issues for developing propylene/propane gas separation membranes is to identify the minimum required membrane performances. Herein, we reported the technical and economic feasibility of facilitated propylene transport membranes containing silver nanoparticles, which produces 99.6% purity of propylene with 97% recovery for 46,000 kg/h capacity. In order to suggest minimum specification, the membrane separation process is compared with advanced distillation process employing direct vapor recompression process. The distillation process is optimized using a stochastic solver interfaced with a commercial process simulator. With the distillation process, the energy and total costs are approximately $4.40 and 18.6$ to produce per ton of propylene, respectively. The single-stage membrane processes with various stage-cut conditions were evaluated to meet the same total propylene production cost. Result indicates that required membrane permeance and selectivity ranges between 11.3 to 251.5 GPU (permeance unit, 1 GPU = 1 × 10−6 cm3(STP)/(cm s cmHg)) and 61.9 to 1950 depending on stage-cut. Sensitivity analysis was also performed according to membrane costs, feed flow rates and composition.},
 bibtype = {article},
 author = {Lee, U. and Kim, J. and Seok Chae, I. and Han, C.},
 doi = {10.1016/j.cep.2017.05.013},
 journal = {Chemical Engineering and Processing - Process Intensification}
}

© 2017 One of the most important issues for developing propylene/propane gas separation membranes is to identify the minimum required membrane performances. Herein, we reported the technical and economic feasibility of facilitated propylene transport membranes containing silver nanoparticles, which produces 99.6% purity of propylene with 97% recovery for 46,000 kg/h capacity. In order to suggest minimum specification, the membrane separation process is compared with advanced distillation process employing direct vapor recompression process. The distillation process is optimized using a stochastic solver interfaced with a commercial process simulator. With the distillation process, the energy and total costs are approximately $4.40 and 18.6$ to produce per ton of propylene, respectively. The single-stage membrane processes with various stage-cut conditions were evaluated to meet the same total propylene production cost. Result indicates that required membrane permeance and selectivity ranges between 11.3 to 251.5 GPU (permeance unit, 1 GPU = 1 × 10−6 cm3(STP)/(cm s cmHg)) and 61.9 to 1950 depending on stage-cut. Sensitivity analysis was also performed according to membrane costs, feed flow rates and composition.

@article{
 title = {Superstructure based techno-economic optimization of the organic rankine cycle using LNG cryogenic energy},
 type = {article},
 year = {2017},
 keywords = {Direct contact heater,Genetic algorithm,LNG,Multi component working fluid,Multi stage rankine cycle,ORC,Optimization,Superstructure},
 volume = {137},
 id = {916bbd91-1cab-3c49-a40c-4c3f86ca571b},
 created = {2019-02-13T12:19:07.626Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.626Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2017 Elsevier Ltd A process design of the organic Rankine cycle utilizing LNG cryogenic exergy is proposed using superstructure optimization. The superstructure imbeds about 1024 possible process alternatives, and the most profitable process configuration and the operating condition are decided simultaneously using a stochastic optimization solver and Aspen Plus-MATLAB interface. The optimum process configuration includes a multi stream cryogenic heat exchanger, a five-stage turbine with reheaters, three stage vapor re-condensation processes and direct contact heaters. In addition, the exergy transfer from the LNG to the working fluid is maximized by using a multi component mixture as working fluid. The 1st law efficiency of the proposed process reaches about 26.2% with 85 °C of waste heat source and it is about 42% higher than that of the conventional ORC. The annual profit of the optimum process is about 39 M$ and it can be interpreted as 24$ of profit per kg LNG evaporation. Sensitivity analysis is also presented to show the reliability of the stochastic solution found in this study.},
 bibtype = {article},
 author = {Lee, U. and Jeon, J. and Han, C. and Lim, Y.},
 doi = {10.1016/j.energy.2017.07.019},
 journal = {Energy}
}

© 2017 Elsevier Ltd A process design of the organic Rankine cycle utilizing LNG cryogenic exergy is proposed using superstructure optimization. The superstructure imbeds about 1024 possible process alternatives, and the most profitable process configuration and the operating condition are decided simultaneously using a stochastic optimization solver and Aspen Plus-MATLAB interface. The optimum process configuration includes a multi stream cryogenic heat exchanger, a five-stage turbine with reheaters, three stage vapor re-condensation processes and direct contact heaters. In addition, the exergy transfer from the LNG to the working fluid is maximized by using a multi component mixture as working fluid. The 1st law efficiency of the proposed process reaches about 26.2% with 85 °C of waste heat source and it is about 42% higher than that of the conventional ORC. The annual profit of the optimum process is about 39 M$ and it can be interpreted as 24$ of profit per kg LNG evaporation. Sensitivity analysis is also presented to show the reliability of the stochastic solution found in this study.

@article{
 title = {Optimal retrofit of a CO<inf>2</inf> capture pilot plant using superstructure and rate-based models},
 type = {article},
 year = {2016},
 keywords = {Exergy analysis,MEA,Post-combustion carbon capture process,Process retrofit,Stochastic algorithms for optimization,Superstructure},
 volume = {50},
 id = {1d25d2ac-4b2d-374f-8a5e-ad6b3ffb753a},
 created = {2019-02-13T12:19:07.486Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.486Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2016 Elsevier Ltd. Finding an optimal retrofit for existing plants is a very challenging problem, since it often requires rigorous process models for describing the currently operating process and consequently the corresponding optimization problems typically become very complex. One of the possible ways to optimize such a complex problem is to limit the process alternatives considered, which bears the risk to overlook the optimal solution. Herein, a superstructure-based methodology is proposed for optimal retrofit of a CO2 capture pilot plant using rigorous rate-based model for the reactive distillation. The methodology is applied to the Boryeong pilot plant in South Korea. Process alternatives implemented in the superstructure are selected based on thermodynamic analysis of the pilot plant and operational experience. As a result, the problem size of the superstructure can be substantially reduced and optimization can be performed using commercially available process simulators and optimization solvers. The optimum process configuration and operating conditions are obtained stochastically using a genetic algorithm. Results indicate that the optimum retrofit process includes three stages solvent recirculation, lean vapor recompression, and mechanical vapor recompression. Thermal energy and total energy consumption in the optimal retrofit process are reduced about 59% and 27%, respectively.},
 bibtype = {article},
 author = {Lee, U. and Mitsos, A. and Han, C.},
 doi = {10.1016/j.ijggc.2016.03.024},
 journal = {International Journal of Greenhouse Gas Control}
}

© 2016 Elsevier Ltd. Finding an optimal retrofit for existing plants is a very challenging problem, since it often requires rigorous process models for describing the currently operating process and consequently the corresponding optimization problems typically become very complex. One of the possible ways to optimize such a complex problem is to limit the process alternatives considered, which bears the risk to overlook the optimal solution. Herein, a superstructure-based methodology is proposed for optimal retrofit of a CO2 capture pilot plant using rigorous rate-based model for the reactive distillation. The methodology is applied to the Boryeong pilot plant in South Korea. Process alternatives implemented in the superstructure are selected based on thermodynamic analysis of the pilot plant and operational experience. As a result, the problem size of the superstructure can be substantially reduced and optimization can be performed using commercially available process simulators and optimization solvers. The optimum process configuration and operating conditions are obtained stochastically using a genetic algorithm. Results indicate that the optimum retrofit process includes three stages solvent recirculation, lean vapor recompression, and mechanical vapor recompression. Thermal energy and total energy consumption in the optimal retrofit process are reduced about 59% and 27%, respectively.

@article{
 title = {A semi-analytical method for determining the optimal stripper pressure in CO<inf>2</inf> capture and liquefaction using monoethanolamine (MEA)},
 type = {article},
 year = {2016},
 keywords = {CCS,MEA,Optimal stripper pressure,Optimization,Process design,Process integration},
 volume = {46},
 id = {01acef31-ac20-30cc-b868-7921ef1a783c},
 created = {2019-02-13T12:19:07.939Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.939Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2016 Elsevier Ltd. The operation pressure of a distillation column is one of the key variables in optimizing the required energy in a carbon capture and storage (CCS) chain. It affects the steam drag point in power plants, the regeneration energy in capture process and the compression energy in the liquefaction process. A new semi-analytical method for determining optimal stripper pressure for the CCS process using MEA as an absorbent is proposed based on the integrated simulation model. Total required energy is represented as a function of the pressure based on the equivalent work. Two different method - simultaneous and sequential - are applied to solve the optimization problem. The results show that the total energy has a monotonous decreasing function with respect to the stripper pressure and the higher stripper pressure is favorable when a terminal pressure is above 10 bar. When the terminal pressure has a small value near 5 bar, the total energy shows a convex form and the optimal stripper pressure is located between 1 and 2.2 bar.},
 bibtype = {article},
 author = {Park, T. and Lee, S.G. and Kim, S.H. and Lee, U. and Han, C. and Lee, J.M.},
 doi = {10.1016/j.ijggc.2016.01.019},
 journal = {International Journal of Greenhouse Gas Control}
}

© 2016 Elsevier Ltd. The operation pressure of a distillation column is one of the key variables in optimizing the required energy in a carbon capture and storage (CCS) chain. It affects the steam drag point in power plants, the regeneration energy in capture process and the compression energy in the liquefaction process. A new semi-analytical method for determining optimal stripper pressure for the CCS process using MEA as an absorbent is proposed based on the integrated simulation model. Total required energy is represented as a function of the pressure based on the equivalent work. Two different method - simultaneous and sequential - are applied to solve the optimization problem. The results show that the total energy has a monotonous decreasing function with respect to the stripper pressure and the higher stripper pressure is favorable when a terminal pressure is above 10 bar. When the terminal pressure has a small value near 5 bar, the total energy shows a convex form and the optimal stripper pressure is located between 1 and 2.2 bar.

@article{
 title = {Techno-economic Optimization of a Green-Field Post-Combustion CO<inf>2</inf> Capture Process Using Superstructure and Rate-Based Models},
 type = {article},
 year = {2016},
 volume = {55},
 id = {d1c79cf5-9fcc-302e-954a-7b76fc014708},
 created = {2019-02-13T12:19:07.998Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.998Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2016 American Chemical Society. A techno-economic optimization of a commercial-scale, amine-based, post-combustion CO2 capture process is carried out. The most economically favorable process configuration, sizing and operating conditions are identified using a superstructure formulation. The superstructure has 12 288 possible process configurations and unit operations in the superstructure are described using rigorous, rate-based models. In order to simplify the optimization problem, the problem is decomposed and process simulations are explicitly handled in the process simulator. Optimization is performed externally using a genetic algorithm. The best found process configuration includes the absorber intercooling, the rich vapor recompression, and the cold solvent split. The result of this study is compared in terms of the cost of capture basis and shows 38% reduction on the annual operation cost, compared to the conventional amine-based CO2 capture process. Moreover, the savings on the total annualized cost is ∼13%, which is an increase of 30% on the annualized investment cost resulting from additional unit operations. (Figure Presented).},
 bibtype = {article},
 author = {Lee, U. and Burre, J. and Caspari, A. and Kleinekorte, J. and Schweidtmann, A.M. and Mitsos, A.},
 doi = {10.1021/acs.iecr.6b01668},
 journal = {Industrial and Engineering Chemistry Research},
 number = {46}
}

© 2016 American Chemical Society. A techno-economic optimization of a commercial-scale, amine-based, post-combustion CO2 capture process is carried out. The most economically favorable process configuration, sizing and operating conditions are identified using a superstructure formulation. The superstructure has 12 288 possible process configurations and unit operations in the superstructure are described using rigorous, rate-based models. In order to simplify the optimization problem, the problem is decomposed and process simulations are explicitly handled in the process simulator. Optimization is performed externally using a genetic algorithm. The best found process configuration includes the absorber intercooling, the rich vapor recompression, and the cold solvent split. The result of this study is compared in terms of the cost of capture basis and shows 38% reduction on the annual operation cost, compared to the conventional amine-based CO2 capture process. Moreover, the savings on the total annualized cost is ∼13%, which is an increase of 30% on the annualized investment cost resulting from additional unit operations. (Figure Presented).

@article{
 title = {Simulation and optimization of multi-component organic Rankine cycle integrated with post-combustion capture process},
 type = {article},
 year = {2015},
 keywords = {CO  capture 2,Exergy optimization,LNG,Multi-component working fluid,ORC,Regasification},
 volume = {83},
 id = {2942858c-55a2-3dad-b36d-b84fde30d959},
 created = {2019-02-13T12:19:07.250Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.250Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2015 Published by Elsevier Ltd. A multi-component working fluid organic Rankine cycle (ORC) with advanced configuration is proposed and optimized in this paper. The proposed ORC utilizes the wasted heat of a CO2 capture process as a heat source, and waste heat utilization is optimized through heat integration. The ORC employs advanced configurations: multi component working fluid, a cold energy recuperating in multi stream cryogenic heat exchanger (MSCHE), and a vapor recondensation process (VRP), thus, its power generation efficiency is much higher than that of conventional ORCs that utilize wasted heat. Process optimization is achieved through exergy evaluation. The results indicate that the proposed cycle is able to produce 304 kJ per kg liquefied natural gas (LNG), and its corresponding second-law efficiency is approximately 46.2%. With the power generation of the ORC, the power de-rate caused by the CO2 capture process installation is completely compensated and produces more electricity compared with the original power plant.},
 bibtype = {article},
 author = {Lee, U. and Han, C.},
 doi = {10.1016/j.compchemeng.2015.03.021},
 journal = {Computers and Chemical Engineering}
}

© 2015 Published by Elsevier Ltd. A multi-component working fluid organic Rankine cycle (ORC) with advanced configuration is proposed and optimized in this paper. The proposed ORC utilizes the wasted heat of a CO2 capture process as a heat source, and waste heat utilization is optimized through heat integration. The ORC employs advanced configurations: multi component working fluid, a cold energy recuperating in multi stream cryogenic heat exchanger (MSCHE), and a vapor recondensation process (VRP), thus, its power generation efficiency is much higher than that of conventional ORCs that utilize wasted heat. Process optimization is achieved through exergy evaluation. The results indicate that the proposed cycle is able to produce 304 kJ per kg liquefied natural gas (LNG), and its corresponding second-law efficiency is approximately 46.2%. With the power generation of the ORC, the power de-rate caused by the CO2 capture process installation is completely compensated and produces more electricity compared with the original power plant.

@article{
 title = {Design and optimization of cascade organic Rankine cycle for recovering cryogenic energy from liquefied natural gas using binary working fluid},
 type = {article},
 year = {2015},
 keywords = {Cascade,Exergy,LNG,ORC,Optimization,Regasification},
 volume = {88},
 id = {25ab6b84-39ad-31be-8087-e69d628e1499},
 created = {2019-02-13T12:19:07.311Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.311Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2015 Elsevier Ltd. A cascade power generation system that utilized the cold exergy of liquefied natural gas (LNG) was proposed in this study. The proposed system adopts binary working fluids for each stage to minimize the exergy destroyed in the condensers of each stage of the cycle. The best combination of working fluids was selected through minimization of the amount of destroyed exergy by varying the flow rate, composition, and pressure of the working fluid. After selecting the working fluids, process optimization was performed through a parametric study. In addition, a sensitivity analysis was performed to observe the effect of temperature variation of the heat sources in the range of 25-85 °C on the net power generation. As a result, the proposed cycle generated 151.78 kJ/h kgLNG under a 25 °C heat source and showed an efficiency of 18.64%. The performance of the proposed cycle was linearly increased according to the temperature of heat source. For instance, the proposed system generated 248.79 kJ/h kgLNG, with exergy efficiency of 27.11% under an 85 °C heat source.},
 bibtype = {article},
 author = {Kim, K. and Lee, U. and Kim, C. and Han, C.},
 doi = {10.1016/j.energy.2015.05.047},
 journal = {Energy}
}

© 2015 Elsevier Ltd. A cascade power generation system that utilized the cold exergy of liquefied natural gas (LNG) was proposed in this study. The proposed system adopts binary working fluids for each stage to minimize the exergy destroyed in the condensers of each stage of the cycle. The best combination of working fluids was selected through minimization of the amount of destroyed exergy by varying the flow rate, composition, and pressure of the working fluid. After selecting the working fluids, process optimization was performed through a parametric study. In addition, a sensitivity analysis was performed to observe the effect of temperature variation of the heat sources in the range of 25-85 °C on the net power generation. As a result, the proposed cycle generated 151.78 kJ/h kgLNG under a 25 °C heat source and showed an efficiency of 18.64%. The performance of the proposed cycle was linearly increased according to the temperature of heat source. For instance, the proposed system generated 248.79 kJ/h kgLNG, with exergy efficiency of 27.11% under an 85 °C heat source.

@book{
 title = {Integration of Retrofitted Coal-fired Power Plant with CCS: Power De-rate Minimization},
 type = {book},
 year = {2015},
 source = {Computer Aided Chemical Engineering},
 keywords = {CCS,Parametric optimization,Power de-rate,Variable evaluation},
 volume = {37},
 id = {4c8eac08-f9e3-39ad-b42c-8958dc9dd41e},
 created = {2019-02-13T12:19:07.543Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.543Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2015 Elsevier B.V. Post-combustion carbon dioxide (CO2) capture using aqueous monoethanolamine (MEA) has been the most widely implicated method utilizing existing coal-fired power plants. However, the heat and energy requirement of the solvent regeneration and CO2 liquefaction results in a 30% decrease in net power output, which is called "power de-rate". In this study, optimum operating conditions of the integrated CCS process are proposed by simulation-based parametric optimization to reduce the power de-rate. Post-combustion CO2 capture with aqueous MEA and CO2 liquefaction integrated with a 550MWe supercritical coal-fired power plant was simulated base on the data of a 0.1MW pilot plant in South Korea. The stripper operating pressure and liquid to gas ratio were chosen as the manipulated variables based on the variable evaluation. The power de-rate was reduced to 17.4% when operating at optimum conditions.},
 bibtype = {book},
 author = {An, J. and Lee, U. and Jung, J. and Han, C.},
 doi = {10.1016/B978-0-444-63578-5.50086-4}
}

© 2015 Elsevier B.V. Post-combustion carbon dioxide (CO2) capture using aqueous monoethanolamine (MEA) has been the most widely implicated method utilizing existing coal-fired power plants. However, the heat and energy requirement of the solvent regeneration and CO2 liquefaction results in a 30% decrease in net power output, which is called "power de-rate". In this study, optimum operating conditions of the integrated CCS process are proposed by simulation-based parametric optimization to reduce the power de-rate. Post-combustion CO2 capture with aqueous MEA and CO2 liquefaction integrated with a 550MWe supercritical coal-fired power plant was simulated base on the data of a 0.1MW pilot plant in South Korea. The stripper operating pressure and liquid to gas ratio were chosen as the manipulated variables based on the variable evaluation. The power de-rate was reduced to 17.4% when operating at optimum conditions.

@article{
 title = {Parametric Optimization for Power De-Rate Reduction in the Integrated Coal-Fired Power Plant with Carbon Capture and Storage},
 type = {article},
 year = {2015},
 volume = {54},
 id = {aa78c339-ac95-352c-b3d7-5582a7f6df5c},
 created = {2019-02-13T12:19:07.580Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.580Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2015 American Chemical Society. Carbon capture and storage (CCS) has attracted worldwide attention as a near-term technology to decelerate global warming. Postcombustion CO<inf>2</inf> capture utilizes existing coal-fired power plants, and aqueous monoethanolamine (MEA) scrubbing is the most common capture technology. However, the heat and energy requirements of solvent regeneration and CO<inf>2</inf> liquefaction cause a 30% decrease in net power output. This power de-rate is a major obstacle to implementing CCS. In this study, simulation-based parametric optimization was performed to minimize the power de-rate. Postcombustion CO<inf>2</inf> capture with aqueous MEA scrubbing (85%, 90%, and 95% removals) and CO<inf>2</inf> liquefaction integrated with a 550 MWe supercritical coal-fired power plant was simulated. The liquid to gas ratio and stripper operating pressure of the CO<inf>2</inf> capture process were the manipulated variables with steam extracted from the intermediate pressure-low pressure crossover pipe and the first low pressure turbine as possible heat sources. The power de-rate was reduced to 17.7% when operating at optimum conditions.},
 bibtype = {article},
 author = {An, J. and Lee, U. and Jung, J. and Han, C.},
 doi = {10.1021/ie504557a},
 journal = {Industrial and Engineering Chemistry Research},
 number = {18}
}

© 2015 American Chemical Society. Carbon capture and storage (CCS) has attracted worldwide attention as a near-term technology to decelerate global warming. Postcombustion CO2 capture utilizes existing coal-fired power plants, and aqueous monoethanolamine (MEA) scrubbing is the most common capture technology. However, the heat and energy requirements of solvent regeneration and CO2 liquefaction cause a 30% decrease in net power output. This power de-rate is a major obstacle to implementing CCS. In this study, simulation-based parametric optimization was performed to minimize the power de-rate. Postcombustion CO2 capture with aqueous MEA scrubbing (85%, 90%, and 95% removals) and CO2 liquefaction integrated with a 550 MWe supercritical coal-fired power plant was simulated. The liquid to gas ratio and stripper operating pressure of the CO2 capture process were the manipulated variables with steam extracted from the intermediate pressure-low pressure crossover pipe and the first low pressure turbine as possible heat sources. The power de-rate was reduced to 17.7% when operating at optimum conditions.

@article{
 title = {New configuration of the CO<inf>2</inf> capture process using aqueous monoethanolamine for coal-fired power plants},
 type = {article},
 year = {2015},
 volume = {54},
 id = {a9ba5598-e81d-3f01-af64-37748f8c1112},
 created = {2019-02-13T12:19:07.651Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.651Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2015 American Chemical Society. Postcombustion CO<inf>2</inf> capture with aqueous monoethanolamine (MEA) scrubbing is one of the most promising and well-proven techniques for reducing CO<inf>2</inf> emissions into the atmosphere. However, this process has a critical problem: the high reboiler heat energy requirement for solvent regeneration at the stripper reboiler. To reduce the reboiler heat requirement, this paper suggests a new stripper configuration for CO<inf>2</inf> capture with MEA, namely a combined rich vapor recompression (RVR) and cold solvent split (CSS). The RVR is a newly developed configuration, involving vaporizing a cold solvent in the heat exchanger, thereby maximizing the heat exchanger preheating duty under low pressure. The CSS is a well-known configuration, feeding the split cold solvent to the stripper top and eliminating the reflux rate in the stripper by cooling the stripper top. The RVR process is dramatically improved when it is combined with the CSS configuration. To show the effect of this combined process, this study includes simulation of the Base process and of five alternative processes and also comparisons with reported data. A base model was established based on the operating data from a 0.1 MW pilot plant in South Korea. Consequently, the reboiler heat requirement in the combined the RVR and CSS process was reduced from 3.44 MJ<inf>th</inf>/kg CO<inf>2</inf> to 2.75 MJ<inf>th</inf>/kg CO<inf>2</inf>. The total equivalent energy requirement for CO<inf>2</inf> capture and the compression process was reduced from 1.224 MJ<inf>e</inf>/kg CO<inf>2</inf> to 1.150 MJ<inf>e</inf>/kg CO<inf>2</inf>. This combined configuration reduced the total equivalent work by up to 6.0% compared with the conventional MEA process and was 1.7-3.4% lower than that of the lean vapor recompression (LVR) process, which is a well-known advanced MEA process.},
 bibtype = {article},
 author = {Jung, J. and Jeong, Y.S. and Lee, U. and Lim, Y. and Han, C.},
 doi = {10.1021/ie504784p},
 journal = {Industrial and Engineering Chemistry Research},
 number = {15}
}

© 2015 American Chemical Society. Postcombustion CO2 capture with aqueous monoethanolamine (MEA) scrubbing is one of the most promising and well-proven techniques for reducing CO2 emissions into the atmosphere. However, this process has a critical problem: the high reboiler heat energy requirement for solvent regeneration at the stripper reboiler. To reduce the reboiler heat requirement, this paper suggests a new stripper configuration for CO2 capture with MEA, namely a combined rich vapor recompression (RVR) and cold solvent split (CSS). The RVR is a newly developed configuration, involving vaporizing a cold solvent in the heat exchanger, thereby maximizing the heat exchanger preheating duty under low pressure. The CSS is a well-known configuration, feeding the split cold solvent to the stripper top and eliminating the reflux rate in the stripper by cooling the stripper top. The RVR process is dramatically improved when it is combined with the CSS configuration. To show the effect of this combined process, this study includes simulation of the Base process and of five alternative processes and also comparisons with reported data. A base model was established based on the operating data from a 0.1 MW pilot plant in South Korea. Consequently, the reboiler heat requirement in the combined the RVR and CSS process was reduced from 3.44 MJth/kg CO2 to 2.75 MJth/kg CO2. The total equivalent energy requirement for CO2 capture and the compression process was reduced from 1.224 MJe/kg CO2 to 1.150 MJe/kg CO2. This combined configuration reduced the total equivalent work by up to 6.0% compared with the conventional MEA process and was 1.7-3.4% lower than that of the lean vapor recompression (LVR) process, which is a well-known advanced MEA process.

@article{
 title = {Design and operation strategy of CO<inf>2</inf> terminal},
 type = {article},
 year = {2015},
 volume = {54},
 id = {d11835d6-a36b-3a0b-ba52-db72218e1f8e},
 created = {2019-02-13T12:19:07.680Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.680Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2015 American Chemical Society. With recent advancements in the carbon capture and storage (CCS), much interest has been developed in the CO2 transport options. An infrastructure including pipelines, ships, tanker truck, and railways will be collectively required for a large scale CO2 transport network. In particular, ship transportation can play a special role in the early phase of CCS infrastructure development as it offers flexible routes between source and offshore storage sites. This work is focused on the design and operational strategy of the CO2 terminal which acts as a connecting link between CO2 liquefaction and the shipping section. The study is performed using dynamic simulation in order to have a more realistic understanding of the process. Four scenarios have been developed to define the operational strategy of the terminal: loading case, holding case, unloading case, and emergency shutdown. A reasonable equipment sizing has been done after consultation with vendors data and available literature. The heat influxes to storage tanks include the heat leak from the bottom surface, dry wall, and wet wall for the precise quantification of heat flow across the system. Reasonable control loops are appended to keep the process variables at their set points to allow the safe operation of the CO2 terminal within the operational limits. Finally, a sensitivity analysis has been performed on some of the important design variables in order to understand their effect on the process performance and terminal operation. The results show that boil-off gas (BOG) generation within the CO2 terminal depends on storage tank size, operating pressure, ambient conditions, insulation thickness, and the filling level of the vessel.},
 bibtype = {article},
 author = {Zahid, U. and An, J. and Lee, C.-J. and Lee, U. and Han, C.},
 doi = {10.1021/ie503696x},
 journal = {Industrial and Engineering Chemistry Research},
 number = {8}
}

© 2015 American Chemical Society. With recent advancements in the carbon capture and storage (CCS), much interest has been developed in the CO2 transport options. An infrastructure including pipelines, ships, tanker truck, and railways will be collectively required for a large scale CO2 transport network. In particular, ship transportation can play a special role in the early phase of CCS infrastructure development as it offers flexible routes between source and offshore storage sites. This work is focused on the design and operational strategy of the CO2 terminal which acts as a connecting link between CO2 liquefaction and the shipping section. The study is performed using dynamic simulation in order to have a more realistic understanding of the process. Four scenarios have been developed to define the operational strategy of the terminal: loading case, holding case, unloading case, and emergency shutdown. A reasonable equipment sizing has been done after consultation with vendors data and available literature. The heat influxes to storage tanks include the heat leak from the bottom surface, dry wall, and wet wall for the precise quantification of heat flow across the system. Reasonable control loops are appended to keep the process variables at their set points to allow the safe operation of the CO2 terminal within the operational limits. Finally, a sensitivity analysis has been performed on some of the important design variables in order to understand their effect on the process performance and terminal operation. The results show that boil-off gas (BOG) generation within the CO2 terminal depends on storage tank size, operating pressure, ambient conditions, insulation thickness, and the filling level of the vessel.

@article{
 title = {Techno-economic analysis of mechanical vapor recompression for process integration of post-combustion CO<inf>2</inf> capture with downstream compression},
 type = {article},
 year = {2015},
 keywords = {Economic analysis,Exergy analysis,Post-combustion CO  capture 2,Process integration,Vapor recompression},
 volume = {104},
 id = {007cfb2f-8eab-3780-a7a1-6524f3ebb60c},
 created = {2019-02-13T12:19:07.756Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.756Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2015 The Institution of Chemical Engineers. Post-combustion capture of CO2 using amine solvent is by far the most practical and mature technology, however, energy requirement for solvent regeneration still remains as the biggest obstacle to overcome. In this article, post-combustion CO2 capture process model was validated using experimental data of an existing test bed. Based on the validated model, mechanical vapor recompression (MVR) process is proposed which reduces thermal energy for solvent regeneration by recovering heat from compression process required for CO2 transportation. MVR process not only reduces the amount of steam extracted from the power plant, but can also serve as an interface between CO2 capture and compression for process integration. According to the simulation results, energy saving of 8.4% was observed in comparison with the base case, which is a conventional CO2 capture process followed by 2-stage compression. In addition to energy analysis, exergy analysis based on the 2nd law of thermodynamics and economic evaluation were performed to determine optimal operating condition of the MVR process.},
 bibtype = {article},
 author = {Jeong, Y.S. and Jung, J. and Lee, U. and Yang, C. and Han, C.},
 doi = {10.1016/j.cherd.2015.08.016},
 journal = {Chemical Engineering Research and Design}
}

© 2015 The Institution of Chemical Engineers. Post-combustion capture of CO2 using amine solvent is by far the most practical and mature technology, however, energy requirement for solvent regeneration still remains as the biggest obstacle to overcome. In this article, post-combustion CO2 capture process model was validated using experimental data of an existing test bed. Based on the validated model, mechanical vapor recompression (MVR) process is proposed which reduces thermal energy for solvent regeneration by recovering heat from compression process required for CO2 transportation. MVR process not only reduces the amount of steam extracted from the power plant, but can also serve as an interface between CO2 capture and compression for process integration. According to the simulation results, energy saving of 8.4% was observed in comparison with the base case, which is a conventional CO2 capture process followed by 2-stage compression. In addition to energy analysis, exergy analysis based on the 2nd law of thermodynamics and economic evaluation were performed to determine optimal operating condition of the MVR process.

@article{
 title = {A novel dynamic modeling methodology for boil-off gas recondensers in liquefied natural gas terminals},
 type = {article},
 year = {2015},
 keywords = {BOG recondenser,Dynamic modeling,Dynamic simulation,HYSYS dynamics,LNG receiving terminal},
 volume = {48},
 id = {10b94e34-1eb1-3b64-9cf9-c2bbff0fbe07},
 created = {2019-02-13T12:19:07.830Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.830Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2015 The Society of Chemical Engineers, Japan. In a liquefied natural gas (LNG) terminal operation, the reduction of boil-off gas (BOG) is critical for economy and safety. The BOG recondenser, which is a key piece of equipment for dealing with BOG, is commonly used in receiving terminals. The dynamic behavior of a BOG recondenser is complex and difficult to stabilize. Therefore, an exact dynamic model of the equipment needs to be developed that will help improve the operation. In this research, we propose an advanced dynamic modeling methodology for BOG recondensers using HYSYS dynamics to achieve better accuracy than previous studies. The main feature of the proposed methodology is that variable flash efficiency depending on the LNG input rate is allowed, enabling the description of non-equilibrium phenomena inside the recondenser. The proposed methodology was verified by using the operating data from the BOG recondenser in a real terminal, and it showed less than 2% errors in the measurements of the liquid level, temperature, and pressure.},
 bibtype = {article},
 author = {Lee, S. and Jeon, J. and Lee, U. and Lee, C.-J. and Han, C.},
 doi = {10.1252/jcej.14we201},
 journal = {Journal of Chemical Engineering of Japan},
 number = {10}
}

© 2015 The Society of Chemical Engineers, Japan. In a liquefied natural gas (LNG) terminal operation, the reduction of boil-off gas (BOG) is critical for economy and safety. The BOG recondenser, which is a key piece of equipment for dealing with BOG, is commonly used in receiving terminals. The dynamic behavior of a BOG recondenser is complex and difficult to stabilize. Therefore, an exact dynamic model of the equipment needs to be developed that will help improve the operation. In this research, we propose an advanced dynamic modeling methodology for BOG recondensers using HYSYS dynamics to achieve better accuracy than previous studies. The main feature of the proposed methodology is that variable flash efficiency depending on the LNG input rate is allowed, enabling the description of non-equilibrium phenomena inside the recondenser. The proposed methodology was verified by using the operating data from the BOG recondenser in a real terminal, and it showed less than 2% errors in the measurements of the liquid level, temperature, and pressure.

@article{
 title = {Design and modeling of large-scale cross-current multichannel Fischer-Tropsch reactor using channel decomposition and cell-coupling method},
 type = {article},
 year = {2015},
 keywords = {Distributed parameter model,Fischer-Tropsch,Gas-to-liquid process,Micro channel reactor,Reactor design},
 volume = {134},
 id = {f460337e-b04c-3e60-9060-26b8454c8cb1},
 created = {2019-02-13T12:19:08.050Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:08.050Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2015. Design and modeling of a micro channel Fischer-Tropsch reactor was considered in this study. A cross-current heat-exchange reactor was modeled using a new method, in which all the process and cooling channels are decomposed into a number of unit cells. Each neighboring process and cooling channel unit cells are coupled to set up material and energy balance equations, including heat-transfer equations for the entire reactor domain, which are then solved simultaneously. The model results were compared with the experimental data for a pilot-scale reactor described in the literature, and were found to be in good agreement. Several case studies were performed to see the effect of variables such as catalyst loading ratio, coolant flow rate, and channel layout on design of a reactor with state-of-the-art Fischer-Tropsch catalyst. The developed model could handle more than 5800 process channels, 7500 cooling channels, and 130 layers, with implementation of six complex reaction kinetics.},
 bibtype = {article},
 author = {Park, S. and Jung, I. and Lee, U. and Na, J. and Kshetrimayum, K.S. and Lee, Y. and Lee, C.-J. and Han, C.},
 doi = {10.1016/j.ces.2015.05.057},
 journal = {Chemical Engineering Science}
}

© 2015. Design and modeling of a micro channel Fischer-Tropsch reactor was considered in this study. A cross-current heat-exchange reactor was modeled using a new method, in which all the process and cooling channels are decomposed into a number of unit cells. Each neighboring process and cooling channel unit cells are coupled to set up material and energy balance equations, including heat-transfer equations for the entire reactor domain, which are then solved simultaneously. The model results were compared with the experimental data for a pilot-scale reactor described in the literature, and were found to be in good agreement. Several case studies were performed to see the effect of variables such as catalyst loading ratio, coolant flow rate, and channel layout on design of a reactor with state-of-the-art Fischer-Tropsch catalyst. The developed model could handle more than 5800 process channels, 7500 cooling channels, and 130 layers, with implementation of six complex reaction kinetics.

@article{
 title = {Design and modeling of large-scale cross-current multichannel Fischer-Tropsch reactor using channel decomposition and cell-coupling method},
 type = {article},
 year = {2015},
 keywords = {Distributed parameter model,Fischer-Tropsch,Gas-to-liquid process,Micro channel reactor,Reactor design},
 volume = {134},
 id = {43924bd5-68af-3799-a8a3-5f5fbc97dbda},
 created = {2021-03-23T08:23:13.805Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-03-23T08:50:12.999Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 abstract = {© 2015. Design and modeling of a micro channel Fischer-Tropsch reactor was considered in this study. A cross-current heat-exchange reactor was modeled using a new method, in which all the process and cooling channels are decomposed into a number of unit cells. Each neighboring process and cooling channel unit cells are coupled to set up material and energy balance equations, including heat-transfer equations for the entire reactor domain, which are then solved simultaneously. The model results were compared with the experimental data for a pilot-scale reactor described in the literature, and were found to be in good agreement. Several case studies were performed to see the effect of variables such as catalyst loading ratio, coolant flow rate, and channel layout on design of a reactor with state-of-the-art Fischer-Tropsch catalyst. The developed model could handle more than 5800 process channels, 7500 cooling channels, and 130 layers, with implementation of six complex reaction kinetics.},
 bibtype = {article},
 author = {Park, S and Jung, I and Lee, U and Na, J and Kshetrimayum, K S and Lee, Y and Lee, C.-J. and Han, C},
 doi = {10.1016/j.ces.2015.05.057},
 journal = {Chemical Engineering Science}
}

© 2015. Design and modeling of a micro channel Fischer-Tropsch reactor was considered in this study. A cross-current heat-exchange reactor was modeled using a new method, in which all the process and cooling channels are decomposed into a number of unit cells. Each neighboring process and cooling channel unit cells are coupled to set up material and energy balance equations, including heat-transfer equations for the entire reactor domain, which are then solved simultaneously. The model results were compared with the experimental data for a pilot-scale reactor described in the literature, and were found to be in good agreement. Several case studies were performed to see the effect of variables such as catalyst loading ratio, coolant flow rate, and channel layout on design of a reactor with state-of-the-art Fischer-Tropsch catalyst. The developed model could handle more than 5800 process channels, 7500 cooling channels, and 130 layers, with implementation of six complex reaction kinetics.

@article{
 title = {Design and operation strategy of CO<inf>2</inf> terminal},
 type = {article},
 year = {2015},
 volume = {54},
 id = {fc998ee4-db86-3d94-be6a-6089fca67be2},
 created = {2021-03-23T08:23:14.147Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-03-23T08:50:12.648Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 abstract = {© 2015 American Chemical Society. With recent advancements in the carbon capture and storage (CCS), much interest has been developed in the CO2 transport options. An infrastructure including pipelines, ships, tanker truck, and railways will be collectively required for a large scale CO2 transport network. In particular, ship transportation can play a special role in the early phase of CCS infrastructure development as it offers flexible routes between source and offshore storage sites. This work is focused on the design and operational strategy of the CO2 terminal which acts as a connecting link between CO2 liquefaction and the shipping section. The study is performed using dynamic simulation in order to have a more realistic understanding of the process. Four scenarios have been developed to define the operational strategy of the terminal: loading case, holding case, unloading case, and emergency shutdown. A reasonable equipment sizing has been done after consultation with vendors data and available literature. The heat influxes to storage tanks include the heat leak from the bottom surface, dry wall, and wet wall for the precise quantification of heat flow across the system. Reasonable control loops are appended to keep the process variables at their set points to allow the safe operation of the CO2 terminal within the operational limits. Finally, a sensitivity analysis has been performed on some of the important design variables in order to understand their effect on the process performance and terminal operation. The results show that boil-off gas (BOG) generation within the CO2 terminal depends on storage tank size, operating pressure, ambient conditions, insulation thickness, and the filling level of the vessel.},
 bibtype = {article},
 author = {Zahid, U and An, J and Lee, C.-J. and Lee, U and Han, C},
 doi = {10.1021/ie503696x},
 journal = {Industrial and Engineering Chemistry Research},
 number = {8}
}

© 2015 American Chemical Society. With recent advancements in the carbon capture and storage (CCS), much interest has been developed in the CO2 transport options. An infrastructure including pipelines, ships, tanker truck, and railways will be collectively required for a large scale CO2 transport network. In particular, ship transportation can play a special role in the early phase of CCS infrastructure development as it offers flexible routes between source and offshore storage sites. This work is focused on the design and operational strategy of the CO2 terminal which acts as a connecting link between CO2 liquefaction and the shipping section. The study is performed using dynamic simulation in order to have a more realistic understanding of the process. Four scenarios have been developed to define the operational strategy of the terminal: loading case, holding case, unloading case, and emergency shutdown. A reasonable equipment sizing has been done after consultation with vendors data and available literature. The heat influxes to storage tanks include the heat leak from the bottom surface, dry wall, and wet wall for the precise quantification of heat flow across the system. Reasonable control loops are appended to keep the process variables at their set points to allow the safe operation of the CO2 terminal within the operational limits. Finally, a sensitivity analysis has been performed on some of the important design variables in order to understand their effect on the process performance and terminal operation. The results show that boil-off gas (BOG) generation within the CO2 terminal depends on storage tank size, operating pressure, ambient conditions, insulation thickness, and the filling level of the vessel.

@article{
 title = {Parametric Optimization for Power De-Rate Reduction in the Integrated Coal-Fired Power Plant with Carbon Capture and Storage},
 type = {article},
 year = {2015},
 volume = {54},
 id = {034b30c2-af71-3a1f-a794-0d69f7836906},
 created = {2021-03-23T08:23:14.327Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-03-23T08:50:11.753Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 abstract = {© 2015 American Chemical Society. Carbon capture and storage (CCS) has attracted worldwide attention as a near-term technology to decelerate global warming. Postcombustion CO<inf>2</inf> capture utilizes existing coal-fired power plants, and aqueous monoethanolamine (MEA) scrubbing is the most common capture technology. However, the heat and energy requirements of solvent regeneration and CO<inf>2</inf> liquefaction cause a 30% decrease in net power output. This power de-rate is a major obstacle to implementing CCS. In this study, simulation-based parametric optimization was performed to minimize the power de-rate. Postcombustion CO<inf>2</inf> capture with aqueous MEA scrubbing (85%, 90%, and 95% removals) and CO<inf>2</inf> liquefaction integrated with a 550 MWe supercritical coal-fired power plant was simulated. The liquid to gas ratio and stripper operating pressure of the CO<inf>2</inf> capture process were the manipulated variables with steam extracted from the intermediate pressure-low pressure crossover pipe and the first low pressure turbine as possible heat sources. The power de-rate was reduced to 17.7% when operating at optimum conditions.},
 bibtype = {article},
 author = {An, J and Lee, U and Jung, J and Han, C},
 doi = {10.1021/ie504557a},
 journal = {Industrial and Engineering Chemistry Research},
 number = {18}
}

© 2015 American Chemical Society. Carbon capture and storage (CCS) has attracted worldwide attention as a near-term technology to decelerate global warming. Postcombustion CO2 capture utilizes existing coal-fired power plants, and aqueous monoethanolamine (MEA) scrubbing is the most common capture technology. However, the heat and energy requirements of solvent regeneration and CO2 liquefaction cause a 30% decrease in net power output. This power de-rate is a major obstacle to implementing CCS. In this study, simulation-based parametric optimization was performed to minimize the power de-rate. Postcombustion CO2 capture with aqueous MEA scrubbing (85%, 90%, and 95% removals) and CO2 liquefaction integrated with a 550 MWe supercritical coal-fired power plant was simulated. The liquid to gas ratio and stripper operating pressure of the CO2 capture process were the manipulated variables with steam extracted from the intermediate pressure-low pressure crossover pipe and the first low pressure turbine as possible heat sources. The power de-rate was reduced to 17.7% when operating at optimum conditions.

@book{
 title = {Design and Exergy Analysis of Combined Rankine Cycle Using LNG Cold Energy},
 type = {book},
 year = {2014},
 source = {Computer Aided Chemical Engineering},
 keywords = {CCS,Combined cycle,LNG,ORC},
 volume = {33},
 id = {9abd9c1f-179b-358b-bd13-e54227665466},
 created = {2019-02-13T12:19:07.252Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.252Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {In this study, a 90MWe combined Rankine cycle utilizing LNG cold exergy was proposed. Utilizing LNG cold exergy and waste heat from the conventional steam cycle, this process was able to generate additional power in the CO2 organic Rankine cycle (ORC). A conventional steam cycle generates only 42MW electric power; this combined Rankine cycle produced more than twice as much power as the conventional steam cycle while consuming the same amount of fossil fuel. Through parameter sensitivity analysis and exergy analysis, the optimum design and operating conditions were also determined. Finally, reduction of the power plant de-rate by introducing a CO2 capture process was also analyzed. © 2014 Elsevier B.V.},
 bibtype = {book},
 author = {Lee, U. and Han, C.},
 doi = {10.1016/B978-0-444-63455-9.50116-1}
}

In this study, a 90MWe combined Rankine cycle utilizing LNG cold exergy was proposed. Utilizing LNG cold exergy and waste heat from the conventional steam cycle, this process was able to generate additional power in the CO2 organic Rankine cycle (ORC). A conventional steam cycle generates only 42MW electric power; this combined Rankine cycle produced more than twice as much power as the conventional steam cycle while consuming the same amount of fossil fuel. Through parameter sensitivity analysis and exergy analysis, the optimum design and operating conditions were also determined. Finally, reduction of the power plant de-rate by introducing a CO2 capture process was also analyzed. © 2014 Elsevier B.V.

@inproceedings{
 title = {Design and optimization of Low-CO<inf>2</inf>-Emitting organic rankine cycle for liquefied natural gas cold exergy recovery},
 type = {inproceedings},
 year = {2014},
 volume = {2},
 id = {33f70ca1-729a-3703-8e4a-6c600f5bea7e},
 created = {2019-02-13T12:19:07.432Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.432Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 bibtype = {inproceedings},
 author = {Lee, U. and Kim, K. and Han, C.},
 booktitle = {Computing and Systems Technology Division 2014 - Core Programming Area at the 2014 AIChE Annual Meeting}
}

@article{
 title = {Design and optimization of multi-component organic rankine cycle using liquefied natural gas cryogenic exergy},
 type = {article},
 year = {2014},
 keywords = {CO  liquefaction 2,Combined cycle,LNG,Multicomponent,ORC,Steam cycle},
 volume = {77},
 id = {ec0757ab-3212-36a3-a0b5-5d09711c9703},
 created = {2019-02-13T12:19:07.478Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.478Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2014 Elsevier Ltd. In this study, an ORC (organic Rankine cycle) utilizing both low-grade steam from a pulverized coal power plant and LNG (liquefied natural gas) cold exergy is proposed and optimized. The proposed ORC is composed of a pump, a preheater, an evaporator, a superheater, a reheater, a two stage turbine, and a condenser which utilizing LNG as cold sink of the working fluid. The ORC uses R601-R23-R14 ternary mixture as its working fluid and is integrated with a steam cycle as a bottoming cycle. By utilizing the hot and cold exergy of low-pressure steam and LNG that are initially wasted, the ORC is able to generate additional power without consuming fossil fuel. The non-isothermal condensing nature of the ternary mixture working fluid can reduce the exergy loss of the system, and the consequent power generation and efficiency of the ORC are significantly improved. Power generation from the ternary mixture ORC is increased by about 56% and 59% as compared with the pure and binary mixture ORCs, respectively. Important design parameters such as pump discharge pressure, working fluid composition, and turbine inlet and outlet pressure are also optimized to recover the maximum power from the ORC.},
 bibtype = {article},
 author = {Lee, U. and Kim, K. and Han, C.},
 doi = {10.1016/j.energy.2014.09.036},
 journal = {Energy}
}

© 2014 Elsevier Ltd. In this study, an ORC (organic Rankine cycle) utilizing both low-grade steam from a pulverized coal power plant and LNG (liquefied natural gas) cold exergy is proposed and optimized. The proposed ORC is composed of a pump, a preheater, an evaporator, a superheater, a reheater, a two stage turbine, and a condenser which utilizing LNG as cold sink of the working fluid. The ORC uses R601-R23-R14 ternary mixture as its working fluid and is integrated with a steam cycle as a bottoming cycle. By utilizing the hot and cold exergy of low-pressure steam and LNG that are initially wasted, the ORC is able to generate additional power without consuming fossil fuel. The non-isothermal condensing nature of the ternary mixture working fluid can reduce the exergy loss of the system, and the consequent power generation and efficiency of the ORC are significantly improved. Power generation from the ternary mixture ORC is increased by about 56% and 59% as compared with the pure and binary mixture ORCs, respectively. Important design parameters such as pump discharge pressure, working fluid composition, and turbine inlet and outlet pressure are also optimized to recover the maximum power from the ORC.

@inproceedings{
 title = {Design and optimization of low-CO<inf>2</inf>-emitting organic rankine cycle for liquefied natural gas cold exergy recovery},
 type = {inproceedings},
 year = {2014},
 volume = {3},
 id = {a87d19cd-7746-3ad9-9c53-0feac20c2363},
 created = {2019-02-13T12:19:07.533Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.533Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 bibtype = {inproceedings},
 author = {Lee, U. and Kim, K. and Han, C.},
 booktitle = {International Congress on Energy 2014, ICE 2014 - Topical Conference at the 2014 AIChE Annual Meeting}
}

@book{
 title = {Effect of Liquefaction Plant Performance and Location on the Cost of CO<inf>2</inf> Transport},
 type = {book},
 year = {2014},
 source = {Computer Aided Chemical Engineering},
 keywords = {Economic analysis},
 volume = {33},
 id = {554ef588-027e-3b6a-9435-6d47d8effc83},
 created = {2019-02-13T12:19:07.598Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.598Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {Carbon capture and storage (CCS), a key technology for addressing global warming is in between demonstration to commercialization phase. Transportation of CO2 is required since storage sites are not necessarily present under the source sites. Ships can be used for long distance transport of CO2; liquefaction being a vital component in ship transportation. In this study, a state of art CO2 liquefaction process has been designed by taking account of source facilities (i.e. post-combustion and pre-combustion). The proposed liquefaction process offers lower liquefaction energy requirement compared with other available literature. Three different scenarios for post-combustion and pre-combustion each have been studied on the basis of liquefaction plant location. The considered scenarios are categorized as: a) capture site, liquefaction plant and shipping terminal are located close to each other; b) capture site and liquefaction plant are far from shipping terminal; c) capture site is far from liquefaction plant and shipping terminal. Finally, an economic analysis is performed in order to evaluate the feasibility of CO2 transport from source sites to ship loading terminal including liquefaction plant. © 2014 Elsevier B.V.},
 bibtype = {book},
 author = {Zahid, U. and An, J. and Lee, U. and Han, C.},
 doi = {10.1016/B978-0-444-63455-9.50110-0}
}

Carbon capture and storage (CCS), a key technology for addressing global warming is in between demonstration to commercialization phase. Transportation of CO2 is required since storage sites are not necessarily present under the source sites. Ships can be used for long distance transport of CO2; liquefaction being a vital component in ship transportation. In this study, a state of art CO2 liquefaction process has been designed by taking account of source facilities (i.e. post-combustion and pre-combustion). The proposed liquefaction process offers lower liquefaction energy requirement compared with other available literature. Three different scenarios for post-combustion and pre-combustion each have been studied on the basis of liquefaction plant location. The considered scenarios are categorized as: a) capture site, liquefaction plant and shipping terminal are located close to each other; b) capture site and liquefaction plant are far from shipping terminal; c) capture site is far from liquefaction plant and shipping terminal. Finally, an economic analysis is performed in order to evaluate the feasibility of CO2 transport from source sites to ship loading terminal including liquefaction plant. © 2014 Elsevier B.V.

@article{
 title = {Automatic model-based soft sensor generation for liquefied natural gas terminal pipeline},
 type = {article},
 year = {2014},
 volume = {53},
 id = {d1d59f83-c211-325d-8831-3940a0dc875f},
 created = {2019-02-13T12:19:07.700Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.700Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2014 American Chemical Society. A liquefied natural gas (LNG) receiving terminal is a facility to receive, store, and produce natural gas to demand. In the terminal, there are many pipelines that carry LNG, which is dangerous when it evaporates, but the number of sensors are not sufficient to monitor the property of fluids at all position of pipeline because of the cost of sensors. To solve the data insufficiency problem, a methodology for automatic model-based soft sensor generation is proposed in this paper. This methodology is composed of positional information extraction, automatic model formulation, and simulation with minimum errors. With the software based on this methodology, even the user who does not have a chemical or mathematical background can monitor the fluid property at whole terminal pipelines. For validation, the methodology is applied to an LNG terminal unloading pipeline, and it showed good accuracy and accessibility of various data types.},
 bibtype = {article},
 author = {Lee, S. and Jung, J. and Park, C. and Lee, U. and Han, C.},
 doi = {10.1021/ie502180w},
 journal = {Industrial and Engineering Chemistry Research},
 number = {39}
}

© 2014 American Chemical Society. A liquefied natural gas (LNG) receiving terminal is a facility to receive, store, and produce natural gas to demand. In the terminal, there are many pipelines that carry LNG, which is dangerous when it evaporates, but the number of sensors are not sufficient to monitor the property of fluids at all position of pipeline because of the cost of sensors. To solve the data insufficiency problem, a methodology for automatic model-based soft sensor generation is proposed in this paper. This methodology is composed of positional information extraction, automatic model formulation, and simulation with minimum errors. With the software based on this methodology, even the user who does not have a chemical or mathematical background can monitor the fluid property at whole terminal pipelines. For validation, the methodology is applied to an LNG terminal unloading pipeline, and it showed good accuracy and accessibility of various data types.

@article{
 title = {Techno-economic assessment of CO<inf>2</inf> liquefaction for ship transportation},
 type = {article},
 year = {2014},
 keywords = {CO  liquefaction 2,CO  transport 2,carbon capture and storage,economic analysis},
 volume = {4},
 id = {a7d0b0ce-4077-3c72-88df-c2d4791b9d9c},
 created = {2019-02-13T12:19:07.776Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.776Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2014 Society of Chemical Industry and John Wiley  &  Sons, Ltd. Carbon capture and storage (CCS) is a key technology for addressing global warming by capturing carbon dioxide and storing it somewhere, usually underground. The transportation of CO2 is required since storage sites are not necessarily present near the source sites. Ships can be used for long distance transport of CO2. However, CO2 sources are not always located near the coast; hence onshore transportation may be required in addition to ship for transportation of CO2 from source sites to storage site. Liquefaction is a vital component in ship transportation. In this study, a state-of-the-art CO2 liquefaction processes have been designed by taking CO2 capture facilities into account. The proposed processes require lower liquefaction energy compared to other processes found in the literature. Suitable thermodynamic conditions are required for economical transport of CO2. Therefore, three scenarios each for post-combustion and pre-combustion have been studied in order to explore the effect of thermodynamic conditions on the economics of CO2 transport. The considered scenarios are categorized on the basis of liquefaction plant location as: (i) the capture site, liquefaction plant and shipping terminal are located close to each other; (ii) the capture site and liquefaction plant are far from shipping terminal; (iii) the capture site is far from liquefaction plant and shipping terminal. The scenarios results were useful for deciding the optimum liquefaction plant location. Finally, an economic analysis is performed in order to evaluate the feasibility of CO2 transport from source sites to ship loading terminal.},
 bibtype = {article},
 author = {Zahid, U. and An, J. and Lee, U. and Choi, S.P. and Han, C.},
 doi = {10.1002/ghg.1439},
 journal = {Greenhouse Gases: Science and Technology},
 number = {6}
}

© 2014 Society of Chemical Industry and John Wiley & Sons, Ltd. Carbon capture and storage (CCS) is a key technology for addressing global warming by capturing carbon dioxide and storing it somewhere, usually underground. The transportation of CO2 is required since storage sites are not necessarily present near the source sites. Ships can be used for long distance transport of CO2. However, CO2 sources are not always located near the coast; hence onshore transportation may be required in addition to ship for transportation of CO2 from source sites to storage site. Liquefaction is a vital component in ship transportation. In this study, a state-of-the-art CO2 liquefaction processes have been designed by taking CO2 capture facilities into account. The proposed processes require lower liquefaction energy compared to other processes found in the literature. Suitable thermodynamic conditions are required for economical transport of CO2. Therefore, three scenarios each for post-combustion and pre-combustion have been studied in order to explore the effect of thermodynamic conditions on the economics of CO2 transport. The considered scenarios are categorized on the basis of liquefaction plant location as: (i) the capture site, liquefaction plant and shipping terminal are located close to each other; (ii) the capture site and liquefaction plant are far from shipping terminal; (iii) the capture site is far from liquefaction plant and shipping terminal. The scenarios results were useful for deciding the optimum liquefaction plant location. Finally, an economic analysis is performed in order to evaluate the feasibility of CO2 transport from source sites to ship loading terminal.

@article{
 title = {Design and analysis of a combined Rankine cycle for waste heat recovery of a coal power plant using LNG cryogenic exergy},
 type = {article},
 year = {2014},
 volume = {53},
 id = {272328bb-7d42-3337-b6d2-e3070fcb4fcb},
 created = {2019-02-13T12:19:07.830Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.830Z},
 read = {false},
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 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {In this study, a combined Rankine cycle was modeled and optimized. This process consists of a coal combustion unit, a steam cycle, a CO2 capture process, a gas conditioning process, and a CO2 organic Rankine cycle (ORC). This process is able to extract additional power without consuming additional fossil fuel by integrating the CO2-ORC with the steam cycle and a liquefied natural gas (LNG) evaporation process. Unlike conventional ORC, the CO2-ORC utilizes the low grade waste heat only for super heating of working fluid, while the main evaporation process is achieved by seawater. The CO2 condensation process in the ORC takes place at a temperature lower than the ambient temperature by coupling with the LNG evaporation system as a cold sink. Furthermore, a fraction of liquefied CO2 is purged for the sequestration. Therefore, CO2 liquefaction can be achieved without an additional refrigeration cycle. This process not only produces more power with the same fuel consumption but also reduces CO2 removal energy. The gross power is increased from 42.21 to 90.54 MWe compared with the conventional power plant, and total CO2 removal energy is decreased about 9%. The optimum design and operating conditions were also obtained through parameter sensitivity analysis. The power reduction of the proposed process resulting due to the CO2 capture process installation was identified as 19.3%. However, the net power generation is about 73% higher than that of the conventional power cycle even without CO2 capture. © 2014 American Chemical Society.},
 bibtype = {article},
 author = {Lee, U. and Park, K. and Jeong, Y.S. and Lee, S. and Han, C.},
 doi = {10.1021/ie500110v},
 journal = {Industrial and Engineering Chemistry Research},
 number = {23}
}

In this study, a combined Rankine cycle was modeled and optimized. This process consists of a coal combustion unit, a steam cycle, a CO2 capture process, a gas conditioning process, and a CO2 organic Rankine cycle (ORC). This process is able to extract additional power without consuming additional fossil fuel by integrating the CO2-ORC with the steam cycle and a liquefied natural gas (LNG) evaporation process. Unlike conventional ORC, the CO2-ORC utilizes the low grade waste heat only for super heating of working fluid, while the main evaporation process is achieved by seawater. The CO2 condensation process in the ORC takes place at a temperature lower than the ambient temperature by coupling with the LNG evaporation system as a cold sink. Furthermore, a fraction of liquefied CO2 is purged for the sequestration. Therefore, CO2 liquefaction can be achieved without an additional refrigeration cycle. This process not only produces more power with the same fuel consumption but also reduces CO2 removal energy. The gross power is increased from 42.21 to 90.54 MWe compared with the conventional power plant, and total CO2 removal energy is decreased about 9%. The optimum design and operating conditions were also obtained through parameter sensitivity analysis. The power reduction of the proposed process resulting due to the CO2 capture process installation was identified as 19.3%. However, the net power generation is about 73% higher than that of the conventional power cycle even without CO2 capture. © 2014 American Chemical Society.

@article{
 title = {Economic analysis for the transport and storage of captured carbon dioxide in South Korea},
 type = {article},
 year = {2014},
 keywords = {carbon capture and storage (CCS),economic analysis},
 volume = {33},
 id = {cbcd0a8c-7336-3b71-a327-58e2e75c7c4f},
 created = {2019-02-13T12:19:07.879Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.879Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {The continuous rise of CO2 emissions is a major cause of global climate change. Carbon capture and storage (CCS) is widely seen as a practical technology for reducing CO2 emissions. CCS mainly consists of capturing CO2 from large emitting sources and its transportation to a sequestration site where it can be stored safely for a long period of time. The average CO2 emission growth rate of Korea is 1.0% which is the second highest among the Organization for Economic Co-operation and Development (OECD) countries. It becomes even more challenging when CO2 is transported to an offshore storage since there is little experience with subsea pipelines for CO2 transportation. In this study, a plausible transport and storage model scheme has been developed and then employed to study different offshore CO2 transportation cases for South Korea as: CO2 transport in liquid phase (Temperature= -20°C, Pressure= 6.50 MPa); CO2 transport in liquid phase (Temperature= 5°C, Pressure= 9.30 MPa); CO2 transport in supercritical phase (Temperature= 40°C, Pressure= 15.00 MPa). CO2 storage capacity in sedimentary basins of Korea is evaluated between 19 and 27.2 Gt (giga-ton) of CO 2. Finally, this paper explores the costs associated with transport and geologic sequestration of CO2. Transport cost varies from 10.9 to 15.5 US$/tCO2 while the storage cost ranges from 20.8 to 21.3 US$/tCO2 depending on the specific scenario and depth at which CO2 is stored. Sensitivity analysis showed a decrease in storage cost of 62.4% and 93.6% in 2030 and 2050 respectively for projected CO2 volumes in Korea. © 2013 American Institute of Chemical Engineers.},
 bibtype = {article},
 author = {Zahid, U. and Lee, U. and An, J. and Lim, Y. and Han, C.},
 doi = {10.1002/ep.11832},
 journal = {Environmental Progress and Sustainable Energy},
 number = {3}
}

The continuous rise of CO2 emissions is a major cause of global climate change. Carbon capture and storage (CCS) is widely seen as a practical technology for reducing CO2 emissions. CCS mainly consists of capturing CO2 from large emitting sources and its transportation to a sequestration site where it can be stored safely for a long period of time. The average CO2 emission growth rate of Korea is 1.0% which is the second highest among the Organization for Economic Co-operation and Development (OECD) countries. It becomes even more challenging when CO2 is transported to an offshore storage since there is little experience with subsea pipelines for CO2 transportation. In this study, a plausible transport and storage model scheme has been developed and then employed to study different offshore CO2 transportation cases for South Korea as: CO2 transport in liquid phase (Temperature= -20°C, Pressure= 6.50 MPa); CO2 transport in liquid phase (Temperature= 5°C, Pressure= 9.30 MPa); CO2 transport in supercritical phase (Temperature= 40°C, Pressure= 15.00 MPa). CO2 storage capacity in sedimentary basins of Korea is evaluated between 19 and 27.2 Gt (giga-ton) of CO 2. Finally, this paper explores the costs associated with transport and geologic sequestration of CO2. Transport cost varies from 10.9 to 15.5 US$/tCO2 while the storage cost ranges from 20.8 to 21.3 US$/tCO2 depending on the specific scenario and depth at which CO2 is stored. Sensitivity analysis showed a decrease in storage cost of 62.4% and 93.6% in 2030 and 2050 respectively for projected CO2 volumes in Korea. © 2013 American Institute of Chemical Engineers.

@article{
 title = {Comparative study of process integration and retrofit design of a liquefied natural gas (LNG) regasification process based on exergy analyses: A case study of an LNG regasification process in South Korea},
 type = {article},
 year = {2014},
 volume = {53},
 id = {b84af873-5ebd-3212-a139-c0458fe41741},
 created = {2019-02-13T12:19:07.884Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.884Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2014 American Chemical Society. Exergy analysis of the retrofit design scheme of a conventional liquefied natural gas (LNG) regasification process in South Korea was considered in this study. A new exergy evaluation method called exergy decomposition is introduced, in which the exergy is decomposed into thermal and chemical exergies. In studying the conventional LNG regasification process, we found that a large portion of chemical exergy is lost by boil-off gas flaring. Of 17 MW of thermal exergy transferred from cold LNG to seawater in the regasification unit, a fraction as large as 16 MW (close to 95%) is wasted because of heat-transfer irreversibility, limiting the rational exergetic efficiency of the overall process to merely 0.847. Previously reported design schemes, namely, the dual Brayton cycle and the organic Rankine cycle, with low-grade heat sources were also evaluated using the new method and were found to limit the overall rational exergetic efficiencies to 0.890 and 0.849, respectively. A new integrated, retrofitted scheme for LNG regasification with a gas-to-liquid (GTL) process is proposed as an alternative to minimize thermal and chemical exergy losses. The integrated LNG regasification-GTL process improves the overall rational exergetic efficiency to 0.868.},
 bibtype = {article},
 author = {Park, S. and Park, C. and Lee, U. and Jung, I. and Na, J. and Kshetrimayum, K.S. and Han, C.},
 doi = {10.1021/ie501583m},
 journal = {Industrial and Engineering Chemistry Research},
 number = {37}
}

© 2014 American Chemical Society. Exergy analysis of the retrofit design scheme of a conventional liquefied natural gas (LNG) regasification process in South Korea was considered in this study. A new exergy evaluation method called exergy decomposition is introduced, in which the exergy is decomposed into thermal and chemical exergies. In studying the conventional LNG regasification process, we found that a large portion of chemical exergy is lost by boil-off gas flaring. Of 17 MW of thermal exergy transferred from cold LNG to seawater in the regasification unit, a fraction as large as 16 MW (close to 95%) is wasted because of heat-transfer irreversibility, limiting the rational exergetic efficiency of the overall process to merely 0.847. Previously reported design schemes, namely, the dual Brayton cycle and the organic Rankine cycle, with low-grade heat sources were also evaluated using the new method and were found to limit the overall rational exergetic efficiencies to 0.890 and 0.849, respectively. A new integrated, retrofitted scheme for LNG regasification with a gas-to-liquid (GTL) process is proposed as an alternative to minimize thermal and chemical exergy losses. The integrated LNG regasification-GTL process improves the overall rational exergetic efficiency to 0.868.

@article{
 title = {Economic analysis for the transport and storage of captured carbon dioxide in South Korea},
 type = {article},
 year = {2014},
 keywords = {carbon capture and storage (CCS),economic analysis},
 volume = {33},
 id = {96155576-32ad-3415-a8aa-3ae30b5a99c0},
 created = {2021-03-23T08:23:13.963Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-03-23T08:50:11.894Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 abstract = {The continuous rise of CO2 emissions is a major cause of global climate change. Carbon capture and storage (CCS) is widely seen as a practical technology for reducing CO2 emissions. CCS mainly consists of capturing CO2 from large emitting sources and its transportation to a sequestration site where it can be stored safely for a long period of time. The average CO2 emission growth rate of Korea is 1.0% which is the second highest among the Organization for Economic Co-operation and Development (OECD) countries. It becomes even more challenging when CO2 is transported to an offshore storage since there is little experience with subsea pipelines for CO2 transportation. In this study, a plausible transport and storage model scheme has been developed and then employed to study different offshore CO2 transportation cases for South Korea as: CO2 transport in liquid phase (Temperature= -20°C, Pressure= 6.50 MPa); CO2 transport in liquid phase (Temperature= 5°C, Pressure= 9.30 MPa); CO2 transport in supercritical phase (Temperature= 40°C, Pressure= 15.00 MPa). CO2 storage capacity in sedimentary basins of Korea is evaluated between 19 and 27.2 Gt (giga-ton) of CO 2. Finally, this paper explores the costs associated with transport and geologic sequestration of CO2. Transport cost varies from 10.9 to 15.5 US/tCO2 while the storage cost ranges from 20.8 to 21.3 US/tCO2 depending on the specific scenario and depth at which CO2 is stored. Sensitivity analysis showed a decrease in storage cost of 62.4% and 93.6% in 2030 and 2050 respectively for projected CO2 volumes in Korea. © 2013 American Institute of Chemical Engineers.},
 bibtype = {article},
 author = {Zahid, U and Lee, U and An, J and Lim, Y and Han, C},
 doi = {10.1002/ep.11832},
 journal = {Environmental Progress and Sustainable Energy},
 number = {3}
}

The continuous rise of CO2 emissions is a major cause of global climate change. Carbon capture and storage (CCS) is widely seen as a practical technology for reducing CO2 emissions. CCS mainly consists of capturing CO2 from large emitting sources and its transportation to a sequestration site where it can be stored safely for a long period of time. The average CO2 emission growth rate of Korea is 1.0% which is the second highest among the Organization for Economic Co-operation and Development (OECD) countries. It becomes even more challenging when CO2 is transported to an offshore storage since there is little experience with subsea pipelines for CO2 transportation. In this study, a plausible transport and storage model scheme has been developed and then employed to study different offshore CO2 transportation cases for South Korea as: CO2 transport in liquid phase (Temperature= -20°C, Pressure= 6.50 MPa); CO2 transport in liquid phase (Temperature= 5°C, Pressure= 9.30 MPa); CO2 transport in supercritical phase (Temperature= 40°C, Pressure= 15.00 MPa). CO2 storage capacity in sedimentary basins of Korea is evaluated between 19 and 27.2 Gt (giga-ton) of CO 2. Finally, this paper explores the costs associated with transport and geologic sequestration of CO2. Transport cost varies from 10.9 to 15.5 US/tCO2 while the storage cost ranges from 20.8 to 21.3 US/tCO2 depending on the specific scenario and depth at which CO2 is stored. Sensitivity analysis showed a decrease in storage cost of 62.4% and 93.6% in 2030 and 2050 respectively for projected CO2 volumes in Korea. © 2013 American Institute of Chemical Engineers.

@article{
 title = {Design and analysis of a combined Rankine cycle for waste heat recovery of a coal power plant using LNG cryogenic exergy},
 type = {article},
 year = {2014},
 volume = {53},
 id = {7baf9e9b-f9d2-3d19-97dd-1d1806c3c1b7},
 created = {2021-03-23T08:23:14.024Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-03-23T08:50:11.197Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 source_type = {article},
 private_publication = {false},
 abstract = {In this study, a combined Rankine cycle was modeled and optimized. This process consists of a coal combustion unit, a steam cycle, a CO2 capture process, a gas conditioning process, and a CO2 organic Rankine cycle (ORC). This process is able to extract additional power without consuming additional fossil fuel by integrating the CO2-ORC with the steam cycle and a liquefied natural gas (LNG) evaporation process. Unlike conventional ORC, the CO2-ORC utilizes the low grade waste heat only for super heating of working fluid, while the main evaporation process is achieved by seawater. The CO2 condensation process in the ORC takes place at a temperature lower than the ambient temperature by coupling with the LNG evaporation system as a cold sink. Furthermore, a fraction of liquefied CO2 is purged for the sequestration. Therefore, CO2 liquefaction can be achieved without an additional refrigeration cycle. This process not only produces more power with the same fuel consumption but also reduces CO2 removal energy. The gross power is increased from 42.21 to 90.54 MWe compared with the conventional power plant, and total CO2 removal energy is decreased about 9%. The optimum design and operating conditions were also obtained through parameter sensitivity analysis. The power reduction of the proposed process resulting due to the CO2 capture process installation was identified as 19.3%. However, the net power generation is about 73% higher than that of the conventional power cycle even without CO2 capture. © 2014 American Chemical Society.},
 bibtype = {article},
 author = {Lee, U and Park, K and Jeong, Y S and Lee, S and Han, C},
 doi = {10.1021/ie500110v},
 journal = {Industrial and Engineering Chemistry Research},
 number = {23}
}

In this study, a combined Rankine cycle was modeled and optimized. This process consists of a coal combustion unit, a steam cycle, a CO2 capture process, a gas conditioning process, and a CO2 organic Rankine cycle (ORC). This process is able to extract additional power without consuming additional fossil fuel by integrating the CO2-ORC with the steam cycle and a liquefied natural gas (LNG) evaporation process. Unlike conventional ORC, the CO2-ORC utilizes the low grade waste heat only for super heating of working fluid, while the main evaporation process is achieved by seawater. The CO2 condensation process in the ORC takes place at a temperature lower than the ambient temperature by coupling with the LNG evaporation system as a cold sink. Furthermore, a fraction of liquefied CO2 is purged for the sequestration. Therefore, CO2 liquefaction can be achieved without an additional refrigeration cycle. This process not only produces more power with the same fuel consumption but also reduces CO2 removal energy. The gross power is increased from 42.21 to 90.54 MWe compared with the conventional power plant, and total CO2 removal energy is decreased about 9%. The optimum design and operating conditions were also obtained through parameter sensitivity analysis. The power reduction of the proposed process resulting due to the CO2 capture process installation was identified as 19.3%. However, the net power generation is about 73% higher than that of the conventional power cycle even without CO2 capture. © 2014 American Chemical Society.

@article{
 title = {CO <inf>2</inf> storage terminal for ship transportation},
 type = {article},
 year = {2012},
 volume = {51},
 id = {8f5aea20-e0f0-3548-9e25-a23ab91e2dcc},
 created = {2019-02-13T12:19:07.727Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.727Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {In this article, an intermediate CO 2 storage system for long-distance ship transportation was modeled. The storage terminal links the continuous CO 2 liquefaction process to discrete marine ship transportation and performs as a buffer between them. It is composed of four distinct processes: a CO 2 input process, a storage tank and loading process, a recirculation process, and a BOG (boiled-off gas) reliquefaction process. The entire system should be operated as a liquid phase. Consequently, operation conditions, tank capacity, insulation specification, and streamflow rates play a major role in operating the storage terminal securely. The goal of this study is to design a base case of the storage terminal and propose its appropriate operation condition which makes the terminal operate with minimum operation energy. Results of the base case simulations are compared with improperly insulated systems on the pipeline and tanks that generate more BOG than the base case. The total operation energies of the base case and case studies are presented, and it turns out that approximately three times the operation energy is required if the system is not properly designed. © 2011 American Chemical Society.},
 bibtype = {article},
 author = {Lee, U. and Lim, Y. and Lee, S. and Jung, J. and Han, C.},
 doi = {10.1021/ie200762f},
 journal = {Industrial and Engineering Chemistry Research},
 number = {1}
}

In this article, an intermediate CO 2 storage system for long-distance ship transportation was modeled. The storage terminal links the continuous CO 2 liquefaction process to discrete marine ship transportation and performs as a buffer between them. It is composed of four distinct processes: a CO 2 input process, a storage tank and loading process, a recirculation process, and a BOG (boiled-off gas) reliquefaction process. The entire system should be operated as a liquid phase. Consequently, operation conditions, tank capacity, insulation specification, and streamflow rates play a major role in operating the storage terminal securely. The goal of this study is to design a base case of the storage terminal and propose its appropriate operation condition which makes the terminal operate with minimum operation energy. Results of the base case simulations are compared with improperly insulated systems on the pipeline and tanks that generate more BOG than the base case. The total operation energies of the base case and case studies are presented, and it turns out that approximately three times the operation energy is required if the system is not properly designed. © 2011 American Chemical Society.

@book{
 title = {Carbon Dioxide Liquefaction Process for Ship Transportation},
 type = {book},
 year = {2012},
 source = {Computer Aided Chemical Engineering},
 keywords = {Add three to five keywords here},
 volume = {30},
 id = {957d5d56-8f13-3e78-8200-85b1c09e02c8},
 created = {2019-02-13T12:19:07.937Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.937Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {In this study, an optimal carbon dioxide liquefaction process is studied. This process uses multistage expansion and the cold vapor streams are directly mixed with compressor input streams in order to enhance the compressor efficiency. Consequently, this process does not employ expensive additional multi stage heat exchanger and operates system more efficiently. The optimal operation condition is also achieved by compressor ratio optimization using constrained nonlinear programming. As a result, about 99.1 KWh/ton C02 is consumed which is only 92.8% of total operation energy of existing carbon dioxide liquefaction process. © 2012 Elsevier B.V.},
 bibtype = {book},
 author = {Lee, U. and Yang, S. and Jeong, Y.S. and Jung, J. and Lim, Y. and Han, C.},
 doi = {10.1016/B978-0-444-59519-5.50049-6}
}

In this study, an optimal carbon dioxide liquefaction process is studied. This process uses multistage expansion and the cold vapor streams are directly mixed with compressor input streams in order to enhance the compressor efficiency. Consequently, this process does not employ expensive additional multi stage heat exchanger and operates system more efficiently. The optimal operation condition is also achieved by compressor ratio optimization using constrained nonlinear programming. As a result, about 99.1 KWh/ton C02 is consumed which is only 92.8% of total operation energy of existing carbon dioxide liquefaction process. © 2012 Elsevier B.V.

@article{
 title = {Carbon dioxide liquefaction process for ship transportation},
 type = {article},
 year = {2012},
 volume = {51},
 id = {ab099495-bd83-3dc4-911b-e567b03c4238},
 created = {2019-02-13T12:19:07.992Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:07.992Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {CO2 liquefaction is an essential process for long-distance ship transportation. The conventional CO2 liquefaction process employs either an external coolant or liquid expansion followed by multistage compression to obtain liquefied CO2 at low pressure. However, these processes consume considerable amounts of energy, which presents an obstacle to commercialization. Thus, the CO2 liquefaction process needs to be carefully researched and designed to reduce the operating energy. In this study, two alternative CO2 liquefaction processes are proposed and evaluated. These alternative processes use multistage expansion and multistream heat exchangers to lower the input stream temperature for the compressor. In addition, the system is operated in a more efficient manner by operating the process with an optimized compression ratio. Evaluation of the economic feasibility was performed in this study for a complete assessment of the alternative processes. As a result, about 98.1 kWh/t of CO2 was consumed for alternative process 2, which is only 91.8% of the total operating energy of existing CO2 liquefaction processes, and the CO2 liquefaction costs for alternative process 2 were reduced by 5.5%. © 2012 American Chemical Society.},
 bibtype = {article},
 author = {Lee, U. and Yang, S. and Jeong, Y.S. and Lim, Y. and Lee, C.S. and Han, C.},
 doi = {10.1021/ie300431z},
 journal = {Industrial and Engineering Chemistry Research},
 number = {46}
}

CO2 liquefaction is an essential process for long-distance ship transportation. The conventional CO2 liquefaction process employs either an external coolant or liquid expansion followed by multistage compression to obtain liquefied CO2 at low pressure. However, these processes consume considerable amounts of energy, which presents an obstacle to commercialization. Thus, the CO2 liquefaction process needs to be carefully researched and designed to reduce the operating energy. In this study, two alternative CO2 liquefaction processes are proposed and evaluated. These alternative processes use multistage expansion and multistream heat exchangers to lower the input stream temperature for the compressor. In addition, the system is operated in a more efficient manner by operating the process with an optimized compression ratio. Evaluation of the economic feasibility was performed in this study for a complete assessment of the alternative processes. As a result, about 98.1 kWh/t of CO2 was consumed for alternative process 2, which is only 91.8% of the total operating energy of existing CO2 liquefaction processes, and the CO2 liquefaction costs for alternative process 2 were reduced by 5.5%. © 2012 American Chemical Society.

@book{
 title = {Post-Combustion CO 2 Capture Process with Aqueous MEA. An Advanced MEA Process using a Phase Separation Heat Exchanger},
 type = {book},
 year = {2012},
 source = {Computer Aided Chemical Engineering},
 keywords = {CO   Capture Process 2,MEA Scrubbing,Phase Separation Heat Exchanger,Post Combustion CO   Capture 2,Split Flow Configuration},
 volume = {31},
 id = {76ef4d74-40a2-3609-bcd9-08f581135b47},
 created = {2019-02-13T12:19:08.063Z},
 file_attached = {false},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2019-02-13T12:19:08.063Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {A CO 2 capture process using MEA (Monoethanolamine) scrubbing has been considered a leading technology in the early phase of the CCS (Carbon Capture & Storage) market due to its high CO 2 capture capacity and feasibility of use with existing power plant facilities. In spite of these advantages, this process has a disadvantage of requiring high energy for solvent regeneration in the stripper. For this reason, various improved solvents and process alternatives have been developed to reduce the solvent regeneration energy. This paper suggests an advanced MEA scrubbing process with a PSHE (phase separation heat exchanger) and shows its energy reduction effect using a commercial simulator. The main idea of the PSHE process is to reduce the reflux ratio of the stripper by sacrificing a part of the sensible heat recovery in the heat exchanger. In order to mitigate this sensible heat recovery loss, the PSHE process uses a phase separation heat exchanger. As a result, the PSHE process saves 123MJ/hr of condenser cooling energy while losing 51MJ/hr of sensible heat recovery in the phase separation heat exchanger. Consequently, the net energy reduction is 72MJ/hr, and the ton CO 2 capture energy decreases about 14%, from 3.31 GJ/ton CO 2 to 2.86 GJ/ton CO 2. © 2012 Elsevier B.V.},
 bibtype = {book},
 author = {Jung, J. and Jeong, Y.S. and Lee, U. and Lim, Y. and Yang, S. and Lee, C.S. and Kim, J. and Han, C.},
 doi = {10.1016/B978-0-444-59507-2.50093-7}
}

A CO 2 capture process using MEA (Monoethanolamine) scrubbing has been considered a leading technology in the early phase of the CCS (Carbon Capture & Storage) market due to its high CO 2 capture capacity and feasibility of use with existing power plant facilities. In spite of these advantages, this process has a disadvantage of requiring high energy for solvent regeneration in the stripper. For this reason, various improved solvents and process alternatives have been developed to reduce the solvent regeneration energy. This paper suggests an advanced MEA scrubbing process with a PSHE (phase separation heat exchanger) and shows its energy reduction effect using a commercial simulator. The main idea of the PSHE process is to reduce the reflux ratio of the stripper by sacrificing a part of the sensible heat recovery in the heat exchanger. In order to mitigate this sensible heat recovery loss, the PSHE process uses a phase separation heat exchanger. As a result, the PSHE process saves 123MJ/hr of condenser cooling energy while losing 51MJ/hr of sensible heat recovery in the phase separation heat exchanger. Consequently, the net energy reduction is 72MJ/hr, and the ton CO 2 capture energy decreases about 14%, from 3.31 GJ/ton CO 2 to 2.86 GJ/ton CO 2. © 2012 Elsevier B.V.

@book{
 title = {Post-Combustion CO 2 Capture Process with Aqueous MEA. An Advanced MEA Process using a Phase Separation Heat Exchanger},
 type = {book},
 year = {2012},
 source = {Computer Aided Chemical Engineering},
 keywords = {CO   Capture Process 2,MEA Scrubbing,Phase Separation Heat Exchanger,Post Combustion CO   Capture 2,Split Flow Configuration},
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 source_type = {book},
 private_publication = {false},
 abstract = {A CO 2 capture process using MEA (Monoethanolamine) scrubbing has been considered a leading technology in the early phase of the CCS (Carbon Capture & Storage) market due to its high CO 2 capture capacity and feasibility of use with existing power plant facilities. In spite of these advantages, this process has a disadvantage of requiring high energy for solvent regeneration in the stripper. For this reason, various improved solvents and process alternatives have been developed to reduce the solvent regeneration energy. This paper suggests an advanced MEA scrubbing process with a PSHE (phase separation heat exchanger) and shows its energy reduction effect using a commercial simulator. The main idea of the PSHE process is to reduce the reflux ratio of the stripper by sacrificing a part of the sensible heat recovery in the heat exchanger. In order to mitigate this sensible heat recovery loss, the PSHE process uses a phase separation heat exchanger. As a result, the PSHE process saves 123MJ/hr of condenser cooling energy while losing 51MJ/hr of sensible heat recovery in the phase separation heat exchanger. Consequently, the net energy reduction is 72MJ/hr, and the ton CO 2 capture energy decreases about 14%, from 3.31 GJ/ton CO 2 to 2.86 GJ/ton CO 2. © 2012 Elsevier B.V.},
 bibtype = {book},
 author = {Jung, J and Jeong, Y S and Lee, U and Lim, Y and Yang, S and Lee, C S and Kim, J and Han, C},
 doi = {10.1016/B978-0-444-59507-2.50093-7}
}

A CO 2 capture process using MEA (Monoethanolamine) scrubbing has been considered a leading technology in the early phase of the CCS (Carbon Capture & Storage) market due to its high CO 2 capture capacity and feasibility of use with existing power plant facilities. In spite of these advantages, this process has a disadvantage of requiring high energy for solvent regeneration in the stripper. For this reason, various improved solvents and process alternatives have been developed to reduce the solvent regeneration energy. This paper suggests an advanced MEA scrubbing process with a PSHE (phase separation heat exchanger) and shows its energy reduction effect using a commercial simulator. The main idea of the PSHE process is to reduce the reflux ratio of the stripper by sacrificing a part of the sensible heat recovery in the heat exchanger. In order to mitigate this sensible heat recovery loss, the PSHE process uses a phase separation heat exchanger. As a result, the PSHE process saves 123MJ/hr of condenser cooling energy while losing 51MJ/hr of sensible heat recovery in the phase separation heat exchanger. Consequently, the net energy reduction is 72MJ/hr, and the ton CO 2 capture energy decreases about 14%, from 3.31 GJ/ton CO 2 to 2.86 GJ/ton CO 2. © 2012 Elsevier B.V.

@article{
 title = {Population balance model-based hybrid neural network for a pharmaceutical milling process},
 type = {article},
 year = {2010},
 keywords = {Breakage function,Hybrid model,Milling,Modeling,Neural net,Pharmaceutical processing,Population balance},
 pages = {161-168},
 volume = {5},
 id = {8602cce3-4b7c-3c5e-ba46-3e04ea9c49f3},
 created = {2021-08-11T18:02:59.167Z},
 file_attached = {true},
 profile_id = {e2d2f261-b93b-3381-802e-ec4f45d345ec},
 last_modified = {2021-08-11T18:03:02.156Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 private_publication = {false},
 abstract = {Introduction: Population balances are generally used to predict the particle size distribution resulting from the processing of a particulate material in a milling unit. The key component of such a model is the breakage function. In this work we present an approach to model breakage functions that has utility for situations in which determination of the breakage function from first principles is difficult. Traditionally, heuristic models have been used in those situations but the unstructured nature of such models limits their applicability and reliability. Methods: To address this gap, we propose a semi-empirical hybrid model that integrates first principles knowledge with a data-driven methodology that takes into account the material properties, mill characteristics, and operating conditions. The hybrid model combines a discrete form of population balance model with a neural network model that predicts the milled particle size distribution given material and mill information. Results: We demonstrate the usefulness of this approach for compacted API ribbons milled in a lab scale Quadra conical mill for different materials and mill conditions. Comparisons are also given to the predictions obtained via a purely neural network model and a population balance model with a linear breakage kernel. © Springer Science+Business Media, LLC 2010.},
 bibtype = {article},
 author = {Akkisetty, Pavan Kumar and Lee, Ung and Reklaitis, Gintaras V. and Venkatasubramanian, Venkat},
 doi = {10.1007/s12247-010-9090-2},
 journal = {Journal of Pharmaceutical Innovation},
 number = {4}
}

Introduction: Population balances are generally used to predict the particle size distribution resulting from the processing of a particulate material in a milling unit. The key component of such a model is the breakage function. In this work we present an approach to model breakage functions that has utility for situations in which determination of the breakage function from first principles is difficult. Traditionally, heuristic models have been used in those situations but the unstructured nature of such models limits their applicability and reliability. Methods: To address this gap, we propose a semi-empirical hybrid model that integrates first principles knowledge with a data-driven methodology that takes into account the material properties, mill characteristics, and operating conditions. The hybrid model combines a discrete form of population balance model with a neural network model that predicts the milled particle size distribution given material and mill information. Results: We demonstrate the usefulness of this approach for compacted API ribbons milled in a lab scale Quadra conical mill for different materials and mill conditions. Comparisons are also given to the predictions obtained via a purely neural network model and a population balance model with a linear breakage kernel. © Springer Science+Business Media, LLC 2010.