A methodological framework for the development of feasible CO₂ conversion processes

Roh, Kosan,Lee, Jay H.,Gani, Rafiqul Elsevier 2016 INTERNATIONAL JOURNAL OF GREENHOUSE GAS CONTROL Vol.47 No.-

<P><B>Abstract</B></P> <P>Converting captured CO<SUB>2</SUB> feedstock into valuable chemical products is viewed as one of the potential ways to reduce atmospheric CO<SUB>2</SUB> emission. To this end, a methodological framework is suggested to support the development of feasible CO<SUB>2</SUB> conversion processes that can contribute to the CO<SUB>2</SUB> reduction by replacing non-CO<SUB>2</SUB> utilizing processes or non CO<SUB>2</SUB>-based products. The framework encompasses several execution and decision steps and uses three main criteria, which are the demand availability, CO<SUB>2</SUB> reduction feasibility, and economic feasibility. As an illustrative example, a methanol plant employing combined reforming (CR) of methane reaction is developed. To supply the CO<SUB>2</SUB> feedstock, the aMDEA-based CO<SUB>2</SUB> capture applied to a SMR-based H<SUB>2</SUB> plant is considered. A baseline process is developed and is compared with a non-CO<SUB>2</SUB> utilizing conventional methanol plant (process substitution) and a gasoline production process (product substitution) in terms of the established criteria. For the former, it is verified that the methanol production via combined reforming leads to cheaper unit production cost as well as lower net CO<SUB>2</SUB> emission compared to the conventional methanol plant. For the latter, it is shown that the feasibility of the CO<SUB>2</SUB>-based methanol as an alternative fuel to gasoline highly depends on the type and price of the raw materials. To improve the developed baseline CO<SUB>2</SUB> conversion process further, (1) some of the combined reforming reaction related design variables are fine-tuned using a sensitivity analysis and an equilibrated syngas plot, and (2) utilization of various renewable energy resources for the internal electricity demand is examined.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A methodological framework for feasible CO<SUB>2</SUB> conversion process development. </LI> <LI> Replacement of a conventional methanol plant by the CO<SUB>2</SUB> conversion process. </LI> <LI> Replacement of gasoline by the CO<SUB>2</SUB>-based methanol. </LI> <LI> Reduction of net CO<SUB>2</SUB> emission of the developed process through a graphical approach. </LI> <LI> Utilization of various renewable energy resources for internal electricity demand. </LI> </UL> </P>

Dynamic Modeling and Control Studies for the Elevated Pressure Air Separation Unit in an IGCC Power Plant

Kosan Roh,Hyojin Lee,Jay H. Lee 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10

IGCC (Integrated Gasification Combined Cycle) power plant is one of the promising power generation systems for the future as it can utilize the plentiful resource of coal in an eco-friendly way. The IGCC system is more complicated than the conventional pulverized coal power plant, so its dynamics should be investigated and an appropriate control strategy must be devised to ensure stable and efficient operation. In this research, Elevated Pressure Air Separation Unit (EP ASU) in an IGCC power plant is studied from the viewpoint of dynamic systems analysis. EP ASU separates cryogenic air feed into oxygen and nitrogen in a high pressure column and sends them to the gasification unit and gas turbine. Equation-based modeling of the cryogenic rectification column in EP ASU has been carried out using the software platform of gPROMS. Also, the transient behavior in response to various disturbances is studied through the dynamic simulation. Based on dynamic analysis, a control strategy is suggested at the end.

Control Structure Selection for the Elevated-Pressure Air Separation Unit in an IGCC Power Plant: Self-Optimizing Control Structure for Economical Operation

Roh, Kosan,Lee, Jay H. American Chemical Society 2014 INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH - Vol.53 No.18

<P>The air separation unit (ASU) is one of the core elements of integrated gasification combined cycle (IGCC) power plants. The ASU separates air into pure oxygen and nitrogen, to be sent to the gasifier and the gas turbine, respectively. This system consumes about 10% of the gross power output generated in IGCC, so its economical operation is important for lowering the overall power generation cost. The use of an elevated-pressure air separation unit (EP ASU), in which the operating pressure is higher than in a conventional ASU, is known to lead to significant energy savings. In this research, controlled variable selection for an EP ASU was studied, considering both the controllability and economics, that is, with the objective of maintaining economically near-optimal operations in the presence of anticipated load changes. The main tool used for this was the so-called “minimum singular value rule” within the overall framework of self-optimizing control (SOC). For the purpose of selecting and testing self-optimizing control structures, equation-based modeling of EP ASU was carried out and implemented on the commercial software platform gPROMS. Then, the minimum singular value rule was applied using steady-state gain matrices (obtained from the simulator) to select a small number of candidate sets for controlled variables, to which rigorous analyses based on nonlinear simulation and optimization could be applied to pick the top choice. Before the minimum singular value rule was applied, however, certain process insights and heuristics were used to reduce the number of candidate sets down to a manageable level. The economic losses as a result of adopting a fixed control structure were assessed by comparing the hourly operating costs achieved under SOC with the equivalent values obtained by performing full nonlinear optimizations for the given scenarios. In addition, for the suggested control structure, proportional plus integral (PI) control loops were designed, and their dynamic performance was tested in order to make sure that it is attractive in terms of not only economics but also controllability. The finally selected control structure is compared with those presented in previous works.</P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ie402909j'>ACS Electronic Supporting Info</A></P>

Sustainability analysis of CO₂ capture and utilization processes using a computer-aided tool

Roh, Kosan,Lim, Hyungmuk,Chung, Wonseok,Oh, Jaewoo,Yoo, Haeun,Al-Hunaidy, Ali S.,Imran, Hasan,Lee, Jay H. Elsevier 2018 Journal of CO₂ utilization Vol.26 No.-

<P><B>Abstract</B></P> <P>CO<SUB>2</SUB> capture and utilization technologies (CCU) are recently attracting attention as ways to reduce CO<SUB>2</SUB> emission and generate economic benefits at the same time. Since numerous potential products from CO<SUB>2</SUB> may be considered and multiple processing pathways are possible for each product, there is a growing demand for a tool that can aid in techno-economic and life cycle CO<SUB>2</SUB> analyses of a large number of CCU options, in order to identify promising ones. This work introduces a computer-aided analysis tool called ArKa-TAC<SUP>3</SUP> tailored for this purpose. ArKa-TAC<SUP>3</SUP> can calculate both techno-economic and CO<SUB>2</SUB> reduction metrics of CCU processes in a fast and convenient manner. Sufficient flexibility is assured by adopting a superstructure model framework, which allows the user to conveniently describe a CCU processing network composed of multiple processing steps with a large number of technical options. To demonstrate the tool, a CCU process of acetic acid production is designed and its sustainability is analyzed by using it. By implementing the designed process in four different countries, it is verified that the CCU process can be made sustainable by adopting the process substitution strategies its implementation. Some perspectives on potential applications of the developed tool are given.</P> <P><B>Highlights</B></P> <P> <UL> <LI> ArKa-TAC<SUP>3</SUP>, a computer-aided analysis tool tailored to CCU processes is developed. </LI> <LI> Multiple CCU paths can be handled by adopting superstructure model framework. </LI> <LI> Techno-economic and CO<SUB>2</SUB> reduction metrics of CCU processes cab be calculated simultaneously. </LI> <LI> Implementation of a CO<SUB>2</SUB>-based acetic acid plant in four different countries is examined. </LI> </UL> </P>

Synthesis of the optimal heat and water recovery system for reduction of the refinery CO₂ emission

Haeun Yoo,Kosan Roh,Ali S. Al Hunaidy,Hasan Imran,Jay H. Lee 제어로봇시스템학회 2017 제어로봇시스템학회 국제학술대회 논문집 Vol.2017 No.10

Petroleum refinery is one of the major CO₂ emitters in the global industrial sector. The refinery has a number of various CO₂ emission points including the utility plants and furnaces. Also, it consumes a large amount of industrial water as feedstock for utility. In particular, for those located in the Middle East area which is arid, the supply of the water resource turns out to be a serious problem, so it is highly demanded to utilize the water resource more efficiently. To overcome these challenges, the heat and water recovery (HWR) system applied to the steam plant of the petroleum refinery is proposed. The system allows recovering heat energy of hot flue gas streams to heat the condensate water through heat exchangers. Moreover, the flue gas streams are further cooled below the water dew point to recover water. The goal of this study is to formulate and solve an optimization problem for the heat exchanger network (HEN) synthesis of the system. The potential to CO₂ reduction and cost saving are obtained with the optimal HEN configuration. In addition, sensitivity analysis is conducted by perturbing several economic parameters that affect the optimization results.

Development of Bicarbonate-based Microalgae Cultivation System Combined with Electrochemical CO₂ Absorption Process

Ga-Yeong KIM,Kosan ROH,Jong-In HAN 한국생물공학회 2018 한국생물공학회 학술대회 Vol.2018 No.10

Design, simulation and feasibility study of a combined CO₂ mineralization and brackish water desalination process

Oh, Jaewoo,Jung, Dabin,Oh, Seung Hwan,Roh, Kosan,Ga, Seongbin,Lee, Jay H. Elsevier 2019 Journal of CO₂ utilization Vol.34 No.-

<P><B>Abstract</B></P> <P>This study presents a novel process integration scheme between CO<SUB>2</SUB> mineralization and brackish water reverse osmosis (BWRO). The integration is based on the reciprocal nature of these two processes: While CO<SUB>2</SUB> mineralization needs metal ions such as Na<SUP>+</SUP> to convert CO<SUB>2</SUB> into mineral carbonates like sodium bicarbonate, BWRO is designed to reject such ions to produce fresh water. Thus, there is a potential synergy that can be gained through their integration. To examine the feasibility of such process integration, techno-economic analysis (TEA) and CO<SUB>2</SUB> life cycle assessment (LCA) are conducted for various possible configurations of the integrated process. A key requirement for TEA and CO<SUB>2</SUB> LCA is the availability of mass and energy balance data. Therefore, the process is simulated with the commercial simulation software tool of <I>Aspen Plus</I> combined <I>MATLAB</I>. Another requirement is the selection of appropriate evaluation scenarios. Based on a market analysis, the proposed process is assumed to be installed either in the US or in the China to replace a respective conventional benchmark process. Also, two sources of electricity (coal and wind onshore) are considered in the evaluation in order to investigate the sensitivity of the process performance on the type of electricity used. As a result of the analysis, the CO<SUB>2</SUB> avoidance cost of the designed process is calculated to be 132˜245$/metric ton of CO<SUB>2</SUB> with wind-based electricity. Given other advantages of the mineralization over the geological storage, the presented process integration between CO<SUB>2</SUB> mineralization and BWRO deserves further investigation as a means to produce useful chemicals and fresh water while curbing CO<SUB>2</SUB> emission.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Integration between CO<SUB>2</SUB> mineralization and desalination. </LI> <LI> Integrated process is designed and simulated. </LI> <LI> Economic viability and CO<SUB>2</SUB> reduction potential are examined. </LI> <LI> Using wind-based electricity significantly improves the process performance. </LI> </UL> </P>

Techno-Economic Analysis on Green Hydrogen Production from Curtailed Renewable Power in Jeju Island, the Republic of Korea

Woohyun Kim,Kyoung Soo Kang,Seong Uk Jeong,Kosan Roh 한국신재생에너지학회 2022 AFORE Vol.2022 No.9

Optimization analysis of the absorption-stabilization process for fluid catalytic cracking unit

Hussain Muhammad Saddam,Ahmed Ashfaq,Yibin Liu,Amin Muhammad Nadeem,Zahoor Tahir,Saleem Muhammad Afnan,Roh Kosan,Hussain Murid,Abu Bakar Muhammad Saifullah,박영권 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.7

The absorption-stabilization process (ASP), an important part of petroleum refinery used in the end-use products of petroleum (such as stable gasoline, liquid petroleum gas, and dry gas), is energy-intensive and has low product quality. Aspen Plus process simulator was used for the development of the ASP process model. The developed process model was validated with the actual plant data. The validated model was used to optimize to minimize the cost of the ASP. This work shows that the optimization analysis of the ASP can further improve the product quality and reduce thermal energy consumption. In the new process, changing feeding parameters of supplementary absorption oil, stripping tower intermediate reboiler, and feeding position of stabilization tower reduced the C3 contents of dry gas considerably and lowered the C2 and lighter contents of LPG. Additionally, the new process saved 1.32 MW of thermal energy consumption compared with the existing process. The operating cost has been reduced from 10.921 million USD annually to 9.830 million USD per year. Furthermore, the cost-saving effect of this optimization is about 9.99% (1.091 million USD per year).

국내 MW급 그린수소 기술 연구 동향 및 기술 경제성 분석

김우현(Woohyun Kim),강경수(Kyoung Soo Kang),고희상(Heesang Ko),정윤철(Yoon-cheul Jeung),노고산(Kosan Roh) 한국에너지기후변화학회 2023 한국에너지기후변화학회 학술대회 Vol.2023 No.11