• Korean Chemical Engineering Research
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• v.49 no.6
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• pp.764-768
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• 2011

The process of $CO_2$ capture using aqueous Monoethanolamine(MEA) has been considered as one of the leading technologies for intermediate-term strategy to reduce the $CO_2$ emission. This MEA process, however, consumes relatively a large amount of energy in the stripper for absorbent regeneration. For this reason, various process alternatives are recently established to reduce the regeneration energy. This paper suggests a flue gas split configuration as one of MEA process alternatives and then simulates this process using commercial simulator. This flue gas splitting has an effect on reducing the temperature of the lower section of absorber as well as decreasing the absorbent flow rate. Compared to the base model, this optimized flue gas split process provides 6.4% reduction of solvent flow rate and 5.8% reduction of absorbent regeneration energy.

• Journal of the Korean Institute of Gas
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• v.16 no.3
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• pp.35-41
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• 2012

Manifold researches for carbon capture and storage (CCS) have been developed and large scale-carbon capture system can be performed recently. Hence, the technologies for $CO_2$ sequestration or storage become necessary to handle the captured $CO_2$. Among them, enhanced oil recovery using $CO_2$ can be a solution since it guarantees both oil recovery and $CO_2$ sequestration. In this study, the miscible flow of oil and $CO_2$ in porous media is modeled to analyze the effect of enhanced oil recovery and $CO_2$ sequestration. Based on Darcy-Muskat law, the equation is modified to consider miscibility of oil and $CO_2$ and the change of viscosity. Finite volume method is used for numerical modeling. As results, the pressure and oil saturation changes with time can be predicted when oil, water, and $CO_2$ are injected, respectively, and $CO_2$ injection is more efficient than water injection for oil recovery.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.1
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• pp.15-21
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• 2015

This paper presents the feasibility study on $CO_2$ carrier for carbon dioxide marine geological storage. Conceptual design was carried out to acquire $CO_2$ carriers by retrofitting existing vessels and new ship-building. Based on conceptual design, the acquisition cost of $CO_2$ carriers was estimated. Finally, necessary expense and number of ships were estimated based on operational plans for the assumed scenario.

• Korean Chemical Engineering Research
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• v.50 no.6
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• pp.988-993
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• 2012

Energy and cost analysis of the preprocessing for carbon capture and storage transportation such as supercritical compression and liquefaction is done using chemical simulation model. Direct compression to supercritical phase (process 1-1), liquefaction and pumping (process 1-2), carbon dioxide compression and expansion as a refrigerant itself (process 2), usage of other refrigerant with compression and expansion (process 3-1), with absorption chiller (process 3-2), cascade refrigeration (process 3-2) have been simulated and evaluated. The specific cost is about 4 to 7 $/ton.

• Journal of Environmental Policy
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• v.13 no.1
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• pp.3-23
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• 2014

TThe CCS, gathering attention as a practical measure against climate change, has various potential risks within itself. Identifying those risks and developing proper countermeasures for each one, therefore, is essential. Failure to take proper measures against such risks may result in significant damages and accidents, causing social anxiety and unwillingness to accept CCS. This study proposes the precautionary principle as a fundamental principle for CCS risk management. While the justifications for the precautionary principle are acceptable, there have been criticisms on its limitations including its impracticality. The purpose of this study was, therefore, to identify detailed application strategies to overcome those limitations. The risk factors related to CCS consist of quantifiable risk domains as well as a number of those with high uncertainty and ambiguity. Thus, there is a need to develop differentiated coping measures, meaning that the precautionary principle should be applied. The risk assessment and management applying the precautionary principle has implication of social appraisal based on wide participation and communication among the interested parties, which may be a useful approach for expanding social applicability.

• Journal of the Korean Ceramic Society
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• v.50 no.1
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• pp.18-24
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• 2013

This study was conducted to recycle fly ash containing an abundance of CaO generated from combustion in a circulating layer as a carbon storage medium. The study utilized XRD, TG-DTA and XRF analyses during the hydration of fly ash and identified calcium substances within fly ash that could be used in a carbonation process. $Ca^{2+}$ ions in the calcium substances were easily converted to hydrates. A carbonation experiment was done, which used the method of $CO_2$ gas injection to produce suspensions by mixing fly ash with distilled water. The results were analyzed using TG-DTA, XRD, and pH meter measurements. The study was able to verify that the reaction was completed at a $CO_2$ flow rate of 300cc/min approximately 30 minutes after an injection into a solution with a solid-liquid ratio of 1 : 10 of fly ash and distilled water. Moreover, the stirring time of the suspensions did not influence the reaction, and the reaction time was found to diminish as the portion of the fly ash became smaller. Thus, this study produced carbon storage fly ash having a $CO_2$ storage rate of about 71% through the utilization of the CaO content contained within fly ash.

• Journal of the Korean Institute of Gas
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• v.16 no.6
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• pp.55-66
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• 2012

The practical way to minimize the greenhouse gas is to reduce the emission of carbon dioxide. For this reason, CCS(Carbon Capture and Storage) technology, which could reduce carbon dioxide emission, has risen as a realistic alternative in recent years. In addition, the researcher is recently working into ways of applying CCS technologies with deep saline aquifer. In this study, the evaluation model on the feasibility of $CO_2$ sequestration in the deep saline aquifer using ANN(Artificial Neural Network) was developed. In order to develop the efficiency-evaluation model, basic model was created in the deep saline aquifer and sensitivity analysis was performed for the aquifer characteristics by utilizing the commercial simulator of GEM. Based on the sensitivity analysis, the factors and ranges affecting $CO_2$ sequestration in the deep saline aquifer were chosen. The result from ANN training scenario were confirmed $CO_2$ sequestration by solubility trapping and residual trapping mechanism. The result from ANN model evaluation indicated there is the increase of correlation coefficient up to 0.99. It has been confirmed that the developed model can be utilized in feasibility of $CO_2$ sequestration at deep saline aquifer.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.3
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• pp.285-292
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• 2012

The integrated gasification combined cycle (IGCC) system is well known for its high efficiency compared with that of other coal fueled power generation system. IGCC offers substantial advantages over pulverized coal combustion when carbon capture and storage (CCS) is required. Commercial plants employ different types of quenching system to meet the purpose of the system. Depending on that, the downstream units of IGCC can be modeled using different operating conditions and units. In case with $CO_2$ separation and capture, the gasifier product must be converted to hydrogen-rich syngas using Water Gas Shift (WGS) reaction. In most WGS processes, the water gas shift reactor is the biggest and heaviest component because the reaction is relatively slow compared to the other reactions and is inhibited at higher temperatures by thermodynamics. In this study, tehchno-econimic assessments were found according to the quench types and operating conditions in the WGS system. These results can improve the efficiency and reduce the cost of coal gasification.

• Korean Chemical Engineering Research
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• v.52 no.5
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• pp.574-580
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• 2014

Storage tanks of Carbon dioxide ($CO_2$) carriers utilized for the purpose of carbon capture and storage (CCS) into subsea strata have to undergo a pre-cooling session before beginning to load cryogenic liquid cargos in order to prevent physical and thermal deterioration of tanks which may result from cryogenic $CO_2$ contacting tank walls directly. In this study we propose dynamic model to calculate the tank inflow of $CO_2$ gas injected for precooling process and its dynamic simulation results under proportional-integral control algorithm. We selected two cases in which each of them had one controlled variable (CV) as either the tank pressure or the tank temperature and discussed the results of that decision-making on the pre-cooling process. As a result we demonstrated that the controlling instability arising from nonlinearity and singularity of the mathematical model could be avoided by choosing tank pressure as CV instead of tank temperature.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.130.2-130.2
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• 2010

2020년까지 대형 CCS (Carbon Capture and Storage) Demo Plant 시장 (100MW 이상) 이 형성될 전망이다. 발전 부문에서 대규모 CCS 실증 프로젝트는 총 44개이며 연소전(41%), 연소후(28%), 순산소(3%) 프로젝트가 계획되어 있다. 순산소 연소 기술은 실증진입단계, 연소후(USC) 기술은 상용화 추진단계, 연소전 (IGCC) 기술은 실증완료 이후 상용화 진입 단계이다. IGCC 발전의 석탄가스화 기술은 타 산업분야에 서 상용화 되어있어 기술신뢰성이 높다. IGCC 단위설비 기술 개발을 통한 성능개선 및 비용절감에 대한 잠재력을 가지고 있기 때문에 미래의 석탄발전기술로 고려되고 있다. IGCC 기술은 가장 상용화에 앞서있지만 아직까지 IGCC+CCS 대형 설비가 운전된 사례가 전 세계적으로 없으며 미국 EPRI 등에서 Feasibility Study 단계이다. 현재 국책과제로 수행중인 300MW급 태안 IGCC 플랜트를 대상으로 향후 CCS 설비를 적용했을 경우에 대해 기술 타당성 검증을 목적으로 IGCC+CCS 모델링을 수행하였다. 모델링은 스크러버 후단의 합성 가스를 대상으로 하였다. Water Gas Shift Reaction (WGSR) 공정 및 Selexol 공정을 구성하여 최종 단에서 수소 연료를 생산할 수 있도록 하였다. WGSR 공정은 Co/Mo 촉매반응기로 구성되었다. WGSR 모델링을 통하여 주입되는 스팀량 (1~2 mol-steam/mol-CO) 및 온도 변화 ($220-550^{\circ}C$)에 따른 CO가스의 전환율을 분석하여 경제적인 설계조건을 선정하였다. Selexol 공정은 $H_2S$ Absorber, $H_2S$ Stripper, $CO_2$ Absorber, $CO_2$ Flash Drum으로 구성된다. Selexol 공정의 $CO_2$와 $H_2S$ 선택도를 분석 하였으며 단위 설비별 설계 조건을 예측하였다. 모델링 결과 59kg/s의 합성가스($137^{\circ}C$, 41bar, 가스 조성은 $CO_2$ 1.2%, CO 57.2%, $H_2$ 23.2%, $H_2S$ 0.02%)가 WGSR Process를 통해 98% CO가 $CO_2$ 로 전환되었다. Selexol 공정을 통해 $H_2S$ 제거율은 99.9%, $CO_2$제거율은 96.4%이었고 14.9kg/s의 $H_2$(86.9%) 연료를 얻었다. 모델링 결과는 신뢰성 검증을 통해 IGCC+CCS 전체 플랜트의 성능예측과 Feasibility Study를 위한 자료로 활용될 예정이다.