Performance, economic and exergy analyses of carbon capture processes for a 300 MW class integrated gasification combined cycle power plant

The techno-economic analysis of the CCPs was performed for a 300 MW class integrated coal gasification combined cycle (IGCC) power plant. In the study, the a-MDEA and Selexol processes were selected for the analysis as the representative of the chemical and physical solvent-based carbon capture process (CCPs). A rigorous evaluation of dual-stage CCPs, including power generation, economic evaluations, and exergy destruction, was performed. The net power of a-MDEA and Selexol processes was 267.3 MW and 291.4 MW, respectively, which corresponded to the thermal efficiencies of the dual-stage a-MDEA process of 32.3% and Selexol process of 35.2%. According to the economic analysis, the CAPEX of the Selexol process was approximately 1.39 times more expensive than that of the a-MDEA process. However, the OPEX of the Selexol process for removing a ton of CO2 was approximately one third of that of the a-MDEA process. The exergy flow and destruction were also discussed to evaluate the associated impact on the major components of CCPs. Based on the exergy analysis, the suggestion to improve thermal efficiency was made and result was also briefly discussed. These results can aid in decision-making and in process development for commercial-scale CCPs with respect to thermodynamic and economic analyses.