Energy, exergy and economic (3E) analysis of a novel integration process based on coal-fired power plant with CO2 capture & storage, CO2 refrigeration, and waste heat recovery

CO2 capture, utilization, and storage (CCUS) are critical technical measures to effectively mitigate the global climate change problem. However, most of the existing research has focused on the capture end and lacks in-depth analysis of subsequent processes such as compression, leading to limitations in the improvement of system economics. Therefore, a novel CCS system for a 300 MW coal-fired power plant was proposed in this paper with two strategies: (1) a CCS system integrating CO2 refrigeration cycle (CFPP-CCS-CRC); and (2) a CCS co-generation plant integrating CO2 refrigeration cycle (CHP-CCS-CRC). The proposed systems’ performance was comparatively evaluated by applying energy, exergy, and economic (3E) analyses. The results demonstrated that at different CO2 capture percentages (13.1 %∼72.9 %), the CHP-CCS-CRC system has improved energy utilization efficiency by 1.2 %∼5.6 % and exergy efficiency by 7.7 %∼25.8 %, compared to the conventional CCUS system (CFPP-CCS). In particular, at a percentage of 13.1 %, the combined energy consumption of the CHP-CCS-CRC system was 0.39 GJ/tCO2, a 79 % reduction compared to 1.87 GJ/tCO2 of the CFPP-CCS system, which resulted in a static payback period of less than 2 years. In general, the newly proposed system features more adequate energy utilization, lower operating costs, and higher economic efficiency.