Optimized process configurations of post-combustion CO2 capture for natural-gas-fired power plant - Power plant efficiency analysis

Carbon dioxide was removed by chemical absorption processes from the flue gases of natural-gas-fired combined-cycle power plant. The main challenge of chemical absorption processes is reducing the energy requirement. This paper discusses the selection of most important parameters necessary to obtain 90% capture ratio and the lowest energy consumption for the CO2 capture and compression plants. The integrated capture processes with power plant were evaluated by using the net power-plant efficiency. Several chemical absorption process configurations were analyzed and the design parameters were compared for the different cases. The findings show decreased reboiler energy consumption for the Base case chemical absorption process configuration with 3.74-2.71 MJ/kg CO2 for the modified chemical absorption process configuration of lean vapor recompression with absorber inter-cooling. The net power plant efficiency with CO2 capture and compression was increased from 49.4% (LHV) for the Base case chemical absorption process to 50.2% (LHV) for the chemical absorption process with absorber inter-cooling and lean vapor recompression. The power output reduction due to CO2 capture and compression was decreased from 48 MW for the Base case chemical absorption process to 42.5 MW for the case with absorber inter-cooling and lean vapor recompression. (C) 2012 Elsevier Ltd. All rights reserved.