Performance Comparison on the Evaporative Gas Turbine Cycles Combined with Different CO2-Capture Options

Abstract

This article studied the integration of CO2 capture with evaporative gas turbine (EvGT) cycles. Two CO2 capture technologies are involved: MEA-based (monoethanolamine-based) chemical-absorption capture and O2/CO2 recycle combustion capture. Based on them, three system configurations were analyzed: (1) EvGT cycle without CO2 capture, (2) EvGT cycle with chemical-absorption capture, and (3) EvGT cycle with O2/CO2 recycle combustion capture. Simulation results show that the EvGT cycle with chemical-absorption capture has a higher electrical efficiency (39.73%) than the EvGT cycle with O2/CO2 recycle combustion capture (37.45%). Compared with the EvGT cycle without CO2 capture, the penalty on electrical efficiency caused by CO2 capture is 11.91% if EvGT is combined with chemical-absorption capture, and 14.19% if EvGT is combined with O2/CO2 recycle combustion capture. Moreover compared with combined cycles, EvGT cycles have a smaller gross electricity generation and a lower electrical efficiency no matter if they are combined with CO2 capture or not. Based on the analysis results of this article, several suggestions are also proposed to improve the net electrical efficiency of EvGT cycles with CO2 capture.