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.

Keywords:

• Evaporative gas turbines
• Humid air turbines
• CO₂ capture
• Chemical absorption
• O₂/CO₂ recycle combustion
• Oxy-fuel combustion
• Performance analysis

ACKNOWLEDGMENTS

Financial supports from the Swedish Energy Agency (STEM), SINTEF (Norway), and European Union are gratefully acknowledged.