Integration of Evaporative Gas Turbine with Oxy-Fuel Combustion for Carbon Dioxide Capture

Abstract

This paper studied the integration of Evaporative Gas Turbine (EvGT) cycle with oxy-fuel combustion for CO₂ capture. The impact of key parameters on system electrical efficiency, such as the oxygen purity, Water/Gas ratio (W/G) has been investigated concerning thermal efficiency. The performance of dry recycle and wet recycle also has be analyzed and compared. Simulation results shows that: (1) 97% can be considered as the optimum oxygen purity taking into account the trade-off between the air separation unit (ASU) consumption penalty of producing higher-purity oxygen and electrical efficiency; (2) there exists an optimum point of W/G for both EvGT and EvGT combined with oxy-fuel combustion CO₂ capture technology; (3) dry recycle has a considerably higher electrical efficiency comparing with wet recycle, but more cooled water can be saved in the wet recycle. The performance of EvGT cycle was also compared to the combined cycle (CC) when CO₂ capture was considered. The comparison shows that CC has a higher net power output and electrical efficiency than the EvGT cycle no matter if combined with oxy-fuel combustion CO₂ capture technology or not.

Keywords:

• Evaporative gas turbine
• Humid air turbines
• CO₂ capture
• Oxy-fuel combustion
• Electrical efficiency

ACKNOWLEDGMENTS

Financial supports from the China Scholarship Council (CSC) and Royal Institute of Technology (KTH) are gratefully acknowledged.