Energy and exergy analyses of oxy-fuel combustion power plants with chemical looping air separation

摘要

This paper integrated chemical looping air separation (CLAS) with oxy-fuel combustion power plants. The results reveal that this type of oxy-fuel combustion technology displays higher energy efficiency than other systems such as post-combustion and oxy-fuel combustion with cryogenic air separation. Energy analysis reveals that the arrangement of a steam generation system based on a conventional pulverized coal power plant is more efficient for oxy-fuel combustion power plants with integrated CLAS technology. Thus, a power generation efficiency of 41.6% can be achieved. However, CO2 compression imposes an additional energy penalty of similar to 4%, resulting in a net power efficiency of 37.6%. On the other hand, exergy analysis reveals that the most significant exergy destruction portion of the system occurs in the combustion process. CO2 compression also imposes large exergy destruction. Finally, we concluded that the exergy destruction could be alleviated by reasonable arrangement of the heat exchangers.