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

Authors: Shiyi Chen; Ahsanullah Soomro; Jun Hu; Wenguo Xiang

Addresses: Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, China ' Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, China ' Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, China ' Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, China

Abstract: 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 ~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.

Keywords: chemical looping air separation; oxy-fuel combustion; CO₂ capture; exergy analysis; power plant.

DOI: 10.1504/IJEX.2018.093904

International Journal of Exergy, 2018 Vol.27 No.1, pp.121 - 145

Received: 30 Dec 2017
Accepted: 21 Mar 2018
Published online: 08 Aug 2018 *

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