Coal direct chemical looping process: 250 kW pilot-scale testing for power generation and carbon capture

• Published in: Applied energy Vol. 282; no. PA
• Main Authors: Zhang, Yitao, Wang, Dawei, Pottimurthy, Yaswanth, Kong, Fanhe, Hsieh, Tien-Lin, Sakadjian, Bartev, Chung, Cheng, Park, Cody, Xu, Dikai, Bao, Jinhua, Velazquez-Vargas, Luis, Guo, Mengqing, Sandvik, Peter, Nadgouda, Sourabh, Flynn, Thomas J., Tong, Andrew, Fan, Liang-Shih
• Format: Journal Article
• Language: English
• Published: United States Elsevier 11.11.2020
• Subjects: 10 SYNTHETIC FUELS; Carbon capture; Chemical looping; CoalPilot-scale unit; Energy & Fuels; Engineering; Power production
• ISSN: 0306-2619; 1872-9118

Chemical looping combustion (CLC) is an energy conversion technology that can produce concentrated CO2 stream without the need for a gas separation step, and thus, has the potential to drastically reduce the energy consumption and cost associated with CO2 capture in power generation. The coal-direct chemical looping (CDCL) process is a CLC technology that uses a moving bed reducer configuration that can directly consume coal as a feedstock without requiring an upstream gasification step. An integrated 250 kWth CDCL pilot unit using iron-based oxygen carriers was constructed and demonstrated for over 1000 h of testing. The principles for the CDCL pilot unit design and operation are summarized in this article. During the 288-hour continuous operation testing, the CDCL pilot unit achieved >96% coal conversion with a CO2 purity of >97%. Low carbon carryover into the combustor, i.e. <2%, was also confirmed during the test, which shows the capability of the moving bed reactor to retain and convert coal using the oxygen available on the iron-based oxygen carrier. The results from the pilot unit testing confirms the CDCL concept as a promising coal combustion technology for heat and power generation with CO2 capture.