Moving Bed Chemical Looping Technology for Carbonaceous Fuel Combustion and Hydrogen Production: Process Development and Assessment

Authors: 
Tong, A., The Ohio State University
Xu, D., The Ohio State University
Zhang, Y., The Ohio State University
Wang, D., The Ohio State University
He, P., The Ohio State University
Hsieh, T. L., The Ohio State University
Guo, M., The Ohio State University
Nadgouda, S., The Ohio State University
Velazquez-Vargas, L. G., Babcock & Wilcox Company
Flynn, T., Babcock & Wilcox Company
Fan, L. S., The Ohio State University
Chemical looping technologies are a promising alternative for the efficient conversion of carbonaceous fuels to electricity and/or high value chemicals with minimal carbon emissions. These processes utilize an oxygen carrier solid material to indirectly supply oxygen to the fuel source. Ohio State applies the chemical looping concept for power and H2 production from coal and natural with in-situ CO2 capture. Specifically, Ohio State has developed the coal direct chemical looping (CDCL) process for power production applications from coal and the syngas chemical looping process (SCL) process for high purity hydrogen production from gasified coal or natural gas with nearly 100% CO2 in both processes. The counter-current moving bed reactor design the CDCL and SCL process ensure nearly full fuel conversion to CO2 with minimal solid circulation and capability of producing high purity H2. The reduced metal oxides from the reducer operation are regenerated via an oxidation reaction with air. Various active metal oxides or metal oxide composites can be utilized. A high pressure 250 kWth SCL pilot plant was constructed and tested at the National Carbon Capture Center proving the capability of the moving bed process for hydrogen production. A 250 kWth CDCL pilot plant was constructed at the Babcock & Wilcox Research Center showing nearly full coal conversion with nearly 100% CO2 capture. The present presentation summarizes the oxygen carrier particle development for both systems, the operational results from the 250kWth CDCL and SCL pilot plant operations. Key process design features, process performance analysis, and techno-economic assessments will be discussed. Results from recent demonstrations and process assessments show how the chemical looping concept has the potential to transform the way carbonaceous fuels are used today to produce power and high value chemical products.