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

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 kW_th 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 kW_th 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 250kW_th 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.