Process Integration and Analysis of Chemical Looping Based Power and Fuel Generation Systems

Chemical looping gasification (CLG) process can flexibly convert carbonaceous fuel such as coal and biomass into hydrogen, liquid fuels and electricity while effectively capturing the CO₂ byproduct. The unique features of the CLG process are in light of its indirect conversion scheme via redox cycles of metal oxide based oxygen carriers. In the first step, fuel is converted into CO₂ and H₂O by high oxidation state oxygen carrier in one reactor. The reduced metal oxide can be reoxidized in a subsequent reactor by either steam for hydrogen production, or air for heat and power generation.  This study first illustrates the CLG process configurations. Then we will concentrate on two process intensification cases based on the CLG process. The integration between the CLG and the SOFC technology provides a closed loop between the chemical looping oxidizer and the SOFC anode through the circulation of the gaseous mixture of steam and H₂, which can significantly enhance the electricity generation. Another novel process that integrates CLG process with CO₂ hydrogenation is proposed for liquid fuel synthesis. Both exergy analysis and process simulation studies confirm the advantages of the proposed processes. The results indicate that, through process intensification, the chemical looping gasification strategies have the potential to notably increase process efficiencies in carbonaceous fuel conversions.