Conceptual design and technoeconomic evaluation of integration of chemical looping gasification and chemical looping combustion to dry gasification oxy combustion power generation system

Dry Gasification Oxy-Combustion (DGOC) is a budding technology for power production using coal or any other fuel with the advantage of in-situ sulphur capture, CO2 capture and low water usage. The penalty for oxygen production for combustion can be reduced by the use of metal oxide for oxygen demand instead of an air separation unit. This work presents design, parametric, energy, exergy and economic analysis of three variants of Dry Gasification Oxy-Combustion with step-by-step replacement of air separation unit by metal oxide, viz., Dry autothermal chemical looping gasification oxy-combustion (DaCLGOC), Dry autothermal gasification chemical looping combustion (DaGCLC) and Dry autothermal chemical looping gasification chemical looping combustion (DaCLGCLC). CuO and Fe2O3 are used as both oxygen carrier (OC) and sulphur capture sorbents. These sorbents are regenerated and reused to improve the efficiency and economics of the proposed technology. Energy analysis has been done for various operating pressures. Energy analysis shows that DaCLGCLC with Fe2O3 reaches a maximum efficiency of 51.8 % at 10 bar operating pressure. Exergy analysis shows that chemical looping combustion and chemical looping gasification reduces the exergy loses and thus improves the process. Economic analysis shows that although CLG and CLC are costlier than conventional gasification and combustion, the overall process is economically viable with LCOE reaching as low as 56.54<euro>/MWhnet.