Integration of thermo-chemical energy storage for flexible operation of decarbonized power plants

Abstract

This work evaluates the integration of an innovative thermo-chemical energy storage system based on calcium-derived sorbents for flexible operation of decarbonized coalfueled super-critical power plant. The reactive gas-solid cycle is used for both power plant decarbonization as well as a time-flexible thermo-chemical energy storage system in conjunction to a 500 MW net power output plant with 90% carbon capture rate. Overall techno-economic and environmental implications of flexible decarbonized power plant with calcium-based thermo-chemical energy storage system were evaluated using process flow modeling and thermal integration. For comparison reason, similar decarbonized power plant operated in base-load conditions as well as a non-capture power plant were also considered. As the results show, the utilization of calcium looping cycle for time-flexible thermo-chemical energy storage system in conjunction to a decarbonized fossil-based power plant bring significant benefits in term of reducing the specific capital cost (down to about 8%), the electricity production cost (down to about 3.6%), the CO 2 capture costs (down to about 3.5%), all compared to the base-load operation of similar decarbonized power plant. Although very promising in delivering better techno-economic performance indicators, the calcium looping technology still requires significant scale-up efforts from the current development level (up to 10 MW) to full industrial sizes.