Feasibility analysis of a combined chemical looping combustion and renewable-energy-based methane production system for CO2 capture and utilization

Abstract

Power-to-Methane represents an innovative approach to convert electrical into chemical energy. Such a technology could actually be successful only when the coupling of a cost-effective source of electrical energy and a pure CO2 stream is carried out. Under this perspective, this paper numerically investigates an innovative process layout that integrates a fluidized beds chemical looping system for the combustion of solid fuels and a renewable- based Power-to-Methane system. Process performances were evaluated by considering a coal and three sewage sludge, differing in water content, as fuels, CuO supported on zirconia as oxygen carrier, hydrogen production via water electrolysis, and Ni supported on alumina as methanation catalyst. Autothermal feasibility of the process was assessed by considering that part of the produced methane can eventually be burned to dry high-moisture-content fuels. Finally, by considering that only electric energy from renewable sources is used, the capability of the proposed process to be used as an energy storage system was evaluated.