Energy, exergy and economic (3E) evaluations of a novel power generation system combining supercritical water gasification of coal with chemical heat recovery

•A novel power system with integrated SCWG of coal and chemical heat recovery is proposed, and analyzed.•Energy, exergy and economic analyses are conducted out.•Maximum power generation efficiency of 49.06% is obtained.•The levelized cost of electricity of the novel power system is 0.2963 ¥/kWh.