Energy self-sufficiency of a supercritical water oxidation system with an improved cooled-wall reactor for power generation

•A supercritical water oxidation system with an inverse cool-wall reactor is proposed.•The energy recovered from the reactor effluent is upgraded for power generation.•High exergy efficiency and low energy consumption can be achieved.•The increase of Twf or feed concentration is beneficial for energy self-efficiency.•Additional heat transfer areas are needed at high feed concentrations.