Design and performance evaluation of a new waste incineration power system integrated with a supercritical CO2 power cycle and a coal-fired power plant

A novel waste incineration power system highly integrated with a supercritical CO2 power cycle and a coal-fired power plant has been developed. In the hybrid configuration, the supercritical CO2 cycle gains energy from the superheater of the waste-to-energy (WTE) boiler, and the saturated steam produced by the WTE boiler is employed to heat the feedwater of the coal power plant. Consequently, the cascade energy utilization of the waste can be realized with the improvement of the WTE process. The performance of the proposed integrated scheme was thermodynamically and economically evaluated as compared to the conventional separate scheme, based on a 500 t/d incineration unit and a 300 MW coal power plant. The results indicate that the waste-to-electricity efficiency is promoted by 8.34 percentage points with an additional net power output of 3.33 MW, when adopting the proposal. The total exergy efficiency and the exergy efficiency of waste-to-electricity are increased by 0.43 and 7.88 percentage points. Additionally, the proposed system performs excellently under various boiler loads. Due to the integration, the net present value of the WTE project rises by 18.17 M$ and the dynamic payback period is reduced by 4.20 years. Therefore, the new design is extremely feasible and profitable.