A partial gasification combined cycle with CO2 recovery is proposed in this paper. Partial gasification adopts cascade conversion of the composition of coal. Active composition of coal is simply gasified, while inactive composition, that is char, is burnt in a boiler. Oxy-fuel combustion of syngas produces only CO2 and H2O, so the CO2 can be separated through cooling the working fluid. This decreases the amount of energy consumed to separate CO2 compared with conventional methods. The novel system integrates the above two key technologies, by injecting steam from a steam turbine into the combustion chamber of a gas turbine, to combine the Rankine cycle with the Brayton cycle. The thermal efficiency of this system will be higher based on the cascade utilization of energy level. Compared to the conventional IGCC, the compressor of the gas turbine, HRSG and gasifier are substituted for a pump, reheater and partial gasifier, so the system is simplified obviously. Furthermore, the novel system is investigated by means of EUD (Energy-Utilization Diagram) methodology and provides a simple analysis of their economic and environmental performance. As a result, the thermal efficiency of this system may be expected to be 46%, with recovery of 50% of CO2, which is 3–5% higher than that of an IGCC system. At the same time, the total investment cost of the new system is about 21.5% lower than that of an IGCC. The promising results obtained here with higher thermal efficiency, lower cost and less environmental impact provide an attractive option for clean coal utilization technology.

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