Dimethyl ether (DME) is a promising alternative fuel, but direct combustion of DME will result in extra energy penalty for CO2 separation. In this paper, an advanced power-generation system with CO2 recovery integrating DME-fueled chemical-looping combustion is proposed. In the reduction reactor, DME is oxidized by Fe2O3 into CO2 and H2O, and Fe2O3 is reduced into FeO simultaneously. Since the endothermic reduction of Fe2O3 with DME requires relatively low-grade thermal energy around 180°C, waste heat is used to provide the reaction heat. FeO is oxidized into Fe2O3 by air in the oxidation reactor, producing high-temperature flue gas to generate electricity through a thermal cycle. The gas production from the fuel reactor only consists of CO2 and H2O, so CO2 can be easily separated through condensing with no extra energy penalty. As a result, the thermal efficiency could be expected to be 58.6% at a turbine inlet temperature of 1288°C. Additionally, experiments on DME-fueled Chemical-looping combustion are carried out to verify the feasibility of the core process. This proposed system may provide a new approach for high efficient use of DME in the industrial fields, and offer a possibility of chemical-looping combustion with inherent CO2 capture for the alternative fuel.
Integrated power-to-gas and power generation system through chemical looping combustion: a conceptual design
