A Novel Technique based on Coal Gasification Integrated with Chemical Looping Air Separation

Abstract

To reduce the oxygen production cost in the coal gasification process and to utilize the CO2 , this study presents a novel technique based on coal gasification integrated with chemical looping air separation (CLAS) by thermodynamic methods. CLAS offers an advantage over the other mature technologies in that it can significantly reduce its capital cost with about less than 40-60% operating costs of conventional oxygen production technologies, while recycling CO2 separated from gasification gas by CCS could not only promote oxygen production (oxygen uncoupling) of CLAS, but also enhance the coal gasification process by boudouard reaction. The thermodynamic performances, as the conversion of metal oxides (Mn2 O3 /Mn3 O4 ) during oxidation and reduction process, gasification gaseous compositions and cold gas efficiency (η) were the main subject of focus. The effects of three key variables, as air flow rate, reduction temperature, and recycling CO2 ratio (β) were investigated. Highlights: 1. The chemical looping air separation is providing oxygen and steam as gasification agents to coal gasification process. 2. CO2 is getting full used by acting as inert component and also as coal gasification agent.