CO2-gasification of a lignite char in a micro-fluidized bed thermogravimetric analysis (MFB-TGA) for chemical looping combustion and chemical looping with oxygen uncoupling (CLC/CLOU)

Chemical looping combustion (CLC) and chemical looping with oxygen uncoupling (CLOU) are novel combustion technologies with low energy penalty CO2 capture. In a CLC/CLOU unit, the gasification of char is the rate-controlling step, due to the slow gasification kinetics of char under a CO2 and H2O atmosphere. Reliable measurements of char gasification kinetics are absolutely necessary for CLC/CLOU reactor design, operation, and optimization, and are the focus of this paper. In order to solve the problems of measuring gasification kinetics using thermogravimetric analysis (TGA) and fluidized bed (FB) reactors with gas measuring, a micro-fluidized bed thermogravimetric analysis (MFB-TGA) method was developed and reported in this paper to investigate the CO2 gasification of a lignite char. The feasibility of the novel MFB-TGA approach was tested, and its stability and accuracy were validated. MFB-TGA was then used to study the CO2 gasification of a lignite char. First, the CO2 gasification kinetics of the lign...