Investigation on the Chemical-Looping Reaction Characteristics of Ningdong Coal with Manganese Ore

In order to explore an efficient and clean conversion way of Ningdong coal, the chemical-looping reaction of Ningdong coal was conducted in a laboratory-scale fluidized-bed reactor using manganese ore as the oxygen carrier (OC), and the reaction characteristics were investigated in combination by thermogravimetric analysis. Experiments included the investigation of the reaction of the manganese ore with 5 vol % H-2 and with coal powder at 900 degrees C, the catalytic and OC effect of manganese ore on coal gasification, the reaction efficiency and reaction products under different mass ratios of OC to coal (O/C), and the effect of multiple cycles on the reaction performance of the manganese ore. At 900 degrees C, the OC exhibited higher reactivity with coal syngas, significantly reducing the time of coal gasification (similar to 48% reduction). The manganese ore itself contained alkali metals, exhibiting a certain capacity for sulfur fixation, but the sulfur fixation was gradually weakened during multicycle experiments. The manganese ore did not exhibit any inhibition effect on NOx emission. From the wear rate of the manganese ore during fluidized reaction, its service life could be deduced to be about 150 h. Hence, it is necessary to improve the strength of the manganese ore OC.