Transformation of K₂CO₃ as a catalyst during coal char pyrolysis and its effect on coal char catalytic gasification

The transformation of K₂CO₃ in the course of Shenfu char catalytic pyrolysis under different temperatures was studied in the fixed-bed reactor; the influence of loading methods of K₂CO₃ and particle size on gasification reactivity was investigated in a TG-DSC analytical reactor. The results showed that with the increase of temperature, the effect of loading methods on gasification rate is weakened; K catalyst shows high dispersity by means of SEM/EDX analysis of pyrolysis residue. CO₂ and CO are produced through the interaction of K₂CO₃ and coal char in the pyrolysis and there is a linear relation between the amount of released gas and temperature. The particle size of K₂CO₃ and coal char has notable impact on gasification; the gasification rate increase with a thinner particle at 650 ℃. K₂CO₃ shows high mobility within the coal char phase at elevated temperature, which is consistent with its catalytic activities; the effect of loading methods on gasification should be considered under a temperature below 700 ℃.