Catalytic CO₂ Gasification of Coal Char with Ca/K Compounds

In this study, the catalytic CO₂ gasification performances of coal char with Ca/K compounds in a micro fluidized bed reaction analyzer (MFBRA) were studied, and the activation energies were detailed. The effects of gasification temperature (860, 890, 920, and 950 ) and catalyst load (Ca: 0.5%, 1%, 1.5%, 2%; K: 3%, 5%, 7%) were also studied. The results indicated that the heat and mass transfers were enhanced in the MFBRA to eliminate the effect of external diffusion inhibition, and the gasification performances were improved by increases in the gasification temperatures and catalyst loads. However, there was a threshold of loading amount, beyond which the catalytic effect will not be enhanced or even weakened. At 950 , Ca and K catalysts exhibited the strongest catalytic effects on coal char gasification at loading ratios of 1.5% and 5%, respectively. The corresponding calculated activation energies were 147.81 kJ/mol and 147.65 kJ/mol, respectively. In all experiments, the binary catalyst of 0.5% Ca + 5% K exhibited the best synergistic effect.