Thermodynamic and kinetic behaviors of coal gasification

The thermodynamic and kinetic behaviors of coal gasification were studied via thermodynamic calculations and high-temperature simulation experiments. The results show that, at temperatures greater than 1173 K, the equilibrium concentrations of H2O(g) and CO2 are low and decrease with increasing temperature. With increasing CO2 volume fraction in the gas, the gas utilization rate gradually increases, and with increasing H2O(g) volume fraction, the rate gradually decreases. As the gasification temperature increases, the time required for completion of coal gasification is shortened, and the rate of coal gasification increases. The activation energies of internal diffusion and the interface reaction are 84.205 kJ/mol and 81.935 kJ/mol, respectively. In the early stage, the controlling factor of coal gasification is the interface reaction. As the reaction ratio increases, the controlling factor gradually changes from the interfacial reaction to internal diffusion. At 1173-1473 K, the controlling step of coal gasification is primarily the interfacial reaction.