Noncatalytic coal char gasification

A simple particle model is used to interpret differential thermogravimetric data taken on the gasification of coal/char with CO₂, H₂ and H₂O. The model takes into account the major physical factors which influence the gasification rate, viz., the changing magnitudes of surface area, porosity, activation energy and effective diffusivity during gasification. Specific reaction rate constants based on surface area and activation energies are extracted from the data. Practical criteria for regimes of reaction rate and diffusion control and for particle isothermality are developed. For isothermal particles at low classical Thiele moduli, the data can be correlated with only one parameter, which has a simple physical interpretation.