MATHEMATICAL-MODELING OF DEVOLATILIZATION OF LARGE COAL PARTICLES IN A CONVECTIVE ENVIRONMENT

A generalized model for devolatilization of large coal particles typically encountered in a gasifier has been developed. The model predicts a time-temperature history of the particle in a convective heat transfer environment. Thermal decomposition of volatile matter is treated as a series of independent chemical reactions in which the rate constants differ only in activation energy. The activation energy is expressed as a Gaussian distribution. Experimental data obtained in a flow reactor are presented and used to validate kinetic and transport parameters of the model. Devolatilization time predicted by the model with updated parameters is also compared with that obtained from a pilot fixed-bed gasifier.