Mathematical models of the thermal decomposition of coal1. The evolution of volatile matter

To assist studies of the coking process, a series of mathematical models of coal carbonization has been developed. Models of the physical properties (e.g. specific heat, density, porosity and thermal conductivity) of coal during decomposition to coke were constructed in terms of the changes in the chemical composition and srructure. These models of physical properties were then used to develop further models of heat and mass transfer in a coke oven charge, although the models may find more general application in studies of coal-based processes. This Paper describes the model of the chemical changes during thermal decomposition. To have sufficient generality for the applications envisaged, the model describes the kinetics of the release of the main volatile matter constituents, thereby permitting the changes in the mass and composition of the solid residue to be estimated by element balances. Correlations for the parameters of the model are derived so that predictions of volatiles evolution can be made from the coal ultimate analysis and volatile matter and the heating profile.