A new char combustion kinetic model 1. Formulation

This paper describes the development and formulation of a novel char combustion kinetic model for pulverised coal. The chemical reaction rate was considered as a function of coal intrinsic reactivity and fuel mass for a global reaction order n. The equation for char combustion reaction rate was devised by dimensional analysis using the Rayleigh method. It shows the dependency of chemical reactivity on coal parameters, such as maceral and mineral composition; char parameters, such as specify surface area and apparent density; devolatilisation time; temperature; and activation energy. The char combustion reaction rate equation developed, unlike most models, is dimensionally homogenous and is expressed by three dimensionless numbers which have physical chemical meaning. The model also exhibit similarities with transport phenomena models described by dimensionless numbers.