Modelling of nonlinear behaviour during combustion of single coal char particle

Experimental and theoretical investigation of combustion of a single coal c har particle is presented. As a model of coal char particle combustion the shell progressive mechanism was considered. The porous structure of an orig inal, devolatilized and partially combusted particle was analyzed. Due to t he bimodal character of the porous structure, the pore size distribution wa s determined by a sorption method and mercury porosimetry. Combustion exper iments were carried out in an equipment where the TGA method was applied fo r process monitoring. This equipment allowed to study the behaviour of the coal char particle during the process of drying, degassing, and combustion. During the combustion process, the particle consisted of two regions - the noncombusted core and the ash layer. The time dependences of the particle mass, temperature in the particle and gas phase, and composition of the com bustion products were measured. The obtained experimental results confirmed that the shell progressive mechanism can be applied for the mathematical d escription of combustion of single coal char particle.