A sectioning method for the kinetics study on anthracite pulverized coal combustion

Abstract

The combustion process of pulverized coal is widely used in different industries as a supplier of energy. Taking Gaoping coal as an example, combustion reaction kinetic of anthracite was studied by thermal analysis curves at different heating rates. Based on the physical and chemical characteristics of combustion process, the characteristic temperatures of combustion process are obtained. Then, anthracite combustion process is divided into two ranges from ignition to burnout temperatures at the temperature where the mass loss rate reaches the maximum. At first range, the combustion reaction temperature is relatively low and the ash layer (solid reaction product) is thin. The primary limiting element is the chemical reaction stage. With the temperature rising and the reaction going on, the chemical reaction rate is increased. Simultaneously, as the solid product is accumulated, the gaseous diffusion process is impeded. The rate-controlling step is turned into the diffusion process. Therefore, interfacial chemical reaction model and internal diffusion model are developed to describe the two ranges of combustion process. The results illustrate that the experimental data are fitted well and correlation coefficients (r 2) exceed 0.90. Finally, the corresponding kinetic parameters are obtained for the utilization of coal resource.