A Modified Quantize Model for Depicting Coal Char Combustion under O2/CO2 Atmosphere

An approximate method is often applied to solve the differential mass conservation equations, of which the solution by exact analytical methods is impossible. The methodology developed in this work is based on an approximate method for decoupling the gas conservation equation. With this strategy, the calculation of gas concentration and solid conversion at any time and position can be converted to the solution of two coupled algebraic equations. A new mathematical model, the modified quantize model (MQM), was applied to depict the reaction rates of coal chars when both chemical reaction and diffusion through the porous char are considered. Compared to the quantize model (QM), carbon conversion rates predicted by the modified quantize model were in closer agreement with the experimental data.