Modified Random Pore Model Study on Coal Char Reactions under O2/CO2 Atmosphere

Evolution characteristics of particle pore structure not only reflect reactive process, but also intensify the complicated degree of the reaction. Variation of pore structure in coal char particles is too complex to be described only by the invariable structure parameter ¿ when the random pore model (RPM) is used to describe reaction process. In this paper, the structural parameter ¿ in random pore model was modified by the pore properties and evolution characteristics of structural parameter were clarified and a new model, modified random pore model (MRPM), was developed. Compared with the simulation results of RPM, it was found that modified random pore model was more satisfied to explain the reaction processes of char, especially at the end of stage. The value of ¿ changes with specific characteristic which could be explained by the pore structure feature. Using the MRPM, isotherm reactive characteristics of coal chars were analyzed at different temperatures under O₂/CO₂ atmosphere.