Contribution TitleStudy on Kinetic Characteristics of Oxidation Reaction in Underground Coal Gasification Based on Thermogravimetric Method

Underground coal gasification (UCG) technology is of great significance in the clean conversion of coal. In-depth study of the kinetic characteristics of its oxidation reaction is crucial for optimizing the process flow. In this study, the oxidation reaction behavior of long flame coal in the process of underground coal gasification was systematically discussed by thermogravimetric analysis. The characteristic temperature was obtained by thermogravimetric (TG) and derivative thermogravimetric (DTG) analysis of long flame coal at different heating rates, and the flammability index, stability index and comprehensive combustion characteristic index were further calculated to comprehensively evaluate its oxidation performance. In addition, by analyzing the thermal effects at different heating rates, the specific conditions of heat absorption and heat release in the reaction process were clarified. Based on the gas-solid reaction mechanism unction, this study determined the oxidation reaction mechanism model of each stage of underground coal gasification, and determined the key kinetic parameters of the oxygen absorption weight gain stage, thermal decomposition stage and oxidation combustion stage. The research results provide theoretical support for in-depth understanding of the oxidation reaction mechanism of coal in the process of underground coal gasification, and provide basic support for improving the efficiency and stability of the technology and promoting its industrial application.