Research On Group Oxidation Mechanism Based On Sulfur-bearing Model Compound

There exist a variety of sulfur-containing organic compounds in coal, which are prone to oxidation, liable to spontaneous combustion, increasing the spontaneous combustion tendency, also harmful gas generated by combustion causing serious pollution to the atmospheric environment. Characteristics and mechanism of sulfur content in coal spontaneous combustion of organic substances is extremely important realistic significance for coal disaster prevention. Low temperature oxidation of sulfur-containing organic matter in coal is a important stage in the spontaneous combustion process. The sulfur coal macromolecule polymer consist of aromatic ring, sulfur-containing functional groups, alkyl side chains and connecting bridge. In the process of sulfur coal and O2 reactions, sulfur-containing functional groups, alkyl side chains and connecting bridge in sulfur coal molecules are at the forefront, which cause spontaneous combustion of coal sulfur oxidation reaction. While chemical properties of aromatic ring in sulfur coal molecules is very stable, aromatic ring could hardly react with O2. Sulfur-bearing model compound therefore be simulated sulfur coal molecules to study the spontaneous combustion of organic sulfur-containing substances in sulfur coal.According to the chemical structure of coal molecular theory and coal spontaneous combustion theory, 5 kinds of Sulfur-bearing Model Compound are identified on the basis of organic sulfur coal surface active groups in this article.With oxygen consumption、oxygen consumption rate of the selected model sulfur compounds, generating capacity、generation rate of oxidation products, we could get chemical properties of sulfhydryl active most by temperature programmed oxidation experiments. The chemical activity order of the reactive groups in these model sulfur compounds is: Cysteine > Benzyl mercaptan > Methyl phenyl sulfide > Diphenyl sulfide > 2-methyl thiophene.The oxidation of these 5 model sulfur compounds shows: Oxidation reaction process of model sulfur compounds is a complex multi-step reaction, part model sulfur compounds and O2 adsorption occurs, then decomposition reaction occurs once or more, CO, CO2 and SO2 gas products will produce during the reaction.By study low temperature programmed oxidation of model sulfur compounds, confirms the oxidation of model sulfur compounds and spontaneous combustion of sulfur-containing reactive groups in coal is a similar process, thus laid a solid experimental basis for spontaneous combustion of coal sulfur reactive groups in chemically level.