Thermal Reaction Model Construction And Oxidation Process Study Of Jurassic Coal

Coal still occupies an important position in the global energy consumption structure,and spontaneous combustion of coal is one of the main disasters affecting coal production.China's Jurassic coal is rich in resources,has a short spontaneous combustion time,and has a high risk of spontaneous combustion.Therefore,it is necessary to conduct an in-depth study on the characteristics and mechanism of coal spontaneous combustion and oxidation,In this paper,Jurassic coal is taken as the research object,combined with theoretical analysis,experimental research and simulation calculation,to study the oxidation characteristics of Jurassic coal.Based on the thermal effect,the coal spontaneous combustion reaction model is constructed and oxidation simulation is carried out to grasp the occurrence and development mechanism of Jurassic coal oxidation.The research results provide a theoretical basis for revealing the mechanism of coal spontaneous combustion and preventing and controlling coal spontaneous combustion disasters.Adopt industrial analyzer,element analyzer,Fourier infrared spectrometer,nuclear magnetic resonance,X-ray photoelectron spectrometer,X-ray diffractometer,C80 microcalorimeter.Systematic study of Jurassic coal's coal quality,element composition,dynamic distribution of functional groups,carbon skeleton structure,element occurrence form,microcrystalline structure and stage changes of macro thermal effects;The Pearson correlation coefficient method was used to analyze the correlation between the heat release rate and the change of functional groups,and further analyze the contribution of the main functional groups to the thermal effect,and finally determine that-CH2 and-C=O in the coal oxidation process are the main heat-contributing functional groups in the exothermic stage;Using computer-aided software,combined with the characterization of coal structural parameters,the Jurassic coal macromolecular structure model was constructed,the molecular formula is C115H92O35N2,the characteristic functional groups in the coal were extracted,and the coal small molecular structure model was simplified,and the molecular formula is C34H30O5.Quantum chemistry software is used to optimize the small molecular structure model of coal,and the potential diagram and front-line orbit are analyzed,and the energy gap value of the coal structure model is lower,indicating that the molecular activity of the coal structure is relatively large and oxidation reactions are prone to occur.And during the reaction,the sequence of oxygen attacking the hydrogen atoms of the four groups is:?-HCOH-CH2-group,?-CHO group,?-CH2-CH2-CH3 group,?-CH2-CH=CH2 group;The oxidation process of the four important groups in the coal structure model is calculated,and it is found that-C-OOH is the key group in the oxidation process of coal.The thermal reaction kinetic parameters such as activation energy,enthalpy change and Gibbs free energy in the reaction process are analyzed.By comparison,it is found that the maximum energy barrier size of the reaction path of four groups is in order:-CHOH-CH2-<-CHO<-CH2-CH2-CH3<-CH2-CH=CH2;The effect of temperature on the oxidation pathways of coal structure was studied,and it was found that the temperature increase has a promoting effect on all pathways,and it has a greater impact on intermediates and products,especially multi-component products,and has a relatively small impact on the transition state.