Investigation on combustion characteristics and molecular structures of Heiyanquan coal in Santanghu coalfield ,Xinjiang, China

Fossil energy such as coal is the main source of energy in the world, in order to better understand the combustion process of coal, the present study takes the coal of Santanghu in Xinjiang as the research object, and the structural parameters of the coal are obtained by using experiments such as ultimate analysis, X-ray photoelectron spectroscopy(XPS), Nuclear magnetic resonance carbon spectrum (13C-NMR), etc. Based on which, the structure of the molecular model of the coal at room temperature is constructed, geometry optimization and annealing optimization of the constructed coal molecular model was carried out using Materials studio software. And the coal samples were heated to different temperature points and analyzed the variation rules of activation energy, functional groups and stripe orientation and length features at different stages of the combustion process using Fourier transform infrared spectrometer (FTIR), Thermogravimetry (TG) and High resolution transmission electron microscope (HRTEM) experiments .The results showed that the molecular formula of the Santanghu coal was C175H125O21N3.As the temperature increases, the reaction process of the water loss and drying phase of spontaneous coal combustion becomes longer, while the oxidation and weight-gaining phase becomes significantly shorter, and the change of the combustion phase is relatively stable.This study is instructive for the efficient utilization of coal, and is important for improving the utilization efficiency of coal energy and protecting the ecological environment, and provides a certain theoretical basis for the spontaneous combustion and mining of actual coal samples.