Experimental study on temperature-increasing oxidation characteristics of lignite in oxygen-poor environment

In order to study the temperature-increasing oxidation characteristics of lignite under oxygen-poor conditions, the coal sample of 1# coal seam of Baorixile 1# coal mine was taken as the research object, and the coal samples were subjected to temperature-oxidation under different oxygen concentrations by thermogravimetry-gas chromatography. The thermal characteristic curves（TG, DTG, DSC） of lignite under oxygen-depleted conditions were obtained through experiments. At the same time, the activation energy of pyrolysis stage and combustion stage of coal samples were calculated by Coats-Redfern kinetic equation. The results show that the oxygen-depleted environment has different degrees of influence on each stage of coal combustion. As the oxygen concentration decreases, the characteristic temperatures T3, T4, and Tmax gradually increase; the weight gain and heat release gradually decrease during the oxygen absorption and weight increase phase; the weight loss, the heat release and the activation energy of the pyrolysis and combustion phases gradually decrease. The peak temperature of CO and CO₂ shifts to the high temperature region and the peak concentration decreases.