Experimental research on spontaneous oxidization combustion characteristics of coal after pre-adsorption CO2

CO2 is injected into coal bodies in advance so that CO2 is fully adsorbed in the crack pores of the coal. It can inhibit the combination of coal and oxygen, so as to prevent and control the natural combustion of coal left in goaf. However, domestic and foreign scholars have little research on the low temperature oxidation characteristics and functional group changes of coal after CO2 pre-injection. In this article, a temperature programmed experimental device is used to analyze the formation of the macro-combustion index gas; a Fourier transform infrared spectroscopy experimental analyzer was determined the content of active functional groups of each component. The results showed that when the coal-sample pre-adsorbed CO2, the generation trend of CO2 formed an approximate "V" shape, the oxygen consumption decreased by about 4%. The initial generation temperature of CO and alkane gases is lagged, and the lag temperature is 20 similar to 30 degrees C. CO2 occupied the surface of the coal surface, and inhibiting the oxidation response of oxygen-containing functional groups. The content of hydroxyl group increases, the oxidative decomposition rate of aliphatic hydrocarbon slows down, and the content of aromatic hydrocarbon increases, which can effectively slow down the course of coal oxidation and spontaneous combustion.