Study on the influence of soluble organic matter on gas adsorption and desorption characteristics of refractory coal in Xinjiang

The coal seam gas in Xinjiang coking coal company is difficult to desorption, which leads to the increased difficulty of extraction.The soluble organic matter in coal has an important influence on the adsorption and desorption of gas.In order to study its effect, tetrahydrofuran was used to extract soluble organic matter from coal, and the pore configuration of coal before and after extraction was tested by low-temperature nitrogen adsorption.The adsorption and desorption experiments of coal samples before and after extraction were carried out by using high pressure gas adsorption device.The results show that after tetrahydrofuran extraction, the average pore size, pore volume and specific surface area of all coal samples are found to be increased in different degrees.It is believed that soluble organic matter in coal is dissolved, forming new micropores, and the original pores are expanded.The adsorption constant a of No.4 coal, No.5 coal and No.6 coal decreased by 2.73%, 16.09% and 14.57%, respectively.The adsorption constant b of No.4 coal and No.5 coal increased by 12.18% and 2.58%, respectively.The adsorption constant b of No.6 coal decreased by 8.59%, the adsorption capacity of coal decreased, and the desorption rate increased.Soluble organic matter promoted the adsorption of coal to gas.