Effect of soluble organic matter in coal on gas sorption and desorption characteristics

Abstract：In order to research the effect tion, the organic matters in coal seam 8 ( of soluble organic matter in coal on characteristics of gas sorption and desorp- Qingdong), coal seam 3 (Xutuan) and coal seam 8 (Suntuan) of Huaibei min- ing area were extracted by THF at nomal temperature and pressure. The gas adsorption capacity, vacuum desorption volume at normal pressure and variation of Ap of raw coal and residual coal were comparatively analyzed. After extrac- tion,the Ap and gas adsorption capacity of coal seam 8 ( Qingdong ) and coal seam 3 (Xutuan) are reduced. Mean- while, the increment for gas adsorption capacity of those coal seams increases first and then decreases with the growing of gas pressure. In contrast, the gas adsorption capacity of coal seam 8 (Suntuan) has not significant change. However, Ap of coal seam 8(Suntuan) increases. The vacuum desorption volume at normal pressure of all there coal samples is increased. The gas dissolutes in soluble organic matter of coal and forms solid solutions in outburst coal seams, which lead to the increase of coal seam gas content, gas emission speed and coal seams outburst risk. Soluble organic matter occupies part of the pores in non-outburst coal seam, which can slow down the gas release and reduce the gas release rate.