Study on methane adsorption characteristics of anthracite in deep coal seam

Abstract

In order to study the deep coal bed methane adsorption characteristics of anthracite, using high temperature and high pressure of coal adsorption test to simulate the deep coal seam environment, we measured soft and hard anthracite coal at different temperatures（40 ℃, 70 ℃, 110 ℃） of the gas adsorption constant, calculated the adsorption potential characteristic curve of the soft and hard coal under different conditions by adsorption potential theory, and analyzed methane adsorption characteristics of the deep coal seam under high temperature and high pressure; we tested the pore structure parameters of soft and hard anthracite before and after the high temperature and high pressure adsorption test based on mercury injection method, and studied the influence of the change of pore structures of soft and hard anthracite in the deep coal seam at different temperature on methane adsorption. The results show that the structure of porous of soft anthracite is more developed than that of hard coal. The adsorption characteristic curve of coal before and after the high temperature and high pressure adsorption test shows a decreasing trend, and the adsorption potential of coal sample decreases with the increase of adsorption space. Under high temperature and pressure, the total pore volume of soft and hard anthracite coal increases and the porosity connectivity is lower than that of raw coal.

Keywords

• deep coal seam
• anthracite coal
• adsorption
• pore structure
• mercury intrusion method