Inspired by the successful test of Enhanced Coal Bed Methane (ECBM) by means of gas injection, the gas injection technology was firstly applied to accelerate coal seam methane emission and drainage in underground coal mine. The adsorption– desorption laws of N2, CO2, CH4 and their mixture on coal have been researched; and a series of lab experiment of displacement adsorption and competition adsorption have be made. Before underground testing, based on Darcy’s law, Fick’s law and Langmuir’s law, a set...