Experimental Studies On Adsorption, Desorption And Flow Of Coalbed Methane In Coalbed Samples

Coal-bed methane is unconventional natural gas and is symbiosis with coal. The exploitation of CBM has important significance in the safety production of coal, environmental protection and the improvement of energy efficiency. The development of coal bed methane is hot topic in domestic and oversea. This article evaluates the basic performance of CBM, such as adsorption and desorption and permeability characteristics by the independently designed instrument and builds up the experimental procedures of the CBM production and ECBM by CO2. This article analyzes the influence of carbon dioxide injection pressure and injection rate. This study provides a theoretical basis and experimental data for enhancing coal-bed methane recovery by gas injection and analyses the mechanical of ECBM. The result shows:the main CBM-adsorption affect factor is pressure. CBM-adsorption quantity changing with time is to be in logarithmic curve. The higher is the moisture content of coal, the lower is its adsorption capacity of methane and the poorer is the gas flow capacity in coal. And the gas permeability of coal decreases with the CBM-adsorption increase. Constant volume of carbon dioxide and methane mixing mining can improve the coal bed methane recovery of 16%. When Carbon dioxide flows by 2 ml/min and the injection volume multiple is 2.5, coal bed methane recovery is 90%. Carbon dioxide-ECBM technology is a new type of environmentally friendly mining technology.