Development and Application of Distributed Purification Equipment for Low Concentration Coalbed Methane

In order to realize the safe pressurization and transportation of low concentration coalbed methane (CH₄≤30%) under the condition of wild and distributed production, a low concentration coalbed methane distributed purification system consisting of a low concentration coal bed gas safety isolation system, a variable pressure adsorption system and a pressurization and transportation system is developed. The system integrates safety isolation, low concentration coal bed gas purification and pressurization and transportation three functions in one, and has characteristics of small size, skid-mounted package, safety, energy saving and environmental protection. The industrial test of typical surface borehole in Jincheng mining area shows that: the CH₄ concentration of the surface borehole is 20% to 35% before the use of purification system and the supercharger can be turned on when the CH₄ concentration is higher than 30%; the CH₄ extraction concentration reaches to about 65% after installing the system to realize continuous supercharging; the utilization rate of CBM is increased from 5.1% to over 80%, which realizes the reuse of low-concentration CBM and reduces greenhouse gas emission.