Coal bed methane purification device and process with molecular sieve function and adopting physical adsorption and desorption principle

The invention relates to a coal bed methane purification device, system and process with a molecular sieve function and adopting physical adsorption and desorption principle. The device comprises a plurality of adsorption plates and a frame for fixing and mounting the adsorption plates; the plurality of adsorption plates are arranged at intervals, the adjacent two adsorption plates are sealed, anda flowing channel for coal bed gas to flow through is formed; the opposite two ends of the frame are provided with a gas inlet and a gas outlet communicated with the two ends of the flowing channel correspondingly; the adsorption plates have a molecular sieve function, can selectively adsorb methane and enables the volume of the molecules in the coal bed gas to be less than the gas molecules of the methane to pass through. The purification device and the system can effectively purify and separate the methane in the coal bed gas on the premise of retaining the original underground coal bed gasextraction and coal bed g