Study On Oxygen Removal From Coal-bed Methane

Coal-bed methane (CBM) is a kind of high quality gas fuel, has considerablepractical value. The development and utilization of coal-bed methane has veryimportant significance, which can make full use of energy, improve energy structure,reduce the coal mine gas disasters and protect the atmospheric environment. Currentlyunderused of coal-bed methane resources, however, this is mainly due to the CBMcontains oxygen. Coal-bed methane with oxygen has always been considered a riskfactor for underground coal mining operations, because it is the risk of explosion canhave serious threat on mining safety and productivity.In order to eliminate the coal-bed methane in the low gassy mine to the safetyhidden peril existed in the seam mining, a deoxidation technique that utilizing thekinetic difference of CH4and O2on carbon molecular sieve was provided. Firstly, thesurface properties of carbon molecular sieve had been used to characterized by DRTmethod plotting the CO2adsorption isotherm,273.15K. The results showed that fivekinds of samples all had the rich Millipore. Then volume method was applied to getkinetic data of pure CH4and O2adsorbed on CMS. The study showed that thediffusion rate of O2is larger than CH4at the initial time of adsorption. And though thebreakthrough curves, it demonstrated that CH4was first through the fixed bed. ThusCH4could be enriched directly at the outlet. Through the comparison of five kinds ofcarbon molecular sieve, we selected CMS-5whose products gas purity and recoveryrate are the highest. At last, the adsorbent was regenerated by the way of reversevacuuming, and can be regenerated completely by adjusting the vacuum timecompletely regenerated.