Security technology of methane recovery from coalbed gas with oxygen
Maoqiong Gong · 2009
In order to ensure the security in the methane recovery process from coalbed gas with oxygen,this paper recommends three kinds of technical means: a.to control the lowest outlet gas temperature;b.to add nonflammable gases into the methane/air mixture;c.to have the fuel gas being deoxidized roughly in advance.By use of explosion triangle theory,these three technical means can be achieved as follows: a.the concentration of outlet gas will be maintained above the upper limit of explosion triangle through keeping on the lowest temperature of the whole process;b.the oxygen concentration within the explosion triangle area under local temperature and pressure will be controlled under the line connecting the upper and lower limits with flammable limits of methane/air mixture.Based on the data collected from references,this paper derived the calculation formula of upper and lower limits of methane/air mixture explosion under different temperatures and pressures.