Analysis of Methane Explosion Limit under Cryogenic Conditions

During the past several years, the explosion risk analysis of each stage in oxygen CBM liquefaction process has been carried out by a large number of domestic scholars. In this work, firstly, safety evaluation of the coalbed methane liquefied process was summarized. Then, the experiment of the explosion limit test under cryogenic condition was introduced. At last, the explosion limit calculated by the empiric formula was compared with the experiment data. The result shows that there are big differences between the calculated result and the experiment data. The existing empiric formula is never applicable when calculating the explosion limit of methane under low temperature conditions. The method of safety evaluation of coalbed methane liquid process using the empiric formula is wrong. It is advised to build a new experimental device to test the explosion limit of methane under cryogenic conditions. The test condition should include initial temperature of 0-170 degrees C and initial pressure of 0.1-0.9 IVIPa.