Experimental Reserach on Law of Carbon Dioxide Enhancing Coal Bed Methane

摘要

Due to more exhausted mines, residual coal, methane in unworkable seam and great pressure of greenhouse gas in China, its experimental makes the study on carbon dioxide enhancing coal bed methane meaningful. First of all, it reveals that coal has stronger adsorbing CO2 capacity than the capacity of adsorbing CH4，as well as the adsorption and desorption rule of different mixed gases by adsorption -desorption experiments of CO2, CH4 and mixed gases.In the adsorptive process of mixed gases including CO2 and CH4，CO2 is adsorbed by coal firstly, while CH4 is desorbed quickly in the process of desorption. There is a close relationship between CH4 desorption rate, C02adsorption rate and the separation factor of different gas components. The separation factor of CO2 is bigger than that of CH4，and the desorption rate of CH4 and adsorption rate of CH4 are higher. Second of all, it can get the mechanism of CO2 enhancing CH4 and influential factors by mixed gases replacing experiments. The more CO2 content in mixed gas is the better for CH4 enhancing. The coal with high separation factor can get better results of replacing. The mechanism of improving CH4 output is CO2 sharing the pressure with CH4and having the reaction of adsorption and replace. The above results can guide the exploration of unworkable seam and CO2 enhancing CH4，and reach the win — win situation that disposing of greenhouse gas and getting economic effects.