Experimental study on coal sample's methane desorption law in different adsorption balance pressures

摘要

Taking 7 group anthracite coal samples which size is 1～3mm from different coal mines of the same mine field as research objects, there carried coal samples' methane adsorption and desorption experiment under the condition of about 1Mpa,2Mpa,3Mpa,4Mpa adsorption equilibrium pressures and adsorption equilibrium temperature 20°C. The coal samples' cumulative methane desorption volume of each minute were measured in the initial 30 minutes time, and there obtained the desorption data. Based on experimental data analysis found that the methane desorption law between cumulative methane desorption volume and desorption time is fit to SUN Chong-xu Formulate (Q=at~i). Then aimed to the same coal sample, the desorption eigenvalues of different adsorption equilibrium pressures were studied using SUN Chong-xu Formulate based on the experiment data. The study results show that the coal sample's desorption eigenvalues of different adsorption equilibrium pressures keeps a constant, and the average eigenvalues is 0.237 for these experiment samples. Then 1～3mm size coal samples can be used to determent methane content when the loss time less than 8 minutes.