Study On Adsorption/desorption Characteristics Of Methane From 11-2 Coal In Pansan Mine

Coalbed methane gas is a very clean natural resource,but it is also a harmful gas in the coal mine production process.China’s coal resources are abundant,and the potential of coalbed gas resources is very large.At the same time,gas has also caused frequent coal mine disasters in China.The gas in the coal seam is mainly present in the adsorbed state on the surface of the microporous wall of the coal,but at the same time it is present in the coal rock in the free free state and the dissolved state.The experimental study on the initial pressure,temperature and particle size of coal have an important role in understanding the adsorption/desorption mechanism and characteristics of coal seam gas,coalbed methane mining and mine gas disaster prevention.In this paper,using 3H-2000 PH high-pressure gas adsorption instrument and constant temperature water bath device as experimental platforms,methane adsorption and desorption experiments of 11-2 coal samples from Pansan Mine of Huainan Mining Group under different pressures,temperatures and particle sizes are carried out.The research results show that the experimental results of methane adsorption of coal samples under different pressures,temperatures and particle sizes all conform to Langmuir equation curve.At the same temperature,the methane adsorption increases with the increase of pressure,but when the methane pressure increases to a certain extent,the rate of methane adsorption increases gradually.Depressurization can promote methane desorption,which lags behind adsorption.Different temperature intervals have different adsorption laws,and the temperature interval between 40 ℃ and 60 ℃ has the greatest influence on methane adsorption.Under the combined action of temperature and pressure,methane adsorption decreases with the increase of temperature,and the effect of temperature on methane adsorption increases with the increase of pressure.The curves of methane adsorption and desorption of coal samples at all temperatures do not coincide,and desorption lags behind adsorption.The hysteresis of methane adsorption and desorption of the same coal sample decreases with the increase of temperature,and desorption becomes easier.According to curve fitting,the adsorption constants A,B and temperature T are all cubic functions.The particle size will affect the adsorption and desorption of methane by coal.The particle size of coal sample ranges from 20-40 mesh to 60-80 mesh.The adsorption amount of methane by coal increases slowly,while the particle size of coal sample decreases from 60-80 mesh to 100-120 mesh.The adsorption amount of methane by coal decreases accordingly.Coal samples with different particle sizes have different methane desorption hysteresis.As the particle size of coal samples decreases,the methane desorption hysteresis of coal samples first decreases and then increases.The experimental results have a certain guiding role for the prevention and control of high temperature thermal recovery of coalbed methane and mine gas and the formulation of appropriate deep coalbed methane mining methods.Figure [43] table [4] reference [76]...