高温高压平衡水分条件下变形煤的吸附-解吸特性

选用平顶山矿区十二矿己组煤层的不同类型变形煤作为研究煤样,模拟深部煤层瓦斯赋存条件,开展高温高压平衡水分条件下的吸附-解吸实验。研究结果表明,50℃条件下,煤的平衡水分含量随煤的破坏程度的增加有增大的趋势;高温高压平衡水分条件下,变形煤表现出吸附-解吸新特性,即随煤的破坏程度增加,朗格缪尔体积VL(无灰基)具有先减小,后增大,再减小的趋势,呈波浪状。分析表明,变形煤表现出的吸附-解吸新特性,是变形煤特有的孔隙结构和水分含量的差异综合作用的结果。变形煤吸附-解吸不可逆,解吸滞后;随着煤的破坏程度增加,煤的吸附-解吸不可逆程度加大。因此,在开展实验研究煤、特别是变形煤的解吸特性时,不能用吸附实验数据简单代替。

Adsorption-Desorption Characteristic on Deformed Coal Under the Conditions of High Temperature and Pressure and Equilibrium Water

Under the conditions of high temperature and pressure and equilibrium water,the adsorp-tion-desorption experiments on CH4 were carried out with four destructive type of coal samples in No.12 Mine of Pingdingshan.The experiment results show that the equilibrium moisture of coal sam-ples increase with the increasing extent of the coal damage in the conditions of 50℃.There are some new features on the adsorption-desorption of deformed coal,Langmuir volume of the VL(ash-free basis) first decreases and then increases,and decreases finally.Therefore,the characteristic of results of this adsorption-desorption experiments are due to the combined effects of the unique pore structure of de-formed coal and water content.The adsorption-desorption isotherms of deformed coal are irreversible,and this irreversible degree increases with increasing extent of the damage of coal.The data selected by adsorption experiments should not be straightforward used in the desorption experiments on a coal,es-pecially deformed coal.