碱性溶液对煤体甲烷吸附特征影响机制

Influence mechanism of alkaline solution on methane adsorption of coal

为探究碱性溶液对煤体的化学增透特性,开展孔隙测试和吸附试验,分析碱溶液对煤体化学侵蚀效果及甲烷吸附能力的影响;以安徽省青东煤矿为研究对象,采用低温液氮吸附法和等温吸附法,测试碱性溶液处理前后煤样的孔隙和甲烷吸附特性,并采用分形理论和吸附理论量化分析试验结果。研究表明:碱溶液可有效改变煤体孔隙结构,提高孔径小于5 nm的微孔含量,试验煤样最大吸附量由17.83 m L/g升高至21.97 m L/g,煤样的吸附能力得到提高。

In order to explore alkaline solution’s enhancement on coal’s chemical permeability,pore test and adsorption test were carried out to analyze influence of alkaline solution on chemical erosion effect of coal and its adsorption capacity of methane.With Qingdong coal mine from Anhui Province as research object,samples’pore and methane capacity characteristics before and after alkaline solution treatment were tested with low temperature liquid nitrogen adsorption method and isothermal adsorption method.Then,experiment results were quantitatively discussed using fractal theory and adsorption theory.The results show that alkaline solution can effectively change pore structure of coal and increase content of micropores at pore size less than 5 nm.Coal samples’adsorption capacity greatly improves with its maximum value increasing from 17.83 m L/g to 21.97 m L/g after alkali treatment.