不同变质程度煤的孔径分布及其对吸附常数的影响

Influence of pore size distribution of different metamorphic grade of coal on adsorption constant

为研究煤的纳米级(<100 nm)孔径对吸附常数的影响,对9种不同煤样的孔径分布和吸附常数进行测试,测试结果表明:煤的变质程度越高,吸附常数a值越大,吸附常数a值随着煤变质程度的降低呈现出线性减小的趋势。煤的变质程度对大孔(>1 000 nm)孔容的影响较大,对微孔(<10 nm)比表面积的影响较大。采用曲线相似度法分析吸附常数a和b的主导因素,结果表明:纳米级孔比表面积决定煤的吸附能力,吸附常数a随着纳米级孔比表面积增加呈线性增加;纳米级孔的容积决定煤的吸附速率,吸附常数b随着纳米级孔容积的增加亦呈线性增加。

In order to study the influence of nanoscale pore on adsorption constant, pore diameter distribution and adsorption constant of nine coal samples were tested in the lab. The results show that the metamorphic grade of coal is higher, adsorption constant a is bigger. The adsorption constant a has linear decreasing trend along with the reduction of coal metamorphic grade. Metamorphic grade of coal has great influence on the volume of big hole （ 〉 1 000 nm） and the specific surface area of micro hole （ 〈 10 nm）. With the method of curve similarity, the leading factors of adsorption constants a and b were analyzed. The analysis results indicate that the specific surface area of nanoscale hole decides adsorption ability of coal. The adsorption constant a has linear increasing along with the increase of the specific surface area of nanoseale hole. The volume of nanoscale hole decides adsorption rate of coal. The adsorption constant b has linear increasing along with the increase of the volume of nanoscale hole.