煤岩显微组分对活性炭表面性质的协同效应机理

Synergistic Mechanism of Coal Macerals on the Surface Properties of Activated Carbon

为探究煤岩显微组分对活性炭表面性质的协同效应机理,按密度分选富集煤岩显微组分,采用KOH活化法制备活性炭,测试了原煤和前驱体煤岩显微组分的性质,分析了活性炭的氮气吸附量、孔结构特征、官能团和润湿性。结果表明:按密度分选可以有效富集煤岩显微组分,煤中活性组分与惰性组分之间的协同效应对活性炭的表面性质有重要影响;中间密度级前驱体的活惰比(活性组分与惰性组分的体积分数比)适中,既有充足的活性组分造孔,又有足够的惰性组分形成骨架,用其制备的活性炭孔结构最发达,比表面积和总孔体积最大(分别为1264.47 m^2/g和0.7000 cm^3/g),中孔率最高(35.71%),氮气吸附量最大;随着前驱体活惰比减小,活性炭的含氧官能团少量减少,而矿物质含量迅速增加,使得KOH电解液对活性炭的润湿性增强。

In order to explore the synergistic mechanism of coal macerals on the surface properties of activated carbon,the activated carbon was prepared by using the KOH activation method and then characterized.The coal macerals were enriched from coal according to the density.Maceral properties of the raw coal and precursor were tested.Specifically,the nitrogen adsorption capacity,pore structural characteristics,functional groups,and wettability of prepared activated carbon were analyzed.The results show that the macerals can be effectively enriched by the density-based separation,and the active and inert components affect synergistically on the surface properties of activated carbon.The ratio(volume fraction)between the active and inert components of the precursor corresponding to the intermediate density is moderate.In this sense,there are not only enough active components for the formation of pores,but also enough inert components for the development of the skeleton.As a result,the activated carbon prepared from such precursor has the largest specific surface area corresponding to 1264.47 m^2/g and the largest total pore volume corresponding to 0.7000 cm^3/g,the highest mesopore ratio corresponding to 35.71%,and the maximum nitrogen adsorption.With decreasing ratio between the active and inert components of the precursor,the oxygen-containing functional groups of the activated carbon decrease slightly,while the mineral content increases rapidly,leading to the enhancement in the wettability of the KOH electrolyte to the activated carbon.