煤热解沥青炭化程度对KOH活化制备活性炭孔隙结构的影响

以煤热解沥青为原料，采用KOH活化法制备活性炭提高附加值.在不同减压蒸馏终温（VDFT）和不同预炭化温度下得到碳质前驱体，研究碳质前驱体的炭化程度对制备的活性炭孔隙结构的影响.研究表明，碳质前驱体合适的炭化程度，即前驱体中适量的挥发分、H原子、表面官能团以及合适的结构排列，有益于KOH活化.减压蒸馏终温为440℃的多联产煤热解沥青活化得到的活性炭比表面积最大，为2 599 m2/g.减压蒸馏终温为360℃的沥青在400℃下炭化2 h，经KOH活化后可以得到比表面积为2 575 m2/g的高比表面积活性炭，但是需要预炭化处理，工艺相对复杂.
Abstract: The activated carbons (ACs) prepared from coal pyrolytic pitches were activated with KOH to increase the added value of the pitches. The carbon precursors were prepared at different vacuum distillation final temperatures (VDFTs) and different pre-carbonization temperatures. The influence of their carbonization degree on the pore structure of ACs was analyzed. Results show that appropriate carbonization degree, which can be presented by the proper amount of the volatile matter, the H atoms, the surface functional groups in carbon precursors and structure arrangement, is beneficial to the KOH activation. The ACs prepared from pitch with VDFT of 440℃ have the highest specific surface area, which is 2 599 m2/g. The ACs obtained from the pitch treated with VDFT of 360℃, pre-carbonized at 400℃ for 2 h, then activated with KOH have high specific surface area, which is 2 575 m2/g. The method is relatively complicated because of the extra pre-carbonization.