以烟杆炭化料为原料,采用微波加热碳酸钾活化法制备了高比表面积活性炭。研究了微波加热时间和碱炭比对活性炭的得率和吸附性能的影响,得到了优化工艺条件,所得活性炭产品的碘吸附值为1834mg/g,亚甲基兰吸附值为517.5mg/g,得率为16.65%。产品的吸附性能超过了双电层电容器专用活性炭(LY/T 1617-2004)标准的要求,同常规加热相比,活化时间缩短了78.26%。同时测定了该活性炭的氮吸附等温线,通过非定域化密度函数理论表征了活性炭的孔结构。该高比表面积活性炭的比表面积为2557m^2/g,总孔体积为1.6470ml/g。
A series of high specific surface area activated carbons was prepared with char of tobacco stems as raw materials and potassium carbonate as activating agent using a microwave heating procedure. The effects of K2CO3/C ratio and microwave heating time on the yield and adsorption properties of activated carbon were systematically studied. The optimum condition has been obtained. Thus the experimental results have shown that the yield of the activated carbon was 25.48% when the methylene blue adsorption reached 517.5mg/g and iodine value was 1834mg/g. The adsorption properties exceeded that of the standard of activated carbon for electric double-layer capacitor. The activation time of microwave heating was shortened 78.26% comparing with that of the conventional process. Furthermore, the activated carbon manufactured under optimum condition was tested by nitrogen adsorption at 77K. The porous structures of the activated carbon were investigated by Non Local Density Function Theory (NLDFT). The results showed that the obtained activated carbon consisted of abundant micropores and mesopores with specific surface area of 2557m^2/g, total pore volume of 1.6470ml/g.