随着国内外活性炭需求量的增大,探索出高效制备活性炭的工艺非常重要。本研究以新疆无烟煤为原料,KOH为活化剂,利用微波加热和传统加热法制备煤基活性炭(CAC),研究煤碱比、活化时间、活化温度、微波功率对CAC吸附性能和产率的影响,获得制备CAC的最佳工艺条件为:微波加热法∶煤碱比1∶2,微波时间8 min,微波功率700 W;传统加热法∶煤碱比1∶1,活化时间5 h,活化温度800℃。利用扫描电镜、氮气等温吸附脱附、零点电荷(pHpzc)、Boehm滴定法对CAC进行表征,结果表明:微波加热法制备的CAC吸附性能优于传统加热法制备的样品,其具有更高的比表面积为1061.93 m^2/g,更高的pHpzc(8.0)及更少的酸性官能团含量(0.986 mmol/g)。上述结果表明微波加热法节能、省时、成本降低,将在材料制备过程中具有显著地应用前景及推广价值。
With the increasing demand of activated carbon(AC) at home and abroad, exploring an efficient preparation process of AC is important. The coal-based activated carbons(CAC) prepared from anthracite coal of Xinjiang with KOH as activator by microwave and conventional heating methods. The effects of coal alkali ratio, radiation time, radiation temperature and microwave power on adsorption capabilities and yield of CAC were investigated. The optimal process conditions were obtained as follows: coal alkali ratio of 1∶1 for 8 min at 700 W of power by microwave heating method and coal alkali ratio of 1∶2 for 5 h at 800 ℃ by conventional heating method. And the textural properties of the samples were characterized by means of SEM and nitrogen adsorption-desorption isotherms, and their surface chemical characteristics were investigated through point of zero charge and Boehm titration. The results showed the CAC prepared by microwave heating method had higher surface area than conventional heating method, which was 1061.93 m2/g. The CAC prepared by microwave heating method also had higher p Hpzc(8.0) and lower acidic oxygen functional group(0.986 mmol/g) than those of CAC prepared by conventional heating method.Moreover, the microwave heating method showed the advantages of short reaction times and energy economy, which would have significant application prospect and promotion value in the process of material preparation.