废弃辣椒秸秆高比表面积活性炭的制备及表征

Preparation and characterization of high specific area activated carbon from abandoned capsicum straw

以废弃的辣椒秸秆为原料,KOH为活化剂,制备高比表面积活性炭,研究了碱炭比、活化温度、炭化温度及活化时间对活性炭吸附性能的影响。结果表明,活性炭制备的最佳工艺条件为:碱炭比为3∶1,活化温度为700℃,炭化温度为450℃,活化时间为40 min。在此条件下,制得的活性炭碘吸附值2 356.40 mg/g,亚甲基蓝吸附值41.3 mL/0.1 g,BET比表面积为2 432.135 m2/g,Langmuir比表面积高达3 270.478 m2/g,吸附总孔容为2.064 cm3/g,平均孔径为3.246 nm。SEM和XRD观察发现,辣椒秆活性炭呈不定形态,具有丰富和发达的蜂窝状孔隙结构。

The active carbon with high specific surface area is prepared from capsicum straw by using KOH as the activation agent.the optimal experimental conditions of preparing activated carbon and the effects of such factors as the ratio of activation agent to capsicum straw,the activation,charring temperature and activation time upon the adsorption properties of active carbon were achieved.Results showed that the optimum preparation conditions were determined as follows：the ratio of the activation agent to capsicum straw being 3∶ 1,activation temperature and time being 700 ℃and 40 min,charring temperature being 450 ℃.Microstructure of the sample show that the activated carbon iodine adsorption value 2 356.40 mg/g and methylene blue adsorption value 41.3 mL/0.1 g,then developed possesses a large apparent surface area（SBET=2 432.135 m2/g,SL=3 270.478 m2/g） and high adsorption pore volume（V=2.064 cm3/g） with average pore size diameter of 3.246 nm.The morphology and structure of active carbon are observed by SEM and X-ray.