磷酸活化法制备棉秆基活性炭实验优化及其孔隙结构表征

Experimental Optimization and Pore Structure Characterization of Activated Carbon Prepared by Phosphoric Acid Activation

本文首先将棉花秸秆热解制得生物炭,而后以磷酸为活化剂对所制备的生物炭进行活化得到棉秆基活性炭,采用正交实验方法研究了活化剂与生物炭比例、浸渍时间、活化温度和活化时间对棉秆基活性炭的持水能力的影响,采用极差分析方法对实验条件进行优化,并对所制备的样品进行了比表面积、SEM等性能测定。结果表明:最优化实验方案为磷酸与生物炭质量比为2∶1,浸渍时间12 h,活化温度450℃,活化时间30 min,该条件下所制备的棉秆基活性炭持水能力为5.11 g/g,平均孔径为3.58 nm,最可几孔径为1.81 nm。

In this paper,biochar was prepared by pyrolysis of cotton straw,then the biochar was activated by phosphoric acid to prepare active carbon. Effects of biochar ratio,soaking time,activation temperature and activation time were studied on the water holding capacity of the activated carbon by orthogonal experimental method. Experimental conditions were optimized by range analysis method and surface area、SEM and other performance measurement were analyzed. The experimental results showed that the optimal experimental scheme were as follows ： the acid quality and biochar mass of 2∶ 1,the soaking time of 12 h,the activation temperature of 450 ℃and the activation time of 30 min. Under the conditions,the water holding capacity,average diameter and the most probable aperture of activated carbon were 5. 11 g/g,3. 58 nm,1. 81 nm respectively.