微波活化氧解褐煤制备密集多孔炭及其吸附性能

Preparation of Dense Porous Carbon from Lignite by Microwave Activation and Its Adsorption Properties

以H2O2处理后的褐煤为碳源,在微波场条件下,利用KOH活化氧解褐煤(OC)制备多孔炭材料(PC)。在单因素实验基础上,使用响应曲面优化实验设计,分别考察微波功率、活化时间和活化剂与OC的质量比对PC碘吸附量的影响,建立响应值与影响因素的回归方程。结果表明:优化PC制备条件为微波功率430 W、活化时间14 min、活化剂与OC的质量比为3∶1;在此优化条件下制备出的PC对碘吸附量达到1060.06 mg/g,与模型预测值1068.43 mg/g接近,预测值与实验值相对误差仅为0.78%;利用扫描电子显微镜(SEM)和N2等温吸脱附对PC进行表征,发现PC具有高孔隙率且孔径分布密集,比表面积达到1129 m2/g,总孔体积达到0.603 cm3/g。

With H2O2-treated lignite being used as carbon source,the oxidized lignite coal(OC)was activated by KOH to prepare the porous carbon material(PC)in the microwave field.Following the principle of the single-factor experiment,the response surface experiments were designed,under which the effects of the microwave power,activation time and m(activator)∶m(OC)on the iodine adsorption capacity of the PC were investigated respectively.Based on the experimental results,the regression equation between the response value and influencing factors was established.The results that the optimal conditions for the preparation of the PC corresponding to the microwave power of 430 W,activation time of 14 min,m(activator)∶m(OC)of 3∶1 are obtained.Under these conditions,the iodine adsorption capacity of PC reach 1060.06 mg/g,which is in line with the model-predicted value corresponding to 1068.43 mg/g.The relative error between the predict value and the experimental value is only 0.78%,which shows that the model establish by the response surface method is feasible.By using the SEM and N2 isothermal adsorption and desorption to characterize the PC,it is found that the PC had a high porosity and dense pore size distribution,with the surface area corresponding to 1129 m2/g,and total pore volume corresponding to 0.603 cm3/g.The characterization results indicat that the PC prepared by using the microwave activation oxidized coal have good adsorption performance.