响应曲面法优化CO_2活化制备夏威夷坚果壳基活性炭

Preparation of activated carbon from Hawaii nut shell via CO_2 activation using response surface methodology

采用CO2物理活化法将废弃的夏威夷坚果壳制备成高品质活性炭。实验研究测定了活化温度、活化时间、CO2流量等因素对活性炭的吸附性能和产率的影响。通过响应曲面法得到实验优化工艺条件:活化温度766℃、活化时间36 min、CO2流量186 m L/min,所制备的活性炭亚甲基蓝值和产率分别为186 mg/g,71.35%。衡量活性炭品质的关键性参数BET比表面积、孔容和平均孔径分别为1 267 m2/g,0.97 m L/g和4.13 nm。此外通过扫描电镜对比炭化料和活性炭分析发现,活性炭表面具有大量无规则孔隙。

Spent Hawaii nut shell was converted into a high-quality activated carbon via CO2 physical activation. The operational variables including activation temperature,activation duration and CO2 flow rate on the adsorption capability and yield of activated carbon were identified. The operating variables were optimized utilizing the response surface methodology and were identified：activation temperature of 766℃,an activation duration of 36 min and a CO2 flow rate of 186 m L/min with the methylene blue adsorption number of 186 mg/g and yield of 71. 35%. The key parameters that characterize quality of the activated carbon such as the BET surface area,total pore volume and average pore diameter were estimated to be 1 267 m2/ g,0. 97 m L/g and 4. 13 nm,respectively. Additionally,through the SEM analyzing of char and activated carbon,the surface of activated carbon has large number of pores of irregular.