活性炭孔结构的混合碱改性

具有较大比表面积的且以微孔孔隙居多的活性炭对气体小分子具有较好的吸附性能,以椰壳活性炭为原料、KOH/NaOH为活化扩孔剂,考察了温度、时间以及KOH与NaOH的质量比对活性炭孔隙结构的影响,使用N2在77 K下对产品活性炭进行表征测试。表征结果表明,当m(KHO)∶m(NaOH)为4∶1、溶液浓度为50%时,活性炭在600℃下活化4 h所得的活性炭产品平均孔径最大。对比HK模型和DFT模型对微孔活性炭孔径分布的分析结果,表明DFT模型更符合实际情况。经过孔结构改性的活性炭对CH4与CO2吸附能力均有提高。

Modification of pore structure in activated carbon by mixed alkali

Activated carbon with large surface area and micropore was important for small gas molecules adsorption,so activated carbon samples were modified from cocoanut activated carbon with KOH/NaOH as activator.Effects of activation temperature,activation time and the ratio of KOH/NaOH on the pore structure of activated carbon were investigated.The activated carbon was measured at 77 K by N2 adsorption,and the result showed that the average pore size of activated carbon sample was larger when mass ratio of KOH/NaOH was 4∶1,the mass ratio of solution was 50% and activated carbon was activated at 600 ℃ for 4 h.Comparing the pore size distribution(PSD) results obtained from HK and DFT models,it was conclused that DFT model was more suitable to analyze PSD of activated carbon.The CO2 and CH4 adsorbed amounts on activated carbon with modified pores were larger than those on unmodified one.