摘要
以石油焦为原料研究了采用KOH活化法制备大比表面积炭质吸附剂时表面及孔隙的发展。实验发现虽然KOH加入量 ,水乙醇溶液中乙醇含量和提高热处理终温以及延长热处理时间都使比表面积增大 ,但是水乙醇加入总量的增加则导致比表面积下降。KOH加入量以 60～ 75%为宜 ,此时其利用率在 40 0m2 g以上。孔隙分布研究表明水乙醇加入总量 ,乙醇含量和热处理温度的提高都使 1～ 2nm微孔孔容及其在 1～ 2 0nm微孔孔容中所占比率增加。实验发现大比表面积炭质吸附剂的比表面积与碘值之间存在一定相关性。由于碘值不存在N2 吸附BET比表面积的过高估计现象 ,因而这给用碘值来更合理评价大比表面积炭质吸附剂的相对吸附能力提供了可能。
The development of surface area and pore structure of carbon adsorbent with large surface area preparet by chemical activation of KOH using petroleum coke as precursor was investigated.The results show that the specific surface area increases with increasing the amount of KOH added, the percent of ethanol in water solution, heat treatment temperature and time of heat treatment, but decreases with increasing the total amount of water and ethanol solution added.With regard to the utilization efficiency of KOH, it is adequate when the amount of KOH added in the mixture of KOH and char was 60～70% wt., and the maximum value of that is above 400 m^2/g.It is also shown that the value of pore volume with a pore size of 1～2 nm and the ratio of 1～2 nm pore volume to 1～20 nm increase with increasing the total amount of water and ethanol solution added, the percent of ethanol in water solution and heat treatment temperature.It is also found that the specific surface area and iodine value are closely correlated.Because iodine value does not like specific surface area of nitrogen adsorption existing overestimation, it is possible that using iodine value to estimate the ability of adsorption is more reasonable than using nitrogen adsorption.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2000年第5期473-477,共5页
Journal of Fuel Chemistry and Technology
基金
大连理工大学碳资源综合利用开放研究实验室资助项目
关键词
大比表面积
活性炭
孔结构
石油焦
制备
吸附剂
large surface area, activated carbon, pore structure, petroleum coke
