摘要
采用农林废弃物制备比表面积大、微孔结构发达的活性炭,能够缓解资源短缺问题,减少环境污染,并且提高活性炭在气相吸附方面的利用价值。以核桃壳为原料、KOH为活化剂,采用单因素法探讨碱炭比、活化温度和活化时间对活性炭得率、碘吸附值的影响,确定了核桃壳基活性炭制备的最佳工艺条件。采用场发射扫描电镜、孔径分析仪、傅里叶红外光谱仪分析了活性炭的微观形貌、孔径结构、表面化学性质。结果表明:当碱炭比为3∶1、活化时间为60 min、活化温度为800℃时,制备的核桃壳基活性炭的比表面积为1 551.85 m2/g,总孔容为0.79 cm3/g,微孔比表面积为1 491.22 m2/g,微孔率为89.87%。该活性炭的比表面积大,微孔结构发达,同时极微孔含量很高。
The focus of this study is to prepare the activated carbon with the cheap-gaining large-sized specific surface of the walnut shells with rich microporous structure through KOH activation,which is favorable for the extensive use of the activated carbon through gasadsorption in addition to alleviating the raw material resource shortage. To achieve the purpose,we have optimized the operating procedures and the technical parameters based on the assessment of the effects on iodine adsorption value and the activated carbon yield,such as the alkali / carbon ratio,the activation temperature and the time length through the so-called single factor analysis. As a result,we have also made it possible to conduct the preparation at 800 ℃during a period of 60 min and under the effects of alkali / carbon ratio（ 2： 1- 5： 1） on the iodine adsorption rate in the activated carbon yield. The results of our investigation and preparation demonstrate that it would be possible to obtain the maximum iodine adsorption rate when the alkali / carbon ratio is kept at 3： 1. We have also confirmed that the preparation of the carbon purified from the walnut shells can be done during the needed 60 min with alkali / carbon ratio being 3： 1. That is to say,the rate of the iodine adsorption can be increased with the increase of temperature by 800 ℃,and then the rate of the iodine adsorption would begin to decrease. And,next,the activated carbon yield tends to decrease slightly with the increase of the alkali / carbon ratio,the activation temperature,as well as the activation time,respectively. And,finally,the micro-morphology,the pore structure and the surface chemical structure of the activated carbon can all be put into evaluation and characterization by using a pore size analyzer,and FTIR along with a FE- SEM. Thus,as a result,we have prepared the activated carbon with a high surface area of 1 551. 85 m2/g,the microporous specific surface area of 1 491. 22 m2/ g and the total pore volume of 0. 79 cm3/ g,with a high microporous rat
出处
《安全与环境学报》
CAS
CSCD
北大核心
2016年第2期262-266,共5页
Journal of Safety and Environment
基金
国家自然科学基金项目(51172028)
关键词
环境工程学
活性炭
核桃壳
KOH
environment engineering
activated carbon
walnut shells
KOH
