热改性对柱状活性炭脱硫能力的影响  

Effect of thermal modification on desulfurization capacity of column activated carbon

作　　者：佘雪峰 刘松昊 王延江 王建芳 王静松 薛庆国 SHE Xue-feng;LIU Song-hao;WANG Yan-jiang;WANG Jian-fang;WANG Jing-song;XUE Qing-guo(State Key Laboratory of Advanced Metallurgy,University of Science and Technology Beijing,Beijing 100083,China;Sintering Plant,Delong Steel,Xingtai 054000,Hebei,China)

机构地区：[1]北京科技大学钢铁冶金新技术国家重点实验室,北京100083 [2]德龙钢铁有限公司烧结厂,河北邢台054000

出　　处：《钢铁》2022年第4期130-137,共8页Iron and Steel

基　　金：国家自然科学基金资助项目(U1960205)。

摘　　要：在N;保护下采用不同温度对柱状活性炭进行热改性,得到了5种改性活性炭(AC-1~AC-5),将改性前后的活性炭(AC)分别置于含有SO;且有水蒸气和氧气存在的条件下进行脱硫试验,利用气体吸附仪和扫描电镜对改性前后活性炭表面的物理性质进行了表征。试验结果表明,当改性温度为700~900℃时,改性后活性炭的脱硫能力随着改性温度的升高而提升,当改性温度为900℃时,所得活性炭的脱硫能力最强,当改性温度达到1100℃时活性炭脱硫能力明显变差。气体吸附仪所得的BET分析结果和扫描电镜的结果表明,在加热过程中活性炭部分原本堵塞的孔道被打开,增大了其吸附表面积,对提升活性炭的初始脱硫率有利,但过高温度会破坏活性炭原有孔径结构,导致AC-4和AC-5样品脱硫能力变差。此外,利用程序升温脱附技术(TPD)对活性炭样品AC~AC-4的酸碱量进行了分析,结果表明,活性炭表面强碱中心的碱量与其脱硫能力存在良好的正线性相关关系,对比样品AC-2和AC-3发现,在活性炭物理性质差别不大的情况下,其脱硫能力的提升主要得益于表面化学性质的改变,尤其是碱性的增强。同时,通过Boehm滴定并结合傅里叶变换红外光谱仪(FTIR)对活性炭样品AC和AC-3的表面酸性官能团变化进行分析,发现在热改性后活性炭表面羧基、内酯基和羟基数量减少,这说明热处理能使活性炭表面的酸性官能团分解,有利于提升其脱硫能力。Five kinds of modified activated carbons(AC-1 to AC-5)were obtained by thermal modification of columnar activated carbons at different temperatures under the protection of N;.The activated carbons(AC)before and after modification were placed in the condition containing SO;and in the presence of water vapor and oxygen respectively for desulfurization experiment.The physical properties of activated carbon surface before and after modification were characterized by gas adsorption apparatus and scanning electron microscope.The experimental results show that when the modification temperature is 700-900℃,the desulfurization ability of the modified activated carbon increases with the increase of the modification temperature,when the modification temperature is 900℃,the desulfurization ability of the activated carbon is the strongest,when the modification temperature is 1100℃,the desulfurization ability of the activated carbon decreases obviously.Gas adsorption apparatus of the proceeds of the BET the results of the analysis,and scanning electron microscopy the results show that activated carbon part was blocked in the process of heating channel is opened,increase its adsorption surface area,to improve the initial activated carbon desulfurization rate is good,but too high temperature will destroy the original structure of aperture,activated carbon in AC-4 and AC-5 samples of the desulfurization ability becomes poor.In addition,temperature-programmed desorption technology(TPD)was used to analyze the pH content of activated carbon samples from AC to AC-4.The results showed that there was a good proportional linear relationship between the ph content of strong alkali center on the surface of activated carbon and its desulfurization ability.By comparing the samples AC-2 and AC-3,it can be found that under the condition of little difference in the physical properties of activated carbon,the improvement of its desulfurization ability mainly benefits from the change of surface chemical properties,especially the enhancemen

关 键 词：活性炭 吸附 热改性 脱硫 官能团 

分 类 号：X757[环境科学与工程—环境工程] TQ424.1[化学工程]