微波改性对活性炭及其甲醇吸附的影响  

Effect of Microwave Modification on Activated Carbon and its Adsorption of Methanol

作　　者：李立清[1] 梁鑫[1] 姚小龙[1] 李海龙[1] 马卫武[1] 刘飒[1] 

机构地区：[1]中南大学能源科学与工程学院,湖南长沙410083

出　　处：《湖南大学学报（自然科学版）》2014年第7期78-83,共6页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(20976200;51206192);APEC科技产业合作基金项目(313001022)

摘　　要：分别在600,700和800℃下对活性炭进行微波辐照加热改性.采用比表面积及孔径分析仪、Boehm滴定、傅立叶转换红外光谱对活性炭的物化性质进行表征.并且在10℃下以甲醇为吸附质进行固定床吸附实验.研究表明:微波改性后,活性炭的比表面积、总孔容小幅度减小,但微孔比表面积显著增大;随着温度升高,活性炭表面酸性基团大量分解,碱性基团逐渐形成.Langmuir方程和Freundlich方程均能较好的描述甲醇在活性炭上的吸附.准二阶动力学方程最适合描述甲醇的动态吸附过程,说明甲醇吸附是一个物理和化学复合的吸附过程,吸附受到活性炭表面官能团的影响.颗粒内扩散模型拟合结果分为3个线性阶段:表面吸附阶段、渐近吸附阶段和吸附平衡阶段.微波改性后活性炭对甲醇的吸附能均增大,吸附能与活性炭表面含氮官能团总量成正比.Activated carbon （AC）was modified with microwave irradiation at 600,700 and 800 ℃re-spectively.Specific surface area and pore size analyzer,Boehm titration and Fourier transformed infrared spectroscopy were used to measure the physicochemical properties of the activated carbons.Fixed-bed ad-sorption experiments were conducted at 10 ℃ with methanol as the adsorbate.The research shows that, after microwave modification,the specific surface area and total pore volume of activated carbons decrease slightly,but the micropore specific surface area increases remarkably.With the rise of temperature,large numbers of surface acidic functional groups of activated carbons resolve and surface basic functional groups are formed gradually.Both the Langmuir equation and Freundlich equation can well describe the adsorp-tion of methanol on the activated carbons.Pseudo-second-order kinetic equation describes the dynamic ad-sorption process of methanol most suitably,which illustrates that methanol adsorption is a physical and chemical composite adsorption process,and adsorption is affected by the surface functional groups of the activated carbons.The fitting result of intra-particle diffusion model is divided into three linear stages：surface adsorption stage,asymptotic adsorption stage and adsorption equilibrium stage.After microwave modification,the adsorption energy of activated carbons for methanol increases,and the adsorption energy is proportional to the contents of surface nitrogen groups of the activated carbon.

关 键 词：微波 改性活性炭 吸附 甲醇 

分 类 号：O613.71[理学—无机化学]