两种酸处理对褐煤半焦表面性质及其脱汞性能的影响  

Effect of acid treatment of lignite semi-coke on its surface properties and mercury removal performance

作　　者：王力[1] 刘秀丽[1] 张林林[1] 李敏[1] 张华伟[1] 

机构地区：[1]山东科技大学化学与环境工程学院,山东青岛266590

出　　处：《功能材料》2014年第11期11046-11050,共5页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(21276146)

摘　　要：分别用浓度为25%HNO3和25%H2SO4溶液制备改性半焦,并在固定床吸附装置上以氮气作为载气携带汞蒸气,对比研究了半焦的脱汞性能,分析了半焦脱汞影响因素。利用酸碱滴定、Boehm滴定、SEM、BET、FT-IR、XRD等方法对改性前后半焦的物化性质进行了表征。结果表明,硝酸和硫酸氧化降低了半焦的灰分含量,提高了改性半焦含氧、含氮和磺酸基团的含量。在吸附温度为30和140℃时,硝酸改性半焦对气态单质汞的脱除效率均提高;而硫酸改性后,只能提高吸附温度为140℃时的除汞效率,这与改性半焦表面性质及其酸性官能团含量有关。The mercury removal performance of lignite semi-coke modified with concentration of 25% HNO3or 25%H2SO4solution has been investigated in a fixed bed adsorption apparatus with nitrogen as a carrier gas to carry mercury vapor,and the influence factors for mercury removal were also analysied. The surface physical and chemical properties of semi-coke modified by sulfuric acid（ S-SC） and semi-coke modified by nitric acid（ N-SC） were characterized by methods of acid-base titration,boehm tirast,brunauer-emmett-teller（ BET） measurements,X-ray powder diffraction（ XRD）and Fourier transform infrared spectroscopy（ FT-IR）. The results show that the oxidation of nitric acid or sulfuric acid results in the decrease in ash content of semi-coke and the increase in content of oxygen,nitrogen and the sulfonic acid groups of modified semi-cokes. Compared with lignite semi-coke（ NM-SC）,the N-SC sample can improve mercury removal efficiency from flue gas at temperature of 30 and 140 ℃,while the S-SC sample only enhance the mercury removal efficiency at 140 ℃,these results are related to the surface properties of semi-coke modified by acid and its content of acidic functional groups.

关 键 词：褐煤半焦 气态单质汞 酸改性半焦 酸性官能团 

分 类 号：TQ536[化学工程—煤化学工程]