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.
出处
《功能材料》
EI
CAS
CSCD
北大核心
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)
关键词
褐煤半焦
气态单质汞
酸改性半焦
酸性官能团
lignite semi-coke
elemental mercury
semi-coke modified by acid
acidic functional group
