酸改性对褐煤半焦脱除烟气中元素态汞性能的影响.pdfVIP

中国环境科学 2014,34(12) ：3056~3061 China Environmental Science 酸改性对褐煤半焦脱除烟气中元素态汞性能的影响 * 王 力,刘秀丽 ,张林林,李 敏,张华伟 ( 山东科技大学化学与环境工程学院, 山东 青岛 266590) 摘要：为减少燃煤烟气中零价汞的排放,利用 HCl 和 HNO3 溶液对褐煤半焦改性研制了一种高效、低成本的吸附剂.运用酸碱滴定、Boehm 滴定、BET 、SEM 和 FTIR 等技术对半焦吸附剂的表面特性进行表征与分析,利用固定床吸附实验装置及烟气测汞仪在线考察了半焦吸附 剂对气态 Hg0 的吸附特性.结果表明,酸改性使半焦灰分含量降低,增加了半焦比表面积和羧基、酚羟基等官能团含量.酸改性处理可提高半 焦对元素态单质汞的脱除效率,特别是盐酸溶液改性褐煤半焦可使吸附温度为 140℃时的脱汞效率显著提高,这与改性半焦表面羧基、酚羟 基和 C-Cl 官能团的含量及性质有关,半焦表面这些官能团能为 Hg0 的化学吸附提供活性位. 关键词：褐煤半焦；Hg0 ；酸改性半焦；酸性官能团 中图分类号：X513,TQ 536.9 文献标识码：A 文章编号：1000-6923(2014)12-3056-06 Effect of lignite semi-coke by acid solution treatment on its performance for elemental mercury removal in the flue gas. WANG Li, LIU Xiu-li*, ZHANG Lin-lin, LI Min, ZHANG Hua-wei (College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao 266590, China). China Environmental Science, 2014,34(12) ：3056~3061 Abstract ：The adsorption performance of modified lignite semi-coke with HCl or HNO 0 3solution for gaseous Hg was investigated to develop more effective and lower price adsorbents for reducing emission of elemental mercury in coal combustion flue. The surface properties of these lignite semi-coke adsorbents were characterized with methods of acid-base titration, Boehm titration, Brunauer-Emmett-Teller (BET) measurement, scanning electron microscope (SEM) and Fourier Transform infrared spectroscopy (FTIR), respectively. The adsorption experiments of semi-coke adsorbents for gas-phase Hg0have been carried out with a laboratory-scale fixed-bed reactor, and elemental mercury analyzer was used to determine the on-line concentrations of gas-phase Hg0. Nitr