摘要
利用Ca(NO_3)_2作为前体,SiO_2为载体,制备了一种担载型CaO吸附剂,在固定床实验装置上分别研究了该吸附剂对元素汞(Hg0)和氯化汞(HgCl_2)等不同形态汞的选择性吸附性能,以及SiO_2对CaO吸附剂汞形态吸附过程的影响,同时结合程序升温脱附和原位红外漫反射表征技术,深入探究了CaO的选择性吸附机理及SiO_2毒化机制。汞形态吸附实验结果表明,在纯N2气氛和掺杂SiO_2气氛下,CaO对Hg0均保持了接近100%的穿透率,而对HgCl_2在两种气氛下则分别表现出66.0%和60.3%的吸附效率,说明SiO_2与HgCl_2在CaO表面存在竞争吸附关系;吸附实验前后CaO的表征结果显示,与Hg0相比,HgCl_2更易与CaO表面各碱性位形成单配位、双配位等多种吸附构型,SiO_2与HgCl_2在易形成单配位的活性位上形成竞争吸附关系,进而在一定程度上降低了CaO对HgCl_2的吸附效率。
Using Ca（NO3）2 as a precursor and SiO2 as carrier, a supported CaO adsorbent was prepared. The selective adsorption performances of elemental mercury（Hg^0） and mercuric chloride（HgCl2） of the sorbent were conducted in a fixed bed, and the effects of SO2 on CaO mercury adsorption process were also investigated. At the same time, combined with the program temperature desorption（TPD） and in situ diffuse reflectance infrared spectroscopy（in-situ DRIFT） characterization technology, the selective adsorption mechanism of CaO and the mechanism of SO2 poisoning were deeply investigated. The mercury adsorption results showed that CaO maintained a breakthrough of nearly 100% for Hg_0 in pure N_2 atmosphere and doped SO2 atmosphere, while HgCl2 manifested 66.0% and 60.3% adsorption efficiency in two atmospheres, respectively, indicating that there was a competitive adsorption relationship between SO2 and HgCl2 on CaO surface. The characterized results of CaO before and after adsorption suggested that as compared with Hg0, HgCl2 was able to form monodentate, bidentate and other adsorption structure with the basic sites on the CaO surface. SO2 and HgCl2 formed a competitive adsorption relationship in the active sites where the bridged bidentate was easily formed, resulting in the reduction of adsorption efficiency of HgCl2 on CaO.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2017年第9期3565-3572,共8页
CIESC Journal
基金
国家重点研发计划项目(2016YFC0201105)
国家自然科学基金项目(51576044
51676041)~~
关键词
CaO吸附剂
HG
HgCl2
选择性吸附
SO2毒化
CaO adsorbents
elemental mercury
mercuric chloride
selective adsorption
sulfur poisoning
作者简介
第一作者：李春峰（1991-），男，硕士研究生。
联系人：段钰锋。
