平板式脱硝催化剂的抗砷中毒性能  

Investigation of arsenic resistance of plate-type De-NO_(x) catalyst

作　　者：岳彦伟 黄力 王素芹 纵宇浩 王虎 李金珂 韩沛 谢兴星 马罗宁 高义博 YUE Yanwei;HUANG Li;WANG Suqin;ZONG Yuhao;WANG Hu;LI Jinke;HAN Pei;XIE Xingxing;MA Luoning;GAO Yibo(Datang Nanjing Environmental Protection Technology Co.,Ltd.,Nanjing 211111,China;Jiangsu JITRI-Topsoe Institute of Advanced Catalytic Technology,Suzhou 215132,China;Jiangsu JITRI-Topsoe Clean Energy R&D Co.,Ltd.,Suzhou 215132,China;Instrumental Analysis Center,Inner Mongolia University of Science&Technology,Baotou 014010,China)

机构地区：[1]大唐南京环保科技有限责任公司,江苏南京211111 [2]江苏集萃托普索先进催化技术研究所,江苏苏州215132 [3]江苏集萃托普索清洁能源研发有限公司,江苏苏州215132 [4]内蒙古科技大学分析测试中心,内蒙古包头014010

出　　处：《洁净煤技术》2024年第11期75-81,共7页Clean Coal Technology

基　　金：江苏省自然科学基金资助项目(BK20210001)。

摘　　要：选择性催化还原(SCR)是目前应用最广的烟气脱硝技术,其核心为SCR脱硝催化剂。燃煤烟气飞灰中由于As元素的存在会导致催化剂的中毒失活及使用寿命大幅下降,影响SCR系统稳定高效运行。为提升V-Mo/Ti催化剂的抗As中毒性能,制备了不同MoO_(3)质量分数(3%和7%)的V-Mo/Ti催化剂。随后,采用模拟中毒法,制备了As中毒催化剂。通过XRF、ICP、XRD、N_(2)-吸附脱附、H_(2)-TPR、XPS、NH_(3)-TPD和O_(2)-TPD,考察了新鲜催化剂和As中毒后催化剂的理化性质。通过固定床微型反应评价装置,测试了各催化剂在230~410℃烟气温度区间内的脱硝效率和N_(2)O生成量。结果显示,As会影响V-Mo/Ti催化剂的孔结构,降低催化剂的比表面积、孔容、还原性能、酸性性能和化学吸附氧含量,从而降低催化剂的脱硝活性,并促进副产物N2O的生成。增加MoO_(3)含量,催化剂的孔结构得到改善,比表面积和孔容下降幅度降低,还原性能和表面酸量提升,催化剂的脱硝活性增加。较高的MoO_(3)质量分数(7%)可以减轻As对催化剂的毒化作用。与V-Mo(3)/Ti-As催化剂相比,V-Mo(7)/Ti-As催化剂在230~410℃烟气温度区间内的脱硝效率更高,说明V-Mo(7)/Ti催化剂具备较强的抗As中毒性能。Selective catalytic reduction(SCR)is currently the most widely used flue gas denitrification technology,with the core method SCR denitrification catalyst.The presence of the As element in coal combustion fly ash can cause catalyst poisoning and a significant decrease in service life,affecting the stable and efficient operation of the SCR system.V-Mo/Ti catalysts with different mass fractions of MoO_(3)(3%and 7%)were prepared,in order to improve the As resistance of V-Mo/Ti catalyst.The As poisoned catalysts were also prepared by wet impregnation method.The physiochemical properties of the fresh and As-poisoned catalysts were characterized by XRF,ICP,XRD,N_(2)-physisorption,H_(2)-TPR,XPS,NH_(3)-TPD,and O_(2)-TPD.The NO_(x) conversion and N_(2)O concentration of the different catalysts in the temperature range 230-410 C were tested via a micro fixed-bed reactor.The results show that As has negative influences on the pore structure of the catalyst,and reduces the specific surface area,pore volume,reducibility,acidity,and the amount of Oa of the catalyst.As a result,the catalytic activity of the catalyst declines and the generation of by-product N_(2)O promotes.With the increase of MoO_(3) content,the pore structure of catalyst is improved,the decrease in specific surface area and pore volume is reduced,the reduction performance and surface acid content are increased,and the denitrification activity of catalyst is increased.High mass fraction of MoO_(3)(7%)can reduce the poisoning effect of As on the V-Mo/Ti catalyst.The catalytic performance of V-Mo(7)/Ti-As catalyst is obviously higher than that of the V-Mo(3)/Ti-As catalyst In the other word,the As resistance of V-Mo(7)/Ti catalyst is superior to that of the V-Mo(3)/Ti catalyst.

关 键 词：脱硝 催化剂 砷 平板式 中毒 

分 类 号：TQ426[化学工程] X511[环境科学与工程—环境工程]