失活V2O5-WO3/TiO2 SCR脱硝催化剂的再生方法  

Regeneration of Deactivated V2O5-WO3/TiO2 Selective Catalytic Reduction Denitration Catalyst

作　　者：周凯 李国波 陆斌 王圣 张亚平 滕玉婷 李娟 ZHOU Kai;LI Guobo;LU Bid;WANG Sheng;ZHANG Yapinf;TENG Yiuing;LI Juan(Guodian Environmental Protection Research Institute Go. Ltd,Nanjing 210031,China;Key Laboratory for Energy ThermalConversion and Control of Ministry of Education,Southeast University,Nanjing 210096,China)

机构地区：[1]国电环境保护研究院有限公司,南京210031 [2]东南大学能源与环境学院,能源热转换及其过程测控教育部重点实验室,南京210096

出　　处：《硅酸盐学报》2019年第7期916-923,共8页Journal of The Chinese Ceramic Society

基　　金：江苏省重点研发计划项目(BE2017716);环保公益性行业科研项目(2016YFC0208102);国家重点研发计划(2017YFB0603201)

摘　　要：针对模拟钙中毒的商业V2O5-WO3/TiO2选择性催化还原(SCR)脱硝催化剂,选用络合剂乙二胺四乙酸(EDTA)、表面活性剂十二烷基苯磺酸(LAS)两种清洗剂配合超声波震荡方法对其进行清洗再生,并结合活性测试以及多种表征手段,研究清洗剂浓度及组配方式和清洗时间对钙中毒催化剂的活性恢复及物化性能变化的影响。结果表明:0.01 mol/L的EDTA水溶液辅助超声波震荡清洗30 min取得较好的再生效果,清洗再生后的催化剂脱硝活性在400℃达到85%以上,恢复到新鲜催化剂活性的近90%,并且CaSO4的去除率达到92%以上,钒和钨的残余率分别为99.4%和98.3%。此外,增加少量的LAS可以微弱地提升CaSO4的去除率和催化剂的脱硝活性。清洗再生机理研究表明,EDTA可以较好地恢复催化剂的微孔结构、去除表面条带状硫酸钙涂覆层、恢复催化剂表面Lewis酸位以及1 680 cm-1处的Br?nsted酸位。EDTA和LAS均可以有效提高催化剂的氧化还原能力。For commercial V2O5-WO3/TiO2 selective catalytic reduction (SCR) denitration catalyst for simulating calcium poisoning, two complexing agents, i.e., ethylenediaminetetraacetic acid (EDTA) and surfactant Dodecylbenzenesulfonic acid (LAS), were selected to clean and regenerate the calcium-poisoned samples with the assistance of ultrasonic oscillation. The effects of concentration of cleaning agent, the combined ratio of cleaning agents and cleaning time on the catalytic performance and physio-chemical properties of the poisoned catalysts were investigated. The results show that aqueous solution of 0.01 mol/L EDTA is assisted by ultrasonic cleaning for 30 min to obtain the effective regeneration. The NOX conversion of Ca-poisoned catalyst can reach > 85% at 400 ℃, the recovery of the fresh counterpart can be 90%, the removal rate of CaSO4 is over 92% and the residual rates of vanadium and tungsten are 99.4% and 98.3%, respectively. The addition of a small amount of LAS can improve the removal rate of CaSO4 and the denitration activity of the catalyst. In addition, the cleaning and regeneration mechanism was also analyzed. It is indicated that EDTA can restore the microporous structure of the catalyst, remove the surface banded calcium sulfate coating layer and recover the Lewis acid sites and the Bronsted acid sites at 1 680 cm-1. EDTA and LAS both can effectively improve the redox ability of the catalyst.

关 键 词：选择性催化还原 脱硝催化剂 钙中毒 再生 机理 

分 类 号：X701.7[环境科学与工程—环境工程]