摘要
以天然白云鄂博稀土尾矿作为脱硝活性组分,拟薄水铝石(y-Al2O3前驱体)为载体,采用混捏法制备催化剂,并用于CO作为还原剂气氛下的NO的脱除反应;在反应温度为600℃条件下探究催化剂焙烧温度、活性组分与载体质量之比、矿料粒径、CO/NO比例等因素对脱硝效率的影响。通过烟气分析仪计算脱硝率,利用热重、SEM、XRD等技术手段表征催化剂性质和微观结构。结果表明,制备催化剂孔隙发达、比表面积较大,对气体的吸脱附效果较好;催化剂的存在对提高CO还原NO时的脱硝效率具有明显的促进作用。催化剂中的部分Fe、Ce、La、Nd、Pr等组分在高温下容易形成共融体,有利于联合协同催化脱硝反应的进行。脱硝率随焙烧温度的增加呈先上升后下降的趋势;随着CO/NO比例的增加、活性组分与载体之比的加大、矿料粒径的减小,脱硝率均呈现逐渐上升的趋势;在焙烧温度为700℃、活性组分与载体之比为1/1、矿料粒径300~400目制备成型的催化剂、在CO/NO比为1. 4的条件下其脱硝效率可达56. 7%。
By using Bayan Obo rare earth tailings as denitrification activity components,pseudo boehmite(y-Al2O3 precursor) as carrier,the catalysts for reduction of NO by CO were prepared by a kneading method. Under the reaction temperature of 600 ℃,effects of calcination temperature,mass ratio of the active components to the carrier,tailings particle size,CO/NO ratio and other factors on the denitration efficiency were investigated. The denitration rate was calculated by using the flue gas analyzer. The properties and microstructures of the catalysts were characterized by thermogravimetry,SEM and XRD.The results show that the prepared catalysts have well-developed pores and large specific surface area,showing good gas absorption and desorption effect. The presence of the catalysts could obviously improve the denitration efficiency of CO reducing NO. Some Fe,Ce,La,Nd,Pr and other components in the catalysts are easy to form co-melts at high temperature,which is beneficial to the synergistic catalytic denitration reaction. The denitrification rate first increased and then decreased with increasing calcination temperature. As the CO/NO ratio increased,the mass ratio of the active components to the carrier increased and tailings particle size decreased,the denitrification rate increased gradually. When the ratio of CO/NO is 1. 4,the denitration efficiency could reach 56. 7% for the catalyst calcined at 700 ℃,the mass ratio of the active components to the carrier was 1/1 and tailings particle size was 300 ~ 400 mesh.
作者
李娜
张舒宁
梅哲跃
龚志军
罗慧娟
武文斐
张凯
LI Na;ZHANG Shu-ning;MEI Zhe-yue;GONG Zhi-jun;LUO Hui-juan;WU Wen-fei;ZHANG Kai(l.Key Laboratory of Integrated Exploitation of Bayanobo Multi-metal Resources,Baotou 014010,China;l.Colloge of Environment and Energy,Inner Mongolia University of Science and Technology,Baotou 014010,China)
出处
《稀土》
EI
CAS
CSCD
北大核心
2019年第6期88-95,共8页
Chinese Rare Earths
基金
国家自然科学基金项目(51866013)
内蒙古自然科学基金项目(2018MS02013
2019MS02005)
内蒙古科技大学创新基金(2017QDL-B16)
关键词
协同催化脱硝
混捏法
稀土尾矿
CO
NO
synergistic catalytic denitrification
kneading method
rare earth tailings
CO
NO
