Mn-Fe/DPC催化剂的NH3-SCR脱硝反应动力学研究  

Kinetic study of selective catalytic reduction of NO by NH3 on Mn-Fe/DPC catalyst

作　　者：刘向辉[1] 杨巧文[1] 王泽宇 刘阳峥 Liu Xianghui;Yang Qiaowen;Wang Zeyu;Liu Yangzheng(School of Chemical&Environmental Engineering,China University of Mining&Technology-Beijing,Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)化学与环境工程学院,北京100083

出　　处：《矿业科学学报》2020年第4期452-457,共6页Journal of Mining Science and Technology

基　　金：中央高校基本科研业务费专项资金(2010Y14);北京市科技计划(Z161100002616038);中国矿业大学(北京)大学生创新计划(201703654)。

摘　　要：以白云石凹凸棒土(DPC)为载体,采用浸渍法负载Mn和Fe制备Mn-Fe/DPC脱硝催化剂。通过考察120℃~180℃下NO转化速率随NH3、NO和O2浓度的变化情况,借助微分反应系统计算各组分的反应级数及活化能等参数。结果表明:NH3起始浓度对NO转化速率影响不大,可以归根于NH3能够迅速在催化剂表面吸附;NO和O2初始浓度越高,催化剂中NO转化速率越快,表明NO和O2主要以气态参与反应;在120℃~180℃温度下,Mn-Fe/DPC催化剂的NH3、NO、O2的反应级数分别为0、1、0.39,从而得到NO转化速率方程为rNO=k[NO][O2]^0.39。通过计算得到该反应的表观反应活化能为40.25 kJ/mol,接近商业钒钛系催化剂和Fe基分子筛类催化剂。Mn-Fe/DPC were prepared by precipitation.The intrinsic kinetics model for Mn-Fe/DPC catalyst was investigated with little internal and external diffusion influence by the way of steady-state dynamics from 120℃~180℃.The apparent activation energy and the reaction order to NH3,NO and O2 was also promoted.The results showed that the initial concentration of NH3 has little effect on the conversion rate of NO,which could be attributed to the rapid adsorption of NH3 on the catalyst surface.Meanwhile,the conversion rate of NO increased with initial concentration of NO and O2,indicating that NO and O2 reacted mainly in gaseous state.The results indicated that the conversion rate of NO increases with initial concentration of NO and O2,NH3 is absorbed and activated quickly on the active sites of catalyst surface.The NH3-SCR reaction over Mn-Fe/DPC exhibits first-order with respect to NO,zero-order to NH3,and nearly 0.39-order to O2 at 120℃~180℃,thus the equation for the NO conversion rate is rNO=k[NO][O2]0.39.The apparent activation energy of catalyst is 40.25 kJ/mol,which is similar to commercial vanadium-titanium based catalyst and molecular sieve based catalysts with Fe.

关 键 词：白云石凹凸棒土 脱硝 动力学 选择性催化还原(SCR) 

分 类 号：TQ[化学工程]