改性炼钢污泥催化剂的催化脱硝性能  

Study of the catalytic denitrification activity of a modified steelmaking sludge catalyst

作　　者：田京雷 侯环宇 郭泽锋 陈靖 邢奕 苏伟 TIAN Jing-lei;HOU Huan-yu;GUO Ze-feng;CHEN Jing;XING Yi;SU Wei(School of Environmental Science and Engineering,Tianjin University,Tianjin 300072,China;HBIS Group Co.Ltd.,Shijiazhuang 050023,China;School of Energy and Environmental Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]天津大学环境科学与工程学院,天津300072 [2]河钢集团有限公司,石家庄050023 [3]北京科技大学能源与环境工程学院,北京100083

出　　处：《工程科学学报》2023年第3期499-508,共10页Chinese Journal of Engineering

基　　金：河钢集团有限公司科技计划重点资助项目(HG2020204-2)。

摘　　要：选择性催化还原技术是工业烟气脱硝技术中最常用的烟气脱硝方法.但催化剂的制备过程较为复杂,并且制备成本较高.本文以钢铁企业在生产过程中产生的炼钢污泥作为原料,采用焙烧改性、硫酸改性和硫酸–焙烧改性三种不同方法对其进行处理,制备了一种用于选择性催化还原氮氧化物的新型催化剂.采用比表面积分析法(BET)、扫描电镜分析(SEM)、X射线衍射分析(XRD)、X射线荧光光谱分析(XRF)和NH3程序升温脱附分析(NH_(3)-TPD)等表征手段,对改性前后炼钢污泥催化剂物理化学性质的变化进行分析研究.结果表明:催化剂的主要活性组分为Fe、Mn、V、Ti;焙烧改性对催化剂活性具有一定的提升效果,可以使催化剂中的Fe_(3)O_(4)转化为具有更好脱硝活性的α-Fe_(2)O_(3);硫酸改性后的催化剂具有优异的催化活性,300℃时可以达到88.5%的脱硝效率;硫酸改性改变了催化剂表面形貌,减小了晶粒尺寸,生成了大量的硫酸盐物种,给催化剂表面提供了更多酸性位点,从而促进催化性能的提升.该研究为低成本脱硝催化剂的开发提供了基础,促进了冶金工业的清洁生产.The most commonly used method for industrial flue gas denitrification is selective catalytic reduction(SCR).However,the catalyst preparation is complex and expensive.The iron and steel industry produces large amounts of waste containing metal oxides that can be used as active catalytic components for SCR of nitrogen oxides.In this study,a novel catalyst for SCR of nitrogen oxides was prepared by roasting,sulfuric acid,and sulfuric acid-roasting modification of steelmaking sludge,which is used as the raw material.The physical and chemical properties of the catalysts from steelmaking sludge before and after modification were analyzed using Brunauer-Emmett-Teller analysis,scanning electron microscopy,X-ray diffraction,X-ray fluorescence,and temperature-programmed desorption of ammonia.It has been revealed that Fe,Mn,V,and Ti are the main active groups of the catalyst.Calcination can transform Fe_(3)O_(4) toα-Fe_(2)O_(3) with better denitrification activity,thus improving the catalyst reactivity.A high calcination temperature can cause a collapse of the pore structure of the catalyst,thereby decreasing the surface area and active sites and ultimately reducing the catalytic activity.The catalyst modified at the optimum calcination temperature of 400°C has the highest catalytic activity at 350°C and a denitrification efficiency of 57.6%.The sulfuric acid-modified catalyst has excellent catalytic activity.Sulfuric acid impregnation changes the surface morphology of the catalyst,reduces the grain size,generates numerous sulfate species,provides more acidic sites on the catalyst surface,and promotes catalyst performance.The 9 mol·L^(−1) sulfuric acid-modified catalyst has the highest denitrification efficiency at 300°C.Compared with the unmodified catalyst,the denitrification efficiency significantly increased from 22.9%to 88.5%.Conversely,a denitrification efficiency of 72.9%is measured for the catalyst modified by sulfuric acid and roasting modification,which is lower than that of the sulfuric acid-modified catal

关 键 词：炼钢污泥 硫酸改性 选择性催化还原 氮氧化物 清洁生产 

分 类 号：X511[环境科学与工程—环境工程]