垃圾焚烧脱硝催化剂钙镁失活与活性恢复特性  

Characteristics of calcium and magnesium deactivation and regeneration of waste incineration SCR catalyst

作　　者：何川[1] 吴国勋 李昂 张发捷 卞子君 卢承政[1] 王丽朋[1] 赵民 HE Chuan;WU Guoxun;LI Ang;ZHANG Fajie;BIAN Zijun;LU Chengzheng;WANG Lipeng;ZHAO Min(Xi’an Thermal Power Research Institute Co.,Ltd.,Suzhou Branch,Suzhou 215153,Jiangsu,China;Huaneng International Power Co.,Ltd.,Dezhou Power Plant,Dezhou 253006,Shandong,China)

机构地区：[1]西安热工研究院有限公司苏州分公司,江苏苏州215153 [2]华能国际电力股份有限公司德州电厂,山东德州253006

出　　处：《化工进展》2023年第5期2413-2420,共8页Chemical Industry and Engineering Progress

基　　金：西安热工研究院有限公司自立科技项目(GU-21-TYK22)。

摘　　要：以国内某垃圾焚烧电厂失活选择性催化还原(SCR)脱硝催化剂为研究对象,针对Ca、Mg失活因素进行失活特性研究,同时探讨垃圾焚烧失活催化剂的活性恢复方法与原理。对新催化剂、失活催化剂和再生催化剂样品进行脱硝性能对比测试。利用扫描电子显微镜(SEM)、N_(2)吸附-脱附和X射线荧光光谱(XRF)表征催化剂样品的表面结构和化学组成;进行X射线光电子能谱(XPS)和傅里叶变换红外光谱(FTIR)测试,分析失活和再生催化剂的化学形态变化;采用NH3程序升温脱附(NH3-TPD)和H_(2)程序升温还原(H_(2)-TPR)研究催化剂的酸性位点变化和氧化还原特性。结果表明,由于受到Ca、Mg等失活因素的影响,失活催化剂脱硝性能大幅下降,300~350℃温度区间内的脱硝效率从新催化剂的95%以上下降到80%左右;利用“EDTA清洗+活性物质负载”方法再生后的催化剂脱硝能力明显恢复,RegCat样品在300~350℃温度区间的脱硝效率可恢复至新催化剂水平。Ca、Mg在催化剂表面形成性质稳定的硫酸盐,同时消耗大量表面活性氧,从而抑制催化剂的活性。此外,Ca还会以CaO的形式在催化剂表面沉积,对催化剂造成物理失活。活性恢复后的催化剂表面Ca、Mg、S等有害物质被有效去除,催化剂表面酸性位点和氧化性能得以明显恢复。The deactivation characteristics of Ca and Mg of selective catalytic reduction(SCR)denitration catalyst were studied on the catalyst from a domestic waste incineration power plant,and the activity recovery method and mechanism of the waste catalyst were discussed.The denitration performance of new catalyst,deactivated catalyst and regenerated catalyst samples was compared and tested.Scanning electron microscopy(SEM),N_(2)adsorption-desorption and X-ray fluorescence spectroscopy(XRF)were used to characterize the surface structure and chemical composition of the catalyst samples.X-ray photoelectron spectroscopy(XPS)and Fourier transform infrared spectroscopy(FTIR)were used to analyze the chemical changes between the deactivated and regenerated catalysts,while NH3 temperature programmed desorption(NH3-TPD)and H_(2)temperature programmed reduction(H_(2)-TPR)were used to study the acid site changes and redox characteristics of the catalysts.The results showed that due to the deactivation of Ca and Mg,the denitration performance of the deactivated catalyst decreased significantly,and the denitration efficiency in the temperature range of 300-350℃decreased from more than 95%of the new catalyst to about 80%.However,the denitration capacity was significantly restored by using the method of“EDTA cleaning+active material loading”,and the denitration efficiency of RegCat could be restored to the level of new catalyst in the temperature range of 300-350℃.Ca and Mg formed sulfate on the surface of the catalyst,and consumed a large amount of surface active oxygen,so as to lower the activity of the catalyst.In addition,Ca would also deposit on the catalyst surface in the form of CaO,causing physical deactivation of the catalyst.After the activity recovery,the harmful substances such as Ca,Mg and S on the catalyst surface were effectively removed,and the acid sites and oxidation properties of the catalyst surface were significantly restored.

关 键 词：烟道气 选择催化还原 催化剂 失活 活性 碱土金属 

分 类 号：X511[环境科学与工程—环境工程]