钙镁氧化物及氢氧化物脱除SO3协同防治催化剂低温失活  

Synergetic control catalyst deactivation at low temperature through SO3 removal by calcium magnesium oxide and hydroxide

作　　者：何川[1] 宋玉宝[1] 马云龙 王乐乐[1] 卞子君 HE Chuan;SONG Yubao;MA Yunlong;WANG Lele;BIAN Zijun(Xi'an Thermal Power Research Institute Co.,Ltd.Suzhou Branch,Suzhou 215153,Jiangsu,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

出　　处：《化工进展》2020年第11期4619-4624,共6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-17-TYK12)。

摘　　要：在实验室中试台架上,开展了Ca(OH)2、CaO、Mg(OH)2和MgO四种碱基吸附剂粉体喷射脱除烟气SO3的实验,研究了碱基吸附剂脱除烟气SO3的影响因素,探究了碱基吸附剂脱除SO3技术对选择性催化还原(SCR)催化剂硫酸氢铵失活温度的影响。采用比表面积法(BET)、傅里叶红外光谱(FTIR)等手段对吸附剂进行表征,以判断吸附产物和吸附机理。结果显示:碱基氢氧化物吸附剂的SO3脱除效果优于碱基氧化物吸附剂;Mg基吸附剂优于Ca基吸附剂;当烟气中SO3浓度为35μL/L时,Mg(OH)2含量为600mg/m^3时具有最高的SO3脱除效率,达到95%左右。对低温失活后的SCR催化剂进行FTIR表征证实了催化剂表面硫酸氢铵的生成。此外,通过碱基吸附剂降低烟气中SO3浓度后,SCR催化剂在低温时的失活得到了显著缓解,可明显降低SCR催化剂的硫酸氢铵失活温度约20℃,有助于挖掘机组调峰深度。The experiments of SO3 removal from flue gas by spraying Ca(OH)2,CaO,Mg(OH)2 and MgO based sorbent powders were carried out on a pilot reactor.The effect of SO3 removal by the base adsorbents on the SCR catalyst ammonium bisulfate deactivation temperature was investigated.The adsorbents were characterized by BET and FTIR to determine the adsorption products and the adsorption mechanism.The results indicated that the SO3 removal efficiency of the alkaline based hydroxides was higher than that of the alkaline based oxides,and the Mg based adsorbent was better than the Ca based adsorbent.When the concentration of SO3 in flue gas was 35μL/L and the content of Mg(OH)2 was 600mg/m^3,the highest SO3 removal efficiency of 95%was achieved.The formation of ammonium bisulfate on the surface of the SCR catalyst was confirmed by FTIR.In addition,the reduction of SO3 concentration in flue gas can reduce the deactivation temperature of the ammonium bisulfate SCR catalyst by about 20℃,and hence the deactivation of the SCR catalyst at low temperature had been significantly alleviated,which could help to expand the peak regulation space of the coal-fired unit.

关 键 词：烟道气 超低排放 选择性催化还原 硫酸氢铵 三氧化硫 吸附剂 化学计量比 

分 类 号：X511[环境科学与工程—环境工程]