失活SCR烟气脱硝催化剂再生工艺工业试验研究
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摘要
SCR烟气脱硝催化剂在广泛使用的同时,失活催化剂大量产生。对失活催化剂进行再生,经济和环保意义重大。以某燃煤电厂运行了近25 000 h的失活SCR烟气脱硝催化剂为研究对象,在分析催化剂失活原理基础上,对催化剂再生过程中主要影响因素(压缩空气吹灰压力、超声清洗时间、清洗液硫酸浓度等)进行研究,并介绍失活催化剂再生处理步骤,包括清灰、预清洗、深度清洗、活性组分负载、热处理等。各类检测结果表明,采用所研发的方案进行再生,失活催化剂中碱金属、碱土金属及硫酸盐等污染物被有效清除,催化剂通孔率高达98.7%,比表面积明显恢复,相对活性提升至99%,抗压强度及单层催化剂SO_2/SO_3转化率符合使用要求,即失活脱硝催化剂各理化、工艺性能及其机械强度得到了有效恢复,可以再安装于脱硝反应器中继续使用。
While the SCR flu-gas de-NO_x catalyst has been used widely, a large number of deactivated catalyst are produced. Thus it is of great importance to regenerate those deactivated catalysts for economic purpose and environmental protection. The deactivated SCR flue gas denitrification catalyst which has been put into operation for nearly 25 000 hours in a coal-fired power plant is taken as the research object. Based on the deactivation principle of the catalyst, the main influencing factors(compressed air soot blowing pressure, ultrasonic cleaning time, etc.) in the regeneration process of the catalyst are analyzed. Then the regeneration process of deactivated catalyst is introduced, including ash removal, pre-cleaning, deep cleaning, active component loading, heat treatment and so on. The various testing results show that the pollutants such as alkali metal, alkaline earth metal and sulfate in the deactivated catalyst are removed effectively after regeneration process with the developed technology. The through-cell ratio of the catalyst reaches up to 98.7%. The specific surface area is obviously recovered and the relative activity of the regenerated catalyst is remarkably improved to 99%. The compressive strength and the single layer SO_2/SO_3 conversion rate of the catalyst are able to satisfy the application requirements, which means the physicochemical properties, the process performance and the mechanical strength of regenerated catalyst are effectively recovered for the continuing usage in the denitrification reactor.
While the SCR flu-gas de-NO_x catalyst has been used widely, a large number of deactivated catalyst are produced. Thus it is of great importance to regenerate those deactivated catalysts for economic purpose and environmental protection. The deactivated SCR flue gas denitrification catalyst which has been put into operation for nearly 25 000 hours in a coal-fired power plant is taken as the research object. Based on the deactivation principle of the catalyst, the main influencing factors(compressed air soot blowing pressure, ultrasonic cleaning time, etc.) in the regeneration process of the catalyst are analyzed. Then the regeneration process of deactivated catalyst is introduced, including ash removal, pre-cleaning, deep cleaning, active component loading, heat treatment and so on. The various testing results show that the pollutants such as alkali metal, alkaline earth metal and sulfate in the deactivated catalyst are removed effectively after regeneration process with the developed technology. The through-cell ratio of the catalyst reaches up to 98.7%. The specific surface area is obviously recovered and the relative activity of the regenerated catalyst is remarkably improved to 99%. The compressive strength and the single layer SO_2/SO_3 conversion rate of the catalyst are able to satisfy the application requirements, which means the physicochemical properties, the process performance and the mechanical strength of regenerated catalyst are effectively recovered for the continuing usage in the denitrification reactor.
引文
[1]刘予,王沛迪,王雪涛,等.燃煤发电机组SCR脱硝催化剂类型与失活的防治措施[J].上海电力学院学报, 2014, 30(3):287–291.LIU Yu, WANG Peidi, WANG Xuetao, et al. Coal-fired generating units SCR denitration catalyst type inactivation and prevention measures[J]. Journal of Shanghai University of Electric Power, 2014,30(3):287–291.
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[7]王平,林海波,姚友工,等. SCR催化剂再生技术在燃煤电厂的应用[J].中国电力, 2015, 48(4):40–43.WANG Ping, LIN Haibo, YAO Yougong, et al. Application of SCR catalyst regeneration technology in coal-fired power plants[J].Electric Power, 2015, 48(4):40–43.
[8]沈艳梅,魏书洲,崔智勇.造成SCR脱硝催化剂失活的关键物质及预防[J].中国电力, 2016, 49(4):1–5.SHEN Yanmei, WEI Shuzhou, CUI Zhiyong. The key substances causing SCR denitration catalyst deactivation and the preventive measures[J]. Electric Power, 2016, 49(4):1–5.
[9]CHEN Liang, LI Junhua, GE Maofa. The poisoning effect of alkali metals doping over nano V2O5–WO3/TiO2catalysts on selective catalytic reduction of NOx by NH3[J]. Chemical Engineering Journal,2011, 170(2-3):531–537.
[10]商雪松,陈进生,姚源,等.商业SCR烟气脱硝催化剂钙中毒研究[J].环境工程学报, 2013, 7(2):624–630.SHANG Xuesong, CHEN Jinsheng, YAO Yuan,et al. Study on calcium poisoning of commercial SCR de-NOxcatalyst[J]. Chinese Journal of Environmental Engineering, 2013, 7(2):624–630.
[11]强华松,刘清才.燃煤电厂SCR脱硝催化剂的失活与再生[J].材料导报, 2008, 22(S3):285–287.QIANG Huasong, LIU Qingcai. Deactivation and regeneration of SCR de-NOx catalyst[J]. Materials Review, 2008, 22(S3):285–287.
[12]BENSON S A, LAUMB J D, CROCKER C R, et al. SCR catalyst performance in flue gases derived from subbituminous and lignite coals[J]. Fuel Processing Technology, 2005, 86(5):577–613.
[13]王宝冬,汪国高,刘斌,等.选择性催化还原脱硝催化剂的失活、失效预防、再生和回收利用研究进展[J].化工进展, 2013, 32(S1):133 –139.WANG Baodong, WANG Guogao, LIU Bin, et al. Development of SCR catalyst deactivation, regeneration and recycling[J]. Chemical Industry and Engineering Progress, 2013, 32(S1):133–139.
[14]李树田.燃煤锅炉烟气SCR脱硝催化剂再生工程实践[J].发电设备, 2013, 27(2):133–135.LI Shutian. Regeneration practice of catalyst in SCR denitration of boiler flue gas[J]. Power Equipment, 2013, 27(2):133–135.
[2]余岳溪,廖永进,束航,等. SO2与H2O对商用钒钨钛脱硝催化剂毒化作用综述[J].中国电力, 2016, 49(12):168–173.YU Yuexi, LIAO Yongjin, SHU Hang, et al. Review of SO2 and H2O poisoning over commercial vanadium-titanium catalysts in the selective catalytic reduction denitration[J]. Electric Power, 2016,49(12):168–173.
[3]盘思伟,杨建波,陈冬林,等. SCR脱硝催化剂动态再生试验研究[J].中国电力, 2014, 47(8):150–153.PAN Siwei, YANG Jianbo, CHEN Donglin,et al. Experimental study on regeneration of SCR de-NOxcatalysts[J]. Electric Power,2014, 47(8):150–153.
[4]张立,陈崇明,王平. SCR脱硝催化剂的再生与回收[J].电站辅机,2012, 33(3):27–30.ZHANG Li, CHEN Chongming, WANG Ping. Regeneration and recovery of SCR catalyst de-NOx[J]. Power Station Auxiliary Equipment, 2012, 33(3):27–30.
[5]张耀,李薇.燃煤锅炉脱硝催化剂再生技术研究进展[J].电力科技与环保, 2014, 30(4):20–22.ZHANG Yao, LI Wei. Progress of study on regeneration technology of coal-fired boiler denitrization catalyst[J]. Electric Power Technology and Environmental Protection, 2014, 30(4):20–22.
[6]吴凡,段竞芳,夏启斌,等. SCR脱硝失活催化剂的清洗再生技术[J].热力发电, 2012, 41(5):95–98.WU Fan, DUAN Jingfang, XIA Qibin, et al. Cleaning regeneration technology used for SCR catalysis in flue gas denitrification[J].Thermal Power Generation, 2012, 41(5):95–98.
[7]王平,林海波,姚友工,等. SCR催化剂再生技术在燃煤电厂的应用[J].中国电力, 2015, 48(4):40–43.WANG Ping, LIN Haibo, YAO Yougong, et al. Application of SCR catalyst regeneration technology in coal-fired power plants[J].Electric Power, 2015, 48(4):40–43.
[8]沈艳梅,魏书洲,崔智勇.造成SCR脱硝催化剂失活的关键物质及预防[J].中国电力, 2016, 49(4):1–5.SHEN Yanmei, WEI Shuzhou, CUI Zhiyong. The key substances causing SCR denitration catalyst deactivation and the preventive measures[J]. Electric Power, 2016, 49(4):1–5.
[9]CHEN Liang, LI Junhua, GE Maofa. The poisoning effect of alkali metals doping over nano V2O5–WO3/TiO2catalysts on selective catalytic reduction of NOx by NH3[J]. Chemical Engineering Journal,2011, 170(2-3):531–537.
[10]商雪松,陈进生,姚源,等.商业SCR烟气脱硝催化剂钙中毒研究[J].环境工程学报, 2013, 7(2):624–630.SHANG Xuesong, CHEN Jinsheng, YAO Yuan,et al. Study on calcium poisoning of commercial SCR de-NOxcatalyst[J]. Chinese Journal of Environmental Engineering, 2013, 7(2):624–630.
[11]强华松,刘清才.燃煤电厂SCR脱硝催化剂的失活与再生[J].材料导报, 2008, 22(S3):285–287.QIANG Huasong, LIU Qingcai. Deactivation and regeneration of SCR de-NOx catalyst[J]. Materials Review, 2008, 22(S3):285–287.
[12]BENSON S A, LAUMB J D, CROCKER C R, et al. SCR catalyst performance in flue gases derived from subbituminous and lignite coals[J]. Fuel Processing Technology, 2005, 86(5):577–613.
[13]王宝冬,汪国高,刘斌,等.选择性催化还原脱硝催化剂的失活、失效预防、再生和回收利用研究进展[J].化工进展, 2013, 32(S1):133 –139.WANG Baodong, WANG Guogao, LIU Bin, et al. Development of SCR catalyst deactivation, regeneration and recycling[J]. Chemical Industry and Engineering Progress, 2013, 32(S1):133–139.
[14]李树田.燃煤锅炉烟气SCR脱硝催化剂再生工程实践[J].发电设备, 2013, 27(2):133–135.LI Shutian. Regeneration practice of catalyst in SCR denitration of boiler flue gas[J]. Power Equipment, 2013, 27(2):133–135.