准东煤飞灰对SCR催化剂活性影响的实验研究
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摘要
锅炉燃用准东煤时,SCR催化剂在长时间运行后容易出现堵塞、磨损和破碎等问题。利用商用的蜂窝状催化剂(V_2O_5-WO_3/TiO_2),通过搭建的携带流积灰和磨蚀系统,模拟了SCR催化剂的实际运行工况,结合催化剂活性测试系统和机械强度、SEM、EDX、XRF等测量手段,分析了致使SCR催化剂失活的主要因素。结果表明:催化剂的机械强度会因磨损而降低,且质量损失速率随磨蚀时间增加而减少。而积灰时间增加时,脱硝效率会随之降低,且变化趋势与烟气流速和积灰浓度有关。
SCR is an effective technology of flue gas denitrification. However, SCR catalyst will be plugged, abraded and crushed after long-time operation while firing Zhundong coals. In this paper, the commercial honeycomb catalyst(V_2O_5-WO_3/TiO_2) was used, and the deactivation behaviors of SCR catalyst was analyzed by fouling erosion systems combined with an efficiency-testing system. Mechanical strength measurement, SEM, EDX and XRF analysis were conducted. The results show that mechanical strength of SCR catalyst will decrease for erosion, and mass loss rate will accelerate with the increase of erosion time. In addition, denitration efficiency decreases with an increase in fouling time, and the trend depends on flue gas velocity and fouling concentration.
SCR is an effective technology of flue gas denitrification. However, SCR catalyst will be plugged, abraded and crushed after long-time operation while firing Zhundong coals. In this paper, the commercial honeycomb catalyst(V_2O_5-WO_3/TiO_2) was used, and the deactivation behaviors of SCR catalyst was analyzed by fouling erosion systems combined with an efficiency-testing system. Mechanical strength measurement, SEM, EDX and XRF analysis were conducted. The results show that mechanical strength of SCR catalyst will decrease for erosion, and mass loss rate will accelerate with the increase of erosion time. In addition, denitration efficiency decreases with an increase in fouling time, and the trend depends on flue gas velocity and fouling concentration.
引文
[1] 齐晓宾,宋国良,宋维健,等.准东高碱煤气化过程中碱金属迁移与结渣特性实验研究[J].燃料化学学报,2015,43(8):906-913.
[2] LIN S,YOSHIZO SUZUKI,HATANO H.Effect of Pressure on NOx Emission from Char Particle Combustion[J].Energy & Fuels,2002,16 (3):634-639.
[3] 吴碧君,刘晓勤,王述刚,等.烟气脱硝工艺及其化学反应机理[J].电力科技与环保,2006,22 (2):29-31.
[4] 钟秦.燃煤烟气脱硫脱硝技术及工程实例[M].1版.北京:化学工业出版社,2007.
[5] LIETTI L,RAMIS G,BERTI F,et al.Chemical,structural and mechanistic aspects on NOx SCR over commercial and model oxide catalysts[J].Catalysis Today,1998,42 (1–2):101-116.
[6] 岑可法.燃烧理论与污染控制[M].1版.北京:机械工业出版社,2004.
[7] CHOO S T,LEE Y G NAM I S,et al.Characteristics of V2O5 supported on sulfated TiO2 for selective catalytic reduction of NO by NH3[J].Applied Catalysis A General,2000,200 (1–2):177-188.
[8] 苏亚欣,毛玉如,徐璋.燃煤氮氧化物排放控制技术[M].1版.北京:化学工业出版社,2005.
[9] 王晓梅.W-Mn-TiO2复合金属氧化物的低温NH3-SCR性能的研究[D].大连:大连理工大学,2015.
[10] 钟标城.Fe-Mn复合金属氧化物催化剂低温SCR脱除NOx研究[D].广州:华南理工大学,2011.
[11] 沈伯雄,刘亭,杨婷婷,等.低温SCR脱硝催化剂过渡金属氧化物改性及硫中毒失活机制研究[J].环境科学,2009,30 (8):2204-2209.
[12] 辛勤.现代催化研究方法[M].1版.北京:科学出版社,2009.
[13] 赵毅,朱振峰,贺瑞华,等.V2O5-WO3/TiO2基SCR催化剂的研究进展[J].材料导报,2009,23 (1):28-31.
[14] 云端,宋蔷,姚强.V2O5-WO3/TiO2 SCR催化剂的失活机理及分析[J].煤炭转化,2009,32 (1):91-96.
[15] DENG L,LIU X,CAO P,et al.A study on deactivation of V2O5-WO3-TiO2 SCR catalyst by alkali metals during entrained-flow combustion[J].Journal of the Energy Institute,2017,90 (5):743-751.
[16] P?RVULESCU VI,GRANGE P,DELMON B.Catalytic removal of NO[J].Catalysis Today,1998,46 (4):233-316.
[2] LIN S,YOSHIZO SUZUKI,HATANO H.Effect of Pressure on NOx Emission from Char Particle Combustion[J].Energy & Fuels,2002,16 (3):634-639.
[3] 吴碧君,刘晓勤,王述刚,等.烟气脱硝工艺及其化学反应机理[J].电力科技与环保,2006,22 (2):29-31.
[4] 钟秦.燃煤烟气脱硫脱硝技术及工程实例[M].1版.北京:化学工业出版社,2007.
[5] LIETTI L,RAMIS G,BERTI F,et al.Chemical,structural and mechanistic aspects on NOx SCR over commercial and model oxide catalysts[J].Catalysis Today,1998,42 (1–2):101-116.
[6] 岑可法.燃烧理论与污染控制[M].1版.北京:机械工业出版社,2004.
[7] CHOO S T,LEE Y G NAM I S,et al.Characteristics of V2O5 supported on sulfated TiO2 for selective catalytic reduction of NO by NH3[J].Applied Catalysis A General,2000,200 (1–2):177-188.
[8] 苏亚欣,毛玉如,徐璋.燃煤氮氧化物排放控制技术[M].1版.北京:化学工业出版社,2005.
[9] 王晓梅.W-Mn-TiO2复合金属氧化物的低温NH3-SCR性能的研究[D].大连:大连理工大学,2015.
[10] 钟标城.Fe-Mn复合金属氧化物催化剂低温SCR脱除NOx研究[D].广州:华南理工大学,2011.
[11] 沈伯雄,刘亭,杨婷婷,等.低温SCR脱硝催化剂过渡金属氧化物改性及硫中毒失活机制研究[J].环境科学,2009,30 (8):2204-2209.
[12] 辛勤.现代催化研究方法[M].1版.北京:科学出版社,2009.
[13] 赵毅,朱振峰,贺瑞华,等.V2O5-WO3/TiO2基SCR催化剂的研究进展[J].材料导报,2009,23 (1):28-31.
[14] 云端,宋蔷,姚强.V2O5-WO3/TiO2 SCR催化剂的失活机理及分析[J].煤炭转化,2009,32 (1):91-96.
[15] DENG L,LIU X,CAO P,et al.A study on deactivation of V2O5-WO3-TiO2 SCR catalyst by alkali metals during entrained-flow combustion[J].Journal of the Energy Institute,2017,90 (5):743-751.
[16] P?RVULESCU VI,GRANGE P,DELMON B.Catalytic removal of NO[J].Catalysis Today,1998,46 (4):233-316.