SCR脱硝伴生硫酸氢铵对飞灰颗粒特性影响的实验研究
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摘要
选择性催化还原法(selective catalytic reduction,SCR)脱硝过程中伴生硫酸氢氨(ABS)引起的空气预热器堵塞和腐蚀问题尤为严重,这与烟气飞灰的物理性质密切相关。基于此,采用试验方法研究了脱硝过程中伴生ABS对烟气飞灰粒径、吸湿性和粘附力等物理性质的影响。灰分粒径筛分结果表明,ABS的存在使得灰样粒径增大,尤其当硫酸氢铵–灰质量比(R)在1/90以上时增大较为明显。吸湿性实验发现飞灰吸湿率随灰中ABS含量和环境相对湿度的增大而增大,并且两者对飞灰吸湿率的影响具有相互促进的作用。通过自主搭建的飞灰粘附力实验平台研究发现,飞灰粘附力随着粒径范围的增大而减小,而灰粒填充度、相对湿度和ABS含量的增大对其起到促进作用,其中相对湿度和ABS含量影响尤为显著。
The blockage and corrosion of air preheater caused by the associated ammonium bisulfate(ABS) in selective catalytic reduction(SCR) denitration process is particularly serious, which is closely related to the physical properties of flue gas fly ash. Base on it, the effects of ABS on particle size, hygroscopicity and adhesion of fly ash during denitrification were studied. The result of screening shows that ABS increases the overall size of ash particles, especially when ABS-ash mass ratio(R) is above 1/90, the particle size increases obviously. It is found that the moisture absorption rate of fly ash increases with the raise of ABS content and relative humidity, and the effect of them on the moisture absorption rate of fly ash has a mutual promotion effect. Through the self-built experimental platform of fly ash adhesion, it is found the adhesion force of fly ash tends to decrease with the increase of particle size, but the raise of ash particle filling, relative humidity and ABS can promote the adhesion of fly ash, the effect of the relative humidity and ABS content are especially significant.
The blockage and corrosion of air preheater caused by the associated ammonium bisulfate(ABS) in selective catalytic reduction(SCR) denitration process is particularly serious, which is closely related to the physical properties of flue gas fly ash. Base on it, the effects of ABS on particle size, hygroscopicity and adhesion of fly ash during denitrification were studied. The result of screening shows that ABS increases the overall size of ash particles, especially when ABS-ash mass ratio(R) is above 1/90, the particle size increases obviously. It is found that the moisture absorption rate of fly ash increases with the raise of ABS content and relative humidity, and the effect of them on the moisture absorption rate of fly ash has a mutual promotion effect. Through the self-built experimental platform of fly ash adhesion, it is found the adhesion force of fly ash tends to decrease with the increase of particle size, but the raise of ash particle filling, relative humidity and ABS can promote the adhesion of fly ash, the effect of the relative humidity and ABS content are especially significant.
引文
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[12]张玉华,束航,范红梅,等.商业V2O5-WO3/TiO2催化剂SCR脱硝过程中PM2.5的排放特性及影响因素研究[J].中国电机工程学报,2015,35(2):383-389.Zhang Yuhua,Shu Hang,Fan Hongmei,et al.Research on emission characteristics and influencing factors of PM2.5 for selective catalytic reduction based on V2O5-WO3/TiO2 commercial catalysts[J].Proceedings of the CSEE,2015,35(2):383-389(in Chinese).
[13]钟礼金,宋玉宝.锅炉SCR烟气脱硝空气预热器堵塞原因及其解决措施[J].热力发电,2012,41(8):45-47,50.Zhong Lijin,Song Yubao.Air preheater blocking in boiler with SCR denitrification device:reason analysis and solutions[J].Thermal Power Generation,2012,41(8):45-47,50(in Chinese).
[14]刘建民,陈国庆,黄启龙,等.燃煤脱硝机组空气预热器蓄热片表面飞灰沉积板结机理研究[J].中国电机工程学报,2016,36(S1):132-139.Liu Jianmin,Chen Guoqing,Huang Qilong,et al.Study on mechanism of fly ash deposition and hardening on the air preheater regenerative piece surface of the coal-fired and denitration unit[J].Proceedings of the CSEE,2016,36(S1):132-139(in Chinese).
[15]Matsuda S,Kamo T,Kato A,et al.Deposition of ammonium bisulfate in the selective catalytic reduction of nitrogen oxides with ammonia[J].Industrial&Engineering Chemistry Product Research&Development,1982,21(1):48-52.
[16]Krishnan A T,Boehman A L.Selective catalytic reduction of nitric oxide with ammonia at low temperatures[J].Applied Catalysis B:Environmental,1998,18(3-4):189-198.
[17]Muzio L,Bogseth S,Himes R,et al.Ammonium bisulfate formation and reduced load SCR operation[J].Fuel,2017,206:180-189.
[18]Wei J Y,Muzio L,Dunn-Rankin D.Formation temperature of ammonium bisulfate at simulated air preheater conditions[C]//Proceedings of the 5th USCombustion Meeting.San Diego,California:Curran Associates,Inc.,2007.
[19]Menasha J,Dunn-Rankin D,Muzio L,et al.Ammonium bisulfate formation temperature in a bench-scale single-channel air preheater[J].Fuel,2011,90(7):2445-2453.
[20]马双忱,邓悦,吴文龙,等.SCR脱硝过程中硫酸氢铵形成特性实验研究[J],动力工程学报,2016,36(2):143-150.Ma Shuangchen,Deng Yue,Wu Wenlong,et al.Experimental research on ABS formation characteristics in SCRdenitrification process[J].Journal of Chinese Society of Power Engineering,2016,36(2):143-150(in Chinese).
[21]马双忱,邓悦,吴文龙,等.SCR脱硝副产物硫酸氢铵与空预器中飞灰反应特性[J].环境工程学报,2016,10(11):6563-6570.Ma Shuangchen,Deng Yue,Wu Wenlong,et al.Reaction characteristic of by-product ammonium bisulfate from SCR denitrification and fly ash in air preheater[J].Chinese Journal of Environmental Engineering,2016,10(11):6563-6570(in Chinese).
[22]梁登科.脱硝过程伴生硫酸氢氨对于烟气灰颗粒性质影响的实验研究[D].济南:山东大学,2014.Liang Dengke.Experimental research on the effects to flue ash particles characteristics of NH4HSO4 generating during the denitrification process[D].Jinan:Shandong University,2014(in Chinese).
[23]王天鹏.准格尔煤灰粘附机理的实验研究[D].保定:华北电力大学(保定),2008.Wang Tianpeng.Experimental study for the adhesion mechanism of Zhungeer coal ash[D].Baoding:North China Electric Power University(Baoding),2008(in Chinese).
[24]李飞.燃煤锅炉烟气含酸灰粒沉积特性与工程酸露点研究[D].济南:山东大学,2014.Li Fei.Research on engineering applications acid dew point and deposition characteristics of acidiferous ash under coal-fired boiler flue gas[D].Jinan:Shandong University,2014(in Chinese).
[2]杨卫娟,周俊虎,刘建忠,等.选择催化还原SCR脱硝技术在电站锅炉的应用[J].热力发电,2005,34(9):10-14.Yang Weijuan,Zhou Junhu,Liu Jianzhong,et al.Application of selective catalyst reduction(SCR)denitrification technology for utility boilers[J].Thermal Power Generation,2005,34(9):10-14(in Chinese).
[3]Ramis G,Li Y,Busca G.Ammonia activation over catalysts for the selective catalytic reduction of NOx and the selective catalytic oxidation of NH3.An FT-IRstudy[J].Catalysis Today,1996,28(4):373-380.
[4]郑方栋,李文华,赵敏,等.全负荷脱硝氨逃逸率与SO3转化率的变化[J].中国电机工程学报,2017,37(9):2607-2613.Zheng Fangdong,Li Wenhua,Zhao Min,et al.Change of ammonia escape rate and SO3 conversion rate of SCRdenitration in full load range[J].Proceedings of the CSEE,2017,37(9):2607-2613(in Chinese).
[5]马双忱,郭蒙,宋卉卉,等.选择性催化还原工艺中硫酸氢铵形成机理及影响因素[J].热力发电,2014,43(2):75-78,86.Ma Shuangchen,Guo Meng,Song Huihui,et al.Formation mechanism and influencing factors of ammonium bisulfate during the selective catalytic reduction process[J].Thermal Power Generation,2014,43(2):75-78,86(in Chinese).
[6]Burke J M,Johnson K L.Ammonium sulfate and bisulfate formation in air preheaters[R].Washington:United States Environment Protection Agency,1982.
[7]Wilburn R T,Wright T L.SCR ammonia slip distribution in coal plant effluents and dependence upon SO3[J].Power Plant Chemistry,2004,6(5):295-304.
[8]范芸珠,曹发海.硫酸铵热分解反应动力学研究[J].高校化学工程学报,2011,25(2):341-346.Fan Yunzhu,Cao Fahai.Thermal decomposition kinetics of ammonium sulfate[J].Journal of Chemical Engineering of Chinese Universities,2011,25(2):341-346(in Chinese).
[9]廖永进,陆继东,黄秋雄,等.选择性催化还原服役后催化剂活性及动力学实验研究[J].中国电机工程学报,2013,33(17):37-44.Liao Yongjin,Lu Jidong,Huang Qiuxiong,et al.Experimental study on activity and kinetics of served SCR catalysts[J].Proceedings of the CSEE,2013,33(17):37-44(in Chinese).
[10]姜烨,高翔,吴卫红,等.选择性催化还原脱硝催化剂失活研究综述[J].中国电机工程学报,2013,33(14):18-31.Jiang Ye,Gao Xiang,Wu Weihong,et al.Review of the deactivation of selective catalytic reduction DeNOx catalysts[J].Proceedings of the CSEE,2013,33(14):18-31(in Chinese).
[11]禾志强,任耿华,祁利明.SCR烟气脱硝系统的负面影响研究[J].电站系统工程,2009,25(3):47-48,50.He Zhiqiang,Ren Genghua,Qi Liming.Study on the disadvantageous influence of SCR denitrification system[J].Power System Engineering,2009,25(3):47-48,50(in Chinese).
[12]张玉华,束航,范红梅,等.商业V2O5-WO3/TiO2催化剂SCR脱硝过程中PM2.5的排放特性及影响因素研究[J].中国电机工程学报,2015,35(2):383-389.Zhang Yuhua,Shu Hang,Fan Hongmei,et al.Research on emission characteristics and influencing factors of PM2.5 for selective catalytic reduction based on V2O5-WO3/TiO2 commercial catalysts[J].Proceedings of the CSEE,2015,35(2):383-389(in Chinese).
[13]钟礼金,宋玉宝.锅炉SCR烟气脱硝空气预热器堵塞原因及其解决措施[J].热力发电,2012,41(8):45-47,50.Zhong Lijin,Song Yubao.Air preheater blocking in boiler with SCR denitrification device:reason analysis and solutions[J].Thermal Power Generation,2012,41(8):45-47,50(in Chinese).
[14]刘建民,陈国庆,黄启龙,等.燃煤脱硝机组空气预热器蓄热片表面飞灰沉积板结机理研究[J].中国电机工程学报,2016,36(S1):132-139.Liu Jianmin,Chen Guoqing,Huang Qilong,et al.Study on mechanism of fly ash deposition and hardening on the air preheater regenerative piece surface of the coal-fired and denitration unit[J].Proceedings of the CSEE,2016,36(S1):132-139(in Chinese).
[15]Matsuda S,Kamo T,Kato A,et al.Deposition of ammonium bisulfate in the selective catalytic reduction of nitrogen oxides with ammonia[J].Industrial&Engineering Chemistry Product Research&Development,1982,21(1):48-52.
[16]Krishnan A T,Boehman A L.Selective catalytic reduction of nitric oxide with ammonia at low temperatures[J].Applied Catalysis B:Environmental,1998,18(3-4):189-198.
[17]Muzio L,Bogseth S,Himes R,et al.Ammonium bisulfate formation and reduced load SCR operation[J].Fuel,2017,206:180-189.
[18]Wei J Y,Muzio L,Dunn-Rankin D.Formation temperature of ammonium bisulfate at simulated air preheater conditions[C]//Proceedings of the 5th USCombustion Meeting.San Diego,California:Curran Associates,Inc.,2007.
[19]Menasha J,Dunn-Rankin D,Muzio L,et al.Ammonium bisulfate formation temperature in a bench-scale single-channel air preheater[J].Fuel,2011,90(7):2445-2453.
[20]马双忱,邓悦,吴文龙,等.SCR脱硝过程中硫酸氢铵形成特性实验研究[J],动力工程学报,2016,36(2):143-150.Ma Shuangchen,Deng Yue,Wu Wenlong,et al.Experimental research on ABS formation characteristics in SCRdenitrification process[J].Journal of Chinese Society of Power Engineering,2016,36(2):143-150(in Chinese).
[21]马双忱,邓悦,吴文龙,等.SCR脱硝副产物硫酸氢铵与空预器中飞灰反应特性[J].环境工程学报,2016,10(11):6563-6570.Ma Shuangchen,Deng Yue,Wu Wenlong,et al.Reaction characteristic of by-product ammonium bisulfate from SCR denitrification and fly ash in air preheater[J].Chinese Journal of Environmental Engineering,2016,10(11):6563-6570(in Chinese).
[22]梁登科.脱硝过程伴生硫酸氢氨对于烟气灰颗粒性质影响的实验研究[D].济南:山东大学,2014.Liang Dengke.Experimental research on the effects to flue ash particles characteristics of NH4HSO4 generating during the denitrification process[D].Jinan:Shandong University,2014(in Chinese).
[23]王天鹏.准格尔煤灰粘附机理的实验研究[D].保定:华北电力大学(保定),2008.Wang Tianpeng.Experimental study for the adhesion mechanism of Zhungeer coal ash[D].Baoding:North China Electric Power University(Baoding),2008(in Chinese).
[24]李飞.燃煤锅炉烟气含酸灰粒沉积特性与工程酸露点研究[D].济南:山东大学,2014.Li Fei.Research on engineering applications acid dew point and deposition characteristics of acidiferous ash under coal-fired boiler flue gas[D].Jinan:Shandong University,2014(in Chinese).