超低排放燃煤电厂SO_3生成及控制的试验研究
|
摘要
针对3×340MW燃煤电厂超低排放改造机组,进行SO3排放控制的试验研究。探究SO3的生成转化规律及排放特征,并对比湿式电除尘技术和化学团聚强化除尘技术在不同机组负荷下对SO3的脱除效果。实验结果表明:SO3在炉膛内的转化率在0.8%～1.4%之间,在SCR催化装置中,SO3的转化率在0.8%～1.3%。SCR装置前后3台机组SO3浓度分别由10.4～30.7mg/m3、22.3～45.5mg/m3以及24.8～48.1mg/m3变为20.2～56.5mg/m3、42.5～74.8mg/m3以及51.4～82.5mg/m3。静电除尘器(electrostaticprecipitator,ESP)对SO3的脱除效率在19.3%～62.3%之间,化学团聚协同ESP对SO3的脱除效率在63.8%～75.2%之间,SO3脱除效率最高可提升51.4%。湿法脱硫系统(wet fluegasdesulfurization,WFGD)对SO3酸雾的脱除效率在50%左右,湿式静电除尘装置及化学团聚协同WFGD脱除SO3效率在50%～70%。超低排放改造后,3台机组的SO3总脱除效率基本维持在80%～90%,排放浓度在5.7～11.4mg/m3。
The formation and emission of SO3 was investigated in 3×340 MW coal-fired power plant that was improved by ultra low emission. It explored the migration and transformation characteristics and emission characteristics of SO3,compared the removal efficiency between chemical agglomeration and wet electrostatic precipitator(WESP)technology in different operating condition. The results show that the converting ratio of SO3 is 0.8%～1.4% in furnace, and is0.8～1.3% in selective catalytic reduction(SCR) system. When the flue gas gets through SCR system, the concentration of SO3 changes from 10.4～30.7 mg/m3、22.3～45.5 mg/m3 and 24.8～48.1 mg/m3 to 20.2～56.5 mg/m3、42.5～74.8 mg/m3 and 51.4～82.5 mg/m3 for Unit 1, Unit 2 and Unit 3 respectively. The efficiency of ESP for SO3 removal varies from 19.3% to 62.3%,when it combined with Chemical agglomeration, the SO3 removal efficiency will be 63.8%～75.2%, which increase by51.4% at most. In general, the efficiency of SO3 removal by wet flue gas desulfurization(WFGD) system is about 50%, when WFGD combines with Chemical agglomeration or WESP, the removal efficiency of SO3 will increase from 50% to 70%. And the total removal efficiency of SO3 is maintained at 80%～90%.The concentration of SO3 emission will be 5.7～11.4 mg/m3 finally.
The formation and emission of SO3 was investigated in 3×340 MW coal-fired power plant that was improved by ultra low emission. It explored the migration and transformation characteristics and emission characteristics of SO3,compared the removal efficiency between chemical agglomeration and wet electrostatic precipitator(WESP)technology in different operating condition. The results show that the converting ratio of SO3 is 0.8%～1.4% in furnace, and is0.8～1.3% in selective catalytic reduction(SCR) system. When the flue gas gets through SCR system, the concentration of SO3 changes from 10.4～30.7 mg/m3、22.3～45.5 mg/m3 and 24.8～48.1 mg/m3 to 20.2～56.5 mg/m3、42.5～74.8 mg/m3 and 51.4～82.5 mg/m3 for Unit 1, Unit 2 and Unit 3 respectively. The efficiency of ESP for SO3 removal varies from 19.3% to 62.3%,when it combined with Chemical agglomeration, the SO3 removal efficiency will be 63.8%～75.2%, which increase by51.4% at most. In general, the efficiency of SO3 removal by wet flue gas desulfurization(WFGD) system is about 50%, when WFGD combines with Chemical agglomeration or WESP, the removal efficiency of SO3 will increase from 50% to 70%. And the total removal efficiency of SO3 is maintained at 80%～90%.The concentration of SO3 emission will be 5.7～11.4 mg/m3 finally.
引文
[1]中华人民共和国国家质量监督检验检疫总局,中国国家标准化管理委员会.GB 13223-2011火电厂大气污染物排放标准[S].北京:中国环境科学出版社,2012.General Administration of Quality Supervision,Inspection and Quarantine of the People's Republic of China,Standardization Administration of China.GB 13223-2011Emission standard of air pollutants for thermal power plants[S].Beijing:China Environmental Science Press,2012(in Chinese).
[2]Belo L P,Elliott L K,Stanger R J,et al.High-temperature conversion of SO2 to SO3:homogeneous experiments and catalytic effect of fly ash from air and oxy-fuel firing码[J].Energy&Fuels,2014,28(11):7243-7251.
[3]J?rgensen T L,Livbjerg H,Glarborg P.Homogeneous and heterogeneously catalyzed oxidation of SO2[J].Chemical Engineering Science,2007,62(16):4496-4499.
[4]Fleig D,Andersson K,Johnsson F.Influence of operating conditions on SO3 formation during air and oxy-fuel combustion[J].Industrial&Engineering Chemistry Research,2012,51(28):9483-9491.
[5]Foster P M.The oxidation of sulphur dioxide in power station plumes[J].Atmospheric Environment(1967),1969,3(2):157-175.
[6]Marier P,Dibbs H P.The catalytic conversion of SO2 to SO3 by fly ash and the capture of SO2 and SO3 by CaOand Mg O[J].Thermochimica Acta,1974,8(1-2):155-165.
[7]Nova I,dall’Acqua L,Lietti L,et al.Study of thermal deactivation of a de-NOx commercial catalyst[J].Applied Catalysis B:Environmental,2001,35(1):31-42.
[8]Dunn J P,Stenger Jr H G,Wachs I E.Molecular structure-reactivity relationships for the oxidation of sulfur dioxide over supported metal oxide catalysts[J].Catalysis Today,1999,53(4):543-556.
[9]Srivastava R K,Miller C A,Erickson C,et al.Emissions of sulfur trioxide from coal-fired power plants[J].Journal of the Air&Waste Management Association,2004,54(6):750-762.
[10]Zhuang Ye,Laumb J,Liggett R,et al.Impacts of acid gases on mercury oxidation across SCR catalyst[J].Fuel Processing Technology,2007,88(10):929-934.
[11]Moser R E.SO3's impacts on plant O&M:Part I[J].Power,2006,150(8):40.
[12]罗浩东.天然碱调质及脱除燃煤烟气SO3的试验研究[D].济南:山东大学,2017.Luo Haodong.Experimental study of the conversion of trona to increase its reactivity with SO3 from coal-fired flue gas[D].Ji’nan:Shandong University,2017(in Chinese).
[13]Cao Yan,Zhou Hongcang,Jiang Wu,et al.Studies of the fate of sulfur trioxide in coal-fired utility boilers based on modified selected condensation methods[J].Environmental Science&Technology,2010,44(9):3429-3434.
[14]Dey L,Venkataraman C.A wet electrostatic precipitator(WESP)for soft nanoparticle collection[J].Aerosol Science and Technology,2012,46(7):750-759.
[15]Lin Guanyu,Tsai C J,Chen S C,et al.An efficient single-stage wet electrostatic precipitator for fine and nanosized particle control[J].Aerosol Science and Technology,2010,44(1):38-45.
[16]刘媛,闫骏,井鹏,等.湿式静电除尘技术研究及应用[J].环境科学与技术,2014,37(6):83-88.Liu Yuan,Yan Jun,Jing Peng,et al.Research and application of wet electrostatic precipitator[J].Environmental Science and Technology,2014,37(6):83-88(in Chinese).
[17]史文峥,杨萌萌,张绪辉,等.燃煤电厂超低排放技术路线与协同脱除[J].中国电机工程学报,2016,36(16):4308-4318.Shi Wenzheng,Yang Mengmeng,Zhang Xuhui,et al.Ultra-low emission technical route of coal-fired power plants and the cooperative removal[J].Proceedings of the CSEE,2016,36(16):4308-4318(in Chinese).
[18]Hu B,Yi Y,Zhang Shuping,et al.SO3 reduction in the flue gas by adding a chemical agent[J].Energy&Fuels,2017,31(11):12399-12406.
[19]陈富华.燃煤超细颗粒物化学团聚理论及系统设计研究[D].武汉:华中科技大学,2012.Chen Fuhua.A theory study and system design of chemical agglomeration for ultrafine particulate matter[D].Wuhan:Huazhong University of Science and Technology,2012(in Chinese).
[20]胡斌,刘勇,任飞,等.低低温电除尘协同脱除细颗粒与SO3实验研究[J].中国电机工程学报,2016,36(16):4319-4325.Hu Bin,Liu Yong,Ren Fei,et al.Experimental study on simultaneous control of fine particle and SO3 by low-low temperature electrostatic precipitator[J].Proceedings of the CSEE,2016,36(16):4319-4325(in Chinese).
[21]EPA.Method 8 Determination of sulfuric acid mist and sulfur dioxide emissions from stationary sources[R].EPA,1998.
[22]叶明立,朱岩,施青红.离子色谱法测定有机溶剂中痕量阴离子[J].分析化学,2005,33(2):187-190.Ye Mingli,Zhu Yan,Shi Qinghong.Determination of trace anions in organic solvent[J].Chinese Journal of Analytical Chemistry,2005,33(2):187-190(in Chinese).
[23]Moretti A L,Jones C S,Asia P G.Advanced emissions control technologies for coal-fired power plants[R].BR-1886,Bangkok,Thailand:Power-Gen Asia,2012.
[24]Fleig D,Normann F,Andersson K,et al.The fate of sulphur during oxy-fuel combustion of lignite[J].Energy Procedia,2009,1(1):383-390.
[25]Kim K H,Choi J S.Kinetics and mechanism of the oxidation of sulfur dioxide onα-Fe2O3[J].The Journal of Physical Chemistry,1981,85(17):2447-2450.
[26]肖海平,董琳,宁翔.Fe2O3对SO2氧化的异相催化作用[J].中国电机工程学报,2016,36(21):5866-5872.Xiao Haiping,Dong Lin,Ning Xiang.Heterogeneous catalytic mechanism of SO2 oxidation with Fe2O3[J].Proceedings of the CSEE,2016,36(21):5866-5872(in Chinese).
[27]Busca G,Lietti L,Ramis G,et al.Chemical and mechanistic aspects of the selective catalytic reduction of NOx by ammonia over oxide catalysts:a review[J].Applied Catalysis B:Environmental,1998,18(1-2):1-36.
[28]Forzatti P.Present status and perspectives in de-NOx SCRcatalysis[J].Applied catalysis A:General,2001,222(1-2):221-236.
[29]Lietti L,Alemany J L,Forzatti P,et al.Reactivity of V2O5-WO3/TiO2 catalysts in the selective catalytic reduction of nitric oxide by ammonia[J].Catalysis Today,1996,29(1-4):143-148.
[30]高岩,栾涛,程凯,等.选择性催化还原蜂窝状催化剂工业试验研究[J].中国电机工程学报,2011,31(35):21-28.Gao Yan,Luan Tao,Cheng Kai,et al.Industrial experiment on selective catalytic reduction honeycomb catalyst[J].Proceedings of the CSEE,2011,31(35):21-28(in Chinese).
[31]Greenwood N N,Earnshaw A.Chemistry of the elements[M].Oxford:Elsevier,1997.
[32]胡斌,刘勇,杨春敏,等.化学团聚促进电除尘脱除烟气中PM2.5和SO3[J].化工学报,2016,67(9):3902-3909.Hu Bin,Liu Yong,Yang Chunmin,et al.Simultaneous control of PM2.5 and SO3 by chemical agglomeration collaborative electrostatic precipitation[J].CIESCJournal,2016,67(9):3902-3909(in Chinese).
[33]郭沂权,张军营,赵永椿,等.50MW燃煤电站锅炉细颗粒物化学团聚示范工程试验研究[J].中国电机工程学报,2016,36(S1):87-94.Guo Yiquan,Zhang Junying,Zhao Yongchun,et al.Experimental research on fine particles chemical agglomeration demonstration project in a 50MWcoal-fired power plant[J].Proceedings of the CSEE,2016,36(S1):87-94(in Chinese).
[34]李清毅,胡达清,张军,等.超低排放脱硫塔和湿式静电对烟气污染物的协同脱除[J].热能动力工程,2017,32(8):138-143.Li Qingyi,Hu Daqing,Zhang Jun,et al.Synergistic removal of WFGD and WESP on gas pollutants with Ultra Low Emission[J].Journal of Engineering for Thermal Energy and Power,2017,32(8):138-143(in Chinese).
[35]Frank M J,Gutberlet H.Retrofit of SCR-systemsFormation of SO3-aerosols and implications on the flue gas cleaning system[C]//ICESP IXConference.Mpumalanga,South Africa,2004.
[2]Belo L P,Elliott L K,Stanger R J,et al.High-temperature conversion of SO2 to SO3:homogeneous experiments and catalytic effect of fly ash from air and oxy-fuel firing码[J].Energy&Fuels,2014,28(11):7243-7251.
[3]J?rgensen T L,Livbjerg H,Glarborg P.Homogeneous and heterogeneously catalyzed oxidation of SO2[J].Chemical Engineering Science,2007,62(16):4496-4499.
[4]Fleig D,Andersson K,Johnsson F.Influence of operating conditions on SO3 formation during air and oxy-fuel combustion[J].Industrial&Engineering Chemistry Research,2012,51(28):9483-9491.
[5]Foster P M.The oxidation of sulphur dioxide in power station plumes[J].Atmospheric Environment(1967),1969,3(2):157-175.
[6]Marier P,Dibbs H P.The catalytic conversion of SO2 to SO3 by fly ash and the capture of SO2 and SO3 by CaOand Mg O[J].Thermochimica Acta,1974,8(1-2):155-165.
[7]Nova I,dall’Acqua L,Lietti L,et al.Study of thermal deactivation of a de-NOx commercial catalyst[J].Applied Catalysis B:Environmental,2001,35(1):31-42.
[8]Dunn J P,Stenger Jr H G,Wachs I E.Molecular structure-reactivity relationships for the oxidation of sulfur dioxide over supported metal oxide catalysts[J].Catalysis Today,1999,53(4):543-556.
[9]Srivastava R K,Miller C A,Erickson C,et al.Emissions of sulfur trioxide from coal-fired power plants[J].Journal of the Air&Waste Management Association,2004,54(6):750-762.
[10]Zhuang Ye,Laumb J,Liggett R,et al.Impacts of acid gases on mercury oxidation across SCR catalyst[J].Fuel Processing Technology,2007,88(10):929-934.
[11]Moser R E.SO3's impacts on plant O&M:Part I[J].Power,2006,150(8):40.
[12]罗浩东.天然碱调质及脱除燃煤烟气SO3的试验研究[D].济南:山东大学,2017.Luo Haodong.Experimental study of the conversion of trona to increase its reactivity with SO3 from coal-fired flue gas[D].Ji’nan:Shandong University,2017(in Chinese).
[13]Cao Yan,Zhou Hongcang,Jiang Wu,et al.Studies of the fate of sulfur trioxide in coal-fired utility boilers based on modified selected condensation methods[J].Environmental Science&Technology,2010,44(9):3429-3434.
[14]Dey L,Venkataraman C.A wet electrostatic precipitator(WESP)for soft nanoparticle collection[J].Aerosol Science and Technology,2012,46(7):750-759.
[15]Lin Guanyu,Tsai C J,Chen S C,et al.An efficient single-stage wet electrostatic precipitator for fine and nanosized particle control[J].Aerosol Science and Technology,2010,44(1):38-45.
[16]刘媛,闫骏,井鹏,等.湿式静电除尘技术研究及应用[J].环境科学与技术,2014,37(6):83-88.Liu Yuan,Yan Jun,Jing Peng,et al.Research and application of wet electrostatic precipitator[J].Environmental Science and Technology,2014,37(6):83-88(in Chinese).
[17]史文峥,杨萌萌,张绪辉,等.燃煤电厂超低排放技术路线与协同脱除[J].中国电机工程学报,2016,36(16):4308-4318.Shi Wenzheng,Yang Mengmeng,Zhang Xuhui,et al.Ultra-low emission technical route of coal-fired power plants and the cooperative removal[J].Proceedings of the CSEE,2016,36(16):4308-4318(in Chinese).
[18]Hu B,Yi Y,Zhang Shuping,et al.SO3 reduction in the flue gas by adding a chemical agent[J].Energy&Fuels,2017,31(11):12399-12406.
[19]陈富华.燃煤超细颗粒物化学团聚理论及系统设计研究[D].武汉:华中科技大学,2012.Chen Fuhua.A theory study and system design of chemical agglomeration for ultrafine particulate matter[D].Wuhan:Huazhong University of Science and Technology,2012(in Chinese).
[20]胡斌,刘勇,任飞,等.低低温电除尘协同脱除细颗粒与SO3实验研究[J].中国电机工程学报,2016,36(16):4319-4325.Hu Bin,Liu Yong,Ren Fei,et al.Experimental study on simultaneous control of fine particle and SO3 by low-low temperature electrostatic precipitator[J].Proceedings of the CSEE,2016,36(16):4319-4325(in Chinese).
[21]EPA.Method 8 Determination of sulfuric acid mist and sulfur dioxide emissions from stationary sources[R].EPA,1998.
[22]叶明立,朱岩,施青红.离子色谱法测定有机溶剂中痕量阴离子[J].分析化学,2005,33(2):187-190.Ye Mingli,Zhu Yan,Shi Qinghong.Determination of trace anions in organic solvent[J].Chinese Journal of Analytical Chemistry,2005,33(2):187-190(in Chinese).
[23]Moretti A L,Jones C S,Asia P G.Advanced emissions control technologies for coal-fired power plants[R].BR-1886,Bangkok,Thailand:Power-Gen Asia,2012.
[24]Fleig D,Normann F,Andersson K,et al.The fate of sulphur during oxy-fuel combustion of lignite[J].Energy Procedia,2009,1(1):383-390.
[25]Kim K H,Choi J S.Kinetics and mechanism of the oxidation of sulfur dioxide onα-Fe2O3[J].The Journal of Physical Chemistry,1981,85(17):2447-2450.
[26]肖海平,董琳,宁翔.Fe2O3对SO2氧化的异相催化作用[J].中国电机工程学报,2016,36(21):5866-5872.Xiao Haiping,Dong Lin,Ning Xiang.Heterogeneous catalytic mechanism of SO2 oxidation with Fe2O3[J].Proceedings of the CSEE,2016,36(21):5866-5872(in Chinese).
[27]Busca G,Lietti L,Ramis G,et al.Chemical and mechanistic aspects of the selective catalytic reduction of NOx by ammonia over oxide catalysts:a review[J].Applied Catalysis B:Environmental,1998,18(1-2):1-36.
[28]Forzatti P.Present status and perspectives in de-NOx SCRcatalysis[J].Applied catalysis A:General,2001,222(1-2):221-236.
[29]Lietti L,Alemany J L,Forzatti P,et al.Reactivity of V2O5-WO3/TiO2 catalysts in the selective catalytic reduction of nitric oxide by ammonia[J].Catalysis Today,1996,29(1-4):143-148.
[30]高岩,栾涛,程凯,等.选择性催化还原蜂窝状催化剂工业试验研究[J].中国电机工程学报,2011,31(35):21-28.Gao Yan,Luan Tao,Cheng Kai,et al.Industrial experiment on selective catalytic reduction honeycomb catalyst[J].Proceedings of the CSEE,2011,31(35):21-28(in Chinese).
[31]Greenwood N N,Earnshaw A.Chemistry of the elements[M].Oxford:Elsevier,1997.
[32]胡斌,刘勇,杨春敏,等.化学团聚促进电除尘脱除烟气中PM2.5和SO3[J].化工学报,2016,67(9):3902-3909.Hu Bin,Liu Yong,Yang Chunmin,et al.Simultaneous control of PM2.5 and SO3 by chemical agglomeration collaborative electrostatic precipitation[J].CIESCJournal,2016,67(9):3902-3909(in Chinese).
[33]郭沂权,张军营,赵永椿,等.50MW燃煤电站锅炉细颗粒物化学团聚示范工程试验研究[J].中国电机工程学报,2016,36(S1):87-94.Guo Yiquan,Zhang Junying,Zhao Yongchun,et al.Experimental research on fine particles chemical agglomeration demonstration project in a 50MWcoal-fired power plant[J].Proceedings of the CSEE,2016,36(S1):87-94(in Chinese).
[34]李清毅,胡达清,张军,等.超低排放脱硫塔和湿式静电对烟气污染物的协同脱除[J].热能动力工程,2017,32(8):138-143.Li Qingyi,Hu Daqing,Zhang Jun,et al.Synergistic removal of WFGD and WESP on gas pollutants with Ultra Low Emission[J].Journal of Engineering for Thermal Energy and Power,2017,32(8):138-143(in Chinese).
[35]Frank M J,Gutberlet H.Retrofit of SCR-systemsFormation of SO3-aerosols and implications on the flue gas cleaning system[C]//ICESP IXConference.Mpumalanga,South Africa,2004.