流化床内纳米TiO_2催化燃烧固硫的数值计算
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摘要
本文首先对一小型流化床试验台的布风均匀性进行数值计算,并用实验手段检验计算结果,数值计算和实验结果一致,都表明了该小型流化床布风均匀;接着通过实验测试不同颗粒在实验台内的流动性能,通过比较选出进行热态实验时的最佳惰性载体。其次对纳米TiO_2促进氧化钙固硫进行了热重实验研究,结果表明:有氧气参与固硫反应时,温度高时,氧化钙的转化率高,而没有氧气的情况下则相反;氧气对氧化钙固硫起着阻碍的作用,纳米TiO_2削弱了这种阻碍作用;添加纳米TiO_2确实能促进氧化钙的转化率,650～750℃时有22%左右的促进效果。本文还利用未反应收缩核模型模拟氧化钙固硫的过程,发现该模型能很好的模拟该过程,表明CaO固硫反应前期为表面化学反应控制阶段,后期转为产物层扩散控制阶段,通过比较添加剂对两个控制阶段的影响,发现纳米TiO_2对产物扩散控制阶段影响较大。
Numerical calculation was carried on a small-scale fluidized bed to reveal its fluidization behavior firstly which was tested by experimentation,and then four different kinds of grains were tested in this fluidized bed to find the best inert carrier for thermal test. And then the promotion effect to CaO desulfurization by nanometer TiO_2 were investigated by thermogravimetric analysis method and the results reveal that: the conversion of CaO is higher in higher temperature in the presence of oxygen, while lower in the absent of oxygen; oxygen act side effect in CaO desulfurization, which may be weakened by nanometer TiO2; Nanometer TiO2 have a promotion effect for CaO conversion which was about 22% in temperature 650～750℃. The kinetic behavior of desulfurization can be described by unreacted shrinking reaction core model which indicate that the overall rate of desulfurization is controlled initially by surface chemical reaction, and then controlled by layer diffusion, and nanometer TiO2 can prominent affect the second stage to promote CaO desulfurization.
Numerical calculation was carried on a small-scale fluidized bed to reveal its fluidization behavior firstly which was tested by experimentation,and then four different kinds of grains were tested in this fluidized bed to find the best inert carrier for thermal test. And then the promotion effect to CaO desulfurization by nanometer TiO_2 were investigated by thermogravimetric analysis method and the results reveal that: the conversion of CaO is higher in higher temperature in the presence of oxygen, while lower in the absent of oxygen; oxygen act side effect in CaO desulfurization, which may be weakened by nanometer TiO2; Nanometer TiO2 have a promotion effect for CaO conversion which was about 22% in temperature 650～750℃. The kinetic behavior of desulfurization can be described by unreacted shrinking reaction core model which indicate that the overall rate of desulfurization is controlled initially by surface chemical reaction, and then controlled by layer diffusion, and nanometer TiO2 can prominent affect the second stage to promote CaO desulfurization.
引文
[1]国家环保局.2005 年中国环境状况年报,2006
[2]国家环保局.2005 年中国环境年鉴,2006
[3]郑集.普通生物化学.北京:人民教育出版社,1982
[4]国家环保局.全国环境质量报告书,2006
[5]江哲生.中国洁净煤发电技术的展望,第十四届国际匹兹堡会议及煤炭利用研讨会论文(单行本).太原,1997:2～4
[6]郝吉明,贺克城.中国燃煤二氧化硫污染控制战略.中国环境科学,1996,16(3),208～212
[7]章名耀,李大骥,蔡宁生.关于我国发展先进燃煤发电技术的建议.动力工程,1994,14(2):1～8
[8]王庆一.我国能源效率比国际先进水平低多少.能源政策研究通讯,1995,8:2
[9]刘炳江,煤中硫的生命周期控制研究:[清华大学博士论文].北京:清华大学,1998
[10]张新生.燃煤烟气脱硫.武汉:中图地质大学出版社.1991
[11]Jun Cheng,Junhu Zhou,Jianzhong Liu,et al. Sulfur Removal at High Temperature during Coal Combustion in Furnaces:a Riview. Progress in Energy and Combustion Science,2003,29:381～405
[12]Chunbo Wang,Xianglin Shen, Yiqian Xu. Investigation on Sulfation of Modified Ca-based Sorbent. Fuel Procession Technology,2002,79(2):121～133
[13]Burnett T A, W L Wells. Conceptual design and economics of an improved magnesium oxide flue gas desulphurization process. ACS Symposium Series, 1982,188:381～415
[14]张基伟.国外燃煤电厂烟气脱硫技术综述.中国电力,1999,32(7):61～65
[15]李彩亭.燃煤锅炉烟气湿式除尘脱硫技术及粉煤灰利用的研究:[博士学位论文].长沙:湖南大学,2002,4～6
[16]郝吉明,马广大.大气污染控制工程.北京:高等教育出版社,2002:306～307
[17]Karatepe,Nilgun. A comparison of flue gas desulfurization processes. Energy Sources,2000,22(3):197～206
[18]Jun Cheng,Junhu Zhou,Jianzhong Liu,Zhijun Zhou, Zhenyu Huang,XinyuCao,Xiang Zhao, Kefa Cen. Progress in Energy and Combustion Science,2003,29(3):381～405 [ 19 ] Rengui Guan , Wen Li , Baoqing L. Effects of Ca-based additives on desulfurization during coal pyrolysis. Fuel,2003,82(5):1961～1966
[20]邹学权,刘毅,武建军.用 TG-FTIR 考察煤燃烧过程中石灰石固硫影响因素.煤炭转化,2002,25(4):39～41
[21]张明旭.用热重分析(TGA)方法研究高硫煤流化床混合燃料.淮南矿业学院学报,1997,17(3):38～42
[22]常丽萍.流化床煤气化炉内石灰石固硫的理论分析.煤炭转化,1996,19(1):57～61
[23]刘锋,朱元洪,凌云.锅炉烟气脱硫技术综述.石油化工环境保护,1996,(3):31～37
[24]R C Ritterhouse. Fighting corrosion in air pollution control systems. Power Eng,1991,95(6):23～29
[25]Xu XC,Chen CH,Qi HY,He R,You CF,Xing GM. Development of coal combustion pollution control for SOx and NOx in China. Fuel Process Technol, 2000,62:153～160
[26]Krishnan SV,Sotirchos SV. Sulfation of high purity limestone under simulated PFBC condition. Can J Chen Eng,1993,71(2):244～255
[27]李彩亭,曾光明.燃煤烟气湿式除尘脱硫技术研究.环境工程,2000,18(4):32～34
[28]Lee D C, Georgakis C. A single Partical-Size Model for Sulfur Retention in Fluidized Coal Combustion. AIChEJ,1981,27:472～480
[29]Marsh D W, Ulrichson D L. Rate and Diffusional Study of the Reaction of Calcium Oxide with sulfur Dioxide. Chem Eng Sci, 1993,40(3) 423～433
[30]钟秦.CaO 和 SO2 反应的热重法研究. 应用化学,1995,12(3):36～39
[31]Burdett N A, Gliddon B J et al. SO3 in Coal-Fired Fluidized Bed Combustors. Inst Energy,1983,9:119～124
[32]Hansen P F B et al. High-Temperature Reaction Between Sulfur Dioxide and Limestone. The Effect of Periodically Changing Oxidizing and reducing conditions. Chem Eng Sci, 1993, 48(7), 1324～1341
[33]Dennis J S, Hayhurst A N. Mechanism of the Sulphation of Calcined Limestone Particles in Combustors. Chem Eng Sci, 1990, 45: 1175～ 1187
[34]Ghardashkhani S, Cooper D. A Thermogravemetric Study of the Reaction Between Sulphur Dioxide and Calcium Oxide. Thermochim Acta, 1990, 161:327～337
[35]Allen D, Hayhurst A N. Reaction Between Gaseous Sulfur Dioxide and Solid Calcium Oxide: Mechanism and Kinetics. J Chem Soc Farady Trans, 1996, 92(7) : 1227～1238
[36]Chan R K, Murthi K S, Harrison D. Thermogravimetric Analysis of Ontario Limestones and Dolomites (Ⅱ) -Reactivity of Sulfur Dioxide with Calcined Samples. Can J Chem, 1970, 48: 2979～2982
[37]Prasannan P C. A model for gas-solid reactions with structure changes in the presence of insert solid. Chem Eng Sci, 1985, 40: 1151～1261.
[38]张洪.燃煤流化床高效脱硫剂的开发研究[博士学位论文].北京:清华大学,1992,29～40.
[39]Hsia C,Pierre G R S. Diffusion through CaSO4 fromed during the reaction of CaO with SO2 and O2.AIChEJ,1993,39(4):698～700.
[40]Paolo D, Gennaro D,Paolo G,et a1.An investigation of the influence of sodium chloride in the desulphurization process of limestone.Fuel,1992,71:831～834.
[41]傅勇,林国珍.型煤燃烧固硫的钠离子效应.环境化学,1994,13(6):492～493.
[42]Juan A.Study of modified calcium hydroxides for enhancing SO2 removal during sorbent injection in pulverized coal boilers.Fuel,1997,76(3):257～265.
[43]Eiii Sasaoka,Norimasa Sada.Preparation of macropous lime from natural lime by swelling method with acetic acid for high-temperature desulfurization. Ind.Eng.Chem,Res.1998,37:1943～1949.
[44]陈鸿伟,王春波.复合调质提高CaO固硫率的实验研究.环境科学学报,1999,19(4):357～361
[45]张良,成思危.Fe2O3 对型煤固硫作用的机理探讨.环境科学,1997,18(1):65～67
[46]庞亚军.掺加粉煤灰提高含钙脱硫剂的烟气脱硫率的试验研究.工程热物理学报,1992,13(4):443～447
[47]武增华,许玲,陈昌和.添加剂对氧化钙固硫促进作用的机理探讨.煤炭转化,2000,23(3):72～76
[48]许玲,武增华.催化剂对固硫反应动力学的影响.杭州:浙江大学出版社,1994,44
[49]Hiroaki Tsuchiai, Tomohiro Ishizuka, et al. Highly active absorbent for SO2 removal prepared form coal fly ash. Ind. Eng. Chem. Res., 1995,34(4):1404～1411
[50]Tomohiro Ishizuka, Takashi Yamamoto, et al. Effect of calcium sulfate addition on the activity of the absorbent for dry flue gas desulfurization. Energy & Fluels, 2001, 15: 436～444
[51]Fernandez J, Renedo M J, et al. Effect of CaSO4 on the structure and use of Ca(OH)2/fly ash sorbents for SO2. Powder Technilogy, 2001,199,201～205
[52]肖佩林,李书年.铁硅系添加剂对型煤燃烧时硫行为的影响.环境科学学报,1996,16(1):97～101
[53]Torres-Ordonez R J. Sulfur reaction as CaS(s) during coal combustion: a modeling study to define mechanisms and possible technolodies. Flue, 1993, 72(5): 633～643.
[54]张立德,牟季美.纳米材料和纳米结构.北京:科学出版社,2001,76～95
[55]常红,王京刚.纳米二氧化钛在环保领域中的应用.矿冶,2002,11(4):73～74
[56]葛军,丁辉.纳米二氧化钛的应用与市场研究.材料导报,2004,18(2):65～68
[57]李骥,罗永刚.纳米级 Ti02 脱硫及再生性能的实验研究.能源研究与利用,2001,(5):28～31
[58]吕俊复,岳光溪等.循环流化床锅炉运行与检修.北京:中国水利水电出版社,2005:10～17.
[59]党黎军.循环流化床锅炉的启动调试与安全运行.北京:中国电力出版社,2005:32～34
[60]韩占中,王敬,兰小平.FLURNT 流体工程仿真计算实例与应用.北京:北京理工大学出版社,2004:19～22
[61]徐祥.循环流化床流动特性的数值模拟:[硕士学位论文].南京:东南大学,2004
[62]宋鸿恩.热天平.北京:计量出版社,1985:6～17
[63]武增华,寇鹏,邱新平等.催化剂对 CaO 固硫反应动力学的影响.化学学报,2000,58(11):1316～1321
[64]郭汉贤等.应用化工动力学.北京:化学工业出版社,2003
[2]国家环保局.2005 年中国环境年鉴,2006
[3]郑集.普通生物化学.北京:人民教育出版社,1982
[4]国家环保局.全国环境质量报告书,2006
[5]江哲生.中国洁净煤发电技术的展望,第十四届国际匹兹堡会议及煤炭利用研讨会论文(单行本).太原,1997:2～4
[6]郝吉明,贺克城.中国燃煤二氧化硫污染控制战略.中国环境科学,1996,16(3),208～212
[7]章名耀,李大骥,蔡宁生.关于我国发展先进燃煤发电技术的建议.动力工程,1994,14(2):1～8
[8]王庆一.我国能源效率比国际先进水平低多少.能源政策研究通讯,1995,8:2
[9]刘炳江,煤中硫的生命周期控制研究:[清华大学博士论文].北京:清华大学,1998
[10]张新生.燃煤烟气脱硫.武汉:中图地质大学出版社.1991
[11]Jun Cheng,Junhu Zhou,Jianzhong Liu,et al. Sulfur Removal at High Temperature during Coal Combustion in Furnaces:a Riview. Progress in Energy and Combustion Science,2003,29:381～405
[12]Chunbo Wang,Xianglin Shen, Yiqian Xu. Investigation on Sulfation of Modified Ca-based Sorbent. Fuel Procession Technology,2002,79(2):121～133
[13]Burnett T A, W L Wells. Conceptual design and economics of an improved magnesium oxide flue gas desulphurization process. ACS Symposium Series, 1982,188:381～415
[14]张基伟.国外燃煤电厂烟气脱硫技术综述.中国电力,1999,32(7):61～65
[15]李彩亭.燃煤锅炉烟气湿式除尘脱硫技术及粉煤灰利用的研究:[博士学位论文].长沙:湖南大学,2002,4～6
[16]郝吉明,马广大.大气污染控制工程.北京:高等教育出版社,2002:306～307
[17]Karatepe,Nilgun. A comparison of flue gas desulfurization processes. Energy Sources,2000,22(3):197～206
[18]Jun Cheng,Junhu Zhou,Jianzhong Liu,Zhijun Zhou, Zhenyu Huang,XinyuCao,Xiang Zhao, Kefa Cen. Progress in Energy and Combustion Science,2003,29(3):381～405 [ 19 ] Rengui Guan , Wen Li , Baoqing L. Effects of Ca-based additives on desulfurization during coal pyrolysis. Fuel,2003,82(5):1961～1966
[20]邹学权,刘毅,武建军.用 TG-FTIR 考察煤燃烧过程中石灰石固硫影响因素.煤炭转化,2002,25(4):39～41
[21]张明旭.用热重分析(TGA)方法研究高硫煤流化床混合燃料.淮南矿业学院学报,1997,17(3):38～42
[22]常丽萍.流化床煤气化炉内石灰石固硫的理论分析.煤炭转化,1996,19(1):57～61
[23]刘锋,朱元洪,凌云.锅炉烟气脱硫技术综述.石油化工环境保护,1996,(3):31～37
[24]R C Ritterhouse. Fighting corrosion in air pollution control systems. Power Eng,1991,95(6):23～29
[25]Xu XC,Chen CH,Qi HY,He R,You CF,Xing GM. Development of coal combustion pollution control for SOx and NOx in China. Fuel Process Technol, 2000,62:153～160
[26]Krishnan SV,Sotirchos SV. Sulfation of high purity limestone under simulated PFBC condition. Can J Chen Eng,1993,71(2):244～255
[27]李彩亭,曾光明.燃煤烟气湿式除尘脱硫技术研究.环境工程,2000,18(4):32～34
[28]Lee D C, Georgakis C. A single Partical-Size Model for Sulfur Retention in Fluidized Coal Combustion. AIChEJ,1981,27:472～480
[29]Marsh D W, Ulrichson D L. Rate and Diffusional Study of the Reaction of Calcium Oxide with sulfur Dioxide. Chem Eng Sci, 1993,40(3) 423～433
[30]钟秦.CaO 和 SO2 反应的热重法研究. 应用化学,1995,12(3):36～39
[31]Burdett N A, Gliddon B J et al. SO3 in Coal-Fired Fluidized Bed Combustors. Inst Energy,1983,9:119～124
[32]Hansen P F B et al. High-Temperature Reaction Between Sulfur Dioxide and Limestone. The Effect of Periodically Changing Oxidizing and reducing conditions. Chem Eng Sci, 1993, 48(7), 1324～1341
[33]Dennis J S, Hayhurst A N. Mechanism of the Sulphation of Calcined Limestone Particles in Combustors. Chem Eng Sci, 1990, 45: 1175～ 1187
[34]Ghardashkhani S, Cooper D. A Thermogravemetric Study of the Reaction Between Sulphur Dioxide and Calcium Oxide. Thermochim Acta, 1990, 161:327～337
[35]Allen D, Hayhurst A N. Reaction Between Gaseous Sulfur Dioxide and Solid Calcium Oxide: Mechanism and Kinetics. J Chem Soc Farady Trans, 1996, 92(7) : 1227～1238
[36]Chan R K, Murthi K S, Harrison D. Thermogravimetric Analysis of Ontario Limestones and Dolomites (Ⅱ) -Reactivity of Sulfur Dioxide with Calcined Samples. Can J Chem, 1970, 48: 2979～2982
[37]Prasannan P C. A model for gas-solid reactions with structure changes in the presence of insert solid. Chem Eng Sci, 1985, 40: 1151～1261.
[38]张洪.燃煤流化床高效脱硫剂的开发研究[博士学位论文].北京:清华大学,1992,29～40.
[39]Hsia C,Pierre G R S. Diffusion through CaSO4 fromed during the reaction of CaO with SO2 and O2.AIChEJ,1993,39(4):698～700.
[40]Paolo D, Gennaro D,Paolo G,et a1.An investigation of the influence of sodium chloride in the desulphurization process of limestone.Fuel,1992,71:831～834.
[41]傅勇,林国珍.型煤燃烧固硫的钠离子效应.环境化学,1994,13(6):492～493.
[42]Juan A.Study of modified calcium hydroxides for enhancing SO2 removal during sorbent injection in pulverized coal boilers.Fuel,1997,76(3):257～265.
[43]Eiii Sasaoka,Norimasa Sada.Preparation of macropous lime from natural lime by swelling method with acetic acid for high-temperature desulfurization. Ind.Eng.Chem,Res.1998,37:1943～1949.
[44]陈鸿伟,王春波.复合调质提高CaO固硫率的实验研究.环境科学学报,1999,19(4):357～361
[45]张良,成思危.Fe2O3 对型煤固硫作用的机理探讨.环境科学,1997,18(1):65～67
[46]庞亚军.掺加粉煤灰提高含钙脱硫剂的烟气脱硫率的试验研究.工程热物理学报,1992,13(4):443～447
[47]武增华,许玲,陈昌和.添加剂对氧化钙固硫促进作用的机理探讨.煤炭转化,2000,23(3):72～76
[48]许玲,武增华.催化剂对固硫反应动力学的影响.杭州:浙江大学出版社,1994,44
[49]Hiroaki Tsuchiai, Tomohiro Ishizuka, et al. Highly active absorbent for SO2 removal prepared form coal fly ash. Ind. Eng. Chem. Res., 1995,34(4):1404～1411
[50]Tomohiro Ishizuka, Takashi Yamamoto, et al. Effect of calcium sulfate addition on the activity of the absorbent for dry flue gas desulfurization. Energy & Fluels, 2001, 15: 436～444
[51]Fernandez J, Renedo M J, et al. Effect of CaSO4 on the structure and use of Ca(OH)2/fly ash sorbents for SO2. Powder Technilogy, 2001,199,201～205
[52]肖佩林,李书年.铁硅系添加剂对型煤燃烧时硫行为的影响.环境科学学报,1996,16(1):97～101
[53]Torres-Ordonez R J. Sulfur reaction as CaS(s) during coal combustion: a modeling study to define mechanisms and possible technolodies. Flue, 1993, 72(5): 633～643.
[54]张立德,牟季美.纳米材料和纳米结构.北京:科学出版社,2001,76～95
[55]常红,王京刚.纳米二氧化钛在环保领域中的应用.矿冶,2002,11(4):73～74
[56]葛军,丁辉.纳米二氧化钛的应用与市场研究.材料导报,2004,18(2):65～68
[57]李骥,罗永刚.纳米级 Ti02 脱硫及再生性能的实验研究.能源研究与利用,2001,(5):28～31
[58]吕俊复,岳光溪等.循环流化床锅炉运行与检修.北京:中国水利水电出版社,2005:10～17.
[59]党黎军.循环流化床锅炉的启动调试与安全运行.北京:中国电力出版社,2005:32～34
[60]韩占中,王敬,兰小平.FLURNT 流体工程仿真计算实例与应用.北京:北京理工大学出版社,2004:19～22
[61]徐祥.循环流化床流动特性的数值模拟:[硕士学位论文].南京:东南大学,2004
[62]宋鸿恩.热天平.北京:计量出版社,1985:6～17
[63]武增华,寇鹏,邱新平等.催化剂对 CaO 固硫反应动力学的影响.化学学报,2000,58(11):1316～1321
[64]郭汉贤等.应用化工动力学.北京:化学工业出版社,2003