循环流化床电石渣脱硫实验研究
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摘要
目前,燃煤污染是我国环境污染的重要方面,其中减少含硫污染物的排放是治理燃煤污染的一项重要内容。电石渣是一种氢氧化钙含量很高的工业废渣,电石渣的大量堆积严重污染周边环境,如果能够利用其脱硫,不仅可以减少环境污染,而且能达到以废制废的目的。
本文采用热分析法,在热天平上进行电石渣脱硫的热重实验研究。实验结果显示,电石渣脱硫反应分为煅烧和吸收两阶段。在实验工况下,温度越高,钙的转化率越高;SO_2浓度越高,反应在化学反应控制阶段持续的时间越短,反应更容易进入到产物层扩散控制阶段。
通过对实验数据的分析,确定了电石渣的脱硫过程,并且讨论了其脱硫机理。利用数学模型研究电石渣脱硫反应动力学特性,计算并分析了动力学参数——活化能E、表面化学反应速率常数ks和产物层扩散系数Ds。结果表明,模型能够很好的描述化学反应控制阶段和产物层扩散控制阶段的脱硫反应过程。
对反应过程做出合理假设,结合未反应收缩核模型和孔分布模型,并采用质量守恒定律和扩散方程建立CaO吸收SO_2的颗粒—孔分布模型。模型计算结果跟实验结果吻合的较好,模型能够较好的描述电石渣的脱硫过程。最后,利用某电厂的实际运行数据再一次验证了模型的准确性。现场运行数据还表明,电石渣的加入对锅炉运行的影响很小。
本研究为开发废弃物型脱硫剂提供理论基础,对促进脱硫技术发展具有重要的理论价值和工程应用指导作用。
At present, coal-fired pollution is the focus of Chinese environmental pollution, in which controlling emissions of sulfur dioxide is a very important element. Carbide slag is industrial waste which includes high sulfur, the bulk deposition of it make heavy-polluted of the envirement around, if we can use it to do desulfurization, not only can decrease the pollution, but also makes good waste utilization.
This article uses the thermal annlysis, makes the thermal analysis research of the carbide slag desulfurization in the thermobalance. The results of the experiment show carbide slag desulfurization reaction is divided into two stages: Calcination and Absorption. In the experimental condition, the higher the temperature is, the higher the conversion of calcium; the higher SO_2 concentration is, the shorter the reaction in chemical reaction control stage continuous time is, reaction easier to enter the product layer controlling stage.
Based on the analysis of the experimental data, we determine the desulfurization process and discuss the desulfurization mechanism. Using the mathematicl models to study the carbide slag desulfuration reaction dynamical characteristic, we calculate and analyze their dynamic parameter—activation energy E, chemical reaction rate constant ks, product layer diffusion coefficient Ds. The results indicate that the mathematical model can describe the desulfurization reaction process well at the chemical reaction controlling stage and at the product layer diffusion controlling stage.
Make reasonable hypothesis of the reaction process, combing unreacted shrinking core model and pore distribution model and use conservation of mass and the diffusion equation to establish CaO absorb the SO_2 particle-pore distribution model. Calculation results of the model and the experimental results are well matched. The model can describe carbide slag desulfurization process well. Finally, using a power plant actual data also proved the accuracy of the model once again. The site operation data also shows that, adding the calcium carbide slag make little effect for the boiler operation.
This study provides theoretical basis for developing the waste type desulfurizer, meanwhile, it has very important theoretical value for promoting the development of desulfurization technology and directive function for engineering application.
本文采用热分析法,在热天平上进行电石渣脱硫的热重实验研究。实验结果显示,电石渣脱硫反应分为煅烧和吸收两阶段。在实验工况下,温度越高,钙的转化率越高;SO_2浓度越高,反应在化学反应控制阶段持续的时间越短,反应更容易进入到产物层扩散控制阶段。
通过对实验数据的分析,确定了电石渣的脱硫过程,并且讨论了其脱硫机理。利用数学模型研究电石渣脱硫反应动力学特性,计算并分析了动力学参数——活化能E、表面化学反应速率常数ks和产物层扩散系数Ds。结果表明,模型能够很好的描述化学反应控制阶段和产物层扩散控制阶段的脱硫反应过程。
对反应过程做出合理假设,结合未反应收缩核模型和孔分布模型,并采用质量守恒定律和扩散方程建立CaO吸收SO_2的颗粒—孔分布模型。模型计算结果跟实验结果吻合的较好,模型能够较好的描述电石渣的脱硫过程。最后,利用某电厂的实际运行数据再一次验证了模型的准确性。现场运行数据还表明,电石渣的加入对锅炉运行的影响很小。
本研究为开发废弃物型脱硫剂提供理论基础,对促进脱硫技术发展具有重要的理论价值和工程应用指导作用。
At present, coal-fired pollution is the focus of Chinese environmental pollution, in which controlling emissions of sulfur dioxide is a very important element. Carbide slag is industrial waste which includes high sulfur, the bulk deposition of it make heavy-polluted of the envirement around, if we can use it to do desulfurization, not only can decrease the pollution, but also makes good waste utilization.
This article uses the thermal annlysis, makes the thermal analysis research of the carbide slag desulfurization in the thermobalance. The results of the experiment show carbide slag desulfurization reaction is divided into two stages: Calcination and Absorption. In the experimental condition, the higher the temperature is, the higher the conversion of calcium; the higher SO_2 concentration is, the shorter the reaction in chemical reaction control stage continuous time is, reaction easier to enter the product layer controlling stage.
Based on the analysis of the experimental data, we determine the desulfurization process and discuss the desulfurization mechanism. Using the mathematicl models to study the carbide slag desulfuration reaction dynamical characteristic, we calculate and analyze their dynamic parameter—activation energy E, chemical reaction rate constant ks, product layer diffusion coefficient Ds. The results indicate that the mathematical model can describe the desulfurization reaction process well at the chemical reaction controlling stage and at the product layer diffusion controlling stage.
Make reasonable hypothesis of the reaction process, combing unreacted shrinking core model and pore distribution model and use conservation of mass and the diffusion equation to establish CaO absorb the SO_2 particle-pore distribution model. Calculation results of the model and the experimental results are well matched. The model can describe carbide slag desulfurization process well. Finally, using a power plant actual data also proved the accuracy of the model once again. The site operation data also shows that, adding the calcium carbide slag make little effect for the boiler operation.
This study provides theoretical basis for developing the waste type desulfurizer, meanwhile, it has very important theoretical value for promoting the development of desulfurization technology and directive function for engineering application.
引文
[1]中国节能投资公司. 2009中国节能减排产业发展报告—迎接低碳经济新时代[M].北京:中国水利水电出版社, 2009: 781-892
[2]汪艳红.我国火电厂烟气脱硫工艺现状及发展综述[J].硫磷设计与粉体工程, 2008(2): 13-24
[3]周生贤. 2009年中国环境状况公报[R].北京:中华人民共和国环境保护部, 2010
[4]龚德鸿,钱进,朱兵.电石渣在电厂烟气脱硫中的应用[J].锅炉技术, 2008, 39(6): 13-17
[5]童艳,周屈兰,惠世恩,等.电石渣在湿法脱硫中的消溶特性[J].动力工程, 2006, 26(6): 884-887
[6]赵旭东,项光明.电石渣在循环流化床烟气脱硫中的应用[J].化学工程, 2006, 34(9): 59-62
[7]朱青青.电石渣在电厂烟气脱硫工艺中的应用[D].兰州:兰州理工大学, 2006
[8]赵晓英,陈曙光,廖维平.电石渣固硫性能的研究[J].污染防治技术, 1999, 12(3): 152-180
[9] Wang Jin-ning, Chen De-fang. Experiments on the utilization of discards from the chemical industrys substitutes for the conventional absorbents of desulfutization[J]. Energy Research and Information, 2000, 16(3): 356-361
[10]张远.利用电石渣脱硫的实验研究[D].贵阳:贵州大学, 2007
[11]王梅,刘素兰,赖春艳,等.应用工业废渣试制型煤用固硫剂的研究[J].中国稀土学报, 2002(20): 589-591
[12]程军,周俊虎,刘建忠,等.电石渣和铝土粉的高温燃烧脱硫特性及微观分析[J].环境科学学报, 2003(09): 641-646
[13]杨明平,罗娟. Fe2O3改性电石渣高温固硫性能的研究[J].煤化工, 2008(4): 19-22
[14]谭娅,李彩亭,曾光明,等.添加剂对燃煤电石渣固硫的促进作用[J].燃料化学学报, 2005, 33(6): 767-770
[15]卫泳波,薛雏汉,郝强,等.电石渣浆在大型火电机组烟气脱硫中的成功应用[J].电力环境保护, 2006, 22(1): 17-19
[16]廖军.用电石渣浆制备烟气脱硫剂[J].化工环保, 2007, 27(4): 361-363
[17]解传明,徐欣宇.电石渣制备脱硫剂的成功应用[J].聚氯乙烯, 2009, 37(9): 45-46
[18]高文英.含碱工业废弃物脱硫性能实验研究[D].济南:山东大学, 2007
[19]郑斌.工业碱基废弃物固硫性能研究[D].济南:山东大学, 2006
[20] Hansen P. F. B., Dam-Johansen K., Bank L. H., et al. Sulfur retention on limestone under FBC conditions-An experimental study[A]. Ed. anthony E. J. Proc. 11th Int. Conf. on FBC[C]. Montreal, Canada: ASME Press, 1991: 73-82
[21]武增华,姚绍军,郭锋,等.氧化物添加剂对CaSO4高温稳定性的影响[J].煤炭转化, 2002, 25(2): 71-73
[22] Wen C. Y.. Noncatalatic heterogeneous solid fluid reaction models[J]. Industrial and Eng Chem, 1998, 60(9): 34-53
[23]邱宽嵘,蒋扮. CaO颗粒脱硫化学反应研究[J].中国矿业大学学报, 1996,25(4): 93-94
[24]刘金权,武增华,王立新. CaO-超细高岭土复合固硫剂固硫动力学研究[J].燃料化学学报, 2004, 32(4): 424-428
[25]赵改菊.含碱工业废弃物硫化反应特性与机理实验研究[D].济南:山东大学, 2007
[26]郭汉贤.应用化工动力学[M].北京:化学工业出版社, 2003: 88-102
[27] Borgwart R. H.. Kinetic of the reaction of SO_2 with calcium limestone[J]. Environ. Sci & Technol, 1990(4):59
[28] O’Neill E. P., Keains D. L.. A Thermogravimetric study of the reaction of limestone and dolomite-the effect of calcination condition[J]. Thermochemic Acta, 1996(14): 209
[29] Marsh D. W., Ulrichson D. L.. Rate and diffusional study of the reaction of calcium oxide with sulfur dioxide[J], Chem. Eng. Sci, 1995, 30(3): 423-433
[30]张洪.燃煤流化床高效脱硫剂的开发研究[D].北京:清华大学, 1992
[31] Ghosh-Dastidar A., Mahuli S.. Ultrafast calcination and sinterning of Ca(OH)2 powder: experimental and modeling[J]. Chem Eng Sci, 1995(50): 2029～2040
[32]田园.含碱工业废弃物煅烧及固硫反应动力学特性研究[D].济南:山东大学. 2006
[33]韩奎华,赵建立,路春美,等.添加剂影响CaO固硫反应活性的动力学分析[J].环境科学, 2006, 27(2): 219-223
[34] Yagi S., Kunii D.. Fluidized-Solids Reactors with Continuous Solids Feed-ⅠResidence Time of Particles in Fluidized Beds[J]. Chem. Eng. Sci.,1961(16): 364
[35] Szekely J., Evans J. W.. A structural model for gas-solid reactions with a moving boundary[J]. Chem. Eng. Sci., 1970(25): 1091-1107
[36] Pugalia N.. Numelical Modeling of Cold Flow and Hot Gas Desulfutization in a Circulating Fluidized Bed[D]. Morgantown: West Virginia Uniwersity, 2001
[37] Hartman M., Coughlin R. W.. Reaction of sulfur dioxide with limestone and the influence of pore structure[J]. Ind. Eng. Chem. Proc. Des. Dev.. 1974(13): 248-255
[38] Hartman M., Coughlin R. W.. Reaction of sulfur dioxide with limestone and the grain model[J]. AIChE J, 1976(22): 490-498
[39] Petersen E. E.. Reaction of porous solids[J]. AIChE Journal, 1957(3): 443-445
[40] Ramachandran P. A., Smith J. M.. A single-pore model for gas-solid non-eatalytie reactions[J]. AIChE J, 1977(23): 353-361
[41] Chrostowski. Modelling desulfurization reactions in FBC[A]. ACS Symposium Series[C], No.65, Chemical Reaction Engineering Houston[M], 1978
[42] Bhatia S. K., Perlmutter D. D.. Arandom pore model for fluid-solid reactions: Isothermal Control[J]. AIChE J, 1980, 26(3): 379-355
[43] Bhatia S. K., Perllnutter D. D.. Arandom Pore model for fluid-solidreactions: Diffusion and transport effeets[J]. AIChE J, 1981, 27(2): 247-256
[44] Christman P. G.. Edgar T. F.. Distributed pore-size model for sulfation of limestone[J]. AIChE J, 1983, 29(3): 388-395
[45] Simons G. A., Garman A. R.. Small pore closure and the deaction of the limestone sulfation reaction[J]. AIChE J, 1986, 32(9): 1491-1499
[46] Simons G. A., Garman A. R.. The kinetie rate of SO_2 sorption by CaO[J]. AIChE J, 1987(33): 211-217
[47] Luo Z. Y., Yin C. G., Li X. T., et al. The fractal dimension of caleined limestone and its sulfur removal reactivity[J]. Energy, 1997, 22(11): 1051-1055
[48] Reyes S., Jensen K. F.. Estimation of effective transport coefficients in porous solids based on percolation concepts[J]. Chem. Eng. Sci., 1985(40): 1723-1734
[49] Reyes S., Jensen K. F.. Percolation concept in modeling of gas-solid reaction: Application to char gasification in diffusion regime[J]. Chem. Eng. Sci., 1986(41): 345-354
[50] Xuantian Li, Zhongyang Luo, Mingjiang Ni, et al. Modeling sulfur retention in circulating fluidized bed combustors[J]. Chem. Eng.Sci., 1992(50): 2235-2242
[51] Coppens M. O., Froment G. F.. Diffusion and reaetion in a fractal catalyst pore-Ⅰ. Geometrical aspects[J]. Chem. Eng. Sci., 1995, 50(6): 1013-1026
[52] Coppens M. O., Froment G. F.. Diffusion and reaetion in a fractal catalyst pore-Ⅱ. Diffusion and first-order reaction[J]. Chem. Eng. Sei., 1995, 50(6): 1027-1039
[53]卢广. CFB富氧燃烧下CaO同时碳酸化硫化特性研究[D]:保定:华北电力大学, 2009
[54]王春波,李永华,危日光,等.钙基脱硫剂煅烧过程中产物CaO孔径分布的模拟[J].动力工程, 2007, 27(4): 625-628
[55] Fuller E. N., Schettler P. D., Giddings J. C.. A new method for Predietion of binary gas phase dision coefficients[J]. Ind. Eng. Che., 1966(58): 19-27
[56] Dam-Johan K., Hansen P. F. B., Ostergard K.. High temperature reaetion between sulfur dioxide and limestone: A grain-micrograin model and its verifieation[J]. Chem. Eng. Sci., 1991, 46(3): 847-853
[57] Adanez J., Gareia L. F., Fierro V.. Modeling for the high temperature sulphation of calcium-based sorbents with cylindrical and plate-like pore geometries[J]. Chem. Eng. Sci., 2000(55): 3665-3683
[2]汪艳红.我国火电厂烟气脱硫工艺现状及发展综述[J].硫磷设计与粉体工程, 2008(2): 13-24
[3]周生贤. 2009年中国环境状况公报[R].北京:中华人民共和国环境保护部, 2010
[4]龚德鸿,钱进,朱兵.电石渣在电厂烟气脱硫中的应用[J].锅炉技术, 2008, 39(6): 13-17
[5]童艳,周屈兰,惠世恩,等.电石渣在湿法脱硫中的消溶特性[J].动力工程, 2006, 26(6): 884-887
[6]赵旭东,项光明.电石渣在循环流化床烟气脱硫中的应用[J].化学工程, 2006, 34(9): 59-62
[7]朱青青.电石渣在电厂烟气脱硫工艺中的应用[D].兰州:兰州理工大学, 2006
[8]赵晓英,陈曙光,廖维平.电石渣固硫性能的研究[J].污染防治技术, 1999, 12(3): 152-180
[9] Wang Jin-ning, Chen De-fang. Experiments on the utilization of discards from the chemical industrys substitutes for the conventional absorbents of desulfutization[J]. Energy Research and Information, 2000, 16(3): 356-361
[10]张远.利用电石渣脱硫的实验研究[D].贵阳:贵州大学, 2007
[11]王梅,刘素兰,赖春艳,等.应用工业废渣试制型煤用固硫剂的研究[J].中国稀土学报, 2002(20): 589-591
[12]程军,周俊虎,刘建忠,等.电石渣和铝土粉的高温燃烧脱硫特性及微观分析[J].环境科学学报, 2003(09): 641-646
[13]杨明平,罗娟. Fe2O3改性电石渣高温固硫性能的研究[J].煤化工, 2008(4): 19-22
[14]谭娅,李彩亭,曾光明,等.添加剂对燃煤电石渣固硫的促进作用[J].燃料化学学报, 2005, 33(6): 767-770
[15]卫泳波,薛雏汉,郝强,等.电石渣浆在大型火电机组烟气脱硫中的成功应用[J].电力环境保护, 2006, 22(1): 17-19
[16]廖军.用电石渣浆制备烟气脱硫剂[J].化工环保, 2007, 27(4): 361-363
[17]解传明,徐欣宇.电石渣制备脱硫剂的成功应用[J].聚氯乙烯, 2009, 37(9): 45-46
[18]高文英.含碱工业废弃物脱硫性能实验研究[D].济南:山东大学, 2007
[19]郑斌.工业碱基废弃物固硫性能研究[D].济南:山东大学, 2006
[20] Hansen P. F. B., Dam-Johansen K., Bank L. H., et al. Sulfur retention on limestone under FBC conditions-An experimental study[A]. Ed. anthony E. J. Proc. 11th Int. Conf. on FBC[C]. Montreal, Canada: ASME Press, 1991: 73-82
[21]武增华,姚绍军,郭锋,等.氧化物添加剂对CaSO4高温稳定性的影响[J].煤炭转化, 2002, 25(2): 71-73
[22] Wen C. Y.. Noncatalatic heterogeneous solid fluid reaction models[J]. Industrial and Eng Chem, 1998, 60(9): 34-53
[23]邱宽嵘,蒋扮. CaO颗粒脱硫化学反应研究[J].中国矿业大学学报, 1996,25(4): 93-94
[24]刘金权,武增华,王立新. CaO-超细高岭土复合固硫剂固硫动力学研究[J].燃料化学学报, 2004, 32(4): 424-428
[25]赵改菊.含碱工业废弃物硫化反应特性与机理实验研究[D].济南:山东大学, 2007
[26]郭汉贤.应用化工动力学[M].北京:化学工业出版社, 2003: 88-102
[27] Borgwart R. H.. Kinetic of the reaction of SO_2 with calcium limestone[J]. Environ. Sci & Technol, 1990(4):59
[28] O’Neill E. P., Keains D. L.. A Thermogravimetric study of the reaction of limestone and dolomite-the effect of calcination condition[J]. Thermochemic Acta, 1996(14): 209
[29] Marsh D. W., Ulrichson D. L.. Rate and diffusional study of the reaction of calcium oxide with sulfur dioxide[J], Chem. Eng. Sci, 1995, 30(3): 423-433
[30]张洪.燃煤流化床高效脱硫剂的开发研究[D].北京:清华大学, 1992
[31] Ghosh-Dastidar A., Mahuli S.. Ultrafast calcination and sinterning of Ca(OH)2 powder: experimental and modeling[J]. Chem Eng Sci, 1995(50): 2029～2040
[32]田园.含碱工业废弃物煅烧及固硫反应动力学特性研究[D].济南:山东大学. 2006
[33]韩奎华,赵建立,路春美,等.添加剂影响CaO固硫反应活性的动力学分析[J].环境科学, 2006, 27(2): 219-223
[34] Yagi S., Kunii D.. Fluidized-Solids Reactors with Continuous Solids Feed-ⅠResidence Time of Particles in Fluidized Beds[J]. Chem. Eng. Sci.,1961(16): 364
[35] Szekely J., Evans J. W.. A structural model for gas-solid reactions with a moving boundary[J]. Chem. Eng. Sci., 1970(25): 1091-1107
[36] Pugalia N.. Numelical Modeling of Cold Flow and Hot Gas Desulfutization in a Circulating Fluidized Bed[D]. Morgantown: West Virginia Uniwersity, 2001
[37] Hartman M., Coughlin R. W.. Reaction of sulfur dioxide with limestone and the influence of pore structure[J]. Ind. Eng. Chem. Proc. Des. Dev.. 1974(13): 248-255
[38] Hartman M., Coughlin R. W.. Reaction of sulfur dioxide with limestone and the grain model[J]. AIChE J, 1976(22): 490-498
[39] Petersen E. E.. Reaction of porous solids[J]. AIChE Journal, 1957(3): 443-445
[40] Ramachandran P. A., Smith J. M.. A single-pore model for gas-solid non-eatalytie reactions[J]. AIChE J, 1977(23): 353-361
[41] Chrostowski. Modelling desulfurization reactions in FBC[A]. ACS Symposium Series[C], No.65, Chemical Reaction Engineering Houston[M], 1978
[42] Bhatia S. K., Perlmutter D. D.. Arandom pore model for fluid-solid reactions: Isothermal Control[J]. AIChE J, 1980, 26(3): 379-355
[43] Bhatia S. K., Perllnutter D. D.. Arandom Pore model for fluid-solidreactions: Diffusion and transport effeets[J]. AIChE J, 1981, 27(2): 247-256
[44] Christman P. G.. Edgar T. F.. Distributed pore-size model for sulfation of limestone[J]. AIChE J, 1983, 29(3): 388-395
[45] Simons G. A., Garman A. R.. Small pore closure and the deaction of the limestone sulfation reaction[J]. AIChE J, 1986, 32(9): 1491-1499
[46] Simons G. A., Garman A. R.. The kinetie rate of SO_2 sorption by CaO[J]. AIChE J, 1987(33): 211-217
[47] Luo Z. Y., Yin C. G., Li X. T., et al. The fractal dimension of caleined limestone and its sulfur removal reactivity[J]. Energy, 1997, 22(11): 1051-1055
[48] Reyes S., Jensen K. F.. Estimation of effective transport coefficients in porous solids based on percolation concepts[J]. Chem. Eng. Sci., 1985(40): 1723-1734
[49] Reyes S., Jensen K. F.. Percolation concept in modeling of gas-solid reaction: Application to char gasification in diffusion regime[J]. Chem. Eng. Sci., 1986(41): 345-354
[50] Xuantian Li, Zhongyang Luo, Mingjiang Ni, et al. Modeling sulfur retention in circulating fluidized bed combustors[J]. Chem. Eng.Sci., 1992(50): 2235-2242
[51] Coppens M. O., Froment G. F.. Diffusion and reaetion in a fractal catalyst pore-Ⅰ. Geometrical aspects[J]. Chem. Eng. Sci., 1995, 50(6): 1013-1026
[52] Coppens M. O., Froment G. F.. Diffusion and reaetion in a fractal catalyst pore-Ⅱ. Diffusion and first-order reaction[J]. Chem. Eng. Sei., 1995, 50(6): 1027-1039
[53]卢广. CFB富氧燃烧下CaO同时碳酸化硫化特性研究[D]:保定:华北电力大学, 2009
[54]王春波,李永华,危日光,等.钙基脱硫剂煅烧过程中产物CaO孔径分布的模拟[J].动力工程, 2007, 27(4): 625-628
[55] Fuller E. N., Schettler P. D., Giddings J. C.. A new method for Predietion of binary gas phase dision coefficients[J]. Ind. Eng. Che., 1966(58): 19-27
[56] Dam-Johan K., Hansen P. F. B., Ostergard K.. High temperature reaetion between sulfur dioxide and limestone: A grain-micrograin model and its verifieation[J]. Chem. Eng. Sci., 1991, 46(3): 847-853
[57] Adanez J., Gareia L. F., Fierro V.. Modeling for the high temperature sulphation of calcium-based sorbents with cylindrical and plate-like pore geometries[J]. Chem. Eng. Sci., 2000(55): 3665-3683