乙烯水合物生成动力学研究
摘要
乙烯水合物的生成条件非常特殊，它在常规气相区域、近临界区域和超临界区域都能够生成水合物。在超临界条件下，乙烯水合物的生成行为有其特殊性。基于乙烯水合物能在超临界条件下生成而开发的超临界水合萃取技术具有广阔的应用前景。本文通过乙烯在纯水中的水合物生成动力学实验对乙烯在不同条件下的水合物生成动力学行为进行了研究。
实验测定了乙烯在常规气体、近临界、超临界三种不同条件下的31组水合物生成动力学数据和4组乙烯溶解度数据。实验温度范围为5.57～15.42℃，压力范围为2.033～6.020MPa。
实验结果表明：乙烯水合物生成的溶解、成核、生长的进行是一连续的过程，诱导过程不明显甚至消失；常规条件下的乙烯动力学为一光滑连续的曲线，在较低温度和较高压力下会有二次成核现象；近临界条件下乙烯生成水合物频繁出现二次成核现象；超临界条件下的乙烯由于其特殊的性质而使生成动力学行为变得更加复杂。
比较了甲烷和常规气体乙烯水合物生成在溶解速率、成核、生长过程的动力学行为。并结合提出的常规条件下水合物生成机理解释两者水合物生成行为的差异。
提出了超临界状态下的水合物生成机理，认为针对水合物生成的溶解、成核和生长三个机理而言，超临界流体的特殊性集中体现在溶解机理上。溶解不是以单个分子的形式扩散进入水相中，而是相界面的流体分子簇通过碰撞、裂解成小规模分子簇后落入水相，在水相中继续受周围分子簇的持续扰动、碰撞和吸引作用解体，最终成为单个流体分子。
The condition of ethylene (temperature and pressure) to form hydrate is very special. It covers normal gaseous area, near-critical area and supercritical area. The ethylene hydrate formation behavior in supercritical condition has its own characteristic. The new separation technology combined ethylene hydrate formation with supercritical extraction has a good application prospect. In this paper, the ethylene hydrate formation behavior in pure water were researched through hydrate formation experiment.
The 31 kinetic data of hydrate formation in gaseous, near-critical and supercritical condition and 4 solubility data were measured. The experiments were conducted at temperature ranging from 5.57-15.42 ℃ , pressure ranging from 2.033~6.020MPa.
The experimental results show that: Solution, nucleation and crystal growth are a continuous process. The induction effect is not apparent in the ethylene hydrate formation. The kinetic curves of ethylene in gaseous condition are very smooth with second nucleation happened in lower temperature and higher pressure. The second nucleation happens constantly in near-critical condition. The hydrate formation behavior of ethylene becomes more complex in supercritical condition.
The hydrate formation behavior of methane and gaseous ethylene were compared, including solution rate, nucleation and crystal growth. The differences of their hydrate formation behavior were explained combined with the proposed hydrate formation mechanism in normal gaseous condition.
A novel dissolution viewpoint was developed to explain the mechanism of hydrate formation in supercritical condition. The hydrate former in supercritical fluid phase doesn't dissolve into the aqueous phase in the form of single molecule. The fluid molecular clusters near the interface crack to form smaller fluid molecular clusters through collision, and then fall into the aqueous phase. The smaller fluid molecular clusters continue breaking through disturbance, collisions and attraction by the neighboring molecular clusters. The process continues until a single fluid molecule is formed.
实验测定了乙烯在常规气体、近临界、超临界三种不同条件下的31组水合物生成动力学数据和4组乙烯溶解度数据。实验温度范围为5.57～15.42℃，压力范围为2.033～6.020MPa。
实验结果表明：乙烯水合物生成的溶解、成核、生长的进行是一连续的过程，诱导过程不明显甚至消失；常规条件下的乙烯动力学为一光滑连续的曲线，在较低温度和较高压力下会有二次成核现象；近临界条件下乙烯生成水合物频繁出现二次成核现象；超临界条件下的乙烯由于其特殊的性质而使生成动力学行为变得更加复杂。
比较了甲烷和常规气体乙烯水合物生成在溶解速率、成核、生长过程的动力学行为。并结合提出的常规条件下水合物生成机理解释两者水合物生成行为的差异。
提出了超临界状态下的水合物生成机理，认为针对水合物生成的溶解、成核和生长三个机理而言，超临界流体的特殊性集中体现在溶解机理上。溶解不是以单个分子的形式扩散进入水相中，而是相界面的流体分子簇通过碰撞、裂解成小规模分子簇后落入水相，在水相中继续受周围分子簇的持续扰动、碰撞和吸引作用解体，最终成为单个流体分子。
The condition of ethylene (temperature and pressure) to form hydrate is very special. It covers normal gaseous area, near-critical area and supercritical area. The ethylene hydrate formation behavior in supercritical condition has its own characteristic. The new separation technology combined ethylene hydrate formation with supercritical extraction has a good application prospect. In this paper, the ethylene hydrate formation behavior in pure water were researched through hydrate formation experiment.
The 31 kinetic data of hydrate formation in gaseous, near-critical and supercritical condition and 4 solubility data were measured. The experiments were conducted at temperature ranging from 5.57-15.42 ℃ , pressure ranging from 2.033~6.020MPa.
The experimental results show that: Solution, nucleation and crystal growth are a continuous process. The induction effect is not apparent in the ethylene hydrate formation. The kinetic curves of ethylene in gaseous condition are very smooth with second nucleation happened in lower temperature and higher pressure. The second nucleation happens constantly in near-critical condition. The hydrate formation behavior of ethylene becomes more complex in supercritical condition.
The hydrate formation behavior of methane and gaseous ethylene were compared, including solution rate, nucleation and crystal growth. The differences of their hydrate formation behavior were explained combined with the proposed hydrate formation mechanism in normal gaseous condition.
A novel dissolution viewpoint was developed to explain the mechanism of hydrate formation in supercritical condition. The hydrate former in supercritical fluid phase doesn't dissolve into the aqueous phase in the form of single molecule. The fluid molecular clusters near the interface crack to form smaller fluid molecular clusters through collision, and then fall into the aqueous phase. The smaller fluid molecular clusters continue breaking through disturbance, collisions and attraction by the neighboring molecular clusters. The process continues until a single fluid molecule is formed.
引文
Christiansen R L, Sloan E D, 1994, Mechanisms and Kinetics of Hydrate Formation, Annals of the New York Academy of Sciences, 715, 283-305.
Englezos P, 1993, Clathrate Hydrates. Ind Eng Chem Res, 32: 1251-1274.
Englezos P, et al, 1987, Kinetics of Formation of Methane and Ethane Gas Hydrates, Chem. Eng. Sci., 42, 2647.
Englezos P, et al, 1987, Kinetics of Gas Hydrate Formation From Mixtures of Methane and Ethane, Chem. Eng. Sci., 42, 2659.
Ershov E D, Yakushev V S, 1992, Experimental Research on Gas Hydrate Decomposition in Frozen Rocks, Cold Reg. Sci. Technol, 20, 147-156.
Falabella B J, 1975, A Study of Natural Gas Hydrates, Ph.D.Thesis, University of Massachusetts.
Glew D N, Hagget M L, 1968, Kinetics of Formation of Ethylene Oxide Hydrate. Part Ⅱ. Incongruent Solutions and Discussion, Can. J. Chem., 46, 3867-3877.
Gudmundsson J S, Borrehaug A, 1996, Natural Gas Hyrate-An Alternative to Liquified Natural Gas, Petroleum Review, 50(592),232-235.
Gudmundsson J S, Parlaktuna M, Khokhar A A, 1994, Storage of Natural Gas as Frozen Hydrate, SPE production Engineering, 2,69-73.
Hammerschmidt E G., 1934, Formation of gas hydrates in natural gas transmission lines. Ind Eng Chem, 26(8), 851-855.
Heist J A, 1979, Freeze Crystallization, Chem.Eng, 7, 72-82.
Hppel J, Hnatow M A, Meyer H, 1994, The Study of Separation of Nitrogen from Methane by Hydrate Formation Using a Novel Apparatus, Annals of the New York Academy of sciences, 715, 412-424.
Huang C P, Fennema O, Powrie W D, 1965, Gas Hydrates in Aqueous Organic Systems 1. Preliminary Studies, Cryobiology, 1, 109-115.
Huang C P, Fennema O, Powrie W D, 1966, Gas Hydrates in Aqueous Organic Systems 2. Concentration by Gas Hydrate Formation, Cryobiology, 2, 240-245.
Hwang M J, Wright D A, 1990, An Experimental Study of Crystallization and Crystal Growth of Methane Hydrates from melting Ice, J. Inclusion Phenom Mol Recognit Chem., 8, 103-106.
Khan A H, 1986, Freezing In Desalination Processes and Multistage Flash Distillation
Practice, Elsever: Msterdam, Chapter5, 55-68.
Knox W G., Hess M, Jones G. E, 1961, The Clathrate Process, Chem. Eng. Prog, 57(2), 66-71.
Lekvam K, Ruoff P, 1994, Reaction Kinetics Simulations of Methane Hydrate Formation in Liquid Water, Annals of the New York Academy of Sciences, 715, 558-560
Makogon Y F, 1981, Hydrate of Natural Ga, Penn Well, Tulsa, Oklahoma, 53-102.
Mark M, Michael E, 1980, Solid Solubilities of Naphthalene and Biphenyl in Supercritical Carbon Dioxide, J. Chem. Eng. Data., 25, 326-329.
Ngan Y T, Englezos P, 1996, Concentration of Mechanical Pulp Mill Effluents and NaCl Solutions through Propane Hydrate Formation, Ind. Eng. Chem. Res., 35, 1894-1900.
Nishikawa N, Morishita M, Uchiyama M, 1992, CO_2 Clathrate Formation and its properties in the Simulated Deep Ocean, Energy. Convers. Manage, 33(5-8), 651-657
Pangborn J B, Barduhn A J, 1970, The Kinetics of Methyl Bromide Hydrate Formation, Desalination, 8(1), 35-68.
Parker A, 1942, A Potable Water from Sea-water, Nature, 149, 184-186.
Perry H R, 1984, Perry's Chemical Engineers' Handbook, 6th ed., McGraw-Hill, New York, 140.
Phillips J B, Nguyen H, John V T, 1991, Protein Recovery form Reversed Micellar Solutions through Contact with a Pressurized Gas Phase, Biotechnol. Prog. 74.-48.
Pinder K L, 1965, A Kinetic Study of the Formation of the Terahydrofurn Gas Hydrate, Can. J. Chem. Eng., 271-274.
Rao A M, Kommareddi N, John V T, 1992, The Use of Pressure to Modify Enzyme Activity in Reversed Micelles., Biotechnol. Prog. 8514-520.
Rao A M, Nguyen H, John V T, 1990, Modification of Enzyme Activity in Reversed Micelles through Clathrate Hydrate Formation., Biotechnol. Prog. 6, 465-471.
Ronald T, Kumik, Samuel J, 1981, Solubilitiy of Solids in Supercritical Carbon Dioxide and Ethylene, J. Chem. Eng. Data., 26,47-51.
Shufen L, Varadarajan, 1991, Solubilities of Theobromine and Caffeine in Supereritieal Carbon Dioxide:Correlation with Density-Based Models., Fluid Phase Equilibria, 68, 263-280.
Sji A, Yoshida H, Kobayashi R, 1992, Fixation of Carbon Dioxide by
Clathrate-Hydrate, Energy. Convers. Manage, 33(5-8), 643-649.
Skovborg P, et al, 1993, Measurement of Induction Times for the Formation of Methane and Ethane Gas Hydrates, Chem. Eng. Sci., 48(3), 445-453.
Sloan E D, 1992, The State-of-the Art of Hydrates as Related to the Nature Gas Industry; Gas Research Institute Topical Report GRI-91/0302; Gas Research Institue: Chicago, IL, June 1.
Sloan E D, Fleyfel F, 1991, A Molecular Mechanism for Gas Hydrate Nucleation from Ice, AIChE J, 37(19), 1281-1292.
VanHulle G, FennemaO, Powrie W D, 1971, Gas Hydrate in Aqueous Organic Systems 4. Formation and Detection of Ethylene Oxide Hydrate in Tissue, Cryobiology, 7, 223-227.
Vysniauskas A, Bishnoi P R, 1983, A Kinetic Study of Methane Hydrate Formation, Chem. Eng. Sci., 38(7), 1061-1072.
Vysniauskas A, Bishnoi P R, 1985, Kinetics of Ethane Hydrate Formation, Chem. Eng. Sci., 40, 299.
Werezak G N, 1969, Unusual Methods of Separation. AIChE Symp. Ser. 65(91), 6-18.
Willson R C, Bulot E, Cooney C L, 1990, Clathrate Hydrate Formation Enhances Near-critical and Supereritical Extraction Equilibria, Chem. Eng. Commun., 47-55.
Yoon J H, Lee H, 1997, Clathrate Phase Equilibria for the Water-Phenol-Carbon Dioxide System, AIChE J, 43(7), 1884-1893.
Yoshio I, Takao F, 1991, Solubilities of Myristic Acid Palmitic Acid and Cetyl Alcohol in Supercritical Carbon Dioxide., J. Chem. Eng. Data. 36. 430-432.
马昌峰，王峰，孙长宇，2002，水合物氢气分离技术及相关动力学研究，石油大学学报，26(2)，76-78．
裘俊红，1996，博士后研究工作报告：甲烷水合物生成动力学研究．北京，石油大学．
胡春，2000，硕士研究生学位论文：甲烷水合物生成动力学研究．杭州，浙江工业大学．
耿昌全，2002，硕士研究生学位论文：结合水合物生成机理研究甲烷在水中的溶解度．杭州，浙江工业大学．
张金峰，2003，硕士研究生学位论文：甲烷水合物在不同休系中的生成动力学研究，浙江工业大学．
Englezos P, 1993, Clathrate Hydrates. Ind Eng Chem Res, 32: 1251-1274.
Englezos P, et al, 1987, Kinetics of Formation of Methane and Ethane Gas Hydrates, Chem. Eng. Sci., 42, 2647.
Englezos P, et al, 1987, Kinetics of Gas Hydrate Formation From Mixtures of Methane and Ethane, Chem. Eng. Sci., 42, 2659.
Ershov E D, Yakushev V S, 1992, Experimental Research on Gas Hydrate Decomposition in Frozen Rocks, Cold Reg. Sci. Technol, 20, 147-156.
Falabella B J, 1975, A Study of Natural Gas Hydrates, Ph.D.Thesis, University of Massachusetts.
Glew D N, Hagget M L, 1968, Kinetics of Formation of Ethylene Oxide Hydrate. Part Ⅱ. Incongruent Solutions and Discussion, Can. J. Chem., 46, 3867-3877.
Gudmundsson J S, Borrehaug A, 1996, Natural Gas Hyrate-An Alternative to Liquified Natural Gas, Petroleum Review, 50(592),232-235.
Gudmundsson J S, Parlaktuna M, Khokhar A A, 1994, Storage of Natural Gas as Frozen Hydrate, SPE production Engineering, 2,69-73.
Hammerschmidt E G., 1934, Formation of gas hydrates in natural gas transmission lines. Ind Eng Chem, 26(8), 851-855.
Heist J A, 1979, Freeze Crystallization, Chem.Eng, 7, 72-82.
Hppel J, Hnatow M A, Meyer H, 1994, The Study of Separation of Nitrogen from Methane by Hydrate Formation Using a Novel Apparatus, Annals of the New York Academy of sciences, 715, 412-424.
Huang C P, Fennema O, Powrie W D, 1965, Gas Hydrates in Aqueous Organic Systems 1. Preliminary Studies, Cryobiology, 1, 109-115.
Huang C P, Fennema O, Powrie W D, 1966, Gas Hydrates in Aqueous Organic Systems 2. Concentration by Gas Hydrate Formation, Cryobiology, 2, 240-245.
Hwang M J, Wright D A, 1990, An Experimental Study of Crystallization and Crystal Growth of Methane Hydrates from melting Ice, J. Inclusion Phenom Mol Recognit Chem., 8, 103-106.
Khan A H, 1986, Freezing In Desalination Processes and Multistage Flash Distillation
Practice, Elsever: Msterdam, Chapter5, 55-68.
Knox W G., Hess M, Jones G. E, 1961, The Clathrate Process, Chem. Eng. Prog, 57(2), 66-71.
Lekvam K, Ruoff P, 1994, Reaction Kinetics Simulations of Methane Hydrate Formation in Liquid Water, Annals of the New York Academy of Sciences, 715, 558-560
Makogon Y F, 1981, Hydrate of Natural Ga, Penn Well, Tulsa, Oklahoma, 53-102.
Mark M, Michael E, 1980, Solid Solubilities of Naphthalene and Biphenyl in Supercritical Carbon Dioxide, J. Chem. Eng. Data., 25, 326-329.
Ngan Y T, Englezos P, 1996, Concentration of Mechanical Pulp Mill Effluents and NaCl Solutions through Propane Hydrate Formation, Ind. Eng. Chem. Res., 35, 1894-1900.
Nishikawa N, Morishita M, Uchiyama M, 1992, CO_2 Clathrate Formation and its properties in the Simulated Deep Ocean, Energy. Convers. Manage, 33(5-8), 651-657
Pangborn J B, Barduhn A J, 1970, The Kinetics of Methyl Bromide Hydrate Formation, Desalination, 8(1), 35-68.
Parker A, 1942, A Potable Water from Sea-water, Nature, 149, 184-186.
Perry H R, 1984, Perry's Chemical Engineers' Handbook, 6th ed., McGraw-Hill, New York, 140.
Phillips J B, Nguyen H, John V T, 1991, Protein Recovery form Reversed Micellar Solutions through Contact with a Pressurized Gas Phase, Biotechnol. Prog. 74.-48.
Pinder K L, 1965, A Kinetic Study of the Formation of the Terahydrofurn Gas Hydrate, Can. J. Chem. Eng., 271-274.
Rao A M, Kommareddi N, John V T, 1992, The Use of Pressure to Modify Enzyme Activity in Reversed Micelles., Biotechnol. Prog. 8514-520.
Rao A M, Nguyen H, John V T, 1990, Modification of Enzyme Activity in Reversed Micelles through Clathrate Hydrate Formation., Biotechnol. Prog. 6, 465-471.
Ronald T, Kumik, Samuel J, 1981, Solubilitiy of Solids in Supercritical Carbon Dioxide and Ethylene, J. Chem. Eng. Data., 26,47-51.
Shufen L, Varadarajan, 1991, Solubilities of Theobromine and Caffeine in Supereritieal Carbon Dioxide:Correlation with Density-Based Models., Fluid Phase Equilibria, 68, 263-280.
Sji A, Yoshida H, Kobayashi R, 1992, Fixation of Carbon Dioxide by
Clathrate-Hydrate, Energy. Convers. Manage, 33(5-8), 643-649.
Skovborg P, et al, 1993, Measurement of Induction Times for the Formation of Methane and Ethane Gas Hydrates, Chem. Eng. Sci., 48(3), 445-453.
Sloan E D, 1992, The State-of-the Art of Hydrates as Related to the Nature Gas Industry; Gas Research Institute Topical Report GRI-91/0302; Gas Research Institue: Chicago, IL, June 1.
Sloan E D, Fleyfel F, 1991, A Molecular Mechanism for Gas Hydrate Nucleation from Ice, AIChE J, 37(19), 1281-1292.
VanHulle G, FennemaO, Powrie W D, 1971, Gas Hydrate in Aqueous Organic Systems 4. Formation and Detection of Ethylene Oxide Hydrate in Tissue, Cryobiology, 7, 223-227.
Vysniauskas A, Bishnoi P R, 1983, A Kinetic Study of Methane Hydrate Formation, Chem. Eng. Sci., 38(7), 1061-1072.
Vysniauskas A, Bishnoi P R, 1985, Kinetics of Ethane Hydrate Formation, Chem. Eng. Sci., 40, 299.
Werezak G N, 1969, Unusual Methods of Separation. AIChE Symp. Ser. 65(91), 6-18.
Willson R C, Bulot E, Cooney C L, 1990, Clathrate Hydrate Formation Enhances Near-critical and Supereritical Extraction Equilibria, Chem. Eng. Commun., 47-55.
Yoon J H, Lee H, 1997, Clathrate Phase Equilibria for the Water-Phenol-Carbon Dioxide System, AIChE J, 43(7), 1884-1893.
Yoshio I, Takao F, 1991, Solubilities of Myristic Acid Palmitic Acid and Cetyl Alcohol in Supercritical Carbon Dioxide., J. Chem. Eng. Data. 36. 430-432.
马昌峰，王峰，孙长宇，2002，水合物氢气分离技术及相关动力学研究，石油大学学报，26(2)，76-78．
裘俊红，1996，博士后研究工作报告：甲烷水合物生成动力学研究．北京，石油大学．
胡春，2000，硕士研究生学位论文：甲烷水合物生成动力学研究．杭州，浙江工业大学．
耿昌全，2002，硕士研究生学位论文：结合水合物生成机理研究甲烷在水中的溶解度．杭州，浙江工业大学．
张金峰，2003，硕士研究生学位论文：甲烷水合物在不同休系中的生成动力学研究，浙江工业大学．