环状化合物-甲烷水合物稳定性的分子模拟
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摘要
分子动力学模拟(MD)可为天然气以水合物形式固化提供微观分析。本文利用计算机模拟,恒温等压(NPT)系综下,分别研究了温度为273K、283K、293K,压力为2MPa条件下,环状化合物环戊烷、四氢呋喃、四氢吡喃3种促进剂对Ⅱ型甲烷水合物体系稳定性的影响。结果表明:添加促进剂可使天然气水合物在温和条件下稳定存在;当温度升高,体系稳定性下降;相同条件下,促进作用排序为环戊烷四氢呋喃四氢吡喃;客体分子直径与晶穴直径之比接近1时体系较稳定。
Molecular dynamics simulation(MD) provides microscopic analysis of natural gas solidification in the form of hydrates. In this paper, using computer simulation and isothermal-isobaric?ensemble(constant-NPT ensemble), the effects of three cyclic compound accelerators, cyclopentane, tetrahydrofuran and tetrahydropyran, on the stability of type Ⅱ methane hydrate system were studied under the conditions of 273 K, 283 K, 293 K and 2 MPa. The results show that the addition of accelerator can make the natural gas hydrate stable under unharsh conditions; when the temperature increases, the stability of the system decreases; under the same conditions, the contribution to the stability is cyclopentane >tetrahydrofuran >tetrahydropyran; and when the ratio of guest molecule diameter to crystal hole diameter is close to 1, the system is relatively stable.
Molecular dynamics simulation(MD) provides microscopic analysis of natural gas solidification in the form of hydrates. In this paper, using computer simulation and isothermal-isobaric?ensemble(constant-NPT ensemble), the effects of three cyclic compound accelerators, cyclopentane, tetrahydrofuran and tetrahydropyran, on the stability of type Ⅱ methane hydrate system were studied under the conditions of 273 K, 283 K, 293 K and 2 MPa. The results show that the addition of accelerator can make the natural gas hydrate stable under unharsh conditions; when the temperature increases, the stability of the system decreases; under the same conditions, the contribution to the stability is cyclopentane >tetrahydrofuran >tetrahydropyran; and when the ratio of guest molecule diameter to crystal hole diameter is close to 1, the system is relatively stable.
引文
[1]胡亚飞,蔡晶,李小森.环戊烷-甲烷水合物生成过程的温度特性[J].化工进展,2016,35(5):1418-1427.
[2]孙强,郭绪强.(CH4+N2+THF)体系水合物生成动力学[J].化工进展,2011,30(S1):514-516.
[3]梁德青,郭开华,樊栓狮,等.Equilibrium data of cyclopentane hydrate[J].化工学报,2001,52(9):753-754.
[4]And J H,Bartell L S.Molecular dynamics simulation of nucleation in the freezing of molten potassium iodide clusters[J].J Phys Chem A,2002,106:2404-2409.
[5]梅东海,李以圭,陆九芳,等.H型气体水合物结构稳定性的分子动力学模拟[J].化工学报,1998,49(6):662-670.
[6]Wu J Y,Chen L J,Chen Y P,et al.Molecular dynamics study on the nucleation of methane+tetrahydrofuran mixed guest hydrate[J].Phys Chem Chem Phys,2016,18:9935.
[7]张庆东,李玉星,王武昌.四氢呋喃-甲烷水合物稳定性的分子动力学模拟[J].化工进展,2014,33(S1):98-105.
[8]张庆东,李玉星,王武昌,等.温度对甲烷水合物形成过程影响的分子动力学模拟[J].油气储运,2015,34(12):1288-1294.
[9]殷开梁,邹定辉,杨波,等.Materials Studio软件涉及力场中氢键的研究[J].计算机与应用化学,2006,23(12):169-174.
[10]耿春宇,丁丽颖,韩清珍,等.气体分子对甲烷水合物稳定性的影响[J].物理化学学报,2008,24(4):595-600.
[11]丁丽颖,耿春宇,赵月红,等.Ⅰ型甲烷水合物晶体稳定性的分子动力学模拟[J].计算机与应用化学,2007,24(5):569-574.
[12]Li J,Ross D K.Evidence for two kinds of hydrogen bond in ice[J].Nature,1993,365:327-329.
[13]胡盛志,谢兆雄,周朝晖.晶体范德华半径的70年[J].物理化学学报,2010,(7):1795-1800.
[14]Hollander F,Jeffrey G A.Neutron diffraction study of the crystal structure of ethylene oxide deuterohydrate at 80°K[J].J Chem Phys,1977,66:4699-4705.
[15]Bernal J D,Fowler R H.A theory of water and ionic solution,with particular reference to hydrogen and hydroxyl ions[J].J Chem Phys,1933,1:515-548.
[16]Duan Z,Sun R.A model to predict phase equilibrium of CH4and CO2clathrate hydrate in aqueous electrolyte solutions[J].American Mineralogist,2006,91:1346-1354.
[17]Berendsen H J C,Postma J P M,van Gunsteren W F,et al.Interaction models for water in relation to protein hydration[M].Springer Netherlands:Intermolecular forces,1981:331-342.
[18]陈光进,孙长宇,马庆兰.气体水合物科学与技术[M].北京:化学工业出版社,2008.
[19]Chialvo A A,Houssa M,Cummings P T.Molecular dynamics study of the structure and thermophysical properties of model sI clathrate hydrates[J].J Phys Chem B,2002,106:442-451.
[2]孙强,郭绪强.(CH4+N2+THF)体系水合物生成动力学[J].化工进展,2011,30(S1):514-516.
[3]梁德青,郭开华,樊栓狮,等.Equilibrium data of cyclopentane hydrate[J].化工学报,2001,52(9):753-754.
[4]And J H,Bartell L S.Molecular dynamics simulation of nucleation in the freezing of molten potassium iodide clusters[J].J Phys Chem A,2002,106:2404-2409.
[5]梅东海,李以圭,陆九芳,等.H型气体水合物结构稳定性的分子动力学模拟[J].化工学报,1998,49(6):662-670.
[6]Wu J Y,Chen L J,Chen Y P,et al.Molecular dynamics study on the nucleation of methane+tetrahydrofuran mixed guest hydrate[J].Phys Chem Chem Phys,2016,18:9935.
[7]张庆东,李玉星,王武昌.四氢呋喃-甲烷水合物稳定性的分子动力学模拟[J].化工进展,2014,33(S1):98-105.
[8]张庆东,李玉星,王武昌,等.温度对甲烷水合物形成过程影响的分子动力学模拟[J].油气储运,2015,34(12):1288-1294.
[9]殷开梁,邹定辉,杨波,等.Materials Studio软件涉及力场中氢键的研究[J].计算机与应用化学,2006,23(12):169-174.
[10]耿春宇,丁丽颖,韩清珍,等.气体分子对甲烷水合物稳定性的影响[J].物理化学学报,2008,24(4):595-600.
[11]丁丽颖,耿春宇,赵月红,等.Ⅰ型甲烷水合物晶体稳定性的分子动力学模拟[J].计算机与应用化学,2007,24(5):569-574.
[12]Li J,Ross D K.Evidence for two kinds of hydrogen bond in ice[J].Nature,1993,365:327-329.
[13]胡盛志,谢兆雄,周朝晖.晶体范德华半径的70年[J].物理化学学报,2010,(7):1795-1800.
[14]Hollander F,Jeffrey G A.Neutron diffraction study of the crystal structure of ethylene oxide deuterohydrate at 80°K[J].J Chem Phys,1977,66:4699-4705.
[15]Bernal J D,Fowler R H.A theory of water and ionic solution,with particular reference to hydrogen and hydroxyl ions[J].J Chem Phys,1933,1:515-548.
[16]Duan Z,Sun R.A model to predict phase equilibrium of CH4and CO2clathrate hydrate in aqueous electrolyte solutions[J].American Mineralogist,2006,91:1346-1354.
[17]Berendsen H J C,Postma J P M,van Gunsteren W F,et al.Interaction models for water in relation to protein hydration[M].Springer Netherlands:Intermolecular forces,1981:331-342.
[18]陈光进,孙长宇,马庆兰.气体水合物科学与技术[M].北京:化学工业出版社,2008.
[19]Chialvo A A,Houssa M,Cummings P T.Molecular dynamics study of the structure and thermophysical properties of model sI clathrate hydrates[J].J Phys Chem B,2002,106:442-451.