1
|
Li K, Chen B, Li M, Jiang L, Song Y, Yang M. Facilitation of Hydrate Dissociation and Structural Evolution by Major Marine Anions under Static Electric Fields. J Phys Chem B 2023; 127:10447-10457. [PMID: 37991934 DOI: 10.1021/acs.jpcb.3c06012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2023]
Abstract
Electric fields have been proven to be capable of significantly affecting the equilibrium state of hydrates. In this study, the thermodynamic properties and structural changes of methane hydrate (MH) in various anion solutions in an electric field at 0.7 V/nm were investigated by molecular dynamics simulations. The presence of anions significantly enhances the instability of methane hydrates under electric fields, leading to a staged dissociation process. First, the anions coexist with MH to form a temporary metastable structure under the action of an electric field. Then, the migration of anions causes the dissociation of nearby hydrates and the formation of flow channels in the hydrate layer, which leads to the complete dissociation of MH after a period. The promotive effects of F-, Br-, I-, and Cl- ions were close, while SO42- was relatively weak. The anions are still in hydration shells in the MH phase, but the structure of the hydration shells differs slightly from that in solution (the coordination numbers of I- and SO42- ions increased). The migration resistances of multiple anions to cross the surface of the hydrate layer are similar. However, inside the hydrate phase, the anions with a larger radius have a higher migration resistance. It is difficult for SO42- ions to migrate inside the hydrate phase, and they tend to form a metastable structure on the hydrate surface. Combining our previous studies, SrCl2 solution has the best hydrate promotion under an electric field environment.
Collapse
Affiliation(s)
- Kehan Li
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian 116024, China
| | - Bingbing Chen
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian 116024, China
| | - Mingjun Li
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian 116024, China
| | - Lanlan Jiang
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian 116024, China
| | - Yongchen Song
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian 116024, China
| | - Mingjun Yang
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian 116024, China
| |
Collapse
|
2
|
Belosludov RV, Gets KV, Zhdanov RK, Bozhko YY, Belosludov VR, Chen LJ, Kawazoe Y. Molecular Dynamics Study of Clathrate-like Ordering of Water in Supersaturated Methane Solution at Low Pressure. Molecules 2023; 28:molecules28072960. [PMID: 37049727 PMCID: PMC10095827 DOI: 10.3390/molecules28072960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/23/2023] [Accepted: 03/24/2023] [Indexed: 03/29/2023] Open
Abstract
Using molecular dynamics, the evolution of a metastable solution for “methane + water” was studied for concentrations of 3.36, 6.5, 9.45, 12.2, and 14.8 mol% methane at 270 K and 1 bar during 100 ns. We have found the intriguing behavior of the system containing over 10,000 water molecules: the formation of hydrate-like structures is observed at 6.5 and 9.45 mol% concentrations throughout the entire solution volume. This formation of “blobs” and the following amorphous hydrate were studied. The creation of a metastable methane solution through supersaturation is the key to triggering the collective process of hydrate formation under low pressure. Even the first stage (0–1 ns), before the first fluctuating cavities appear, is a collective process of H-bond network reorganization. The formation of fluctuation cavities appears before steady hydrate growth begins and is associated with a preceding uniform increase in the water molecule’s tetrahedrality. Later, the constantly presented hydrate cavities become the foundation for a few independent hydrate nucleation centers, this evolution is consistent with the labile cluster and local structure hypotheses. This new mechanism of hydrogen-bond network reorganization depends on the entropy of the cavity arrangement of the guest molecules in the hydrate lattice and leads to hydrate growth.
Collapse
Affiliation(s)
| | - Kirill V. Gets
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090 Novosibirsk, Russia
- Department of Physics, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Ravil K. Zhdanov
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090 Novosibirsk, Russia
- Department of Physics, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Yulia Y. Bozhko
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090 Novosibirsk, Russia
- Department of Physics, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Vladimir R. Belosludov
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090 Novosibirsk, Russia
- Department of Physics, Novosibirsk State University, 630090 Novosibirsk, Russia
- Correspondence:
| | - Li-Jen Chen
- Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Yoshiyuki Kawazoe
- New Industry Creation Hatchery Center, Tohoku University, Sendai 980-8579, Japan
- Department of Physics and Nanotechnology, SRM Institute of Science and Technology, Kattankurathur 603203, India
- School of Physics, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| |
Collapse
|
3
|
Chen B, Li K, Sun H, Jiang L, Yang M, Song Y. Promoting Effect of Common Marine Cations on Hydrate Dissociation and Structural Evolution under a Static Electric Field. J Phys Chem B 2023; 127:698-709. [PMID: 36629388 DOI: 10.1021/acs.jpcb.2c05382] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Natural gas hydrate, a potential energy resource, is attracting worldwide attention. In this study, we propose a new method of hydrate dissociation which uses seawater and electrostatic fields (SE method) cooperatively. The hydrate molecular dissociation mechanism of gas hydrate is a key issue in studying the kinetic properties of gas hydrate using the SE method. Therefore, molecular dynamics simulations were used to investigate the thermodynamic properties and structural changes of methane hydrate (MH) in multiple kinds of salt solutions under an electrostatic field. The results show that the electric field can drive cations into the MH phase to form a series of random semiopen cages, which are essentially temporary and metastable. The variation in free energy indicates that it is more difficult for divalent cations to enter the hydrate phase than monovalent cations, meaning that the hydrate structures formed with divalent cations are more unstable. Then, the ion current occurred in the hydrate phase (called ion migration in this study), which greatly accelerated hydrate dissociation. In contrast, the promotion effect of cations with the same charge on MH dissociation is as follows: Sr2+ > K+ ≈ Na+ > Ca2+ ≈ Mg2+. In general, the presence of common marine cations enhanced the promotion effect of the electric field on gas hydrate dissociation.
Collapse
Affiliation(s)
- Bingbing Chen
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian116024, China
| | - Kehan Li
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian116024, China
| | - Huiru Sun
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian116024, China
| | - Lanlan Jiang
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian116024, China
| | - Mingjun Yang
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian116024, China
| | - Yongchen Song
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian116024, China
| |
Collapse
|
4
|
Song Y, Li K, Sun H, Chen B, Yang M. New Sights on derived behaviors of methane hydrate molecular structure in Na+/Cl- ions invading process. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
|
5
|
Alanine rich amphiphilic peptides as green substitutes for hydrate inhibitors: a molecular simulation study. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.121008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
6
|
Lv W, Deng C, Jin Z, Zhang H, Wang Y. Molecular Simulation of the Effects of Cyclic Organic Compounds on the Stability of Lccbm Hydrates. Molecules 2022; 27:molecules27207077. [PMID: 36296669 PMCID: PMC9612244 DOI: 10.3390/molecules27207077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/17/2022] [Accepted: 10/18/2022] [Indexed: 11/16/2022] Open
Abstract
CH4 can be separated from low-concentration coal bed methane (LCCBM) by using the hydrate-based gas separation (HBGS) method. To study the contribution of different cyclic organic compounds to the separation of CH4 in LCCBM, an LCCBM hydrate model was constructed. Based on the Monte Carlo and molecular dynamics theory, we simulated the effect of three cyclic organic compounds—cyclopentane (CP), cyclopentanone (CP-one), and cyclopentanol (CP-ol)—on the stability of the LCCBM hydrate at P = 2 MPa, various temperatures, and discussed the structural stability of the hydrate in depth in terms of final snapshots, radial distribution function, mean square displacement, diffusion coefficient, and potential energy change. The results showed that for the CH4-N2 LCCMM gas mixture, CP showed the best facilitation effect compared to the other two cyclic compounds by maintaining the stability of the LCCBM hydrate well at T = 293 K. The promotion effect of CP-one is between CP and CP-ol, and when the temperature increases to T = 293 K, the oxygen atoms in the water molecule can maintain the essential stability of the hydrate structure, although the orderliness decreases significantly. Moreover, the structure of the hydrate model containing CP-ol is destroyed at T = 293 K, and the eventual escape of CH4 and N2 molecules in solution occurs as bubbles. The research results are important for further exploration of the mechanism of action of cyclic promoter molecules with LCCBM hydrate molecules and promoter preferences.
Collapse
Affiliation(s)
- Wenbo Lv
- College of Safety and Emergency Management and Engineering, Taiyuan University of Technology, Jinzhong 030600, China
| | - Cunbao Deng
- College of Safety and Emergency Management and Engineering, Taiyuan University of Technology, Jinzhong 030600, China
- Correspondence: (C.D.); (H.Z.); Tel.: +86-133-3343-6997 (C.D.); +86-180-5137-5604 (H.Z.)
| | - Zhixin Jin
- College of Safety and Emergency Management and Engineering, Taiyuan University of Technology, Jinzhong 030600, China
| | - Hao Zhang
- College of Safety and Emergency Management and Engineering, Taiyuan University of Technology, Jinzhong 030600, China
- Datong Coal Mine Group Co., Ltd., Datong 037037, China
- Correspondence: (C.D.); (H.Z.); Tel.: +86-133-3343-6997 (C.D.); +86-180-5137-5604 (H.Z.)
| | - Yansheng Wang
- College of Safety and Emergency Management and Engineering, Taiyuan University of Technology, Jinzhong 030600, China
| |
Collapse
|
7
|
|
8
|
Jing X, Luo Q, Cui X, Wang Q, Liu Y, Fu Z. Molecular Dynamics Simulation of CO2 Hydrate Growth in Salt Water. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
9
|
Ismail NA, Koh CA. Growth Rate and Morphology Study of Tetrahydrofuran Hydrate Single Crystals and the Effect of Salt. CrystEngComm 2022. [DOI: 10.1039/d2ce00176d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
For an advanced gas hydrate management strategy in flow assurance as well as the application of a gas hydrate technology (e.g., desalination), it is important to understand the kinetics and...
Collapse
|
10
|
Xu J, Du S, Hao Y, Yang X, Zhang J. Molecular simulation study of methane hydrate formation mechanism in NaCl solutions with different concentrations. Chem Phys 2021. [DOI: 10.1016/j.chemphys.2021.111323] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
11
|
Zhang L, Sun L, Lu Y, Kuang Y, Ling Z, Yang L, Dong H, Yang S, Zhao J, Song Y. Molecular dynamics simulation and in-situ MRI observation of organic exclusion during CO2 hydrate growth. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2020.138287] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
12
|
Thakre N, Palodkar AV, Dongre HJ, Jana AK. Microscopic Molecular Insights into Hydrate Formation and Growth in Pure and Saline Water Environments. J Phys Chem A 2020; 124:4241-4252. [PMID: 32368914 DOI: 10.1021/acs.jpca.0c00621] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The growth dynamics of natural gas hydrates in saline water has been studied using copious experiments and spectroscopic observations; however, the microscopic evidences to the structural and molecular transformations that they have provided are poorly understood. In this view, we perform extensive molecular dynamics simulations to gain physical insights into the formation and growth mechanism of naturally occurring gas hydrates with a wide variation in the amount of methane (1:5 to 1:18 methane/water ratio) in pure and salt (0-5 wt %) water environments at 50 MPa and 260 K. A couple of new findings analyzed from the number of cages and F4φ order parameter are as follows: (a) 1:6 (methane/water ratio) is an optimum ratio for the rapid growth of a properly ordered hydrate in pure water at which the hydrate growth retards with increasing salt concentration, (b) there is an inconsequential difference between methane hydrate dynamics in pure water and 0.8 and 1.5 wt % salt water at a ratio of 1:12 (methane/water), and (c) lower methane (1:18) and salt (0.8 wt %) concentrations promote hydrate growth. Besides, this study observes the structural coexistence of S-I and S-II methane hydrates as the large 51264 cages appear along with the small 512 and large 51262 cages, in which the low methane concentration favors the S-II structure.
Collapse
Affiliation(s)
- Niraj Thakre
- Energy and Process Engineering Laboratory, Department of Chemical Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Avinash V Palodkar
- Energy and Process Engineering Laboratory, Department of Chemical Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Harshal J Dongre
- Energy and Process Engineering Laboratory, Department of Chemical Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Amiya K Jana
- Energy and Process Engineering Laboratory, Department of Chemical Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| |
Collapse
|
13
|
Liu T, Liu N, Chen L. Microscopic Insights into the Formation of Methane Hydrate in the Absence/Presence of Electrolyte Ions. ChemistrySelect 2020. [DOI: 10.1002/slct.201904693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Tingsong Liu
- University of Shanghai for Science and Technology School of Energy and Power EngineeringUniversity of Shanghai for Science and Technology Shanghai China
| | - Ni Liu
- University of Shanghai for Science and Technology School of Energy and Power EngineeringUniversity of Shanghai for Science and Technology Shanghai China
| | - Litao Chen
- University of Shanghai for Science and Technology School of Energy and Power EngineeringUniversity of Shanghai for Science and Technology Shanghai China
| |
Collapse
|
14
|
Yi L, Zhou X, He Y, Cai Z, Zhao L, Zhang W, Shao Y. Molecular Dynamics Simulation Study on the Growth of Structure II Nitrogen Hydrate. J Phys Chem B 2019; 123:9180-9186. [PMID: 31609605 DOI: 10.1021/acs.jpcb.9b06386] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Crystal growth of N2 hydrate in a three-phase system consisting of N2 hydrate, liquid water, and gaseous N2 was performed by molecular dynamics simulation at 260 K. Pressure influence on hydrate growth was evaluated. The kinetic properties including the growth rates and cage occupancies of the newly formed hydrate and the diffusion coefficient and concentration of N2 molecules in liquid phase were measured. The results showed that the growth of N2 hydrate could be divided into two stages where N2 molecules in gas phase had to dissolve in liquid phase and then form hydrate cages at the liquid-hydrate interface. The diffusion coefficient and concentration of N2 in liquid phase increased linearly with increasing pressure. As the pressure rose from 50 to 100 MPa, the hydrate growth rate kept increasing from 0.11 to 0.62 cages·ns-1·Å-2 and then dropped down to around 0.40 cages·ns-1·Å-2 once the pressure surpassed 100 MPa. During the hydrate formation, the initial sII N2 hydrate phase set in the system served as a template for the subsequent growth of N2 hydrate so that no new crystal structure was found. Analysis on the cage occupancies revealed that the amount of cages occupied by two N2 molecules increased evidently when the pressure was above 100 MPa, which slowed down the growth rate of hydrate cages. Additionally, a small fraction of defective cages including two N2 molecules trapped in 51265 cages and three N2 molecules trapped 51268 cages was observed during the hydrate growth.
Collapse
Affiliation(s)
| | - Xuebing Zhou
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences , Guangzhou 510640 , China
| | | | | | | | | | | |
Collapse
|
15
|
Zúñiga-Hinojosa MA, Martínez J, García-Sánchez F, Macías-Salinas R. Modeling the Hydrate Dissociation Pressure of Light Hydrocarbons in the Presence of Single NaCl, KCl, and CaCl2 Aqueous Solutions Using a Modified Equation of State for Aqueous Electrolyte Solutions with Partial Ionization. Ind Eng Chem Res 2019. [DOI: 10.1021/acs.iecr.9b01880] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- María A. Zúñiga-Hinojosa
- Departamento de Ingeniería Química, SEPI-ESIQIE, Instituto Politécnico Nacional, Ciudad de México, 07738, Mexico
| | - Jeremías Martínez
- Facultad de Química, Universidad Autónoma del Estado de México, Paseo Colón y Paseo Tollocan S/N, Toluca, Estado de México, 50120, Mexico
- Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM, Carretera Toluca-Atlacomulco, km 14.5, Toluca, Estado de México, 50200, Mexico
| | - Fernando García-Sánchez
- Gerencia de Ingeniería de Recuperación Adicional, Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas Norte No. 152, Ciudad de México, 07730, Mexico
| | - Ricardo Macías-Salinas
- Departamento de Ingeniería Química, SEPI-ESIQIE, Instituto Politécnico Nacional, Ciudad de México, 07738, Mexico
| |
Collapse
|
16
|
Jiménez-Ángeles F, Firoozabadi A. Hydrophobic Hydration and the Effect of NaCl Salt in the Adsorption of Hydrocarbons and Surfactants on Clathrate Hydrates. ACS CENTRAL SCIENCE 2018; 4:820-831. [PMID: 30062110 PMCID: PMC6062839 DOI: 10.1021/acscentsci.8b00076] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Indexed: 05/16/2023]
Abstract
Adsorption of functional molecules on the surface of hydrates is key in the understanding of hydrate inhibitors. We investigate the adsorption of a hydrocarbon chain, nonionic and ionic surfactants, and ions at the hydrate-aqueous interface. Our results suggest a strong connection between the water ordering around solutes in bulk and the affinity for the hydrates surface. We distinguish two types of water ordering around solutes: (i) hydrophobic hydration where water molecules form a hydrogen bond network similar to clathrate hydrates, and (ii) ionic hydration where water molecules align according to the polarity of an ionic group. The nonionic surfactant and the hydrocarbon chain induce hydrophobic hydration and are favorably adsorbed on the hydrate surface. Adsorption of ions and the ionic headgroups on the hydrate surface is not favorable because ionic hydration and the hydrogen bond structure of hydrates are incompatible. The nonionic surfactant is adsorbed by the headgroup and tail while adsorption of the ionic surfactants is not favorable through the head. Water ordering is analyzed using the hydrogen bond and tetrahedral density profiles as a function of the distance to the chemical groups. The adsorption of solutes is studied through the free energy profiles as a function of the distance to the hydrate surface. Salt lowers the melting temperature of hydrates, disrupts hydrophobic hydration, reduces the solubility of solutes in the aqueous solution, and increases the propensity of solutes to be adsorbed on hydrate surfaces. Our studies are performed by the unbiased and steered molecular dynamics simulations. The results are in line with experiments on the effect of salt and alkanes in hydrate antiagglomeration.
Collapse
Affiliation(s)
| | - Abbas Firoozabadi
- Reservoir
Engineering Research Institute, Palo Alto, California 94301, United States
- Department
of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06510, United States
- E-mail: . Phone: +1 (650) 326-9172. Fax: +1 (650) 472-9285
| |
Collapse
|
17
|
Gao F, Gupta KM, Yuan S, Jiang J. Decomposition of CH 4 hydrate: effects of temperature and salt from molecular simulations. MOLECULAR SIMULATION 2018. [DOI: 10.1080/08927022.2018.1478090] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Fengfeng Gao
- Department of Chemical Engineering, Zibo Vocational Institute, Zibo, People’s Republic of China
- Key Laboratory of Colloid and Interface Chemistry, Shandong University, Jinan, People’s Republic of China
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore
| | - Krishna M. Gupta
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore
| | - Shiling Yuan
- Key Laboratory of Colloid and Interface Chemistry, Shandong University, Jinan, People’s Republic of China
| | - Jianwen Jiang
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore
| |
Collapse
|
18
|
Yagasaki T, Matsumoto M, Tanaka H. Adsorption of Kinetic Hydrate Inhibitors on Growing Surfaces: A Molecular Dynamics Study. J Phys Chem B 2018; 122:3396-3406. [PMID: 29278335 DOI: 10.1021/acs.jpcb.7b10356] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We investigate the mechanism of a typical kinetic hydrate inhibitor (KHI), polyvinylcaprolactam (PVCap), which has been applied to prevent hydrate plugs from forming in gas pipe lines, using molecular dynamics simulations of crystal growth of ethylene oxide hydrate. Water-soluble ethylene oxide is chosen as a guest species to avoid problems associated with the presence of the gas phase in the simulation cell such as slow crystal growth. A PVCap dodecamer adsorbs irreversibly on the hydrate surface which grows at supercooling of 3 K when the hydrophobic part of two pendent groups are trapped in open cages at the surface. The amide hydrogen bonds make no contribution to the adsorption. PVCap can adsorb on various crystallographic planes of sI hydrate. This is in contrast to antifreeze proteins, each of which prefers a specific plane of ice. The trapped PVCap gives rise to necessarily the concave surface of the hydrate. The crystal growth rate decreases with increasing surface curvature, indicating that the inhibition by PVCap is explained by the Gibbs-Thomson effect.
Collapse
Affiliation(s)
- Takuma Yagasaki
- Research Institute for Interdisciplinary Science , Okayama University , Okayama 700-8530 , Japan
| | - Masakazu Matsumoto
- Research Institute for Interdisciplinary Science , Okayama University , Okayama 700-8530 , Japan
| | - Hideki Tanaka
- Research Institute for Interdisciplinary Science , Okayama University , Okayama 700-8530 , Japan
| |
Collapse
|
19
|
Xu J, Li L, Liu J, Wang X, Yan Y, Zhang J. The molecular mechanism of the inhibition effects of PVCaps on the growth of sI hydrate: an unstable adsorption mechanism. Phys Chem Chem Phys 2018. [DOI: 10.1039/c8cp00010g] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Adsorption and non-binding-hydrate sites produce synergistic effects that lead to unstable adsorption and inhibition effects (recurring destruction of hydrate).
Collapse
Affiliation(s)
- Jiafang Xu
- National Engineering Laboratory for Subsea Equipment Testing and Detection Technology
- School of Petroleum Engineering
- China University of Petroleum (East China)
- Qingdao
- People's Republic of China
| | - Liwen Li
- National Engineering Laboratory for Subsea Equipment Testing and Detection Technology
- School of Petroleum Engineering
- China University of Petroleum (East China)
- Qingdao
- People's Republic of China
| | - Jinxiang Liu
- School of Physics and Technology
- University of Jinan
- Jinan
- People's Republic of China
| | - Xiaopu Wang
- National Engineering Laboratory for Subsea Equipment Testing and Detection Technology
- School of Petroleum Engineering
- China University of Petroleum (East China)
- Qingdao
- People's Republic of China
| | - Youguo Yan
- College of Science
- China University of Petroleum (East China)
- Qingdao
- People's Republic of China
| | - Jun Zhang
- College of Science
- China University of Petroleum (East China)
- Qingdao
- People's Republic of China
| |
Collapse
|
20
|
Xu J, Chen Z, Liu J, Sun Z, Wang X, Zhang J. A molecular dynamic study on the dissociation mechanism of SI methane hydrate in inorganic salt aqueous solutions. J Mol Graph Model 2017; 75:403-412. [PMID: 28666231 DOI: 10.1016/j.jmgm.2017.03.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 03/28/2017] [Accepted: 03/29/2017] [Indexed: 10/19/2022]
Abstract
Gas hydrate is not only a potential energy resource, but also almost the biggest challenge in oil/gas flow assurance. Inorganic salts such as NaCl, KCl and CaCl2 are widely used as the thermodynamic inhibitor to reduce the risk caused by hydrate formation. However, the inhibition mechanism is still unclear. Therefore, molecular dynamic (MD) simulation was performed to study the dissociation of structure I (SI) methane hydrate in existence of inorganic salt aqueous solution on a micro-scale. The simulation results showed that, the dissociation became stagnant due to the presence of liquid film formed by the decomposed water molecules, and more inorganic ions could shorten the stagnation-time. The diffusion coefficients of ions and water molecules were the largest in KCl system. The structures of ion/H2O and H2O/H2O were the most compact in hydrate/NaCl system. The ionic ability to decompose hydrate cells followed the sequence of: Ca2+>2K+>2Cl->2Na+.
Collapse
Affiliation(s)
- Jiafang Xu
- University of Petroleum (East China), Qingdao, China; National Engineering Laboratory for Subsea Equipment Testing and Detection Technology, China.
| | - Zhe Chen
- University of Petroleum (East China), Qingdao, China
| | | | - Zening Sun
- China United Coalbed Methane Corporation, Ltd., Taiyuan, China.
| | - Xiaopu Wang
- University of Petroleum (East China), Qingdao, China
| | - Jun Zhang
- University of Petroleum (East China), Qingdao, China.
| |
Collapse
|
21
|
Structure and energetic characteristics of methane hydrates. From single cage to triple cage: A DFT-D study. J Mol Struct 2017. [DOI: 10.1016/j.molstruc.2016.10.093] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
22
|
Matsunaga S. Effect of Greenhouse Gases Dissolved in Seawater. Int J Mol Sci 2015; 17:ijms17010045. [PMID: 26729101 PMCID: PMC4730290 DOI: 10.3390/ijms17010045] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 11/28/2015] [Accepted: 12/14/2015] [Indexed: 11/16/2022] Open
Abstract
A molecular dynamics simulation has been performed on the greenhouse gases carbon dioxide and methane dissolved in a sodium chloride aqueous solution, as a simple model of seawater. A carbon dioxide molecule is also treated as a hydrogen carbonate ion. The structure, coordination number, diffusion coefficient, shear viscosity, specific heat, and thermal conductivity of the solutions have been discussed. The anomalous behaviors of these properties, especially the negative pressure dependence of thermal conductivity, have been observed in the higher-pressure region.
Collapse
Affiliation(s)
- Shigeki Matsunaga
- National Institute of Technology, Nagaoka College, Nishikatakai 888, Nagaoka 940-8532, Japan.
| |
Collapse
|
23
|
Yagasaki T, Matsumoto M, Tanaka H. Effects of thermodynamic inhibitors on the dissociation of methane hydrate: a molecular dynamics study. Phys Chem Chem Phys 2015; 17:32347-57. [PMID: 26587576 DOI: 10.1039/c5cp03008k] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We investigate the effects of methanol and NaCl, which are known as thermodynamic hydrate inhibitors, on the dissociation kinetics of methane hydrate in aqueous solutions by using molecular dynamics simulations. It is shown that the dissociation rate is not constant but changes with time. The dissociation rate in the initial stage is increased by methanol whereas it is decreased by NaCl. This difference arises from the opposite effects of the two thermodynamic inhibitors on the hydration free energy of methane. The dissociation rate of methane hydrate is increased by the formation of methane bubbles in the aqueous phase because the bubbles absorb surrounding methane molecules. It is found that both methanol and NaCl facilitate the bubble formation. However, their mechanisms are completely different from each other. The presence of ions enhances the hydrophobic interactions between methane molecules. In addition, the ions in the solution cause a highly non-uniform distribution of dissolved methane molecules. These two effects result in the easy formation of bubbles in the NaCl solution. In contrast, methanol assists the bubble formation because of its amphiphilic character.
Collapse
Affiliation(s)
- Takuma Yagasaki
- Department of Chemistry, Faculty of Science, Okayama University, Okayama, 700-8530, Japan
| | - Masakazu Matsumoto
- Department of Chemistry, Faculty of Science, Okayama University, Okayama, 700-8530, Japan
| | - Hideki Tanaka
- Department of Chemistry, Faculty of Science, Okayama University, Okayama, 700-8530, Japan and Research Center of New Functional Materials for Energy Production, Storage and Transport, Okayama, 700-8530, Japan.
| |
Collapse
|
24
|
Xu J, Gu T, Sun Z, Li X, Wang X. Molecular dynamics study on the dissociation of methane hydrate via inorganic salts. Mol Phys 2015. [DOI: 10.1080/00268976.2015.1081708] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
25
|
Yagasaki T, Matsumoto M, Tanaka H. Adsorption Mechanism of Inhibitor and Guest Molecules on the Surface of Gas Hydrates. J Am Chem Soc 2015; 137:12079-85. [DOI: 10.1021/jacs.5b07417] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Takuma Yagasaki
- Department
of Chemistry, Faculty of Science, Okayama University, Okayama, 700-8530, Japan
| | - Masakazu Matsumoto
- Department
of Chemistry, Faculty of Science, Okayama University, Okayama, 700-8530, Japan
| | - Hideki Tanaka
- Department
of Chemistry, Faculty of Science, Okayama University, Okayama, 700-8530, Japan
- Research Center of New Functional Materials for Energy Production, Storage and Transport, Okayama, 700-8530, Japan
| |
Collapse
|
26
|
Bagherzadeh SA, Alavi S, Ripmeester J, Englezos P. Formation of methane nano-bubbles during hydrate decomposition and their effect on hydrate growth. J Chem Phys 2015; 142:214701. [DOI: 10.1063/1.4920971] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
27
|
Yagasaki T, Matsumoto M, Andoh Y, Okazaki S, Tanaka H. Dissociation of Methane Hydrate in Aqueous NaCl Solutions. J Phys Chem B 2014; 118:11797-804. [DOI: 10.1021/jp507978u] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Takuma Yagasaki
- Department
of Chemistry, Faculty of Science, Okayama University, Okayama 700-8530, Japan
| | - Masakazu Matsumoto
- Department
of Chemistry, Faculty of Science, Okayama University, Okayama 700-8530, Japan
| | - Yoshimichi Andoh
- Department
of Applied Chemistry, Nagoya University, Nagoya 464-8603, Japan
| | - Susumu Okazaki
- Department
of Applied Chemistry, Nagoya University, Nagoya 464-8603, Japan
| | - Hideki Tanaka
- Department
of Chemistry, Faculty of Science, Okayama University, Okayama 700-8530, Japan
- Research Center
of New Functional Materials for Energy Production, Storage and Transport, Okayama 700-8530, Japan
| |
Collapse
|