scholarly journals A 3-In-1 Approach to Evaluate Gas Hydrate Inhibitors

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2921
Author(s):  
Narendra Kumar ◽  
Niaz Bahar Chowdhury ◽  
Juan G. Beltran
Keyword(s):  
Constant Temperature ◽  
Gas Hydrates ◽  
Equilibrium Points ◽  
Hydrate Formation ◽  
Temperature Gradients ◽  
Fixed Temperature ◽  
Single Experiment ◽  
Temperature Growth ◽  
Temperature And Pressure ◽  
Methane Gas Hydrates

With a single apparatus and very short experimentation times, we have assessed phase equilibria, apparent kinetics and morphology of methane gas hydrates in the presence of thermodynamic inhibitors ethane-1,2-diol (MEG) and sodium chloride (NaCl); and kinetic hydrate inhibitor polyvinyl-pyrrolidone (PVP). Tight, local temperature control produced highly repeatable crystal morphologies in constant temperature systems and in systems subject to fixed temperature gradients. Hydrate-Liquid-Vapor (HLV) equilibrium points were obtained with minimal temperature and pressure uncertainties ( u T avg = 0 . 13 K and u p = 0 . 005 MPa). By applying a temperature gradient during hydrate formation, it was possible to study multiple subcoolings with a single experiment. Hydrate growth velocities were determined both under temperature gradients and under constant temperature growth. It was found that both NaCl and MEG act as kinetic inhibitors at the studied concentrations. Finally, insights on the mechanism of action of classical inhibitors are presented.

Inhibiting gas hydrate formation using small molecule ice recrystallization inhibitors

RSC Advances ◽  
2015 ◽  
Vol 5 (28) ◽  
pp. 21728-21732 ◽  
Author(s):  
Devin Tonelli ◽  
Chantelle J. Capicciotti ◽  
Malay Doshi ◽  
Robert N. Ben
Keyword(s):  
Small Molecule ◽  
Gas Hydrates ◽  
Gas Hydrate ◽  
Hydrate Formation ◽  
Ice Recrystallization ◽  
Methane Gas ◽  
Gas Hydrate Formation ◽  
Methane Gas Hydrates

Carbohydrate-based inhibitors of ice recrystallization also inhibit the formation of methane gas hydrates.

The formation of gas hydrates under shock wave impact on the bubble media (two-dimensional case)

2010 ◽  
Vol 7 ◽  
pp. 90-97
Author(s):  
M.N. Galimzianov ◽  
I.A. Chiglintsev ◽  
U.O. Agisheva ◽  
V.A. Buzina
Keyword(s):  
Shock Wave ◽  
Gas Hydrates ◽  
Hydrate Formation ◽  
Dimensional Case ◽  
Two Dimensional ◽  
Wave Impact ◽  
Bubble Liquid ◽  
One Dimensional ◽  
Bubble Media ◽  
Main Factors

Formation of gas hydrates under shock wave impact on bubble media (two-dimensional case) The dynamics of plane one-dimensional shock waves applied to the available experimental data for the water–freon media is studied on the base of the theoretical model of the bubble liquid improved with taking into account possible hydrate formation. The scheme of accounting of the bubble crushing in a shock wave that is one of the main factors in the hydrate formation intensification with increasing shock wave amplitude is proposed.

Thermodynamic Modelling of Gas Hydrate Formation in the Presence of Inhibitors and the Consideration of their Effect

2014 ◽  
Vol 14 (1) ◽  
pp. 45
Author(s):  
Peyman Sabzi ◽  
Saheb Noroozi
Keyword(s):  
Gas Hydrates ◽  
Gas Hydrate ◽  
Low Temperatures ◽  
Hydrate Formation ◽  
Transportation Systems ◽  
Flow Lines ◽  
Main Approach ◽  
Efficient Inhibitor ◽  
System A ◽  
Gas Hydrate Formation

Gas hydrates formation is considered as one the greatest obstacles in gas transportation systems. Problems related to gas hydrate formation is more severe when dealing with transportation at low temperatures of deep water. In order to avoid formation of Gas hydrates, different inhibitors are used. Methanol is one of the most common and economically efficient inhibitor. Adding methanol to the flow lines, changes the thermodynamic equilibrium situation of the system. In order to predict these changes in thermodynamic behavior of the system, a series of modelings are performed using Matlab software in this paper. The main approach in this modeling is on the basis of Van der Waals and Plateau's thermodynamic approach. The obtained results of a system containing water, Methane and Methanol showed that hydrate formation pressure increases due to the increase of inhibitor amount in constant temperature and this increase is more in higher temperatures. Furthermore, these results were in harmony with the available empirical data.Keywords: Gas hydrates, thermodynamic inhibitor, modelling, pipeline blockage

scholarly journals Rapid Gas Hydrate Formation—Evaluation of Three Reactor Concepts and Feasibility Study

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3615
Author(s):  
Florian Filarsky ◽  
Julian Wieser ◽  
Heyko Juergen Schultz
Keyword(s):  
Gas Hydrates ◽  
Gas Hydrate ◽  
Hydrate Formation ◽  
Synthetic Natural Gas ◽  
Operation Conditions ◽  
Gas Hydrate Formation ◽  
Gas Conditioning ◽  
And Storage ◽  
Economic Considerations ◽  
High Storage

Gas hydrates show great potential with regard to various technical applications, such as gas conditioning, separation and storage. Hence, there has been an increased interest in applied gas hydrate research worldwide in recent years. This paper describes the development of an energetically promising, highly attractive rapid gas hydrate production process that enables the instantaneous conditioning and storage of gases in the form of solid hydrates, as an alternative to costly established processes, such as, for example, cryogenic demethanization. In the first step of the investigations, three different reactor concepts for rapid hydrate formation were evaluated. It could be shown that coupled spraying with stirring provided the fastest hydrate formation and highest gas uptakes in the hydrate phase. In the second step, extensive experimental series were executed, using various different gas compositions on the example of synthetic natural gas mixtures containing methane, ethane and propane. Methane is eliminated from the gas phase and stored in gas hydrates. The experiments were conducted under moderate conditions (8 bar(g), 9–14 °C), using tetrahydrofuran as a thermodynamic promoter in a stoichiometric concentration of 5.56 mole%. High storage capacities, formation rates and separation efficiencies were achieved at moderate operation conditions supported by rough economic considerations, successfully showing the feasibility of this innovative concept. An adapted McCabe-Thiele diagram was created to approximately determine the necessary theoretical separation stage numbers for high purity gas separation requirements.

PROSPECTS FOR OBTAINING GAS MOTOR FUEL FROM BIOGAS OF ANAEROBIC DIGESTION OF AGRICULTURAL WASTE

2021 ◽  
Vol 3 (144) ◽  
pp. 22-31
Author(s):  
Viktor S. Grigor’yev ◽  
◽  
Il’ya V. Romanov
Keyword(s):  
Anaerobic Digestion ◽  
Gas Hydrates ◽  
Process Model ◽  
Organic Waste ◽  
Agricultural Waste ◽  
Motor Fuel ◽  
Hydrate Formation ◽  
Research Purpose ◽  
Industrial Complex ◽  
Mixed Gas

The ability of gas hydrates to concentrate gas into a solid chelate structure and the properties of self-preservation of gas hydrates at negative temperatures allows us to consider the possibility of developing a method for the utilization of biogas, environmentally safe storage and transportation of biomethane. (Research purpose) The research purpose is in substantiation the technological possibilities of obtaining synthetic mixed gas hydrates of biogas components, their storage and transportation based on the analysis of the existing regularities of the formation of gas hydrates in time, temperature and external pressure. (Materials and methods) The article presents the accumulated results of studies of the process of obtaining artificial hydrates of natural gas and methane- containing gas mixtures at various initial static pressures and temperatures. The object of research to substantiate the parameters of artificial creation of gas hydrates is biogas obtained during anaerobic thermophilic fermentation of organic waste at an existing experimental biogas plant. Mixed feed SK-8 with a humidity of 90-92 percent was used as an organic substrate of constant composition. The composition of biogas was studied using the Optima-7 Biogas gas analyzer. (Results and discussion) The article presents a process model and a technical appearance of an installation for producing gas motor fuel from the biogas of anaerobic digestion of organic waste of the agro-industrial complex. The hydrate formation time depends on the increase in the interfacial surface and the movement of gas bubbles relative to the liquid, which can be regulated by acting on the hydrate formation zone (shock wave, electromagnetic, mechanical, chemical, temperature). (Conclusions) The research results can be used in modeling processes in two-phase media during the formation of gas hydrates and the creation of installations for their production.

Quantification of methane hydrate formation in the Large-scale Reservoir Laboratory Simulator (LARS) by numerical simulations

2021 ◽  
Author(s):  
Zhen Li ◽  
Thomas Kempka ◽  
Erik Spangenberg ◽  
Judith Schicks
Keyword(s):  
Gas Hydrates ◽  
Methane Hydrate ◽  
Large Scale ◽  
Hydrate Formation ◽  
Simulation Environment ◽  
Transport Simulation ◽  
Chemistry Research ◽  
Research Activities ◽  
In Situ Conditions ◽  
Hydrate Bearing Sediments

<p>Natural gas hydrates are considered as one of the most promising alternatives to conventional fossil energy sources, and are thus subject to world-wide research activities for decades. Hydrate formation from methane dissolved in brine is a geogenic process, resulting in the accumulation of gas hydrates in sedimentary formations below the seabed or overlain by permafrost. The LArge scale Reservoir Simulator (LARS) has been developed (Schicks et al., 2011, 2013; Spangenberg et al., 2015) to investigate the formation and dissociation of gas hydrates under simulated in-situ conditions of hydrate deposits. Experimental measurements of the temperatures and bulk saturation of methane hydrates by electrical resistivity tomography have been used to determine the key parameters, describing and characterising methane hydrate formation dynamics in LARS. In the present study, a framework of equations of state to simulate equilibrium methane hydrate formation in LARS has been developed and coupled with the TRANsport Simulation Environment (Kempka, 2020) to study the dynamics of methane hydrate formation and quantify changes in the porous medium properties in LARS. We present our model implementation, its validation against TOUGH-HYDRATE (Gamwo & Liu, 2010) and the findings of the model comparison against the hydrate formation experiments undertaken by Priegnitz et al. (2015). The latter demonstrates that our numerical model implementation is capable of reproducing the main processes of hydrate formation in LARS, and thus may be applied for experiment design as well as to investigate the process of hydrate formation at specific geological settings.</p><p>Key words: dissolved methane; hydrate formation; hydration; python; permeability.</p><p>References</p><p>Schicks, J. M., Spangenberg, E., Giese, R., Steinhauer, B., Klump, J., & Luzi, M. (2011). New approaches for the production of hydrocarbons from hydrate bearing sediments. Energies, 4(1), 151-172, https://doi.org/10.3390/en4010151</p><p>Schicks, J. M., Spangenberg, E., Giese, R., Luzi-Helbing, M., Priegnitz, M., & Beeskow-Strauch, B. (2013). A counter-current heat-exchange reactor for the thermal stimulation of hydrate-bearing sediments. Energies, 6(6), 3002-3016, https://doi.org/10.3390/en6063002</p><p>Spangenberg, E., Priegnitz, M., Heeschen, K., & Schicks, J. M. (2015). Are laboratory-formed hydrate-bearing systems analogous to those in nature?. Journal of Chemical & Engineering Data, 60(2), 258-268, https://doi.org/10.1021/je5005609</p><p>Kempka, T. (2020) Verification of a Python-based TRANsport Simulation Environment for density-driven fluid flow and coupled transport of heat and chemical species. Adv. Geosci., 54, 67–77, https://doi.org/10.5194/adgeo-54-67-2020</p><p>Gamwo, I. K., & Liu, Y. (2010). Mathematical modeling and numerical simulation of methane production in a hydrate reservoir. Industrial & Engineering Chemistry Research, 49(11), 5231-5245, https://doi.org/10.1021/ie901452v</p><p>Priegnitz, M., Thaler, J., Spangenberg, E., Schicks, J. M., Schrötter, J., & Abendroth, S. (2015). Characterizing electrical properties and permeability changes of hydrate bearing sediments using ERT data. Geophysical Journal International, 202(3), 1599-1612, https://doi.org/10.1093/gji/ggv245</p>

scholarly journals NEAR HYDRATION OF SINGLY CHARGED MONOATOMIC IONS IN EXTREMELY DILUTED SOLUTIONS: THE EFFECT OF TEMPERATURE AND PRESSURE

2021 ◽  
pp. 24-31
Author(s):  
Viktor Ivanovych Булавин ◽  
Ivan Nikolajevych V’unik ◽  
Andrii Viktorovych Kramarenko ◽  
Alexandr Ivanovych Rusinov
Keyword(s):  
Ion Solvation ◽  
Effect Of Temperature ◽  
Temperature Growth ◽  
Translational Displacement ◽  
Na Ions ◽  
Extremely Diluted Solutions ◽  
Temperature And Pressure ◽  
Singly Charged ◽  
Direction Opposite ◽  
Structure Breaking

The diffusion coefficient  and the distance of translational displacement of Li+, Na+ K+, Cs+, Cl– and Br– ions  in water at 298.15 K – 423.15 K (25 K step) and pressure from 0.0981 to 784.5 MPa (98.1 MPa step) were calculated from the literature data on limiting molar electrical conductivity. The  values for these ions increase with pressure growth from 0.0981  to 98.1 MPa at 298.15 K. Further pressure increase (up to 785 MPa) leads to decrease in . Temperature growth under isobaric conditions leads to an increase in . Parameter (– ri) (deviation from the Stokes–Einstein law, ri is ion structural radius) was used as a criterion for the type of ion solvation. It is shown that Li+ and Na+ ions behave as cosmotropes, or positively solvated structure–forming ions having (– ri) > 0. The Cs+, Cl–, Br– ions behave as chaotropes, or negatively solvated structure–breaking ions having (– ri) < 0. For the K+ ion, the (– ri) deviation is alternating. At 0.0981 MPa and 298.15 K, the K+ ion is a chaotrope. But at 320 K (Tlim) parameter (– ri) = 0. It corresponds to the transition from negative to positive solvation. Above Tlim at P = const, the K+ ion is a cosmotrope. At 298.15 K and up to 98.1 MPa, the pressure causes the same change in the (– ri) deviation as the temperature. On the contrary, at 320 K and higher, the pressure affects the near hydration in the direction opposite to the temperature.

Accurate and efficient integration for molecular dynamics simulations at constant temperature and pressure

2013 ◽  
Vol 139 (16) ◽  
pp. 164106 ◽  
Author(s):  
Ross A. Lippert ◽  
Cristian Predescu ◽  
Douglas J. Ierardi ◽  
Kenneth M. Mackenzie ◽  
Michael P. Eastwood ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Constant Temperature ◽  
Efficient Integration ◽  
Temperature And Pressure ◽  
Dynamics Simulations

scholarly journals Investigation on Gas Hydrates Formation and Dissociation in Multiphase Gas Dominant Transmission Pipelines

2020 ◽  
Vol 10 (15) ◽  
pp. 5052 ◽  
Author(s):  
Sayani Jai Krishna Sahith ◽  
Srinivasa Rao Pedapati ◽  
Bhajan Lal
Keyword(s):  
Crude Oil ◽  
Phase Behavior ◽  
Gas Hydrates ◽  
Gas Hydrate ◽  
Formation Rate ◽  
Water System ◽  
Hydrate Formation ◽  
Multiphase System ◽  
Gas Hydrate Formation ◽  
Water Cut

In this work, a gas hydrate formation and dissociation study was performed on two multiphase pipeline systems containing gasoline, CO2, water, and crude oil, CO2, water, in the pressure range of 2.5–3.5 MPa with fixed water cut as 15% using gas hydrate rocking cell equipment. The system has 10, 15 and 20 wt.% concentrations of gasoline and crude oil, respectively. From the obtained hydrate-liquid-vapor-equilibrium (HLVE) data, the phase diagrams for the system are constructed and analyzed to represent the phase behavior in the multiphase pipelines. Similarly, induction time and rate of gas hydrate formation studies were performed for gasoline, CO2, and water, and crude oil, CO2, water system. From the evaluation of phase behavior based on the HLVE curve, the multiphase system with gasoline exhibits an inhibition in gas hydrates formation, as the HLVE curve shifts towards the lower temperature and higher-pressure region. The multiphase system containing the crude oil system shows a promotion of gas hydrates formation, as the HLVE curve shifted towards the higher temperature and lower pressure. Similarly, the kinetics of hydrate formation of gas hydrates in the gasoline system is slow. At the same time, crude oil has a rapid gas hydrate formation rate.

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