Phase Equilibrium Study on the Quaternary System H2O-Na2SO4-MgSO4-C3H8 at 0°C and Pressure

2012 ◽  
Vol 550-553 ◽  
pp. 2690-2694 ◽  
Author(s):  
Panpan Chen ◽  
Guoen Li ◽  
Hongfei Guo ◽  
Ji Lin Cao
Keyword(s):  
Phase Equilibrium ◽  
Gas Hydrate ◽  
Mother Liquor ◽  
New Technology ◽  
Hydrate Formation ◽  
Equilibrium Pressure ◽  
Equilibrium Study ◽  
Phase Equilibrium Study ◽  
Gas Hydrate Formation ◽  
Very High

In order to develop a new technology for separating the bloedite by the method of gas hydrate formation, the phase equilibrium of the H2O-Na2SO4-MgSO4-C3H8 system and its subsystems was studied at 0°C and pressure.The equilibrium pressure and the composition of solid and liquid above system were investigated.It was found that equilibrium pressure of gas hydrate formation was increasing with the increase of the Na2SO4( or MgSO4) concentration. The addition of anionic surfactant SDS helped to lower the equilibrium pressure of gas hydrate formation. The mother liquor amount entrained in the gas hydrate after liquid separation by sinking was very high when surfactants was not added. But the equilibrium pressure of gas hydrate formation and the mother liquor amount entrained in gas hydrate were decreased when surfactant was added to the system.

Equilibrium Studies on the System H2O-H2O2-CO(NH2)2-C3H8

2011 ◽  
Vol 233-235 ◽  
pp. 1690-1693
Author(s):  
Yu Ming Gao ◽  
Ji Lin Cao ◽  
Panpan Chen ◽  
Hong Fei Guo ◽  
Zhao Yang Tan
Keyword(s):  
Hydrogen Peroxide ◽  
Gas Hydrate ◽  
Mother Liquor ◽  
Quaternary System ◽  
Hydrate Formation ◽  
Calculated Data ◽  
Equilibrium Studies ◽  
Equilibrium Pressure ◽  
Gas Hydrate Formation ◽  
Very High

The phase equilibrium of the quaternary system H2O-H2O2-CO(NH2)2-C3H8 with gas hydrate formation had been studied at high pressure and low temperature. The temperature and pressure of gas hydrate formed from different hydrogen peroxide concentration aqueous were determined at adding surfactants and no surfactants separately. It was concluded that the equilibrium pressure of gas hydrate formation was increasing with the increase of the hydrogen peroxide concentration, the urea concentration and the temperature, the mother liquor amount entrained in the gas hydrate after liquid separation by sinking was very high when surfactants was not added, but the equilibrium pressure of gas hydrate formation was decreased and the mother liquor amount entrained in gas hydrate was also decreased when surfactants was added to the system. In addition, the equilibrium pressure of gas hydrate formation in the quaternary system H2O-H2O2-CO(NH2)2-C3H8 was calculated according to Chen-Guo thermodynamic model, improved UNIFAC mathematical equation and Aasberg-Peterson fugacity coefficient model. The calculated data was in agreement with the experiment data.

Phase equilibrium modelling of natural gas hydrate formation conditions using LSSVM approach

2016 ◽  
Vol 34 (16) ◽  
pp. 1431-1438 ◽  
Author(s):  
Alireza Baghban ◽  
Saman Namvarrechi ◽  
Le Thi Kim Phung ◽  
Moonyong Lee ◽  
Alireza Bahadori ◽  
...  
Keyword(s):  
Phase Equilibrium ◽  
Natural Gas ◽  
Gas Hydrate ◽  
Hydrate Formation ◽  
Natural Gas Hydrate ◽  
Gas Hydrate Formation ◽  
Formation Conditions

scholarly journals An Experimental Study on the Formation of Natural Gas Hydrate With Thermodynamic Inhibitors

2021 ◽  
Vol 9 ◽  
Author(s):  
Na Wei ◽  
Cuiying Xie ◽  
Wantong Sun ◽  
Haitao Li ◽  
Lin Jiang ◽  
...  
Keyword(s):  
Phase Equilibrium ◽  
Natural Gas ◽  
Gas Hydrate ◽  
Oil And Gas ◽  
Volume Concentration ◽  
Hydrate Formation ◽  
Natural Gas Hydrate ◽  
Gas Hydrate Formation ◽  
Supercooling Degree ◽  
Cavity Structure

Gas hydrates formed in the conditions of high pressure and low temperature in deep sea and in the process of oil and gas transportation, natural gas hydrate (NGH), will seriously affect the safety of drilling and completion operations and marine equipment and threaten the safety of drilling platform. How to prevent the hydrate formation in the process of oil and gas production and transportation has become an urgent problem for the oil and gas industry. For this reason, in view of the formation of NGH in the process of drilling and producing marine NGH, the phase equilibrium calculation research of NGH formation was carried out, the mathematical model of gas hydrate formation phase equilibrium condition was established, and the experimental research on NGH formation was carried out through adding different thermodynamic inhibitors. The experimental phenomena show that, first, the stirring speed has little effect on the inhibition of hydrate formation. Second, when the pressure is 10 MPa and the volume concentration of inhibitor is 1, 3, 5, and 7%, the supercooling degree of hydrate formation is 1.81, 8.89, 11.09, and 9.39°C, respectively. Third, when the volume concentration of inhibitor is 1, 3, 5, and 7%, the induction time of hydrate formation is 10328, 14231, 19576, and 24900 s, respectively. As the polymer molecules in the inhibitor reduce the activity of water in the system and fill the cavity structure of the hydrate, they reduce the generation conditions of NGH and break the original phase equilibrium conditions when NGH is generated, thus forming NGH at a lower temperature or higher pressure.

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.

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