Phase equilibrium conditions for simulated landfill gas hydrate formation in aqueous solutions of tetrabutylammonium nitrate

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.

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A Method To Predict Equilibrium Conditions of Gas Hydrate Formation in Porous Media

Industrial & Engineering Chemistry Research ◽

10.1021/ie980625u ◽

1999 ◽

Vol 38 (6) ◽

pp. 2485-2490 ◽

Cited By ~ 75

Author(s):

Matthew A. Clarke ◽

Mehran Pooladi-Darvish ◽

P. Raj Bishnoi

Keyword(s):

Porous Media ◽

Gas Hydrate ◽

Hydrate Formation ◽

Equilibrium Conditions ◽

Gas Hydrate Formation

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

Frontiers in Energy Research ◽

10.3389/fenrg.2021.699356 ◽

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.

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