Experimental study of methane hydrate formation in the presence of tetrahydrofuran and sodium octyl sulfate as promoters

In this article, the effect of sodium octyl sulfate (SOS) and tetrahydrofuran (THF) on the rate of formation and thermodynamic conditions for methane hydrate formation is studied. Hydrate formation experiments are carried out and relevant data are produced at different temperatures and pressures. According to the results, the formation rate of methane hydrate in the SOS aqueous solution was faster than that in the aqueous THF and aqueous THF+SOS solutions. A small amount of SOS or THF could dramatically promote the formation of methane hydrate, and rapidly increase the amount of hydrate formed. The addition of THF lowered the hydrate equilibrium pressure at a specified temperature and equivalently increased the hydrate equilibrium temperature at a specified pressure. The thermodynamic equilibrium condition of hydrate formation was not affected by the presence of SOS.