| abstract |
Disclosed is a method for recovering and re-employing ionic surfactants from solutions, dispersions and emulsions of water and liquid hydrocarbons, by the addition of a second non-aqueous polar phase and an inorganic salt which changes the ionic strength of the surfactant and causes the surfactant to partition principally into the non-aqueous second polar phase. More specifically, the method applies to recovering hydrate growth inhibitor/modifying compounds, with cationic surfactants such as ammonium, phosphonium and sulphonium alkylated compounds from the effluent of hydrocarbon production wells; the effluent including water, hydrate inhibitor compound, at least one additional polar solvent and inorganic salt. Sufficient additional ions of inorganic salt, and if necessary, an alcohol/glycol are added to the effluent to form a second polar phase that is less polar than the aqueous phase, into which the hydrate inhibitor can then dissolve and be separated from the effluent. |