Abstract: The invention relates to a process for isolating a phenyl ester salt from a mixture comprising sulfolane (tetrahydrothiophene-1,1-dioxide). The invention includes adjusting the temperature of a mixture comprising a phenyl ester salt and sulfolane to a temperature of about 100-150° C. This step leads to the formation of a mixture comprising a solid phenyl ester salt and sulfolane. Next, the solid phenyl ester salt is separated, while maintaining the temperature of the mixture at about 100-150° C. The invention also relates to a process that includes adding a sufficient amount of a solvent to a mixture comprising a phenyl ester salt and sulfolane to decrease the viscosity or the density of the mixture. The solvent added has a density less than about 1.20 g/cm3 at 100° C. or a viscosity of less than about 2.56 centipoise at 100° C. The embodiments of the invention may be used alone or in combination.

Abstract: The invention relates to a process for isolating a phenyl ester salt from a mixture comprising sulfolane (tetrahydrothiophene-1,1-dioxide). The invention includes adjusting the temperature of a mixture comprising a phenyl ester salt and sulfolane to a temperature of about 100-150° C. This step leads to the formation of a mixture comprising a solid phenyl ester salt and sulfolane. Next, the solid phenyl ester salt is separated, while maintaining the temperature of the mixture at about 100-150° C. The invention also relates to a process that includes adding a sufficient amount of a solvent to a mixture comprising a phenyl ester salt and sulfolane to decrease the viscosity or the density of the mixture. The solvent added has a density less than about 1.20 g/cm3 at 100° C. or a viscosity of less than about 2.56 centipoise at 100° C. The embodiments of the invention may be used alone or in combination.