Recovery of glycerine from saline waters
AssigneeShell Oil Company
InventorGeorge C. Blytas
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Abstract
A process for recovery of glycerine from saline waters-containing glycerine comprises evaporating the water to precipitate a major amount of any salts present, separating the liquid phase and diluting it with water to low viscosity, electrodialysing the diluted liquid phase to obtain, (1) a concentrate stream which is recycled to the evaporative step, and (2) a diluate stream which is subjected to fractionation distillation to obtain glycerine as an overhead fraction.
Claims5
A process for recovering glycerine from a saline aqueous stream resulting from the manufacture of epoxy resins and containing from about 1 to about 7% w glycerine and at least about 5% w sodium chloride which process comprises:
- (a) evaporating the feed stream to remove water and to precipitate at least about 85% of the salt content of the feed stream,
- (b) separating the liquid phase from the precipitated salt,
- (c) diluting the liquid phase product of step b in a detention zone with an aqueous stream to obtain a diluted liquid phase product having a viscosity less than about 10 centipoise,
- (d) subjecting the product of step c to an electrodialysis step in which the saline components migrate through fixed anion and cation exchange membranes to a concentrate stream or streams leaving a diluate stream or streams reduced in saline content,
- (e) recycling the concentrate stream from step d to the evaporating step a, and
- (f) recovering glycerine from the diluate stream of step d by fractional distillation.
Dependencies are inferred from the claim text.