GB577241A - An improved process for the purification of organic liquids by fractional distillation - Google Patents

Abstract

577,241. Distilling alcohols &c. STANDARD OIL DEVELOPMENT CO. Dec. 16, 1942, No. 17876. Convention date, Dec. 17, 1941 [Class 32] In the recovery of lower alcohols, ketones: and like organic liquids soluble in water from mixtures containing same and impurities by fractionation of the mixture to produce a first fraction which condenses to form a diphasesystem comprising an aqueous and a non- aqueous phase containing low boiling constituents of the mixture, a second fraction comprising the liquid to be recovered, and a third fraction containing high boiling impurities together with substantial quantities of the liquid to be recovered, and treatment of said residual. fraction with a selective solvent, e.g., water, to extract the liquid, part or all of the non- aqueous phase of the condensate of the first fraction is added to the residual fraction before treatment with the selective solvent. The impure mixture is charged through line 1 into a still 2 surmounted by a column 3 and heated by a coil 6. The low boiling fraction is recovered overhead through line 7 and condensed in a condenser 8 part of the condensate being recycled as reflux. The remainder is stratified in decanter 11. The lower aqueous phase is removed through line 12 for further processing while the upper phase is passed through line 13 to a tank 14 where it is mixed with the high boiling residual fraction and passed through line 18 to extractor 19 where it is treated in counter current with water fed through line 20, the raffinate being withdrawn through line 22 and the water extract through line 21. After the low boiling fractions have been distilled off the purified liquid is recovered through line 16. In the recovery of secondary butyl alcohol from a mixture containing it obtained in the treatment of olefines with sulphuric acid, the distillation residue comprising 64 per cent. butyl alcohol and 36 per cent. residues is mixed with the upper phase of the distillate and extracted with 3 volumes of water and a 99 per cent. recovery of alcohol from the extract is obtained.