GB317462A - Improvements relating to the separation of anhydrous acetic acid from its aqueous solutions - Google Patents

Abstract

317,462. Soc. Anon. des Distilleries des Deux-SÞvres. Aug. 17, 1928, [Convention date]. Acetic acid. - In the process for separating acetic acid from its aqueous solutions by treatment with a solvent and dehydration of the resulting extract of acetic acid, solvent and residual water, as described in Specification 296,974, the dehydrated mixture, of acetic acid and solvent is separated by distilling with an accessory liquid forming with the acetic acid a binary mixture of minimum boiling point. As shown, aqueous acetic acid is treated in a tower 3 with amyl acetate and the resulting extract is distilled with ethyl acetate in a column 6 to remove water, as in the earlier Specification. The anhydrous solution of acetic acid in amyl acetate passes by a pipe 10 to a column 17 charged with a petroleum distillate boiling between 114-116‹ C. Pure amyl acetate issues by a pipe 14; a minimum boiling-point mixture of acetic acid and petroleum is passed to a condenser 12 and is separated into two layers bv the addition of 1 per cent of water. The petroleum is returned to column 17 and the acetic acid passes to a column 15 in which it is freed from small quantities of petroleum and water, and issues in the anhydrous state at the bottom of the column. Other suitable accessory liquids are dimethyl cyclohexanone, toluene, and octane.