Patent relates to the recovery of organic acids from dilute aqueous solutions such as those obtained in the oxygenated compounds fraction of Fischer-Tropsch products. Recovery of such acids by solvent extraction is specifically described. An aqueous solution of lower aliphatic acids derived from the Fischer-Tropsch synthesis and containing less than about 5% acids is introduced into the top of an extraction tower and passes countercurrent to an upward stream of isopropyl ether and methyl-ethyl ketone to the bottom of the tower. The solvents are present in the ratio of 75 parts ketone to 25 of isopropyl ether, a solvent to feed ration of 2:1 is maintained. It was found that 94.9% of the acid present in the Fischer-Tropsch water was removed with a loss of only 3.4% of the ketone in the raffinate.
PALMER, G. H. See abs. 14.