506. DORNTE, R. W. (Standard Oil Development Co.). Recovery of Fatty Acids From Dilute Aqueous Solutions. United States Patent 2,537,658. Jan. 9, 1951; appl. filed Aug. 16, 1948. Serial No. 44,454: 2 claims (Cl. 260-450). Chem. Abs., vol. 45, 1951,

Patent Abstracts

506. DORNTE, R. W. (Standard Oil Development Co.). Recovery of Fatty Acids From Dilute Aqueous Solutions. United States Patent 2,537,658. Jan. 9, 1951; appl. filed Aug. 16, 1948. Serial No. 44,454: 2 claims (Cl. 260-450). Chem. Abs., vol. 45, 1951, p. 3581.

2-stage solvent extraction process uses a high-boiling hydrocarbon (b. above 205° C.) to extract the C₄-C₆ in the 1^st stage and a high-b. (160° C. or higher) polar organic solvent to remove the remaining lower acids in the 2^nd stage. Symmetrical triethyl benzene, naphthalene, methyl naphthalene, diphenyl, diphenyl methane, acenaphthene, dibenzyl, tetrahydronaphthalene, and hexahydronaphthalene are examples of suitable hydrocarbons. Methyl cyclohexanone, furfural, isophorone, and the cresols are suitable polar solvents. The process may be carried out in a standard apparatus. Fresh extractant may be added as needed to the recycled and recovered extractant. 4 United States patents cited.