The formation of acid soaps has been used successfully for the separation of a mixture of fatty acids into high and low iodine value fractions. The acid soaps of saturated acid can be made to crystallize from water leaving their unsaturated counter parts in solution. Acid soaps of saturated fatty acids are well characterized compounds with the formula R-COOM.R-COOH, where R is a straight alkyl chain, and M is sodium, potassium or ammonium.
Optimum crystallization conditions involve a soap concentration of 2–5%, pH adjustment to between 7.0 and 8.0, an initial crystallization temperature not below 25C, and a crystallization period of at least 4 hr during which time cooling to a final temperature of 5–10C must be gradual, and agitation gentle.
This is a preview of subscription content, access via your institution.
U. S. Patent No. 2,293,676—L. D. Myers and V. J. Muckerheide.
The Commercial Solvent Separation of Fatty Acids—R. E. Kistler, V. J. Muckerheide, and L. D. Myers, JAOCS,23, 146 (1946).
U. S. Patent No. 2,107,664—W. P. Gee.
U. S. Patent No. 2,443,184—Edwin W. Colt.
U. S. Patent No. 2,593,458—Leslie G. Jenness.
Kenneth Tomlinson—Private communications.
Fatty Acids and Their Derivatives, by Ralston.
Levi, Gazz chem. Ital.,62, 709 (1932).
U. S. Patent No. 2,298,501—L. D. Myerset al.
U. S. Patent No. 2,421,157—L. D. Myerset al.
About this article
Cite this article
Munns, W.O., Kairys, S., Manion, D.A. et al. The separation of solid fatty acids from liquid fatty acids by the formation of acid soaps. I. Tallow soaps. J Am Oil Chem Soc 39, 189–192 (1962). https://doi.org/10.1007/BF02635813
- Crystallization Time
- Soap Solution
- Soap Stock
- Acid Soap
- Soap Concentration