Application of urea complexes in the purification of fatty acids,esters, and alcohols. I. Oleic acid from inedible animal fats

Summary Urea complex formation has been employed in the preparation of purified oleic acid (oleic acid content, 80–95%) from various grades of inedible animal fats and red oils. Since the urea complex of oleic acid forms in good yield at room temperature, low temperatures are not required in the isolation procedure. Yields of oleic acid are equal to or lower than those obtained by conventional low-temperature crystallization procedures, but the preparation of a polyunsaturate-free oleic acid is apparently not possible by urea complex formation alone. The separation of polyunsaturated acids from oleic acid by urea complex formation is more convenient than but not as efficient as by solvent crystallization, but separation of saturated acids from unsaturated acids is less convenient. Advantages and disadvantages in using urea in the preparation of purified oleic acid are briefly discussed. Presented at the Spring Meeting of the American Oil Chemists' Society held in Houston, Tex., April 28–30, 1952. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration. U. S. Department of Agriculture.