Azelaic Acid → Oleic Acid

Participants

Reaction Steps

A process for the production of purified azelaic acid by working up a reaction mixture containing C1-18 monocarboxylic acids, comprising pelargonic acid, and C4-16 dicarboxylic acids, comprising azelaic acid, obtained from the ozonolysis of oleic acid or a starting mixture containing oleic acid, all but <2% by weight of the monocarboxylic acids and part of the dicarboxylic acids with a chain length of <C9 and >C9 being separated off to obtain a prepurified product containing more than 75% by weight of oleic acid and the prepurified product being concentrated to more than 90% by weight of oleic acid in several process steps of which the last is an overhead distillation step, which comprises: (1), removing the dicarboxylic acids with chain lengths of <C9, present in the prepurified product, as an overhead product by a first fractional distillation; (2), reacting a bottom product from the first distillation with water to split carboxylic anhydrides present in the bottom product to form a reaction mixture and, (3), distilling the reaction mixture to recover as an overhead product the purified azelaic acid, the third process step (3) being carried out after or at the same time as the second process step (2).

Provenance & Evidence