Abstract: The invention is a method for recovering azelaic acid from a mixed oxidation product by prepurifying the azelaic acid and introducing the prepurified azelaic acid into the central portion of a dual countercurrent extraction column operated at an elevated temperature and introducing an aqueous phase into the top of the extraction column and a water immiscible solvent for the monocarboxylic acids in the prepurified azelaic acid into the bottom portion of the extraction column and recovering the purified azelaic acid from the aqueous phase. The azelaic acid can be recovered from the aqueous phase by drying the aqueous phase and separating a low boiling fraction and a high boiling fraction from the azelaic acid product by distillation.

Abstract: Pure azelaic acid is obtained by working up a reaction mixture containing C.sub.1-18 monocarboxylic acids, mainly pelargonic acid, and C.sub.4-16 dicarboxylic acids, mainly 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 <C.sub.9 and >C.sub.9 are separated off to obtain a prepurified product containing more than 75% by weight of oleic acid and the prepurified product is concentrated to more than 90% by weight of oleic acid in several process steps. In a first process step (1), the dicarboxylic acids with chain lengths of <C.sub.9 present in the prepurified product are removed as first runnings by fractional distillation. In a second process step (2), the bottom product obtained is reacted with water to split carboxylic anhydrides present in the bottom product.

Abstract: The present invention is a process for the scission and oxidation of ozonide materials. The process comprises introducing an oxygen-containing gas stream into an agitated liquid body in the form of fine bubbles.

Abstract: The present invention is a process for the scission and oxidation of ozonide materials. The process comprises introducing an oxygen-containing gas stream into an agitated liquid body in the form of fine bubbles.