Oxidative cleavage of glycols derived from unsaturated fatty acids

The PhD project presented in this thesis was carried out in the framework of the European Flagship project First2Run and it was focused on the development and improvement of a new sustainable catalytic process for the valorization of unsaturated fatty acids. Specifically, the present study was focused on the oxidative cleavage of oleic acid (or the corresponding triglyceride) into shorter mono- and di- carboxylic acids. In particular, the oxidative scission was performed in order to produce azelaic acid and pelargonic acid starting from the vicinal glycol obtained by means of the dihydroxylation of the oleic acid contained in cardoon flower oil. The oxidative scission process is currently carried out in industry by using ozone as the oxidant the use of which, however, implies hazardous process conditions. A more sustainable alternative oxidant proposed in the literature is oxygen, which requires specific catalysts. Aim of this research was to investigate various heterogeneous catalysts for the oxidative cleavage of 9,10-dihydroxystearic acid by means of oxygen. Moreover, the most promising catalysts were used for the investigation of the influence of several reaction parameters, such as temperature, time of reaction, stirring rate, oxidant gas pressure, amount of catalyst. Finally, the stability and reusability of the best catalysts were conducted by means of leaching-tests and the development of a regeneration step. Thanks to this research work, it was possible to discover a very promising heterogeneous catalytic system alternative to that one currently used in industry.