Oxidative polymerization of waste cooking oil with air under hydrodynamic cavitation

Abstract

Apart from being a component of some animal feed products, the main industrial use of recycled waste frying oils is biodiesel preparation. With the aim of finding a suitable technology for a cost-effective valorization of used cooking oil, we investigated some oxidative treatments under hydrodynamic cavitation with air flow. This process enabled the preparation of a useful precursor of fatliquor used in the leather industry through the efficient oxidation/polymerization of waste oils at 90°C. The same technique enabled a stable dispersion/emulsification in water without surfactants. Thanks to the use of these innovative techniques, a four-fold reduction of the oxidation time of waste oil was achieved. All the results indicate that the use of a highly efficient rotor-stator generator of hydrodynamic cavitation is compatible with a process scaling up for potential industrial applications.