The processing of vegetable oils and fats is one of the permissive ways to obtain low-sulphur, low-oxygen, aromatic free and ecologically friendly automotive fuels. Oxygen content of bio resources has a significant effect on the resulting fuel properties. Hydrodeoxygenation is a process of oxygenated compounds removal from fatty acids typically in the form of water. Pd-HPS based systems were prepared by wet impregnation method of HPS-MN270 (Purolite, UK) with the solution of calculated amount of Na2PdCl4 in a complex solvent (tetrahydrofuran, methanol and water). So metal-polymer systems with the palladium content (by loading) of 5 wt.% (5%-Pd/HPS), 3 wt.% (3%-Pd/HPS), and 1 wt.% (1%-Pd/HPS) were obtained. All the synthesized catalysts were reduced with hydrogen at 300 ○C for 3 hours. The analysis of synthesized catalysts was performed by TGA, TEM, XPS, nitrogen low-temperature adsorption, CO pulse chemisorptions. Hydrodeoxygenation of stearic acid chosen as a model compound was carried out in a stainless steel reactor Parr – 4307 with the total volume 50 mL (PARR Instrument, USA). Several series of single-factor experiments were performed by varying the catalyst loading ([cat]0), initial concentrations of stearic acid [C]0 = 0.05 ~ 0.2 mol/L, temperature (230 ~ 260 ○C), and hydrogen partial pressure (0.2 ~ 1.8 MPa). On the base of experimental results and the proposed reaction mechanism the reaction rate constants were calculated. To select the most suitable catalyst the experiments were performed using Pd/HPS catalysts under the following conditions: stearic acid initial concentration [C]0 = 0.1 mol×(L)−1, hydrogen pressure 0.6 MPa, temperature 255 °C. The values of TOF defined as the converted amount of substrate at 20% conversion per mole of exposed palladium per unit of time were 0.64, 0.32 and 0.22 mol×molcat-1×s-1 for 1, 3 and 5%-Pd-HPS respectively. On the basis of the results of the preliminary investigation 1%-Pd-HPS was chosen for the further study of the reaction kinetics.The rate equation for the proposed mechanism was the following (Fig. 1).

Pd nanoparticles stabilized in polymeric matrix in fatty acid hydrodeoxygenation

253rd National Meeting (2017)

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