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The authors study the effect of the tungsten oxide in the supports of 0.5% Pt/WOx-Al2O3 catalysts on their acidity, deposited platinum dispersity, and catalytic properties in the hydrodeoxygenation of sunflower oil. It is shown that the of Brønsted acid sites on its surface grows, and the dispersity of deposited platinum in the ready catalyst is reduced when the content of the modifier is increased. The studied samples ensure complete sunflower oil conversion in a hydrogen atmosphere at a liquid weight hourly space velocity (WHSV) of 1 h−1, a temperature of 380°C, and a total pressure of 4 MPa the composition of the support. A nearly stoichiometric yield of C5+ products at a level of 82–86 wt % is attained. The acidic properties of the 0.5% Pt/WOx-Al2O3 system determine the possibility for synthesizing the components of diesels with high contents of iso-alkanes as a result of sunflower oil hydrodeoxygenation. Using a catalyst with a nominal tungsten content of 15 wt % WO3 brings the content of iso-paraffins up to 74% with complete conversion of the initial feedstock for no less than 24 h. [ABSTRACT FROM AUTHOR]

The authors study the effect of the type of zeolite (SAPO-11, ZSM-22, ZSM-23, and ZSM-12) in a support (ratio zeolite : Al2О3 = 30 : 70) on the physicochemical properties of Pt/Al2O3-zeolite catalysts and the composition of products from the hydrodeoxygenation of sunflower oil on them. The possibility of the complete hydrodeoxygenation of sunflower oil at temperatures of 320–350°C, a pressure of 4 MPa, and a weight hourly space velocity (WHSV) of 1 h−1 is shown with 75–82% yields of liquid products. The fraction of iso-alkanes and the yield of direct hydrodeoxygenation products grow along with the concentration of Brønsted acid sites in a catalyst in the order 1%Pt/Al2O3-ZSM-22 < 1%Pt/Al2O3-ZSM-12 < 1%Pt/Al2O3-ZSM-23 < 1%Pt/Al2O3-SAPO-11. [ABSTRACT FROM AUTHOR]

This paper presents the results of an electron paramagnetic resonance (EPR) and thermal analysis (TGA, DTA) study of a series of bifunctional NiMo/WO3–Al2O3 catalysts containing 0 to 30 wt % WO3 modifier before and after testing them in the process of hydrodeoxygenation of vegetable oil. The dependence of the content of carbonaceous deposits in the spent samples (according to EPR and TGA) on the concentration of acid sites as determined by EPR of perylene probe molecules in the initial catalysts is determined. Deactivation is explained by the participation of medium- and weak-strength Brønsted acid sites in the condensation of the initial unsaturated hydrocarbon molecules and their intermediates leading to the formation of various forms of coke precursors. [ABSTRACT FROM AUTHOR]

Tungstate-containing aluminum oxide is suitable as a catalyst support for hydrodeoxygenation of sunflower oil, ensuring 81-83 wt % yield of liquid products at 380°С, 4.0 MPa, and feed space velocity of 1 h-1. The catalyst acidity increases with increasing tungsten oxide content, leading to an increase in the content of decarboxylation/decarbonylation products and isoparaffins in the product mixture. [ABSTRACT FROM AUTHOR]