In this Master's thesis, the conversion of methyl palmitate into shorter-chain alkanes suitable for aviation biofuel production was investigated over two bifunctional Rh/USY catalysts containing 1 and 2 wt.% rhodium. The experiments were carried out in a batch reactor using hexadecane as the solvent at temperatures of 230 to 290 °C and hydrogen pressures of 30 to 70 bar. Additional experiments included the conversion of palmitic acid, reactions of the solvent alone, reactions under a nitrogen atmosphere, and reactions conducted without a catalyst. Based on GC-MS analysis, a reaction network consisting of five reactions was proposed: ester hydrogenolysis to palmitic acid, a combined decarbonylation/decarboxylation pathway to pentadecane, hydrocracking of pentadecane, and hydrocracking of the solvent to pentadecane and to shorter alkanes. The hydrodeoxygenation pathway was excluded because no alcohols were detected among the reaction products. The bell-shaped product distribution with a maximum at C₈–C₁₀ confirms ideal hydrocracking behaviour. The Weisz–Prater and Mears criteria indicated that the system operated under kinetic control. A kinetic model incorporating hydrogen transfer from the gas phase to the liquid phase and competitive adsorption successfully described both experimental series using a single set of parameters. The estimated activation energies were 102.12, 118.29, 128.87, 129.79, and 162.54 kJ mol⁻¹, while the reaction orders with respect to hydrogen for the first two reactions were 1.12 and 1.84, respectively. The only significant difference between the two catalysts was the number of metallic active sites (127 versus 46 μmol g⁻¹), since the acidity of the support was very similar. The catalyst containing 2 wt.% Rh exhibited higher activity; the formation of shorter alkanes at 290 °C and 70 bar H₂ was approximately 50% greater than with the catalyst containing 1 wt.% Rh. This finding indicates that the cracking rate is governed by the number of metal sites rather than the concentration of acidic sites. The most favourable distribution of kerosene-range hydrocarbons was obtained at 290 °C and high hydrogen pressure. Combining the solvent-only experiment with the kinetic model demonstrated that the majority of shorter alkanes originated from the solvent rather than from methyl palmitate.
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