A kinetic model for sunflower oil hydrogenation on a palladium catalyst is proposed based on Horiuty–Polanyi type mechanism and considering either a dissociative or associative adsorption of hydrogen. The derived kinetic laws allow to explain the distinct dependency of saturation and isomerization reactions on hydrogen pressure. Kinetic parameters are identified based on batch slurry hydrogenations carried out at 60–160◦C and 2–31 bar with a powdered Pd/Al2O3 catalyst. A statistical analysis is used to select the most suitable adsorption mechanism for H2. Evaluation of the Weisz–Prater modulus reveals that limitations to intraparticle diffusion occur despite the particle diameter does not exceed 40 μm.