Levulinic acid (LA) is an especially promising feedstock for the production of chemicals and biofuels, because it can be prepared from lignocellulosic biomass. Its conversion to gamma-valerolactone (GVL), a fuel additive and precursor to transportation fuels, appears preferential. In this study, a heterogeneous Ru/C catalyst was employed for investigating the hydrogenation reaction of LA to GVL in the aqueous phase in a three-phase mechanically agitated contactor. To explore kinetics, runs were performed in a chemical-control regime between the temperatures 323-353 K, H-2 partial pressures 0.69-2.07 MPa, initial LA concentrations 4.31-12.93 mmol/L, and catalyst loadings 0.3-0.7 kg/m(3). Langmuir-Hinshelwood-Hougen-Watson (LHHW) models were applied to describe the initial rates of LA disappearance. The model, which presumed that surface reaction between non-dissociatively chemisorbed H-2 and LA is limiting, was most suited to describe reaction kinetics. From an Arrhenius plot, it was found that the value of E-act is 68.1 kJ/mol.