Abstract
The catalytic hydrogenation of cardanol was studied in a stirred three-phase-slurry reactor using palladium on carbon, often referred to as the Pd/C catalyst (5% loading of palladium is supported on activated carbon powder). The effects of various process parameters were examined. The kinetics of hydrogenation, which proceeds through three parallel–series reactions, was investigated. The reaction was observed to be of first order with respect to both hydrogen and cardanol. A simple second-order series reaction model was well fitted to the experimental data. Also, the Langmuir–Hinshelwood–Hougen–Watson approach was used to interpret the possible mechanistic behaviour of the reaction. It was observed that the reaction follows dual site, competitive and dissociative type of adsorption of hydrogen. Surface reaction of the adsorbed reactants was identified as the overall rate controlling step. Various rate constants and adsorption equilibrium constants for the different steps were also estimated. Different thermodynamic parameters associated with these constants were obtained to assess their physical significance. Also, these constants were evaluated statistically using the F-test and t-test.