Intrinsic kinetics study of rosin hydrogenation on a nickel catalyst supported on spent equilibrium catalyst

Abstract

Reaction pathways and intrinsic kinetics of rosin hydrogenation over a spent equilibrium catalyst-supported nickel catalyst were investigated in a batch reactor. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that the reaction pathway of rosin involved isomerization, hydrogenation, and dehydrogenation of various resin acids. In the temperature range between 423 and 453 K and stirring rates above 500 rpm, external and internal mass transfer limitations in catalyst particles with a size of 20-80 μm were eliminated. A power-law model was used to determine the intrinsic kinetic parameters of rosin hydrogenation based on the experimental data. The results showed that reactivity trends of rosin hydrogenation below 453 K are well-fitted by a pseudo-first-order kinetic model. Activation energies for neoabietic acid isomerization, palustric acid isomerization, abietic acid (AA) partial hydrogenation, AA hydrogenation, AA dehydrogenation, and pimaric acids hydrogenation were 66.60, 58.06, 73.02, 86.67, 107.42, 37.60 kJ mol-1, respectively.