Mechanism of Hydrogenation Reaction of Rosin over Raney Nickel Catalyst

The mechanism of catalytic hydrogenation of rosin over Raney nickel catalyst has been studied using 200 # gasoline as a solvent. The optimal processing conditions for hydrogenation of rosin have been attained by the uniform design experiments as follows, temperature 443 K, pressure 5 0 MPa, catalyst content 5 0%(based on rosin), solvent content 50%(based on solution), reaction time 100 min, stirring rate 600 r/min , and the conditions for kinetics experiment were then obtained. The relation between reactant concentration and reaction time was traced on line, and the parameters have been regressed by using EVIEWS. Based on the experiment results, a suitable reaction model has been deduced from Hougen Warson 17 reaction mechanism models. It appeared that a reaction occurrs between abietic acid molecules and hydrogen atom adsorbed on the catalyst surface, and the dissociation adsorption of hydrogen could be the controlling step, and the reaction rate is proportional to the pressure of hydrogen and inversely proportional to the square of product concentration. Comparisons undertaken between melting method and solvent process showed that the hydrogenation reaction rate of the solvent process is greater than that of the melting method.