Kinetics of the reaction of toluene with benzyl alcohol over sulfated zirconia

The title process includes: (i) conversion of benzyl alcohol to dibenzylether; (ii) benzylation of toluene by benzyl alcohol; (iii) benzylation of toluene by dibenzylether. The three reactions were studied in a slurry batch reactor, using cyclohexane as solvent and sulfated zirconia as solid acid catalyst. Runs were carried out at 60-75 degrees C on and (i) and at 35-55 degrees C on (ii), while reaction (iii) was studied separately at 55 'C only. Reaction (iii) takes place only after complete reaction of the alcohol in (i) and (ii), and does not produce benzyl alcohol. Benzyl alcohol is confirmed to be preferentially adsorbed on the catalyst with respect to dibenzylether. The final products are the isomers of benzyltoluene and dibenzyltoluenes, and small amounts of unidentified byproducts. The kinetic results were interpreted by Langmuir-Hinshelwood models, one for (i) + (ii), the other for (iii). The main kinetic and adsorption coefficients involved in the reactions were evaluated.(c) 2006 Elsevier B.V. All rights reserved.