Kinetics of the reaction of toluene with benzyl alcohol over a Nafion-silica composite

The title reaction, a set of concurrent-consecutive steps, was studied in a slurry batch reactor at 50, 65, and 75 degrees C, using cyclohexane as solvent and Nafion SAC-13 as solid acid catalyst. The final products were found to be dibenzylether, the isomers of benzyltoluene and dibenzyltoluenes and small amounts of unidentified byproducts. The kinetic results were interpreted by a Langmuir-Hinshelwood model, evaluating the main kinetics and adsorption coefficient involved in the reactions and their temperature dependence. (c) 2004 Elsevier B.V. All rights reserved

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 \ub0C on and (i) and at 35-55 \ub0C on (ii), while reaction (iii) was studied separately at 55 \ub0C 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

COMPARISON OF DIFFERENT SAMPLES OF HZSM-5 AS CATALYSTS FOR TOLUENE DISPROPORTIONATION

Toluene disproportionation was performed at 300\ub0-360\ub0C in a fixed-bad reactor (carrier H2) over samples of HZSM-5 differing in surface acidity, organic compound used for the synthesis, crystal size and procedure used for decationation. Xylene isomers in the product were in equilibrium ratios. The catalyst activity was found to be clearly dependent on surface acidity. An interpretation is given, in terms of a slow toluene disproportionation within the zeolite pores, followed by fast xylene isomerization on the external surface. Measurements of the reaction rate at 300\ub0C over one of the catalysts confirmed a kinetic model as previously suggested