PLATINUM RHENIUM ALUMINA CATALYST .3. MECHANISM OF C-6-RING HYDROGENATION DEHYDROGENATION REACTIONS

Results of the hydrogenation/dehydration reactions of cyclohexane, cyclohexene and benzene in hydrogen carrier at 4 atm and temperatures between 47 and 375 degree C in continuous flow experiments are presented. The orders of reaction were 0. 9, 0 and 0 for cyclohexane dehydrogenation to benzene, cyclohexene hydrogenation to cyclohexane and benzene hydrogenation to cyclohexane, repectively. Activation energies for these three reactions are 24 kcal/mol, 100 kJ/mol (315-375 degree C), 6 kcal/mol, 25 kJ/mol (47-203 degree C) and 8 kcal/mol, 33 kJ/mol (107-203 degree C), respectively. Rate equations were developed using the dehydrogenation model of Ruiz-Viscaya et al. modified for hydrogenation/dehydrogenation reactions of the three C//6// minus ring hydrocarbons, and their validity with respect to the experimental data is discussed.