Kinetic study of oxidative dehydrogenation of propane over Ni-Co molybdate catalyst

The kinetics of oxidative dehydrogenation of propane over a Ni-Co molybdate catalyst was investigated in an integral reactor by non-linear regression techniques. By performing central composite design experiments, the influence of propane and oxygen partial pressures, propane space-time and temperature were studied. A consecutive reaction network has been proposed for oxidative dehydrogenation of propane. Several possible kinetics models (power-law (PL), Mars-van Krevelen, Eley-Rideal and Langmuir-Hinshelwood) were analyzed using the statistical and thermodynamical criterions. The estimation of kinetic parameters was achieved by solving the system of ordinary differential equations, which describe the outlet of the reactor, and by minimization of the objective function using Matlab software. Data measured over the set of experimental conditions were in good agreement with two surface oxido-reduction models for the propane oxidative dehydrogenation reaction. The difference between the models consists in the surface reduction step in which one 'O' is involved for the first model, while two 'O' are required for the second model. (C) 2003 Elsevier Science B.V All rights reserved.