Kinetic experiments and modeling of a three-phase catalytic hydrogenation reaction in supercritical CO2

The three-phase catalytic hydrogenation of an unsaturated ketone using supe rcritical carbon dioxide as a solvent was studied in order to simulate the performance of a semi-industrial trickle-bed reactor. High pressure kinetic experiments were carried out in a modified internal recycle reactor of Ber ty type. An industrial Pd on alumina supported catalyst was used, in form o f egg-shell pellets. Data were collected over the whole conversion range, a llowing for a thorough inspection of the reaction rate composition dependen cies. It is shown that supercritical CO2 strongly increases the reaction ra te. Experimental data sets were fit using both simple homogeneous power-law kinetics and complex heterogeneous Langmuir-Hinshelood models: here, the e stimation of liquid concentrations was performed through vapor-liquid equil ibrium calculations based on an equation-of-state approach. (C) 1999 Elsevi er Science B.V. All rights reserved.