chapter  6
26 Pages

Kinetics of Hydrogenation of p-Nitrobenzenesulfonamide in a Three-Phase Slurry Reactor

WithMakarand G. Joshi, William E. Pascoe, Dennis E. Butterfield

In catalytic hydrogenations the interaction between the transport processes and the reaction kinetics can play an important role in determining reactor performance. It is essential to know the intrinsic kinetics of the reaction under consideration for proper reactor design, scale-up, and troubleshooting. A reactor system equipped with a PC-based data acquisition system capable of measuring the intrinsic kinetics of catalytic hydrogenations was assembled. Hydrogenation of p-nitrobenzenesulfonamide to p-aminobenzenesulfonamide over Raney cobalt in ethanol was chosen as the model system to be studied. The experimental conditions were chosen to ensure that the reaction was not mass transfer-limited. The hydrogenation was modeled as a three-step series reaction. The kinetics of each of the three steps was represented by the power law model. The orders of the steps with respect to organic substrates and hydrogen were determined from the experimental data. The activation energy for the reaction was also determined. A kinetic expression for the reaction was developed.