A trickle-bed reactor model for hydrogenation of 2,4 dinitrotoluene: experimental verification

A trickle-bed reactor model has been developed for hydrogenation of 2,4 dinitrotoluene (DNT). This model incorporates the contributions of partial wetting and stagnant liquid hold-up effects in addition to external and intraparticle mass transfer resistances for a complex consecutive/parallel reaction scheme under consideration represented by L-H-type kinetics. As the reaction is highly exothermic, the heat effects have also been incorporated in the model. The reactor performance for complete wetting, partial wetting of catalyst particles and in the presence of stagnant liquid pockets has been compared and the significance of different parameters discussed. Experimental data were obtained for different particles sizes, different gas and liquid velocities in a temperature range 318–328 K. The model predictions were compared with experimental data and were found to agree very well for a wide range of operating conditions. The model proposed here also allowed prediction of maximum temperature rise in the catalyst bed and which was also found to agree well with the steady-state experimental data. Under certain conditions, hysteresis behaviour of the reactor performance has been observed.