Efficiency of a trickle bed reactor in the continuous hydrogenation of pharmaceutical intermediates

As a research and production based pharmaceutical company, the optimization of manufacturing processes is a key point for H. Lundbeck A/S. This study looks into the possibility of using a continuous trickle bed reactor as a standard unit for hydrogenation reactions in the production of APIs (active pharmaceutical ingredients).

In this study, two different hydrogenation reactions (see Fig. 1a) using different catalysts were investigated in a bench scale trickle bed reactor. It was seen that both chemistries showed a conversion and selectivity similar to full scale batch runs at similar concentrations, by tuning the process conditions. Temperature, pressure and catalyst particle size were found to be important process parameters to be tuned for a given bed geometry and reaction chemistry. Long-term studies however showed that the catalysts deactivate with time, see Fig. 1b. The rate of catalyst deactivation was reaction and temperature dependent, with the deactivation rate reducing with increase in temperature. However increased temperature also resulted in formation of unwanted by-products. From TEM and CO adsorption studies it was concluded that the deactivation was mainly due to organic carbon species deposited on the active metal particles of the catalyst, which could be partially removed by calcination in air. These results suggest that trickle bed reactors could be a standard reactor unit for hydrogenation chemistries that have a low rate of deactivation.