Acetophenone hydrogenation on Rh/Al2O3 catalyst: Flow regime effect and modeling of a trickle bed reactor
Shinbeom Lee, Arvind Varma
School of Chemical Engineering, Purdue University, 480 Stadium Mall Drive,
West Lafayette, IN 47907, USA
Acetophenone hydrogenation on Rh/Al2O3 catalyst was conducted in a trickle bed reactor, composed of cocurrent downward gas and liquid flows on solid catalysts. Due to complex 3-phase hydrodynamics, trickle-bed reactor has four different flow regimes. Among these, operation in pulsing and bubbly flows as high interaction regimes is promising to enhance reaction conversion and yield. From hydrodynamic tests using transparent tubes, operating conditions for low and high interaction regimes were obtained. Based on the results of hydrodynamic tests, reaction tests with five different liquid flow rates were carried out to confirm flow regime effects on reactor performance. In the reaction tests, enhancement of reaction rate at regime transition point was confirmed, separated by the enhancement for faster liquid flow rates. Sensitivity studies with different gas flow rates, temperature and pressure confirmed the effects of partial wetting and gas or liquid limited reaction. Reactor modeling, including the factor for partial wetting and different flow regimes, was carried out and provided good predictions for both conversion and yield.
Keywords: flow regime effect, trickle bed, acetophenone hydrogenation, hydrodynamics, modeling