RESIDENCE TIME DISTRIBUTION IN THE LIQUID-PHASE IN A COCURRENT GAS-LIQUID TRICKLE-BED REACTOR

The liquid residence time distribution has been evaluated in a trickle bed reactor applying maximum liquid and gas velocities of respectivel y 10 and 140 mm . s(-1). The influence of the liquid viscosity has bee n studied, using the piston now with axial dispersion and mass exchang e (PDE) model to evaluate the experiments. The residence time of the l iquid phase could be well correlated to the liquid Reynolds and a modi fied Galileo numbers. The fraction stagnant liquid holdup as determine d using the PDE model;is less than half the value found from draining experiments and stays constant with increasing liquid velocity for wat er, while it increases for the more viscous liquid. The Bodenstein num ber in the dynamic zone coincides with single phase flow. For water th e NTU between the dynamic and the stagnant zone is about 0.4, while fo r the viscous Liquid it increases gradually to 2.5 with increasing liq uid velocity.