Evaluation of liquid-solid contacting in trickle-bed reactors by tracer methods

The use of dynamic (tracer) methods for the evaluation of liquid‐solid contacting and holdup in trickle‐bed reactors is illustrated. It is shown that both the fraction of external catalyst area wetted and the fraction of total catalyst wetted by liquid can be obtained. External contacting efficiency and dynamic liquid saturation are correlated in terms of the appropriate dimensionless groups over the range of variables typical for trickle‐flow operation. The relationship between catalyst contacting efficiency and catalyst utilization is outlined.