The liquid hold up and axial dispersion in a trickle bed reactor were studied in this investigation. In the range of liquid superficial velocity 6.15× 10-3-2.37×10-2m/s and gas superficial velocity 7.07×10-3-0.56m/s

pressure drop and liquid hold up were obtained simultaneously using four gas-liquid systems and six kinds of packing at 298±1K. In the experimental range used

the dynamic holdup data could be correlated by: The results showed that the liquid hold up in trickle beds with three-lobe particles was higher than that with cylindrical particles ot equivalent sizes. Curves of liquid phase residence time distribution under trickle flow conditions were plotted and interpreted in terms of dispersion model. The results were correlated by: