Trickle‐bed reactors: An experimental study of partial wetting effect

The effect of partial external wetting of catalyst particles on conversion for hydrodesulfurization of dibenzothiophene in a white oil was studied in a 25‐mm trickle‐bed reactor at 10 MPa and 330–370°C with Mo/SiO 2 catalyst. The superficial liquid velocity ( L m ) was varied from 0.092 to 0.557 kg · m −2 · s −1 . Measurements of conversion were augmented by tracer, kinetics and solubility experiments. The objectives were to determine the parameters of a reactor model based on the multizone external wetting (MZEW) model for the overall effectiveness factor, η o , and to compare the measured and predicted values of η o . As the wetting efficiency, f , increases, η o also increases, but, even at the highest L m , catalyst wetting was not complete and consequently η o was lower than the value corresponding to f = 1. The MZEW model describes the experimental data better than the simpler two‐zone model, based on a particular interpretation of f . The difference between the two models can be as high as 200%.