Trickle‐bed reactors: Effect of wetting geometry on overall effectiveness factor

Calculations of the overall effectiveness factor in a trickle‐bed reactor are given that take into account liquid distribution on the external catalyst surface. Two cases are examined: nonvolatile limiting reactant (A), and limiting reactant present in both fluid phases (B). Parameters investigated, for first‐order, isothermal kinetics, are: number of wetted and nonwetted zones, particle shape, Thiele Modulus, wetting efficiency, and Biot numbers. The calculated results fall within the range of limiting solutions obtained independently. For case A the difference between 2‐ and 8‐zone models may reach 40% within the commercially important range of the Thiele modulus. For case B it probably does not exceed 25%. Comparison is also made with experimental data. It is concluded that a multizone model can be useful in the analysis. A new form of approximate model is proposed for case A.