Mass transfer with complex chemical reaction in gas-liquid systems - II: Effect of unequal diffusivities on consecutive reactions

A fundamental description of gas-liquid mass transfer with reversible conse cutive reaction has been given. The Higbie penetration theory has been used and numerical simulations were carried out for isothermal absorption. Alth ough the model can be adapted to reactions of general stoichiometric and ki netic orders, results have been provided for unit orders only. In Part I, r esults have been presented for the case of equal diffusivities of all the c hemical species involved. In Part II, the effect of unequal diffusivity on the absorption rate and, hence, the overall enhancement factor in consecuti ve reaction systems has been presented in detail. Results presented here ar e dedicated to the case where both reaction steps are considered to be reve rsible. Finally, the model presented in this paper has been used to determi ne the selectivity towards the intermediate species using data previously r eported in literature. The model system of chlorination of p-cresol in 1,2, 4-dichlorobenzene has been used for this purpose. The strong influence of t he mass transfer parameters on the selectivity of the intermediate has been shown. (C) 1998 Elsevier Science Ltd. All rights reserved.