Modeling of gas-liquid packed-bed reactors with momentum equations and local interaction closures

An algebraic model for the estimation of gas-liquid packed-bed hydrodynamic parameters is developed, based on one-dimensional material and momentum balances for gas and liquid phases. Underlying momentum exchange closures are critically analyzed, which leads to discarding some interaction models between the phases and development of new models based on local hydrodynamics. The present approach is based on more-relevant assumptions for the particle scale geometry than the slit models presented in the literature. The resulting model requires a one-parameter iterative solution, from which both pressure drop and liquid holdup are obtained. The model can be used without any extra complication in situations where the boundary conditions are specified either at the inlet or at the outlet of the reactor. It is suitable for modeling both low-and high-pressure operations, trickling as well as pulsing flow, upflow and downflow arrangements, and processes with Newtonian as well as non-Newtonian liquids. Finally, the present model is compared to its differential counterpart, and to available experimental data from open literature. Reasonably good agreement was observed for both pressure drop and liquid holdup data from a wide range of operating conditions, using only a single set of Ergun parameters.