A one-dimensional multicomponent two-fluid model of a reacting packed bed including mass, momentum and energy interphase transfer

摘要

In this paper a multicomponent two-phase flow numerical model for reacting packed beds is presented, where one phase is compressible. The model is applied to a catalyst bed which decomposes highly concentrated hydrogen peroxide into oxygen and water vapour. Using dimensional analysis a number of simplifications to the governing equations are made. A pressure based finite volume approach is used to solve the resulting equations where the pressure-velocity-density coupling is established with a SIMPLE algorithm for two-fluid flows. The model is validated against experimental data and shows in general a reasonable agreement given the complexity of the physics. It is shown that with the two-fluid formulation characteristics are predicted that cannot be reproduced with mixture models. Simulations reveal that the largest part of the total mass transfer takes place in a very small section of the catalyst bed at the point where the liquid reaches the boiling point and that most of this transfer is due to evaporation. It is further shown that a thermal description of the packing of the catalyst bed would improve the prediction of temperature distribution in the two-phase regime.