Influence of channel geometry on hydrodynamics and mass transfer in the monolith film flow reactor

The hydrodynamics and the gas-liquid mass transfer as a function of the cha nnel geometry have been investigated for the monolith film flow reactor. Fo r the hydrodynamic studies, the liquid distribution and the flooding bounda ries have been experimentally determined. The liquid distribution improved with increasing liquid flow rate. The flooding limits are in the range of o ther commercial structured packings and allow operation under industrially relevant conditions. Larger channel sizes and lower surface tension expand the operating window, while viscosity seems to have a minor impact. The gas -liquid mass transfer is a strong function of the surface to volume ratio d efined by the channel dimensions. Co- and counter-current flow operation re sult in similar performance. Furthermore, shorter monoliths, with larger co ntribution of the inlet section have significant higher mass transfer due t o the development of the concentration profile. The obtained k(GL)a(V) valu es of around 0.01 s(-1) are in the range of other commercial packings in co unter-current flow operation. A three-dimensional single channel model desc ribing the hydrodynamic and diffusion phenomena in the monolith is in good agreement with the experimental results. The flexibility in channel size an d dimension allows tailoring the monolith reactor to the specific needs of the individual application. (C) 2001 Elsevier Science B.V. All rights reser ved.