Three-phase fixed bed catalytic reactors: application to hydrotreatment processes

O. M. MARTINEZ; M. C. CASSANELLO; A.L. CUKIERMAN

Trends in Chemical Engineering

Research Trends

Lugar: Trivandrum; Año: 1994 vol. 2 p. 393 - 453

0972-4478

The baheviour of three-phsae fixed bed reactors is comp1ex due to hydrodynmic characteristics arising from the gas and liquid flow through the catalytic packed bed. This situation is particularly relevant for hydmtreatement processes studies in laboratory, bench-scale and pilot plant.  The effectiv use of these reactors requires elther the evaluation of the influence of non-idealities on reactor conversions or bed modifications to minimize divergencies with rsapect to ideal reactorbehaviour, namely ideal plug flow beheviour and complete external wetting of catalyst pellets .To achieve these raquierements, three complementary tools have bean analyzed: use of mathemetical models to describe the baheviour of three-phase fixed bed reactors,use of simple criteria in order to verify whether hydrodynamic aspects affect thebehaviour of experimental rsectors and change of either geometrical characteristics or operating conditions in order to achieve an ideal reactor behaviour. For the effective use of any of the  proposed tools, reliable correlations of hydrodynamic and transport parameters are needed; therefore, e review of available correlations for the evaluation of axial dispersion, holdup, wetting efficiency end liquid-solid mass transfer is presented.