Modelling of gas-liquid reactors - stability and dynamic behaviour of a hydroformylation reactor - influence of mass transfer in the kinetics controlled regime

E.P. van Elk, P.C. Borman, J.A.M. Kuipers, G.F. Versteeg

Abstract

In behalf of the development of new hydroformylation reactors, a research project was initiated to examine the dynamics of hydroformylation processes. The current paper presents the results of applying the rigorous reactor model (van Elk et al., 1999 and 2000) and the approximate reactor model (van Elk et al., 1999) on a new, to be developed, hydroformylation reactor with complex kinetics.
The reaction considered is first order in the olefin and the catalyst concentration, while the apparent reaction order in hydrogen varies between 0 and 1 and in CO between -1 and 1, depending on the hydrogen and carbonmonoxide concentrations respectively. The influence of the cooler design and the mass transfer on the dynamic behaviour is investigated in the kinetic controlled regime.
It is shown that this reactor will show oscillatory behaviour under certain realistic operating conditions. From stability analysis it was found that the desired steady state (temperature, conversion) exists for a wide range of mass transfer parameters. However, the cases are only statically similar, but dynamically show an important difference: for some conditions the steady state is found to be dynamically stable, while for other conditions the same steady state is found to be dynamically unstable (limit cycle). This unusual phenomenon is possible due to the negative reaction order in CO.
© 2001 Elsevier Science Ltd. All rights reserved.

Keywords: Hydroformylation reactor model; Dynamic stability; Limit cycle; Bifurcation analysis; Design rules