Design of optimal multiphase reactors exemplified on the hydroformylation of long chain alkenes

In this work, a methodology for the design of optimal multiphase reactors is proposed and illustrated on the hydroformylation of 1-octene using a biphasic ionic liquid system with TPPTS modified Rh catalyst. The applied three level design methodology is apparatus independent and thus able to validate existing and generate innovative reactors.On the first design level, the optimal heat and mass flux profiles, which provide the best route in the thermodynamic state space, are determined by solving a dynamic optimization problem. In case of the investigated hydroformylation system, a selectivity increase of 11.7% is obtained by optimal profiles for the 1-octene, hydrogen, carbon monoxide, and heat flux.On the second design level, the minimum required (kLa)-value and the design variables, which are suited to establish the desired flux profiles, are determined. It is shown that both the space time yield and the selectivity of the hydroformylation process depend strongly on the intensity of gas–liquid mass transfer.The optimal design variable profiles and (kLa)-value of level 2 are approximated by a suited reactor set-up on the third level. By use of static mixers, advanced cooling, and discrete 1-octene dosing, the selectivity of the derived technical reactor is 9.1% higher compared to an optimized reference case.In summary, the proposed methodology is suited for the design of tailor-made superior multiphase reactors. For the example process, namely the hydroformylation of long chain linear alkenes, a new reactor concept was derived, leading to a significantly higher selectivity compared to conventional reactor concepts.

► Best reactor for the hydroformylation of higher alkenes in an IL-system is derived.
► Selectivity increase of 10% compared to an optimized reference case is achieved.
► Reactor has 3 segments with advanced cooling and dosing of syngas and 1-octene.
► Design method is suited to derive classical and innovative multiphase reactors.
► Influence of gl mass transfer on STY and selectivity is investigated with kLa study