Monolithic catalysts with high thermal conductivity for the Fischer–Tropsch synthesis in tubular reactors

The adoption of multitubular reactors loaded with washcoated structured catalysts having highly conductive honeycomb supports has been proposed as an alternative to conventional packed-bed reactors in order to approach the ideal plug-flow behaviour while (i) enabling isothermal operation of highly endo- and exo-thermic reactions, (ii) facilitating the intraparticle mass-transfer, and (iii) limiting pressure drop. The potential of such reactors in the low temperature Fischer–Tropsch synthesis is investigated herein by means of a pseudo-continuous, heterogeneous, two-dimensional mathematical model of a single reactor tube. Simulation results indicate that extruded aluminum honeycomb monoliths, washcoated with a Co/Al2O3 catalyst, are promising for the application at the industrial scale, in particular when adopting supports with high cell densities and catalysts with high activity. Limited temperature gradients are in fact possible even at extreme process conditions, thus leading to interesting volumetric reactor yields with negligible pressure drop. This result is achieved without the need of cofeeding to the reactor large amounts of liquid hydrocarbons to remove the reaction heat, as opposite to existing industrial Fischer–Tropsch packed-bed reactors.

► The potential of washcoated conductive monoliths in the FTS is investigated.
► A 2D heterogeneous mathematical model of a single reactor tube has been used.
► Conduction in the structured support can be exploited to remove the reaction heat.
► Mild T-gradients lead to interesting volumetric reactor yields with negligible ΔP.
► Extruded aluminum monoliths are promising for the industrial application.