Kinetic analysis and microstructured reactors modeling for the Fischer–Tropsch synthesis over a Co–Re/Al2O3 catalyst

• A reduced-complexity kinetic model for the FTS over Co–Re/Al2O3 was formulated.
• The model described well the catalyst performance for CO conversions below 50%.
• Strong diffusional limitations develop at high space-times and CO conversions.
• Isothermal plug-flow model is valid for microreactors at moderate CO conversion.
• Transport effects may become an issue for the FTS in microstructured reactors.

The Fischer–Tropsch synthesis (FTS) in microreactors or microstructured reactors presents appealing advantages. In this work, the kinetics of the low-temperature FTS over a powdered 20%Co–0.5%Re/γ-Al2O3 catalyst is investigated. A reduced-complexity model is formulated with the aim of achieving a tradeoff between accuracy and computational manageability for microreactor simulation purposes. The model satisfactorily described the catalyst performance under conditions at which the CO conversion is below 50% but failed when the diffusional limitations are significant. A steady-state, isothermal plug flow model incorporating the reduced-complexity FTS kinetics was developed to simulate the behavior of several microstructured reactors loaded with the Co–Re/γ-Al2O3 catalyst. The reactors consisted in monoliths, micromonoliths, foams and microchannel reactors. The model suitably described the reactors performance for CO conversions below 50% and if the catalyst layer is sufficiently thin as to reduce the influence of the transport limitations. Further work is necessary to widen the range of validity of the kinetic model in order to include operating conditions interesting for FTS intensification in microstructured reactors. An effort is also necessary from the point of view of reactor development to avoid that transport issues become a limiting factor of the FTS when using microreaction technology.

Transport limitations should be addressed to exploit the full potential of microreactors for the Fischer–Tropsch synthesis.Figure optionsDownload high-quality image (180 K)Download as PowerPoint slide