The Fischer‐Tropsch synthesis was discovered in Germany in the 1920s and has since been developed to industrial scale within a relatively short period of time. In the 21st century, the process is undergoing a renaissance, because an increasing fraction of liquid fuels will have to be produced from alternative raw materials like natural gas, coal or biomass in the future. On industrial scale, multitubular and bubble column reactors are used for this highly exothermic reaction. Due to several disadvantages of both reactor systems, new concepts are presently investigated. For intensification of mass transfer properties of multiphase reactors, alternative catalyst geometries like honeycombs, structured packings or foams are discussed. High catalyst utilization and isothermal operating conditions can be achieved in microstructured reactors. Furthermore, several membrane reactor concepts are under investigation. After an introduction to historical development and state of the art of Fischer‐Tropsch reactors, chances and challenges of new reactor technologies will be discussed.

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Cobalt-based monolithic and powder catalysts for Fischer-Tropsch synthesis were prepared. The aluminasupported catalysts contained cobalt (18.6 ( 0.9 wt %) and rhenium (1.2 ( 0.1 wt %) as active phases. To ensure the comparability of both catalysts, monolithic and powder catalysts were prepared from the same CoRe/γ-Al 2 O 3 active powder. While the monolith was prepared by dip coating, the slurry for the coating procedure was also used for preparation of the powder catalyst. It could be shown that both catalysts have comparable composition, pore structure, Brunauer-Emmett-Teller (BET) surface area, and active metal surface area. Catalytic measurements with suspended powder catalyst in a stirred tank reactor and monolithic catalyst in a fixed-bed reactor in the slug-flow regime were performed during Fischer-Tropsch synthesis. Higher reaction rates at comparable methane selectivities were obtained with the monolithic catalyst. Estimations show that the advantageous mass-transfer characteristics of the monolithic catalyst in the slug-flow regime are responsible for this reaction rate enhancement.

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