Different applications of membranes have been proposed for Fischer–Tropsch synthesis in recent literature. Across membranes, reactants can be fed along the reactor axis or the inhibiting by-product H2O can be selectively removed. Here, the concept of enhanced conversion of CO2 containing synthesis gases to long-chain hydrocarbons by in situ H2O removal is introduced. Experimental results of in situ H2O removal under reactive conditions with an Fe-based catalyst show positive effects on conversion and yield. Additionally, catalytic membranes can be used as a defined reaction zone. In so-called plug-flow contactor membranes, high specific production rates can be achieved. Finally, a catalyst encapsulated by a zeolite membrane layer is presented as a possibility to modify product distribution.