The behavior of the bifunctional catalytic system fused-iron catalyst/zeolite component in the Fischer-Tropsch synthesis using a strongly diluted gas under conditions close to those of the actual industrial process was studied. A kinetic description for the CO conversion in the hydrocarbon formation reaction and the water gas shift reaction that occurs simultaneously was derived in terms of the Langmuir-Hinshelwood equations, which turned out to be suitable for developing on its basis a model industrial fixed-bed catalytic reactor for the Fischer-Tropsch process.