Comprehensive hydrodynamic and heat transfer study of Fischer–Tropsch synthesis (FTS) on a home-based cobalt catalyst, with the presence of water–gas shift (WGS), is conducted with a fixed bed reactor. Two different diameters have been used for the reactor, 4 and 7 inches. To meet the requirements of industrial applications, simulation has been used to scale up the effect on the commercial scale reactor. Synthetic gas was used as a feed stream and its conversion to H2 was considered. Temperature and velocity profiles were obtained for the different scales.