This work proposes a one dimensional heterogeneous model to analyze the performance of combination of Fischer-Tropsch synthesis (FTS) reactors in which a fixed-bed reactor is combined with a membrane assisted fluidized-bed reactor. This model is used to compare the performance of the proposed system with a fixed-bed singlestage reactor. in the new concept, the synthesis gas is converted to FT products in two catalytic reactors. The first reactor is water-cooled fixed-bed type while the second reactor is gas-cooled and fluidized-bed. Due to the decrease of H-2/CO to values far from optimum reactants ratio, the membrane concept is suggested to control hydrogen addition. Moreover, a fluidized-bed system has been proposed to solve some observed drawbacks of industrial fixed-bed reactors such as high pressure drop. heat transfer problem and internal mass transfer limitations. This novel concept which has been named fluidized-bed membrane dual-type reactor is used for production of gasoline from synthesis gas. The reactor model is tested against the pilot plant: data of the Research Institute of Petroleum Industry. Results show an enhancement in the gasoline yield, a main decrease in CO2 formation and a favorable temperature profile along the proposed concept. (C) 2009 Elsevier B.V. All rights reserved.