A multifunctional reactor for carrying out Fischer-Tropsch synthesis is being developed. This is a gas-lift reactor with monolith type catalyst packing. A mathematical model of the reactor has been developed. The behavior of the reactor has been analyzed in wide range of design variables and operational conditions using literature correlations for the parameters included in the model. The computations show, that it is possible to achieve better performance in this reactor than in conventional slurry reactor at the same catalyst loading.