A global kinetic model of the FTS over a Co/Al2O3 state-of-the-art catalyst is developed in a fixed bed micro-reactor under conditions relevant to industrial operation (temperature, 210–235 °C; pressure, 8–25 bar; H2/CO feed molar ratio, 1.8–2.7; gas hourly space velocity, 2000–. On the basis of proposed reaction mechanisms, developed according to the carbide theory and the alkyl mechanism, the kinetic expressions for n-paraffins and α-olefins formation are derived. Both the calculated CO conversion and the hydrocarbon distribution (up to n=49) in FT reaction are satisfactorily predicted.