Kinetic study of Fischer-Tropsch synthesis using a Co/CNTs catalyst

The intrinsic kinetics of the Fischer-Tropsch synthesis reaction in the conversion of synthesis gas into liquid hydrocarbons in a spinning basket reactor over a cobalt catalyst supported on carbon nanotubes were studied. The catalyst was synthesised by the impregnation wetness technique and the reactor tests were done at 215-245 degrees C, 20 bar, a H-2/CO molar ratio of 2 and a gas hourly space velocity of 2.4-12 Nl g(cat)(-1) h(-1). To develop an appropriate kinetic model for syngas consumption, five different mechanisms were considered as possibilities for the Fischer-Tropsch reaction, each with a rate-determining step. The rate equations obtained were based on the Langmuir-Hinshelwood-Hougen-Watson model and statistical analyses were used for comparing the resulting values. The activation energies were found to be limited within the range 89-145 kJ mol(-1) and the adsorption constants of hydrogen and carbon monoxide were in the range -32 to -76 kJ mol(-1) and -13 to -64 kJ mol(-1) respectively.