Fischer-Tropsch cobalt activations: The role of water on catalyst reduction

Fischer-Tropsch synthesis has gained renewed interest for its role in sustainable fuels from renewable feedstocks such as biomass, municipal waste and CO2. This submission highlights the importance of catalyst pre-treatments, such as cobalt activation (reduction), have on the final reactor performance. The role of reduction process controls such as temperature, pressure, partial pressure of hydrogen and water partial pressures are explored, showing the improved catalyst activations with reasonable temperatures, low pressures, high hydrogen concentrations and the need for strict water level control. The activation conditions of the cobalt/titania catalyst are studied with in situ techniques such as XAS, XRD and TPR, and supported by realistic reactor testing for operation at scale. Water is a key by-product from catalyst activation, and if unmanaged it can inhibit further reduction and produce a loss in long-term catalyst activity. As such, reactor bed profiles are explored to highlight the impact of changing process conditions throughout the bed. •Fischer-Tropsch technology demonstrated for waste to fuels plant in Nevada, USA.•Reduction of FT catalysts is crucial to give optimal activity and selectivity.•Water produced can inhibit reduction of cobalt oxides and sintering.•Catalysis testing shows the impact of reduction throughout the catalyst bed.•Partial pressure of hydrogen, temperature and pressure impact reduction process.