Abstract: The invention provides a method for controlling a selectivity profile of products of a Fischer-Tropsch synthesis process, wherein a catalyst promoter, either dissolved in solution or in a powdered form, is directly injected into the reactor medium, typically into the reactor feedstream. The Fischer-Tropsch process is typically a High Temperature Fischer Tropsch (HTFT) process, and a typical chemical promoter for the HTFT process is potassium. By adding or doping the reaction medium with the catalyst promoter during the synthesis process, the selectivity profile of olefins and paraffins in the product stream is significantly changed, with more olefins being formed whilst the level of paraffins is reduced, and typically the level of olefins in the C2-C4 range is increased. The catalyst promoter may form part of a promoter-carrying compound, for example, potassium carbonate.

Abstract: The invention is directed to improving the quality of fluidization of fluidized solids and comprises the addition of fluidization promoters in particle form that have a smaller density and particle size than the neat solids. In a preferred embodiment of the invention the catalyst is a Fischer-Tropsch catalyst and the fluidization promoter comprises carbon particles.