Kinetics of Slurry Phase Fischer-Tropsch Synthesis on a Cobalt Catalyst

While much attention has been paid recently to the impact of the support on the kinetic effect of water, much less so has been paid to the choice of reduction promoter used to facilitate cobalt reduction. Therefore, one irnportant goal of the project is to obtain a ranking of promoters in terms of their ability to promote the formation of cobalt active sites without the expense of deleteriously affecting catalyst performance parameters, such as catalyst activity (i.e., CO conversion rate on a per g catalyst basis), product selectivities, and catalyst stability. Particular effort will be paid to determine which, if any, of the reduction promoters (Pt, Pd, Re, or Ru) form alloys with cobalt, and whether such alloying can benefit catalyst performance. To obtain kinetic parameters, the CAER will utilize a stirred tank slurry reactor (STSR) for this project. The STSR reactors are used as benchmark reactors for commercial slurry bubble column reactors (SBCRs), because they offer much higher uniformity of temperature and concentration throughout the reactor than do their fixed bed reactor counterparts, and are particularly suitable for kinetic studies. Furthermore, STSR behaves much like a perfectly mixed flow reactor at high rotational speeds to eliminate gas-liquid mass transfer resistance and to ensure that the catalyst particles are fully suspended. This allows for direct calculation of product formation rates and consumption rates of reactants from the measured gas flow rate at the exit as well as the product composition. The use of small catalyst particles (less than 45 11m) will ensure that the intraparticle mass transfer (diffusional) resistances are negligible