PATENT

3488. -----[STANDARD OIL CO.] Fischer-Tropsch Synthesis.  British Patent 676,658 July 30, 1952.  Chem. Abs., vol. 47, 1953, p. 7762.

Catalyst fines from Fischer-Tropsch synthesis are separated from the fluidized bed by entrainment in the product gases.  The H₂-CO synthesis gas mixture is fed into a fluidized, finely divided Fe-catalyst bed maintained at 500°-750° F. and 250-750 p.s.i. at such a velocity that particles <20 m in size are entrained in the overhead gases.  The fines are separated and may be agglomerated by sintering, then ground, classified, and reduced for recycling.  By removing the fines continuously from the reaction mixture, wax formation is minimized.  Since the fines contain more C than the larger particles, their removal from the catalyst bed leaves the latter with better heat-transfer and fluidization characteristics than if they are allowed to build up in the bed.  The high C content of the fines also makes them readily susceptible to oxidative regeneration.