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Patent Abstracts

Describes an improved fluidized hydrocarbon-synthesis process wherein the C content of the catalyst is controlled by withdrawing selectively the catalyst particles with high C content. The fluidized stream of catalyst is withdrawn from the treating zone and passed to a segregation zone which contains packing elements. Elements of the saddle type have a maximum diameter of 2 in. are most suitable. The gases flowing up through the packing in the elutriator effect a separation of the catalyst particles according to C content. The particles with the smaller C content are concentrated in the lower portion of the eutriator and returned to the reaction zone in such a quantity that the C concentration on the Fe catalyst is 15-20%. In this process, the catalyst must have a particle size of 20-200μ . Approximately 0.5-3% of the total catalyst is maintained in the elutriation zone.