Calcination of co-based Fischer-Tropsch synthesis catalysts

The calcination of Co-based slurry-phase Fischer - Tropsch synthesis catalysts was investigated. Fischer - Tropsch synthesis is part of the gas-to-liquids (GTL) process that produces gas oil and naphtha from natural gas. For the GTL process, the preparation of highly active Co-based catalysts is of utmost importance. This paper shows that the conditions during the calcination of impregnated cobalt precursors have a significant influence on the performance of the final catalyst. The options of calcination in rotary kilns, furnaces and fluidized-bed reactors were considered. It was found that the catalyst performance is strongly dependent on the heating rate and the air-space velocity during the preferred option of fluidized bed calcination. The postulation that Co3O4 is not the preferred oxide phase of the calcined intermediate catalyst is supported by a temperature-programmed reduction (TPR) study.