Effect of incorporation manner of Cu promoter on Fischer-Tropsch synthesis performances over iron-based catalysts

A series of spherical FeCuK/SiO₂ catalysts for slurry Fischer-Tropsch synthesis (FTS) were prepared by the spray drying method. The effects of incorporation manner of Cu on the crystallite structure, the reduction and carburization behaviors were studied by H₂ temperature-programmed reduction (H₂-TPR) and Mssbauer spectroscopy. The catalytic performances were evaluated in a slurry reactor under the industrial relevant reaction conditions of 250℃, 1.5MPa, H₂/CO=0.67 and a space velocity of 2.0L/gcat-h. The result indicated that the coprecipitated Cu was well dispersed in iron phase, which promoted the reduction, carburization of the catalyst and the catalytic activity. The addition of respective precipitated Cu suppressed the reduction and carburization of the catalyst. All catalysts were stable during 500h on stream. For the hydrocarbon selectivity, the addition of the coprecipitated Cu increased the selectivities of heavy hydrocarbons and olefins, and restrained the formation of oxygenates, compared with others.