关键词: 费托合成, 浆态床, 铁/铜/钾/二氧化硅催化剂

Abstract: Two spherical Fe/Cu/K/SiO2 catalysts with different preparation scale for slurry Fischer-Tropsch (FT) synthesis were prepared by a combination of co-precipitated and spray drying method. The pellet size of the catalyst with a laboratory scale is 5-15μm, whereas that is 40-60μm for the scaled-up catalyst. N2 physical adsorption, H2 temperature-programmed reduction, CO2 temperature-programmed desorption, Mössbauer spectroscopy, and X-ray diffraction were used to characterize the textural properties, reduction and carburization behavior, and phase transformation of the two catalysts. The results show that the scaled-up catalyst has larger crystallize size and pore volume, lower BET surface area, and lower surface basicity than the laboratory-scale catalyst. Moreover, the scaled-up catalyst was more difficult to be reduced and carburized. However, the results of FT synthesis in a slurry bed indicate that the scaled-up catalyst exhibits comparative activity, better reaction stability, and higher selectivity for olefin and heavy hydrocarbons. Scanning electron microscopy results suggest a better attrition resistance of the scaled-up catalyst during the FT reaction tests.

Key words: Fischer-Tropsch synthesis, slurry bed, Fe/Cu/K/SiO2 catalyst