| 摘要 |
PROBLEM TO BE SOLVED: To provide: spherical alumina particles with a controlled degree of macroporosity within a particle and a controlled size dispersion of the macroporosity to have a low density and good mechanical strength; and preparation processes, catalysts comprising the particles as a support, and processes of their use in catalytic hydrocarbon treatment processes, in particular in a catalytic reforming process.SOLUTION: The present invention concerns spherical alumina particles characterized by: a BET specific surface area in the range from 150 to 300 m/g; a mean particle diameter in the range from 1.2 to 3 mm; a particle diameter dispersion, expressed as the standard deviation, not exceeding 0.1; a total pore volume, measured by mercury porosimetry, in the range from 0.50 to 0.85 mL/g; and a degree of macroporosity within a particle of less than 30%, where the dispersion of the diameters of the macropores, expressed as the ratio D90/D50, does not exceed 8. In preferred spherical alumina particles, the value for the settled packing density is in the range from 0.4 to 0.8 g/mL, and the mean grain crushing strength value is at least 25 N.SELECTED DRAWING: None |
