Abstract: The effects of oxychlorination conditions on redispersion of Pt grains in continuous reforming catalyst were investigated ina fixed bed reactor. The results indicated that increasing the temperature of oxychlorination and decreasing the molecular ratio of water to chlorine were beneficial to the redispersion of Pt grains and the metal dispersion of the catalyst. The improvement of metal dispersion was also related to the initial particle size of Pt grains. When the initial particle size of Pt grains was above 100 nm, it was difficult to increase the metal dispersion. Based on the above-mentioned laws, the oxychlorination conditions in an industrial plant were optimized. After 9 months of optimization, the metal dispersion of the catalyst recovered from 0.46 to 0.81 and its appearance was uniform white. The catalytic performance was recovered and the yield of aromatic increased by 2.3 percentage points.

Key words: oxychlorination, metal dispersion, Pt grains, re-dispersion, continuous reforming