摘要 |
A spent zeolite-containing hydrocarbon cracking catalyst is treated by regererating it to remove carbonaceous deposits. A portion of the regenerated catalyst is withdrawn from the circulating catalyst inventory of a hydrocarbon processing unit and slurried with a liquid containing an activating agent to solubilize and/or dislodge contaminants which block the pores of the zeolite and adversely affect the activity of the catalyst. The slurry is agitated to dissolve or dislodge the contaminants from the zeolite pores, and the agitated slurry, without being permitted to settle, is transferred to a fluidized drying zone where the liquid and solubilized and/or dislodged contaminants are removed from the treated catalyst which has a level of cracking activity higher than that of the catalyst in the circulating catalyst inventory. The treated catalyst is then recycled to the unit and contacted with a hydrocarbon feedstock under cracking conditions. |