| 摘要 |
In a process for the fluidized catalytic cracking of hydrocarbon oils to gasolines in which a mixed fresh and recycle oil feed is contacted with catalyst in a reaction zone and catalyst is regenerated in a separate regeneration zone by contact with an oxygen-containing gas, the contact time of hydrocarbon and catalyst and the reaction temperature are adjusted according to the feed to produce a coke deposit on the catalyst such that a temperature of at least 620 DEG C. is maintained in the regeneration zone and the flow of oxygen into the regeneration zone is controlled responsive to the difference in temperature between the catalyst section and the gas outlet section of the regeneration zone to maintain a predetermined temperature difference, whereby the oxygen content of the outlet gas is minimized and after-burning (combustion of carbon monoxide) precluded. The operating variables controlling coke deposition are fresh feed temperature, catalyst circulation rate, fresh feed to recycle oil ratio and space velocity. The regeneration zone temperature is maintained at 620-677 DEG C. and the gas outlet temperature generally not more than 14 DEG C. higher. At the high regeneration temperatures used this temperature difference gives an indication of the oxygen content of the flue gas and by trial and error the necessary difference is found and thereafter maintained corresponding to an oxygen content below 0.2%. |
