摘要 |
A riser cracking operation is described for the production of gasoline and distillate material by the combination of cracking fresh gas oil charged to the base of a riser cracking zone for admixture with freshly regenerated catalyst to form a suspension thereof at an elevated cracking temperature, a second hydrocarbon fraction of more difficult cracking characteristics is charged to the suspension rising in the riser cracking zone at a point selected from 10 to about 30 feet above the riser bottom and the riser inlet temperature is restricted to be within the range of 900 DEG to 1000 DEG F. |