| 摘要 |
A heavy fraction oil is catalytically cracked by contacting the oil with a catalyst mixture consisting of 60 to 95 wt % of a base cracking catalyst containing an ultra stable Y-type zeolite and less than 0.5 wt % of rare-earth metal oxide, and 5 to 40 wt % of an additive containing a shape-selective zeolite, in a fluid catalytic cracking apparatus having a regeneration zone, a down flow-type reaction zone, a separation zone, and a stripping zone, and under conditions that a reaction zone outlet temperature is in the range of 580 to 630° C., the catalyst/oil ratio is in the range of 15 to 40 wt/wt, and the contact time of hydrocarbons in the reaction zone is in the range of 0.1 to 1.0 seconds. According to the fluid catalytic cracking process, the yield of light-fraction olefins can be enhanced.
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