摘要 |
<p>In a process for the production of high octane gasoline and/or other valuable lower molecular weight products from carbo-metallic oils (such as crude oil, topped crude, reduced crude, residua, the extract from solvent de-asphalting and other heavy hydrocarbon fractions) by cracking in a fluid catalytic cracking riser zone operated with a vapour riser residence time of 0.5- 10 secs at 900-1400 DEG F and 10-50 psia, a conversion of at least 50% per pass and a coke production of 4-14% based on the weight of the feed and 0.3 to 3% based on the weight of the catalyst, the catalyst is regenerated to a carbon content of at least 0.25 ml% with at least the major proportion of the coke being burned at a CO:CO2 molar ratio of at least 0.25. This incomplete combustion helps to avoid supplying the regenerated catalyst with more heat than is desirable for cracking the feed.</p> |