| US 7,491,315 B2 | ||
| Dual riser FCC reactor process with light and mixed light/heavy feeds | ||
| Curtis N. Eng, Houston, Tex. (US); and Rik B. Miller, Stillwater, Okla. (US) | ||
| Assigned to Kellogg Brown & Root LLC, Houston, Tex. (US) | ||
| Filed on Aug. 11, 2006, as Appl. No. 11/503,042. | ||
| Prior Publication US 2008/0035527 A1, Feb. 14, 2008 | ||
| Int. Cl. C10G 11/00 (2006.01) | ||
| U.S. Cl. 208—113 [208/71; 208/73; 208/79; 208/80; 208/155; 208/159; 208/164; 208/288; 208/288 S; 585/648; 585/649; 585/650; 585/651; 585/653] | 15 Claims |
| 1. A dual riser FCC process, comprising:
cracking a first hydrocarbon feed having a carbon number less than 12 in a first riser under first-riser FCC conditions to
form a first effluent enriched in ethylene, propylene or a combination thereof;
cracking a second hydrocarbon feed having a carbon number less than 12 in a second riser under second-riser FCC conditions
to form a second effluent enriched in ethylene, propylene or a combination thereof, wherein the first hydrocarbon feed comprises
mixed olefinic C4's and the second hydrocarbon feed comprises mixed paraffinic C4's and the first-riser and second-riser FCC conditions are independently selected to favor production of ethylene, propylene
or a combination thereof;
recovering catalyst and separating gas from the first and second FCC effluents;
regenerating the recovered catalyst by combustion of coke in a regenerator to obtain hot, regenerated catalyst;
recirculating the hot regenerated catalyst to the first and second risers to sustain a continuous operating mode; and
introducing a coke precursor to the first or second riser with the respective first or second hydrocarbon feed at a ratio
of from 1 to 40 parts by weight coke precursor to 100 parts by weight fresh hydrocarbon feed, wherein the coke precursor is
selected from the group consisting of acetylene, substituted acetylene, and mixtures thereof with diolefins.
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