FCC processing with reduced CO2 emissions
Systems and methods are provided for expanding the operating envelope for an FCC reaction system while also reducing or minimizing the net environmental CO 2 emissions associated with the FCC reaction system and/or the resulting FCC products. In some aspects, reducing or minimizing net environmental CO 2 emissions can be achieved during processing of unconventional feeds, such as feeds that are traditionally viewed as having insufficient tendency to coke in order to maintain heat balance within an FCC reaction system. In other aspects, this can correspond to expanding the production of diesel within an FCC reaction system by modifying the reaction conditions in a manner that can cause a reaction system to fall out of heat balance (relative to the heat needed to maintain a target operating temperature) even when using conventional feeds.
1. A method for operating a fluid catalytic cracking reaction system, comprising:
exposing a hydrocarbonaceous feed to a catalyst in a reactor under fluid catalytic cracking conditions comprising greater than 60 wt % conversion of compounds in the hydrocarbonaceous feed with boiling points greater than 221° C. to compounds with boiling points of 221° C. or less to form one or more liquid products and 6.0 wt % or less coke associated with the catalyst;
passing at least a portion of the catalyst and the associated coke into a regenerator;
passing a supplemental fuel into the regenerator, a vessel associated with the regenerator, or a combination thereof, a ratio of an adjusted weight of a low carbon intensity fraction of the supplemental fuel to a weight of the associated coke being 0.01 or more;
combusting, in the regenerator, the vessel associated with the regenerator, or the combination thereof, at least a portion of the associated coke and at least a portion of the supplemental fuel to form at least heated catalyst and CO 2 ; and
passing at least a portion of the heated catalyst into the reactor.
2. The method of claim 1 , wherein the low carbon intensity fraction comprises biomass oil.
3. The method of claim 2 , wherein the biomass oil comprises a heavy pyrolysis oil fraction, the heavy pyrolysis oil fraction being formed by a method comprising:
separating a pyrolysis oil to form the heavy pyrolysis oil fraction and a second pyrolysis oil fraction, the heavy pyrolysis oil fraction having a T50 distillation temperature that is higher than a T90 distillation temperature of the second pyrolysis oil fraction.
4. The method of claim 1 , wherein the low carbon intensity fraction comprises H 2 , a lower heating value of the H 2 comprising less than 30% of a lower heating value of the supplemental fuel.
5. The method of claim 1 , wherein the ratio of an adjusted weight of a low carbon intensity fraction of the supplemental fuel to a weight of the associated coke is 0.1 or more.
6. The method of claim 1 , wherein a ratio of an adjusted weight of the supplemental fuel to a weight of the associated coke is 0.05 or more.
7. The method of claim 1 , wherein the fluid catalytic cracking conditions comprise a temperature of 525° C. or more and a weight ratio of catalyst to oil of 2.0 to 8.0.
8. The method of claim 7 , wherein the fluid catalytic cracking conditions comprise a temperature of 535° C. or more, or wherein the fluid catalytic cracking conditions comprise a weight ratio of catalyst to oil of 2.0 to 6.0, or a combination thereof.
9. The method of claim 7 , wherein the fluid catalytic cracking conditions further comprise a residence time for the hydrocarbonaceous feed under the fluid catalytic cracking conditions of 5.0 seconds or less.
10. The method of claim 1 , wherein exposing the hydrocarbonaceous feed to the catalyst under fluid catalytic cracking conditions forms 5.0 wt % or less of coke associated with the catalyst.
11. The method of claim 1 , wherein the supplemental fuel consists essentially of one or more bio-derived fractions, or wherein the supplemental fuel consists essentially carbon-containing fuel, or a combination thereof.
12. The method of claim 1 , wherein the hydrocarbonaceous feed comprises 25 wt % or less of a bio-derived fraction relative to a weight of the hydrocarbonaceous feed.
13. The method of claim 1 , wherein the fluid catalytic cracking conditions comprise 65 wt % or more conversion of compounds in the hydrocarbonaceous feed with boiling points greater than 221° C. to compounds with boiling points of 221° C. or less.
14. The method of claim 1 , wherein the hydrocarbonaceous feed comprises a T10 distillation point of 221° C. or higher, or wherein the hydrocarbonaceous feed comprises a T50 distillation point of 343° C. or higher, or a combination thereof.
15. The method of claim 1 , wherein the hydrocarbonaceous feed comprises a T10 distillation point of 343° C. or higher, or wherein the hydrocarbonaceous feed comprises at least a portion of a hydroprocessed feedstock, or a combination thereof.
16. The method of claim 1 , wherein the supplemental fuel is passed into a stripping section of the reactor, or wherein the supplemental fuel is passed into a transfer conduit between the reactor and the regenerator, or a combination thereof.
17. A method for operating a fluid catalytic cracking reaction system, comprising:
exposing a hydrocarbonaceous feed to a catalyst in a reactor under fluid catalytic cracking conditions comprising 20 wt % or more conversion of compounds in the hydrocarbonaceous feed with boiling points greater than 221° C. to compounds with boiling points of 221° C. or less to form one or more liquid products and coke associated with the catalyst, the hydrocarbonaceous feed comprising a T10 distillation point of 316° C. or more, a ratio of aliphatic sulfur to total sulfur of 0.15 or more, and a naphthenes to aromatics ratio of 1.0 or more;
passing at least a portion of the catalyst and the associated coke into a regenerator;
passing a supplemental fuel into the regenerator, a vessel associated with the regenerator, or a combination thereof, a ratio of an adjusted weight of the supplemental fuel to a weight of the associated coke being 0.01 or more;
combusting, in the regenerator, the vessel associated with the regenerator, or the combination thereof, at least a portion of the associated coke and at least a portion of the supplemental fuel to form at least heated catalyst and CO 2 ; and
passing at least a portion of the heated catalyst into the reactor.
18. The method of claim 17 , wherein a carbon intensity of the supplemental fuel is equal to or less than a carbon intensity of the hydrocarbonaceous feed.
19. The method of claim 17 , wherein the supplemental fuel comprises natural gas.
20. The method of claim 17 , wherein the supplemental fuel comprises a low carbon intensity fraction, a ratio of an adjusted weight of the low carbon intensity fraction of the supplemental fuel to a weight of the associated coke being 0.01 or more.
21. The method of claim 17 , wherein exposing the hydrocarbonaceous feed to the catalyst under fluid catalytic cracking conditions forms 5.0 wt % or less of coke.
22. A method for operating a fluid catalytic cracking reaction system, comprising:
exposing a hydrocarbonaceous feed to a catalyst in a reactor under fluid catalytic cracking conditions comprising 20 wt % or more conversion of compounds in the hydrocarbonaceous feed with boiling points greater than 221° C. to compounds with boiling points of 221° C. or less to form one or more liquid products and coke associated with the catalyst, the hydrocarbonaceous feed comprising 25 wt % or less of a bio-derived fraction;
passing at least a portion of the catalyst and the associated coke into a regenerator;
passing a supplemental fuel into the regenerator, a vessel associated with the regenerator, or a combination thereof, a ratio of an adjusted weight of the supplemental fuel to a weight of the associated coke being 0.01 or more;
combusting, in the regenerator, the vessel associated with the regenerator, or the combination thereof, at least a portion of the associated coke and at least a portion of the supplemental fuel to form at least heated catalyst and CO 2 ; and
passing at least a portion of the heated catalyst into the reactor.
23. The method of claim 22 , wherein the supplemental fuel comprises a second bio-derived fraction.
24. The method of claim 23 , wherein the second bio-derived fraction comprises a heavy pyrolysis oil fraction, the bio-derived fraction comprises a second pyrolysis oil fraction, and the heavy pyrolysis oil fraction comprises a T50 distillation temperature that is higher than a T90 distillation temperature of the second pyrolysis oil fraction.
25. The method of claim 22 , wherein exposing the hydrocarbonaceous feed to the catalyst under fluid catalytic cracking conditions forms 5.0 wt % or less of coke.