Maximum olefins production utilizing multi-stage catalyst reaction and regeneration
A method and system for increasing olefin production and quality from a hydrocarbon feed comprising a fully integrated multi-stage catalyst regeneration zones with multi-stage reaction zones in series and/or parallel. The multi-stage regeneration with at least one partial and one full burn zone provides an independent control to achieve the lowest possible regenerated catalyst temperature, resulting in highest possible catalyst to oil ratio required to maximize olefins yields through increased catalytic cracking in a multi stage FCC riser/risers.
1. A method for increasing olefin production from a hydrocarbon feed, said method comprises:
delivering from a multi-stage catalyst regenerator a fully-regenerated catalyst from at least one catalyst full regeneration zone to a primary riser reactor;
cracking the hydrocarbon feed in the primary riser reactor to produce a first cracked product, and spent catalyst;
flowing the first cracked product and the spent catalyst from the primary riser reactor to a bed cracking reaction zone atop the primary riser reactor, wherein the bed cracking reaction zone is in fluid communication with the primary riser reactor through a distributor;
further cracking the first cracked product in the bed cracking reaction zone to produce a second cracked product including olefins;
separating the first cracked product and the second cracked product including olefins from the spent catalyst in a reactor vessel comprising the bed cracking reaction zone, wherein an outer perimeter of the bed cracking reaction zone is defined by a side wall of the reactor vessel radially outward of the primary riser reactor such that the primary riser reactor is within the outer perimeter if the bed cracking zone;
recovering the first cracked product and second cracked product including olefins; and
passing the spent catalyst from the reactor vessel to the multi-stage catalyst regenerator comprising the at least one catalyst full regeneration zone and at least one catalyst partial-regeneration zone,
wherein the spent catalyst is partially regenerated in the catalyst partial regeneration zone to provide partially-regenerated catalyst and forwarding the partially-regenerated catalyst to the catalyst full regeneration zone to provide fully regenerated catalyst.
2. The method of claim 1 , wherein the multi-stage catalyst regenerator comprises two catalyst regenerator that operate in series or parallel to one another.
3. The method of claim 1 , wherein the multi-stage catalyst regenerator comprises internals and/or packing to provide separate catalyst regeneration zones.
4. The method of claim 1 , wherein the portion of the partially-regenerated catalyst that is delivered to the catalyst full regeneration zone has a temperature upon delivery that is less than the temperature of the fully-regenerated catalyst that exits the catalyst full regeneration zone.
5. The method of claim 1 , wherein the temperature of the portion of the partially-regenerated catalyst that is delivered to the catalyst full regeneration zone ranges from about 1150° F. to about 1300° F.
6. The method of claim 1 , wherein the temperature of the fully-regenerated catalyst that exits the catalyst full regeneration zone ranges from about 1250° F. to about 1500° F.
7. The method of claim 1 , wherein the hydrocarbon feed is selected from the group consisting of vacuum gas oils, heavy atmospheric gas oil, atmospheric resid, vacuum resid, coker gas oils, visbreaker gas oils, deashalted oils, hydrocracker bottoms, vegetable oils and heavy conversion product issued from biomass, and any combination thereof or hydrotreated counterparts.
8. The method of claim 1 , wherein the cracked product of the riser reactor comprises one or more gaseous product streams comprising C 2 and lighter, C 3 through C 6 light olefins and parafins, C 6 -C 8 light FCC gasoline, light cracked naphtha (LCN), intermediate FCC gasoline comprising benzene and C 8 -C 9 hydrocarbons, heavy FCC gasoline comprising C 9 -C 11 hydrocarbons and other gasoline boiling range products comprising materials boiling in the range C 5 to about 430° F., middle distillate boiling in the range from about 330° F. to about 630° F., and uncracked bottoms boiling range from about 650° F. to about 900° F.
9. The method of claim 1 , further comprising cracking a recycle feed in a secondary riser reactor, wherein the recycle feed contains at least one product from the group consisting of C 4 's, light FCC gasoline (LCN), light cycle oil (LCO), heavy cycle oil product (HCO) and slurry oil.
10. The method of claim 1 , further comprising cracking a recycle feed in a secondary riser reactor, wherein the recycle feed stream includes hydrocarbons from other refinery and petrochemical units.
11. The method of claim 1 , further comprising cracking a recycle feed in a secondary riser reactor, wherein the recycle feed stream is coker naphtha.
12. The method of claim 1 , wherein the primary riser reactor operates with an outlet temperature of from 840° F. to about 1100° F.
13. The method of claim 1 , wherein said spent catalyst is stripped before regeneration.
14. The method of claim 1 , wherein the multi-stage catalyst regenerator comprises internals and/or packing.
15. The method of claim 1 , wherein the catalyst partial regeneration zone and the catalyst full regeneration zone provide multi stage regeneration of the catalyst.
16. The method of claim 1 , wherein the catalyst full regeneration zone and the catalyst partial regeneration zone are in a single regenerator vessel.
17. The method of claim 1 , further comprising feeding at least one of the fully-regenerated catalyst or the partially-regenerated catalyst into a the primary riser reactor, via withdraw well.
18. The method of claim 1 , wherein the distributor is disposed within the bed cracking reaction zone above an outlet of the primary riser reactor to form a separation between the primary riser reactor and the bed cracking reaction zone.
19. A method for increasing olefin production from a hydrocarbon feed, said method comprises:
delivering from a multi-stage catalyst regenerator a fully-regenerated catalyst from at least one catalyst full regeneration zone to in a primary riser reactor defining a first reaction zone;
cracking the hydrocarbon feed in the primary riser reactor to produce a first cracked product, and spent catalyst;
flowing the first cracked product and the spent catalyst from the primary riser reactor to a bed cracking reaction zone, defining a second reaction zone, atop the primary riser reactor, wherein the bed cracking reaction zone is in fluid communication with the primary riser reactor through a distributor, the distributor separating the first reaction zone and the second reaction zone;
further cracking the first cracked product while flowing upwards in the bed cracking reaction zone having additional multi-stage catalyst to produce a second cracked product including olefins;
separating the first cracked product and the second cracked product including olefins from the spent catalyst in a reactor vessel comprising the bed cracking reaction zone having an interface between a bed level and a dilute phase;
recovering the first cracked product and second cracked product including olefins via vapor passing through the dilute phase above the bed cracking reaction zone; and
passing the spent catalyst from the reactor vessel down to the multi-stage catalyst regenerator through a stripper section, the multistage catalyst regenerator comprising the at least one catalyst full regeneration zone and at least one catalyst partial-regeneration zone,
wherein the spent catalyst is partially regenerated in the catalyst partial regeneration zone to provide partially-regenerated catalyst and forwarding the partially-regenerated catalyst to the catalyst full regeneration zone to provide fully regenerated catalyst.
20. The method of claim 19 , wherein further cracking the first cracked product in the bed cracking reaction zone having additional multi-stage catalyst to produce a second cracked product including olefins, further comprises,
increasing a residence time of first cracked product vapors within a catalyst bed of the reaction zone and dilute phase of the reactor vessel to boost production of the second cracked product including maximizing olefins prior to separating the first cracked product and the second cracked product from the spent catalyst.