Claims
- 1. A process for producing increased amounts of propylene from naphtha-boiling-range feedstreams in a process unit comprising at least a reaction zone, a stripping zone, a regenerator zone, and at least one fractionation zone, which process comprises:
(a) fractionating said naphtha-boiling-range feedstream to produce a C6-rich fraction and a C6-lean fraction; (b) injecting at least a portion of said C6-lean fraction into the reaction zone, said reaction zone containing a cracking catalyst comprising at least one molecular sieve having an average pore diameter of less than about 0.7 nm wherein said C6-lean fraction contacts said zeolite cracking catalyst under effective conditions thereby resulting in at least spent catalyst particles having carbon deposited thereon and a product stream; (c) injecting at least a portion of said C6-rich fraction at a place in the process unit selected from: i) downstream of the C6-lean fraction; ii) the stripping zone; and iii) a dilute phase above the stripping zone; (d) contacting at least a portion of said spent catalyst particles with a stripping gas in the stripping zone under conditions effective at removing at least a portion of any volatiles therefrom thereby resulting in at least stripped spent catalyst particles; (e) regenerating at least a portion of said stripped spent catalysts in a regeneration zone in the presence of an oxygen-containing gas under conditions effective at burning off at least a portion of said carbon deposited thereon thereby producing at least regenerated catalyst particles; (f) recycling at least a portion of said regenerated catalyst particles to said reaction zone; (g) fractionating at least a portion of said product stream of step (b) to produce at least a fraction rich in propylene; and (h) collecting at least a portion of the fraction rich in propylene.
- 2. The process of claim 1 wherein the at least one molecular sieve is selected from zeolites and silicoaluminophosphates.
- 3. The process of claim 2 wherein the at least one molecular sieve is a medium-pore zeolite.
- 4. The process of claim 3 wherein the medium-pore zeolite is selected from the group consisting of ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-48, and ZSM-50.
- 5. The process of claim 2 wherein the silicoaluminophosphates is selected from the group consisting of SAPO-11, SAPO-34, SAPO-41, and SAPO-42.
- 6. The process of claim 1 wherein the propylene rich fraction has a propylene concentration greater than about 60 wt %.
- 7. The process of claim 1 wherein said effective conditions in the reaction zone include temperatures from about 500° C. to about 650° C.
- 8. The process of claim 1 wherein the C6 rich fraction contains at least about 50 wt. % of C6 compounds.
- 9. The process according to claim 1 wherein said reaction zone comprises at least one catalyst bed selected from dynamic catalyst beds.
- 10. The process according to claim 9 wherein said dynamic catalyst bed is selected from fluidized, slurried and ebullating catalyst beds.
- 11. The process according to claim 1 wherein said molecular sieve comprises about 10 wt. % to about 50 wt. % of the total fluidized catalyst composition.
- 12. The process according to claim 1 wherein said molecular sieve is selected from chromosilicates, gallium silicates, iron silicates, aluminum phosphates (ALPO), titanium aluminosilicates (TASO), boron silicates, titanium aluminophosphates (TAPO), and iron aluminosilicates.
- 13. The process of claim 1 wherein said cracking catalyst further comprises an inorganic oxide matrix component.
- 14. The process of claim 13 wherein said inorganic oxide matrix component is not catalytically active and is selected from oxides of silicon and aluminum.
- 15. A process for producing increased amounts of propylene from naphtha-boiling-range feedstreams in a process unit comprising at least a reaction zone, a stripping zone, a regenerator zone, and at least one fractionation zone, which process comprises:
(a) injecting a naphtha-boiling-range feedstream into the reaction zone, said reaction zone containing a cracking catalyst comprising at least one molecular sieve having an average pore diameter of less than about 0.7 nm wherein said naphtha-boiling-range feedstream contacts said cracking catalyst under effective conditions thereby resulting in at least spent catalyst particles having carbon deposited thereon and a product stream; (b) contacting at least a portion of said spent catalyst particles with a stripping gas in the stripping zone under conditions effective at removing at least a portion of any volatiles therefrom thereby resulting in at least stripped spent catalyst particles; (c) regenerating at least a portion of said stripped spent catalysts in a regeneration zone in the presence of an oxygen-containing gas under conditions effective at to burning off at least a portion of said carbon deposited thereon thereby producing at least regenerated catalyst particles; (d) recycling at least a portion of said regenerated catalyst particles to said reaction zone; (e) fractionating at least a portion of said product stream of step (a) to produce at least a fraction rich in propylene, a C6-rich fraction, and a C6-lean fraction; and (f) collecting at least a portion of the fraction rich in propylene and the C6-lean fraction and recycling at least a portion of the C6-rich fraction to a place in the process unit selected from: i) downstream of the C6-lean fraction; ii) the stripping zone; iii) with the C6-lean fraction; and iv) a dilute phase above the stripping zone.
- 16. The process of claim 15 wherein the at least one molecular sieve is selected from zeolites and silicoaluminophosphates.
- 17. The process of claim 16 wherein the at least one molecular sieve is a medium-pore zeolite.
- 18. The process of claim 17 wherein the medium-pore zeolite is selected from the group consisting of ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-48, and ZSM-50.
- 19. The process of claim 16 wherein the silicoaluminophosphates is selected from the group consisting of SAPO-11, SAPO-34, SAPO-41, and SAPO-42.
- 20. The process of claim 14 wherein the propylene rich fraction has a propylene concentration greater than about 60 wt %.
- 21. The process of claim 14 wherein said effective conditions in the reaction zone include temperatures from about 500° C. to about 650° C.
- 22. The process of claim 14 wherein the C6 rich fraction contains at least about 50 wt. % of C6 compounds.
- 23. The process according to claim 15 wherein said reaction zone comprises at least one catalyst bed selected from dynamic catalyst beds.
- 24. The process according to claim 23 wherein said dynamic catalyst bed is selected from fluidized, slurried and ebullating catalyst beds.
- 25. The process according to claim 15 wherein said molecular sieve comprises about 10 wt. % to about 50 wt. % of the total fluidized catalyst composition.
- 26. The process according to claim 15 wherein said molecular sieve is selected from chromosilicates, gallium silicates, iron silicates, aluminum phosphates (ALPO), titanium aluminosilicates (TASO), boron silicates, titanium aluminophosphates (TAPO), and iron aluminosilicates.
- 27. The process of claim 15 wherein said cracking catalyst further comprises an inorganic oxide matrix component.
- 28. The process of claim 27 wherein said inorganic oxide matrix component is not catalytically active and is selected from oxides of silicon and aluminum.
- 29. A process for producing increased amounts of propylene from naphtha-boiling-range feedstreams in a process unit comprising at least a reaction zone, a stripping zone, a regenerator zone, and at least one fractionation zone, which process comprises:
(a) fractionating said naphtha-boiling-range feedstream to produce a C6-rich feed fraction and a C6-lean feed fraction; (b) injecting at least a portion of said C6-lean feed fraction into the reaction zone, said reaction zone containing a cracking catalyst comprising at least one molecular sieve having an average pore diameter of less than about 0.7 nm wherein said C6-lean feed fraction contacts said cracking catalyst under effective conditions thereby resulting in at least spent catalyst particles having carbon deposited thereon and a product stream; (c) injecting at least a portion of said C6-rich feed fraction at a place in the process unit selected from: i) downstream of the C6-lean fraction; ii) the stripping zone; and iii) a dilute phase above the stripping zone; (d) contacting at least a portion of said spent catalyst particles with a stripping gas in the stripping zone under conditions effective at removing at least a portion of any volatiles therefrom thereby resulting in at least stripped spent catalyst particles; (e) regenerating at least a portion of said stripped spent catalysts in a regeneration zone in the presence of an oxygen-containing gas, said regeneration zone operated under conditions effective at burning-off at least a portion of said carbon deposited thereon thereby producing at least regenerated catalyst particles; (f) recycling at least a portion of said regenerated catalyst particles to said reaction zone; (g) fractionating at least a portion of said product stream of step (b) to produce at least a fraction rich in propylene; a C6-rich product fraction, and C6-lean product fraction; and (h) collecting at least a portion of the propylene and C6-lean product fraction and recycling at least a portion of the C6-rich product fraction to a place in the process unit selected from: i) downstream the C6-lean feed fraction; ii) the stripping zone; and iii) a dilute phase above the stripping zone.
- 30. The process of claim 29 wherein the at least one molecular sieve is selected from zeolites and silicoaluminophosphates.
- 31. The process of claim 31 wherein the at least one molecular sieve is a medium-pore zeolite.
- 32. The process of claim 31 wherein the medium-pore zeolite is selected from the group consisting of ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-48, and ZSM-50.
- 33. The process of claim 30 wherein the silicoaluminophosphates is selected from the group consisting of SAPO-11, SAPO-34, SAPO-41, and SAPO-42.
- 34. The process of claim 29 wherein the propylene rich fraction has a propylene concentration greater than about 60 wt %.
- 35. The process of claim 29 wherein said effective conditions in the reaction zone include temperatures from about 500° C. to about 650° C.
- 36. The process of claim 29 wherein the C6 rich fraction contains at least about 50 wt. % of C6 compounds.
- 37. The process according to claim 29 wherein said reaction zone comprises at least one catalyst bed selected from dynamic catalyst beds.
- 38. The process according to claim 37 wherein said dynamic catalyst bed is selected from fluidized, slurried and ebullating catalyst beds.
- 39. The process according to claim 29 wherein said molecular sieve comprises about 10 wt. % to about 50 wt. % of the total fluidized catalyst composition.
- 40. The process according to claim 29 wherein said molecular sieve is selected from chromosilicates, gallium silicates, iron silicates, aluminum phosphates (ALPO), titanium aluminosilicates (TASO), boron silicates, titanium aluminophosphates (TAPO), and iron aluminosilicates.
- 41. The process of claim 29 wherein said cracking catalyst further comprises an inorganic oxide matrix component.
- 42. The process of claim 41 wherein said inorganic oxide matrix component is not catalytically active and is selected from oxides of silicon and aluminum.
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims benefit of U.S. provisional patent application serial No. 60/451,184 filed Feb. 28, 2003.
Provisional Applications (1)
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Number |
Date |
Country |
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60451184 |
Feb 2003 |
US |