IL42265A

IL42265A - Process for the regeneration of fluidized catalyst

Info

Publication number: IL42265A
Application number: IL42265A
Authority: IL
Original assignee: Universal Oil Prod Co
Priority date: 1972-05-30
Filing date: 1973-05-14
Publication date: 1976-04-30
Also published as: NL7307445A; DK133016B; YU39207B; JPS5331114B2; DE2326072B2; CA998036A; FI58265C; DK133016C; GB1439531A; FR2186291A1; YU139773A; EG11214A; PH10202A; IT985235B; IL42265A0; DE2326072A1; FI58265B; BG25981A3; NL176475C; ES415063A1

Claims

42265/2 CLAIMS:

1. Ά process for regenerating coke-contaminated particle form spent catalyst withdrawn from a hydrocarbon conversion zone at a pressure from about atmospheric to about 4*5 atm.>, comprising the steps of: (a) introducing said spent catalyst and an oxygen-containing regeneration gas into a first dense bed of fluidized particles and therein partially regenerating said catalyst by combustion of said coke at a temperature of 620-720eC and producing partially spent regeneration gas containing CO; (b) passing resulting partially regenerated catalyst and partially spent regeneration gas directly from said dense bed upwardly in dilute phase into and through a dilute phase transport riser and therein effecting further combustion of coke at a temperature of 650-800eC from said partially regenerated catalyst; and therein also oxidizing a substantial portion of said CO to CO2 in said dilute phase transport riser (c) separating resulting regenerated catalyst from regeneration gas; (d) recovering said regenerated catalyst as a second dense bed of particles; and (e) withdrawing regenerated catalyst from said second dense bed for return to said conversion zone*

2. Process of Claim 1 wharein the hydrocarbon conversion zone is a fluidized catalytic cracking zone.

3. Process of Claim 1 or 2 wherein the temperature of regenerated catalyst is controlled by adding a regulated amount of a combustible fluid to said dilute phase transport riser.

4. Process of any of Claims 1 to 3 wherein the temperature of regenerated catalyst is controlled by adding a regulated amount of a combustible fluid to said first dense bed.

5. Process of Claim 3 or 4 wherein said combustible fluid is selected from the group of fuel gas and liquid hydrocarbons.

6. Process of any of Claims 1 to 5 wherein the coke level on regenerated catalyst is controlled by limiting the flow of said fresh regeneration gas to said first dense bed.

7. Process of any of Claims 1 to 6 wherein the coke level on regenerated catalyst is controlled by limiting the temperature in said first dense bed.

8. Process of any of Claims 1 to 7 wherein additional regeneration gas is added to said dilute phase transport riser.

9. Process of any of Claims 1 to 8 wherein residence time of said spent catalyst in said first dense bed is less than two minutes.

10. Process of Claim 9 wherein spent catalyst residence time in said second dense bed is less than about 30 seconds.

11. Process of any of claims 1 to 10 wherein said regenerated catalyst is stripped of regeneration gas in said second dense bed.

12. Process of Claim 11 wherein regenerated catalyst is stripped with superheated steam.

13. Process of Claim 12 wherein residence time of said spent catalyst in said second dense bed is less than about one minute.

14. Process of any of claims 1 to 13 wherein total residence time of regeneration gas in said first dense bed and said dilute phase transport riser is less than ten seconds .

15. Process of any of Claims 1 to 14 wherein said first dense bed temperature is about 620 to 760°C, and the superficial gas velocity is about 0.9 to 3.0 meters per second

16. Process of any of Claims 1 to 15 wherein said dilute phase transport riser temperature is about 650 to 800°C and the superficial gas velocity is about 3.0 to 7.5 meters per second.

17. Process of any of Claims 1 to 16 wherein said first dense bed of fluidized particles is in a lower portion of a regeneration vessel and regenerated catalyst is separated from regeneration gas in an upper portion of said regeneration vessel. 42265/2

18. Process for regenerating a coke-contaminated particle-form catalyst withdrawn from a hydrocarbon conversion reaction zone, which comprises introducing said catalyst into the lower portion of a vertically elongated confined regeneration chamber, having three sections comprising a lower Section of relatively large cross-sectional area, an uupex section of a predetermined relatively smaller cross-sectional area and an intermediate transitional section, introducing into the bottom portion and withdrawing from the top portion of said chamber a stream of an oxygen-containing regenerating gas at a rate which maintains the accumulated catalyst in said lower section in a dense phase fluidized bed condition and which provides in said transitional section and in said upper section gas velocities which lift said catalyst from said transitional section and transports said catalyst in a dilute phase condition through said upper section, maintaining the oxygen content of said introduced regenerating gas at a level which (1) effects combustion of a substantial portion of said coke from said catalyst in said lower section while forming and CO in said regenerating gas (2) effects combustion of a lesser portion of coke from said catalyst during transit through said upper section, and (3) effects conversion of a substantial portion of said CO into C02 during passage of regenerating gas through said upper section; and separating resulting substantially regenerated catalyst from regenerating gas withdrawn from said upper section of said regeneration chamber. 42265/2

19. Process of any of Claims 1 to 18 wherein pressures in said first dense bed, said dilute phase transport riser, and said second dense bed are about 2 to 3.5 atmospheres, absolute.

20. A process for regenerating coke contaminated spent catalyst according to any of Claims 1 to 19 substantially as hereinbefore described. - 37 -