Process for upgrading residuums by combined donor visbreaking and coking

• US 4,604,186 A
• Filed: 11/06/1985
• Issued: 08/05/1986
• Est. Priority Date: 06/05/1984
• Status: Expired due to Term

• Current Assignee: DM International Inc.
• Original Assignee: DM International Inc.
• Inventors: Lutz, Irvin H., Wilson, Thomas M.
• Primary Examiner(s): Metz, Andrew H.
• Assistant Examiner(s): Caldarola, Glenn A.
• Application Number:
  US06/795,713
• Time in Patent Office: 272 Days
• Field of Search: 208/50, 208/56, 208/106, 208/131, 208/127
• US Class Current: 208/50
• CPC Class Codes: C10G 47/34 Organic compounds, e.g. hydrogenated hydrocarbons
• CPC Class Codes: C10G 65/10 including only cracking steps

Abstract

A process for upgrading petroleum residuums by hydrogen diluent donor visbreaking employs coking of a higher boiling fraction of the visbreaker effluent wherein the hydrogen donor is also supplied to the coker feed either by excess feed to the visbreaker or by mixing a portion with the coker feed. Controlling the quantity of hydrogen donor in the visbreaker and coker feed proportionally controls the quantity of coke produced.

Claims

1. A process for upgrading petroleum residuums to more valuable products comprising the steps of

mixing a hydrogenated aromatic donor fraction with the petroleum residuums to form a vis breaker feed;

donor visbreaking the visbreaker feed in a thermal visbreaker to crank heavy hydrocarbons into lighter products wherein the hydrogenated fraction in the visbreaker feed reacts to donate hydrogen to prevent formation of coke and reduce the quantity of coke precursors;

coking a coker feed including substantially all of the high boiling portion and substantially all of the aromatic donor fraction of the effluent from the visbreaker in a coker under nonpremium coker conditions to produce coke and overhead products whereby the reduction of coke precursors by the donor visbreaking reduces the quantity of coke product and increases the quantity of overhead productd;

fractionating the overhead products from the coker in a fractionater to produce one or more light product fractions, and an aromatic donor recycle fraction; and

hydrogenating the aromatic donor recycle fraction from the fractionator to form the hydrogenated donor formation for the visbreaker feed.

2. A process as claimed in claim 1 wherein hydrogenated donor material is included in the coker feed such that the hydrogenated donor material transfers hydrogen to reactive fragments produced during coking to reduce the quantity of coke product and increase the quantity of overhead products.

3. A process as claimed in claim 2 wherein the hydrogenated donor fraction in the visbreaker feed is selected large enough to supply the hydrogenated donor material in the coker feed.

4. A process as claimed in claim 3 wherein a percentage in the range from 30 to 60 percent of the hydrogenated donor fraction passes unreacted through the visbreaker to the coker feed.

5. A process as claimed in claim 1 including the step of separating the effluent from the visbreaker into high and low boiling fractions and the separated high boiling fraction is included in the coker feed.

6. A process as claimed in claim 5 wherein the separated low boiling fraction from the visbreaker effluent is also fed to the fractionator.

7. A process as claimed in claim 5 wherein the separating is performed by flashing the effluent from the visbreaker.

16. A process as claimed in claim 4 wherein the coking is performed by fluid coking.

8. A process for upgrading petroleum residuums to more valuable products comprising the steps of

mixing a hydrogenated aromatic heavy gas oil fraction with the petroleum residuums to form a visbreaker feed;

visbreaking the visbreaker feed in a thermal visbreaker to crack heavy hydrocarbons into lighter products wherein a portion of the hydrogenated aromatic heavy gas oil fraction reacts to donate hydrogen to prevent formation of coke while leaving a substantial unreacted portion of the hydrogenated fraction in the effluent from the visbreaker;

separating the effluent from the visbreaker into high and low boiling fractions wherein the high boiling fraction includes substantially all of the reacted and unreacted portions of the hydrogenated aromatic heavy gas oil fraction along with substantially all of the high boiling portion of the visbreaker effluent;

coking the high-boiling fraction in a coker under nonpremium coking conditions to produce coke and overhead products wherein the unreacted portion of the hydrogenated aromatic heavy gas oil reacts to donate hydrogen to reduce the quantity of coke product and to increase the quantity of overhead products;

fractionating the overhead products from the coker in a fractionator to produce one or more light product fraction, an aromatic heavy gas oil fraction, and the coker bottoms fraction for the above coker feed mixing; and

hydrogenating the aromatic heavy gas oil fraction from the fractionator to form the hydrogenated aromatic heavy gas oil fraction for the above visbreaker feed mixing.

9. A process as claimed in claim 8 wherein the heavy gas oil fraction from the fractionator has a boiling range within the range from about 370°

to 510°

C., the visbreaking is performed at a temperature in the range from about 427°

to 527°

C., the high boiling fraction is separated from the visbreaker effluent to remove distillate boiling up to about 370°

C. in the low boiling fraction, and the coking is performed at a temperature in the range from about 480°

to 527°

C.

10. A process as claimed in claim 8 wherein the hydrogenated heavy gas oil fraction is mixed with the residuum in a ratio of from 0.2 to 2 weights of hydrogenated heavy gas oil fraction per weight of residuum.

11. A process as claimed in claim 9 wherein the visbreaking is performed at a temperature in the range from 443°

to 482°

C., the high boiling fraction is separated from the visbreaker effluent to remove distillate boiling up to about 440°

C., and the coking is performed at a temperature in the range from about 488°

to 496°

C.

12. A process as claimed in claim 9 wherein the visbreaking is performed over a reaction time sufficient to obtain a conversion of 10% or more of feed to C₄ -220°

C. gasoline.

13. A process as claimed in claim 8 wherein the separated low boiling fraction from the visbreaker effluent is fed to the fractionator.

14. A process as claimed in claim 8 wherein the separating is performed by flashing the effluent from the visbreaker.

15. A process as claimed in claim 8 wherein the separating is performed by distilling the effluent from the visbreaker.

17. In a process for upgrading petroleum residuums to more valuable products wherein a residuum feed is mixed with a coker bottoms recycle to form a coker feed, the coker feed is coked in a coker under nonpremium coker conditions to produce coke and fluid products, and the fluid products are fractionated in a fractionator to produce the coker bottoms recycle and lighter products;

the improvement comprising hydrogenating an aromatic heavy gas oil fraction from the fractionator;

mixing the hydrogenated aromatic heavy gas oil fraction with residuums to form a visbreaker feed, visbreaking the visbreaker feed in a thermal visbreaker to crack heavy hydrocarbons into lighter products wherein a portion of the hydrogenated aromatic heavy gas oil reacts to donate hydrogen to minimize formation of coke and reduce the quantity of coke precursors while leaving a substantial unreacted portion of the hydrogenated heavy gas oil fraction in the effluent from the visbreaker, separating the effluent from the visbreaker into high and low boiling fractions wherein the high boiling fraction forms the coker feed and includes substantially all of the unreacted portion of the hydrogenated aromatic heavy gas oil fraction and uncracked reacted heavy gas oil along with substantially all of the high boiling portion of the visbreaker effluent and whereby the unreacted portion of the hydrogenated aromatic heavy gas oil fraction in the coker feed reacts to donate hydrogen to reduce the quantity of coke produced in the coker and increase the quantity of fluid products.

18. The improvement as claimed in claim 17 wherein the heavy gas oil fraction fromthe fractionator has a boiling range within the range from the about 370°

to 510°

C., the visbreaking is performed at a temperature in the range from about 427°

to 527°

C., the high boiling fraction is separated from the visbreaker effluent to remove distillate boiling up to about 370°

C. in the low boiling fraction, and the coking is performed at a temperature in the range from about 400°

to 527°

C.

19. The improvement as claimed in claim 17 wherein the hydrogenated heavy gas oil fraction is mixed with the residuum in a ratio of from 0.2 to 2 weights of hydrogenated heavy gas oil fraction per weight of residuum.

20. The improvement as claimed in claim 17 wherein the separated low boiling fraction from the visbreaker effluent is fed to the fractionator.

21. The improvement as claimed in claim 17 wherein the separating is performed by flashing the effluent from the visbreaker.

22. The improvement as claimed in claim 17 wherein the separating is performed by distilling the effluent from the visbreaker.

23. In a hydrogen donor diluent cracking process wherein residuums are mixed with an aromatic hydrogenated heavy gas oil fraction to form a visbreaker feed, the visbreaker feed is thermally cracked in a visbreaker such that hydrogenated aromatic gas oil reacts to donate hydrogen to minimize formation of coke in the visbreaker and reduce the quantity of coke precursors, a fractionator feed from the visbreaker is fractionated in a fractionator to produce an aromatic heavy gas oil fraction and lighter products, and the aromatic heavy gas oil fraction is hydrogenated to form the hydrogenated aromatic heavy gas oil fraction for mixing with the residuums;

the improvement comprising selecting the heavy gas oil fraction from the fractionator to produce sufficient hydrogenated aromatic heavy gas oil to leave a substantial unreacted portion of the hydrogenated aromatic gas oil fraction in the effluent from the visbreaker;

separating the effluent from the visbreaker into high and low boiling fractions wherein the high boiling fraction includes substantially all of the high boiling portion of the visbreaker effluent and substantially all of the unreacted portion of the hydrogenated aromatic heavy gas oil fraction and uncracked reacted aromatic heavy gas oil, mixing the high boiling fraction with a coker bottoms fraction from the fractionator to form a coker feed, and coking the coker feed in a coker under nonpremium coker conditions to produce coke and fluid products which form at least a portion of the fractionator feed.

24. The improvement as claimed in claim 23 wherein the heavy gas oil fraction from the fractionator has a boiling range within the range from about 370°

to 510°

C., the visbreaking is performed at a temperature in the range from about 427°

to 527°

C., the high boiling fraction is separated from the visbreaker effluent to remove distillate boiling up to about 370°

C. in the low boiling fraction, and the coking is performed at a temperature in the range from about 400°

to 527°

C.

25. The improvement as claimed in claim 23 wherein the hydrogenated heavy gas oil fraction is mixed with the residuum in a ratio of from 0.2 to 2 weights of hydrogenated heavy gas oil fraction per weight of residuum.

26. The improvement as claimed in claim 23 wherein the separated low boiling fraction from the visbreaker effluent is fed to the fractionator.

27. The improvement as claimed in claim 23 wherein the separating is performed by flashing the effluent from the visbreaker.

28. The improvement as claimed in claim 23 wherein the separating is performed by distilling the effluent from the visbreaker.