Claims
- 1. A process of upgrading a sulfur-containing feed fraction boiling in the gasoline boiling range which comprises:
- contacting the sulfur-containing feed fraction with a hydrodesulfurization catalyst in a first reaction zone, operating under a combination of elevated temperature, elevated pressure and an atmosphere comprising hydrogen, to produce an intermediate product comprising a normally liquid fraction which has a reduced sulfur content and a reduced octane number as compared to the feed;
- contacting at least the gasoline boiling range portion of the intermediate product in a second reaction zone with a catalyst of acidic functionality comprising a zeolite having a reduced surface acidity, said zeolite having been contacted with dicarboxylic acid to effect a reduction in surface acidity without a substantial reduction in overall acid activity, to convert it to a product comprising a fraction boiling in the gasoline boiling range having a higher octane number than the gasoline boiling range fraction of the intermediate product.
- 2. The process as claimed in claim 1 in which said feed fraction comprises a light naphtha fraction having a boiling range within the range of C.sub.6 to 330.degree. F.
- 3. The process as claimed in claim 1 in which said feed fraction comprises a full range naphtha fraction having a boiling range within the range of C.sub.5 to 420.degree. F.
- 4. The process as claimed in claim 1 in which said feed fraction comprises a heavy naphtha fraction having a boiling range within the range of 330.degree. to 500.degree. F.
- 5. The process as claimed in claim 1 in which said feed fraction comprises a heavy naphtha fraction having a boiling range within the range of 330.degree. to 412.degree. F.
- 6. The process as claimed in claim 1 in which said feed is a cracked naphtha fraction comprising olefins.
- 7. The process as claimed in claim 1 in which said feed fraction comprises a naphtha fraction having a 95 percent point of at least about 350.degree. F.
- 8. The process as claimed in claim 7 in which said feed fraction comprises a naphtha fraction having a 95 percent point of at least about 380.degree. F.
- 9. The process as claimed in claim 8 in which said feed fraction comprises a naphtha fraction having a 95 percent point of at least about 400.degree. F.
- 10. The process as claimed in claim 1 in which the reduction in surface acidity of the zeolite is further effected by steaming.
- 11. The process as claimed in claim 1 in which the zeolite having a reduced surface acidity is an intermediate pore size zeolite.
- 12. The process as claimed in claim 11 in which the intermediate pore size zeolite has the topology of ZSM-5.
- 13. The process as claimed in claim 12 in which the intermediate pore size zeolite is in the aluminosilicate form.
- 14. The process as claimed in claim 1 in which the acidic catalyst includes a metal component having hydrogenation functionality.
- 15. The process as claimed in claim 1 in which the hydrodesulfurization catalyst comprises a Group VIII and a Group VI metal.
- 16. The process as claimed in claim 1 in which the hydrodesulfurization is carried out at a temperature of about 400.degree. to 800.degree. F., a pressure of about 50 to 1500 psig, a space velocity of about 0.5 to 10 LHSV, and a hydrogen to hydrocarbon ratio of about 500 to 5000 standard cubic feet of hydrogen per barrel of feed.
- 17. The process as claimed in claim 16 in which the hydrodesulfurization is carried out at a temperature of about 500.degree. to 750.degree. F., a pressure of about 300 to 1000 psig, a space velocity of about 1 to 6 LHSV, and a hydrogen to hydrocarbon ratio of about 1000 to 2500 standard cubic feet of hydrogen per barrel of feed.
- 18. The process as claimed in claim 1 in which the second stage upgrading is carried out at a temperature of about 300.degree. to 900.degree. F., a pressure of about 50 to 1500 psig, a space velocity of about 0.5 to 10 LHSV, and a hydrogen to hydrocarbon ratio of about 0 to 5000 standard cubic feet of hydrogen per barrel of feed.
- 19. The process as claimed in claim 18 in which the second stage upgrading is carried out at a temperature of about 350.degree. to 800.degree. F., a pressure of about 300 to 1000 psig, a space velocity of about 1 to 6 LHSV, and a hydrogen to hydrocarbon ratio of about 100 to 2500 standard cubic feet of hydrogen per barrel of feed.
- 20. The process as claimed in claim 1 which is carried out in two stages with an interstage separation of light ends and heavy ends with the heavy ends fed to the second reaction zone.
- 21. The process as claimed in claim 20 in which the normally liquid intermediate product from the first reaction zone comprises a C.sub.8 + fraction having an initial point of at least 210.degree. F.
- 22. A process of upgrading a sulfur-containing feed fraction boiling in the gasoline boiling range which comprises:
- hydrodesulfurizing a catalytically cracked, olefinic, sulfur-containing gasoline feed having a sulfur content of at least 50 ppmw, an olefin content of at least 5 percent and a 95 percent point of at least 325.degree. F. with a hydrodesulfurization catalyst in a hydrodesulfurization zone, operating under a combination of elevated temperature, elevated pressure and an atmosphere comprising hydrogen, to produce an intermediate product comprising a normally liquid fraction which has a reduced sulfur content and a reduced octane number as compared to the feed;
- contacting at least the gasoline boiling range portion of the intermediate product in a second reaction zone with a catalyst of acidic functionality comprising a zeolite having a reduced surface acidity, said zeolite having been contacted with dicarboxylic acid to effect a reduction in surface acidity without a substantial reduction in overall acid activity, to convert it to a product comprising a fraction boiling in the gasoline boiling range having a higher octane number than the gasoline boiling range fraction of the intermediate product.
- 23. The process as claimed in claim 22 in which the feed fraction has a 95 percent point of at least 350.degree. F., an olefin content of 10 to 20 weight percent, a sulfur content from 100 to 5,000 ppmw and a nitrogen content of 5 to 250 ppmw.
- 24. The process as claimed in claim 23 in which said feed fraction comprises a naphtha fraction having a 95 percent point of at least about 380.degree. F.
- 25. The process as claimed in claim 22 in which the zeolite having a reduced surface acidity has a Constraint Index of greater than about 1.
- 26. The process as claimed in claim 22 in which the zeolite having a reduced surface acidity is an organic-containing zeolite.
- 27. The process as claimed in claim 22 in which the zeolite having a reduced surface acidity is an intermediate pore size zeolite.
- 28. The process as claimed in claim 27 in which the intermediate pore size zeolite has the topology of ZSM-5 and is in the aluminosilicate form.
- 29. The process as claimed in claim 22 in which the acidic catalyst includes a metal component having hydrogenation functionality.
- 30. The process as claimed in claim 22 in which the hydrodesulfurization is carried out at a temperature of about 500.degree. to 800.degree. F., a pressure of about 300 to 1000 psig, a space velocity of about 1 to 6 LHSV, and a hydrogen to hydrocarbon ratio of about 1000 to 2500 standard cubic feet of hydrogen per barrel of feed.
- 31. The process as claimed in claim 22 in which the second stage upgrading is carried out at a temperature of about 350.degree. to 800.degree. F., a pressure of about 300 to 1000 psig, a space velocity of about 1 to 6 LHSV, and a hydrogen to hydrocarbon ratio of about 100 to 2500 standard cubic feet of hydrogen per barrel of feed.
- 32. The process as claimed in claim 22 which is carried out in two stages with an interstage separation of light ends and heavy ends with the heavy ends fed to the second reaction zone.
- 33. The process as claimed in claim 22 which is carried out in cascade mode with the entire effluent from the first reaction passed to the second reaction zone.
- 34. The process of claim 22 wherein said reduction in surface acidity is determined by dealkylation of tri-tertbutylbenzene.
- 35. The process of claim 22 wherein said surface acidity is reduced by at least about 25%.
- 36. The process of claim 22 wherein said surface acidity is reduced by at least 40%.
- 37. The process of claim 22 wherein said dicarboxylic acid is in solution.
- 38. The process of claim 37 wherein said solution of dicarboxylic acid is at a volume ratio of solution to catalyst of at least about 1:1.
- 39. The process of claim 22 wherein said dicarboxylic acid is an aqueous dicarboxylic acid solution.
- 40. The process of claim 22 wherein said dicarboxylic acid is in a concentration in the range of from about 0.01 to about 4M.
- 41. The process of claim 22 wherein said dicarboxylic acid is selected from the group consisting of oxalic, malonic, succinic, glutaric, adipic, maleic, phthalic, isophthalic, terephthalic, fumaric, tartaric and mixtures thereof.
- 42. The process of claim 22 wherein said dicarboxylic acid is oxalic acid.
- 43. The process of claim 22 wherein said contacting with dicarboxylic acid is for a time of at least about 10 minutes.
- 44. The process of claim 22 wherein said contacting with dicarboxylic acid is at a temperature in the range of from about 60.degree. to about 200.degree. F.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 07/850,106, filed Mar. 12, 1992 which is a continuation-in-part of application Ser. No. 07/745,311, filed Aug. 15, 1991, pending
US Referenced Citations (14)
Foreign Referenced Citations (1)
Number |
Date |
Country |
0259526B1 |
Sep 1991 |
EPX |
Continuation in Parts (2)
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Number |
Date |
Country |
Parent |
850106 |
Mar 1992 |
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Parent |
745311 |
Aug 1991 |
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