Claims
- 1. An integrated process for converting a hydrocarbon feedstock having components boiling above about 100° C. into steam cracked products, which process comprises:a) passing said hydrocarbon feedstock in the presence of a hydrogen source and at least two hydrotreating catalysts in sequence through a hydrotreating zone at an elevated temperature and pressure to effect substantially complete decomposition of organic sulfur and/or nitrogen compounds contained therein, where a first hydrotreating catalyst comprises a component selected from the group consisting of Group VIB metals, Group VIB oxides, Group VIB sulfides, Group VIII metals, Group VIII oxides, Group VIII sulfides and mixtures thereof, supported on an amorphous carrier, and where a second hydrotreating catalyst comprises a Group VIB component selected from the group consisting of tungsten, molybdenum and mixtures thereof, a Group VIII component selected from the group consisting of nickel, cobalt and mixtures thereof, and an acidic carrier selected from the group consisting of amorphous silica-alumina and molecular sieves having a pore diameter greater than about six angstroms admixed with an inorganic oxide binder selected from the group consisting of alumina, silica, silica-alumina and mixtures thereof, b) passing the product from said hydrotreating zone to an aromatics saturation zone wherein said product is contacted at elevated pressure and a temperature in the range of from about 200° C. to about 370° C. with a hydrogen source and an aromatics saturation catalyst comprising one or more Group VIII noble metal hydrogenation components on a zeolitic support comprising a modified Y-type zeolite having a unit cell size between 24.18 and 24.35 Å and a SiO2/Al2O2 molar ratio of at least 25, c) passing the product from said aromatics saturation zone to a steam cracking zone wherein said product is contacted with steam at temperatures greater than about 700° C., and d) recovering hydrogen and C1-C4 hydrocarbons, steam cracked naphtha, steam cracked gas oil and steam cracked tar therefrom, wherein the amount of steam cracked tar produced is reduced by at least about 40 percent, basis the starting hydrocarbon feedstock which has not been subjected to hydrotreating and aromatics saturation.
- 2. The process of claim 1 wherein said hydrocarbon feedstock has components boiling in the range of from about 150° C. to about 650° C.
- 3. The process of claim 1 wherein in step a), the sulfur level of the hydrocarbon feedstock is reduced to below about 100 parts per million and the nitrogen level of the hydrocarbon feedstock is reduced to below about 15 parts per million.
- 4. The process of claim 3 wherein in step a), the sulfur level of the hydrocarbon feedstock is reduced to below about 50 parts per million and the nitrogen level of the hydrocarbon feedstock is reduced to below about 5 parts per million.
- 5. The process of claim 4 wherein in step a), the sulfur level of the hydrocarbon feedstock is reduced to below about 25 parts per million and the nitrogen level of the hydrocarbon feedstock is reduced to below about 3 parts per million.
- 6. The process of claim 1 wherein said first hydrotreating catalyst and said second hydrotreating catalyst are arranged in said hydrotreating zone in a stacked bed configuration.
- 7. The process of claim 1 wherein said hydrotreating zone in step a) is operated at a temperature ranging from about 200° C. to about 550° C. and a pressure ranging from about 400 psig to about 3,000 psig.
- 8. the process of claim 1 wherein said catalyst in the aromatics saturation zone in step b) is supported on a zeolitic support comprising a modified Y-type zeolite having a unit cell size between 24.18 and 24.35 Å and a SiO2/Al2O2 molar ratio of from about 35:1 to about 50:1.
- 9. The process of claim 1 wherein said Group VIII noble metal in said catalyst in the aromatic saturation zone in step b) is selected from the group consisting of palladium and mixtures of platinum and palladium.
- 10. The process of claim 1 wherein said aromatics saturation zone in step b) is operated at a temperature ranging from about 250° C. to about 350° C. and a pressure ranging from about 400 psig to about 3,000 psig.
- 11. The process of claim 1 wherein said aromatics saturation zone in step b) is operated at a temperature ranging from about 275° C. to about 350° C. and a pressure ranging from about 400 psig to about 1,500 psig.
- 12. The process of claim 1 wherein said steam cracking zone in step c) is operated at a temperature greater than about 700° C. and a coil outlet pressure ranging from about 0 psig to about 75 psig.
- 13. The process of claim 1 wherein said steam cracking zone in step c) is operated at a temperature ranging from about 700° C. to about 925° C. and a coil outlet pressure ranging from about 0 psig to about 50 psig.
- 14. The process of claim 1 wherein the yields of ethylene and propylene and butadiene in the H2 and C1-C4 hydrocarbons fraction are each increased by at least about 2.5 percent, and the yields of isoprene, cis-pentadiene, trans-pentadiene, cyclopentadiene, methylcyclopentadiene and benzene in the steam cracked naphtha fraction are each increased by at least about 15 percent, basis the starting hydrocarbon feedstock which has not been subjected to hydrotreating and aromatics saturation.
- 15. An integrated process for converting a hydrocarbon feedstock having components boiling above about 100° C. into steam cracked products, which process comprises:a) passing said hydrocarbon feedstock in the presence of a hydrogen source and a first hydrotreating catalyst through a first hydrotreating zone at an elevated temperature and pressure to reduce the levels of organic sulfur and/or nitrogen compounds contained therein, where the first hydrotreating catalyst comprises a component selected from the group consisting of Group VIB metals, Group VIB oxides, Group VIB sulfides, Group VIII metals, Group VIII oxides, Group VIII sulfides and mixtures thereof, supported on an amorphous carrier, b) passing the product from said first hydrotreating zone to a second hydrotreating zone wherein said product is contacted at elevated pressure and a temperature in the range of from about 200° C. to about 550° C. with a hydrogen source and a second hydrotreating catalyst comprising one or more hydrotreating components selected from the group consisting of Group VIB metals, Group VIB oxides and Group VIB sulfides, where the Group VIB metal is selected from the group consisting of tungsten, molybdenum and mixtures thereof, Group VIII metals, Group VIII oxides and Group VIII sulfides, where the Group VIII metal is selected from the group consisting of nickel, cobalt and mixtures thereof, and mixtures thereof, supported on an acidic carrier selected from molecular sieves having a pore diameter greater than about six angstroms admixed with an inorganic oxide binder selected from the group consisting of alumina, silica, silica-alumina and mixtures thereof, to effect substantially complete decomposition of organic sulfur and/or nitrogen compounds contained in the product from the first hydrotreating zone, c) passing the product from said second hydrotreating zone to an aromatics saturation zone wherein said product is contacted at elevated pressure and a temperature in the range of from about 200° C. to about 370° C. with a hydrogen source and an aromatics saturation catalyst comprising one or more Group VIII noble metal hydrogenation components on a zeolitic support comprising a modified Y-type zeolite having a unit cell size between 24.18 and 24.35 Å and a SiO2/Al2O2 molar ratio of at least 25, d) passing the product from said aromatics saturation zone to a steam cracking zone wherein said product is contacted with steam at temperatures greater than about 700° C., and e) recovering hydrogen and C1-C4 hydrocarbons, steam cracked naphtha, steam cracked gas oil and steam cracked tar therefrom, wherein the amount of steam cracked gas oil produced is reduced by at least about 30 percent and the amount of steam cracked tar produced is reduced by at least about 40 percent, basis the starting hydrocarbon feedstock which has not been subjected to hydrotreating and aromatics saturation.
- 16. The process of claim 15 wherein said hydrocarbon feedstock has components boiling in the range of from about 150° C. to about 650° C.
- 17. The process of claim 15 wherein in step a), the sulfur level of the hydrocarbon feedstock is reduced to below about 500 parts per million and the nitrogen level of the hydrocarbon feedstock is reduced to below about 50 parts per million.
- 18. The process of claim 17 wherein in step a), the sulfur level of the hydrocarbon feedstock is reduced to below about 200 parts per million and the nitrogen level of the hydrocarbon feedstock is reduced to below about 25 parts per million.
- 19. The process of claim 15 wherein said first hydrotreating zone in step a) is operated at a temperature ranging from about 200° C. to about 550° C. and a pressure ranging from about 400 psig to about 3,000 psig.
- 20. The process of claim 15 wherein said second hydrotreating catalyst in step b) the Group VIII component is nickel, the Group VIB compound is selected from the group consisting of molybdenum, tungsten and mixtures thereof, the molecular sieve is zeolite Y having a unit cell size between 24.18 and 24.35 Å and the binder is alumina.
- 21. The process of claim 15 wherein in step b), the sulfur level of the hydrocarbon feedstock is reduced to below about 100 parts per million and the nitrogen level of the hydrocarbon feedstock is reduced to below about 15 parts per million.
- 22. The process of claim 21 wherein in step b), the sulfur level of the hydrocarbon feedstock is reduced to below about 50 parts per million and the nitrogen level of the hydrocarbon feedstock is reduced to below about 5 parts per million.
- 23. The process of claim 22 wherein in step b), the sulfur level of the hydrocarbon feedstock is reduced to below about 25 parts per million and the nitrogen level of the hydrocarbon feedstock is reduced to below about 3 parts per million.
- 24. The process of claim 15 wherein said second hydrotreating zone in step b) is operated at a temperature ranging from about 250° C. to about 500° C. and a pressure ranging from about 400 psig to about 3,000 psig.
- 25. The process of claim 15 wherein said catalyst in the aromatics saturation zone in step c) is supported on a zeolitic support comprising a modified Y-type zeolite having a unit cell size between 24.18 and 24.35 Å and a SiO2/Al2O2 molar ratio of from about 35:1 to about 50:1.
- 26. The process of claim 15 wherein the Group VIII noble metal in said catalyst in the aromatic saturation zone in step c) is selected from the group consisting of palladium and mixtures of platinum and palladium.
- 27. The process of claim 18 wherein said aromatics saturation zone in step c) is operated at a temperature ranging from about 250° C. to about 350° C. and a pressure ranging from about 400 psig to about 3,000 psig.
- 28. The process of claim 15 wherein said aromatics saturation zone in step b) is operated at a temperature ranging from about 275° C. to about 350° C. and a pressure ranging from about 400 psig to about 1,500 psig.
- 29. The process of claim 15 wherein said steam cracking zone in step d) is operated at a temperature greater than about 700° C. and a coil outlet pressure ranging from about 0 psig to about 75 psig.
- 30. The process of claim 15 wherein said steam cracking zone in step d) is operated at a temperature ranging from about 700° C. to about 925° C. and a coil outlet pressure ranging from about 0 psig to about 50 psig.
- 31. The process of claim 15 wherein the yields of ethylene and propylene and butadiene in the H2 and C1-C4 hydrocarbons fraction are each increased by at least about 2.5 percent, and the yields of isoprene, cis-pentadiene, trans-pentadiene, cyclopentadiene, methylcyclopentadiene and benzene in the steam cracked naphtha fraction are each increased by at least about 15 percent, basis the starting hydrocarbon feedstock which has not been subjected to hydrotreating and aromatics saturation.
Parent Case Info
This application claims the benefit of the filing of U.S. Provisional patent applications No. 60/027,859, filed Aug. 15, 1996 and 60/034,612, filed Dec. 31, 1996 relating to the hydrocarbon conversion process.
US Referenced Citations (18)
Provisional Applications (2)
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Number |
Date |
Country |
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60/027859 |
Aug 1996 |
US |
|
60/034612 |
Dec 1996 |
US |