Process for the conversion of heavy charges such as heavy crude oils and distillation residues

• US 20060157385A1
• Filed: 12/20/2005
• Published: 07/20/2006
• Est. Priority Date: 12/22/2004
• Status: Active Grant

• Current Assignee: Eni SPA (Eni Petroleum Company Incorporated), EniTecnologie S.p.A. (Eni Petroleum Company Incorporated), Snamprogetti S.p.A.
• Original Assignee: Eni SPA (Eni Petroleum Company Incorporated), EniTecnologie S.p.A. (Eni Petroleum Company Incorporated), Snamprogetti S.p.A.
• Inventors: Panariti, Nicoletta, Rosi, Sergio, Marchionna, Mario, Delbianco, Alberto, Montanari, Romolo
• Granted Patent: US 7,691,256 B2
• Time in Patent Office: Days
• US Class Current: 208/49
• CPC Class Codes: C10G 2300/1033 Oil well production fluids
• CPC Class Codes: C10G 2300/107 Atmospheric residues having a boiling point of at least about 538 °C
• CPC Class Codes: C10G 2300/1077 Vacuum residues
• CPC Class Codes: C10G 2300/206 Asphaltenes
• CPC Class Codes: C10G 2300/207 Acid gases, e.g. H2S, COS, SO2, HCN
• CPC Class Codes: C10G 2300/4081 Recycling aspects
• CPC Class Codes: C10G 2300/44 Solvents
• CPC Class Codes: C10G 2300/706 Catalytic metal recovery
• CPC Class Codes: C10G 65/18 including only cracking steps
• CPC Class Codes: C10G 67/049 The hydrotreatment being a hydrocracking

Abstract

Heavy hydrocarbon charges are converted in a deasphalting section in the presence of solvents and obtaining two streams, one consisting of deasphalted oil and the other one containing asphaltenes, mixing the deasphalted oil stream with a hydrogenation catalyst and passing the thus obtained mixture to a hydroprocessing section containing hydrogen or hydrogen/H₂S, mixing the stream consisting of asphaltenes discharged from the deasphalting section with an appropriate hydrogenation catalyst and passing the obtained mixture to a second hydroprocessing section where it is reacted with hydrogen or a mixture of hydrogen and H₂S, passing both the stream containing the reaction product with dispersed catalyst from the hydroprocessing section and the stream containing the reaction product with dispersed catalyst from the second hydroprocessing section, to one or more distillation or flash stages, whereby the more volatile fractions are separated from the distillation residue (tar) or from the liquid discharged from the flash unit, sending the distillation residue (tar) or the liquid discharged from the flash unit, containing the catalyst in the dispersed phase, with a high content of metal sulphides, produced by demetallization of the charge, to a second deasphalting section thereby obtaining deasphalted oil and asphaltenes.

Claims

1. Process for the conversion of heavy charges chosen among heavy and extra heavy crude oils, distillation residues, “

heavy oils”

coming from catalytic processes, “

thermal tars”

, bitumens from “

oil sands”

, coals of various nature and other high-boiling charges of hydrocarbon origin known as black oils, by means of the joint use of at least the three following process units;

deasphalting (SDA1), hydroconversion with catalysts in slurry phase (HT1), distillation or flash (D), characterized by the fact of comprising the following stages;

sending the heavy charge to a deasphalting section (SDA1) in presence of solvents obtaining two streams, one consisting of deasphalted oil (DAO 1 from (SDA1)), the other one containing asphaltenes;

mixing the stream consisting of deasphalted oil (DAO 1 from (SDA1)) coming out of the deasphalting section (SDA1) with an appropriate hydrogenation catalyst and sending the thus obtained mixture to a hydroprocessing section (HT1) and introducing into it hydrogen or a mixture containing hydrogen and H₂S;

mixing the stream consisting of asphaltenes coming out of the deasphalting section (SDA1) with an appropriate hydrogenation catalyst and sending the thus obtained mixture to a second hydroprocessing section (HT2) and introducing into it hydrogen or a mixture containing hydrogen and H₂S;

sending both the stream containing the reaction product from the hydroprocessing section (HT1) with the catalyst in the dispersed phase and the stream containing the reaction product from the second hydroprocessing section (HT2) with the catalyst in the dispersed phase, to one or more distillation or flash stages (D), by means of which the more volatile fractions, including the gases produced in the two hydroprocessing reactions (HT1 and HT2), are separated from the distillation residue (tar) or from the liquid coming out of the flash unit;

sending the distillation residue (tar) or the liquid coming out of the flash unit, containing the catalyst in the dispersed phase, and possibly containing coke, with a high content of metal sulphides, produced by demetallization of the charge, to a second deasphalting section (SDA2) in presence of solvents obtaining two streams, one consisting of deasphalted oil (DAO 2 (from SDA2)), the other one consisting of asphaltenes of which, unless there is a drainage, a part is recycled to the hydroprocessing section (HT1), while the other part is recycled to the second hydroprocessing section (HT2).

2. The process according to claim 1, where the weight ratio between the asphaltenic part, obtained from the second deasphalting section (SDA2) recycled to the hydroprocessing section (HT1), and the part recycled to the second hydroprocessing section (HT2) is from 8/1 to 2/1.

3. The process according to claim 2, where the weight ratio between the part recycled to the hydroprocessing section (HT1) and the part recycled to the second hydroprocessing section (HT2) is from 4/1 to 2/1.

4. The process according to claim 3, where the weight ratio between the part recycled to the hydroprocessing section (HT1) and the part recycled to the second hydroprocessing section (HT2) is of about 3/1.

5. The process according to claim 1, where the distillation tillation stages are performed at a reduced pressure from 0.001 to 0.5 MPa.

6. The process according to claim 5, where the distillation stages are performed at a reduce pressure from 0.01 to 0.3 MPa.

7. The process according to claim 1, where the hydroprocessing stage (HT1) is performed at a temperature from 380 to 470°

C. and at a pressure from 3 to 30 MPa.

8. The process according to claim 7, where the hydroprocessing stage (HT1) is performed at a temperature from 390 to 440°

C. and at a pressure from 10 to 20 MPa.

9. The process according to claim 1, where the deasphalting stage (SDA1) is performed at temperatures from 40 to 200°

C. and at a pressure from 0.1 to 7 MPa.

10. The process according to claim 1, where the solvent of the deasphalting stage (SDA1) is a light paraffin with a number of carbon atoms from 3 to 6.

11. The process according to claim 1, where the solvent of the deasphalting stage (SDA1) is a light paraffin with a number of carbon atoms from 4 to 5.

12. The process according to claim 1, where the deasphalting stage (SDA1) is performed by means of an extraction with a solvent operating in supercritical conditions.

13. The process according to claim 1, where the deasphalting stage (SDA1) is performed with recovery of the solvent in supercritical phase.

14. The process according to claim 12 or 13, where the deasphalting stage (SDA1) is performed at temperatures from 40 to 160°

C. and at a pressure from 0.1 to 6 MPa.

15. The process according to claim 1, where the solvent of the second deasphalting stage (SDA2) is a light paraffin with a number of carbon atoms from 3 to 6.

16. The process according to claim 15, where the solvent of the second deasphalting stage (SDA2) is a light paraffin with a number of carbon atoms from 3 to 4.

17. The process according to claim 1, where the second deasphalting stage (SDA2) is performed with recovery of the solvent in supercritical phase.

18. The process according to claim 16 or 17, where the second deasphalting stage (SDA2) is performed at temperatures from 40 and 160°

C. and at a pressure from 0.1 to 6 MPa.

19. The process according to claim 1, where the second hydroprocessing stage (HT2) is performed at a temperature from 360 to 450°

C. and at a pressure from 3 to 30 MPa.

20. The process according to claim 19, where the second hydroprocessing stage (HT2) is performed at a temperature from 390 to 420°

C. and at a pressure from 10 to 20 MPa.

21. The process according to claim 1, where the hydrogenation catalyst is an easily decomposable precursor or a preformed compound based on one or more transition metals.

22. The process according to claim 1, where the transition metal is molybdenum.

23. The process according to claim 1, where the catalyst concentration in the hydroconversion reactors (HT1 and HT2), defined according to the metal or metals present, is from 350 to 100000 ppm.

24. The process according to claim 23, where the catalyst concentration in the hydroconversion reactors (HT1 and HT2) is from 5000 to 30000 ppm.

25. The process according to claim 24, where the catalyst concentration in the two hydroprocessing sections (HT1 and HT2) is from 8000 to 15000 ppm.

26. The process according to claim 1, where the two hydroprocessing section (HT1 and HT2) use the same hydrogenation catalyst.

27. The process according to claim 1, where the stream containing the reaction product of the hydroprocessing section (HT1) and the catalyst in the dispersed phase and/or the stream containing the reaction product of the second hydroprocessing section (HT2) and the catalyst in the dispersed phase, before being sent to one or more distillation or flash stages, is or are subjected to a separation pre-stage performed at high pressure in such a way as to obtain a light and a heavy fraction, being said heavy fraction only sent to said distillation stage or stages (D).

28. The process according to claim 27, where the light fraction obtained from the high pressure separation stage is sent to a secondary hydrogenation post-processing section thus producing a lighter fraction containing gas C₁-C₄ and H₂S and less light fraction containing hydroprocessed naphtha and fuel oil.

29. The process according to claim 28, where the hydrogenation post-processing reaction is performed at a pressure from 7 to 14 MPa.

30. The process according to claim 1, where a fraction of the asphaltene containing stream is sent to a processing section with an appropriate solvent to separate the product into a solid and a liquid phase from which said solvent can subsequently be separated.

31. The process according to claim 30, where the drainage stream is in quantities from 0.t to 10% in volume relative to the fresh charge.

32. The process according to claim 30, where at least a part of the liquid fraction coming out of the drainage processing section is sent in its current state or after separation from the solvent and/or after the addition of an appropriate fluxing agent to the fuel oil fraction.

33. The process according to claim 32, where at least a part of the liquid fraction coming out of the drainage processing section is recycled to the hydroprocessing reactor (HT).

34. The process according to claim 30, where the solvent used in the drainage processing section is an aromatic solvent or a mixture of fuel oils produced in the process itself or available in the refinery.

35. The process according to claim 34, where the aromatic solvent is toluene and/or a mixture of xylenes.

36. The process according to claim 30, where the volumetric ratio solvent/drainage stream varies from 1 to 10.

37. The process according to claim 36, where the volumetric ratio solvent drainage stream varies from 1 to 5.

38. The process according to claim 37, where the volumetric ratio solvent drainage stream varies from 1.5 to 3.5.

39. The process according to claims 27 and 21, where the solid fraction of the processed product is sent to a further process of selective recovery of transition metal or metals contained in the hydrogenation catalyst.

40. The process according to claim 39, where the recovered transition metal or metals are recycled to the hydroprocessing reactor (HT1) and/or to the secondary hydroprocessing reactor (HT2).