Process for hydroconversion and upgrading of heavy crudes of high metal and asphaltene content

• US 4,591,426 A
• Filed: 03/28/1983
• Issued: 05/27/1986
• Est. Priority Date: 10/08/1981
• Status: Expired due to Term

• Current Assignee: Intevep, S.A. (PDVSA Gas SA)
• Original Assignee: Intevep, S.A. (PDVSA Gas SA)
• Inventors: Krasuk, Julio H., Galiasso, Roberto E., Souto, Alfredo, Silva, Fernando J.
• Primary Examiner(s): Metz, Andrew H.
• Assistant Examiner(s): Chaudhuri, O.
• Application Number:
  US06/479,394
• Time in Patent Office: 1,156 Days
• Field of Search: 208/110, 208/111, 208/112, 208/216 R, 208/216 PP, 208/210, 208/96, 208/97, 208/251 H, 208/162
• US Class Current: 208/96
• CPC Class Codes: B01J 21/04 Alumina
• CPC Class Codes: C10G 49/02 characterised by the catalyst used
• CPC Class Codes: C10G 65/12 including cracking steps and other hydrotreatment steps
• CPC Class Codes: C10G 67/0454 Solvent desasphalting

Abstract

A process for upgrading feedstocks containing not less than about 200 ppm metals, an API gravity of less than about 20°, a Conradson Carbon of more than about 8%, by hydroconversion with hydrogen in the presence of a naturally occurring inorganic material as a catalyst. The invention further provides, inter alia, subsequently fractionating the hydroconverted product and solvent deasphalting the distillation bottoms and optionally hydrodesulfurizing atmospheric distillates and the mix of vacuum gas oils and deasphalted oils separately. When a heavy crude of 12° API, 10% Conradson Carbon, 3.2% sulfur and 350 ppm metals is fed to this process, more than 90% (v/v) of a synthetic crude of 25°API, 0.17% sulfur and only 13.8% (v/v) 950° F.+ fraction may be obtained.

Claims

1. The process for hydroconverting a heavy hydrocarbon feedstock containing at least 200 ppm metals, having less than 20% API gravity and more than 8% Conradson carbon, which comprises contacting said feedstock in a hydroconversion reaction zone with hydrogen in the presence of a natural inorganic material as a catalyst, said inorganic material being selected from the group consisting of (1) iron laterite having a chemical formula consisting essentially of ((γ

FeOOH . (1-γ

) Fe₂ O₃ . nH₂ O α

AlO(OH)) (SiO₂)_x (FeTiO₃)_y (TiO₂)_z with γ

much greater than (1-γ

)) with a Fe₂ O₃ content of greater than or equal to 45.0 wt.%, (2) limonite having a chemical formula consisting essentially of ((γ

Fe₂ O₃ . nH₂ O) (1-γ

) Fe₃ (PO₄)₂.8H₂ O α

Al₂ O₃.nH₂ O (SiO₂)_x with γ

much greater than (1-γ

)) with an Fe₂ O₃ content of greater than or equal to 45.0 wt.%, and (3) mixtures thereof.

2. The process as defined in claim 1 further including enhancing the activity of said natural inorganic material by subjecting said natural inorganic material to a thermal treatment at a temperature between about 400°

C. and 1100°

C. for about 1 minute to about 4 hours and results in the following catalyst characteristics;

(a) a specific surface area, Sg, in square meters per gram of about 10 to about 200;

(b) a specific pore volume, Vp, in cubic centimeters per gram of about 0.1 to about 0.9;

(c) an average pore diameter, d, in angstroms of about 20 to about 3600, where d, =4Vp/Sg; and

(d) a pore size distribution in accordance with the following;

space="preserve" listing-type="tabular">______________________________________ Pores of Radius r Percentage (in angstroms) of Total Pore Volume ______________________________________ greater than 1000 5 to 60 1000 to greater than 300 5 to 50 300 to greater than 100 5 to 30 100 to greater than 40 6 to 30 40 or less 4 to 60 ______________________________________

3. The process as defined in claim 2 wherein the specific surface area, Sg, in square meters per gram is about 20 to 150, the specific pore volume, Vp, in cubic centimeters per gram is about 0.2 to 0.8 and the average pore diameter, d, in angstroms is about 53 to 1600, where d=4Vp/Sg.

4. The process as defined in claim 1 wherein before contacting the heavy crude, said catalyst is presulphided by contacting said catalyst with a sulphur containing liquid stream.

5. The process as defined in claim 1 wherein said catalyst has a surface area of 20 to 150 m² /g, a specific pore volume of 0.1 to 0.9 cm³ /g, an average pore diameter of 53 to 1600 Å

and a pore size distribution in accordance with the following;

space="preserve" listing-type="tabular">______________________________________ Pores of Radius r Percentage (in angstroms) of Total Pore Volume ______________________________________ greater than 1000 20 to 50 1000 to greater than 300 10 to 40 300 to greater than 100 8 to 25 100 to greater than 40 6 to 10 40 or less 4 to 30 ______________________________________

6. The process as defined in claim 1 wherein before contacting the heavy crude, said catalyst is presulphided in a hydrogen/hydrogen sulphide atmosphere.

7. The process as defined in claim 1 wherein said catalyst has a particle diameter between 0.001 cm and 0.1 cm, wherein said catalyst is fed to the hydroconversion reaction zone in an amount of 1 to 15% by weight based on the total amount of feedstock and catalyst, and wherein the catalyst inventory in said reaction zone is between 5 and 30% by weight.

8. The process as defined in claim 1 wherein said catalyst has a particle diameter between 0.05 and 0.5 inches, wherein said catalyst is fed to a moving bed reaction zone in an amount of 1 to 15% by weight based upon the total amount of feedstock and catalyst, and wherein the catalyst inventory in said reaction zone is between 20% and 80% by weight.

9. The process as defined in claim 1 wherein the process includes fractionating the hydroconversion product and recycling at least a portion of the product boiling higher than about 1000°

F. to the hydroconversion reaction zone.

10. The process as defined in claim 6 wherein the process additionally includes separating the catalyst from said hydroconversion reaction zone.

11. The process as defined in claim 7 wherein the process additionally includes separating the catalyst from said hydroconversion reaction zone.

12. The process as defined in claim 1 wherein the process additionally includes separating the catalyst from said hydroconversion reaction zone.

13. The process of claim 12 wherein the catalyst is separated from the said hydroconversion product by means of centrifugal decanting, centrifuging or a combination of centrifugal decanting and centrifuging.

14. The process as defined in claim 1 wherein the liquid hour space velocity in the hydroconversion reaction zone is between about 0.1 h^-1 and about 100 h^-1 (V feedstock/V reaction zone"h) and the hydrogen-to feedstock ratio is between about 560 and about 60,000 scfH₂ /b.

15. The process as defined in claim 1 wherein the hydrogen pressure in said hydroconversion reaction zone is between about 600 and about 4000 psig and the temperature is between about 660 and about 950°

F.

16. The process as defined in claim 1 wherein said process additionally includes fractionating the hydroconversion product into a distillate fraction and a bottoms fraction, and deasphalting the bottoms fraction with a light solvent having 3 or more carbon atoms to produce a deasphalted oil, with the solvent being added in the deasphalting unit such that the total solvent/bottoms ratio is between about 4:

1 and 1;

1 by weight.

17. The process as defined in claim 1 wherein said process additionally includes fractionating the hydroconversion product into a distillate fraction and a bottoms fraction, and deasphalting the bottoms fraction with a light solvent having 3 or more carbon atoms to produce a deasphalted oil, with the solvent being added in the deasphalting unit such that the total solvent/bottoms ratio is between about 4:

1 and 1;

1 by weight, and wherein said solvent is a 230°

-410°

F. fraction of the distillate fraction generated by the process.

18. The process as defined in claim 1 wherein said process additionally includes fractionating the hydroconversion product into a distillate fraction and a bottoms fraction, and deasphalting the bottoms fraction with a light solvent having 3 or more carbon atoms to produce a deasphalted oil, with the solvent being added in the deasphalting unit such that the total solvent/bottoms ratio is between about 4:

1 and 1;

1 by weight, and wherein the temperature of the deasphalting is between about 80° and

about 400°

F. and the total pressure is between about 1 and about 60 atmospheres.

19. The process as defined in claim 1 wherein said process additionally includes fractionating the hydroconversion product into a distillate fraction and a bottoms fraction, and deasphalting the bottoms fraction with a light solvent having 3 or more carbon atoms to produce a deasphalted oil, with the solvent being added in the deasphalting unit such that the total solvent/bottoms ratio is between about 4:

1 and 1;

1 by weight, and wherein the process additionally comprises desulfurizing the deasphalted oil employing fixed beds composed of one or more desulfurizing catalysts arranged in one or more desulfurizing reaction zones.

20. The process as defined in claim 1 further comprising separating the hydroconversion catalyst, regenerating the separated hydroconversion catalyst with carbon thereon by contacting the catalyst at elevated temperatures with an oxygen-containing gas to reduce the carbon content of the hydroconversion catalyst, and recycling at least a portion of the regenerated hydroconversion catalyst to the hydroconversion reaction zone.

21. The process as defined in claim 1 further comprising separating the hydroconversion catalyst and totally or partially recycling said catalyst back to the hydroconversion reaction zone.

22. The process as defined in claim 19 wherein each desulfurizing reaction zone is operated at substantially the same temperature and pressure, said temperature being between about 660 and about 840°

F. and said pressure being between about 200 to about 3000 psig, at a residence time in the desulfurizing reaction zone of between about 0.5 and about 3.5 hours, and at a linear liquid velocity in the desulfurizing reaction zone between about 15 and about 150 feet/hour.

23. The process as defined in claim 19 wherein the desulfurizing catalyst employed in the desulfurizing reaction zone is prepared by successive impregnation of macroporous alumina with metals of Group VIB and Group VIII, said impregnation employing soluble salts of said metals, a contact time between about 1 and about 5 hours, a drying temperature between about 170°

and about 250°

F., and a calcination temperature between about 750° and

about 1100°

F.

24. The process as defined in claim 19 wherein the desulfurizing catalyst employed in a first desulfurizing catalytic bed contains up to about 10% by weight Group VIB metals and up to about 8% by weight Group VIII metals, and wherein the desulfurizing catalyst employed in other desulfurizing catalytic beds contains up to about 20% by weight Group VIB metals and up to about 8% by weight Group VIII metals.

25. The process as defined in claim 19 wherein the desulfurizing catalyst employed in a first desulfurizing catalytic bed contains up to about 10% by weight Group VIB metals and up to about 8% by weight Group VIII metals, and wherein the desulfurizing catalyst employed in other desulfurizing catalytic beds contains up to about 20% by weight Group VIB metals and up to about 8% by weight Group VIII metals, wherein the desulfurizing catalyst in said first bed has a pore volume distribution with up to about 50% of the pore volume of radii larger than about 100 Å

and with up to about 40% of the pore volume of radii between about 50 and about 100 Å

, and wherein the desulfurizing catalyst in the other of said beds has a pore volume distribution with up to about 20% of the pore volume of radii larger than about 100 Å and

with about 20 to about 40% of the pore volume of radii between 30 and 100 Å

.

26. The process as defined in claim 20 wherein the recycled catalyst exhibits a molar ratio of vanadium to iron of less than about 5.0:

1 and a molar ratio of vanadium to Al₂ O₃ plus SiO₂ of less than about 20;

1.

27. The process as defined in claim 20 wherein said process additionally includes fractionating the hydroconversion product into a distillate fraction and a bottoms fraction, deasphalting the bottoms fraction with a light solvent having 3 or more carbon atoms to produce a deasphalted oil, with the solvent being added in the deasphalting unit such that the total solvent/bottoms ratio is between about 4:

1 and 1;

1 by weight, and further comprising separating the hydroconversion catalyst fines by filtration after said deasphalting and after diluting the asphalt with less than 40% by weight of a hydrocarbon diluent.

28. The process as defined in claim 20 wherein said process additionally includes fractionating the hydroconversion product in vacuum and atmospheric towers into a distillate fraction and a bottoms fraction, desulfurizing the distillate fraction thereof, deasphalting the bottoms fraction with a light solvent having 3 or more carbon atoms to produce a deasphalted oil, with the solvent being added in the deasphalting unit such that the total solvent/bottoms ratio is between about 4:

1 and 1;

1 by weight, and employing the asphalt residue thereof as a fuel for steam and energy production.

29. The process as defined in claim 20 wherein said process additionally includes fractionating the hydroconversion product into a distillate fraction, a vacuum gas-oil fraction and a vacuum bottoms fraction, desulfurizing the resulting distillates and vacuum gas-oils and employing the bottoms fraction thereof as a fuel for steam and energy production.