PROCESS TO PRODUCE AROMATICS FROM CRUDE OIL

• US 20150321975A1
• Filed: 05/12/2014
• Published: 11/12/2015
• Est. Priority Date: 05/12/2014
• Status: Active Grant

• Current Assignee: Saudi Arabian Oil Company (Government of Saudi Arabia)
• Original Assignee: Saudi Arabian Oil Company (Government of Saudi Arabia)
• Inventors: Choi, Ki-Hyouk, Lee, Joo-Hyeong, Shafei, Emad N., Al-Faqeer, Faisal M.
• Granted Patent: US 9,505,678 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C07C 4/04 Thermal processes C07C4/025 takes precedence
• CPC Class Codes: C07C 7/005 Processes comprising at least two steps in series
• CPC Class Codes: C07C 7/10 by extraction, i.e. purification or separation of liquid hydrocarbons with the aid of liquids
• CPC Class Codes: C10G 21/00 Refining of hydrocarbon oils, in the absence of hydrogen, by extraction with selective solvents C10G17/00, C10G19/00 take precedence
• CPC Class Codes: C10G 2300/4006 Temperature
• CPC Class Codes: C10G 2300/4012 Pressure
• CPC Class Codes: C10G 2400/30 Aromatics
• CPC Class Codes: C10G 33/00 Dewatering or demulsification of hydrocarbon oils by distillation C10G7/04
• CPC Class Codes: C10G 55/04 including at least one thermal cracking step
• CPC Class Codes: C10G 9/00 Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
• CPC Class Codes: C10G 9/002 Cooling of cracked gases

Abstract

A process for producing aromatics from a hydrocarbon source in the presence of supercritical water comprising the steps of mixing a pressurized, pre-heated water stream with a pressurized, pre-heated petroleum feedstock, the pressurized, pre-heated water stream at a pressure above the critical pressure of water and a temperature above the critical temperature of water, feeding the combined stream to a supercritical water reactor to create a modified stream, cooling and depressurizing the modified stream, separating the depressurized stream in a vapor-liquid separator, condensing the vapor stream, separating the condensed stream into a water recovery stream and a light product recovery stream, extracting the aromatics from the light product recovery stream, depressurizing the liquid stream, separating the depressurized liquid stream in a heavy separator into an upgraded product stream, and recycling part of the upgraded product stream to the pressurized, pre-heated petroleum feedstock as a product recycle.

Claims

1. A process for producing aromatics from a hydrocarbon source in the presence of supercritical water, the process comprising the steps of:

mixing a pressurized, pre-heated water stream with a pressurized, pre-heated petroleum feedstock to create a combined stream,

wherein the pressurized, pre-heated water stream and the pressurized, pre-heated petroleum feedstock are at a pressure above a critical pressure of water,

wherein the pressurized, pre-heated water stream is heated to a temperature above a critical temperature of water,

wherein the pressurized, pre-heated petroleum feedstock is heated to a temperature between 10°

C. and 300°

C.;

feeding the combined stream to a supercritical water reactor to create a modified stream, wherein the supercritical water reactor is in an absence of an external supply of hydrogen gas, wherein the supercritical water reactor is in an absence of catalyst;

cooling the modified stream in a reactor cooler to create a cooled stream, wherein the cooled stream is cooled to a temperature below 200°

C.;

depressurizing the cooled stream in a pressure reducer to create a depressurized stream, the depressurized stream comprising water, aromatics, gases, and other hydrocarbons, wherein a pressure of the depressurized stream is between 0.05 MPa and 2.2 MPa;

separating the depressurized stream in a vapor-liquid separator to create a vapor stream and a liquid stream, the vapor stream comprising an amount of water, wherein the amount of water being water present in the depressurized stream;

condensing the vapor stream in a condenser to create a condensed stream;

separating the condensed stream in a lights separator into a water recovery stream and a light product recovery stream, wherein the light product recovery stream contains the aromatics;

extracting the aromatics in an extraction unit from the light product recovery stream to create an aromatic extract stream and a light product stream;

depressurizing the liquid stream in a heavy pressure reducer to create a depressurized liquid stream, wherein a pressure of the depressurized liquid stream is below 1 MPa;

separating the depressurized liquid stream in a heavy separator into an upgraded product stream and a bottoms water stream, wherein the upgraded product stream comprises upgraded hydrocarbons relative to the pressurized, pre-heated petroleum feedstock; and

recycling part of the upgraded product stream to the pressurized, pre-heated petroleum feedstock as a product recycle.

2. The process of claim 1, wherein the product recycle is split in a 1:

1 ratio with a product stream.

3. The process of claim 1, wherein the supercritical water reactor is a two-stage reactor, the two-stage reactor comprising a first stage and a second stage, wherein a ratio of a residence time of the first stage to a residence time of the second stage is between 1.2:

1 and 20;

1.

4. The process of claim 3, wherein a temperature difference between the first stage and the second stage of the two-stage reactor is between 5°

C. and 100°

C.

5. The process of claim 3, wherein the first stage of the two-stage reactor is an upflow reactor.

6. The process of claim 3, wherein the second stage of the two-stage reactor is a downflow reactor.

7. The process of claim 1, wherein the aromatic extract stream comprises benzene, toluene, and xylene.

8. The process of claim 1, wherein the modified stream has a higher content of aromatics and a lower content of impurities as compared to the pressurized, pre-heated petroleum feedstock.

9. The process of claim 1, wherein the amount of water in the vapor stream is greater than 90 wt % of the water present in the depressurized stream.

10. A process for producing aromatics from a hydrocarbon source in the presence of supercritical water, the process comprising the steps of:

mixing a pressurized, pre-heated water stream with a pressurized, pre-heated petroleum feedstock to create a combined stream,

wherein the pressurized, pre-heated water stream and the pressurized, pre-heated petroleum feedstock are at a pressure above a critical pressure of water,

wherein the pressurized, pre-heated water stream is heated to a temperature above a critical temperature of water,

wherein the pressurized, pre-heated petroleum feedstock is heated to a temperature between 10°

C. and 300°

C.;

feeding the combined stream to a supercritical water reactor to create a modified stream, wherein the supercritical water reactor is in an absence of an external supply of hydrogen gas, wherein the supercritical water reactor is in an absence of catalyst;

cooling the modified stream in a reactor cooler to create a cooled stream, wherein the cooled stream is cooled to a temperature below 200°

C.;

depressurizing the cooled stream in a pressure reducer to create a depressurized stream, the depressurized stream comprising water and upgraded hydrocarbons, wherein a pressure of the depressurized stream is between 0.3 MPa and 2.2 MPa;

separating the depressurized stream in a vapor-liquid separator to generate a vapor stream and a liquid stream, wherein the liquid stream comprises the water and the upgraded hydrocarbons;

separating the liquid stream in a heavy separator to produce a petroleum recovery stream and a water recovery stream;

separating the petroleum recovery stream in a distillation column to produce a light product recovery stream and an upgraded product stream,

wherein the light product recovery stream comprises aromatics, and

wherein the upgraded product stream comprises the upgraded hydrocarbons, the upgraded product stream having a higher API gravity, lower sulfur content, and lower metal content compared to the pressurized, pre-heated petroleum feedstock;

extracting the light product recovery stream in an extraction unit to produce a light product stream and an aromatic extract stream;

mixing the light product stream with the upgraded product stream to create a mixed product stream; and

recycling part of the mixed product stream to the pressurized, pre-heated petroleum feedstock as a product recycle.

11. The process of claim 10, wherein the product recycle is split in a 1:

1 ratio with a product stream.

12. The process of claim 10, wherein the supercritical water reactor is a two-stage reactor, the two-stage reactor comprising a first stage and a second stage, wherein a ratio of a residence time of the first stage to a residence time of the second stage is between 1.2:

1 and 20;

1.

13. The process of claim 12, wherein a temperature difference between the first stage and the second stage of the two-stage reactor is between 5°

C. and 100°

C.

14. The process of claim 12, wherein the first stage of the two-stage reactor is an upflow reactor.

15. The process of claim 12, wherein the second stage of the two-stage reactor is a downflow reactor.

16. The process of claim 10, wherein the aromatic extract stream comprises benzene, toluene, and xylene.

17. The process of claim 10, wherein the modified stream has a higher content of the aromatics and a lower content of impurities as compared to the pressurized, pre-heated petroleum feedstock.