Process for maximizing production of xylenes from heavy reformate without purge

Patent metadata

Field	Value
Publication number	US-10464868-B2
Application number	US-201916244704-A
Country	US
Kind code	B2
Filing date	Jan 10, 2019
Priority date	May 26, 2017
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

A method for producing xylenes from a heavy reformate feed includes the steps of introducing the heavy reformate feed and a hydrogen feed to a dealkylation reactor, reacting the heavy reformate feed with the hydrogen gas in the presence of the dealkylation catalyst in the dealkylation reactor to produce a dealkylation effluent, introducing the dealkylation effluent to a splitter unit, separating the dealkylation effluent into a light gas stream, a toluene stream, a benzene stream, a C9 aromatics stream, a C10+ aromatics stream, and a mixed xylene stream in the splitter unit, introducing the toluene stream, the C9 aromatics stream, and a hydrogen stream into a transalkylation reactor, reacting the toluene stream and the C9 aromatics stream in the presence of the transalkylation catalyst to produce a transalkylation effluent, introducing the transalkylation effluent to the splitter unit, and separating the transalkylation effluent in the splitter unit.

First claim

That which is claimed is:

1. A method for producing mixed xylenes from a heavy reformate feed, the method comprising the steps of:
introducing the heavy reformate feed and a hydrogen feed to a dealkylation reactor, wherein the dealkylation reactor comprises a dealkylation catalyst, wherein the heavy reformate feed comprises aromatic hydrocarbons with nine or more carbon atoms (C9+ aromatics), wherein the hydrogen feed comprises hydrogen gas;
reacting the heavy reformate feed with the hydrogen feed in the presence of the dealkylation catalyst in the dealkylation reactor to produce a dealkylation effluent, wherein the dealkylation reactor is at a dealkylation temperature, wherein the dealkylation reactor is at a dealkylation pressure, wherein the dealkylation reactor has a liquid hourly space velocity;
introducing the dealkylation effluent to a splitter unit, where the dealkylation effluent comprises light gases, toluene, benzene, mixed xylenes, and C9+ aromatics;
separating the dealkylation effluent into a light gas stream, a toluene stream, a benzene stream, a C9 aromatics stream, a C10+ aromatics stream, and a mixed xylene stream in the splitter unit, wherein the light gas stream comprises light hydrocarbons and hydrogen, wherein the toluene stream comprises toluene, wherein the benzene stream comprises benzene, wherein the mixed xylene stream comprises mixed xylenes, wherein the C9 stream comprises C9 aromatics, wherein the C10+ aromatics stream comprises C10+ aromatics;
introducing the toluene stream, the C9 aromatics stream, and a hydrogen stream into a transalkylation reactor, wherein the transalkylation reactor comprises a transalkylation catalyst, wherein the hydrogen stream comprises hydrogen gas;
reacting the toluene stream, the C9 aromatics stream, and the hydrogen stream in the presence of the transalkylation catalyst in the transalkylation reactor to produce a transalkylation effluent, wherein the transalkylation reactor is at a transalkylation temperature, wherein the transalkylation reactor is at a transalkylation pressure, wherein the transalkylation reactor has a liquid hourly space velocity;
introducing the transalkylation effluent to the splitter unit, wherein the transalkylation effluent comprises light gases, toluene, benzene, mixed xylenes, and C9+ aromatics;
separating the transalkylation effluent in the splitter unit such that mixed xylenes in the transalkylation effluent exit the splitter unit as part of the mixed xylene stream;
introducing the C10+ aromatics stream to a hydrocracking reactor;
introducing a hydrogen gas stream to the hydrocracking reactor;
reacting the C10+ aromatics stream and the hydrogen gas stream in the presence of a selective hydrocracking catalyst to produce a treated aromatics stream, wherein the hydrocracking reactor is at a hydrocracking temperature, wherein the hydrocracking reactor is at a hydrocracking pressure, wherein the hydrocracking reactor has a liquid space velocity, wherein the treated aromatics stream comprises single ring aromatic compounds; and
recycling the treated aromatics stream to the dealkylation reactor.

2. The method of claim 1 further comprising the steps of:
introducing the light gas stream to a gas separator; and
separating the light gas stream into a produced hydrogen and a light gas product.

3. The method of claim 1 further comprising the step of introducing the benzene stream to the transalkylation reactor.

4. The method of claim 1 further comprising the step of supplying an added aromatic stream to the transalkylation reactor, such that there is an excess of toluene for transalkylation reactions in the transalkylation reactor.

5. The method of claim 1 , wherein the dealkylation temperature is between 200 deg C. and 500 deg C., wherein the dealkylation pressure is between 5 bar and 40 bar, wherein the liquid hourly space velocity in the dealkylation reactor is between 1 hr −1 and 10 hr −1 .

6. The method of claim 1 , wherein the transalkylation temperature is between 300 deg C. and 500 deg C., wherein the transalkylation pressure is between 10 bar and 40 bar, wherein the liquid hourly space velocity in the transalkylation reactor is between 0.5 hr −1 and 6 hr −1 .

7. The method of claim 1 , wherein the hydrocracking temperature is between 200 deg C. and 540 deg C.

8. The method of claim 1 , wherein the hydrocracking pressure is between 10 bar and 50 bar.

9. The method of claim 1 , wherein the liquid hourly space velocity in the hydrocracking reactor is between 1 hr −1 and 20 hr −1 .

10. An apparatus for producing xylenes from a heavy reformate feed, the apparatus comprising:
a dealkylation reactor, the dealkylation reactor configured to convert the heavy reformate feed and a hydrogen feed in the presence of a dealkylation catalyst to produce a dealkylation effluent, wherein the heavy reformate feed comprises aromatic hydrocarbons with nine or more carbon atoms (C9+ aromatics), wherein the hydrogen feed comprises hydrogen gas, wherein the dealkylation reactor is at a dealkylation temperature, wherein the dealkylation reactor is at a dealkylation pressure, wherein the dealkylation reactor has a liquid hourly space velocity, wherein the dealkylation effluent comprises light gases, toluene, benzene, mixed xylenes, and C9+ aromatics;
a splitter unit fluidly connected to the dealkylation reactor, the splitter unit configured to separate the dealkylation effluent and a transalkylation effluent into a light gas stream, a toluene stream, a benzene stream, a C9 aromatics stream, a C10+ aromatics stream, and a mixed xylene stream, wherein the light gas stream comprises light hydrocarbons and hydrogen, wherein the toluene stream comprises toluene, wherein the benzene stream comprises benzene, wherein the mixed xylene stream comprises mixed xylenes, wherein the C9 aromatics stream comprises C9 aromatics, wherein the C10+ aromatics stream comprises C10+ aromatics;
a transalkylation reactor fluidly connected to the splitter unit, the transalkylation reactor configured to convert the C9 aromatics stream, the toluene stream, and a hydrogen stream in the presence of a transalkylation catalyst to produce a transalkylation effluent, wherein the hydrogen stream comprises hydrogen gas, wherein the transalkylation reactor is at a transalkylation temperature, wherein the transalkylation reactor is at a transalkylation pressure, wherein the transalkylation reactor has a liquid hourly space velocity; and
a hydrocracking reactor fluidly connected to the splitter unit, the hydrocracking reactor configured to convert the C10+ aromatics stream and a hydrogen gas stream in the presence of a selective hydrocracking catalyst to a treated aromatics stream, wherein the hydrogen gas stream comprises hydrogen gas, wherein the hydrocracking reactor is at a hydrocracking temperature, wherein the hydrocracking reactor is at a hydrocracking pressure, wherein the hydrocracking reactor has a liquid space velocity, wherein the treated aromatics stream comprises single ring aromatic compounds.

11. The apparatus of claim 10 further comprising a gas separator fluidly connected to the splitter unit, the gas separator configured to separate the light gas stream into a produced hydrogen and a light gas product.

12. The apparatus of claim 10 , wherein the dealkylation temperature is between 200 deg C. and 500 deg C.

13. The apparatus of claim 10 , wherein the dealkylation pressure is between 5 bar and 40 bar.

14. The apparatus of claim 10 , wherein the liquid hourly space velocity in the dealkylation reactor is between 1 hr −1 and 10 hr −1 .

15. The apparatus of claim 10 ,

Assignees

• Saudi Arabian Oil Co

Inventors

• Xu Qi
• Abudawoud Raed

Classifications

• C10G65/043

  at least one step being a change in the structural skeleton · CPC title

• C10G45/44

  Hydrogenation of the aromatic hydrocarbons · CPC title

• B01J2219/00051

  Controlling the temperature · CPC title

• C07C6/126

  of more than one hydrocarbon · CPC title

• C10G47/00

  Cracking of hydrocarbon oils, in the presence of hydrogen or hydrogen- generating compounds, to obtain lower boiling fractions (C10G15/00 takes precedence; destructive hydrogenation of non-melting solid carbonaceous or similar materials C10G1/06) · CPC title