Process for recovering benzene and fuel gas in an aromatics complex

Patent metadata

Field	Value
Publication number	US-10427993-B2
Application number	US-201715692210-A
Country	US
Kind code	B2
Filing date	Aug 31, 2017
Priority date	Aug 31, 2017
Publication date	Oct 1, 2019
Grant date	Oct 1, 2019

Abstract

A process for separating xylene from a feedstock in which the feedstock is separated into a xylene stream, a benzene rich stream and a light ends stream. Two separation zones may be utilized in which liquid from both is sent to a compression zone and the vapor from the compression zone is combined with a stream prior to the stream entering the second separation zone.

First claim

The invention claimed is:

1. A process for the recovery of a benzene rich liquid stream and a light ends vapor stream in a xylene isomerization process from a feedstock, the process comprising:
passing a feedstock into a deheptanizer in which the feedstock is separated into a deheptanizer vapor phase and a deheptanizer liquid phase, the deheptanizer vapor phase containing hydrocarbons with seven carbon atoms or less, and the deheptanizer liquid phase containing hydrocarbons with eight carbon atoms or more;
passing the deheptanizer vapor phase from the deheptanizer to a first separation zone;
separating the deheptanizer vapor phase in the first separation zone into a first liquid phase and a first vapor phase;
passing the first liquid phase from the first separation zone to a toluene recovery zone;
passing the first vapor phase from the first separation zone to a compression zone in which the first vapor phase is compressed and partially condensed to provide a compressed and partially condensed vapor phase;
passing the compressed and partially condensed vapor phase from the compression zone to a second separation zone;
separating the compressed and partially condensed vapor phase into the benzene rich liquid stream and a second vapor phase in the second separation zone, the second vapor phase being a light ends vapor stream;
recovering the light ends vapor stream;
recovering the benzene rich liquid stream; and
sending the benzene rich liquid stream to extraction.

2. The process of claim 1 further comprising passing a portion of the first liquid phase to the deheptanizer.

3. The process of claim 1 further comprising passing the benzene rich liquid stream to the extraction to recover a benzene stream.

4. The process of claim 1 further comprising passing the benzene rich liquid stream to storage.

5. The process of claim 1 further comprising compressing the deheptanizer vapor phase before the deheptanizer vapor stream enters the first separation zone.

6. The process of claim 5 wherein a temperature of the first separation zone is between approximately 32° C. to 149° C.

7. The process of claim 6 wherein a temperature of the second separation zone is between approximately 10° C. to 149° C.

8. The process of claim 1 wherein a temperature of the first separation zone is between approximately 10° C. to 149° C. and a temperature of the second separation zone is between approximately 10° C. to 149° C.

9. A process for the recovery of a benzene rich liquid stream and a light ends vapor stream in a xylene isomerization process from a feedstock, the process comprising:
passing a feedstock into a distillation column in which the feedstock is separated into a distillation vapor and a distillation liquid, the distillation vapor containing mostly hydrocarbons with seven carbon atoms or less;
condensing the distillation vapor;
separating the distillation vapor into a first liquid phase and a first vapor phase;
passing the first liquid phase to a toluene recovery zone;
compressing the first vapor phase into a compressed vapor phase;
separating the compressed vapor phase into the benzene rich liquid stream and a second vapor phase, the second vapor phase being a light ends vapor stream;
recovering the light ends vapor stream;
recovering the benzene rich liquid stream; and
sending the benzene rich liquid stream to extraction.

10. The process of claim 9 wherein a temperature of the first liquid phase is between approximately 32° C. to 149° C.

11. The process of claim 10 wherein a temperature of the compressed vapor phase is between approximately 10° C. to 149° C.

12. The process of claim 9 further comprising passing a portion of the first liquid phase to the distillation column.

13. The process of claim 9 further comprising passing the benzene rich liquid stream to the extraction to recover a benzene stream.

14. The process of claim 9 further comprising passing the benzene rich liquid stream to storage.

15. A process for the recovery of a benzene rich liquid stream and a light ends vapor stream in a xylene isomerization process from a feedstock, the process comprising:
passing a feedstock into a separation zone in which the feedstock is separated into a vapor stream and a liquid stream, the vapor stream containing mostly hydrocarbons with seven carbon atoms or less, the liquid stream comprising xylene;
condensing the vapor stream;
separating the condensed vapor stream into a first liquid phase and a first vapor phase;
passing the first liquid phase to a toluene recovery zone;
passing the first vapor phase to a compression zone;
compressing the first vapor phase into a compressed vapor phase;
separating the compressed vapor phase into the benzene rich liquid stream and a second vapor phase, the second vapor phase being a light ends vapor stream;
recovering the light ends vapor stream; and
recovering the benzene rich liquid stream; and
sending the benzene rich liquid stream to extraction.

16. The process of claim 15 wherein a temperature of the first liquid phase is between approximately 32° C. to 149° C.

17. The process of claim 15 wherein a temperature of the compressed vapor phase is between approximately 10° C. to 149° C.

Assignees

• Uop Llc

Inventors

• Bresler Leonid
• Whitchurch Patrick C
• Corradi Jason T

Classifications

• C07C5/2702

  Catalytic processes not covered by C07C5/2732 - C07C5/31; Catalytic processes covered by both C07C5/2732 and C07C5/277 simultaneously · CPC title

• C07C7/10

  by extraction, i.e. purification or separation of liquid hydrocarbons with the aid of liquids · CPC title

• C07C7/09

  by fractional condensation · CPC title

• C07C15/08

  Xylenes · CPC title

• C07C7/005

  Processes comprising at least two steps in series · CPC title