Hydrocarbon Extraction and/or Separation Processes Utilizing a Membrane Separator

Patent metadata

Field	Value
Publication number	US-2023295063-A1
Application number	US-202118004200-A
Country	US
Kind code	A1
Filing date	Jul 7, 2021
Priority date	Jul 31, 2020
Publication date	Sep 21, 2023
Grant date	—

Abstract

A membrane separator comprising a membrane is used to separate various streams in processes for separating aromatic hydrocarbons from non-aromatic hydrocarbons. Such streams can be a lean-solvent stream, a rich-solvent stream, or a hydrocarbon stream comprising both aromatic and non- aromatic hydrocarbons. The membrane separator is advantageously used in combination with an extraction sub-system including a liquid—liquid distillation column and/or an extraction distillation column.

First claim

What is claimed is:

1 . A process for extracting aromatic hydrocarbons from a mixture feed comprising aromatic hydrocarbons and non-aromatic hydrocarbons, the process comprising:
(A-1) feeding the mixture feed into an extraction column; (A-2) providing a first lean-solvent stream comprising a polar solvent at a concentration of c(ps) wt %, and heavy components at a total concentration of c(hcom) wt %; based on the total weight of the lean-solvent stream, where 75 ≤c(ps) ≤99.99; (A-3) feeding the first lean-solvent stream into a membrane separator, wherein: the membrane separator comprises a vessel having a first volume, a second volume, and a membrane between the first volume and the second volume; the first volume is separated from the second volume by the membrane; the membrane is more permeable to the polar solvent than to the heavy components; and the first lean-solvent stream is fed into the first volume; (A-4) obtaining a retentate stream exiting the first volume of the membrane separator, wherein the retentate steam is rich in the heavy components relative to the first lean-solvent stream; (A-5) obtaining a permeate stream exiting the second volume of the membrane separator, wherein the permeate stream is depleted in the heavy components relative to the first lean-solvent stream; and (A-6) feeding at least a portion of the permeate stream into the extraction column.

2 . The process of claim 1 , further comprising:
(A-7) phase separating at least a portion of the retentate stream to obtain a heavy components stream and a solvent stream saturated with heavy components; and (A-8) feeding at least a portion of the solvent stream saturated with heavy components to the extraction column.

3 . The process of claim 2 , wherein the solvent stream saturated with heavy components comprises the heavy components at a total concentration in a range from 3 to 15 wt %, based on the total weight of the solvent stream saturated with the heavy components.

4 . The process of claim 1 , wherein:
the extraction column is an extraction distillation column.

5 . The process of claim 1 ,. wherein:
the extraction column is a liquid-liquid extraction column.

6 . The process of claim 1 , wherein:
the polar solvent is selected from tetraethylene glycol, triethylene glycol, diethylene glycol, ethylene glycol, methoxy triglycol ether, diglycolamine, dipropylene glycol, N-formyl morpholine, N-methyl pyrrolidone, 2,3,4,5-tetrahydrothiophene-1,1-dioxide (“sulfolane”), 3-methylsulfolane and dimethyl sulfoxide, tetramethylenesulfone, mixtures thereof, and/or admixtures with water thereof.

7 . The process of claim 1 , wherein:
the membrane comprises a polyimide membrane, and/or a membrane comprising an ionic liquid.

8 . The process of claim 1 , wherein:
the first lean-solvent stream has a temperature in a range from 25 to 80° C. when fed into the membrane separator, and a positive pressure gradient of deltaP kPa exists from the first volume to the second volume of the membrane separator, and delta ranges from 345 to 10,342 kilopascal.

9 . The process of claim 1 , wherein 0.01 ≤c(hcom) ≤20.

10 . The process of claim 9 , wherein 1 ≤c(hcom) ≤15.

11 . The process of claim 1 , further comprising:
(A-9) feeding a second lean-solvent stream comprising the polar solvent into the extraction column.

12 . The process of claim 11 , wherein in a given time period, the first lean-solvent stream comprises the polar solvent at a total weight of the second lean-solvent stream comprises the polar solvent at a total weight of W 2 , and 0.5% ≤W 1 /(W 1 +W 2 )*100% ≤10%.

13 . The process of claim 12 , wherein 0.5% ≤W 1 /(W 1 +W 2 )*100% ≤8%.

14 . The process of claim 11 , wherein the first lean-solvent stream and the second lean-solvent stream are derived from a common lean-solvent stream.

15 . The process of claim 14 , wherein the common lean-solvent stream comprise the heavy components at a total concentration of c(hcom-cs) wt %, based on the total weight of the common lean-solvent stream, and the process further comprises:
(A-10) monitoring c(hcom-cs); and (A-11) implementing step (A-3) to (A-8) only if c(hcom-cs) ≥1.

16 . The process of claim 1 . further comprising:
(A-12) obtaining a bottoms stream from the extraction column, wherein the bottoms stream is rich in aromatic hydrocarbons and the polar solvent relative to the mixture feed; (A-13) separating at least a portion of the bottoms stream in a stripping column to obtain an aromatic hydrocarbons-rich stream comprising steam and depleted in the polar solvent relative to the bottoms stream, and a third lean-solvent stream depleted in aromatic hydrocarbons relative to the bottoms stream; and (A-14) deriving at least one of the first lean-solvent stream, the second lean-solvent stream, and the common lean-solvent stream from the third lean-solvent stream.

17 . The process of claim 16 , further comprising:
(A-15) deriving a fourth lean-solvent stream from the third lean-solvent stream; (A-16) regenerating the fourth lean-solvent stream in a steam stripping regeneration column and/or a vacuum regeneration column to obtain a regenerated lean-solvent stream comprising steam and a bottoms heavy stream; and (A-17) feeding the regenerated lean-solvent stream into one or more of the stripping column, the extraction column, and the membrane separator as at least a portion of the first lean-solvent stream.

18 . The process of claim 17 , further comprising:
(A-18) condensing at least a portion of the aromatic hydrocarbons-rich stream to obtain a mixture comprising an aqueous liquid phase and an oil liquid phase; (A-19) separating the aqueous liquid phase to obtain a water stream; (A-20) heating the water stream to obtain a steam stream; and (A-21) feeding the steam stream to the steam stripping regeneration column.

19 . The process of claim 18 , wherein in step (A-21), the steam stream is at least partly heated by a portion of the third lean-solvent stream.

20 . A process for extracting aromatic hydrocarbons from a mixture feed comprising aromatic hydrocarbons and non-aromatic hydrocarbons, the process comprising:
(A-1) feeding the mixture feed into an extraction column; (A-2) providing a first lean-solvent stream comprising a polar solvent at a concentration of c(ps) wt %, and heavy components at a total concentration of c(hcom) wt %, based on the total weight of the lean-solvent stream; (A-3) feeding the first lean-solvent stream into a membrane separator, wherein: the membrane separator comprises a vessel having a first volume, a second volume, and a membrane between the first volume and the second volume; the first volume is separated from the second volume by the membrane; the membrane is more permeable to the polar solvent than to the heavy components; and the first lean-solvent stream is fed into the first volume; (A-4) obtaining a retentate stream exiting the first volume of the membrane separator, wherein the retentate steam is rich in the heavy components relative to the first lean-solvent stream; (A-5) obtaining a permeate stream exiting the second volume of the membrane separator, wherein the permeate stream is depleted in the heavy components relative to the first lean-solvent stream; (A-6) feeding at least a portion of the permeate stream into the extraction column; (A-9) feeding a second lean-solvent stream comprising the polar solvent into the extraction column, wherein in a given time period, the first lean-solvent stre

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Detjen Todd E
• Wang Chong-Jhoo
• Tinger Robert G

Classifications

• C07C7/144 Primary

  using membranes, e.g. selective permeation · CPC title

• C10G21/28

  Recovery of used solvent · CPC title

• C10G31/11

  by dialysis · CPC title

• C07C7/04

  by distillation · CPC title