Facilitated transport membrane for the separation of aromatics from non-aromatics

Patent metadata

Field	Value
Publication number	US-9056283-B2
Application number	US-201313781881-A
Country	US
Kind code	B2
Filing date	Mar 1, 2013
Priority date	Mar 2, 2012
Publication date	Jun 16, 2015
Grant date	Jun 16, 2015

Abstract

Certain embodiments of the invention provide an apparatus for separating aromatic hydrocarbons from an aromatic hydrocarbon feed stream. The apparatus includes a membrane support, and a hydrophilic polymer membrane matrix disposed on the membrane support. The hydrophilic polymer membrane matrix includes an effective amount of polyvinyl alcohol and an effective amount of sodium alginate. The apparatus further includes a carrier agent bonded to the hydrophilic polymer membrane matrix using a cross-linking agent. The carrier agent exhibits a greater affinity for aromatics compared to aliphatics. The apparatus further includes a membrane housing configured to hold the membrane support. The membrane housing includes an inlet, a permeate outlet, and a retentate outlet, the inlet being operable to receive the aromatic hydrocarbon feed stream, the permeate outlet being operable to discharge a permeate stream, and the retentate outlet being operable to discharge a retentate stream.

First claim

I claim:

1. An apparatus for separating aromatic hydrocarbons from an aromatic hydrocarbon feed stream, the apparatus comprising:
a membrane support;
a hydrophilic polymer membrane matrix disposed on the membrane support, the hydrophilic polymer membrane matrix comprising polyvinyl alcohol and sodium alginate;
a carrier agent bonded to the hydrophilic polymer membrane matrix using a cross-linking agent, the carrier agent exhibiting a greater affinity for aromatics compared to aliphatics; and
a membrane housing configured to hold the membrane support, the membrane housing comprising an inlet, a permeate outlet, and a retentate outlet, the inlet being operable to receive the aromatic hydrocarbon feed stream, the permeate outlet being operable to discharge a permeate stream, and the retentate outlet being operable to discharge a retentate stream,
wherein the apparatus is operable to separate aromatic hydrocarbons from non-aromatic hydrocarbons when the aromatic hydrocarbon feed stream is introduced into the membrane housing.

2. The apparatus as claimed in claim 1 , wherein the carrier agent is selected from the group consisting of metal salts, amines and combinations thereof.

3. The apparatus as claimed in claim 1 , wherein the carrier agent is bonded to the hydrophilic polymer membrane matrix by obtaining a carrier solution and contacting the carrier solution with the hydrophilic polymer membrane matrix, the carrier solution comprising silver nitrate in an amount from about 2 to about 15 weight percent and glutaraldehyde in an amount of about 5 weight percent with water.

4. The apparatus as claimed in claim 1 , wherein the membrane support comprises polyacrylonitrile.

5. The apparatus as claimed in claim 1 , wherein the hydrophilic polymer membrane matrix further comprises an additional hydrophilic polymer selected from the group consisting of polyacrylic acid, chitosan, polyacryl amide, polyvinyl amine, and combinations thereof.

6. The apparatus as claimed in claim 1 , wherein the hydrophilic polymer membrane matrix is disposed on the membrane support by coating the membrane support with a casting solution, the casting solution comprising polyvinyl alcohol in an amount from about 1 to about 5 weight percent and sodium alginate in an amount from about 1 to about 5 weight percent with water.

7. The apparatus as claimed in claim 1 , wherein the cross-linking agent comprises glutaraldehyde.

8. The apparatus as claimed in claim 1 , wherein the membrane housing is selected from the group consisting of a spiral wound housing, a plate and frame housing, and a hollow-fiber bundled housing.

9. The apparatus as claimed in claim 1 , wherein the hydrophilic polymer membrane matrix is operable to have a selectivity of at least about 40 for aromatic hydrocarbons.

10. A method for using a facilitated transport membrane to separate aromatic components from non-aromatic components, the method comprising:
feeding a hydrocarbon stream comprising aromatic components and non-aromatic components into the inlet of the apparatus of claim 1 under membrane operating conditions such that at least a portion of the aromatic components diffuse across the hydrophilic polymer membrane matrix;
withdrawing a permeate stream enriched in aromatic components compared to the hydrocarbon stream through the permeate outlet; and
withdrawing a retentate stream enriched in non-aromatic components compared to the hydrocarbon stream through the retentate outlet.

11. The method as claimed in claim 10 , further comprising:
introducing the retentate stream to a distillation column under distillation conditions to remove additional aromatic components to form a lean non-aromatic stream and a lean aromatic stream.

12. The method as claimed in claim 10 , wherein the membrane operating conditions comprise pervaporation conditions.

13. The method as claimed in claim 10 , wherein the hydrocarbon stream is in a liquid phase.

14. A method of making a facilitated transport membrane, the method comprising:
obtaining a casting solution comprising a hydrophilic polymer and distilled water, the hydrophilic polymer comprising polyvinyl alcohol and sodium alginate;
coating a membrane support with the casting solution to form a hydrophilic polymer membrane support;
drying the hydrophilic polymer membrane support after the step of coating;
obtaining a carrier solution comprising a carrier agent, a cross-linking agent, and distilled water;
contacting the carrier solution to the hydrophilic polymer membrane support after the step of drying the hydrophilic polymer membrane support; and
drying the hydrophilic polymer membrane support after the step of contacting the carrier solution to form the facilitated transport membrane, the facilitated transport membrane being operable to separate aromatic components from non-aromatic components when a hydrocarbon stream comprised of aromatic and non-aromatic hydrocarbons is introduced to the facilitated transport membrane under membrane operating conditions.

15. The method as claimed in claim 14 , wherein the carrier agent is selected from the group consisting of metal salts, amines and combinations thereof.

16. The method as claimed in claim 14 , wherein the obtaining the carrier solution further comprises dissolving silver nitrate in an amount from about two to about fifteen weight percent with glutaraldehyde in an amount of about five weight percent in distilled water.

17. The method as claimed in claim 14 , wherein the obtaining the casting solution further comprises dissolving from 2 to 5 weight percent of the hydrophilic polymer in distilled water.

18. The method as claimed in claim 14 , wherein the obtaining the casting solution further comprises dissolving polyvinyl alcohol in an amount from about 1 to about 5 weight percent with sodium alginate in an amount from about 1 to about 5 weight percent in distilled water.

19. The method as claimed in claim 14 , wherein the membrane operating conditions comprise pervaporation conditions.

Assignees

• Saudi Arabian Oil Co

Inventors

• Yahaya Garba O

Classifications

• B01D69/142

  with "carriers" · CPC title

• B01D61/362 Primary

  Pervaporation · CPC title

• B01D67/0093

  Chemical modification · CPC title

• C07C15/04

  Benzene · CPC title

• B01D53/228

  characterised by specific membranes · CPC title