Separation of water using a membrane

Patent metadata

Field	Value
Publication number	US-9844758-B2
Application number	US-201314421606-A
Country	US
Kind code	B2
Filing date	Aug 14, 2013
Priority date	Aug 15, 2012
Publication date	Dec 19, 2017
Grant date	Dec 19, 2017

Abstract

This invention relates to uses of graphene oxide, and in particular graphene oxide on a porous support, and a membrane comprising these materials. This invention also relates to methods of dehydration, which include vapour phase separation and pervaporation. Pervaporation is a method of separating mixtures of liquids using a membrane. Pervaporation consists of two basic steps: permeation of the permeate through the membrane and evaporation of the permeate from the other side of the membrane. Pervaporation is a mild which can be used to separate components which would not survive the comparatively harsh conditions needed for distillation (high temp, and/or low pressure).

First claim

The invention claimed is:

1. A method of separating water from a product, the method comprising:
contacting a mixture of the water and the product with a first surface of a graphene oxide membrane, wherein the graphene oxide membrane comprises a layer of graphene oxide supported on a layer of a porous membrane; and wherein the layer of graphene oxide comprises a stack of a plurality of randomly oriented single molecular graphene oxide layers;
removing the water from a second surface of the graphene oxide membrane.

2. The method of claim 1 , wherein the layer of graphene oxide layer is between 100 nm and 10 μm thick.

3. The method of claim 1 , wherein the porous membrane comprises a polymer.

4. The method of claim 1 , wherein the porous membrane comprises an inorganic material.

5. The method of claim 4 , wherein the inorganic material is a ceramic.

6. The method of claim 4 , wherein the inorganic material comprises alumina.

7. The method of claim 1 , wherein the mixture of the water and the product is a gaseous mixture of water vapour and the product, the product being a gas.

8. The method of claim 7 , wherein the method is a method of detecting a gaseous product and, once the water has passed through the graphene oxide membrane, the method comprises the step of detecting the product.

9. The method of claim 1 , wherein the method is a method of separating the water from the product by pervaporation.

10. The method of claim 9 , wherein the mixture of the water and the product is a fermentation broth or has been extracted from a fermentation broth.

11. The method of claim 1 , wherein the porous membrane is formed of a polymeric material selected from polytetrafluoroethylene(PTFE), poly(vinylidene difluoride) (PVDF) and cyclopore polycarbonate.

12. The method of claim 1 , wherein the porous membrane has a surface roughness which is the same as or smoother than as polytetrafluoroethylene(PTFE).

13. The method of claim 1 , wherein the ratio of the thickness of the graphene oxide layer to the thickness of the porous membrane is in the range from 10:1 to 1:10.

14. The method of claim 1 , wherein the porous membrane is no more hydrophobic than polytetrafluoroethylene(PTFE).

Assignees

• Univ Manchester

Inventors

• Nair Rahul
• Budd Peter
• Geim Andre

Classifications

• B01D2325/20

  Specific permeability or cut-off range · CPC title

• C02F1/448

  by pervaporation · CPC title

• B01D71/024 Primary

  Oxides · CPC title

• B01D69/10

  Supported membranes; Membrane supports · CPC title

• B01D2313/06

  External membrane module supporting or fixing means · CPC title