METHOD, EQUIPMENT AND SPECIFIC DRAWER FOR MEMBRANE SEPARATION UTILIZING CONCENTRATION POLARIZATION

• US 20100044310A1
• Filed: 03/05/2008
• Published: 02/25/2010
• Est. Priority Date: 03/23/2007
• Status: Active Grant

• Current Assignee: Institute of Process Engineering Chinese Academy of Sciences (Chinese Academy of Sciences)
• Original Assignee: Institute of Process Engineering Chinese Academy of Sciences (Chinese Academy of Sciences)
• Inventors: Chen, Xiangrong, Shen, Fei, Wan, Yinhua, Jiao, Xiaoguang, Ma, Guanghui, Su, Zhiguo, Cui, Zhanfeng
• Granted Patent: US 8,252,184 B2
• Time in Patent Office: Days
• US Class Current: 210/637
• CPC Class Codes: B01D 2321/26 By suction
• CPC Class Codes: B01D 61/145 Ultrafiltration
• CPC Class Codes: B01D 61/147 Microfiltration
• CPC Class Codes: B01D 63/0822 Plate-and-frame devices
• CPC Class Codes: B01D 65/08 Prevention of membrane fouling or of concentration polarisation

Abstract

The present invention relates to a membrane separation method and a relevant equipment, in particular to a method and an equipment for membrane separation utilizing concentration polarization during membrane filtration process, especially, to a concentration process and equipment and a drawer special for drawing a concentration polarization layer. The direct removal of the concentration polarization layer from membrane surface not only decreases the adverse influence of concentration polarization on membrane separation but also obtains concentrated retention components, thereby significantly improving the ability to maintain membrane flux, solving the twinborn problems concerning concentration polarization and membrane fouling during the membrane separation process, and achieving a high-efficiency concentration for retention components. The method and equipment of the present invention can be widely applied in various membrane techniques, in particular in a membrane separation process for concentrating biomacromolecule and organic micromolecule products such as sugars, organic acids and polypeptides etc.

Claims

1. A membrane separation method, comprising:

a) loading a fluid containing a retention component and a permeation component at a separation side of a separation membrane;

b) exerting a driving force on the fluid to allow at least part of permeation component passing through the separation membrane and arriving at a permeation side of the separation membrane, thereby a retention component-enriched concentration polarization layer is formed at the separation side of said separation membrane; and

c) removing at least part of the concentration polarization layer from the separation side.

2. The membrane separation method according to claim 1, wherein the driving force is produced by a pressure difference, a concentration difference, a potential difference or a temperature difference, in particular a pressure difference.

3. The membrane separation method according to claim 2, wherein the driving force produced by the pressure difference generates a transmembrane pressure ranging from 0.005 MPa to 10 MPa, preferably from 0.01 MPa to 4 MPa.

4. The membrane separation method according to claim 1, wherein all or part of the steps of said membrane separation method are performed continuously, semi-continuously or in intermittent manner.

5. The membrane separation method according to claim 3, wherein the concentration polarization layer is continuously removed by a drawing operation.

6. The membrane separation method according to claim 3, wherein the concentration polarization layer is removed by an intermittent drawing operation manner, wherein when the transmembrane pressure or the permeation flux or thickness of the concentration polarization layer reaches a first predetermined value, the drawing of the concentration polarization layer is initiated;

when the transmembrane pressure or the permeation flux or thickness of the concentration polarization layer reaches a second predetermined value, the drawing operation stops; and

these two steps are performed repeatedly.

7. The membrane separation method according to claim 1, wherein the membrane separation is a membrane concentration, a membrane filtration, a membrane distillation, a membrane extraction or a membrane absorption.

8. A membrane separation equipment, comprising a separation membrane and a drawer, wherein the drawer is configured to remove at least part of a concentration polarization layer from a separation side of the separation membrane during membrane separation process.

9. The membrane separation equipment according to claim 8, wherein the drawer may be located at the separation side or permeation side of the separation membrane, inside the separation membrane or on the separation membrane.

10. The membrane separation equipment according to claim 8, wherein the relative distance and relative position between the drawer and the separation membrane is fixed or adjustable.

11. The membrane separation equipment according to claim 8, wherein the drawer together with the separation membrane form a membrane module.

12. The membrane separation equipment according to claim 8, wherein the drawer comprises a hollow structure having at least one opening which is operably located inside the concentration polarization layer at the separation side of the separation membrane and operably allows at least part of the concentration polarization layer to pass through the opening so as to enter into the hollow structure and to be removed.

13. The membrane separation equipment according to claim 12, wherein the at least one opening of the hollow structure of the drawer is one or more holes with essential round, polygonal or abnormal shape.

14. The membrane separation equipment according to claim 12, wherein the at least one opening of the hollow structure of the drawer has a size ranging from 0.01 to 5 mm, preferably from 0.1 to 2.0 mm, more preferably from 0.1 to 0.5 mm.

15. The membrane separation equipment according to claim 8, wherein the separation membrane is a tabular, plate-and-frame, spiral, tubular or hollow fiber separation membrane.

16. The membrane separation equipment according to claim 15, the separation membrane is a nanofiltration membrane, ultrafiltration membrane or microfiltration membrane made of celluloses, poly(ether sulfone)s, polysulfones, polyolefins, polyamides, polypiperazidines, metals, glasses or ceramics.

17. A drawer for drawing a concentration polarization layer from a separation side of a separation membrane during a membrane separation process, wherein the drawer comprises a hollow structure having at least one opening, and the drawer is configured to be operably located inside the concentration polarization layer at the separation side of the separation membrane and operably allows at least part of the concentration polarization layer to pass through the opening so as to enter into the hollow structure, thereby removing at least part of the concentration polarization layer.

18. The drawer according to claim 17, wherein the drawer further comprises a channel connecting with the hollow structure, and the channel is configured to allow the concentration polarization layer in the hollow structure to leave the hollow structure.

19. The drawer according to claim 17, wherein the drawer further comprises a connection means, and the connection means is configured to allow the distance and relative position between the drawer and the separation membrane to be fixed or adjustable.

20. The drawer according to claim 17, wherein the drawer may essentially cover at least part of a separation surface of the separation membrane in a fixed or movable manner.

21. The drawer according to claim 17, wherein the section with the at least one opening of the hollow structure is essentially in planar, cruciate, spiral, latticed, suspending needle shape or a combination thereof.

22. The drawer according to claim 17, wherein the section with the at least one opening of the hollow structure as a whole may substantially match with the surface of the separation membrane.

23. The drawer according to claim 17, wherein the hollow structure has more than one opening, and these openings may be located regularly or randomly on the surface of the hollow structure of said drawer that faces toward the separation membrane.

24. The drawer according to claim 17, wherein the at least one opening of the hollow structure of the drawer may be a hole in essential round, slit, polygonal or abnormal shape.

25. The drawer according to claim 17, wherein the at least one opening has a size ranging from 0.01 to 5 mm.