WO2017132973A1

WO2017132973A1 - Reverse osmosis membrane and method of processing the same

Info

Publication number: WO2017132973A1
Application number: PCT/CN2016/073595
Authority: WO
Inventors: Changquan QIU; Minling Liu; Kai Huang
Original assignee: Honeywell International Inc.
Priority date: 2016-02-05
Filing date: 2016-02-05
Publication date: 2017-08-10
Also published as: CN109070013A

Abstract

A reverse osmosis membrane (100) and a method of processing the same are described herein. The reverse osmosis membrane (100) includes a polymer material (102), a nonwoven fabric material (106), and a nanofiber material (104) between the polymer material (102) and the nonwoven fabric material (106). The method includes forming the nanofiber material (104) on the nonwoven fabric material (106), and forming the polymer material (102) on the nanofiber material (104).

Description

REVERSE OSMOSIS MEMBRANE AND METHOD OF PROCESSINGTHE SAME

Technical Field

The present disclosure relates to reverse osmosis membranes and methods of processing the same.

Background

Reverse osmosis is a water purification (e.g., filtering) process in which pressure is used to force water through a semipermeable membrane, which removes particles from the water. Reverse osmosis can be used, for instance, to convert salt water (e.g., sea water) and/or brackish water into clean drinking water by removing the salt and other effluent materials from the water. As an additional example, reverse osmosis can be used to remove potentially harmful contaminants, such as heavy metals and/or pesticide residues, from the water.

Existing reverse osmosis membranes, however, may operate at a relatively high pressure. That is, a relatively high pressure may be needed to force the water through the membranes currently being used in reverse osmosis processes. As a result, current reverse osmosis processes (e.g., reverse osmosis processes that use existing reverse osmosis membranes) can have a high energy consumption and/or high cost.

Further, reverse osmosis processes that use existing reverse osmosis membranes may produce large amounts and/or large concentrations of waste water, and/or may have a relatively low water recovery rate. For instance, existing reverse osmosis membranes may have a relatively low water flux, and as such reverse osmosis processes that use existing reverse osmosis membranes may produce a low amount of purified water relative to the initial amount of water that passes through the membrane.

Brief Description of the Drawings

Figure 1 illustrates an angled perspective view of the schematic structure of a reverse osmosis membrane in accordance with one or more embodiments of the present disclosure.

Figure 2 illustrates an image of a nanofiber material of a reverse osmosis membrane in accordance with one or more embodiments of the present disclosure.

Figure 3 illustrates an image of a polymer material and a nanofiber material of a reverse osmosis membrane in accordance with one or more embodiments of the present disclosure.

Detailed Description

A reverse osmosis membrane and a method of processing the same are described herein. For example, one or more embodiments include a polymer material, a nonwoven fabric material, and a nanofiber material between the polymer material and the nonwoven fabric material. As an additional example, one or more embodiments include forming a nanofiber material on a nonwoven fabric material, and forming a polymer material on the nanofiber material.

Reverse osmosis processes that use a reverse osmosis membrane in accordance with the present disclosure can be less costly and/or use less energy than reverse osmosis processes that use previous reverse osmosis membranes. Further, reverse osmosis processes that use a reverse osmosis membrane in accordance with the present disclosure may produce less waste water than reverse osmosis processes that use previous reverse osmosis membranes, and may have a higher water recovery rate than reverse osmosis processes that use previous reverse osmosis membranes. For example, a reverse osmosis membrane in accordance with the present disclosure can have higher water flux than previous reverse osmosis membranes, and as such reverse osmosis processes that use a reverse osmosis membrane in accordance with the present disclosure may be able to produce a greater amount of purified (e.g., filtered) water than reverse osmosis processes that use previous reverse osmosis membranes.

In the following detailed description, reference is made to the accompanying drawings that form a part hereof. The drawings show by way of illustration how one or more embodiments of the disclosure may be practiced.

These embodiments are described in sufficient detail to enable those of ordinary skill in the art to practice one or more embodiments of this disclosure. It is to be understood that other embodiments may be utilized and that mechanical, electrical, and/or process changes may be made without departing from the scope of the present disclosure.

As will be appreciated, elements shown in the various embodiments herein can be added, exchanged, combined, and/or eliminated so as to provide a number of additional embodiments of the present disclosure. The proportion and the relative scale of the elements provided in the figures are intended to illustrate the embodiments of the present disclosure, and should not be taken in a limiting sense.

The figures herein follow a numbering convention in which the first digit or digits correspond to the drawing figure number and the remaining digits identify an element or component in the drawing. Similar elements or components between different figures may be identified by the use of similar digits. For example, 104 may reference element “04” in Figure 1, and a similar element may be referenced as 204 in Figure 2.

As used herein, “a” or “anumber of” something can refer to one or more such things. For example, “anumber of fibers” can refer to one or more fibers.

Figure 1 illustrates an angled perspective view of the schematic structure of a reverse osmosis membrane 100 in accordance with one or more embodiments of the present disclosure. Reverse osmosis membrane 100 can be part of (e.g., used in) a reverse osmosis water purification (e.g., filtering) system. For instance, pressure can be used to force water through membrane 100, and membrane 100 can remove particles from the water as it flows through the membrane, as will be appreciated by one of skill in the art.

As an example, reverse osmosis membrane 100 can be used to remove potentially harmful contaminants, such as heavy metals (e.g., arsenic, mercury, lead, cadmium, etc. ) and/or pesticide residues, from the water. Further, membrane 100 can be part of a point-of-use water purification system, such as, for instance, a residential (e.g., domestic) water purification system used to filter the tap and/or drinking water of a residence. However, embodiments of the present disclosure are not limited to a particular type of use or application for membrane 100.

As shown in Figure 1, reverse osmosis membrane 100 can include a polymer material 102, a nonwoven fabric material 106, and a nanofiber material 104 between polymer material 102 and nonwoven fabric material 106. For example, nanofiber material 104 can be formed on nonwoven fabric material 106, and polymer material 102 can be formed on nanofiber material 104, as illustrated in Figure 1.

During a reverse osmosis water purification process that uses reverse osmosis membrane 100 (e.g. during which pressure is used to force water through membrane 100) , polymer material 102 can selectively separate contaminants, such as heavy metals and/or pesticide residues, for instance, from the water. Nanofiber material 104 and nonwoven fabric material 106 can provide mechanical support for polymer material 102.

Polymer material 102 can be a cross-linked polymer material. For example, polymer material 102 can be a cross-linked polyamide material. Further, polymer material 102 can be a thin material, as will be further described herein.

Nanofiber material 104 can be a nanofiber scaffold. For example, nanofiber material 104 can be a polysulfone material, a polyethersulfone material, a polyacrylonitrile material, a polyamide material, a polyvinylidene fluoride material, or a mixture thereof. Nanofiber material 104 can include a number of individual nanofibers, as will be further described herein (e.g., in connection with Figures 2 and 3) . Further, nanofiber material 104 can be a highly porous material (e.g., have high pore interconnectivity) , as will be further described herein.

Nanofiber material 104 can be formed on nonwoven fabric material 106 by, for example, electrospinning nanofiber material 104 on nonwoven fabric material 106. For instance, nanofiber material 104 can be formed on nonwoven fabric material 106 using electrospinning conditions of an applied voltage of 20 kilovolts, an 8 weighted percent polysulfone/N-methyl-2-pyrrolidone (NMP) solution, a flowrate of 30 microliters per minute, and a 15 centimeter distance between nonwoven fabric material 106 and the spinneret. However, embodiments of the present disclosure are not limited to particular electrospinning conditions.

Polymer material 102 can be formed on nanofiber material 104 using, for example, an interfacial polymerization process. The interfacial polymerization process can include, for instance, reacting polyfunctional amines with polyfunctional acid chlorides on the surface of nanofiber material 104 by spraying an amine monomer solution and an acid chloride monomer solution on the surface of nanofiber material 104. However, embodiments of the present disclosure are not limited to a particular interfacial polymerization process.

In contrast to reverse osmosis membranes of the present disclosure (e.g., membrane 100 illustrated in Figure 1) , previous reverse osmosis membranes may include a polymeric material (e.g., instead of a nanofiber material) between a polymer material and a nonwoven fabric material. For example, previous reverse osmosis membranes may include a nonwoven fabric material, a polymeric material (e.g., instead of a nanofiber material) on the nonwoven fabric material, and a polymer material on (e.g., supported by) the polymeric material.

The polymeric material of such previous reverse osmosis membranes, however, may be denser and/or less porous than a nanofiber material (e.g., nanofiber material 104) . For example, the polymeric material of such previous reverse osmosis membranes may have a thickness of 40-70 micrometers (μm) , and a porosity of less than 50％. In contrast, nanofiber material 104 of reverse osmosis membrane 100 can have a thickness of 10-50 μm, and a porosity of 60-80％. Further, each individual nanofiber of nanofiber material 104 can have a diameter of 50-200 nanometers (nm) .

As a result of nanofiber material 104 of reverse osmosis membrane 100 being less dense (e.g., thinner) and/or more porous than the polymeric material of previous reverse osmosis membranes, polymer material 102 and nonwoven fabric material 106 of membrane 100 can be thinner and/or more porous than the polymer material and nonwoven fabric material of previous reverse osmosis membranes. For example, the polymer material of such previous reverse osmosis membranes may have a thickness of 100-300 nm, while polymer material 102 of membrane 100 can have a thickness of 40-100 nm. For instance, in some embodiments, polymer material 102 can have a thickness of less than 50 nm. Further, the nonwoven fabric material of such previous reverse osmosis membranes may have a thickness of 100 μm and a porosity of 20-30％, while nonwoven fabric material 106 may have a thickness of 30-100 μm and a porosity of 30-50％.

Because polymer material 102, nanofiber material 104, and nonwoven fabric material 106 of reverse osmosis membrane 100 can be less dense (e.g., thinner) and/or more porous than the polymer material, polymeric material, and nonwoven fabric material, respectively, of previous reverse osmosis membranes, reverse osmosis membrane 100 can have a higher water flux than previous reverse osmosis membranes. For example, the water flux of reverse osmosis membrane 100 can be more than twice the water flux of previous reverse osmosis membranes.

Because the water flux of reverse osmosis membrane 100 can be higher than the water flux of previous reverse osmosis membranes, reverse osmosis membrane 100 may be able to produce a greater amount of purified (e.g., filtered) water than previous reverse osmosis membranes. For example, membrane 100 may produce less wastewater, and/or have a higher water recovery rate, than previous reverse osmosis membranes.

Further, because polymer material 102, nanofiber material 104, and nonwoven fabric material 106 of reverse osmosis membrane 100 can be less dense and/or more porous than the polymer material, polymeric material, and nonwoven fabric material, respectively, of previous reverse osmosis membranes, (e.g., because membrane 100 can have a higher water flux than previous reverse osmosis membranes) , membrane 100 can operate at a lower pressure than previous reverse osmosis membranes. For example, the amount of pressure needed to force water through membrane 100 can be less than the amount of pressure needed to force water through previous reverse osmosis membranes. As such, the operation of membrane 100 (e.g., during a reverse osmosis water purification process) can be less costly and/or use less energy than the operation of previous reverse osmosis membranes.

Figure 2 illustrates an image of a nanofiber material 204 of a reverse osmosis membrane in accordance with one or more embodiments of the present disclosure. The image shown in Figure 2 is a scanning electron microscope (SEM) image of nanofiber material 204.

Nanofiber material 204 can be, for example, nanofiber material 104 of reverse osmosis membrane 100 previously described in connection with Figure 1. For example, the image shown in Figure 2 can be a top view of the reverse osmosis membrane after nanofiber material 204 has been formed on the nonwoven fabric material of the membrane, but before the polymer material has been formed on nanofiber material 204.

Nanofiber material 204 can be a nanofiber scaffold, such as, for instance, a polysulfone material, a polyethersulfone material, a polyacrylonitrile material, a polyamide material, a polyvinylidene fluoride material, or a mixture thereof, as previously described herein (e.g., in connection with Figure 1) . As shown in Figure 2, nanofiber material 204 can include a number of individual nanofibers. Each individual nanofiber of nanofiber material 204 can have a diameter of 50-200 nm, for example. Further, nanofiber material 204 can have a thickness of 10-50 μm, and a porosity of 60-80％, for example. As such, nanofiber material 204 can be a highly porous material having a low density, as previously described herein.

Figure 3 illustrates an image of a polymer material 302 and a nanofiber material 304 of a reverse osmosis membrane in accordance with one or more embodiments of the present disclosure. The image shown in Figure 3 is a scanning electron microscope (SEM) image of polymer material 302 and nanofiber material 304.

Polymer material 302 and nanofiber material 304 can be, for example, polymer material 102 and nanofiber material 104, respectively, of reverse osmosis membrane 100 previously described in connection with Figure 1. For example, the image shown in Figure 3 can be a cross-sectional view of the reverse osmosis membrane after polymer material 302 has been formed on nanofiber material 304. Nanofiber material 304 can be a highly porous material having a low density, as previously described herein.

Polymer material 302 can be a cross-linked polymer material, such as, for instance, a cross-linked polyamide material, as previously described herein (e.g., in connection with Figure 1) . Further, polymer material 302 can have a thickness of 40-100 nm, as previously described herein. As such, polymer material 302 can be a thin, porous material, as previously described herein. Accordingly, the reverse osmosis membrane that includes polymer material 302 and nanofiber material 304 can have a high water flux and operate at a low pressure, as previously described herein.

Although specific embodiments have been illustrated and described herein, those of ordinary skill in the art will appreciate that any arrangement calculated to achieve the same techniques can be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments of the disclosure.

It is to be understood that the above description has been made in an illustrative fashion, and not a restrictive one. Combination of the above embodiments, and other embodiments not specifically described herein will be apparent to those of skill in the art upon reviewing the above description.

The scope of the various embodiments of the disclosure includes any other applications in which the above structures and methods are used. Therefore, the scope of various embodiments of the disclosure should be determined with reference to the appended claims, along with the full range of equivalents to which such claims are entitled.

In the foregoing Detailed Description, various features are grouped together in example embodiments illustrated in the figures for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the embodiments of the disclosure require more features than are expressly recited in each claim.

Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.

Claims

A reverse osmosis membrane, comprising:

a polymer material；

a nonwoven fabric material； and

a nanofiber material between the polymer material and the nonwoven fabric material.
The reverse osmosis membrane of claim 1, wherein the polymer material is a cross-linked polyamide material.
The reverse osmosis membrane of claim 1, wherein the nanofiber material is a nanofiber scaffold.
The reverse osmosis membrane of claim 1, wherein the nanofiber material is a polysulfone material.
The reverse osmosis membrane of claim 1, wherein the nanofiber material is a polyacrylonitrile material.
The reverse osmosis membrane of claim 1, wherein the nanofiber material is a polyethersulfone material.
The reverse osmosis membrane of claim 1, wherein the nanofiber material is a polyvinylidene fluoride material.
The reverse osmosis membrane of claim 1, wherein the nanofiber material is a polyamide material.
The reverse osmosis membrane of claim 1, wherein:

the nanofiber material has a thickness of 10-50 micrometers and a porosity of 60-80 ％； and

the nanofiber material includes a number of nanofibers, wherein each of the number of nanofibers has a diameter of 50-200 nanometers.
The reverse osmosis membrane of claim 1, wherein the polymer material has a thickness of 40-100 nanometers.