TWI831355B - Preparation method and application of tubular pervaporation membrane - Google Patents

Abstract

The invention is a preparation method that adopts leaching method or interfacial polymerization method to generate a thin film selection layer on the inside of a general tubular membrane and upgrade it to a tubular pervaporation membrane. The tubular pervaporation membrane of the present invention is used in filtration equipment or systems to separate and obtain clean water from dirty water-containing mixed liquids.

Description

Preparation method and application of tubular pervaporation membrane

The invention relates to a method. A general tubular membrane prepares a thin film selection layer, which is upgraded to a tubular pervaporation membrane, and is used in filtration equipment or systems to separate and obtain clean water sources.

Known membrane separation technology is used in wastewater treatment, seawater desalination treatment, drinking water preparation, separation and purification of organic matter contained in food and water, drug release, gas and/or liquid purification, concentration and fractionation of liquid mixtures, and preparation of electronics Industrial processes such as ultrapure water required by industry show that membrane separation technology has a wide range of applications, rapid and efficient economic benefits. However, it is difficult for traditional tubular membranes to handle the separation of azeotropic and near-boiling systems.

In the past ten years, we have focused on pervaporation, which has the characteristics of high separation, simple operation, no pollution and low energy consumption. For example, Jianan University of Pharmacology and Science proposed a "preparation method for ion exchange membranes with pervaporation separation efficiency and a method for forming asymmetric membranes", which can be used in the pervaporation separation of aqueous organic mixtures such as ethanol-aqueous solutions and organic acids-water. The procedure to obtain Taiwan patent No. I368630 is documented.

In view of this, the inventor of this case proposed a preparation method. One of its main purposes is to use the leaching method or the interfacial polymerization method to generate a thin film selection layer on the inside of a general tubular membrane, so that the tubular membrane can be upgraded to a tubular pervaporation membrane. .

Secondly, one of the main purposes of the present invention is to apply the tubular pervaporation membrane in filtration equipment or systems to separate and obtain clean water from dirty water-containing mixed liquids.

To achieve the above objectives, the preparation method of the present invention includes: preparing a tubular membrane, which is composed of at least a two-layer structure with an outer layer surrounding the base film layer; distributing the solution inside the base film layer; and drying the solution Select layers for the membrane and attach the inside of the base membrane layer, making the tubular membrane a tubular pervaporation membrane.

In terms of the leaching method, the preparation method is specifically subdivided into: the solution is selected from polyvinyl alcohol (PVA), cellulose acetate (CA), polydimethylsiloxane (PDMS), carboxymethylcellulose (CMC), collagen, chitosan and chitin are mixed into a polymer solution. Among them, the tubular membrane receives a polymer solution, and the polymer solution is distributed inside the base film layer and dried by a heating device to form a hydrophilic and dense film selection layer. To distribute evenly, the polymer solution flows into the inside of the base film layer, rotate the tubular membrane for a period of time so that the polymer solution is distributed inside the base film layer, lay the tubular membrane flat and pour out the excess polymer solution. Can.

From the perspective of interfacial polymerization, the solution is selected from monomers containing amine functional groups and pure water to form an amine aqueous solution with a concentration of 0.1% to 5%. The tubular membrane is soaked in the amine aqueous solution and taken out, and the chlorine solution is mixed with The amine aqueous solution on the inside of the base film layer polymerizes into a hydrophilic and dense film selective layer and is dried by the heating equipment. Wherein, the chloride solution is selected from monomers containing chloride functional groups and an alkane solution to a concentration of 0.1% to 5%, so that the material of the film selection layer contains polyamide (Polyamide, PA for short) of organic polymers.

In this way, the present invention generates a thin film selection layer on the inside of a general tubular membrane through the immersion method or the interfacial polymerization method, thereby completing the preparation process of upgrading the tubular membrane to a tubular pervaporation membrane.

At the application level, the present invention proposes that the tubular pervaporation membrane prepared by the aforementioned method is used in filtration equipment or systems for aqueous mixed liquids. Specifically, the membrane selection layer separates the filtration device or system into a liquid phase chamber and a gas phase chamber. The water-containing mixed liquid passes through the liquid phase chamber, and the liquid water molecules adsorb to the surface of the hydrophilic film selective layer. Water molecules evaporated into gaseous state under low pressure can penetrate the membrane selection layer and diffuse to the other side. The water molecules in the selective layer of the desorbed film enter the gas phase chamber and condense into water.

In this way, the present invention applies the tubular pervaporation membrane to the filtration equipment or system to separate and obtain clean water from the dirty water-containing mixed liquid.

In order to make the purpose, features and advantages of the present invention easy to understand, one or more preferred embodiments are described in detail below with reference to the attached drawings.

Next, embodiments of the present case will be described with reference to the drawings. In the drawings, the same reference numerals are used to represent the same or similar structures or units. It is foreseeable that the described embodiments are only some examples of this case, not all the embodiments. Based on the above example, other embodiments can be deduced, or the structure can be modified or changed as necessary, which all fall within the scope of protection of this case.

In the following description, directional terms such as "upper", "lower", "left", "right", "front", "rear", "inside", "outside" and "side" only refer to the direction of the drawings. . The use of directional terms is for a better and clearer description and understanding of this case. It does not express or imply that the devices or components described must have specific orientations, structures, and operations, and therefore cannot be understood as limiting the technical content of this case.

Unless there are specific and clear specifications and limitations, in the following description, "installed", "connected", "connected" or "located on" should be understood in a broad sense, such as fixed connection, detachable connection, integral connection, mechanical connection , directly connected, indirectly connected or internally connected between two components. For those skilled in the field of this case, they can understand the specific meaning of the above terms in each embodiment and even this case based on common knowledge or experience.

Unless otherwise stated, in the following description, "plurality" means two or more.

As shown in Figures 1 to 4, the first set of processes of the preparation method of the present invention upgrades the general tubular membrane 10 to a tubular pervaporation membrane.

Usually, the preparation method of the present invention: first prepare the tubular membrane 10, which has the outer layer 11 surrounding the middle layer 12, and the middle layer 12 surrounds the base film layer 13, together forming a three-layer structure; distribute the solution on the base film layer 13 The solution is dried into a thin film selection layer 15 and attached to the inside of the base film layer 13, so that the tubular membrane 10 becomes a tubular pervaporation membrane.

Among them, the outer layer 11 is made of non-woven fabrics or non-woven fabrics made of organic polymers such as polypropylene (PP), polyethylene terephthalate (PET), nylon (Nylon) and polylactic acid (PLA). Cloth or woven fabric serves as the first supporting layer of the tubular membrane 10 .

Furthermore, the middle layer 12 is made of the same material as the outer layer 11 and becomes the second supporting layer of the tubular membrane 10 .

In addition, the base film layer 13 is made of polyvinylidene fluoride (PVDF), polyphenylene ether styrene (PES), polyarylene sulfide (PSU), polyacrylonitrile (PAN), acetate fiber (Acetate Fiber), polytetraethylene It is an organic polymer made of vinyl fluoride (PTFE), nylon (Nylon) and polyvinyl chloride (PVC). It achieves an asymmetric hole structure based on wet phase conversion method or electrospinning technology.

The solution is selected from the group consisting of polyvinyl alcohol (PVA), cellulose acetate (CA), polydimethylsiloxane (PDMS), carboxymethylcellulose (CMC), collagen, chitosan and chitin. One of the substances is prepared into a polymer solution 14. Let the polymer solution 14 flow into the tubular membrane 10 and be distributed inside the base film layer 13 . Alternatively, the tubular membrane 10 is allowed to stand for 15 to 60 minutes, and the excess polymer solution 14 is poured out (see Figure 2). To distribute evenly, rotate the tubular membrane 10 in the direction of arrow 16 (see Figure 3) for about 3 to 10 minutes, so that the polymer solution 14 is distributed inside the base membrane layer 13. Place the tubular membrane 10 into the heating device 17, and dry the tubular membrane 10 with a heat source 18 of 60°C to 80°C for about 30 to 60 minutes, so that the polymer solution 14 attached to the inside of the base film layer 13 becomes hydrophilic and dense. The thin film selection layer 15 is used, so the tubular membrane 10 is upgraded to a tubular pervaporation membrane.

As shown in Figures 5 to 7, the second set of processes of the preparation method of the present invention can upgrade the general tubular membrane 10 to a tubular pervaporation membrane.

The described preparation method: first prepare the tubular membrane 10, which is composed of an outer layer 11 surrounding the base film layer 13 to form a two-layer structure; distribute the solution inside the base film layer 13; dry the solution into a thin film selection layer 23 and attach it to the base film. The inside of the membrane layer 13 makes the tubular membrane 10 a tubular pervaporation membrane.

Wherein, the solution is selected from monomers containing amine functional groups and pure water to form an amine aqueous solution 21 with a concentration of 0.1% to 5%, and a container 20 is used to receive the required amine aqueous solution 21 for the tubular membrane 10 to soak 3 ~10 minutes before taking it out. The monomer containing the chloride functional group and the alkane solution are mixed into a chloride solution 22 with a concentration of 0.1% to 5%. The chloride solution 22 flows into the inside of the base film layer 13 and polymerizes with the amine aqueous solution 21 for 1 to 10 minutes. The heating device 17 is used for about The heat source 18 is dried at 60°C to 80°C for 10 to 50 minutes to obtain a hydrophilic and dense film selection layer 23, which can also upgrade the tubular membrane 10 to a tubular pervaporation membrane. In addition, the material of the thin film selection layer 23 contains an organic polymer such as polyamide (PA).

Whether it is the immersion method or the interfacial polymerization method, the thin film selection layer 15 or 23 is generated on the inside of the general tubular membrane 10 to complete the upgrade of the tubular pervaporation membrane.

In Figures 8 and 9, the tubular pervaporation membrane is used in filtration equipment (or systems) to separate and obtain clean water from aqueous mixed liquids. Among them, the filtration equipment (or system) uses a set of pipelines to connect a raw water tank 30, a filter pump 31 and a filter 32 together to form a circulating filtration (or separation) loop. The filtration equipment (or system) uses other pipelines to connect a heat pump 33, a first heat exchanger 34, a first circulation pump 35, a second heat exchanger 36, a second circulation pump 37 and a The 38 vacuum pumps are combined into a cyclic heat exchange circuit.

After being powered on, the heat pump 33 converts electrical energy into fluid heat energy, which is heat exchanged to the above-mentioned filtration (or separation) loop through the first heat exchanger 34 to cool down, and then returned to the heat pump 33 through the first circulation pump 35 to heat up, and then transmitted. to the first heat exchanger 34. The vacuum pump 38 draws the gas from the filter 32 to depressurize the filter 32 . The fluid in the second heat exchanger 36 absorbs the air temperature of the filter 32, exchanges heat to the heat pump 33 to cool down, returns to the second heat exchanger 36 via the second circulation pump 37, and absorbs the air temperature of the filter 32 again.

From a separation perspective, the water-containing mixed liquid in the raw water tank 30 receives the heat energy from the first heat exchanger 34 and is heated up when the filter pump 31 transports it to the filter 32 and returns to the raw water tank 30 . The tubular pervaporation membrane produced by the aforementioned method is used in the filter 32 to separate (filtrate) the aqueous mixed liquid.

The membrane selection layer 15 separates the filter 32 into a liquid phase chamber 40 and a gas phase chamber 43 . The aqueous mixed liquid passes through the liquid phase chamber 40, and the membrane selection layer 15 intercepts large particles of dirt 42. Based on the condition that the vapor partial pressure is less than the saturated vapor pressure, liquid water molecules 41 are adsorbed on the surface of the film selection layer 15 and vaporized into smaller water molecules 44 . Gaseous water molecules 44 penetrate into one side of the thin film selection layer 15 and diffuse to the other side along the width 24 direction with the concentration gradient ( _ΔC ) as the driving force. The water molecules 44 of the desorbed film selection layer 15 enter the gas phase chamber 43 , are heat exchanged in the second heat exchanger 36 , and are condensed into water from the gaseous state, and flow to other places through the vacuum pump 38 .

In this way, the present invention applies the tubular pervaporation membrane to the filtration equipment or system to separate and obtain clean water from the dirty water-containing mixed liquid.

Those skilled in the art can understand and make changes to the above embodiments without departing from the broad concept of the present invention. Therefore, this case is not limited to the specific embodiments disclosed in the specification. All modifications made based on the spirit and technical scope of this case should be covered and protected by the textual content defined in the scope of the patent application.

10: Tubular membrane 11: Outer layer 12:Middle layer 13: Basement membrane layer 14:Polymer solution 15, 23: Thin film selection layer 16:arrow 17:Heating equipment 18:Heat source 20:Container 21: Amine aqueous solution 22: Chlorine solution 24:Width 30:Original sink 31:Filter pump 32:Filter 33:Heat pump 34:First heat exchanger 35: First circulation pump 36: Second heat exchanger 37: Second circulation pump 38: Vacuum pump 40:Liquid phase chamber 41, 44: water molecules 42: Dirt 43:Gas phase chamber

Figures 1 to 4 show the first set of processes for preparing tubular pervaporation membranes according to the present invention. Figures 5 to 7 depict the second set of processes for preparing tubular pervaporation membranes according to the present invention. Figures 8 and 9 show the configuration diagram of tubular pervaporation membrane application, with partial enlargement of the use state.

15: Thin film selection layer

30:Original sink

31:Filter pump

32:Filter

33:Heat pump

34:First heat exchanger

35: First circulation pump

36: Second heat exchanger

37: Second circulation pump

38: Vacuum pump

Claims (7)

A method for preparing a tubular pervaporation membrane, including: preparing a tubular membrane (10), which consists of at least a two-layer structure with an outer layer (11) surrounding a base film layer (13); distributing a solution on the base film layer (13) Inside, the solution is selected from polyvinyl alcohol (PVA), cellulose acetate (CA), polydimethylsiloxane (PDMS), carboxymethylcellulose (CMC), chitosan and chitosan One of the substances is prepared into a polymer solution (14); and the solution is dried into a hydrophilic and dense film selection layer (15 or 23) and attached to the inside of the base film layer (13), so that the tubular membrane (10) becomes Tubular pervaporation membrane. The tubular pervaporation membrane preparation method as described in claim 1, wherein the tubular membrane (10) receives a polymer solution (14), and the polymer solution (14) is distributed inside the base film layer (13) to heat The equipment (17) dries the tubular membrane (10) so that the polymer solution (14) becomes a thin film selection layer (15) and adheres to the inside of the base film layer (13). The tubular pervaporation membrane preparation method as described in claim 2, wherein the polymer solution (14) flows into the inside of the base membrane layer (13), and the tubular membrane (10) is rotated for a period of time, so that the polymer solution (14) is distributed inside the base film layer (13), lay the tubular membrane (10) flat and pour out the excess polymer solution (14). The tubular pervaporation membrane preparation method as described in claim 1, wherein the solution is selected from monomers containing amine functional groups and pure water to form an amine aqueous solution (21) with a concentration of 0.1% to 5%. The formula membrane (10) is soaked in the amine aqueous solution (21) and taken out, allowing the chlorine solution (22) to contact the base membrane layer (13) The amine aqueous solution (21) inside is polymerized into a thin film selection layer (23), and the tubular membrane (10) is dried with a heating device (17), so that the thin film selection layer (23) is attached to the inside of the base film layer (13). The tubular pervaporation membrane preparation method as described in claim 4, wherein the chloride solution (22) is selected from a monomer containing a chlorine functional group and an alkane solution to be prepared at a concentration of 0.1% to 5%. An application of a tubular pervaporation membrane, in which the tubular pervaporation membrane prepared by any one of the methods of claims 1 to 5 is used in a filtration equipment or system for aqueous mixed liquids. The tubular pervaporation membrane application as described in claim 6, wherein the membrane selection layer (15) separates the filtration equipment or system into a liquid phase chamber (40) and a gas phase chamber (43), and the water-containing mixed liquid Through the liquid phase chamber (40), liquid water molecules (41) are adsorbed on the surface of the hydrophilic membrane selection layer (15), evaporate under low pressure into gaseous water molecules (44), and can penetrate the membrane selection layer (15) and diffuse to the other side. , the film selection layer (15) is desorbed and enters the gas phase chamber (43) to be condensed into water.

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