JP6526440B2 - Positive penetration treatment system - Google Patents

Description

  The present invention relates to a forward osmosis treatment system in which water is permeated from a low osmotic solution to a high osmotic solution using an osmotic pressure difference as a driving force.

In the forward osmosis treatment, solutions having different solute concentrations are brought into contact via a semipermeable membrane, and the osmotic pressure difference resulting from the solute concentration difference is used as a driving force to dilute solution from low solute concentration to concentrated solution with high solute concentration. Is a process of making
By means of forward osmosis, dilute solutions can be concentrated or concentrated solutions can be diluted. The generator can also be driven by the positive osmotic energy as the fluid penetrates from the dilute solution to the concentrated solution.
The forward osmosis process is common to the reverse osmosis process in that the semipermeable membrane is used to preferentially permeate water over solutes. However, in the forward osmosis treatment, the osmotic pressure difference is used to permeate water from the dilute solution side to the concentrated solution side, and in this point, the water is concentrated by pressurizing the concentrated solution side against the osmotic pressure difference. This is different from reverse osmosis treatment in which solution side permeates to dilute solution side. Therefore, even if the semipermeable membrane used in reverse osmosis treatment is applied as it is to forward osmosis treatment, it is not necessarily suitable for forward osmosis treatment.

  In reverse osmosis treatment, the concentrated solution is placed by placing the concentrated solution on one side of the membrane and the dilute solution on the other side, and pressurizing the concentrated solution side against the osmotic pressure difference of both solutions to concentrate the water. Permeate the dilute solution side from the side. Therefore, the reverse osmosis membrane is required to have a strength enough to withstand the pressure on the side of the concentrated solution. Therefore, it is necessary for the reverse osmosis membrane to secure the strength of the support layer without increasing the porosity of the support layer so much. As a result, the space in which the solute freely diffuses in the support layer is limited, but in the reverse osmosis membrane, the internal polarization does not occur in the support layer because the advancing direction of water permeability and the leakage direction of the salt are the same. The influence of the structure of (1) on the water permeability of the membrane (transmembrane flow rate) is not critical. Therefore, as the pressure applied to the concentrated solution increases, the water permeability of the membrane can be increased as well.

  On the other hand, in the forward osmosis membrane, the internal concentration polarization of the support layer greatly affects the water permeability of the membrane. In the forward osmosis treatment, a concentrated solution is placed on one side of the membrane and a dilute solution is placed on the other side, and water is permeated from the dilute solution side to the concentrated solution side using the osmotic pressure difference of both solutions as a driving force. . At this time, in order to increase the water permeability of the forward osmosis membrane, it is important to reduce the internal concentration polarization of the support layer as much as possible and to increase the effective osmotic pressure difference of the skin layer. If the space in which the solute freely diffuses in the support layer is limited, concentration polarization of the solute in the support layer is likely to occur, making it difficult to secure a sufficient amount of water permeability. Therefore, in the forward osmosis membrane, the support layer is a material having a high porosity so as not to limit the diffusion of the solute inside as much as possible, and also capable of securing a predetermined strength even if formed as such It is important to construct the film from the point of imparting the desired film performance.

  So far, various semipermeable membranes have been considered as membranes for forward osmosis treatment (forward osmosis membranes). For example, Patent Document 1 discloses a forward osmosis membrane in which a polyamide skin layer is laminated on a support layer of polyacrylonitrile, polyacrylonitrile-vinyl acetate copolymer, polysulfone or the like. Further, Patent Document 2 discloses a forward osmosis membrane in which a polyamide skin layer is laminated on an epoxy resin support layer, and Patent Document 3 discloses that a polyamide skin layer is laminated on a polyethylene terephthalate (PET) or polypropylene support layer. Forward osmosis membranes are disclosed.

Thus, although various forward osmosis membranes have been studied conventionally, there are still few forward osmosis membranes having high water permeability performance, and a high performance forward osmosis membrane is desired. Moreover, in the conventional polymer forward osmosis membrane, there are problems in the durability and heat resistance to an acid and an organic solvent, and the application range is limited.
On the other hand, Patent Document 4 proposes a forward osmosis membrane flow system using a forward osmosis membrane excellent in durability containing zeolite which is an inorganic material.
However, since the water permeability of the semipermeable membrane is extremely low, and durability and water permeability performance can not be compatible, there is a problem in practicality as a forward osmosis membrane flow system.

JP, 2012-519593, A JP, 2013-013888, A JP, 2013-502323, A JP, 2014-039915, A

  The present invention has been made in view of the conventional circumstances as described above, and an object of the present invention is to provide a forward osmosis treatment system having sufficient durability particularly to organic compounds and excellent in water permeability. It is to provide.

As a result of intensive studies to solve the above problems, the present inventors set a porous polyketone membrane as a support layer of a forward osmosis membrane, and a semipermeable membrane on one of the front and back surfaces or the inner and outer surfaces. By laminating the skin layer, the internal polarization of the support layer can be effectively reduced, the amount of water permeation can be increased, the durability to organic compounds is high, and a high amount of water permeation can be maintained as a forward osmosis treatment system And completed the present invention. That is, the present invention is as follows.
[1]
A semipermeable membrane unit,
First and second regions separated from each other by the semipermeable membrane unit;
A hypotonic solution supply unit for supplying a hypotonic solution to the first region;
A hyperosmotic solution supply unit for supplying a hyperosmotic solution to the second region;
Forward osmosis treatment that causes fluid movement through the semipermeable membrane unit from the first region to which the hypotonic solution is supplied to the second region to which the hypertonic solution is supplied A system,
A composite semipermeable membrane comprising: a polyketone porous membrane support layer comprising a copolymer of carbon monoxide and an olefin; and a semipermeable membrane skin layer disposed on the polyketone porous membrane support layer. Including
The porosity of the said polyketone porous membrane support layer is 60%-95%, The forward osmosis processing system characterized by the above-mentioned.
[2]
The forward osmosis treatment system according to [1], wherein the polyketone porous membrane support layer has a hollow fiber shape or a flat plate shape.
[3]
The forward osmosis treatment according to [1] or [2], wherein the semipermeable membrane skin layer comprises any of cellulose acetate, polyamide, polyvinyl alcohol / polypiperazinamide, sulfonated polyether sulfone, polypiperazinamide, polyimide system.
[4]
The forward osmosis treatment system according to any one of [1] to [3], wherein an organic compound is contained in at least one of the hypotonic solution and the hypertonic solution.
[5]
After passing water from the hypotonic solution to the hyperosmotic solution using the forward osmosis treatment system according to any one of [1] to [4], water is recovered from the hyperosmotic solution It is characterized by the method of water production.
[6]
A method for concentrating water-containing matter, comprising removing water from the water-containing matter using the forward osmosis treatment system according to any one of [1] to [4].
[7]
Using the forward osmosis treatment system according to any one of [1] to [4], the hyperosmotic solution is diluted with water permeating from the hypotonic solution to the hyperosmotic solution. How to dilute it.
[8]
Using the forward osmosis treatment system according to any one of [1] to [4], the flow rate of the high osmotic pressure solution is increased, and the water flow generator is driven with the increased flow rate to generate electric power. How to generate electricity.

  The forward osmosis treatment system of the present invention can suppress the internal concentration polarization of the support layer and can effectively increase the water permeability by using the polyketone porous membrane as the support layer of the semipermeable membrane. Furthermore, the durability to a low osmotic pressure fluid containing an organic compound can be enhanced, and it can be used as a stable forward osmosis treatment system with long-time performance. Therefore, the forward osmosis treatment system according to the present invention is, for example, desalination of seawater, desalination of brackish water, waste water treatment, concentration of various valuables, treatment of accompanying water in oil and gas drilling, different osmotic pressure 2 It can be suitably used for power generation using a liquid, dilution of sugars, fertilizers and refrigerants.

Sectional drawing which shows one structural example of the semipermeable membrane unit (hollow fiber module) used in the forward osmosis processing system of this invention. BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows typically one structural example of the regular osmosis processing system of this invention. Sectional drawing which shows the structure of the spinneret (cylindrical double tube) used in order to form a polyketone hollow fiber membrane. The figure which shows typically another structural example of the regular osmosis processing system of this invention.

Hereinafter, an example of the embodiment of the present invention will be described in detail. The following description relates to an example of the present invention, and the present invention is not limited thereto.
FIG. 1 is a view schematically showing a configuration example of a forward osmosis treatment system according to the present invention.
The forward osmosis processing system supplies a low osmotic pressure solution to the semipermeable membrane unit, and the first area A1 and the second area A2 separated from each other via the semipermeable membrane unit, and the first area A1. A hypotonic solution supply unit and a hypertonic solution supply unit for supplying the hypertonic solution to the second region A2 are provided.
The forward osmosis treatment system of the present invention utilizes forward osmosis. That is, in this forward osmosis treatment system, a low osmotic pressure solution is disposed on one surface side (first region A1) of the semipermeable membrane unit, and low osmotic pressure is applied to the other surface side (second region A2). Supply hypertonic solution with higher osmotic pressure than solution. Then, the fluid movement from the hypotonic solution side to the hyperosmotic solution side occurs, thereby increasing the flow rate on the hyperosmotic solution side.

FIG. 1 is a cross-sectional view schematically showing a configuration example of a semipermeable membrane unit used in the forward osmosis treatment system of the present invention. In this embodiment, although the case where a hollow fiber-shaped semipermeable membrane is used as a semipermeable membrane unit is described as an example, the present invention is not limited thereto, and a flat plate-shaped (flat membrane-shaped) semipermeable membrane is used. You can also.
As shown in FIG. 1, the hollow fiber membrane module 1 accommodates a hollow fiber membrane bundle 5 comprising a plurality of hollow fiber membranes (semipermeable membrane units) 5 a having openings at both ends, and the hollow fiber membrane bundle 5. A cylindrical case 2 and adhesion fixing layers 6 and 7 for adhering and fixing both ends of the hollow fiber membrane bundle 5 to the cylindrical case 2 are provided. The adhesion fixing layers 6 and 7 separate a region where the opening of the hollow fiber membrane 5a is exposed and a region outside the hollow fiber membrane 5a in communication with the above region. Here, although the case where the both ends side of hollow fiber membrane bundle 5 is made into the 1st field A1, and the outside of hollow fiber membrane 5a is made into the 2nd field A2 is mentioned as an example, and the 1st field A1 and The second area A2 may be reversed.

The cylindrical case 2 is provided with shell side conduits 3 and 4 for fluid flow in and out, and the shell side conduits 3 and 4 are provided to project outward from the cylindrical case 2.
At both ends of the cylindrical case 2, header parts 8 and 9 to which pipes are connected are arranged. The header parts 8 and 9 are provided with core side conduits 10 and 11 which become inlets and outlets of fluid, respectively.
Further, at both ends of the hollow fiber membrane bundle 5 housed in the cylindrical case 2, a bias regulating member (not shown) is disposed in order to reduce the bias of the density distribution of the plurality of hollow fiber membranes 5 a. It may be

FIG. 2: is a figure which shows typically one structural example of the regular osmosis processing system of this invention. In this forward osmosis processing system, a hollow fiber membrane module 1 as shown in FIG. 1 is used.
As shown in FIG. 2, the forward osmosis treatment system 100 is, for example, a forward osmosis treatment application, in the hollow fiber membrane module 1 from the shell side conduit 4 to the second region A2 outside the hollow fiber membrane 5a. The hypertonic solution is supplied, and the hypotonic solution is supplied from the header portion 8 to the first regions A1 which are both end sides of the hollow fiber membrane bundle 5.

The forward osmosis processing system 100 is connected to the shell side conduit 4 of the hollow fiber membrane module 1 and is connected to the supply piping 101 for supplying the hyperosmotic solution from the hyperosmotic pressure supply unit 110 and the shell side conduit 3 for circulation. And a circulation pipe 102 for feeding the liquid. The circulation pipe 102 is connected to the high osmotic pressure supply unit 110. Further, a pressure gauge or various valves (not shown) may be disposed in the middle of the supply pipe 101 and the circulation pipe 102.
In addition, the forward osmosis processing system 100 is connected to the core-side conduit 10 of the hollow fiber membrane module 1 and connected to the supply pipe 103 for supplying the low osmotic pressure solution from the low osmotic pressure supply unit 111 and the core-side conduit 11 And a circulation pipe 104 for delivering the hypotonic solution. The circulation pipe 104 is connected to the low osmotic pressure supply unit 111. Further, a pressure gauge or various valves (not shown) may be disposed in the middle of the supply pipe 103 and the circulation pipe 104.

  In the hollow fiber membrane module 1, the shell-side conduit 3 is connected to the circulation pipe 102, and the core-side conduit 10 of the header portion 8 is connected to the low osmotic pressure solution supply pipe 103. In addition, the shell side conduit 4 is connected to the supply pipe 101 of the hyperosmotic solution, and the core side conduit 11 of the header portion 9 is connected to the circulation pipe 104.

In such a forward osmosis treatment system 100, the hyperosmotic solution is the second of the hollow fiber membrane module 1 outside the hollow fiber membrane 5a of the hollow fiber membrane module 1 from the hypertonic pressure supply unit 110 through the supply pipe 101 and the shell side conduit 4. Is introduced into the area A2. The low osmotic pressure solution is introduced from the low osmotic pressure supply unit 111 through the supply piping 103 and the core-side conduit 10 into the first region A1 of the hollow fiber membrane module 1, which is the both end sides of the hollow fiber membrane bundle 5. .
The hypotonic solution supplied to the first region A1 on the header portion 8 flows inside the hollow fiber membrane 5a, but at this time, part of the solvent (for example, water) of the hypotonic solution is a hollow fiber It passes through the membrane 5a (semipermeable membrane) and moves to the second area A2 which is the outside of the hollow fiber membrane 5a. For example, the hyperosmotic solution flowing in the second area A2 is diluted by the solvent transferred to the second area A2. The hypotonic solution moved to the header 9 side is discharged from the opening of the end of the hollow fiber membrane 5 a to the first area A 1 in the header 9 and discharged to the circulation pipe 104 through the core side conduit 11. The diluted hypertonic solution is discharged from the second region A2 through the shell side conduit 3.
In addition, although the case where a hyperosmotic solution is diluted using the forward osmosis processing system 100 was demonstrated here, it is not limited to this, Another forward osmosis process can also be performed.
Further, in the above description, in the hollow fiber membrane module 1, both end sides of the hollow fiber membrane bundle 5 are taken as a first area A1 (low osmotic pressure side), and the outside of the hollow fiber membrane 5a is taken as a second area A2 (high Although the case of the osmotic pressure side was described as an example, the present invention is not limited to this, and both end sides of the hollow fiber membrane bundle 5 are used as a second region A2 (hyperosmotic side). The outer side of the first region A1 (hypotonic side) may be used.

The forward osmosis treatment system of the present invention is characterized in that a composite semipermeable membrane in which a semipermeable membrane skin layer is laminated on a polyketone porous membrane supporting layer is used as the semipermeable membrane unit. Specifically, in the present embodiment, as the hollow fiber membrane 5a (semipermeable membrane unit) in the hollow fiber membrane module 1 of FIG. 1, the inner surface or the outer surface of the polyketone hollow fiber membrane (polyketone porous membrane support layer) is The one in which the permeable skin layer is laminated is used.
In the semipermeable membrane, by using the polyketone porous membrane as the support layer and laminating the semipermeable membrane skin layer on either the front or back or the inner or outer surface, the internal polarization of the support layer is effectively reduced The amount can be increased, the durability to organic compounds is high, and a high water permeability can be maintained as a forward osmosis treatment system.

  The semipermeable membrane may be laminated with a cloth such as a woven fabric or a non-woven fabric, a membrane, etc. on one side or both sides of the composite semipermeable membrane for the purpose of suppressing performance degradation due to adsorption of contaminants.

  The polyketone polymer (hereinafter, polyketone) constituting the polyketone porous film is made of a copolymer of carbon monoxide and an olefin. By forming the support layer from polyketone, it is possible to form a support layer having a high porosity while securing strength. Also, in the past, there have been cases in which a reverse osmosis membrane requires a supporting substrate such as a non-woven fabric. However, since the polyketone support layer is highly self-supporting, such a support substrate is also unnecessary. This also enables thinning of the forward osmosis membrane. Furthermore, since the polyketone can be easily formed into an arbitrary shape such as flat plate (flat membrane) or hollow fiber, application to a conventionally known membrane module becomes easy.

  From the viewpoint of securing strength and forming a support layer having a high porosity, the polyketone support layer is 10% by mass or more and 100% by mass or less of polyketone which is a copolymer of carbon monoxide and one or more types of olefins. It is preferable to include in the ratio of Furthermore, the polyketone content of the polyketone support layer is preferably as high as possible. For example, 70 mass% or more is preferable, as for the polyketone content rate in a polyketone support layer, 80 mass% or more is more preferable, and 90 mass% or more is further more preferable. The content of the polyketone in the polyketone support layer is a method of dissolving and removing the polyketone with a solvent that dissolves only the polyketone among the components that constitute the support layer, and dissolving and removing the other than the polyketone with a solvent that dissolves other than the polyketone. It can be confirmed by the method.

  In the synthesis of the polyketone, as the olefin to be copolymerized with carbon monoxide, any kind of compound can be selected depending on the purpose. Examples of olefins include linear olefins such as ethylene, propylene, butene, hexene, octene and decene, alkenyl aromatic compounds such as styrene and α-methylstyrene, cyclopentene, norbornene, 5-methyl norbornene, tetracyclododecene, And cyclic olefins such as tricyclodecene, pentacyclopentadecene and pentacyclohexadecene, halogenated alkenes such as vinyl chloride and vinyl fluoride, acrylic esters such as ethyl acrylate and methyl methacrylate, and vinyl acetate. From the viewpoint of securing the strength of the polyketone support layer, the number of types of olefins to be copolymerized is preferably one to three, more preferably one to two, and still more preferably one.

The polyketone is preferably one having a repeating unit represented by the following formula (1).
-RC (= O)-(1)
[Wherein, R represents a hydrocarbon group having 2 to 20 carbon atoms which may have a substituent, and as the substituent, hydrogen, halogen, a hydroxyl group, an ether group, a primary amino group, a secondary amino group Tertiary amino group, quaternary ammonium group, sulfonic acid group, sulfonic acid ester group, carboxylic acid group, carboxylic acid ester group, phosphoric acid group, phosphoric acid group, phosphoric acid ester group, thiol group, sulfide group, alkoxysilyl group, and silanol It contains one or more functional groups selected from the group consisting of groups. ]
In the above formula (1), the repeating unit (that is, the ketone repeating unit) of the polyketone may be composed of only one type, or may be a combination of two or more types.
As for carbon number of hydrocarbon group R of said Formula (1), 2-8 are more preferable, 2-3 are more preferable, and 2 is the most preferable. In particular, it is preferable that the repeating unit which comprises a polyketone contains many 1-oxo trimethylene repeating units represented by following formula (2).
_{-CH 2 -CH 2 -C (= O} ) - ··· (2)

  From the viewpoint of securing the strength of the polyketone support layer, the proportion of 1-oxotrimethylene repeating units in repeating units constituting the polyketone is preferably 70 mol% or more, more preferably 90 mol% or more. More preferably, it is 95 mol% or more. The proportion of 1-oxotrimethylene repeating units may be 100 mol%. Here, 100 mol% means that no repeating unit other than 1-oxotrimethylene is observed except for polymer end groups in an analyzer such as known elemental analysis, NMR (nuclear magnetic resonance) and gas chromatography. Means Typically, the structure of the repeating units that make up the polyketone and the amount of each structure are confirmed by NMR.

  The support layer composed of polyketone has a porous structure, and solutes and water can pass through the internal through pores. In order to effectively suppress the internal concentration polarization in the support layer, it is preferable that pores having a larger pore diameter be formed in the support layer. From this point of view, the polyketone support layer has a maximum pore diameter of 50 nm or more It is preferable that the pore of is formed. The maximum pore size is measured by the bubble point method (based on ASTM F316-86 or JIS K3832). When a polyketone porous membrane with a maximum pore size of 50 nm or more is used as a support layer for a forward osmosis membrane, it is possible to reduce the internal concentration polarization in the support layer, so it is possible to improve the performance of the forward osmosis membrane Become. Since the internal concentration polarization is reduced as the maximum pore diameter is increased, the maximum pore diameter of the polyketone support layer is preferably 50 nm or more, more preferably 80 nm or more, and most preferably 130 nm or more. On the other hand, since it becomes difficult to support the active layer as the maximum pore size is increased and the pressure resistance may deteriorate, the maximum pore size of the polyketone support layer is preferably 2 μm or less, more preferably 1.5 μm or less The thickness is more preferably 1 μm or less, and most preferably 0.6 μm or less.

The porosity of the polyketone support layer is not particularly limited, but the higher the porosity, the easier it is for the solute to diffuse in the support layer, and the internal concentration polarization of the support layer is suppressed to increase the water permeability of the forward osmosis membrane. It will be possible. From this, the porosity of the polyketone support layer is preferably 60% to 95%, more preferably 70% to 95%, and still more preferably 80% to 95%. The porosity of the polyketone support layer (porous membrane) is calculated by the following equation (3).
Porosity (%) = (1-G / ρ / V) × 100 (3)
[Wherein, G is the mass (g) of the polyketone support layer, ρ is the mass average density (g / cm ³ ) of all the resins constituting the polyketone support layer, and V is the volume (cm of the polyketone support layer ³ ) ]

In the above formula (3), when the polyketone support layer is constituted by complexing a resin having a density different from that of the polyketone and the polyketone resin, the mass average density は corresponds to the constituent mass ratio to the density of each resin It is the sum of the values multiplied by. For example, when fibers having densities of AA and BB are respectively combined with a non-woven fabric composed of mass ratios of GA and GB, and a polyketone of density pp is mass ratio of Gp, the mass average density is It is represented by 4).
Mass average density = (= A · GA + ρB · GB + ρp · Gp) / (GA + GB + Gp) (4)

The porous membrane constituting the polyketone support layer may be a symmetrical membrane or an asymmetric membrane. When the polyketone porous membrane is an asymmetric membrane, it is preferable that the semipermeable membrane skin layer be provided on the dense surface of the polyketone porous membrane.
The shape of the polyketone support layer may be any shape such as flat (flat membrane) or hollow fiber. These polyketone support layers can be produced by known methods. For example, a polyketone is prepared by dissolving a polyketone in a solution containing a metal halide salt (eg, a zinc halide salt or an alkali metal halide salt) to prepare a polyketone dope, which is used as a film die or a double pipe orifice (see FIG. 3). The solution is discharged into a coagulating bath through the above to form a flat plate or hollow fiber. By further washing and drying, a polyketone porous membrane is obtained. In this case, for example, the porosity and pore diameter of the polyketone porous film can be changed by adjusting the polymer concentration in the dope and the temperature of the coagulation bath. In addition, the polyketone is dissolved in a good solvent (for example, resorcinol, hexafluoroisopropanol, m-cresol, o-chlorophenol, etc.). Then, the obtained solution can be cast on a substrate and immersed in a nonsolvent (for example, methanol, isopropanol, acetone, water, etc.), followed by washing and drying to obtain a polyketone porous film. In this case, for example, the porosity and pore diameter of the polyketone porous film can be changed by adjusting the mixing ratio between the polyketone and the good solvent and the type of non-solvent. The polyketone can be obtained, for example, by polymerizing carbon monoxide and an olefin using palladium or nickel as a catalyst. For the production of the polyketone support layer, for example, the methods described in JP-A-2002-348401 and JP-A-2-4431 can be referred to.

  A semipermeable membrane skin layer is formed on the polyketone support layer. The semipermeable membrane skin layer may be a known material used in conventional forward osmosis membranes and reverse osmosis membranes, and is a material having an ability to efficiently permeate water from the dilute solution side to the concentrated solution side using an osmotic pressure difference. Any skin layer may be used, and a semipermeable membrane generally used as a reverse osmosis (RO) membrane or a nanofilter (NF) can be used. For example, cellulose acetate, polyamide, polyvinyl alcohol / polypiperazineamide, sulfonated polyethersulfone, polypiperazineamide, and polyimide are preferably used. The semipermeable membrane may be selected in consideration of the resistance to a low osmotic pressure solution or a high osmotic pressure solution. In particular, a polyamide skin layer is preferably used in terms of the ease of forming a thin film on a polyketone hollow fiber membrane.

Furthermore, if the semipermeable membrane skin layer is a polyamide skin layer, it is preferably obtained by polymerizing a polyamine and a polycarboxylic acid derivative, and the amino group of the polyamine and the carbonyl group of the polycarboxylic acid derivative are preferably It is preferable that it condenses and an amide group is formed.
In this case, the polyamide skin layer can be obtained by polymerizing a polyamine and a polycarboxylic acid derivative. At this time, the polyamide skin layer can be bonded to the polyketone support layer by reacting the polyamine with the carbonyl group of the polyketone. For example, when the polyamide skin layer is formed by interfacial polymerization, the polyamide skin layer can be bonded to the polyketone support layer, whereby the polyamide skin layer can be firmly formed on the polyketone support layer. That is, the polyamide skin layer can be bonded to the polyketone support layer by interfacial polymerization.

  From the viewpoint of suppressing salt leakage as much as possible, the polyamide skin layer is preferably bonded to the polyketone support layer. The bonding includes chemical bonding and physical bonding. The chemical bond may be like a covalent bond. The covalent bond includes a C—C bond, a C = N bond, a bond via a pyrrole ring, and the like. On the other hand, as a physically bound state, intermolecular forces such as hydrogen bonding, van der Waals force, electrostatic attraction, hydrophobic interaction, etc., a state such as adsorption or adhesion bound without chemical bonding It can be mentioned. Preferably, the polyamine is in a state of being chemically bonded to the polyketone.

  The polyamide skin layer is preferably obtained by interfacial polymerization of a polyamine and a polycarboxylic acid derivative. Specifically, the polyamide skin layer is obtained by disposing a polyamine on a polyketone support layer, disposing a polycarboxylic acid derivative thereon, and interfacially polymerizing the polyamine and the polycarboxylic acid derivative. Is preferred. For example, an aqueous solution of polyamine is applied on a polyketone support layer, and a solution (polycarboxylic acid derivative-containing solution) in which a polycarboxylic acid derivative is dissolved in an organic solvent is further applied thereon to interfacially polymerize polyamine and polycarboxylic acid derivative. By doing this, a polyamide skin layer can be formed on the polyketone support layer. As the organic solvent which dissolves the polycarboxylic acid derivative, one having low solubility in water is preferable, and, for example, hydrocarbon solvents such as hexane, octane, cyclohexane and the like can be used. The pore diameter and thickness of the polyamide skin layer can be changed by adjusting the concentration and application amount of the polyamine aqueous solution and the polycarboxylic acid derivative-containing solution, whereby the separation ability of the skin layer can be adjusted. The formation of the polyamide skin layer may be referred to, for example, the methods described in JP-A-58-24303 and JP-A-1-180208.

  The polyamide skin layer can be obtained by polymerizing a polyamine and a polycarboxylic acid derivative. At this time, the polyamide skin layer can be bonded to the polyketone support layer by reacting the polyamine with the carbonyl group of the polyketone. For example, when the polyamide skin layer is formed by interfacial polymerization, the polyamide skin layer can be bonded to the polyketone support layer, whereby the polyamide skin layer can be firmly formed on the polyketone support layer. That is, the polyamide skin layer can be bonded to the polyketone support layer by interfacial polymerization.

The time from application of the polyamine aqueous solution on the polyketone support layer to application of the polycarboxylic acid derivative-containing solution may be adjusted to, for example, about 10 seconds to 180 seconds. After the aqueous solution of polyamine is applied onto the polyketone support layer and the polycarboxylic acid derivative-containing solution is applied thereon to form the skin layer, it is preferable to remove the excess polycarboxylic acid derivative-containing solution and to anneal. Annealing may be performed by a known method, and examples thereof include a method by heat treatment and a method of washing with hot water and then washing with an aqueous solution of sodium hypochlorite. Annealing can enhance the performance of the skin layer. When annealing is performed by heating, for example, the temperature may be in the range of 70 ° C. to 160 ° C. (preferably 80 ° C. to 130 ° C.) for 1 minute to 20 minutes (preferably 3 minutes to 15 minutes).
The thickness of the skin layer is not particularly limited, but is usually about 0.05 μm to 2 μm, preferably 0.05 μm to 1 μm. The thickness of the skin layer can be measured by observing the cross section with an SEM.

The forward osmosis treatment system of the present invention contains an organic compound in at least one of a hypotonic solution and a hypertonic solution.
When the low osmotic pressure solution contains an organic compound, examples of the organic compound include lower alcohols such as methanol, ethanol, 1-propanol and 2-propanol, higher alcohols having 6 or more carbon atoms, ethylene glycol, Industrial industries such as glycols such as propylene glycol, hydrocarbons such as pentane, hexane, decane, undecane and cyclooctane, aromatic hydrocarbons such as benzene, toluene and xylene, mineral oil, dimethylformamide, dimethylsulfoxide, dimethylacetamide and pyridine For example, common organic solvents that are used for the purpose of use and for research and research.
Since the polyketone constituting the support layer is stable to various organic compounds such as the above-mentioned organic compounds, the forward osmosis treatment system of the present invention should be used, for example, in waste water treatment, concentration and dehydration. Therefore, stable operation for a long time becomes possible.

The hyperosmotic solution in the case where the hypotonic solution contains an organic compound may have a relative osmotic pressure higher than that of the hypotonic solution, and its solute is not particularly limited, for example, sodium chloride, potassium chloride, Water-soluble salts such as sodium sulfate, ammonium chloride, ammonium sulfate and ammonium carbonate, alcohols such as methanol, ethanol, 1-propanol and 2-propanol, glycols such as ethylene glycol and propylene glycol, polyethylene oxide, propylene oxide And polymers thereof, copolymers of these polymers, and the like.
In particular, when a high viscosity solution such as a solution containing a polymer is used, the internal polarization can be increased by using a porous polyketone film having a high porosity and a low bending rate, and having a thin dense layer of a support layer. It can be effectively suppressed and the water permeability can be increased.

  When the hyperosmotic solution contains an organic compound, the organic compound is not particularly limited, but examples include solute components for increasing the relative osmotic pressure compared to the low osmotic pressure solution. Specific examples of the organic compound include, for example, saccharides such as glucose and fructose, fertilizers, refrigerants, alcohols such as methanol, ethanol, 1-propanol and 2-propanol, glycols such as ethylene glycol and propylene glycol, Examples thereof include polymers such as polyethylene oxide and propylene oxide, and copolymers of the aforementioned polymers.

  When water is recovered from the hyperosmotic solution, from the viewpoint of facilitating recovery, a solute is preferably used which allows solid-liquid separation or liquid-liquid separation of the solute and water depending on the temperature. As such a solute, for example, a temperature responsive polymer such as poly (N-isopropyl acrylamide) or a low molecular weight diol (eg, 1,2-propanediol, 1,3-propanediol or 1,2-ethanediol) And a random copolymer or a sequential copolymer.

Since the polyketone constituting the support layer is stable to various organic compounds such as the organic compounds described above, the forward osmosis treatment system of the present invention can be used, for example, when waste water treatment and concentration are performed. Stable operation for a long time is possible.
In particular, when a high viscosity solution such as a solution containing a polymer is used, the internal polarization can be increased by using a porous polyketone film having a high porosity and a low bending rate, and having a thin dense layer of a support layer. It can be effectively suppressed and the water permeability can be increased.

In addition, although the case where the hollow fiber-shaped semipermeable membrane unit was used was mentioned as the example and demonstrated in the description mentioned above, a flat-plate-like (flat-membrane-like) semipermeable membrane unit can also be used.
FIG. 4: is a figure which shows typically one structural example of the forward osmosis processing system of this invention which used the flat semi-permeable membrane unit.
This forward osmosis processing system includes a semipermeable membrane unit 120 including a flat semipermeable membrane 121 housed in a rectangular parallelepiped case, and a first area A1 and a first area A1 separated from each other via the semipermeable membrane 121. A low-osmotic solution supply unit 110 for supplying a low-osmotic solution to the first region A1; a hyper-osmotic solution supply unit 111 for supplying a hyper-osmotic solution to the second region A2; Equipped with
The forward osmosis processing system includes a supply pipe 101 for supplying the hyperosmotic solution from the hyperosmotic pressure supply unit 110, and a circulation pipe 102 for discharging the circulating fluid. The forward osmosis processing system further includes a supply pipe 103 for supplying the low osmotic pressure solution from the low osmotic pressure supply unit 111, and a circulation pipe 104 for supplying the low osmotic pressure solution. Furthermore, a pressure gauge or various valves (not shown) may be disposed in the middle of the supply pipes 101 and 103 and the circulation pipes 102 and 104.
More specifically, the semipermeable membrane unit may, for example, be a spiral type module as disclosed in JP-A-2014-23985.

[Method of water production]
The water production method of the present invention uses the above-mentioned forward osmosis treatment system of the present invention as a membrane separation means.
In the water production method of the present invention, using a forward osmosis membrane unit (semipermeable membrane unit), a low osmotic pressure solution is brought into contact with the semipermeable membrane skin layer side which is the separation active layer, Or contact the hyperosmotic solution on the semipermeable membrane skin layer side and the hypotonic solution on the opposite side. Then, water is allowed to permeate from the low osmotic pressure solution to the high osmotic pressure solution through the forward osmosis membrane unit, and then water is created by recovering the water from the high osmotic pressure solution.
The hypotonic solution may contain an inorganic solute.
The hypotonic solution and hyperosmotic solution may be subjected to pretreatment according to a known technique such as filtration to remove foreign matter such as fine particles before being treated with the forward osmosis treatment system of the present invention.
The temperature at the time of creating water is not particularly limited.

[Concentration method of water content]
The method for concentrating water content of the present invention uses the forward osmosis treatment system of the present invention.
In the method of the present invention for concentrating water, using a forward osmosis membrane unit (semipermeable membrane unit), a semipermeable membrane skin layer side is brought into contact with a low osmotic pressure solution, and the opposite side is brought into contact with a hyperosmotic solution. Alternatively, the hyperosmotic solution is brought into contact with the semipermeable membrane skin layer side, and the hypotonic solution is brought into contact with the opposite side. Then, water is made to permeate from the water-containing material to the osmotic hypertonic solution through the membrane, whereby the water-containing material is concentrated or dehydrated.

The water-containing material to be concentrated or dehydrated is not particularly limited as long as the water-containing material can be concentrated by the forward osmosis membrane unit, and any of an organic compound or an inorganic compound may be used.
For example, when a solution containing an organic compound is concentrated or dehydrated, examples of the organic compound include carboxylic acids such as acetic acid, acrylic acid, propionic acid, formic acid, lactic acid, oxalic acid, tartaric acid, and benzoic acid, and sulfones Acid, sulfinic acid, habituric acid, uric acid, phenol, enol, diketone type compound, thiophenol, imide, oxime, aromatic sulfonamide, organic acids such as primary and secondary nitro compounds, methanol, ethanol, 1- Lower alcohols such as propanol and 2-propanol, higher alcohols having 6 or more carbon atoms, glycols such as ethylene glycol and propylene glycol, hydrocarbons such as pentane, hexane, decane, undecane and cyclooctane, benzene, toluene, xylene Aromatic hydrocarbons such as Oil, ketones such as acetone and methyl isobutyl ketone, aldehydes such as acetaldehyde, ethers such as dioxane and tetrahydrofuran, amides such as dimethylformamide and N-methylpyrrolidone, organic compounds containing nitrogen such as pyridine, acetates, acrylics Esters such as acid esters and others, common organic solvents used for industrial and test research such as dimethyl sulfoxide, saccharides, fertilizers and enzymes can be mentioned.

  Further, as the organic matter of the water-containing organic matter, a high molecular compound which forms a mixture with water may be used. Examples of such a polymer compound include, for example, polyols such as polyethylene glycol and polyvinyl alcohol, polyamines, polysulfonic acids such as polysulfonic acids and polyacrylic acids, polycarboxylic acid esters such as polyacrylic esters, and grafting Examples thereof include modified polymer compounds obtained by modifying polymers by polymerization and the like, and copolymer polymer compounds obtained by copolymerization of a nonpolar monomer such as olefin and a polar monomer having a polar group such as a carboxyl group.

  The water-containing organic substance may be an azeotropic mixture such as an aqueous ethanol solution. Specifically, a mixture of alcohols and water such as ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, a mixture of esters such as ethyl acetate, ethyl acrylate and methyl methacrylate and water And mixtures of water with carboxylic acids such as formic acid, isobutyric acid and valeric acid, mixtures of water with aromatic organic compounds such as phenol and aniline, and mixtures of water with nitrogen-containing compounds such as acetonitrile and acrylonitrile. . By using the forward osmosis treatment system of the present invention, water can be selectively removed to concentrate water-containing organic matter more efficiently than concentration by distillation.

  Furthermore, the water-containing organic substance may be a mixture of water and a polymer, such as latex. Examples of the polymer used for the latex include polyvinyl acetate, polyvinyl alcohol, acrylic resin, polyolefin, olefin-polar monomer copolymer such as ethylene-vinyl alcohol copolymer, polystyrene, polyvinyl ether, polyamide, polyester, cellulose derivative Thermoplastic resins such as urea resin, phenol resin, epoxy resin, polyurethane, etc. Rubbers such as natural rubber, polyisoprene, butadiene copolymer such as polychloroprene and styrene-butadiene copolymer, etc. are mentioned. Be The latex may contain a surfactant.

Furthermore, examples of the water-containing organic substance include liquid foods such as fruit juice, liquors, and vinegar, liquid fertilizer, domestic wastewater, industrial wastewater, and an aqueous solution obtained by recovering volatile organic compounds (VOCs). Unlike liquid foods such as fruit juices, liquors and vinegar, as long as they are concentrated by a forward osmosis membrane (complex), unlike methods such as evaporation, they can be concentrated even at low temperatures, so concentration and reduction can be achieved without losing flavor. Particularly desirable in that it is acceptable.
In addition, since the forward osmosis membrane (complex) of the present invention has acid resistance, it can be used for concentration of organic acid from a mixture of water and organic acid such as acetic acid, removal of water in the system for promoting esterification reaction, etc. Can also be used effectively.
On the other hand, when concentrating or dehydrating a solution containing an inorganic compound, examples of the inorganic compound include metal particles, metal ions, anions such as sulfate ions and nitrate ions, and the like.

[Dilution method]
The dilution method of the present invention uses the forward osmosis treatment system of the present invention.
In the dilution method of the present invention, using a forward osmosis membrane unit (semipermeable membrane unit), the low osmotic pressure solution is brought into contact with the semipermeable membrane skin layer side which is the separation active layer, and the hyperosmotic solution is Contact or contact the hyperosmotic solution with the semipermeable membrane skin layer side and the hypotonic solution with the opposite side. Then, the hyperosmotic solution is diluted by permeating water from the hypotonic solution to the hyperosmotic solution through the forward osmosis membrane. The target to be diluted is not particularly limited, and examples include fertilizers and refrigerants.
The hypotonic solution and hyperosmotic solution may be subjected to pretreatment according to a known technique such as filtration prior to being treated with the forward osmosis treatment system of the present invention to remove foreign matter such as fine particles.
The temperature at which the dilution is performed is not particularly limited.

[Power generation method]
The power generation method of the present invention uses the forward osmosis treatment system of the present invention.
In the power generation method of the present invention, using a forward osmosis membrane unit (semipermeable membrane unit), the low osmotic pressure solution is brought into contact with the semipermeable membrane skin layer side which is the separation active layer, and the hyperosmotic solution is Contact or contact the hyperosmotic solution with the semipermeable membrane skin layer side and the hypotonic solution with the opposite side. Then, water is allowed to permeate from the low osmotic pressure solution to the high osmotic pressure solution through the forward osmosis membrane to increase the flow rate flowing to the high osmotic pressure solution and drive the water flow generator at the increased flow rate to generate power. .

Hereinafter, the present invention will be described in more detail by way of examples. In the following description, although a specific compound, a numerical value, etc. are mentioned and explained, the scope of the present invention is not limited to these.
The measuring method of each measured value used in the following examples is as follows.

(1) Maximum pore size: d
Measured according to JIS K3832 (Bubble Point Method) using a PMI palm polometer (model: CFP-1200AEX) and using PMI Garlic (surface tension = 15.6 dynes / cm) as the immersion liquid. did.

(2) Measurement of the average thickness of the membrane portion of the polyketone support layer (hollow fiber) and the semipermeable membrane skin layer (polyamide) The polyketone hollow fiber membrane on which the polyamide skin layer is laminated is frozen and cut to obtain hollow fiber cross section samples Was produced. This was observed using a scanning electron microscope (manufactured by Hitachi, Ltd., type S-4800) under conditions of an acceleration voltage of 1.0 kV, a WD 5 mm reference ± 0.7 mm, and an emission current setting of 10 ± 1 μA. The average thickness of the membrane portion of the polyketone hollow fiber membrane and the polyamide skin layer was measured from the photograph.

(3) Measurement of water permeability of the forward osmosis membrane flow system and reverse diffusion of salt when the hyperosmotic solution is saline solution: (Examples 1 to 3 and Comparative Examples 1 to 3)
Test solution A (pure water 30 L), test solution B (pure water 28.5 L and toluene 1) in the core side conduits (10 and 11 in FIG. 1) of the composite hollow fiber membrane module obtained in each example and comparative example. Connect a 50 L tank containing either .73 L, weight ratio 95: 5) or test solution C (29.85 L pure water and 0.19 L acetone, 99.5: 0.5 weight ratio) by piping The pump was used to circulate pure water. The tank is equipped with a conductivity meter, which can measure the transfer of salt to pure water. On the other hand, in the shell side conduits (3 and 4 in FIG. 1), a 50 L tank containing 20 L of saline having a concentration of 3.5 mass% was connected by piping, and the saline was circulated by a pump. The tank on the core side and the shell side are placed on the balance respectively, and the movement of water can be measured. The flow rate on the core side was simultaneously operated at 2.2 L / min and the flow rate on the shell side was 8.8 L / min, and the transfer amount of salt and the transfer amount of water were respectively measured. The amount of water permeation was calculated from the amount of movement of water, and the reverse diffusion of the salt was calculated from the amount of movement of salt.

(4) Water permeability of forward osmosis membrane flow system in the case where the hyperosmotic solution is a solution containing an organic compound: (Example 4 and Comparative Example 4)
A 50 L tank containing 30 L of pure water is connected by piping to the core side conduits (10 and 11 in FIG. 1) of the composite hollow fiber membrane modules obtained in each example and comparative example, and the pure water is circulated by a pump The On the other hand, a 50 L tank containing 20 L of an aqueous solution of polyethylene glycol 200 (manufactured by Tokyo Chemical Industry Co., Ltd.) having a concentration of 15 mass% is connected to the shell side conduits (3 and 4 in FIG. I did. The tank on the core side and the shell side are placed on the balance respectively, and the movement of water can be measured. The flow rate of the water was measured by simultaneously operating the flow rate on the core side at 2.2 L / min and the flow rate on the shell side at 8.8 L / min. The amount of water permeation was calculated from the amount of movement of water.
Furthermore, for polyethylene glycol leakage, 10 ml of the solution on the core side (pure water) after 10 tests is taken out on a glass plate, heated at 100 ° C. for 20 minutes to remove water, and the remaining substance is subjected to infrared spectroscopy The presence or absence of polyethylene glycol was evaluated using a photometer (manufactured by JASCO Corporation, type FT / IR-6200).

Example 1
A completely alternating copolymer of ethylene and carbon monoxide and having an intrinsic viscosity of 2.2 dl / g is added to a 65 wt% resorcin aqueous solution at a polymer concentration of 15 wt%, stirred and dissolved at 80 ° C for 2 hours, and defoamed To obtain a uniform and transparent dope.
Using the spinneret of the double pipe orifice 14 shown in FIG. 3 (outside diameter D ₁ : 0.6 mm, outside diameter D ₂ : 0.33 mm, inside and outside diameter D ₃ : 0.22 mm), The dope (dope viscosity: 100 poise) was simultaneously discharged from the outer annular orifice 12 and 25% by weight aqueous methanol solution from the inner circular orifice 13 into a coagulation bath of 40% aqueous methanol solution. It was pulled up and wound up while washing with water. The obtained hollow fiber membranes were cut into bundles of 70 cm in length. After further washing with water, solvent substitution was carried out with acetone, solvent substitution was further carried out with hexane, and drying was carried out at 50 ° C. The porosity of the polyketone hollow fiber membrane obtained in this manner was 78%, and the maximum pore size was 130 nm.
A polyketone having a structure shown in FIG. 1 by filling the above-mentioned 1,500 polyketone hollow fiber membranes in a 5 cm diameter, 50 cm long cylindrical plastic housing (cylindrical case) and fixing both ends with an adhesive. A hollow fiber membrane module was produced.

  Next, an aqueous solution (first monomer solution) containing 2.0% by weight of m-phenylenediamine, 4.0% by weight of camphorsulfonic acid, 2.0% by weight of triethylamine, and 0.25% by weight of sodium dodecyl sulfate, It packed in the core side (inner side of hollow fiber) of the above-mentioned module, and left still for 300 seconds. Thereafter, the solution was drained, air was passed through the core side, and the solution excessively attached to the hollow fiber membrane was removed. Then, a hexane solution (second monomer solution) of 0.15% by weight of trimesic acid chloride was fed to the core side of the module at a flow rate of 1.5 L / min for 120 seconds to carry out interfacial polymerization. The core side pressure and the shell side pressure at this time were both normal pressure, and the polymerization temperature was 25 ° C. Next, flow the nitrogen at 90 ° C. for 600 seconds on the core side of the module, and wash both the shell side and the core side with pure water to form a positive polyamide skin layer laminated on the inner surface of the polyketone hollow fiber membrane. An osmotic hollow fiber membrane module (semipermeable membrane unit) was produced.

The water permeation rate of this forward osmosis hollow fiber module was measured using test solution A (pure water 30 L), and it was 18.5 kg / (m ² × hr), and the reverse diffusion of the salt was 1.2 g / (m ² × hr).
Furthermore, the same measurement was performed nine times (a total of ten times) using the forward osmosis hollow fiber module after measurement. The tenth water permeability was 18.5 kg / (m ² × hr), and the reverse diffusion of the salt was 1.2 g / (m ² × hr). The module was disassembled and measured. The diameter of the polyketone hollow fiber membrane was 1080 μm, and the thickness of the membrane portion was 150 μm. The thickness of the polyamide skin layer was 0.8 μm.

As can be seen from the comparison with Comparative Example 1 described later, in Example 1 in which the polyketone hollow fiber membrane was used, it was possible to increase the amount of water permeation and to suppress the leakage of the salt. Even when an organic compound such as toluene is contained, the durability of the support layer does not lower the performance even after repeated use.
The diameter of the polyketone hollow fiber membrane measured by disassembling this module was 1080 μm, and the thickness of the membrane portion was 150 μm. The thickness of the polyamide skin layer was 0.8 μm. With the naked eye observation, no particular change was observed in the appearance of the support layer.

Example 2
The water permeation amount was measured using test liquid B (pure water 28.5 L and toluene 1.73 L, weight ratio 95: 5) using the polyketone forward osmosis hollow fiber membrane module manufactured by the same method as Example 1. As a result, the water permeability was 16.0 kg / (m ² × hr), and the reverse diffusion of the salt was 1.2 g / (m ² × hr). The 10th water permeability after repeated measurement in the same manner as in Example 1 is 16.0 kg / (m ² × hr), and the back diffusion of salt is 1.2 g / (m ² × hr). The Even when an organic compound such as toluene is contained, the durability of the support layer does not lower the performance even after repeated use.
The module was disassembled and measured. The diameter of the polyketone hollow fiber membrane was 1080 μm, and the thickness of the membrane portion was 150 μm. The thickness of the polyamide skin layer was 0.8 μm.

Example 3
Using a polyketone forward osmosis hollow fiber membrane module produced in the same manner as in Example 1, using the test solution C (29.85 L of pure water and 0.19 L of acetone, weight ratio 99.5: 0.5) When the water permeability was 15.4 kg / (m ² × hr), the reverse diffusion of the salt was 1.2 g / (m ² × hr). The 10th water permeability after repeated measurement in the same manner as in Example 1 is 15.4 kg / (m ² × hr), and the back diffusion of salt is 1.2 g / (m ² × hr). The Even when an organic compound such as acetone is contained, the durability of the support layer does not lower the performance even after repeated use.
The module was disassembled and measured. The diameter of the polyketone hollow fiber membrane was 1080 μm, and the thickness of the membrane portion was 150 μm. The thickness of the polyamide skin layer was 0.8 μm.

Comparative Example 1
Polyether sulfone (manufactured by BASF, trade name Ultrason) is added to N-methyl-2-pyrrolidone at a polymer concentration of 20% by weight, stirred and dissolved at 80 ° C. for 2 hours, and defoaming to form a uniform transparent dope I got
This 50 ° C. dope (dope viscosity: 60 poise) is introduced from the outer annular orifice 12 at the same time from the inner annular orifice 13 into the water coagulation bath using the double pipe orifice 14 (see FIG. 3) It discharged. It was pulled up and wound up while washing with water. The obtained hollow fiber membranes were cut into bundles of 70 cm in length, further washed with water, and then dried. The porosity of the polyethersulfone hollow fiber membrane obtained in this manner was 69%, and the maximum pore size was 80 nm.
A module was produced in the same manner as in Example 1 using the polyethersulfone hollow fiber membrane. Subsequently, the same interfacial polymerization as in Example 1 was performed to produce a forward osmosis hollow fiber membrane module in which a polyamide skin layer was laminated on the inner surface of the polyethersulfone hollow fiber membrane.

The water permeation rate of this forward osmosis hollow fiber module was measured using test solution A (pure water 30 L) was 7.5 kg / (m ² × hr), and the reverse diffusion of the salt was 21.0 g / (m ² × hr). The 10th water permeability after repeated measurement in the same manner as in Example 1 is 7.0 kg / (m ² × hr), and the back diffusion of salt is 21.2 g / (m ² × hr). The
This module was disassembled and measured. The diameter of the polyethersulfone hollow fiber membrane was 1000 μm, and the thickness of the membrane portion was 230 μm. The thickness of the polyamide skin layer was 0.8 μm.

Comparative Example 2
Using the polyethersulfone forward osmosis hollow fiber membrane module produced by the same method as Comparative Example 1, measure the water permeability using test solution B (pure water 28.5 L and toluene 1.73 L, weight ratio 95: 5) As a result, the water permeability was 7.2 kg / (m ² × hr), and the reverse diffusion of the salt was 30.0 g / (m ² × hr). Furthermore, the same measurement was performed nine times (a total of ten times) using the forward osmosis hollow fiber module after measurement. The tenth water permeability was 9.0 kg / (m ² × hr), and the reverse diffusion of the salt was 35.8 g / (m ² × hr).
The toluene sulfone support layer was deteriorated by toluene, and the performance tended to be deteriorated after prolonged use.
This module was disassembled and measured. The diameter of the polyethersulfone hollow fiber membrane was 1000 μm, and the thickness of the membrane portion was 230 μm. The thickness of the polyamide skin layer was 0.8 μm. When the cross section was observed with the naked eye, it appeared to be swelling.

Comparative Example 3
Using a polyethersulfone forward osmosis hollow fiber membrane module produced by the same method as Comparative Example 1, using test solution C (29.85 L of pure water and 0.19 L of acetone, weight ratio 99.5: 0.5) When the water permeability was measured, the water permeability was 7.0 kg / (m ² × hr), and the reverse diffusion of the salt was 35.0 g / (m ² × hr). Furthermore, the same measurement was performed nine times (a total of ten times) using the forward osmosis hollow fiber module after measurement. The tenth water permeability was 10.0 kg / (m ² × hr), and the reverse diffusion of the salt was 40.2 g / (m ² × hr). Acetone degraded the polyethersulfone supporting layer, and the performance tended to deteriorate after prolonged use.
This module was disassembled and measured. The diameter of the polyethersulfone hollow fiber membrane was 1000 μm, and the thickness of the membrane portion was 230 μm. The thickness of the polyamide skin layer was 0.8 μm. When the cross section was observed with the naked eye, it appeared to be swelling.
The above results are summarized in Table 1.

  As is clear from Table 1, in the forward osmosis membrane system of the present invention having a porous polyketone membrane as a support layer, a low osmotic pressure solution contains an organic compound which is corrosive to the support layer, such as toluene. Even if this is the case, it has been confirmed that high water permeability can be exhibited stably for a long time, and also the back diffusion of the salt from the hyperosmotic solution can be maintained at a low level.

Example 4
The water permeability of a polyketone forward osmosis hollow fiber membrane module produced by the same method as in Example 1 is 5.6 kg / (water) when water is used as a low osmotic pressure solution and polyethylene glycol 200 aqueous solution is used as a high osmotic pressure solution. m ² × hr).
Furthermore, the same measurement was performed nine times (a total of ten times) using the forward osmosis hollow fiber module after measurement. The 10th water permeability was 5.6 kg / (m ² × hr). No polyethylene glycol was detected from the solution on the core side (pure water) after the 10th test.
Even when an organic compound such as ethylene glycol is contained, the durability of the support layer does not lower the performance even after repeated use.
The diameter of the polyketone hollow fiber membrane measured by disassembling this module was 1080 μm, and the thickness of the membrane portion was 150 μm. The thickness of the polyamide skin layer was 0.8 μm. With the naked eye observation, no particular change was observed in the appearance of the support layer.

Comparative Example 4
The water permeation amount was measured in the same manner as in Example 4 using the polyethersulfone forward osmosis hollow fiber membrane module produced by the same method as Comparative Example 1.
The water permeability of this forward osmosis hollow fiber module was 2.2 kg / (m ² × hr). The 10th water permeability after repeated measurement in the same manner as in Example 1 was 4.0 kg / (m ² × hr). Polyethylene glycol was detected from the solution on the core side (pure water) after the 10th test.
Polyethylene glycol degrades the polyethersulfone supporting layer, and the performance tends to decrease after prolonged use.
The diameter of the polyethersulfone hollow fiber membrane measured by disassembling this module was 1000 μm, and the thickness of the membrane portion was 230 μm. The thickness of the polyamide skin layer was 0.8 μm. When the cross section was observed with the naked eye, it appeared to be swelling.
The above results are summarized in Table 2.

  As apparent from Table 2, in the forward osmosis membrane system according to the present invention having a porous polyketone membrane as a support layer, an organic compound which is corrosive to the support layer such as polyethylene glycol is contained in the hyperosmotic solution However, it has been confirmed that high permeability can be exhibited stably for a long time, and back diffusion of solute components from the hyperosmotic solution can be maintained at a low level.

As mentioned above, although embodiment of this invention was described, this invention is not limited to this, It can change suitably in the range which does not deviate from the meaning of invention.
For example, in the embodiment described above, the case where the polyketone porous membrane support layer has a hollow fiber shape has been described as an example, but the present invention is not limited to this, and film-like (plate-like) etc. The present invention is also applicable to the case of the shape of.

  The forward osmosis treatment system of the present invention has sufficient durability to organic compounds and is excellent in water permeability, desalination of seawater, desalination of brine, wastewater treatment, concentration of various valuables, Furthermore, it can be suitably used for treatment of accompanying water in oil and gas drilling, power generation using two liquids having different osmotic pressure, and dilution of sugars, fertilizers and refrigerants.

1: hollow fiber membrane module 2: cylindrical case 3: shell side conduit 4: shell side conduit 5: hollow fiber membrane bundle 5 a: hollow fiber membrane 6: adhesive fixing layer 7: adhesive fixing layer 8: header part 9: header part 10: core side conduit 11: core side conduit 12: annular orifice 13: circular orifice 14: double pipe orifice 100: positive osmosis treatment system 101: supply piping 102: circulation piping 103: supply piping 104: circulation piping 110: high Osmotic pressure supply part 111: Low osmotic pressure supply part A1: First area A2: Second area

Claims (8)

A semipermeable membrane unit,
First and second regions separated from each other by the semipermeable membrane unit;
A hypotonic solution supply unit for supplying a hypotonic solution to the first region;
A hyperosmotic solution supply unit for supplying a hyperosmotic solution to the second region;
A forward osmosis treatment system that causes fluid movement via the semipermeable membrane unit from the first area to which the hypotonic solution is supplied to the second area to which the hyperosmotic solution is supplied. And
A composite semipermeable membrane comprising: a polyketone porous membrane support layer comprising a copolymer of carbon monoxide and an olefin; and a semipermeable membrane skin layer disposed on the polyketone porous membrane support layer. Including
The porosity of the said polyketone porous membrane support layer is 60%-95%, The forward osmosis processing system characterized by the above-mentioned.   The forward osmosis treatment system according to claim 1, wherein the polyketone porous membrane support layer has a hollow fiber shape or a flat plate shape.   The forward osmosis treatment system according to claim 1 or 2, wherein the semipermeable membrane skin layer comprises any of cellulose acetate, polyamide, polyvinyl alcohol / polypiperazinamide, sulfonated polyethersulfone, polypiperazinamide, and polyimide.   The forward osmosis treatment system according to any one of claims 1 to 3, wherein at least one of the hypotonic solution and the hypertonic solution contains an organic compound.   The water is recovered from the hyperosmotic solution after passing water from the hypotonic solution to the hyperosmotic solution using the forward osmosis treatment system according to any one of claims 1 to 4. It is characterized by the method of water production.   A method for concentrating water-containing matter, comprising removing water from the water-containing matter using the forward osmosis treatment system according to any one of claims 1 to 4.   5. The hyperosmotic solution is diluted with water permeating the hypotonic solution to the hyperosmotic solution using the forward osmosis treatment system according to any one of claims 1 to 4. How to dilute it.   The forward osmosis treatment system according to any one of claims 1 to 4, wherein the flow rate of the high osmotic pressure solution is increased, and the water flow generator is driven to generate electric power at the increased flow rate. How to generate electricity.

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