Evaluation methods and apparatus for forward osmosis membrane modules

Abstract

This invention relates to a method and apparatus for evaluating forward osmosis membrane modules, providing a practical method and apparatus capable of accurately measuring the performance of forward osmosis membranes. The invention provides a method for evaluating forward osmosis membrane modules. The method includes the following steps: in a forward osmosis membrane module having spaces separated by a forward osmosis membrane (which has a porous support and a separation functional layer laminated thereon), connecting the space on the separation functional layer side to a feed solution line, and connecting the space on the porous support side to a drive solution line; adjusting the physical pressure difference between the forward osmosis membranes to a constant value within a range greater than 0 kPa and less than 200 kPa, while simultaneously moving the solvent in the feed solution into the drive solution.

Description

Technical Field

[0001] This disclosure relates to evaluation methods and apparatus for forward osmosis membrane modules. Background Technology

[0002] In the selective separation of liquid mixtures, membrane separation technology is widely used in fields such as seawater desalination, ultrapure water production, wastewater treatment, and the food industry. Microfiltration membranes, ultrafiltration membranes, nanofiltration membranes, and reverse osmosis membranes are well-known examples of membranes used in membrane separation technology. In recent years, forward osmosis membranes, which can achieve high concentrations that are impossible with reverse osmosis membranes, have attracted considerable attention.

[0003] Forward osmosis membranes use the osmotic pressure difference generated by the separation functional layer as the driving force to move water from the feed solution to the driving solution through the principle of forward osmosis. Typically, the separation functional layer is mostly a thin film. Therefore, composite semi-permeable membranes, which are formed by laminating the separation functional layer on a porous support or non-woven fabric and providing physical support, are often used as forward osmosis membranes.

[0004] Forward osmosis membranes can be used in the form of a forward osmosis membrane module having an outer casing (module housing) and at least one forward osmosis membrane housed within the outer casing and separating spaces within the outer casing. Typically, the forward osmosis membrane module is connected to a feed solution line (which delivers a solvent-containing feed solution to one side of the spaces separated by the forward osmosis membrane) and a drive solution line (which delivers a drive solution with an osmotic pressure higher than the feed solution to the other side of the spaces) for evaluation and practical use.

[0005] For example, Patent Document 1 discloses a forward osmosis treatment method, which includes the following forward osmosis step: contacting a feed solution (raw solution) with a draw solution having an osmotic pressure higher than that of the feed solution through a semi-permeable membrane, thereby causing water contained in the feed solution to move into the draw solution. Patent Document 1 also discloses a forward osmosis treatment method in which, in the forward osmosis step, the physical pressure difference between the feed solution and the draw solution is adjusted to reduce the variation in the amount of water moving from the feed solution to the draw solution, i.e., the permeate flow rate.

[0006] Patent Document 2 describes a pressure-regulated forward osmosis device comprising: an inflow water (feed solution) storage tank; a drive solution storage tank for storing a high-concentration drive solution; a forward osmosis membrane module; a high-pressure pump installed on a pipe from the inflow water storage tank to the forward osmosis membrane module, which provides pressure to the forward osmosis membrane module by adjusting the pressure based on external control; and a back pressure valve installed on a concentrated water pipe discharged from the forward osmosis membrane module, which adjusts the pressure applied to the forward osmosis membrane module based on external control.

[0007] Patent Document 3 discloses an evaluation device for a permeation membrane module, which has a structure that separates a high-concentration section for supplying a high-concentration side solution (driving solution) from a low-concentration section for supplying a low-concentration side solution (feed solution) using a semi-permeable membrane. This evaluation device includes: a high-concentration side solution supply unit for the high-concentration section, a low-concentration side solution supply unit for the low-concentration section, an electrodialysis apparatus, a reverse osmosis membrane module, a first inlet path for introducing the effluent from the high-concentration section into the electrodialysis apparatus, a second inlet path for introducing the effluent from the low-concentration section into the reverse osmosis membrane module, a first return path for recirculating the concentrate discharged from the electrodialysis apparatus back into the high-concentration side solution supply unit, a second return path for recirculating the permeate discharged from the reverse osmosis membrane module back into the low-concentration side solution supply unit, a third inlet path for introducing the desalination solution discharged from the electrodialysis apparatus into the reverse osmosis membrane module, and a fourth inlet path for introducing the concentrate discharged from the reverse osmosis membrane module into the electrodialysis apparatus. Patent document 3 also describes a scheme to provide pressure adjustment units in the high-concentration side solution supply unit and the low-concentration side solution supply unit.

[0008] Patent document 4 describes a method for evaluating the water permeability of a filter membrane having a support layer and a separation functional layer. The method includes: immersing the filter membrane in an electrolyte; applying one or more alternating currents of various frequencies to the electrolyte by placing electrodes between the filter membrane and respectively disposed on one and the other sides in the water permeation direction; measuring the impedance between one and the other sides of the filter membrane while the alternating current is applied; applying pressure to the electrolyte from one or the other side of the filter membrane; and evaluating the water permeability of the filter membrane based on the mitigation characteristics of the impedance relative to the pressure corresponding to one or more specific frequencies.

[0009] Existing technical documents

[0010] Patent documents

[0011] Patent Document 1: International Publication No. 2020 / 022218

[0012] Patent Document 2: Korean Patent Publication No. 2013-0140370

[0013] Patent Document 3: Japanese Patent Application Publication No. 2016-16384

[0014] Patent Document 4: Japanese Patent Application Publication No. 2021-16811 Summary of the Invention

[0015] The problem that the invention aims to solve

[0016] In practical applications of forward osmosis, feed solution and drive solution are typically supplied to the forward osmosis membrane module via pumps or other delivery units. Therefore, regardless of the user's intentions, physical pressure is often temporarily generated at startup and during operation in the direction that causes the separation layer to peel off from the support membrane. The inventors discovered that, in cases where the physical durability of the forward osmosis membrane is low, the separation layer may peel off from the support membrane due to this physical pressure, or the separation layer may be damaged, potentially reducing membrane performance.

[0017] However, forward osmosis is a separation method driven by the osmotic pressure difference generated by the separation functional layer. Existing evaluation methods for forward osmosis membrane modules involve adjusting the physical pressures of the feed solution and drive solution in the forward osmosis membrane configuration equally. Therefore, existing evaluation methods cannot account for the impact of the physical pressure generated in the direction of peeling the separation functional layer from the support membrane during actual use, and thus cannot accurately evaluate the practical performance of forward osmosis membranes, including both the support membrane and the separation functional layer.

[0018] In view of the above-mentioned issues, one of the objectives of this disclosure is to provide a practical evaluation method and apparatus capable of accurately measuring the performance of forward osmosis membranes.

[0019] Methods for solving problems

[0020] Examples of embodiments of this disclosure are listed below. [1]

[0022] An evaluation method for a forward osmosis membrane module, which is an evaluation method for a forward osmosis membrane module having spaces separated by a forward osmosis membrane, wherein,

[0023] The aforementioned forward osmosis membrane has a support membrane with a porous support and a separation functional layer disposed on the porous support.

[0024] The above method includes the following steps:

[0025] The process of preparing a feed liquid line for feeding a feed liquid containing solvent into the aforementioned forward osmosis membrane module, and a drive solution line for feeding a drive solution with an osmotic pressure higher than that of the feed liquid into the aforementioned forward osmosis membrane module.

[0026] The steps of connecting the space on the separation functional layer side of the aforementioned forward osmosis membrane module to the aforementioned feed liquid line, and connecting the space on the porous support side to the aforementioned drive solution line; and

[0027] The process involves using the aforementioned forward osmosis membrane to allow the feed solution and the driving solution to flow in convection or co-flow, ensuring that the porous support side is positive and adjusting the physical pressure difference between the forward osmosis membranes to a constant range greater than 0 kPa and less than 200 kPa, while simultaneously moving the solvent in the feed solution into the driving solution. [2]

[0029] The method described in Project 1, further comprising, prior to the step of connecting the forward osmosis membrane module to the feed liquid line and the drive solution line:

[0030] The process of circulating the driving solution outside the forward osmosis membrane module while adjusting the physical pressure of the driving solution to be greater than 0 kPa and less than 200 kPa. [3]

[0032] The method described in Project 1 or 2, wherein the aforementioned physical pressure difference is 20 kPa to 100 kPa. [4]

[0034] The method as described in any one of items 1 to 3, wherein, prior to the step of connecting the aforementioned forward osmosis membrane module to the aforementioned feed liquid line and the aforementioned drive solution line, further comprises:

[0035] The process of adjusting the temperature difference between the above-mentioned raw material solution and the above-mentioned driving solution to within 10°C. [5]

[0037] The method as described in any one of items 1 to 4, wherein, prior to the step of connecting the aforementioned forward osmosis membrane module to the aforementioned feed liquid line and the aforementioned drive solution line, further comprises:

[0038] The adjustment process involves adjusting the flow rates of the feed solution and the driving solution so that, after connecting the forward osmosis membrane module, the difference between the residence time of the feed solution in the space on the separation functional layer side and the residence time of the driving solution in the space on the porous support side is within 20 seconds. [6]

[0040] The method as described in any one of items 1 to 5, wherein the solvent is water. [7]

[0042] The method described in Project 6, wherein the driving solution is supplied after the feed liquid is supplied to the forward osmosis membrane module. [8]

[0044] The method as described in any one of items 1 to 7, wherein the solution containing the feed liquid that has been supplied to and exited the forward osmosis membrane module is not returned to the feed liquid tank. [9]

[0046] As described in Project 8, the difference between the feed solution and the solution containing the feed solution after being supplied to and leaving the forward osmosis membrane module is measured, and at least one of the following parameters is selected: conductivity, refractive index, total organic carbon, chemical oxygen demand, biochemical oxygen demand, absorbance, and transmittance. This parameter is compared with the driving solution to evaluate the performance of the forward osmosis membrane.

[10]

[0048] The method described in Project 8 or 9, wherein the evaluation begins 10 seconds after the moment when the above-mentioned feed solution is first discharged from the above-mentioned forward osmosis membrane module.

[11]

[0050] The method of any one of items 1 to 10, wherein the driving solute contained in the driving solution is selected from at least one of inorganic salts and hydrophilic organic compounds.

[12]

[0052] The method described in Project 11, wherein the number-average molecular weight of the driving solute is 20 to 300.

[13]

[0054] The method described in Item 11 or 12, wherein the driving solute comprises a monovalent salt.

[14]

[0056] The method of any one of items 11 to 13, wherein the driving solute comprises an alcohol and / or acetonitrile having 1 to 4 carbon atoms.

[15]

[0058] The method as described in any one of items 11 to 14, wherein the concentration of the driving solute is 1% by mass or more, based on the total mass of the driving solution.

[16]

[0060] The method as described in any one of items 1 to 15, wherein the aforementioned forward osmosis membrane module is a hollow fiber membrane module.

[17]

[0062] An evaluation device for a forward osmosis membrane module having a forward osmosis membrane, comprising:

[0063] Raw material liquid storage tank;

[0064] The feed liquid pipeline connects the feed liquid tank to the forward osmosis membrane module.

[0065] The feed liquid supply unit supplies the feed liquid from the feed liquid tank to the forward osmosis membrane module through the feed liquid pipeline.

[0066] A drive solution tank stores a drive solution with an osmotic pressure higher than that of the aforementioned raw material solution;

[0067] A drive solution line is used to connect the drive solution tank to the forward osmosis membrane assembly.

[0068] The driving solution supply unit supplies the driving solution from the driving solution tank to the forward osmosis membrane module through the driving solution pipeline.

[0069] A pressure adjustment unit, which is installed on the aforementioned drive solution pipeline and is capable of physically pressurizing the drive solution before, during, and after the evaluation of the forward osmosis membrane module, is configured to maintain a constant physical pressure difference between the drive solution and the feed solution within a range greater than 0 kPa and less than 200 kPa via the forward osmosis membrane; and

[0070] A pressure sensor is installed on the aforementioned drive solution pipeline and is capable of measuring the physical pressure of the aforementioned drive solution.

[18]

[0072] The evaluation device described in Item 17 is an evaluation device for a forward osmosis membrane assembly having a forward osmosis membrane having a support membrane having a porous support and a separation functional layer disposed on the porous support.

[19]

[0074] The evaluation apparatus as described in item 17 or 18, wherein the driving solution line has a circulation structure that allows the driving solution to circulate outside the forward osmosis membrane assembly before being connected to the forward osmosis membrane assembly, and includes a driving solution bypass line that forms part of the circulation structure of the driving solution line and can be detached from the forward osmosis membrane assembly.

[20]

[0076] The evaluation apparatus as described in any one of items 17 to 19, wherein the feed liquid line has a circulation structure that allows the feed liquid to circulate outside the forward osmosis membrane module before being connected to the forward osmosis membrane module, and includes a feed liquid bypass line that forms part of the circulation structure of the feed liquid line and can be detached from the forward osmosis membrane module. [twenty one]

[0078] The evaluation device as described in any one of items 17 to 20, wherein at least one selected from a pressure adjustment unit and a temperature control unit is provided on the aforementioned raw material liquid pipeline. [twenty two]

[0080] The evaluation apparatus as described in any one of items 17 to 21, wherein a temperature control unit is further provided on the aforementioned drive solution pipeline. [twenty three]

[0082] The evaluation device as described in any one of items 17 to 22, wherein at least one of the group consisting of a pressure sensor, a temperature sensor, a flow sensor, a conductivity sensor, and a refractive index sensor is provided on the aforementioned raw material liquid pipeline. [twenty four]

[0084] The evaluation device as described in any one of items 17 to 23, wherein the driving solution pipeline is equipped with at least one selected from the group consisting of a temperature sensor, a flow sensor, a conductivity sensor, and a refractive index sensor.

[25]

[0086] The evaluation apparatus as described in any one of items 17 to 24, wherein a temperature control unit is provided in the raw material tank or the driving solution tank, or both.

[26]

[0088] The evaluation device as described in any one of items 17 to 25, wherein the raw material tank or the driving solution tank, or both, is equipped with at least one of the group consisting of a temperature sensor, a conductivity sensor and a refractive index sensor.

[27]

[0090] The evaluation apparatus as described in any one of items 17 to 26, wherein it comprises a plurality of the above-mentioned feed liquid lines and the above-mentioned drive solution lines, is capable of performing parallel evaluations on a plurality of forward osmosis membrane modules.

[28]

[0092] The evaluation device as described in any one of items 17 to 27 is configured in such a way that it monitors in real time the values ​​and times measured by the various sensors it possesses, stores them in a database, and is able to detect the difference between the values ​​of the aforementioned feed solution or the aforementioned driving solution or both during solution circulation before evaluation and the values ​​during the evaluation of the forward osmosis membrane module.

[29]

[0094] The evaluation device as described in any one of items 17 to 28, wherein...

[0095] The aforementioned raw material pipeline is equipped with a pressure regulating unit, a pressure sensor, and a flow sensor.

[0096] A flow sensor is further provided on the aforementioned drive solution pipeline.

[0097] The aforementioned evaluation device further includes a control device that is combined with the respective pressure sensor, flow sensor, and pressure adjustment unit on the aforementioned raw material liquid pipeline and the aforementioned driving solution pipeline, as well as the aforementioned raw material liquid supply unit and the aforementioned driving solution supply unit.

[0098] The control device is configured to compare the physical pressure difference, flow rate, and minimum flow rate of the raw material liquid and the driving solution in real time, and is configured to control the pressure adjustment unit, the raw material liquid supply unit, and the driving solution supply unit to maintain the desired physical pressure difference and the flow rate above the minimum flow rate.

[30]

[0100] The evaluation device described in Project 29 is configured to maintain the aforementioned real-time physical pressure difference within the aforementioned desired physical pressure difference ±1 kPa.

[31]

[0102] The evaluation device described in Item 29 or 30 is configured such that by inputting information on the cross-sectional areas of the feed solution supply section and the drive solution supply section within the forward osmosis membrane module, the desired physical pressure difference, and the desired minimum flow rate of the feed solution, the pressure and flow rate of the drive solution can be determined and controlled in advance before the evaluation of the forward osmosis membrane module.

[32]

[0104] The evaluation device as described in any one of items 29 to 31, wherein the control device includes a processor configured to perform proportional-integral-derivative control operations.

[33]

[0106] The evaluation apparatus as described in any one of items 17 to 32, wherein the driving solution pipeline and / or the driving solution tank further comprises a concentration adjustment unit capable of removing solvent from the driving solution, adding a high concentration of driving solution to the driving solution, or adding at least one of the driving solutes.

[34]

[0108] The evaluation device as described in any one of items 17 to 33, wherein the aforementioned forward osmosis membrane module is a hollow fiber membrane module.

[0109] The effects of the invention

[0110] According to this disclosure, a practical evaluation method and evaluation apparatus are provided that can accurately determine the performance of forward osmosis membranes. Attached Figure Description

[0111] Figure 1 This is a schematic diagram of the cross-section of the forward osmosis membrane in the evaluation method of this disclosure.

[0112] Figure 2 This is a schematic diagram illustrating an example of an evaluation method for a forward osmosis membrane assembly using the evaluation apparatus of this disclosure.

[0113] Figure 3 This is a schematic diagram illustrating an example of a hollow fiber membrane module.

[0114] Figure 4 This is a schematic diagram illustrating an example of an evaluation method for evaluating hollow fiber membrane modules using the evaluation apparatus of this disclosure. Detailed Implementation

[0115] Evaluation Methods for Forward Osmosis Membrane Modules

[0116] The evaluation method for the forward osmosis membrane module disclosed herein includes the following steps:

[0117] The separate processes for preparing the raw material liquid pipeline and the drive solution pipeline;

[0118] The process of connecting the forward osmosis membrane module to the feed solution line and the drive solution line;

[0119] The process of moving the solvent in the feed solution into the drive solution by means of a forward osmosis membrane, through convection or co-flow of the feed solution and the drive solution (hereinafter also referred to as the "evaluation process"). In this evaluation process, the porous support side is positive and the physical pressure difference between the forward osmosis membranes is adjusted to a constant range of greater than 0 kPa and less than 200 kPa, while the performance of the forward osmosis membrane module is evaluated.

[0120] In practical applications of forward osmosis, feed solution and drive solution are typically supplied to the forward osmosis membrane module via pumps or other delivery units. Therefore, regardless of the user's intentions, physical pressure is often temporarily generated at startup and during operation in the direction of peeling the separation layer from the support membrane. However, forward osmosis is a separation method driven by the osmotic pressure difference generated by the separation layer. Existing evaluation methods for forward osmosis membrane modules adjust the physical pressure of the feed solution and drive solution supplied through the forward osmosis membrane equally. Therefore, existing evaluation methods cannot account for the impact of the physical pressure generated in the direction of peeling the separation layer from the support membrane during practical use, and cannot accurately evaluate the practical performance of the forward osmosis membrane, including both the support membrane and the separation layer. In this regard, the evaluation method of this disclosure, by intentionally applying a specific physical pressure difference, can appropriately account for the impact of the physical pressure generated in the direction of peeling the separation layer from the porous support during the practical use of the forward osmosis membrane module. Therefore, the method of this disclosure can accurately evaluate the practical performance of the forward osmosis membrane, including both the support membrane and the separation layer.

[0121] Forward Osmosis Membrane Module

[0122] The forward osmosis membrane module to which the evaluation method of this disclosure is applied is a forward osmosis membrane module having a space separated by a forward osmosis membrane, wherein the forward osmosis membrane has a support membrane having a porous support and a separation functional layer disposed on the porous support. The space within the forward osmosis membrane module has a space on the porous support side and a space on the separation functional layer side. The forward osmosis membrane module may have an outer casing (module housing) for housing the forward osmosis membrane.

[0123] The forward osmosis membrane comprises: a support membrane having a porous support, and a separation functional layer disposed on the porous support. The support membrane can be a composite of a substrate and a porous support, preferably without a substrate, and more preferably composed only of a porous support. When the support membrane does not have a substrate or is composed only of a porous support, the solution diffuses easily in the support membrane, thus easily maintaining a higher osmotic pressure between the forward osmosis membranes. From this perspective, the forward osmosis membrane tends to have increased water permeability. However, the forward osmosis membrane has lower mechanical strength and the separation functional layer tends to peel off more easily from the porous support, thus the evaluation method of this disclosure can be performed more significantly.

[0124] The substrate preferably provides strength to the porous support and / or separation layer and is porous to allow water to pass through. The substrate typically does not have a separation function, but it may be capable of separating solid substances such as particles. Examples of substrate materials include polyesters, polyamides, polyolefins, or mixtures and copolymers thereof. Examples of substrate forms include woven fabrics, nonwoven fabrics, mesh screens, and foamed sintered sheets. The substrate is typically a porous body with a pore size larger than that of the porous support and separation layer. The pore size of the substrate is typically around 0.1 μm to 100 μm, and is more commonly evaluated by basis weight and air permeability, with a basis weight of 20 g / m³. 2 ~150g / m 2 Around 0.5 cc / (cm²) was measured using the Fraser method (JIS L1096). 2 ×sec)~30cc / (cm 2 Approximately (×sec). In this disclosure, the support film preferably does not have these substrates.

[0125] The porous support provides strength to the separation layer. While it can separate solid substances such as particles, it preferably does not substantially separate solutes such as ions. Here, "not substantially separating solutes such as ions" means that the separation function exhibited by the porous support is lower than that exhibited by the separation layer in the separation of solutes such as ions.

[0126] The material for the porous support is preferably a resin, particularly a thermoplastic resin. A thermoplastic resin is formed from chain polymers and refers to a resin that exhibits the property of deforming or flowing under external force when heated. Examples of thermoplastic resins include homopolymers or copolymers such as polysulfone, polyethersulfone, polyvinylidene fluoride, polyketone, polyamide, polyester, cellulose polymers, vinyl polymers, polyphenylene sulfide, polyphenylene sulfone, polyphenylene sulfone, and polyphenylene ether. Examples of cellulose polymers include cellulose acetate and cellulose nitrate. Examples of vinyl polymers include polyethylene, polypropylene, polyvinyl chloride, chlorinated polyvinyl chloride, polyacrylonitrile, and polyvinyl alcohol. Derivatives of these polymers having arbitrary functional groups in their main chain, side chains, or terminals can also be used as thermoplastic resins. A thermoplastic resin can be used alone or in blends of two or more.

[0127] When the support membrane is a composite of a substrate and a porous support, the thickness of the porous support is preferably 0.02 mm to 0.10 mm, considering both water permeation resistance and strength. When the support membrane is composed solely of a porous support, the thickness of the porous support is preferably 0.02 mm to 3.00 mm, considering strength; more preferably 0.10 mm to 1.00 mm, and even more preferably 0.15 mm to 0.50 mm, considering both water permeation resistance and strength. When the support membrane is composed solely of a porous support, the porous support is preferably in the form of a membrane, a tubular structure, or a hollow fiber, or in a form formed by chemical or physical deformation. The porous support is preferably hollow fiber. In the case of a hollow fiber structure, when manufacturing the assembly, compared to a sheet-like membrane, the feed solution and driving solution are more easily and uniformly distributed on each membrane surface, allowing for greater enjoyment of the advantage of less evaluation deviation of the present invention, and because a larger membrane area can be accommodated in a smaller space, the size of the evaluation device can be reduced.

[0128] The separation layer is disposed on the porous support of the supporting membrane and essentially performs the function of solute separation in a forward osmosis membrane. More specifically, it separates dissolved solutes such as ions from the solvent in the feed solution. The composition and thickness of the separation layer can be set according to the intended use of the forward osmosis membrane.

[0129] The materials for separating the functional layers can be, for example, polymers, inorganic materials, and organic-inorganic hybrid materials, as well as materials in which any inorganic or organic compounds are dispersed or contained. One material for separating the functional layers can be used alone, or two or more materials can be used in combination.

[0130] A separation layer of a polymer is a membrane that preferentially allows solvents to pass through while blocking solutes, and thus possesses substantial separation properties. Examples of separation layers for polymers include polyamides, polyvinyl alcohol, piperazine amides, sulfonated polyethersulfones, polypiperazine amides, and polyimides, as well as composites thereof. From the perspective of balancing separation functionality and solvent permeability, polyamides are a suitable material for the separation layer.

[0131] In a forward osmosis membrane module, the forward osmosis membrane can be one or more sheets. More specifically, examples of forward osmosis membrane module forms include a flat-plate module with planar forward osmosis membranes, a spiral-type module in which the planar forward osmosis membranes are arranged in a vortex shape around a perforated water collection pipe as an axis, and a hollow fiber membrane module in which hollow fiber-shaped forward osmosis membranes are bundled together. A hollow fiber membrane module is preferred. In the case of a hollow fiber membrane module, compared to a sheet-type membrane module, the feed solution and driving solution are more easily and uniformly distributed on each membrane surface during module manufacturing, allowing for greater enjoyment of the advantage of lower evaluation deviation of the present invention. Furthermore, because a larger membrane area can be accommodated in a smaller space, the size of the evaluation device can be reduced.

[0132] In hollow fiber membrane modules, the bundles of hollow fiber membranes are typically fixed within the module housing using a bonding resin, thereby isolating the space on the porous support side from the space on the separation functional layer side. The module housing has a feed liquid inlet for introducing the feed liquid, a feed liquid outlet for recovering the feed liquid, a drive solution inlet for introducing the drive solution, and a drive solution outlet for recovering the drive solution. The size and shape of the module housing are not particularly limited; for example, a cylindrical housing with a diameter of 5 mm to 500 mm and a length of 20 mm to 10,000 mm can be used. As the bonding resin, for example, urethane-based and epoxy-based bonding resins can be used.

[0133] <Preparation Process>

[0134] The evaluation method for forward osmosis membrane modules disclosed herein includes steps of preparing a feed solution line for supplying a solvent-containing feed solution to the forward osmosis membrane module and a drive solution line for supplying a drive solution with an osmotic pressure higher than that of the feed solution to the forward osmosis membrane module. Preferably, the feed solution line can recover and circulate the feed solution from the forward osmosis membrane module, and the drive solution line can recover and circulate the drive solution from the forward osmosis membrane module. Recovering and circulating each solution from the forward osmosis membrane module reduces the amount of each solution used, making it economical. More preferably, the feed solution line can circulate the feed solution outside the forward osmosis membrane module before being connected to it, and more preferably, the drive solution line can circulate the drive solution outside the forward osmosis membrane module before being connected to it. For details regarding the structure of the feed solution line and the drive solution line, please refer to the "Evaluation Apparatus for Forward Osmosis Membrane Modules" section described later. By circulating each solution outside the forward osmosis membrane module, the adjustment steps described later are easier to perform, and the evaluation accuracy can be improved from the beginning of the evaluation.

[0135] The feed solution contains a solvent. The feed solution may or may not contain solutes such as ions that are the target for separation. Water is the preferred solvent. If water is used, there is less risk of damage to the membrane beyond its tolerance, thus allowing for safer evaluation and increasing the range of options for forward osmosis membrane modules to be evaluated. Pure water is a more preferred feed solution.

[0136] The driving solution is a solution with an osmotic pressure higher than that of the feed solution. Compared to the feed solution containing the target substance being separated or concentrated in actual use, the driving solution exhibits a high osmotic pressure and has the function of causing the solvent to move from the feed solution through the forward osmosis membrane. The driving solution contains a high concentration of driving solute, thereby having a high osmotic pressure. Based on the total mass of the driving solution, the concentration of the driving solute is preferably 1% by mass or more. As a result, the solvent can easily and moderately permeate the separation functional layer, the evaluation time can be shortened, and the detection accuracy is good due to the high initial concentration. The concentration of the driving solute can more preferably be 1% by mass or more and 10% by mass or less, and even more preferably 1% by mass or more and 5% by mass or less.

[0137] The driving solute contained in the driving solution is preferably selected from at least one of inorganic salts and hydrophilic organic compounds. Examples of inorganic salts include alkali metal salts, alkaline earth metal salts, and ammonium salts. Examples of hydrophilic organic compounds include sugars, monools, glycols, and water-soluble polymers.

[0138] Examples of alkali metal salts include sodium chloride, potassium chloride, sodium sulfate, sodium thiosulfate, and sodium sulfite. Examples of alkaline earth metal salts include magnesium chloride, calcium chloride, and magnesium sulfate. Examples of ammonium salts include ammonium chloride, ammonium sulfate, and ammonium carbonate. Examples of sugars include common sugars such as sucrose, fructose, and glucose, as well as special sugars such as oligosaccharides and rare sugars. Examples of monools include methanol, ethanol, 1-propanol, and 2-propanol. Examples of diols include ethylene glycol and propylene glycol. Examples of water-soluble polymers include polyethylene oxide and polypropylene oxide, as well as copolymers of ethylene oxide and propylene oxide. From the perspective of easy and moderate permeation of the separation functional layer by the solvent and shortening the evaluation time, the number-average molecular weight of the driving solute is preferably 20 to 300. Furthermore, from the perspective of easy detection by conductivity and / or refractive index, it is also preferable that the driving solute contains a monovalent salt. From the same perspective, it is also preferred that the driving solute comprises an alcohol and / or acetonitrile having 1 to 4 carbon atoms.

[0139] <Adjusting the process>

[0140] The evaluation method for forward osmosis membrane modules disclosed herein may include an adjustment step prior to the connection process, in which the physical parameters of the feed solution and / or drive solution supplied to the forward osmosis membrane module are adjusted. Examples of physical parameters include the physical pressure, temperature, and flow rate of the feed solution and / or drive solution. The adjustment step is preferred as it shortens the evaluation time and yields more accurate evaluation results.

[0141] The method disclosed herein may further include, for example, a step prior to the connection process, adjusting the physical pressure of the drive solution to be greater than 0 kPa and less than 200 kPa while circulating the drive solution outside the forward osmosis membrane module. By pre-adjusting the physical pressure of the drive solution before connecting the drive solution line to the forward osmosis membrane module, the evaluation results of the forward osmosis membrane module can be more stable, and evaluations can be performed with good accuracy in a shorter time. From the perspective of performing evaluations with good accuracy in a shorter time, the physical pressure of the drive solution is preferably adjusted to 5 kPa to 200 kPa, more preferably 10 kPa to 200 kPa, further preferably 15 kPa to 150 kPa, and particularly preferably 20 kPa to 100 kPa before the connection process.

[0142] The method disclosed herein preferably includes, for example, a step of adjusting the temperature difference between the feed solution and the drive solution to within 10°C before the connection process. More preferably, the temperature difference is within 5°C, further preferably within 3°C, and even more preferably within 1°C. By adjusting the temperature difference between the feed solution and the drive solution before the connection process, individual differences in the ease of cooling or heating of the feed solution and drive solution caused by the forward osmosis membrane module can be taken into account. Furthermore, since the osmotic pressure of the feed solution and drive solution can be maintained more consistently, the permeability and salt back diffusion values ​​can be stabilized, resulting in more stable evaluation results for the forward osmosis membrane module and allowing for more accurate evaluation in a shorter time. The temperature adjustment of the feed solution can be performed while circulating the feed solution outside the forward osmosis membrane module. Similarly, the temperature adjustment of the drive solution can be performed while circulating the drive solution outside the forward osmosis membrane module. The temperatures of the feed solution and drive solution can be ambient temperature, for example, around 25±5°C.

[0143] The method disclosed herein preferably includes, for example, a step of adjusting the flow rates of the feed solution and the drive solution before the connection step. In the flow rate adjustment step, it is preferable to pre-adjust the flow rates of the feed solution and the drive solution before the connection step, so that the difference between the residence time of the feed solution in the space on the separation functional layer side and the residence time of the drive solution in the space on the porous support side after the connection of the forward osmosis membrane module is within 20 seconds. The residence time difference is adjusted more preferably to within 15 seconds, further preferably within 10 seconds, even more preferably within 5 seconds, and particularly preferably within 1 second. By setting the residence time after connection and pre-adjusting the flow rate before connection, individual differences in the forward osmosis membrane module can be taken into account, resulting in more stable evaluation results and accurate evaluation within a shorter time. Furthermore, by shortening the residence time difference, the concentration rate of the feed solution and the dilution rate of the drive solution within the forward osmosis membrane module can be easily controlled, leading to more stable evaluation results. The feed solution flow rate can be adjusted while the feed solution is circulating outside the forward osmosis membrane module, and the drive solution flow rate can also be adjusted while the drive solution is circulating outside the forward osmosis membrane module. The residence time of the feed solution is preferably 1 to 10 seconds, more preferably 1 to 5 seconds. The residence time of the drive solution is also preferably 1 to 10 seconds, more preferably 1 to 5 seconds. When the residence times of the feed solution and drive solution are within this range, excessive concentration of the feed solution and dilution of the drive solution will not occur, allowing for more precise evaluation of the forward osmosis membrane performance within the entire forward osmosis membrane module.

[0144] In the flow rate adjustment process, it is preferable to pre-adjust the flow rates of the feed solution and the drive solution before the connection process, so that the difference between the linear velocity of the feed solution in the space on the separation functional layer side and the linear velocity of the drive solution in the space on the porous support side after the connection of the forward osmosis membrane module is within 10 cm / s. The linear velocity difference is more preferably within 5 cm / s, and even more preferably within 1 cm / s. By setting the linear velocity after connection and pre-adjusting the flow rate before connection, individual differences in the forward osmosis membrane module can be taken into account, resulting in more stable evaluation results and accurate evaluation within a shorter time. The linear velocity of the feed solution is preferably 1 cm / s to 10 cm / s, more preferably about 1 cm / s to 5 cm / s. The linear velocity of the drive solution is also preferably 1 cm / s to 10 cm / s, more preferably about 1 cm / s to 5 cm / s. Here, the linear velocity refers to the linear velocity of the forward osmosis membrane surface. Depending on the shape of the forward osmosis membrane module, the residence time can also be adjusted by adjusting the linear velocity.

[0145] The flow rate can be adjusted before the connection process based on the cross-sectional areas of the feed solution supply section and the drive solution supply section within the forward osmosis membrane module. The feed solution supply section and the drive solution supply section refer to the spaces through which the feed solution flows within the portion of the forward osmosis membrane module that functions as a forward osmosis membrane (effective membrane area portion), respectively. The cross-sectional area is the cross-sectional area in the direction perpendicular to the flow direction of the feed solution and the drive solution. For example, in the case of a hollow fiber membrane module with a separation functional layer on its inner surface, the portion filled with hollow fiber bundles and functioning as a forward osmosis membrane is the effective membrane area portion, where the feed solution supply section corresponds to the inner side of the hollow fibers (separation functional layer side), and the drive solution supply section corresponds to the outer side of the hollow fibers. In the case of complex structures where the cross-sectional area varies depending on the location of the cross-section, the effective membrane area portion can be calculated based on the largest proportion of the same cross-sectional area within the forward osmosis membrane module. Besides hollow fiber membrane modules, other forms of forward osmosis membrane modules include flat-plate modules and spiral modules, and the flow rate can be adjusted based on the cross-sectional area using the same concept.

[0146] It should be noted that even without knowing the cross-sectional area of ​​the forward osmosis membrane module, as a preliminary experiment, water can be flowed through the forward osmosis membrane module, and a certain dye (e.g., brilliant blue) can be instantaneously added. The time until the dye is discharged can be measured, thereby determining the relationship between flow rate and residence time. The flow rate can then be adjusted based on the relationship between flow rate and residence time in each part of the feed solution supply section and the drive solution supply section.

[0147] The method disclosed herein preferably includes, prior to the connection process, the adjustment of at least one physical parameter selected from the group consisting of adjustments to physical pressure, temperature, and flow rate. Regarding the adjustment of the physical parameters, these can be pre-controlled based on information about the forward osmosis membrane module used, the feed solution, and the drive solution. For example, the pressure and flow rate of the drive solution can be determined based on information about the cross-sectional areas of the feed solution supply section and the drive solution supply section within the forward osmosis membrane module, the desired physical pressure difference, and the desired minimum flow rate of the feed solution, and controlled pre-controlled before the connection process. This allows for more stable evaluation results of the forward osmosis membrane module and enables accurate evaluation in a shorter time.

[0148] <Connection Process>

[0149] The evaluation method for a forward osmosis membrane module disclosed herein includes connecting the space on the separation functional layer side of the forward osmosis membrane module to a feed solution line and connecting the space on the porous support side to a drive solution line. This allows feed solution to be supplied to the space on the separation functional layer side of the forward osmosis membrane module, and drive solution to be supplied to the space on the porous support side. The feed solution line is preferably connected in a manner that allows for the recovery and circulation of feed solution from the forward osmosis membrane module, and the drive solution line is preferably connected in a manner that allows for the recovery and circulation of drive solution from the forward osmosis membrane module. The connection of the feed solution line and the drive solution line can be performed in a manner that allows the feed solution and drive solution to flow in opposite or concurrent directions. When connected in a concurrent direction, the feed solution and drive solution can be contacted via the forward osmosis membrane immediately after evaluation, thus allowing for an earlier start time for evaluation. Furthermore, in the case of an apparatus that longitudinally arranges the hollow fiber membrane module, air bubbles within the module are easily removed, enabling more accurate evaluation in a shorter time, which is therefore preferable. It should be noted that vertically arranging the hollow fiber membrane module is advantageous in terms of reducing the size of the device. On the other hand, when connected in a convection manner, the concentrated feed solution comes into contact with the undiluted drive solution within the module, and the undiluted feed solution comes into contact with the diluted drive solution, thereby maintaining a high osmotic pressure differential throughout the module, which is therefore preferred.

[0150] <Evaluation Process>

[0151] In the evaluation process, the feed solution and the drive solution are first convected or co-flowed using a forward osmosis membrane. Regarding the order of supplying the feed solution and drive solution to the forward osmosis membrane module, either the feed solution or the drive solution can be supplied first, or both can be supplied simultaneously. The method disclosed herein involves supplying the feed solution to the separation functional layer side of the forward osmosis membrane for forward osmosis evaluation. When the solvent of the feed solution is water, it is preferable to supply the feed solution to the forward osmosis membrane module followed by the drive solution. If water is used, it does not have osmotic pressure; therefore, even if it is supplied to the forward osmosis membrane module before the drive solution, there is less phenomenon of air bubbles (so-called air pockets) being mixed into the forward osmosis membrane, especially in the thick portion of the support membrane, allowing for simpler and more accurate evaluation. Furthermore, by supplying water first as the feed solution, some of the feed solution in the forward osmosis membrane module can be removed by air bubbles without adversely affecting the evaluation results, enabling accurate evaluation of permeability and salt back diffusion from the initial stage of the evaluation.

[0152] In the evaluation process, the porous support side is positioned positive, and the physical pressure difference between the forward osmosis membranes is adjusted to a constant range between 0 kPa and 200 kPa, while the solvent in the feed solution moves towards the drive solution. By keeping the physical pressure difference below 200 kPa, the membrane of the forward osmosis membrane module is less likely to suffer unnecessary damage; and by keeping it above 0 kPa, the influence of the physical pressure generated in the direction of peeling the separation functional layer from the porous support during actual use can be appropriately taken into account. Therefore, the method of this disclosure can accurately evaluate the practical performance of forward osmosis membranes, including the support membrane and the separation functional layer.

[0153] From the perspective of better evaluation accuracy, taking the porous support side as the positive side, the physical pressure difference is preferably 5 kPa to 200 kPa, more preferably 10 kPa to 200 kPa, further preferably 15 kPa to 150 kPa, and particularly preferably 20 kPa to 100 kPa. Specifically, from the perspective of solvent movement from the feed solution to the driving solution, the physical pressure difference can be less than or equal to the osmotic pressure difference between the feed solution and the driving solution. Regarding the physical pressure difference, it is preferable to monitor and maintain it in real time, and more preferably, the real-time physical pressure difference should be maintained within ±1 kPa of the desired physical pressure difference. By maintaining the physical pressure difference within the above range, the diffusivity of the driving solution within the porous support of the forward osmosis membrane can be promoted, further promoting the renewal of the driving solution near the separation functional layer, and the decrease in permeability caused by pressurization from the driving solution side can be suppressed to below a certain value. Therefore, the deviation of the evaluation results (permeability, salt back diffusion) is small, and the practical performance can be accurate.

[0154] The temperature difference between the feed solution and the driving solution in the evaluation process is preferably adjusted to within 10°C. More preferably, the temperature difference is within 5°C, further preferably within 3°C, and even more preferably within 1°C. By adjusting the temperature difference to a smaller value, the evaluation results of the forward osmosis membrane module can be more stable and the evaluation accuracy can be improved. The temperature of the feed solution and the driving solution can be ambient temperature, for example, around 25±5°C.

[0155] In the evaluation process, the flow rates of the feed solution and the driving solution are preferably adjusted such that the difference between the residence time of the feed solution in the space on the separation functional layer side and the residence time of the driving solution in the space on the porous support side is within 20 seconds. The residence time difference is more preferably within 15 seconds, further preferably within 10 seconds, even more preferably within 5 seconds, and particularly preferably within 1 second. By adjusting the residence time difference to a smaller value, the evaluation results of the forward osmosis membrane module can be more stable and the evaluation accuracy can be improved. The residence time of the feed solution is preferably between 1 and 10 seconds, more preferably around 1 to 5 seconds. The residence time of the driving solution is also preferably between 1 and 10 seconds, more preferably around 1 to 5 seconds.

[0156] In the evaluation process, the flow rates of the feed solution and the driving solution are preferably adjusted such that the difference between the linear velocity of the feed solution in the space on the separation functional layer side and the linear velocity of the driving solution in the space on the porous support side is within 10 cm / s. The linear velocity difference is more preferably within 5 cm / s, and even more preferably within 1 cm / s. By adjusting the linear velocity difference to a smaller value, the evaluation results of the forward osmosis membrane module can be more stable and the evaluation accuracy can be improved. The linear velocity of the feed solution is preferably between 1 cm / s and 10 cm / s, more preferably around 1 cm / s to 5 cm / s. The linear velocity of the driving solution is also preferably between 1 cm / s and 10 cm / s, more preferably around 1 cm / s to 5 cm / s. By appropriately reducing the linear velocity, damage to the membrane itself caused by the evaluation can be suppressed. By appropriately increasing the linear velocity, excessive concentration of the feed solution and excessive dilution of the driving solution due to the retention of each solution within the forward osmosis membrane module can be suppressed, making it easier to evaluate under constant conditions, thus resulting in more stable evaluation results.

[0157] In the evaluation process, the solution containing feedstock after being supplied to and leaving the forward osmosis membrane module (hereinafter referred to as "post-feed feedstock") can be either a recirculating type, directly returned to the feedstock tank, or indirectly returned to the feedstock tank with additional treatment, or a one-way type that does not return to the feedstock tank. In the recirculating type, the amount of reverse diffusion of the driving solute can be managed and evaluated using only one feedstock tank in one evaluation of a single forward osmosis membrane module, thus enabling more precise evaluation of the salt reverse diffusion of the forward osmosis membrane module. In the indirect return type, for example, the post-feed feedstock containing trace amounts of salt can be desalinated and ultimately returned to the feedstock tank. In the one-way type, solution can be simultaneously fed from one feedstock tank to multiple modules, or the driving solute can remain in the feedstock tank even after forward osmosis evaluation (without contaminating the feedstock tank), thus further reducing time when performing multiple evaluations.

[0158] In the case of a one-way flow type, the difference between at least one of the following parameters—electroelectricity, refractive index, total organic carbon (TOC), chemical oxygen demand (COD), biochemical oxygen demand (BOD), absorbance, and transmittance—of the feed solution and the post-feed feed solution is measured. This parameter is then compared with the drive solution, allowing for a simple evaluation of the forward osmosis membrane performance without contaminating the feed solution tank. For example, regarding the feed solution, by measuring the difference in conductivity between the inlet and outlet sides of the forward osmosis membrane module over time, the extent of salt migration in the one-way flow type can be estimated. By measuring the differences in TOC, COD, and BOD over time, the extent of organic matter migration in the one-way flow type can be estimated. By measuring the difference in absorbance over time, the extent of migration of absorbant substances (e.g., pigments, aromatic compounds, compounds with conjugated bonds) in the one-way flow type can be estimated. By measuring the difference in transmittance over time, the extent to which particles and crystalline substances have moved in the one-way flow type can be estimated. From the perspective of ease of evaluation and minimal bias, the one-way flow type is preferred in evaluations selected from at least one of the group consisting of conductivity, refractive index, and absorbance. These measurements can be used individually, or multiple measurements can be combined to improve evaluation accuracy. The above-mentioned determination of the physical properties of the feed solution after delivery can be performed at any stage after leaving the forward osmosis membrane module. For example, the feed solution discharged from the one-way flow type can be recovered into a separate tank from the feed solution tank, and the physical properties of the recovered feed solution can be directly measured.

[0159] In the case of a one-way flow method, evaluation is preferably performed 10 seconds after the feed solution is supplied to and leaves the forward osmosis membrane module. More specifically, the point at which the feed solution begins to drain from the forward osmosis membrane module is defined as 0 seconds, and the continuous draining of the feed solution after supply within 10 seconds is preferably not used for evaluation. That is, it is preferable to use at least 10 seconds as a stabilization time to stabilize the evaluation results, and not use it for evaluation, but use the subsequent measurement values ​​for evaluation. With a stabilization time, especially in the one-way flow method, changes in the properties of the feed solution after supply that may be observed in the early stages of the forward osmosis membrane can be avoided, thus enabling evaluation with good accuracy. The stabilization time is preferably 30 seconds or more, more preferably 1 minute or more, and preferably 30 minutes or less, more preferably 20 minutes or less, further preferably 10 minutes or less, and even more preferably 5 minutes or less, from the perspective of short evaluation time.

[0160] In the evaluation process, at least one physical parameter of the feed liquid and drive solution, selected from the group consisting of physical pressure difference, temperature, flow rate, minimum flow rate, conductivity, and refractive index, can be monitored and maintained in real time. For example, it is preferable to monitor the physical pressure difference, flow rate, and minimum flow rate of the feed liquid and drive solution in real time, maintaining the desired physical pressure difference and flow rate above the minimum flow rate. This ensures stability of each physical parameter, reduces fluctuations, and allows for more accurate evaluation. For the reasons of reduced fluctuations and more accurate evaluation, proportional-integral-derivative (PDI) control is preferred.

[0161] As an example of the performance characteristics of a forward osmosis membrane module that can be evaluated using the evaluation method of the forward osmosis membrane module disclosed herein, salt reverse diffusion rate (RSF) (g / (m²)) can be cited. 2 ×hr), permeability (Flux) (kg / (m³) 2 The salt permeability (RSF / Flux) (g / kg) is obtained by dividing RSF by Flux.

[0162] RSF refers to the amount of driving solute that moves from the driving solution to the feed solution when a forward osmosis membrane is sandwiched in the middle, with the feed solution to be concentrated flowing on the separation functional layer side and a driving solution with a higher osmotic pressure placed on the support membrane side. RSF is defined by the following equation (1).

[0163] RSF=G / (M×H)···Equation (1)

[0164] In the formula, G is the amount of driving solute moved (g), and M is the effective membrane area of ​​the forward osmosis membrane (m²). 2 H is time (hr). Here, the effective membrane area uses the membrane area of ​​the side with the separation functional layer. A lower RSF is preferred. If the RSF is too high, problems may occur such as the driving solute in the driving solution mixing into the feed solution, or the solute in the feed solution mixing into the driving solution, the purity of the feed solution concentrate decreasing and thus disrupting the component balance, the driving solution becoming contaminated, and the components in the driving solution decreasing over time.

[0165] Flux refers to the amount of solvent (mainly water) that moves from the feed solution to the drive solution when a forward osmosis membrane is sandwiched in the middle, with the feed solution to be concentrated flowing on the separation functional layer side and a drive solution with a higher osmotic pressure on the support membrane side. Flux is defined by the following equation (2).

[0166] Flux = L / (M×H)···Equation (2)

[0167] In the formula, L is the amount of solvent permeated (kg), and M is the effective surface area of ​​the forward osmosis membrane (m²). 2), and H is time (hr). Here, the effective membrane area uses the membrane area of ​​the side with the separation functional layer. From the perspective of achieving high-efficiency solvent movement, a higher Flux is preferred.

[0168] RSF / Flux is an indicator of the selectivity of solvent permeability and salt permeability. The lower the value, the less likely the salt is to permeate and the more likely the solvent is to permeate, which is preferred.

[0169] In the forward osmosis membrane module evaluation method disclosed herein, forward osmosis evaluation is performed by setting a physical pressure difference between the membranes, allowing for evaluation that considers physical durability as part of the forward osmosis membrane's performance. When the physical durability of the forward osmosis membrane is low, it cannot withstand the physical pressure difference, causing a portion of the separation functional layer to peel off from the porous support, resulting in cracking of the separation functional layer and irreversible deterioration. This leads to easy permeation of the drive solution to the feed solution side, and the values ​​of RSF and RSF / Flux increase significantly compared to evaluation under a physical pressure difference of 0 kPa. Even when the forward osmosis membrane has physical durability and has not undergone irreversible deterioration, the drive solution typically permeates easily due to the physical pressure from the drive solution side, and the values ​​of RSF and RSF / Flux usually increase compared to evaluation under a physical pressure difference of 0 kPa. Therefore, the method of this disclosure can accurately evaluate the RSF and RSF / Flux values ​​in practical use.

[0170] Evaluation Device for Forward Osmosis Membrane Modules

[0171] The evaluation apparatus for the forward osmosis membrane module disclosed herein includes a feed liquid tank, a feed liquid line, a feed liquid supply unit, a drive solution tank, a drive solution line, a drive solution supply unit, a pressure adjustment unit disposed on the drive solution line, and a pressure sensor disposed on the drive solution line. The forward osmosis membrane module to be evaluated is a forward osmosis membrane module having a forward osmosis membrane, preferably a forward osmosis membrane module having a forward osmosis membrane and the forward osmosis membrane having a support membrane having a porous substrate and a separation functional layer disposed on the porous substrate. A hollow fiber membrane module is more preferably a forward osmosis membrane module. For detailed information on the forward osmosis membrane module, please refer to the "Forward Osmosis Membrane Module" section in the aforementioned "Evaluation Method for Forward Osmosis Membrane Modules".

[0172] <Raw material tank and drive solution tank>

[0173] The feed solution tank stores the feed solution, and the drive solution tank stores the drive solution. The feed solution tank and / or drive solution tank may be equipped with a stirrer. The feed solution tank or drive solution tank, or preferably both, are each equipped with a temperature control unit capable of adjusting the temperature of the feed solution or drive solution. By equipping the feed solution tank and / or drive solution tank with temperature control units, individual differences in the ease of cooling or heating of the feed solution and drive solution caused by the forward osmosis membrane module can be taken into account, resulting in more stable evaluation results for the forward osmosis membrane module and enabling accurate evaluation in a shorter time.

[0174] The feed liquid tank or the driving solution tank, or preferably both, further comprises at least one selected from the group consisting of a temperature sensor, a conductivity sensor, and a refractive index sensor capable of measuring the temperature, conductivity, or refractive index of the feed liquid or the driving solution. By equipping the feed liquid tank and / or the driving solution tank with these sensors, the measured values ​​can be compared in real time, making control easier.

[0175] <Feed Liquid Pipeline>

[0176] The feedstock line connects the feedstock tank to the forward osmosis membrane module and is configured such that the feedstock can be supplied from the feedstock tank to the forward osmosis membrane module via the feedstock line using a feedstock supply unit. The feedstock supply unit can be, for example, a pump (hereinafter also referred to as a "feedstock supply pump"). The feedstock line is further preferably configured such that the feedstock can be recovered by the forward osmosis membrane module, returned to the feedstock tank, and then supplied to the forward osmosis membrane module again (for circulation).

[0177] The feedstock line can have a circulation structure that allows the feedstock to circulate outside the forward osmosis membrane module before connection, and it also includes a feedstock bypass line (which forms part of the feedstock line's circulation structure and can be detached from the forward osmosis membrane module). The bypass line is a line that allows circulation of the feedstock without passing through the forward osmosis membrane module. By having a circulation structure outside the forward osmosis membrane module, it is easier to adjust the physical parameters of the feedstock, such as pressure, temperature, and flow rate, before connection. Furthermore, with the feedstock bypass line, the feedstock flow path, after its physical parameters have been adjusted, can be connected to the forward osmosis membrane module, allowing for better and faster evaluation of accuracy. The bypass line only needs to be a structure that allows solution circulation outside the forward osmosis membrane module. For example, by branching off and connecting the forward osmosis membrane module and the bypass line in parallel, the solution can be sealed off at the forward osmosis membrane module side using valves or other means to prevent flow, while the solution circulates outside the forward osmosis membrane module through the bypass line. After circulating the solution using a bypass line, the bypass line side is sealed, while the forward osmosis membrane module side is opened, thereby enabling the solution to be supplied to the forward osmosis membrane module.

[0178] The feedstock line preferably includes a pressure regulating unit. This pressure regulating unit assists in maintaining a constant physical pressure difference between the feedstock and the drive solution within a range greater than 0 kPa and less than 200 kPa via the forward osmosis membrane. More preferably, the pressure regulating unit is configured to adjust the physical pressure of the feedstock before, during, and after the evaluation of the forward osmosis membrane module by providing a circulation structure to the feedstock line. Examples of pressure regulating units include valves (also called "pressure regulating valves"), back pressure valves, pump-based pressurization, and combinations thereof.

[0179] Preferably, the feedstock line includes a temperature control unit. This temperature control unit assists in adjusting the temperature difference between the feedstock and the drive solution to within 10°C. More preferably, the feedstock line is configured such that the temperature control unit can adjust the feedstock temperature before, during, and after the evaluation of the forward osmosis membrane module by having a circulation structure. Examples of temperature control units include, for instance, a coaxial heat exchanger, a temperature-regulating cooler, and a heater.

[0180] Preferably, the feedstock line further comprises at least one of a group consisting of a pressure sensor, a temperature sensor, a flow sensor, a conductivity sensor, and a refractive index sensor, which are installed on the feedstock line to measure the physical pressure, temperature, flow rate, conductivity, or refractive index of the feedstock. By equipping the feedstock line with these sensors, the various physical parameters of the feedstock can be more easily controlled, thus enabling more accurate evaluation in a shorter time. These sensors can be configured either before or after the forward osmosis membrane module, or both.

[0181] <Drive solution pipeline>

[0182] The drive solution line connects the drive solution tank to the forward osmosis membrane module and is configured such that the drive solution can be supplied from the drive solution tank to the forward osmosis membrane module via the drive solution line using a drive solution supply unit. The drive solution supply unit can be, for example, a pump (hereinafter also referred to as a "drive solution supply pump"). The drive solution line is further preferably configured such that the drive solution can be recovered from the forward osmosis membrane module, returned to the drive solution tank, and supplied to the forward osmosis membrane module again (for circulation).

[0183] The drive solution line preferably has a circulation structure that allows the drive solution to circulate outside the forward osmosis membrane module before connection to the module, and also includes a drive solution bypass line (which forms part of the circulation structure of the drive solution line and can be detached from the forward osmosis membrane module). Because the drive solution line has a circulation structure outside the forward osmosis membrane module, it is easier to adjust the physical parameters of the drive solution, such as physical pressure, temperature, and flow rate, before connection to the module. Furthermore, by having a drive solution bypass line, the flow path of the drive solution with adjusted physical parameters can be connected to the forward osmosis membrane module, thus enabling more accurate evaluation in a shorter time. Other advantages are the same as those of the feed solution bypass line.

[0184] The drive solution line includes a pressure regulating unit installed on the drive solution line, capable of physically pressurizing the drive solution before, during, and after the evaluation of the forward osmosis membrane module. The pressure regulating unit is configured to maintain a constant physical pressure difference between the drive solution and the feed solution within a range greater than 0 kPa and less than 200 kPa via the forward osmosis membrane. The drive solution line further includes a pressure sensor installed on the drive solution line, capable of measuring the physical pressure of the drive solution. This makes it easier to maintain a constant physical pressure difference. Examples of pressure regulating units include valves (also called "pressure regulating valves"), pump-based pressurization, and combinations thereof.

[0185] The drive solution line preferably includes a temperature adjustment unit. This temperature adjustment unit assists in adjusting the temperature difference between the feed solution and the drive solution to within 10°C. More preferably, the drive solution line is configured such that the temperature adjustment unit can adjust the temperature of the drive solution before, during, and after the evaluation of the forward osmosis membrane module by having a circulation structure. Examples of temperature adjustment units include, for instance, a coaxial heat exchanger, a temperature-regulating cooler, and a heater.

[0186] Preferably, the drive solution line further includes at least one sensor selected from the group consisting of a temperature sensor, a flow sensor, a conductivity sensor, and a refractive index sensor, capable of measuring the temperature, flow rate, conductivity, or refractive index of the drive solution. By incorporating these sensors into the drive solution line, the various physical parameters of the drive solution can be more easily controlled, thus enabling more accurate evaluation in a shorter time. These sensors can be configured either before or after the forward osmosis membrane module, or both.

[0187] The drive solution line and / or the aforementioned drive solution tank preferably further include a concentration adjustment unit capable of removing solvent from the drive solution, adding a high concentration of drive solution to the drive solution, or adding at least one of the drive solutes. When the drive solution line and / or the aforementioned drive solution tank has a circulation structure, by including the concentration adjustment unit in the drive solution line, the concentration of the circulating drive solution can be effectively regenerated, thus enabling more accurate evaluation. As a means of removing solvent from the drive solution, an evaporation unit that removes solvent by evaporation can be cited as an example. The evaporation unit is preferably a unit other than membrane distillation, such as a distillation process, a vacuum distillation process, or a natural drying process. The concentration of the drive solute in the high-concentration drive solution only needs to be higher than the concentration in the drive solution diluted by the forward osmosis membrane module, and can also be a saturated solution. As a method of adding a high concentration of drive solution or adding a drive solute, a solution containing the same or different solute as the drive solute can be added. For example, when the driving solute is NaCl, one could add a few drops of a saturated NaCl solution as the same solute. Alternatively, when the driving solution is a 1% by mass aqueous solution of NaCl, one could add a 10% by mass driving solution of MgCl2, whose osmotic pressure is higher than that of NaCl, as a different solute. In this disclosure, from the perspective of easily analyzing the results and performing measurements with high accuracy in a shorter time, it is preferable to control the concentration by adding a high-concentration driving solution with the same driving solute. Examples of methods for adding a high-concentration driving solution include: adding it directly to the tank; and pumping it from the tank to another system, concentrating it through an evaporation unit, etc., and then returning it to the tank.

[0188] The evaluation apparatus disclosed herein only needs to have at least one set of feed solution lines and drive solution lines, preferably multiple sets, enabling parallel evaluation of multiple forward osmosis membrane modules. With multiple sets of feed solution lines and drive solution lines, the evaluation efficiency is dramatically improved, and it is easy to extract poor-performing forward osmosis membrane modules from multiple sets of forward osmosis membrane modules.

[0189] <Control Device>

[0190] The evaluation apparatus disclosed herein is preferably configured as follows: it utilizes sensors, including pressure sensors, installed on the drive solution line to monitor the measured values ​​and time in real time, stores the data in a database, and can detect the difference between the values ​​of the feed solution or drive solution, or both, during solution circulation before evaluation and the values ​​at the time of evaluation of the forward osmosis membrane module. Therefore, as described below, it can be configured to monitor and maintain the physical parameters of the feed solution and drive solution in real time, thus enabling more accurate evaluation.

[0191] The evaluation apparatus disclosed herein can be configured to further include a control device capable of real-time monitoring and maintaining at least one physical parameter selected from the group consisting of the physical pressure difference, temperature, flow rate, minimum flow rate, conductivity, and refractive index of the feed liquid and the driving solution. For example, if a pressure adjustment unit, a pressure sensor, and a flow sensor are provided on the feed liquid pipeline, and a flow sensor is further provided on the driving solution pipeline, the evaluation apparatus can further include a control device combined with the respective pressure sensors, flow sensors, and pressure adjustment units on the feed liquid and driving solution pipelines, as well as the feed liquid supply unit and the driving solution supply unit. Furthermore, the control device is preferably configured to perform real-time comparisons of the physical pressure difference, flow rate, and minimum flow rate between the feed liquid and the driving solution. Additionally, the control device is preferably configured to control the respective pressure adjustment unit, feed liquid supply unit, and driving solution supply unit to maintain the desired physical pressure difference between the feed liquid and the driving solution, and the flow rate above the minimum flow rate. This allows for more stable physical parameters with less fluctuation and more accurate evaluation.

[0192] When comparing physical pressure differences in real time, the control device is preferably configured to maintain the real-time physical pressure difference within the desired physical pressure difference ±1 kPa.

[0193] The control device can be configured to control at least one of the physical parameters, such as physical pressure, temperature, and flow rate, of the feed solution and drive solution based on input information about the forward osmosis membrane module, feed solution, and drive solution. For example, the control device is preferably configured to determine and pre-control the pressure and flow rate of the drive solution before evaluating the forward osmosis membrane module by inputting information about the cross-sectional areas of the feed solution supply section and the drive solution supply section within the forward osmosis membrane module, the desired physical pressure difference, and the desired minimum flow rate of the feed solution. This allows for more stable physical parameters with less fluctuation and more accurate evaluation.

[0194] When real-time control of physical parameters such as physical pressure difference is required, the control device preferably includes a processor configured to perform proportional-integral-derivative (PDI) control. This allows for more stable and less volatile physical parameters, resulting in more accurate evaluation. PID control is a type of feedback control in control engineering, a control method that controls the input value based on the deviation between the output value and the target value, as well as its integral and derivative. For example, it can be configured as follows: real-time monitoring (output value) of the physical pressure difference, flow rate, and minimum flow rate of the feed liquid and drive solution; and controlling the operating quantities (input values) of the respective pressure adjustment unit, feed liquid supply unit, and drive solution supply unit based on the deviation from the desired physical pressure difference and the desired flow rate above the minimum flow rate (target value), as well as their integral and derivative.

[0195] Examples of evaluation methods and devices for forward osmosis membrane modules

[0196] Figure 1 This is a schematic diagram of the cross-section of the forward osmosis membrane used in the evaluation method of this disclosure. For example... Figure 1 The diagram schematically illustrates, for example, a forward osmosis membrane (11) composed of a porous support (11a) and a separation functional layer (11b), assuming that the driving solution is supplied to the space (10a) on the porous support (11a) side and the feed solution is supplied to the space (10b) on the separation functional layer (11b) side. It should be noted that the direction of the dashed arrows indicates the flow direction of the driving solution, and the direction of the solid arrows indicates the flow direction of the feed solution. Figure 1 The diagram is drawn in the manner of co-flow of the driving solution and the feed solution, but it can also be drawn in the manner of convection (backflow). The driving solution and the feed solution are in contact through the forward osmosis membrane (11), generating an osmotic pressure difference. The solvent moves from the feed solution to the driving solution in the direction of solvent movement (P1) based on the osmotic pressure difference. On the other hand, the physical pressure difference between the driving solution and the feed solution is adjusted to be constant in the direction of physical pressure application (P2), that is, with the porous support side as positive (high pressure), in a range greater than 0 kPa and less than 200 kPa, while the performance of the forward osmosis membrane module is evaluated.

[0197] Figure 2 This is a schematic diagram illustrating an example of an evaluation method for a forward osmosis membrane assembly using the evaluation apparatus of this disclosure. Figure 2In the forward osmosis membrane module (10), there is a forward osmosis membrane (11) consisting of a porous support and a separation functional layer (not shown). The space within the forward osmosis membrane module is separated into a space (10a) on the porous support side and a space (10b) on the separation functional layer side by the forward osmosis membrane. A feed liquid line (20) and a drive solution line (30) are prepared respectively. In the feed liquid line (20), a feed liquid supply pump (22) is provided as a feed liquid supply unit for feeding feed liquid from the feed liquid tank (21) to the forward osmosis membrane module. The feed liquid line (20) is configured such that it is fluidly connected to the space (10b) on the separation functional layer side, and can circulate the feed liquid from the forward osmosis membrane module back to the feed liquid tank. In the drive solution line (30), a drive solution supply pump (32) is provided as a drive solution supply unit for feeding drive solution from the drive solution tank (31) to the forward osmosis membrane module. The drive solution line (30) is configured such that it is fluidly connected to the space (10a) on the porous support side, recovers the drive solution from the forward osmosis membrane module, and returns it to the drive solution tank, enabling circulation. Furthermore, the drive solution line (30) includes a pressure regulating valve (33) as a pressure regulating unit for adjusting the physical pressure of the drive solution, and a pressure sensor (34) for measuring the physical pressure of the drive solution. The pressure regulating valve (33) and the pressure sensor (34) are configured such that they are connected to a control device (not shown), compare the physical pressure difference between the feed solution and the drive solution in real time, keep the porous support side positive, and adjust the physical pressure difference to a constant range greater than 0 kPa and less than 200 kPa.

[0198] Figure 3 This is a schematic diagram illustrating an example of a hollow fiber membrane module. Figure 3 In this context, the forward osmosis membrane module (10) is a hollow fiber membrane module comprising a hollow fiber bundle composed of a forward osmosis membrane (11). The hollow fibers of the forward osmosis membrane (11) have a porous support on their outer side (corresponding to...). Figure 1 11a), which has a separation function layer on the inner side (corresponding to Figure 1(11b) Hollow fiber bundles are filled inside the cylindrical component housing, and the two ends of the hollow fiber bundles are fixed inside the component housing using adhesive fixing parts (14). The adhesive fixing parts (14) are cured in a manner that does not block the pores at both ends of the hollow fibers. As a result, the space inside the component housing is separated into a space (10a) on the side of the porous support (11a) and a space (10b) on the side of the separation functional layer (11b). The component housing further has inner conduits (12) at both ends that are in fluid communication with the inner side of the hollow fibers (i.e., the space (10b) on the side of the separation functional layer) and outer conduits (13) on its side that are in fluid communication with the outer side of the hollow fibers (i.e., the space (10a) on the side of the porous support). The raw material liquid can be introduced into the space (10b) on the side of the separation functional layer through the inner conduits (12) and removed from the space (10b) on the side of the separation functional layer. Alternatively, the driving solution can be introduced into the space (10a) on the porous support side via the outer conduit (13), and the driving solution can be removed from the space (10a) on the porous support side. The feed liquid flowing inside the hollow fiber and the driving solution flowing outside can be in contact solely through the hollow fiber membrane. The hollow fiber membrane module has an effective membrane area portion (15) that serves as the part that performs the separation function. Figure 3 In this section, the effective membrane area portion (15) is the portion of the hollow fiber bundle that substantially performs the separation function, excluding the adhesive fixing portion (14). It should be noted that... Figure 3 The diagram illustrates hollow fibers with the separation functional layer located internally; therefore, the effective membrane area is calculated based on the total inner surface area of ​​the hollow fibers. In the case where the separation functional layer is located on the external hollow fibers (not shown), the calculation is based on the total outer surface area of ​​the hollow fibers.

[0199] Figure 4 This is a schematic diagram illustrating an example of an evaluation method for a hollow fiber membrane module using the evaluation apparatus of this disclosure. Figure 4 In the middle, the forward osmosis membrane module (10) is as described above. Figure 3The hollow fiber membrane module described herein. The hollow fiber membrane module has a forward osmosis membrane (11) made of hollow fibers (which are composed of a porous support and a separation functional layer), and the space inside the forward osmosis membrane module is divided into a space on the porous support side and a space on the separation functional layer side by the forward osmosis membrane. A feed liquid line (20) and a drive solution line (30) are prepared respectively. In the feed liquid line (20), a feed liquid supply pump (22) is provided as a feed liquid supply unit for feeding the feed liquid from the feed liquid tank (21) to the hollow fiber membrane module. The feed liquid line (20) is configured such that it is fluidly connected to the space on the separation functional layer side, and the feed liquid is recovered from the hollow fiber membrane module and returned to the feed liquid tank, so that it can be circulated. In the drive solution line (30), a drive solution supply pump (32) is provided as a drive solution supply unit for feeding the drive solution from the drive solution tank (31) to the hollow fiber membrane module. The drive solution line (30) is configured such that it is fluidly connected to the space on the porous support side, recovers the drive solution from the hollow fiber membrane module, and returns it to the drive solution tank, enabling circulation. Furthermore, the drive solution line (30) includes a pressure regulating valve (33) as a pressure regulating unit for adjusting the physical pressure of the drive solution, and a pressure sensor (34) for measuring the physical pressure of the drive solution on the line recovering the drive solution from the hollow fiber membrane module. The pressure regulating valve (33) and the pressure sensor (34) are configured such that they are connected to a control device (not shown), compare the physical pressure difference between the feed liquid and the drive solution in real time, keep the porous support side positive, and adjust the physical pressure difference to a constant range greater than 0 kPa and less than 200 kPa.

[0200] Example

[0201] Determination Method

[0202] <Size of the supporting membrane>

[0203] When the supporting membrane is a hollow fiber supporting membrane, the inner diameter, outer diameter, and membrane thickness are measured as dimensions of the supporting membrane. In the case of a hollow fiber supporting membrane, the membrane is cut along a plane perpendicular to the membrane surface (length direction), and the dimensions are measured using an optical microscope photograph (cross-sectional image) of the resulting cross-section. The outer and inner diameters of this cross-sectional image are measured using a ruler. Furthermore, the membrane thickness is calculated by dividing the difference between the outer and inner diameters by 2. Here, the outer and inner diameters refer to the outer and inner diameters of the hollow fiber, respectively. Regarding the inner diameter, outer diameter, and membrane thickness of the supporting membrane, the principle is to measure them in the case of a hollow fiber supporting membrane only, but values ​​measured in the case of a forward osmosis membrane (where a separation functional layer is present on the inner surface of the hollow fiber supporting membrane) can also be used. It should be noted that even when measurements are performed in the case of a forward osmosis membrane, they are confirmed to be substantially the same within the error range of measurements performed in the case of a hollow fiber supporting membrane only.

[0204] Example of manufacturing a forward osmosis membrane

[0205] <Manufacturing Example 1>

[0206] Fabrication of hollow fiber support membrane:

[0207] As the spinning solution, a homogeneous polymer solution was prepared, consisting of 19% by mass of polysulfone (Solvay Specialty polymers, Udel-P3500), 61% by mass of N-methyl-2-pyrrolidone (Fujifilm and Koko Pure Chemical Industries, Ltd.), and 20% by mass of tetraethylene glycol (Tokyo Chemicals Co., Ltd.). The solution was filled into a wet hollow fiber spinning machine equipped with dual spinnerets. The solution at 40°C and the internal coagulation liquid (water) at 25°C were discharged from the dual spinnerets and moved 250 mm in air at 30°C and 98% relative humidity. It was then coagulated in a coagulation bath filled with 30°C water (external coagulation liquid), and wound with a tension of 20g using a free roller as a rotating roller to obtain a hollow fiber support membrane. The obtained hollow fiber support membrane had an outer diameter of 1.02 mm, an inner diameter of 0.62 mm, and a thickness of 0.20 mm.

[0208] Supports the fabrication of membrane modules:

[0209] 130 hollow fiber support membranes were cut into 120mm pieces and then filled into a cylindrical plastic shell with a diameter of 20mm and a length of 100mm. The two ends were fixed with adhesive and then cut to create open ends, thus producing a membrane with an effective length of 80mm and an effective inner surface area of ​​0.02m². 2 Support membrane components.

[0210] Formation of separate functional layers:

[0211] An aqueous solution (Solution 1) containing 2.0% m-phenylenediamine and 0.15% sodium lauryl sulfate was introduced into the hollow fiber of the aforementioned supporting membrane module for 20 minutes. After the introduction was complete, Solution 1 was allowed to drain naturally from the piping at the bottom of the module. Then, with the inner side of the hollow fiber still wetted by Solution 1, the outer side of the supporting membrane module was depressurized to 90 kPaG and held at this pressure for 1 minute. Subsequently, air was circulated into the inner side of the hollow fiber for 1 minute to remove the remaining Solution 1. Next, a cyclohexane solution containing 0.20% pyromellitic acid chloride (Solution 2) was introduced into the inner side of the hollow fiber for 2 minutes to perform interfacial polymerization, forming a separation functional layer on the inner surface of the hollow fiber. Subsequently, nitrogen gas was circulated to remove the remaining Solution 2, and then hot water at 85°C was circulated into the inner side of the hollow fiber for 30 minutes. The module was then placed in an autoclave (Tomy Seiko SX-500, Inc.) with its interior and exterior open, and high-temperature steam at 121°C was continuously supplied to the chamber for 20 minutes. The inside of the hollow fiber was then washed with water at 20°C for 30 minutes to obtain the forward osmosis membrane module.

[0212] <Manufacturing Example 2>

[0213] Fabrication of hollow fiber support membrane:

[0214] As the spinning solution, a homogeneous polymer solution consisting of 18% by mass of terminally hydroxylated polyethersulfone (manufactured by BASF, Ultrason E2020PSR) and 80% by mass of N,N-dimethylacetamide (manufactured by Fujifilm and Kojun Chemical Co., Ltd.) was prepared. The solution was filled into a wet hollow fiber spinning machine equipped with dual spinnerets. The solution at 40°C and the internal coagulation solution at 45°C were discharged from the dual spinnerets and moved 200 mm in air at 30°C and 98% relative humidity. It was then coagulated in a coagulation bath filled with water at 50°C (external coagulation solution), and wound using a free roller as a rotating roller at a tension of 10g to obtain a hollow fiber support film. At this time, a solution consisting of 50% by mass of water and 50% by mass of tetraethylene glycol was used as the internal coagulation solution. The resulting hollow fiber support membrane has an outer diameter of 1.00 mm, an inner diameter of 0.70 mm, and a membrane thickness of 0.15 mm.

[0215] Supports the fabrication of membrane modules and the formation of separation functional layers:

[0216] Except for using the hollow fiber support membrane described above, the forward osmosis membrane module was fabricated in the same manner as in Example 1.

[0217] <Manufacturing Example 3>

[0218] In the formation of the separation functional layer, no autoclave-based treatment is performed; otherwise, the forward osmosis membrane module is manufactured in the same manner as in Manufacturing Example 1.

[0219] It should be noted that Example 1 is a method for stably obtaining a high-performance forward osmosis membrane module, Example 2 is a method for unstablely obtaining a high-performance forward osmosis membrane module, and Example 3 is a method for stably obtaining a forward osmosis membrane module with intermediate performance. In this embodiment, high performance refers to an RSF / Flux value of 0.04 g / L (g / kg) or less under a membrane differential pressure of 20 kPa (high pressure on the driving solution side) in the basic performance evaluation; low performance refers to an RSF / Flux value of 0.08 g / L (g / kg) or more; and intermediate performance refers to an RSF / Flux value greater than 0.04 g / L (g / kg) and less than 0.08 g / L (g / kg).

[0220] Forward Osmosis Membrane Evaluation Device

[0221] The following is an example of an apparatus that can constitute a forward osmosis membrane evaluation device, but the present invention is not limited to the following example.

[0222] Temperature regulating cooler: NCC-3000C (Tokyo Riken Co., Ltd.); Coil-and-tube heat exchanger with temperature regulation range of -10 to 80°C: HEX-MHE-20A-200-T (MDI Co., Ltd.); All-titanium

[0223] Pump: GJ series (Sanwa Tsusho Co., Ltd.) magnetic gear pump

[0224] Pressure sensor: GP-M series (GP-M010T) (Keyence Corporation)

[0225] Flow sensor: FD-X series (FD-XS8) (Keyence Corporation)

[0226] Balance scale: EA715CA-22(A&D)

[0227] Conductivity sensor: DS70 series (Horiba Manufacturing Co., Ltd.) online type

[0228] Refractive index sensor: L-Rix series (L-Rix 5200) (Anton-Paar) online type

[0229] Temperature sensor: Online temperature sensor, type L (Toho Electronics Co., Ltd.)

[0230] Back pressure valve: 44-2300 series (TESCOM) with electric motor-controlled opening and closing degree.

[0231] Data Logger: GL840 Series (Graphtec Corporation)

[0232] Examples 1-20, Comparative Examples 1-4, and Reference Example 1

[0233] The forward osmosis membrane evaluation apparatus is constructed using the aforementioned equipment as follows. First, a feed liquid tank and a feed liquid pipeline connecting the feed liquid tank to the forward osmosis membrane module are prepared. A balance is provided below the feed liquid tank and the drive solution tank. The balance can measure the weight change of the feed liquid and the drive solution tank, and based on the weight change of the feed liquid, the permeability can be measured. A pump for supplying the feed liquid from the feed liquid tank to the forward osmosis membrane module manufactured in the above-described manufacturing example, and a flow meter for measuring the flow rate of the feed liquid are provided on the feed liquid pipeline. The feed liquid pipeline has a bypass pipeline that allows the feed liquid to be circulated before connection to the forward osmosis membrane module. Additionally, a pressure sensor for measuring the physical pressure of the feed liquid is provided on the feed liquid pipeline at both the inlet and outlet sides of the module. The heat medium for the temperature regulating cooler is connected in a manner that enters the aforementioned shell-and-tube heat exchanger, and the feed liquid pipeline flows through the inner side of the shell-and-tube heat exchanger. A thermometer for measuring the temperature of the feed liquid is provided on the feed liquid pipeline exiting the shell-and-tube heat exchanger. Therefore, the feed solution is temperature-regulated before entering the forward osmosis membrane module. The feed solution flows out of the feed solution tank and sequentially through a pump, flow meter, pressure gauge (inlet-side pressure), heat exchanger, thermometer, forward osmosis membrane module, pressure gauge (outlet-side pressure), and then back to the feed solution tank. A drive solution tank and a drive solution line connecting the drive solution tank to the forward osmosis membrane module are prepared. The drive solution line has a bypass line that allows the drive solution to circulate before connection to the forward osmosis membrane module. The aforementioned pump, which supplies the drive solution from the drive solution tank to the forward osmosis membrane module, and a flow meter for measuring the flow rate of the drive solution are installed on the drive solution line. A back pressure valve, which physically pressurizes the drive solution and adjusts the physical pressure difference between the feed solution and the drive solution, is installed on the drive solution line. Additionally, a pressure sensor, measuring the physical pressure of the drive solution, is installed on both the inlet and outlet sides of the module on the drive solution line. The heat medium for the aforementioned temperature-regulating cooler is connected in a manner that allows it to enter the aforementioned shell-and-tube heat exchanger, and is configured such that the feed liquid line and the drive solution line flow inside the shell-and-tube heat exchanger. A thermometer for measuring the temperature of the drive solution is installed on the drive solution line leaving the shell-and-tube heat exchanger. Thus, the temperature of the drive solution is regulated before it enters the forward osmosis membrane module. The flow direction of the drive solution is as follows: it leaves the drive solution tank and sequentially passes through the pump, flow meter, pressure gauge (inlet-side pressure), heat exchanger, thermometer, forward osmosis membrane module, pressure gauge (outlet-side pressure), and back pressure valve, before returning to the drive solution tank. This forward osmosis membrane evaluation device was used in the basic performance evaluation of the forward osmosis membranes in Examples 1 to 20, Comparative Examples 1 to 4, and Reference Example 1, as described below.

[0234] <Basic Performance Evaluation of Forward Osmosis Membranes>

[0235] For the forward osmosis membranes obtained in Examples 1 to 3, after performing forward osmosis operation under the following conditions, the permeability (Flux) and salt reverse diffusion (RSF) were determined, and the salt permeability (RSF / Flux) was calculated.

[0236] Raw material solution: purified water, 25℃, flow rate approximately 88 mL / min (linear velocity approximately 3.7 cm / s, residence time approximately 2 seconds), solution volume 3 L

[0237] Driving solution: 3.5% sodium chloride aqueous solution, 25°C, flow rate 390 mL / min (linear velocity approximately 3.7 cm / s, residence time approximately 2 seconds), solution volume 3 L.

[0238] Physical pressure difference: 20 kPa, pre-circulated in the bypass line, adjusted using the back pressure valve on the driving solution side.

[0239] Temperature: Adjusted beforehand using a shell-and-tube heat exchanger and a temperature-regulating cooler.

[0240] Operating time: Liquid flow begins from the raw material solution, followed by the flow of the driving solution. The driving solution is discharged from the component for the first time 20 minutes later.

[0241] In Example 7, the temperature of the raw material solution was adjusted to 15°C and the temperature of the driving solution was adjusted to 30°C.

[0242] A saturated sodium chloride aqueous solution was added to the drive solution to maintain a constant concentration while performing forward osmosis. Regarding the intermembrane differential pressure, the back pressure valve on the drive solution side was set to positive (high pressure) on the drive solution side (the supporting membrane side of the forward osmosis membrane). Each measurement was performed once for each of the five modules manufactured using the same method. Specifically, for Reference Example 1, one module manufactured in the same manner as in Example 1 was evaluated five times. In Examples 19 and 20, and Comparative Example 4, two modules were manufactured using different methods: three of one and two of the other, for a total of five modules, and each was measured once. The mean and standard deviation were calculated from the five obtained RSF / Flux values. The coefficient of variation was calculated by dividing the standard deviation by the mean, and expressed as a percentage.

[0243] Examples 21 and 22

[0244] Regarding Examples 21 and 22, a forward osmosis membrane device with the following structure was used for the basic performance evaluation of the forward osmosis membrane. First, a feed liquid tank and a feed liquid line connecting the feed liquid tank to the forward osmosis membrane module were prepared. A balance was provided below the feed liquid tank and the drive solution tank. The balance could measure the weight change of the feed liquid and the drive solution tank, and based on the weight change of the feed liquid, the permeability could be measured. A pump for supplying the feed liquid from the feed liquid tank to the forward osmosis membrane module manufactured in the above-described manufacturing example and a flow meter for measuring the flow rate of the feed liquid were provided on the feed liquid line. The feed liquid line had a bypass line that allowed the feed liquid to be circulated before connection to the forward osmosis membrane module. Furthermore, a pressure sensor for measuring the physical pressure of the feed liquid was provided on the feed liquid line at both the inlet and outlet sides of the module. Additionally, a conductivity sensor for measuring the conductivity of the feed liquid was provided on the feed liquid line at both the inlet and outlet sides of the module. The heat medium for the aforementioned temperature-regulating cooler is connected in a manner that allows it to enter the aforementioned shell-and-tube heat exchanger, and the feed liquid line is configured to flow inside the shell-and-tube heat exchanger. A thermometer for measuring the temperature of the feed liquid is installed on the feed liquid line leaving the shell-and-tube heat exchanger. Thus, the feed liquid is temperature-regulated before entering the forward osmosis membrane module. The feed liquid flows in a unidirectional direction, leaving the feed liquid tank and sequentially passing through a pump, flow meter, conductivity meter (inlet-side conductivity), pressure gauge (inlet-side pressure), heat exchanger, thermometer, forward osmosis membrane module, pressure gauge (outlet-side pressure), conductivity meter (outlet-side conductivity), and then being recycled to another tank without returning to the feed liquid tank. A balance is installed below the other tanks to measure the weight of the feed liquid flowing out unidirectionally. A drive solution tank and a drive solution line connecting the drive solution tank to the forward osmosis membrane module are prepared. The drive solution line has a bypass line that allows the drive solution to be circulated before connection to the forward osmosis membrane module. A pump for supplying the driving solution from the driving solution tank to the forward osmosis membrane module, and a flow meter for measuring the flow rate of the driving solution, are installed on the driving solution line. A back pressure valve for physically pressurizing the driving solution and adjusting the physical pressure difference between the feed solution and the driving solution is also installed on the driving solution line. Additionally, pressure sensors for measuring the physical pressure of the driving solution are installed on both the inlet and outlet sides of the module on the driving solution line. The heat medium for the temperature regulating cooler is connected in a manner that enters the shell-and-tube heat exchanger, and is configured such that the feed solution line and the driving solution line flow inside the shell-and-tube heat exchanger. A thermometer for measuring the temperature of the driving solution is installed on the driving solution line exiting the shell-and-tube heat exchanger. Thus, the driving solution is temperature-regulated before entering the forward osmosis membrane module.Regarding the flow direction of the driving solution, it is the flow direction that leaves the driving solution tank and passes sequentially through the pump, flow meter, pressure gauge (inlet side pressure), heat exchanger, thermometer, forward osmosis membrane module, pressure gauge (outlet side pressure), and back pressure valve, and then returns to the driving solution tank.

[0245] Regarding Examples 21 and 22, the feed solution flowed in a unidirectional direction, and the RSF was calculated by measuring the conductivity and weight of the feed solution discharged from the forward osmosis membrane module. Additionally, the Flux was calculated by measuring the weight increase of the drive solution. The drive solution was pre-circulated and pressurized within the forward osmosis membrane module, followed by feed solution flushing for evaluation. Regarding Example 21, the stabilization time was defined as the moment the feed solution initially discharged from the forward osmosis membrane module as 0 seconds, and data from 30 seconds later were used for evaluation. Regarding Example 22, no stabilization time was set, and data was used for evaluation from the moment the feed solution was discharged from the forward osmosis membrane module and could be measured. Furthermore, the feed solution flow rate was approximately 30 mL / min for unidirectional flow, and the drive solution flow rate was approximately 100 mL / min for circulation; other conditions were as described in the table. The evaluation was performed in the same manner as in Example 1. Regarding the evaluation interval, which includes post-evaluation device cleaning and raw material concentration adjustment, it requires more than 10 minutes in Example 1, compared to less than 2 minutes in Examples 21 and 22.

[0246] Regarding the calculation of RSF, in the case of inorganic salts, a pre-prepared calibration curve is used, and the weight of the driving solute moving from the driving solution side to the feed solution side is calculated based on the conductivity value measured using a conductivity meter, thereby determining the RSF. In the case where multiple components are involved in the conductivity, the amount of cations ionized from the driving solute being measured is continuously measured using an ICP-MS (Inductively Coupled Plasma Mass Analyzer) device manufactured by Thermo Fishier Scientific, model "iCAP Q," and the RSF is similarly determined. For example, in Reference Example 1, the amount of cations ionized from the driving solute being measured is determined by measuring Na... + And calculations are performed. In Example 17, regarding the RSF measurement target, the Na content of NaCl is measured. + Calculations are then performed. In the case of organic compounds, the RSF is calculated using a pre-prepared calibration curve. The weight of the driving solute moving from the driving solution side to the feed solution side is calculated based on the area values ​​of each peak determined by gas chromatography, and thus the RSF is determined. It should be noted that the performance of the forward osmosis membrane depends on the intermembrane pressure difference; the higher the pressure on the driving solution side, the greater the amount of salt moving from the driving solution to the feed solution. This is due to the application of a so-called reverse osmosis treatment (i.e., applying pressure in the opposite direction to the osmotic pressure difference) simultaneously with the forward osmosis treatment.

[0247] <Simulated Fluid Operation>

[0248] Next, to confirm the practical performance of the forward osmosis membranes obtained in Manufacturing Examples 1-3, forward osmosis treatment was performed under the following conditions. After the basic performance evaluation of the forward osmosis membrane modules described above, the forward osmosis membrane modules were rinsed with water for more than 5 hours and then concentrated 5 times with the following simulated solution. Each of the five modules was tested once, for a total of five tests. Specifically, for Reference Example 1, one module was evaluated five times.

[0249] Raw material solution: Add magnesium chloride to a 20% (w / w) sucrose aqueous solution, according to the Mg content in the solution. 2+ The analyte was prepared by dilution to achieve an ion concentration of 60 ppm. Initial temperature: 20°C; flow rate: approximately 88 mL / min (linear velocity approximately 3.7 cm / s; residence time approximately 2 seconds); solution volume: 10 L.

[0250] Driven solution: 30% magnesium chloride aqueous solution, initial temperature 25℃, flow rate 390 mL / min (linear velocity approximately 3.7 cm / s, residence time approximately 2 seconds), solution volume 10 L

[0251] Physical pressure difference: This is left unadjusted and allowed to develop. The feed solution and driving solution are delivered using a tubular pump, creating pulsations and applying accompanying pressure variations. The pressure applied through these pulsations also depends on the viscosity of the solution; therefore, the physical pressure difference changes over time.

[0252] Temperature: No adjustments will be made; allow it to develop. Ambient temperature: 25℃

[0253] Operating time: The scale is marked so that the internal liquid volume can be calculated in advance based on the liquid level in both the feed liquid side and the drive solution tank. The amount of water movement is measured based on the shift of the liquid level in the feed liquid tank. The operation is stopped when the feed liquid reaches approximately 2L after about 5 times concentration, based on the amount of water moving from the feed liquid to the drive solution. The amount of water and each salt movement is then measured separately.

[0254] In the assay, a small, saturated concentration of the driving solution was added in portions to the diluted driving solution to maintain the initial concentration. The assay was performed at 25°C. To calculate the amount of salt movement, an inductively coupled plasma mass spectrometry (ICP-MS) instrument, model "iCAP Q," manufactured by ThermoFishier Scientific, was used to determine the cations (MgO from magnesium chloride, the solute in the driving solution). 2+ The amount of ions.

[0255] <Evaluation of Mg Concentration After Simulation Solution Concentration: Practical Deviation Evaluation>

[0256] As a practical benchmark for deviation evaluation, the simulated solution was concentrated using five components (one component × five times in Example 1), and the Mg that diffused from the driving solution into the feed solution was calculated. 2+ The difference between the maximum and minimum ion concentrations, i.e., the difference between the result showing the highest value and the result showing the lowest value among the five components (five times in Reference Example 1), was evaluated according to the following criteria A to C. The results are shown in Table 1.

[0257] A: Mg in the concentrated feed solution 2+ Cases where the difference between the maximum and minimum ion concentrations is less than 100 ppm by mass.

[0258] B: Mg in the concentrated feed solution 2+ The case where the difference between the maximum and minimum ion concentrations is greater than 100 ppm by mass and less than 500 ppm by mass.

[0259] C: Mg in the concentrated feed solution 2+ When the difference between the maximum and minimum ion concentrations is greater than 500 ppm by mass.

[0260] <Judgment of Evaluation Accuracy>

[0261] The accuracy of the evaluation is assessed based on the fundamental performance evaluation results of the forward osmosis membrane and the practical deviations observed in the simulated solution. When the fundamental performance evaluation results of the forward osmosis membrane module can accurately evaluate the practical performance of the membrane, the following conditions should be met: If the RSF / Flux coefficient of variation of the fundamental performance evaluation results is below 20%, it should tend to have low deviation in the simulated solution (Evaluation A); if it is between 20% and 40%, even with the simulated solution, there should be some degree of deviation (Evaluation B); if it is above 40%, it should tend to have large deviation in the simulated solution (Evaluation C). Therefore, cases meeting these tendencies are considered good accuracy (B), with cases where the RSF / Flux coefficient of variation of the fundamental performance evaluation results is below 10%, allowing for better performance evaluation, being considered excellent accuracy (A). Cases not meeting these tendencies are considered poor accuracy (C).

[0262] The measurement and evaluation results are recorded in Tables 1 to 4 below. The abbreviations used in the tables are as follows.

[0263] FS: Feed Solution

[0264] DS: Draw Solution

[0265] NaCl: Sodium chloride (aqueous solution)

[0266] MgCl2: Magnesium chloride (aqueous solution)

[0267] MgSO4: Magnesium sulfate (aqueous solution)

[0268] IPA: Isopropanol (aqueous solution)

[0269] MeCN: Acetonitrile

[0270]

[0271]

[0272] [Table 3]

[0273]

[0274] [Table 4]

[0275]

[0276] As shown in Tables 3 and 4, the practical performance of the forward osmosis membrane was evaluated with good accuracy in the evaluation methods of the embodiments. In the evaluation method of Comparative Example 1, the evaluation could not be performed with good accuracy because the pressure of the driving solution was atmospheric pressure (0 kPa). In the evaluation method of Comparative Example 2, the pressure of the driving solution was atmospheric pressure (0 kPa), and although the feed solution was pressurized (20 kPa), the evaluation could not be performed with good accuracy. In the evaluation method of Comparative Example 3, the pressure of the driving solution was high, at 350 kPa, so it can be considered that the separation functional layer had peeled off or been damaged. Reference Example 1 is an example of eliminating deviations caused by individual differences in the component by repeatedly measuring the same component, showing that the evaluation method of this disclosure has a small coefficient of variation and high evaluation accuracy in performance evaluation.

[0277] Industrial applicability

[0278] The evaluation method and evaluation apparatus disclosed herein can be used to determine the practical performance of forward osmosis membranes, and in particular, can be suitably used to determine the practical performance of forward osmosis membranes including a supporting membrane and a separation functional layer.

[0279] Explanation of symbols

[0280] 10 Forward Osmosis Membrane Module

[0281] 10a Space on the side of the porous support

[0282] 10b Separation of functional layer side space

[0283] 11 Forward Osmosis Membrane

[0284] 11a Porous support

[0285] 11b Separate functional layers

[0286] 12. Inner catheter

[0287] 13 Lateral catheter

[0288] 14 Adhesive fixing part

[0289] 15. Effective membrane area

[0290] 20. Raw material liquid pipeline

[0291] 21 Raw material liquid tank

[0292] 22 Raw material liquid supply pump

[0293] 30 Drive solution pipeline

[0294] 31 Drive solution tank

[0295] 32 Drive solution supply pump

[0296] 33 Pressure regulating valve

[0297] 34 Pressure Sensors

[0298] Evaluation system for 100 forward osmosis membrane modules

[0299] P1 Solvent movement direction

[0300] P2 Direction of physical pressure application

Claims

1. A method for evaluating a forward osmosis membrane module, wherein the evaluation method is for a forward osmosis membrane module having spaces separated by a forward osmosis membrane, wherein, The forward osmosis membrane has a support membrane with a porous support and a separation functional layer disposed on the porous support. The method includes the following steps: The preparation process includes preparing a feed liquid line for feeding a feed liquid containing solvent into the forward osmosis membrane module, and a drive solution line for feeding a drive solution with an osmotic pressure higher than that of the feed liquid into the forward osmosis membrane module. The connection process involves connecting the space on the separation functional layer side of the forward osmosis membrane assembly to the feed liquid line, and connecting the space on the porous support side to the drive solution line. as well as The evaluation process involves using the forward osmosis membrane to allow the feed solution and the driving solution to flow in convection or co-flow, ensuring the porous support side is positive and adjusting the physical pressure difference between the forward osmosis membranes to a constant range greater than 0 kPa and less than 200 kPa, while simultaneously moving the solvent in the feed solution into the driving solution.

2. The method as described in claim 1, wherein, Prior to the step of connecting the forward osmosis membrane module to the feed solution line and the drive solution line, the process further includes: The process of circulating the driving solution outside the forward osmosis membrane module while adjusting the physical pressure of the driving solution to be greater than 0 kPa and less than 200 kPa.

3. The method as described in claim 1 or 2, wherein, The physical pressure difference is 20 kPa to 100 kPa.

4. The method as described in claim 1 or 2, wherein, Prior to the step of connecting the forward osmosis membrane module to the feed solution line and the drive solution line, the process further includes: The process of adjusting the temperature difference between the raw material solution and the driving solution to within 10°C.

5. The method as described in claim 1 or 2, wherein, Prior to the step of connecting the forward osmosis membrane module to the feed solution line and the drive solution line, the process further includes: The adjustment process involves adjusting the flow rates of the feed solution and the driving solution so that, after connecting the forward osmosis membrane assembly, the difference between the residence time of the feed solution in the space on the separation functional layer side and the residence time of the driving solution in the space on the porous support side is within 20 seconds.

6. The method as described in claim 1 or 2, wherein, The solvent is water.

7. The method of claim 6, wherein, The driving solution is supplied after the feed solution is supplied to the forward osmosis membrane module.

8. The method as claimed in claim 1 or 2, wherein, The solution containing the feed solution that has been supplied to and left the forward osmosis membrane module is not returned to the feed solution tank.

9. The method of claim 8, wherein, The performance of the forward osmosis membrane is evaluated by measuring at least one of the following parameters: conductivity, refractive index, total organic carbon, chemical oxygen demand, biochemical oxygen demand, absorbance, and transmittance, between the feed solution and the solution containing the feed solution after it has been supplied to and exited the forward osmosis membrane module. The measured parameters are then compared with the driving solution.

10. The method of claim 8, wherein, Evaluation begins 10 seconds after the feed solution is first discharged from the forward osmosis membrane module.

11. The method as claimed in claim 1 or 2, wherein, The driving solute contained in the driving solution is selected from at least one of inorganic salts and hydrophilic organic compounds.

12. The method of claim 11, wherein, The number-average molecular weight of the driving solute is 20 to 300.

13. The method of claim 11, wherein, The driving solute comprises a monovalent salt.

14. The method of claim 11, wherein, The driving solute comprises an alcohol and / or acetonitrile with 1 to 4 carbon atoms.

15. The method of claim 11, wherein, Based on the total mass of the driving solution, the concentration of the driving solute is 1% by mass or more.

16. The method as claimed in claim 1 or 2, wherein, The forward osmosis membrane module is a hollow fiber membrane module.

17. The method as claimed in claim 1 or 2, wherein, Prior to the step of connecting the forward osmosis membrane module to the feed solution line and the drive solution line, the process further includes: The adjustment process involves adjusting the flow rates of the feed solution and the driving solution so that, after connecting the forward osmosis membrane assembly, the difference between the linear velocity of the feed solution in the space on the separation functional layer side and the linear velocity of the driving solution in the space on the porous support side is within 10 cm / s.

18. The method as claimed in claim 1 or 2, wherein, The physical pressure difference is less than or equal to the osmotic pressure difference between the feed solution and the driving solution.

19. The method as claimed in claim 1 or 2, wherein, In the evaluation process, the temperature difference between the raw material solution and the driving solution is adjusted to within 10°C.

20. The method of claim 1 or 2, wherein, In the evaluation process, the flow rates of the raw material liquid and the driving solution are adjusted such that the difference between the residence time of the raw material liquid in the space on the separation functional layer side and the residence time of the driving solution in the space on the porous support side is within 20 seconds.

21. The method as claimed in claim 1 or 2, wherein, In the evaluation process, the flow rates of the raw material liquid and the driving solution are adjusted such that the difference between the linear velocity of the raw material liquid in the space on the separation functional layer side and the linear velocity of the driving solution in the space on the porous support side is within 10 cm / s.

22. The method as claimed in claim 1 or 2, wherein, The performance of the forward osmosis membrane module for evaluation is selected from the salt reverse diffusion rate RSF (g / (m³)). 2 ×hr), Flux permeability (kg / (m³) 2 At least one of the following groups: (×hr) and salt permeability RSF / Flux (g / kg) obtained by dividing RSF by Flux.

23. An evaluation device for a forward osmosis membrane module having a forward osmosis membrane, the forward osmosis membrane having a support membrane having a porous support and a separation functional layer disposed on the porous support, the evaluation device comprising: Raw material liquid storage tank; A feed liquid pipeline connects the feed liquid tank to the forward osmosis membrane module; The feed liquid supply unit supplies the feed liquid from the feed liquid tank to the forward osmosis membrane module through the feed liquid pipeline; A drive solution tank stores a drive solution with an osmotic pressure higher than that of the raw material solution; A drive solution line is used to connect the drive solution tank to the forward osmosis membrane assembly; A drive solution supply unit supplies the drive solution from the drive solution tank to the forward osmosis membrane module through the drive solution pipeline; A pressure adjustment unit, which is installed on the drive solution line and is capable of physically pressurizing the drive solution before, during, and after the evaluation of the forward osmosis membrane module, is configured to maintain a constant physical pressure difference between the drive solution and the feed solution within a range greater than 0 kPa and less than 200 kPa via the forward osmosis membrane; and A pressure sensor is installed on the drive solution pipeline and is capable of measuring the physical pressure of the drive solution.

24. The evaluation apparatus as claimed in claim 23, wherein, The drive solution line has a circulation structure that allows the drive solution to circulate outside the forward osmosis membrane module before being connected to it, and includes a drive solution bypass line that forms part of the circulation structure of the drive solution line and can be installed and removed from the forward osmosis membrane module.

25. The evaluation apparatus as described in claim 23 or 24, wherein, The feedstock line has a circulation structure that allows the feedstock to circulate outside the forward osmosis membrane module before being connected to it, and also includes a feedstock bypass line that forms part of the circulation structure of the feedstock line and can be detached from the forward osmosis membrane module.

26. The evaluation apparatus as claimed in claim 23 or 24, wherein, The raw material pipeline is equipped with at least one of a pressure regulating unit and a temperature regulating unit.

27. The evaluation apparatus as described in claim 23 or 24, wherein, The driving solution pipeline is further provided with a temperature regulation unit.

28. The evaluation apparatus as described in claim 23 or 24, wherein, The raw material pipeline is equipped with at least one of the following: a pressure sensor, a temperature sensor, a flow sensor, a conductivity sensor, and a refractive index sensor.

29. The evaluation apparatus as described in claim 23 or 24, wherein, The drive solution pipeline includes at least one of the group consisting of a temperature sensor, a flow sensor, a conductivity sensor, and a refractive index sensor.

30. The evaluation apparatus as described in claim 23 or 24, wherein, A temperature control unit is provided in the raw material tank or the driving solution tank, or both.

31. The evaluation apparatus as described in claim 23 or 24, wherein, The raw material tank or the driving solution tank, or both, may have at least one of the group consisting of a temperature sensor, a conductivity sensor, and a refractive index sensor.

32. The evaluation apparatus as described in claim 23 or 24, wherein, It has multiple sets of feed liquid lines and drive solution lines, enabling parallel evaluation of multiple forward osmosis membrane modules.

33. The evaluation device as described in claim 23 or 24, configured in such a way that it monitors in real time the values ​​and times measured by the various sensors it possesses, stores them in a database, and is capable of detecting the difference between the values ​​of the feed solution or the driving solution, or both, during solution circulation before evaluation and the values ​​during evaluation of the forward osmosis membrane module.

34. The evaluation apparatus as described in claim 23 or 24, wherein, The raw material pipeline is equipped with a pressure regulating unit, a pressure sensor, and a flow sensor. A flow sensor is further provided on the drive solution line. The evaluation device further includes a control device integrated with the respective pressure sensor, flow sensor, and pressure adjustment unit on the raw material pipeline and the driving solution pipeline, as well as the raw material supply unit and the driving solution supply unit. The control device is configured to compare the physical pressure difference, flow rate, and minimum flow rate of the raw material liquid and the driving solution in real time, and is configured to control the pressure adjustment unit, the raw material liquid supply unit, and the driving solution supply unit to maintain the desired physical pressure difference and the flow rate above the minimum flow rate.

35. The evaluation apparatus of claim 34, configured to maintain the real-time physical pressure difference within ±1 kPa of the desired physical pressure difference.

36. The evaluation apparatus of claim 34 is configured such that by inputting information on the cross-sectional areas of the feed solution supply section and the drive solution supply section within the forward osmosis membrane module, the desired physical pressure difference, and the desired minimum flow rate of the feed solution, the pressure and flow rate of the drive solution can be determined and controlled in advance before the evaluation of the forward osmosis membrane module.

37. The evaluation apparatus as claimed in claim 34, wherein, The control device includes a processor configured to perform proportional-integral-derivative control operations.

38. The evaluation apparatus as described in claim 23 or 24, wherein, The driving solution pipeline and / or the driving solution tank further includes a concentration adjustment unit, which is capable of removing solvent from the driving solution, adding a high concentration of driving solution to the driving solution, or adding at least one of the driving solutes.

39. The evaluation apparatus as described in claim 23 or 24, wherein, The forward osmosis membrane module is a hollow fiber membrane module.

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