Dehydration methods for organic feedstock liquid

Abstract

This invention provides a method for treating a feedstock containing a small amount of water as an organic solution under non-heating conditions via forward osmosis to obtain a dehydrated feedstock without decomposition or deterioration of the solute. A method for dehydrating a feedstock containing a first organic solvent, water, and a first solute is provided, comprising a dehydration step in which the feedstock is contacted with a driving organic liquid containing a second organic solvent through a forward osmosis membrane to obtain a dehydrated feedstock with a water content of less than 1% by mass. In one embodiment, the initial water content of the feedstock in the dehydration step is 1% by mass or more and less than 30% by mass, and the initial water content of the driving organic liquid is less than the initial water content of the feedstock.

Description

Technical Field

[0001] This invention relates to a method for dehydrating organic feedstock solutions. More specifically, it relates to a method for dehydrating water from a feedstock solution containing an organic solvent, a small amount of water, and a solute via forward osmosis. Background Technology

[0002] In various chemical processes, there are dehydration steps to remove water contained in organic liquids. For example, there are cases where dehydration is carried out from the feed solution before a chemical reaction known as an anhydrous reaction (a reaction in which the desired outcome will not occur in the presence of water); cases where the water content in an organic solution is adjusted in order to recrystallize the solute to obtain crystals of the desired shape, size, or purity; cases where water generated as a byproduct in an equilibrium reaction is removed from the reaction system to increase the yield of the target product; and so on.

[0003] Common dehydration methods include azeotropic evaporation, which involves adding an organic solvent that forms an azeotropic mixture with water to the feed liquid and heating the feed liquid to remove water and the added organic solvent; and methods involving adding a desiccant that selectively adsorbs water to the feed liquid.

[0004] However, in the azeotropic evaporation method, there are problems such as changes in the quality of the components in the feed liquid due to heating. In methods where a desiccant is added to the feed liquid, there is a risk that solutes in the feed liquid may also be adsorbed, and that the added desiccant may need to be removed from the feed liquid before the next process. Furthermore, as the scale of the dehydration process increases, there are also problems such as difficulty in achieving reproducible dehydration.

[0005] Therefore, as another useful dehydration method, forward osmosis (FO) is known to separate the solvent in the feed solution using the difference in osmotic pressure. Forward osmosis involves contacting the feed solution with a driving fluid having a higher osmotic pressure than the feed solution through a forward osmosis (FO) membrane, causing the solvent to migrate from the feed solution to the driving fluid, thereby concentrating the feed solution. When the solvent is water, forward osmosis can be used to dehydrate and concentrate aqueous solutions. Forward osmosis does not require heating or pressurization. Therefore, it is expected that forward osmosis can prevent the decomposition or deterioration of the solute and can treat the solution while maintaining the quality of the solute.

[0006] For example, Patent Document 1 describes a method for dehydrating an alcohol-water solution using forward osmosis. Patent Document 2 describes a system for treating a solution containing organic compounds using a forward osmosis membrane with polyketide as the membrane material, and a method for removing water from an aqueous solution using this system.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: International Publication No. 2010 / 080208

[0010] Patent Document 2: International Publication No. 2016 / 024573 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] However, the techniques described in Patent Documents 1 and 2 cannot achieve a solution for removing small amounts of water contained in an organic solution. In view of the above, one aspect of the present invention provides a method for dehydrating a raw material solution, which is an organic solution containing a small amount of water, without decomposing or deteriorating the solute contained therein.

[0013] Methods for solving problems

[0014] That is, the following shows an example of a way of implementing the present invention.

[0015] [1] A method for dehydrating a feed liquid comprising a first organic solvent, water and a first solute, wherein,

[0016] The method includes a dehydration step in which the above-mentioned feed liquid is brought into contact with a driving organic liquid containing a second organic solvent through a forward osmosis membrane to obtain a dehydrated feed liquid with a water content of less than 1% by mass.

[0017] Here, the initial moisture content of the raw material liquid in the above-mentioned dehydration process is more than 1% by mass and less than 30% by mass, and the initial moisture content of the driving organic liquid is less than the initial moisture content of the raw material liquid.

[0018] [2] As described in method 1 above, wherein,

[0019] The aforementioned forward osmosis membrane is a composite membrane consisting of a separation active layer and a microporous support membrane.

[0020] The difference in solubility parameters, ΔHSP, between the aforementioned driving organic liquid and the aforementioned separation active layer is ΔHSP < 16 (MPa). 0.5 ,and

[0021] The saturated water content of the aforementioned driving organic liquid is 0.5% by mass or more.

[0022] [3] As described in method 1 or 2 above, wherein the solubility parameter of the driving organic liquid is 13 (MPa). 0.5 ≦δd≦20(MPa) 0.5 2 (MPa) 0.5 ≦δp≦18(MPa) 0.5 2 (MPa) 0.5≦δH≦28(MPa) 0.5 .

[0023] [4] The method as described in any one of the above methods 1 to 3, wherein the driving organic liquid further comprises a second solute and / or a desiccant.

[0024] [5] The method as described in any one of methods 1 to 4 above, wherein,

[0025] The above-mentioned dehydration process is carried out in a dehydration apparatus equipped with a raw material liquid system for circulating the above-mentioned raw material liquid and a drive liquid system for circulating the above-mentioned driving organic liquid.

[0026] The above-mentioned raw material liquid system and the above-mentioned driving liquid system are configured in a manner that inhibits the migration of the first organic solvent and the second organic solvent to the outside of the system due to vaporization.

[0027] [6] The method as described in any one of embodiments 1 to 5 above, wherein the second organic solvent is selected from tetrahydrofuran, 2-methyltetrahydrofuran, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, toluene, cyclopentyl methyl ether, tert-butyl methyl ether, acetonitrile, dimethylacetamide, N-methylpyrrolidone, hexafluoroisopropanol, acetic acid, acetone, anisole, benzene, chlorobenzene, carbon tetrachloride, chloroform, cumene, cyclohexane, 1,2-di( ... At least one of the following groups: chloroethane, 1,2-dichloroethylene, dichloromethane, 1,2-dimethoxyethane, N,N-dimethylformamide, dimethyl sulfoxide, 1,4-dioxane, diethyl ether, ethyl formate, formamide, formic acid, heptane, hexane, methyl butyl ketone, methyl cyclohexane, methyl ethyl ketone, methyl isobutyl ketone, pentane, nitromethane, pyridine, sulfolane, tetrahydronaphthalene, 1,1,1-trichloroethane, 1,1,2-trichloroethylene, and xylene.

[0028] [7] The method as described in any one of the above methods 1 to 6, wherein, in the above dehydration step, an organic liquid containing the above first organic solvent and having a moisture content of 0.5% by mass or less is added to the above raw material liquid, which has been reduced in volume due to dehydration and concentration.

[0029] [8] The method of any one of the above methods 1 to 7, wherein the first solute in the above dehydrated raw material liquid is supplied in an anhydrous reaction in which the first solute and other reagents are chemically reacted under anhydrous conditions.

[0030] [9] The method as described in any one of the above methods 1 to 8, wherein the method further includes a crystallization step of refining the first solute by crystallization.

[0031]

[10] The method as described in any one of embodiments 1 to 9 above, wherein,

[0032] The above method further includes a separation step of extracting the organic layer from the liquid containing the first solute before the above dehydration step.

[0033] The organic layer described above is used as the raw material solution described above.

[0034]

[11] The method as described in any one of embodiments 1 to 10 above, wherein,

[0035] The above method further includes a regeneration process.

[0036] The above-mentioned regeneration process is a process of removing water that migrates from the above-mentioned raw material liquid to the above-mentioned driving organic liquid from the above-mentioned driving organic liquid.

[0037]

[12] The method described in the above manner 11, wherein, in the above regeneration process, a desiccant or a dehydrating agent is added to the above driving organic liquid.

[0038]

[13] The method as described in method 11 or 12 above, wherein, in the above regeneration process, the driving organic liquid is dehydrated by azeotropic distillation or membrane treatment.

[0039]

[14] The method as described in any one of methods 1 to 13 above, wherein,

[0040] The above method further includes a coarse dewatering step before the aforementioned dewatering step.

[0041] The above-mentioned crude dehydration process involves contacting the crude feed liquid with a driving aqueous solution containing a third solute through a forward osmosis membrane to obtain a feed liquid with a water content of 1% by mass or more and less than 30% by mass.

[0042]

[15] As described in method 14 above, wherein,

[0043] The aforementioned coarse dewatering process is carried out in a dewatering apparatus equipped with a raw material liquid system for circulating the aforementioned coarse raw material liquid and a drive liquid system for circulating the aforementioned drive aqueous solution.

[0044] The above-mentioned raw material liquid system is configured to suppress the migration of the first organic solvent out of the system due to vaporization.

[0045]

[16] The method as described in method 14 or 15 above, wherein, in the above-described crude dehydration step, an organic liquid containing the above-described first organic solvent and having a moisture content of 0.5% by mass or less is added to the above-described crude raw material liquid, which has been reduced in volume due to dehydration and concentration.

[0046]

[17] The method as described in any one of the above methods 1 to 16, wherein the above method is used for the manufacture of a drug.

[0047] The effects of the invention

[0048] According to one aspect of the invention, a method can be used to dehydrate an organic solution containing a small amount of water and solute under non-heating conditions without decomposition or deterioration of the solute. This method can be suitably used, for example, in the manufacture of pharmaceuticals to dehydrate organic solutions containing solutes. Attached Figure Description

[0049] Figure 1 This is a schematic diagram illustrating an example of a dehydration apparatus used in the method of the present invention.

[0050] Figure 2 This is a cross-sectional view illustrating an example of a forward osmosis membrane assembly used in the method of the present invention.

[0051] Figure 3 This is a flowchart illustrating a first embodiment of the method of the present invention.

[0052] Figure 4 This is a flowchart illustrating a second embodiment of the method of the present invention.

[0053] Figure 5 This is a schematic diagram illustrating an example of an apparatus used to manufacture a forward osmosis membrane module. Detailed Implementation

[0054] The exemplary embodiments for carrying out the present invention (hereinafter also referred to as these embodiments) will now be described in detail with reference to the accompanying drawings, which are non-limiting examples. Various features shown in the following embodiments can be combined with each other.

[0055] Overview of Dehydration Methods for Organic Feed Liquids

[0056] Figure 1 This is a schematic diagram illustrating an example of a dehydration device. Figure 2 This is a cross-sectional view showing an example of a forward osmosis membrane module. Figure 3 and Figure 4 This is a flowchart illustrating the process of the method described in this embodiment. (Refer to...) Figures 1-4 The method of this embodiment is used for dehydrating a feed liquid 4 containing a first organic solvent, water, and a first solute. The method of this embodiment is characterized by a dehydration step S103, in which the feed liquid 4 is contacted with a driving organic liquid 5 containing a second organic solvent through a forward osmosis membrane 23 to obtain a dehydrated feed liquid with a water content of less than 1% by mass. The feed liquid 4 can be, for example, an organic layer extracted from a liquid containing the first solute in a separation step S101 performed prior to the dehydration step S103.

[0057] The method of this embodiment may further include a regeneration step S104, which is a step of removing water that has migrated from the raw material liquid 4 to the driving organic liquid 5 from the driving organic liquid 5. The driving organic liquid 5, from which water has been removed in the regeneration step S104, is reused in a dehydration step S103 for the dehydration of the raw material liquid 4.

[0058] The dehydration step S103 can be performed before the anhydrous reaction step S106 (where the first solute undergoes a chemical reaction with other reagents under anhydrous conditions). Furthermore, the method of this embodiment may further include a crystallization step S105, which purifies the first solute by crystallization. The crystallization step S105 can be performed before the dehydration step S103, or it can be performed after the dehydration step S103, replacing the anhydrous reaction step S106. Additionally, the dehydration step S103 can be performed on the reaction solution of the equilibrium reaction. The equilibrium reaction can be batch (intermittent) or flow (continuous).

[0059] The method of this embodiment may further include a coarse dehydration step S102 before the dehydration step S103. Specifically, the coarse dehydration step S102 is the following step: contacting the crude feed liquid with a driving aqueous solution containing a third solute through a forward osmosis membrane 23 to obtain the feed liquid 4 of this embodiment, which is dehydrated to a water content of 1% by mass or more and less than 30% by mass. The crude feed liquid is, for example, the organic layer extracted in the separation step S101 performed before the coarse dehydration step S102.

[0060] Composition of Dehydration Device 1

[0061] Reference Figures 1-4 An example of the configuration of the dehydration apparatus 1 that performs the dehydration process S103 will be described. The dehydration apparatus 1 consists of a feed liquid system 12 and a drive liquid system 13 that are in contact with each other across the forward osmosis membrane module 20. Each component will be described below.

[0062] <Forward Osmosis Membrane Module 20>

[0063] Reference Figure 1 and 2 The forward osmosis membrane module 20 has a structure in which a hollow fiber membrane bundle composed of a plurality of hollow fiber-shaped forward osmosis membranes 23 is filled in a cylindrical outer shell 30, and the two ends of the hollow fiber membrane bundle are fixed to the outer shell 30 by adhesive fixing parts 24 and 25. The outer shell 30 has shell-side conduits 21 and 22 on its side and top caps 26 and 27 at both ends. The adhesive fixing parts 24 and 25 are cured in a manner that the hollow part of the hollow fiber is not blocked.

[0064] Top caps 26 and 27 each have core-side conduits 28 and 29 that communicate with the inner side (hollow portion) of the hollow fibrous forward osmosis membrane 23 but not with the outer side of the membrane. The core-side conduits 28 and 29 allow liquid to be introduced into and removed from the inner side of the membrane 23. Shell-side conduits 21 and 22 communicate with the outer side of the membrane 23 but not with the inner side. The shell-side conduits 21 and 22 allow liquid to be introduced into and removed from the outer side of the membrane 23.

[0065] <Feed Liquid System 12>

[0066] like Figure 1 As shown, the feedstock system 12 includes a feedstock tank 2, feedstock delivery pipes 6 and 7, and a feedstock delivery pump 8. Feedstock 4 is filled in the feedstock tank 2 and circulates within the feedstock system 12. Specifically, feedstock 4 enters the forward osmosis membrane module 20 from the core-side conduit 28 via the feedstock delivery pipe 6 using the feedstock delivery pump 8. After passing through the inside of the forward osmosis membrane 23, feedstock 4 is discharged from the core-side conduit 29 and returned to the feedstock tank 2 via the feedstock delivery pipe 7.

[0067] <Driving Fluid System 13>

[0068] The drive fluid system 13 includes a drive fluid tank 3, drive fluid delivery pipes 9 and 10, and a drive fluid delivery pump 11. Drive organic fluid 5 is filled in the drive fluid tank 3 and circulates within the drive fluid system 13. Specifically, the drive organic fluid 5 enters the forward osmosis membrane module 20 from the shell-side conduit 21 via the drive fluid delivery pipe 9 using the drive fluid delivery pump 11. After passing through the outside of the forward osmosis membrane 23, the drive organic fluid 5 is discharged from the shell-side conduit 22 and returned to the drive fluid tank 3 via the drive fluid delivery pipe 10.

[0069] Here, the feed solution 4 and the driving organic liquid 5 are in contact through the wall of the hollow fiber forward osmosis membrane 23, but they do not mix directly. Furthermore, when the feed solution 4 and the driving organic liquid 5 are in contact through the wall of the forward osmosis membrane 23, water in the feed solution 4 migrates through the forward osmosis membrane 23 into the driving organic liquid 5, thus dehydrating the feed solution 4. The flow direction of the feed solution 4 and the driving organic liquid 5 in the forward osmosis membrane module 20 can be the same direction (co-current) through the wall of the forward osmosis membrane 23, or it can be the opposite direction (convection) through the wall of the forward osmosis membrane 23.

[0070] The feed liquid system 12 and the driving liquid system 13 are preferably configured to suppress the migration of the first and second organic solvents out of the system due to vaporization. Specifically, each component of the feed liquid system 12 and the driving liquid system 13 is preferably configured to prevent gas leakage from the feed liquid tank 2 and the driving liquid tank 3. For example, this can be achieved by making the feed liquid tank 2 and the driving liquid tank 3 covered tanks, or by providing condensers for condensing the vaporized organic solvents and returning them to the tanks. It should be noted that safety valves and / or back pressure valves can be installed in the feed liquid system 12 and the driving liquid system 13 to adjust their respective internal pressures. By preventing the volatilization of the first and second organic solvents, the moisture content of the feed liquid 4 and the driving organic liquid 5 can be prevented from increasing, and dehydration can be effectively performed.

[0071] <Forward Osmosis Membrane 23>

[0072] As the forward osmosis membrane 23, any membrane with the property of allowing water to pass through can be used without restriction. From the perspective of ensuring high membrane strength, the forward osmosis membrane 23 is preferably a composite membrane having a separation active layer on a support layer (support membrane). The support membrane can be a flat membrane or a hollow fiber membrane. When the support membrane is a flat membrane, the separation active layer can be on one or both sides of the support membrane. When the support membrane is a hollow fiber membrane, the separation active layer can be on the outer surface or the inner surface of the hollow fiber membrane, or both surfaces.

[0073] Regarding the forward osmosis membrane 23, modularization is convenient as described above. In the forward osmosis membrane module 20, if the forward osmosis membrane is a flat membrane, it can be, for example, a pleated module, a spiral module, etc.; if the forward osmosis membrane is a hollow fiber membrane, it can be, for example, a hollow fiber membrane module in which a bundle of the hollow fiber membrane is filled inside a cylinder. Here, the forward osmosis membrane module 20 is preferably a module formed by filling a bundle of the forward osmosis membrane 23, which is a hollow fiber membrane, inside a cylinder.

[0074] The supporting membrane is preferably a microporous hollow fiber supporting membrane. The microporous hollow fiber supporting membrane has micropores on its inner surface, preferably with a pore size of 0.001 μm to 2 μm, more preferably 0.001 μm to 0.2 μm. Materials used in ultrafiltration membranes, microfiltration membranes, etc., can be used as materials for the microporous hollow fiber supporting membrane. Specifically, examples of materials for the hollow fiber supporting membrane include polysulfone, polyethersulfone, polyvinylidene fluoride, polyacrylonitrile, polyethylene, polypropylene, cellulose-based polymers, polybenzimidazole, polyketone, polyamide, polyimide, polyetheretherketone, and their crosslinks, preferably containing at least one selected from these and / or one selected from these as a main component (i.e., the most abundant component). More preferably, the material of the hollow fiber supporting membrane contains at least one selected from polysulfone, polyethersulfone, polyketone, polyamide, polyimide, and their crosslinks, and / or one selected from these as a main component, and even more preferably polyketone.

[0075] As the separation active layer, a film layer comprising, for example, at least one polymer selected from polysulfone, polyethersulfone, polyvinylidene fluoride, polyacrylonitrile, polyethylene, polypropylene, polyamide, polyimide, cellulose acetate, etc., and / or one of them as the main component is preferred. These polymers may or may not be cross-linked. When the separation active layer is a cross-linked polymer, the degree of cross-linking can be arbitrary. Considering the dehydration efficiency of the feed liquid 4 and the ease of formation on the support layer, the separation active layer is preferably a polyamide layer, and one or more selected from non-cross-linked polyamides and cross-linked polyamides can be used. The polyamide constituting the separation active layer can be formed, for example, by interfacial polymerization of a multifunctional aromatic acyl halide with a multifunctional aromatic amine.

[0076] Multifunctional aromatic acyl halides are aromatic acyl halide compounds having two or more acyl halide groups in one molecule. Specifically, examples include pyromellitic tricarboxylate halides, trimellitic tricarboxylate halides, phthaloyl halides, isophthaloyl halides, terephthaloyl halides, pyromellitic tetracarboxylate halides, benzophenone tetracarboxylate halides, biphenyl dicarboxylate halides, naphthyl dicarboxylate halides, pyridine dicarboxylate halides, and benzene disulfonyl halides, etc., and one or a mixture of two or more of them can be used. In this invention, it is particularly preferred to use pyromellitic tricarboxylate chloride alone, or a mixture of pyromellitic tricarboxylate chloride and isophthaloyl chloride, or a mixture of pyromellitic tricarboxylate chloride and terephthaloyl chloride.

[0077] Polyfunctional aromatic amines are aromatic amino compounds having two or more amino groups in one molecule. Specifically, examples include m-phenylenediamine, p-phenylenediamine, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylamine, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenylamine, 3,5-diaminobenzoic acid, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 1,3,5'-triaminobenzene, and 1,5-diaminonaphthalene, etc., and one or a mixture of two or more of them can be used. In this embodiment, it is particularly preferred to use one or more selected from m-phenylenediamine and p-phenylenediamine.

[0078] <Raw Material Liquid 4>

[0079] The feed liquid 4 is an organic solution containing a first organic solvent, water, and a first solute. Here, the initial moisture content of the feed liquid 4 in the dehydration step S103 is 1% by mass or more and less than 30% by mass, preferably 1% by mass or more and less than 20% by mass, and more preferably 1% by mass or more and less than 15% by mass. Here, "initial moisture content" refers to the moisture content of the feed liquid 4 or the driving organic liquid 5 at the moment the feed liquid 4 is prepared in the feed liquid tank 2, or at the moment the driving organic liquid 5 is prepared in the driving liquid tank 3, and the same applies below. The method for determining the moisture content is described below.

[0080] The first organic solvent can be an ether (e.g., a cyclic ether), an ester, a hydrocarbon, a nitrogen-containing compound, a sulfur-containing compound, a halide, a ketone, etc. Specifically, it can be selected from tetrahydrofuran, 2-methyltetrahydrofuran, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, toluene, cyclopentyl methyl ether, tert-butyl methyl ether, acetonitrile, dimethylacetamide, N-methylpyrrolidone, hexafluoroisopropanol, acetic acid, acetone, anisole, benzene, chlorobenzene, carbon tetrachloride, chloroform, cumene, cyclohexane. The first organic solvent is at least one selected from the group consisting of alkanes, 1,2-dichloroethane, 1,2-dichloroethylene, dichloromethane, 1,2-dimethoxyethane, N,N-dimethylformamide, dimethyl sulfoxide, 1,4-dioxane, diethyl ether, ethyl formate, formamide, formic acid, heptane, hexane, methyl butyl ketone, methyl cyclohexane, methyl ethyl ketone, methyl isobutyl ketone, pentane, nitromethane, pyridine, sulfolane, tetrahydronaphthalene, 1,1,1-trichloroethane, 1,1,2-trichloroethylene, and xylene. The first organic solvent is preferably at least one selected from the group consisting of tetrahydrofuran, 2-methyltetrahydrofuran, ethyl acetate, isopropyl acetate, toluene, cyclopentyl methyl ether, and tert-butyl methyl ether; more preferably at least one selected from the group consisting of tetrahydrofuran, ethyl acetate, isopropyl acetate, toluene, and tert-butyl methyl ether; and even more preferably at least one selected from the group consisting of tetrahydrofuran, ethyl acetate, and isopropyl acetate.

[0081] The first solute can be any substance that does not pass through the forward osmosis membrane 23, and is not limited to a specific type. In one embodiment of the method, it is used for the manufacture of a drug. The first solute may be, for example, a raw material used in the pharmaceutical industry (e.g., amino acids such as phenylalanine, sugars such as sucrose, natural substances such as alkaloids isolated from nature such as quinine, compounds known as synthetic building blocks, etc.), an intermediate compound (e.g., a compound chemically synthesized or modified from raw materials such as octaacetyl sucrose, etc.), or a final compound (e.g., a drug substance) (e.g., a low-molecular-weight drug, a medium-molecular-weight drug such as a peptide or nucleic acid, a high-molecular-weight drug such as a protein, a vaccine, an antibiotic, etc.). The solute may be a solid or a liquid, or a mixture of multiple substances. It should be noted that the first organic solvent and the first solute are selected to be different substances.

[0082] Regarding the molecular weight of the first solute, from the perspective of preventing the first solute from permeating through the forward osmosis membrane 23 and preventing the first solute from adhering to the forward osmosis membrane 23, it is preferably 100 to 30,000 or less, more preferably 150 to 10,000 or less, and even more preferably 200 to 1,000 or less. Furthermore, when the useful substance is a polymer, the above molecular weight refers to the number-average molecular weight converted from polyethylene oxide as determined by gel permeation chromatography; when the useful substance is not a polymer, the above molecular weight refers to a value based on atomic weight. The concentration of the solute is not limited to a specific value and can be appropriately selected within a range soluble in the first organic solvent. Specifically, for example, relative to the total mass of the feed liquid 4, it can be 0.1% to 60% by mass, preferably 1% to 50% by mass, and even more preferably 5% to 40% by mass. By setting the concentration of the first solute to a predetermined value or higher, the amount of solute that can be processed in the dehydration device 1 at one time increases, thereby improving processing efficiency. By setting the concentration to a predetermined value or lower, the feed liquid 4 can be circulated within the dehydration device 1 without the first solute precipitating out.

[0083] <Drive Organic Liquid 5>

[0084] The driving organic liquid 5 contains a second organic solvent. Here, the second organic solvent is an organic liquid that does not permeate through the forward osmosis membrane 23. The driving organic liquid 5 is not an aqueous solution but an organic liquid containing a second organic solvent that does not permeate through the forward osmosis membrane 23, thereby preventing water from diffusing from the driving organic liquid 5 into the feed liquid 4, and enabling effective dehydration of the feed liquid 4 containing a small amount of water.

[0085] The solubility parameter difference ΔHSP between the driving organic liquid 5 and the separation active layer of the forward osmosis membrane 23 is preferably ΔHSP < 16 (MPa). 0.5It is believed that when the driving organic liquid and the separation active layer meet this condition, the separation active layer swells moderately, increasing the water permeation path and thus enabling suitable dehydration. ΔHSP is more preferably 15 MPa. 0.5 Below, or 14 (MPa) 0.5 Below, or 13 (MPa) 0.5 The following is a preferred approach: ΔHSP is small, but for ease of selection when choosing the combination of driving organic liquid and separation active layer, it can be 5 (MPa) in one configuration. 0.5 Above, or 6 (MPa) 0.5 Above, or 7 (MPa) 0.5 above.

[0086] The solubility parameter disclosed herein is the Hansen solubility parameter (HSP). The difference in solubility parameter ΔHSP between two substances can be calculated based on the dispersion term δd, polarity term δp, and hydrogen bonding term δH of the HSP using the following formula.

[0087] [Number 1]

[0088]

[0089] Regarding the HSP value of the separated active layer, the chemical structure of the polymer constituting the separated active layer can be converted into monomers through the steps shown below. The HSP of the monomers is calculated using the Hansen SP&QSPR model, an add-on to the commercially available software Winmostar 9.4.11, and this value is considered as the HSP of the separated active layer. For example, if the polymer is a linear, non-crosslinked polymer without branches, the repeating units of the polymer are removed, and the bonding portions between the repeating units are replaced with methyl groups. Then, the HSP of the monomers is calculated. On the other hand, if the polymer is a crosslinked polymer with branches, the repeating units are removed, and all uncrosslinked functional groups that may remain in an unreacted state outside the polymer ends are replaced with hydrogen groups. After converting the polymer and repeating units into a linear structure, the bonding portions between the converted repeating units are replaced with methyl groups. Then, the HSP of the monomers is calculated. The specific steps are described below.

[0090] The HSP value of the driving organic liquid can be determined based on the HSP values ​​of the n liquid components (component 1, 2, ... n) and their volume fractions in the driving organic liquid. Specifically, the calculation is performed as shown in the following formula. Solid components in the driving organic liquid are not considered in the HSP value calculation.

[0091] [Number 2]

[0092] V1 + V2 + ... + Vn = 1

[0093] δd=δd 1×V1+δd 2×V2+···+δdn×Vn

[0094] δp=δp 1×V1+δp 2×V 2+···+δpn×Vn

[0095] δH=δH 1×V1+δH 2×V 2+···+δHn×Vn

[0096] (in the formula,

[0097] V1, V2, ... Vn are the volume fractions of components 1, 2, ... n, respectively.

[0098] δd1, δd2, ..., δdn are the dispersion terms of the HSPs of components 1, 2, ..., n.

[0099] δp1, δp2, ..., δpn are the polar terms of the HSPs of components 1, 2, ..., n.

[0100] δH1, δH2, ..., δHn are the hydrogen bonding terms of the HSPs of components 1, 2, ..., n.

[0101] The HSP values ​​of each liquid component driving the organic liquid can be calculated using the Hansen SP&QSPR model, which is an add-on to the commercially available software Winmostar 9.4.11.

[0102] The solubility parameter (HSP) value for separating the active layer is preferably 15 (MPa). 0.5 Above, or 16 (MPa) 0.5 Above, or 17 (MPa) 0.5 The preferred pressure is 40 MPa. 0.5 Below, or 39 (MPa) 0.5 Below, or 38 (MPa) 0.5 the following.

[0103] The solubility parameter (HSP) value of the driving organic liquid is preferably 13 (MPa). 0.5 Above, or 14 (MPa) 0.5 Above, or 15 (MPa) 0.5 The preferred pressure is 39 MPa. 0.5 Below, or 38 (MPa) 0.5 Below, or 37 (MPa) 0.5 the following.

[0104] Among the solubility parameters for separating the active layer, δd is preferably 15 (MPa). 0.5 Above, or 16 (MPa) 0.5Above, or 17 (MPa) 0.5 The preferred pressure is 26 MPa. 0.5 Below, or 25 (MPa) 0.5 Below, or 24 (MPa) 0.5 Hereinafter, δp is preferably 2 (MPa). 0.5 Above, or 3 (MPa) 0.5 Above, or 4 (MPa) 0.5 The preferred pressure is 26 MPa. 0.5 Below, or 25 (MPa) 0.5 Below, or 24 (MPa) 0.5 Hereinafter, δH is preferably 1 (MPa). 0.5 Above, or 2 (MPa) 0.5 Above, or 3 (MPa) 0.5 The preferred pressure is 20 MPa. 0.5 Below, or 19 (MPa) 0.5 Below, or 18 (MPa) 0.5 the following.

[0105] Among the solubility parameters driving the organic liquid, δd is preferably 13 (MPa). 0.5 Above, or 14 (MPa) 0.5 Above, or 15 (MPa) 0.5 The preferred pressure is 20 MPa. 0.5 Below, or 19 (MPa) 0.5 Below, or 18 (MPa) 0.5 Hereinafter, δp is preferably 2 (MPa). 0.5 Above, or 3 (MPa) 0.5 Above, or 4 (MPa) 0.5 The preferred value is 18 MPa. 0.5 Below, or 17 (MPa) 0.5 Below, or 16 (MPa) 0.5 Hereinafter, δH is preferably 2 (MPa). 0.5 Above, or 3 (MPa) 0.5 Above, or 4 (MPa) 0.5 The preferred pressure is 28 MPa. 0.5 Below, or 27 (MPa) 0.5 Below, or 26 (MPa) 0.5 the following.

[0106] The saturated water content of the driving organic liquid is preferably 0.5% by mass or more, or 1.0% by mass or more, or 2.0% by mass or more. It is believed that by satisfying this condition, water can be suitably migrated from the feed liquid into the driving organic liquid. The saturated water content is preferably 100% (i.e., arbitrarily mixable with water), and from the perspective of dehydration efficiency, it can be, for example, 99% by mass or less, or 98% by mass or less, or 97% by mass or less.

[0107] The saturated water content of the driving organic liquid can be determined using the following steps. Water and the driving organic liquid are mixed in equal weight using a separatory funnel. If no two layers (water and organic) are formed, the driving organic liquid and water are considered to be mixed in any proportion. If two layers are formed, separation is performed, and the moisture content of the resulting organic layer is considered the saturated water content. The method for determining the moisture content is described below.

[0108] When the saturated water content of the driving organic liquid is unknown and the driving organic liquid contains solvents that can be mixed with water in any way, water is added to the driving organic liquid little by little. The water content is calculated by the following formula based on the amount of water (g) added until the two phases are about to be formed and the amount of driving organic liquid used (g), and this is taken as the saturated water content.

[0109] [Number 3]

[0110]

[0111] The dehydration efficiency can be calculated based on the moisture content and volume of the feed liquid (FS) using the following formula. Additionally, the t-minute value below can be selected as approximately one-eighth to one-quarter of the total operating time. The degree of dehydration at the end of the operation can be inferred from the dehydration efficiency at the beginning of operation.

[0112] [Number 4]

[0113]

[0114] For example, if the first solute and / or the second solute precipitates during operation, consider the following correction to the dehydration efficiency. Stop operation when solute precipitation is confirmed, and measure the total weight (A) of the feed liquid. Then measure the moisture content of the supernatant. Use this moisture content as the moisture content of the feed liquid (FS) after t minutes. Additionally, filter out the precipitated solute and measure its weight (B). Use the weight of (A) - (B) as the volume of the feed liquid (FS) after t minutes.

[0115] The second organic solvent can be an ether (e.g., a cyclic ether), an ester, a hydrocarbon, a nitrogen-containing compound, a sulfur-containing compound, a halogen, a ketone, an alcohol, etc. Specifically, it can be selected from tetrahydrofuran, 2-methyltetrahydrofuran, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, toluene, cyclopentyl methyl ether, tert-butyl methyl ether, acetonitrile, dimethylacetamide, N-methylpyrrolidone, hexafluoroisopropanol, acetic acid, acetone, anisole, benzene, chlorobenzene, carbon tetrachloride, chloroform, cumene, cyclohexane, 1, The second organic solvent is at least one selected from the group consisting of 2-dichloroethane, 1,2-dichloroethylene, dichloromethane, 1,2-dimethoxyethane, N,N-dimethylformamide, dimethyl sulfoxide, 1,4-dioxane, diethyl ether, ethyl formate, formamide, formic acid, heptane, hexane, methyl butyl ketone, methyl cyclohexane, methyl ethyl ketone, methyl isobutyl ketone, pentane, nitromethane, pyridine, sulfolane, tetrahydronaphthalene, 1,1,1-trichloroethane, 1,1,2-trichloroethylene, xylene, methanol, ethanol, and isopropanol. The second organic solvent is preferably at least one selected from the group consisting of tetrahydrofuran, 2-methyltetrahydrofuran, ethyl acetate, isopropyl acetate, toluene, cyclopentyl methyl ether, and tert-butyl methyl ether; more preferably at least one selected from the group consisting of tetrahydrofuran, ethyl acetate, isopropyl acetate, toluene, and tert-butyl methyl ether; and even more preferably at least one selected from the group consisting of tetrahydrofuran, ethyl acetate, and isopropyl acetate.

[0116] The first organic solvent and the second organic solvent can be the same type or different types.

[0117] In the dehydration process S103, the initial moisture content of the driving organic liquid 5 is less than that of the feed liquid 4. Here, when the driving organic liquid 5 contains a second solute and / or a desiccant, the initial moisture content of the driving organic liquid 5 is measured with these components added. It should be noted that in the driving organic liquid 5 containing a desiccant, the portion other than the desiccant (specifically, the supernatant) is sampled and the moisture content is measured. However, when the driving organic liquid 5 contains a dehydrating agent as a second solute, the moisture content of the liquid (in one embodiment, a second organic solvent) in the state before the addition of the dehydrating agent is added is considered as the moisture content of the driving organic liquid 5. Since the forward osmosis membrane is a semi-permeable membrane that allows water to pass through, it can be assumed that water migrates from the feed liquid 4 side, which has more water molecules, to the driving organic liquid 5 side, which has fewer water molecules, through diffusion. This allows the removal of small amounts of water contained in the feed liquid 4, which is an organic solution. Regarding the difference between the initial moisture content (mass%) of the driving organic liquid 5 and the initial moisture content (mass%) of the raw material liquid 4 in the dehydration process S103, in one mode it can be 0.5% or more, or 0.7% or more, or 1% or more, and in another mode it can be less than 20% or less, or less than 15% or less, or less than 10% or less.

[0118] The driving organic liquid 5 may further contain a second solute and / or a desiccant. The second solute is a substance dissolved in or completely mixed with the second organic solvent and does not permeate through the forward osmosis membrane. The second solute only needs to be at least partially dissolved in or completely mixed with the second organic solvent at the concentration in the driving organic liquid 5. On the other hand, the desiccant is a substance that removes water by physical adsorption of water in the solution, or by introducing water as water of crystallization. The desiccant can be a substance soluble in the driving organic liquid 5 or insoluble therein. In one embodiment, the desiccant is a substance that remains solid in the driving organic liquid 5 at 20°C containing the second organic solvent; more typically, it is a substance insoluble in the second organic solvent. Using a desiccant, water from the feed solution 4 permeating through the forward osmosis membrane 23 can be removed from the driving organic liquid 5, enabling more efficient dehydration of the feed solution 4.

[0119] Regarding the second solute, specifically, it may be, for example, one or more of the following: branched monools with three carbon atoms, such as 2-propanol, 2-butanol, and 2-methyl-2-propanol; nonpolar solvents such as toluene; polymers such as polyethylene glycol and polypropylene glycol; dehydrating agents such as orthoesters, sodium, calcium hydride, and phosphorus pentoxide; and organic acids such as p-toluenesulfonic acid and p-toluenesulfonic acid pyridinium. The dehydrating agent here refers to a reagent that removes water by chemically reacting with water in the solution, distinct from the aforementioned drying agents that do not involve a chemical reaction during dehydration. Orthoesters may be, for example, trimethyl orthoate and triethyl orthoate. It should be noted that the second organic solvent and the second solute are selected to be different substances.

[0120] The second solute is preferably one or more selected from orthoester-based dehydrating agents such as trimethyl orthoformate and triethyl orthoformate; and compounds with a toluene structure such as toluene, p-toluenesulfonic acid, and p-toluenesulfonium pyridinium, more preferably one or more selected from trimethyl orthoformate, triethyl orthoformate, p-toluenesulfonic acid, and p-toluenesulfonium pyridinium, and even more preferably triethyl orthoformate and p-toluenesulfonic acid, or p-toluenesulfonium pyridinium pyridinium. It can be considered that by including the second solute in the driving organic liquid 5, the osmotic pressure of the driving organic liquid 5 is increased, thereby improving the dehydration effect of the feed liquid 4. Compounds with hydrophobic structures such as toluene can effectively increase the osmotic pressure of the driving organic liquid 5 through the contribution of these hydrophobic structures.

[0121] Regarding the concentration of the second solute contained in the driving organic liquid 5, in one embodiment it can be 0.01% by mass or more, or 0.1% by mass or more, or 1% by mass or more; in another embodiment it can be 60% by mass or less, or 50% by mass or less, or 40% by mass or less, or 30% by mass or less, or 20% by mass or less, or 10% by mass or less. The concentration of polymers such as polyethylene glycol and polypropylene glycol contained in the driving organic liquid 5 is preferably 0.1% by mass or more and 60% by mass or less, more preferably 0.5% by mass or more and 50% by mass or less, relative to the total mass of the driving organic liquid 5. By setting the polymer concentration to a predetermined value or more, the osmotic pressure of the driving organic liquid 5 can be further increased; by setting the concentration to a predetermined value or less, a viscosity suitable for circulating the driving organic liquid 5 within the dehydration device 1 can be achieved. The concentration of the orthoester-based dehydrating agent contained in the driving organic liquid 5 is preferably 1% by mass or more and 60% by mass or less, more preferably 5% by mass or more and 40% by mass or less, relative to the total mass of the driving organic liquid 5. By setting the concentration of the orthoester-based dehydrating agent to a predetermined value or higher, water migrating from the feed solution 4 to the driving organic liquid 5 can be effectively removed. By setting the concentration to a predetermined value or lower, deterioration of the forward osmosis membrane 23 due to the heat of reaction of the dehydrating agent can be prevented. The amount of organic acid contained in the driving organic liquid 5 can be the amount of catalyst, preferably 0.01% by mass or more and 10% by mass or less relative to the total mass of the driving organic liquid 5, more preferably 0.1% by mass or more and 5% by mass or less.

[0122] Examples of desiccants include porous materials such as silica gel and molecular sieves, and hydrate-forming compounds such as sodium sulfate and magnesium sulfate, which are commonly used for dehydration of organic solvents. The desiccant is preferably selected from one or more of the group consisting of molecular sieves and magnesium sulfate, and more preferably a molecular sieve. The amount of desiccant contained in the driving organic liquid 5 is preferably 1% to 60% by mass and more preferably 5% to 50% by mass relative to the total mass of the driving organic liquid 5. By ensuring the amount of desiccant is at or above a predetermined value, water migrating from the raw material liquid 4 into the driving organic liquid 5 can be effectively removed; by ensuring the amount of desiccant is below a predetermined value, pressure loss inside the driving liquid tank 3 can be reduced.

[0123] The method of the first embodiment

[0124] Reference Figure 3 The method of the first embodiment will be described. This method assumes, for example, a process in the manufacture of a drug, in which an organic layer containing water is extracted by liquid-liquid separation, and then crystallization or anhydrous reaction is carried out after dehydration to a desired water content.

[0125] exist Figure 3In the separation step S101, an organic solution containing a first solute, which is a product of a certain chemical reaction, is extracted by separation. Since the organic solution extracted by separation contains water, dehydration is performed in the rough dehydration step S102 and the dehydration step S103. If the water content of the organic solution is 1% by mass or more and less than 30% by mass, preferably 1% by mass or more and less than 20% by mass, and more preferably 1% by mass or more and less than 15% by mass, the rough dehydration step S102 can be omitted, and the dehydration step S103 can be performed instead.

[0126] Figure 3 In the crude dehydration step S102, the crude raw material liquid, which is an organic solution extracted in the separation step S101, is contacted with a driving aqueous solution containing a third solute through a forward osmosis membrane 23 to obtain a raw material liquid 4 with a water content of more than 1% by mass and less than 30% by mass. By using an aqueous driving aqueous solution that is less prone to vaporization than organic solvents and can be easily processed, and dehydrating to a certain extent, the time of the dehydration step S103 can be shortened.

[0127] Here, the third solute can be, for example, one or more selected from the group consisting of halides, nitrates, sulfates, acetates, ureas, alcohols, glycols, polymers, and sugars. Specifically, it can be, for example, one or more selected from the group consisting of sodium chloride, potassium chloride, magnesium chloride, ammonium chloride, potassium nitrate, ammonium nitrate, sodium sulfate, magnesium sulfate, ammonium sulfate, sodium acetate, potassium acetate, methanol, ethanol, 1-propanol, 2-propanol, ethylene glycol, propylene glycol, polyethylene glycol, and polypropylene glycol.

[0128] The coarse dehydration step S102 is carried out in a dehydration apparatus 1 equipped with a feed liquid system 12 for circulating the crude feed liquid and a drive liquid system 13 for circulating the driving aqueous solution. Here, it is preferable that the feed liquid system 12 is configured in a way that suppresses the migration of the first organic solvent out of the system due to vaporization. By preventing the volatilization of the first organic solvent, the moisture content of the feed liquid 4 can be prevented from increasing.

[0129] Preferably, in the coarse dehydration step S102, an organic liquid containing a first organic solvent and having a moisture content of 0.5% by mass or less is added to the crude raw material liquid that has been reduced in volume due to dehydration and concentration. By adding organic liquid to the reduced-volume raw material liquid 4, the moisture content of the raw material liquid 4 can be further reduced. The moisture content of the organic liquid can be 0.4% by mass or less, or 0.3% by mass or less, and from the perspective of the ease of obtaining the organic liquid, it can be 0.001% by mass or more, or 0.01% by mass or more, or 0.1% by mass or more.

[0130] exist Figure 3In the dehydration step S103, a raw material liquid 4, which has undergone coarse dehydration in the coarse dehydration step S102, and a driving organic liquid 5 containing a second organic solvent and having a water content less than that of the raw material liquid 4, are first prepared. Then, the raw material liquid 4 and the driving organic liquid 5 are brought into contact through a forward osmosis membrane 23 to obtain a dehydrated raw material liquid with a water content less than 1% by mass. Compared with conventional dehydration methods that concentrate the organic solution extracted by liquid-liquid separation using azeotropic distillation, the dehydration method of this embodiment can shorten the time required for dehydration and prevent the decomposition or deterioration of the first solute due to heating. The water content of the dehydrated raw material liquid is preferably 0.95% by mass or less, or 0.9% by mass or less, or 0.85% by mass or less, or 0.8% by mass or less, or 0.75% by mass or less, or 0.7% by mass or less. A low moisture content in the dehydrated feed liquor is preferred, but from the perspective of process efficiency, in one method it can be 0.01% by mass or more, or 0.05% by mass or more, or 0.1% by mass or more, or 0.2% by mass or more, or 0.3% by mass or more, or 0.4% by mass or more.

[0131] The dehydration step S103 is performed in a dehydration apparatus 1 equipped with a raw material liquid system 12 for circulating the raw material liquid 4 and a drive liquid system 13 for circulating the drive organic liquid 5. Here, it is preferable that the raw material liquid system 12 and the drive liquid system 13 are configured in a manner that suppresses the migration of the first and second organic solvents out of the system due to vaporization. This prevents the volatilization of the first and second organic solvents and prevents an increase in the moisture content of the raw material liquid 4 and the drive organic liquid 5.

[0132] Preferably, in the dehydration step S103, an organic liquid containing a first organic solvent and having a moisture content of 0.5% by mass or less is added to the raw material liquid 4, which has been reduced in volume due to dehydration and concentration. By adding organic liquid to the reduced-volume raw material liquid 4, the moisture content of the raw material liquid 4 can be further reduced. The moisture content of the organic liquid can be 0.4% by mass or less, or 0.3% by mass or less, and from the perspective of the ease of obtaining the organic liquid, it can be 0.001% by mass or more, or 0.01% by mass or more, or 0.1% by mass or more.

[0133] Figure 3 In the regeneration step S104, in order to obtain the driving organic liquid 5 that can be reused in the dehydration step S103, water that migrated from the feed liquid 4 to the driving organic liquid 5 is removed from the driving organic liquid 5. After the regeneration step S104, the driving organic liquid 5 treated in the regeneration step S104 can be used to perform the dehydration step S103 again. Thus, dehydration can be carried out while maintaining the osmotic pressure of the driving organic liquid 5 higher than that of the feed liquid 4, and the final moisture content of the dehydrated feed liquid can be further reduced.

[0134] In the regeneration step S104, the driving organic liquid 5 is preferably dehydrated by azeotropic distillation or membrane treatment. Azeotropic distillation here can be vacuum distillation, etc. Membrane treatment here can be a method using a selectively permeable water pervaporation membrane to evaporate water from the driving organic liquid 5 and remove it. More preferably, a desiccant or dehydrating agent is added to the driving organic liquid 5 in the regeneration step S104. The aforementioned substances can be used as the desiccant and dehydrating agent.

[0135] Next, crystallization process S105 or water-free reaction process S106 is carried out. Figure 3 In the crystallization step S105, the first solute is separated and purified from the dehydrated feed liquid obtained from the dehydration step S103 by crystallization. Crystallization can be carried out by methods commonly used by those skilled in the art. To prevent deterioration of the first solute due to heating or pressure operation, it is preferable to use a method of cooling the dehydrated feed liquid or to add a solvent that is difficult to dissolve the first solute to the dehydrated feed liquid.

[0136] exist Figure 3 In the anhydrous reaction step S106, other reagents are added to the dehydrated feed liquid obtained from the dehydration step S103, and a chemical reaction is carried out under anhydrous conditions. The chemical reaction in the anhydrous reaction step S106 is an anhydrous reaction in which the desired reaction is inhibited in the presence of water. Other reagents here can be, for example, Grignard reagents, butyllithium, or other organometallic reagents.

[0137] The method of the second embodiment

[0138] Reference Figure 4 As a second embodiment, a method is described that assumes a process in the manufacture of a drug in which, after crystallization of a solute from an aqueous solution, the resulting wet crystals are dissolved in an organic solvent, dehydrated, and then subjected to an anhydrous reaction.

[0139] exist Figure 4 In the crystallization step S105, wet crystals containing water are separated from an aqueous solution containing a first solute that is a product of a certain chemical reaction. The obtained wet crystals are dissolved in a first organic solvent and dehydrated in a rough dehydration step S102 and a dehydration step S103 to obtain a crude feed liquid and a feed liquid 4. Alternatively, the rough dehydration step S102 can be omitted. Compared with conventional dehydration methods that dry wet crystals by heating under reduced pressure, the dehydration method of this embodiment can shorten the time required for dehydration and prevent the decomposition or deterioration of the first solute due to heating.

[0140] Figure 4The coarse dehydration process S102, dehydration process S103, regeneration process S104 and water-free reaction process S106 in the embodiment can be the same as in the first embodiment, and therefore will not be described again.

[0141] Example

[0142] The present invention will be specifically described below based on embodiments, but the present invention is not limited to the embodiments.

[0143] Experimental Methods

[0144] (Fabrication of forward osmosis membrane modules)

[0145] Polyketone with an intrinsic viscosity of 2.2 dL / g, obtained by alternating copolymerization of ethylene and carbon monoxide, was added to a 65% resorcinol aqueous solution at a polymer concentration of 15% by mass. The solution was stirred at 80°C for 2 hours to dissolve and then degassed to obtain a uniform and transparent spinning solution. The spinning solution was then filled into a wet hollow fiber spinning machine equipped with dual spinnerets. A 25% methanol aqueous solution was extruded from the inside of the dual spinnerets, and the spinning solution was extruded from the outside into a coagulation tank filled with a 40% methanol aqueous solution. Hollow fiber membranes were formed through phase separation.

[0146] The obtained hollow fiber membranes were cut into 70cm lengths and bundled together, then washed with water. The washed hollow fiber membrane bundles were then replaced with acetone, followed by hexane, and dried at 50°C. The resulting polyketone hollow fiber membrane had an outer diameter of 0.8mm, an inner diameter of 0.5mm, a porosity of 78%, and a maximum pore size of 130nm. A hollow fiber membrane bundle consisting of 80 of these polyketone hollow fiber membranes was housed within a cylindrical assembly shell (cylindrical shell) with a diameter of 2cm and a length of 10cm. The two ends of the hollow fiber membrane bundle were fixed with adhesive, thus fabricating a polyketone hollow fiber supported membrane assembly.

[0147] Using the obtained polyketone hollow fiber supported membrane assembly, interfacial polymerization was carried out on the inner surface of each hollow fiber membrane as follows. In a 1L container, 20.216g of m-phenylenediamine and 1.52g of sodium lauryl sulfate were added, followed by the addition of 991g of pure water to dissolve them, preparing the first solution for interfacial polymerization. In another 1L container, 0.6g of trimesoyl chloride was added, followed by the addition of 300g of n-hexane to dissolve them, preparing the second solution for interfacial polymerization.

[0148] Reference Figure 5 The method for forming a separation active layer based on interface polymerization is described. Figure 5In the illustrated apparatus, the hollow fiber support membrane assembly 41, in which the inner side (core side) of the hollow fiber support membrane is filled with a first solution, has a second solution delivery pipe 45 connected to the inlet of the core side from a second solution storage tank 44, and a second solution delivery pump 46 connected midway to pressurize the second solution. The outlet of the core side is connected to a second solution discharge pipe 48 from a second solution discharge tank 47, and a core-side pressure adjusting device 42 for controlling the pressure inside the hollow fibers of the hollow fiber support membrane assembly 41 is connected from this tank. An end cap 49 is inserted into the lower conduit on the shell side of the hollow fiber support membrane assembly 41, and a shell-side pressure adjusting device 43 for controlling the shell pressure is connected to the upper conduit. The first solution is filled into the core side (inner side of the hollow fibers) of the hollow fiber support membrane assembly 41, and after standing for 5 minutes, the liquid is extracted. The assembly is then installed in a state where the inner side of the hollow fibers is wetted by the first solution. Figure 5 In the apparatus shown, the core-side pressure is set to atmospheric pressure using the core-side pressure adjustment device 42, and the shell-side pressure is set to reduced pressure (core-side pressure > shell-side pressure) using the shell-side pressure adjustment device 43, with an absolute pressure of 10 kPa. After standing for 2 minutes in this state, the second solution is pumped to the core side at a flow rate of 40 cc / min for 3 minutes while maintaining this pressure, to carry out interfacial polymerization. The polymerization temperature is set to 25°C.

[0149] Next, the hollow fiber supported membrane module was removed from the device and placed in a constant temperature bath set at 50°C for 5 minutes to remove n-hexane through vaporization. The shell side and core side were then further cleaned with pure water, thus producing the forward osmosis membrane module.

[0150] (Calculation of HSP)

[0151] The HSP of the separated active layer is calculated by modeling as described below. Typically, the repeating unit of the separated active layer obtained by interfacial polymerization using this method is represented by the following equation (1).

[0152] [Chemistry 1]

[0153]

[0154] (In the formula, x and y are each independent integers greater than or equal to 1.)

[0155] As indicated by the above formula (1), the separated active layer is a structure in which part of the portion of the pyromellitic chloride source is cross-linked and part is not cross-linked (i.e., hydrolyzed).

[0156] In the above polymer structure, firstly, all uncrosslinked functional groups (i.e., hydrolyzable structural parts, hydrolyzed structural parts, and branched structural parts in repeating units) that may remain in an unreacted state outside the polymer ends are replaced with hydrogen groups. This yields the following equation (2):

[0157] [Chemistry 2]

[0158]

[0159] The structure is shown. Next, in the above polymer structure, the part related to the chemical bond of the repeating unit is replaced with a methyl group. This yields the following formula (3):

[0160] [Chemistry 3]

[0161]

[0162] The represented monomer structure.

[0163] The HSP of the monolithic structure obtained through the above modeling was calculated using the Hansen SP & QSPR model, which is an add-on component of the commercially available software Winmostar 9.4.11. The result was δd = 20.5 (MPa). 0.5 δp = 11.47 (MPa) 0.5 δH = 7.22 (MPa) 0.5 The HSP is 24.58 (MPa). 0.5 .

[0164] In addition, the HSP of the second organic solvent driving the organic liquid was also calculated using the Hansen SP&QSPR model, which is an add-on to the commercially available software Winmostar 9.4.11, just as described above.

[0165] The results are summarized in Table 1.

[0166] (Determination of moisture content)

[0167] Using a 1mL syringe, draw approximately 0.5mL of the raw material solution, crude raw material solution, or driving organic liquid, and inject approximately 0.1mL into a Karl Fischer moisture analyzer (model CA-200, manufactured by Mitsubishi Chemical Analysis Technology Co., Ltd.). Measure the moisture content. It should be noted that in Examples 4 and 6, where the driving organic liquid contains molecular sieves as a desiccant, only the supernatant of the driving organic liquid is sampled.

[0168] In Examples 1 to 3, where the second solute was a dehydrating agent, the Karl Fischer reaction competed with the dehydration reaction; therefore, the moisture content of the second organic solvent before the addition of the dehydrating agent was considered as the driving moisture content of the organic liquid. The statement "moisture content less than 0.01% by mass" in Examples 1 to 3 refers to the moisture content of the second organic solvent without the dehydrating agent being 0.01% by mass, and it is inferred that the moisture content further decreased after the addition of the dehydrating agent.

[0169] (Dehydration efficiency)

[0170] The dehydration efficiency is calculated based on the moisture content and volume of the feed liquor (FS) using the following formula. Additionally, t is assumed to be 30 minutes.

[0171] [Number 5]

[0172]

[0173] The dehydration efficiency (%) value is evaluated according to the following criteria.

[0174] A: More than 40%

[0175] B: 30% or more but less than 40%

[0176] C: Less than 30%

[0177] Example 1

[0178] In this embodiment, using Figure 1 The dehydration apparatus shown was operated at room temperature (23°C). As the feed solution, 200 mL of isopropyl acetate solution containing 10% by mass of octaacetyl sucrose as the first solute was used. The initial moisture content of the feed solution was 2.0% by mass. As the driving organic liquid, 400 mL of isopropyl acetate solution containing 10% by mass of triethyl orthoformate as the second solute and a catalyst amount of pyridinium p-toluenesulfonate (PPTS) was used. The initial moisture content of the driving organic liquid was less than 0.01% by mass. The feed solution tank and the driving liquid tank were capped to prevent the organic solvent from migrating outside the tanks due to vaporization. The feed solution was circulated at a flow rate of 40 mL / min, and the driving organic liquid was circulated at a flow rate of 340 mL / min, with contact occurring through a forward osmosis membrane. After the dehydration apparatus operated for 4 hours, the moisture content of the recovered dehydrated feed solution was 0.6% by mass.

[0179] Example 2

[0180] As the feed liquid, 200 mL of an ethyl acetate solution containing 10% by mass of octaacetyl sucrose as the first solute was used. The initial moisture content of the feed liquid was 3.0% by mass. As the driving organic liquid, 400 mL of an ethyl acetate solution containing 10% by mass of triethyl orthoformate as the second solute and a catalyst amount of p-toluenesulfonic acid was used. The initial moisture content of the driving organic liquid was less than 0.01% by mass. The feed liquid tank and the driving liquid tank were capped to prevent the organic solvent from migrating outside the tanks due to vaporization. After operating the dehydration apparatus under the same conditions as in Example 1, the moisture content of the recovered dehydrated feed liquid was 0.7% by mass.

[0181] Example 3

[0182] As the feed solution, 200 mL of a tetrahydrofuran (THF) solution containing 10% by mass of quinine as the first solute was used. The initial moisture content of the feed solution was 9.0% by mass. As the driving solution, 400 mL of a tetrahydrofuran solution containing 10% by mass of triethyl orthoformate as the second solute and a catalyst amount of pyridinium p-toluenesulfonate (PPTS) was used. The initial moisture content of the driving organic liquid was less than 0.01% by mass. The feed solution tank and the driving liquid tank were capped to prevent the organic solvent from migrating outside the tanks due to vaporization. After operating the dehydration apparatus under the same conditions as in Example 1, the moisture content of the recovered dehydrated feed solution was 0.8% by mass.

[0183] Example 4

[0184] As the feed solution, 200 mL of a tetrahydrofuran solution containing 10% by mass of quinine as the first solute was used. The initial moisture content of the feed solution was 9.0% by mass. As the driving solution, 400 mL of a tetrahydrofuran solution containing 10% by mass of toluene as the second solute and approximately 100 g of molecular sieve as a desiccant was used. The initial moisture content of the driving organic liquid was 0.01% by mass. The feed solution tank and the driving liquid tank were capped to prevent the organic solvent from migrating outside the tanks due to vaporization. After operating the dehydration apparatus under the same conditions as in Example 1, the moisture content of the recovered dehydrated feed solution was 0.9% by mass.

[0185] Example 5

[0186] As the feed liquid, 200 mL of a tetrahydrofuran solution containing 10% by mass of quinine as the first solute was used. The initial moisture content of the feed liquid was 3.0% by mass. As the driving organic liquid, 2000 mL of tetrahydrofuran was used as the second organic solvent. The initial moisture content of the driving organic liquid was 0.1% by mass. The feed liquid tank and the driving liquid tank were capped to prevent the organic solvent from migrating outside the tanks due to vaporization. After the dehydration apparatus was operated for 7 hours under the same conditions as in Example 1, the moisture content of the recovered dehydrated feed liquid was 0.9% by mass.

[0187] Example 6

[0188] As the feed liquid, 200 mL of isopropyl acetate solution containing 10% by mass of octaacetyl sucrose as the first solute was used. The initial moisture content of the feed liquid was 2.0% by mass. As the driving organic liquid, 600 mL of isopropyl acetate containing approximately 100 g of molecular sieve as a desiccant was used. The initial moisture content of the driving organic liquid was 0.01% by mass. In this embodiment, the dehydration operation was performed with the feed liquid tank and the driving liquid tank uncovered. After running the dehydration apparatus for 5 hours under the same conditions as in Example 1, the moisture content of the recovered dehydrated feed liquid was 0.8% by mass.

[0189] Comparative Example 1

[0190] In Comparative Example 1, an aqueous solution was used instead of an organic liquid as the driving fluid. 200 mL of a tetrahydrofuran solution containing 10% by mass of quinine as the first solute was used as the feed liquid. The initial water content of the feed liquid was 9.0% by mass. 400 mL of an aqueous solution containing 20% ​​by mass of magnesium chloride as the second solute was used as the driving fluid. The feed liquid tank and the driving fluid tank were capped to prevent solvent from migrating outside the tanks due to vaporization. After operating the dehydration apparatus for 1.5 hours under the same conditions as in Example 1, the water content of the recovered dehydrated feed liquid was measured, and the result was 7.2% by mass. Although the water content of the feed liquid decreased, it did not fall below 1% by mass.

[0191] Comparative Example 2

[0192] In Comparative Example 2, an aqueous solution was used as the driving fluid, similar to Comparative Example 1. As the feed liquid, 200 mL of a tetrahydrofuran solution containing 10% by mass of quinine as the first solute was used. The initial water content of the feed liquid was 1.3% by mass. As the driving fluid, 400 mL of an aqueous solution containing 20% ​​by mass of magnesium chloride as the second solute was used. The feed liquid tank and the driving fluid tank were capped to prevent the solvent from migrating outside the tanks due to vaporization. After operating the dehydration apparatus for 1.5 hours under the same conditions as in Example 1, the water content of the recovered dehydrated feed liquid was measured, and the result was 4.8% by mass. The water content of the feed liquid increased, indicating that dehydration of the feed liquid was not achieved.

[0193] Comparative Example 3

[0194] In Comparative Example 3, an aqueous solution was used as the driving fluid, similar to Comparative Example 1. As the feed liquid, 200 mL of an ethyl acetate solution containing 10% by mass of octaacetyl sucrose as the first solute was used. The initial water content of the feed liquid was 2.1% by mass. As the driving fluid, 400 mL of an aqueous solution containing 20% ​​by mass of magnesium chloride as the second solute was used. The feed liquid tank and the driving fluid tank were capped to prevent the solvent from migrating outside the tanks due to vaporization. After operating the dehydration apparatus for 1.5 hours under the same conditions as in Example 1, the water content of the recovered dehydrated feed liquid was measured, and the result was 2.4% by mass. The water content of the feed liquid increased, indicating that dehydration of the feed liquid was not achieved.

[0195] Comparative Example 4

[0196] In Comparative Example 4, an aqueous solution was used as the driving fluid, similar to Comparative Example 1. Furthermore, methanol, which is permeable to a forward osmosis membrane, was selected as the first organic solvent. 1000 mL of a methanol solution containing 1% by mass of octaacetyl sucrose as the first solute was used as the feed solution. The initial water content of the feed solution was 10.2% by mass. 1600 mL of an aqueous solution containing 10% by mass of magnesium chloride as the second solute was used as the driving fluid. The feed solution tank and the driving fluid tank were capped to prevent solvent from migrating outside the tanks due to vaporization. After operating the dehydration apparatus for 7 hours under the same conditions as in Example 1, the water content of the recovered dehydrated feed solution was measured, and the result was 38.5% by mass. The water content of the feed solution increased, indicating that dehydration of the feed solution was not achieved.

[0197] Comparative Example 5

[0198] In Comparative Example 5, methanol, which is permeable to a forward osmosis membrane, was selected as both the first and second organic solvents. As the feed liquid, 900 mL of a methanol solution containing 1% by mass of octaacetyl sucrose as the first solute was used. The initial moisture content of the feed liquid was 9.4% by mass. As the driving organic liquid, 1400 mL of a methanol solution containing 10% by mass of magnesium chloride as the second solute was used. The initial moisture content of the driving organic liquid was 0.13% by mass. The feed liquid tank and the driving liquid tank were capped to prevent the organic solvent from migrating outside the tanks due to vaporization. After operating the dehydration apparatus for 3.5 hours under the same conditions as in Example 1, the moisture content of the recovered dehydrated feed liquid was measured, and the result was 3.0% by mass. Although the moisture content of the feed liquid decreased, it did not fall below 1% by mass.

[0199] Comparative Example 6

[0200] In Comparative Example 6, the experiment was conducted under conditions where the initial moisture content of the driving organic liquid was higher than that of the feed liquid. As the feed liquid, 200 mL of a tert-butyl methyl ether solution containing 5% by mass of octaacetyl sucrose as the first solute was used. The initial moisture content of the feed liquid was 1.3% by mass. As the driving liquid, 600 mL of an isopropyl acetate solution containing 10% by mass of toluene as the second solute was used. The initial moisture content of the driving organic liquid was 1.5% by mass. Both the feed liquid tank and the driving liquid tank were capped to prevent the organic solvent from migrating outside the tanks due to vaporization. After operating the dehydration apparatus for 1 hour under the same conditions as in Example 1, the moisture content of the recovered dehydrated feed liquid was measured, and the result was 1.4% by mass. The result indicated an increase in the moisture content of the feed liquid, and dehydration of the feed liquid was not achieved.

[0201] Example 7

[0202] As the feed liquid, 200 g of a tetrahydrofuran solution containing 0.1% by mass of octaacetyl sucrose as the first solute was used. The initial moisture content of the feed liquid was 1.1% by mass. As the driving organic liquid, 400 g of tetrahydrofuran was used. The initial moisture content of the driving organic liquid was 0.01% by mass. The feed liquid tank and the driving liquid tank were capped to prevent the organic solvent from migrating outside the tanks due to vaporization. After running the dehydration apparatus for 2 hours under the same conditions as in Example 1, the moisture content of the recovered dehydrated feed liquid was 0.4% by mass. In addition, the dehydration efficiency, calculated based on the moisture content and weight of the feed liquid measured after 0 minutes and 30 minutes, was 33% (Evaluation B).

[0203] Example 8

[0204] As the feed liquid, 200 g of a tetrahydrofuran solution containing 0.1% by mass of octaacetyl sucrose as the first solute was used. The initial moisture content of the feed liquid was 1.1% by mass. As the driving organic liquid, 400 g of ethyl acetate was used. The initial moisture content of the driving organic liquid was 0.01% by mass. The feed liquid tank and the driving liquid tank were capped to prevent the organic solvent from migrating outside the tank due to vaporization. After running the dehydration apparatus for 2 hours under the same conditions as in Example 1, the moisture content of the recovered dehydrated feed liquid was 0.4% by mass. In addition, the dehydration efficiency, calculated based on the moisture content and weight of the feed liquid measured after 0 minutes and 30 minutes, was 42% (Evaluation A).

[0205] Example 9

[0206] As the feed liquid, 200 g of a tetrahydrofuran solution containing 0.1% by mass of octaacetyl sucrose as the first solute was used. The initial moisture content of the feed liquid was 1.1% by mass. As the driving organic liquid, 400 g of methanol was used. The initial moisture content of the driving organic liquid was 0.01% by mass. The feed liquid tank and the driving liquid tank were capped to prevent the organic solvent from migrating outside the tank due to vaporization. After running the dehydration apparatus for 2 hours under the same conditions as in Example 1, the moisture content of the recovered dehydrated feed liquid was 0.5% by mass. In addition, the dehydration efficiency, calculated based on the moisture content and weight of the feed liquid measured after 0 minutes and 30 minutes, was 23% (Evaluation C).

[0207] Example 10

[0208] As the feed liquid, 200 g of a tetrahydrofuran solution containing 0.1% by mass of octaacetyl sucrose as the first solute was used. The initial moisture content of the feed liquid was 1.1% by mass. As the driving organic liquid, 400 g of a solution prepared by mixing tetrahydrofuran and cyclohexane at a volume ratio of 1:3 was used. The initial moisture content of the driving organic liquid was 0.01% by mass. The feed liquid tank and the driving liquid tank were capped to prevent the organic solvent from migrating outside the tank due to vaporization. After running the dehydration apparatus for 2 hours under the same conditions as in Example 1, the moisture content of the recovered dehydrated feed liquid was 0.9% by mass. Furthermore, the dehydration efficiency, calculated based on the moisture content and weight of the feed liquid measured after 0 minutes and 30 minutes, was 27% (Evaluation C).

[0209] Example 11

[0210] As the feed liquid, 200 g of a tetrahydrofuran solution containing 0.1% by mass of octaacetyl sucrose as the first solute was used. The initial moisture content of the feed liquid was 1.1% by mass. As the driving solution, 400 g of a solution prepared by mixing tetrahydrofuran and cyclohexane at a volume ratio of 1:1 was used. The initial moisture content of the driving organic liquid was 0.01% by mass. The feed liquid tank and the driving liquid tank were capped to prevent the organic solvent from migrating outside the tank due to vaporization. After running the dehydration apparatus for 2 hours under the same conditions as in Example 1, the moisture content of the recovered dehydrated feed liquid was 0.8% by mass. Furthermore, the dehydration efficiency, calculated based on the moisture content and weight of the feed liquid measured after 0 minutes and 30 minutes, was 39% (Evaluation B).

[0211] Example 12

[0212] As the feed liquid, 200 g of a tetrahydrofuran solution containing 0.1% by mass of octaacetyl sucrose as the first solute was used. The initial moisture content of the feed liquid was 1.1% by mass. As the driving solution, 400 g of a solution prepared by mixing tetrahydrofuran and N-methylpyrrolidone at a volume ratio of 1:1 was used. The initial moisture content of the driving organic liquid was 0.01% by mass. The feed liquid tank and the driving liquid tank were capped to prevent the organic solvent from migrating outside the tank due to vaporization. After running the dehydration apparatus for 2 hours under the same conditions as in Example 1, the moisture content of the recovered dehydrated feed liquid was 0.4% by mass. In addition, the dehydration efficiency, calculated based on the moisture content and weight of the feed liquid measured after 0 minutes and 30 minutes, was 32% (Evaluation B).

[0213] Example 13

[0214] As the feed liquid, 200 g of a tetrahydrofuran solution containing 0.1% by mass of octaacetyl sucrose as the first solute was used. The initial moisture content of the feed liquid was 1.1% by mass. As the driving solution, 400 g of a solution prepared by mixing tetrahydrofuran and dichloromethane at a volume ratio of 1:1 was used. The initial moisture content of the driving organic liquid was 0.01% by mass. The feed liquid tank and the driving liquid tank were capped to prevent the organic solvent from migrating outside the tank due to vaporization. After operating the dehydration apparatus for 2 hours under the same conditions as in Example 1, the moisture content of the recovered dehydrated feed liquid was 0.5% by mass. Furthermore, the dehydration efficiency, calculated based on the moisture content and weight of the feed liquid measured after 0 minutes and 30 minutes, was 41% (Evaluation A).

[0215] Example 14

[0216] As the feed liquid, 200 g of a tetrahydrofuran solution containing 0.1% by mass of octaacetyl sucrose as the first solute was used. The initial moisture content of the feed liquid was 1.1% by mass. As the driving solution, a solution prepared by mixing tetrahydrofuran and dichloromethane at a volume ratio of 1:3 was used. The initial moisture content of the driving organic liquid was 0.01% by mass. The feed liquid tank and the driving liquid tank were capped to prevent the organic solvent from migrating outside the tank due to vaporization. After operating the dehydration apparatus for 2 hours under the same conditions as in Example 1, the moisture content of the recovered dehydrated feed liquid was 0.8% by mass. Furthermore, the dehydration efficiency, calculated based on the moisture content and weight of the feed liquid measured after 0 minutes and 30 minutes, was 38% (Evaluation B).

[0217] Example 15

[0218] As the feed liquid, 200 g of a tetrahydrofuran solution containing 0.1% by mass of octaacetyl sucrose as the first solute was used. The initial moisture content of the feed liquid was 1.1% by mass. As the driving solution, 400 g of a solution prepared by mixing tetrahydrofuran and dichloromethane at a volume ratio of 1:9 was used. The initial moisture content of the driving organic liquid was 0.01% by mass. The feed liquid tank and the driving liquid tank were capped to prevent the organic solvent from migrating outside the tank due to vaporization. After running the dehydration apparatus for 2 hours under the same conditions as in Example 1, the moisture content of the recovered dehydrated feed liquid was 0.9% by mass. Furthermore, the dehydration efficiency, calculated based on the moisture content and weight of the feed liquid measured after 0 minutes and 30 minutes, was 37% (Evaluation B).

[0219] The results of the above embodiments and comparative examples are shown in Tables 2 and 3.

[0220] [Table 1]

[0221]

[0222]

[0223]

[0224] Explanation of symbols

[0225] 1 Dehydration device

[0226] 2 Raw material liquid tank

[0227] 3 drive tanks

[0228] 4 raw material liquid

[0229] 5-Drive Organic Liquid

[0230] 6.7 Raw material liquid delivery piping

[0231] 8 raw material liquid delivery pumps

[0232] 9.10 Drive fluid supply piping

[0233] 11 Driven liquid delivery pump

[0234] 12 Feed Liquid System

[0235] 13 Driving Fluid System

[0236] 20 forward osmosis membrane modules

[0237] 21, 22 Shell-side conduits

[0238] 23 Forward Osmosis Membrane

[0239] 24, 25 Adhesive fixing parts

[0240] 26, 27 Top Cover

[0241] 28 and 29 core-side catheters

[0242] 30 casing

[0243] 41 Hollow Fiber Supported Membrane Module

[0244] 42-core side pressure adjustment device

[0245] 43 Shell-side pressure adjustment device

[0246] 44. Second solution storage tank

[0247] 45 2nd solution delivery piping

[0248] 46 2nd solution delivery pump

[0249] 47. Second solution drain tank

[0250] 48 2nd solution drain piping

[0251] 49 end caps

[0252] S101 Separation Process

[0253] S102 coarse dewatering process

[0254] S103 Dehydration Process

[0255] S104 Regeneration Process

[0256] S105 crystallization process

[0257] S106 Water-free reaction process

Claims

1. A method for dehydrating a feed solution comprising a first organic solvent, water, and a first solute, wherein, The method includes a dehydration step in which the feed liquid is brought into contact with a driving organic liquid containing a second organic solvent through a forward osmosis membrane to obtain a dehydrated feed liquid with a water content of less than 1% by mass. Here, the initial moisture content of the raw material liquid in the dehydration process is greater than 1% by mass and less than 30% by mass, and the initial moisture content of the driving organic liquid is less than the initial moisture content of the raw material liquid. The forward osmosis membrane is a composite membrane consisting of a separation active layer and a microporous support membrane. The difference in solubility parameter ΔHSP between the driving organic liquid and the separation active layer is ΔHSP < 16 (MPa). 0.5 .

2. The method as described in claim 1, wherein, The saturated water content of the driving organic liquid is 0.5% by mass or more.

3. The method as described in claim 1 or 2, wherein, The solubility parameter of the driving organic liquid is 13 (MPa). 0.5 ≦δd≦20(MPa) 0.5 2 (MPa) 0.5 ≦δp≦18(MPa) 0.5 2 (MPa) 0.5 ≦δH≦28(MPa) 0.5 .

4. The method as described in claim 1 or 2, wherein, The driving organic liquid further comprises a second solute and / or a desiccant.

5. The method as described in claim 1 or 2, wherein, The dehydration process is carried out in a dehydration apparatus that includes a raw material liquid system for circulating the raw material liquid and a drive liquid system for circulating the driving organic liquid. The feed liquid system and the driving liquid system are configured to suppress the migration of the first organic solvent and the second organic solvent out of the system due to vaporization.

6. The method as described in claim 1 or 2, wherein, The second organic solvent is selected from tetrahydrofuran, 2-methyltetrahydrofuran, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, toluene, cyclopentyl methyl ether, tert-butyl methyl ether, acetonitrile, dimethylacetamide, N-methylpyrrolidone, hexafluoroisopropanol, acetic acid, acetone, anisole, benzene, chlorobenzene, carbon tetrachloride, chloroform, cumene, cyclohexane, 1,2-dichloroethane, and 1,2-dichloroethylene. At least one of the following groups: dichloromethane, 1,2-dimethoxyethane, N,N-dimethylformamide, dimethyl sulfoxide, 1,4-dioxane, diethyl ether, ethyl formate, formamide, formic acid, heptane, hexane, methyl butyl ketone, methyl cyclohexane, methyl ethyl ketone, methyl isobutyl ketone, pentane, nitromethane, pyridine, sulfolane, tetrahydronaphthalene, 1,1,1-trichloroethane, 1,1,2-trichloroethylene, and xylene.

7. The method as described in claim 1 or 2, wherein, In the dehydration process, an organic liquid containing the first organic solvent and having a moisture content of less than 0.5% by mass is added to the raw material liquid, which has been reduced in volume due to dehydration and concentration.

8. The method as claimed in claim 1 or 2, wherein, The first solute in the dehydrated feed solution is used in an anhydrous reaction in which the first solute reacts with other reagents under anhydrous conditions.

9. The method as claimed in claim 1 or 2, wherein, The method further includes a crystallization step of refining the first solute by crystallization.

10. The method as claimed in claim 1 or 2, wherein, The method further includes a separation step prior to the dehydration step, which involves extracting the organic layer from the liquid containing the first solute. The organic layer is used as the raw material solution.

11. The method as claimed in claim 1 or 2, wherein, The method further includes a regeneration process. The regeneration process is a process of removing water that has migrated from the feed liquid to the driving organic liquid from the driving organic liquid.

12. The method of claim 11, wherein, In the regeneration process, a desiccant or dehydrating agent is added to the driving organic liquid.

13. The method of claim 11, wherein, In the regeneration process, the driving organic liquid is dehydrated by azeotropic distillation or membrane treatment.

14. The method of claim 11, wherein, The driving organic liquid from which water has been removed in the regeneration process is reused in the dehydration process.

15. The method as claimed in claim 1 or 2, wherein, The method further includes a coarse dewatering step before the dewatering step. The crude dehydration process involves contacting the crude raw material solution with a driving aqueous solution containing a third solute through a forward osmosis membrane to obtain a raw material solution dehydrated to a moisture content of 1% by mass or more and less than 30% by mass.

16. The method of claim 15, wherein, The crude dehydration process is carried out in a dehydration device equipped with a raw material liquid system for circulating the crude raw material liquid and a drive liquid system for circulating the drive aqueous solution. The raw material liquid system is configured to suppress the migration of the first organic solvent out of the system due to vaporization.

17. The method of claim 15, wherein, In the crude dehydration process, an organic liquid containing the first organic solvent and having a moisture content of less than 0.5% by mass is added to the crude raw material liquid, which has been reduced in volume due to dehydration and concentration.

18. The method as claimed in claim 1 or 2, wherein, The method is used for the manufacture of pharmaceuticals.

19. The method of claim 2, wherein, The separation active layer is a polyamide layer.

20. The method of claim 2, wherein, The microporous support membrane is a microporous hollow fiber support membrane.

21. The method of claim 20, wherein, The material of the microporous hollow fiber support membrane includes polyketone.

22. The method as claimed in claim 1 or 2, wherein, The initial moisture content of the raw material liquid in the dehydration process is more than 1% by mass and less than 15% by mass.

23. The method as claimed in claim 1 or 2, wherein, The first organic solvent is at least one selected from the group consisting of tetrahydrofuran, 2-methyltetrahydrofuran, ethyl acetate, isopropyl acetate, toluene, cyclopentyl methyl ether, and tert-butyl methyl ether.

24. The method of claim 2, wherein, The difference in solubility parameter ΔHSP between the driving organic liquid and the separation active layer is 5 (MPa). 0.5 Above 13(MPa) 0.5 the following.

25. The method as claimed in claim 1 or 2, wherein, The moisture content of the dehydrated raw material liquid obtained in the dehydration process is less than 0.9% by mass.

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