JP2020138119A - Raw material liquid concentration system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a freeze-dried concentrate in which components in a raw material liquid are highly maintained by arranging an appropriate pretreatment step for freeze-drying in a raw material liquid concentration system using a freeze-drying method. To provide a liquid concentration system.
SOLUTION: A raw material solution a containing a solvent b and a solute and an induction solution d are brought into contact with each other via a normal osmotic film o, and the solvent b in the raw material solution a is moved into the induction solution d to concentrate. It has a first step of obtaining the raw material c and the dilution induction solution e, and a second step of freeze-drying the concentrated raw material solution c to further concentrate it, and at the end of the first step, at the temperature at that time. A raw material solution concentration system in which the first step is performed so that the measured osmotic pressure of the concentrated raw material solution c is in the range of 1.52 MPa (15 atm) or more and 65.9 MPa (650 atm) or less.
[Selection diagram] Fig. 1

Description

The present invention relates to a raw material liquid concentration system. Specifically, a part of the solvent is separated from the raw material liquid by the forward osmosis method to concentrate the raw material liquid, and then the raw material liquid is further concentrated by the freeze-drying method to suppress deterioration and decrease of the components in the raw material liquid. The present invention relates to a raw material liquid concentration system capable of efficiently concentrating a raw material liquid in terms of time and energy.

In various applications, it is an object to concentrate a specific component (solute) existing in a raw material liquid. As a traditional concentration method, an evaporation method in which a raw material liquid is heated to remove a solvent is known. However, in the evaporation method, there is a concern that the quality of the components in the raw material liquid may change due to heat, the solid components may collapse, and the like.

As another concentration method, a reverse osmosis (RO: Reverse Osmosis) method using a membrane that allows a solvent to permeate at the molecular level is known. In the RO method, the raw material liquid is pressurized to a predetermined pressure higher than the osmotic pressure of the raw material liquid, then supplied to the reverse osmosis (RO) membrane module, permeated through the RO membrane, and the solvent in the raw material liquid (typically). It is a method of concentrating the raw material liquid by removing water). However, since this RO method requires pressurization, clogging of the RO film is likely to occur when applied to a raw material solution containing a large amount of solid matter, high molecular weight substance, or the like. Therefore, the RO method may be inappropriate for application to raw material liquids such as foods, beverages, and pharmaceuticals. Further, in the RO method, the osmotic pressure of the solvent (filtered solvent) of the concentrated raw material liquid does not exceed the pressure of the high-pressure pump used for pressurization. Therefore, there is a limit to the concentration rate of the raw material liquid by the RO method according to the capacity of the pump.
This RO method is mainly used for desalination of seawater, focusing on the solvent (water) removed from the raw material liquid.

As another method for concentrating the raw material liquid, a forward osmosis (FO: Forward Osmosis) method is known in which the solvent in the raw material liquid is separated by utilizing the difference in osmotic pressure. In the FO method, a raw material solution and an inductive solution having a higher osmotic pressure than the raw material solution are brought into contact with each other through a forward osmosis (FO) membrane to diffuse the solvent from the raw material solution to the inductive solution. This is a method of concentrating the liquid. Since the FO method does not require pressurization, it is expected that the desired concentration effect can be maintained for a long period of time even with a raw material solution containing a large amount of solids, high molecular weight substances and the like.

As a method for concentrating the raw material liquid other than these, a freeze-drying method is known in which the raw material liquid is frozen and then the solvent in the raw material liquid is sublimated to concentrate the raw material liquid. Since the freeze-drying method does not require high-temperature heating or the like, it is possible to concentrate while suppressing alteration of components in the raw material liquid, deformation of solid content, and the like. Foods that have been freeze-dried (freeze-dried foods), for example, have little change in nutritional components such as vitamins, flavor, etc., can be stored for a long time at room temperature, and are relatively lightweight and transportable due to their low moisture content. There are advantages such as high. Because of these advantages, the freeze-drying method is currently applied to a wide variety of foods, pharmaceuticals, and the like.

On the other hand, the freeze-drying method requires a vacuum pump for creating a high vacuum, a heat source for sublimation, a cooling unit for recovering solvent vapor generated from the raw material liquid as a liquid or a solid, and the energy thereof. The cost is high. Further, in addition to the need to completely freeze the raw material liquid in advance, the drying time increases remarkably as the volume, thickness and the like of the frozen body increase. Therefore, in order to apply the freeze-drying method to the concentration of the raw material liquid, it is required to concentrate the raw material liquid before being subjected to freeze-drying as much as possible.
Further, it is known that the water content in the raw material liquid is involved in the retention rate of the components of the concentrate after freeze-drying. For example, Non-Patent Document 1 discloses that the components in the raw material liquid decrease in proportion to the water removal rate during freeze-drying. For this reason as well, in order to obtain a freeze-dried concentrate having a higher retention rate of components, it is required to concentrate the raw material liquid to be freeze-dried as much as possible.

As a concentration step in such a freeze-drying pretreatment, for example, Patent Document 1 proposes a method using the RO method in two steps. Further, Patent Document 2 proposes to use a centrifugation method or a limit filtration method as another concentration step in the pretreatment for freeze-drying.

JP-A-11-75759 International Publication No. 2011/151726

Nippon Shokuhin Kogyo Gakkaishi 1982, 30 (2), pp125-132

The RO method described in Patent Document 1 is a method in which heating is not essential, so that the components are less likely to be altered by heat. However, since the RO method requires pressurization of the raw material liquid, if the raw material liquid contains solid substances, pressure-sensitive substances, etc., they may be deteriorated. Further, since the concentration rate of the RO method is limited by the pressurizing capacity of the pump, it may not be possible to concentrate the frozen body of the raw material liquid after freeze-drying so much. In addition to these, the RO method has the above-mentioned problems.

In the centrifugal separation method described in Patent Document 2, since the raw material liquid is pressurized by centrifugal force, alteration of components, deformation of solid content, and the like may occur. Further, in the case of the centrifugation method using a filter, a desired concentration ratio may not be obtained due to clogging of the membrane or the like. Further, in the centrifugal separation method, the apparatus may become large in order to withstand the centrifugal force due to rotation, and the capacity of the raw material liquid that can be processed at one time may be limited.
On the other hand, even in the ultrafiltration method, since pressure is applied to the raw material liquid, deterioration of components, deformation of solid content, clogging of the film, and the like may occur. Further, a substance having a molecular weight of less than the molecular weight of the ultrafiltration membrane cannot be concentrated while maintaining the component composition in the raw material liquid because a part or all of the substance permeates the membrane.

As described above, as a method for concentrating the raw material liquid in the freeze-drying pretreatment, it is possible to obtain a concentrated product having a desired concentration ratio while suppressing deterioration, deformation, and outflow of the components in the raw material liquid as much as possible. Moreover, a method with a large amount of processing is required. An effective system for concentrating the raw material liquid by combining the freeze-drying pretreatment method having such characteristics and the freeze-drying method has not yet been established.
Therefore, an object of the present invention is to obtain a freeze-dried concentrate in which the components in the raw material liquid are highly maintained by arranging a pretreatment step suitable for freeze-drying in a raw material liquid concentration system using a freeze-drying method. It is to provide a raw material liquid concentration system for this purpose.

The present invention is as follows.
<< Aspect 1 >>
A raw material solution containing a solvent and a solute and an inducing solution are brought into contact with each other via a forward osmosis membrane, and the solvent in the raw material solution is moved into the inducing solution to obtain a concentrated raw material solution and a dilution inducing solution. One step and
It has a second step of freeze-drying the concentrated raw material liquid and further concentrating it.
At the end of the first step, the osmotic pressure of the concentrated raw material solution measured at the temperature at that time is in the range of 1.52 MPa (15 atm) or more and 65.9 MPa (650 atm) or less. Perform the process,
Raw material liquid concentration system.
<< Aspect 2 >>
The concentration system according to aspect 1, wherein the solvent is water.
<< Aspect 3 >>
The concentration system according to aspect 1 or 2, wherein the first step is performed by cross-flow filtration.
<< Aspect 4 >>
The concentration system according to any one of aspects 1 to 3, wherein the temperature of the raw material liquid is adjusted to a range of 5 ° C. or higher and 50 ° C. or lower in the first step.
<< Aspect 5 >>
The item according to any one of aspects 1 to 4, further comprising an induction solution regeneration step of removing the solvent from the dilution induction solution to obtain a regeneration induction solution and using the obtained regeneration induction solution as an induction solution again. Concentration system.
<< Aspect 6 >>
The concentration system according to aspect 5, wherein the removal of the solvent from the dilution induction solution in the induction solution regeneration step is performed by an evaporation means.
<< Aspect 7 >>
Aspects 1 to 4, further comprising an induction solution regeneration step of removing the solvent from the induction solution to obtain a concentration induction solution, and using a mixture of the obtained concentration induction solution and the dilution induction solution as an induction solution. Concentration system according to any one item.
<< Aspect 8 >>
The concentration system according to aspect 7, wherein the removal of the solvent from the induction solution in the induction solution regeneration step is performed by an evaporation means.
<< Aspect 9 >>
The concentration system according to any one of aspects 1 to 8, wherein the induction solution is an inorganic salt solution.
<< Aspect 10 >>
The concentration system according to any one of aspects 1 to 9, wherein the forward osmosis membrane is a hollow filamentous membrane.
<< Aspect 11 >>
The forward osmotic membrane is a membrane having a thin film layer containing at least one selected from the group consisting of polyethersulfone, polysulfone, polyketone, polyvinylidene fluoride, polyacrylonitrile, polyimine, and polyamide as a main component. The concentration system according to any one of 10.
<< Aspect 12 >>
The concentration system according to any one of aspects 1 to 11, further comprising a circulation mechanism in which the concentrated raw material liquid obtained in the first step is used as the raw material liquid in the first step.
<< Aspect 13 >>
The item according to any one of aspects 1 to 12, wherein the initial permeation flow velocity of the forward osmosis membrane at the start of the first step is 1 kg / (m ² × hr) or more and 100 kg / (m ² × hr) or less. Concentration system.
<< Aspect 14 >>
At the end of the first step, the osmotic pressure of the concentrated raw material solution measured at the temperature at that time is in the range of 2.03 MPa (20 atm) or more and 50.7 MPa (500 atm) or less. The concentration system according to any one of aspects 1 to 13, wherein the step is performed.
<< Aspect 15 >>
At the end of the first step, the osmotic pressure of the concentrated raw material solution measured at the temperature at that time is in the range of 2.53 MPa (25 atm) or more and 35.5 MPa (350 atm) or less. The concentration system according to aspect 14, wherein the step is performed.

The raw material liquid concentration system of the present invention is a combination of concentration of the raw material liquid by the forward osmosis method and concentration by the freeze-drying method. By such a raw material liquid concentration system of the present invention, a freeze-dried concentrate in which the component composition in the raw material liquid is highly maintained can be obtained with high efficiency.
The present invention includes, for example, concentration of oral liquids (liquid foods, beverages, etc.), treatment of precursor solutions for chemical species synthesis, treatment of accompanying water discharged from gas fields (including shale gas fields) and oil fields, etc. It can be suitably applied to the application. The above-mentioned oral liquid means the whole thing that a person or an animal eats, and includes both a thing taken orally and a thing excreted after being put in the mouth. Examples of oral ingestions include beverages such as juices and soft drinks; fluid foods such as various soup stocks, seasonings and soups; health supplements; oral medicines; and raw materials thereof. Examples of substances that are discharged after being put in the mouth include mouthwash, mouthwash, and raw materials thereof.

It is a conceptual diagram for demonstrating an example of embodiment of the raw material liquid concentration system of this invention. It is a conceptual diagram for demonstrating another example of embodiment of the raw material liquid concentration system of this invention. It is a conceptual diagram for demonstrating still another example of embodiment of the raw material liquid concentration system of this invention. It is a conceptual diagram for demonstrating still another example of embodiment of the raw material liquid concentration system of this invention. It is a conceptual diagram for demonstrating still another example of embodiment of the raw material liquid concentration system of this invention.

Hereinafter, preferred embodiments of the present invention will be specifically described in detail as non-limiting examples.

<Raw material liquid concentration system>
The raw material liquid concentration system of the present invention
A raw material solution containing a solvent and a solute and an inducing solution are brought into contact with each other via a forward osmosis membrane, and the solvent in the raw material solution is moved into the inducing solution to obtain a concentrated raw material solution and a dilution inducing solution. One step and
It has a second step of freeze-drying the concentrated raw material liquid and further concentrating it.
At the end of the first step, the osmotic pressure of the concentrated raw material solution measured at the temperature at that time is in the range of 1.52 MPa (15 atm) or more and 65.9 MPa (650 atm) or less. It is characterized by performing.

The outline of the raw material liquid concentration system of the present invention will be described with reference to the drawings as necessary.

In the first step, the raw material solution and the inducing solution are brought into contact with each other through a forward osmosis membrane, and the solvent in the raw material solution is moved to the inducing solution to concentrate the raw material solution and dilute the inducing solution. Then, a concentrated raw material solution and a dilution induction solution are obtained.
In the second step, the concentrated raw material liquid obtained in the first step is further concentrated by a freeze-drying method to obtain a product (concentrate) having a water content preferably reduced to 5% by mass or less.

Between the first step and the second step, there may be a step of performing a pre-stage of the freeze-drying method.
Examples of the pre-stage step of the freeze-drying method include a preliminary freezing step and a sterilization step.
The first step and the second step may be performed continuously without any time interval, or may be performed with a predetermined time interval. For example, the concentrated raw material liquid obtained in the first step may be temporarily stored, and the second step may be performed after a predetermined time has elapsed. However, it is more preferable from the viewpoint of time efficiency that the first step and the second step are connected and the concentration is continuously performed without any time interval.

Even if an osmotic pressure measuring step is included between the first step and the second step to confirm that the concentrated raw material liquid obtained in the first step is concentrated to a predetermined osmotic pressure. Good. The osmotic pressure in the osmotic pressure measuring step may be measured in the apparatus in which the first step is performed, or a part of the concentrated raw material liquid may be extracted after the first step.

FIG. 1 shows a schematic diagram for explaining an example of the raw material liquid concentrating system of the present invention having the first and second steps.
In the first step of the raw material liquid concentration system of FIG. 1, a forward osmosis membrane unit having a forward osmosis membrane o and performing a forward osmosis process is used. The internal space of the forward osmosis membrane unit is divided into two, a raw material liquid side space R and an induction solution side space D, by the forward osmosis membrane o. The raw material liquid a, which is the object to be concentrated, is introduced into the space R on the raw material liquid side of the forward osmosis membrane unit. On the other hand, the induction solution d is introduced into the induction solution side space D of the forward osmosis membrane unit.
The raw material liquid a contains a solute and a solvent b. The inducing solution d contains an inducing substance and a solvent b. The osmotic pressure of the inductive solution d is set to be higher than that of the raw material solution a.

Then, when the raw material solution a and the induction solution d are brought into contact with each other via the forward osmosis membrane o, the solvent b in the raw material liquid a passes through the forward osmosis membrane o using the osmotic pressure difference between the two solutions as a driving force. Moves to the induction solution d side. As a result, a concentrated raw material solution c, which is a concentrated raw material solution, and a diluted induction solution e, which is a diluted induction solution, can be obtained. In the first step in FIG. 1, the raw material solution a and the induction solution d are countercurrent, but parallel flow may be used.
The forward osmosis treatment in the first step may be performed by a total amount filtration method or a cross-flow filtration method, but the cross-flow filtration method is preferable from the viewpoint of filtration flow velocity and suppression of membrane contamination.

In the raw material liquid concentration system of FIG. 1, the osmotic pressure of the concentrated raw material liquid c obtained in the first step is measured at the position of "P".

In the second step of the raw material liquid concentration system of FIG. 1, freeze-drying is performed.
Lyophilization typically involves three steps within the chamber:
(A) Freezing stage;
(B) Primary drying stage; and (C) Secondary drying stage.
The step (A) is a step of freezing the solvent in the concentrated raw material liquid c obtained by the first step. In step (B), the chamber pressure is reduced (eg, up to 13.3 Pa (0.1 toll)) and heat is applied to the product to sublimate the frozen solvent. In step (C), the temperature is increased and the binding solvent, such as water of crystallization, is also removed until the residual solvent content drops to the desired level. In this way, the product f in which the concentrated raw material liquid c is further concentrated is obtained. Here, as a method for promoting desolvation, in addition to the decrease in the chamber pressure, a method in which a dried gas is allowed to flow may be used.

FIG. 2 shows a schematic diagram for explaining another example of the raw material liquid concentrating system of the present invention having the first and second steps.
The forward osmosis membrane unit and the second step in the first step in the raw material liquid concentrating system of FIG. 2 are the same as the first step and the second step in the raw material liquid concentrating system of FIG. 1, respectively. Good. However, the raw material liquid concentrating system of FIG. 2 has a circulation mechanism for reusing the concentrated raw material liquid obtained in the first step as the raw material liquid in the first step. In this embodiment, for example, when the osmotic pressure of the concentrated raw material liquid obtained by passing the raw material liquid a once in the first step does not reach the predetermined range of the present invention, at least a part of the concentrated raw material liquid. Has an advantage that a concentrated raw material liquid c having a predetermined osmotic pressure can be obtained by passing the above through the first step a plurality of times.
In this case, the number of times the raw material liquid a is passed through the first step is arbitrary.

FIG. 3 shows a schematic diagram for explaining still another example of the raw material liquid concentrating system of the present invention having the first and second steps.
The first step and the second step in the raw material liquid concentrating system of FIG. 3 may be the same as the first step and the second step of the raw material liquid concentrating system of FIG. 1, respectively. However, the raw material liquid concentration system of FIG. 3 further includes an induction solution regeneration step. In this induction solution regeneration step, the solvent b is removed from the dilution induction solution e obtained in the first step and concentrated to obtain a regeneration induction solution g, and the obtained regeneration induction solution g is reconstituted with the induction solution d. It may have a function to be used for circulation. The removal of the solvent b from the dilution induction solution e may be carried out by a known concentration means, for example, an evaporation means or the like.

FIG. 4 shows a schematic diagram for explaining still another example of the raw material liquid concentration system of the present invention having the first and second steps.
The first step and the second step in the raw material liquid concentrating system of FIG. 4 may be the same as the first step and the second step of the raw material liquid concentrating system of FIG. 1, respectively. However, the raw material liquid concentrating system of FIG. 4 has an induction solution regeneration step of an embodiment different from that of the raw material liquid concentrating system of FIG. In the induction solution regeneration step in the raw material solution concentration system of FIG. 4, first, the solvent b is removed from the induction solution d to obtain a concentration induction solution h. Then, the concentrated induction solution h obtained here and the dilution induction solution e obtained in the first step are mixed to obtain a regeneration induction solution g, and this regeneration induction solution g is used as the induction solution d. It may have a function. In this induction solution regeneration step, the removal of the solvent b from the induction solution d may be carried out by a known concentration means, for example, an evaporation means or the like. Mixing of the concentration-inducing solution h and the dilution-inducing solution e may be performed, for example, in a buffer tank as shown in FIG.

FIG. 5 shows a schematic diagram for explaining still another example of the raw material liquid concentrating system of the present invention having the first and second steps.
The forward osmosis membrane unit and the second step in the first step in the raw material liquid concentrating system of FIG. 5 are the same as the first step and the second step in the raw material liquid concentrating system of FIG. 1, respectively. Good. The raw material liquid concentration system of FIG. 5 has the circulation mechanism shown in FIG. 2 and the induction solution regeneration step shown in FIG. 4 in an overlapping manner.
In the raw material liquid concentrating system of FIG. 5, the mode shown in FIG. 3 may be adopted as the induction liquid regeneration step.

<< Each element of the raw material liquid concentration system >>
The outline of the concentration of the raw material liquid by the raw material liquid concentration system of the present invention has been described above. Subsequently, each element constituting the raw material liquid concentration system of the present invention will be described in detail below.

<Raw material liquid a>
The raw material liquid a is a fluid containing a solute and a solvent b, and is scheduled to be concentrated by the system of the present invention. The raw material liquid a may be an emulsion as long as it is a fluid.

Examples of the raw material liquid a applied to the present invention include foods, pharmaceutical raw materials, seawater, accompanying water discharged from gas fields and oil fields, and the like. In the raw material liquid concentration system of the present invention, a concentrate from which the solvent has been removed can be obtained while maintaining the composition of the raw material liquid a substantially as it is. Therefore, when the raw material liquid concentration system of the present invention is applied to foods, it is possible to concentrate with less loss of aroma components. Further, when the system of the present invention is applied to the concentration of a drug or a raw material thereof, it becomes possible to concentrate the drug while maintaining its efficacy.
As the raw material liquid a applied to the present invention, for example, foods, sugars, amino acids, peptides (oligopeptides, etc.) and the like are preferable.

Food is preferable as the raw material liquid a applied to the present invention.
Concentrated foods include, for example, coffee extract, juice (eg, orange juice, tomato juice, etc.), alcoholic beverages (liquids containing ethanol, such as wine, beer, etc.), dairy products (eg, lactic acid bacteria beverage, raw milk). Etc.), juice (eg, kelp stock, eel juice, etc.), tea extract, flavored emulsion (eg, emulsion of vanilla essence, strawberry essence, etc.), honeys (eg, maple syrup, honey, etc.), food oil Emulsion (for example, emulsion of olive oil, rapeseed oil, sunflower oil, red flowers, corn, etc.) and the like can be mentioned.

Examples of the sugar to be concentrated include monosaccharides (eg, glucose, fructose, galactose, mannose, ribose, deoxyribose, etc.), disaccharides (eg, maltose, sucrose, lactose, etc.), sugar chains (eg, glucose, galactose, etc.). , Mannose, fucose, xylose, glucuronic acid, isulonic acid, etc .; saccharide derivatives such as N-acetylglucosamine, N-acetylgalactosamine, N-acetylneuraminic acid, etc.) and the like.

The amino acids to be concentrated include, for example, essential amino acids (eg, tryptophan, lysine, methionine, phenylalanine, threonine, valine, leucine, isoleucine, etc.), non-essential amino acids (eg, arginine, glycine, alanine, serine, tyrosine, cysteine, etc.) Asparagine, glutamine, proline, aspartic acid, glutamic acid, etc.), unnatural amino acids and the like can be mentioned. The "unnatural amino acid" refers to any non-naturally occurring artificial compound having an amino acid skeleton in the same molecule, and can be produced by binding various labeled compounds to the amino acid skeleton. The "amino acid skeleton" contains a carboxyl group, an amino group, and a portion connecting these groups in the amino acid. "Labeled compound" refers to dye compounds, fluorescent substances, chemical / bioluminescent substances, enzyme substrates, coenzymes, antigenic substances, and protein binding substances known to those skilled in the art.
As an example of an unnatural amino acid, for example, "labeled amino acid" which is an amino acid bound to a labeled compound can be mentioned. Examples of the labeled amino acid include an amino acid in which a labeled compound is bound to an amino acid having an amino acid skeleton containing an aromatic ring such as a benzene ring in the side chain. In addition, examples of unnatural amino acids to which a specific function is given include, for example, photoresponsive amino acids, optical switch amino acids, fluorescent probe amino acids, and fluorescently labeled amino acids.

Examples of the oligopeptide to be concentrated include L-alanyl-L-glutamine, β-alanyl-L-histidine cyclosporine, glutathione and the like. Here, the "oligopeptide" refers to a compound to which any amino acid having 2 or more residues and less than 50 residues is bound. The oligopeptide may be chain-like or cyclic.

<Induction solution d>
The inducing solution d is a fluid that contains an inducing substance and a solvent b, has a higher osmotic pressure than the raw material liquid a, and does not significantly denature the forward osmotic membrane o.

<Inducing substance>
Examples of the inducer that can be used in the present invention include inorganic salts, sugars, alcohols, polymers and the like. Therefore, the induction solution in the present invention may be a solution containing one or more selected from inorganic salts, sugars, alcohols, polymers and the like.
Examples of the inorganic salt include sodium chloride, potassium chloride, magnesium chloride, calcium chloride, sodium sulfate, magnesium sulfate, sodium thiosulfate, sodium sulfite, ammonium chloride, ammonium sulfate, ammonium carbonate and the like;
Examples of sugars include general sugars such as sucrose, fructose, and glucose, and special sugars such as oligosaccharides and rare sugars;
Examples of the alcohol include monoalcohols such as methanol, ethanol, 1-propanol and 2-propanol; and glycols such as ethylene glycol and propylene glycol.
Examples of the polymer include polymers such as polyethylene oxide and propylene oxide, and copolymers thereof.

The concentration of the inducing substance in the inducing solution d is set so that the osmotic pressure of the inducing solution d is higher than the osmotic pressure of the raw material liquid a. The osmotic pressure of the inductive solution d may fluctuate within the range as long as it is higher than the osmotic pressure of the raw material solution a.
To determine the osmotic pressure difference between the two liquids, for example, one of the following methods can be used.
(1) When two liquids are mixed and then separated into two phases: After the two phases are separated, it is judged that the osmotic pressure of the liquid with the larger volume is higher, or
(2) When the two liquids are mixed and not separated into two phases: The two liquids are brought into contact with each other through the forward osmosis membrane o, and it is judged that the osmotic pressure of the liquid whose volume has increased after a certain period of time is high. The constant time at this time depends on the osmotic pressure difference, but is generally in the range of several minutes to several hours.

<Solvent of raw material liquid a>
The solvent b in the raw material liquid a can be any inorganic solvent or organic solvent as long as it is a liquid and can dissolve or disperse the components in the raw material liquid a. The solvent b is often water. The solvent b in the present invention is typically water.

(Solvent of induction solution d)
The solvent in the inductive solution d is preferably the same type as the solvent b to be separated from the raw material solution a. For example, when the solvent of the raw material solution a is water, it is preferable that the solvent of the induction solution d is also water.

<Concentrated raw material liquid c>
The concentrated raw material liquid c obtained by concentrating the raw material liquid a through the first step is obtained by maintaining the components in the raw material liquid a and preferentially separating the solvent b. In the raw material liquid concentrating system of the present invention, the amount of the solvent b separated from the raw material liquid a can be arbitrarily controlled.
In particular, in the present invention, the osmotic pressure of the concentrated raw material liquid c measured at the temperature at the end of the first step is in the range of 1.52 MPa (15 atm) or more and 65.9 MPa (650 atm) or less. Perform the process. The osmotic pressure of the concentrated raw material liquid c measured at the temperature at the end of the first step is preferably in the range of 2.03 MPa (20 atm) or more and 50.7 MPa (500 atm) or less, and is 2.53 MPa (25 atm) or more and 35. It is more preferable that the range is 5.5 MPa (350 atm) or less.

If the osmotic pressure of the concentrated raw material liquid c measured at the temperature at the end of the first step is less than 1.52 MPa (15 atm), a sufficient concentration effect cannot be obtained, and the components are often not sufficiently maintained. .. Further, when the osmotic pressure of the concentrated raw material solution c measured at the temperature at the end of the first step exceeds 65.9 MPa (650 atm), an extremely high concentration of the induction solution d is often required. In this case, although the reason is not clear, the amount of the inducer transferred from the inducer solution d to the concentrated raw material solution c tends to increase through the forward osmosis membrane o.

According to the first step of the present invention, as long as the osmotic pressure of the raw material solution a does not exceed the osmotic pressure of the induction solution d, it is possible to concentrate to near the saturation concentration of the raw material solution a. After that, by going through the second step described later, the freeze-drying time can be shortened even when the amount of the raw material liquid a is large. As described above, by performing the first step until the osmotic pressure of the raw material liquid a becomes sufficiently high, the freeze-drying step having a large time and energy load can be made more efficient.

The first step of the present invention is a forward osmosis process. Therefore, it is possible to obtain a high concentration ratio while maintaining a high level of raw material liquid components. In addition, since an arbitrary concentration ratio can be obtained by changing the inducer, there are various types of raw material liquids to which this system can be applied, and substantially any liquid can be concentrated. Therefore, according to the present invention, a high quality concentrate can be obtained with high efficiency even when it is impossible or difficult to apply the prior art.

<First step>
In the first step of the raw material liquid concentration system of the present invention, a forward osmosis process is performed.
The forward osmosis process in the present invention may be carried out using, for example, a forward osmosis membrane unit in which the internal space is divided into two, a raw material liquid side space R and an induction solution side space D, by the forward osmosis membrane o.

<Forward osmosis membrane o of the forward osmosis membrane unit>
The forward osmosis membrane o of the forward osmosis membrane unit is a membrane having a function of allowing the solvent b to permeate but not allowing the solute to permeate or making it difficult to permeate.
The forward osmosis membrane o used in the first step of the raw material liquid concentration system of the present invention may be a membrane also having a function as a reverse osmosis membrane. However, the reverse osmosis process in which the solvent is removed by pressure and the forward osmosis process in which the difference in osmotic pressure between the raw material solution and the inductive solution is utilized are appropriate due to the difference in the driving force utilized for solvent removal. The membrane structure is different.
In a system in which a forward osmosis process is incorporated into a series of steps, such as the raw material liquid concentration system of the present invention, it is preferable to use a membrane having a higher function as a forward osmosis membrane.

Examples of the shape of the forward osmosis membrane o include a hollow filamentous shape, a flat membrane shape, a spiral membrane shape, and the like.
The forward osmosis membrane o is preferably a composite type membrane having a separation active layer on the support layer (support membrane). The support membrane may be a flat membrane or a hollow fiber membrane.
When the flat membrane is used as a support membrane, it may have a separation active layer on one side or both sides of the support membrane.
When the hollow fiber membrane is used as a support membrane, the hollow fiber membrane may have a separation active layer on the outer surface or the inner surface of the hollow fiber membrane, or both surfaces.

The support membrane in the present embodiment is a membrane for supporting the separation active layer, and it is preferable that the support membrane itself does not substantially exhibit separation performance with respect to the separation target. As the support film, any known microporous support film, non-woven fabric and the like can be used.
The preferred support membrane in this embodiment is a microporous hollow fiber support membrane. The fine pore hollow fiber support membrane has fine pores having a pore diameter of preferably 0.001 μm or more and 0.1 μm or less, more preferably 0.005 μm or more and 0.05 μm or less on the inner surface thereof. On the other hand, regarding the structure from the inner surface of the microporous hollow fiber support membrane to the outer surface in the depth direction of the membrane, in order to reduce the permeation resistance of the permeating fluid, the structure is as sparse as possible while maintaining the strength. It is preferable to have. The sparse structure of this portion is preferably, for example, a net-like structure, a finger-like void, or a mixed structure thereof.

As the separation active layer in the flat membrane-like or hollow filament-like forward osmosis membrane o, since the inhibition rate of the inducer is high, for example, polysulfone, polyethersulfone, polyvinylidene fluoride, polyacrylonitrile, polyethylene, polypropylene, polyamide, acetic acid. It is preferably a thin film layer containing at least one selected from cellulose and the like as a main component. More preferably, the main component is at least one selected from polysulfone, polyethersulfone, polyvinylidene fluoride, polyacrylonitrile, and polyamide, and a layer of polyamide is particularly preferable.
The polyamide in the separation active layer can be formed by interfacial polymerization of a polyfunctional acid halide and a polyfunctional aromatic amine.

The polyfunctional aromatic acid halide is an aromatic acid halide compound having two or more acid halide groups in one molecule. Specifically, for example, trimesic acid halide, trimellitic acid halide, isophthalic acid halide, terephthalic acid halide, pyromellitic acid halide, benzophenonetetracarboxylic acid halide, biphenyldicarboxylic acid halide, naphthalenedicarboxylic acid halide, pyridinedicarboxylic acid halide, etc. Examples thereof include benzenedisulfonic acid halide and the like, and these can be used alone or in combination thereof. Examples of the halide ion in these aromatic acid halide compounds include chloride ion, bromide ion, and iodide ion. In the present invention, trimesic acid chloride alone, a mixture of trimesic acid chloride and isophthalic acid chloride, or a mixture of trimesic acid chloride and terephthalic acid chloride is particularly preferably used.

The polyfunctional aromatic amine is an aromatic amino compound having two or more amino groups in one molecule. Specifically, for example, 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'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 1,3,5-triamino Benzene, 1,5-diaminonaphthalene and the like can be mentioned, and these can be used alone or in admixture thereof. In the present invention, in particular, one or more selected from m-phenylenediamine and p-phenylenediamine are preferably used.

Interfacial polymerization of polyfunctional acid halides and polyfunctional aromatic amines can be carried out according to a conventional method.

In the present embodiment, it is preferable to use a hollow fiber-shaped forward osmosis membrane, and it is particularly preferable to use a composite hollow fiber having a separation active layer made of a polymer thin film on the inner surface of the hollow fiber-shaped porous support membrane.
As the forward osmosis membrane unit, it is preferable to use one in the form of a forward osmosis membrane module in which a plurality of forward osmosis membrane thread bundles are preferably housed in a suitable housing.

The permeation flux of the forward osmosis membrane o with respect to the solvent b is preferably 1 kg / (m ² × hr) or more and 100 kg / (m ² × hr) as the initial permeation flow velocity at the start of the first step. If the initial permeation flux is less than 1 kg / (m ² x hr), the separation efficiency of the solvent b may be impaired, and if it exceeds 100 kg / (m ² x hr), the solvent b is passed through the forward osmosis membrane o. The amount of the inducing substance transferred from the inducing solution d to the concentrated raw material liquid c may increase.
The permeated flux with respect to the solvent b in the present specification means the amount of the solvent b passing through the forward osmosis membrane o, which is allocated per unit area of the forward osmosis membrane o and per unit time. It is defined by the following formula (1).
F = L / (M × H) (1)
Here, F is the permeated flux (kg / (m ² × hr)) for the solvent b, L is the amount (kg) of the permeated solvent b, and M is the surface area (m ² ) of the forward osmosis membrane o. ), And H is the time (hr).
The permeated flux when the solvent b is water is generally called "water permeability", and can be measured using, for example, pure water as the treatment solution and 3.5 wt% saline solution as the induction solution. ..

<Introduction of raw material solution a and inductive solution d into the forward osmosis membrane unit>
The raw material liquid a to be concentrated is introduced into the raw material liquid side space R of the forward osmosis membrane unit, and the induction solution d is introduced into the induction solution side space D. The direction of these flows may be countercurrent or parallel.
The flow rate of the raw material liquid a introduced into the raw material liquid side space R of the forward osmosis membrane unit is arbitrary, but as a typical example, per 1 m ² of the surface area of the forward osmosis membrane in the forward osmosis membrane unit, per minute. 50mL / ^{(m 2} · min) or more 1,500mL / ^{(m 2} · min) can be exemplified the following range, 100mL / ^{(m 2} · min) or more 1,000mL / ^{(m 2} · min) or less and It is preferable to do so.

Although the flow rate of the draw solution d which is introduced into the draw solution side space D of the forward osmosis membrane unit is arbitrary, illustrate 100mL / ^{(m 2} · min) or more 5,000mL / ^{(m 2} · min) the range it can, it is preferable to 500mL / ^{(m 2} · min) or more 2,000mL / ^{(m 2} · min) or less.

<Temperature of raw material solution a and induction solution d>
In the first step, the temperature of the raw material liquid a introduced into the raw material liquid side space R of the forward osmosis membrane unit is not particularly limited, but is preferably 3 ° C. or higher and 60 ° C. or lower, and more preferably 5 ° C. or higher and 50 ° C. or higher. It is below ° C. Although the reason is not clear, when the temperature of the raw material liquid a is less than 3 ° C., the permeation flow velocity may be slow, and when the temperature is 60 ° C. or higher, some of the components in the raw material liquid a may be denatured.
The temperature of the induction solution d introduced into the induction solution side space D of the forward osmosis membrane unit is not particularly limited, but is preferably 5 ° C. or higher and 60 ° C. or lower, and more preferably 10 ° C. or higher and 50 ° C. or lower. Although the reason is not clear, when the temperature of the inducing solution d is less than 5 ° C. or higher than 60 ° C., the amount of the inducing substance transferred from the inducing solution d to the raw material liquid a through the forward osmosis membrane o increases. Cases can be seen.

<Osmotic pressure measurement of concentrated raw material liquid c>
As described above, the concentrated raw material c obtained by the first step has an osmotic pressure in the range of 1.52 MPa (15 atm) or more and 65.9 MPa (650 atm) or less measured at the temperature at the end of the first step. Be adjusted.
The osmotic pressure of the concentrated raw material liquid c can be measured by using any of the following methods 1 to 3.
1: A solution similar to the concentrated raw material solution c obtained separately through the same steps as the first step is brought into contact with an aqueous inorganic salt solution having a predetermined concentration via a semipermeable membrane, and 30 minutes later, each solution is prepared. The osmotic pressure of the inorganic salt aqueous solution when the volume change was 5% or less was defined as the osmotic pressure of the concentrated raw material solution c. Here, as the inorganic salt aqueous solution, a sodium chloride aqueous solution or a magnesium chloride aqueous solution may be typically used. The osmotic pressure of the aqueous inorganic salt solution can be measured using a known osmotic pressure measuring device (for example, OSK 40BU200-240 manufactured by Ogawa Seiki Co., Ltd.). When the measurement limit value is exceeded, for example, the change in osmotic pressure due to the weight% concentration of the inorganic salt solution can be measured, at least 10 points or more can be plotted, and then a quadratic approximation formula can be created and calculated. it can.
2: A part of the concentrated raw material solution c obtained in the first step is extracted and brought into contact with an aqueous inorganic salt solution having a predetermined concentration through a semipermeable membrane, and the volume change of each solution after 30 minutes is 5% or less. The osmotic pressure of the aqueous solution of the inorganic salt at that time may be the osmotic pressure of the concentrated raw material solution c.
3: A part of the concentrated raw material liquid c obtained through the first step can be extracted and measured using a known osmotic pressure measuring device (for example, OSK 40BU200-240 manufactured by Ogawa Seiki Co., Ltd.).

<Second step>
In the second step in the raw material liquid concentration system of the present invention, the concentrated raw material liquid c obtained in the first step is freeze-dried to obtain a further concentrated product f.
Any known technique may be used for lyophilization in this system, the typical process of which is as described above.

<Induction solution regeneration process>
The inductive solution regeneration step arbitrarily adopted in the raw material liquid concentration system of the present embodiment may be any of the following steps.
A step of removing the solvent b from the dilution induction solution e to obtain a regeneration induction solution g which is a concentrate of the dilution induction solution e, and using the obtained regeneration induction solution g as the induction solution d (first induction solution). In the regeneration step (for example, in the case of FIG. 3), or by removing the solvent b from the induction solution d to obtain a concentration induction solution h which is a concentrate of the induction solution d, the obtained concentration induction solution h and the dilution induction solution e A step of preparing a regeneration-inducing solution g by mixing with and using the obtained regeneration-inducing solution g as an induction solution d (second induction solution regeneration step, for example, in the case of FIG. 4).

The removal of the solvent b from the dilution induction solution e in the first induction solution regeneration step and the removal of the solvent b from the induction solution d in the second induction solution regeneration step may be performed, for example, by means of evaporation. .. As the evaporation means, for example, a distillation process, a forward osmosis process, a membrane distillation process or the like can be used.
In the distillation process, the dilution induction solution e or the induction solution d is adjusted to a predetermined temperature and then fed into a distillation tower to obtain a solvent b from the top of the column, and the solvent b is removed from the bottom of the column to concentrate. This is a step of obtaining a concentrated induction solution h, which is a concentrated induction solution from which the regeneration-inducing solution g, which is the diluted induction solution, or the solvent b has been removed.

In the forward osmosis process, the dilution induction solution e or the induction solution d is circulated so as to be in contact with the forward osmosis membrane, and the solvent b contained in the dilution induction solution e or the induction solution d is removed through the forward osmosis membrane. This is a step of separating the solvent b from the regeneration-inducing solution g or the concentration-inducing solution h.
In the membrane distillation process, a membrane unit having a separation chamber divided into a liquid phase portion and a gas phase portion by a semipermeable membrane is used. By introducing the dilution induction solution e or the induction solution d into the liquid phase portion of the membrane unit for membrane distillation and reducing the pressure in the gas phase portion, the solvent b contained in the dilution induction solution e or the induction solution d becomes a liquid. It moves from the phase part through the semitransparent film to the gas phase part under reduced pressure. Thereby, the solvent b can be removed from the dilution induction solution e or the induction solution d to obtain the regeneration induction solution g or the concentration induction solution h.

As the regeneration process of the dilution induction solution, a forward osmosis process using a forward osmosis membrane or a membrane distillation process using a semipermeable membrane is preferable because the equipment size is small, and the dilution induction solution e or the induction solution d is transferred to the solvent b. A membrane distillation process using a semipermeable membrane is more preferable because it can suppress the movement of the inducer.
The elements used in the membrane distillation process will be described below.

<Semipermeable membrane of membrane distillation process>
Examples of the shape of the semipermeable membrane used in the membrane distillation process include a hollow filament shape, a flat membrane shape, and a spiral membrane shape.
The flat membrane-like semipermeable membrane may be composed of, for example, a single layer, or may have a support layer and a separation active layer on the support layer. The hollow fiber-like semipermeable membrane may be, for example, a hollow fiber composed of a single layer, a hollow fiber-like support layer, an outer surface or an inner surface of the support layer, or both surfaces thereof. It may have the above separation active layer.
The material of the support layer and the separation active layer in the semipermeable membrane may be composed of any material selected from the materials exemplified above for the forward osmosis membrane o in the first step, respectively.

The permeation flux of the semipermeable membrane with respect to the solvent b is preferably 1 kg / (m ² × hr) or more and 200 kg / (m ² × hr) or less. If this permeated flux is less than 1 kg / (m ² x hr), the efficient separation of solvent b may be impaired, and if it exceeds 200 kg / (m ² x hr), it is semipermeable from the inductive solution d. The amount of inducer that passes through the membrane and moves to solvent b may increase.
This permeation flux is defined in the same way as the permeation flux for the solvent b of the forward osmosis membrane o in the first step.

<Temperature of dilution induction solution e or induction solution d introduced into the membrane distillation process>
It is preferable that the temperature of the dilution induction solution e or the induction solution d is adjusted in the range of 20 ° C. or higher and 90 ° C. or lower before being introduced into the liquid phase portion. If this temperature is less than 20 ° C., the efficiency of separation of the solvent b by membrane distillation may be impaired, and if it exceeds 90 ° C., the inducer contained in the dilution induction solution e or the induction solution flow d becomes semipermeable. The amount transferred to the solvent b through the membrane may increase.
As a heat source for heating the dilution induction solution e or the induction solution flow d, for example, a heat exchanger can be used, or exhaust heat from an industrial process or the like can be used. Utilizing exhaust heat as a heat source is preferable because the amount of energy newly consumed for separating the solvent b can be reduced.

<Phase part in membrane distillation process>
The gas phase portion of the membrane unit for membrane distillation used in the membrane distillation process is preferably depressurized to a predetermined pressure. The pressure of the gas phase portion may be appropriately set according to the scale of the apparatus, the concentration of the induced solution flow d, the production rate of the desired solvent b, etc., but is preferably 0.1 kPa or more and 80 kPa or less, for example. More preferably, it is 1 kPa or more and 50 kPa or less.
Examples of the decompression device for depressurizing the gas phase portion of the membrane unit for membrane distillation include a diaphragm vacuum pump, a dry pump, an oil rotary vacuum pump, an ejector, and an aspirator.

<Products obtained in the induction solution regeneration process>
According to the first induction solution regeneration step, the solvent b is separated from the dilution induction solution e to become the regeneration induction solution g which is a concentrated dilution induction solution, and is discharged from the membrane unit for membrane distillation. The obtained regeneration-inducing solution g can be reused as the inducing solution d after being mixed with the dilution-inducing solution e as necessary and adjusted to a predetermined concentration. When reusing the regeneration-inducing solution g, the temperature of the regeneration-inducing solution g may be adjusted by using a cooling device.
According to the second induction solution regeneration step, the solvent b is separated from the induction solution d to become a concentrated induction solution f, which is a concentrated induction solution, and is discharged from the membrane unit for membrane distillation. The obtained concentration-inducing solution h is mixed with the dilution-inducing solution e and adjusted to a predetermined concentration to become a regeneration-inducing solution g, which can be reused as it is as an inducing solution d. When reusing the concentration-inducing solution h, the temperature of the concentration-inducing solution h may be adjusted by using a cooling device.
As the cooling device in the above, for example, a chiller, a heat exchanger, or the like can be used.
The solvent b separated from the induction solution d by the induction solution regeneration step may be reused if necessary.

<Component retention of the raw material liquid concentration system of the present invention>
According to the raw material liquid concentration system of the present invention as described above, it is possible to efficiently obtain a high-concentration concentrate in which the composition of the components contained in the raw material liquid is substantially maintained.
The analysis of the components in the obtained concentrate may be appropriately selected depending on the type of the raw material liquid and the components contained in the concentrate. For example, ICP-MS (inductively coupled high frequency plasma mass spectrometry), nuclear magnetic resonance spectroscopy (NMR), gas chromatography mass spectrometry (GC / MS), colorimetric method, fluorescence method, high performance liquid chromatography (HPLC), etc. Various known analytical methods can be used.

Hereinafter, the present invention will be specifically described based on Examples, but the present invention is not limited to the following Examples.
The following examples were carried out using the raw material liquid concentration system having the configuration shown in FIG.

<< Preparation of raw material liquid concentration system >>
<Preparation of a forward osmosis membrane unit having a forward osmosis membrane o>
(1) Preparation of Hollow Fiber Support Membrane Module Polyether sulfone (manufactured by BASF, trade name "Ultrason") is dissolved in N-methyl-2-pyrrolidone (manufactured by Wako Pure Chemical Industries, Ltd.) to obtain 20% by mass. A hollow fiber spinning stock solution was prepared. A wet hollow yarn spinning machine equipped with a double spinner was filled with the above stock solution and extruded into a coagulation tank filled with water to form hollow yarn by phase separation. The obtained hollow yarn was wound on a winder. The outer diameter of the obtained hollow yarn was 1.0 mm, the inner diameter was 0.7 mm, the diameter of the fine pores on the inner surface was 0.05 μm, and the water permeability was 1,020 kg / (m ² × hr) / 100 kPa.
This hollow yarn was used as a support layer.
The structure shown in FIG. 1 is formed by filling a cylindrical plastic housing having a diameter of 5.5 cm and a length of 50 cm with a bundle of 1,750 hollow thread-shaped support layers and fixing both ends with an adhesive. A module of a hollow filamentous support layer having an effective inner surface area of 1.65 m ² was prepared.

(2) Preparation of Forward Osmosis Membrane Unit 100 g of m-phenylenediamine and 8 g of sodium lauryl sulfate were placed in a 10 L container, and 4,892 g of pure water was further added and dissolved to prepare 5 kg of a first solution used for interfacial polymerization.
8 g of trimesic acid chloride was placed in another 10 L container, and 3,992 g of n-hexane was added and dissolved to prepare 4 kg of a second solution used for interfacial polymerization.
The core side (inside of the hollow fiber) of the module of the hollow fiber-like support layer manufactured above is filled with the first solution, allowed to stand for 30 minutes, then drained, and a thin film of the first solution is formed inside the hollow fiber. Was formed. In this state, the second solution was sent to the core side at a flow rate of 1.75 L / min for 3 minutes to perform interfacial polymerization. The polymerization temperature was 25 ° C.
Next, nitrogen at 50 ° C. was flowed through the core side of the hollow filamentous support membrane module for 30 minutes to evaporate and remove n-hexane. Further, by washing both the shell side and the core side with pure water, a forward osmosis membrane unit which is a module having a hollow thread-like forward osmosis membrane o was produced.

The water permeation amount of this forward osmosis membrane unit was 10.12 kg / (m ² × hr) when pure water was used as the treatment solution and 3.5 mass% saline solution was used as the induction solution.

<Freeze-drying chamber>
As the freeze-drying chamber in the second step, a square dry chamber (DRC-1000) manufactured by Tokyo Science Instruments Co., Ltd. is used, and the second step is performed by connecting with the freeze-drying machine (FDU-2110) manufactured by the same company. went.

<Dilution induction solution regeneration means>
(Preparation of membrane distillation unit)
As the diluting inducing solution concentrating means in the inducing solution regeneration step, a membrane distillation unit prepared as follows was used.
23 parts by mass of hydrophobic silica (AEROSIL-R972, manufactured by Nippon Aerosil Co., Ltd.) with an average primary particle size of 0.016 μm and a specific surface area of 110 m ² / g, 31 parts by mass of octyl (DOP) when phthalate, and butyl when phthalate ( 6 parts by mass of DBP) was mixed with a Henschel mixer, 40 parts by mass of vinylidene polyvinylfluoride (SOLVAY, Solef® 6010) having a weight average molecular weight of 310,000 was added thereto, and mixed again with a Henschel mixer. did. This mixture was mixed with a twin-screw kneading extruder and pelletized.
The obtained pellets were melt-kneaded at 240 ° C. by a twin-screw kneading extruder and extruded into hollow threads to obtain hollow fibers. At this time, a hollow fiber forming spun is attached to the extrusion port in the head at the tip of the extruder, and the melt is extruded from the melt extrusion annular hole on the extrusion surface to obtain an extrusion, and at the same time, the extrusion product is obtained. Hollow fiber-shaped extruded product was obtained by discharging nitrogen gas from a circular hole for discharging a hollow portion-forming fluid inside the annular hole for extruding a melt and circulating it in the hollow portion of the extruded product. The obtained hollow thread-like extruded product was introduced into a water bath (40 ° C.) at a free running distance of 20 cm and wound at a speed of 20 m / min.

The obtained hollow filamentous extruded product was continuously picked up by a pair of first endless track type belt pickers at a speed of 20 m / min, and the space temperature was controlled to 40 ° C. in the first heating tank (0.8 m length). Was passed through. After that, it was picked up at a speed of 40 m / min by a second track-type belt picker similar to the first track-type belt picker, and stretched 2.0 times. Then, after passing through a second heating tank (0.8 m long) in which the space temperature was controlled to 80 ° C., the mixture was cooled while being periodically bent on the water surface of the cooling water tank at 20 ° C. Then, it was picked up at a speed of 30 m / min by a third endless track type belt picker, the drawn yarn was contracted to 1.5 times, and then wound up with a skein having a circumference of about 3 m. Periodic bending on the water surface of the cooling water tank was performed by continuously sandwiching hollow yarns at a rotation speed of 170 rpm using a pair of uneven rolls having a circumference of about 0.20 m and four ridges.

The wound hollow filamentous extrusion was immersed in methylene chloride to extract and remove DOP and DBP in the hollow filamentous extrusion, and then dried. Then, after immersing in a 50 mass% ethanol aqueous solution, the silica in the hollow filamentous extruded product was extracted and removed by immersing in a 5 mass% sodium hydroxide aqueous solution at 40 ° C. for 1 hour. Then, it was washed with water and dried to obtain a hollow yarn. The outer diameter of the obtained hollow yarn was 1.25 mm, the inner diameter was 0.68 mm, and the diameter of the fine pores on the inner surface was 0.1 μm. This hollow fiber was used as a semipermeable membrane for membrane distillation. By filling a cylindrical plastic housing having a diameter of 13 cm and a length of 75 cm with 4,700 semipermeable membranes made of the above hollow fibers and fixing both ends with an adhesive, membrane distillation with an effective inner surface area of 7.5 m ² is performed. The unit was made.

The water permeability of this membrane distillation unit was 20.02 kg / (m ² × hr) when 3.5 mass% saline solution was used as the treatment liquid.

<Concentrated tea extract>
As the tea extract, an extract of green tea leaves was used.
Water was used as the solvent b.

<< GC / MS measurement conditions >>
The measurement of gas chromatography-mass spectrometry (GC / MS) in the component analysis of the following examples and comparative examples was performed under the following conditions.
GC device: Made by Agilent, model number "7890A"
MS device: JEOL Ltd., model number "JMS Q-1000"
Column: Made by Agilent, product name "J & W DB-5", 30 m x 0.25 mm I. D. × Liquid phase thickness 0.25 μm)
Column temperature rise condition: After holding at 40 ° C for 2 minutes, raise the temperature to 190 ° C at 10 ° C / min, then raise the temperature to 250 ° C at 30 ° C / min, hold at 250 ° C for 6 minutes, and finish the carrier. Gas: Helium Carrier gas flow rate: 1 mL / min
Injection port temperature: 250 ° C
Interface temperature: 280 ° C
Split ratio: Splitless Ion source temperature: 230 ° C
Ionization method: Electron ionization method Ionization voltage: 70 eV
Measurement mass range: 10 to 500

<< Examples 1 to 6 and Comparative Examples 1 to 6 >>
In Examples 1 to 6 and Comparative Examples 1 to 6, the coffee extract was concentrated.
The coffee extract as the raw material liquid a was prepared as follows.
After sufficiently preheating a 1.2-liter SUS304 closed container with a drip-type coffee filter, 70 g of crushed coffee beans (manufactured by Doutor Coffee Co., Ltd.) was added, and 100 mL of hot water at 85 ° C was added and steamed for 1 minute. After that, 900 mL of hot water at 85 ° C. was added to extract the coffee component for 10 minutes. A coffee extract was obtained by transferring 0.5 L of the obtained extract to a PTFE tank having a capacity of 1 L while filtering it with a filter in a closed system and cooling it to 25 ° C. This operation was repeated to obtain 8 L of coffee extract.

<Example 1>
In Example 1, the above coffee extract was concentrated using the raw material liquid concentration system having the configuration shown in FIG. The circulation mechanism was used as needed.

(1) First step In the raw material solution concentrating system shown in FIG. 5, the raw material solution a (coffee extract) is applied to the forward osmosis membrane unit of the first step at a flow velocity of 2 L / min, and the induction solution d is applied to the flow velocity. Each flow was performed at 7 L / min. At this time, the temperature of the raw material liquid a was maintained at 25 ° C., and filtration was set to be performed by a cross-flow method.
As the inducing solution d, an aqueous solution containing 20% by mass of magnesium chloride was used as the inducing substance.
In the implementation time of the first step, when the raw material liquid a is concentrated while circulating using a circulation mechanism as necessary, the entire amount (8 L) of the raw material liquid a is concentrated to a concentration showing a predetermined osmotic pressure. However, the maximum time was 12 hours. When the concentration could not be concentrated to a predetermined concentration within 12 hours, the first step was completed 12 hours after the start, and the concentrated raw material liquid c at that time was directly applied to the second step. If the concentration could be concentrated to a predetermined concentration by passing the forward osmosis membrane unit only once, the circulation mechanism was not used.
A part of the concentrated raw material liquid c obtained through the first step is extracted, and the osmotic pressure of the concentrated raw material liquid c is measured using a commercially available osmotic pressure measuring instrument (OSK 40BU200-240 manufactured by Ogawa Seiki Co., Ltd.). It was measured.

(2) Second Step In the second step in the raw material liquid concentration system shown in FIG. 4, the concentrated raw material liquid c obtained in the first step is introduced into the freeze-drying chamber and pre-frozen at −40 ° C. After that, the pressure was reduced to 10 Pa or less in a freeze-dryer and freeze-dried. Only one freeze-dryer was used, and the concentrated raw material liquid c was freeze-dried up to 2 L at a time. For example, in the case of Example 1, the total volume of the concentrated raw material liquid c was 3,920 mL, so these were freeze-dried in two portions of 2,000 mL and 1,920 mL.
When the volume of the concentrated raw material liquid c exceeds 2 L, the second and subsequent liquids are freeze-dried using the same equipment after the previous freeze-drying is completed, and the total amount of the obtained freeze-dried product is measured. Together, it was the product f.
Then, it was confirmed by the Carl Fisher moisture measurement system (manufactured by Metrohm, MATi10) that the water content of the obtained product f was 3% by mass or less.

(Evaluation of the number of processes in the second process)
The number of times the second step was performed to process the entire amount of the raw material liquid a, which was originally 8 L, by the first and second steps was counted and evaluated according to the following criteria. The evaluation results are shown in Table 1.
A: The number of second steps required to process 8 L of the raw material liquid a is once or twice. This is the case where the efficiency of concentration of the raw material liquid a by the first step is extremely high.
B: The number of second steps required to process 8 L of the raw material liquid a is 3 times. This is the case where the efficiency of concentration of the raw material liquid a by the first step is high.
C: The number of second steps required to process the 8 L raw material liquid a is 4 or more. This is a case where the efficiency of concentration of the raw material liquid a by the first step is insufficient.

(3) Induction Solution Regeneration Step In the induction solution regeneration step for keeping the induction concentration of the induction solution constant, the membrane distillation unit prepared above was used.
The dilution induction solution e is flowed through the membrane distillation unit in the induction solution regeneration step at a flow rate of 4 L / min, and the pressure at the gas phase of the membrane distillation unit is adjusted by a vacuum pump so that the absolute pressure is 10 kPa, and the membrane distillation is performed. Was carried out to obtain a concentrated induction solution h.
The dilution induction solution e obtained in the first step and the concentration induction solution h obtained by membrane distillation are mixed in a buffer tank to prepare (regenerate) the induction solution d, which is circulated in the first step. used.

(Evaluation of the concentrate of coffee extract)
A solution obtained by adding 1 ml of water to 1 mg of the obtained product (lyophilized product) was used as a sample. 1 mL of the sample is placed in a headspace bottle having a capacity of 20 mL, purged with nitrogen, heated at 80 ° C. for 1 hour, and then solid-phase microextraction (SPME) is performed for 15 minutes on the gas phase portion, and then GC / MS is performed. Used for analysis.
All organic components present in the gas phase portion were used as aroma components, and their quantification was performed. The retention rate (mass%) of the aroma components was examined, converted into a component reduction rate, and evaluated according to the following criteria. The evaluation results are shown in Table 1.
A: When the component reduction rate of the product obtained in Comparative Example 1 (described later) is 100% and the component reduction rate is 80% or less.
B: When the component reduction rate of the product obtained in Comparative Example 1 is 100%, and the component reduction rate is more than 80% and less than 90%.
C: When the component reduction rate of the product obtained in Comparative Example 1 is 100% and the component reduction rate is 90% or more.

<Examples 2 to 6>
The same as in Example 1 except that the type and concentration of the inducing substance in the inducing solution d used in the first step and the temperature at the time of concentration in the first step were as shown in Table 1, respectively. The coffee extract was concentrated and various evaluations were performed. The evaluation results are shown in Table 1.

<Comparative Examples 1 to 6>
In Comparative Example 1, the coffee extract as the raw material liquid a was directly subjected to freeze-drying in the second step without performing the first step.
In Comparative Example 2, a distillation column was used instead of the first step, and the distillation operation was performed at 100 ° C.
In Comparative Example 3, vacuum distillation was performed at 50 ° C. and 10.7 to 13.3 kPa (80 to 100 Torr) using a distillation column incorporating a vacuum reduction system instead of the first step.
In Comparative Example 4, the reverse osmosis membrane method was used instead of the first step. A product number "NTR-759HR" manufactured by Nitto Denko Corporation was used as the reverse osmosis membrane, and the raw material liquid a was concentrated at an operating pressure of 3.0 MPa.
In Comparative Example 5, an ultrafiltration method was used instead of the first step. As the ultrafiltration membrane, a Hydrosart (registered trademark) / Sartorius License Casset (exclusion limit molecular weight: 10 K, membrane area: 0.1 m ² , material: regenerated cellulose membrane, manufactured by Sartorius AG) is used as a membrane holder (Sartcon Slice Holder). Used by mounting on Sartorius AG), and treated by cross-flow filtration method under the condition of intermembrane differential pressure (TMP) of about 0.05 MPa using pumps (Rikiport NE1.300, manufactured by KNE). It was.
In Comparative Example 6, after performing the first step in the same manner as in Example 2, the obtained concentrated raw material liquid a was placed in a plastic container having a depth of 10 cm, and the humidity was adjusted to 30% RH and a high temperature of 25 ° C. It was allowed to stand in a constant humidity room for 3 weeks and allowed to air dry.
The results of evaluation of the obtained products in the same manner as in Example 1 are shown in Table 1.

<< Example 7 and Comparative Examples 7 to 11 >>
In Examples 1 to 6 and Comparative Examples 1 to 6, the L-alanyl-L-glutamine aqueous solution was concentrated.
The L-alanyl-L-glutamine aqueous solution as the raw material liquid a was prepared as follows.
100 g of commercially available L-alanyl-L-glutamine (white powder state, manufactured by Nacalai Tesque, Inc.) was dissolved in 1 L of ion-exchanged water at 25 ° C. to obtain a 100 g / L L-alanyl-L-glutamine aqueous solution. .. The same operation was repeated to obtain 8 L of L-alanyl-L-glutamine aqueous solution.

<Example 7>
The same as in Example 1 except that the above-mentioned L-alanyl-L-glutamine aqueous solution was used as the raw material solution a instead of the coffee extract and the aqueous solution containing 35% by mass of magnesium chloride was used as the induction solution d. Then, the raw material liquid a was concentrated and various evaluations were performed. The component evaluation of the L-alanyl-L-glutamine aqueous solution concentrate was carried out by the following method. Other evaluations were performed in the same manner as in Example 1. The evaluation results are shown in Table 2.

(Evaluation of components of concentrate of L-alanyl-L-glutamine aqueous solution)
The entire amount of the obtained product (lyophilized product) was dissolved in 8 L of ion-exchanged water and diluted, and the obtained diluted solution was used as a sample for analysis by ¹ H-NMR. ¹ The measurement conditions of ¹ H-NMR are as follows.
Measuring device: "AVANCE500" (500MHz) manufactured by Bruker Biospin Co., Ltd.
Sample volume: 10 μL
Solvent: DEUTERIUM OXIDE + 0.1% TMSP (manufactured by euriso-top) 700 μL
Internal standard substance: 3- (trimethylsilyl) -1-sodium propanesulfonate (DSS, manufactured by Tokyo Chemical Industry Co., Ltd.), 0.004 mol / L
In the obtained ¹ H-NMR spectrum, the ratio of the peak area of the methyl group of alanyl glutamine around 1.52 ppm to the peak area of the methyl group of DSS near 0 ppm was quantified to determine the concentration of alanyl glutamine. , The component reduction rate from the raw material liquid a before concentration was calculated and evaluated according to the following criteria.
A: When the component reduction rate of the product obtained in Comparative Example 7 (described later) is 100% and the component reduction rate is 80% or less.
B: When the component reduction rate of the product obtained in Comparative Example 7 is 100%, and the component reduction rate is more than 80% and less than 90%.
C: When the component reduction rate of the product obtained in Comparative Example 7 is 100% and the component reduction rate is 90% or more.

<Comparative Examples 7 to 11>
In Comparative Example 7, the L-alanyl-L-glutamine aqueous solution as the raw material liquid a was directly subjected to freeze-drying in the second step without performing the first step.
In Comparative Examples 8 to 11, instead of the first step prescribed in the present invention, a distillation method, a vacuum distillation method, a reverse osmosis method, and an ultrafiltration method were performed, respectively, and then subjected to the second step. The conditions of the distillation method, the vacuum distillation method, the reverse osmosis method, and the ultrafiltration method in these comparative examples are the same as those in the comparative examples 2 to 5, respectively.
The results of evaluation of the obtained products in the same manner as in Example 7 are shown in Table 2.

<< Examples 8 and 9 and Comparative Examples 12 to 16 >>
In Examples 8 and 9 and Comparative Examples 12 to 16, the tea extract was concentrated.
As the tea extract as the raw material liquid a, a liquid obtained by extracting tea leaves of green tea with hot water was used.

<Examples 8 and 9>
As the raw material solution a, the above tea extract is used instead of the coffee extract, and as the induction solution d, an aqueous solution containing 25% by mass (Example 8) or 35% by mass (Example 9) of magnesium chloride is used. In addition to the above, the raw material liquid a was concentrated and various evaluations were performed in the same manner as in Example 1. The components of the tea extract concentrate were evaluated by the following method. Other evaluations were performed in the same manner as in Example 1. The evaluation results are shown in Table 3.

(Evaluation of the components of the concentrate of tea extract)
A diluted solution obtained by dissolving the obtained concentrate (lyophilized product) in water was used as a sample for GC / MS analysis, and the concentration of each flavor component was measured relative to the β-ionone concentration from the peak area of the total ion chromatogram. Asked as. Specifically, the following operation was performed.
A diluent prepared by dissolving 1 mg of the obtained concentrate in 1 mL of ion-exchanged water was placed in a 20 mL screw vial for headspace, sealed with a screw cap with a septum, and heated at 80 ° C. for 15 minutes. Next, SPME Fiber (thickness 65 μm, coating layer: polydimethylsiloxane-divinylbenzene) manufactured by SIGMA-ALDRIC was inserted into the vial through the septum of the cap, and the volatile components were collected at 80 ° C. for 15 minutes. The collected volatile components were introduced into GC / MS from SPME Fiber, quantified by performing GC / MS analysis, and the obtained values were converted into component reduction rates and evaluated according to the following criteria. The evaluation results are shown in Table 3.
A: When the component reduction rate of the product obtained in Comparative Example 12 (described later) is 100% and the component reduction rate is 80% or less.
B: When the component reduction rate of the product obtained in Comparative Example 12 is 100%, and the component reduction rate is more than 80% and less than 90%.
C: When the component reduction rate of the product obtained in Comparative Example 12 is 100% and the component reduction rate is 90% or more.

<Comparative Examples 12 to 16>
In Comparative Example 12, the tea extract as the raw material liquid a was directly subjected to freeze-drying in the second step without performing the first step.
In Comparative Examples 13 to 16, instead of the first step prescribed in the present invention, a distillation method, a vacuum distillation method, a reverse osmosis method, and an ultrafiltration method were performed, respectively, and then subjected to the second step. The conditions of the distillation method, the vacuum distillation method, the reverse osmosis method, and the ultrafiltration method in these comparative examples are the same as those in the comparative examples 2 to 5, respectively.
The results of evaluation of the obtained products in the same manner as in Examples 8 and 9 are shown in Table 3.

Referring to Tables 1 to 3, the component retention of the concentrated products obtained in Comparative Examples 1 to 16 was evaluated as "B" or "C", whereas the component retention in Examples 1 to 9 was performed. All of the properties were evaluated as "A", and it was verified that the concentration method of the present invention can concentrate with high efficiency while maintaining the component composition of the raw material liquid.

In Comparative Examples 1, 7, and 12 in which the raw material liquid was directly freeze-dried without performing the first step, four treatments were required to freeze-dry the 8 L raw material liquid.
The concentration efficiencies of each Example and Comparative Example were compared based on the component retention rate in these Comparative Examples.
In Comparative Examples 2, 8 and 13 in which the distillation method was adopted in the first step, the deterioration and decrease of the components were remarkable. For example, in Comparative Example 2 in which the coffee extract was concentrated, the comparison was performed only by freeze-drying. The component reduction rate as compared with the case of Example 1 reached 197% (evaluation "C"). Probably the effect of heating during distillation.

In Comparative Examples 3, 9, and 14 in which the vacuum distillation method was adopted in the first step, there was alteration and reduction of the components. For example, in Comparative Example 3 in which the coffee extract was concentrated, the component reduction rate reached 188% as compared with the case of Comparative Example 1 in which only freeze-drying was performed (evaluation "C"). Presumably, the alteration of the components is due to heating during vacuum distillation, and the phenomenon of the components is due to exhaust.
In Comparative Examples 4, 10 and 14 in which the reverse osmosis method was adopted in the first step, clogging of the reverse osmosis membrane was frequently observed, and the amount of water permeation was significantly reduced. For example, in Comparative Example 4 in which the coffee extract was concentrated, the water permeability at the initial stage of concentration was 26.2 kg / (m ² × hr), but the water permeability decreased significantly with time, and 8 L of coffee was extracted. After the liquid was concentrated, it decreased to 0.1 kg / (m ² × hr), and it was confirmed that the reverse osmosis membrane was largely clogged by the concentration operation. The amount of the concentrated raw material liquid c obtained after the operation for 12 hours was 6 L, and the freeze-drying treatment required 3 times. The component reduction rate as compared with the case of Comparative Example 1 that had undergone only freeze-drying was 92% (evaluation "C").

In Comparative Examples 5, 11 and 12 in which the ultrafiltration method was adopted in the first step, clogging of the ultrafiltration membrane was frequently observed, and the amount of water permeation was significantly reduced. For example, in Comparative Example 5 in which the coffee extract was concentrated, the water permeability at the initial stage of concentration was 120 kg / (m ² × hr), but the water permeability decreased significantly with time, and 8 L of the coffee extract. After the concentration, the weight was 10 kg / (m ² × hr), and it was confirmed that the ultrafiltration membrane was largely clogged by the concentration operation. After 12 hours of operation, the amount of concentrated raw material liquid c obtained was 2 L. However, the osmotic pressure of the concentrated product c was low. In addition, as compared with the case of Comparative Example 1 which had undergone only freeze-drying, the number of components was significantly reduced, and some components were hardly observed after concentration. It is probable that most of the components in the raw material liquid a have flowed out by the ultrafiltration method.

Comparative Example 16 is a comparative example in which the forward osmosis method was adopted in the first step, but the natural drying method was adopted instead of the second step to concentrate the coffee extract.
In Comparative Example 16, about 3,900 mL of the concentrated product c obtained in the first step was air-dried, and the water content of the product was 23% by mass even after 3 weeks. When the natural drying method is adopted instead of the second step, not only the complete drying with a water content of 3% by mass or less is not achieved, but also the components are significantly reduced as compared with the case of Comparative Example 1 which has undergone only freeze-drying. Some components were rarely observed after concentration.

In contrast to these comparative examples, in Examples 1 to 9 in which the first and second steps prescribed in the present invention are adopted, it is possible to concentrate to a predetermined osmotic pressure by the first step. As a result, the capacity of the second step was reduced, and the number of processes in the second step could be reduced. It was also confirmed that the component reduction rate of the obtained product was suppressed to a low level.

a Raw material solution b Solvent c Concentrated raw material solution d Induction solution e Dilution inducing solution f Product g Regeneration inducing solution h Concentration inducing solution o Forward osmosis membrane D Induction solution side space P Omission pressure measurement position R Raw material solution side space

Claims (15)

A raw material solution containing a solvent and a solute and an inducing solution are brought into contact with each other via a forward osmosis membrane, and the solvent in the raw material solution is moved into the inducing solution to obtain a concentrated raw material solution and a dilution inducing solution. One step and
It has a second step of freeze-drying the concentrated raw material liquid and further concentrating it.
At the end of the first step, the osmotic pressure of the concentrated raw material solution measured at the temperature at that time is in the range of 1.52 MPa (15 atm) or more and 65.9 MPa (650 atm) or less. Perform the process,
Raw material liquid concentration system. The concentration system according to claim 1, wherein the solvent is water. The concentration system according to claim 1 or 2, wherein the first step is performed by cross-flow filtration. The concentration system according to any one of claims 1 to 3, wherein in the first step, the temperature of the raw material liquid is adjusted to a range of 5 ° C. or higher and 50 ° C. or lower. The invention according to any one of claims 1 to 4, further comprising an induction solution regeneration step of removing the solvent from the dilution induction solution to obtain a regeneration induction solution and using the obtained regeneration induction solution as an induction solution again. The enrichment system described. The concentration system according to claim 5, wherein the removal of the solvent from the dilution induction solution in the induction solution regeneration step is performed by an evaporation means. Claims 1 to 4 further include an induction solution regeneration step of removing the solvent from the induction solution to obtain a concentration induction solution, and using a mixture of the obtained concentration induction solution and the dilution induction solution as an induction solution. Concentration system according to any one of the above. The concentration system according to claim 7, wherein the removal of the solvent from the induction solution in the induction solution regeneration step is performed by an evaporation means. The concentration system according to any one of claims 1 to 8, wherein the induction solution is an inorganic salt solution. The concentration system according to any one of claims 1 to 9, wherein the forward osmosis membrane is a hollow filamentous membrane. 1. The forward osmotic membrane is a membrane having a thin film layer containing at least one selected from the group consisting of polyethersulfone, polysulfone, polyketone, polyvinylidene fluoride, polyacrylonitrile, polyimine, and polyamide as a main component. 10. The concentration system according to any one of 10. The concentration system according to any one of claims 1 to 11, further comprising a circulation mechanism in which the concentrated raw material liquid obtained in the first step is used as the raw material liquid in the first step. According to any one of claims 1 to 12, the initial permeation flow velocity of the forward osmosis membrane at the start of the first step is 1 kg / (m ² x hr) or more and 100 kg / (m ² x hr) or less. The enrichment system described. At the end of the first step, the osmotic pressure of the concentrated raw material solution measured at the temperature at that time is in the range of 2.03 MPa (20 atm) or more and 50.7 MPa (500 atm) or less. The concentration system according to any one of claims 1 to 13, wherein the step is performed. At the end of the first step, the osmotic pressure of the concentrated raw material solution measured at the temperature at that time is in the range of 2.53 MPa (25 atm) or more and 35.5 MPa (350 atm) or less. The concentration system according to claim 14, wherein the step is performed.

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