JP2011173035A - Method and device for separating and recovering intentional substance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To separate each substance of a mixture of not less than two intentional substances whose trends of membrane permeability are approximate at high purity. <P>SOLUTION: The method is for separating an intentional substance 1 contained in a raw material solution into a final penetrant fluid and an intentional substance 2 into the final residue, using a separation means for separating a liquid to be treated as the residue and the penetrant fluid. This method is characteristic in that (1) the separation is carried out by using a multi-stage counter flow separation operation constituted so as to send the residue obtained by separation operation to the latter stage, and return the penetrant fluid as a liquid to be treated and/or a cleaning fluid of the former stage and (2) the raw material solution is supplied to either one of the intermediate stages of the multi-stage counterflow separation operation except the initial and the final stages. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention is a valuable substance that is a widely used target substance in the fermentation industry, pharmaceutical industry, refined sugar industry, amino acid industry, food industry, dye industry, pigment industry, chemical industry, metal refining industry, waste treatment industry, etc. And a method for separating and recovering salt of impurities. More specifically, a plurality of target substances (for example, valuables and impurities) are separated, removed, and purified using multistage countercurrent separation means.

For example, in the fermentation industry, the protein amino acid industry, and the pharmaceutical industry, microorganisms are cultured to produce amino acids, brew them, and produce antibiotics. Specifically, the fermentation broth is separated into a product liquid containing valuable materials such as amino acids using a separation membrane, a centrifuge, etc., and the separated product liquid is subjected to a target substance (valuable materials) by evaporating operation with steam or the like. ), And microbial cells are left as a separation residue.
In the dye industry, the pigment industry, the chemical industry, and the like, salting out operations are performed in the manufacturing process, and thereafter, the salt that becomes an impurity is removed.
In collecting valuable materials remaining in the separation residue, membrane treatment is often applied instead of the conventional filtration separation method and the like. Membrane treatment is also used for the above-described salt removal.
As a specific separation method for membrane treatment technology, separation of easily permeable substances and difficultly permeable substances is performed by supplying fresh cleaning liquid at the final stage and using the permeated liquid obtained at that stage in multiple stages. There is known a technique using a time-differential multi-stage counter flow method in which the target substance is obtained at a high recovery rate and only a small amount of the target substance remains in the final residual liquid. (Patent Document 1)
Further, in Patent Document 2, the inventors used the first stage permeate in the first stage multistage countercurrent separation operation for the purpose of efficiently recovering valuable materials, impurities, and the like from the object to be processed. It has been disclosed to take out as a final permeate of the system, and to perform a second system of separation with respect to other permeate (or residual liquid) generated by the multistage countercurrent separation operation of the first system. As a result, high separation performance was obtained as a whole, and high concentration recovery of the target substance was made possible.
In patent document 3, the inventor performs a precise separation and purification method such as removal of diglycerin and triglycerin from a decaglycerin mixture by controlling the permeation tendency by adjusting operating conditions for separation of substances having different permeation tendencies. Disclosed.

By the way, for some water-soluble oligomers and water-soluble polymers, obtaining a purified product fractionated in a narrow molecular weight range from a mixture of similar substances with different molecular weights is a function of the substance and its derivatives. It is said that it is often important for sexual expression.
However, in the techniques of Patent Document 1 and Patent Document 2, there are cases where there is a large difference in the blocking rate and transmittance (Transmittance) when separating with a membrane that employs permeable substances, or a substance that hardly transmits. Although it is possible to separate substances that permeate, it is difficult to efficiently separate the two when the transmission tendency of both is small or when the transmission tendency is close. That is, when separating the target substance 1 having a relatively high transmittance and the target substance 2 having a relatively low transmittance, if the transmittance of the target substance used by both of the target substances is close, the separation is performed from the stage where the raw material solution is supplied. In the permeated liquid, in addition to the target substance 1, the target substance 2 is mixed at a concentration that cannot be ignored, and it is difficult to efficiently recover the target substance 2.

Japanese Patent No. 3694871 JP 2004-17035 A JP 2008-229559 A

  In the present invention, when two or more substances are separated from the raw material solution, even when the permeation tendency indicated by the blocking rate or the transmittance of these substances by the membrane is close, they are efficiently separated. Let it be an issue.

<Claim 1>
In the method of separating the target substance 1 in the raw material solution into the final permeate and the target substance 2 into the final residual liquid using a separation means for separating the liquid to be treated into the residual liquid and the permeate.
(1) Performing using a multistage countercurrent separation operation configured to send the residual liquid from the separation operation to the subsequent stage and return the permeate as the liquid to be treated and / or the cleaning liquid in the previous stage;
(2) supplying the raw material solution to one of the intermediate stages except the first and last stages of the multistage countercurrent separation operation;
A membrane separation method for a raw material solution.

〔The invention's effect〕
When separating the target substance 1 and the target substance 2 that are close to each other in membrane permeation, for example, even if the target substance 1 has a higher permeation tendency, the permeate separated from the first stage of supplying the raw material solution is used. It is highly possible that the target substance 2 is also mixed at a relatively high concentration. Conventionally, the permeate is further separated to obtain the target substance 1, and the substance (target substance 2) in the residual liquid is usually discarded or separated by a completely different system of separation means. there were. In the present invention, the permeate is further separated by the multistage countercurrent separation means, and the residual liquid is supplied to the subsequent separation means, so that the target substance 2 can be obtained in the final state of the multistage countercurrent separation means in a higher concentration state. It can be separated as a residual liquid. On the other hand, the permeate containing the target substance 1 separated after the raw material supply stage is sequentially used as a cleaning liquid for the stage before the separated stage, thereby increasing the concentration of the target substance 1 in the permeate of the previous stage. Is possible. The target substance 1 is separated as the final permeate of the multistage countercurrent means. With such a configuration, both the target substance 1 and the target substance 2 can be efficiently separated with high yield.

<Claim 2>
The membrane separation method for a raw material solution according to claim 1, wherein the multistage countercurrent separation operation is performed using an apparatus in which a plurality of membrane separation means are arranged in series.

〔The invention's effect〕
With the above-described configuration, it is possible to integrally change or adjust the steps and amounts for supplying the raw material solution, the cleaning liquid, the cleaning water, and the cleaning solvent for the separation operation of the two target substances.

<Claim 3>
The multistage countercurrent separation operation is performed in a plurality of cycles,
Each cycle is composed of four or more stages, and the separation operation of each stage is performed using a plurality of cleaning liquids having different concentrations of the target liquid 1 separately stored from the liquid to be processed. The concentration of the target substance 1 or the ratio of the target substance 1 to the target substance 2 is increased,
The residual liquid at the last stage of each cycle is taken out as the final residual liquid, and the permeated liquid at each stage is stored in a separately provided storage means, and as the first stage liquid to be processed in the separation operation of the subsequent cycle, or Supply by using it as a cleaning liquid before the stage separated in the previous cycle,
The method for membrane separation of a raw material solution according to claim 1.

[Effect of the invention] Time-difference multistage countercurrent The multistage countercurrent separation means uses a time-difference multistage countercurrent that uses the permeate in the multistage countercurrent separation means of the previous cycle as the cleaning liquid of the multistage countercurrent separation means of the next cycle. It is possible. Preferably, a cleaning liquid substantially free of the target substance 1 is used for the cleaning in the last stage. Moreover, this washing | cleaning liquid may contain the target substance 1 if the ratio with respect to the target substance 2 isolate | separated as a final residual liquid is a grade low enough to refine | purify. Advantages of time-difference multistage counterflow include that it can be achieved with a single separation means, and that space can be saved, and a large amount of washing water is not required, and the amount of drainage is small, thereby reducing costs. .

<Claim 4>
The part or all of the permeate obtained from the stage excluding the last two stages of the multi-stage countercurrent separation operation is returned to the stage two or more stages prior to the stage as the liquid to be treated. The membrane separation method of the raw material solution as described in 2.

〔The invention's effect〕
According to the present invention, even when substances having low permeability are separated from each other by a membrane, the treatment at the start of separation in the first stage is achieved by using a plurality of stages of permeate as the treatment liquid at the start of separation in the first stage. By appropriately securing the amount or concentration of the liquid and using it with one or more stages of the permeate, the permeate flow rate used per stage can be reduced, and the permeate and the treatment target per stage. The composition change of the liquid can be secured.

<Claim 5>
The raw material solution membrane separation method according to any one of claims 1 to 4, wherein the raw material solution is supplied in a plurality of stages in a multistage countercurrent separation operation of four or more stages.

〔The invention's effect〕
Rather than supplying the raw material solution to a single stage, diluting with a cleaning liquid as necessary, and supplying it in multiple stages, so that the amount of liquid in the intermediate stage is insufficient particularly in time-differential multistage countercurrent separation. Prevention becomes possible.

<Claim 6>
The raw material solution membrane separation method according to claim 1, wherein the liquid to be treated to be supplied to the first stage in the multistage countercurrent separation operation is concentrated before the treatment.

〔The invention's effect〕
The purpose is to make the concentration of the liquid to be treated in the first stage appropriate. In particular, in a multistage countercurrent separation means having multiple cycles, the permeate in the previous cycle has a lower concentration than the desired circulating fluid concentration to be treated to be supplied to the first stage. A liquid may not be obtained. Therefore, by performing a concentration operation on the collected liquid of the target previous cycle before the first stage processing, the concentration of the liquid to be processed at the start of separation is increased and the permeation between the target substance 1 and the target substance 2 is performed. By widening the difference in rate and concentrating more permeate, it becomes possible to secure a desired amount of circulating fluid.

<Claim 7>
The raw material solution according to any one of claims 1 to 6, wherein at least a part of the residual liquid separated from the final stage of the multistage countercurrent separation operation is supplied to any stage after the raw material solution supply stage. Membrane separation method.

〔The invention's effect〕
Supplying at least a part of the residual liquid separated from the final stage of the multistage countercurrent separation means to any of the stages subsequent to the raw material solution supply stage results in a shortage of circulating fluid necessary for continuing the membrane separation operation. The amount of liquid in the stage can be secured. Moreover, it becomes possible to improve and stabilize the composition of a refined product by supplying the residual liquid which has been refined to any stage.

<Claim 8>
From a raw material solution containing at least three kinds of target substances, by a multistage countercurrent separation operation,
(1) a step of separating the target substance 1 from the final permeate of the multistage countercurrent separation operation;
(2) a step of separating the target substance 2 from the final residual liquid of the multistage countercurrent separation operation;
(3) From either stage of the multistage countercurrent separation operation, all or part of the permeate or residual liquid is supplied to a separation means different from the multistage separation operation, and the final permeate of the other separation means Or a step of separating the target substance 3 into the final residual liquid,
The membrane separation method of the raw material solution in any one of Claims 1-7 containing these.

〔The invention's effect〕
Three or more kinds of target substances can be separated. The third separation means may be a multistage countercurrent separation means or another separation means.

<Claim 9>
9. The raw material solution membrane separation method according to claim 3, wherein at least part of the permeate in the first stage is used as part of the liquid to be treated in the next cycle.

〔The invention's effect〕
While preventing discharge of permeate that does not reach a predetermined composition, the amount of liquid to be treated required in the first stage of the next cycle can be ensured, and the amount of permeate after the first stage can be reduced or the stage can be omitted. . Moreover, the composition of the liquid to be treated can be stabilized by repeating the present invention for a plurality of cycles.
Note that the present invention is not necessarily applied to all cycles, and may be applied to a necessary cycle among a plurality of cycles.

<Claim 10>
The first stage of the permeate is the next cycle until the target substance 1 in the permeate has a predetermined concentration or more and / or the ratio of the concentration of the target substance 1 in the permeate to the concentration of the target substance 2 becomes a predetermined ratio or more. The liquid to be treated is taken out of the system as a final permeate when a predetermined concentration and / or a predetermined ratio is reached, and the second stage permeate is used as a liquid to be treated in the next cycle. The membrane separation method of the raw material solution in any one of 8.

〔The invention's effect〕
In addition to the effect of the eighth aspect, the composition of the final permeate can be stabilized.

<Claim 11>
The membrane separation method according to any one of claims 3 to 10, wherein the same separation means is used for membrane separation in a plurality of stages of multistage countercurrent operation.

〔The invention's effect〕
According to the present invention, it is possible to reduce the number of accessory devices and control mechanisms such as a membrane separation means and a circulation tank, which makes it easy to operate, facilitates automation, and saves space and costs.

<Claim 12>
A membrane separation apparatus comprising a separation means for separating a liquid to be treated into a residual liquid and a permeate, and separating a target substance 1 in a raw material solution into a final permeate and a target substance 2 into a final residual liquid,
(1) By the multistage countercurrent separation operation in which the residual liquid from the separation operation is sent to the subsequent stage and the permeate is returned as the liquid to be treated and / or the cleaning liquid in the previous stage.
(2) The raw material solution is supplied to one of the intermediate stages except the first and last stages of the multistage countercurrent separation operation.
A raw material solution membrane separator configured as described above.

<Claim 13>
13. The raw material solution membrane separation apparatus according to claim 12, comprising a plurality of membrane separation means arranged in series, and performing the multistage countercurrent separation operation using the plurality of membrane separation means.

  In the present invention, when two or more substances are separated from the raw material solution, they can be efficiently separated even if the blocking rate and permeation tendency of these substances by the membrane are close to each other. Further, the recovery rate and concentration of substances from the raw material solution are high, high purity can be realized, and both the amount of waste water and the amount of washing water can be reduced.

It is a flowchart of a separation apparatus. It is the figure which showed the structure of each stage of a multistage separator. It is the flowchart which showed an example of the structure of each stage of a multistage separator. It is the flowchart which showed the other example of the structure of each stage of a multistage separator. 6 is a flowchart of multistage separation in Example 2. FIG. FIG. 6 is a flow diagram of multi-stage separation in Example 3. It is a flowchart which shows the other example of the apparatus used for time difference multistage countercurrent. It is a liquid chromatograph chart of each polyethylene glycol (PEG) related substance used as a standard substance. (A) Diethylene glycol, (B) PEG200, (C) PEG300. 2 is a liquid chromatograph chart of a final residual liquid in Example 1. FIG. (A) 5th cycle final residue, (B) 6th cycle final residue, (C) 7th cycle final residue, (D) 8th cycle final residue, (E) 9th cycle The final residual liquid. 2 is a liquid chromatograph chart of a final permeate in Example 1. FIG. (A) 5th cycle final permeate, (B) 6th cycle final permeate, (C) 7th cycle final permeate, (D) 8th cycle final permeate, (E) 9th cycle Final permeate.

Each technique related to the means for solving the problem is described in detail, and a more appropriate form is presented below.
The present invention separates a target substance using a multistage countercurrent separator (hereinafter referred to as a continuous multistage countercurrent separator) in which a plurality of separators are arranged in series or a time-differential multistage countercurrent separator. .
By the way, in this invention, the liquid which permeate | transmitted the separation membrane in the separation apparatus is called permeate, and the liquid which does not permeate | transmit a membrane is called residual liquid. In the time-differential multi-stage countercurrent separation device, the residual liquid including the liquid remaining in the membrane apparatus, the storage tank, and the pipes constituting the circulation system constituting the operation is referred to as a residual liquid. A raw material solution is a liquid containing a raw material that has not been subjected to a separation operation, and refers to a raw material solution or a diluted solution thereof. Moreover, not only a so-called solution is shown, but a slurry or suspension that is a mixture of a solution and a solid material is included.

The terms in the multistage countercurrent separation operation are defined as follows.
<Processed liquid>
The liquid to be treated is a general term for liquids containing a target substance supplied to the separation process in each stage. The liquid to be treated in the continuous multistage countercurrent separation apparatus includes the residual liquid supplied from the preceding membrane separation apparatus and the permeate from the subsequent stage, and also includes the raw material solution in the stage where the raw material solution is supplied.
On the other hand, in the time-differential multistage countercurrent separation device, the liquid is a membrane device or a circulatory system at the start of each stage, and includes the permeate in the previous cycle.

<Cleaning liquid>
Diafiltration, which is a technique for removing a target substance from a target liquid by separating the permeate using membrane separation while adding a solvent such as water to the liquid to be treated, is a means for purifying the substance. Widely used. In the present invention, the liquid added to the liquid to be treated is called a cleaning liquid. Specifically, pure water, washing water, permeated liquid from the subsequent stage, organic solvent, and the like. The target substance may be contained in the cleaning liquid.

<Stage>
Of a plurality of continuous membrane separation processes, a process using an apparatus for one stage is called a stage. In the continuous multistage countercurrent separator, it means a separation step performed in individual separators arranged in series or the separator itself. On the other hand, in the time-differential multi-stage countercurrent apparatus, the separation process is divided in accordance with the permeated liquid containers to be used in sequence, and operations from the division to the next division are performed. In addition, let the permeate | liquid corresponded in the meantime be the permeate | transistor for the 1st step. For example, a plurality of containers may be prepared for each stage, and the process until the continuously obtained permeate is put into the container may be one stage. In addition, a plurality of containers can be used in parallel, and they can be collectively referred to as one stage.

<Transmissivity>
The ratio of the concentration of the focused substance in the handling liquid such as the circulating liquid, the concentrated liquid, and the supply liquid to the membrane device of the permeated liquid of the substance exiting the separation membrane is called “permeability” of the focused substance.

<About raw material solutions and steps>
Even if the raw material supply method in the stage where the raw material solution is supplied is performed on the circulation system in the membrane apparatus in parallel with the acquisition of the permeate, the remaining liquid after the permeate is acquired in the previous stage, Prior to acquisition of the permeated liquid at that stage, it may be performed flexibly, including a method of adding washing water or the like together with the raw material supply.

[Continuous multi-stage counter-current separator]
As a first embodiment, a method of using a continuous multistage countercurrent separator is disclosed with reference to FIGS.
The continuous multistage countercurrent separator is composed of a plurality of membrane separators provided in series as shown in FIGS. The liquid to be treated is separated into a permeate and a residual liquid by each membrane separator, and the residual liquid is supplied as a liquid to be treated in the next membrane separator, and the permeate is returned to the previous membrane separator as a cleaning liquid. It is configured as follows. 2, 3 and 4 show examples of individual membrane separation apparatuses. What is necessary is just to use it combining suitably.

  The apparatus shown in FIG. 2 supplies a liquid 61 to be treated and a cleaning liquid 62 to a separation membrane 65 having a different permeability for the target substance 1 and the target substance 2 and a membrane separation apparatus 65 provided with a pressure pump, a pressure control function, etc. Perform the operation. A permeated liquid 63 and a residual liquid 64 are obtained from the liquid to be treated and the cleaning liquid supplied to the membrane separation device 65. In addition, pressure / temperature control functions such as a RO membrane for concentration, a booster pump for that purpose, and a heat exchanger are provided as needed.

  The apparatus of FIG. 3 performs separation while circulating the residual liquid using the circulating liquid tank 70 and the circulating pump 67, and ensures a cross flow on the membrane surface. Separation is performed while adding the cleaning liquid 62, and when a predetermined separation concentration is reached, the remaining liquid is supplied to the next stage as a liquid to be processed. The permeate is supplied as a cleaning liquid to the circulating fluid tank in the previous stage, but it is preferable to provide a permeate tank 71, a permeate pump 68, and the like so that the flow rate can be adjusted.

  The apparatus shown in FIG. 4 uses a circulation pump 67 to secure a cross flow without using a circulating liquid tank. The operation pressure of the target stage is controlled using the pressure control valve 66. In the membrane unit 65, a plurality of membrane modules are partially arranged in parallel and partially in series. The liquid 61 to be treated is pressurized by a circulation pump 67 and supplied. Part of the residual liquid 64 from the membrane module in the membrane unit 65 is returned to the circulation pump 67. This circulation system can secure the necessary cross flow in the membrane module. Further, the permeated liquid from each module gathers in the collecting pipe and is extracted from the membrane unit 65 as the permeated liquid 63.

  By the way, the raw material solution 81 is supplied to an intermediate stage (fifth stage in FIG. 6) among a plurality of separation apparatuses. Here, the separation operation on the upstream side when viewed from the raw material solution supply stage is referred to as “first multistage countercurrent separation operation”, and the separation process on the raw material supply stage and the downstream side is referred to as “second multistage countercurrent separation operation”. Further, the membrane separation devices corresponding to them are referred to as “first multistage countercurrent separation device” and “second multistage countercurrent separation device”. For convenience, the first and second multi-stage countercurrent separation operations are counted as the first and second from the youngest number of stages, respectively.

  In the flowchart of FIG. 6, the raw material solution is supplied to the first membrane separation device of the second multistage countercurrent separation device. The supply position can select an appropriate supply point from the piping part and storage tank before and behind the membrane unit. The residual liquid separated by the membrane separator is supplied to the second membrane separator. On the other hand, the permeate is supplied as a cleaning liquid to the first multistage countercurrent separator. In the second membrane separation device of the second multistage countercurrent separation device, the liquid to be treated previously supplied is separated into the second permeate and the residual liquid. Here, the second permeate is supplied to the first membrane separator, and the second residual liquid is supplied to the third membrane separator. Hereinafter, similarly, the permeated liquid is supplied as a front-stage cleaning liquid, and the remaining liquid is supplied as a rear-stage processing liquid. The residual liquid in the final stage of the second multistage countercurrent separation device is taken out as the final residual liquid that contains the most target substance that hardly permeates. A permeate concentration stage is provided on the upstream side of the first membrane separator of the first multistage countercurrent separator.

In the apparatus of FIG. 5, the concentrated permeate 85 is obtained by performing an operation of concentrating the permeate obtained in the first and second to a predetermined concentration, for example, about 20% by weight. The concentration operation is not particularly limited even during the multistage separation countercurrent operation or before the separation operation. If necessary, the permeated liquid after the third stage may be concentrated and used as a cleaning liquid. In the first separation operation following the concentration stage, an operation of adding the permeate obtained in the third stage as a washing liquid is performed to obtain a final permeate 83.
In the first multistage countercurrent separator, a part of the processing liquid obtained from the raw material solution in advance may be supplied.

  On the other hand, multistage countercurrent separation is similarly performed in the second multistage countercurrent separator, and the remaining liquid of the final membrane separator of the first multistage countercurrent separator is the second multistage countercurrent separator. Is returned as the liquid to be treated. The permeate separated from the first membrane separator of the first multistage countercurrent separator is taken out as a final permeate containing a target substance that easily permeates the membrane.

  In the final stage and the previous stage, pure water 82 is exclusively used as the cleaning liquid, and the final residual liquid 84 is obtained from the final stage. The concentration of each stage can be maintained at about 25% by weight, and the concentration can be adjusted by measuring the concentration of those stages or representative stages, increasing the amount of permeate from the downstream stage, or in stages other than the last two stages. This can be done by adding pure water or returning the acquired permeate to the same stage. Moreover, what is necessary is just to adjust the pressure of each stage to the pressure suitable for each stage. Specifically, the pressure control valve is adjusted when the residual liquid is transferred to the downstream side, thereby adjusting in the piping system that sequentially transfers from the upstream stage to the downstream stage. Further, the booster pump is used in the first stage, and the operation pressure of each membrane unit can be adjusted in the subsequent stages by a booster function using a circulation pump and a pressure control function such as a pressure control valve.

  Note that the permeated liquid obtained in each of the first and second multistage countercurrent separation apparatuses is used as the preceding stage cleaning liquid, but the return destination is not limited to the immediately preceding stage. Further, as shown in FIG. As described above, by supplying the step permeate separated in the direction opposite to the traveling direction of the separation operation, it becomes possible to use the permeate as a cleaning liquid having a high concentration driving force.

  The permeate obtained from other than the first stage of the second multistage countercurrent separator is used as the washing liquid of the first multistage countercurrent separator, and the first multistage countercurrent separator and the second multistage separator are used. It is preferable to use a series of separation operations by a countercurrent separation device.

For example, the amount of substance permeated from a membrane with a low permeability is necessary for the composition change of the residual liquid, and in the separation of a substance targeted for the target substance by a membrane with a low permeability, a significant change in the composition of the residual liquid Requires a large amount of permeate acquisition. However, even if a too large amount of the cleaning solution having the same concentration composition is used in the same separation step, the change in concentration decreases as the processing proceeds. In such a case, it is effective to skip a plurality of steps. Further, even if the number of stages is increased, the present invention can be applied to a case where the difference in composition between adjacent stages becomes small.
Also, the amount of cleaning liquid required at the receiving stage, that is, the amount of cleaning liquid to be added before obtaining the target permeate amount, or the amount of contents such as the sugar content in the target permeate is obtained. The amount of the cleaning liquid to be added to the liquid does not necessarily match the preliminarily prepared permeate amount, and it is not always necessary to match. In the present invention, the usage of the number of stages is described so that the permeated liquid separated in the latter stage is used up in the front stage, but they are not indispensable and can flexibly cope with the balance of the liquid amount.
When membrane separation is performed, the permeate generally has a lower concentration than the circulating fluid, and the concentration during the separation operation can be optimized by concentrating the permeate.

Particularly in the present invention, the liquid to be treated supplied to the first stage of the first multistage countercurrent separation device is important, and by maintaining its concentration appropriately, the permeate concentration can be secured, Also in the next stage, it is possible to secure the liquid to be processed and the permeate concentration at the start, and the entire operation can be smoothly advanced. In addition, even when the concentration of the liquid to be treated is reduced, such as when the operation is temporarily stopped or the target substance is insufficient, the permeate concentration can be ensured to an appropriate concentration by concentrating the liquid once.
Further, not only the concentration of the liquid to be treated at the start of the first multistage countercurrent means but also the concentration during the separation operation allows the first multistage countercurrent means to separate the target substance 1 into the permeate. At the same time, the recovery of the target substance 2 to the remaining liquid side is facilitated. As a result, mixing of the target substance 2 in the final permeate can be suppressed. This concentration is suitable when the target substance 1 is a substance having a low transmittance. In the case of many nanofiltration membranes, if the concentration on the residual liquid side is low, the transmittance tends to be low, and this concentration operation is particularly effective for increasing the concentration of the permeated liquid. As the concentration method, a known method such as evaporation, distillation, filtration, adsorption or the like may be used in addition to the method using a membrane.

<Membrane or separation membrane>
RO membrane (reverse osmosis membrane), NF membrane (nanofiltration membrane), UF membrane (ultrafiltration membrane), MF membrane (microfiltration membrane), dialysis membrane, You can select from ion exchange membranes. In particular, a nanofiltration membrane is preferable for separation with a molecular weight of about 1000 or less.
Although these membranes are used in a single stage, it is difficult to sharply separate two target substances having similar permeation tendencies into a permeate and a residual liquid. However, by using the multistage countercurrent operation of the present invention, such permeation can be achieved. Even in the case of a combination of the separation membrane and the target substance 1 and the target substance 2 that are close to each other, it is possible to fractionate the substance with high purity in a high yield.

<About processing liquid such as circulating liquid, permeated liquid, and cleaning liquid>
When the target substance 1 and the target substance 2 are concentrated with a membrane, a membrane that does not easily penetrate both the target substance 1 and the target substance 2 such as a separation membrane such as an RO membrane, an NF membrane, and a UF membrane is selected. Further, even a membrane through which the target substance 1 and / or the target substance 2 permeates can be employed by a method of increasing the recovery rate of the original liquid to the concentrated liquid by repeating permeation a plurality of times. By concentrating the treatment liquid with the membrane, the permeate concentration, the cleaning solution concentration, and the liquid concentration to be treated are increased, and the material composition can be changed with a small amount of liquid.
Further, the permeation liquid or the cleaning liquid can be concentrated independently of the multistage operation. As a result, it is possible to make the permeate and the cleaning liquid have a high concentration in advance, reduce the storage capacity, and use the cleaning water and other cleaning medium liquid at any timing.

<Multistage counter-current device / circulation use of residual liquid after operation>
In addition, at least a part of the residual liquid separated from the final stage of the second multistage countercurrent separation device may be supplied to any stage of the second multistage countercurrent separation apparatus as a part of the liquid to be treated. preferable. The supply destination may be the second multi-stage countercurrent separator including the final stage, and it is preferable to supply to the stage where the amount of circulating fluid necessary for continuing the membrane separation operation is insufficient. Further, the supply destination is not limited to one stage, and may be supplied to a plurality of stages. In this way, the amount of liquid to be treated can be increased by supplying the residual liquid to the first multi-stage countercurrent separator, and the purified liquid can be supplied by supplying the residual liquid that has been refined. The composition can be improved and stabilized. Further, even if the residual liquid does not meet the target in the course of purification, it can be reprocessed without being taken out of the system as a product.

  As a second embodiment, a method using a time-differential multistage countercurrent separation device is disclosed. A time-differential multi-stage countercurrent separator is provided with a plurality of storage tanks for receiving a permeate separated from a membrane separator for a single membrane separator, and by separating permeates that change over time, Multi-stage countercurrent separation is performed.

The terms in the time-differential multistage countercurrent separation operation are defined as follows.
<Cycle>
In a time-differential multistage countercurrent separation operation, a series of multistage countercurrent operations (a first multistage countercurrent separation and a second multistage countercurrent separation are performed in series) The operation from the start to the end is called one “cycle”. Even if an operation such as concentration performed in association with the cycle is included, it may be called a cycle.

<Circulating fluid>
In the time-differential multi-stage countercurrent separation operation, the liquid to be treated and the cleaning liquid supplied to each stage circulate in the circulation system constituted by the membrane device and the circulating liquid tank. The liquid existing in the circulation system is called a circulation liquid. Circulating fluid exists in the circulation system with various concentration distributions. In addition, the composition of the entire circulation system changes with the progress of the separation operation and the addition of the raw material solution and the cleaning liquid.

<Permeate storage and jump>
In order to efficiently achieve a change in the composition or concentration of the circulating fluid and permeate in the multi-stage countercurrent operation, the jump stage is used before the adjacent previous stage in performing the diafiltration in the multistage countercurrent method. Means the operation of using the permeated liquid as the cleaning liquid in the stage located at the position. In continuous multi-stage countercurrent separation operation, a plurality of separation devices are connected, the separation devices to be used correspond to the respective stages, and the obtained permeate is supplied as a cleaning liquid to the separation device before the adjacent previous separation device. Means.

  In addition, the jump step in the time-dependent multi-stage countercurrent separation operation can be described as the step corresponding to the same order of the multiple cycles in which the cleaning liquid acquisition in each step repeats the operation and the substance amount in the same pattern. This means that the acquired permeate is used as a cleaning liquid in a stage positioned before the adjacent previous stage in the next cycle. Considering the operation of using all of the obtained permeate as a cleaning liquid in the adjacent preceding stage of the next cycle, the objective of 1 minute of the target substance in the raw material solution supplied in 1 cycle in the final permeate obtained in the first stage When obtaining the amount of the substance, the first stage must contain at least a cleaning liquid containing the target substance for 1 minute or more. If the target substance 1 has a low transmittance, the permeate amount required Is larger than that when the transmittance is high, and the amount of permeate in the next stage is also large. This also makes it difficult to change the concentration and composition ratio of the liquid to be processed at each stage even when a large amount of cleaning liquid is used. As a result of intensive studies, the inventor reduced the amount or flow rate of permeate used per stage in a continuous multi-stage countercurrent method in which the permeate was skipped by one or more stages and used as a cleaning liquid. It has been found that the composition change between the permeated liquid and the liquid to be treated can be secured, and the driving force for the composition change of the cleaning liquid and the liquid to be treated at each stage can be secured. The separation shown in Example 2 is possible, and it has been found that increasing or decreasing the number of steps or the number of steps is effective as a response to the case of transmittance different from the case illustrated in Example 2.

  In the time-differential multi-stage countercurrent separation operation, the amount of permeate to be extracted is temporarily stored in the container for each stage, so that a different target liquid volume can be set for each stage, or the same liquid volume can be set for each stage. Can do. The amount of liquid can be appropriately changed according to the operation, and a plurality of containers with the same capacity can be used for one stage of permeate, and the number of stages and jumping stages can be changed in each multistage countercurrent operation. .

An outline of the time-differential multistage countercurrent separator is shown in FIG.
As the washing water 52, ion-exchanged water at room temperature or temperature can be used.
The permeated liquid 53 is a liquid that has permeated the separation membrane of the membrane module. It can be transferred from the nozzle of each membrane module to the permeate container 15 or the like. If necessary, the entire permeate can be returned to the circulating liquid tank through the return pipe 30.

  The remaining liquid 54 is a circulating liquid during the separation process, and the liquid remaining in the circulating system after the individual separation is finally completed is referred to as a residual liquid. The final residual liquid refers to the liquid remaining in the circulation system between the circulating liquid tank and the membrane module after the separation process in the final stage is completed.

The return permeate 55 is a permeate that comes out of the membrane module and returns to the circulating fluid tank.
The cleaning liquid 56 is supplied from outside the system to the circulation system, and a part of the permeated liquid 53 or cleaning water is used. In the final stage of the cycle, an operation for obtaining a permeated liquid is performed using the cleaning water 52 which is ion-exchanged water separately from the cleaning liquid. Wash water is used at any stage including the final stage.

  The circulating fluid tank 1 is connected to the circulating fluid tank 1 from the inlet piping 3 of the booster pump, the booster pump 4, the heat exchanger (cooler) 5-A, the membrane modules 6-A, 6-B, 6-C, and pressure control. The valve 9, the circulating fluid outlet pipe / hose 10, the heat exchanger (heater) 5-B, and the main storage mechanism of the liquid that forms the circulating system of the circulating fluid tank 1, are installed on the scale 2, pH A total of 8 liquid processing mechanism (not shown), a circulating fluid extraction mechanism 22, and a circulating fluid concentration maintaining mechanism 27 by controlling the cleaning liquid supply amount are attached. ◇ The attached scale 2 is connected to the function of maintaining the weight of the liquid in the circulating liquid tank, and can maintain the amount of liquid in the circulating liquid tank together with the cleaning liquid supply mechanism.

The washing water storage tank 13 holds heated washing water 59 that has been heated or washing water that has not been heated as the washing water 52. The washing water 52 is used in the separation operation, and can be used for preheating membrane modules, piping and containers, extracting the circulating fluid from the circulation system, and washing the separation membrane with warm water. A washing water pump 14-A is used for the supply.
The cleaning liquid 56 or dilute liquid 57 received in the cleaning liquid container 13 -B or ion exchange water is filled with a liquid to be added to the circulating liquid tank through the cleaning liquid control valve 33 and the cleaning liquid supply mechanism 23. The cleaning liquid pump 14-B is used for the supply. The dilute liquid 57 is a liquid that is generated when the final residual liquid is taken out and is diluted with the warm water 59 for cleaning.

  The permeate container 15 is a container having a volume of about 20 to 30 liters and is placed on the scale 2 to receive the permeate 53 from the membrane module. A part of the received permeate is withdrawn out of the system as a final permeate, and most of the permeate is stored as a cleaning liquid 56 during or before and after the multistage countercurrent operation, and from the permeate container 15 to the cleaning liquid container 13-B. To be used as a cleaning solution.

  The permeate from the permeate nozzle on the upper side of the membrane module can be sent to the permeate tank through the permeate pipe / hose 16. Can be used in the same way as the permeate piping / hose 16 described above for permeate sampling. Permeate when circulating fluid tank weight is abnormally low, circulating fluid concentration is abnormally high, permeate acquisition is stopped, or temporarily stopped. It is also used for the purpose of extracting the permeate stored in the liquid or the membrane module. The permeate sampling can be performed from a hose or the like.

The control panel controls, monitors, controls, and transmits alarms for circulating fluid temperature, circulating fluid tank volume, circulating fluid concentration, displays and records the scale value, and displays the measured values of the pH meter and saccharimeter Record.
Further, the total value of the sugar content of the permeate is displayed, the total value of the permeate sugar is calculated, the permeate flow rate is calculated from the change of the permeate weight, and the target management of the permeate acquisition amount is assisted. The temperature of the circulating fluid is adjusted by controlling the supply of the cooling water 58 to the heat exchanger (cooler) 5-A or the heating water 60 to the heating heat exchanger 5-B. The upstream and downstream pressures of the membrane modules 6-B and 6-C are indicated by two pressure gauges 7 respectively, and the pressure at the module outlet is mechanically adjusted by the pressure regulating valve 9, and the setting of the regulating valve is the main of the module. The management is performed in the operating state of the module in the pressure gauge 7 on the upstream side.

  A stock solution supply mechanism (not shown) is used as means for feeding the stock solution to the circulating fluid tank 1. For example, it is possible to combine known devices such as use of a line mixer and pumps, assuming that mixing with the circulating fluid is attempted. The supply mechanism includes a funnel. In the case of a high-viscosity fluid, a part of the circulating fluid / return fluid that has exited from the pressure control valve 9 is guided to the stock solution supply mechanism, and is sufficiently mixed with the stock solution and circulating fluid / return fluid and / or washing water, washing fluid, or permeate. It can be supplied to the circulating fluid tank later or while mixing. In addition, the diluting solution of the stock solution can be added to the tank as a cleaning solution or a solution equivalent to the circulating solution. At the same time as the stock solution is supplied, it can be controlled to maintain the circulating solution concentration by supplying normal or heated washing water or washing water. At the time of supplying the stock solution, the supply of cleaning water heated at the same time is controlled to maintain the circulating fluid concentration.

  The circulating fluid extraction mechanism 22 is used when extracting the circulating fluid after the separation process is completed, or when extracting the circulating liquid once to another place in order to interrupt the separation process. It is not indispensable to use the circulating fluid extraction mechanism 22 attached to the piping. Even if the circulating fluid stored in the circulating fluid tank is directly taken out to another container, the circulating fluid tank itself is extracted as a container. You can also. Among the circulating liquid, the liquid in the membrane module and the piping can be extracted by pushing it out with the hot water 59 for cleaning. The diluted circulating liquid generated at that time can be supplied to the preceding batch storage tank 31 and used in the next batch in place of the washing water or used as the diluting liquid 57 of the raw material solution. As a result, loss of the target substance 2 in the purified residual liquid can be suppressed, and the amount used for pure water to be used can be reduced, and at the same time, unnecessary dilution of the recovered residual liquid can be prevented. The final residual liquid extracted into the residual liquid container 12 is once stored and then circulated or extracted outside the system. Moreover, it may be used also for extracting liquid during washing with detergent. In the detergent cleaning, the separation membrane, the membrane module, the booster pump and other related devices may also be cleaned using a circulating liquid tank. As the detergent, an enzyme detergent or the like can be used.

The cleaning liquid supply mechanism 23 controls the mechanism for supplying the cleaning liquid to the circulating liquid tank, thereby controlling the concentration of the circulating liquid and the amount of liquid in the circulating liquid tank.
The permeate extraction mechanism 24 is a mechanism for controlling the stop state and the possible state of the permeate extraction from the circulation system, and can use flow path selection by a three-way valve, opening / closing of the valve, and the like.
The permeate flow rate measuring mechanism 25 is a function for measuring the flow rate by recording the total weight of the permeate contained in the permeate container and the time at that time, but the mechanism for measuring the flow rate itself may also be used. Good.

As the circulating fluid concentration measuring mechanism 26, a sugar meter of the type capable of continuously measuring the sugar content is used.
The circulating fluid concentration maintaining mechanism 27 by controlling the supply amount of the cleaning fluid is a mechanism for adjusting the concentration of the circulating fluid by controlling the supply of the cleaning fluid 56 or the cleaning water 52 with an automatic valve. This operation and the concentration of the circulating fluid can be controlled by the membrane and the return of the permeate to the circulating fluid tank. When the concentration of the circulating fluid becomes excessive or when the amount of liquid in the circulating fluid tank is predicted to be insufficient, the extraction to the permeate tank is stopped, and the permeate is returned to the permeate return valve 34 in the circulation. The amount of circulating fluid can be secured by opening / closing control. It is also possible to secure the circulating fluid concentration and the circulating fluid amount by mixing the circulating fluid with a high concentration liquid such as a stock solution and adding the cleaning water 52 or the cleaning fluid 56 to the circulating fluid tank.

  The permeate concentration measuring mechanism 28 has a function of measuring the permeate concentration based on the sugar content. Here, a continuous saccharimeter was used. As a result, the sugar content of the permeate generated every moment can be measured and monitored, and the content of the sugar content in the permeate obtained at each stage is grasped by combining these instantaneous values and the data on the weight increase of the permeate. I can do things. Also, put the submersible pump in the permeate container, and calculate the total amount of the target substance to be taken out in the permeate at the target stage by the product of the sugar content of the permeate taken out from it and the weight measurement value of the permeate. I can grasp it.

  The circulating fluid temperature maintenance mechanism 29 controls the supply of the cooling water 58 to the cooling heat exchanger 5-A or the heating water 60 to the heating heat exchanger 5-B, thereby controlling the circulating fluid. This is a mechanism for maintaining and adjusting the temperature at a desired temperature. This heating can be changed to overheating of the circulating fluid by an electric heater or the like.

  The small submersible pump is put into a permeate container and measures the sugar content by circulating the permeate in the container with a saccharimeter. Thereby, the total amount of sugar content of the permeate obtained by one operation such as one step can be grasped.

  The cleaning liquid control valve 33 controls the addition of the cleaning water to be added and the cleaning liquid to the circulating liquid tank for the purpose of measuring and controlling the amount of liquid and the sugar content in the circulating liquid tank.

[Combination of time-difference multistage countercurrent method and continuous method]
A multistage countercurrent separation operation may be used in combination of a time-differential multistage countercurrent separation operation and a continuous multistage countercurrent separation operation.
More specifically, before and after the raw material solution supply stage is performed by a continuous multistage countercurrent operation, and a time-differential multistage method is appropriately applied to the front part and the rear part of the continuous multistage operation.

By continuously performing before and after the raw material solution supply stage, the raw material solution can be supplied to the continuous multi-stage countercurrent separation operation. As a result, substances that are unstable in the raw material state can be immediately separated, and the storage device for the permeate and raw material solution can be reduced, with a time difference between each stage near the start stage and each stage near the final stage. Multi-stage countercurrent operation can reduce the number of separators by using one apparatus for multiple stages, and can perform time-differential multistage countercurrent method and continuous multistage countercurrent method.

<Concentration of circulating fluid>
The membrane device for concentrating the circulating fluid is difficult to permeate the target substance 1 and can be installed for the purpose of concentrating the mixture containing the target substance 1 and the target substance 2. In order to smoothly perform separation at the separation membrane used for separating the target substance 1 and the target substance 2, the operation pressure control of the circulating liquid concentration membrane apparatus is performed independently of the control of the operation pressure of the separation membrane apparatus. Therefore, it is possible to cope with the case where the cleaning liquid or the circulating liquid becomes diluted for some reason.

<Management of permeate>
By controlling the permeate concentration, it is possible to operate each stage appropriately. That is, in order to extract the sugar content of the planned amount into the permeate, it is necessary to measure the concentration index such as the sugar content in the permeate. The permeated liquid is obtained until the minute is reached, and in some cases, it is possible to determine the addition of cleaning liquid, the addition of cleaning water or cleaning medium liquid, and the end of the cleaning process, and these can be used as indicators for automatic operation. Can be.

<Removal of low molecular impurities>
It is also possible to separate the target substance 1 and the target substance 2 after separating the target substance 3 such as a low-molecular impurity from the mixture of the target substance 1 and the target substance 2 in advance. Specifically, a stock solution containing impurities and the like is supplied to a concentrating membrane that generally blocks the target substances 1 and 2, thereby separating water and low-molecular substances. The separation timing may be at the raw material solution supply stage or its peripheral stage. As a result, impurities and the like can be extracted from the permeate of the concentrating membrane, so that impurities can be mixed into the final permeate to extract the target substance 1 and the final residual liquid from which the target substance 2 is extracted. Suppressed separation is possible. Note that the substance to be separated by the concentration membrane may be not only the impurity but also the useful target substance 3. On the contrary, by separating a substance having a high molecular weight from a mixture of the target substance 1 and the target substance 2 in advance, the target substance 1 and the target substance 2 can be easily separated or the value of the target substance after separation is increased. Can do.

<Adjustment of concentration distribution of cleaning liquid for each stage for multi-stage countercurrent operation>
In order to separate the raw material solution into the desired final permeate and final residual liquid, it is necessary for the cleaning liquid to be within a certain range. A solution prepared by another method is used as a cleaning solution.

  The cleaning liquid can be prepared from a raw material solution that has not been separated. As a specific method, there is a method in which a cleaning liquid is used as a diluting solution of a raw material solution in advance, a liquid in which substances that are difficult to separate is accumulated by a multi-stage countercurrent separation operation, and a liquid in which separation is repeated in the previous stage.

  More specifically, the cleaning liquid is prepared in advance as a diluent for the raw material solution, the starting liquid to be processed is used as the raw material solution diluent, a countercurrent multistage separation operation is performed on the liquid to be processed, and the permeation is performed. Obtain a liquid. A new liquid to be treated is prepared by, for example, concentrating the obtained permeate, and separation operation is promoted. Regarding the final residual liquid, a possible amount is obtained out of the system when the composition has reached the desired composition. Similarly, the final permeate obtained from the first stage is withdrawn out of the system when the first stage permeate is concentrated as necessary to obtain a desired composition.

  When the final residual liquid does not satisfy the desired composition, it is preferable to mix the total amount of the final residual liquid into the raw solution supply stage of the next cycle or the circulating liquid between the raw solution supply stage and the final stage. On the other hand, if the final permeate does not satisfy the desired composition, it can be mixed with other stages of permeate or circulating liquid, or can continue to be used as the liquid to be treated at the start without being discharged out of the system. The permeate obtained in (1) can be mixed with the circulating liquid instead of the raw material solution supply stage, or between the first stage and the raw material solution supply stage, or as a cleaning liquid.

  When at least one of the final residual liquid and the final permeate is taken out of the system from the start of operation, the raw material solution is not only the raw material solution supply stage but, if necessary, the circulating liquid in the stage close to the raw material solution supply stage, or the permeate. It is desirable to mix and supply.

<Supply of raw material solution>
The raw material solution supply amount and supply method may be the same between the supply cycles, and correspond to the operation conditions including the operating conditions such as the capacity of the handling container, the increase / reduction of the processing amount, and the stop of the processing. May be supplied. Further, the supply does not need to be performed at one time, and the raw material solution may be supplied in parallel to a series of separation operations to some continuous plural stages. The flow rate may be fixed, or may be changed in accordance with the measurement value selected from the liquid amount or the analysis value or physical property value.

  In addition, this invention is not limited to the installation disclosed in FIG. 6, It is also possible to apply a well-known time-difference multistage countercurrent apparatus. For example, equipment as shown in FIG. 7 can be used.

  The equipment shown in FIG. 7 includes a circulating liquid tank 104 equipped with a stirring mechanism for performing a cleaning operation in the center, and a processing stock solution tank 101 and a plurality of cleaning liquid tanks 102 (individual cleaning liquid tanks) are provided above the tank 104. In this embodiment, cleaning liquids having different concentration ratios of the target substance 1 and the target substance 2 are added, and the number of the cleaning liquid tanks 102 is arbitrarily determined.) The cleaning water tank 103 is provided, and the liquids in the tanks 101 to 103 are disposed below each tank. The flow rate is adjusted by the provided control valve 108 and supplied to the circulating liquid tank 104. The liquid supplied into the circulating liquid tank 104 is mixed by the stirring mechanism and used for membrane separation.

  The liquid to be processed mixed in the circulating liquid tank 105 is sent to the film processing apparatus 107 by the pump 109. The permeate is sent out of the system through the permeate reservoir 106 by the pump 110, or is supplied to one of the wash baths 102 because it is used as a membrane separation wash before the next cycle or before the previous cycle. .

  Since the remaining liquid of the membrane separation device 107 is used for the subsequent or subsequent membrane separation, it is returned to the circulating liquid tank 105 and mixed with the cleaning liquid and the cleaning water. When the concentration of the target substance 2 in the residual liquid is sufficiently higher than that of the target substance 1, the residual liquid is sent to the residual liquid storage tank 105. The circulating fluid and permeate are controlled by the liquid level control valve LC and the level sensor LS.

  The membrane separation device 107 has a pressure control valve that adjusts the operating pressure of the device, a heat exchanger that adjusts the circulating fluid temperature, and a temperature control valve, and is supplied with solutions such as cooling water and power.

Using the apparatus shown in FIG. 1, a separation method using a time-differential multistage countercurrent separation apparatus for polyethylene glycol (PEG) 200 and each measurement data are disclosed as Example 1 below.
<Contents of 1 PEG200 separation>
Fractionation of PEG200 (manufactured by Sanyo Chemical Industries, Ltd.) containing commercially available triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol and the like was performed. PEG 200 is a mixture of these substances. This was separated into a mixture having the maximum concentration of triethylene glycol and a mixture having the maximum concentration of pentaethylene glycol.

<2 Device Description>
<Separation membrane> separation membrane used was PCI Membranes manufactured B1 type membrane module 6-A to the 0.9m ² AFC80, membrane module 6-B, the AFC30 of 0.9 m ² to 6-C mounted one each A total of three membrane modules were used. Since AFC80 does not substantially permeate the components in PEG200, it is a nanofiltration membrane used as a membrane for concentration performed before the multistage countercurrent operation. AFC30 is a nanofiltration membrane used for fractionation of each substance in PEG200.

<Measurement Function> Atago CM-780 was used for the circulating fluid concentration measurement mechanism 26 and the sugar content meter 28 for the sugar content measurement mechanism of the permeate. The sugar content of the obtained permeate was measured by circulating between the sugar clock and the container using a pump.

<Overview of operation>
In preparation for the permeated liquid from the previous cycle, the first to eighth stages of the first cycle of the aqueous PEG200 solution, which is the cleaning liquid in Table 1, are prepared. These are put in a circulating liquid tank, and the pressure increasing valve 4 is started with the pressure control valve fully opened, and the circulation is continued while extracting the liquid remaining in the membrane module, piping and the like. All the permeated liquid of AFC30 was returned to the circulating liquid tank. Thereafter, the permeated solution of AFC80 was drawn out into a container, and the PEG200 stock solution was added with stirring so that the sugar content of the circulating solution was 17%. At the same time, the permeate from the separation membrane AFC80 was taken out of the system and concentrated. Concentration operation was performed at 40 Bar, during which all permeate from AFC 30 was returned to the circulating fluid tank.
At this time, the temperature of the circulating liquid is adjusted by indirect cooling and indirect heating so as to be about 50 ° C.

  In one cycle, the first stage was prepared, proceeding to the first, second, and third stages. In the fifth stage, 1.62 kg of the raw material solution 51 was added and the process proceeded to the tenth stage. Up to 10 stages were carried out, and the final residual liquid of the first cycle was extracted, and a part thereof was mixed with the circulating liquid in the final stage and the preceding stage in the next cycle. The pre-concentration of the second cycle, the first stage, the second stage, and the second cycle were completed, and the third cycle, the fourth cycle, and so on were similarly promoted until the ninth cycle.

The target sugar amount in the first cycle and the sugar content in the permeate (weight equivalent to sugar content), that is, permeate weight (kg) x permeate sugar content reading (%) ÷ 100 Although not included, the pressure at the membrane module inlet / outlet is used as an index using the fact that the influence of the refractive index indicates the amount of dissolved substance in the permeate similar to sugar, and to ensure a predetermined value in operation. The operating pressure was adjusted while looking at the total 7. In other words, the transition of the permeate weight (kg) and permeate sugar content (%), and when the permeate amount reaches the target value, the operating pressure is adjusted so that the sugar content at that time is close to the target value. did.
Further, when the sugar content did not reach the target value as a result of the operation, the amount of dissolved substance in the permeate was increased by acquiring the permeate from AFC80, thereby increasing the amount of dissolved substance in the permeate.

<First cycle>
<First stage>
Return to the description of the first cycle. The permeated liquid was obtained from the circulating liquid, and at the same time, the first stage cleaning liquid prepared in advance was supplied so that the circulating liquid concentration was 17%. This cleaning liquid is once put in the cleaning liquid tank and supplied to the circulating liquid tank through the cleaning liquid pump and the control valve. Table 1 shows the amount of PEG 200 in the same amount of the cleaning solution prepared in the first stage. The cleaning liquid for the first stage was prepared in a container for the third stage permeate to be described later. When the cleaning liquid for the first stage is almost empty, the process moves to the next stage.
The operating pressure was adjusted to about 32 Bar. The circulating fluid temperature was maintained at about 50 ° C. throughout each cycle and stage operation.

<Second stage><Thirdstage><Fourthstage>
The cleaning liquid for the second stage was prepared in a container for the fourth stage permeated liquid to obtain a second stage permeated liquid.
The cleaning liquid for the third stage was prepared in a container for the fifth stage permeate to obtain a third stage permeate.
The cleaning liquid for the fourth stage was prepared in a container for the sixth stage permeated liquid to obtain the fourth stage permeated liquid.

<5th stage>
Before entering the fifth stage, once the operating pressure is adjusted to about 10 Bar or less, the raw material solution 51 and ion-exchanged water are added to the circulating liquid to adjust the sugar content to 17%, and then the fifth stage cleaning liquid is added to the eighth stage. A fifth stage permeate was obtained by preparing in a stage permeate container. The operating pressure was adjusted to about 32 Bar.

<6th stage, 7th stage, 8th stage>
The sixth stage cleaning liquid was prepared in the eighth stage permeate container to obtain a sixth stage permeate.
The seventh-stage cleaning liquid was prepared in the eighth-stage permeate container to obtain a seventh-stage permeate.
The eighth stage cleaning liquid was prepared in the eighth stage permeate container to obtain an eighth stage permeate.

<9th stage, 10th stage>
In the ninth stage, a predetermined amount of the ninth stage permeate was obtained while supplying wash water to the circulating liquid tank.
In the 10th stage, a predetermined amount of the 10th stage permeate was obtained while supplying the wash water to the circulating liquid tank.

<First cycle supplement>
In the first cycle, when it is judged that the amount of circulating fluid decreases and it is difficult to operate, the processing stock solution is appropriately added to the circulating fluid, and at the same time, the necessary cleaning fluid (or cleaning water) is added, while ensuring a circulating fluid sugar content of 17%, The operation is continued to obtain a final residual liquid, and 1 to 10 stages of permeate are obtained in the permeate container.

<Handling of final residual liquid>
Part of the final residual liquid obtained in the 10th stage is mixed with the circulating liquid in the 10th stage of the cycle, and the remaining liquid is taken out of the system.

<Second cycle>
<Preparation of liquid to be treated>
The total amounts of the first, second, and third permeates obtained in the first cycle were sequentially put into a circulating fluid container and concentrated by AFC80 to make the circulating fluid concentration 17%. Each permeate is directly fed into the circulating liquid tank, but once it is put into the washing liquid tank, it may be concentrated to obtain a predetermined liquid to be treated.

<First stage>
The first cycle of the fourth permeate was used as the cleaning solution, and a second cycle first stage permeate was obtained. When the target sugar content set in advance in the first stage permeate is obtained, the first stage is completed. If the set sugar content cannot be obtained even if the set target permeate amount is exceeded, the target sugar content is obtained within a range where there is room in the container. The first stage to the fourth stage were carried out with this policy after the second cycle. The operating pressure at a concentration of the circulating fluid having a sugar content of about 17% was maintained at about 24 Bar, and the circulating fluid temperature was maintained at about 50 ° C.
Table 1 shows the target permeate amount and target sugar content.

<Second stage, third stage, fourth stage>
The second stage permeate was obtained in the same manner as the first stage, using a part of the permeate of the fourth and fifth stages of the first cycle as the second stage cleaning liquid.
The third stage permeate was obtained in the same manner as in the first stage, using a part of the permeate of the fifth stage and the sixth stage as the cleaning liquid for the third stage.
The fourth stage cleaning liquid uses the remainder of the sixth stage permeated liquid in the first cycle, and while maintaining the raw water solution to be processed, the washing water is added and the sugar content is maintained at about 17%, and the operation is continued until a predetermined sugar content is obtained. As a result, a fourth-stage permeate was obtained. In operation with a sugar content of about 17%, it was set to about 32 Bar.

<5th stage>
The raw material solution to be processed is adjusted so that the amount of liquid in the circulating liquid tank is about 20 kg (the circulating liquid tank is for 30 liters, the amount of liquid in the membrane module and piping is about 10 kg, and the total liquid volume is about 30 kg). While gradually added, washing water was supplied so as to have a sugar content of about 17%, and after circulating operation for about 15 minutes, a fifth-stage permeate was obtained using the seventh-stage permeate as a washing liquid. .

<6th stage, 7th stage, 8th stage>

Thereafter, steps 6, 7, and 8 were performed in the same manner as in the first cycle to obtain a sixth-stage permeate, a seventh-stage permeate, and an eighth-stage permeate.
After that, similarly to the first cycle, the ninth-stage permeate and the tenth-stage permeate were obtained using washing water.

<Operation policy in subsequent Example 1>
<Operation after the third cycle>
The operation after the third cycle was advanced to the seventh cycle in the same manner as the second cycle, and the amount of the raw material solution supplied in each cycle was set to the amount shown in Table 2. The eighth and ninth cycles after reducing the raw material solution supply were operated up to 9 stages.

<Understanding separation status by liquid chromatograph>
A liquid chromatograph chart of the final permeate and the final residual liquid was obtained under the following conditions.
Column: Hitachi GL. W520-S aqueous SEC analysis column
Eluent: H ₂ O
Flow rate: 0.3 mL / min Sample injection volume: 50 μL (30 ° C.)
Measurement time: 50 minutes Detector: RID

<Analytical result of final permeate and final residual liquid in Example 1>
The state of separation was judged from the chart of the final permeate obtained by the operation of each cycle and the final residual liquid using a liquid chromatograph. The chart in FIG. 8 is obtained by measuring a PEG-related substance as a standard substance. FIG. 8A shows diethylene glycol, FIG. 8B shows a PEG200 mixture, and FIG. 8C shows a PEG300 mixture. Diethylene glycol as a standard substance has a peak at about 32 minutes. The PEG200 mixture has the highest peak at about 30.2 minutes, and peaks at both sides of 29.5 and 31 minutes. Judging from the fact that the sample is a polyethylene glycol mixture having an average molecular weight of 200 and the peak of diethylene glycol, diethylene glycol (molecular weight 106) is 32 minutes, triethylene glycol (molecular weight 150) is 31 minutes, tetraethylene glycol (molecular weight 194) Can be determined to have a peak at 30.2 minutes and pentaethylene glycol (molecular weight 238) at 29.5 minutes. In addition, in the mixture of polyethylene glycol having an average molecular weight of 300, the largest peaks are at 28.8 minutes and 28.2 minutes, which are hexaethylene glycol (molecular weight 282) and heptaethylene glycol (molecular weight 326). ), The average of them is close to the average molecular weight 300 of PEG300, and the residence time and molecular weight of each substance are aligned consistently.

  Referring to the retention period corresponding to each substance in the liquid chromatograph described above, looking at the chart of the final permeate and the final residual liquid, FIGS. 9 and 10 show the final residual liquid and the final permeation in cycles 5 to 9, respectively. The maximum peak of the final residual liquid in each chart of FIG. 9 is at the residence time corresponding to pentaethylene glycol, and the triethylene glycol portion is about 25% or less of the maximum peak. There is no polyethylene glycol having a reduced triethylene glycol content. Conversely, the maximum peak of the final permeate according to the chromatographic chart shown in FIG. 10 is around 31 minutes, indicating that it is triethylene glycol, and the height of the chart corresponding to the residence time of pentaethylene glycol on that chart. Is about 25% or less of the maximum peak, and polyethylene glycol having a reduced pentaethylene glycol content is obtained.

  In both Example 2, Example 3, and Comparative Example, a 25 wt% aqueous solution of a mixture of 60 wt% substance 1 (triethylene glycol) and 40 wt% substance 2 (pentaethylene glycol) was used as a target raw material. Are separated by a multistage countercurrent operation. Substance 1 has a transmittance of 0.69, and substance 2 has a transmittance of 0.4. The target raw material is 90% in Example 2 with a content of substance 1 in the final permeate, 85% in Example 3, and 10% in Example 2 with a content of Substance 1 in the final residual liquid. Separated to 20%.

  As a separation membrane, AFC30 of PCI Membranes was used, and as a membrane for concentration, AFC80 of PCI Membranes, which is an RO membrane, was used. Other conditions not specifically described were performed under the same conditions as in Example 1.

<Device and Operation of Example 2>
FIG. 5 uses the apparatus disclosed in FIG. 5 in the second embodiment.
The series of multi-stage countercurrent separation operations of Example 2 consists of a 21-stage membrane separation operation including a concentration stage (not shown in Table 3). The 20 stages excluding the concentration stage have a total of 146 substances 1 and 2 in the residual liquid from each stage with respect to the total 100 weight flow units of substances 1 and 2 in the raw material solution in the steady state. The first multistage countercurrent separating means having six weight flow units and the second multistage countercurrent separating means having 246 weight flow units have a total concentration of 25% by weight of substance 1 and substance 2 in the residual liquid. We drove while securing it to be about%. The raw material is supplied as an about 25 wt% aqueous solution together with dilution water before the start of the sixth stage. In the first stage, an RO membrane or NF membrane that does not allow the permeated liquid from the next stage to permeate either Substance 1 or Substance 2 is used. Approximately 360 weight flow units are removed, and the second through eighteenth stages are appropriately selected, and the next stage permeate is used as the washing liquid as the washing liquid. Necessary for adjusting the concentration of each stage. Depending on the concentration, the RO membrane is reconstituted or the permeate is replenished with water. In the last two stages of the concentration operation section, fresh washing water 526 and 555 weight flow units are supplied, and the residual liquid concentration in each stage. It is a driving | running result at the time of continuing the driving | running made into 25 weight% aqueous solution.

<Results of Example 2>
Table 3 summarizes the results under the above operating conditions. In the table, F, C and P indicate the total weight flow unit (moisture removal) of substance 1 and substance 2, F is the value in the supply liquid, C is the residual liquid in each stage, and P is the permeate in each stage. Medium value. In the first stage, a larger amount of permeate corresponding to the substances 1 and 2 than P shown in Table 3 is obtained, and the permeate corresponding to the value of P in the first stage is extracted out of the system. The operation of returning the remaining permeate to the first stage is possible. Even in the final stage, more residual liquid is obtained than the residual liquid corresponding to the value of C in Table 3, the residual liquid corresponding to the value of C in the final stage is drawn out of the system, and the remaining residual liquid is finally obtained. Operation to return to the stage is possible.

  Xc and Yp are the ratio of the mass flow rate of the substance 1 to the total mass flow rate of the substances 1 and 2 in the residual liquid and permeate of each stage (substance 1 / (substance 1 + substance 2)).

<Equipment and operation of Example 3>
In Example 3, the apparatus disclosed in FIG. 6 was used.
The series of multi-stage countercurrent washing / separation operations of Example 3 includes 11 stages of membrane separation operations including a concentration stage (not shown in Tables 4-1 and 4-2). The flow rate units and weight fractions of the substances 1 and 2 at each stage are shown in Table 4-1, and the weight flow units of the treatment liquid containing the substances 1, 2 and water are shown in Table 4-2. Ten stages excluding the concentration stage are the sum of substance 1 and substance 2 in the residual liquid from each stage with respect to the total 100 weight flow units of substance 1 and substance 2 in the feedstock solution in the steady state. 4 stages as the first multistage countercurrent washing and separating means with 438 weight flow units and 6 stages as the second multistage countercurrent washing and separating means with 838 weight flow units, and the substances 1 and 2 in the residual liquid The operation is performed while ensuring that the total concentration is about 25% by weight. The raw material was supplied as an aqueous solution of about 25% by weight with dilution water before the start of the fifth stage. In the first stage, the permeated liquid from the next stage was supplied as a cleaning liquid after removing moisture of about 304 weight flow units using an RO membrane or NF membrane that did not pass through either Substance 1 or Substance 2. In appropriately selected stages from the second stage to the tenth stage, the permeated liquid of the next stage is used as a cleaning liquid, and concentration adjustment by RO membrane or moisture in the permeated liquid as necessary for the concentration adjustment of each stage. An operation to replenish was performed. In the last stage of the second multistage countercurrent separation operation section, fresh washing water 809 weight flow unit was supplied. Table 4-3 shows the concentration of each component and the total concentration in the final permeate and the final residual liquid when the operation of setting the residual liquid concentration in each stage to a 25% by weight aqueous solution is continued.

Comparative example

  Table 5 shows, as a comparative example, the results of using the nine-stage multi-stage countercurrent separation means by supplying the stock solution to the first stage of the first multistage countercurrent separation process without using the second multistage countercurrent separation process. It describes.

  The outline of the operation method is as follows. The first stage permeate is obtained by supplying the first stage of the apparatus while adjusting the amount of water to be added so that the total concentration of substance 1 and substance 2 in the raw material solution is about 25% by weight. At the same time, a part of the permeate obtained in the first stage is used as a diluent for the raw material solution, and the second stage permeate is added as a cleaning liquid. The remaining liquid is sequentially processed from the 1st stage to the 2nd stage and the 3rd stage, washing water is added to the final stage, and the permeate obtained in the final stage is added as a washing liquid for the preceding stage.

  Since the permeate obtained from the first stage described in Table 5 is affected by the concentration of the mixture charged in the first stage, only a mixture of substance 1 and substance 2 containing about 74% by weight of substance 1 is obtained. It is substantially difficult to obtain a mixture containing 90% by weight or more of substance 1.

  The present invention is a natural product obtained in the chemical industry, the refined sugar industry, the fermentation industry, the amino acid industry, etc., a synthetic substance, a substance that is difficult to purify using a difference in properties between molecules, a difference in vapor pressure, etc., and a low thermal stability. When purifying a substance, the valuable material can be efficiently separated from a mixture containing impurities of similar properties, and has industrial applicability in the industrial field. .

DESCRIPTION OF SYMBOLS 1 ... Circulating fluid tank 2 ... Scale 3 ... Booster pump inlet piping 4 ... Booster pump 5-A ... Heat exchanger (cooler)
5-B ... Heat exchanger (heater)
6-A, 6-B, 6-C ... Membrane module 7 ... Pressure gauge 8 ... pH meter 9 ... Pressure control valve 10 ... Circulating fluid outlet pipe / hose 11 ... Hot water container for circulating separation membrane cleaning liquid 12 ... Residual liquid container DESCRIPTION OF SYMBOLS 13 ... Washing water storage tank 13-B ... Cleaning liquid container 14-A ... Washing water pump 14-B ... Cleaning liquid pump 15 ... Permeate liquid container 16 ... Permeate liquid piping / hose 22 ... Circulating liquid extraction mechanism 23 ... Cleaning liquid supply mechanism DESCRIPTION OF SYMBOLS 24 ... Permeate extraction mechanism 25 ... Permeate flow measurement mechanism 26 ... Circulating fluid concentration measurement mechanism 27 ... Circulating fluid concentration maintenance mechanism by controlling the amount of cleaning liquid supplied 28 ... Glucometer for permeate sugar content measurement mechanism 29 ... Circulating fluid temperature maintenance mechanism 30 ... return piping 31 ... preceding batch storage tank 33 ... cleaning liquid control valve 34 ... permeate returning valve 51 ... raw material solution 52 ... cleaning water 53 ... permeate 54 ... residual liquid 55 ... return permeate 56 ... Washing Liquid 57 ... Dilute liquid 58 ... Cooling water 59 ... Washing hot water 60 ... Heating water 61 ... Target liquid 62 ... Cleaning liquid 63 ... Permeate liquid 64 ... Residual liquid 65 ... Membrane unit 66 ... Pressure control valve 67 ... Circulation pump 68 ... Permeate Pump 69 ... Booster pump 70 ... Circulating fluid tank 71 ... Permeate tank 81 ... Raw material solution 82 ... Pure water 83 ... Final permeate 84 ... Final residual solution 85 ... Concentrated permeate

Claims (13)

In the method of separating the target substance 1 in the raw material solution into the final permeate and the target substance 2 into the final residual liquid using a separation means for separating the liquid to be treated into the residual liquid and the permeate.
(1) Performing using a multistage countercurrent separation operation configured to send the residual liquid from the separation operation to the subsequent stage and return the permeate as the liquid to be treated and / or the cleaning liquid in the previous stage;
(2) supplying the raw material solution to one of the intermediate stages except the first and last stages of the multistage countercurrent separation operation;
A membrane separation method for a raw material solution.   The membrane separation method for a raw material solution according to claim 1, wherein the multistage countercurrent separation operation is performed using an apparatus in which a plurality of membrane separation means are arranged in series. The multistage countercurrent separation operation is performed in a plurality of cycles,
Each cycle is composed of four or more stages, and the separation operation of each stage is performed using a plurality of cleaning liquids having different concentrations of the target liquid 1 separately stored from the liquid to be processed. The concentration of the target substance 1 or the ratio of the target substance 1 to the target substance 2 is increased,
The residual liquid at the last stage of each cycle is taken out as the final residual liquid, and the permeated liquid at each stage is stored in a separately provided storage means, and as the first stage liquid to be processed in the separation operation of the subsequent cycle, or Supply by using it as a cleaning liquid before the stage separated in the previous cycle,
The method for membrane separation of a raw material solution according to claim 1.   The part or all of the permeate obtained from the stage excluding the last two stages of the multi-stage countercurrent separation operation is returned to the stage two or more stages prior to the stage as the liquid to be treated. The membrane separation method of the raw material solution as described in 2.   The raw material solution membrane separation method according to any one of claims 1 to 4, wherein the raw material solution is supplied in a plurality of stages in a multistage countercurrent separation operation of four or more stages.   The raw material solution membrane separation method according to claim 1, wherein the liquid to be treated to be supplied to the first stage in the multistage countercurrent separation operation is concentrated before the treatment.   The raw material solution according to any one of claims 1 to 6, wherein at least a part of the residual liquid separated from the final stage of the multistage countercurrent separation operation is supplied to any stage after the raw material solution supply stage. Membrane separation method. From a raw material solution containing at least three kinds of target substances, by a multistage countercurrent separation operation,
(1) a step of separating the target substance 1 from the final permeate of the multistage countercurrent separation operation;
(2) a step of separating the target substance 2 from the final residual liquid of the multistage countercurrent separation operation;
(3) From either stage of the multistage countercurrent separation operation, all or part of the permeate or residual liquid is supplied to a separation means different from the multistage separation operation, and the final permeate of the other separation means Or a step of separating the target substance 3 into the final residual liquid,
The membrane separation method of the raw material solution in any one of Claims 1-7 containing these.   9. The raw material solution membrane separation method according to any one of claims 3 to 8, wherein at least part of the first stage permeate is used as part of the liquid to be treated in the next cycle.   The first stage of the permeate is the next cycle until the target substance 1 in the permeate has a predetermined concentration or more and / or the ratio of the concentration of the target substance 1 in the permeate to the concentration of the target substance 2 becomes a predetermined ratio or more. The liquid to be treated is taken out of the system as a final permeate when a predetermined concentration and / or a predetermined ratio is reached, and the second stage permeate is used as a liquid to be treated in the next cycle. The membrane separation method of the raw material solution in any one of 8.   The membrane separation method according to any one of claims 3 to 10, wherein the same separation means is used for membrane separation in a plurality of stages of multistage countercurrent operation. A membrane separation apparatus comprising a separation means for separating a liquid to be treated into a residual liquid and a permeate, and separating a target substance 1 in a raw material solution into a final permeate and a target substance 2 into a final residual liquid,
(1) Using a multistage countercurrent separation operation in which the residual liquid from the separation operation is sent to the subsequent stage and the permeate is returned as the liquid to be treated and / or the cleaning liquid in the previous stage.
(2) The raw material solution is supplied to one of the intermediate stages except the first and last stages of the multistage countercurrent separation operation.
A raw material solution membrane separator configured as described above.   13. The raw material solution membrane separation apparatus according to claim 12, comprising a plurality of membrane separation means arranged in series, and performing the multistage countercurrent separation operation using the plurality of membrane separation means.

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