JP4832393B2 - Method and apparatus for separating polyglycerin using a membrane - Google Patents

Description

  The present invention relates to a membrane separation method and apparatus for separating a polyglycerin composition containing a plurality of types of polyglycerin components into a permeate and a residual liquid (non-permeate) having a molecular weight distribution according to the purpose.

Polyglycerin derived from petrochemicals or derived from fats and oils is commonly used, and is generally obtained by dehydration condensation reaction of glycerin in the presence of an alkali catalyst. These polyglycerins are a mixture of diglycerin, triglycerin and the like having a low degree of polymerization, a polymer having a degree of polymerization higher than decaglycerin, and a mixture containing cyclic polyglycerin and by-products. There are several types and has a broad molecular weight distribution.
In addition, polyglycerin produces various forms by dehydration condensation between glycerin, glycerin / polyglycerin, or between polyglycerin, that is, linear polyglycerin, branched polyglycerin, and cyclic polyglycerin. It is also used as a mixture and a purified product from which impurities are removed. Among them, vegetable glycerol-derived polyglycerol is usually purified by a reaction using an alkali catalyst, and its composition is a mixture having a broad composition. Many of these are commercially available with polyglycerol having a molecular weight of 1000 or less as a main component. It is also used as a raw material for glycerin fatty acid esters.
Separation of a mixed liquid containing a plurality of polyglycerols into a low molecular weight polyglycerin and a high molecular weight polyglycerin according to the purpose is to use the desired polyglycerin. This is important for obtaining a mixed solution.
For example, when trying to synthesize a polyglycerin fatty acid ester, which is one of the typical nonionic surfactants, directly from this polyglycerin, the reaction of polyglycerin and other fatty acids with a lower degree of polycondensation such as glycerin Since the property is higher than that of polyglycerin having a higher degree of polycondensation, it is impossible to produce a hydrophilic polyglycerin fatty acid ester that can be expected as a result of the formation of an ester having a low HLB value.
Moreover, about the polyglycerol fatty acid ester which uses polyglycerol as a raw material, the specification of a specific polyglycerol fatty acid ester exists, and the polyglycerol of a desired molecular weight area | region is calculated | required about the polyglycerol as a raw material. (For example, Non-Patent Document 1)
Therefore, attempts have been made to increase, decrease, or further separate the specific component from the polyglycerin mixture depending on the intended use. As a method for fractional purification of polyglycerol used for this purpose, a molecular distillation purification method, which is a separation method through a gas phase, is known (for example, Patent Document 1).
In addition, there is also one in which a polyglycerin composition is added to a strongly acidic ion exchange resin, and thereafter, components with a high degree of polymerization are sequentially extracted using an eluent (Patent Document 2).
Japanese Patent No. 3717193 Japanese Patent No. 3166289 EFEMA index of food emulsifiers January 2004 4th edition Polyglycerin ester / Sakamoto Yakuhin Kogyo Co., Ltd. Osaka: Sakamoto Yakuhin Kogyo, 1994, 3 issued, 35, 36, 40 pages

However, when applying to polyglycene using the molecular distillation purification method, there are restrictions on the vapor pressure of the material to be handled, the temperature necessary for gasifying the material, and the alteration of the material at that temperature. That is,
1) When diglycerin and triglycerin are removed by distillation, high temperature and high vacuum conditions are required. Since the polyglycerin mixed solution contains water, it is generally difficult to set high vacuum conditions of several tens of pascals or less, and naturally, a high temperature of 170 ° C. or higher is required.
In addition, since polyglycerin is generally obtained by dehydration condensation of glycerin, there is a high possibility that alteration of the polyglycerin in the stock solution (change in the degree of condensation polymerization, etc.) will occur under the above conditions.
In addition, for handling in a high vacuum, it is necessary to adapt a large apparatus.
This is an important constraint when trying to fractionate polyglycerin in a desired degree of polymerization or molecular weight region, and is a major constraint on the molecular weight region to be separated.
For the above reasons, the desired degree of polymerization or molecular weight to be selected in consideration of the hydrophilicity / hydrophobicity of each polyglycerin, viscosity, reactivity with other substances, various functions of the reaction products, standards and regulations, etc. As a means of realizing the region polyglycerin / polyglycerin mixture, there is a limit (more than triglycerin and tetraglycerin).
On the other hand, the technique described in Prior Art Document 2 requires an adsorbent such as a strongly acidic ion exchange resin and an eluent, and also requires a new facility for treating the drained water after elution. Is complicated and the system is complicated.

The present invention has been made in view of such circumstances, and uses a nanomembrane or an ultrafiltration membrane to suppress an increase in the scale of equipment, and a polyglycerin mixture on a large molecule side and a small molecule side polyglycerin. To be separated.
More specifically, the polyglycerin mixed solution is divided into a permeate and a residual solution, the polyglycerin having a low molecular weight is separated on the permeate side, and the polyglycerin having a high molecular weight is left on the residual solution side, or from the polyglycerin mixed solution A method of extracting polyglycerin having a low molecular weight to the permeate side by a diafiltration method, or a form of separation operation using a membrane. It is intended to provide a separation method for managing and adjusting the permeation tendency of a target substance using measured values and analysis values representing the separation state of the membrane device such as concentration and physical property values.

The inventors of the present invention are able to obtain polyglycerin obtained by various methods as a polyglycerin mixed solution having different polymerization degree distributions depending on the raw materials and reaction methods, and the reaction products of the product or product as they are. Focusing on the fact that the polyglycerin mixed solution can be separated into liquids with different compositions or mixed and adjusted after separation without using the raw materials, and the knowledge that it is effective to use nanomembranes and ultrafiltration membranes as the separation method Obtained.
In the separation using a nanomembrane or an ultrafiltration membrane, it is possible to select a membrane in consideration of the permeability tendency of the membrane to be used and its operating conditions in accordance with the material to be separated and the material to be separated. This is different from the vacuum distillation method and molecular distillation purification method based on evaporation to the gas phase. In membrane separation, the vapor pressure of the material to be handled and the temperature necessary to gasify the material and the material at that temperature are used. There is no restriction on the alteration of the material, and nano-membranes and ultrafiltration membranes can be selected even in the separation for a substance having a large molecular weight, and the separation object can be widely selected. That is, separation can be performed in consideration of the influence of molecular weight, degree of polymerization, and molecular shape, that is, linear, cyclic, or steric shape.
That is, it is said that the boiling point of polyglycerin at normal pressure is approximately 240 ° C. for diglycerin, and that the boiling point is increased by approximately 40 ° C. as the degree of polymerization increases. (Polyglycerin ester published by Sakamoto Pharmaceutical Co., Ltd., page 35. Non-patent document 2) From this, in the separation method via the gas phase, separation is difficult due to the temperature and degree of vacuum necessary to make a large molecular weight polyglycerin such as decaglycerin into the gas phase and the influence on the alteration of each substance. However, in the present invention using a nanomembrane or an ultrafiltration membrane, there is no restriction due to vapor pressure or the like, and no operation in a range that can avoid the influence of temperature is necessary.
In this respect, the membrane purification method has an advantage that the quality of the stock solution can be maintained because the purification can be performed under mild conditions.

The present invention relates to a membrane characterized in that a mixed liquid containing a plurality of types of polyglycerin components is separated into liquids having different content ratios with respect to the polyglycerin components using a nanomembrane and / or an ultrafiltration membrane as a separation membrane. Is a method for separating polyglycerin using
In addition, the present invention is characterized in that a plurality of types of nanomembranes and / or ultrafiltration membranes having different permeation tendencies are used.
Further, the present invention provides the separation method wherein at least one selected from the concentration, sugar content, specific gravity, viscosity, and pressure loss of the concentrate and / or permeate produced after membrane separation of the mixed solution or in the process of membrane separation. It includes a membrane separation operation or diafiltration that measures the measurement items, supplies dilution liquid or cleaning liquid based on those values, and controls the ratio of permeate to residual liquid and the supply amount of dilution liquid or cleaning liquid. It is characterized by.
Further, the present invention provides a target value for at least one item selected from the concentration, sugar content, specific gravity, viscosity, and pressure loss of the concentrate and / or permeate, measures the corresponding measurement items, and sets these values. Based on the end point of separation in batch operation, the ratio of residual liquid flow rate and permeate flow rate in continuous operation, and the supply amount when adding washing liquid or dilution liquid, the membrane separation operation is automatically controlled. It is characterized by.
Further, the present invention is characterized in that a membrane separation operation or diafiltration is performed by a function of adjusting the supply of a mixed solution, a diluting solution or a cleaning solution containing a plurality of types of polyglycerol.
Further, the present invention is characterized in that the operation of maintaining the operating temperature of the membrane separation apparatus at 35 ° C. or higher and lower than 100 ° C. is performed.
Further, the present invention is characterized in that heating is performed so that the temperature of the membrane separation device is in a range of 35 ° C. or more and less than 100 ° C. prior to the supply of the polyglycerol stock solution to the membrane separation device.
Further, the present invention is characterized in that the sugar content of the concentrated liquid is measured, and based on the measured value, a diluting liquid or a cleaning liquid is added to a mixed liquid containing a plurality of types of polyglycerin, or mixed and supplied with a circulating liquid.

The present invention also provides a diafil for supplying a stock solution containing a plurality of target substances to a membrane separation apparatus, extracting the target substance from the permeate obtained from the membrane separation apparatus, and separating the remaining other target substances into a residual liquid. In the truncation, at least one operation item selected from the permeate flow rate, the operating pressure of the membrane separation device, the operating temperature, the circulating fluid concentration, and the circulating fluid amount using the separation state index and / or the progress indicator of the separation operation. The transmission tendency of the target substance is controlled by adjusting or controlling to a set range.
In addition, the present invention is characterized by using a tubular nanomembrane and / or a UF membrane.
Further, the present invention is characterized in that the nano membrane and / or the UF membrane permeate a plurality of times.
The invention of the present application is characterized in that the mixed liquid containing a plurality of types of polyglycerin is a mixed liquid containing salts.
In the invention of the present application, the mixed liquid containing the plurality of types of polyglycerin components is a polyglycerin mixed liquid manufactured by a manufacturing process including a reaction process under an alkali catalyst using glycerin and / or polyglycerin as a raw material. It is characterized by.
The present invention also provides a diafil for supplying a stock solution containing a plurality of target substances to a membrane separation apparatus, extracting the target substance from the permeate obtained from the membrane separation apparatus, and separating the remaining other target substances into a residual liquid. In the trough facility, at least one item selected from the separation state indicator and / or progress indicator of the separation operation, the permeate flow rate, the operating pressure of the membrane separator, the operating temperature, the circulating fluid concentration, and the circulating fluid amount A polyglycerol mixed liquid separation apparatus using a membrane, characterized in that a control means for controlling operation items is provided.
The present invention also provides a function for setting an operating pressure and / or a permeate flow rate based on at least one of a permeate concentration, a permeate sugar content, a cumulative permeate amount, or an elapsed time, a corresponding circulating fluid concentration, a circulating fluid It is characterized by an adjustment function for supplying the cleaning liquid while adjusting the sugar content or the circulating fluid flow rate, and performing diafiltration.
The present invention also includes a step of separating a mixed liquid containing a plurality of types of polyglycerin components into liquids having different content ratios for the polyglycerin components using nanomembranes and / or ultrafiltration membranes as separation membranes. Polyglycerin produced by the method.

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to isolate | separate the liquid mixture containing several types of polyglycerol into the polyglycerol containing a desired molecular area | region. Moreover, since the liquid mixture containing the polyglycerin component is separated using the separation membrane, the increase in the scale of the facility can be suppressed, and the polyglycerin can be taken out without the need for special drainage treatment.
Further, according to the present invention, diafiltration in which the permeation tendency of the target substance is controlled becomes possible, and the substances having close permeation tendency in membrane separation can be precisely separated.
In addition, according to the present invention, it becomes possible to separate substances that are close to each other in permeation tendency by membrane separation that can be operated at a low temperature, thereby enabling separation that is difficult to be thermally decomposed and thermally denatured, A simple separation process without additives and waste during membrane separation is possible.

  According to the present invention, when the raw material for treatment contains salts such as salt, salt is removed together with low-molecular glycerin and polyglycerin, and recovered as polyglycerin in which salts such as salt are reduced in the remaining liquid. It becomes possible. As the membrane to be selected, a nano membrane or an ultrafiltration membrane can be appropriately used according to the purpose.

  In the present invention, when the mixed solution is polyglycerin, polyglycerin can be purified by permeation of a small molecular weight substance using a nanofiltration membrane, an ultrafiltration membrane, or a reverse osmosis membrane.

According to the present invention, diglycerin can be removed from a mixed solution containing a plurality of types of polyglycerin. Specifically, it is possible to carry out purification to remove glycerin, diglycerin, and triglycerin.
Moreover, polyglycerin having a low degree of polycondensation containing glycerin and diglycerin can be removed using a polyglycerin mixed solution as a raw material, and polyglycerin having a low degree of dispersion can be obtained.
By using this purified polyglycerin, it has become possible to produce a polyglycerin fatty acid ester having an unprecedented high HLB value. The polyglycerin fatty acid ester thus obtained is suitably used as a solubilizer for foods, cosmetics, pharmaceuticals, etc., an aqueous rinsing agent for tableware, and a cleaning agent.
Since polyglycerol obtained by dehydrating and condensing glycerol contains a salt derived from a catalyst and further organic acids, it is commonly used after the reaction to be purified by an ion exchange resin or the like. Another advantage of using the membrane is that these low-molecular impurities can be removed at the same time by membrane purification.

  Various nanomembranes and ultrafiltration membranes that are available on the market show rough indicators of the performance of blocking substances such as the fractional molecular weight, but the permeation tendency such as the blocking rate of actual molecules Is affected by various factors as described above. The present invention is a method and apparatus for performing desirable separation by appropriately controlling the permeation tendency of a membrane separation apparatus with respect to a mixed liquid containing a plurality of types of polyglycerin.

  The inventor of the present application can maintain the permeation tendency of these substances within an appropriate range in order to appropriately perform separation of the polyglycerin mixed solution having a permeation tendency close by diafiltration by membrane separation. In order to realize an operating state suitable for promoting the permeation of substances that are thought to be important and promoting permeation and for suppressing the permeation of substances that do not want to suppress permeation, the operating pressure, operating temperature, and operation as the operation items in the membrane separation device We tackled the issue of how to use the effect of concentration and hydrogen ion concentration (pH) on permeation tendency.

  Next, terms used in this specification will be described below.

<Diafiltration>
In the present invention, the diafiltration used for membrane separation is “adding a washing liquid to a suspension, a liquid mixture or a liquid being processed as an object of the membrane separation operation, and taking out the permeate from the membrane separator. , "The operation of separating the target substance into permeate and non-permeate (residual liquid and internal circulating liquid) by obtaining the residual liquid" Describe as the target substance.

<Undiluted solution>
The “stock solution” used in the present invention is a mixed solution containing a plurality of types of polyglycerin, in addition to a plurality of types of polyglycerin as a target substance, organic substances, inorganic substances, salts, reaction raw materials, products, by-products, valuable substances, It may contain various target substances for separation purposes such as harmful substances.
In many cases, it is desirable that the concentration of the concentrate be close to the upper limit of the range that can be handled by the membrane separator. However, when the concentrate is supplied in a dilute state, the diafil that extracts the target substance into the permeate without adding a cleaning solution. It is also possible to carry out the diafiltration after the concentration in the membrane separator. When handling the diluted solution of the residual liquid generated in the batch performed in advance or the permeate obtained in the related process as a stock solution, concentrate it in advance or separate membrane device in parallel with diafiltration, etc. It is desirable to concentrate using Conversely, it is also possible to previously dilute the concentration of the solid matter or stock solution with a cleaning solution or a circulating solution.
The undiluted solution is used in the processing apparatus as “circulating liquid” or “internal circulating liquid” in the course of the membrane treatment, and is extracted into the processing apparatus as “residual liquid” at the time or stage when the processing proceeds. .

<Solvent>
The “solvent” used in the present invention is a liquid used for handling the stock solution, and itself contains an aqueous solution of a water-soluble solvent such as water, hot water, cold water, ethanol, an organic solvent, or a mixture thereof.

<Membrane cleaning solution>
For the purpose of film cleaning using a detergent or a solvent, the cleaning liquid used in the film cleaning is described as the film cleaning liquid.

<Cleaning liquid>
The “cleaning liquid” used in the present invention refers to all liquids added to the stock solution, the circulating fluid, or the internal circulating fluid in the diafiltration operation. That is, the liquid filled in the apparatus before operation is also included in the category of the cleaning liquid, and the liquid supplied for cleaning by diafiltration is the cleaning liquid. Specifically, a liquid containing a target substance such as a permeate, a water-soluble solvent such as water, hot water, cold water, and ethanol water, an organic solvent such as hexane, and the like are supplied from outside the system suitable for the target separation, or Select from liquids supplied from outside the system.
The cleaning liquid may be used as an extraction solvent (extractant). That is, a washing liquid is added as an extract for the purpose of extracting substances contained in the dispersed phase, particularly in the dispersed phase, and the target substance in the stock solution is extracted from the stock solution as a permeate in a form excluding substances blocked by the membrane. A liquid can be obtained.

<Separation membrane>
The “separation membrane” used in the present invention is also referred to as “membrane”, and is a membrane that uses reverse osmosis membrane (RO membrane), nanomembrane (nanofiltration membrane, NF membrane), and ultrafiltration membrane (UF membrane) pressure drive. Point to. These membranes are used by being incorporated in membrane modules or membrane separation devices such as tubular, spiral, hollow fiber, flat membrane, etc., and the liquid to be treated supplied to the membrane separation device is used as permeate and non-permeate (residual or concentrated). Liquid). The membrane module is preferably a tubular membrane that tends to make the concentration distribution on the membrane surface uniform, but a membrane using a pressure drive such as a spiral membrane, a hollow fiber membrane, or a flat membrane can be used. As the material of the film, an organic film, an inorganic film, or a composite film thereof can be used.

<Membrane separator>
The basic configuration of the “membrane separation apparatus” used in the present invention is an appropriately selected separation membrane and its membrane module or assembly of membrane modules. In some cases, including internal circulation pumps, heat exchangers, and pipes connecting them, liquids to be treated, raw solutions, cleaning liquids, dia waters, etc. are supplied to the membrane separator with a pressure booster pump or supplied in advance. It is received in the membrane separator through a flow control valve and pressure control valve. The operating pressure of the membrane separation device is controlled by an appropriately selected pressure adjusting mechanism such as a control valve in the piping for extracting the residual liquid discharged from the membrane module and a control valve in the return piping of the booster pump. In addition, a means for extracting the permeate from the membrane module is provided.

<NF film>
IUPAC (International Pure and Applied Chemistry Association) defines nanofiltration as “a pressure-driven membrane separation process in which particles and polymers with a size of less than 2 nm are blocked.” In the present invention, nanofiltration is performed according to this definition. The membrane is referred to as a nano membrane (nanofiltration membrane, NF membrane). Nanomembranes include nanomembranes used in aqueous systems and hydrophobic nanofilms used exclusively in organic solvent systems.
Examples of NF membranes used in water systems include PCI Membranes AFC80, AFC30, AFC40, Osmonics Desal 5DL, Desal 51HL, Nitto Denko NTR7450, FILMTEC NF-2540, and the like. Examples of membranes mainly used in organic solvent systems include Davison Membranes's STARMEM 120, STARMEM 240, etc. (STARTM is a registered trademark of Davison Membranes).

<UF membrane>
Similarly, IUPAC defines ultrafiltration as “a pressure-driven membrane separation process in which particles and polymers in the range of 0.1 μm to 2 nm are blocked.” In the present invention, a membrane that performs ultrafiltration according to this definition. Is described as an ultrafiltration membrane (UF membrane).
Examples of the UF membrane include CA202, EM006, ES006, ESP04, ES404, PU608, ES209, PU120, FPT03, FPA03, FP100, FPI20, FPA20, FP200, and L6000 manufactured by PCI Membranes.

<RO membrane>
Similarly, IUPAC refers to reverse osmosis as “a liquid-phase pressure-driven separation process in which selective movement of a solvent in the opposite direction to the osmotic pressure difference is caused by pressurization on one side of the membrane.” A membrane that performs osmosis is referred to as a reverse osmosis membrane (RO membrane).
An example of the RO membrane is AFC99 manufactured by PCI Membranes.

<Internal circulation, circulating fluid tank, circulating fluid, residual liquid>
In the present invention, the circulation by the circulation pump from the outlet of the membrane module to the inlet of the membrane module for securing the flow rate at the membrane surface in the membrane module is called “internal circulation”, and the liquid is called the internal circulation liquid.
In addition, when a circulating fluid tank is used in the present invention, a flow that circulates from the circulating fluid tank to the booster pump, the membrane separator, and the circulating fluid tank and the device between them are referred to as a “circulation system” and circulates between them. This liquid is called “circulating liquid”. The internal circulating fluid and the circulating fluid may be collectively referred to as a circulating fluid.
In addition, the above-mentioned circulating liquid was referred to as “residual liquid” when the processing up to a certain point was completed.

<Operation items>
In the present invention, the operation item is an item that directly affects the separation of the target substance by the membrane. Set the item as an operation item in the membrane separation apparatus, and set the separation state index as a setting area or directly set the setting area for the operation item based on the progress indicator, and maintain, change, adjust or adjust the operation item. It is something to control.
Specific operation items include the flow rate of the permeate from the membrane module of the membrane separator, the operating pressure of the membrane separator represented by the outlet or pressure of the circulating fluid from the membrane separator, and the circulating fluid (or the remaining liquid). Liquid) operating temperature, hydrogen ion concentration (pH), circulating fluid concentration and circulating fluid amount serving as a reference for control by supplying cleaning fluid can be selected. The setting range of the operation item can be determined according to the progress of the membrane separation state, the operation state, or the membrane separation operation by the separation state index and the progress progress index.
As an example of usage, a permeate flow rate setting range is provided as an operation item, and the permeate flow rate, which is a separation status index, is operated while operating control is performed so that the operating temperature and circulating fluid concentration (sugar content) are constant. There is a method of controlling the transmission tendency by ensuring within the set range by adjusting the pressure. Similarly, a permeate flow rate setting range is provided as an operation item, and the concentration setting value for circulating fluid concentration control with diafiltration water supply amount control while controlling operation so that the operation temperature and operation pressure are constant. There is a method of achieving the set permeate flow rate by adjusting the. The circulating fluid temperature is the cooling water supply amount, the circulating fluid concentration is the diafiltration fluid supply amount, and the operating pressure can be adjusted by the control valve provided in the circulating fluid or the discharge system.
The permeate flow rate is normally the permeate flow rate obtained per unit time from a membrane in a membrane separation apparatus using the same type of membrane, but some of the flow rates from all the membranes in the membrane separation apparatus are also used. The value from the membrane may be a permeation flux (kg / m 2 / hour) or a permeate flow rate. Here, the setting range does not necessarily define both the upper and lower limits, and may be provided as a target value.

<Separation state index>
In the present invention, the separation state index is an index for quantitatively grasping the separation state of the membrane separation apparatus in operation, and it is an index for maintaining, changing, adjusting or controlling the operation item setting range. is there. Specifically, the measured value or analytical value of the circulating fluid and / or permeate or the permeate accumulated in the container, the sugar content, the density, the light transmittance, the electrical conductivity, the infrared spectroscopic sensor or the analysis device, Alternatively, the differential value based on the progress index of the above measured value or analysis value, that is, the value obtained by numerical processing such as the elapsed time, the permeate liquid amount, the cleaning liquid amount, the differential value, the rate of change, the average value, the integral value, or the circulating fluid Relational indexes such as similar values, ratios of similar values of permeate and circulating fluid, and ratios of these values to values obtained at the previous time point can be used.
As the usage of the separation state index, in the operation of the membrane separator, select the operation item, provide a setting area for the separation state index, and set the corresponding separation state index obtained by measurement or calculation based on the measurement in the setting area It is used for adjustment and control of operation items with the goal of becoming an area.
<Setting range as operation item of permeate flow rate and setting as separation state index>
The permeate flow rate and the permeation flux can be provided with setting areas both as operation items and as separation state indicators. First, when a setting area is provided with the permeate flow rate as an operation item, the measured value can be used as both a separation state index and an operation item. Operate to enter the setting range through adjustment of. In addition, when controlling diafiltration while using measured values and analytical values obtained as separation state indicators for control of operation items other than the permeate flow rate, for example, adjusting the circulating fluid concentration as an operation item, There is a method to control the setting area. That is, the permeate flow rate and permeate flux can be used as one or both of the operation item and the separation state index.

<Progress progress index>
In the present invention, the progress indicator is an indicator for quantitatively grasping the degree of progress of the separation operation by the membrane, or determining the transition from the operation stage to the end or the end. Specifically, quantitative indicators such as time, liquid volume, etc., indicators indicating the results of separation such as residual liquid, permeate liquid, stock solution concentration, ratio of circulating fluid concentration to permeate concentration or sugar content ratio, Physical properties such as viscosity, electrical conductivity, pH, amount of supply liquid such as cleaning liquid, amount of liquid to be treated that changes with the progress of separation operation, measured value, analytical value, calculated value using them, or permeated liquid A measured value, an analytical value, or a calculated value using them can be used. Further, the permeate to be targeted can be the permeate generated at that time or the total or partially accumulated permeate since the start of the separation operation. The setting value of the separation status index corresponding to the value of the progress indicator can be set, and the operation item setting value corresponding to the value of the progress indicator can also be set directly. It can be adjusted or controlled.

また、供給液の濃度に代えて、循環液の濃度を用いて評価することも可能である。 <Passage and blocking rate>
The separation performance of the target substance by the nanomembrane or UF membrane in the membrane separator is the same as that of the supply liquid with the apparent rejection rate Rapp (hereinafter referred to as rejection rate) of each substance and the one-component concentration Cp of the target substance in the permeate. It can be expressed as a passage calculated as a ratio to the component concentration (Cb).
Cp: concentration of one component (g / kg) of the target substance in the permeate,
Cb: Concentration of the same component of the liquid supplied to the module (g / kg)

It is also possible to evaluate using the concentration of the circulating liquid instead of the concentration of the supply liquid.

<Control of transmission tendency>
The passage of one component can be used when the flow rate of permeate increases and the passage becomes smaller and vice versa. The permeate flow rate and permeation flux as the operation items are related to the permeation tendency of each component in the selected separation membrane or membrane separation device, and the passage is changed depending on the operating pressure and operating temperature of the membrane device. The permeate flow rate due to various operation operations can be changed by various operations, and the permeation tendency also changes at the same time. The change can be changed together even with substances having similar transmission tendencies, and the transmission tendency can be controlled by using such an action.
The control of the specific permeation tendency in a batch system can be realized by adjusting the operation pressure to realize a desired permeate flow rate setting range in many cases. The permeation tendency is affected by the state of the membrane, the temperature of the circulating fluid, the circulating fluid concentration, pH, and the circulating fluid volume. The permeate flow rate to be used may not always be the same. Can be quickly controlled by changing the permeate flow rate. Desirably, it is possible to control by grasping the separation state by the separation state index reflecting the composition of the permeate and setting, maintaining, changing, adjusting and controlling the operation items such as the permeate flow rate and the operating pressure and the setting range thereof. Even if the separation state indicator is not used in some cases, appropriate membrane separation can be performed by setting, maintaining, changing, adjusting, and controlling the setting range of the operation item using the progress indicator such as the permeate amount and the elapsed time. .
In addition, the temperature of the circulating fluid varies depending on factors that fluctuate during the operation process, such as heat input from the pump and the temperature of the input fluid, while the items to be controlled are cooling and heating by the heat exchanger. Can adjust the flow rate and composition of the permeate. The permeation tendency can be adjusted and controlled by controlling the temperature and controlling other operating items such as pressure and concentration.
In addition, the composition and pH of the circulating fluid affect the permeate flow rate and the tendency to permeate, and the content concentration in the circulating fluid measured by sugar content, electrical conductivity, etc. directly affects the permeate flow rate. Also, the concentration can be controlled by changing the set amount of the supplied cleaning fluid and circulating fluid, or by adjusting the concentration by adjusting the amount of permeate returned to the circulating fluid, and the pH can be controlled by adding an acidic or alkaline substance. It is also possible to control the pH by adjusting the pH.
The permeation tendency can be controlled by combining these fluctuation factors of the permeation tendency, and preferably by combining the control based on the operating pressure of the permeation flux.

<Measured values related to composition, circulating fluid concentration, concentration of contained substances>
In the present invention, the composition obtained from a sensor such as a refractometer, a saccharimeter, a density meter, a light transmittance measuring device, an electrical conductivity meter, etc. for the stock solution, the circulating fluid at the start of operation, the circulating fluid of the membrane separation device, and the permeate The measured value related to the concentration can be used as an index indicating the state of the circulating fluid or permeate. In particular, in the management of the circulating fluid, such as the concentration of the circulating fluid and the supply amount of the cleaning fluid, it is important to manage the measured values regarding the composition and concentration of the circulating fluid, which is suitable for the operation of the membrane separator. If the concentration is too high, abrupt fouling is likely to occur and the operating time is shortened. If the concentration is low, the effect of diafiltration is reduced. Therefore, measured values such as sugar content, density, refractive index, and electrical conductivity are used for the management of circulating fluids, and those measured values for fluids containing multiple components are not only the total concentration of substances and substance groups. Although it is affected by the composition ratio, temperature, and other complexities, it is not essential that the measured values correspond to the concentrations of actual substances or substance groups. Using these measured values and values based on them, It is important to use it as an index for realizing appropriate circulating fluid volume management and concentration management. In measurement, it is desirable to perform temperature correction, sample temperature management, and the like as necessary.
In the case of using the concentration of the circulating fluid in the meaning of the concentration related to the concentration range suitable for membrane separation, the explanation was made using “total substance concentration”.

<Sugar content, sugar content ratio, concentration>
The “sugar content ratio” used in the present invention refers to [sugar content of permeate] ÷ [sugar content of circulating fluid], and can be used as a separation state index or a progress indicator. That is, for the same circulating fluid, the sugar ratio is large in the operation with a large permeation tendency, and the sugar ratio is small in the operation with a small permeation tendency. it can. This sugar content ratio can also be used as an indicator of the progress of membrane purification by changing the operation stage or ending the operation stage.
Further, the sugar content ratio and the sugar content of the permeate represent changes in permeation tendency. In membrane separation using pressure as a driving force, it is generally considered to occur in conjunction with the rise and fall of the reference substance passage and the rise and fall of other passages. The sugar content or sugar content ratio appears as a change in the concentration of each substance due to a change in the permeation tendency of each substance in the passage, that is, membrane separation, and the concentration of the permeated liquid in the circulating fluid after operation from the circulating fluid at the start of the same concentration is It reflects both the concentration reached by the previous operation and the separation performance up to that point, and can be grasped as a comprehensive index.
The sugar content is measured by the same method as the principle of refractive index measurement, and can be applied to glycerins and glycols in addition to sugar. In addition to sugar content, electrical conductivity, TOC (total organic carbon), and liquid density can also be used as an index to indicate the concentration of circulating fluid or permeate, similar to sugar content, and are important as separate state indicators. It is.

<Indicators for controlling the flow state>
Indicators that integrate changes in density and viscosity, such as the pressure difference between the inlet and outlet of the membrane module, can be used to control or manage the concentration of the circulating fluid. That is, it is possible to control the circulating fluid concentration by using a method such as adding a cleaning solution so that the pressure loss becomes a certain value or less. That is, it is possible to operate in a range where the concentration does not hinder membrane separation by a method such as making pressure loss constant.

<Diafiltration progress>
As the diafiltration progresses, even if the setting area of the operation item is made constant or the setting area of the operation item is changed gradually or step by step, it depends on the separation state of the circulating fluid and permeate. Separation performance can be ensured. Preferably, other operating conditions can be changed as necessary, and the permeate flow rate can be changed in accordance with the separation status index or progress result index.
Further, as the diafiltration progresses, the setting range of the operation item may be made constant, or may be gradually changed to ensure the separation performance according to the separation state of the circulating fluid and permeate.

  Further, the diafiltration can be divided into a plurality of stages, and a setting area for each selected operation item can be set for each stage. In other words, by controlling the end point and start point of each stage by controlling the permeate flow rate, operating pressure, operating temperature setting range, changing the pH by adding chemicals, etc. In addition, by achieving a desired separation state for each stage of membrane separation, the separation results obtained by repeated diafiltration for the separation desired for the entire diafiltration are in line with each separation purpose. .

<Change in the sugar content of the mixture by changing the permeate flow rate>
Assuming that the passage of two types of substances in the starting operating conditions is 0.1 for substance A and 0.0 for substance B, 10% for substance A and 10% for substance B. The liquid at the start of the explanation of the sugar content equivalent) is operated to maintain the total sugar content at 20% while reducing the concentration of the substance A by diafiltration, and the concentration of the substance B gradually increases. Try to get closer to%. Here, the sugar content and the total amount gradually decrease, and the concentration of the substance A approaches 0%.
When the original permeate flow rate is maintained and the concentration of substance A is 1.5% and the passage is 0.1, the sugar content measurement is 0.15% (1.5% x 0.1). If the measurement limit of the sugar content meter is 0.2%, this state cannot be detected. However, if the flow rate of the permeate is lowered and the passage 0.1 is operated at 0.2, the sugar content of the permeate becomes 0.3% (1.5% × 0.2), which can be measured by a saccharimeter. Get into the range. Phenomena based on the above explanations are not limited to cases near the detection limit, such as grasping, confirming, or switching the concentration status of permeate and circulating fluid at appropriate situations such as at the start, end, and stage changes. It can also be used when judging driving.

  In addition, there is a target substance A that easily permeates a large amount of membrane by separation in a multi-component mixed system, and the permeation tendency between substance A and substance B is maintained while retaining substance B that is difficult to permeate the membrane and does not permeate. When the substance C having the above characteristic is to be removed, the permeation tendency is first performed by operating with a low permeation tendency mainly consisting of the permeation of the substance A, and then carrying out the operation of promoting the permeation of the substance B. The retention of the substance C can be realized.

When diafiltration is performed, the separation effect is higher when the volume of the circulating fluid is reduced and the concentration of the target substance is higher. Therefore, for example, by using a saccharimeter and maintaining the concentration of the circulating fluid at an appropriate concentration in the diafiltration stage, the diafiltration can proceed efficiently. It is not always better to set the concentration high, and it is desirable to provide a margin in the set area for operational stability and protection of the membrane surface.
In addition, a large amount of easily permeable substances are contained in the first stage when the raw materials are added, but the concentration of the circulating fluid and internal circulating fluid is controlled only at the stage where the composition change of the circulating fluid is large. For example, management based on the amount of liquid can be performed.

<Separation of polyglycerin mixed solution by nanomembrane and / or ultrafiltration membrane>
The nanomembrane is a membrane in which particles and molecules with a size of less than 2 nm are blocked. For various polyglycerins having a molecular weight of 1000 or less, a membrane that can be handled as separation of easily permeable polyglycerol and difficult to permeate polyglycerol can be selected.
When polyglycerin having a low degree of polymerization is separated on the permeate side and polyglycerin on which polymerization has proceeded further is separated, for example, diglycerin or triglycerin shown in Example 1 is left on the permeate side, and tetraglycerin or more remains. When separation is desired on the liquid side, nano membranes such as AFC30 and AFC40 manufactured by PCI Memranes in the range of nano membranes can be selected. In addition, when polyglycerol having undergone polymerization is a target to be removed, it is possible to use a membrane in the nano membrane range, and a membrane using a membrane in the ultra filtration membrane range can also be selected. For example, by using XP197 manufactured by PCI Membranes, more low molecular components can be obtained on the permeate side, while more polyglycerin having a large molecular weight can be left on the remaining liquid side.
In this case, separation by diafiltration can be used or not, and the degree of separation can be selected for the purpose of separation.
In addition, about polyglycerin which separated low-molecular-weight polyglycerin using nanomembrane, by separating large-molecular-weight polyglycerin using another nanomembrane or ultrafiltration membrane, low molecular weight side and large molecule Polyglycerin from which the side has been removed can be obtained. Here, whether or not to use diafiltration can be selected depending on the molecular weight region of each polyglycerol to be separated from the membrane to be selected, the amount ratio thereof, and whether or not the concentration can be maintained suitable for the separation operation of the operation target liquid. . By this method, it is possible to produce polyglycerin or a polyglycerin mixture having a narrow molecular weight region.
In separating the low molecular weight side and the high molecular weight side, it may be separated first from either side as a separation process.
Separation of the low molecular side and the high molecular side can be performed using different types of NF membranes or ultrafiltration membranes, and the same type of membrane can be operated with different operating pressures, operating concentrations, operating temperatures, etc. Can be used for the same purpose.
The polyglycerin mixture synthesized using an alkali catalyst is initially mixed with an alkali catalyst and folded. By separating the polyglycerin, the alkali catalyst is permeated to the low molecular weight side, thereby using diafiltration. The amount of alkali catalyst on the residual liquid side can be reduced.

  In this example, a polyglycerin mixture that is usually available as decaglycerin as a stock solution, and a polyglycerin mixed liquid containing a highly polymerized product of glycerin, diglycerin, triglycerin and tetraglycerin or higher is used for purification by membrane. It was. Record the sugar content of the permeated liquid from the membrane separation device using nanomembranes, and when the sugar content reaches a predetermined value, lower the operating pressure to lower the permeate flow rate. An example of reduction to about one tenth or less of is shown.

<Undiluted solution>
Raw material composition Moisture 28.7wt%
Polyglycerin total concentration balance
Average degree of polymerization 10mer

<Analysis method>
Remove the water with a concentrator to make a concentrated sample. After preparing an internal standard solution in which a certain amount of pyridine was added to tetradecane, the internal standard solution, hexamethyldisilazane, chloromethylsilane, and chlorotrimethylsilane were added to the concentrated sample, heated, and converted to TMS. Analyzed by gas chromatography. The data on the composition shown in Table 2 is an index obtained from the area ratio in the gas chromatography analysis with respect to the internal standard substance added to the concentrated sample excluding the water.

<Apparatus> Details of the membrane separation apparatus will be described below.
A membrane separator BRO / BUF manufactured by PCI Membranes was used with two AFC30, 1.2 m membrane modules manufactured by the same PCI Membranes. Separately, one AFC80, 1.2m membrane module was also mounted for concentration adjustment.
The pressure gauge was installed between the two AFC30 membrane modules and behind the rear membrane module.
FIG. 1 shows a flow sheet of the membrane separation apparatus.

  The membrane separation apparatus 100 includes a booster pump 4, a heat exchanger 5, a membrane module 6A (AFC80), a pressure gauge 7, a membrane module 6B (AFC30), a membrane module 6C (AFC30), a pressure control valve 9, and a connection pipe connecting them. Consists of. The pressure regulating valve 9 can be circulated from the pressure regulating valve to the circulating fluid tank by circulating fluid piping / hose 10. The circulating fluid can also be charged into another membrane cleaning container or sampling container.

  The cleaning liquid storage tank 13 has a drum can as a container, and three base parts are connected by pipes. Each container is connected to the cleaning liquid pump 14 and the booster pump inlet pipe 3 through valves through valves, and is 40 ° C to 55 ° C. Store warm water. The discharge of the cleaning liquid pump is connected to a hose for supplying cleaning liquid to the circulating liquid tank via a control valve.

  The permeated liquid of the membrane module 6B and the membrane module 6C is automatically measured over time by the balance 2 for the permeated liquid container. Each permeate from the upper permeate nozzles of the membrane module B and the membrane module C can be put into each plastic container via a permeate pipe / hose 16.

  The circulation system during the normal operation of the membrane separation apparatus includes a circulating liquid tank 1, a booster pump inlet pipe 3, a booster pump 4, a heat exchanger 5, a membrane module A 6A, a membrane module B 6B, and a membrane module C 6C. In addition, when circulating hot water, which will be described later, by connecting pipes and hoses connecting them, the circulating liquid tank is changed to a container 11 for circulating hot water film cleaning liquid.

  The control panel 18 adjusts the measured value of the circulating fluid temperature downstream of the pressure control valve 9 to the set value, and maintains the measured value of the weight of the circulating fluid tank 1 at the specified measured value. A circulating fluid temperature adjustment mechanism for controlling the supply of chiller water from the chiller water unit 19, a total weight display mechanism for the permeate, and a permeate flow rate display function for calculating the change in permeate weight over time and the time between them, There is a circulating fluid sugar content display function for displaying the sugar content downstream of the pressure control valve 9.

<Figure 1 Example of batch operation>
An example of batch operation will be described below with reference to FIG.
FIG. 1 is a flow sheet showing the entire apparatus for performing batch diafiltration by one membrane separation apparatus according to the present invention. This device does not use internal circulation. The circulating fluid tank 1 is a container of an arbitrary shape made of metal, synthetic resin or the like, devised as appropriate so that the entire amount of the liquid in the tank can be extracted from the bottom, and the weight, It is desirable that the liquid level and the like can be constantly monitored and appropriate cleaning can be performed. The circulating fluid tank 1 includes a pH meter 8, a thermometer, a circulating fluid concentration measuring function 26, a circulating fluid temperature maintaining mechanism 29, a permeate returning amount adjusting mechanism 30, a stock solution supplying mechanism 21, The circulating fluid extraction mechanism 22, the cleaning fluid supply mechanism 23, and the like can be attached, but these may be connected to or attached to the circulating fluid outlet pipe / hose 10 or the booster pump inlet pipe 3.

  The circulating liquid tank 1 has a receiving liquid mixing function that mixes each received liquid in advance and introduces the liquid into the tank, prevents generation of unnecessary concentration distribution in the tank, prevents sedimentation of solids, or deposits on the wall surface. For the purpose of prevention, a stirring mechanism, a baffle, a vibration mechanism, a showering mechanism, an external circulation pump, a measurement mechanism for managing the circulating fluid concentration such as a saccharimeter and a density meter can be provided. In the circulating liquid tank 1, in order to effectively use the concentration difference between the liquid that stays in the tank for a long time and the liquid that has just been supplied to the tank, the function of dividing the tank, for example, the divided tank A function of moving the liquid in the tank sequentially by connecting the tanks, a function of using a plurality of tanks as the circulating liquid tank 1 as a whole by switching between a tank for sequentially receiving the liquid and a tank for extracting the liquid. Can do.

  In addition, the circulating liquid tank 1 can be provided with measures against leakage of gas in the tank and odor related to the gas phase, such as a gas sealing function, as necessary. The scale 2 for the circulating fluid tank is used to measure the amount of liquid in the circulating fluid tank as a weight. In addition to the circulating fluid tank, the circulating fluid is also present in the membrane separator and piping, but even if it is not possible to always capture the total amount of the circulating fluid itself, such as the total weight, from the point of operational management. As long as the amount of liquid in the circulating liquid tank can be managed.

The booster pump inlet pipe 3 is connected to the circulating liquid tank and the booster pump 4, and can be connected to a warm water film cleaning liquid circulation container 11, a cleaning liquid pump 14, a circulating liquid extraction container 12, a strainer and a filter for protecting the pump. it can.
In addition, the circulating liquid tank 1 has a stirring function, an anti-settling function for solids, a vibration function, a showering function, and an anti-adhesion function for preventing the occurrence of unnecessary concentration distribution in the tank as described above. In order to improve the effect of separation using a membrane, the circulating fluid tank 1 is divided into a plurality of tanks, and these are connected and used, or a plurality of divided portions are used alternately. Thus, the concentration change in the circulating fluid can be advanced step by step.

  The membrane separation device includes a booster pump 4, a pressure gauge 7, a heat exchanger 5, a membrane module A 6A, a membrane module B 6B, a membrane module C 6C, a pressure control valve 9, and a connection pipe. The circulating fluid at the outlet of the pressure control valve 9 can be introduced into the circulating fluid tank through the circulating fluid outlet pipe / hose 10. An AFC 80, which is an RO membrane, can be inserted into the membrane modules A and 6A, and an AFC 30 can be inserted into the membrane modules B 6B and C 6C. Here, AFC30 was used for separation and purification of the target raw material. The AFC 80 is used to adjust the concentration, and with the exception of the adjustment of the circulating fluid concentration and the membrane cleaning, all permeate during normal operation is returned to the circulating fluid tank 1.

  The operating pressure of the membrane module is grasped by an instruction from the pressure gauge 7. The pressure gauge can be installed at a process position from immediately downstream of the booster pump to the pressure control valve, but a measurement position that reflects the pressure before or after the membrane module as much as possible is desirable. When arranging the modules, it is possible to select a position where a representative membrane module can be found, and it is possible to select a position where the pressure of the entire membrane module group can be seen. The same applies when a pressure gauge is attached to the downstream side of the membrane module, and the same applies when a differential pressure gauge upstream and downstream of the membrane module is provided in addition to the pressure gauge.

  Control of the pressure of the membrane module is set by a pressure control valve, but other methods, for example, a method by a pressure control mechanism by a return line from the booster pump outlet to the circulating fluid tank, or rotation of the booster pump by an inverter A method of controlling the number may be employed.

  The installation position of the heat exchanger 5 may be provided downstream of the pressure control valve in addition to the outlet of the booster pump 4 or may be attached to the circulating fluid tank, and preferably has a heating and cooling function. It suffices if the circulating fluid temperature can be controlled within a necessary range only by the function or the heating function. The heat exchanger can also be used for membrane cleaning, sterilization, storage processing, and the like.

  The cleaning liquid storage tank 13 is connected to the liquid supply side of the cleaning liquid pump 14 by a hose and a pipe, and is connected so that the cleaning liquid can be directly supplied to the circulating liquid tank 1 and / or the circulating liquid pipe / hose 10 and the booster pump inlet pipe 3. ing. The supply of the cleaning liquid by the cleaning liquid pump is managed by a method such as maintaining / controlling a predetermined circulating liquid concentration using a control valve or supplying the circulating liquid tank to the circulating liquid tank at a predetermined flow rate. A cleaning method using a detergent or a solvent can be applied to the system such as the membrane separation apparatus 20, the circulating liquid tank 1, and other pipes using the liquid in the cleaning liquid storage tank or a liquid prepared separately, and the membrane cleaning is performed when necessary. The membrane cleaning solution can be used after pretreatment such as heating, cooling, concentration, purification / separation by membrane separation, pH adjustment, chemical addition and the like.

<Operation method and history>
The circulation system of the apparatus was preliminarily filled with about 30 ° C. of 0.5 wt% enzyme detergent (ULTRASIL 53), and the apparatus was circulated and washed, and then replaced with ion-exchanged water. After that, ion-exchanged water heated to about 50 ° C. is prepared in the hot water membrane cleaning liquid circulation container 11, hot water is circulated with the membrane separation device, and the permeated liquid is extracted several times from the drain nozzle outside the system. , Circulating water system (hot water membrane cleaning liquid circulation container, pump inlet piping, boost pump, heat exchanger, membrane module A, membrane module B, membrane module C, pressure control valve, circulation The operation is to circulate both the liquid outlet pipe / hose and the container for circulating the warm water membrane cleaning liquid) and the permeate system (between the membrane modules B and C from the permeate side and between the hose and the warm water membrane cleaning liquid circulation container). It was in the state which can be maintained at 50-53 degreeC.

Separately, a polyglycerin mixed solution containing about 70 wt% water at about 50 ° C. was diluted and stirred with heated ion-exchanged water, and about 50 ° C. and 30 wt% polyglycerin were prepared in a circulating liquid tank.
While extracting a part of the hot water contained in the circulatory membrane separator, it is replaced with the polyglycerin mixture, the circulatory system is replaced with the polyglycerin liquid, and all the permeate is returned to the circulating liquid tank. did.

The operating pressure was initially set to 33 bar, the AFC80 permeate was discharged out of the system, and the circulating fluid concentration once lowered was recovered to about 25%, and then all the AFC80 permeate was returned to the circulating fluid tank 1. The AFC30 permeate was taken out into a 20 liter permeate container. Subsequently, while maintaining the operating temperature at 50 to 53 ° C., the circulating fluid tank is continuously operated so that the sugar content of the circulating fluid is initially maintained at about 25%, and the ion exchange water heated to about 50 ° C. is diafiltered. The permeated liquid from the two AFC30 modules was taken out of the system while being supplied to the circulating liquid tank as the ration water. The module A inlet pressure was adjusted with a manual pressure control valve so that the total flow rate of the permeate was about 30 to 45 kg / hour. On the way, the permeate was sequentially taken out into a 20 liter container. Continued operation with the policy of ensuring that the flow rate of the permeate flow in the downstream module B is at least half the flow rate of the permeate on the upstream module A side. The operation was continued with the policy of securing the total permeate flow rate and the permeate flow rate of module B, that is, the downstream module A, by increasing the operating concentration or decreasing the operating concentration.

Diafiltration was continued while measuring the sugar content of the permeated liquid. When the sugar content of the permeated liquid reached 0.6%, the operating pressure was changed to 22 Bar and the subsequent operation was started.
After entering the latter stage, an operation was carried out to maintain the flow rate of the permeate at about 15 to 25 kg / hour. While the permeate was taken out into a 20 liter container as in the previous stage, the circulating fluid was operated at a sugar content of about 22%.
After the operation was continued in this way, the operation of the membrane separator was stopped when the sugar content of the permeate showed 0.4%, and the water supply of diafiltration was also stopped almost simultaneously. Thereafter, the polyglycerin solution as a residual liquid was extracted from the circulating liquid tank, and 27.3 kg of a polyglycerin liquid corresponding to 22 wt% was obtained from 32.6 kg of the initial 30 wt% polyglycerin liquid. Table 1 summarizes the driving history.
The analysis result of the obtained polyglycerin liquid is shown in sample number C7 in Table 2. Subsequently, the polyglycerin solution in the circulation system with hot water was pushed out of the system from the membrane module by a circulation pump and recovered.

As a result of the above operation, a dry weight of 6.0 kg polyglycerin having an area ratio with respect to the internal standard substance in column C7 in Table 2 from 9.8 kg of polyglycerin as a dry weight contained in 14.8 kg of the raw material. Obtained.
Table 3 tracks changes in the components of each sample using the ratio of the area ratio of the circulating fluid sample to the internal standard substance to the area ratio at the start.
The progress index calculated as the ratio of the cumulative permeate volume to the initial circulating fluid volume shown in Table 3 is 2.1, and glycerin can be reduced to 1/10 or less of the conventional glycerin content. The progress index was reduced to 1/10 at 5.0.
And the recovered product is glycerin less than the measurement range, diglycerin is less than 1/10 of the desired conventional content, triglycerin is less than 1/2 of the conventional content desired initially, The content of tetraglycerin or higher increased.
In the above operation, the permeate flow rate and the permeate sugar content are used as the separation state indicators in the present invention, and the ratio of the permeate amount to the initial circulating fluid amount is used as the progress indicator in the present invention. Also used as. In other words, the permeate flow rate is used as an index for knowing the separation state. First, the permeate flow rate, which is also the separation state index, is measured so that the permeate amount, which is an operation item, is maintained within the range from the setting range 30 to 45 kg / hour. While adjusting the operating pressure, when the sugar content of the permeate, which is the progress indicator, has decreased to 0.6%, the permeate flow rate is changed to a setting range of 15 to 25 kg / hr in the operation item, By adjusting and adjusting the circulating fluid concentration set value, the permeate flow rate as the separation state index was adjusted to the set range, and the separation and purification was stopped when the sugar content of the permeate as the progress indicator reached 0.4%. .
Here, the operation temperature is maintained at 50 to 53 ° C. set in advance, and the operation items are maintained although the operation items are not changed. The circulating fluid concentration is also used as an operation item when the permeate flow rate of the downstream module B is secured to 1/2 or more of the upstream side. In this operation, pH was not used as an operation item. Although the circulating fluid amount is not used as an operation item, the change in the circulating fluid concentration is directly related to the change in the circulating fluid amount, and the meaning as the operation item is similar. That is, increasing the concentration of the circulating fluid means that the amount of circulating fluid is small, and can be applied in the same manner as the circulating fluid concentration.
Here, the permeate flow rate is directly used as an operation item or a separation state index, but only the upstream module is used as an index, the sum of the upstream and downstream sides, or the downstream side can be used. It is also possible to use as the value of the permeation flux divided by the separation membrane area.
Here, although the sugar content value of the circulating fluid varies between 22 and 25%, the difference is not large. Therefore, the sugar content of the permeate is used as the progress indicator or the separation state indicator. The value obtained by dividing by the sugar content of the circulating fluid, that is, the sugar content ratio has an advantage in grasping the state of the circulating fluid and the state of membrane separation.

Next, the system described above will be further described.
FIG. 2 is a diagram illustrating a configuration of a separation system according to another embodiment (first embodiment).
The circulating liquid tank 1 has a receiving liquid mixing function for mixing each received liquid in advance and introducing it into the tank. In addition, the circulating liquid tank 1 can take measures against leakage of gas in the tank and odor related to the gas phase, such as a gas sealing function, as necessary.
The booster pump 4 supplies the liquid put in the circulating liquid tank 1 to the membrane separation device 20.
The membrane separator 20 separates the circulating fluid in the circulating fluid tank 1 supplied by the booster pump 4, supplies the permeated liquid to the subsequent stage, and supplies the circulating liquid that has not been permeated to the circulating fluid tank 1.
The pressure adjustment valve 9 is provided between the membrane separation device 20 and the circulating fluid tank 1 and adjusts the supply pressure of the circulating fluid supplied from the membrane separation device 20 to the circulating fluid tank 1.
The permeate flow meter 100 measures the flow rate of the permeate separated by the membrane separator 20 and flowing out of the membrane separator 20. The pressure gauge 101 measures the operating pressure of the membrane module of the membrane separation device 20. The operating pressure of the membrane separation device 20 is adjusted by the pressure regulating valve 9.

Next, changes in the sugar content of the permeate when the separation system of FIG. 2 is used will be described with reference to FIG. In FIG. 3A, the vertical axis represents the operating pressure, the horizontal axis represents the operating time, and in FIG. 3B, the vertical axis represents the permeated sugar content, and the horizontal axis represents the operating time.
While maintaining the operation pressure at “pressure stage 1” (FIG. 3A), membrane separation is performed until the permeated sugar content target sugar content set value becomes “setting 1” (FIG. 3B). ). When the permeated sugar content reaches the target sugar content setting value 1 (FIG. 3A), after the operating pressure is set to the pressure stage 2 and the operating pressure is switched to the setting 2, the measured value of the permeated sugar content is measured. , Once increases, but then decreases so as to approach the setting value 2 of the target sugar content, and the permeate sugar content reaches the target sugar content setting value 2 or, after reaching the target sugar content, the membrane separation is completed within a certain time. To do.

  Next, another embodiment of the separation system of FIG. 2 will be described. FIG. 4 is a schematic configuration diagram of another embodiment of the separation system of FIG. The separation system in FIG. 4 is obtained by adding a new function to the separation system in FIG. That is, here, the point that the cleaning liquid is supplied to the circulating liquid tank 1 is different. The circulating fluid supply mechanism 23 supplies the circulating fluid to the circulating fluid tank 1. As a timing for adding the cleaning liquid to the circulating liquid tank 1, for example, in a state where no cleaning liquid is added, the circulating liquid stored in the circulating liquid tank 1 is separated, and the remaining amount of the circulating liquid in the circulating liquid tank 1 is a reference. Add when it is less than the amount.

According to the embodiment described above, polyglycerin having a low degree of dispersion could be obtained by removing polyglycerin having a low degree of polycondensation containing glycerin and diglycerin from this polyglycerin by membrane technology. . By using this purified polyglycerol, it has become possible to produce a polyglycerol fatty acid ester having an unprecedented high HLB value. The polyglycerin fatty acid ester thus obtained can be suitably used as a solubilizing agent for foods, cosmetics, pharmaceuticals, etc., an aqueous rinsing agent for tableware, a cleaning agent and the like.
In addition, since the polyglycerol obtained by dehydration condensation of glycerol contains a salt derived from the catalyst and further organic acids, it is commonly used after the reaction to be purified by an ion exchange resin or the like. . Another advantage of using the membrane is that these low-molecular impurities can be removed at the same time by membrane purification.

An example of separation of diglycerin and triglycerin from the stock solution using the decaglycerin mixed solution before the desalting treatment as a stock solution is illustrated.
<Undiluted solution>
Polyglycerin total concentration about 25wt%
Salt 0.28wt%
Moisture balance
Average degree of polymerization 10mer <Analytical method>
Polyglycerin was analyzed in the same manner as in Example 1.
For salt content, ES421 manufactured by Atago Co., Ltd. was used.
<Device>
Using the same apparatus as in Example 1, the separation membrane AFC30 was loaded into the membrane module C and used.
<Operation method and history>
The same method as in Example 1 was performed. A circulation system that returns to the circulation liquid tank is formed via the circulation liquid tank 1, the booster pump 4, the heat exchanger 5, the membrane module 6 </ b> C provided with XP197, and the pressure control valve 9. The temperature was raised to about 50 ° C. by circulating pre-heated ion exchange water in the circulation system. The aqueous solution of the stock solution is preliminarily maintained at 50 ° C. in the circulating liquid tank to make the liquid to be treated. The liquid to be treated in the circulating liquid tank is supplied to the circulation system, the ion exchange water exiting the pressure control valve 9 is discharged out of the system, and the entire circulation system is replaced with the liquid to be treated.
Here, it is preferable to operate the membrane separation apparatus while maintaining the operating temperature at 35 ° C. or higher and lower than 100 ° C. That is, since polyglycerin is sticky, if the separation is performed at a low operating temperature, the separation efficiency is lowered due to the stickiness. Therefore, it is preferable to heat in advance and raise the operating temperature before separation.

<Results>
Table 4 lists the results of Example 2. The data of diglycerin, triglycerin, tetraglycerin, and pentaglycerin described here are indices obtained in the same manner as in Example 1, and removal of diglycerin is the same as in Example 1 by the treatment according to Example 2. At the same time, the salt content was reduced.

An example of separation of a polymer substance using a separation membrane from a decaglycerin mixed solution is illustrated.
<Undiluted solution>
Polyglycerin total concentration about 25wt%
Moisture balance Average polymerization degree Decamer <Analysis method>
Polyglycerin was analyzed in the same manner as in Example 1.

<Device>
The same apparatus as in Example 1 was used, and a PCI membrane XP197 was used as a separation membrane.
<Operation method and history>
After heating the circulatory system with warm water in advance, using the above-mentioned booster pump, the raw polyglycerin aqueous solution containing 16.47 kg of polyglycerin is extruded with 75 kg of permeate 1 and the remaining hot water in the circulatory system. Was separated into 19.8 kg of the remaining liquid 1.
After replacing the circulation system with ion-exchanged water heated to about 50 ° C. in advance, the circulation system was replaced with permeate 1 and separated into 48 kg of permeate 2 and 19.8 kg of residual liquid 2 by membrane separation.
During these operations, contamination of ion exchange water and loss of polyglycerin occur.
Table 6 shows the GPC analysis results of the polyglycerin composition of the stock solution, the permeate 1 and the permeate 2 obtained by the above operation.

２GPC分析結果

<Results>
From the results of GPC analysis, polyglycerin on the polymer side is reduced by the permeation of the membrane in both the first and second permeates. In addition, the effect of reducing the polymer side substance is exerted more by passing through XP197 multiple times.
From these facts, it was found that the substance on the polymer side of polyglycerin can be separated, removed and reduced by permeating once or multiple times through a separation membrane having a significant difference in permeation tendency in the desired molecular weight region. .

2GPC analysis results

It is drawing which shows an example of the flow sheet for performing batch type diafiltration. It is drawing which shows the structure of the separation system in other embodiment (1st Embodiment). It is drawing for demonstrating the change of the permeate sugar content in the separation system of FIG. It is a schematic block diagram in other embodiment of the separation system of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Circulating fluid tank 2 Scale 3 Booster pump inlet piping 4 Booster pump 5 Heat exchanger 6A Membrane module A
6B Membrane module B
6C Membrane module C
7 Pressure gauge 8 pH meter 9 Pressure control valve 10 Circulating fluid outlet piping / hose 11 Hot water membrane cleaning fluid circulation vessel 12 Circulating fluid extraction vessel 13 Cleaning fluid storage tank 14 Cleaning fluid pump 15 Permeating fluid vessel 16 Permeating fluid piping / hose 17 Permeating fluid Drain hose 18 Control panel 19 Chiller water unit 20 Membrane separation device 21 Stock solution supply mechanism 22 Circulating fluid extraction mechanism 23 Cleaning fluid supply mechanism 24 Permeate extraction mechanism 25 Permeate flow rate measurement mechanism 26 Circulating fluid concentration measurement mechanism 27 Circulating fluid concentration maintaining mechanism 28 by control of cleaning liquid supply amount Permeate concentration measuring mechanism 29 Circulating fluid temperature maintaining mechanism 30 Permeate returning amount adjusting mechanism to circulating fluid 31 Predecessor batch storage tank 32 Internal circulation pump 33 Cleaning fluid adjusting valve 51 Stock solution 52 Cleaning solution 53 Permeate 54 Residual liquid 55 Return permeate 100 Permeate flow meter 101 Pressure gauge 130 Flow Regulating valve 135 flow rate control valve 140 the flow rate control valve 145 the pump 150 flow rate control valve

Claims (15)

  A poly using a membrane characterized by separating a mixed liquid containing a plurality of types of polyglycerin components into a liquid having a different content ratio for the polyglycerin component using a nanomembrane and / or ultrafiltration membrane as a separation membrane. Method for separating glycerin.   The method for separating polyglycerin using a membrane according to claim 1, wherein a plurality of types of nanomembranes and / or ultrafiltration membranes having different permeation tendencies are used. The method for separating polyglycerin using a membrane according to claim 1 or 2 , wherein the operation of maintaining the operating temperature of the membrane separation apparatus at 35 ° C or higher and lower than 100 ° C is performed. The separation method measures at least one measurement item selected from the concentration, sugar content, specific gravity, viscosity, and pressure loss of the concentrated liquid and / or permeated liquid produced after membrane separation of the mixed liquid or in the process of membrane separation, The present invention includes a membrane separation operation or diafiltration for supplying a diluting liquid or a cleaning liquid based on those values and controlling a ratio of a permeate and a residual liquid and a supply amount of the diluting liquid or the cleaning liquid. 3. A method for separating polyglycerol using the membrane according to 3 . A target value is set for at least one item selected from the concentration, sugar content, specific gravity, viscosity, and pressure loss of the concentrate and / or permeate, and the corresponding measurement item is measured. Based on these values, batch operation is performed. The membrane separation operation is automatically controlled by controlling the end point of the separation, the ratio of the residual liquid flow rate to the permeate flow rate in the continuous operation, and the supply amount in the case of adding a cleaning liquid or a diluent. A method for separating polyglycerol using the membrane according to 3 or 4 . Mixture containing plural kinds of polyglycerol, the ability to regulate the supply of the diluent or washing liquid, according to any one of claims 3 to 5 which comprises carrying out the membrane separation operation or diafiltration Of separating polyglycerin using the above membrane. Prior to the supply of polyglycerol stock to the membrane separation unit, any one of claims 3 to 6, characterized in that the heating to a range of the temperature 35 ° C. or more but less than 100 ° C. of the membrane separator A method for separating polyglycerol using the membrane described in 1. The concentrate sugar content is measured, the diluent or washing liquid on the basis of the value, any one of claims 3 to 7, characterized in that mixing and supply the added or circulating fluid mixture containing a plurality of types of polyglycerol A method for separating polyglycerol using the membrane according to item 1. Separation operation is performed in diafiltration in which a stock solution containing a plurality of target substances is supplied to a membrane separation apparatus, the target substance is extracted from the permeate obtained from the membrane separation apparatus, and the remaining other target substances are separated into residual liquid. Using the separation status indicator and / or progress indicator, adjust or control at least one operation item selected from the permeate flow rate, the operating pressure of the membrane separator, the operating temperature, the circulating fluid concentration, and the circulating fluid volume within the set range. the method of separating polyglycerol using a membrane according to any one of claims 3 to 8 with a membrane, characterized by controlling the transmission tendency of a target substance by. The method of separating polyglycerol using a membrane according to any one of claims 3 to 9, characterized by using a nano-film and / or UF membrane tubular. The method for separating polyglycerol using the membrane according to any one of claims 3 to 10, wherein the membrane permeates the nano membrane and / or the UF membrane a plurality of times. The method for separating polyglycerol using a membrane according to any one of claims 3 to 11, wherein the mixed solution containing a plurality of types of polyglycerol is a mixed solution containing salts. The mixed liquid containing the plurality of types of polyglycerin components is a polyglycerin mixed liquid produced by a production process including a reaction process under an alkali catalyst using glycerin and / or polyglycerin as a raw material. A method for separating polyglycerol using the membrane according to any one of 3 to 12 . A stock solution containing a plurality of target substances is supplied to a membrane separation apparatus having a nano membrane and / or an ultrafiltration membrane as a separation membrane , and the target substance is extracted from the permeate obtained from the membrane separation apparatus, and the remaining other In a diafiltration facility that separates the target substance into the residual liquid, a container for circulating hot water membrane cleaning liquid that circulates hot water between the membrane separator and warms the membrane separator before membrane separation of the stock solution, and separation operation And a control means for controlling at least one operation item selected from the permeate flow rate, the operating pressure of the membrane separator, the operating temperature, the circulating fluid concentration, and the circulating fluid amount. An apparatus for separating a polyglycerin mixed solution using a membrane characterized by comprising:   A function for setting the operating pressure and / or the permeate flow rate based on at least one of the permeate concentration, the permeate sugar content, the accumulated permeate amount, or the elapsed time, the corresponding circulating fluid concentration, the circulating fluid sugar content, or the circulating fluid flow rate The apparatus for separating a polyglycerin mixed liquid using a membrane according to claim 14, wherein the apparatus is equipped with an adjusting function for supplying a cleaning liquid while adjusting the pressure to perform diafiltration.

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