WO2021060334A1 - Acetoin production method - Google Patents

Acetoin production method Download PDF

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WO2021060334A1
WO2021060334A1 PCT/JP2020/035929 JP2020035929W WO2021060334A1 WO 2021060334 A1 WO2021060334 A1 WO 2021060334A1 JP 2020035929 W JP2020035929 W JP 2020035929W WO 2021060334 A1 WO2021060334 A1 WO 2021060334A1
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acetoin
membrane
nanofiltration membrane
polyamide
producing
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PCT/JP2020/035929
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French (fr)
Japanese (ja)
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塚本大治郎
河村健司
伊藤正照
山田勝成
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東レ株式会社
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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
    • C07C45/78—Separation; Purification; Stabilisation; Use of additives
    • C07C45/786—Separation; Purification; Stabilisation; Use of additives by membrane separation process, e.g. pervaporation, perstraction, reverse osmosis
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/58—Multistep processes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06—Organic material
    • B01D71/56—Polyamides, e.g. polyester-amides
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
    • C07C45/78—Separation; Purification; Stabilisation; Use of additives
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C49/00—Ketones; Ketenes; Dimeric ketenes; Ketonic chelates
    • C07C49/20—Unsaturated compounds containing keto groups bound to acyclic carbon atoms
    • C07C49/24—Unsaturated compounds containing keto groups bound to acyclic carbon atoms containing hydroxy groups

Definitions

  • the present invention relates to a method for producing acetoin by separating acetoin from an acetoin-containing solution. More specifically, the present invention relates to a method for producing acetoin, which comprises a step of removing inorganic salts, sugars, proteins, catalyst components and the like remaining in the acetoin-containing solution by a nanofiltration membrane.
  • Acetoin (3-hydroxy-2-butanone) is a compound with a yogurt and butter-like scent, and is used as a food additive and a raw material for cosmetics.
  • Diacetyl (2,3-butandione) which is a compound similar to acetoin, is used not only as a food additive but also in pharmaceutical production.
  • the mainstream method for producing acetoin is by chemical synthesis, but there are problems such as a decrease in crude oil resources and soaring prices, and since acetoin is a metabolite of microorganisms, biomass is used as a raw material and microorganisms are used. An alternative to the manufacturing method is expected.
  • acetoin As a method for purifying acetoin in the case of producing acetoin using biomass as a raw material using microorganisms or the like, it is considered that a general method for isolating and purifying an ordinary water-soluble neutral substance can be applied. After removing the bacterial cells from the acetoin culture solution, impurities are removed from the culture supernatant by treatment with activated charcoal, ion exchange resin, microfiltration membrane, ultrafiltration membrane, nanofiltration membrane, back-penetration membrane, etc. It is considered that acetoin can be isolated and purified by methods such as distillation, gas stripping, permeation vaporization, extraction with an organic solvent, and recrystallization (Patent Documents 1 to 5). However, since the development of a method for producing acetoin using biomass as a raw material has just begun, a method for purifying acetoin from an acetoin culture solution has not been technically established.
  • an object of the present invention is to solve the above-mentioned problems in purifying acetoin and to find a method for separating and recovering acetoin with high purity and low cost.
  • the present inventor focused on the purification of acetoin using a nanofiltration membrane or a reverse osmosis membrane.
  • the permeability of nanofiltration membranes and reverse osmosis membranes of substances cannot be predicted simply by the relationship between the molecular weight of substances and the fractional molecular weights of these separation membranes, and the permeability of nanofiltration membranes and reverse osmosis membranes of acetoin.
  • the present inventor has found a process capable of obtaining high-purity and high-concentration acetoin by using these separation membranes, and has completed the present invention.
  • the present invention is composed of the following (1) to (7).
  • a method for producing acetoin which comprises step A of filtering the acetoin-containing solution through a nanofiltration membrane and recovering the acetoin-containing solution from the permeation side.
  • R represents -H or -CH 3
  • n represents an integer from 0 to 3.
  • step B The method for producing acetoin according to any one of (1) to (4), which comprises step B in which the acetoin-containing solution obtained in step A is passed through a reverse osmosis membrane to increase the acetoin concentration.
  • the permeate recovered from the step A or the concentrated solution recovered from the step B is further subjected to a step C of distilling at 25 ° C. or higher and 200 ° C. or lower under a pressure of 1 Pa or more and atmospheric pressure or less.
  • An acetoin composition derived from an acetoin-containing microbial culture solution and having an acetoin weight purity of 80% or more.
  • metal catalysts, inorganic salts, and sugars present in a chemical synthesis reaction solution containing acetoin or a fermentation culture solution can be removed by a simple operation to improve the recovery rate and reduce the cost, so that acetoin can be highly purified. It can be manufactured at low cost.
  • the acetoin production method of the present invention is a method for producing acetoin by separating acetoin from an acetoin-containing solution, and is a step of passing the acetoin-containing solution through a nanofiltration membrane to remove a metal catalyst, an inorganic salt, a saccharide, or the like.
  • the present invention relates to a method for producing acetoin, including.
  • the acetoin that can be produced in the present invention is an organic compound also called 3-hydroxy-2-butanone, acetylmethylcarbinol, or dimethyl kettle.
  • the method for producing the acetin-containing solution used in the present invention is not particularly limited as long as it is a method known to those skilled in the art, and when a chemical synthesis method is used, a method for synthesizing by partial reduction of diacetyl or double addition reaction of acetaldehyde. and so on.
  • acetoin can be produced by culturing a microorganism capable of producing acetoin in the presence of carbon sources such as sugars, cellulose, hemicellulose, lignin, and decomposition products thereof.
  • the microorganism having an acetoin-producing ability may be one having an ability to produce acetoin from the beginning, or one having a production ability given by breeding, mutation treatment, gene recombination treatment, or the like.
  • the type of bacterium is not particularly limited, but is limited to coryneform bacteria, Escherichia coli, Bacillus bacterium, Geobacillus bacterium, Lactobacillus bacterium, Lactococcus genus bacterium, Staphylococcus. ) Bacteria, Klebsiella bacteria, Streptococcus bacteria, Zymomonas bacteria, filamentous fungi, yeasts and the like.
  • the preferred method for producing the acetoin-containing solution used in the present invention is a fermentation culture method for microorganisms, in which case the fermentation culture solution containing acetoin itself can be used as an acetoin-containing solution to be applied to a nanofilter membrane.
  • the nanofiltration membrane used in the present invention is also called a nanofiltration membrane or an NF membrane, and is a membrane generally defined as "a membrane that allows monovalent ions to permeate and blocks divalent ions". .. It is a membrane that is considered to have microvoids of several nanometers, and is mainly used to block fine particles, molecules, ions, salts, etc. in water.
  • passing through the nanofiltration membrane means that the acetoin-containing solution is filtered through the nanofiltration membrane, impurities other than acetoin are removed to the non-permeate side, and the acetoin-containing solution is recovered from the permeate side. Means.
  • cellulose acetate-based polymers polyamides, polyesters, polyimides, vinyl polymers such as polyvinyl alcohol, and polymer materials such as polysulfone are known as materials for nanofilter membranes, and can be used in the present invention.
  • a nanofiltration membrane having a polyamide as a functional layer is preferably used because of its high purification effect.
  • the functional layer may be a film containing a plurality of other film materials.
  • the membrane structure is formed on an asymmetric membrane having a dense layer on at least one surface of the membrane and having fine pores having a gradually larger pore diameter from the dense layer toward the inside of the membrane or the other surface, or on the dense layer of the asymmetric membrane.
  • a composite membrane for example, a composite membrane described in Japanese Patent Application Laid-Open No. 62-201606 in which a nanofiltration membrane made of a functional layer of polyamide is formed on a support membrane using polysulfone as a membrane material can be used.
  • the nanofiltration membrane having a polyamide functional layer preferably used in the present invention is preferably a composite membrane having high pressure resistance, high water permeability, and high solute removal performance. Further, in order to maintain durability against operating pressure, high water permeability, and blocking performance, a structure in which polyamide is used as a functional layer and the polyamide is held by a support made of a porous film or a non-woven fabric is preferable.
  • preferable carboxylic acid components of the monomer constituting polyamide include, for example, trimesic acid, benzophenone tetracarboxylic acid, trimellitic acid, pyrrometic acid, isophthalic acid, terephthalic acid, and naphthalene.
  • Aromatic carboxylic acids such as dicarboxylic acid, diphenylcarboxylic acid, and pyridinecarboxylic acid can be mentioned, but trimesic acid, isophthalic acid, terephthalic acid, or a mixture thereof is more preferable in consideration of solubility in a film-forming solvent.
  • Preferred amine components of the monomer constituting the polyamide include m-phenylenediamine, p-phenylenediamine, benzidine, methylenebisdianiline, 4,4'-diaminobiphenyl ether, dianisidine, 3,3', 4-.
  • Triaminobiphenyl ether 3,3', 4,4'-tetraaminobiphenyl ether, 3,3'-dioxybenzidine, 1,8-naphthalenediamine, m (p) -monomethylphenylenediamine, 3,3'- Monomethylamino-4,4'-diaminobiphenyl ether, 4,N, N'-(4-aminobenzoyl) -p (m) -phenylenediamine-2,2'-bis (4-aminophenylbenzoimidazole), 2 , 2'-bis (4-aminophenylbenzoxazole), 2,2'-bis (4-aminophenylbenzothiazole) and other primary diamines with aromatic rings, piperazine, piperidine or derivatives thereof and the like.
  • a nanofiltration membrane having a crosslinked polyamide containing piperazine or piperidine as a monomer as a functional layer is preferably used because it has heat resistance and chemical resistance in addition to pressure resistance and durability.
  • a nanofiltration membrane containing the crosslinked piperazine polyamide or the crosslinked piperazine polyamide as a main component is more preferable, and the crosslinked piperazine polyamide or the crosslinked piperazine polyamide is a main component and contains the constituent component represented by the chemical formula 1.
  • nanofiltration membrane containing the crosslinked piperazine polyamide as a main component and the polyamide containing the constituent component represented by the chemical formula (1) as a functional layer examples include those described in JP-A-62-201606. Specific examples thereof include UTC60, which is a crosslinked piperazine polyamide-based nanofiltration membrane manufactured by Toray Industries, Inc.
  • the nanofiltration membrane is generally used as a spiral type membrane element, but the nanofiltration membrane used in the present invention can also be preferably used as a spiral type membrane element.
  • a preferable nanofiltration membrane for example, UTC60 manufactured by Toray Industries, Inc., which contains a crosslinked piperazine polyamide as a main component and a polyamide containing a constituent component represented by the chemical formula (1) as a functional layer, was used.
  • the company's nanofilter modules SU-210, SU-220, SU-600, and SU-610 can also be used.
  • the acetoin-containing solution may be filtered by a nanofiltration membrane under pressure. If the filtration pressure is lower than 0.1 MPa, the membrane permeation rate decreases, and if it is higher than 8 MPa, it affects the damage to the membrane. Therefore, it is preferably used in the range of 0.1 MPa or more and 8 MPa or less, but 0.5 MPa or more and 7 MPa. When used below, it is more preferable to use it at 1 MPa or more and 6 MPa or less because it has a high membrane permeation flux and can efficiently permeate acetoin and is less likely to affect the damage to the membrane. preferable.
  • the filtration of the acetoin-containing solution with the nanofiltration membrane can improve the recovery rate of acetoin by returning the non-permeated solution to raw water and filtering repeatedly.
  • the recovery rate of acetoin can be calculated by Equation 1 by measuring the total amount of acetoin before nanofiltration and the total amount of acetoin permeated through the nanofiltration membrane.
  • Acetoin recovery rate (%) (total amount of acetoin permeated through nanofiltration membrane / total amount of acetoin before nanofiltration) x 100 ... (Equation 1).
  • the membrane separation performance of the nanofiltration membrane used in the present invention is such that the salt removal rate is 45% or more when an aqueous sodium chloride solution (500 mg / L) adjusted to a temperature of 25 ° C. and a pH of 6.5 is evaluated at a filtration pressure of 0.75 MPa. Is preferably used.
  • the salt removal rate referred to here can be calculated by Equation 2 by measuring the permeate salt concentration of the sodium chloride aqueous solution.
  • Salt removal rate 100 x ⁇ 1- (salt concentration in permeate / salt concentration in feed water) ⁇ ... (Equation 2).
  • the membrane permeation flux (m 3 / (m 2 days)) of the sodium chloride aqueous solution (500 mg / L) is 0.3 or more at a filtration pressure of 0.3 MPa. Is preferably used.
  • the membrane permeation flux can be calculated by Equation 3 by measuring the permeated liquid amount, the time at which the permeated liquid amount is sampled, and the membrane area.
  • the impurities separated from the acetoin-containing solution to the non-permeate side by the nanofiltration membrane include inorganic substances such as calcium, sodium, sulfuric acid, nitric acid and phosphoric acid, glucose, fructose, xylose, sucrose, galactose and starch. Examples thereof include sugars and proteins, and even a mixture thereof is preferably separated.
  • the nanofiltration membrane permeability of acetoin in the present invention can be evaluated by calculating the acetoin transmittance.
  • the transmittance of acetoin is contained in the acetoin concentration (raw acetoin concentration) and the permeate (acetoin solution) contained in raw water (solution containing acetoin) by analysis typified by high-speed liquid chromatography and gas chromatography. It can be calculated by Equation 4 by measuring the acetoin concentration (permeate acetoin concentration).
  • Acetine transmittance (%) (permeate acetoin concentration / raw water acetoin concentration) x 100 ... (Equation 4).
  • the nanofiltration membrane permeate is preferably concentrated when the concentration of the target substance is low.
  • a method for concentrating the nanofiltration membrane permeate a method for removing water using a general concentrator typified by an evaporator or a zeolite membrane can be applied in the present invention, but the heat capacity of water is higher than that of an organic solvent. Because it is much larger, the energy and time required for enrichment is enormous.
  • concentration by a reverse osmosis membrane is superior to concentration by an evaporator from the viewpoint of energy cost reduction, and is preferably applied in the present invention.
  • the reverse osmosis membrane in the present invention is a filtration membrane that removes ions and low molecular weight molecules by using a pressure difference equal to or higher than the osmotic pressure of the water to be treated as a driving force.
  • a membrane obtained by polycondensing a polyfunctional acid halide and providing a polyamide separation functional layer on a microporous support membrane can be adopted.
  • an aqueous solution of a compound having at least one reactive group that reacts with an acid halide group is coated on the surface of the polyamide separation functional layer and remains on the surface of the separation functional layer.
  • a low fouling back-penetration film mainly for sewage treatment in which a covalent bond is formed between the acid halide group and the reactive group is also preferably adopted. Since most of the divalent ions can be removed in the step of filtering through the nanofiltration membrane of the present invention, stable membrane concentration can be performed without the formation of scale on the reverse osmosis membrane surface.
  • passing through the reverse osmosis membrane means that the acetoin-containing solution that has permeated the nanofiltration membrane is concentrated through the reverse osmosis membrane, and the solution containing acetoin on the concentrated solution side (non-permeating solution side) is recovered. Means to do.
  • a composite membrane having a cellulose acetate-based polymer as a functional layer (hereinafter, also referred to as a cellulose acetate-based reverse osmosis membrane) or a composite membrane having a polyamide as a functional layer (hereinafter, referred to as a functional layer).
  • a functional layer a composite membrane having a polyamide as a functional layer
  • a polyamide-based reverse osmosis membrane examples of the cellulose acetate-based polymer include those using organic acid esters of cellulose such as cellulose acetate, cellulose diacetate, cellulose triacetate, cellulose propionate, and cellulose butyrate alone or a mixture thereof, and mixed esters. Be done.
  • polyamide examples include linear polymers or crosslinked polymers using aliphatic and / or aromatic diamines as monomers.
  • the membrane morphology an appropriate morphology such as a flat membrane type, a spiral type, and a hollow fiber type can be used.
  • reverse osmosis membrane used in the present invention include, for example, low-pressure type SU-710, SU-720, SU-720F, and SU-710L which are polyamide-based reverse osmosis membrane modules manufactured by Toray Industries, Inc.
  • SU-720L, SU-720LF, SU-720R, SU-710P, SU-720P, high-pressure type SU-810, SU-820, SU-820L, SU-820FA which includes UTC70 as a reverse osmosis membrane Cellulose acetate reverse osmosis membrane SC-L100R, SC-L200R, SC-1100, SC-1200, SC-2100, SC-2200, SC-3100, SC-3200, SC-8100, SC-8200, Nitto Denko Co., Ltd.
  • the nanofiltration membrane permeate is filtered by a reverse osmosis membrane under pressure. If the filtration pressure is lower than 1 MPa, the membrane permeation rate decreases, and if it is higher than 8 MPa, it affects the damage to the membrane. Therefore, it is preferably in the range of 1 MPa or more and 8 MPa or less. Further, when the filtration pressure is in the range of 1 MPa or more and 7 MPa or less, the membrane permeation flux is high, so that the acetoin solution can be efficiently concentrated. Most preferably, it is in the range of 2 MPa or more and 6 MPa or less because it is unlikely to affect the damage of the film.
  • high-purity acetoin can be obtained by subjecting the nanofiltration membrane permeate to the step C of distillation.
  • the distillation step is preferably carried out under a reduced pressure of 1 Pa or more and atmospheric pressure (normal pressure, about 101 kPa) or less, and more preferably 100 Pa or more and 15 kPa or less.
  • the distillation temperature is preferably 20 ° C. or higher and 200 ° C. or lower, and more preferably 50 ° C. or higher and 150 ° C. or lower.
  • the present invention can increase the purity of acetoin in an acetoin composition derived from an acetoin-containing microbial culture solution.
  • an acetoin composition having a weight purity of 80% or more, preferably 90% or more, more preferably 95% or more can be obtained from a microbial culture solution containing acetoin.
  • a high-purity acetoin composition has been produced by chemical synthesis using crude oil as a raw material, but according to the present invention, a high-purity acetoin composition can also be produced from an acetoin-containing microbial culture solution obtained from a biomass raw material. become able to.
  • the high-purity acetoin composition derived from a biomass raw material is suitable for food additive applications and cosmetic applications from the viewpoint of safety.
  • GC analysis conditions GC equipment: GC2010 plus (manufactured by Shimadzu Corporation) Column: Rt- ⁇ -DEX, length 30 m, inner diameter 0.32 mm (manufactured by RESTEK) Carrier gas: helium, constant linear velocity (35.0 cm / sec) Vaporization chamber temperature: 250 ° C Detector temperature: 250 ° C Column oven temperature: constant at 75 ° C (18 minutes) Detector: FID.
  • Example 1 Purification of acetoin from a model culture solution using a nanofiltration membrane 200 L of the acetoin model culture solution prepared in Reference Example 1 was injected into the raw water tank 1 of the membrane filtration device shown in FIG.
  • a crosslinked piperazine polyamide-based nanofiltration membrane “UTC60” nanofiltration membrane 1; manufactured by Toray Co., Ltd.
  • the pressure of the high pressure pump 3 was adjusted to 2 MPa at 10 ° C., and the permeate 4 at each pressure was recovered.
  • the acetoin concentration contained in the raw water tank 1 and the permeate 4 was analyzed by GC, and the acetoin transmittance was calculated. The results are shown in Table 2.
  • 10 L of permeate was recovered, then 10 L of distilled water was added, and the permeate was recovered again 7 times. As a result, acetoin was recovered. The recovery rate was 77%.
  • 100 L of the acetoin-containing solution obtained from the permeation side of the nanofiltration membrane was placed in the raw water tank 1 of the membrane filtration apparatus shown in FIG.
  • a 90 ⁇ reverse osmosis film of reference numeral 7 in FIG. 2 a polyamide reverse osmosis film (UTC-70, manufactured by Toray Co., Ltd.) is attached to a stainless steel (SUS316) cell, the pressure of the high pressure pump 3 is 5 MPa, and the raw water temperature is 20. The temperature was adjusted to ° C. and membrane filtration was performed to remove 90 L of reverse osmosis membrane permeated water 4. The permeated water did not contain acetoin.
  • Example 2 Acetin was purified in the same manner as in Example 1 except that the cellulose acetate-based nanofiltration membrane "GEsepa” (nanofiltration membrane 2; manufactured by GE Osmonics) was used instead of the crosslinked piperazine polyamide-based nanofiltration membrane "UTC60". .. The results are shown in Tables 2 and 3.
  • GEsepa nanofiltration membrane 2; manufactured by GE Osmonics
  • Example 1 Acetoin was purified in the same manner as in Example 1 except that the nanofiltration membrane treatment was not performed. At this time, not only clogging occurred when concentrating with the reverse osmosis membrane, but also many precipitates were generated when concentrating with the rotary evaporator. In the vacuum distillation, it took more time to distill acetoin as compared with Example 1.
  • 1,3-propanediol had a membrane permeability of 35% in the nanofiltration membrane 1 which was lower than that of acetoin. That is, although the molecular weight of 1,3-propanediol and the acetoin shown in Example 1 is smaller than that of 1,3-propanediol, the nanofiltration membrane permeability of acetoin is significantly higher than that of acetoin. It was shown that the compound is more suitable for purification of nanofiltration membranes.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
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Abstract

In the present invention, high-purity acetoin can be separated and recovered at a low cost, through a step A in which an acetoin-containing solution is filtered through a nanofiltration membrane, and the acetoin-containing solution is recovered from the permeation side of the membrane.

Description

アセトインの製造方法Acetoin manufacturing method
　本発明は、アセトイン含有溶液からアセトインを分離することによるアセトインの製造方法に関する。詳しくは、アセトイン含有溶液中に残存している無機塩、糖、タンパク質類または触媒成分などをナノろ過膜によって除去する工程を含むアセトインの製造方法に関する。 The present invention relates to a method for producing acetoin by separating acetoin from an acetoin-containing solution. More specifically, the present invention relates to a method for producing acetoin, which comprises a step of removing inorganic salts, sugars, proteins, catalyst components and the like remaining in the acetoin-containing solution by a nanofiltration membrane.
　アセトイン（３－ヒドロキシ－２－ブタノン）は、ヨーグルト、バター様の香りを持つ化合物であり、食品添加物、化粧品原料として使用される。またアセトインに類似する化合物であるジアセチル（２，３－ブタンジオン）は、食品添加物として用いられるのみならず、医薬品製造においても利用されている。アセトインの製造法は化学合成による製造が主流であるが、原油資源の減少や価格高騰の問題があること、また、アセトインは微生物の代謝産物であることから、バイオマスを原料として微生物等を用いて製造する方法への代替が期待されている。 Acetoin (3-hydroxy-2-butanone) is a compound with a yogurt and butter-like scent, and is used as a food additive and a raw material for cosmetics. Diacetyl (2,3-butandione), which is a compound similar to acetoin, is used not only as a food additive but also in pharmaceutical production. The mainstream method for producing acetoin is by chemical synthesis, but there are problems such as a decrease in crude oil resources and soaring prices, and since acetoin is a metabolite of microorganisms, biomass is used as a raw material and microorganisms are used. An alternative to the manufacturing method is expected.
　バイオマスを原料として微生物等を用いてアセトインを製造する場合、通常、酢酸や乳酸などの他の代謝産物と一緒に生成されるためにアセトインの分離精製が困難であると考えられてきたため、近年は製造対象物としてのアセトインの選択性を高める微生物の開発が進められており（特許文献１および２）、これら微生物を用いたアセトインの製造法の実用化が現実味を帯びてきている。 When acetoin is produced from biomass as a raw material using microorganisms, it has been considered difficult to separate and purify acetoin because it is usually produced together with other metabolites such as acetic acid and lactic acid. The development of microorganisms that enhance the selectivity of acetoin as a production target is underway (Patent Documents 1 and 2), and the practical application of a method for producing acetoin using these microorganisms has become a reality.
　バイオマスを原料として微生物等を用いてアセトインを製造する場合のアセトインの精製方法としては、通常の水溶性中性物質を単離精製する一般的な方法を応用することができると考えられ、具体的には、アセトイン培養液から菌体を除去した後、培養上清液について活性炭、イオン交換樹脂、精密ろ過膜、限外ろ過膜、ナノろ過膜、逆浸透膜等の処理で不純物を除去した後に、蒸留、ガスストリッピング、浸透気化法、有機溶媒による抽出、再結晶等の方法によりアセトインを単離・精製することができると考えられる（特許文献１～５）。また、しかしながら、バイオマスを原料とするアセトインの製造法の開発は始まったばかりであることもあり、アセトイン培養液からアセトインを精製する方法は技術的に確立していない。 As a method for purifying acetoin in the case of producing acetoin using biomass as a raw material using microorganisms or the like, it is considered that a general method for isolating and purifying an ordinary water-soluble neutral substance can be applied. After removing the bacterial cells from the acetoin culture solution, impurities are removed from the culture supernatant by treatment with activated charcoal, ion exchange resin, microfiltration membrane, ultrafiltration membrane, nanofiltration membrane, back-penetration membrane, etc. It is considered that acetoin can be isolated and purified by methods such as distillation, gas stripping, permeation vaporization, extraction with an organic solvent, and recrystallization (Patent Documents 1 to 5). However, since the development of a method for producing acetoin using biomass as a raw material has just begun, a method for purifying acetoin from an acetoin culture solution has not been technically established.
特開２０１２－１０５５８２号公報Japanese Unexamined Patent Publication No. 2012-105582 特表２０１７－５２５３８８号公報Special Table 2017-525388 特開２０１５－２２７２９８号公報Japanese Unexamined Patent Publication No. 2015-227298 特表２００８－５００８２３号公報Japanese Patent Publication No. 2008-500823 特表２０１３－５１８０８１号公報Japanese Patent Application Laid-Open No. 2013-51881
　アルコール培養液を蒸留する場合は、培養液中に残存する糖類やアミノ酸の他、有機酸などの副代謝産物などを加熱することで副生成物が発生し、蒸留留分中に不純物として混入することが問題となるため、アルコール蒸留に先だってこれらの不純物を除去する必要があるが、本発明者はアセトインの場合にも同様の課題があることを見いだした。 When distilling an alcohol culture solution, by heating sugars and amino acids remaining in the culture solution, as well as by-metabolites such as organic acids, by-products are generated and mixed as impurities in the distilled fraction. Since this is a problem, it is necessary to remove these impurities prior to alcohol distillation, but the present inventor has found that there is a similar problem in the case of acetoin.
　そこで本発明では、アセトインを精製する場合における前述の課題を解決し、アセトインを高純度・低コストで分離・回収する方法を見いだすことを目的とする。 Therefore, an object of the present invention is to solve the above-mentioned problems in purifying acetoin and to find a method for separating and recovering acetoin with high purity and low cost.
　本発明者は、上記課題を解決するため鋭意研究を行った結果、ナノろ過膜や逆浸透膜によるアセトインの精製に着目した。物質のナノろ過膜や逆浸透膜の透過性は単純に物質の分子量とこれら分離膜の分画分子量の関係だけで予想できるものではなく、また、アセトインのナノろ過膜や逆浸透膜の透過性はこれまでに知られていなかったが、本発明者はこれら分離膜を利用することによって高純度・高濃度のアセトインを得ることができるプロセスを見いだし、本発明を完成するに至った。 As a result of diligent research to solve the above problems, the present inventor focused on the purification of acetoin using a nanofiltration membrane or a reverse osmosis membrane. The permeability of nanofiltration membranes and reverse osmosis membranes of substances cannot be predicted simply by the relationship between the molecular weight of substances and the fractional molecular weights of these separation membranes, and the permeability of nanofiltration membranes and reverse osmosis membranes of acetoin. Although not known so far, the present inventor has found a process capable of obtaining high-purity and high-concentration acetoin by using these separation membranes, and has completed the present invention.
　すなわち、本発明は以下の（１）～（７）から構成される。 That is, the present invention is composed of the following (1) to (7).
　（１）アセトイン含有溶液をナノろ過膜に通じて濾過し、透過側からアセトイン含有溶液を回収する工程Ａを含む、アセトインの製造方法。 (1) A method for producing acetoin, which comprises step A of filtering the acetoin-containing solution through a nanofiltration membrane and recovering the acetoin-containing solution from the permeation side.
　（２）前記ナノろ過膜に通じて濾過するアセトイン含有溶液が、微生物発酵によって得られる培養液である（１）に記載のアセトインの製造方法。 (2) The method for producing acetoin according to (1), wherein the acetoin-containing solution filtered through the nanofiltration membrane is a culture solution obtained by microbial fermentation.
　（３）前記ナノろ過膜の機能層がポリアミドを含む、（１）または（２）に記載のアセトインの製造方法。 (3) The method for producing acetoin according to (1) or (2), wherein the functional layer of the nanofiltration membrane contains polyamide.
　（４）前記ポリアミドが架橋ピペラジンポリアミドを主成分とし、かつ、化学式１で示される構成成分を含有することを特徴とする（３）に記載のアセトインの製造方法。 (4) The method for producing acetoin according to (3), wherein the polyamide contains a crosslinked piperazine polyamide as a main component and contains a constituent component represented by the chemical formula 1.
Figure JPOXMLDOC01-appb-C000002
Figure JPOXMLDOC01-appb-C000002
（式中、Ｒは－Ｈまたは－ＣＨ３、ｎは０から３までの整数を表す。）。 (In the formula, R represents -H or -CH 3 , and n represents an integer from 0 to 3.).
　（５）前記工程Ａより得られたアセトイン含有溶液を逆浸透膜に通じてアセトイン濃度を高める工程Ｂを含む、（１）～（４）のいずれかに記載のアセトインの製造方法。 (5) The method for producing acetoin according to any one of (1) to (4), which comprises step B in which the acetoin-containing solution obtained in step A is passed through a reverse osmosis membrane to increase the acetoin concentration.
　（６）前記工程Ａから回収された透過液、または前記工程Ｂから回収された濃縮液を、さらに１Ｐａ以上大気圧以下の圧力下において、２５℃以上２００℃以下で蒸留する工程Ｃに供する、（１）～（５）のいずれかに記載のアセトインの製造方法。 (6) The permeate recovered from the step A or the concentrated solution recovered from the step B is further subjected to a step C of distilling at 25 ° C. or higher and 200 ° C. or lower under a pressure of 1 Pa or more and atmospheric pressure or less. The method for producing acetoin according to any one of (1) to (5).
　（７）アセトイン含有微生物培養液由来であり、アセトイン重量純度が８０％以上であるアセトイン組成物。 (7) An acetoin composition derived from an acetoin-containing microbial culture solution and having an acetoin weight purity of 80% or more.
　本発明によって、アセトインを含む化学合成反応液または発酵培養液中に存在する金属触媒または無機塩、糖類を簡単な操作により除去し、回収率の向上とコスト削減ができるため、アセトインを高純度かつ低コストに製造することができる。 According to the present invention, metal catalysts, inorganic salts, and sugars present in a chemical synthesis reaction solution containing acetoin or a fermentation culture solution can be removed by a simple operation to improve the recovery rate and reduce the cost, so that acetoin can be highly purified. It can be manufactured at low cost.
本発明で用いたナノろ過膜および逆浸透膜分離装置の一つの実施の形態を示す概要図である。It is a schematic diagram which shows one Embodiment of the nanofiltration membrane and the reverse osmosis membrane separation apparatus used in this invention. 本発明で用いたナノろ過膜および逆浸透膜分離装置の逆浸透膜が装着されたセル断面図の一つの実施の形態を示す概要図である。It is a schematic diagram which shows one Embodiment of the cell sectional view which attached the nanofiltration membrane and the reverse osmosis membrane of the reverse osmosis membrane separator used in this invention.
　以下、本発明をより詳細に説明する。 Hereinafter, the present invention will be described in more detail.
　本発明のアセトイン製造方法は、アセトイン含有溶液よりアセトインを分離することによるアセトインの製造方法であって、該アセトイン含有溶液をナノろ過膜に通じて、金属触媒または無機塩・糖類などを除去する工程を含む、アセトインの製造方法に関する。 The acetoin production method of the present invention is a method for producing acetoin by separating acetoin from an acetoin-containing solution, and is a step of passing the acetoin-containing solution through a nanofiltration membrane to remove a metal catalyst, an inorganic salt, a saccharide, or the like. The present invention relates to a method for producing acetoin, including.
　本発明で製造できるアセトインは、３－ヒドロキシ－２－ブタノン、アセチルメチルカルビノール、ジメチルケトルとも呼ばれる有機化合物である。 The acetoin that can be produced in the present invention is an organic compound also called 3-hydroxy-2-butanone, acetylmethylcarbinol, or dimethyl kettle.
　本発明に用いられるアセトイン含有溶液の製造方法としては、当業者に公知の方法であれば特に制限はなく、化学合成法を用いる場合はジアセチルの部分還元、アセトアルデヒドの２分子付加反応によって合成する方法などがある。また、糖類、セルロース、ヘミセルロース、リグニン、これらの分解物などの炭素源存在下で、アセトイン産生能を有する微生物を培養することによってアセトインを生産することができる。 The method for producing the acetin-containing solution used in the present invention is not particularly limited as long as it is a method known to those skilled in the art, and when a chemical synthesis method is used, a method for synthesizing by partial reduction of diacetyl or double addition reaction of acetaldehyde. and so on. In addition, acetoin can be produced by culturing a microorganism capable of producing acetoin in the presence of carbon sources such as sugars, cellulose, hemicellulose, lignin, and decomposition products thereof.
　アセトイン産生能を有する微生物は、当初よりアセトインを生産する能力を持つものであっても、育種、変異処理、遺伝子組換え処理等により生産能力を付与されたものであってもよい。微生物の種類は、特に制限されないが、コリネ型細菌、大腸菌、バチルス（Ｂａｃｉｌｌｕｓ）属細菌、ジオバチルス（Ｇｅｏｂａｃｉｌｌｕｓ）属細菌、ラクトバシラス（Ｌａｃｔｏｂａｃｉｌｌｕｓ）属細菌、ラクトコッカス（Ｌａｃｔｏｃｏｃｃｕｓ）属細菌、スタフィロコッカス（Ｓｔａｐｈｙｌｏｃｏｃｃｕｓ）属細菌、クレブシエラ（Ｋｌｅｂｓｉｅｌｌａ）属細菌、ストレプトコッカス属（Ｓｔｒｅｐｔｏｃｏｃｃｕｓ）属細菌、ザイモモナス（Ｚｙｍｏｍｏｎａｓ）属細菌、糸状菌、酵母菌等が挙げられる。 The microorganism having an acetoin-producing ability may be one having an ability to produce acetoin from the beginning, or one having a production ability given by breeding, mutation treatment, gene recombination treatment, or the like. The type of bacterium is not particularly limited, but is limited to coryneform bacteria, Escherichia coli, Bacillus bacterium, Geobacillus bacterium, Lactobacillus bacterium, Lactococcus genus bacterium, Staphylococcus. ) Bacteria, Klebsiella bacteria, Streptococcus bacteria, Zymomonas bacteria, filamentous fungi, yeasts and the like.
　本発明に用いられるアセトイン含有溶液の好ましい製造方法は微生物の発酵培養法であり、その場合、アセトインを含有する発酵培養液そのものをナノろ過膜に供するアセトイン含有溶液として使用することができる。 The preferred method for producing the acetoin-containing solution used in the present invention is a fermentation culture method for microorganisms, in which case the fermentation culture solution containing acetoin itself can be used as an acetoin-containing solution to be applied to a nanofilter membrane.
　本発明で用いるナノろ過膜とは、ナノフィルトレーション膜、ＮＦ膜とも呼ばれるも
のであり、「一価のイオンは透過し、二価のイオンを阻止する膜」と一般に定義される膜である。数ナノメートル程度の微小空隙を有していると考えられる膜で、主として、水中の微小粒子や分子、イオン、塩類等を阻止するために用いられる。 The nanofiltration membrane used in the present invention is also called a nanofiltration membrane or an NF membrane, and is a membrane generally defined as "a membrane that allows monovalent ions to permeate and blocks divalent ions". .. It is a membrane that is considered to have microvoids of several nanometers, and is mainly used to block fine particles, molecules, ions, salts, etc. in water.
　また、「ナノろ過膜に通じる」とは、アセトイン含有溶液を、ナノろ過膜に通じて濾過し、アセトイン以外の不純物を非透過液側に除去し、透過液側からアセトイン含有溶液を回収することを意味する。 Further, "passing through the nanofiltration membrane" means that the acetoin-containing solution is filtered through the nanofiltration membrane, impurities other than acetoin are removed to the non-permeate side, and the acetoin-containing solution is recovered from the permeate side. Means.
　ナノろ過膜の素材には一般的に、酢酸セルロース系ポリマー、ポリアミド、ポリエステル、ポリイミド、ポリビニルアルコールなどのビニルポリマー、ポリスルホンなどの高分子素材が知られており、本発明に使用できる。中でも、本発明においては、その精製効果が高いことから、ポリアミドを機能層に持つナノろ過膜が好ましく使用される。機能層にポリアミドを含んでいれば、その他の複数の膜素材を含む膜であってもよい。またその膜構造は、膜の少なくとも片面に緻密層を持ち、緻密層から膜内部あるいはもう片方の面に向けて徐々に大きな孔径の微細孔を有する非対称膜や、非対称膜の緻密層の上に別の素材で形成された非常に薄い機能層を有する複合膜のどちらでもよい。複合膜としては、例えば、特開昭６２－２０１６０６号公報に記載の、ポリスルホンを膜素材とする支持膜にポリアミドの機能層からなるナノろ過膜を構成させた複合膜を用いることができる。 Generally, cellulose acetate-based polymers, polyamides, polyesters, polyimides, vinyl polymers such as polyvinyl alcohol, and polymer materials such as polysulfone are known as materials for nanofilter membranes, and can be used in the present invention. Above all, in the present invention, a nanofiltration membrane having a polyamide as a functional layer is preferably used because of its high purification effect. As long as the functional layer contains polyamide, it may be a film containing a plurality of other film materials. Further, the membrane structure is formed on an asymmetric membrane having a dense layer on at least one surface of the membrane and having fine pores having a gradually larger pore diameter from the dense layer toward the inside of the membrane or the other surface, or on the dense layer of the asymmetric membrane. It may be either a composite membrane having a very thin functional layer formed of another material. As the composite membrane, for example, a composite membrane described in Japanese Patent Application Laid-Open No. 62-201606 in which a nanofiltration membrane made of a functional layer of polyamide is formed on a support membrane using polysulfone as a membrane material can be used.
　本発明で好ましく使用されるポリアミド機能層を有するナノろ過膜は、高耐圧性と高透水性、高溶質除去性能を兼ね備えた複合膜であることが好ましい。さらに操作圧力に対する耐久性と、高い透水性、阻止性能を維持できるためには、ポリアミドを機能層とし、それを多孔質膜や不織布からなる支持体で保持する構造のものが好ましい。ポリアミドを機能層とするナノろ過膜において、ポリアミドを構成する単量体の好ましいカルボン酸成分としては、例えば、トリメシン酸、ベンゾフェノンテトラカルボン酸、トリメリット酸、ピロメット酸、イソフタル酸、テレフタル酸、ナフタレンジカルボン酸、ジフェニルカルボン酸、ピリジンカルボン酸などの芳香族カルボン酸が挙げられるが、製膜溶媒に対する溶解性を考慮すると、トリメシン酸、イソフタル酸、テレフタル酸またはこれらの混合物がより好ましい。 The nanofiltration membrane having a polyamide functional layer preferably used in the present invention is preferably a composite membrane having high pressure resistance, high water permeability, and high solute removal performance. Further, in order to maintain durability against operating pressure, high water permeability, and blocking performance, a structure in which polyamide is used as a functional layer and the polyamide is held by a support made of a porous film or a non-woven fabric is preferable. In the nanofilter membrane having polyamide as a functional layer, preferable carboxylic acid components of the monomer constituting polyamide include, for example, trimesic acid, benzophenone tetracarboxylic acid, trimellitic acid, pyrrometic acid, isophthalic acid, terephthalic acid, and naphthalene. Aromatic carboxylic acids such as dicarboxylic acid, diphenylcarboxylic acid, and pyridinecarboxylic acid can be mentioned, but trimesic acid, isophthalic acid, terephthalic acid, or a mixture thereof is more preferable in consideration of solubility in a film-forming solvent.
　前記ポリアミドを構成する単量体の好ましいアミン成分としては、ｍ－フェニレンジアミン、ｐ－フェニレンジアミン、ベンジジン、メチレンビスジアニリン、４，４’－ジアミノビフェニルエーテル、ジアニシジン、３，３’，４－トリアミノビフェニルエーテル、３，３’，４，４’－テトラアミノビフェニルエーテル、３，３’－ジオキシベンジジン、１，８－ナフタレンジアミン、ｍ（ｐ）－モノメチルフェニレンジアミン、３，３’－モノメチルアミノ－４，４’－ジアミノビフェニルエーテル、４，Ｎ，Ｎ’－（４－アミノベンゾイル）－ｐ（ｍ）－フェニレンジアミン－２，２’－ビス（４－アミノフェニルベンゾイミダゾール）、２，２’－ビス（４－アミノフェニルベンゾオキサゾール）、２，２’－ビス（４－アミノフェニルベンゾチアゾール）等の芳香環を有する一級ジアミン、ピペラジン、ピペリジンまたはこれらの誘導体等の二級ジアミンが挙げられ、中でもピペラジンまたはピペリジンを単量体として含む架橋ポリアミドを機能層とするナノろ過膜は耐圧性、耐久性の他に、耐熱性、耐薬品性を有していることから好ましく用いられる。より好ましくは前記架橋ピペラジンポリアミドまたは架橋ピペリジンポリアミドを主成分とするナノろ過膜であり、さらに好ましくは前記架橋ピペラジンポリアミドまたは架橋ピペリジンポリアミドを主成分とし、かつ、前記化学式１で示される構成成分を含有するポリアミドであり、さらに好ましくは架橋ピペラジンポリアミドを主成分とし、かつ、前記化学式１で示される構成成分を含有するポリアミドである。また、前記化学式１中、ｎ＝３のものが好ましく用いられる。架橋ピペラジンポリアミドを主成分とし、かつ前記化学式（１）で示される構成成分を含有するポリアミドを機能層とするナノろ過膜としては、例えば、特開昭６２－２０１６０６号公報に記載のものが挙げられ、具体例としては、東レ株式会社製の架橋ピペラジンポリアミド系ナノろ過膜のＵＴＣ６０が挙げられる。 Preferred amine components of the monomer constituting the polyamide include m-phenylenediamine, p-phenylenediamine, benzidine, methylenebisdianiline, 4,4'-diaminobiphenyl ether, dianisidine, 3,3', 4-. Triaminobiphenyl ether, 3,3', 4,4'-tetraaminobiphenyl ether, 3,3'-dioxybenzidine, 1,8-naphthalenediamine, m (p) -monomethylphenylenediamine, 3,3'- Monomethylamino-4,4'-diaminobiphenyl ether, 4,N, N'-(4-aminobenzoyl) -p (m) -phenylenediamine-2,2'-bis (4-aminophenylbenzoimidazole), 2 , 2'-bis (4-aminophenylbenzoxazole), 2,2'-bis (4-aminophenylbenzothiazole) and other primary diamines with aromatic rings, piperazine, piperidine or derivatives thereof and the like. Among them, a nanofiltration membrane having a crosslinked polyamide containing piperazine or piperidine as a monomer as a functional layer is preferably used because it has heat resistance and chemical resistance in addition to pressure resistance and durability. A nanofiltration membrane containing the crosslinked piperazine polyamide or the crosslinked piperazine polyamide as a main component is more preferable, and the crosslinked piperazine polyamide or the crosslinked piperazine polyamide is a main component and contains the constituent component represented by the chemical formula 1. The polyamide is more preferably a crosslinked piperazine polyamide as a main component and containing a constituent component represented by the above chemical formula 1. Further, in the chemical formula 1, the one having n = 3 is preferably used. Examples of the nanofiltration membrane containing the crosslinked piperazine polyamide as a main component and the polyamide containing the constituent component represented by the chemical formula (1) as a functional layer include those described in JP-A-62-201606. Specific examples thereof include UTC60, which is a crosslinked piperazine polyamide-based nanofiltration membrane manufactured by Toray Industries, Inc.
　ナノろ過膜は一般にスパイラル型の膜エレメントとして使用されるが、本発明で用いるナノろ過膜も、スパイラル型の膜エレメントとして使用されることが好ましく採用できる。好ましいナノろ過膜の具体例としては、例えば、架橋ピペラジンポリアミドを主成分とし、かつ前記化学式（１）で示される構成成分を含有するポリアミドを機能層とする、東レ株式会社製のＵＴＣ６０を用いた同社製ナノフィルターモジュールＳＵ－２１０、ＳＵ－２２０、ＳＵ－６００、ＳＵ－６１０も使用することができる。また、架橋ピペラジンポリアミドを機能層とするフィルムテック社製ナノろ過膜のＮＦ－４５、ＮＦ－９０、ＮＦ－２００、ＮＦ－４００、あるいはポリアミドを機能層とするアルファラバル社製ナノろ過膜のＮＦ９９、ＮＦ９７、ＮＦ９９ＨＦなどが挙げられる。 The nanofiltration membrane is generally used as a spiral type membrane element, but the nanofiltration membrane used in the present invention can also be preferably used as a spiral type membrane element. As a specific example of a preferable nanofiltration membrane, for example, UTC60 manufactured by Toray Industries, Inc., which contains a crosslinked piperazine polyamide as a main component and a polyamide containing a constituent component represented by the chemical formula (1) as a functional layer, was used. The company's nanofilter modules SU-210, SU-220, SU-600, and SU-610 can also be used. Further, NF-45, NF-90, NF-200, NF-400 of a filmtech nanofiltration membrane having a crosslinked piperazine polyamide as a functional layer, or NF99 of an Alfa Laval nanofiltration membrane having a polyamide as a functional layer. , NF97, NF99HF and the like.
　本発明において、アセトイン含有溶液のナノろ過膜による濾過は、圧力をかけて行ってもよい。その濾過圧は、０．１ＭＰａより低ければ膜透過速度が低下し、８ＭＰａより高ければ膜の損傷に影響を与えるため、０．１ＭＰａ以上８ＭＰａ以下の範囲で好ましく用いられるが、０．５ＭＰａ以上７ＭＰａ以下で用いれば、膜透過流束が高いことから、アセトインを効率的に透過させることができ、膜の損傷に影響を与える可能性が少ないことからより好ましく、１ＭＰａ以上６ＭＰａ以下で用いることが特に好ましい。 In the present invention, the acetoin-containing solution may be filtered by a nanofiltration membrane under pressure. If the filtration pressure is lower than 0.1 MPa, the membrane permeation rate decreases, and if it is higher than 8 MPa, it affects the damage to the membrane. Therefore, it is preferably used in the range of 0.1 MPa or more and 8 MPa or less, but 0.5 MPa or more and 7 MPa. When used below, it is more preferable to use it at 1 MPa or more and 6 MPa or less because it has a high membrane permeation flux and can efficiently permeate acetoin and is less likely to affect the damage to the membrane. preferable.
　本発明において、アセトイン含有溶液のナノろ過膜による濾過は、非透過液を再び原水に戻し、繰り返し濾過することでアセトインの回収率を向上させることができる。アセトインの回収率は、ナノ濾過前のアセトイン総量およびナノろ過膜透過アセトイン総量を測定することで、式１によって算出することができる。 In the present invention, the filtration of the acetoin-containing solution with the nanofiltration membrane can improve the recovery rate of acetoin by returning the non-permeated solution to raw water and filtering repeatedly. The recovery rate of acetoin can be calculated by Equation 1 by measuring the total amount of acetoin before nanofiltration and the total amount of acetoin permeated through the nanofiltration membrane.
　アセトイン回収率（％）＝（ナノろ過膜透過アセトイン総量／ナノ濾過前のアセトイン総量）×１００・・・（式１）。 Acetoin recovery rate (%) = (total amount of acetoin permeated through nanofiltration membrane / total amount of acetoin before nanofiltration) x 100 ... (Equation 1).
　本発明で用いるナノろ過膜の膜分離性能としては、温度２５℃、ｐＨ６．５に調整した塩化ナトリウム水溶液（５００ｍｇ／Ｌ）を０．７５ＭＰａの濾過圧で評価したとき塩除去率が４５％以上のものが好ましく用いられる。ここでいう塩除去率は前記塩化ナトリウム水溶液の透過液塩濃度を測定することにより、式２によって算出することができる。 The membrane separation performance of the nanofiltration membrane used in the present invention is such that the salt removal rate is 45% or more when an aqueous sodium chloride solution (500 mg / L) adjusted to a temperature of 25 ° C. and a pH of 6.5 is evaluated at a filtration pressure of 0.75 MPa. Is preferably used. The salt removal rate referred to here can be calculated by Equation 2 by measuring the permeate salt concentration of the sodium chloride aqueous solution.
　塩除去率＝１００×｛１－（透過液中の塩濃度／供給水中の塩濃度）｝・・・（式２）。 Salt removal rate = 100 x {1- (salt concentration in permeate / salt concentration in feed water)} ... (Equation 2).
　また、ナノろ過膜の透過性能としては、０．３ＭＰａの濾過圧において、塩化ナトリウム水溶液（５００ｍｇ／Ｌ）の膜透過流束（ｍ３／（ｍ２・日））が０．３以上のものが好ましく用いられる。膜透過流束は透過液量および透過液量を採水した時間および膜面積を測定することで、式３によって算出することができる。 As for the permeation performance of the nanofiltration membrane, the membrane permeation flux (m 3 / (m 2 days)) of the sodium chloride aqueous solution (500 mg / L) is 0.3 or more at a filtration pressure of 0.3 MPa. Is preferably used. The membrane permeation flux can be calculated by Equation 3 by measuring the permeated liquid amount, the time at which the permeated liquid amount is sampled, and the membrane area.
　膜透過流束（ｍ３／（ｍ２・日））＝透過液量／（膜面積×採水時間）・・・（式３）。 Membrane permeation flux (m 3 / (m 2 · day)) = permeate volume / (membrane area x water sampling time) ... (Equation 3).
　本発明においてアセトイン含有溶液からナノろ過膜により非透過液側に分離される不純物としては、カルシウム、ナトリウム、硫酸、硝酸、リン酸などの無機物や、グルコース、フルクトース、キシロース、スクロース、ガラクトース、澱粉などの糖類や、タンパク質などが挙げられ、これらの混合物であっても好ましく分離される。 In the present invention, the impurities separated from the acetoin-containing solution to the non-permeate side by the nanofiltration membrane include inorganic substances such as calcium, sodium, sulfuric acid, nitric acid and phosphoric acid, glucose, fructose, xylose, sucrose, galactose and starch. Examples thereof include sugars and proteins, and even a mixture thereof is preferably separated.
　本発明におけるアセトインのナノろ過膜透過性は、アセトイン透過率を算出することで評価できる。アセトインの透過率は、高速液体クロマトグラフィー、ガスクロマトグラフィーに代表される分析により、原水（アセトインを含んだ溶液）中に含まれるアセトイン濃度（原水アセトイン濃度）および透過液（アセトイン溶液）中に含まれるアセトイン濃度（透過液アセトイン濃度）を測定することで、式４によって算出することができる。 The nanofiltration membrane permeability of acetoin in the present invention can be evaluated by calculating the acetoin transmittance. The transmittance of acetoin is contained in the acetoin concentration (raw acetoin concentration) and the permeate (acetoin solution) contained in raw water (solution containing acetoin) by analysis typified by high-speed liquid chromatography and gas chromatography. It can be calculated by Equation 4 by measuring the acetoin concentration (permeate acetoin concentration).
　アセトイン透過率（％）＝（透過液アセトイン濃度／原水アセトイン濃度）×１００・・・（式４）。 Acetine transmittance (%) = (permeate acetoin concentration / raw water acetoin concentration) x 100 ... (Equation 4).
　前記ナノろ過膜透過液は、その目的物質濃度が低い場合には濃縮されることが好ましい。ナノろ過膜透過液の濃縮方法としてはエバポレーターに代表される一般的な濃縮装置やゼオライト膜を利用して水分を除去する方法が本発明においても適用されうるが、水の熱容量は有機溶媒に比べてはるかに大きいため、濃縮にかかるエネルギーや時間は莫大である。一方、逆浸透膜による濃縮（工程Ｂ）はエネルギー・コスト削減という観点でエバポレーターによる濃縮より優れており、本発明において好ましく適用される。 The nanofiltration membrane permeate is preferably concentrated when the concentration of the target substance is low. As a method for concentrating the nanofiltration membrane permeate, a method for removing water using a general concentrator typified by an evaporator or a zeolite membrane can be applied in the present invention, but the heat capacity of water is higher than that of an organic solvent. Because it is much larger, the energy and time required for enrichment is enormous. On the other hand, concentration by a reverse osmosis membrane (step B) is superior to concentration by an evaporator from the viewpoint of energy cost reduction, and is preferably applied in the present invention.
　本発明における逆浸透膜とは、被処理水の浸透圧以上の圧力差を駆動力にイオンや低分子量分子を除去する濾過膜であり、例えば酢酸セルロースなどのセルロース系や、多官能アミン化合物と多官能酸ハロゲン化物とを重縮合させて微多孔性支持膜上にポリアミド分離機能層を設けた膜などが採用できる。逆浸透膜表面の汚れすなわちファウリングを抑制するために、酸ハライド基と反応する反応性基を少なくとも１個有する化合物の水溶液をポリアミド分離機能層の表面に被覆して、分離機能層表面に残存する酸ハロゲン基と該反応性基との間で共有結合を形成させた主に下水処理用の低ファウリング逆浸透膜なども好ましく採用できる。本発明のナノろ過膜に通じて濾過する工程で２価のイオンを大部分除去できているため、逆浸透膜面でのスケールの生成もなく安定した膜濃縮が行える。 The reverse osmosis membrane in the present invention is a filtration membrane that removes ions and low molecular weight molecules by using a pressure difference equal to or higher than the osmotic pressure of the water to be treated as a driving force. A membrane obtained by polycondensing a polyfunctional acid halide and providing a polyamide separation functional layer on a microporous support membrane can be adopted. In order to suppress stains on the surface of the back-penetrating film, that is, fouling, an aqueous solution of a compound having at least one reactive group that reacts with an acid halide group is coated on the surface of the polyamide separation functional layer and remains on the surface of the separation functional layer. A low fouling back-penetration film mainly for sewage treatment in which a covalent bond is formed between the acid halide group and the reactive group is also preferably adopted. Since most of the divalent ions can be removed in the step of filtering through the nanofiltration membrane of the present invention, stable membrane concentration can be performed without the formation of scale on the reverse osmosis membrane surface.
　また、「逆浸透膜に通じる」とは、ナノろ過膜を透過したアセトイン含有溶液を、逆浸透膜に通じて濃縮し、該濃縮液側（非透過液側）にアセトインを含んだ溶液を回収することを意味する。 Further, "passing through the reverse osmosis membrane" means that the acetoin-containing solution that has permeated the nanofiltration membrane is concentrated through the reverse osmosis membrane, and the solution containing acetoin on the concentrated solution side (non-permeating solution side) is recovered. Means to do.
　本発明で好ましく使用される逆浸透膜としては、酢酸セルロール系のポリマーを機能層とした複合膜（以下、酢酸セルロース系の逆浸透膜ともいう）またはポリアミドを機能層とした複合膜（以下、ポリアミド系の逆浸透膜ともいう）が挙げられる。ここで、酢酸セルロース系のポリマーとしては、酢酸セルロース、二酢酸セルロース、三酢酸セルロース、プロピオン酸セルロース、酪酸セルロース等のセルロースの有機酸エステルの単独もしくはこれらの混合物並びに混合エステルを用いたものが挙げられる。ポリアミドとしては、脂肪族および／または芳香族のジアミンをモノマーとする線状ポリマーまたは架橋ポリマーが挙げられる。膜形態としては、平膜型、スパイラル型、中空糸型など適宜の形態のものが使用できる。 As the reverse osmosis membrane preferably used in the present invention, a composite membrane having a cellulose acetate-based polymer as a functional layer (hereinafter, also referred to as a cellulose acetate-based reverse osmosis membrane) or a composite membrane having a polyamide as a functional layer (hereinafter, referred to as a functional layer). (Also referred to as a polyamide-based reverse osmosis membrane). Here, examples of the cellulose acetate-based polymer include those using organic acid esters of cellulose such as cellulose acetate, cellulose diacetate, cellulose triacetate, cellulose propionate, and cellulose butyrate alone or a mixture thereof, and mixed esters. Be done. Examples of the polyamide include linear polymers or crosslinked polymers using aliphatic and / or aromatic diamines as monomers. As the membrane morphology, an appropriate morphology such as a flat membrane type, a spiral type, and a hollow fiber type can be used.
　本発明で使用される逆浸透膜の具体例としては、例えば、例えば、東レ（株）製ポリアミド系逆浸透膜モジュールである低圧タイプのＳＵ－７１０、ＳＵ－７２０、ＳＵ－７２０Ｆ、ＳＵ－７１０Ｌ、ＳＵ－７２０Ｌ、ＳＵ－７２０ＬＦ、ＳＵ－７２０Ｒ、ＳＵ－７１０Ｐ、ＳＵ－７２０Ｐの他、逆浸透膜としてＵＴＣ７０を含む高圧タイプのＳＵ－８１０、ＳＵ－８２０、ＳＵ－８２０Ｌ、ＳＵ－８２０ＦＡ、同社酢酸セルロース系逆浸透膜ＳＣ－Ｌ１００Ｒ、ＳＣ－Ｌ２００Ｒ、ＳＣ－１１００、ＳＣ－１２００、ＳＣ－２１００、ＳＣ－２２００、ＳＣ－３１００、ＳＣ－３２００、ＳＣ－８１００、ＳＣ－８２００、日東電工（株）製ＮＴＲ－７５９ＨＲ、ＮＴＲ－７２９ＨＦ、ＮＴＲ－７０ＳＷＣ、ＥＳ１０－Ｄ、ＥＳ２０－Ｄ、ＥＳ２０－Ｕ、ＥＳ１５－Ｄ、ＥＳ１５－Ｕ、ＬＦ１０－Ｄ、アルファラバル製ＲＯ９８ｐＨｔ、ＲＯ９９、ＨＲ９８ＰＰ、ＣＥ４０４０Ｃ－３０Ｄ、ＧＥ製ＧＥ　Ｓｅｐａ、Ｆｉｌｍｔｅｃ製ＢＷ３０－４０４０、ＴＷ３０－４０４０、ＸＬＥ－４０４０、ＬＰ－４０４０、ＬＥ－４０４０、ＳＷ３０－４０４０、ＳＷ３０ＨＲＬＥ－４０４０などが挙げられる。 Specific examples of the reverse osmosis membrane used in the present invention include, for example, low-pressure type SU-710, SU-720, SU-720F, and SU-710L which are polyamide-based reverse osmosis membrane modules manufactured by Toray Industries, Inc. , SU-720L, SU-720LF, SU-720R, SU-710P, SU-720P, high-pressure type SU-810, SU-820, SU-820L, SU-820FA, which includes UTC70 as a reverse osmosis membrane Cellulose acetate reverse osmosis membrane SC-L100R, SC-L200R, SC-1100, SC-1200, SC-2100, SC-2200, SC-3100, SC-3200, SC-8100, SC-8200, Nitto Denko Co., Ltd. ) NTR-759HR, NTR-729HF, NTR-70SWC, ES10-D, ES20-D, ES20-U, ES15-D, ES15-U, LF10-D, Alpha Laval RO98pHt, RO99, HR98PP, CE4040C-30D , GE Sepa, Filmtec BW30-4040, TW30-4040, XLE-4040, LP-4040, LE-4040, SW30-4040, SW30HRLE-4040 and the like.
　本発明において、ナノろ過膜透過液の逆浸透膜による濾過は、圧力をかけて行うが、その濾過圧は、１ＭＰａより低ければ膜透過速度が低下し、８ＭＰａより高ければ膜の損傷に影響を与えるため、１ＭＰａ以上８ＭＰａ以下の範囲であることが好ましい。また、濾過圧が１ＭＰａ以上７ＭＰａ以下の範囲であれば、膜透過流束が高いことから、アセトイン溶液を効率的に濃縮することができる。膜の損傷に影響を与える可能性が少ないことから最も好ましくは、２ＭＰａ以上６ＭＰａ以下の範囲である。 In the present invention, the nanofiltration membrane permeate is filtered by a reverse osmosis membrane under pressure. If the filtration pressure is lower than 1 MPa, the membrane permeation rate decreases, and if it is higher than 8 MPa, it affects the damage to the membrane. Therefore, it is preferably in the range of 1 MPa or more and 8 MPa or less. Further, when the filtration pressure is in the range of 1 MPa or more and 7 MPa or less, the membrane permeation flux is high, so that the acetoin solution can be efficiently concentrated. Most preferably, it is in the range of 2 MPa or more and 6 MPa or less because it is unlikely to affect the damage of the film.
　さらに、本発明においてはナノろ過膜透過液を蒸留する工程Ｃに供することで、高純度のアセトインを得ることができる。蒸留工程は、１Ｐａ以上大気圧（常圧、約１０１ｋＰａ）以下の減圧下で行うことが好ましく、１００Ｐａ以上１５ｋＰａ以下の減圧下で行うことがより好ましい。減圧下で行う場合の蒸留温度は、２０℃以上２００℃以下で行うことが好ましく、５０℃以上１５０℃以下で行うことがより好ましい。 Further, in the present invention, high-purity acetoin can be obtained by subjecting the nanofiltration membrane permeate to the step C of distillation. The distillation step is preferably carried out under a reduced pressure of 1 Pa or more and atmospheric pressure (normal pressure, about 101 kPa) or less, and more preferably 100 Pa or more and 15 kPa or less. When the distillation is performed under reduced pressure, the distillation temperature is preferably 20 ° C. or higher and 200 ° C. or lower, and more preferably 50 ° C. or higher and 150 ° C. or lower.
　本発明はアセトイン含有微生物培養液由来のアセトイン組成物のアセトイン純度を高めることができる。具体的には、アセトインを含有する微生物培養液から、アセトインの重量純度が８０％以上、好ましくは９０％以上、より好ましくは９５％以上のアセトイン組成物を得ることができる。従来、このような高純度のアセトイン組成物は原油を原料として化学合成により製造されていたが、本発明により、バイオマス原料から得られたアセトイン含有微生物培養液からも高純度のアセトイン組成物を製造できるようになる。バイオマス原料由来の高純度アセトイン組成物は、安全性の観点から食品添加物用途や化粧品用途に好適である。 The present invention can increase the purity of acetoin in an acetoin composition derived from an acetoin-containing microbial culture solution. Specifically, an acetoin composition having a weight purity of 80% or more, preferably 90% or more, more preferably 95% or more can be obtained from a microbial culture solution containing acetoin. Conventionally, such a high-purity acetoin composition has been produced by chemical synthesis using crude oil as a raw material, but according to the present invention, a high-purity acetoin composition can also be produced from an acetoin-containing microbial culture solution obtained from a biomass raw material. become able to. The high-purity acetoin composition derived from a biomass raw material is suitable for food additive applications and cosmetic applications from the viewpoint of safety.
　以下、実施例を用いて本発明をより詳細に説明するが、本発明は以下の実施例に限定されるものではない。アセトイン含有溶液中のアセトイン濃度、アセトインのＧＣ純度（％：ＧＣ　ＡＲＥＡ基準）、重量純度（ｗｔ％）は、ガスクロマトグラフィー（ＧＣ）により分析した。アセトインの定量は絶対検量線法により行った。ＧＣの分析条件を以下に示す。 Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples. The acetoin concentration in the acetoin-containing solution, the GC purity of acetoin (%: GC AREA standard), and the weight purity (wt%) were analyzed by gas chromatography (GC). Acetoin was quantified by the absolute calibration curve method. The analysis conditions of GC are shown below.
　（ＧＣ分析条件）
ＧＣ装置：ＧＣ２０１０　ｐｌｕｓ（株式会社島津製作所社製）
カラム：Ｒｔ－β－ＤＥＸ、長さ３０ｍ、内径０．３２ｍｍ（ＲＥＳＴＥＫ社製）
キャリアガス：ヘリウム、線速度一定（３５．０ｃｍ／秒）
気化室温度：２５０℃
検出器温度：２５０℃
カラムオーブン温度：７５℃で一定（１８分）
検出器：ＦＩＤ。 (GC analysis conditions)
GC equipment: GC2010 plus (manufactured by Shimadzu Corporation)
Column: Rt-β-DEX, length 30 m, inner diameter 0.32 mm (manufactured by RESTEK)
Carrier gas: helium, constant linear velocity (35.0 cm / sec)
Vaporization chamber temperature: 250 ° C
Detector temperature: 250 ° C
Column oven temperature: constant at 75 ° C (18 minutes)
Detector: FID.
　（参考例１）アセトインモデル培養液の調製
　超純水に、アセトイン（東京化成工業株式会社製）、グルコース（富士フイルム和光株式会社製）、フルクトース（富士フイルム和光株式会社製）、スクロース（富士フイルム和光株式会社製）、リン酸二水素カリウム（富士フイルム和光株式会社製）、リン酸水素二カリウム（富士フイルム和光株式会社製）、硫酸アンモニウム（富士フイルム和光株式会社製）、塩化ナトリウム（富士フイルム和光株式会社製）、Ｂａｃｔｏトリプトン（Ｄｉｆｃｏ　Ｌａｂｏｒａｔｏｒｉｅｓ社製）、Ｂａｃｔｏ酵母エキス（Ｄｉｆｃｏ　Ｌａｂｏｒａｔｏｒｉｅｓ社製）を添加し、表１に示す組成のアセトイン水溶液を調製し、モデル培養液とした。 (Reference Example 1) Preparation of acetoin model culture solution In ultra-pure water, acetoin (manufactured by Tokyo Kasei Kogyo Co., Ltd.), glucose (manufactured by Fujifilm Wako Co., Ltd.), fructose (manufactured by Fujifilm Wako Co., Ltd.), sucrose (manufactured by Fujifilm) Wako Co., Ltd.), Potassium Dihydrogen Phosphate (Fujifilm Wako Co., Ltd.), Dipotassium Hydrogen Phosphate (Fujifilm Wako Co., Ltd.), Ammonium Sulfate (Fujifilm Wako Co., Ltd.), Sodium Chloride (Fujifilm Wako Co., Ltd.) Bacto Tripton (manufactured by Difco Laboratories) and Bacto yeast extract (manufactured by Difco Laboratories) were added to prepare an acetoin aqueous solution having the composition shown in Table 1 and used as a model culture solution.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　（実施例１）ナノろ過膜を用いたモデル培養液中からのアセトインの精製
　参考例１で調製したアセトインモデル培養液２００Ｌを、図１に示す膜濾過装置の原水槽１に注入した。図２の符号７の９０φナノろ過膜として、架橋ピペラジンポリアミド系ナノろ過膜“ＵＴＣ６０”（ナノろ過膜１；東レ株式会社製）をステンレス（ＳＵＳ３１６製）製のセルにそれぞれセットし、原水温度を１０℃、高圧ポンプ３の圧力をそれぞれ２ＭＰａに調整し、それぞれの圧力における透過液４を回収した。原水槽１、透過液４に含まれる、アセトイン濃度をＧＣ分析し、アセトインの透過率を算出した。この結果を表２に示す。なお、前述の式１で算出されるアセトインの回収率を高めるため、透過液１０Ｌを回収した後、蒸留水１０Ｌを加えて再度、透過液を回収する、という操作を７回繰り返したところ、アセトインの回収率が７７％となった。 (Example 1) Purification of acetoin from a model culture solution using a nanofiltration membrane 200 L of the acetoin model culture solution prepared in Reference Example 1 was injected into the raw water tank 1 of the membrane filtration device shown in FIG. As the 90φ nanofiltration membrane of reference numeral 7 in FIG. 2, a crosslinked piperazine polyamide-based nanofiltration membrane “UTC60” (nanofiltration membrane 1; manufactured by Toray Co., Ltd.) was set in a cell made of stainless steel (manufactured by SUS316), and the raw water temperature was adjusted. The pressure of the high pressure pump 3 was adjusted to 2 MPa at 10 ° C., and the permeate 4 at each pressure was recovered. The acetoin concentration contained in the raw water tank 1 and the permeate 4 was analyzed by GC, and the acetoin transmittance was calculated. The results are shown in Table 2. In order to increase the recovery rate of acetoin calculated by the above formula 1, 10 L of permeate was recovered, then 10 L of distilled water was added, and the permeate was recovered again 7 times. As a result, acetoin was recovered. The recovery rate was 77%.
　また、ナノろ過膜の透過側から得たアセトイン含有溶液１００Ｌを図１に示す膜濾過装置の原水槽１に入れた。図２の符号７の９０φ逆浸透膜として、ポリアミド系逆浸透膜（ＵＴＣ－７０、東レ株式会社製）をステンレス（ＳＵＳ３１６製）製セルに取付け、高圧ポンプ３の圧力を５ＭＰａ、原水温度を２０℃に調整して膜濾過を行い、逆浸透膜透過水４を９０Ｌ除去した。該透過水にアセトインは含まれていなかった。こうして得られた濃縮液１０Ｌを、ロータリーエバポレーター（東京理化器械株式会社製）を用いて１Ｌ程度になるまで濃縮してから、釜温度１００℃、１３０ｍｍＨｇにて、アセトインを蒸留・分離した。濃縮前後のアセトイン濃度、得られたアセトインのＧＣ純度、重量純度を表３に示す。 Further, 100 L of the acetoin-containing solution obtained from the permeation side of the nanofiltration membrane was placed in the raw water tank 1 of the membrane filtration apparatus shown in FIG. As a 90φ reverse osmosis film of reference numeral 7 in FIG. 2, a polyamide reverse osmosis film (UTC-70, manufactured by Toray Co., Ltd.) is attached to a stainless steel (SUS316) cell, the pressure of the high pressure pump 3 is 5 MPa, and the raw water temperature is 20. The temperature was adjusted to ° C. and membrane filtration was performed to remove 90 L of reverse osmosis membrane permeated water 4. The permeated water did not contain acetoin. 10 L of the concentrated solution thus obtained was concentrated to about 1 L using a rotary evaporator (manufactured by Tokyo Rika Kikai Co., Ltd.), and then acetoin was distilled and separated at a kettle temperature of 100 ° C. and 130 mmHg. Table 3 shows the acetoin concentration before and after concentration, the GC purity of the obtained acetoin, and the weight purity.
　（実施例２）
　架橋ピペラジンポリアミド系ナノろ過膜“ＵＴＣ６０”の代わりに酢酸セルロース系ナノろ過膜“ＧＥｓｅｐａ”（ナノろ過膜２；ＧＥ　Ｏｓｍｏｎｉｃｓ製）を用いた以外は、実施例１と同様にアセトインの精製を行った。結果を表２および表３に示す。 (Example 2)
Acetin was purified in the same manner as in Example 1 except that the cellulose acetate-based nanofiltration membrane "GEsepa" (nanofiltration membrane 2; manufactured by GE Osmonics) was used instead of the crosslinked piperazine polyamide-based nanofiltration membrane "UTC60". .. The results are shown in Tables 2 and 3.
　（比較例１）
　ナノろ過膜処理を行わなかったこと以外は、実施例１と同様にアセトインの精製を行った。この際、逆浸透膜での濃縮では目詰まりが生じた他、ロータリーエバポレーターによる濃縮時にも多くの析出物が生じた。減圧蒸留では、実施例１と比較して、アセトインの留出に時間を要した。 (Comparative Example 1)
Acetoin was purified in the same manner as in Example 1 except that the nanofiltration membrane treatment was not performed. At this time, not only clogging occurred when concentrating with the reverse osmosis membrane, but also many precipitates were generated when concentrating with the rotary evaporator. In the vacuum distillation, it took more time to distill acetoin as compared with Example 1.
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
　すべてのナノろ過膜を用いた場合も、良好な透過率でアセトインがナノろ過膜を透過した。透過側からアセトイン含有溶液を回収することにより、糖類を除去することが可能であった。また、黄色のモデル培養液から無色透明な溶液が得られたことから、その他の不純物も大部分が除去されたことが推察された。また、架橋ピペラジンポリアミド素材のナノろ過膜のアセトイン透過率が高く、ＧＣ純度、重量純度も向上した。さらに、ナノろ過膜を通じることにより、アセトイン含有溶液の逆浸透膜および蒸発法による濃縮が容易になることが分かった。 Even when all nanofiltration membranes were used, acetoin permeated the nanofiltration membrane with good transmittance. By recovering the acetoin-containing solution from the permeation side, it was possible to remove the saccharides. In addition, since a colorless and transparent solution was obtained from the yellow model culture solution, it was inferred that most of the other impurities were also removed. In addition, the acetoin transmittance of the nanofiltration membrane of the crosslinked piperazine polyamide material was high, and the GC purity and the weight purity were also improved. Furthermore, it was found that the acetoin-containing solution can be easily concentrated by the reverse osmosis membrane and the evaporation method by passing through the nanofiltration membrane.
　このことから、アセトイン含有溶液をナノろ過膜に通じて、透過側からアセトイン含有溶液を回収する工程を含むアセトインの精製により、高純度のアセトインが低コストで製造可能となることが示された。 From this, it was shown that high-purity acetoin can be produced at low cost by purifying acetoin including a step of passing the acetoin-containing solution through a nanofiltration membrane and recovering the acetoin-containing solution from the permeation side.
　（比較例２）ナノろ過膜による１，３－プロパンジオールの精製
　アセトインの代わりに１，３－プロパンジオールが１０ｇ／Ｌとなるようにした以外は、参考例１と同様に１，３－プロパンジオールのモデル培養液を調製した。該培養液を上記実施例１と同様にナノろ過膜処理した。これをさらに、上記実施例１と同様に逆浸透膜を用いて濃縮し、９７℃で減圧蒸留（５ｍｍＨｇ）を行った。 (Comparative Example 2) Purification of 1,3-propanediol using a nanofiltration membrane 1,3-propane is the same as in Reference Example 1 except that 1,3-propanediol is 10 g / L instead of acetoin. A model culture solution of diol was prepared. The culture solution was treated with a nanofiltration membrane in the same manner as in Example 1 above. This was further concentrated using a reverse osmosis membrane in the same manner as in Example 1 above, and subjected to vacuum distillation (5 mmHg) at 97 ° C.
　その結果、１，３－プロパンジオールのＧＣ純度は９９.７％であった。このことから、ナノろ過膜を用いることで高純度の１，３－プロパンジオール精製が可能であることが示唆された。しかしながら、１，３－プロパンジオールはナノろ過膜１における膜透過性が３５％とアセトインに比べて低かった。すなわち、１，３－プロパンジオールと実施例１に示したアセトインでは分子量が１，３－プロパンジオールの方が小さいにもかかわらず、アセトインの方がナノろ過膜透過率は顕著に高く、アセトインの方がよりナノろ過膜精製に適した化合物であることが示された。 As a result, the GC purity of 1,3-propanediol was 99.7%. This suggests that high-purity 1,3-propanediol purification is possible by using nanofiltration membranes. However, 1,3-propanediol had a membrane permeability of 35% in the nanofiltration membrane 1 which was lower than that of acetoin. That is, although the molecular weight of 1,3-propanediol and the acetoin shown in Example 1 is smaller than that of 1,3-propanediol, the nanofiltration membrane permeability of acetoin is significantly higher than that of acetoin. It was shown that the compound is more suitable for purification of nanofiltration membranes.
１　原水槽
２　ナノろ過膜または逆浸透膜が装着されたセル
３　高圧ポンプ
４　膜透過液の流れ
５　膜濃縮液の流れ
６　高圧ポンプにより送液された培養液またはナノろ過膜透過液の流れ
７　ナノろ過膜または逆浸透膜
８　支持板 1 Raw water tank 2 Cell equipped with nanofiltration membrane or reverse osmosis membrane 3 High-pressure pump 4 Flow of membrane permeate 5 Flow of membrane concentrate 6 Flow of culture solution or nanofiltration membrane permeate sent by high-pressure pump 7 Nanofiltration membrane or reverse osmosis membrane 8 Support plate

Claims (7)

  1. 　アセトイン含有溶液をナノろ過膜に通じて濾過し、透過側からアセトイン含有溶液を回収する工程Ａを含む、アセトインの製造方法。 A method for producing acetoin, which comprises step A of filtering the acetoin-containing solution through a nanofiltration membrane and recovering the acetoin-containing solution from the permeation side.
  2. 　前記ナノろ過膜に通じて濾過するアセトイン含有溶液が微生物発酵によって得られる培養液である、請求項１に記載のアセトインの製造方法。 The method for producing acetoin according to claim 1, wherein the acetoin-containing solution filtered through the nanofiltration membrane is a culture solution obtained by microbial fermentation.
  3. 　前記ナノろ過膜の機能層がポリアミドを含む、請求項１または２に記載のアセトインの製造方法。 The method for producing acetoin according to claim 1 or 2, wherein the functional layer of the nanofiltration membrane contains polyamide.
  4. 　前記ポリアミドが架橋ピペラジンポリアミドを主成分とし、かつ、化学式１で示される構成成分を含有することを特徴とする、請求項３のいずれかに記載のアセトインの製造方法。
    Figure JPOXMLDOC01-appb-C000001
     （式中、Ｒは－Ｈまたは－ＣＨ３、ｎは０から３までの整数を表す。）     The method for producing acetoin according to any one of claims 3, wherein the polyamide contains a crosslinked piperazine polyamide as a main component and contains a constituent component represented by the chemical formula 1.
    Figure JPOXMLDOC01-appb-C000001
     (In the formula, R represents -H or -CH 3 , and n represents an integer from 0 to 3.)
  5. 　前記工程Ａより得られたアセトイン含有溶液を逆浸透膜に通じてアセトイン濃度を高める工程Ｂを含む、請求項１～４のいずれかに記載のアセトインの製造方法。 The method for producing acetoin according to any one of claims 1 to 4, which comprises step B in which the acetoin-containing solution obtained in the step A is passed through a reverse osmosis membrane to increase the acetoin concentration.
  6. 　前記工程Ａから回収された透過液、または前記工程Ｂから回収された濃縮液を、さらに１Ｐａ以上大気圧以下の圧力下において、２５℃以上２００℃以下で蒸留する工程Ｃに供する、請求項１～５のいずれかに記載のアセトインの製造方法。 1. The permeate recovered from the step A or the concentrated solution recovered from the step B is further subjected to a step C of distilling at 25 ° C. or higher and 200 ° C. or lower under a pressure of 1 Pa or more and atmospheric pressure or less. The method for producing acetoin according to any one of 5 to 5.
  7. 　アセトイン含有微生物培養液由来であり、アセトイン重量純度が８０％以上である、アセトイン組成物。 An acetoin composition derived from an acetoin-containing microbial culture solution and having an acetoin weight purity of 80% or more.
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WO2023198993A1 (en) 2022-04-15 2023-10-19 Lesaffre Et Compagnie Method for obtaining acetoin

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JPH024401A (en) * 1988-01-14 1990-01-09 Huels Ag Separation of valent substance from aqueous solution
JP2013518081A (en) * 2010-01-29 2013-05-20 ワッカー ケミー アクチエンゲゼルシャフト Process for producing carboxylic acids having 1 to 3 carbon atoms from renewable raw materials
US20150329927A1 (en) * 2014-05-17 2015-11-19 Sweetwater Energy, Inc. Sugar Separation and Purification Through Filtration
JP2015227298A (en) * 2014-05-30 2015-12-17 三菱化学株式会社 Production method of 2,3-butanediol
CN109852478A (en) * 2019-01-30 2019-06-07 四川中烟工业有限责任公司 A method of extracting original flavor wine aroma flavor substance from spirit distiller grain

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EP0253091A2 (en) * 1986-07-15 1988-01-20 Hüls Aktiengesellschaft Process for the separation of low molecular weight alcohols from aqueous solutions
JPH024401A (en) * 1988-01-14 1990-01-09 Huels Ag Separation of valent substance from aqueous solution
JP2013518081A (en) * 2010-01-29 2013-05-20 ワッカー ケミー アクチエンゲゼルシャフト Process for producing carboxylic acids having 1 to 3 carbon atoms from renewable raw materials
US20150329927A1 (en) * 2014-05-17 2015-11-19 Sweetwater Energy, Inc. Sugar Separation and Purification Through Filtration
JP2015227298A (en) * 2014-05-30 2015-12-17 三菱化学株式会社 Production method of 2,3-butanediol
CN109852478A (en) * 2019-01-30 2019-06-07 四川中烟工业有限责任公司 A method of extracting original flavor wine aroma flavor substance from spirit distiller grain

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023198993A1 (en) 2022-04-15 2023-10-19 Lesaffre Et Compagnie Method for obtaining acetoin
FR3134575A1 (en) 2022-04-15 2023-10-20 Lesaffre Et Compagnie Process for obtaining acetoin

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