Method for preparation of branched 3-hydroxypropionic acid prepolymer and acrylic acid

Abstract

The present invention relates to: a method for preparing a fermented liquid by fermenting a strain having a 3-hydroxypropionic acid-producing ability in the presence of a polyol, and for preparing a branched 3-hydroxypropionic acid prepolymer by polymerizing same in the presence of the polyol; and a method for preparing a bioacrylic acid by pyrolyzing the branched 3-hydroxypropionic acid prepolymer.

Description

Method for producing branched 3-hydroxypropionic acid prepolymer and acrylic acid

[0001] Cross-citation with related application(s)

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0071883, filed May 31, 2024, and Korean Patent Application No. 10-2025-0070312, filed May 29, 2025, the entire contents of which are incorporated herein by reference.

[0003] The present invention relates to a method for producing a high-purity branched 3-hydroxypropionic acid prepolymer and bio-acrylic acid.

[0004] Organic acids are commercially important chemicals with diverse applications in the food, cosmetics, pharmaceutical, and polymer industries. Representative organic acids include lactic acid and 3-hydroxypropionic acid (3-HP). Among them, 3-hydroxypropionic acid (3HP) is a valuable raw material for the production of acrylic acid, 1,3-propanediol, acrylamide, malonic acid, and biopolymers.

[0005] Organic acids are produced largely through two methods: chemical and biological. However, chemical methods are criticized as being unfriendly due to the high cost of initial materials and the generation of toxic substances during the production process. Therefore, environmentally friendly bioprocesses are gaining attention.

[0006] When producing organic acids through microbial fermentation, byproducts other than organic acids such as 3-hydroxypropionic acid are also produced during the fermentation process. Therefore, purification processes such as electrodialysis and ion exchange resins are required to extract and separate the organic acids from the fermentation broth. However, these purification processes are lengthy and expensive. Therefore, there is a need for a method to efficiently convert raw materials such as biopolymers into low-purity organic acids such as 3-hydroxypropionic acid containing byproducts.

[0007] The present invention relates to a method for producing a high molecular weight and high purity branched prepolymer from low purity crude 3-hydroxypropionic acid at an efficient and low process cost, and for producing bio-acrylic acid by pyrolysis thereof.

[0008] In the present specification, a method for producing a branched 3-hydroxypropionic acid prepolymer is provided, comprising the steps of: fermenting a strain having 3-hydroxypropionic acid production ability under a polyol to produce a fermentation solution containing the polyol and 3-hydroxypropionic acid; and polymerizing the 3-hydroxypropionic acid under the polyol to produce a branched 3-hydroxypropionic acid prepolymer.

[0009] In addition, the present specification provides a method for producing acrylic acid, comprising the steps of: fermenting a strain having 3-hydroxypropionic acid production ability under a polyol to produce a fermentation solution containing the polyol and 3-hydroxypropionic acid; polymerizing the 3-hydroxypropionic acid under the polyol to produce a branched 3-hydroxypropionic acid prepolymer; and thermally decomposing the branched 3-hydroxypropionic acid prepolymer to produce acrylic acid.

[0010] Hereinafter, a method for producing a branched 3-hydroxypropionic acid prepolymer and acrylic acid according to a specific embodiment of the invention will be described in more detail.

[0011] The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this specification, it should be understood that the terms "comprise," "include," or "have" indicate the presence of a feature, number, step, component, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, components, or combinations thereof.

[0012] The present invention is susceptible to various modifications and takes various forms. Specific embodiments are illustrated and described in detail below. However, this is not intended to limit the present invention to specific disclosed forms, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

[0013] Furthermore, unless the steps constituting the manufacturing method described herein are explicitly stated to be sequential or consecutive, or there is another special order, the order of one step constituting a manufacturing method from another step is not limited to the order described in the specification. Accordingly, the order of the steps constituting the manufacturing method may be varied within a range readily understandable to those skilled in the art, and in such cases, any subsequent changes apparent to those skilled in the art are within the scope of the present invention.

[0014] In this specification, a prepolymer may be a polymer having a low degree of polymerization in which a polymerization reaction is stopped in the middle stage, and a 3-hydroxypropionic acid prepolymer may be a polymer obtained by polymerizing 3-hydroxypropionic acid to form an oligomer, and may mean a 3-hydroxypropionic acid oligomer.

[0015] In this specification, alkali metal may mean both alkali metal and alkaline earth metal.

[0016] In addition, in the present specification, the weight average molecular weight (Mw) and the number average molecular weight (Mn) refer to the molecular weight (unit: Da (Dalton)) equivalent to polystyrene measured by gel permeation chromatography (GPC). In the process of measuring the weight average molecular weight equivalent to polystyrene measured by the GPC method, a commonly known analysis device and a detector such as a refractive index detector and an analysis column can be used, and commonly applied temperature conditions, solvents, and flow rates can be applied. Specific examples of the measurement conditions include a temperature of 30°C, a chloroform solvent, and a flow rate of 1 mL / min. A specific example of the above measurement conditions is that using a Polymer Laboratories PLgel MIX-B 300 mm length column, a Waters PL-GPC220 instrument, an evaluation temperature of 160 ℃, 1,2,4-trichlorobenzene as a solvent, a flow rate of 1 mL / min, a sample prepared at a concentration of 10 mg / 10 mL, and then supplied in an amount of 200 μL, the values ​​of Mw and Mn can be obtained using a calibration curve formed using polystyrene standards, respectively. The molecular weights of the polystyrene standards were 9 types: 2,000 / 10,000 / 30,000 / 70,000 / 200,000 / 700,000 / 2,000,000 / 4,000,000 / 10,000,000.

[0017] The term "substituted or unsubstituted" as used herein means a group that is unsubstituted or substituted with one or more substituents selected from the group consisting of deuterium; a halogen group; a nitrile group; a nitro group; a hydroxy group; a carbonyl group; an ester group; an imide group; an amino group; a phosphine oxide group; an alkoxy group; an aryloxy group; an alkylthioxy group; an arylthioxy group; an alkylsulfoxy group; an arylsulfoxy group; a silyl group; a boron group; an alkyl group; a cycloalkyl group; an alkenyl group; an aryl group; an aralkyl group; an aralkenyl group; an alkylaryl group; an alkylamine group; an aralkylamine group; a heteroarylamine group; an arylphosphine group; or a heterocyclic group containing at least one of N, O, and S atoms, or a substituted or unsubstituted group in which two or more of the above-mentioned substituents are linked. For example, the "substituent linked with two or more substituents" may be a biphenyl group. That is, the biphenyl group can be an aryl group or can be interpreted as a substituent in which two phenyl groups are connected.

[0018] In this specification, the number of carbon atoms in the carbonyl group is not particularly limited, but is preferably 1 to 40 carbon atoms. Specifically, it may be a compound having the following structure, but is not limited thereto.

[0019]

[0020] In the present specification, the ester group may have the oxygen of the ester group replaced by a straight-chain, branched-chain or cyclic alkyl group having 1 to 25 carbon atoms or an aryl group having 6 to 25 carbon atoms. Specifically, the ester group may be a compound having the following structural formula, but is not limited thereto.

[0021]

[0022] In this specification, the number of carbon atoms in the imide group is not particularly limited, but is preferably 1 to 25 carbon atoms. Specifically, it may be a compound having the following structure, but is not limited thereto.

[0023]

[0024] In the present specification, the silyl group specifically includes, but is not limited to, a trimethylsilyl group, a triethylsilyl group, a t-butyldimethylsilyl group, a vinyldimethylsilyl group, a propyldimethylsilyl group, a triphenylsilyl group, a diphenylsilyl group, a phenylsilyl group, etc.

[0025] In this specification, the boron group specifically includes, but is not limited to, a trimethyl boron group, a triethyl boron group, a t-butyldimethyl boron group, a triphenyl boron group, a phenyl boron group, etc.

[0026] In this specification, examples of halogen groups include fluorine, chlorine, bromine, or iodine.

[0027] In the present specification, the alkyl group may be linear or branched, and the number of carbon atoms is not particularly limited, but is preferably 1 to 40. According to one embodiment, the number of carbon atoms of the alkyl group is 1 to 20. According to another embodiment, the number of carbon atoms of the alkyl group is 1 to 10. According to another embodiment, the number of carbon atoms of the alkyl group is 1 to 6. Specific examples of alkyl groups include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl, n-heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohectylmethyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, isohexyl, Examples include, but are not limited to, 4-methylhexyl and 5-methylhexyl.

[0028] In the present specification, the alkenyl group may be linear or branched, and the number of carbon atoms is not particularly limited, but is preferably 2 to 40. According to one embodiment, the number of carbon atoms in the alkenyl group is 2 to 20. According to another embodiment, the number of carbon atoms in the alkenyl group is 2 to 10. According to another embodiment, the number of carbon atoms in the alkenyl group is 2 to 6. Specific examples include, but are not limited to, vinyl, 1-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 3-methyl-1-butenyl, 1,3-butadienyl, allyl, 1-phenylvinyl-1-yl, 2-phenylvinyl-1-yl, 2,2-diphenylvinyl-1-yl, 2-phenyl-2-(naphthyl-1-yl)vinyl-1-yl, 2,2-bis(diphenyl-1-yl)vinyl-1-yl, stilbenyl, and styrenyl.

[0029] In the present specification, the cycloalkyl group is not particularly limited, but preferably has 3 to 60 carbon atoms. According to one embodiment, the cycloalkyl group has 3 to 30 carbon atoms. According to another embodiment, the cycloalkyl group has 3 to 20 carbon atoms. According to another embodiment, the cycloalkyl group has 3 to 6 carbon atoms. Specifically, examples thereof include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, 3-methylcyclopentyl, 2,3-dimethylcyclopentyl, cyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 2,3-dimethylcyclohexyl, 3,4,5-trimethylcyclohexyl, 4-tert-butylcyclohexyl, cycloheptyl, cyclooctyl, and the like.

[0030] In the present specification, the aryl group is not particularly limited, but preferably has 6 to 60 carbon atoms, and may be a monocyclic aryl group or a polycyclic aryl group. According to one embodiment, the aryl group has 6 to 30 carbon atoms. According to one embodiment, the aryl group has 6 to 20 carbon atoms. The monocyclic aryl group may be, but is not limited to, a phenyl group, a biphenyl group, a terphenyl group, etc. The polycyclic aryl group may be, but is not limited to, a naphthyl group, an anthracenyl group, a phenanthryl group, a pyrenyl group, a perylenyl group, a chrysenyl group, a fluorenyl group, etc.

[0031] In the present specification, the fluorenyl group may be substituted, and two substituents may combine with each other to form a spiro structure. When the fluorenyl group is substituted,

[0032]

[0033] It can be, but is not limited to, the following.

[0034] In the present specification, a heteroaryl group is a heterocyclic group that contains at least one of O, N, Si, and S as a heteroatom and has aromaticity, and the number of carbon atoms is not particularly limited, but is preferably 2 to 60 carbon atoms. Examples of heteroaryl groups include thiophene group, furan group, pyrrole group, imidazole group, thiazole group, oxazole group, oxadiazole group, triazole group, pyridyl group, bipyridyl group, pyrimidyl group, triazine group, acridyl group, pyridazine group, pyrazinyl group, quinolinyl group, quinazoline group, quinoxalinyl group, phthalazinyl group, pyrido pyrimidinyl group, pyrido pyrazinyl group, pyrazino pyrazinyl group, isoquinoline group, indole group, carbazole group, benzoxazole group, benzimidazole group, benzothiazole group, benzocarbazole group, benzothiophene group, dibenzothiophene group, benzofuranyl group, phenanthroline group, thiazolyl group, isoxazolyl group, Examples include, but are not limited to, oxadiazolyl group, thiadiazolyl group, benzothiazolyl group, phenothiazinyl group, and dibenzofuranyl group.

[0035] In this specification, the aryl group among the aralkyl group, the aralkenyl group, the alkylaryl group, and the arylamine group is the same as the examples of the aryl group described above. In this specification, the alkyl group among the aralkyl group, the alkylaryl group, and the alkylamine group is the same as the examples of the alkyl group described above. In this specification, the heteroaryl among the heteroarylamine may be applied to the description of the heterocyclic group described above. In this specification, the alkenyl group among the aralkenyl group is the same as the examples of the alkenyl group described above. In this specification, the description of the aryl group described above may be applied to the arylene except that it is a divalent group. In this specification, the description of the heterocyclic group described above may be applied to the heteroarylene except that it is a divalent group. In this specification, the description of the aryl group or the cycloalkyl group described above may be applied to the hydrocarbon ring except that it is not a monovalent group but is formed by combining two substituents. In this specification, the description of the heterocyclic group described above may be applied, except that the heterocyclic group is not monovalent and is formed by combining two substituents.

[0036]

[0037] According to one embodiment of the invention, a method for producing a branched 3-hydroxypropionic acid prepolymer is provided, comprising the steps of: fermenting a strain having 3-hydroxypropionic acid production ability under a polyol to produce a fermentation solution containing the polyol and 3-hydroxypropionic acid; and polymerizing the 3-hydroxypropionic acid under the polyol to produce a branched 3-hydroxypropionic acid prepolymer.

[0038] When producing 3-hydroxypropionic acid by biological methods, other byproducts such as inorganic and organic impurities are also produced. In addition, 3-hydroxypropionic acid has a high possibility of thermal decomposition despite having almost the same boiling point as water, making it difficult to separate it through distillation, which is used in the purification of other organic acids. Therefore, in the past, complex processes such as electrodialysis, ion exchange resin, and SMB (Simulated Moving Bed) were performed to purify 3-hydroxypropionic acid, and these processes had the problem of high equipment costs and process operation costs.

[0039] In this regard, the inventors of the present invention have confirmed that when a strain having 3-hydroxypropionic acid production ability is used to polymerize 3-hydroxypropionic acid using a polyol used in fermentation, a high molecular weight, branched 3-hydroxypropionic acid prepolymer can be produced, and that such a prepolymer exhibits hydrophobicity, so that when washed in the washing process described below, inorganic and organic impurities can be easily removed.

[0040] In addition, since the polyol used in the fermentation of the strain having the ability to produce 3-hydroxypropionic acid in the polymerization process is used without performing a purification process (for example, processes such as electrodialysis, ion exchange resin, and SMB, which require high equipment and process costs, are not performed), the process cost can be significantly reduced compared to the past while being efficient, and ultimately, a 3-hydroxypropionic acid prepolymer can be manufactured with high purity and high yield.

[0041] In particular, in the case of the purification process, there is a problem that the target product of purification (3-hydroxypropionic acid) is lost at each stage, and as the purification process becomes more diverse, the ultimate loss also increases. However, in the case of the above-mentioned embodiment, the number of purification stages in which loss occurs is small, so that the 3-hydroxypropionic acid prepolymer can be manufactured with a high yield.

[0042] In addition, the above embodiment can improve the hydrophobicity of the 3-hydroxypropionic acid prepolymer by controlling the polyol content, polymerization temperature, molecular weight of the prepolymer, content of terminal vinyl groups of the prepolymer, etc. during polymerization to easily remove impurities in the process of washing the 3-hydroxypropionic acid prepolymer.

[0043] Furthermore, high value-added bio-acrylic acid can be produced by thermal decomposition of 3-hydroxypropionic acid prepolymer as described below, and such bio-acrylic acid has the advantage of being easy to separate through distillation.

[0044]

[0045] The method for producing a branched 3-hydroxypropionic acid prepolymer according to the above embodiment includes a step of fermenting a strain having 3-hydroxypropionic acid production ability under a polyol to produce a fermentation solution containing the polyol and 3-hydroxypropionic acid.

[0046] Microorganisms such as strains capable of producing 3-hydroxypropionic acid can produce a 3-hydroxypropionic acid fermentation solution by fermenting low-molecular-weight sugars. These microorganisms can be natural or engineered microorganisms, and the microorganisms can be, for example, bacteria such as cellulolytic bacteria, fungi such as yeast, plants, or protists such as algae, protozoa, or fungal-like protists such as slime molds. A mixture of organisms can be used if the organisms do not cause an adverse reaction.

[0047] For example, a strain having 3-hydroxypropionic acid production ability may include a gene encoding one or more proteins selected from the group consisting of glycerol dehydratase and aldehyde dehydrogenase, or two of the above. In one example, the 3-hydroxypropionic acid producing strain may further include a gene (gdrAB) encoding glycerol dehydratase reactivase (GdrAB). In one example, the 3-hydroxypropionic acid producing strain may further include a gene encoding vitamin B. 12 It may be a strain capable of biosynthesizing .

[0048] The above glycerol dehydratase may be encoded by, but is not limited to, the dhaB (GenBank accession no. U30903.1) gene. The dhaB gene may be an enzyme derived from, but is not limited to, Klebsiella pneumonia. The gene encoding the glycerol dehydratase may include a gene encoding dhaB1, dhaB2, and / or dhaB3. The glycerol dehydratase protein and the gene encoding the same may include mutations in the gene and / or amino acid sequence within a range that maintains an enzymatic activity that decomposes glycerol into 3-hydroxypropanal (3-HPA) and water (H2O).

[0049] The gene (aldH) encoding the above aldehyde dehydrogenase (ALDH) may be, for example, an aldH (GenBank Accession no. U00096.3; EaldH) gene derived from Escherichia coli or an E. coli K12 MG1655 cell line, a puuC gene derived from Klebsiella pneumoniae, and / or a KGSADH gene derived from Azospirillum brasilense, but is not limited thereto. The above aldehyde dehydrogenase protein and the gene encoding the same may include mutations in the gene and / or amino acid sequence within a range that maintains the activity for producing 3-hydroxypropionic acid from 3-hydroxypropanal.

[0050] The medium for producing the above fermentation solution may be selected without limitation within the scope of the purpose for producing 3-hydroxypropionic acid. In one example, the medium may include a polyol such as glycerol as a carbon source. In another example, the medium may be waste glycerol (crude glycerol) and / or pretreated waste glycerol, but is not limited thereto. In one example, the production medium may include vitamin B. 12 may additionally include:

[0051] In the step of producing a fermentation solution containing the polyol and 3-hydroxypropionic acid by fermenting a strain having the ability to produce 3-hydroxypropionic acid under the above polyol, the concentration of 3-hydroxypropionic acid contained in the fermentation solution may be 1 g / L or more and 200 g / L or less, 10 g / L or more and 150 g / L or less, 30 g / L or more and 130 g / L or less, or 40 g / L or more and 100 g / L or less.

[0052] In addition, the fermentation may be a neutral fermentation, for example, the pH may be maintained in a range of 6.0 to 8.0, 6.5 to 7.5, or 6.5 to 7.5, but is not limited thereto. The pH range may be appropriately adjusted as needed. The alkali metal salt may be added for the neutral fermentation. The alkali metal salt may be Mg 2+ , Ca 2+ Or it may include a mixture thereof. In addition, the alkali metal salt may be, but is not limited to, Ca(OH)2 or Mg(OH)2.

[0053]

[0054] In addition, the method for producing a branched 3-hydroxypropionic acid prepolymer according to the above embodiment may further include a step of fermenting a strain having 3-hydroxypropionic acid production ability under the polyol to produce a fermentation broth containing the polyol and 3-hydroxypropionic acid, followed by a step of isolating the strain having 3-hydroxypropionic acid production ability; and / or a step of adding an acid to the fermentation broth containing the polyol and 3-hydroxypropionic acid to produce and isolate metal salt crystals.

[0055] Specifically, after the preparation of the fermentation solution, a strain having the ability to produce 3-hydroxypropionic acid can be separated from the fermentation solution, and the strain separation can be performed by selecting any method known in the art without limitation within the scope of the strain removal purpose. In one example, the strain separation can be performed by performing centrifugation.

[0056] In addition, after the fermentation liquid production step or the strain removal step, an acid may be added to the fermentation liquid to produce and separate metal salt crystals. The metal salt crystals produced by the acid addition may be CaSO4(s) or MgSO4(s), but are not limited thereto. At this time, the acid is not particularly limited as long as it can control the pH of the fermentation liquid to 5 or lower, and may be, for example, one selected from the group consisting of sulfuric acid, hydrochloric acid, phosphoric acid, carbonic acid, and nitric acid. In addition, by adding an acid to the fermentation liquid, the pH of the fermentation liquid can be controlled to 5.0 or lower, 4.0 or lower, 3.0 or lower, 2.0 or lower, 1.0 or lower, or 0.5 or lower.

[0057] In addition, after the fermentation liquid production step, the strain removal step, or the metal salt crystal removal step, 3-hydroxypropionic acid can be protonated by additionally adding an acid or an acid-based catalyst, and this protonation can also be achieved with an acid added in the metal salt crystal removal step without additionally adding an acid.

[0058]

[0059] The method for producing a branched 3-hydroxypropionic acid prepolymer according to the above embodiment includes a step of producing a branched 3-hydroxypropionic acid prepolymer by polymerizing the 3-hydroxypropionic acid under the polyol.

[0060] The above polyol may be a carbon source used for producing a 3-hydroxypropionic acid fermentation solution, a by-product generated after fermentation of a strain having 3-hydroxypropionic acid production ability, or a mixture thereof. The method for producing a branched 3-hydroxypropionic acid prepolymer according to the above embodiment can produce a branched prepolymer by polymerizing 3-hydroxypropionic acid under a polyol used in the fermentation or generated during the fermentation without adding a separate polyol during the reaction during the polymerization of 3-hydroxypropionic acid.

[0061] In addition, the manufacturing method according to the above embodiment does not perform a separate purification process immediately after the fermentation process in order to reuse the polyol for polymerization, so the process is efficient and the process cost is significantly reduced compared to the conventional method, and the loss of the purified product (3-hydroxypropionic acid) due to the purification process can be prevented.

[0062] Furthermore, polyols and inorganic by-products can be easily removed through a subsequent prepolymer washing process, thereby producing a high-purity, high-yield branched 3-hydroxypropionic acid prepolymer.

[0063]

[0064] In addition, since the 3-hydroxypropionic acid is polymerized under the polyol, a branched prepolymer is produced, and since this branched prepolymer has a large molecular weight, impurities can be easily removed during a subsequent washing process. Specifically, in the case of 3-hydroxypropionic acid, dehydration occurs, and the monomer reaction terminal is converted into a vinyl group, thereby terminating the polymerization, and / or a low-molecular-weight cyclic structure is formed during the condensation polymerization process, making it difficult to increase the molecular weight. However, the manufacturing method according to the above embodiment can produce a prepolymer having a large molecular weight and a branched structure by using the polyol in the polymerization process.

[0065] The above polyol is not particularly limited in type as long as it is used for producing a 3-hydroxypropionic acid fermentation liquid, but may include, for example, at least one selected from the group consisting of glycerol, pentaerythritol, 4-arm-poly(ethyleneglycol)n=2~10, di(trimethylolpropane), dipentaerythritol, tripentaerythritol, xylitol, sorbitol, inositol, cholic acid, β-cyclodextrin, and tetrahydroxyperylene.

[0066] In addition, during polymerization of 3-hydroxypropionic acid, the polyol may be included in an amount of 0.01 wt% or more and 10.0 wt% or less relative to 100 wt% of the 3-hydroxypropionic acid, for example, 0.03 wt% or more, 0.05 wt% or more, 0.08 wt% or more, or 10.0 wt% or less, 9.0 wt% or less, 8.0 wt% or less, 7.0 wt% or less, 6.0 wt% or less, 5.0 wt% or less, 4.0 wt% or less, 3.0 wt% or less, 2.0 wt% or less, 1.5 wt% or less, 1.0 wt% or less, 0.8 wt% or less. A branched prepolymer capable of achieving the desired task can be manufactured within the above content range, and if the polyol is contained too little, the branched prepolymer cannot be manufactured, and if the polyol is contained too much, impurities may be generated during polymerization, or a gelation phenomenon may occur.

[0067]

[0068] The polymerization of 3-hydroxypropionic acid under the above polyol can be carried out at a temperature of 70° C. or higher and 100° C. or lower, for example, at a polymerization temperature of 75° C. or higher, 78° C. or higher, 80° C. or higher, 83° C. or higher, or 85° C. or higher, or at a polymerization temperature of 98° C. or lower, 95° C. or lower, 93° C. or lower, or 90° C. or lower. If the polymerization temperature is too low, polymerization hardly progresses, and a 3-hydroxypropionic acid prepolymer having a low molecular weight may be produced, and if the polymerization temperature is too high, 3-hydroxypropionic acid dehydration may occur, and the monomer reaction terminal may be converted into a vinyl group, and a 3-hydroxypropionic acid prepolymer may not be produced.

[0069] The above polymerization can be carried out under a vacuum. Here, the vacuum state means a pressure lower than atmospheric pressure, for example, a pressure of 500 torr or less. Although not particularly limited, the above polymerization can be carried out under a pressure of 100 torr or less, 50 torr or less, 10 torr or less, 1 torr or less, or 0.1 torr or less.

[0070] The above polymerization can be carried out for 1 to 70 hours. Specifically, the polymerization carried out within the above-described vacuum condition and temperature range can be carried out for 2 hours or more, 3 hours or more, 4 hours or more, 5 hours or more, 8 hours or more, 10 hours or more, 15 hours or more, 20 hours or more, and can be carried out for 60 hours or less, 55 hours or less, 50 hours or less, 45 hours or less, 40 hours or less, 35 hours or less, 30 hours or less, 25 hours or less. At this time, the polymerization can be carried out for a period of time during which side reactions are suppressed and a sufficient yield can be secured.

[0071] In addition, the polymerization may be carried out in the absence of a catalyst, or the polymerization may be carried out in the presence of a catalyst. When a catalyst is used, it is advantageous to promote the polymerization reaction and to suppress the formation of cyclic oligomers during the polymerization process. The type of catalyst is not particularly limited as long as it does not hinder the progress of the polymerization reaction or the achievement of the technical problem of the present application. The usable catalyst may be, for example, an acid catalyst or a tin-based catalyst. The acid catalyst may be, for example, a sulfonic acid-based catalyst or may include the same, and the sulfonic acid-based catalyst may include, for example, p-toluenesulfonic acid, m-xylene-4-sulfonic acid, 2-mesitylenesulfonic acid, and / or p-xylene-2-sulfonic acid. In addition, the tin-based catalyst may be, for example, SnCl2 or Sn(oct)2.

[0072] The catalyst may be used within a predetermined content range. For example, the polymerization may be performed using the catalyst in an amount of 0.001 to 1.0 mol% relative to the 3-hydroxypropionic acid. Specifically, the content of the catalyst may be 0.01 mol% or more, 0.05 mol% or more, or 0.1 mol% or more, and the upper limit thereof may be, for example, 0.9 mol% or less, 0.8 mol% or less, 0.7 mol% or less, 0.6 mol% or less, or 0.5 mol% or less. When the catalyst is used within the above-described content range, it may be more advantageous in promoting polymerization while simultaneously suppressing the formation of cyclic oligomers.

[0073]

[0074] In the method for producing a branched 3-hydroxypropionic acid prepolymer according to the above embodiment, the branched 3-hydroxypropionic acid prepolymer can be represented by the following chemical formula 1.

[0075] [Chemical Formula 1]

[0076] R-[A-(B)nC] k

[0077] In the above chemical formula 1,

[0078] R is a trivalent or higher functional group derived from the above polyol,

[0079] A is a direct bond or a linking group derived from ether, sulfide, ester, thioester, ketone, sulfoxide, sulfone, sulfonate ester, amine, amide, imine, imide, or urethane,

[0080] B is a substituent represented by the following chemical formula 2 or chemical formula 3,

[0081] [Chemical Formula 2]

[0082]

[0083] [Chemical Formula 3]

[0084]

[0085] * is the part connected to A, k is an integer greater than or equal to 3, n is an integer from 1 to 700,

[0086] C is a substituent represented by the following chemical formula 4 or chemical formula 5.

[0087] [Chemical Formula 4]

[0088]

[0089] [Chemical Formula 5]

[0090] .

[0091] At this time, branched refers to a polymer of monomers in which each functional group has 3 or more or 4 or more, and the R portion in chemical formula 1 is defined as a branched structure.

[0092] For example, branching structure

[0093] , It can mean a structure such as, but is not limited to, etc. In each branched unit, n can independently have any integer value from 1 to 700.

[0094] In one example, k in Chemical Formula 1 may be an integer greater than or equal to 3, greater than or equal to 4, greater than or equal to 5, greater than or equal to 6, greater than or equal to 7, or greater than or equal to 8. Although not particularly limited, k in Chemical Formula 1 may be less than or equal to 20, less than or equal to 18, less than or equal to 16, less than or equal to 14, less than or equal to 12, less than or equal to 10, less than or equal to 8, or less than or equal to 6.

[0095] In one example, R is substituted or unsubstituted C 1-60 Alkyl, substituted or unsubstituted C 3-60 Cycloalkyl, substituted or unsubstituted C 6-60 Aryl or substituted or unsubstituted C containing one or more of N, O and S 2-60 It may be a trivalent or higher linking group derived from heteroaryl. At this time, at least one of the carbon atoms of the alkyl, cycloalkyl, aryl and heteroaryl may be substituted or unsubstituted with at least one heteroatom or carbonyl selected from the group consisting of N, O and S.

[0096]

[0097] In addition, in the branched 3-hydroxypropionic acid prepolymer, the number ratio of the chemical formula 5 to the sum of the chemical formulas 4 and 5, i.e., the branch terminal vinyl group content, may be 5% or more, 7% or more, 10% or more, 13% or more, 15% or more, 20% or more, 25% or more, 30% or more, or 100% or less, 95% or less, 90% or less, 80% or less, 75% or less, 72% or less, 70% or less, 65% or less, 60% or less, 56% or less. Since the branched 3-hydroxypropionic acid prepolymer exhibits the above-described branch terminal vinyl group content, the content of hydrophobic vinyl groups instead of hydrophilic hydroxyl groups may be increased.

[0098] Furthermore, as the molecular weight of the branched 3-hydroxypropionic acid prepolymer increases through polymerization of 3-hydroxypropionic acid, the ratio of hydrophilic carboxyl groups and hydroxyl groups decreases, resulting in hydrophobicity. Furthermore, the terminal hydroxyl groups of the hydrophobic prepolymer can be converted to vinyl groups, thereby further enhancing hydrophobicity. When such a prepolymer is washed in the washing process described below, inorganic and organic impurities can be easily removed.

[0099] Meanwhile, the number ratio of chemical formula 5 to the sum of chemical formulas 4 and 5 (branch terminal vinyl group content) is 1. H -The vinyl group structure at the end of the prepolymer chain can be determined by measuring it using NMR.

[0100] Specifically, the vinyl group content at the branch terminal is 1 H -Using NMR, the CH peak value (①) of the vinyl group of chemical formula 5 at the branch terminal of each prepolymer and the terminal beta CH peak value (②) of chemical formula 4 can be measured and calculated by the following equation 1.

[0101]

[0102] [Formula 1]

[0103]

[0104] In the above formula 1, ① is the CH peak value of the vinyl group of chemical formula 5 at the branch terminal of the branched 3-hydroxypropionic acid prepolymer, and ② is the terminal beta CH peak value of chemical formula 4 at the branch terminal of the 3-hydroxypropionic acid prepolymer.

[0105] At this time, in the chemical formula 4 or 5, * may be a part connected to B.

[0106]

[0107] Additionally, the branched 3-hydroxypropionic acid prepolymer satisfies an acid value of 150 meq / kg or less. Specifically, the acid value of the branched prepolymer may be, for example, 140 meq / kg or less, 135 meq / kg or less, 130 meq / kg or less, 125 meq / kg or less, 120 meq / kg or less, 115 meq / kg or less, 110 meq / kg or less, 105 meq / kg or less, 100 meq / kg or less, 95 meq / kg or less, 90 meq / kg or less, 85 meq / kg or less, 80 meq / kg or less, 75 meq / kg or less, 70 meq / kg or less, 65 meq / kg or less, 60 meq / kg or less, 55 meq / kg or less, 50 meq / kg or less, 45 meq / kg or less, 40 meq / kg or less, 35 meq / kg or less, or 30 meq / kg or less. Within the acid value range as described above, the branched prepolymer can be in a stable state, and the acid value can be measured by titrating a 0.02 N potassium methoxide solution as a titrant solution.

[0108]

[0109] In addition, the branched 3-hydroxypropionic acid prepolymer may have a weight average molecular weight of 1,800 or more and 90,000 or less, 2,000 or more, 3,000 or more, 5,000 or more, 7,000 or more, 9,000 or more, 10,000 or more, or 85,000 or less, 80,000 or less, 75,000 or less, 70,000 or less, 65,000 or less, 60,000 or less, 50,000 or less, 40,000 or less, 30,000 or less, or 20,000 or less.

[0110] In addition, the branched 3-hydroxypropionic acid prepolymer may have a number average molecular weight of 1,200 or more and 80,000 or less, 1,500 or more, 1,800 or more, 2,000 or more, 3,000 or more, 5,000 or more, 7,000 or more, 8,000 or more, or 75,000 or less, 70,000 or less, 65,000 or less, 60,000 or less, 55,000 or less, 50,000 or less, 45,000 or less, 40,000 or less, 35,000 or less, 30,000 or less, 25,000 or less, 20,000 or less, 15,000 or less, or 10,000 or less.

[0111] If the weight average molecular weight and number average molecular weight of the branched 3-hydroxypropionic acid prepolymer are excessively low, the prepolymer may exhibit hydrophilicity, making it difficult to remove impurities contained in the prepolymer during the washing process. In particular, it may be difficult to recover the prepolymer from which impurities have been removed during layer separation after the washing process. If the weight average molecular weight and number average molecular weight are excessively high, the prepolymer may easily coagulate during layer separation after the subsequent washing process, making process control difficult. In addition, it may be difficult to manufacture acrylic acid during the subsequent thermal decomposition process.

[0112] Additionally, the branched prepolymer may have a polydispersity index (PDI) within a range of 1.0 to 13.0. Specifically, the polydispersity index (PDI) of the prepolymer may be, for example, 1.2 or more, 1.4 or more, 1.6 or more, 1.8 or more, 2.0 or more, 3.0 or more, and its upper limit may be, for example, 12.0 or less, 11.5 or less, 11.0 or less, 10.5 or less, 10.0 or less, 9.5 or less, 9.0 or less, 8.5 or less, 8.0 or less, 7.5 or less, 6.5 or less, 6.0 or less, 5.5 or less, 5.0 or less, 4.0 or less.

[0113]

[0114] In addition, when polymerizing the above 3-hydroxypropionic acid, a linear 3-hydroxypropionic acid prepolymer can also be produced in addition to a branched 3-hydroxypropionic acid prepolymer, but the branched prepolymer can be included in an amount of 70 wt% or more, 80 wt% or more, 85 wt% or more, 90 wt% or more, 95 wt% or more, or 100 wt% of the total of the branched and linear prepolymers.

[0115] Since the branched 3-hydroxypropionic acid prepolymer has a significantly larger molecular weight than the linear 3-hydroxypropionic acid prepolymer and exhibits hydrophobicity, impurities contained in the prepolymer can be easily removed during the washing process.

[0116]

[0117] The method for producing a branched 3-hydroxypropionic acid prepolymer according to the above embodiment may include a step of washing the branched 3-hydroxypropionic acid prepolymer.

[0118] The washing process is a simple and inexpensive process that uses a hydrophilic solvent such as water to remove impurities contained in a target material. However, it is difficult to remove impurities from the monomer 3-hydroxypropionic acid by washing, but the branched 3-hydroxypropionic acid prepolymer manufactured by the manufacturing method according to the above embodiment exhibits hydrophobicity, so that impurities such as inorganic ions can be easily removed by washing.

[0119] Accordingly, if the branched 3-hydroxypropionic acid prepolymer is not washed, the prepolymer may contain a large amount of impurities, particularly hydrophilic inorganic impurities, which may lower the purity of the prepolymer. In addition, if the prepolymer is later pyrolyzed to convert it into another monomer such as acrylic acid, the purity of the monomer may also be lowered, and the time required for pyrolysis and purification may also be excessive due to the impurities.

[0120] For example, impurities can be removed by mixing the above-mentioned branched 3-hydroxypropionic acid prepolymer with a washing solution, and when the impurities are removed by mixing the prepolymer with the washing solution while it is flowable, the purity of the final recovered prepolymer can be higher.

[0121] In addition, after mixing or centrifuging the liquid prepolymer and the washing solution, the prepolymer can be separated into an oil phase (or lower layer) containing the prepolymer and an aqueous phase (or upper layer) containing the washing solution, thereby recovering a high-purity prepolymer.

[0122] In addition, the washing may be performed at a temperature of 60°C or higher and 90°C or lower and for a time of 1 minute or higher and 30 minutes or lower, and the washing temperature may be, for example, 63°C or higher, 65°C or higher, 67°C or higher, 70°C or higher, 72°C or higher, or 88°C or lower, 87°C or lower, or 86°C or lower. If the washing temperature is excessively low, the prepolymer may not exhibit flowability, resulting in low impurity removal efficiency, and if the washing temperature is excessively high, the prepolymer may be hydrolyzed, resulting in loss of 3-hydroxypropionic acid.

[0123] Additionally, the washing may be performed for a time of 3 minutes or more, 5 minutes or more, 7 minutes or more, 10 minutes or more, 25 minutes or less, 20 minutes or less, or 15 minutes or less. If the washing time is too short, impurities may not be removed, and if the washing time is too long, the prepolymer may be hydrolyzed, shortening its length and causing loss of 3-hydroxypropionic acid.

[0124]

[0125] The above washing may be performed with a washing solution containing water and / or a basic compound. The washing solution may be, for example, ammonia water, and the basic compound is not particularly limited as long as it is a basic compound that does not contain a metal ion, but examples thereof include quaternary ammonium compounds, amines, etc.

[0126] Examples of the above quaternary ammonium compounds include tetramethylammonium hydroxide (TMAH), trimethyl-2-hydroxyethylammonium hydroxide (choline), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylphenyl ammonium hydroxide, and benzyltrimethyl ammonium hydroxide.

[0127] The above amine may be a first-grade aliphatic amine, a second-grade aliphatic amine, a tertiary aliphatic amine, or an alicyclic amine. For example, the first-grade aliphatic amine may be monoethanol amine, ethylene diamine, 2-(2-amino ethoxy ethanol), 2-(2-amino ethylamino) ethanol, diethylene triamine, triethylene tetramine, etc.; the second-grade aliphatic amine may be diethanol amine, N-methyl amino ethanol, N-hydroxy ethyl amino ethanol, dipropyl amine, 2-ethyl amino ethanol, etc.; the tertiary aliphatic amine may be triethanol amine, dimethyl amino ethanol, ethyldiethanol amine, etc.; and the alicyclic amine may be cyclopentyl amine, cyclohexyl amine, etc.

[0128] The content of the basic compound included in the above-mentioned cleaning solution may be included in an amount of 1 wt% or more, 3 wt% or more, 5 wt% or more, 7 wt% or more, 8 wt% or more, or 10 wt% or more, and may be included in an amount of 30 wt% or less, 25 wt% or less, 20 wt% or less, 15 wt% or less, or 10 wt% or less, based on 100 wt% of the total cleaning solution.

[0129] In addition, during the above washing, the washing solution can be used in a weight of 1.0 times or more and 30.0 times or less relative to the weight of the prepolymer, for example, it can be used in a weight of 1.2 times or more, 1.4 times or more, 1.5 times or more, 2.0 times or more, 3.0 times or more, and 25.0 times or less, 20.0 times or less, 15.0 times or less, or 10.0 times or less.

[0130] Additionally, the purity of the recovered prepolymer after the washing process can be 90% or more, 93% or more, 95% or more, 98% or more, 99% or more, or 100%.

[0131]

[0132] According to another embodiment of the invention, a method for producing acrylic acid is provided, comprising the steps of: fermenting a strain having the ability to produce 3-hydroxypropionic acid under a polyol to produce a fermentation solution containing the polyol and 3-hydroxypropionic acid; polymerizing the 3-hydroxypropionic acid under the polyol to produce a branched 3-hydroxypropionic acid prepolymer; and thermally decomposing the branched 3-hydroxypropionic acid prepolymer to produce acrylic acid.

[0133] In the above acrylic acid manufacturing method, the 'step of fermenting a strain having 3-hydroxypropionic acid production ability under a polyol to produce a fermentation broth containing the polyol and 3-hydroxypropionic acid; the step of polymerizing the 3-hydroxypropionic acid under the polyol to produce a branched 3-hydroxypropionic acid prepolymer' is the same as the above-described branched 3-hydroxypropionic acid prepolymer manufacturing method, and, like the above manufacturing method, the step of isolating the strain having 3-hydroxypropionic acid production ability; the step of adding an acid to the fermentation broth containing the polyol and 3-hydroxypropionic acid to produce and separate metal salt crystals; and / or the step of washing the branched 3-hydroxypropionic acid prepolymer may be further included.

[0134]

[0135] The method for producing acrylic acid according to the above other embodiment includes a step of producing acrylic acid by thermally decomposing the branched 3-hydroxypropionic acid prepolymer.

[0136] The above acrylic acid is manufactured by thermal decomposition of a prepolymer polymerized with 3-hydroxypropionic acid manufactured through a biological process, and is environmentally friendly and economical. The above acrylic acid can be recycled into a bio-superabsorbent polymer (SAP) or bio-acrylate.

[0137] The above thermal decomposition can be carried out at a temperature of 170°C or higher and 250°C or lower, for example, 180°C or higher, 185°C or higher, 190°C or higher, 195°C or higher, 240°C or lower, 230°C or lower, 225°C or lower, 220°C or lower, 215°C or lower, or 210°C or lower. If the thermal decomposition temperature is too low, thermal decomposition of the branched 3-hydroxypropionic acid prepolymer may not be carried out, and if the thermal decomposition temperature is too high, the cost of operating the thermal decomposition process may increase, or a large amount of unexpected impurities may be generated.

[0138] The above acrylic acid may have a biocarbon content of 80 wt% or more as measured by ASTM 6866-21, for example, 85 wt% or more, 90 wt% or more, 95 wt% or more, or 100 wt%. The biocarbon content refers to the biocarbon content with respect to the total carbon content included in the acrylic acid, and the larger this value, the more environmentally friendly the compound may be. As a measuring method, for example, carbon atoms included in the target compound may be made into graphite or carbon dioxide gas and measured with a mass spectrometer, or measured according to liquid scintillation spectrometry. At this time, together with the mass spectrometer, etc. 14 C ion 12By using an accelerator to separate the two isotopes from the C ion, the content and content ratio can be measured using a mass spectrometer.

[0139] According to the present invention, a method for producing a high molecular weight and high purity branched prepolymer from low purity crude 3-hydroxypropionic acid at an efficient and low process cost and producing bio-acrylic acid by thermal decomposition thereof can be provided.

[0140] Hereinafter, embodiments of the present invention will be described in more detail in the following examples. However, the following examples are merely illustrative of embodiments of the present invention, and the content of the present invention is not limited by the following examples.

[0141]

[0142] Example 1

[0143] (1) Production and purification of 3-hydroxypropionic acid fermentation solution

[0144] A recombinant vector was constructed by introducing genes encoding glycerol dehydratase and aldehyde dehydrogenase, which are known to produce 3-hydroxypropionic acid (3HP) using glycerol as a substrate. The constructed recombinant vector was introduced into E. coli W3110 strain to construct a 3-hydroxypropionic acid-producing strain.

[0145] More specifically, the BtuR gene encoding adenosyltransferase was cloned into plasmid pCDF containing a gene encoding glycerol dehydratase (dhaB), a gene encoding aldehyde dehydrogenase (aldH), and a gene encoding glycerol dehydratase reactivase (gdrAB), and the pCDF_J23101_dhaB_gdrAB_J23100_aldH_btuR vector was introduced into W3110 strain (KCCM 40219) by electroporation using an electroporation device (Bio-Rad, Gene Pulser Xcell) to construct a 3-hydroxypropionic acid producing strain. The process for producing a 3-hydroxypropionic acid producing strain of Preparation Example 1 and the vector, primers, and enzymes used were performed with reference to Example 1 of Korean Patent Publication No. 10-2020-0051375.

[0146] The prepared 3-hydroxypropionic acid-producing strain was fermented at 35°C in a 5 L fermenter using crude glycerol as a carbon source to produce 3-hydroxypropionic acid. To prevent a decrease in pH due to 3-hydroxypropionic acid production, calcium hydroxide (Ca(OH)2), an alkali metal salt, was added to maintain the pH at neutral during fermentation.

[0147] After fermentation culture, the strain was removed by centrifugation (4000 rpm, 10 min, 4 ℃), and the fermentation broth was titrated to pH 2 using sulfuric acid (H2SO4). Afterwards, the mixture was evaporated and concentrated under the conditions of 45 ℃ and 20 torr, and the gypsum (Ca(SO)4) crystals generated during the sulfuric acid titration process were removed through solid-liquid separation. Afterwards, 0.2 wt% of sulfuric acid was added to perform protonation of 3-hydroxypropionic acid, and water was distilled for 4 hours under the conditions of 80 ℃ and 60 torr to produce 3-hydroxypropionic acid. At this time, the 3-hydroxypropionic acid contains glycerol in an amount of 0.08 wt% based on 100 wt% of 3-hydroxypropionic acid.

[0148] (2) Prepolymer manufacturing

[0149] 80 g of 3-hydroxypropionic acid containing the above glycerol and 250 mg of p-toluenesulfonic acid (p-TSA) catalyst were added to a 100 ml glass reactor, and polymerization was performed for 24 hours at 90°C and under FV (Full Vacuum) conditions to produce a branched 3-hydroxypropionic acid prepolymer (weight average molecular weight: 5,000, number average molecular weight: 3,000).

[0150] (3) Prepolymer washing

[0151] A washing solution was prepared by mixing 1000 ml of water and 100 ml of ammonia water, and the 3-hydroxypropionic acid prepolymer was washed twice at a speed of 150 rpm for 10 minutes at a temperature of 85°C. At this time, the washing solution was used in an amount 1.5 times the weight of the 3-hydroxypropionic acid prepolymer. Afterwards, the lower layer containing the washed prepolymer was recovered through phase separation (layer separation), and dried in an oven at 40°C for 20 hours, and finally the dried 3-hydroxypropionic acid prepolymer (purity: 99% (excluding water), moisture content: <5 wt%) was recovered.

[0152]

[0153] Example 2

[0154] A 3-hydroxypropionic acid prepolymer was prepared in the same manner as in Example 1, except that the prepolymer was not washed.

[0155]

[0156] Reference Example 1

[0157] A strain for producing 3-hydroxypropionic acid was cultured using the same method as in Example 1 to produce 3-hydroxypropionic acid, and the strain was removed by centrifugation (4000 rpm, 10 minutes, 4°C). The primary fermentation liquid was purified (primary purification) using activated carbon. Specifically, activated carbon was added to the fermentation liquid from which the cells had been removed by centrifugation, mixed well, and then centrifuged again to separate the activated carbon. Afterwards, the fermentation liquid from which the activated carbon had been separated was filtered through a 0.7 um filter paper with a vacuum pump to purify the 3-hydroxypropionic acid fermentation liquid.

[0158] The concentration of 3-hydroxypropionic acid in the fermentation solution that completed the first purification is 50 to 100 g / L, and the fermentation solution is concentrated to a concentration of 600 g / L using a rotary evaporator (50°C, 50 mbar) to prepare a concentrate. Ethanol in an amount twice the volume of the concentrate is added and stirred (300 rpm) at room temperature to produce Ca(3HP)2 crystals. At this time, the concentration of the alkali metal salt in the concentrate was 493.3 g / L (based on Ca(OH)2). The produced crystals are washed three times using ethanol (EtOH) and dried in an oven at 50°C to finally recover the crystals.

[0159] An aqueous solution containing 600 g / L of the recovered Ca(3HP)2 crystals was prepared and stirred for 10 minutes at a temperature of 25°C and 350 rpm. 37 m L of a 5M sulfuric acid solution was added uniformly to 77 m L of the aqueous solution over 5 minutes and stirred for an additional 30 minutes to form a slurry containing CaSO4 precipitate and 3-hydroxypropionic acid. To separate the CaSO4 precipitate, filtration was performed using a filtration flask and a vacuum pump, and a filtrate containing 3-hydroxypropionic acid was obtained.

[0160]

[0161] evaluation

[0162] 1. Measurement of inorganic impurity content

[0163] The content of inorganic impurities in the 3-hydroxypropionic acid prepolymer of Example 1 and the 3-hydroxypropionic acid of Reference Example 1, which were finally recovered after the washing, was measured using ICP-OES (Inductively Coupled Plasma - Optical Emission Spectrometry), and the results are shown in Table 1 below. Meanwhile, if not detected, it was indicated as ND (Not Detect).

[0164] Specifically, 0.5 mL of nitric acid was added to approximately 0.1 g of the sample, and the sample was dissolved by shaking overnight at room temperature. To promote the reaction of the sample, a small amount of hydrogen peroxide was added to dissolve it, and when the sample was completely dissolved and clear, it was diluted to 10 mL with tertiary ultrapure water, and the undissolved components were removed using a 0.45 μm PTFE filter, and the remaining filtrate was put into ICP-OES equipment (AVIO 500, Perkin Elmer) to perform component analysis.

[0165] <ICP-OES 분석조건>

[0166] RF Power: 1300W

[0167] Torch Height: 15 mm

[0168] Plasma gas flow rate: 15 L / min

[0169] Sample gas flow rate: 0.8 L / min

[0170] Auxiliary gas flow rate: 0.20 L / min

[0171] Pump speed: 1.5 ml / min

[0172]

[0173] 2. Yield measurement

[0174] The yield of the 3-hydroxypropionic acid prepolymer of Example 1 finally recovered after the above washing was measured through weight measurement and GPC / FT-RI, and the yield of 3-hydroxypropionic acid of Reference Example 1 was measured through concentration measurement through HPLC (high performance liquid chromatography), and the results are shown in Table 1 below.

[0175] Specifically, the measurement by GPC was performed using a 150C ALC / GPC (manufactured and sold by Waters Assoc. Co., USA), and the measurement by FT-IR was performed by dissolving 20 to 30 mg of a sample in 15 ml of trichlorobenzene having a temperature of 140°C, and applying 500 to 1,000 μl of the obtained solution to an FT-IR device (Perkin-Elmer 1760X, Perkin Elmer Cetus, USA).

[0176] In addition, HPLC analysis was performed using an HPLC system (e2695 separations module, 2998 photodiode array detector) from Waters, and the column used was Capcellpak C18 (4.6 mm ID X 50 mm L, particle size: 3 μm) from Shiseido at 40°C. After degassing acetonitrile (ACN, for HPLC, JT Baker) and ultrapure water (MILLIPORE, Mili-Q, 18.2 MΩ) as the mobile phase, the ratio of ACN / H2O was gradient-flowed from 20 / 80 (v / v) to 60 / 40 (v / v) over 20 minutes, and the flow rate was set to 1 mL / min. 10 uL of the analysis sample was injected, and the chromatogram was measured at 280 nm using a photodiode array detector (PDA).

[0177]

[0178] Inorganic Impurity Content (ppm)Yield (%)Na + K + Ca 2+ Cl - S - P - Example 11090237189142150N.D.93 Example 22308237723537031275373095 Reference Example 12140356389320027202792

[0179] According to Table 1 above, Examples 1 and 2 confirmed that a hydrophobic branched 3-hydroxypropionic acid prepolymer (weight average molecular weight: 5,000, number average molecular weight: 3,000) was produced by polymerizing 3-hydroxypropionic acid under glycerol used in the 3-hydroxypropionic acid production process. In addition, Examples 1 and 2 were confirmed to have a high yield due to a small loss of 3-hydroxypropionic acid due to the fewer steps of the purification process compared to the conventional purification process, and to have a higher yield than Reference Example 1, which includes an activated carbon treatment process, an electrodialysis process, etc.

[0180] In particular, Example 1, which performed a process of washing the prepolymer, confirmed that it contained less inorganic impurities and showed an equivalent level of yield with a similar content to Reference Example 1 with only a polymerization process and a water washing process, even though it did not perform two activated carbon treatment processes, an electrodialysis process, and a purification process using an ion exchange resin as in Reference Example 1. Meanwhile, sulfur ions (S - ) is due to the catalyst used during the polymerization process, it is expected that the amount of sulfur ions contained can be controlled by controlling the amount of catalyst used in the polymerization process.

[0181]

[0182] Example 3: Preparation of acrylic acid

[0183] 10 g of the 3-hydroxypropionic acid prepolymer manufactured and washed in Example 1 was placed in a flask and heated to 200°C, and the distilled acrylic acid was then recovered. After the reaction, a total of 3 g of acrylic acid was recovered (recovery rate: 30%).

[0184]

[0185] Example 4: Preparation of acrylic acid

[0186] 10 g of the 3-hydroxypropionic acid prepolymer manufactured and washed in Example 1 and 10 mg of hydroquinone (polymerization inhibitor) were placed in a flask and heated to 200°C, and the distilled acrylic acid was then recovered. After the reaction, a total of 7 g of acrylic acid was recovered (recovery rate: 70%).

[0187]

[0188] Example 5: Preparation of acrylic acid

[0189] 10 g of the 3-hydroxypropionic acid prepolymer manufactured and washed in Example 1 and 0.3 g of N,N,N',N'',N''-pentamethyldiethylenetriamine (high boiling point organic base) were added to a flask and heated to 200°C, and then the distilled acrylic acid was recovered. After the reaction, a total of 8.5 g of acrylic acid was recovered (recovery rate: 85%).

[0190]

[0191] Example 6: Preparation of acrylic acid

[0192] 10 g of the 3-hydroxypropionic acid prepolymer manufactured and washed in Example 1 and 15 mg of sodium hydroxide (NaOH, an inorganic base) were placed in a flask and heated to 200°C, and the distilled acrylic acid was then recovered. After the reaction, a total of 5 g of acrylic acid was recovered (recovery rate: 50%).

Claims

1. A step of fermenting a strain having the ability to produce 3-hydroxypropionic acid under polyol to produce a fermentation solution containing the polyol and 3-hydroxypropionic acid: and A step of polymerizing the 3-hydroxypropionic acid under the polyol to produce a branched 3-hydroxypropionic acid prepolymer; A method for producing branched 3-hydroxypropionic acid prepolymer.

2. In paragraph 1, A method for producing a branched 3-hydroxypropionic acid prepolymer, wherein the above polymerization is performed at a temperature of 70°C or higher and 100°C or lower.

3. In paragraph 1, A method for producing a branched 3-hydroxypropionic acid prepolymer, wherein the polyol comprises at least one selected from the group consisting of glycerol, pentaerythritol, 4-arm-poly(ethyleneglycol)n=2-10, di(trimethylolpropane), dipentaerythritol, tripentaerythritol, xylitol, sorbitol, inositol, cholic acid, β-cyclodextrin, and tetrahydroxyperylene.

4. In paragraph 1, A method for producing a branched 3-hydroxypropionic acid prepolymer, wherein the polyol is contained in an amount of 0.01 wt% or more and 10.0 wt% or less relative to 100 wt% of the 3-hydroxypropionic acid during the polymerization.

5. In paragraph 1, A method for producing a branched 3-hydroxypropionic acid prepolymer, further comprising a step of washing the branched 3-hydroxypropionic acid prepolymer.

6. In paragraph 5, A method for producing a branched 3-hydroxypropionic acid prepolymer, wherein the washing is performed with a washing solution containing water and / or a basic compound.

7. In paragraph 5, A method for producing a branched 3-hydroxypropionic acid prepolymer, wherein the washing is performed at a temperature of 60°C or higher and 90°C or lower and for a time of 1 minute or higher and 30 minutes or lower.

8. In paragraph 1, After the step of fermenting a strain having the ability to produce 3-hydroxypropionic acid under the above polyol, and producing a fermentation liquid containing the above polyol and 3-hydroxypropionic acid, A step of isolating a strain having the above 3-hydroxypropionic acid production ability; and / or A method for producing a branched 3-hydroxypropionic acid prepolymer, further comprising the step of adding an acid to a fermentation solution containing the polyol and 3-hydroxypropionic acid to produce and separate metal salt crystals.

9. In paragraph 1, The above branched 3-hydroxypropionic acid prepolymer is represented by the following chemical formula 1, and is a method for producing a branched 3-hydroxypropionic acid prepolymer: [Chemical Formula 1] R-[A-(B)n-C] k In the above chemical formula 1, R is a trivalent or higher functional group derived from the above polyol, A is a direct bond or a linking group derived from ether, sulfide, ester, thioester, ketone, sulfoxide, sulfone, sulfonate ester, amine, amide, imine, imide, or urethane, B is a substituent represented by the following chemical formula 2 or chemical formula 3, [Chemical Formula 2] [Chemical Formula 3] * is the part connected to A, k is an integer greater than or equal to 3, n is an integer from 1 to 700, C is a substituent represented by the following chemical formula 4 or chemical formula 5. [Chemical Formula 4] [Chemical Formula 5] .

10. In paragraph 9, A method for producing a branched 3-hydroxypropionic acid prepolymer, wherein the number ratio of chemical formula 5 to the sum of chemical formulas 4 and 5 is 5% or more.

11. In paragraph 1, A method for producing a branched 3-hydroxypropionic acid prepolymer, wherein the above branched 3-hydroxypropionic acid prepolymer has a weight average molecular weight of 1,800 or more and 90,000 or less.

12. A step of fermenting a strain having the ability to produce 3-hydroxypropionic acid under polyol to produce a fermentation solution containing the polyol and 3-hydroxypropionic acid; A step of polymerizing the 3-hydroxypropionic acid under the polyol to produce a branched 3-hydroxypropionic acid prepolymer; and A step of producing acrylic acid by thermally decomposing the above branched 3-hydroxypropionic acid prepolymer; comprising; Method for manufacturing acrylic acid.

13. In paragraph 12, A method for producing acrylic acid, wherein the above thermal decomposition is performed at a temperature of 170°C or higher and 250°C or lower.

14. In paragraph 12, A method for producing acrylic acid, wherein the acrylic acid has a biocarbon content of 80 wt% or more as measured by ASTM 6866-21.

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