Method for manufacturing organic acid or salt thereof

Abstract

To provide a method for manufacturing an organic acid or a salt thereof by which it is possible to manufacture the organic acid or the salt thereof by a more simple operation.SOLUTION: One embodiment of the present invention provides a method for manufacturing an organic acid or a salt thereof. The method includes: preparing a raw material including carbohydrate and a catalyst including a piezoelectric material; and obtaining an organic acid or a salt thereof by activating the catalyst by applying impact force to the catalyst so as to decompose the carbohydrate by the action of the activated catalyst.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for producing an organic acid or a salt thereof. [Background technology]

[0002] Organic acids are highly useful compounds because they can be used as raw materials for synthesizing polymer compounds. A method for producing such organic acids by culturing specific cyanobacteria has been proposed (see Patent Document 1). However, this method requires complicated procedures such as preparing the specific cyanobacteria, culturing them, and collecting the organic acid. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-153524 Summary of the Invention [Problem to be solved by the invention]

[0004] In view of the above circumstances, the present invention provides a method for producing an organic acid or a salt thereof, which can produce an organic acid or a salt thereof by a simpler procedure. [Means for solving the problem]

[0005] According to one aspect of the present invention, there is provided a method for producing an organic acid or a salt thereof, which comprises the steps of: preparing a raw material containing a carbohydrate and a catalyst containing a piezoelectric material; activating the catalyst by applying an impact force to the catalyst; and decomposing the carbohydrate by the action of the activated catalyst to obtain the organic acid or a salt thereof.

[0006] According to this embodiment, the organic acid or a salt thereof can be produced by a simpler procedure. [Brief explanation of the drawings]

[0007] [Figure 1]Photographs showing the process of Example 1. [Figure 2] 1 is a photograph showing the state of the product of Example 2. [Figure 3] 1 is an NMR chart analyzing the product or glucose obtained in Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0008] The following describes embodiments of the present invention. Various features shown in the following embodiments can be combined with each other. The method for producing an organic acid or a salt thereof of this embodiment includes a first step of preparing a raw material containing a carbohydrate and a catalyst containing a piezoelectric material, a second step of activating the catalyst by applying an impact force to the catalyst, and decomposing the carbohydrate by the action of the activated catalyst to obtain an organic acid or a salt thereof, and a third step of recovering the organic acid or a salt thereof from the product. Each step will be explained below in order.

[0009] <First step> First, a raw material containing a carbohydrate and a catalyst containing a piezoelectric material are prepared. [Carbohydrates] Carbohydrates are classified into sugars, oligosaccharides, polysaccharides and sugar alcohols. Examples of sugars include monosaccharides such as trioses such as glyceraldehyde, tetroses such as erythrose, pentoses such as arabinose, rhamnose, and xylose, hexoses such as glucose, fructose, galactose, mannose, and sorbose, and disaccharides such as sucrose, maltose, isomaltose, trehalose, lactose, lactulose, and cellobiose.

[0010] Examples of oligosaccharides include maltotriose, raffinose, melezitose, acarbose, and stachyose. Examples of polysaccharides include xylan, panose, glycogen, starch, modified starch, cellulose, dextrin, glucan, fructan, hydroxylated hemicellulose, and chitin. Examples of sugar alcohols include maltitol, lactitol, sorbitol, mannitol, xylitol, palatinite, erythritol, and reduced oligosaccharides.

[0011] As the carbohydrate, sugars, oligosaccharides, or polysaccharides are preferred because they are easy to handle. Note that the carbohydrate may be used alone or in combination of two or more kinds. Among these, the carbohydrate (saccharide or oligosaccharide) preferably contains at least one selected from the group consisting of glucose, galactose, mannose, fructose, rhamnose, arabinose, xylose, erythrose, glyceraldehyde, maltose, cellobiose, lactose, and maltotriose. These carbohydrates are compounds with small molecular weights, and therefore can be decomposed into smaller molecules in a relatively short time by the action of a catalyst described below, and converted into an organic acid or a salt thereof. From the viewpoint of increasing the yield of the organic acid or its salt, it is preferable to select a compound with a smaller molecular weight (number of carbon atoms) as the carbohydrate.

[0012] Furthermore, the carbohydrate (polysaccharide) preferably contains at least one selected from the group consisting of xylan, cellulose, and starch. These carbohydrates are readily available as raw materials, and can be relatively easily recovered (purified) from the raw materials. Examples of raw materials from which carbohydrates can be recovered include sugarcane, sugar beet, wood, rice straw, wheat straw, rice husks, agricultural residues, herbaceous plants, seaweed, and (waste) molasses. Such raw materials may be used as raw materials either directly or after pretreatment. Examples of pretreatment include cutting, crushing, heat treatment, acid treatment, and alkali treatment. The raw material preferably further contains a salt for forming a salt of the organic acid. If a raw material containing a salt is used, it is easy to form a salt of the organic acid in preference to the organic acid. The salt is appropriately selected depending on the type of the target organic acid salt. Examples of the salt include hydrochlorides, nitrates, sulfates, carbonates, and phosphates of potassium, sodium, calcium, magnesium, iron, etc. Specifically, these salts may be used alone or in combination of two or more.

[0013] [catalyst] The catalyst contains a piezoelectric material, which emits electrons when subjected to an impact force, and it is believed that these electrons promote the decomposition of carbohydrates. The piezoelectric material may be polyvinylidene fluoride, quartz, or the like, but is preferably a metal oxide (piezoelectric ceramic) having a perovskite crystal structure, since metal oxides have a relatively high mechanical strength that can withstand impact forces and are therefore less likely to collapse even when subjected to impact forces. Examples of such metal oxides include lead titanate, barium titanate, lead zirconate titanate, lead zirconate, lead lanthanum titanate, lithium tantalate, lithium niobate, potassium niobate, lead lanthanum zirconate titanate, lead zirconium niobate titanate, magnesium zirconium niobate lead titanate, bismuth layer structure compounds, etc. These metal oxides may be used alone or in combination of two or more.

[0014] The content of the piezoelectric material in the catalyst is not particularly limited, but is preferably about 75% by mass or more, more preferably about 85% by mass or more, even more preferably about 95% by mass or more, and may be 100% by mass. The catalyst may be in the form of, for example, particles, flakes, lumps, pellets, blocks, or plates. The particulate catalyst (hereinafter also referred to as "catalyst particles") preferably has an average particle diameter of approximately 0.01 μm to 100 μm, more preferably approximately 0.1 μm to 50 μm, and even more preferably approximately 0.3 μm to 8 μm. Here, the average particle diameter is the volume cumulative particle diameter D50 value measured by a laser diffraction particle size analyzer. Catalyst particles having such an average particle diameter are easy to handle and can sufficiently increase the contact area with the raw material.

[0015] <Second process> Next, the catalyst is activated by applying an impact force to it, which causes the carbohydrate to be decomposed by the action of the activated catalyst (the action of the released electrons) to produce an organic acid or a salt thereof. In this operation, for example, the raw material may be placed on a flat catalyst plate and struck with a striking tool (such as a hammer). In this operation, for example, an impact force may be applied to the mixture of the raw material and the catalyst using a pulverizer, kneader, etc. In this case, it is easier to apply the impact force more uniformly and reliably to the catalyst.

[0016] Examples of the grinding machine include a ball mill (planetary ball mill), bead mill, hammer mill, sand mill, attritor, vibration mill, cutter mill, stamp mill, pin mill, colloid mill, atomizer, rotoplex, jet mill (fluidized bed jet mill, collision plate jet mill), roll crusher, mortar, crusher, high-pressure disperser, and stone mill grinder. Examples of the kneading machine include a kneader, an extruder, a two-roll mill, a three-roll mill, a lab blast mill, a Banbury mixer, a ribbon mixer, a Henschel mixer kneading roll, a single-screw extruder, a twin-screw extruder, and a multi-screw extruder having three or more screws.

[0017] Among these, in consideration of ease of handling, it is preferable to use a ball mill or a bead mill, which applies an impact force to the catalyst (catalyst particles) by colliding balls with the catalyst (catalyst particles). The size of the balls used in the ball mill or bead mill may be selected appropriately depending on the type of carbohydrate, the amount of carbohydrate to be processed, etc. The diameter of the balls is preferably about 0.03 mmφ or more and 40 mmφ or less, more preferably about 0.3 mmφ or more and 30 mmφ or less, and even more preferably about 5 mmφ or more and 10 mmφ or less. Examples of materials that can be used to form the ball include ceramic materials such as zirconium oxide and silicon nitride, and hard materials such as metal materials such as stainless steel, chrome steel, and tungsten carbide.

[0018] The rotation speed of the ball mill may be set appropriately depending on the type of carbohydrate, the amount of carbohydrate to be processed, etc. The rotation speed is preferably about 100 rpm or more and 5000 rpm or less, more preferably about 200 rpm or more and 4000 rpm or less, even more preferably about 300 rpm or more and 3000 rpm or less, and particularly preferably about 400 rpm or more and 1000 rpm or less. Note that by alternately repeating high-speed and low-speed rotation, it is possible to prevent a decrease in the carbohydrate processing speed while suppressing heat generation due to collision energy generated when an impact force is applied to the catalyst. The processing time may also be set appropriately depending on the type of carbohydrate, the amount of carbohydrate to be processed, etc. The processing time is preferably about 1 minute to about 10 hours, more preferably about 2 minutes to about 7.5 hours, even more preferably about 3 minutes to about 5 hours, particularly preferably about 4 minutes to about 2.5 hours, and most preferably about 5 minutes to about 1 hour.

[0019] The amount of carbohydrates to be treated at one time is preferably about 5 to 500 parts by mass, more preferably about 10 to 250 parts by mass, and even more preferably about 15 to 100 parts by mass, relative to 100 parts by mass of catalyst. By setting the amount of carbohydrates to be treated at one time within the above range, sufficient decomposition can be achieved regardless of the type of carbohydrate. When a salt is used in combination, the amount added is preferably about 10 to 500 parts by mass, more preferably about 15 to 400 parts by mass, and even more preferably about 20 to 300 parts by mass, per 100 parts by mass of the carbohydrate. In this case, the salt of the organic acid can be obtained preferentially over the organic acid.

[0020] As described above, when an impact force is applied to a catalyst, heat is generated by the collision energy. Therefore, when a pulverizer, kneader, or the like is used, it is preferable to provide a cooling mechanism for cooling the container when applying an impact force to the catalyst. This makes it possible to suitably prevent the organic acid or salt thereof produced from being unintentionally thermally decomposed due to excessive heat generation. In this case, it is preferable to use a grinder, kneader, or the like equipped with a highly airtight container. This can prevent or suppress the generated organic acid or its salt from volatilizing and dissipating. From this perspective, it is preferable to lower the temperature of the container to about room temperature after the second step and before opening the container. This may be done by either natural cooling or forced cooling. Furthermore, the atmosphere inside the container may be an air atmosphere, or, depending on the type of organic acid or its salt to be produced, may be, for example, a reduced pressure atmosphere, an oxidizing atmosphere, a reducing atmosphere, an inert gas atmosphere, or the like.

[0021] <Third process> Next, the organic acid or its salt is recovered from the resulting product. The organic acid or its salt can be recovered, for example, as follows. First, the product is dissolved or dispersed in a liquid medium to prepare a liquid to be treated. Next, solids are removed from this liquid by centrifugation, filtration, etc. Thereafter, the organic acid or a salt thereof can be recovered from the liquid from which the solids have been removed by crystallization (crystallization), column chromatography (HPLC), column purification using an ion exchange resin, etc. Examples of liquid media include water (pure water, ultrapure water, ion-exchanged water, distilled water, RO water, etc.), alcohols (ethanol, etc.), esters (ethyl acetate, etc.), ethers (diethyl ether, etc.), or mixtures containing these.

[0022] Examples of the organic acid that can be obtained include formic acid, acetic acid, propionic acid, citric acid, oxalic acid, succinic acid, fumaric acid, malic acid, lactic acid, etc. As the organic acid, one of these may be produced alone, or two or more may be produced. Among these, the obtained organic acid preferably contains formic acid. Formic acid is useful as a raw material for synthesizing polymer compounds, a hydrogen storage material, a preservative, an antibacterial agent, a copper etching agent, a bleaching agent, a pH adjuster, a leather tanning agent, etc. In addition, its salt is solid at room temperature and easier to handle than formic acid, which is liquid at room temperature, so it is suitably used as a substitute for formic acid and is also useful as a cement admixture for increasing the strength of cement products.

[0023] The salt of the organic acid may be any type of salt, but is preferably at least one selected from the group consisting of alkali metal salts and alkaline earth metal salts, more preferably at least one selected from the group consisting of lithium salts, sodium salts, potassium salts, magnesium salts, and calcium salts, and is preferably at least one selected from the group consisting of potassium salts and calcium salts. Potassium formate and / or calcium formate are particularly suitable because they are easy to handle and can be used in a wide range of applications, even among the applications mentioned above. According to the above-described embodiment, an organic acid or a salt thereof can be produced from a carbohydrate by a simple operation of applying an impact force to a catalyst containing a piezoelectric material (piezoelectric catalyst). Furthermore, it may be provided in the following aspects.

[0024] (1) A method for producing an organic acid or a salt thereof, comprising the steps of: preparing a raw material containing a carbohydrate and a catalyst containing a piezoelectric material; activating the catalyst by applying an impact force to the catalyst; and decomposing the carbohydrate by the action of the activated catalyst to obtain the organic acid or a salt thereof.

[0025] (2) The method for producing an organic acid or a salt thereof according to (1) above, wherein the raw material further contains a salt for forming the salt of the organic acid.

[0026] (3) The method for producing an organic acid or a salt thereof according to (1) or (2) above, wherein the impact force is applied to a mixture of the raw material and the catalyst in the step of obtaining the organic acid or the salt thereof.

[0027] (4) The method for producing an organic acid or a salt thereof according to any one of (1) to (3) above, wherein the impact force is applied to the catalyst by colliding a ball with the catalyst.

[0028] (5) The method for producing an organic acid or a salt thereof according to any one of (1) to (4) above, wherein the carbohydrate comprises at least one selected from the group consisting of glucose, galactose, mannose, fructose, rhamnose, arabinose, xylose, erythrose, glyceraldehyde, maltose, cellobiose, lactose, and maltotriose.

[0029] (6) The method for producing an organic acid or a salt thereof according to any one of (1) to (5) above, wherein the carbohydrate comprises at least one selected from the group consisting of xylan, cellulose, and starch.

[0030] (7) The method for producing an organic acid or a salt thereof according to any one of (1) to (6) above, wherein the piezoelectric material is a metal oxide having a perovskite-type crystal structure.

[0031] (8) The method for producing an organic acid or a salt thereof according to any one of (1) to (7) above, wherein the organic acid includes formic acid.

[0032] (9) The method for producing an organic acid or a salt thereof according to any one of (1) to (8) above, wherein the salt of the organic acid is at least one selected from the group consisting of potassium salts and calcium salts. Of course, this is not the case.

[0033] Finally, while various embodiments of the present disclosure have been described, they are presented as examples and are not intended to limit the scope of the invention. The novel embodiments may be embodied in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. Such embodiments and modifications are intended to be included within the scope and spirit of the invention, as well as within the scope of the inventions and their equivalents as defined in the claims. [Example]

[0034] The present invention will be described in more detail below using the following examples, but the present invention is not limited to the following examples. 1. Production of organic acids or their salts Example 1 First, 0.5 g of glucose (sugar) and 3.23 g of barium titanate particles (catalyst particles) were mixed to obtain a mixture (see FIG. 1(a)). Next, the mixture and zirconia balls (diameter: 10 mm) shown in Figure 1(b) were placed in a bead mill (manufactured by Thinky Corporation), and a set of treatments at 1000 rpm for 5 minutes and 400 rpm for 1 minute was repeated six times. Note that this treatment was carried out with the temperature inside the bead mill container set to 10°C to reduce heat generation. In this way, an organic acid or a salt thereof was produced (see FIG. 1(c)).

[0035] Example 2 First, 4.5 g of glucose (sugar) and 29.15 g of barium titanate particles (catalyst particles) were mixed to obtain a mixture. Next, the mixture and silicon nitride balls (diameter: 5 mm) were placed in a planetary ball mill (manufactured by Fritsch Japan) and processed at a rotation speed of 400 rpm for 60 minutes. In this way, an organic acid or a salt thereof was produced (see FIG. 2). (See Figure 2).

[0036] 2. Analysis of organic acids or their salts Using a sample prepared by dissolving the product obtained in Example 1 or glucose in heavy water, NMR was performed at a measurement frequency of 500 MHz using an NMR apparatus (manufactured by Bruker, "Ascend 500"). 1 H-NMR measurements were carried out. The results are shown in Figure 3. The upper chart in Figure 3 is for the product and the lower chart is for glucose. In the NMR chart (upper side) shown in FIG. 3, a peak derived from formic acid was observed, confirming that formic acid was produced from glucose. Furthermore, in the NMR chart shown in Figure 3, multiple peaks are observed in addition to the peak derived from glucose, the raw material carbohydrate, and it is believed that organic acids other than formic acid are also produced.

[0037] Furthermore, as shown in FIG. 2, the product obtained in Example 2 adhered to the surface of the ball and the inner surface of the container, and it is believed that liquid formic acid was produced at room temperature. Furthermore, similar results to those described above can be obtained by using other carbohydrates as raw materials instead of glucose and producing the product using an organic acid or a salt thereof in the same manner as in Example 1. Furthermore, similar results to those described above can be obtained by using a catalyst containing another piezoelectric material instead of barium titanate, and producing the piezoelectric material using an organic acid or a salt thereof in the same manner as in Example 1. Furthermore, by adding salts to the raw materials, it is possible to obtain salts of organic acids in preference to organic acids themselves.

Claims

1. A method for producing an organic acid or a salt thereof, comprising: preparing a raw material containing a carbohydrate and a catalyst containing a piezoelectric material; a step of activating the catalyst by applying an impact force to the catalyst, and decomposing the carbohydrate by the action of the activated catalyst to obtain the organic acid or its salt.

2. The method for producing an organic acid or a salt thereof according to claim 1, The method for producing an organic acid or a salt thereof, wherein the raw material further contains a salt for forming a salt of the organic acid.

3. The method for producing an organic acid or a salt thereof according to claim 1, The method for producing an organic acid or a salt thereof, wherein the impact force is applied to a mixture of the raw material and the catalyst in the step of obtaining the organic acid or the salt thereof.

4. The method for producing an organic acid or a salt thereof according to claim 1, The method for producing an organic acid or a salt thereof includes applying the impact force to the catalyst by colliding a ball with the catalyst.

5. The method for producing an organic acid or a salt thereof according to claim 1, The method for producing an organic acid or a salt thereof, wherein the carbohydrate comprises at least one selected from the group consisting of glucose, galactose, mannose, fructose, rhamnose, arabinose, xylose, erythrose, glyceraldehyde, maltose, cellobiose, lactose, and maltotriose.

6. The method for producing an organic acid or a salt thereof according to claim 1, The method for producing an organic acid or a salt thereof, wherein the carbohydrate comprises at least one selected from the group consisting of xylan, cellulose, and starch.

7. The method for producing an organic acid or a salt thereof according to claim 1, The piezoelectric material is a metal oxide having a perovskite crystal structure.

8. The method for producing an organic acid or a salt thereof according to claim 1, The method for producing an organic acid or a salt thereof, wherein the organic acid includes formic acid.

9. The method for producing an organic acid or a salt thereof according to claim 1, The method for producing an organic acid or a salt thereof, wherein the salt of the organic acid is at least one selected from the group consisting of potassium salts and calcium salts.

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