JP3337587B2 - Organic acid production method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel method for producing organic acids from salts of organic acids by electrodialysis using a bipolar membrane. Specifically, a method for producing an organic acid that enables the production of an organic acid with high current efficiency by using a weak base salt as a salt of the organic acid and performing electrodialysis with a specific ion exchange membrane combination. is there.

[0002]

2. Description of the Related Art Conventionally, a method for obtaining an organic acid from a salt of the organic acid includes a method in which an aqueous solution of an organic acid salt is brought into contact with a proton-type cation exchange resin, and a method in which an organic acid salt is once converted into an ester. There is known a method of obtaining an organic acid by hydrolysis after separating an ester.

[0003] Japanese Patent Publication No. 33-2023 discloses a two-chamber electrodialysis method using a bipolar membrane and an anion exchange membrane or a cation exchange membrane to convert an acid and alkali solution from a salt solution comprising a weak acid or a weak base. There has been proposed a method of recovering the water. In the above document, a method specifically shown as a method for producing an organic acid uses an aqueous solution of a strong base salt of an organic acid such as a sodium salt of the organic acid.

[0004]

However, the method of using a proton-type cation exchange resin and the method of converting a salt of an organic acid into an ester are complicated in equipment for regenerating an ion-exchange resin and equipment for subsequent hydrolysis. In addition to requiring a complicated process, it requires expensive equipment.

[0005] In the above two-chamber electrodialysis method, an electrodialysis apparatus comprising a bipolar membrane and an anion exchange membrane is used, and an aqueous solution of a strong base salt of an organic acid shown as an organic acid salt is used as a raw material. When electrodialysis was performed as above, a strong base having a high degree of dissociation was generated simultaneously with the organic acid, and the dissociated ions significantly reduced the current efficiency, making it difficult to efficiently obtain the organic acid.

[0006]

Means for Solving the Problems The present inventors have been keen to solve the above-mentioned problem of the method for producing an organic acid and to develop a method for producing an organic acid more efficiently and more easily than a salt of an organic acid. Repeated research. As a result, as a salt of an organic acid as a raw material, a weak base salt of an organic acid is selected, and a solution of the weak base salt of the organic acid is formed by alternately arranging a bipolar membrane and an anion exchange membrane between electrodes. By performing electrodialysis by supplying to the base chamber out of the acid chamber and the base chamber, the degree of dissociation of the base generated in the base chamber simultaneously with the organic acid generated in the acid chamber is small, and the base reduces the current efficiency. Has been found to be effectively suppressed.

However, in the above method, since the amount of ions leaking from the base chamber is extremely small, the electric resistance of the acid chamber in which the recovered organic acid exists is increased, and it is difficult to carry out the method industrially. Was confirmed by the present inventors.

As a result of further study on such a problem, a solution containing a strong acid or a salt that dissociates in water is supplied to the acid chamber to perform electrodialysis, thereby achieving low voltage and high current efficiency. Establish a method that can produce organic acids,
The present invention has been proposed.

That is, the present invention is directed to an electrodialysis apparatus having an acid chamber and a base chamber formed by alternately arranging a bipolar membrane and an anion exchange membrane between electrodes, wherein the weak base of an organic acid is contained in the base chamber. A solution containing a salt is supplied, and a solution containing a strong acid or a salt that dissociates in water is supplied to the acid chamber, electrodialysis is performed, and an organic acid is produced in the acid chamber. It is a manufacturing method.

In the present invention, the electrodes of the electrodialysis device are
Known ones can be used without any limitation. That is, platinum, titanium / platinum, carbon, nickel, ruthenium / titanium, iridium / titanium and the like are often used as the anode. As the cathode, iron, nickel, platinum,
Titanium / platinum, carbon, stainless steel, etc. are often used. In addition, a known structure is employed without particular limitation for the structure of the electrode. Examples of a general structure include a mesh shape and a lattice shape.

In the present invention, the bipolar membrane of the electrodialysis apparatus is not particularly limited, and a conventionally known bipolar membrane, that is, a known bipolar membrane having a structure in which a cation exchange membrane and an anion exchange membrane are bonded to each other. Can be used.

[0012] Such a bipolar film can be manufactured by various known methods. For example, a method of laminating a cation exchange membrane and an anion exchange membrane with a mixture of polyethyleneimine-epichlorohydrin and bonding them together (Japanese Patent Publication No. 32-3962), bonding the cation exchange membrane and the anion exchange membrane with an ion exchange adhesive Method (Japanese Patent Publication No. 34-
No. 3961), a method in which a cation exchange membrane and an anion exchange membrane are coated with a fine powder of an ion exchange resin, or a paste-like mixture of an anion or cation exchange resin and a thermoplastic material, and pressed (Japanese Patent Publication No. 35-14531). A method of applying a paste-like substance comprising vinylpyridine and an epoxy compound to the surface of a cation exchange membrane and irradiating it with a paste (Japanese Patent Publication No. 38-16633); Of ion-exchange radiation and cross-linking after adhering an allylamine with a polymer electrolyte (Japanese Patent Publication No. 51-4113), a dispersion system of an ion exchange resin having an opposite charge on the surface of an ion exchange membrane, and a base polymer (Japanese Patent Application Laid-Open No. 53-37190), a sheet formed by impregnating and polymerizing a polyethylene film with styrene and divinylbenzene. The put scissors in a stainless steel frame,
After one side is sulfonated, the sheet is removed and the remaining part is chlormethylated and then aminated (US Pat. No. 3,562,139), or a specific metal ion is applied to the surface of the anion-cation exchange membrane. A method of pressing both ion-exchange membranes together (Electrochemical
Actor 31, pp. 1175-1176 (1986)).

The base material of the bipolar membrane in the present invention depends on the cation exchange membrane and the anion exchange membrane to be joined.
A styrene-divinylbenzene copolymer film, net, knit, woven fabric, non-woven fabric, or the like is used.

The cation exchange groups of the cation exchange membrane constituting the bipolar membrane are not particularly limited, and known cation exchange groups such as sulfonic acid groups and carboxylic acid groups can be used. In particular, a sulfonic acid group in which the exchange group is dissociated even under acidic conditions is desirable from the application of the bipolar membrane. Further, the anion exchange group of the anion exchange membrane constituting the bipolar membrane is not particularly limited, and known anion exchange groups such as ammonium base, pyridinium base, primary amino group, secondary amino group and tertiary amino group Ion exchange groups such as groups can be used. Among them, an ammonium base whose exchange group is dissociated even under basic conditions is desirable.

Further, in the present invention, the anion exchange membrane of the electrodialysis device is not particularly limited, and a known anion exchange membrane can be used. For example, a quaternary ammonium group,
An anion exchange membrane in which primary amino groups, secondary amino groups, tertiary amino groups, and a plurality of these ion exchange groups are mixed can be used. In addition, the anion exchange membrane can be any of a polymerization type, a condensation type, a uniform type, and a non-uniform type. In addition, the presence or absence of a reinforcing core material, a hydrocarbon type, a fluorine type, and an anion derived from a material and a production method are used. Any type and type of ion exchange membrane may be used.

In the present invention, the electrodialysis apparatus is constituted by alternately arranging bipolar membranes and anion exchange membranes between electrodes to form an acid chamber and a base chamber.

FIG. 1 shows a schematic diagram of a typical embodiment of the electrodialysis apparatus used in the present invention.

That is, in FIG. 1, the electrodialysis apparatus has a bipolar membrane (B) 1 and an anion exchange membrane (A) 2 as membranes.
Are alternately arranged to form two chambers, an acid chamber and a base chamber. Here, the chamber between the anion exchanger side of the bipolar membrane (B) and the anion exchange membrane (A) is the base chamber 12, and the chamber between the cation exchanger side of the bipolar membrane (B) and the anion exchange membrane (A). Is an acid chamber 11. A typical configuration of the electrodes (the anode 15 and the cathode 16) and the membrane is an anode- (B
-A) _n -cathode (where n is the number of repetitions of the arrangement of the bipolar membrane and anion exchange membrane), and n is generally suitably 1 to 100.

As the structure of the electrodialysis apparatus, a known structure is employed without any particular limitation. The most preferable structure is a so-called filter press type structure in which bipolar membranes and anion exchange membranes are alternately arranged via a chamber frame having a cutout portion at the center for forming each chamber, and tightened from both ends. .
Each chamber frame is provided with a liquid supply port and a liquid discharge port, and each liquid supply port and the liquid discharge port are connected to a main pipe via a branch pipe as necessary. In addition, it is common to provide a spacer having a flow distribution function for keeping the thickness of the chamber frame uniform and making the flow of the supplied liquid uniform within the chamber frame.

In the present invention, in the electrodialysis method using the above-mentioned electrodialysis apparatus, an external tank for supplying a liquid to be supplied to each of the acid chamber and the base chamber is provided, and the liquid is supplied between each chamber and the external tank. The method of performing electrodialysis while circulating is preferably adopted.

The organic acids to be used in the present invention include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, trimethylacetic acid, fluoroacetic acid, chloroacetic acid, glycolic acid,
Lactic acid, methoxyacetic acid, succinic acid, citric acid, tartaric acid, malic acid, glyoxylic acid, malonic acid, fumaric acid, acrylic acid, methacrylic acid, benzoic acid; and high molecular acids such as polyacrylic acid.

Among them, the present invention relates to formic acid, acetic acid, lactic acid,
It can be particularly preferably applied to the production of succinic acid, citric acid and malic acid.

In the present invention, the weak base salt of an organic acid includes the above-mentioned organic acid and a weakly basic compound such as ammonia,
Primary, secondary, and tertiary amines, specifically, ammonia, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, butylamine, ethylenediamine, 1,6-hexanediamine, diethylenetriamine, benzylamine, pyridine , Picolin, piperidine, aniline, hydrazine and the like.

Specific examples include ammonium lactate, ammonium citrate, ammonium malate, ammonium formate, ammonium acetate, ammonium succinate, ammonium acrylate, methyl ammonium acetate, ethyl ammonium butyrate and the like. Among them, in the case of a salt and in the case of a free acid, 1
Those which dissolve at 0% by weight or more are preferably used.

The above-mentioned solution is basically preferably an aqueous solution, but may be a solution containing an organic solvent as long as a current can be passed when the above-mentioned weak base salt of the organic acid is dissolved. Specifically, a solution containing a polar solvent such as methanol, ethanol, dimethylformamide and the like can be mentioned.

When a solution of the above weak base salt of an organic acid is supplied to a base chamber and electrodialysis is performed, an organic acid is generated from the acid chamber.

Usually, organic acids have a very low degree of dissociation under acidic conditions, so that organic acids generated in the acid chamber have low electric conductivity,
It becomes difficult to perform electrodialysis at a high current density.

In the present invention, a high current can be applied at a low voltage by allowing a dilute electrolyte such as a strong acid or a salt dissociated in water to be present in such an acid chamber. This has enabled the industrial production of organic acids.

Specific examples of a salt which can be suitably used as a strong acid or a salt dissociated in water include hydrochloric acid, sulfuric acid,
Strong acids such as nitric acid and phosphoric acid, ammonium chloride, lithium chloride, sodium chloride, potassium chloride, ammonium bromide, lithium bromide, sodium bromide, potassium bromide, ammonium fluoride, lithium fluoride, sodium fluoride, potassium fluoride , Ammonium nitrate, lithium nitrate, sodium nitrate, potassium nitrate, ammonium sulfate, lithium sulfate, sodium sulfate, potassium sulfate, ammonium phosphate, sodium phosphate, potassium phosphate, ammonium formate, sodium formate, potassium formate, ammonium acetate, sodium acetate, potassium acetate, butyric acid Ammonium, sodium butyrate, potassium butyrate, ammonium lactate, sodium lactate, potassium lactate, ammonium succinate, sodium succinate, potassium succinate, ammonium citrate, sodium citrate Potassium citrate, ammonium tartrate, sodium tartrate, potassium tartrate, ammonium malate, sodium malate, potassium malate, ammonium malonate, sodium malonate, potassium malonate, sodium polyacrylate,
Salts such as sodium polystyrene sulfonate can be exemplified.

The use of mineral acids among the abovementioned compounds is particularly advantageous for the separation from the organic acids formed. In particular, hydrochloric acid is easily removed by means such as aeration and distillation, and is preferably used.

In the present invention, the concentration of the strong acid or salt is set so that the electric conductivity is 1 mS / cm or more, preferably 5 mS / cm or more.
It is desirable to adjust so as to be at least mS / cm.
However, the use of such a high concentration of a strong acid or salt may increase the labor required for purification, and it is preferable to adjust the concentration to 100 mS / cm or less.

In the present invention, the acid chamber of the electrodialyzer is supplied with a solution of a strong acid or a salt which dissociates in water in advance.
Electrodialysis is performed by supplying a solution of a weak base salt of an organic acid to the base chamber. When electrodialysis is continued, an organic acid is generated in the acid chamber, and a weak base salt of the organic acid is reduced in the base chamber to generate a weak base. When the concentration of the organic acid generated in the acid chamber rises to some extent, the solution may be recovered, and if necessary, the organic acid and the mineral acid or salt may be separated. For such separation, in the case of an organic acid and a mineral acid, a distillation method utilizing a difference in boiling point or a method of removing only a mineral acid by contacting with a weakly basic ion exchange resin is preferable.

When the weak base is ammonia, when the ammonia concentration is increased, the weak base penetrates into the bipolar membrane and gasifies in the membrane to generate blisters in the bipolar membrane. Therefore, the generated ammonia concentration in the base chamber is 1 mol /
It is preferable to adjust the dialysis to 1 or less, preferably 0.5 mol / l or less. In addition, since this ammonia is volatile, it is preferable to strip, remove, refine and recover the ammonia by blowing air or the like into the base tank.

When the ammonium salt of an organic acid is obtained by organic acid fermentation, the ammonia recovered by the method of the present invention can be used again as a pH control or nutrient for organic acid fermentation. The method of (1) is suitably adopted.

In the present invention, the temperature of the various liquids during electrodialysis is usually in the range of 5 to 70 ° C., preferably 20 to 50 ° C. The current density is not particularly limited, but is generally 1 to 30 A / dm ² , preferably ² to 20 A / dm ² .

[0036]

According to the present invention, it is possible to produce an organic acid from a weak base salt of an organic acid at a low voltage, a high current density and a high current efficiency by using an electrodialysis method, It enables industrial production of organic acids.

Further, the weak base salt of an organic acid may contain a polyvalent metal ion such as calcium or magnesium depending on the production method. The reason is not clear yet, but the polyvalent metal ion is not easily understood. Even if it is contained, these polyvalent metal ions do not cause precipitation of polyvalent metal hydroxide despite the increase in the pH of the base chamber. Conventionally, in the electrodialysis technology, when polyvalent metal ions are contained in the water to be treated, they have been removed by a chelating resin or the like.However, according to the method of the present invention, the operation of removing the polyvalent metal ions is unnecessary. This has a great economic effect.

[0038]

EXAMPLES The present invention will be described more specifically with reference to Examples and Comparative Examples below, but the present invention is not limited to these Examples. Example 1 As an inoculum, L-lactic acid-producing Lactococcus lactis was used. 10 ml of a liquid medium (pH 6.8) composed of 20 g / l of glucose, 50 g / l of polypeptone, and 5 g / l of yeast extract was dispensed into a medium test tube.
High-pressure steam sterilization was performed at 15 ° C. for 15 minutes. One loopful of the inoculum was inoculated with the inoculated bacteria, and the cells were cultured at 37 ° C. for 24 hours. 10 ml of this culture solution was similarly sterilized with 100 ml of glucose 20 g / l, polypeptone 10 g / l, yeast extract 5
A seed medium was prepared by inoculating a liquid medium (pH 6.8) containing g / l and 10 g / l ammonium phosphate, and culturing the mixture at 37 ° C. for 15 hours.

As a medium for the main culture, glucose 100
g / l, yeast extract 20 g / l, polypeptone 8 g /
1, potassium dihydrogen phosphate 0.3 g / l, magnesium sulfate 0.05 g / l, and calcium chloride 0.01 g / l. The above medium 1 was placed in a 20-liter glass fermenter.
After dispensing 0 liter, sterilizing and cooling to room temperature, 1 liter of the seed was inoculated and gently stirred at 37 ° C. while adjusting the pH to 6.8 with a 10% aqueous ammonia solution. Time went.

The fermentation broth was centrifuged to obtain a clear solution. The suspension had a suspension concentration of 1 ppm. The components of this solution are shown in Table 1.

[0041]

[Table 1]

As shown in FIG. 1, the electrodialysis apparatus includes an anion exchange membrane (manufactured by Tokuyama Corporation,
Product name: Neosepta AMH) and bipolar membrane (Neosepta BP-1) are 5 sheets, 5 sheets, respectively (the effective membrane area of anion exchange membrane and bipolar membrane is 1 each)
dm ² / sheet, the total membrane area was 5,5 dm ² ), respectively, and a filter press type electrodialysis apparatus having a base chamber and an acid chamber was used. The above-mentioned 5 liter ammonium lactate solution is placed in the base compartment and the cathode compartment, and 0.1 N HCl
Two liters of an aqueous solution (electric conductivity was 39 mS / cm) was provided in each of the corresponding tanks at 6 cm / sec.
And circulated at a linear velocity of

5 L of a 5% sulfuric acid aqueous solution was circulated in the anode chamber, and electrodialysis was performed at 25 ° C. and a current density of 10 A / dm ² for 3 hours. The average voltage at this time was 3.3 volts / unit cell.

As a result, 2.2 liters (containing 353 g of lactic acid) of a mixed aqueous solution of hydrochloric acid and lactic acid were obtained from the acid chamber, and 4.8 liters (containing 116 g of ammonium lactate) were obtained from the base chamber.
g, 67 g of ammonia).

The current efficiency was 70%.

In the above-mentioned electrodialysis, a liquid containing ammonium lactate and ammonia discharged from the base chamber was given as a nutrient source and a pH control of the lactic acid culture, but ammonium lactate could be produced without any trouble.

The above operation of electrodialysis was repeated 10 times, but no increase in voltage was observed. In the base room,
No white suspended matter due to hydroxides of calcium and magnesium was observed, and no change was observed in the bipolar membrane and the anion exchange membrane.

COMPARATIVE EXAMPLE 1 The same operation as in Example 1 was carried out except that a 1 mol / l aqueous lactic acid solution was used in place of the 0.1 mol / l aqueous hydrochloric acid solution in the acid chamber. An attempt was made to pass a current, but the voltage was too high and a current having a current density of 3 A / dm ² could not be passed.

Example 2 81 g / l of ammonium citrate, 12 p of magnesium
An aqueous solution containing pm and 6 ppm of calcium ions was prepared. The electrodialyzer used in Example 1 was used.

The above-mentioned 5 liter ammonium citrate solution was placed in the base compartment and the cathode compartment, and a 0.1 mol / l sulfuric acid aqueous solution (the electric conductivity was 25 mS / cm) in the acid compartment.
6cm / s with 2 liter tanks
It was fed and circulated at a linear speed of ec. 5 L of a 5% sulfuric acid aqueous solution was circulated in the anode chamber. 25 ° C, current density 5A / d
Electrodialysis was performed at m ² for 6 hours. The average voltage at this time was 3.7 volts / unit cell.

As a result, from the acid chamber, 2.2 liters of a mixed aqueous solution of sulfuric acid and citric acid (including 233 g of citric acid)
However, a 4.8 liter solution (containing 233 g of ammonium citrate and 62 g of ammonia) was obtained from the base chamber.

The current efficiency was 65%.

Further, the above-mentioned electrodialysis operation was repeated 5 times, but no increase in voltage was observed. In the base chamber, no white suspended matter due to hydroxides of calcium and magnesium was observed. No change was observed in the ion exchange membrane.

Comparative Example 2 An electrodialysis apparatus was prepared in the same manner as in Example 2 except that the acid chamber was replaced with a 1 mol / l citric acid aqueous solution instead of the 0.1 mol / l hydrochloric acid aqueous solution. , But the voltage was too high to allow a current density of 3 A / dm ² to flow.

Examples 3 and 4 Comparative Example 3 2 L of 0.1 N hydrochloric acid as an acid solution and 0.4, 0.8 and 1.6 N ammonium malate solutions as a base solution in the electrodialyzer of Example 1. Was electrodialyzed at a current density of 5 A / dm ² for 9 hours. The results were as shown in Table 2.

[0056]

[Table 2]

When the electrodialysis apparatus was disassembled, Example 3
In No. 4, no abnormality was found in the bipolar membrane, but in Comparative Example 3, blisters were found.

Example 5 The same operation as in Example 2 was carried out except that 5 liter of an aqueous solution in which 133 g of butylammonium acetate was dissolved was used in the base chamber instead of ammonium citrate. The voltage at this time was 2.7 volts / unit cell.

As a result, 4.8 liters of a mixed aqueous solution of butylamine and butylammonium acetate (including 4.5 moles of butylamine) was obtained from the base chamber, and 2.8 liters of butylamine was added from the acid chamber.
A solution of 2 liters (containing 4.5 mol of acetic acid) was obtained.

The current efficiency was 80%.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a typical embodiment of an electrodialysis apparatus used in the present invention.

[Explanation of symbols]

 Reference Signs List 1 bipolar membrane (B) 2 anion exchange membrane (A) 11 acid chamber 12 base chamber 13 anode chamber 14 cathode chamber 15 anode 16 cathode

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁷ identification code FI C07C 59/265 C07C 59/265 (58) Field surveyed (Int.Cl. ⁷ , DB name) B01D 61/00-65/10

Claims (1)

(57) [Claims] 1. An electrodialysis apparatus having an acid chamber and a base chamber formed by alternately arranging bipolar membranes and anion exchange membranes between electrodes, wherein the base chamber contains a weak base salt of an organic acid. A method for producing an organic acid, comprising supplying a solution, supplying a solution containing a strong acid or a salt that dissociates in water to an acid chamber, and performing electrodialysis to generate an organic acid in the acid chamber.