Method for producing alkali metal / alkaline earth metal hydroxides, and application of said production method to carboxylate waste recycling technology.

Abstract

A method for producing an alkali metal hydroxide / alkaline earth metal comprising subjecting a liquid comprising RA-COOMB and / or (RA-COO)2MC and water to an electrochemical reaction to produce Kolbe electrolysis at the anode to generate at least RA-RA and carbon dioxide and MB+ ion and / or MC2+ ion, and neutralizing the MB+ ion and / or MC2+ ion by OH- ion produced by electrolysis of water at the cathode.　RA represents a hydrocarbon group, MB represents an alkali metal, and MC represents an alkaline earth metal.

Description

[Technical Field]

[0001] This invention relates to a method for producing alkali metal / alkaline earth metal hydroxides, and to the application of said production method to carboxylate waste recycling technology. [Background technology]

[0002] Vegetable oils are produced by pressing plant materials such as soybeans and rapeseed to extract crude oil, which is then subjected to various processes such as degumming, deacidification, decolorization, and deodorization (see Figure 1). In the deacidification process, alkali metal hydroxides such as caustic soda (NaOH) are added to convert fatty acids into fatty acid salts, and these fatty acid salts are precipitated to separate and remove them from the oil. The fraction containing these removed fatty acid salts generally contains about 30-60% by mass of fatty acid salts, about 30-50% by mass of water, and about 10-30% by mass of other oils, and is called oil residue (foots). This oil residue is generated at a rate of 0.5-20% by mass of the total vegetable oil production.

[0003] Oil residue contains moisture, is alkaline, and is a highly viscous paste, making it difficult to handle, and therefore is often disposed of as waste. On the other hand, due to the large amount of oil residue generated, its effective utilization is also being considered. For example, it has been proposed to add sulfuric acid to oil residue to acid-decompose it, and then distill the fraction called dark oil to obtain fatty acids. The use of oil residue as fuel is also being considered. For example, Patent Document 1 describes neutralizing oil residue produced as a by-product in the deacidification process with acid, drying this neutralized oil residue, mixing it with undried neutralized oil residue, controlling its properties to have appropriate fluidity, and then mixing it with fossil fuels to use as fuel. However, the reuse of the above-mentioned fatty acids is limited to the reuse of the dark oil fraction obtained from the oil residue, and the aqueous phase residue containing sodium ions is disposed of as waste. Furthermore, the method described in Patent Document 1 involves subjecting the oil residue to a certain treatment before using it as fuel, which is time-consuming and costly to prepare. On the other hand, if oil residue is incinerated as fuel as is, problems such as boiler damage due to alkali or boiler blockage due to non-combustible salts in the incineration residue can occur.

[0004] The effective utilization of carboxylates is desired not only in the vegetable oil industry mentioned above. For example, in the production of fatty acid esters, edible oils are reacted with alcohols such as methanol in the presence of alkaline catalysts such as caustic soda or caustic potash to obtain fatty acid esters, which are then used as biodiesel fuel (see Figure 2). The crude fatty acid ester fraction obtained by the reaction of edible oil and alcohol contains fatty acid salts as impurities, and these fatty acid salts are transferred into the washing water during the washing process of the crude fatty acid ester fraction and discarded as soapy wastewater. In the papermaking process, wood chips are placed in a digester and boiled with chemicals containing alkali metal hydroxides such as caustic soda and alkaline earth metals such as calcium hydroxide to dissolve (digest) the lignin and extract cellulose fibers. The extracted cellulose fibers are then washed to remove the lignin and bleached to obtain paper, pulp, cellulose nanofibers, etc. (see Figure 3). In this washing process after digestion, a black liquor is produced in which lignin and other substances have dissolved. This black liquor contains a large amount of cinnamic acid salts (cinnamic acid, sinapic acid, coumaric acid, caffeic acid, etc.), which are lignin decomposition products.

[0005] It has been proposed to use carboxylic acids and their salts as a hydrocarbon source to replace petroleum. For example, Patent Document 2 describes subjecting fatty acids or their salts obtained by hydrolysis of oils and fats to a Kolbe electrolysis reaction to produce hydrocarbons at the anode. The Kolbe electrolysis reaction is a well-known electrochemical organic synthesis reaction of hydrocarbons. In the Kolbe electrolysis reaction, the conjugated anions of fatty acids undergo one-electron oxidation and decarboxylation at the anode electrode, and hydrocarbons are obtained in which the aliphatic chains of fatty acids are dimerized. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Patent No. 6594617 [Patent Document 2] Japanese National Publication of International Patent Application No. 2017-527682

Summary of the Invention

Problem to be Solved by the Invention

[0007] An object of the present invention is to provide a technology that enables not only use as a hydrocarbon source, but also effective utilization of substantially the entire of a liquid containing a salt of a fatty acid or a derivative thereof and water as a resource without requiring any particularly complicated operation.

Means for Solving the Problem

[0008] The above object of the present invention is solved by the following means. [1] R A -COOM B and / or (R A -COO)2M C and water is subjected to an electrochemical reaction, a Kolbe electrolysis reaction occurs at the anode to produce at least R A -R A , carbon dioxide, and M B+ ions and / or M C2+ ions, and the OH- ions generated by electrolysis of water at the cathode neutralize the aforementioned M - ions and / or M B+ ions and / or M C2+ ions, a method for producing an alkali metal / alkaline earth metal hydroxide (M B -OH / M C -(OH)2). R A represents a hydrocarbon group, M B represents an alkali metal, and M C represents an alkaline earth metal. [2] The aforementioned R A -COOM B and / or (R A -COO)2M C and water, wherein the liquid contains at least one waste liquid selected from the following (a) to (c), the production method according to [1]. (a) Soapstock generated in the deacidification step in the production of vegetable fats and oils, (b) Black liquor produced in the post-pulping washing process in papermaking, and (c) Soap wastewater generated during the washing process of the crude fatty acid ester fraction in the production of fatty acid esters. [3] M produced by the aforementioned neutralization B -OH and / or M C A reaction solution containing -(OH)2 is placed on one side of a tank separated by an ion-permeable membrane, and water is placed on the other side of the tank separated by the membrane, and the M B -OH and / or M C The manufacturing method according to [1] or [2], wherein -(OH)2 is transferred into the water. [4] The manufacturing method according to [1] or [2], wherein the electrolytic cell is separated by an ion-permeable membrane in the electrochemical reaction described above. [5] The above diaphragm separates the anode side from the cathode side, and the above R is on the anode side. A -COOM B and / or (R A -COO)2M C The manufacturing method described in [4], wherein a liquid containing water is added, water is added to the cathode side, and the electrochemical reaction described above is carried out. [6] In the electrochemical reaction described above, the anode and the cathode are placed on one side of the electrolytic cell separated by the diaphragm, and M is introduced into the reaction solution by the electrochemical reaction. B -OH and / or M C -(OH)2 is produced, and water is placed on the other side of the electrolytic cell separated by the diaphragm, and the M is introduced into the water. B -OH and / or M C The manufacturing method described in [4], which involves transferring -(OH)2. [7] The manufacturing method according to any one of [3] to [6], wherein the diaphragm is a cation exchange membrane. [8] The above M B A manufacturing method according to any one of [1] to [7], wherein sodium and / or potassium are included as alkali metals. [9] In the manufacturing method described in any one of [1] to [8], the above R A -COOM B and / or (R A -COO)2M C As a liquid containing water, an alkali metal hydroxide (M) is used, which contains oil residue generated in the deoxidation process in the production of vegetable oils. B -OH) and / or alkaline earth metal hydroxides (M C A method for producing vegetable oil, comprising obtaining -(OH)2 and using this alkali metal hydroxide and / or alkaline earth metal hydroxide in a deoxidation step in the production of vegetable oil.

[10] In the manufacturing method described in any one of [1] to [8], the above R A -COOM B and / or (R A -COO)2M C As a liquid containing water, an alkali metal hydroxide (M) is used, which contains the black liquor produced in the washing process after pulping in papermaking. B -OH) and / or alkaline earth metal hydroxides (M C A papermaking method comprising obtaining -(OH)2 and utilizing this alkali metal hydroxide and / or alkaline earth metal hydroxide in the pulping process in papermaking.

[11] In the manufacturing method described in any one of [1] to [8], the above R A -COOM B and / or (R A -COO)2M C As a liquid containing water, an alkali metal hydroxide (M) is used, which contains soapy wastewater generated in the washing step of the crude fatty acid ester fraction in the production of fatty acid esters. B -OH) and / or alkaline earth metal hydroxides (M C A method for producing fatty acid esters, comprising obtaining -(OH)2 and utilizing this alkali metal hydroxide and / or alkaline earth metal hydroxide in the reaction for producing crude fatty acid esters in the production of fatty acid esters.

[12] The electrochemical apparatus comprises an anode, a cathode, and an electrolytic cell, and a tank whose interior is separated by an ion-permeable diaphragm. The electrochemical apparatus is used to subject a liquid containing oil residue generated in the deoxidation process of vegetable oil production to an electrochemical reaction, and M is added to the reaction solution. B -OH and / or M C -(OH)2 is produced, the resulting reaction solution is placed on one side of the tank separated by the diaphragm, and water is placed on the other side of the tank separated by the diaphragm, and M in the reaction solution B -OH and / or M C An apparatus for producing alkali metal / alkaline earth metal hydroxides, which transfers -(OH)2 into the water.

[13] An apparatus for producing alkali metal / alkaline earth metal hydroxides, having an electrolytic cell equipped with an anode, a cathode, and an ion-permeable diaphragm separating the anode and cathode sides, and carrying out an electrochemical reaction by placing a liquid containing oil residue generated in the deoxidation process of vegetable oil production on the anode side and water on the cathode side.

[14] It comprises an electrolytic cell separated by an ion-permeable diaphragm, and an anode and a cathode located on one side separated by the diaphragm. A liquid containing oil residue generated in the deoxidation process during the production of vegetable oils is placed in one side of the electrolytic cell separated by the diaphragm, and M is added to the reaction solution by an electrochemical reaction. B -OH and / or M C -(OH)2 is produced, and water is placed on the other side of the electrolytic cell separated by the diaphragm, and M in the reaction solution B -OH and / or M C An apparatus for producing alkali metal / alkaline earth metal hydroxides, which transfers -(OH)2 into the water.

[15] A recycling system for alkali metal / alkaline earth metal hydroxides, comprising a manufacturing apparatus described in any one of

[12] to

[14] , and means for supplying alkali metal hydroxides and / or alkaline earth metal hydroxides manufactured using the manufacturing apparatus to a deoxidation step in the production of vegetable oils and fats.

[16] The electrochemical apparatus comprises an anode, a cathode, and an electrolytic cell, and a tank whose interior is separated by an ion-permeable diaphragm. The electrochemical apparatus is used to subject the liquid containing black liquor, which is produced in the washing process after pulping in papermaking, to an electrochemical reaction, and M is added to the reaction solution. B -OH and / or M C -(OH)2 is produced, the resulting reaction solution is placed on one side of the tank separated by the diaphragm, and water is placed on the other side of the tank separated by the diaphragm, and M in the reaction solution B -OH and / or M C An apparatus for producing alkali metal / alkaline earth metal hydroxides, which transfers -(OH)2 into the water.

[17] An apparatus for producing alkali metal / alkaline earth metal hydroxides, comprising an electrolytic cell equipped with an anode, a cathode, and an ion-permeable diaphragm separating the anode and cathode sides, wherein an electrochemical reaction is carried out by placing a liquid containing black liquor, which is produced in the washing process after pulping in papermaking, on the anode side and water on the cathode side.

[18] It comprises an electrolytic cell separated by an ion-permeable diaphragm, and an anode and a cathode located on one side separated by the diaphragm. The liquid containing black liquor produced in the washing process after pulping in papermaking is placed in one side of the electrolytic cell separated by the diaphragm, and M is added to the reaction solution by an electrochemical reaction. B -OH and / or M C -(OH)2 is produced, and water is placed on the other side of the electrolytic cell separated by the diaphragm, and M in the reaction solution B -OH and / or M C An apparatus for producing alkali metal / alkaline earth metal hydroxides, which transfers -(OH)2 into the water.

[19] A recycling system for alkali metal / alkaline earth metal hydroxides, comprising a manufacturing apparatus described in any one of

[16] to

[18] , and means for supplying alkali metal hydroxides and / or alkaline earth metal hydroxides manufactured using the manufacturing apparatus to a pulping process in papermaking.

[20] The electrochemical apparatus comprises an anode, a cathode, and an electrolytic cell, and a tank whose interior is separated by an ion-permeable diaphragm. The electrochemical apparatus is used to subject a liquid containing soapy wastewater generated in the washing step of the crude fatty acid ester fraction in the production of fatty acid esters to an electrochemical reaction, and M is added to the reaction solution. B -OH and / or M C -(OH)2 is produced, the resulting reaction solution is placed on one side of the tank separated by the diaphragm, and water is placed on the other side of the tank separated by the diaphragm, and M in the reaction solution B -OH and / or M C An apparatus for producing alkali metal / alkaline earth metal hydroxides, which transfers -(OH)2 into the water. 〔twenty one〕 An apparatus for producing alkali metal / alkaline earth metal hydroxides, having an electrolytic cell equipped with an anode, a cathode, and an ion-permeable diaphragm separating the anode and cathode sides, wherein an electrochemical reaction is carried out by placing a liquid containing soapy wastewater generated in the washing step of the crude fatty acid ester fraction in the production of fatty acid esters on the anode side and water on the cathode side. 〔twenty two〕 It comprises an electrolytic cell separated by an ion-permeable diaphragm, and an anode and a cathode located on one side separated by the diaphragm. A liquid containing soapy wastewater generated in the washing step of the crude fatty acid ester fraction in the production of fatty acid esters is placed in one side of the electrolytic cell separated by the diaphragm, and M is added to the reaction solution by an electrochemical reaction. B -OH and / or M C -(OH)2 is produced, and water is placed on the other side of the electrolytic cell separated by the diaphragm, and M in the reaction solution B -OH and / or M C An apparatus for producing alkali metal / alkaline earth metal hydroxides, which transfers -(OH)2 into the water. 〔twenty three〕 A recycling system for alkali metal / alkaline earth metal hydroxides, comprising a manufacturing apparatus described in any one of

[20] to

[22] , and means for supplying alkali metal hydroxides and / or alkaline earth metal hydroxides manufactured using the manufacturing apparatus to a crude fatty acid ester production reaction step in the production of fatty acid esters. [Effects of the Invention]

[0009] According to the present invention, a technology is provided that enables the effective utilization of a liquid containing a fatty acid salt or its derivative and water not only as a hydrocarbon source, but also substantially the entire liquid, without requiring any particularly complicated operations. [Brief explanation of the drawing]

[0010] [Figure 1] This is a flowchart illustrating the manufacturing process of vegetable oils. [Figure 2] This is a flowchart illustrating the manufacturing process of fatty acid esters. [Figure 3] This is a flowchart illustrating the papermaking process. [Figure 4] This is a schematic diagram illustrating one embodiment of an apparatus for producing alkali metal / alkaline earth metal hydroxides. [Figure 5] This is a schematic diagram illustrating another embodiment of an alkali metal / alkaline earth metal hydroxide production apparatus. [Figure 6] This is a schematic diagram illustrating yet another embodiment of an alkali metal / alkaline earth metal hydroxide production apparatus. [Figure 7] This is a schematic diagram illustrating yet another embodiment of an alkali metal / alkaline earth metal hydroxide production apparatus. [Modes for carrying out the invention]

[0011] [Method for producing alkali metal / alkaline earth metal hydroxides] In one embodiment, the present invention provides a method for producing alkali metal hydroxides / alkaline earth metals. That is, R A -COOM B and / or (R A -COO)2M C A solution containing water is subjected to an electrochemical reaction, and a Kolbe electrolytic reaction occurs at the anode, producing at least R A -R A carbon dioxide and M B+ Ions and / or M C2+ It generates ions, and at the cathode, OH is produced by the electrolysis of water. -the above M with ions B+ ions and / or M C2+ neutralizing ions, and provides a method for producing an alkali metal / alkaline earth metal hydroxide (M B -OH / M C -(OH)2). R A represents a hydrocarbon group, M B represents an alkali metal, and M C represents an alkaline earth metal. The above-mentioned "neutralization" means that electrical neutrality is maintained by cations and anions. R A -COOM B and / or (R A -COO)2M C and water has not been previously known to produce alkali metal hydroxides and / or alkaline earth metal hydroxides when subjected to a Kolbe electrolysis reaction, and the present invention has been completed based on this new finding. That is, according to the present invention, by subjecting a liquid containing R A -COOM B and / or (R A -COO)2M C and water to a Kolbe electrolysis reaction, R A -R A (hydrocarbon compound) is obtained by an anodic reaction, while alkali metal hydroxide and / or alkaline earth metal hydroxide are produced in the liquid, and for example, industrially useful caustic soda and the like can be obtained. Therefore, a liquid containing R A -COOM B and / or (R A -COO)2M C and water can be effectively utilized as a resource only by subjecting substantially the entire liquid to an electrochemical reaction without requiring any particularly complicated operation.

[0012] The above hydrocarbon group of R A may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. Further, the hydrocarbon group of R A may be a linear or branched aliphatic group, may be an aromatic hydrocarbon group, or may be a group formed by combining these. R AThe hydrocarbon group may have substituents. A There are no particular restrictions on the substituents that the hydrocarbon group can take. For example, sinapic acid, coumaric acid, and caffeic acid, which are contained in the black liquor generated in the papermaking process described above, are all R A -COOM B It is included in R. A Typical examples of substituents that the hydrocarbon group can adopt include alkoxy groups (preferably lower alkoxy groups having 1 to 3 carbon atoms, more preferably methoxy groups), hydroxyl groups, and carboxyl groups. R A The number of carbon atoms in the hydrocarbon group is preferably 1 to 40, more preferably 3 to 35, even more preferably 5 to 30, and particularly preferably 8 to 25. This number of carbon atoms includes the carbon atoms in the substituents if the hydrocarbon group has substituents.

[0013] The above M B Examples of alkali metals include lithium, sodium, potassium, rubidium, and cesium. A -COOM B It is preferable that it includes the form of a sodium salt and / or a potassium salt, and more preferably a sodium salt and / or a potassium salt. Therefore, M B -OH preferably contains caustic soda (NaOH) and / or KOH, and more preferably caustic soda and / or KOH. The above M C Examples of alkaline earth metals include beryllium, magnesium, calcium, strontium, and barium. (R A -COO)2M C It is preferable that it includes magnesium salts and / or calcium salts, and more preferably magnesium salts and / or calcium salts. Therefore, M C -(OH)2 preferably comprises Mg(OH)2 and / or Ca(OH)2, and more preferably Mg(OH)2 and / or Ca(OH)2.

[0014] In the present invention's method for producing alkali metal / alkaline earth metal hydroxides, the liquid subjected to the electrochemical reaction contains R A -COOM B or (R A -COO)2M C It contains one or more compounds represented by [the specified formula].

[0015] R A -COOM B and (R A -COO)2M C Specific examples include: Alkali metal salts or alkaline earth metal salts of saturated fatty acids such as acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, behenic acid, lignoceric acid, cerotic acid, montanic acid, and mellic acid; Alkali metal salts or alkaline earth metal salts of unsaturated fatty acids such as palmitoleic acid, oleic acid, vaccenic acid, linoleic acid, (9,12,15)-linolenic acid, (6,9,12)-linolenic acid, eleostearic acid, arachidic acid, meadic acid, arachidonic acid, nervonic acid, erucic acid, eicosapentanoic acid, docosahexaenoic acid, sorbic acid, and ricinoleic acid; Alkali metal salts or alkaline earth metal salts of aromatic group-containing carboxylic acid compounds such as benzoic acid, cinnamic acid, sinapic acid, coumaric acid, and caffeic acid; These are some examples, and one or more of these can be used.

[0016] R A -COOM B and / or (R A -COO)2M C A liquid containing water may be made to the extent that it does not impair the effects of the present invention, R A -COOM B , (R A -COO)2M C Other than water, the product may also contain other components. For example, it may contain oils and fats or their decomposition products, lignin decomposition products of non-carboxylate salts, organic solvents, organic and inorganic salts, etc.

[0017] R A -COOM B and / or (R A -COO)2M C R in a liquid containing water A -COOM B and (R A -COO)2M C The sum of the contents of each can be adjusted as appropriate to obtain the desired concentration of alkali metal hydroxide. A -COOM B and (R A -COO)2M C The total content of each of the elements can be appropriately adjusted, for example, within a range of 1 to 90% by mass, preferably 2 to 60% by mass, and more preferably 5 to 50% by mass. Similarly, the water content in the liquid can be appropriately adjusted, for example, within a range of 10 to 99% by mass, preferably 40 to 98% by mass, and more preferably 50 to 95% by mass.

[0018] The present invention's method for producing alkali metal hydroxides is R A -COOM B and / or (R A -COO)2M C The liquid containing water may be in a form that includes at least one of the following waste liquids: (a) to (c). (a) Oil residue generated in the deacidification process in the production of vegetable oils, (b) Black liquor produced in the post-pulping washing process in papermaking, and (c) Soap wastewater generated during the washing process of the crude fatty acid ester fraction in the production of fatty acid esters. The above (a) to (c) are R A -COOM B and / or (R A -COO)2M C As described above, it is a liquid containing water. In the present invention, "R A -COOM B and / or (R A -COO)2M C "A liquid containing water contains at least one of the waste liquids from (a) to (c)" means R A -COOMB and / or (R A -COO)2M C This means that at least a portion of the liquid containing water is at least one of the waste liquids described in (a) to (c) above. For example, R A -COOM B and / or (R A -COO)2M C The liquid containing water may be at least one of the waste liquids described in (a) to (c) above, a diluted version of at least one of the waste liquids described in (a) to (c) above, or a concentrated version of at least one of the waste liquids described in (a) to (c) above. The present invention's method for producing alkali metal / alkaline earth metal hydroxides is R A -COOM B and / or (R A -COO)2M C It is more preferable that the liquid containing water contains one of the above (a) to (c) but does not contain the other two.

[0019] <Electrochemical reaction> The electrochemical reaction in the method for producing alkali metal hydroxides according to the present invention will now be described. Figure 4 is a schematic diagram illustrating the basic configuration of the electrochemical reactor used in the above electrochemical reaction. The electrochemical reactor used in the present invention can be configured in accordance with the configuration of a normal electrochemical reactor. That is, the electrochemical reactor comprises an anode 1 and a cathode 2. There are no particular restrictions on the material constituting the anode 1, and any anode material commonly used in electrochemical reactions can be used as appropriate. For example, platinum, stainless steel, nickel, iron, aluminum, graphite, and aluminum / magnesium alloy (duralumin) can be used as the anode material. The material constituting the cathode 2 can also be any cathode material commonly used in electrochemical reactions. For example, platinum, titanium, nickel, iron, aluminum, and graphite can be used as the cathode material. Furthermore, the shapes of anode 1 and cathode 2 are not limited to any particular shape. The shapes of anode 1 and cathode 2 are preferably rod-shaped, plate-shaped, and / or foil-shaped. Anode 1 and cathode 2 may also have a shape with holes, such as wire mesh or mesh.

[0020] The electrolytic cell 3 of the electrochemical reaction apparatus shown in Figure 4 uses the above-mentioned R as the electrolyte. A -COOM B Let's take the example of a state where the container is filled with liquid 4 containing water. In this state, when a voltage is applied between the anode 1 and the cathode 2, the Kolbe electrolytic reaction shown in equation (1) below occurs on the anode 1 side, and at least R A -R A A dimerized hydrocarbon represented by M, carbon dioxide, B+ Ions are generated. 2R A -COOM B →R A -R A +2CO2+2e - +2M B+ (1)

[0021] Furthermore, at cathode 2, the electrolysis reaction of water shown in equation (2) below occurs, and OH - Ions and hydrogen are produced. 2H2O + 2e - →2OH - +H2(2)

[0022] Combining equations (1) and (2) above, the reaction equation shown in equation (3) below can be derived. 2R A -COOM B +2H2O→R A -R A +2CO2+H2+2M B OH (3)

[0023] That is, R A -COOM BA liquid 4 containing water is subjected to an electrochemical reaction, and at the anode 1 a Kolbe electrolysis reaction occurs, producing at least hydrocarbons, carbon dioxide, and alkali metal ions. These alkali metal ions then undergo electrolysis of water at the cathode 2, producing OH - Neutralized by ions, alkali metal hydroxide (M B -OH) is produced. Up until now, R A -COOM B It was known that when a liquid containing and water is subjected to an electrochemical reaction, hydrocarbons are produced at the anode. However, the resulting M B+ The behavior of the ions, that is, whether the reaction in equation (3) actually occurs, was unknown. This point will be explained in more detail. The carbon dioxide (CO2) generated by equation (1) above has significantly higher solubility in water compared to hydrogen and oxygen. When carbon dioxide is dissolved in water, it forms bicarbonate ions (HCO3). - ) becomes M B+ One option is to neutralize (make electrically neutral) the OH generated in equation (2) above. - It is thought that the ions are oxidized at anode 1 to form oxygen molecules, similar to the electrolysis of ordinary water. However, as a result of the inventors' investigation, as shown in the examples described later, R A -COOM B When a solution containing water was subjected to an electrochemical reaction, an organic synthesis reaction of hydrocarbons occurred at anode 1, and the pH of the solution rose to above pH 10 in a few minutes. This revealed that alkali metal hydroxides were being produced with high efficiency by the reaction of formula (3) above. B+ It is neutralized by bicarbonate ions to form HCO3M B If this occurs, the pH of the liquid will remain at around 8-9. Note that the above refers to R A -COOM B The form using has been explained, but the above explanation is (R A -COO)2M C This is equally valid when using [the specified method].

[0024] The above electrochemical reaction is preferably carried out at 10 to 60°C, more preferably 15 to 50°C, and even more preferably 20 to 40°C. Furthermore, the current density applied in the electrochemical reaction of the present invention is preferably 0.05 to 2.00 A / cm². 2 , more preferably 0.1~1.0 A / cm 2 More preferably 0.2 to 0.6 A / cm² 2 That is the case.

[0025] In the electrochemical reaction described above, hydrocarbons are generated at the anode, and these hydrocarbons can be recovered and utilized as a resource. Specifically, if the hydrocarbons produced by the Kolbe electrolysis are gases, a mixed gas containing hydrocarbons, carbon dioxide, and air can be recovered. From this recovered mixed gas, hydrocarbons can be selectively recovered by membrane separation, liquefaction of hydrocarbons by compression or cooling, etc. Furthermore, if the hydrocarbons produced by the Kolbe electrolysis are liquids or solids, they undergo phase separation from a hydrophilic liquid containing alkali metal hydroxides and water, allowing for easy separation and recovery of the target hydrocarbons. The recovered hydrocarbons can be used, for example, as fuel, wax, insulating material, moisture-proof material, waterproofing material, abrasive, pharmaceutical, cosmetic, molding material, organic solvent, wax, lubricant, etc. A -COOM B and / or (R A -COO)2M C If the liquid containing water contains, for example, at least one of the above-mentioned waste liquids such as oil residue, black liquor, and soapy wastewater, the recovered hydrocarbons are of plant origin, and the fuel containing these hydrocarbons is carbon neutral.

[0026] Alkali metal hydroxides produced by electrochemical reactions can be recovered as aqueous solutions. These aqueous solutions of alkali metal hydroxides can be concentrated or impurities removed as needed and used industrially as caustic soda solutions, etc.

[0027] To obtain a high-purity aqueous solution of alkali metal hydroxide, the anode and cathode can be separated by an ion-permeable membrane in the above electrolysis reaction. By separating the two electrodes with an ion-permeable membrane, the concentration gradient or electrical gradient can be used to control the reaction. B+ Aeon and M C2+ Ions can be moved to the cathode side almost selectively, and as a result, the concentration and purity of alkali metal hydroxides or alkaline earth hydroxides on the cathode side can be increased compared to the anode side. Preferred examples of such membranes include cation exchange membranes, semipermeable membranes, cellophane membranes, and zeolite membranes, and M produced on the anode side B+ Aeon and M C2+ A cation exchange membrane is preferred from the viewpoint of more efficiently transferring ions to the cathode side. The cation exchange membrane can be either a strongly acidic or weakly acidic cation exchange membrane. The cation exchange group of the cation exchange membrane may be in a form containing hydrogen atoms, or it may be in a state where it has been exchanged (substituted) with alkali metal ions. When used with the cation exchange group containing hydrogen atoms, if an electrochemical reaction is carried out, the hydrogen atoms will be converted to M over time. B+ Aeon and M C2+ It was replaced by ion, and then M B+ Aeon and M C2+ This allows for a smoother transfer of ions to the cathode.

[0028] In particular, in the electrochemical reaction described above, the anode and cathode sides are separated by an ion-permeable membrane, and R is introduced on the anode side. A -COOM B and / or (R A -COO)2M C A preferred method for producing alkali metal / alkaline earth metal hydroxides according to the present invention is to introduce a liquid containing alkali metal hydroxide and / or alkaline earth metal hydroxide, with water placed on the cathode side, and to carry out an electrochemical reaction. By adopting this configuration, a highly pure aqueous solution of alkali metal hydroxide and / or alkaline earth metal hydroxide can be obtained on the cathode side. The two electrodes are separated by an ion-permeable diaphragm 5, and R is on the anode side. A -COOM BFigure 5 schematically shows a configuration in which a liquid 4 containing water is added, and water 6 is added to the cathode side to carry out the electrochemical reaction. As shown in Figure 5, M is produced at the anode. B+ Ions selectively migrate towards the cathode side according to the concentration gradient, and OH forms on the cathode side. - The solution is neutralized by ions, and a high-purity aqueous solution of alkali metal hydroxide is obtained at the cathode. The water used at the cathode can be tap water, distilled water, or pure water, as appropriate. Furthermore, in this invention, "water" may contain alkali metal hydroxide, other electrolytes, etc., as long as it does not impair the effects of the invention.

[0029] Furthermore, the electrochemical reaction can be carried out in the configuration shown in Figure 4, and the resulting reaction solution (electrolyte) can be placed in one side of a tank (a separate tank from the electrolytic cell) separated by an ion-permeable membrane, with water placed on the other side of the tank separated by the membrane. For example, R A -COOM B Figure 6 shows a configuration in which a liquid 4 containing water is subjected to an electrochemical reaction, and the resulting reaction solution is placed in another tank. From one side separated by the diaphragm, M is transferred to the other side. B -OH(M B+ The ions migrate according to the concentration gradient, resulting in higher purity M B An aqueous solution of -OH can be obtained.

[0030] Furthermore, a modified version of the configuration shown in Figure 6 is shown in Figure 7. In the configuration of Figure 7, the inside of the electrolytic cell is separated by an ion-permeable diaphragm, and both the anode and cathode are placed on one side separated by the diaphragm to carry out the electrochemical reaction, while water is placed on the other side separated by the diaphragm. As a result, M is generated by the electrochemical reaction B -OH(M B+ The ions move towards the side where water is added according to the concentration gradient, resulting in a higher purity M B An aqueous solution of -OH can be obtained.

[0031] The present invention's method for producing alkali metal / alkaline earth metal hydroxides can be applied to a method for producing vegetable oils that effectively utilizes wastewater generated in the vegetable oil production process. That is, according to the present invention, the above RA -COOM B and / or (R A -COO)2M C A method for producing vegetable oil is provided, which includes obtaining alkali metal hydroxides and / or alkaline earth metal hydroxides using a liquid containing water and oil residue generated in the deoxidation step of vegetable oil production, and utilizing these in the deoxidation step of vegetable oil production. In this case, the alkali metal hydroxides and / or alkaline earth metal hydroxides usually include caustic soda (NaOH). "R A -COOM B and / or (R A -COO)2M C "As a liquid containing water, we use a liquid containing oil residue generated in the deacidification process in the production of vegetable oils." A -COOM B and / or (R A -COO)2M C This means using oil residue as at least part of a liquid containing water. For example, R A -COOM B and / or (R A -COO)2M C The liquid containing water may be the oil residue itself, a diluted version of the oil residue, or a concentrated version of the oil residue.

[0032] Furthermore, the method for producing alkali metal / alkaline earth metal hydroxides of the present invention can be applied to papermaking methods that effectively utilize wastewater generated in the papermaking process. That is, according to the present invention, the above R A -COOM B and / or (R A -COO)2M C A papermaking method is provided, which involves obtaining alkali metal hydroxides and / or alkaline earth metal hydroxides using a liquid containing water, including black liquor produced in the washing step after pulping in papermaking, and utilizing these in the pulping step of papermaking. In this case, the alkali metal hydroxides and / or alkaline earth metal hydroxides usually include caustic soda (NaOH). "R A -COOM Band / or (R A -COO)2M C "As a liquid containing water, we use a liquid containing black liquor produced in the washing process after pulping in papermaking." A -COOM B and / or (R A -COO)2M C This means using black liquor as at least part of a liquid containing water. For example, R A -COOM B and / or (R A -COO)2M C The liquid containing water may be black liquor itself, a diluted black liquor, or a concentrated black liquor.

[0033] Furthermore, the alkali metal / alkaline earth metal hydroxide production method of the present invention can be applied to a method for producing fatty acid esters that effectively utilizes wastewater generated in the production process of fatty acid esters such as biodiesel. In other words, according to the present invention, the above R A -COOM B and / or (R A -COO)2M C A method for producing fatty acid esters is provided, which includes obtaining alkali metal hydroxides and / or alkaline earth metal hydroxides using a liquid containing water, which contains soapy wastewater generated in the washing step of the crude fatty acid ester fraction in the production of fatty acid esters, and utilizing these in the crude fatty acid ester formation reaction in the production of fatty acid esters. In the crude fatty acid ester formation reaction, the alkali metal hydroxides and / or alkaline earth metal hydroxides act as alkaline catalysts. The alkali metal hydroxides and / or alkaline earth metal hydroxides mentioned above usually include caustic soda (NaOH) or caustic potash (KOH). "R A -COOM B and / or (R A -COO)2M C "The liquid containing water is a liquid containing soapy wastewater generated in the washing process of the crude fatty acid ester fraction in the production of fatty acid esters." A -COOM B and / or (RA -COO)2M C This means using the above-mentioned soapy wastewater as at least a portion of the liquid containing water. For example, R A -COOM B and / or (R A -COO)2M C The liquid containing water may be the soap wastewater itself, a diluted version of the soap wastewater, or a concentrated version of the soap wastewater. As an example of the above-mentioned method for producing fatty acid esters, a method for producing fatty acid methyl esters is preferably mentioned.

[0034] In the above-described methods for producing vegetable oils and fats, papermaking, and fatty acid esters, the resulting alkali metal hydroxides and / or alkaline earth metal hydroxides are usually in the form of aqueous solutions. These aqueous solutions can be concentrated and dried as appropriate before use in each manufacturing process. Alternatively, the concentration of alkali metal hydroxides and / or alkaline earth metal hydroxides can be adjusted before use in each manufacturing process. The concentration of alkali metal hydroxides and / or alkaline earth metal hydroxides can be adjusted by removing water from the recovered solution by heating, vacuum drying, etc., or by adding water to the recovered solution of alkali metal hydroxides and / or alkaline earth metal hydroxides.

[0035] In relation to the above-mentioned methods for producing alkali metal / alkaline earth metal hydroxides or vegetable oils, the present invention provides the following apparatus for producing alkali metal / alkaline earth metal hydroxides, and a recycling system for alkali metal / alkaline earth metal hydroxides using the same. In other words, according to the present invention, an electrochemical apparatus comprising an anode, a cathode and an electrolytic cell, and a tank whose interior is separated by an ion-permeable diaphragm, wherein the electrochemical apparatus is subjected to an electrochemical reaction in which a liquid containing oil residue generated in the deoxidation step of vegetable oil production is mixed with M in the reaction solution. B -OH and / or M C -(OH)2 is produced, the resulting reaction solution is placed on one side of the tank separated by the diaphragm, and water is placed on the other side of the tank separated by the diaphragm, and M in the reaction solution B-OH and / or M C An apparatus for producing alkali metal / alkaline earth metal hydroxides is provided, which transfers -(OH)2 into the water. Furthermore, the present invention provides an apparatus for producing alkali metal / alkaline earth metal hydroxides, which has an electrolytic cell comprising an anode, a cathode, and an ion-permeable diaphragm separating the anode side and the cathode side, and carries out an electrochemical reaction by placing a liquid containing oil residue generated in the deoxidation step of vegetable oil production on the anode side and water on the cathode side. Furthermore, according to the present invention, an electrolytic cell separated by an ion-permeable diaphragm, and an anode and a cathode located on one side separated by the diaphragm, wherein a liquid containing oil residue generated in the deoxidation process in the production of vegetable oils is placed on one side of the electrolytic cell separated by the diaphragm, and M is added to the reaction solution by an electrochemical reaction. B -OH and / or M C -(OH)2 is produced, and water is placed on the other side of the electrolytic cell separated by the diaphragm, and M in the reaction solution B -OH and / or M C An apparatus for producing alkali metal / alkaline earth metal hydroxides is provided, which transfers -(OH)2 into the water. Furthermore, a recycling system for alkali metal / alkaline earth metal hydroxides is provided, comprising these manufacturing apparatuses and means for supplying the alkali metal hydroxides and / or alkaline earth metal hydroxides produced using these manufacturing apparatuses to a deoxidation step in the production of vegetable oils. The size of the alkali metal / alkaline earth metal hydroxide production apparatus described above is designed appropriately according to the purpose. The means of supplying alkali metal hydroxides and / or alkaline earth metal hydroxides to the deoxidation process in the production of vegetable oils are not particularly limited and include all means that can transport alkali metal hydroxides and / or alkaline earth metal hydroxides (usually in aqueous solution form) to the site of the deoxidation process in the production of vegetable oils. For example, alkali metal hydroxides and / or alkaline earth metal hydroxides can be transported to the site of the deoxidation process by connecting the electrolytic cell and the deoxidation process site with piping and circulating the aqueous solution of alkali metal hydroxides and / or alkaline earth metal hydroxides through the piping. Alternatively, the aqueous solution of alkali metal hydroxides and / or alkaline earth metal hydroxides recovered from the electrolytic cell may be transported to the site of the deoxidation process by truck, forklift, etc.

[0036] Furthermore, in relation to the above-mentioned method for producing alkali metal / alkaline earth metal hydroxides or papermaking methods, the present invention provides the following apparatus for producing alkali metal / alkaline earth metal hydroxides, and a recycling system for alkali metal / alkaline earth metal hydroxides using the same. In other words, according to the present invention, an electrochemical apparatus comprising an anode, a cathode, and an electrolytic cell, and a tank whose interior is separated by an ion-permeable diaphragm, wherein the electrochemical apparatus is subjected to an electrochemical reaction in which a liquid containing black liquor produced in the washing process after digestion in papermaking is mixed with M in the reaction solution. B -OH and / or M C -(OH)2 is produced, the resulting reaction solution is placed on one side of the tank separated by the diaphragm, and water is placed on the other side of the tank separated by the diaphragm, and M in the reaction solution B -OH and / or M C An apparatus for producing alkali metal / alkaline earth metal hydroxides is provided, which transfers -(OH)2 into the water. Furthermore, the present invention provides an apparatus for producing alkali metal / alkaline earth metal hydroxides, which has an electrolytic cell comprising an anode, a cathode, and an ion-permeable diaphragm separating the anode side and the cathode side, and carries out an electrochemical reaction by placing a liquid containing black liquor generated in the washing process after pulping in papermaking on the anode side and water on the cathode side. Furthermore, according to the present invention, an electrolytic cell separated by an ion-permeable diaphragm, and an anode and a cathode located on one side separated by the diaphragm, wherein a liquid containing black liquor produced in the washing process after pulping in papermaking is placed on one side of the electrolytic cell separated by the diaphragm, and M is added to the reaction solution by an electrochemical reaction. B -OH and / or M C -(OH)2 is produced, and water is placed on the other side of the electrolytic cell separated by the diaphragm, and M in the reaction solution B -OH and / or M C An apparatus for producing alkali metal / alkaline earth metal hydroxides is provided, which transfers -(OH)2 into the water. Furthermore, a recycling system for alkali metal / alkaline earth metal hydroxides is provided, comprising these manufacturing apparatuses and means for supplying the alkali metal hydroxides and / or alkaline earth metal hydroxides generated on the cathode side of these manufacturing apparatuses to the pulping process in papermaking. The size of the alkali metal / alkaline earth metal hydroxide production apparatus described above is designed appropriately according to the purpose. The means of supplying alkali metal hydroxides and / or alkaline earth metal hydroxides to the pulping process in papermaking are not particularly limited and include all means that can transport alkali metal hydroxides and / or alkaline earth metal hydroxides (usually in aqueous solution form) to the pulping process site in papermaking. For example, alkali metal hydroxides and / or alkaline earth metal hydroxides can be transported to the pulping process site by connecting the electrolytic cell and the pulping site with piping and circulating the aqueous solution of alkali metal hydroxides and / or alkaline earth metal hydroxides through the piping. Alternatively, the aqueous solution of alkali metal hydroxides and / or alkaline earth metal hydroxides recovered from the electrolytic cell may be transported to the pulping process site by truck, forklift, or the like.

[0037] Furthermore, in relation to the above-mentioned methods for producing alkali metal / alkaline earth metal hydroxides or fatty acid esters, the present invention provides the following apparatus for producing alkali metal / alkaline earth metal hydroxides, and a recycling system for alkali metal / alkaline earth metal hydroxides using the same. In other words, according to the present invention, an electrochemical apparatus comprising an anode, a cathode, and an electrolytic cell, and a tank whose interior is separated by an ion-permeable diaphragm, wherein the electrochemical apparatus is subjected to an electrochemical reaction in which a liquid containing soapy wastewater generated in the washing step of the crude fatty acid ester fraction in the production of fatty acid esters is subjected to an electrochemical reaction and M is added to the reaction solution B -OH and / or M C -(OH)2 is produced, the resulting reaction solution is placed on one side of the tank separated by the diaphragm, and water is placed on the other side of the tank separated by the diaphragm, and M in the reaction solution B -OH and / or M C An apparatus for producing alkali metal / alkaline earth metal hydroxides is provided, which transfers -(OH)2 into the water. Furthermore, the present invention provides an apparatus for producing alkali metal / alkaline earth metal hydroxides, which has an electrolytic cell comprising an anode, a cathode, and an ion-permeable diaphragm separating the anode side and the cathode side, and carries out an electrochemical reaction by placing a liquid containing soapy wastewater generated in the washing step of the crude fatty acid ester fraction in the production of fatty acid esters on the anode side and water on the cathode side. Furthermore, according to the present invention, an electrolytic cell separated by an ion-permeable diaphragm, and an anode and a cathode located on one side separated by the diaphragm, wherein a liquid containing soapy wastewater generated in the washing step of the crude fatty acid ester fraction in the production of fatty acid esters is placed on one side of the electrolytic cell separated by the diaphragm, and M is added to the reaction solution by an electrochemical reaction. B -OH and / or M C -(OH)2 is produced, and water is placed on the other side of the electrolytic cell separated by the diaphragm, and M in the reaction solution B -OH and / or M C An apparatus for producing alkali metal / alkaline earth metal hydroxides is provided, which transfers -(OH)2 into the water. Furthermore, a recycling system for alkali metal / alkaline earth metal hydroxides is provided, comprising these manufacturing apparatuses and means for supplying alkali metal hydroxides and / or alkaline earth metal hydroxides produced using these manufacturing apparatuses to the crude fatty acid ester formation reaction step in the production of fatty acid esters. The size of the alkali metal / alkaline earth metal hydroxide production apparatus described above is designed appropriately according to the purpose. The means of supplying alkali metal hydroxides to the crude fatty acid ester formation reaction step in the production of fatty acid esters are not particularly limited, and any means of transporting alkali metal hydroxides and / or alkaline earth metal hydroxides to the site of the crude fatty acid ester formation reaction step in the production of fatty acid esters is included. For example, alkali metal hydroxides and / or alkaline earth metal hydroxides can be transported to the site of the formation reaction step by connecting the electrolytic cell and the site of the formation reaction step with piping and circulating an aqueous solution of alkali metal hydroxides and / or alkaline earth metal hydroxides through the piping. Alternatively, the aqueous solution of alkali metal hydroxides and / or alkaline earth metal hydroxides recovered from the electrolytic cell may be transported to the site of the formation reaction step by truck, forklift, or the like. [Examples]

[0038] The present invention will be described in more detail below based on examples, but the present invention is not limited to these forms other than those specified herein.

[0039] [Example 1] The electrolytic cell 3 (volume 150 cm³) of the electrochemical reaction apparatus with the configuration shown in Figure 4. 3 ) to, R A -COOM B A 100 mL (pH 8.8) aqueous solution of 2% by mass (0.12 mol / L) sodium caprylate was added as a solution containing water. Platinum foil was used as the anode 1 and platinum foil as the cathode 2, at 40°C and a current density of 0.2 A / cm². 2 Under these conditions, the mixture was subjected to an electrochemical reaction for 15 minutes. Over time, an oil phase floated to the surface. This indicates that organic substances such as hydrocarbons were being generated by Kolbe electrolysis. The oil phase was separated and recovered, and the pH change of the liquid in electrolytic cell 3 was monitored. As a result, the pH of the liquid increased from around 9 initially to over 11 6 minutes after the start of the electrochemical reaction, and the pH at the end of the reaction (15 minutes after the start of the electrochemical reaction) was 12.7 (Table 1 below). In other words, alkali metal hydroxides (MB This confirmed that -OH) is generated with high efficiency.

[0040] [Examples 2-7] In Example 1, R A -COOM B The electrochemical reaction was carried out in the same manner as in Example 1, except that the type of reagent, its aqueous solution concentration, reaction temperature, and current density were as shown in Table 1 below. In all of Examples 2 to 7, as in Example 1, the oil phase floated to the surface over time. The oil phase was separated and recovered, and the pH change of the liquid in electrolytic cell 3 was monitored. The results are shown in Table 1 below. As shown in Table 1 below, in all of Examples 2 to 7, the pH increased significantly in a short time due to the electrochemical reaction, and alkali metal hydroxide (M B This confirmed that -OH) is generated with high efficiency.

[0041] [Table 1]

[0042] [Example 8] An electrochemical reaction was carried out using an electrochemical reactor configured as shown in Figure 5. In this electrochemical reactor, the two electrodes in the electrolytic cell 3 are separated by an ion-permeable diaphragm 5 (product name: Nafion NRE-212, manufactured by Merck), and the volume of the anode side (anode cell) of the electrolytic cell 3 is 75 cm³. 3 The volume of the cathode side (cathode chamber) is also 75 cm³. 3 That is the case. On the anode side of electrolytic cell 3, R A -COOM B A 50 mL aqueous solution of 2% by mass (0.12 mol / L) sodium caprylate was added as a solution containing water. Additionally, 50 mL of water was added to the cathode side. In this state, the pH of the solution in the anode bath was 7.8, and the pH of the solution in the cathode bath was 6.8. Platinum foil was used as both anode 1 and cathode 2, at 50°C and a current density of 0.2 A / cm². 2Under these conditions, the system was subjected to an electrochemical reaction for 15 minutes. Over time, an oil phase formed on the surface only in the anode tank. This confirmed that organic substances such as hydrocarbons were being generated at the anode by Kolbe electrolysis. This oil phase was separated and recovered, and the pH changes of the liquids in the anode and cathode tanks were monitored. As a result, at the end of the reaction (15 minutes after the start of the electrochemical reaction), the pH of the liquid in the anode tank was 7.5, while the pH of the liquid in the cathode tank had risen significantly to 12.5 (Table 2 below). On the other hand, analysis of the liquid in the cathode tank after the reaction by gas chromatography revealed no organic substances. This indicates that all organic substances such as hydrocarbons generated by Kolbe electrolysis remained in the anode tank. For reference, without applying voltage (current density 0.0 A / cm²), 2 When the pH was measured 15 minutes later, almost no change in the pH of the solutions in the anode and cathode baths was observed (see Table 2 below). In this way, by separating the two electrodes of the electrolytic cell with a diaphragm and performing the electrochemical reaction defined in this invention, the organic matter produced by Kolbe electrolysis is transferred to the anode cell, alkali metal hydroxide (M B It was confirmed that -OH) can be selectively separated into the cathode bath.

[0043] [Table 2]

[0044] The above results are from R A -COOM B and / or (R A -COO)2M C By subjecting the above-mentioned oil slag, black liquor, soapy wastewater, etc., which are liquids containing water, to an electrochemical reaction, an organic synthesis reaction occurs on the anode side, R A -R AThis demonstrates that while obtaining hydrocarbon compounds consisting of [the specified components], industrially useful alkali metal hydroxides and / or alkaline earth metal hydroxides can be efficiently obtained in the liquid simultaneously. Furthermore, it is shown that by separating the electrolytic cells with a diaphragm, it is possible to selectively separate the organic matter produced by Kolbe electrolysis into the anode cell and the alkali metal hydroxides and / or alkaline earth metal hydroxides into the cathode cell.

[0045] Although we have described the present invention along with its embodiments, we do not intend to limit our invention in any detail of the description unless specifically designated, and we believe that it should be interpreted broadly without contradicting the spirit and scope of the invention as set forth in the appended claims.

[0046] This application claims priority based on Japanese Patent Application No. 2021-035809, filed in Japan on March 5, 2021, the contents of which are incorporated herein by reference as part of this specification. [Explanation of Symbols]

[0047] 1 Anode 2 cathode 3 Electrolytic cell 4 R A -COOM B A liquid containing water 5. Ion-permeable diaphragm 6 water

Claims

1. The anode side and the cathode side of an electrolytic cell are separated by a cation exchange membrane, and R is provided on the anode side Ａ -COOM Ｂ and / or (R Ａ -COO) ２ ₂M Ｃ and water, a liquid containing soapstock generated in the deacidification step in the production of vegetable fats and oils is introduced into the anode side, water is introduced into the cathode side, and the system is subjected to an electrochemical reaction, a Kolbe electrolysis reaction occurs at the anode to produce at least R Ａ -R Ａ , carbon dioxide, M Ｂ＋ ⁺ ions and / or M Ｃ２＋ ²⁺ ions, and OH generated by electrolysis of water at the cathode － ⁻ ions neutralize the M Ｂ＋ ⁺ ions and / or M Ｃ２＋ ²⁺ ions that have migrated from the anode side to the cathode side to obtain an alkali metal hydroxide and / or an alkaline earth metal hydroxide, and the method comprises using this alkali metal hydroxide and / or alkaline earth metal hydroxide in a deacidification step in the production of vegetable fats and oils. A method for producing vegetable fats and oils. R Ａ indicates a hydrocarbon group, M Ｂ This indicates alkali metals, M Ｃ This indicates alkaline earth metals.

2. The anode and cathode are placed on one side of the electrolytic cell, separated by a cation exchange membrane, R Ａ -COOM Ｂ and / or (R Ａ -COO) ２ M Ｃ A liquid containing water and oil residue generated in the deoxidation process of vegetable oil production is subjected to an electrochemical reaction, and a Kolbe electrolytic reaction occurs at the anode, generating at least R Ａ -R Ａ carbon dioxide and M Ｂ＋ Ions and / or M Ｃ２＋ Ions are generated, and OH is produced by the electrolysis of water at the cathode. － The M Ｂ＋ Ions and / or M Ｃ２＋ Neutralize the ions and add M to the reaction solution. Ｂ -OH and / or M Ｃ - (OH) ２ This generates water, and water is introduced into the other side of the electrolytic cell separated by the cation exchange membrane, and the M Ｂ -OH and / or M Ｃ - (OH) ２ A method for producing vegetable oil, comprising obtaining alkali metal hydroxides and / or alkaline earth metal hydroxides by transferring [a certain substance], and utilizing these alkali metal hydroxides and / or alkaline earth metal hydroxides in a deoxidation step in the production of vegetable oil. R Ａ indicates a hydrocarbon group, M Ｂ This indicates alkali metals, M Ｃ This indicates alkaline earth metals.

3. A cation exchange membrane separates the anode and cathode sides of the electrolytic cell, and R is located on the anode side. Ａ -COOM Ｂ and / or (R Ａ -COO) ２ M Ｃ A liquid containing water is added, which includes the black liquor produced in the washing process after pulping in papermaking. Water is then added to the cathode side and subjected to an electrochemical reaction, causing a Kolbe electrolytic reaction at the anode to occur, resulting in at least R Ａ -R Ａ carbon dioxide and M Ｂ＋ Ions and / or M Ｃ２＋ Ions are generated, and OH is produced by the electrolysis of water at the cathode. － The M that migrated from the anode side to the cathode side due to ions Ｂ＋ Ions and / or M Ｃ２＋ A papermaking method comprising obtaining an alkali metal hydroxide and / or an alkaline earth metal hydroxide by neutralizing ions, and utilizing this alkali metal hydroxide and / or alkaline earth metal hydroxide in the pulping process in papermaking. R Ａ indicates a hydrocarbon group, M Ｂ This indicates alkali metals, M Ｃ This indicates alkaline earth metals.

4. The anode and cathode are placed on one side of the electrolytic cell, separated by a cation exchange membrane, R Ａ -COOM Ｂ and / or (R Ａ -COO) ２ M Ｃ A liquid containing water and black liquor, which is produced in the washing process after pulping in papermaking, is subjected to an electrochemical reaction, and a Kolbe electrolytic reaction occurs at the anode, producing at least R Ａ -R Ａ carbon dioxide and M Ｂ＋ Ions and / or M Ｃ２＋ Ions are generated, and OH is produced by the electrolysis of water at the cathode. － The M Ｂ＋ Ions and / or M Ｃ２＋ Neutralize the ions and add M to the reaction solution. Ｂ -OH and / or M Ｃ - (OH) ２ This generates water, and water is introduced into the other side of the electrolytic cell separated by the cation exchange membrane, and the M Ｂ -OH and / or M Ｃ - (OH) ２ A papermaking method comprising obtaining an alkali metal hydroxide and / or alkaline earth metal hydroxide by transferring [a certain substance], and utilizing this alkali metal hydroxide and / or alkaline earth metal hydroxide in the pulping process in papermaking. R Ａ indicates a hydrocarbon group, M Ｂ This indicates alkali metals, M Ｃ This indicates alkaline earth metals.

5. A cation exchange membrane separates the anode and cathode sides of the electrolytic cell, and R is located on the anode side. Ａ -COOM Ｂ and / or (R Ａ -COO) ２ M Ｃ A liquid containing water is added, along with soapy wastewater generated in the washing step of the crude fatty acid ester fraction in the production of fatty acid esters. Water is then added to the cathode side and subjected to an electrochemical reaction, causing a Kolbe electrolytic reaction at the anode to occur, resulting in at least R Ａ -R Ａ carbon dioxide and M Ｂ＋ Ions and / or M Ｃ２＋ Ions are generated, and OH is produced by the electrolysis of water at the cathode. － The M that migrated from the anode side to the cathode side due to ions Ｂ＋ Ions and / or M Ｃ２＋ A method for producing fatty acid esters, comprising obtaining alkali metal hydroxides and / or alkaline earth metal hydroxides by neutralizing ions, and utilizing these alkali metal hydroxides and / or alkaline earth metal hydroxides in the reaction for producing crude fatty acid esters in the production of fatty acid esters. R Ａ indicates a hydrocarbon group, M Ｂ This indicates alkali metals, M Ｃ This indicates alkaline earth metals.

6. An anode and a cathode are arranged on one side partitioned by a cation exchange membrane of an electrolytic cell, and R Ａ -COOM Ｂ and / or (R Ａ -COO) ２ M Ｃ and water, which contains soap wastewater generated in a washing step of a crude fatty acid ester fraction in fatty acid ester production, is subjected to an electrochemical reaction, a Kolbe electrolysis reaction is caused to occur at the anode to produce at least R Ａ -R Ａ and carbon dioxide, and M Ｂ＋ ions and / or M Ｃ２＋ ions; OH ions generated by electrolysis of water at the cathode neutralize the aforementioned M － ions and / or M Ｂ＋ ions and / or M Ｃ２＋ ions to produce M Ｂ -OH and / or M Ｃ -(OH) ２ ; water is introduced into the other side of the electrolytic cell partitioned by the cation exchange membrane, and the aforementioned M Ｂ -OH and / or M Ｃ -(OH) ２ is migrated into the water to obtain an alkali metal hydroxide and / or an alkaline earth metal hydroxide, and the alkali metal hydroxide and / or alkaline earth metal hydroxide is used in a crude fatty acid ester generation reaction in fatty acid ester production. A method for producing a fatty acid ester. R Ａ indicates a hydrocarbon group, M Ｂ This indicates alkali metals, M Ｃ This indicates alkaline earth metals.

7. Said M Ｂ The method according to any one of claims 1 to 6, wherein the alkali metal is sodium and / or potassium.

8. An apparatus for producing alkali metal / alkaline earth metal hydroxides, comprising an electrolytic cell having an anode, a cathode, and a cation exchange membrane separating the anode side and the cathode side, wherein an electrochemical reaction is carried out by placing a liquid containing oil residue generated in the deoxidation process of vegetable oil production on the anode side and water on the cathode side; Means for supplying alkali metal hydroxides and / or alkaline earth metal hydroxides produced using the manufacturing apparatus to a deoxidation step in the production of vegetable oils and fats; A recycling system for alkali metals / alkaline earth metal hydroxides that includes the following features.

9. The electrolytic cell is separated by a cation exchange membrane, and an anode and a cathode are located on one side separated by the cation exchange membrane. A liquid containing oil residue generated in the deoxidation process during the production of vegetable oils is placed in the electrolytic cell on one side separated by the cation exchange membrane, and M is added to the reaction solution by an electrochemical reaction. Ｂ -OH and / or M Ｃ - (OH) ２ This generates water on the other side of the electrolytic cell separated by the cation exchange membrane, and M in the reaction solution Ｂ -OH and / or M Ｃ - (OH) ２ A production apparatus for alkali metal / alkaline earth metal hydroxides that transfers the above into the water; Means for supplying alkali metal hydroxides and / or alkaline earth metal hydroxides produced using the manufacturing apparatus to a deoxidation step in the production of vegetable oils and fats; A recycling system for alkali metals / alkaline earth metal hydroxides that includes the following features.

10. An apparatus for producing alkali metal / alkaline earth metal hydroxides, comprising an electrolytic cell having an anode, a cathode, and a cation exchange membrane separating the anode and cathode sides, wherein an electrochemical reaction is carried out by introducing a liquid containing black liquor produced in the washing process after pulping in papermaking to the anode side and water to the cathode side; Means for supplying alkali metal hydroxides and / or alkaline earth metal hydroxides produced using the manufacturing apparatus to the pulping process in papermaking; A recycling system for alkali metals / alkaline earth metal hydroxides that includes the following features.

11. The electrolytic cell is separated by a cation exchange membrane, and an anode and a cathode are located on one side separated by the cation exchange membrane. The liquid containing black liquor produced in the washing process after pulping in papermaking is placed in one side of the electrolytic cell separated by the cation exchange membrane, and an electrochemical reaction occurs in the reaction solution, bringing M into the solution. Ｂ -OH and / or M Ｃ - (OH) ２ This generates water on the other side of the electrolytic cell separated by the cation exchange membrane, and M in the reaction solution Ｂ -OH and / or M Ｃ - (OH) ２ A production apparatus for alkali metal / alkaline earth metal hydroxides that transfers the above into the water; Means for supplying alkali metal hydroxides and / or alkaline earth metal hydroxides produced using the manufacturing apparatus to the pulping process in papermaking; A recycling system for alkali metals / alkaline earth metal hydroxides that includes the following features.

12. An apparatus for producing alkali metal / alkaline earth metal hydroxides, comprising an electrolytic cell having an anode, a cathode, and a cation exchange membrane separating the anode and cathode sides, wherein an electrochemical reaction is carried out by introducing a liquid containing soapy wastewater generated in the washing step of the crude fatty acid ester fraction in the production of fatty acid esters into the anode side and water into the cathode side; Means for supplying alkali metal hydroxides and / or alkaline earth metal hydroxides produced using the manufacturing apparatus to the crude fatty acid ester formation reaction step in the production of fatty acid esters; A recycling system for alkali metals / alkaline earth metal hydroxides that includes the following features.

13. The electrolytic cell is separated by a cation exchange membrane, and an anode and a cathode are located on one side separated by the cation exchange membrane. A liquid containing soapy wastewater generated in the washing step of the crude fatty acid ester fraction in the production of fatty acid esters is placed in the electrolytic cell on one side separated by the cation exchange membrane, and M is added to the reaction solution by an electrochemical reaction. Ｂ -OH and / or M Ｃ - (OH) ２ This generates water on the other side of the electrolytic cell separated by the cation exchange membrane, and M in the reaction solution Ｂ -OH and / or M Ｃ - (OH) ２ A production apparatus for alkali metal / alkaline earth metal hydroxides that transfers the above into the water; Means for supplying alkali metal hydroxides and / or alkaline earth metal hydroxides produced using the manufacturing apparatus to the crude fatty acid ester formation reaction step in the production of fatty acid esters; A recycling system for alkali metals / alkaline earth metal hydroxides that includes the following features.

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