Electrochemical method preparation device

Abstract

The utility model discloses a device for preparing by an electrochemical method. The device comprises an electrolytic bath body, a diaphragm, a partition plate, an anode electrode and a cathode electrode, the diaphragm divides the electrolytic bath body into a first flowing area and a second flowing area; the first flowing area is divided into an A1 subarea, an A2 subarea, a K3 subarea and a K4 subarea by partition plates, the A1A2 subarea is provided with an anode electrode, the K3 subarea and the K4 subarea are provided with a cathode electrode, and the liquid flowing direction is A1-A2-K3-K4; the second flowing area is divided into a K1 subarea, a K2 subarea, an A3 subarea and an A4 subarea by partition plates, the K1 subarea and the K2 subarea are provided with cathode electrodes, the A3 subarea and the A4 subarea are provided with anode electrodes, and the liquid flowing direction is K1-K2-A3-A4. The effect of preparing the hypohalous acid solution and the high-concentration alkaline water is achieved by adopting the micro-permeable membrane and the platinum-free electrode, the dependence on a platinum material and an ionic membrane is eliminated, and the threshold and the cost of preparing the acid-alkaline water are greatly reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of electrochemical preparation of acid and alkaline water, and more specifically, to a device and process for preparing acid and alkaline water by electrochemical method. On this basis, it also relates to a device for preparing hypochlorous acid disinfectant water. Background Art

[0002] The traditional device for preparing acid-base water includes an electrolytic cell, an anode, a cathode, and an ion membrane. In order to make the anode active, the structure of the anode is a titanium metal substrate, and platinum is plated on the surface of the substrate, or coated with platinum group metal (ruthenium, iridium, palladium) oxide. By setting an ion membrane that only allows certain specific ions to pass between the anode and the cathode, ion exchange is performed to produce acid-base water. Since the ion membrane deposits hydrated particles during use, it will cause blockage of the ion membrane. In order to avoid blockage of the ion membrane, a method of exchanging the anode and the cathode, that is, reversing the polarity, is adopted to generate a reverse voltage to conduct the deposited particles. Since the polarity needs to be reversed, the anode is transformed into the cathode, and the cathode is transformed into the anode. Therefore, the traditional device not only requires the anode to be coated with platinum (or platinum group metal), but also the cathode to be coated with platinum (or platinum group metal).

[0003] More importantly, even if the above-mentioned high price problem is put aside, the existing device still has the problem of electrode life being damaged, the electrode cannot be fully utilized, and the material value cannot be brought into play. For example, Masatsugu Motimitsu, Ryuichi Otogolwa, Morio Matsunaga (Electrochemica Acta 40 (2000) 401-406) et al. have studied the anode reversal operation of titanium-based iridium dioxide and tantalum pentoxide coatings. The results show that when the electrode material is operated as an anode at an ultra-high current density of 10,000 amperes per square meter in a mixed solution of sodium sulfate and sulfuric acid, its working life can reach more than 7,000 hours. And as a cathode, it operates at a current of 500 amperes per square meter, and its working life is less than 200 hours. From the results, it can be found that the cathode and anode exchange after reversal will greatly affect the service life of the electrode, which undoubtedly makes the device cost more expensive.

[0004] Therefore, in order to reduce the cost of acid-base water preparation equipment, save precious metal resources, reduce the import of high-end ion membranes, and increase the service life of the equipment, it is urgent to improve the existing acid-base water preparation equipment and process. Utility Model Content

[0005] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the utility model is to provide an electrochemical preparation device and a method for preparing acidic and alkaline water using the device.

[0006] The technical solution adopted by the utility model to solve its technical problems is:

[0007] An electrochemical preparation device comprises an electrolytic cell body, a diaphragm, a partition, an anode electrode and a cathode electrode;

[0008] The diaphragm separates the electrolytic cell into a first flow area and a second flow area, and the liquids in the first flow area and the second flow area flow in the same direction;

[0009] The first flow zone is divided into A1, A2, K3 and K4 partitions by a partition, the A1 partition and the A2 partition are provided with anode electrodes, the K3 partition and the K4 partition are provided with cathode electrodes, and the liquid flows in a direction of A1→A2→K3→K4;

[0010] The second flow zone is divided into K1, K2, A3 and A4 partitions by partitions. The K1 partition and the K2 partition are provided with cathode electrodes, and the A3 partition and the A4 partition are provided with anode electrodes. The liquid flows in the direction of K1→K2→A3→A4.

[0011] Specifically, the K2 partition derives an alkaline solution, the A3 partition injects pure water, and the A4 partition derives an acidic solution.

[0012] Pure water flows into the A1 and A2 partitions of the first flow zone, and absorbs halogen elements through an electrochemical method to prepare halogen acid and hypohalogen acid.

[0013] The reaction formula is as follows (taking potassium chloride as an example):

[0014] 2Cl - -2e - =Cl2

[0015] H2O+Cl2=HCl+HClO

[0016] The halide salt solution flows into the K1 and K2 partitions of the second flow zone, loses the halogen elements and undergoes hydrogen evolution reaction through an electrochemical method, and prepares a corresponding hydroxide solution.

[0017] The reaction formula is as follows (taking potassium chloride as an example):

[0018] 2H2O+2e - =2OH - +H2↑

[0019] 2K + +2OH - =2KOH

[0020] The hypohalous acid solution prepared in the A1 and A2 partitions flows into the K3 and K4 partitions of the first flow zone, loses halogen elements through an electrochemical method and undergoes a hydrogen evolution reaction to prepare alkaline water rich in hydrogen ions.

[0021] The reaction formula is as follows (taking hypochlorous acid as an example):

[0022] 2H2O+2e - =2OH - +H2↑

[0023] Pure water flows into the A3 and A4 partitions of the second flow zone, and the halogen elements of the anions are electrochemically introduced to the anode zone to undergo halogen evolution reaction to prepare halogen acid and hypohalogen acid.

[0024] The reaction formula is as follows (taking hypochlorous acid as an example):

[0025] 2Cl - -2e - →Cl2↑

[0026] H2O+Cl2=HCl+HClO

[0027] As an improved solution, only K3 and K4 partitions can be used as the first flow zone, and A3 and A4 partitions can be used as the second flow zone. Hypohalous acid can be injected into the K3 partition, and pure water can be injected into the A3 partition. Through electrochemical reaction, a higher concentration of metal ion-free hydrogen-rich alkaline water (PH>11) can be produced in the K4 partition, and a higher concentration of hypohalous acid water (PH<2) can be produced in the A4 partition.

[0028] In the electrochemical preparation device, the diaphragm and the partition are micro-permeable membranes. Specifically, any material having micro-permeability that allows halogen ions to pass through and does not react with various reactants can be used.

[0029] The material of the anode electrode is preferably a material that is resistant to halogen ion corrosion, catalytic for halogen evolution reaction, antioxidant, and catalytic for oxygen evolution reaction, such as graphite, platinum, titanium-based precious metal oxide coating, etc.

[0030] The material of the cathode electrode is preferably titanium and titanium alloy.

[0031] As an improved solution, the A1, K1, and A3 partitions are provided with liquid inlets; and the K2, A4, and K4 partitions are provided with liquid outlets.

[0032] As an improved solution, the liquid inlet and / or the liquid outlet is provided with a flow limiting valve.

[0033] In the above preparation process, the halide added in the K1 zone may have an anion element such as chlorine, bromine, iodine, fluorine, etc., and a cationic element such as sodium, magnesium, aluminum, iron, calcium, potassium, etc., or a non-metallic cation such as ammonium.

[0034] The invention discloses a method for preparing hypohalous acid and an alkaline solution containing metal ions and an alkaline solution not containing metal ions by using the above-mentioned equipment.

[0035] Including the first and second phases:

[0036] The first stage includes the third electrochemical reaction carried out in the A1 and A2 partitions and the fourth electrochemical reaction carried out in the Y1 and Y2 partitions;

[0037] The third electrochemical reaction is:

[0038] 2X - -2e - →X2↑;

[0039] H2O+X2→HX+HXO;

[0040] The fourth electrochemical reaction is:

[0041] 2H2O+2e - →2OH - +H2↑;

[0042] 2Y + +2OH - →2YOH;

[0043] The second stage: includes the first electrochemical reaction carried out in the A3 and A4 partitions and the second electrochemical reaction carried out in the K3 and K4 partitions;

[0044] The first electrochemical reaction is: H2O+X2→HX+HXO;

[0045] The second electrochemical reaction is: 2H2O+2e-→2HO-+H2↑;

[0046] The X is a halogen element, and the Y is a cation such as sodium, magnesium, aluminum, potassium, iron, calcium, or ammonium. Preferably, X is chlorine, and Y is potassium.

[0047] As an improved solution, only the second stage may be carried out, hypohalous acid and water are added, and hypohalous acid and an alkaline solution free of metal ions are prepared by an electrochemical method.

[0048] As an improvement, by controlling the speed of the solution flowing in and out, specifically, making the flow rate of A3-A4 faster than the flow rate of K3-K4, the pH value of the produced alkaline solution containing metal ions can be made greater than 11, and the pH value of the produced hypohalous acid solution can be made less than 2.

[0049] Taking hypochlorous acid as an example, in the A3-A4 partition, a chlorine evolution reaction is carried out. At room temperature, one volume of water can dissolve about two volumes of chlorine, and a hydrolysis reaction occurs to generate hydrochloric acid and hypochlorous acid. The chloride ion concentration under this state is estimated as follows: the atomic weight of chlorine is 35.5, the molecular weight is 71, and the volume of one gram molecule of gas under standard conditions is 22.4 liters. The volume of two liters of chlorine is 2 / 22.4*71=6.34 grams. One molecule of chlorine is hydrolyzed to produce one molecule of hydrochloric acid and one molecule of hypochlorous acid, both of which are strong electrolytes with high dissociation degree.

[0050] 6.34 / 71 = 0.089 gram molecules * 2 = 0.178 gram molecules

[0051] According to calculations, 2 liters of chlorine gas dissolved in 1 liter of water can be hydrolyzed to produce an acid solution of 0.178 gram molecules / liter, which can reach a pH value of <2.

[0052] In addition, the chlorine evolution reaction can be controlled by controlling the outflow from the anode region, so that the solution reaches chlorine saturation and no chlorine gas escapes out of the system.

[0053] Compared with the prior art, the beneficial effects of the utility model are:

[0054] The utility model adopts a micro-permeable membrane and an electrode that is not platinum-plated to achieve the effect of preparing hypohalous acid and high-concentration acid-base water, gets rid of the dependence on platinum materials and ion membranes, and greatly reduces the threshold and cost of preparing acid-base water.

[0055] The utility model does not require a polarity reversal operation, thus saving time and labor costs for equipment maintenance and reducing the loss rate of equipment.

[0056] The utility model can prepare acid and alkaline water and disinfectant water at the same time, and cleverly utilizes the electrochemical reaction mechanism.

[0057] The utility model has simple process steps, and the acid-base water and disinfectant water produced have great practical value. At the same time, the acid-base water and disinfectant water are produced simultaneously in one process, which saves electric energy and further reduces production costs.

[0058] The utility model can prepare metal ion-free alkaline water with a pH value greater than 10 and metal ion-free acidic water with a pH value less than 3 by controlling the flow rate, and the product has good quality and high value.

[0059] The utility model can connect a plurality of first flow areas and second flow areas in parallel or in series, which is convenient for expanding the production scale, reduces the cost of expanding the production capacity, and is easy for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 The utility model is a schematic diagram of a top view of the electrochemical preparation device.

[0061] Figure 2 This is a schematic top view of the structure of an expanded version of an electrochemical preparation device of the utility model.

[0062] Figure 3 This is a potassium ion concentration test report of metal ion-free alkaline water prepared by an electrochemical preparation device of the present invention.

[0063] Among them, 1: diaphragm; 2: partition; 3: electrolytic cell body; 4: anode electrode; 5: cathode electrode; 6: liquid inlet; 7: liquid outlet. DETAILED DESCRIPTION

[0064] The present invention is further explained and illustrated by specific implementation methods below. It should be understood that the purpose of the following implementation methods is to make the technical solution of the present invention clearer and easier to understand, and does not limit the protection scope of the claims.

[0065] Implementation Case 1:

[0066] As attached Figure 1 As shown, an electrochemical preparation device includes an electrolytic cell body, a diaphragm, a partition, an anode electrode and a cathode electrode;

[0067] The diaphragm separates the electrolytic cell into a first flow area and a second flow area, and the liquids in the first flow area and the second flow area flow in the same direction;

[0068] The first flow zone is divided into A1, A2, K3 and K4 partitions by a partition, the A1 partition and the A2 partition are provided with anode electrodes, the K3 partition and the K4 partition are provided with cathode electrodes, and the liquid flows in a direction of A1→A2→K3→K4;

[0069] The second flow zone is divided into K1, K2, A3 and A4 partitions by partitions. The K1 partition and the K2 partition are provided with cathode electrodes, and the A3 partition and the A4 partition are provided with anode electrodes. The liquid flows in the direction of K1→K2→A3→A4.

[0070] Specifically, the K2 region derives an alkaline solution containing metal ions, the A3 region adds pure water, and the A4 region derives a halogen acid and hypohalogen acid solution.

[0071] Pure water flows into the A1 and A2 partitions of the first flow zone, and absorbs halogen elements through an electrochemical method to prepare halogen acid and hypohalogen acid.

[0072] The reaction formula is as follows (taking potassium chloride as an example):

[0073] 2Cl - -2e - =Cl2

[0074] H2O+Cl2=HCl+HClO

[0075] The halide salt solution flows into the K1 and K2 partitions of the second flow zone, loses the halogen elements and undergoes hydrogen evolution reaction through an electrochemical method, and prepares a corresponding hydroxide solution.

[0076] The reaction formula is as follows (taking potassium chloride as an example):

[0077] 2H2O+2e - =2OH - +H2↑

[0078] 2K + +2OH - =2KOH

[0079] The hypohalous acid solution prepared in the A1 and A2 partitions flows into the K3 and K4 partitions of the first flow zone, loses halogen elements through an electrochemical method and undergoes a hydrogen evolution reaction to prepare alkaline water rich in hydrogen ions.

[0080] The reaction formula is as follows (taking hypochlorous acid as an example):

[0081] 2H2O+2e - =2OH - +H2↑

[0082] Pure water flows into the A3 and A4 partitions of the second flow zone, and absorbs halogen elements through an electrochemical method to produce halogen acid and hypohalous acid by halogen evolution reaction.

[0083] The reaction formula is as follows (taking hypochlorous acid as an example):

[0084] 2Cl - -2e - →Cl2↑

[0085] H2O+Cl2=HCl+HClO

[0086] It is also possible to use only K3 and K4 partitions as the first flow zone, and A3 and A4 partitions as the second flow zone, inject hypohalous acid into the K3 partition, and inject pure water into the A3 partition. Through electrochemical reaction, a higher concentration of metal ion-free hydrogen-rich alkaline water (PH>11) is produced in the K4 partition, and a higher concentration of hypohalous acid water (PH<2) is produced in the A4 partition.

[0087] In the electrochemical preparation device, the diaphragm and the partition are micro-permeable membranes. Specifically, any material having micro-permeability that allows halogen ions to pass through and does not react with various reactants can be used.

[0088] The material of the anode electrode is preferably a material that is resistant to halogen ion corrosion, catalytic for halogen evolution reaction, antioxidant, and catalytic for oxygen evolution reaction, such as graphite, platinum, titanium-based precious metal oxide coating, titanium, etc.

[0089] The material of the cathode electrode is preferably titanium and titanium-based alloys.

[0090] In the above preparation process, the halide added in the K1 zone may have an anion element such as chlorine, bromine, iodine, fluorine, etc., and a cationic element such as sodium, magnesium, aluminum, iron, calcium, potassium, etc., or a non-metallic cation such as ammonium.

[0091] The principle of the method for preparing hypohalous acid and alkaline solution containing metal ions and alkaline solution without metal ions using the above equipment is as follows:

[0092] Including the first and second phases:

[0093] The first stage includes the third electrochemical reaction carried out in the A1 and A2 partitions and the fourth electrochemical reaction carried out in the Y1 and Y2 partitions;

[0094] The third electrochemical reaction is:

[0095] 2X - -2e - →X2↑;

[0096] H2O+X2→HX+HXO;

[0097] The fourth electrochemical reaction is:

[0098] 2H2O+2e - →2OH - +H2↑;

[0099] 2Y + +2OH - →2YOH;

[0100] The second stage: includes the first electrochemical reaction carried out in the A3 and A4 partitions and the second electrochemical reaction carried out in the K3 and K4 partitions;

[0101] The first electrochemical reaction is: H2O+X2→HX+HXO;

[0102] The second electrochemical reaction is: 2H2O+2e - →2HO - +H2↑;

[0103] The X is a halogen element, and the Y is a cation such as sodium, magnesium, aluminum, potassium, iron, calcium, or ammonium. Preferably, X is chlorine, and Y is potassium.

[0104] Alternatively, only the second stage may be carried out, wherein hypohalous acid and water are added to prepare hypohalous acid and an alkaline solution free of metal ions by an electrochemical method.

[0105] By controlling the speed of the solution flowing in and out, specifically, making the flow rate of A3-A4 faster than the flow rate of K3-K4, the pH value of the prepared alkaline solution containing metal ions can be greater than 11, and the pH value of the prepared hypohalous acid solution can be less than 2.

[0106] Take hypochlorous acid as an example. In the A3-A4 partition, a chlorine evolution reaction is carried out. At room temperature, one volume of water can dissolve about two volumes of chlorine, and a hydrolysis reaction occurs to generate hydrochloric acid and hypochlorous acid. The chloride ion concentration under this state is estimated as follows: the atomic weight of chlorine is 35.5, the molecular weight is 71, and the volume of one gram molecule of gas under standard conditions is 22.4 liters. The volume of two liters of chlorine is 2 / 22.4*71=6.34 grams. One molecule of chlorine is hydrolyzed to produce one molecule of hydrochloric acid and one molecule of hypochlorous acid, both of which are strong electrolytes with high dissociation degree.

[0107] 6.34 / 71 = 0.089 gram molecules * 2 = 0.178 gram molecules

[0108] According to calculations, 2 liters of chlorine gas dissolved in 1 liter of water can be hydrolyzed to produce 0.178 g / L of acid solution, which can reach a pH value of <2.

[0109] In addition, the chlorine evolution reaction can be controlled by controlling the outflow from the anode region, so that the solution reaches chlorine saturation and no chlorine gas escapes out of the system.

[0110] Implementation Case 2:

[0111] As attached Figure 2 As shown, compared with implementation case 1, the diaphragm separates the electrolytic cell body into a plurality of first flow zones and second flow zones, and the first flow zones and the second flow zones are spaced apart from each other. Such an arrangement mode is conducive to fully completing the electrochemical reaction on the one hand, and is easy to expand the production scale at low cost on the other hand.

[0112] In summary, after reading the utility model document, ordinary technicians in this field can make various other corresponding transformation schemes based on the technical scheme and technical concept of the utility model without creative mental labor, and different application scenarios all fall within the scope of protection of the utility model.

Claims

1. An electrochemical preparation device, characterized in that: It includes an electrolytic cell body, a diaphragm, a partition, an anode electrode and a cathode electrode; The diaphragm separates the electrolytic cell into a first flow area and a second flow area, and the liquids in the first flow area and the second flow area flow in the same direction; The first flow zone is separated into an acid-base water preparation cathode reaction zone by a partition, and the acid-base water preparation cathode reaction zone includes a K3 partition and a K4 partition, and the K3 partition and the K4 partition are provided with cathode electrodes, and the liquid flows from the K3 partition to the K4 partition; The second flow zone is separated into an acid-base water preparation anode reaction zone by a partition, and the acid-base water preparation anode reaction zone includes an A3 partition and an A4 partition. The A3 partition and the A4 partition are provided with anode electrodes, and the liquid flows from the A3 partition to the A4 partition.

2. The electrochemical preparation device according to claim 1, characterized in that: The first flow zone is divided into an alkaline solution preparation anode reaction zone and an acid-base water preparation cathode reaction zone by a partition, the alkaline solution preparation anode reaction zone includes A1 and A2 partitions, the acid-base water preparation cathode reaction zone includes K3 and K4 partitions, the A1 partition and A2 partition are provided with anode electrodes, the K3 partition and K4 partition are provided with cathode electrodes, and the liquid flow direction is A1→A2→K3→K4; The second flow zone is separated by a partition into a cathode reaction zone for preparing an alkaline solution and an anode reaction zone for preparing an acid-base water. The cathode reaction zone for preparing an alkaline solution includes K1 and K2 partitions, and the anode reaction zone for preparing an acid-base water includes A3 and A4 partitions. The K1 partition and the K2 partition are provided with cathode electrodes, and the A3 partition and the A4 partition are provided with anode electrodes. The liquid flow direction is K1→K2→A3→A4.

3. The electrochemical preparation device according to claim 1 or 2, characterized in that: It comprises a plurality of first flow areas and second flow areas, wherein the first flow areas and the second flow areas are arranged side by side in turn.

4. The electrochemical preparation device according to claim 2, characterized in that: The A1, K1, and A3 partitions are provided with liquid inlets; and the K2, A4, and K4 partitions are provided with liquid outlets.

5. The electrochemical preparation device according to claim 4, characterized in that: The liquid inlet and / or the liquid outlet is provided with a flow limiting valve.

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