JP5392158B2 - Perchlorate production apparatus and production method - Google Patents

Description

  The present invention relates to a perchlorate production apparatus and production method.

Perchlorate, including a solid fuel rocket propellant oxidizer (ammonium perchlorate), lithium battery supporting electrolyte (lithium perchlorate) and airbag igniter (potassium perchlorate) It is used for various purposes.
Here, as described in detail in Non-Patent Document 1, as a manufacturing method of perchlorate, industrially, a sodium chlorate aqueous solution synthesized by electrolytic oxidation of a sodium chloride aqueous solution is further electrolytically oxidized to obtain a perchlorate. After sodium chlorate is synthesized, it is manufactured through a predetermined treatment. Therefore, in the conventional techniques so far, as described in, for example, Patent Document 1 and Patent Document 2, a method for efficiently electrolytically synthesizing a sodium perchlorate (NaClO ₄ ) aqueous solution has been focused. Has been.

Japanese Patent Laid-Open No. 3-199387 JP 2007-197740 A

J. et al. C. Schumacher (ed.), Perchlorates, A.M. C. S. Monograph No. 146, Reinhold, New York, 1960

However, in producing perchlorates other than sodium perchlorate, it is not always necessary to go through sodium perchlorate. Accordingly, the inventors of the present application have devised a method for producing a perchlorate in which the production process is simplified without going through the production of sodium perchlorate. In this manufacturing method, an electrolytic cell in which an anode side on which an anode is provided and a cathode side on which a cathode is provided is partitioned by a cation exchange membrane, and sodium chloride aqueous solution or sodium chlorate aqueous solution is electrolytically oxidized on the anode side to produce perchlorine. While generating an acid aqueous solution, the sodium ion which exists in the anode side used as the impurity of a final product moves to the cathode side through a cation exchange membrane from the anode side, and is removed. Then, a predetermined alkaline aqueous solution is added to the perchloric acid aqueous solution generated by this electrolytic oxidation, and a perchlorate is synthesized by a neutralization reaction.
By the way, in this production method, in controlling the concentration of the perchlorate which is the final product, the sodium ion concentration present in the anolyte, that is, sodium ions that move from the anode side to the cathode side with the above electrolytic oxidation Monitoring the amount of movement is essential. Usually, liquid ion chromatography or ICP (Inductive Coupled Plasma) emission analyzer is used to measure the sodium ion concentration. However, the analysis apparatus has high analysis accuracy, but it takes time and labor to analyze, so it is not suitable as a means for monitoring the amount of movement of sodium ions.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a perchlorate production apparatus and a production method for easily monitoring the amount of sodium ion migration.

  In order to solve the above problems, the present invention provides an anode side on which an anode is provided and a cathode side on which a cathode is provided, which is partitioned by a cation exchange membrane, and an aqueous sodium chloride solution or an aqueous sodium chlorate solution is electrolyzed on the anode side. Based on the electrolytic cell to be oxidized and the pH value, water temperature, and liquid volume that change with the electrolytic oxidation on the cathode side, it passes through the cation exchange membrane from the anode side to the cathode side with the electrolytic oxidation. A perchlorate production apparatus having a measuring device for measuring the amount of movement of the moved sodium ions is employed.

Furthermore, in the present invention, the measuring device employs a configuration in which the measured amount of sodium ion movement is corrected based on the amount of carbon dioxide contained in the atmosphere dissolved on the cathode side.
On the other hand, in the present invention, the cathode side is provided with a hydrogen gas exhaust pipe for exhausting the hydrogen gas generated at the cathode accompanying the electrolytic oxidation into the atmosphere. A configuration is employed in which a trap for preventing the inflow of carbon dioxide from the cathode to the cathode side is employed.

  In the present invention, an electrolytic cell in which the anode side on which the anode is provided and the cathode side on which the cathode is provided is partitioned by a cation exchange membrane, and sodium chloride aqueous solution or sodium chlorate aqueous solution is electrolyzed on the anode side. Based on the step of oxidizing and the pH value, water temperature, and liquid volume on the cathode side, the amount of sodium ions transferred from the anode side to the cathode side through the cation exchange membrane with the electrolytic oxidation is determined. A method for producing a perchlorate having a measuring step is employed.

According to the present invention, the amount of movement of sodium ions can be made easier than before by measuring the amount of movement of sodium ions based on the pH value on the cathode side, the water temperature, and the amount of liquid, which does not take time and effort for detection. Can be monitored.
Here, the pH value is a value that depends on the amount of movement of sodium ions (the amount of sodium hydroxide generated) that moves from the anode side to the cathode side through the cation exchange membrane with electrolytic oxidation. The water temperature is a value that changes with time due to Joule heat when a voltage is applied to both electrodes. The amount of liquid is a value that changes with time due to water accompanying protons and sodium ions that move from the anode side to the cathode side through the cation exchange membrane with electrolytic oxidation, and the amount of liquid per unit time The change of depends on the current density. Changes in the water temperature and the liquid volume affect the pH value on the cathode side, as does the amount of sodium ion migration.
That is, in the present invention, the amount of sodium ions transferred can be reduced by taking into account the pH value that changes depending on the amount of sodium ion transfer accompanying electrolytic oxidation, and the change in the water temperature and the amount of liquid that affect the pH value. It becomes possible to monitor.

As factors affecting the pH value on the cathode side, in addition to the water temperature and the amount of liquid, there is dissolution of carbon dioxide present in the atmosphere into the cathode liquid. In the present invention, the amount of dissolved carbon dioxide is further increased. It is possible to improve the accuracy of monitoring by considering the above.
In addition, the carbon dioxide may flow from a pipe that exhausts the hydrogen gas generated at the cathode to the atmosphere, and by providing a trap for carbon dioxide in this pipe to reduce the influence of dissolution of carbon dioxide, It becomes possible to improve the accuracy of monitoring.

It is a flowchart which shows the manufacturing process of the ammonium perchlorate in embodiment of this invention. It is a schematic block diagram of the ammonium perchlorate manufacturing apparatus in embodiment of this invention. It is a block diagram of the primary electrolytic cell in embodiment of this invention. It is a block diagram of the trap for carbon dioxide in embodiment of this invention. It is a block diagram of the secondary electrolytic cell in embodiment of this invention.

  Hereinafter, the manufacturing apparatus and manufacturing method of the perchlorate of embodiment of this invention are demonstrated with reference to drawings. Hereinafter, an example in which the present invention is applied to an ammonium perchlorate production apparatus and production method will be described.

FIG. 1 is a flow diagram showing a process for producing ammonium perchlorate in an embodiment of the present invention. As shown in the figure, the production process of ammonium perchlorate according to the present invention is roughly divided into four steps: a primary electrolysis step S1, a secondary electrolysis step S2, a reaction step S3, and a crystallization step S4.
The primary electrolysis step S1 is a step of electrolytically oxidizing a sodium chloride aqueous solution to generate an aqueous solution containing chloric acid as a main component. The next secondary electrolysis step S2 is a step of electrolytically oxidizing the aqueous solution containing chloric acid as a main component generated in the primary electrolysis step S1 to generate a perchloric acid aqueous solution. The next reaction step S3 is a step of adding ammonium aqueous solution to the perchloric acid aqueous solution generated in the secondary electrolysis step S2 to synthesize ammonium perchlorate by a neutralization reaction. The last crystallization step S4 is a step of crystallizing ammonium perchlorate by evaporating the aqueous solution after the neutralization reaction in a vacuum environment.

Then, the ammonium perchlorate manufacturing apparatus which implements this manufacturing process is demonstrated.
FIG. 2 is a schematic configuration diagram of an ammonium perchlorate production apparatus (perchlorate production apparatus) A in the embodiment of the present invention. The symbols g, l, and s in the figure indicate a gas, liquid, and solid state, respectively. The ammonium perchlorate production apparatus A of the embodiment includes a primary electrolytic cell 1 that performs a primary electrolysis step S1, a secondary electrolytic cell 2 that performs a secondary electrolysis step S2, a reaction step that performs a reaction step S3 and a crystallization step S4. Evaporation tank 3 is provided.

FIG. 3 is a configuration diagram of the primary electrolytic cell 1 in the embodiment of the present invention.
The primary electrolytic cell 1 has a cation exchange membrane 6 provided so as to partition an anode side 4A where the anode 4 is provided and a cathode side 5A where the cathode 5 is provided. Since the anode side solution (anolyte) becomes strongly acidic and the cathode side solution (catholyte) becomes strongly alkaline due to the electrolytic oxidation described later, the primary electrolytic cell 1 has a chemical resistant chemical on the main body of the primary electrolytic cell 1. It is desirable to use a material having excellent stability, such as Teflon (DuPont, registered trademark), vinyl chloride, or glass. In addition, it is desirable to use a pipe joint having excellent chemical resistance, for example, Teflon (DuPont Co., Ltd., registered trademark).

  The cation exchange membrane 6 constitutes a zero-gap electrolytic cell sandwiched between the anode 4 and the cathode 5 in the primary electrolytic cell 1 without a gap. This cation exchange membrane 6 is a membrane having the characteristics that a cation can pass and an anion cannot pass. In this embodiment, Nafion 424 (Nafion, DuPont, Inc.) Registered trademark). As the cation exchange membrane, Aciplex (Asahi Kasei Co., Ltd., registered trademark) or Flemion (Asahi Glass Co., Ltd., registered trademark) widely used in caustic soda production may be used.

The anode 4 is made of an expanded metal coated with a catalyst in order to promote the electrolytic synthesis reaction of chlorate ions on the anode side 4A. The anode 4 of this embodiment is an electrode in which the surface of a titanium expanded metal as a substrate is coated with a catalyst layer made of iridium oxide and platinum by a firing method, which has an effect of suppressing generation of oxygen gas, or oxidized by a firing method. An electrode coated with a catalyst layer made of iridium and ruthenium oxide, an electrode coated with a catalyst layer made of iridium oxide, ruthenium oxide and platinum by a firing method, or a catalyst layer made of tantalum oxide and platinum by a firing method Consists of electrodes.
On the other hand, the cathode 5 paired with the anode 4 is composed of an electrode in which the surface of a titanium expanded metal as a base is covered with a platinum catalyst layer by electrolytic plating, or an electrode made of nickel expanded metal.

  The anode side 4A is provided with an anolyte tank 4B for storing the anolyte (hereinafter, the anode side 4A of the electrolytic cell 1 is referred to as an anode side electrolytic cell 2A). The liquid level of the anolyte in the anolyte tank 4B is higher than the liquid level in the anode side electrolytic cell 2A. The anolyte tank 4B and the anode side electrolytic cell 2A are connected by a pipe 27a and a pipe 27b. The pipe 27a connects the bottom of the anode electrolytic cell 2A and the bottom of the anolyte tank 4B, and the pipe 27b connects the top of the anode electrolytic tank 2A and the side of the anolyte tank 4B. Is. An ultrasonic transducer 4B1 is provided at the bottom of the anolyte tank 4B to keep the concentration of the anolyte uniform.

  On the other hand, the cathode side 5A is provided with a catholyte tank 5B for storing catholyte (hereinafter, the cathode side 5A of the electrolytic cell 1 is referred to as a cathode side electrolytic cell 2B). The liquid level of the catholyte in the catholyte tank 5B is higher than the liquid level in the cathode side electrolytic cell 2B. The catholyte tank 5B and the cathode side electrolytic cell 2B are connected by a pipe 28a and a pipe 28b. The piping 28a connects the bottom of the cathode side electrolytic cell 2B and the bottom of the catholyte tank 5B, and the piping 28b connects the top of the cathode side electrolytic cell 2B and the side of the catholyte tank 5B. Is. An ultrasonic transducer 5B1 for keeping the concentration of the catholyte uniform is provided at the bottom of the catholyte tank 5B.

  An anolyte introduction pipe 21 is connected to the top of the anolyte tank 4B, and an aqueous sodium chloride solution is introduced through the anolyte introduction pipe 21 to connect the anode side 4A (the anode side electrolytic cell 2A and the anolyte tank 4B). Satisfy). Further, a pH adjuster introduction pipe 11 for introducing a sodium hydroxide aqueous solution as a pH adjuster for adjusting the pH value of the anolyte during electrolytic oxidation is connected to the top of the anolyte tank 4B. The anolyte tank 4B is provided with a pH meter 12 for measuring the pH value of the anolyte.

  On the other hand, a catholyte introduction pipe 22 is connected to the top of the catholyte tank 5B, and pure water is introduced through the catholyte introduction pipe 22, and the cathode side 5A (cathode side electrolytic cell 2B, catholyte tank 5B). Meet). The catholyte tank 5B includes a pH meter 14 that measures the pH value of the catholyte, a water temperature meter 15 that measures the water temperature of the catholyte, and a catholyte liquid based on the liquid level of the catholyte tank 5B. A level gauge 16 for measuring the amount is provided.

When a voltage is applied to both the anode 4 and the cathode 5 immersed in each solution inside the primary electrolytic cell 1, the following reaction proceeds.
On the anode side 4A, the aqueous sodium chloride solution is electrolytically oxidized, and the reactions shown in the following reaction formulas (1) and (2) occur.
2Cl ⁻ → Cl ₂ + 2e ⁻ ... (1)
2H ₂ O → O ₂ + 4H ⁺ + 4e ⁻ ... (2)
The chlorine gas generated here causes the equilibrium reaction shown in the following reaction formulas (3) and (4). The form of this equilibrium reaction changes depending on the pH value of the aqueous solution.
Cl ₂ + H ₂ O⇔H ⁺ + Cl ⁻ + HClO (3)
HClO⇔H ⁺ + ClO ⁻ (4)

When the hypochlorous acid generated by this reaction is electrolytically oxidized, chlorous acid is generated by the reactions shown in the following reaction formulas (5) and (6).
ClO ⁻ + H ₂ O → ClO ₂ ⁻ + 2H ⁺ + 2e ⁻ ... (5)
HClO + H ₂ O → HClO ₂ ⁻ + 2H ⁺ + 2e ⁻ (6)
When the produced chlorous acid is further electrolytically oxidized, chloric acid is produced by the reactions shown in the following reaction formulas (7) and (8).
ClO ₂ ⁻ + H ₂ O → ClO ₃ ⁻ + 2H ⁺ + 2e ⁻ ... (7)
HClO ₂ + H ₂ O → HClO ₃ ⁻ + 2H ⁺ + 2e ⁻ ... (8)

As shown in the reaction formulas (1) to (8), in the primary electrolysis process, oxygen gas is generated as chloric acid and by-products.
Here, sodium ions contained in the liquid on the anode side 4A move from the anode side 4A to the cathode side 5A through the cation exchange membrane 6 due to the potential difference between the two electrodes. On the other hand, hypochlorite ions and chlorite ions cannot pass through the cation exchange membrane 6 and become chlorate ions by a reaction at the three interfaces constituted by the aqueous solution-anode 4-cation exchange membrane 6.

The oxygen gas (bubbles) generated in the anode side electrolytic cell 2A is guided to the anolyte tank 4B through the pipe 27b. An oxygen gas pipe 23 is provided at the top of the anolyte tank 4B, and oxygen gas is sequentially exhausted to the outside through the oxygen gas pipe 23.
In addition, since the anolyte is sequentially introduced from the anolyte tank 4B from the bottom of the anode side electrolytic cell 2A through the pipe 27a due to the difference in liquid level (water pressure difference), the electrolytically oxidized anolyte is It is extruded from the electrolytic cell 2A to the anolyte tank 4B side through the pipe 27b. Accordingly, since the anolyte circulates between the anode side electrolytic cell 2A and the anolyte tank 4B regardless of the driving mechanism such as a pump, more anolyte is electrolytically oxidized in the anode side electrolytic cell 2A.

On the cathode side 5A, the reactions shown in the following reaction formulas (9) and (10) occur, and hydrogen gas and sodium hydroxide are generated.
2H ⁺ + 2e ⁻ → H ₂ (9)
2Na ⁺ + 2H ₂ O + 2e ⁻ → 2NaOH + H ₂ (10)
The hydrogen gas (bubbles) generated in the cathode side electrolytic cell 2B is guided to the catholyte tank 5B through the pipe 28b. A hydrogen gas pipe (between hydrogen gas exhausts) 24 is provided at the top of the catholyte tank 5B, and the hydrogen gas is sequentially exhausted to the outside through the hydrogen gas pipe 24. Similarly to the circulation of the anolyte at the anode side 4A, the circulation of the catholyte can be obtained at the cathode side 5A.
The hydrogen gas pipe 24 of the present embodiment is provided with a trap 18 that prevents intrusion of carbon dioxide contained in the atmosphere from the outside to the cathode side 5A. As shown in FIG. 4, the trap 18 is configured to immerse the front end opening of the hydrogen gas pipe 24 in the water W and prevent the intrusion of carbon dioxide from the opening. In addition, the trap 18 may be comprised by making the hydrogen gas piping 24 into a U shape, for example, and retaining the water which adsorb | sucks a carbon dioxide in the U-shaped site | part.

The measuring device 13 monitors the amount of movement of sodium ions accompanying the electrolytic oxidation. The measuring device 13 uses a pH meter 14, a water temperature meter 15, a liquid level meter 16, and a computing device 17, and accompanies the electrolytic oxidation on the cathode side 5A. Based on the changing pH value, water temperature, and liquid volume, the amount of movement of sodium ions from the anode side 4A to the cathode side 5A is calculated, and the amount of movement is measured in real time. The computing device 17 is electrically connected to the pH meter 14, the water temperature meter 15, and the liquid level meter 16, and data of measurement results from each is input, and the amount of movement of sodium ions is computed based on the data. Has an arithmetic program.
Hereinafter, this calculation program will be described in detail.

The measurement values required when calculating the amount of movement of sodium ions are the pH value, water temperature, and liquid volume of the cathode side 5A.
Here, as shown in the reaction formula (10), the pH value is the amount of movement of sodium ions (hydroxylation) that passes through the cation exchange membrane 6 and moves from the anode side 4A to the cathode side 5A along with electrolytic oxidation. This value depends on the amount of sodium produced. The water temperature is a value that changes with time due to Joule heat when a voltage is applied to both electrodes. The liquid amount is a value that changes with time due to water accompanying protons and sodium ions that move from the anode side 4A to the cathode side 5A through the cation exchange membrane 6 in accordance with electrolytic oxidation, and per unit time. The change in the amount of liquid depends on the current density. The change in the water temperature and the liquid volume affects the pH value of the cathode side 5A, similarly to the movement amount of sodium ions.
For this reason, this calculation method takes into account the pH value that changes depending on the amount of sodium ion migration associated with electrolytic oxidation, and the change in water temperature and liquid volume that affects the pH value. Calculate the amount.

  The amount of migration (mol) of sodium ions moved from the anode side 4A to the cathode side 5A after t hours from the start of electrolytic oxidation by applying voltage to both electrodes is the sodium ion present on the cathode side 5A before electrolysis. It can be expressed by the following mathematical formula (a) by the difference from the amount of. The subscript t here represents t hours after the start of electrolytic oxidation, and 0 represents the start before electrolytic oxidation.

  Since the degree of ionization of sodium hydroxide is 1, the increase amount (mol) of hydroxide ions in the catholyte tank 5B can be regarded as being equal to the amount of sodium ion migration, and therefore can be expressed by the following mathematical formula (b). it can.

Since the ionic product X ₀ of water before electrolytic oxidation is the product of the molar concentration of hydroxide ions [OH ⁻ ] and the molar concentration of hydrogen ions [H ⁺ ], the molar amount of hydroxide ions before electrolytic oxidation is expressed as When (OH ⁻ ), the molar amount of hydrogen ions before electrolytic oxidation is (H ⁺ ), and the amount of catholyte on the cathode side 5A before electrolytic oxidation is V ₀ , the following formula (c) is used. Can do.

  The ion product X is a temperature-dependent variable, and can be expressed by the following mathematical formulas (d) and (e) from the relationship with the standard enthalpy ΔH obtained by modifying the relational equation with the standard Gibbs free energy. Here, T represents the water temperature of the catholyte, R represents the molar gas constant (8.314 J / mol · K), and ΔH represents the molar standard enthalpy (56500 J / mol) of the ionization equilibrium of water.

  The ion product Xt after t hours from the start of the electrolytic oxidation takes into consideration the water flowing into the cathode side 5A accompanying the cation from the anode side 4A with respect to the amount of the catholyte liquid t hours after the start of electrolysis, If the increase amount is v, it can be expressed by the following mathematical formula (f).

  Here, when the mathematical formula (c) is transformed into a formula representing the molar amount of hydroxide ions, it can be represented by the following mathematical formula (g).

  Further, when the mathematical formula (g) is transformed into a formula showing the molar amount of hydroxide ions after t hours from the start of the electrolytic oxidation, it can be expressed by the following mathematical formula (h).

  When the mathematical formula (g) and the mathematical formula (h) are substituted into the mathematical formula (b), the amount of movement of sodium ions can be expressed by the following mathematical formula (i).

  According to the mathematical formula (i), since the amount of sodium ions transferred after t time can be calculated based on the pH value, water temperature and liquid volume after t time from the start of electrolytic oxidation, Real-time measurement is possible.

The reaction shown in the reaction formula (11) is caused by the dissolution of carbon dioxide in the atmosphere into the catholyte.
CO ₂ + H ₂ O → H ⁺ + CO ₃ ⁻ ... (11)
In this embodiment, since the trap 18 for carbon dioxide is installed in the hydrogen gas pipe 24, in calculating the amount of movement of sodium ions, a decrease in pH value due to dissolution of atmospheric carbon dioxide into the catholyte is taken into account. There is little need. However, even in the case where the trap 18 is not provided, this calculation formula can be applied. Therefore, in consideration of a decrease in pH value due to dissolution of carbon dioxide, the correction formula can be expressed as follows.

When the concentration of hydrogen ions before electrolytic oxidation due to the dissolution of carbon dioxide is y ₀ and the hydrogen ion concentration after t hours from the start of electrolytic oxidation is y _t , the mathematical formula (i) is corrected, and the following mathematical formula (j) -It can represent with Numerical formula (l).

The hydrogen ion concentration y ₀ and the hydrogen ion concentration y _t are known values depending on temperature if the partial pressure of carbon dioxide is constant, that is, the solubility S of carbon dioxide, the density Z of carbon dioxide in the atmosphere, The acid dissociation constant Ka in i) and the partial pressure p can be expressed by the following mathematical formula (m). Therefore, the correction formula considering the decrease in pH value due to the dissolution of carbon dioxide can be expressed by substituting Formula (k) to Formula (m) into Formula (j).

The measuring device 13 monitors the movement amount of sodium ions accompanying electrolytic oxidation based on the above arithmetic program. And the sodium ion density | concentration of 4 A of anode sides is grasped | ascertained from the movement amount.
An anolyte (including sodium chlorate) in which a sufficient amount of chloric acid has been generated by electrolytic oxidation in the primary electrolytic cell 1 is anodeed via an anolyte transport pipe 25 in which the valve 25A is opened from the closed state. It is transported from the liquid tank 4B to the secondary electrolytic cell 2. On the other hand, the catholyte is transported to the outside from the catholyte tank 5B through the catholyte transport pipe 26 in which the valve 26A is opened from the closed state.

FIG. 5 is a configuration diagram of the secondary electrolytic cell 2 in the embodiment of the present invention.
The secondary electrolytic cell 2 generates perchloric acid by electrolytically oxidizing the anolyte mainly composed of chloric acid generated in the primary electrolytic cell 1.
In addition, in order to avoid duplication description, the structure of the secondary electrolytic cell 2 demonstrated below attaches | subjects the same code | symbol about the same or equivalent component as the above-mentioned primary electrolytic cell 1, and the description is simplified or abbreviate | omitted.

In the secondary electrolytic cell 2, the cation exchange membrane 6 constitutes a zero-gap electrolytic cell sandwiched between the anode 4 'and the cathode 5' without a gap.
The anode 4 'is made of expanded metal coated with a catalyst in order to promote the electrolytic synthesis reaction of perchlorate ions on the anode side 4A. The anode 4 'is composed of an electrode in which the surface of a titanium expanded metal as a base is coated with a platinum catalyst layer by electrolytic plating.
On the other hand, the cathode 5 'paired with the anode 4' is made of expanded metal coated with a catalyst. The cathode 5 'is composed of an electrode in which the surface of a titanium expanded metal as a base is covered with a platinum catalyst layer by electrolytic plating, an electrode made of SUS316 expanded metal, or an electrode made of nickel expanded metal.

  An anolyte transport pipe 25 of the primary electrolyzer 1 is connected to the top of the anolyte tank 4B of the secondary electrolyzer 2 as an anolyte introduction pipe, and the anolyte after the primary electrolysis step is anolyte transport pipe 25. To fill the anode side 4A (including the anode side electrolytic cell 2A and the anolyte tank 4B). On the other hand, a catholyte introduction pipe 22 is connected to the top of the catholyte tank 5B, and pure water is introduced through the catholyte introduction pipe 22, and the cathode side 5A (cathode side electrolytic cell 2B, catholyte tank 5B). Meet). When a voltage is applied to both the anode 4 'and the cathode 5' immersed in each solution inside the secondary electrolytic cell 2, the following reaction proceeds.

On the anode side 4A, the anolyte that has undergone the primary electrolysis step is electrolytically oxidized, and oxygen gas is generated as perchlorate ions and by-products as shown in the following reaction formulas (12) and (13). The In addition, although it is a trace amount, as shown in the following reaction formula (14), ozone gas is also generated as a by-product.
ClO ₃ ⁻ + H ₂ O → ClO ₄ ⁻ + 2H ⁺ + 2e ⁻ (12)
2H ₂ O → O ₂ + 4H ⁺ + 4e ⁻ ... (13)
3H ₂ O → O ₃ + 6H ⁺ + 6e ⁻ ... (14)
Here, sodium ions contained in the anolyte on the anode side 4A move from the anode side 4A to the cathode side 5A through the cation exchange membrane 6 due to the potential difference between the two electrodes. On the other hand, chlorate ions cannot pass through the cation exchange membrane 6 and become perchlorate ions by the reaction shown in the reaction formula (12) at the three interfaces constituted by the aqueous solution-anode 4'-cation exchange membrane 6.

On the cathode side 5A, the reactions shown in the following reaction formulas (15) and (16) occur, and hydrogen gas and sodium hydroxide are generated.
2H ⁺ + 2e ⁻ → H ₂ (15)
2Na ⁺ + 2H ₂ O + 2e ⁻ → 2NaOH + H ₂ (16)

The measuring device 13 of the secondary electrolytic cell 2 monitors the amount of movement of sodium ions accompanying electrolytic oxidation based on the aforementioned arithmetic program. And the sodium ion density | concentration of 4 A of anode sides is grasped | ascertained from the movement amount.
The anolyte in which a sufficient amount of perchlorate ions has been generated is transported from the anolyte tank 4B to the reaction / evaporation tank 3 via the anolyte transport pipe 25 'in which the valve 25A is opened from the closed state. On the other hand, the catholyte is transported to the outside from the catholyte tank 5B through the catholyte transport pipe 26 in which the valve 26A is opened from the closed state.

In the reaction / evaporation tank 3, a step of synthesizing ammonium perchlorate by adding an aqueous ammonia solution to the anolyte after electrolytic oxidation, and evaporating the synthesized anolyte under reduced pressure to crystallize ammonium perchlorate. And performing the analysis process. Here, ammonia gas may be added by bubbling instead of the aqueous ammonia solution.
An ammonia supply pipe 31 is connected to the reaction / evaporation tank 3 to supply an aqueous ammonia solution into the anolyte after electrolytic oxidation. When an aqueous ammonia solution is added to the anolyte after electrolytic oxidation, a neutralization reaction shown in the following reaction formula (17) occurs, and ammonium perchlorate is synthesized.
HClO ₄ + NH ₄ OH → NH ₄ ClO ₄ + H ₂ O ... (17)

  Next, in the reaction / evaporation tank 3, the synthesized anolyte is evaporated in a vacuum environment to take out ammonium perchlorate as crystals. As shown in the reaction formula (17), since the by-product obtained together with ammonium perchlorate is water, high-purity ammonium perchlorate crystals can be obtained simply by evaporating the water.

  As described above, according to the present embodiment, the anode side 4A provided with the anode 4 and the cathode side 5A provided with the cathode 5 are partitioned by the cation exchange membrane 6, and the sodium chloride aqueous solution is electrolytically oxidized on the anode side 4A. The cation exchange membrane 6 from the anode side 4A to the electrolytic oxidation based on the pH value, the water temperature and the amount of liquid that change with the electrolytic oxidation at the cathode side 5A. By adopting an ammonium perchlorate production apparatus A having a measuring device 13 that measures the amount of sodium ions that have moved to the cathode side 5A after passing through the cathode side, the detection of the cathode side 5A that does not take time and effort for detection By calculating the amount of movement of sodium ions based on the pH value, the water temperature, and the amount of liquid, the amount of movement of sodium ions can be monitored more easily than before.

Further, in the present embodiment, the amount of movement of sodium ions is considered by considering the pH value that changes depending on the amount of movement of sodium ions accompanying electrolytic oxidation, and the change in water temperature and liquid volume that affects the pH value. Can be accurately monitored.
As factors affecting the pH value on the cathode side, in addition to the water temperature and the amount of liquid, there is dissolution of carbon dioxide present in the atmosphere into the cathode liquid. In this embodiment, the amount of dissolved carbon dioxide It is possible to further improve the accuracy of monitoring by using a correction formula that takes into account.

  As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, in the above-described embodiment, a mode in which electrolytic oxidation is performed using a sodium chloride aqueous solution as a raw material to be electrolytically oxidized on the anode side of the electrolytic cell has been described, but a mode in which electrolytic oxidation is performed using a sodium chlorate aqueous solution May be.

  Further, for example, the present invention is not limited to application to the above-described ammonium perchlorate production apparatus, but an alkali metal perchlorate production apparatus such as lithium perchlorate or potassium perchlorate, The present invention can also be applied to an apparatus for producing alkaline earth metal perchlorates such as calcium chlorate and an apparatus for producing silver perchlorate.

  A ... Ammonium perchlorate production device (perchlorate production device), S1 ... Primary electrolysis step, ..., S2 ... Secondary electrolysis step, S3 ... Reaction step (synthesis step), S4 ... Crystalling step, 1 ... Primary electrolytic cell, 2 ... Secondary electrolytic cell, 3 ... Reaction / evaporation tank, 4 ... Anode, 4 '... Anode, 4A ... Anode side, 5 ... Cathode, 5' ... Cathode, 5A ... Cathode side, 6 ... Cation Exchange membrane, 13 ... measuring device, 14 ... pH meter, 15 ... water temperature meter, 16 ... liquid level meter, 17 ... computing device, 18 ... trap, 24 ... hydrogen gas pipe (hydrogen gas exhaust pipe)

Claims (4)

An electrolytic cell for partitioning an anode side on which an anode is provided and a cathode side on which a cathode is provided with a cation exchange membrane, and electrolytically oxidizing a sodium chloride aqueous solution or a sodium chlorate aqueous solution on the anode side;
Movement of sodium ions that have moved from the anode side to the cathode side through the cation exchange membrane with the electrolytic oxidation based on the pH value, water temperature, and liquid volume that change with the electrolytic oxidation on the cathode side A perchlorate production apparatus, comprising: a measurement device for measuring the amount.   2. The perchlorate according to claim 1, wherein the measuring device corrects the measured amount of sodium ion movement based on a dissolution amount of carbon dioxide contained in the atmosphere to the cathode side. Manufacturing equipment. On the cathode side, a hydrogen gas exhaust pipe for exhausting hydrogen gas generated at the cathode accompanying the electrolytic oxidation into the atmosphere is provided,
The apparatus for producing perchlorate according to claim 1 or 2, wherein the hydrogen gas exhaust pipe has a trap for preventing inflow of carbon dioxide from the atmosphere to the cathode side. Using an electrolytic cell in which an anode side provided with an anode and a cathode side provided with a cathode are partitioned by a cation exchange membrane, and electrolytically oxidizing a sodium chloride aqueous solution or a sodium chlorate aqueous solution on the anode side;
Based on the pH value on the cathode side, the water temperature, and the amount of liquid, measuring the amount of sodium ions that have moved from the anode side to the cathode side through the cation exchange membrane accompanying the electrolytic oxidation, and A method for producing perchlorate, comprising:

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