A chlor-alkali hydrogen peroxide co-production system employing a fluid diffusion electrode

Abstract

This invention belongs to the technical field of electrochemical reaction systems and discloses a chlor-alkali hydrogen peroxide co-production system using a fluid diffusion electrode. The system includes an electrochemical reaction device, a cathode module, an anode module, and a system control module. The electrochemical reaction device includes at least one electrochemical reaction unit, which comprises an anode chamber, a cation exchange membrane, and a cathode chamber. The cathode module provides the cathode electrolyte and collects the cathode product, while the anode module provides the cathode electrolyte and separates and collects the anode product. The system control module collects and provides feedback information from the electrochemical reaction device, cathode module, and anode module to maintain the stable operation of the entire system. This invention enables the efficient production of sodium hydroxide and hydrogen peroxide using only oxygen and water, meeting the product requirements for disinfectants and bleaching solutions with different compositions. Compared with traditional chlor-alkali systems, it is not only safer but also has a higher degree of internal integration, and the production unit can be customized in size according to requirements.

Description

Technical Field

[0001] This invention belongs to the technical field of electrochemical reaction systems, specifically, it relates to a chlor-alkali hydrogen peroxide co-production system using a fluid diffusion electrode. Background Technology

[0002] Hydrogen peroxide is a green chemical product that decomposes into water and oxygen. It possesses strong oxidizing properties under both acidic and alkaline conditions, far exceeding the applicability of other oxidants in industrial production. It can be used as a bleaching agent, oxidant, disinfectant, polymer initiator, and crosslinking agent, and is widely applied in industries such as chemical, papermaking, environmental protection, electronics, food, pharmaceuticals, and textiles. Currently, the main methods for preparing hydrogen peroxide include electrolysis, the anthraquinone method, and the isopropanol oxidation method. Industrially, the anthraquinone method is the primary method, but it is costly and generates large amounts of industrial wastewater, causing environmental pollution and contradicting the principles of green chemistry. Meanwhile, sodium hypochlorite is also a very important disinfectant product, characterized by high speed, high efficiency, non-toxicity, harmlessness, and no residue, making it one of the most widely used disinfectants on the market. Currently, sodium hypochlorite is prepared industrially using an electrochemical method, which produces high purity, few chlorine byproducts, and is safe. Summary of the Invention

[0003] In order to achieve the co-production of chlor-alkali and hydrogen peroxide, this invention develops a system using fluid diffusion.

[0004] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0005] This invention provides a chlor-alkali hydrogen peroxide co-production system employing a fluid diffusion electrode, comprising an electrochemical reaction device, a cathode module, an anode module, and a system control module;

[0006] The electrochemical reaction device includes at least one electrochemical reaction unit and a DC power supply; each electrochemical reaction unit includes an anode chamber, a cation exchange membrane, and a cathode chamber; the anode chamber contains an anode catalyst, and the cathode chamber contains a fluid diffusion cathode catalyst; the DC power supply is used to provide electrical energy to the electrochemical reaction unit;

[0007] The cathode module includes an oxygen supply device, a mass flow meter, a check valve, a pure water supply device, a water replenishment pump, a cathode buffer unit, a cathode circulation pump, and a level gauge;

[0008] The oxygen supply device is connected to the cathode inlet of the cathode chamber in sequence through the mass flow meter and the one-way valve, and is used to provide oxygen for the cathode catalytic reaction;

[0009] The pure water supply device is connected to the cathode replenishment port of the cathode buffer unit via the replenishment pump; the cathode buffer unit is equipped with a level gauge, which is signal-connected to the system control module; the system control module can discharge cathode products through the cathode product outlet of the cathode buffer unit based on the feedback control of the level gauge.

[0010] The cathode circulation outlet of the cathode buffer unit is connected to the cathode inlet of the cathode chamber via the cathode circulation pump, and the cathode outlet of the cathode chamber is connected to the cathode circulation inlet of the cathode buffer unit.

[0011] The anode module includes a neutralizing liquid replenishment device, a neutralizing liquid buffer tank, a neutralizing liquid replenishment pump, a gas-liquid separation unit, an anode circulation pump, an anode buffer unit, an anode liquid replenishment pump, and a salt preparation tank;

[0012] The anode outlet of the anode chamber is connected to the anode circulation inlet of the gas-liquid separation unit, and the gas outlet of the gas-liquid separation unit is used to discharge gaseous products.

[0013] The outlet of the neutralizing liquid replenishment device is connected to the inlet of the neutralizing liquid buffer tank, and the outlet of the neutralizing liquid buffer tank is connected to the neutralizing liquid replenishment port of the gas-liquid separation unit through the neutralizing liquid replenishment pump; a pH detector is installed inside the gas-liquid separation unit, and the pH detector is signal-connected to the system control module; the system control module controls the neutralizing liquid replenishment pump to replenish the gas-liquid separation unit with neutralizing liquid based on the feedback from the pH detector;

[0014] The inlet of the salt-making tank is connected to the liquid outlet of the gas-liquid separation unit, and the installation height of the liquid outlet is higher than the inlet height of the salt-making tank, so that the liquid neutralized by the gas-liquid separation unit flows into the salt-making tank. The outlet of the salt-making tank is connected to the inlet of the anode buffer unit through the anode liquid replenishment pump; the outlet of the anode buffer unit is connected to the anode inlet of the anode chamber through the anode circulation pump.

[0015] The system control module is used to collect and control information from the electrochemical reaction device, the cathode module, and the anode module to maintain the stable operation of the entire system.

[0016] Preferably, the single-cell voltage of the electrochemical reaction device is 2.1 to 3.1 V.

[0017] Preferably, the electrochemical reaction device is equipped with an external temperature control system to maintain the temperature of the electrochemical reaction device between 45 and 55°C.

[0018] Preferably, the cathode module is provided with a humidifier between the one-way valve and the cathode chamber for humidifying the oxygen.

[0019] Preferably, the flow rate of the cathode circulation pump is 75 ml / min to 180 ml / min, and the flow rate of the anode circulation pump is 200 ml / min to 350 ml / min.

[0020] Preferably, the concentration of hydrogen peroxide in the cathode buffer unit is maintained at 1 mol / L, and the concentration of sodium hydroxide is maintained at 2 mol / L.

[0021] Preferably, the neutralizing liquid buffer tank is filled with alkaline hydrogen peroxide to eliminate sodium hypochlorite generated by the gas-liquid separation unit.

[0022] Preferably, the pH value inside the gas-liquid separation unit is maintained between 2 and 5.

[0023] Preferably, a check valve is installed in the connecting pipeline between the gas-liquid separation unit and the gas outlet to prevent gas backflow.

[0024] Preferably, the salt-making tank contains sodium chloride solid that has had calcium and magnesium ions removed, so that the unsaturated sodium chloride solution in the gas-liquid separation unit becomes saturated sodium chloride after passing through the salt-making tank, and then enters the anode buffer unit again by the anode liquid replenishment pump.

[0025] The beneficial effects of this invention are:

[0026] This invention expands and upgrades upon the traditional chlor-alkali system. The anode is the same as in traditional chlor-alkali systems, while the cathode uses a fluid diffusion electrode, enabling efficient production of sodium hydroxide and hydrogen peroxide using only oxygen and water. The system can simultaneously produce hydrogen peroxide and sodium hypochlorite, meeting the needs of products requiring different components in disinfectants and bleaching solutions. Compared to traditional chlor-alkali systems, it is not only safer but also highly integrated, with production unit size customizable to meet various production conditions. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the chlor-alkali hydrogen peroxide co-production system of the present invention;

[0028] Figure 2 This is a schematic diagram of the electrochemical reaction device in the chlor-alkali hydrogen peroxide co-production system of the present invention;

[0029] Figure 3 This is a schematic diagram of the inlet and outlet of the electrochemical reaction unit in the chlor-alkali hydrogen peroxide co-production system of the present invention;

[0030] Figure 4 This is a schematic diagram of the cathode buffer unit of the cathode module in the chlor-alkali hydrogen peroxide co-production system of the present invention;

[0031] Figure 5 This is a schematic diagram of the gas-liquid separation unit of the anode module in the chlor-alkali hydrogen peroxide co-production system of the present invention.

[0032] In the above figure:

[0033] 1-Cathode Module; 101-Oxygen Supply Unit, 102-Mass Flow Meter, 103-Check Valve, 104-Humidifier, 105-Pure Water Supply System, 106-Make-up Water Pump, 107-Cathode Buffer Unit, 108-Cathode Circulation Pump, 109-Level Gauge, 110-Cathode Liquid Inlet, 111-Cathode Product Outlet, 112-Cathode Circulation Outlet, 113-Cathode Circulation Inlet; 2-Anode Module; 201-Neutralization Liquid Replenishment Unit, 202-Neutralization Liquid Buffer Tank, 203-Neutralization Liquid Replenishment Pump, 204-Gas-Liquid Separation Unit, 205-Anode Circulation Pump, 206-Anode 207-Anodic solution replenishment pump, 208-Salt preparation tank, 209-Anodic circulation inlet, 210-Gas outlet, 211-Neutralization solution replenishment port, 212-Liquid outlet, 213-pH detector; 3-Electrochemical reaction device; 301-DC power supply, 302-Cathode chamber, 303-Anodic chamber, 304-Cation membrane, 305-Fluid diffusion cathode catalyst material, 306-Anodic catalyst material, 307-Constant temperature system, 308-Cathode inlet, 309-Cathode outlet, 310-Anodic inlet, 311-Anodic outlet; 4-System control module; Detailed Implementation

[0034] The present invention will be further described in detail below through specific embodiments. These embodiments will enable those skilled in the art to have a more comprehensive understanding of the present invention, but will not limit the present invention in any way.

[0035] like Figure 1 As shown, this invention provides a chlor-alkali hydrogen peroxide co-production system employing a fluid diffusion electrode, comprising an electrochemical reaction device 3, a cathode module 1, an anode module 2, and a system control module 4. The electrochemical reaction device 3 includes at least one electrochemical reaction unit, which includes an anode chamber 303, a cation exchange membrane 304, and a cathode chamber 302. The cathode module 1 provides the cathode electrolyte and collects the cathode product; the anode module 2 provides the cathode electrolyte and separates and collects the anode product; and the system control module 4 collects and provides feedback on information from the electrochemical reaction device 3, cathode module 1, and anode module 2 to maintain the stable operation of the entire system.

[0036] like Figure 2As shown, the electrochemical reaction device 3 includes at least one electrochemical reaction unit and an external DC power supply 301. Each electrochemical reaction unit includes an anode chamber 303 and a cathode chamber 302, which are separated by a cation exchange membrane 304. An anode catalyst 306 is disposed in the anode chamber 303, and a fluid diffusion cathode catalyst 305 is disposed in the cathode chamber 302.

[0037] The DC power supply 301 provides electrical energy to the electrochemical reaction unit. Multiple electrochemical reaction units can be connected in parallel to meet the demands of higher production volumes. The dimensions of the anode chamber 303, anode catalyst 306, cation separator 304, cathode chamber 302, and fluid diffusion cathode catalyst 305 can be modified according to requirements to meet different space needs.

[0038] In a preferred embodiment, the single-cell voltage of the electrochemical reaction device 3 is 2.1 to 3.1V. The number of electrolytic cells in the electrochemical reaction device 3 can be increased and the corresponding flow rate can be increased as needed.

[0039] In a preferred embodiment, a temperature control system 307 is installed on the outside of the electrochemical reaction device 3 to ensure that the temperature of the electrochemical reaction device 3 is maintained between 45 and 55°C.

[0040] The cathode module 1 includes an oxygen supply device 101, a mass flow meter 102, a one-way valve 103, a humidifier 104, a pure water supply device 105, a makeup water pump 106, a cathode buffer unit 107, a cathode circulation pump 108, and a level gauge 109. The oxygen supply device 101 is connected to the cathode inlet 308 of the cathode chamber 302 via the mass flow meter 102 and the one-way valve 103, thereby providing oxygen for the cathode catalytic reaction. The one-way valve 103 serves to protect the mass flow meter 102.

[0041] In a preferred embodiment, since the cathode chamber 302 contains a fluid diffusion cathode catalyst material 305, in order to achieve a better catalytic effect by distributing oxygen and water evenly on the surface of the fluid diffusion cathode catalyst material 305, a humidifier 104 is provided between the one-way valve 103 and the cathode chamber 302 to wet the oxygen.

[0042] Combination Figure 4 As shown, the cathode circulation outlet 112 of the cathode buffer unit 107 is connected to the cathode inlet 308 of the cathode chamber 302 via the cathode circulation pump 108, thereby pumping the liquid from the cathode buffer unit 107 into the cathode chamber 302 for cathode catalytic reaction. The cathode outlet 309 of the cathode chamber 302 is connected to the cathode circulation inlet 113 of the cathode buffer unit 107, allowing the liquid after the cathode catalytic reaction in the cathode chamber 302 to flow back to the cathode buffer unit 107.

[0043] The flow rate of the cathode circulation pump 108 should ideally be maintained between 75 ml / min and 180 ml / min.

[0044] The pure water supply device 105 is connected to the cathode replenishment port 110 of the cathode buffer unit 107 via a water replenishment pump 106 to dilute the cathode product to the target concentration. The cathode buffer unit 107 is equipped with a level gauge 109, which is signal-connected to the system control module 4. After the cathode product in the cathode buffer unit 107 is diluted to the target concentration, feedback from the level gauge 109 indicates that the cathode product has reached the control level. The system control module 4 then controls the cathode product to be discharged from the cathode product outlet 111 of the cathode buffer unit 107.

[0045] In a preferred embodiment, the concentration of hydrogen peroxide in the cathode buffer unit 107 is maintained at 1 mol / L, and the concentration of sodium hydroxide is maintained at 2 mol / L.

[0046] The anode module 2 includes a neutralizing liquid replenishment device 201, a neutralizing liquid buffer tank 202, a neutralizing liquid replenishment pump 203, a gas-liquid separation unit 204, an anode circulation pump 205, an anode buffer unit 206, an anode liquid replenishment pump 207, and a salt production tank 208.

[0047] The outlet of the anode buffer unit 206 is connected to the anode inlet 310 of the anode chamber 303 via the anode circulation pump 205, which is used to pump the liquid from the anode buffer unit 206 into the anode chamber 303 for anode catalytic reaction.

[0048] The flow rate of the anode circulation pump 205 is preferably controlled between 200 ml / min and 350 ml / min.

[0049] Combination Figure 5 As shown, the anode circulation inlet 209 of the gas-liquid separation unit 204 is connected to the anode outlet 311 of the anode chamber 303, allowing the gaseous product to enter the gas-liquid separation unit 204 and be discharged through the gas outlet 210 of the gas-liquid separation unit 204. The outlet of the neutralizing liquid replenishment device 201 is connected to the inlet of the neutralizing liquid buffer tank 202, and the outlet of the neutralizing liquid buffer tank 202 is connected to the neutralizing liquid replenishment port 211 of the gas-liquid separation unit 204 through the neutralizing liquid replenishment pump 203.

[0050] In a preferred embodiment, the neutralizing liquid buffer tank 202 is filled with alkaline hydrogen peroxide to eliminate sodium hypochlorite generated by the gas-liquid separation unit 204.

[0051] A pH detector 213 is installed inside the gas-liquid separation unit 204, and the pH detector 213 is connected to the system control module 4. Based on the feedback from the pH detector 213, the system control module 4 controls the replenishment of neutralizing liquid. Preferably, the pH value inside the gas-liquid separation unit 204 is maintained between 2 and 5. When the pH value is lower than 2, the system control module 4 controls the neutralizing liquid replenishment pump 203 to start in order to neutralize sodium hypochlorite.

[0052] The inlet of the salt tank 208 is connected to the liquid outlet 212 of the gas-liquid separation unit 204, and the installation height of the liquid outlet 212 is higher than the inlet height of the salt tank 208; so that the liquid neutralized by the gas-liquid separation unit 204 flows into the salt tank 208, and the outlet of the salt tank 208 is connected to the inlet of the anode buffer unit 206 through the anode liquid replenishment pump 207.

[0053] In a preferred embodiment, a check valve is installed in the connecting pipeline between the gas-liquid separation unit 204 and the gas outlet 210 to prevent gas backflow and the generation of excessive sodium hypochlorite.

[0054] In a preferred embodiment, the salt tank 208 contains sodium chloride solid with calcium and magnesium ions removed. After the unsaturated sodium chloride solution in the gas-liquid separation unit 204 is converted into saturated sodium chloride through the salt layer of the salt tank 208, it will be re-entered into the anode buffer unit 206 by the anode liquid replenishment pump 207.

[0055] The chlor-alkali hydrogen peroxide co-production system of the present invention, which adopts a fluid diffusion electrode, does not generate hydrogen compared with the traditional chlor-alkali system, thus making it safer. At the same time, the system has a high degree of internal integration, which can be conveniently and quickly installed near factories with inconvenient transportation, enabling immediate production and use, greatly reducing transportation costs. In addition, the size of the production unit can be customized according to needs, which can better adapt to various different production requirements.

[0056] Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many specific modifications under the guidance of the present invention without departing from the spirit and scope of the claims, and these modifications all fall within the scope of protection of the present invention.

Claims

1. A chlor-alkali hydrogen peroxide co-production system employing a fluid diffusion electrode, characterized in that, It includes an electrochemical reaction device, a cathode module, an anode module, and a system control module; The electrochemical reaction device includes at least one electrochemical reaction unit and a DC power supply; each electrochemical reaction unit includes an anode chamber, a cation exchange membrane, and a cathode chamber; the anode chamber contains an anode catalyst, and the cathode chamber contains a fluid diffusion cathode catalyst; the DC power supply is used to provide electrical energy to the electrochemical reaction unit; The cathode module includes an oxygen supply device, a mass flow meter, a check valve, a pure water supply device, a water replenishment pump, a cathode buffer unit, a cathode circulation pump, and a level gauge; The oxygen supply device is connected to the cathode inlet of the cathode chamber in sequence through the mass flow meter and the one-way valve, and is used to provide oxygen for the cathode catalytic reaction; a humidifier is provided between the one-way valve and the cathode chamber to humidify the oxygen. The pure water supply device is connected to the cathode replenishment port of the cathode buffer unit via the replenishment pump; the cathode buffer unit is equipped with a level gauge, which is signal-connected to the system control module; the system control module can discharge cathode products through the cathode product outlet of the cathode buffer unit based on the feedback control of the level gauge. The cathode circulation outlet of the cathode buffer unit is connected to the cathode inlet of the cathode chamber via the cathode circulation pump, and the cathode outlet of the cathode chamber is connected to the cathode circulation inlet of the cathode buffer unit. The anode module includes a neutralizing liquid replenishment device, a neutralizing liquid buffer tank, a neutralizing liquid replenishment pump, a gas-liquid separation unit, an anode circulation pump, an anode buffer unit, an anode liquid replenishment pump, and a salt preparation tank; The anode outlet of the anode chamber is connected to the anode circulation inlet of the gas-liquid separation unit, and the gas outlet of the gas-liquid separation unit is used to discharge gaseous products. The outlet of the neutralizing liquid replenishment device is connected to the inlet of the neutralizing liquid buffer tank, and the outlet of the neutralizing liquid buffer tank is connected to the neutralizing liquid replenishment port of the gas-liquid separation unit through the neutralizing liquid replenishment pump; a pH detector is installed inside the gas-liquid separation unit, and the pH detector is signal-connected to the system control module. The system control module controls the neutralization liquid replenishment pump to replenish the gas-liquid separation unit based on the feedback from the pH detector; the neutralization liquid buffer tank is filled with alkaline hydrogen peroxide to eliminate sodium hypochlorite generated by the gas-liquid separation unit. The inlet of the salt-making tank is connected to the liquid outlet of the gas-liquid separation unit, and the installation height of the liquid outlet is higher than the inlet height of the salt-making tank, so that the liquid neutralized by the gas-liquid separation unit flows into the salt-making tank. The outlet of the salt-making tank is connected to the inlet of the anode buffer unit through the anode liquid replenishment pump; the outlet of the anode buffer unit is connected to the anode inlet of the anode chamber through the anode circulation pump. The salt-making tank contains sodium chloride solid with calcium and magnesium ions removed. After the unsaturated sodium chloride solution in the gas-liquid separation unit is converted into saturated sodium chloride in the salt-making tank, it is then re-entered into the anode buffer unit by the anode liquid replenishment pump. The system control module is used to collect and control information from the electrochemical reaction device, the cathode module, and the anode module to maintain the stable operation of the entire system.

2. The chlor-alkali hydrogen peroxide co-production system using a fluid diffusion electrode according to claim 1, characterized in that, The single-cell voltage of the electrochemical reaction device is 2.1–3.1 V.

3. A chlor-alkali hydrogen peroxide co-production system employing a fluid diffusion electrode according to claim 1, characterized in that, The electrochemical reaction device is equipped with an external temperature control system to maintain the temperature of the electrochemical reaction device between 45 and 55°C.

4. A chlor-alkali hydrogen peroxide co-production system employing a fluid diffusion electrode according to claim 1, characterized in that, The flow rate of the cathode circulation pump is 75 ml / min to 180 ml / min, and the flow rate of the anode circulation pump is 200 ml / min to 350 ml / min.

5. A chlor-alkali hydrogen peroxide co-production system employing a fluid diffusion electrode according to claim 1, characterized in that, The concentration of hydrogen peroxide in the cathode buffer unit is maintained at 1 mol / L, and the concentration of sodium hydroxide is maintained at 2 mol / L.

6. A chlor-alkali hydrogen peroxide co-production system employing a fluid diffusion electrode according to claim 1, characterized in that, The pH value inside the gas-liquid separation unit is maintained between 2 and 5.

7. A chlor-alkali hydrogen peroxide co-production system employing a fluid diffusion electrode according to claim 1, characterized in that, A check valve is installed in the connecting pipeline between the gas-liquid separation unit and the gas outlet to prevent gas backflow.

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