A system for producing hydrogen by electrolysis of water coupled with production of hydrogen peroxide

Abstract

The present application proposes a system for coupling hydrogen production by electrolysis of water with hydrogen peroxide production, comprising an electrolysis hydrogen production mechanism, an electrolyte heat exchanger, a circulating cooling mechanism and a hydrogen peroxide production mechanism, wherein the electrolysis hydrogen production mechanism supplies hydrogen and oxygen to the hydrogen peroxide production mechanism through a first pipeline and a second pipeline respectively, the electrolyte of the electrolysis hydrogen production mechanism is passed into the electrolyte heat exchanger to exchange heat with the circulating water, the hydrogen peroxide production mechanism passes hydrogen peroxide to the circulating cooling mechanism through a fourth pipeline, and the hydrogen peroxide is used to disinfect the circulating cooling mechanism. By coupling the hydrogen production mechanism and the hydrogen peroxide production mechanism, hydrogen and oxygen generated by hydrogen production by electrolysis of water are used as raw materials to produce hydrogen peroxide, thereby effectively avoiding carbon emissions caused by the process of producing hydrogen peroxide using "grey hydrogen", and at the same time absorbing the oxygen generated in the process of hydrogen production by electrolysis of water.

Description

Technical Field

[0001] The present application relates to the technical field of hydrogen production by electrolysis, and in particular to a system for hydrogen production by electrolysis of water coupled with hydrogen peroxide production. Background Art

[0002] In recent years, with the development of the hydrogen energy industry, water electrolysis has gradually become the most promising large-scale hydrogen production technology. Hydrogen has the dual attributes of industrial raw materials and energy products. When green hydrogen is used as an industrial raw material, it can greatly reduce CO2 emissions in the industrial production process, which is of great significance for promoting industrial decarbonization.

[0003] Hydrogen peroxide is an important chemical product, which is widely used in chemical synthesis, food, textile, metallurgy, medicine, papermaking and environmental protection industries. Since it only produces water and oxygen during use, it is an environmentally friendly chemical product.

[0004] The raw materials for hydrogen peroxide production are hydrogen and oxygen. Currently, the hydrogen used in the hydrogen peroxide production process is usually "gray hydrogen" from fossil fuels. The "gray hydrogen" production process will lead to the emission of carbon dioxide, and in the electrolytic hydrogen production industry, oxygen is generally discharged directly into the air as a by-product, thereby causing a waste of resources. Summary of the invention

[0005] The present application aims to solve one of the technical problems in the related art at least to some extent.

[0006] To this end, the purpose of this application is to propose a system for coupling hydrogen peroxide production by electrolysis of water. By coupling the hydrogen production mechanism and the hydrogen peroxide production mechanism, the hydrogen produced by the hydrogen production by electrolysis of water and oxygen are used as raw materials to produce hydrogen peroxide, which can effectively avoid the carbon emissions caused by the use of "gray hydrogen" to produce hydrogen peroxide, and at the same time, the oxygen produced in the process of hydrogen production by electrolysis of water can be consumed. In addition, the impurities such as CO and H2S contained in the hydrogen obtained by traditional coal-to-hydrogen production are easy to cause catalyst poisoning. Hydrogen production by electrolysis of water can effectively avoid this problem. Waste heat is generated in the process of hydrogen production by electrolysis of water. The required temperature can be provided for hydrogen peroxide synthesis through the electrolyte heat exchanger, and the circulation is carried out through the circulating cooling mechanism, which improves the energy conversion efficiency of the entire system. The circulating cooling system needs to add disinfectants regularly. The hydrogen peroxide produced by the hydrogen peroxide production mechanism can be used as a disinfectant, which can reduce the cost of purchasing disinfectants.

[0007] To achieve the above-mentioned purpose, the present application proposes a system for coupling hydrogen peroxide production by electrolysis of water, comprising an electrolytic hydrogen production mechanism, an electrolyte heat exchanger, a circulating cooling mechanism and a hydrogen peroxide production mechanism, wherein the electrolytic hydrogen production mechanism supplies hydrogen and oxygen to the hydrogen peroxide production mechanism through a first pipeline and a second pipeline respectively, and the circulating cooling mechanism sequentially connects the electrolytic hydrogen production mechanism, the electrolyte heat exchanger and the hydrogen peroxide mechanism through a third pipeline to form a circulation loop, and the circulating water of the circulating cooling mechanism passes through the electrolytic hydrogen production mechanism, the electrolyte heat exchanger and the hydrogen peroxide production mechanism in sequence, and the electrolyte of the electrolytic hydrogen production mechanism is passed into the electrolyte heat exchanger to exchange heat with the circulating water, and the hydrogen peroxide production mechanism passes hydrogen peroxide to the circulating cooling mechanism through a fourth pipeline, and the hydrogen peroxide is used to disinfect the circulating cooling mechanism.

[0008] Furthermore, the hydrogen peroxide production mechanism includes a working fluid thermostat, a hydrogenation unit, an oxidation unit and an extraction unit connected in sequence through pipelines, the extraction unit is also connected to the working fluid thermostat through a reflux pipeline to circulate and reflux the working fluid, the outlet end of the working fluid thermostat is connected to the circulating cooling mechanism through the third pipeline, and the inlet end of the working fluid thermostat is connected to the electrolyte heat exchanger through the third pipeline.

[0009] Furthermore, the hydrogen peroxide production mechanism also includes a purification unit, which is connected to the extraction unit via a pipeline, and the purification unit is connected to the circulating cooling mechanism via the fourth pipeline to pass hydrogen peroxide into the circulating cooling mechanism.

[0010] Furthermore, the water electrolysis hydrogen production mechanism includes an electrolyzer, a gas-liquid separator and a gas cooler connected in sequence through pipelines, the inlet end of the gas cooler is connected to the circulating cooling mechanism through a third pipeline, the outlet end of the gas cooler is connected to the electrolyte heat exchanger through a third pipeline, and the gas-liquid separator, the electrolyte heat exchanger and the electrolyzer are connected end to end through pipelines to recycle the electrolyte.

[0011] Furthermore, the water electrolysis hydrogen production mechanism also includes a water mist droplet catcher, which is connected to the gas cooler through a pipeline, and the water mist droplet catcher is connected to the hydrogenation unit through the first pipeline to supply hydrogen to the hydrogenation unit, and the water mist droplet catcher is connected to the oxidation unit through the second pipeline to supply oxygen to the oxidation unit.

[0012] Furthermore, the water mist droplet collector is also provided with an external pipeline, and the external pipeline is used to connect to an external hydrogen storage tank.

[0013] Furthermore, it also includes a pure water preheating mechanism, the water inlet end of the pure water preheating mechanism is connected to the electrolyte heat exchanger through a pipeline, the water outlet end of the pure water preheating mechanism is connected to the circulating cooling mechanism through a pipeline, the pure water preheating mechanism is used to pass the circulating water to preheat the pure water, and the pure water preheating mechanism is also connected to the extraction unit to supply pure water to the extraction unit.

[0014] Furthermore, it also includes a water replenishment mechanism, wherein pure water is introduced into the inlet end of the water replenishment mechanism, and the outlet end of the water replenishment mechanism is connected to the electrolytic cell.

[0015] Furthermore, the hydrogenation unit comprises a hydrogen dissolving device and a reactor which are interconnected, wherein the hydrogen dissolving device is used to mix and dissolve the working solution and hydrogen flowing out of the working liquid thermostat to obtain a hydrogen-dissolved flow, and the reactor is used to catalyze the hydrogen-dissolved flow to perform a hydrogenation reaction.

[0016] Furthermore, the reactor includes one of a fixed bed reactor, a fluidized bed reactor or a tubular reactor.

[0017] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0019] Figure 1 It is a structural schematic diagram of a system for producing hydrogen by electrolysis of water coupled with hydrogen peroxide production proposed in one embodiment of the present application. DETAILED DESCRIPTION

[0020] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be construed as limiting the present application. On the contrary, the embodiments of the present application include all changes, modifications and equivalents that fall within the spirit and connotation of the appended claims.

[0021] Figure 1 It is a structural schematic diagram of a system for producing hydrogen by electrolysis of water coupled with hydrogen peroxide production proposed in one embodiment of the present application.

[0022] See also Figure 1A system for coupling hydrogen production by electrolysis with hydrogen peroxide production, comprising an electrolytic hydrogen production mechanism, an electrolyte heat exchanger 1, a circulating cooling mechanism 2 and a hydrogen peroxide production mechanism, wherein the electrolytic hydrogen production mechanism supplies hydrogen and oxygen to the hydrogen peroxide production mechanism through a first pipeline 3 and a second pipeline 4 respectively, and the circulating cooling mechanism 2 is sequentially connected to the electrolytic hydrogen production mechanism, the electrolyte heat exchanger 1 and the hydrogen peroxide production mechanism through a third pipeline 5 to form a circulation loop, and the circulating water of the circulating cooling mechanism 2 passes through the electrolytic hydrogen production mechanism, the electrolyte heat exchanger 1 and the hydrogen peroxide production mechanism in sequence, and the electrolyte of the electrolytic hydrogen production mechanism is passed into the electrolyte heat exchanger 1 to exchange heat with the circulating water, and the hydrogen peroxide production mechanism passes hydrogen peroxide to the circulating cooling mechanism 2 through a fourth pipeline 6, and the hydrogen peroxide is used to disinfect the circulating cooling mechanism 2.

[0023] In this embodiment, the third pipeline 5 is a cooling water circulation pipeline. The third pipeline 3 is connected to realize the end-to-end connection of the circulating cooling mechanism 2, the gas cooler, the electrolyte heat exchanger and the working fluid thermostat to form a circulating water circulation loop. The circulating water continuously circulates between the circulating cooling mechanism, the electrolytic hydrogen production mechanism, the electrolyte heat exchanger and the hydrogen peroxide production mechanism, and the waste heat of the hydrogen electrolysis mechanism is transferred to the hydrogen peroxide mechanism, so as to realize the utilization of the waste heat generated by the hydrogen electrolysis mechanism and improve the energy conversion efficiency of the whole system.

[0024] The electrolyte heat exchanger 1 serves as the hub between the electrolytic hydrogen production mechanism and the hydrogen peroxide production mechanism. On the one hand, the electrolyte of the electrolytic hydrogen production mechanism is introduced, and on the other hand, the circulating water of the hydrogen peroxide production mechanism is introduced. The circulating water and the electrolyte exchange heat to realize the utilization of the waste heat of the electrolytic hydrogen production mechanism.

[0025] The electrolysis water hydrogen production mechanism uses renewable energy to generate electricity and electrolyze water to produce hydrogen. The hydrogen and oxygen produced by electrolysis are purified and then enter the hydrogen peroxide production mechanism as raw material. Part of the hydrogen is used as raw material for hydrogen peroxide production, and the rest can be stored and used as energy. In addition, during the electrolysis water hydrogen production process, the circulating water outlet of the electrolyte heat exchanger can be used as a heat source to adjust the temperature of the working fluid in the hydrogen peroxide production process. Part of the hydrogen peroxide produced by the hydrogen peroxide production mechanism can be used as a disinfectant for the cooling water circulation mechanism, and part of it can be sold and used downstream as a product.

[0026] The hydrogen peroxide production mechanism includes a working liquid thermostat 7, a hydrogenation unit 8, an oxidation unit 9 and an extraction unit 10 connected in sequence through pipelines. The extraction unit 10 is also connected to the working liquid thermostat 7 through a reflux pipeline 11 to circulate and reflux the working liquid. The outlet end of the working liquid thermostat 7 is connected to the circulating cooling mechanism 2 through the third pipeline 5, and the inlet end of the working liquid thermostat 7 is connected to the electrolyte heat exchanger 1 through the third pipeline 5. The hydrogen peroxide production mechanism includes three reaction units of hydrogenation, oxidation and extraction. In the hydrogenation unit, the working solution prepared by 2-alkylanthraquinone and an organic solvent and the hydrogen generated by electrolysis enter the hydrogen dissolving device through a liquid phase introduction pipeline and a gas phase introduction pipeline respectively, and are mixed and dissolved in the hydrogen dissolving device to obtain a hydrogen dissolving flow. The hydrogen dissolving device can be a conventional tubular static mixer structure, or a structure with a turbulent component filled inside, or a dissolved gas pump, which is not limited in this application. The dissolved hydrogen stream is subjected to hydrogenation reaction in the reactor at a pressure of 0.2 to 0.4 MPa, a temperature of 45 to 75°C, and the presence of a catalyst. The reactor may be a fixed bed reactor, a fluidized bed reactor, or a tubular reactor, and the present application is not limited in comparison. The oxidation unit may be an oxidation tower, and the extraction unit may be an extraction tower. In the oxidation unit, the hydrogenated liquid and oxygen are oxidized in the oxidation tower at a pressure of 0.2 to 0.22 MPa and 40 to 55°C. The interior of the oxidation tower may be one or more of a multi-layer sieve plate structure, a packing structure, and a sieve plate and packing combination structure; the obtained oxidized liquid is separated by pure water extraction in the extraction tower to obtain hydrogen peroxide and a working liquid, and a portion of the obtained hydrogen peroxide is used as a disinfectant for the circulating cooling mechanism, and the rest is sold and used downstream as a product, and the working liquid is recycled after treatment.

[0027] The hydrogen peroxide production mechanism further includes a purification unit 12, which is connected to the extraction unit 10 through a pipeline, and is connected to the circulating cooling mechanism 2 through the fourth pipeline 6 to pass hydrogen peroxide into the circulating cooling mechanism 2. The purification unit 12 is used to purify the hydrogen peroxide produced by the extraction unit 10, a part of which is stored in an external pipeline, and a part of which is passed into the circulating cooling mechanism 2 for disinfection. The purification unit 12 can be a purification tower, and usually a qualified hydrogen peroxide aqueous solution is obtained by heavy aromatics purification in the purification tower.

[0028] The electrolytic water hydrogen production mechanism includes an electrolytic cell 13, a gas-liquid separator 14 and a gas cooler 15 connected in sequence through pipelines, the inlet end of the gas cooler 15 is connected to the circulating cooling mechanism 2 through a third pipeline 5, the outlet end of the gas cooler 15 is connected to the electrolyte heat exchanger 1 through a third pipeline 5, and the gas-liquid separator 14, the electrolyte heat exchanger 1 and the electrolytic cell 13 are connected end to end through pipelines to recycle the electrolyte. The hydrogen and oxygen produced by electrolysis in the electrolytic cell 13 are separated by gas and liquid in the gas-liquid separator and cooled by the gas cooler, and a part of them are supplied to the hydrogen peroxide production mechanism as raw materials, and a part of them are stored for subsequent use.

[0029] The water electrolysis hydrogen production mechanism also includes a water mist droplet catcher 16, which is connected to the gas cooler 15 through a pipeline, and the water mist droplet catcher 16 is connected to the hydrogenation unit 8 through the first pipeline 3 to supply hydrogen to the hydrogenation unit 8, and the water mist droplet catcher 16 is connected to the oxidation unit 9 through the second pipeline 4 to supply oxygen to the oxidation unit 9. The water mist droplet catcher 16 further filters the liquid in the gas produced by the electrolyzer to obtain dry gas for easy use, a part of which is supplied to the hydrogen peroxide production mechanism, and a part is stored for use.

[0030] The water mist droplet catcher 16 is also provided with an external pipeline, and the external pipeline is used to connect to an external hydrogen storage tank. The hydrogen passing through the water mist droplet catcher is transported to the hydrogen storage tank through the external pipeline for easy storage and utilization.

[0031] A system for producing hydrogen by electrolysis of water coupled with hydrogen peroxide production also includes a pure water preheating mechanism 17, the water inlet end of the pure water preheating mechanism 17 is connected to the electrolyte heat exchanger 1 through a pipeline, the water outlet end of the pure water preheating mechanism 17 is connected to the circulating cooling mechanism 2 through a pipeline, the pure water preheating mechanism 17 is used to pass the circulating water to preheat the pure water, and the pure water preheating mechanism 17 is also connected to the extraction unit 10 to supply pure water to the extraction unit. The pure water preheating mechanism heats the pure water by heat exchange with the electrolyte heat exchanger, and the heated pure water is passed into the extraction unit to facilitate the extraction of hydrogen peroxide.

[0032] A system for producing hydrogen by electrolysis of water coupled with hydrogen peroxide production further includes a water replenishment mechanism 18, wherein pure water is introduced into the inlet of the water replenishment mechanism 18, and the outlet of the water replenishment mechanism 18 is connected to the electrolytic cell 13. The water replenishment mechanism 18 mainly supplies pure water to the electrolytic cell to achieve sustainable electrolysis of water in the electrolytic cell. Specifically, the water replenishment mechanism can be a set of devices composed of a pure water tank, a pure water pump, etc., which replenish the raw water consumed by the electrolytic cell.

[0033] The hydrogenation unit comprises a hydrogen dissolving device and a reactor which are interconnected. The hydrogen dissolving device is used to mix and dissolve the working solution and hydrogen flowing out of the working liquid thermostat to obtain a hydrogen-dissolved stream. The reactor is used to catalyze the hydrogen-dissolved stream to perform a hydrogenation reaction.

[0034] The reactor includes a fixed bed reactor, a fluidized bed reactor or a tubular reactor. The specific form of the reactor can be selected according to the assembly requirements of the system, and the present application does not limit this.

[0035] The circulating water outlet of the gas cooler is connected to the circulating water inlet of the electrolyte heat exchanger; the circulating water outlet of the electrolyte heat exchanger is divided into two routes, one route is connected to the circulating water inlet of the working liquid thermostat in the hydrogen peroxide production mechanism, and the other route is connected to the circulating water inlet of the pure water preheating mechanism in the hydrogen peroxide production mechanism; the circulating cooling mechanism is connected to the circulating water inlet of the gas cooler; the working liquid thermostat and the pure water preheating mechanism are connected to the circulating cooling mechanism. The circulating water in the circulating cooling mechanism enters the gas cooler to cool down the electrolysis reaction product after the liquid is separated, and then enters the electrolyte heat exchanger to exchange heat with the electrolyte. After the electrolyte temperature decreases, it returns to the electrolytic cell to participate in the electrolysis reaction; after the circulating water temperature increases, it enters the working liquid thermostat and the pure water preheating mechanism to exchange heat with the working liquid and pure water. After the heat exchange, the circulating water enters the circulating cooling mechanism. After the heat exchange, the working liquid and pure water temperatures increase and enter the hydrogenation reactor and the extraction tower respectively.

[0036] It should be noted that, in the description of this application, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" is two or more.

[0037] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0038] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0039] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A system for producing hydrogen by electrolysis of water coupled with hydrogen peroxide production, characterized in that: It comprises an electrolytic hydrogen production mechanism, an electrolyte heat exchanger, a circulating cooling mechanism and a hydrogen peroxide production mechanism, wherein the electrolytic hydrogen production mechanism supplies hydrogen and oxygen to the hydrogen peroxide production mechanism through a first pipeline and a second pipeline respectively, and the circulating cooling mechanism sequentially connects the electrolytic hydrogen production mechanism, the electrolyte heat exchanger and the hydrogen peroxide production mechanism through a third pipeline to form a circulation loop, and the circulating water of the circulating cooling mechanism sequentially passes through the electrolytic hydrogen production mechanism, the electrolyte heat exchanger and the hydrogen peroxide production mechanism, and the electrolyte of the electrolytic hydrogen production mechanism is passed into the electrolyte heat exchanger to exchange heat with the circulating water, and the hydrogen peroxide production mechanism passes hydrogen peroxide to the circulating cooling mechanism through a fourth pipeline, and the hydrogen peroxide is used to disinfect the circulating cooling mechanism; The hydrogen peroxide production mechanism comprises a working fluid thermostat, a hydrogenation unit, an oxidation unit, a purification unit and an extraction unit connected in sequence through pipelines, the extraction unit is also connected to the working fluid thermostat through a reflux pipeline to circulate and reflux the working fluid, the outlet end of the working fluid thermostat is connected to the circulating cooling mechanism through the third pipeline, the inlet end of the working fluid thermostat is connected to the electrolyte heat exchanger through the third pipeline, the purification unit is connected to the extraction unit through a pipeline, and the purification unit is connected to the circulating cooling mechanism through the fourth pipeline to pass hydrogen peroxide into the circulating cooling mechanism; It also includes a pure water preheating mechanism, the water inlet end of the pure water preheating mechanism is connected to the electrolyte heat exchanger through a pipeline, the water outlet end of the pure water preheating mechanism is connected to the circulating cooling mechanism through a pipeline, the pure water preheating mechanism is used to pass the circulating water to preheat the pure water, and the pure water preheating mechanism is also connected to the extraction unit to supply pure water to the extraction unit.

2. The system for producing hydrogen by electrolysis of water coupled with hydrogen peroxide production as claimed in claim 1, characterized in that: The electrolytic hydrogen production mechanism includes an electrolytic cell, a gas-liquid separator and a gas cooler which are connected in sequence through pipelines. The inlet end of the gas cooler is connected to the circulating cooling mechanism through a third pipeline, and the outlet end of the gas cooler is connected to the electrolyte heat exchanger through a third pipeline. The gas-liquid separator, the electrolyte heat exchanger and the electrolytic cell are connected end to end through pipelines to circulate the electrolyte.

3. The system for producing hydrogen by electrolysis of water coupled with hydrogen peroxide production as claimed in claim 2, characterized in that: The electrolytic hydrogen production mechanism also includes a water mist droplet collector, which is connected to the gas cooler through a pipeline. The water mist droplet collector is connected to the hydrogenation unit through the first pipeline to supply hydrogen to the hydrogenation unit, and the water mist droplet collector is connected to the oxidation unit through the second pipeline to supply oxygen to the oxidation unit.

4. The system for producing hydrogen by electrolysis of water coupled with hydrogen peroxide production as claimed in claim 3, characterized in that: The water mist droplet collector is also provided with an external pipeline, and the external pipeline is used for connecting to an external hydrogen storage tank.

5. The system for producing hydrogen by electrolysis of water coupled with hydrogen peroxide production as claimed in claim 2, characterized in that: It also includes a water replenishment mechanism, wherein pure water is introduced into the inlet end of the water replenishment mechanism, and the outlet end of the water replenishment mechanism is connected to the electrolytic cell.

6. The system for producing hydrogen by electrolysis of water coupled with hydrogen peroxide production as claimed in claim 1, characterized in that: The hydrogenation unit comprises a hydrogen dissolving device and a reactor which are interconnected. The hydrogen dissolving device is used to mix and dissolve the working solution and hydrogen flowing out of the working liquid thermostat to obtain a hydrogen-dissolved stream. The reactor is used to catalyze the hydrogen-dissolved stream to perform a hydrogenation reaction.

7. The system for producing hydrogen by electrolysis of water coupled with hydrogen peroxide production as claimed in claim 6, characterized in that: The reactor includes one of a fixed bed reactor, a fluidized bed reactor or a tubular reactor.

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