CN115652347A - A self-heating equilibrium electrolysis water hydrogen production system and hydrogen production method - Google Patents

Abstract

The invention provides a self-heating balance water electrolysis hydrogen production system and a hydrogen production method, and belongs to the field of water electrolysis hydrogen production. The system comprises an electrolysis device and a gas post-treatment device which are connected with each other, wherein the gas post-treatment device is provided with a liquid loop, and the liquid loop is communicated with the electrolysis device through a pump. The method comprises the steps that the electrolysis device is electrolyzed under the direct current action with the cell voltage of 1-3V to prepare hydrogen and oxygen, and the temperature of electrolyte in the electrolysis device is kept at 100-160 ℃ by utilizing heat generated in the self work; the working pressure is 1.0-3.5MPa; the invention optimizes the whole process, recycles the heat dissipation of the electrolytic cell and the heat exchange of the alkali liquor cooler on the premise of canceling the alkali liquor cooling system, realizes the self-heating balance of the electrolytic system, reduces the energy loss, improves the working temperature of the electrolytic cell, can effectively reduce the electrolytic voltage, improves the current density of the electrolytic cell, reduces the volume of the electrolytic cell and reduces the whole energy consumption in the operation process of the electrolytic cell.

Description

A self-heating equilibrium electrolysis water hydrogen production system and hydrogen production method

technical field

The invention relates to the field of hydrogen production by electrolysis of water, in particular to a self-heating equilibrium electrolysis water hydrogen production system and a hydrogen production method.

Background technique

As the environmental problems faced by human beings continue to intensify, fossil energy has to quickly turn to "clean, low-carbon, safe, and efficient" renewable energy. Hydrogen energy is by far the most ideal clean energy. Currently, the hydrogen production method commonly used in industry There are methanol conversion hydrogen production, natural gas conversion hydrogen production, coal gasification hydrogen production, ammonia cracking hydrogen production, etc., all of which are non-renewable processes. There are consumption of fossil resources and _CO2 emissions, which do not conform to the concept of low-carbon industry. The use of water electrolysis to produce hydrogen is a clean and renewable process that does not consume fossil resources and produces hydrogen and oxygen without burdening the environment.

As far as the current technology is concerned, according to the type of electrolyte used, hydrogen production by electrolysis of water can be divided into hydrogen production by alkaline water electrolysis (AWE), hydrogen production by proton exchange membrane water electrolysis (PEM), and hydrogen production by solid oxide water electrolysis (SOEC). and anion exchange membrane water electrolysis hydrogen production (AEM) four categories. Among them, AWE is the earliest industrial water electrolysis technology, with decades of application experience, and is currently the most mature industrial hydrogen production technology by electrolysis of water; the electrolysis efficiency of proton exchange membrane electrolysis water technology is high, and the volume of electrolytic cell is small, which can adapt to dynamic operation, but due to the use of precious metals, the cost of equipment is high, and it is currently unable to achieve large-scale industrialization; the reaction temperature of solid oxide electrolysis of water for hydrogen production is high, and the temperature resistance of materials is demanding, and it is still in the laboratory research stage; anion exchange membrane Hydrogen production by electrolysis of water uses transition metals instead of noble metal catalysts, which reduces costs, has stable performance, and has broad development prospects. It is currently in the laboratory research stage.

The existing industrial alkaline water electrolysis hydrogen production system is generally composed of an electrolyzer and a post-processing frame. The working temperature of the industrial electrolyzer is generally 85°C-95°C, and the polyphenylene sulfide diaphragm is often used to meet the needs of industrial production. Its high temperature resistance is poor, and the working temperature cannot exceed 100°C. It is easy to break down and rupture when working at high temperature, resulting in the danger of hydrogen and oxygen cross gas.

In addition, the heat released during the operation of industrialized electrolyzers includes heat Q ₁ taken away by water vapor, heat Q ₂ absorbed by supplementary water, heat Q ₃ taken away by hydrogen and oxygen, heat Q ₄ taken away by cooling water, and electrolysis The heat dissipation loss Q ₅ of the equipment, the heat Q ₄ taken away by the cooling water during operation mainly includes the heat exchange of the hydrogen-oxygen cooler and the heat exchange of the lye circulation system, the temperature of the lye in the electrolytic cell is mainly regulated by the cooling water, through Control the flow of cooling water to control the temperature of the lye. It is possible to make rational use of these wasted heat if the working temperature of the electrolyzer is increased. In the prior art, the diaphragm is modified to produce a high temperature resistant composite diaphragm for alkaline water electrolysis, made of polyphenylene sulfide, polysulfone, polyether ether ketone, polypropylene, styrene-CO-propylene Nitrile, etc. are used as supporting structures, and its hydrophilicity and high temperature resistance are improved by adding SiO ₂ , Al ₂ O ₃ , Mg(OH) ₂ , dimethyl sulfoxide, zirconium hydroxide, phosphorus pentoxide, potassium titanate, etc. The modified composite diaphragm can work stably at a high temperature of 220°C to ensure gas purity. This makes it possible to increase the working temperature of the electrolyzer.

Under ideal conditions, if Q ₄ ＝Q ₅ ＝0, the thermal efficiency reaches the maximum at this time. Considering the stable operation of the post-processing system, the heat transfer capacity of the hydrogen-oxygen cooler must be guaranteed. How to rationally recycle Q ₄ through overall process adjustment The heat used for the heat exchange of the lye system and the heat dissipation of the electrolysis equipment, increasing the electrolysis temperature to effectively reduce the electrolysis voltage, and reducing the overall energy consumption in the electrolysis process are technical problems that need to be solved.

In view of this, this application is proposed.

Contents of the invention

The purpose of the present invention is to provide a hydrogen production system and method for self-heating equilibrium electrolysis of water, which can realize rational utilization of heat, improve energy conversion efficiency, and reduce electrolysis without changing the existing industrialized electrolyte and electrode system. Voltage.

For realizing above object, technical scheme of the present invention is as follows:

A self-heating balance electrolysis water hydrogen production system, comprising interconnected electrolysis device and gas post-processing device, the gas post-processing device is provided with a liquid circuit, the liquid circuit communicates with the electrolysis device through a pump, and the liquid circuit No cooling system is provided.

Optionally, an electrolyte supply device is connected upstream of the electrolysis device, and the liquid circuit is connected to the electrolysis device in parallel with the electrolyte supply device. The electrolyte supply device supplies electrolyte to enter the electrolysis device when the liquid circuit cannot meet the needs of the electrolysis process.

Further, the gas post-processing device includes a hydrogen separator and an oxygen separator respectively connected to the electrolysis device.

Further, the hydrogen separator and the oxygen separator are respectively connected to the electrolysis device through the liquid circuit.

Preferably, the outer periphery of the electrolysis device is wrapped with an insulating layer to avoid heat loss during the electrolysis process.

Preferably, a hydrogen cooler is connected downstream of the hydrogen separator, and an oxygen cooler is connected downstream of the oxygen separator. More preferably, the hydrogen cooler and the oxygen cooler are provided with a circulation cooling device on the outer periphery.

Further, a hydrogen storage tank is connected downstream of the hydrogen cooler, and an oxygen storage tank is connected downstream of the oxygen cooler.

The present invention also provides a hydrogen production method using the self-heating equilibrium electrolysis water hydrogen production system: the electrolysis device electrolyzes hydrogen and oxygen under the action of a direct current with a voltage of 1-3V, and the electrolysis obtains a gas-liquid mixture After entering the hydrogen separator and oxygen separator, hydrogen and oxygen are separated, and the rest of the liquid enters the electrolysis device through the liquid circuit for recycling.

Preferably, the heat generated by the electrolysis itself is maintained by the insulation layer to heat the circulating return liquid flowing into the electrolysis device in the liquid circuit, and due to the high temperature resistance of the electrolysis device and the diaphragm material, no cooling system is required.

Further, the working temperature of the electrolyte in the electrolysis device is 100-160° C., and the working pressure is 1.0-3.5 MPa.

Compared with the prior art, the self-heating balance electrolyzed water hydrogen production system of the present invention reduces the electrolyte cooling system, and sets the insulation layer of the electrolysis device, which realizes the rational utilization of the heat of the electrolysis reaction itself, without changing the existing industrial electrolysis In the case of liquid and electrode systems, the energy conversion efficiency is improved, and the electrolysis voltage is also reduced.

The electrode, diaphragm and other materials in this system are all existing commercial products without special modified materials. Only through the optimization of the overall process system, the self-heating balance has been realized, the energy loss has been reduced, the working temperature has been increased, and the temperature has been effectively reduced. The electrolysis voltage is improved, thereby increasing the current density, reducing the overall energy consumption of the electrolysis process, and reducing the volume of the electrolytic cell; at the same time, the equipment investment of the cooling system is reduced, and the equipment cost is reduced.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and thus should be considered as limiting the scope of the invention.

Figure 1 is a schematic structural view of the self-heating equilibrium electrolysis water hydrogen production system of the present invention.

Explanation of reference signs:

1-electrolyzer; 2-insulation layer; 3-liquid circuit; 4-hydrogen separator; 5-oxygen separator; 6-hydrogen cooler; 7-oxygen cooler; 8-circulating cooling water system.

Detailed ways

As used herein:

"Prepared from" is synonymous with "comprising". As used herein, the terms "comprises," "including," "has," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, step, method, article, or device comprising listed elements is not necessarily limited to those elements, but may include other elements not explicitly listed or inherent to such composition, step, method, article, or device. elements.

When amounts, concentrations, or other values or parameters are expressed in terms of ranges, preferred ranges, or ranges bounded by a series of upper preferred values and lower preferred values, it is to be understood that any range upper or preferred value combined with any lower range limit is specifically disclosed. All ranges formed by any pairing of values or preferred values, whether or not such ranges are individually disclosed. For example, when the range "1-5" is disclosed, the described range should be construed to include the ranges "1-4", "1-3", "1-2", "1-2 and 4-5" , "1 ~ 3 and 5" and so on. When a numerical range is described herein, unless otherwise stated, that range is intended to include its endpoints and all integers and fractions within the range.

"And/or" is used to indicate that one or both of the stated situations may occur, for example, A and/or B includes (A and B) and (A or B).

The technical solutions of the present invention will be described in detail below in conjunction with specific examples, but those skilled in the art will understand that the following examples are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Those who do not indicate the specific conditions in the examples are carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments used were not indicated by the manufacturer, and they were all conventional products that could be purchased from the market.

Example 1

A self-thermal balance electrolysis water hydrogen production system, as shown in Figure 1, includes an electrolyzer 1 and a gas post-processing device connected to each other, the gas post-processing device is provided with a liquid circuit 3, and the liquid circuit 3 and the electrolyzer 1 are pumped Connected and no cooling system is set on the liquid circuit 3. The gas post-treatment device includes a hydrogen separator 4 and an oxygen separator 5 respectively connected to the electrolysis device. The hydrogen separator 4 and the oxygen separator 5 are respectively connected to the electrolytic cell 1 through the liquid circuit 3 . The outer periphery of the electrolytic cell 1 is wrapped with an insulating layer 2 to avoid heat loss during the electrolysis process.

A hydrogen cooler 6 is connected downstream of the hydrogen separator 4 , and an oxygen cooler 7 is connected downstream of the oxygen separator 5 . The hydrogen cooler 6 and the oxygen cooler 7 are provided with a circulating cooling device 8 for cooling the hydrogen and oxygen.

In a preferred embodiment, an electrolyte supply device may also be connected upstream of the electrolytic cell 1 , and the liquid circuit 3 is connected to the electrolytic cell 1 in parallel with the electrolyte supply device. When the liquid circuit 3 cannot meet the needs of the electrolysis process, the electrolyte supply device supplies electrolyte to enter the electrolytic cell 1 .

In other embodiments, the hydrogen storage tank may be connected downstream of the hydrogen cooler 6 , and the oxygen storage tank may be connected downstream of the oxygen cooler 7 .

The hydrogen production process is as follows: 30% potassium hydroxide solution is passed into the electrolytic cell 1, and the DC power supply is connected to start electrolysis. Under the action of direct current, hydrogen and oxygen are produced by electrolysis. The liquid separated in the hydrogen separator 4 and the oxygen separator 5 enters the electrolytic cell 1 for recycling through the liquid circuit 3 . Under the insulation effect of the insulation layer 2, the heat generated by the electrolysis reaction itself heats the electrolyte entering the electrolytic cell 1 to achieve its own thermal balance. The temperature in the electrolytic cell 1 is 110°C; the working pressure is 1.95MPa. It is measured that the chamber voltage is 1.9V, the current density is 7273A/m ² , and the energy consumption is 4.6kWh/Nm ³ .

The hydrogen and oxygen separated from the hydrogen separator 4 and the oxygen separator 5 enter the hydrogen cooler 6 and the oxygen cooler 7 respectively, and are cooled by the circulating cooling device 8 before being used.

Example 2

The electrolysis system is the same as in Example 1. The hydrogen production process is as follows: 30% potassium hydroxide solution is passed into the electrolytic cell 1, and the DC power supply is connected to start electrolysis. Under the action of direct current, hydrogen and oxygen are produced by electrolysis. The liquid separated in the hydrogen separator 4 and the oxygen separator 5 enters the electrolytic cell 1 for recycling through the liquid circuit 3 . Under the heat preservation effect of the insulation layer 2, the heat generated by the electrolysis reaction itself heats the electrolyte entering the electrolytic cell 1 to achieve its own thermal balance. The temperature in the electrolytic cell 1 is 120 ° C; the working pressure is 2.5 MPa. It is measured that the chamber voltage is 1.9V, the current density is 8333A/m ² , and the energy consumption is 4.5kWh/Nm ³ . All the other processes are the same as in Example 1.

Example 3

The electrolysis system is the same as in Example 1. The hydrogen production process is as follows: 30% potassium hydroxide solution is passed into the electrolytic cell 1, and the DC power supply is connected to start electrolysis. Under the action of direct current, hydrogen and oxygen are produced by electrolysis. The liquid separated in the hydrogen separator 4 and the oxygen separator 5 enters the electrolytic cell 1 for recycling through the liquid circuit 3 . Under the heat preservation effect of the insulation layer 2, the heat generated by the electrolysis reaction itself heats the electrolyte entering the electrolytic cell 1 to achieve its own thermal balance. The temperature in the electrolytic cell 1 is 140°C; the working pressure is 2.97MPa. It is measured that the chamber voltage is 1.88V, the current density is 9045A/m ² , and the energy consumption is 4.5kWh/Nm ³ .

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the various embodiments of the present invention. scope.

Furthermore, those skilled in the art will understand that although some embodiments herein include some features included in other embodiments but not others, combinations of features from different embodiments are meant to be within the scope of the invention. And form different embodiments. For example, in the following claims, any one of the claimed embodiments may be used in any combination. The information disclosed in this Background section is only intended to enhance the understanding of the general background of the present invention, and should not be considered as an acknowledgment or any form of suggestion that the information constitutes the prior art that is already known to those skilled in the art.

Claims (10)

1. The utility model provides a system for producing hydrogen from self-heating balanced electrolytic water, includes electrolytic device and gaseous aftertreatment device interconnect, its characterized in that: the gas post-treatment device is provided with a liquid loop, the liquid loop is communicated with the electrolysis device through a pump, and the liquid loop is not provided with a cooling system.

2. The system for autothermal equilibrium electrolytic water hydrogen production of claim 1, wherein the gas post-treatment device comprises a hydrogen separator and an oxygen separator connected to the electrolyzer, respectively.

3. The system for autothermal equilibrium electrolytic water hydrogen production of claim 2, wherein the hydrogen separator and oxygen separator are each connected to the electrolyzer via the liquid loop.

4. The system for self-heating equilibrium electrolytic water hydrogen production according to any one of claims 1 to 3, wherein the electrolysis device is wrapped with an insulating layer.

5. The system for autothermal equilibrium electrolytic water hydrogen production of claim 4, wherein a hydrogen cooler is connected downstream of the hydrogen separator, and an oxygen cooler is connected downstream of the oxygen separator.

6. The system for self-heating equilibrium electrolytic water hydrogen production according to claim 5, wherein the hydrogen cooler and the oxygen cooler are provided with circulating cooling means around their peripheries.

7. The system for autothermal equilibrium electrolytic water hydrogen production of claim 1, wherein an electrolyte supply is further coupled upstream of the electrolyzer, and the liquid loop is coupled to the electrolyzer in parallel with the electrolyte supply.

8. A method for producing hydrogen by using the self-heating balance water electrolysis hydrogen production system as claimed in any one of claims 1 to 9, wherein the electrolysis device is used for electrolyzing hydrogen and oxygen under the action of direct current with the cell voltage of 1-3V, a gas-liquid mixture obtained by electrolysis enters the hydrogen separator and the oxygen separator, hydrogen and oxygen are separated, and the rest liquid enters the electrolysis device through the liquid loop for recycling.

9. The method for producing hydrogen of claim 8 wherein the heat generated by electrolysis heats a recirculating liquid in the liquid loop flowing into the electrolyzer while maintained by a thermal insulator.

10. The method for producing hydrogen according to claim 8 or 9, wherein the operating temperature of the electrolyte in the electrolysis apparatus is 100 to 160 ℃ and the operating pressure is 1.0 to 3.5MPa.

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