Hydrogen purification system and hydrogen purification method

Abstract

This invention provides a hydrogen purification system and a hydrogen purification method. [Solution] The hydrogen purification system includes a purification device 110, a water supply device 120, and a hydrogen-containing gas supply device 130. The purification device includes an anode 114, a cathode 112, and an electrolyte membrane 116 located between the anode and the cathode. The water supply device is connected to the cathode and supplies liquid water to the cathode. The hydrogen-containing gas supply device is connected to the anode and supplies hydrogen-containing gas to the anode. During the hydrogen purification process, liquid water is continuously supplied to the cathode without interruption.

Description

[Technical Field]

[0001] This invention relates to hydrogen purification technology, and more particularly to a hydrogen purification system and a hydrogen purification method. [Background technology]

[0002] With the advancement of science and technology, achieving net-zero carbon emissions is one of the goals to be achieved in development. For this reason, hydrogen energy is considered one of the important alternative energy sources. In the semiconductor industry, the demand for high-purity hydrogen is increasing significantly with the expansion of advanced manufacturing processes. In light of this, the current research challenge is how to effectively provide high-throughput, high-recovery, and high-purity hydrogen, as well as its recovery and purification technologies. [Overview of the project] [Problems that the invention aims to solve]

[0003] The present invention provides a hydrogen purification system and a hydrogen purification method that can improve the stability of the hydrogen purification system by continuously supplying liquid water to the cathode.

[0004] The hydrogen purification system of the present invention includes a purification device, a water supply device, and a hydrogen-containing gas supply device. The purification device includes an anode, a cathode, and an electrolyte membrane located between the anode and the cathode. The water supply device is connected to the cathode and supplies liquid water to the cathode. The hydrogen-containing gas supply device is connected to the anode and supplies hydrogen-containing gas to the anode. During the hydrogen purification process, liquid water is continuously supplied to the cathode without interruption.

[0005] The hydrogen purification method of the present invention includes using the hydrogen purification system described above, starting a water supply device and supplying liquid water to the cathode, introducing a hydrogen-containing gas, and carrying out a hydrogen purification reaction. During the hydrogen purification process, liquid water is continuously supplied to the cathode without interruption. [Effects of the Invention]

[0006] Based on the above, the hydrogen purification system of the present invention includes a water supply device that is connected to the cathode and continuously supplies liquid water to the cathode without interruption. This provides the hydrogen purification system and the hydrogen purification method using the same with good hydrogen purification stability.

[0007] To further facilitate understanding of the above-mentioned features and advantages of the present invention, embodiments will be described in detail below with reference to the drawings. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram of a hydrogen purification system according to one embodiment of the present invention. [Figure 2] This is a schematic flowchart of a hydrogen purification method according to one embodiment of the present invention. [Figure 3] This shows the change in current density measured over time during the hydrogen purification period of the hydrogen purification system according to Example 1 of the present invention. [Figure 4] This shows the change in current density measured over time during the hydrogen purification period of the hydrogen purification system according to Comparative Example 1 of the present invention. [Figure 5] This shows the change in current density measured over time during the hydrogen purification period of the hydrogen purification system according to Comparative Example 2 of the present invention. [Modes for carrying out the invention]

[0009] Illustrative embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention can be carried out in many different forms and should not be construed as being limited to the embodiments described herein. For clarity, the drawings may not show the size and thickness of each component, part, and layer to the actual scale. Directional terms such as “top,” “bottom,” “front,” and “back” as used herein are used solely to refer to the directions in the accompanying drawings. Therefore, the directional terms used are used to describe and understand the present application, but not to limit it. In addition, unless otherwise stated in the specification, the term “includes” is understood to mean including the described components, but not excluding other components. For ease of understanding, the same components are referred to by the same reference numerals in the following description.

[0010] The details of implementation presented in the embodiments are for illustrative purposes only and do not reduce the scope of protection claimed by the present invention. Those skilled in the art can modify or change these implementation details as needed for actual implementation. Furthermore, descriptions of well-known devices, methods, and materials may be omitted to avoid ambiguity in the description of the principles of the present invention.

[0011] In this specification, a range may be expressed as "approximately" one specific value to "approximately" another specific value, or directly as one specific value and / or another specific value. When a range is expressed, another embodiment includes one specific value to and / or another specific value. Similarly, when "approximately" is used to indicate that a value is an approximation, it should be understood that the specific value forms another embodiment. It should be further understood that the endpoints of each range are clearly related to or unrelated to the other endpoint.

[0012] In this specification, non-restrictive terms (e.g., possible, can, for example, or other similar terms) mean implementation, inclusion, addition, or presence that is not required or optional.

[0013] In this specification, “connection” refers to direct or indirect connection. In a direct connection, two members are directly connected by physical contact, and there is no intermediate member between them. In an indirect connection, there is another suitable member between the two members, and the two members are connected to each other by an intermediate member located between them, and there does not need to be physical contact between the two members.

[0014] Unless otherwise defined, terms used herein (including technical and scientific terms) have the same meaning as those generally understood by those skilled in the art. Furthermore, terms (as defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the relevant technical context, and not as such unless explicitly defined as an idealized or overly formal meaning.

[0015] Figure 1 is a schematic diagram of a hydrogen purification system according to one embodiment of the present invention. Figure 2 is a schematic flow diagram of a hydrogen purification method according to one embodiment of the present invention.

[0016] Referring simultaneously to Figures 1 and 2, the hydrogen purification system 100 is used in step S220. The hydrogen purification system 100 includes a purification device 110, a water supply device 120, and a hydrogen-containing gas supply device 130. In this embodiment, the hydrogen purification system 100 may further include a gas-liquid separator 140, a power supply 150, an AC impedance analyzer 160, a controller 170, or other components well known to those skilled in the art, which are not described in detail here.

[0017] The purification apparatus 110 includes a cathode 112, an anode 114, and an electrolyte membrane 116.

[0018] The cathode 112 may include a cathode catalyst layer 112a and a cathode gas diffusion layer 112b. The cathode catalyst layer 112a may be in contact with the electrolyte membrane 116. For example, the cathode catalyst layer 112a may be in contact with one main surface 116a of the electrolyte membrane 116. The cathode gas diffusion layer 112b may be in contact with the cathode separator 113. By having a cathode flow path 112c between the cathode separator 113 and the cathode 112, the liquid water provided by the water supply device 120 may pass through. For example, by having a cathode inlet 113a and a cathode outlet 113b in the cathode separator 113, the liquid water provided by the water supply device 120 may penetrate from the outer surface to the inner surface of the cathode separator 113. The liquid water provided by the water supply device 120 may flow into the inner surface of the cathode separator 113 via the cathode inlet 113a of the cathode separator 113 and pass through the cathode flow path 112c, and the treated liquid water and purified hydrogen may flow out through the cathode outlet 113b of the cathode separator 113.

[0019] The material of the cathode 112 may include metal, carbon, plastic, or other suitable materials. The material of the cathode catalyst layer 112a may include platinum, platinum alloy, nickel, or other suitable materials. The material of the cathode gas diffusion layer 112b may include porous metal, carbon paper, carbon cloth, or other suitable materials. The material of the cathode separator 113 may include metal, graphite, conductive plastic, or other suitable materials. The shape of the cathode flow path 112c is not particularly limited, and an appropriate shape may be selected as needed. For example, the cathode flow path 112c may be a groove-shaped flow path formed on the cathode separator 113.

[0020] The anode 114 may include an anode catalyst layer 114a and an anode gas diffusion layer 114b. The anode catalyst layer 114a may be in contact with the electrolyte membrane 116. For example, the anode catalyst layer 114a may be in contact with the other main surface 116b of the electrolyte membrane 116. The anode gas diffusion layer 114b may be in contact with the anode separator 115. By having an anode flow path 114c between the anode separator 115 and the anode 114, the hydrogen-containing gas provided by the hydrogen-containing gas supply device 130 is passed through. For example, by having an anode inlet 115a and an anode outlet 115b in the anode separator 115, the hydrogen-containing gas provided by the hydrogen-containing gas supply device 130 can penetrate from the outer surface to the inner surface of the anode separator 115. The hydrogen-containing gas provided by the hydrogen-containing gas supply device 130 is introduced into the inner surface of the anode separator 115 via the anode inlet 115a of the anode separator 115, and the hydrogen-containing gas that has not passed through the cathode 112 is discharged through the anode outlet 115b of the anode separator 115.

[0021] The material of the anode 114 may include metal, carbon, plastic, or other suitable materials. The material of the anode catalyst layer 114a may include platinum, platinum alloy, nickel, or other suitable materials. The material of the anode gas diffusion layer 114b may include porous metal, carbon paper, carbon cloth, or other suitable materials. The material of the anode separator 115 may include metal, graphite, conductive plastic, or other suitable materials. The material of the anode 114 and the material of the cathode 112 may be the same or different. The material of the anode catalyst layer 114a and the material of the cathode catalyst layer 112a may be the same or different. The material of the anode gas diffusion layer 114b and the material of the cathode gas diffusion layer 112b may be the same or different. The material of the anode separator 115 and the material of the cathode separator 113 may be the same or different.

[0022] The shape of the anode channel 114c is not particularly limited, and an appropriate shape may be selected as needed. For example, the anode channel 114c may be a groove-shaped channel formed on the anode separator 115. The shapes of the anode channel 114c and the cathode channel 112c may be the same or different.

[0023] The electrolyte membrane 116 is located between the cathode 112 and the anode 114. The electrolyte membrane 116 may include two main surfaces 116a and 116b facing opposite directions. The main surfaces 116a and 116b may be in contact with the cathode 112 and the anode 114, respectively. In this embodiment, the main surface 116a may be in direct contact with the cathode catalyst layer 112a. The main surface 116b may be in direct contact with the anode catalyst layer 114a. The material of the electrolyte membrane 116 may include a fluorocarbon polymer, a hydrocarbon polymer, an ion exchange resin, or other suitable material.

[0024] The controller 170 may be positioned to operate the water supply device 120, the hydrogen-containing gas supply device 130, and the power supply 150. For example, the controller 170 may start supplying liquid water to the water supply device 120 connected to the cathode 112, so that the liquid water fills the cathode channel 112c. The controller 170 may start supplying hydrogen-containing gas to the hydrogen-containing gas supply device 130 connected to the anode 114, so that the hydrogen-containing gas fills the anode channel 114c. The controller 170 may start the power supply 150, so that current flows through the hydrogen purification system 100 in a predetermined direction.

[0025] Next, in step S210, the water supply device 120 of the hydrogen purification system 100 is started and liquid water is supplied to the cathode 112. The water supply device 120 is connected to the cathode 112 and supplies liquid water to the cathode 112. For example, the water supply device 120 and the cathode 112 may further include components such as a cathode flow path 112c. The connection between the water supply device 120 and the cathode 112 is made by connecting them to each other via other components. The connection between the water supply device 120 and the cathode 112 is an indirect connection. Liquid water is continuously supplied to the cathode 112 by the water supply device 120 without interruption. This allows for a continuous electrochemical hydrogen purification reaction to be carried out by continuously humidifying the hydrogen-containing gas without interruption when the hydrogen purification reaction is later performed. For example, the hydrogen purification system does not need to include a switch to control whether or not to allow liquid water to flow into the cathode. For example, the water supply device 120 may start supplying liquid water when connected to the cathode 112, and may continue to supply liquid water to the cathode 112 without interruption during the hydrogen purification reaction period.

[0026] In this embodiment, liquid water may be continuously supplied to the cathode 112 by the water supply device 120 at a temperature of 10°C to 80°C without interruption, and preferably at a temperature of 50°C to 70°C. For example, liquid water may be supplied to the cathode 112 at a fixed predetermined temperature (i.e., a constant temperature) (for example, 50°C liquid water may be supplied to the cathode 112 after being discharged by the water supply device), and then the hydrogen purification reaction may be started. The maximum predetermined hydrogen purification flow rate is 100 mL / min. Under the condition of hydrogen purification amount per L / min, liquid water may be continuously supplied to the cathode 112 at an introduction flow rate ratio of 0.067 L / min to 0.67 L / min (i.e., 6.7 mL / min to 67 mL / min in this embodiment) without interruption. For hydrogen purification amount per L / min, it is preferable that liquid water is continuously supplied to the cathode 112 at a flow rate ratio of approximately 0.5 L / min without interruption.

[0027] Subsequently, in step S220, it is confirmed that the AC impedance value of the purification device 110 of the hydrogen purification system 100 has already met the predetermined impedance conditions. For example, the power supply 150 may be configured to cause current to flow between the anode catalyst layer 114a and the cathode catalyst layer 112a of the hydrogen purification system 100 along a predetermined direction, and an AC impedance analyzer 160 may be connected to the purification device and used to measure the AC impedance value of the purification device 110. For example, the AC impedance analyzer 160 may be connected to the anode gas diffusion layer 114b and the cathode gas diffusion layer 112b to measure the AC impedance value of the purification device 110. When the AC impedance analyzer 160 is started, it can generate a current that flows between the anode gas diffusion layer 114b and the cathode gas diffusion layer 112b of the hydrogen purification system 100. At this time, the AC impedance analyzer 160 can measure the impedance value of the current, i.e., the AC impedance value.

[0028] The AC impedance value of the purification device 110 may vary depending on the material of the electrolyte membrane 116. The predetermined impedance condition may be selected appropriately depending on the material of the electrolyte membrane 116. In this embodiment, the predetermined impedance condition is that the AC impedance value of the purification device 110 is less than the purification setting impedance value. The purification setting impedance value may vary depending on the material of the electrolyte membrane 116. For example, if the material of the electrolyte membrane 116 is a fluorocarbon polymer, the purification setting impedance value is 0.001 ohms (Ω) / cm 2 ~0.002 ohms / cm 2 It may be set to 0.002 ohms / cm if the material of the electrolyte membrane 116 is a hydrocarbon polymer. 2 ~0.005 ohms / cm 2 It may be set to 0.004 ohms / cm². If the material of the electrolyte membrane 116 is ion exchange resin, the purification setting impedance value is 0.004 ohms / cm². 2 ~0.010 ohms / cm 2It may be set to this. The hydrogen-containing gas supply device 130 may be started when the predetermined impedance conditions are met.

[0029] Subsequently, in step S230, the hydrogen-containing gas supply device 130 of the hydrogen purification system 100 is started and hydrogen-containing gas is supplied to the anode 114. The hydrogen-containing gas supply device 130 supplies hydrogen-containing gas to the anode 114 by being connected to the anode 114. For example, the hydrogen-containing gas supply device 130 and the anode 114 further include components such as an anode flow path 114c. The connection between the hydrogen-containing gas supply device 130 and the anode 114 is made by connecting them to each other via other components. The connection between the hydrogen-containing gas supply device 130 and the anode 114 is indirect. The hydrogen-containing gas may be a mixed gas. Specifically, the hydrogen-containing gas must contain hydrogen and may further contain nitrogen, carbon dioxide, water vapor, or other gases.

[0030] Next, in step S240, a hydrogen purification reaction is performed to remove non-hydrogen gases from the hydrogen-containing gas and increase the hydrogen concentration. During the hydrogen purification reaction, hydrogen is produced at the cathode 112. The purified hydrogen, along with the liquid water remaining after the hydrogen purification reaction (abbreviated as "treated liquid water"), flows out through the cathode outlet 113b of the cathode separator 113.

[0031] The purified hydrogen and treated liquid water may further pass through a gas-liquid separator 140. The gas-liquid separator 140 separates the treated liquid water and purified hydrogen that have flowed out from the cathode outlet 113b of the cathode separator 113. The purified hydrogen discharged from the gas-liquid separator 140 may be released into a purified hydrogen discharge path 180 and collected.

[0032] In this embodiment, the treated liquid water that flows out from the cathode outlet 113b of the cathode separator 113 may flow to the water supply device 120 after passing through the gas-liquid separator 140 and then flow back into the cathode inlet 113a of the cathode separator 113. As a result, the treated liquid water that flows back into the cathode 112 through the cathode inlet 113a of the cathode separator 113 can be reused repeatedly and circulated. However, the present invention is not limited thereto. In other embodiments, the treated liquid water that flows out from the cathode outlet 113b of the cathode separator 113 may be discharged directly from the hydrogen purification system 100 without passing through the gas-liquid separator 140, or it may be discharged from the hydrogen purification system 100 after passing through the gas-liquid separator 140. The treated liquid water that flows out from the cathode inlet 113b of the cathode separator 113 may be discharged from the hydrogen purification system 100 and may not be reused. Example 1

[0033] The active area of ​​the purification apparatus in the hydrogen purification system used in Example 1 is 12.25 cm². 2 Furthermore, the operating temperature of the purification apparatus was set to 50°C. A hydrogen-containing gas at room temperature (a mixture of hydrogen and nitrogen, with a hydrogen introduction flow rate of 100 mL / min and a nitrogen introduction flow rate of 100 mL / min) was introduced to the anode, and liquid water at room temperature was introduced to the cathode (the water introduction flow rate under the condition of hydrogen purification amount per 1 L / min may be set to 0.067 L / min to 0.67 L / min, and in this embodiment, the introduction flow rate was set to 10 mL / min). The hydrogen purification reaction was carried out continuously for 20 hours under the condition of an applied voltage of 0.08 V. The results showed that the current was stable during the purification period and no current decay was observed (illustrated in Figure 3). Comparative Example 1

[0034] The active area of ​​the purification apparatus in the hydrogen purification system used in Comparative Example 1 is 12.25 cm². 2The operating temperature of the purification device was set to 50°C. A hydrogen-containing gas at room temperature (a mixed gas of hydrogen and nitrogen, with the introduced flow rate of hydrogen being 100 mL / min and the introduced flow rate of nitrogen being 100 mL / min) was introduced into the anode, and steam with a relative humidity of 100% was introduced from the anode inlet to humidify the interface of the hydrogen purification reaction. Under the condition that the applied voltage was 0.08 V, a hydrogen purification reaction was continuously carried out for 4 hours. The results showed that during the purification reaction process in the purification period, protons were transported to the cathode in the form of hydronium ions and reduced to hydrogen, moisture was discharged from the cathode, and the humidifying gas with a relative humidity of 100% could no longer maintain the wettability required by the reaction interface, indicating that the humidity was insufficient and the purification reaction became unstable (illustrated in Figure 4). Comparative Example 2

[0035] The active area of the purification device of the hydrogen purification reaction system used in Comparative Example 2 was 12.25 cm 2 The operating temperature of the purification device was set to 50°C. A hydrogen-containing gas at room temperature (a mixed gas of hydrogen and nitrogen, with the introduced flow rate of hydrogen being 100 mL / min and the introduced flow rate of nitrogen being 100 mL / min) was introduced into the anode, and steam with a relative humidity of 100% was introduced from the anode inlet to humidify the interface of the hydrogen purification reaction. Under the condition that the applied voltage was 0.08 V, a hydrogen purification reaction was continuously carried out for 2 hours. The results showed that the initial value of the purification current was higher than that in Comparative Example 1, indicating that the humidifying gas with a relative humidity higher than 100% could relatively maintain the wettability required by the reaction interface. However, due to being placed in a highly humid environment, condensed water was generated, increasing the impedance at the moment of drainage and causing the instantaneous current to jump up (illustrated in Figure 5). Also, the results showed that the operation in a highly humid state over a long time caused problems such as local flooding, reducing the purification current, and the above-mentioned factors accelerated the deterioration of the materials, indicating that it was not suitable for actual applications.

[0036] In summary, the hydrogen purification system of the present invention includes a water supply device connected to the cathode and continuously supplying liquid water to the cathode without interruption. As a result, the hydrogen purification system and the hydrogen purification method using the same can perform a continuous hydrogen purification reaction while executing the hydrogen purification reaction, and the stability and applicability of the reaction process can be improved.

[0037] Although the present invention has been disclosed above by embodiments, these are not intended to limit the present invention, and those skilled in the art can make several modifications and changes without departing from the spirit and scope of the invention, and therefore the scope of protection of the present invention is defined by the appended claims. [Industrial applicability]

[0038] The hydrogen purification system and hydrogen purification method of the present invention can be applied to the manufacturing processes of the semiconductor industry. [Explanation of symbols]

[0039] 100: Hydrogen purification system 110: Refined equipment 112: Cathode 112a: Cathode catalyst layer 112b: Cathode gas diffusion layer 112c: Cathode channel 113: Cathode separator 113a: Cathode inlet 113b: Cathode outlet 114: Anode 114a: Anode catalyst layer 114b: Anode gas diffusion layer 114c:Anode channel 115: Anode separator 115a:Anode inlet 115b: Anode outlet 116: Electrolyte membrane 116a, 116b: Main surface 120: Water supply device 130: Hydrogen-containing gas supply equipment 140: Gas-liquid separation equipment 150: Power supply 160: AC Impedance Analyzer 170: Controller 180: Purified hydrogen release pathway S200, S210, S220, S230, S240: Step

Claims

1. A purification apparatus comprising an anode, a cathode, and an electrolyte membrane located between the anode and the cathode, A water supply device connected to the cathode and supplying liquid water to the cathode, A hydrogen-containing gas supply device is connected to the anode to supply hydrogen-containing gas to the anode. Includes, During the hydrogen purification process, the liquid water is continuously supplied to the cathode without interruption. Hydrogen purification system.

2. The aforementioned liquid water is continuously supplied to the cathode without interruption at a temperature of 10°C to 80°C. The hydrogen purification system according to claim 1.

3. Under the condition of a hydrogen purification rate of 1 L / min, the liquid water is continuously supplied to the cathode at a flow rate of 0.067 L / min to 0.67 L / min without interruption. The hydrogen purification system according to claim 1.

4. The cathode comprises a cathode catalyst layer and a cathode gas diffusion layer, the cathode catalyst layer is in contact with the electrolyte membrane, and the cathode gas diffusion layer is in contact with the cathode separator. A cathode channel is provided between the cathode separator and the cathode. The liquid water flows in through the cathode inlet of the cathode separator, and after passing through the cathode channel, the liquid water and purified hydrogen are discharged from the cathode outlet of the cathode separator. The hydrogen purification system according to claim 1.

5. By further including a gas-liquid separation device, the liquid water and the purified hydrogen that flow out from the cathode outlet of the cathode separator are separated. The hydrogen purification system according to claim 4.

6. Gas-liquid separator It further includes, The liquid water that flows out from the cathode outlet of the cathode separator passes through the gas-liquid separator, then flows to the water supply device and flows back into the cathode inlet of the cathode separator. The hydrogen purification system according to claim 4.

7. The anode includes an anode catalyst layer and an anode gas diffusion layer, the anode catalyst layer is in contact with the electrolyte membrane, and the anode gas diffusion layer is in contact with the anode separator. There is an anode channel between the anode separator and the anode. The hydrogen-containing gas is introduced through the anode inlet of the anode separator, and after passing through the anode flow path, the hydrogen-containing gas that has not passed through the cathode is discharged through the anode outlet of the anode separator. The hydrogen purification system according to claim 1.

8. The system further includes an AC impedance analyzer connected to the purification apparatus, which measures the AC impedance value of the purification apparatus. The hydrogen purification system according to claim 1.

9. Using the hydrogen purification system described in any one of claims 1 to 8, The water supply device is started to supply the liquid water to the cathode, Introducing the aforementioned hydrogen-containing gas To carry out the hydrogen purification reaction and Includes, During the hydrogen purification process, the liquid water is continuously supplied to the cathode without interruption. Hydrogen purification method.

10. After the supply of the liquid water is started, it is first determined whether the AC impedance value of the purification device has already met the predetermined impedance conditions, and then the hydrogen-containing gas is introduced. The hydrogen purification method according to claim 9.

11. The predetermined impedance condition is that the AC impedance value of the purification apparatus is less than the set impedance value for purification. The hydrogen purification method according to claim 10.

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