Method for manufacturing neon and apparatus for manufacturing neon

Abstract

A method is provided for manufacturing neon from a raw material mixed gas containing neon, helium, hydrogen, and nitrogen, which reduces the load on an adsorption tower and enables the efficient production of neon. A method for manufacturing neon from a raw material mixed gas containing neon, helium, hydrogen, and nitrogen comprises: a hydrogen gas conversion process in which hydrogen gas is converted into water by contacting the raw material mixed gas and an oxygen-containing gas with a catalyst; a moisture removal process in which water is removed from the gas obtained through the hydrogen gas conversion process; a first nitrogen rectification separation process in which nitrogen is removed by rectifying the gas obtained through the moisture removal process; an impurity gas adsorption separation process in which nitrogen is removed by contacting the gas obtained through the first nitrogen rectification separation process with an adsorbent; and a helium rectification separation process in which helium gas is removed by rectifying the gas obtained through the impurity gas adsorption separation process.

Description

Technology Field

[0001] The present invention relates to a method for manufacturing neon and an apparatus for manufacturing neon. Background Technology

[0002] Neon is used as a discharge sealing gas for fluorescent lamps, etc., or for applications such as lasers related to semiconductors or liquid crystals.

[0003] Neon is present in the air at a concentration of approximately 18 ppm and can be produced by separating it from the gas remaining when oxygen, nitrogen, argon, etc., are separated from raw air using an Air Separation Unit (ASU) (hereinafter referred to as "residual gas"). When raw air is liquefied and distilled to produce oxygen, nitrogen, argon, etc., helium, neon, hydrogen, and other substances with boiling points lower than nitrogen are released from the top of the lower rectification column as uncondensed residual gases. This release is sometimes called helium removal. Since the residual gas released by helium removal contains neon, neon can be produced by separating it from the residual gas. In addition to neon, the residual gas contains helium and hydrogen, but nitrogen is also mixed in. In the production of neon, it is important to determine how to remove nitrogen before the neon is purified.

[0004] As a method for producing neon from residual gas, the technology described in Non-Patent Document 1 and Patent Document 1 is known. Non-Patent Document 1 describes a method of producing neon by rectifying residual gas in a rectification column to reduce the nitrogen concentration to 33%, then removing hydrogen by contacting hydrogen and oxygen with a catalyst, followed by performing low-temperature adsorption twice, and finally purifying the gas. Patent Document 1 describes a method for producing neon and helium comprising a process of removing most of the nitrogen from residual gas by condensation separation operation, a process of removing residual nitrogen by a room-temperature pressure swing adsorption method using synthetic zeolite, and a process of separating neon and helium by removing hydrogen by a low-temperature pressure swing adsorption method at -100°C or lower using activated carbon. Prior art literature

[0005] Japanese Patent No. 3268177

[0006] WH Isalski, 「Separation of Gases」 (Monographs on cryogenics. 5), Clarendon Press, 1989, p.100-101 The problem to be solved

[0007] In Non-Patent Literature 1, liquid hydrogen is used as a refrigerant for the final purification of neon. However, since the temperature of liquid hydrogen is -259.2°C to -253°C and the solidification temperature of nitrogen is -210°C, if the gas used for final purification contains nitrogen, the nitrogen solidifies during the final purification process and clogs the piping, etc. Therefore, in Non-Patent Literature 1, it is necessary to perform low-temperature adsorption twice before the final purification process in order to remove nitrogen as much as possible. Patent Literature 1 uses a combination of a room-temperature pressure-switching adsorption tower equipped with synthetic zeolite and a low-temperature pressure-switching adsorption tower equipped with activated carbon that operates at -100°C or lower. In operating such an adsorption tower, it is necessary to regenerate the adsorbent by desorbing the gas adsorbed by the adsorbent equipped in the adsorption tower from the adsorbent. Therefore, to ensure continuous operation, it is necessary to arrange multiple adsorption towers, adsorbing a specific gas in one tower while desorbing the adsorbed gas in another. Furthermore, as the types and quantities of gases removed by adsorption increase, the load on the towers rises; consequently, it is necessary to shorten the operating time of the towers to repeatedly switch between adsorption and regeneration. Alternatively, it is necessary to increase the number of adsorption towers or enlarge them to enhance processing capacity.

[0008] The problem that the present invention aims to solve is to provide a method for efficiently manufacturing neon by reducing the load on the adsorption tower in the production of neon from a raw material mixed gas comprising neon, helium, hydrogen, and nitrogen. Another problem addressed by the method of the present invention is to provide an apparatus capable of efficiently manufacturing neon. means of solving the problem

[0009] The present invention is as follows.

[0010] [1] A method for producing neon from a raw material mixed gas containing neon, helium, hydrogen, and nitrogen, comprising: a hydrogen gas conversion process in which hydrogen gas is converted into water by contacting the raw material mixed gas and the oxygen-containing gas with a catalyst; a water removal process in which water is removed from the gas obtained through the hydrogen gas conversion process; a first nitrogen rectification separation process in which nitrogen is removed by rectifying the gas obtained through the water removal process; an impurity gas adsorption separation process in which impurity gas is removed by contacting the gas obtained through the first nitrogen rectification separation process with an adsorbent; and a helium rectification separation process in which helium gas is removed by rectifying the gas obtained through the impurity gas adsorption separation process.

[0011] [2] A method for manufacturing the above [1], wherein between the first nitrogen rectification separation process and the impurity gas adsorption separation process, the gas obtained through the first nitrogen rectification separation process is heat-exchanged with a refrigerant at -196°C to -210°C, and then gas is separated by gas-liquid separation, and in the impurity gas adsorption separation process, the gas obtained through the gas separation process is brought into contact with an adsorbent.

[0012] [3] In the above [2], the impurity gas adsorption separation process is a manufacturing method for removing impurity gas by a temperature swing adsorption method at -100°C or lower.

[0013] [4] A method for manufacturing the above [1], wherein between the impurity gas adsorption separation process and the helium rectification separation process, a second nitrogen rectification separation process is included to remove nitrogen by rectifying the gas obtained through the impurity gas adsorption separation process, and in the helium rectification separation process, the gas obtained through the second nitrogen rectification separation process is rectified to remove helium gas.

[0014] [5] In the above [4], the impurity gas adsorption separation process is a manufacturing method that removes impurity gas by pressure swing adsorption at room temperature.

[0015] [6] A manufacturing method comprising, in any one of [1] to [5] above, a raw material mixed gas further comprising carbon monoxide, and a carbon monoxide conversion process for converting the carbon monoxide contained in the raw material mixed gas into carbon dioxide.

[0016] [7] A method of manufacturing comprising, in any one of [1] to [5] above, a raw material mixed gas further comprising carbon monoxide, a carbon monoxide conversion process for converting carbon monoxide contained in the raw material mixed gas into carbon dioxide, and a carbon dioxide removal process for removing carbon dioxide from the gas obtained through the carbon monoxide conversion process.

[0017] [8] A device for manufacturing neon from a raw material mixed gas containing neon, helium, hydrogen, and nitrogen, comprising a catalytic tower having a catalyst that contacts the raw material mixed gas and the oxygen-containing gas, a water removal facility that removes water contained in the gas from the catalytic tower, a first nitrogen removal rectification tower that rectifies the gas from the water removal facility to remove nitrogen, a heat exchanger that exchanges heat between the gas from the first nitrogen removal rectification tower and a refrigerant at -196°C to -210°C, a gas-liquid separator that separates the fluid from the heat exchanger into gas and liquid, a temperature swing adsorption tower that adsorbs impurity gas contained in the gas from the gas-liquid separator by a temperature swing adsorption method, and a neon purification rectification tower that rectifies the gas from the temperature swing adsorption tower to remove helium gas and purify neon.

[0018] [9] A device for manufacturing neon from a raw material mixed gas containing neon, helium, hydrogen, and nitrogen, comprising a catalytic tower having a catalyst that contacts the raw material mixed gas and an oxygen-containing gas, a water removal facility that removes water contained in the gas from the catalytic tower, a first nitrogen removal rectification tower that rectifies the gas from the water removal facility to remove nitrogen, a pressure swing adsorption tower that adsorbs impurity gas contained in the gas from the first nitrogen removal rectification tower by pressure swing adsorption, a second nitrogen removal rectification tower that rectifies the gas from the pressure swing adsorption tower to remove nitrogen, and a neon purification rectification tower that rectifies the gas from the second nitrogen removal rectification tower to remove helium gas and purify neon.

[0019]

[10] In the above [8] or [9], the raw material mixed gas further comprises carbon monoxide, and the manufacturing apparatus comprises a second catalyst tower having a catalyst to which the raw material mixed gas contacts.

[0020]

[11] In the above [8] or [9], the raw material mixed gas further comprises carbon monoxide, and the manufacturing apparatus comprises a second catalytic tower having a catalyst to which the raw material mixed gas contacts, and a carbon dioxide removal facility for removing carbon dioxide contained in the gas from the second catalytic tower. Effects of the invention

[0021] According to the neon manufacturing method of the present invention, when manufacturing neon from a raw material mixed gas comprising neon, helium, hydrogen, and nitrogen, the load on the adsorption tower can be reduced and neon can be manufactured efficiently. According to the neon manufacturing apparatus of the present invention, neon can be manufactured efficiently. Brief explanation of the drawing

[0022] FIG. 1 is a schematic diagram illustrating Example 1 of a neon manufacturing apparatus according to the present invention. FIG. 2 is a schematic diagram illustrating Example 2 of a neon manufacturing apparatus according to the present invention. Specific details for implementing the invention

[0023] The present invention will be described in detail below based on examples, but the present invention is not limited to the following examples, and modifications may be made within a scope suitable for the purpose of the above and subsequent descriptions, and all such modifications are included within the technical scope of the present invention.

[0024] The method for manufacturing neon according to the present invention is a method for manufacturing neon from a raw material mixed gas comprising neon, helium, hydrogen, and nitrogen, comprising: a hydrogen gas conversion process in which hydrogen gas is converted into water by contacting the raw material mixed gas and an oxygen-containing gas with a catalyst; a moisture removal process in which water is removed from the gas obtained through the hydrogen gas conversion process; a first nitrogen rectification separation process in which nitrogen is removed by rectifying the gas obtained through the moisture removal process; an impurity gas adsorption separation process in which impurity gas is removed by contacting the gas obtained through the first nitrogen rectification separation process with an adsorbent; and a helium rectification separation process in which helium gas is removed by rectifying the gas obtained through the impurity gas adsorption separation process.

[0025] According to an embodiment of the method for manufacturing neon according to the present invention, hydrogen gas contained in a raw material mixed gas is converted into water by contacting it with oxygen and a catalyst, and after removing the obtained water, impurity gas is removed in a first nitrogen rectification separation process and an impurity gas adsorption separation process. Thus, before removing nitrogen in the first nitrogen rectification separation process, the hydrogen gas contained in the raw material mixed gas is converted into water (hydrogen gas conversion process), and by removing the obtained water (water removal process), the oxygen used for the conversion from hydrogen gas to water can be removed together with nitrogen in the first nitrogen rectification separation process. As a result, since the gas obtained through the first nitrogen rectification separation process contains almost no hydrogen or oxygen, the load on the adsorption tower used in the impurity gas adsorption separation process can be reduced. Therefore, the operating time of the adsorption tower can be extended, and the manufacturing efficiency of neon can be increased. Furthermore, since there is no need to increase the number of adsorption towers or enlarge the adsorption towers to increase processing capacity, the facility space can be saved and manufacturing costs can be reduced.

[0026] The following describes each process.

[0027] [Hydrogen Gas Conversion Process]

[0028] In the hydrogen gas conversion process, hydrogen gas is converted into water by contacting a raw material mixed gas containing neon, helium, hydrogen, and nitrogen with an oxygen-containing gas to a catalyst. As the catalyst, a catalyst that produces water by reacting hydrogen with oxygen is used. Known catalysts that produce water by reacting hydrogen with oxygen can be used. As the raw material mixed gas to be contacted to the catalyst, for example, the residual gas discharged from the top of the lower rectification column (so-called helium removal) when raw air is liquefied and distilled to produce oxygen, nitrogen, argon, etc., may be used. An oxygen-containing gas is used as the source of oxygen to be contacted to the catalyst. For example, air or oxygen gas may be used as the oxygen-containing gas, but it is preferable to use oxygen gas.

[0029] [Moisture Removal Process]

[0030] In the moisture removal process, water is removed from the gas obtained through the hydrogen gas conversion process. The method for removing water contained in the gas is not particularly limited; examples include removing water using an adsorbent that adsorbs water or removing water by membrane separation. Among these, the method of removing water using an adsorbent that adsorbs water is preferred. Known adsorbents that adsorb water may be used.

[0031] The raw material mixed gas may additionally contain carbon monoxide. If the raw material mixed gas contains carbon monoxide, the hydrogen gas conversion process may also serve as a carbon monoxide conversion process in which carbon monoxide is brought into contact with oxygen and converted into carbon dioxide. In this case, a catalyst that converts hydrogen gas into water may be used. Carbon monoxide can be converted into carbon dioxide by bringing carbon monoxide and oxygen into contact with a catalyst that converts hydrogen gas into water. If the raw material mixed gas contains carbon monoxide, the water removal process may also serve as a carbon dioxide removal process in which carbon dioxide is removed from the gas obtained through the hydrogen gas conversion process.

[0032] If the raw material mixed gas contains carbon monoxide, a carbon monoxide conversion process may be included as a process distinct from the hydrogen gas conversion process to convert the carbon monoxide contained in the raw material mixed gas into carbon dioxide. The method for converting carbon monoxide into carbon dioxide is not particularly limited; for example, a method using a catalyst that converts carbon monoxide into carbon dioxide by contacting carbon monoxide with oxygen may be cited. A known catalyst that converts carbon monoxide into carbon dioxide by contacting carbon monoxide with oxygen may be used. Furthermore, if the raw material mixed gas contains carbon monoxide, a carbon dioxide removal process may be included as a process distinct from the moisture removal process to remove carbon dioxide from the gas obtained through the carbon monoxide conversion process. When including a carbon monoxide conversion process and a carbon dioxide removal process, the order of the hydrogen gas conversion process and the moisture removal process is not specifically limited; the hydrogen gas conversion process and the moisture removal process may be performed first, followed by the carbon monoxide conversion process and the carbon dioxide removal process, or the hydrogen gas conversion process and the carbon monoxide conversion process may be performed in any order, followed by the moisture removal process and the carbon dioxide removal process. Additionally, after performing the conversion from hydrogen to water and the conversion from carbon monoxide to carbon dioxide in the hydrogen gas conversion process, the moisture removal process and the carbon dioxide removal process may be performed as separate processes.

[0033] Methods for removing carbon dioxide contained in gas include, for example, using an adsorbent that adsorbs carbon dioxide or removing carbon dioxide by membrane separation. When removing carbon dioxide using an adsorbent, the adsorbent used in the carbon dioxide removal process may be the same as the adsorbent used to remove water, or an adsorbent that selectively removes carbon dioxide may be used. Known adsorbents that selectively remove carbon dioxide may be used.

[0034] [1st Nitrogen Rectification Separation Process]

[0035] In the first nitrogen rectification separation process, nitrogen is removed by rectifying the gas obtained through a moisture removal process (or carbon dioxide removal process). The form of nitrogen removed in the first nitrogen rectification separation process is not particularly limited and may be in a gaseous or liquid state, and it is preferable to remove it in a liquid state. When nitrogen is removed in a liquid state, the removed liquid nitrogen can be used, for example, as a refrigerant.

[0036] [Impurity Gas Adsorption Separation Process]

[0037] In the impurity gas adsorption separation process, the gas obtained through the first nitrogen rectification separation process is brought into contact with an adsorbent to remove impurity gases. The impurity gases are, for example, nitrogen, oxygen, hydrogen, etc. A known adsorbent can be used to remove the impurity gases. By removing the impurity gases using an adsorbent, it is possible to prevent the nitrogen contained in the impurity gases from solidifying and clogging pipes, etc., when purifying neon in the helium rectification separation process described later.

[0038] [Helium Rectification Separation Process]

[0039] In the helium rectification separation process, the gas obtained through the impurity gas adsorption separation process is rectified to remove helium gas. By removing helium gas, neon can be manufactured. The form of the manufactured neon is not particularly limited and may be in a gaseous state or a liquid state, but liquid neon is preferred.

[0040] As an example of the neon manufacturing method of the present invention, (1) between the first nitrogen rectification separation process and the impurity gas adsorption separation process, a gas separation process may be included in which the gas obtained through the first nitrogen rectification separation process is heat-exchanged between a refrigerant at -196°C to -210°C and then separated into gas and liquid to separate the gas, or (2) between the impurity gas adsorption separation process and the helium rectification separation process, a second nitrogen rectification separation process may be included in which the gas obtained through the impurity gas adsorption separation process is rectified to remove nitrogen. A form including the gas separation process may be referred to as Example 1 below, and a form including the second nitrogen rectification separation process may be referred to as Example 2 below.

[0041] (1) Example 1

[0042] In the gas separation process of Example 1, the gas obtained through the first nitrogen rectification separation process is heat-exchanged with a refrigerant at -196°C to -210°C, and then gas-liquid separated to separate the gas. By heat-exchanging the gas obtained through the first nitrogen rectification separation process with the refrigerant, the nitrogen contained in the gas obtained through the first nitrogen rectification separation process is liquefied, and by removing the liquid from the fluid obtained through heat exchange by gas-liquid separation, the nitrogen contained in the gas being separated can be further reduced. As a result, it is not necessary to repeat low-temperature adsorption twice as in Non-Patent Literature 1. The gas obtained through the gas separation process has residual impurity gas removed by contacting it with an adsorbent in the above-mentioned impurity gas adsorption separation process. By performing a gas separation process between the first nitrogen rectification separation process and the impurity gas adsorption separation process in this manner, the load on the adsorption tower used in the impurity gas adsorption separation process can be reduced, thereby extending the operating time of the adsorption tower and further increasing the manufacturing efficiency of neon. The temperature of the refrigerant is not limited as long as it is a temperature capable of liquefying the nitrogen contained in the gas obtained through the first nitrogen rectification separation process, but it is in the range of -196°C to -210°C, preferably as low as possible, and more preferably -200°C to -210°C.

[0043] In the impurity gas adsorption separation process of Example 1, impurity gas may be removed by a temperature swing adsorption method. The temperature at which impurity gas is removed by the temperature swing adsorption method may be, for example, a low temperature of -100°C or lower. By removing impurity gas by a temperature swing adsorption method of -100°C or lower, the concentration of impurity gas can be reduced to several ppb, thereby enabling the production of high-purity neon.

[0044] (2) Example 2

[0045] In the second nitrogen rectification separation process in Example 2, the gas obtained through the impurity gas adsorption separation process is rectified to remove nitrogen. By performing a second rectification to remove nitrogen, the nitrogen contained in the gas used in the helium rectification separation process can be further reduced. The temperature of the refrigerant used for rectification in the second nitrogen rectification separation process may be lower than the temperature at which nitrogen liquefies, and more preferably, lower than the temperature at which nitrogen solidifies. The gas obtained through the second nitrogen rectification separation process is rectified in the helium rectification separation process described above to remove helium gas. As a result, high-purity neon can be produced.

[0046] In the impurity gas adsorption separation process of Example 2, impurity gas may be removed by pressure swing adsorption. The temperature at which impurity gas is removed by pressure swing adsorption may be, for example, room temperature (20℃±15℃). By removing impurity gas by pressure swing adsorption at room temperature, the concentration of impurity gas can be reduced to a few ppm. By reducing the concentration of impurity gas to a few ppm, a refrigerant with a temperature below the solidification temperature of nitrogen can be used in the second nitrogen rectification separation process, thereby allowing for sufficient removal of nitrogen and the production of high-purity neon.

[0047] According to an example of the method for manufacturing neon according to the present invention, high-purity neon with a purity of 99.999% or higher can be manufactured.

[0048] Next, an example of a neon manufacturing apparatus according to the present invention will be described.

[0049] Example 1 of the neon manufacturing apparatus according to the present invention is an apparatus for manufacturing neon from a raw material mixed gas containing neon, helium, hydrogen, and nitrogen, comprising: a catalyst tower having a catalyst that contacts the raw material mixed gas and an oxygen-containing gas; a moisture removal facility that removes water contained in the gas from the catalyst tower; a first nitrogen removal rectification tower that rectifies the gas from the moisture removal facility to remove nitrogen; a heat exchanger that exchanges heat between the gas from the first nitrogen removal rectification tower and a refrigerant at -196°C to -210°C; a gas-liquid separator that separates the fluid from the heat exchanger into gas and liquid; a temperature swing adsorption tower that adsorbs impurity gas contained in the gas from the gas-liquid separator by a temperature swing adsorption method; and a neon purification rectification tower that rectifies the gas from the temperature swing adsorption tower to remove helium gas and purify neon.

[0050] Example 2 of the neon manufacturing apparatus according to the present invention is an apparatus for manufacturing neon from a raw material mixed gas comprising neon, helium, hydrogen, and nitrogen, comprising: a catalyst tower having a catalyst that contacts the raw material mixed gas with an oxygen-containing gas; a moisture removal facility for removing water contained in the gas from the catalyst tower; a first nitrogen removal rectification tower for removing nitrogen by rectifying the gas from the moisture removal facility; a pressure swing adsorption tower for adsorbing impurity gas contained in the gas from the first nitrogen removal rectification tower by a pressure swing adsorption method; a second nitrogen removal rectification tower for removing nitrogen by rectifying the gas from the pressure swing adsorption tower; and a neon purification rectification tower for removing helium gas by rectifying the gas from the second nitrogen removal rectification tower and purifying neon.

[0051] Examples 1 and 2 of the neon manufacturing apparatus are in common in that they include a catalyst tower equipped with a catalyst that contacts a raw material mixed gas and an oxygen-containing gas, a moisture removal facility that removes water contained in the gas from the catalyst tower, a first nitrogen removal rectification tower that rectifies the gas from the moisture removal facility to remove nitrogen, an adsorption tower that adsorbs impurity gas (at least nitrogen), and a neon purification rectification tower that rectifies the gas from the adsorption tower to remove helium gas and purify neon.

[0052] Hereinafter, embodiments of a neon manufacturing apparatus according to the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the illustrated examples, and modifications may be made to suit the purpose of the above and subsequent descriptions, and all such modifications are included within the technical scope of the present invention. In each drawing, the same reference numerals are used to avoid redundant descriptions of identical parts. In addition, in each drawing, symbols, etc., may be omitted; in such cases, the specification or other drawings are referenced.

[0053] (Example 1)

[0054] FIG. 1 is a schematic diagram illustrating Example 1 of a neon manufacturing apparatus according to the present invention. As shown in FIG. 1, the neon manufacturing apparatus in Example 1 comprises a catalyst tower (1), a moisture removal facility (2), a first nitrogen removal rectification tower (3), a heat exchanger (4a), a gas-liquid separator (5), a temperature swing adsorption tower (6a, 6b), and a neon purification rectification tower (7). The heat exchanger (4a) is provided in a container (4).

[0055] The catalyst tower (1) is equipped with a catalyst that reacts hydrogen with oxygen to produce water. A raw material mixed gas is supplied to the catalyst tower (1) from a raw material mixed gas supply means (101). As the raw material mixed gas, for example, residual gas released from the top of a lower rectification tower (so-called helium removal) when producing oxygen, nitrogen, argon, etc., by liquefying and distilling raw air may be used. An oxygen-containing gas is supplied to the catalyst tower (1) from an oxygen-containing gas supply means (not shown). As the oxygen-containing gas, for example, air may be used or oxygen gas may be used, but it is preferable to use oxygen gas. In the catalyst tower (1), hydrogen contained in the raw material mixed gas and oxygen contained in the oxygen-containing gas come into contact with the catalyst, and water is produced. The gas containing the produced water is supplied from the catalyst tower (1) to a water removal facility (2).

[0056] As for the moisture removal equipment (2), for example, an adsorption tower equipped with an adsorbent that adsorbs water, or a membrane separation device equipped with a membrane capable of separating water and other gases, can be used. Among these, it is preferable to use an adsorption tower. In addition, an adsorption tower and a membrane separation device may be used in combination. Although FIG. 1 shows a configuration example with one moisture removal equipment (2), the number of moisture removal equipment (2) is not limited to one and may be two or more. The gas from which water has been removed in the moisture removal equipment (2) is supplied from the moisture removal equipment (2) to the first nitrogen removal rectification tower (3).

[0057] The raw material mixed gas may additionally contain carbon monoxide. If the raw material mixed gas contains carbon monoxide, carbon monoxide and oxygen may be brought into contact with a catalyst in the catalyst tower (1) to convert the carbon monoxide into carbon dioxide. In this case, the catalyst used in the catalyst tower (1) may be a catalyst that converts hydrogen gas into water. If the raw material mixed gas contains carbon monoxide, carbon dioxide may be removed from the gas obtained through the catalyst tower (1) in the moisture removal facility (2).

[0058] If the raw material mixed gas contains carbon monoxide, the neon manufacturing apparatus may be equipped with a second catalyst tower, which is equipped with a catalyst to which the raw material mixed gas comes into contact, separately from the catalyst tower (1). A catalyst that converts carbon monoxide into carbon dioxide by contacting carbon monoxide with oxygen may be placed in the second catalyst tower. As a catalyst that converts carbon monoxide into carbon dioxide by contacting carbon monoxide with oxygen, for example, a catalyst that converts hydrogen gas into water may be used. If the neon manufacturing apparatus includes the second catalyst tower, the arrangement order of the catalyst tower (1) and the second catalyst tower is not particularly limited, and the second catalyst tower may be placed downstream of the catalyst tower (1), or the second catalyst tower may be placed upstream of the catalyst tower (1). Additionally, if the raw material mixed gas contains carbon monoxide, the neon manufacturing apparatus may be equipped with a carbon dioxide removal facility that removes carbon dioxide contained in the gas supplied from the second catalyst tower, separately from the moisture removal facility (2). If the neon manufacturing apparatus includes a second catalyst tower, the arrangement order of the catalyst tower (1) and the moisture removal equipment (2) is not specifically limited, and the second catalyst tower may be arranged after the catalyst tower (1) and the moisture removal equipment (2) are arranged in this order, or the second catalyst tower may be arranged in any order, and then the moisture removal equipment (2) may be arranged in any order. If the neon manufacturing apparatus includes a carbon dioxide removal equipment, the arrangement order of the catalyst tower (1) and the moisture removal equipment (2) is not specifically limited, and the carbon dioxide removal equipment may be arranged after the catalyst tower (1) and the moisture removal equipment (2) are arranged in this order, or the carbon dioxide removal equipment may be arranged after the catalyst tower (1) is arranged, and then the moisture removal equipment (2) and the carbon dioxide removal equipment may be arranged in any order.When a neon manufacturing apparatus includes a second catalyst tower and a carbon dioxide removal facility, the arrangement order of the catalyst tower (1) and the moisture removal facility (2) is not specifically limited. The catalyst tower (1) and the moisture removal facility (2) may be arranged in this order, followed by the second catalyst tower and the carbon dioxide removal facility, or the catalyst tower (1) and the second catalyst tower may be arranged in any order, followed by the moisture removal facility (2) and the carbon dioxide removal facility. Additionally, the neon manufacturing apparatus may include the catalyst tower (1) and not include the second catalyst tower, and may include both the moisture removal facility (2) and the carbon dioxide removal facility.

[0059] Examples of carbon dioxide removal equipment include a carbon dioxide adsorption tower equipped with an adsorbent that adsorbs carbon dioxide, or a membrane separator that removes carbon dioxide by membrane separation. When removing carbon dioxide using an adsorbent, the adsorbent used in the carbon dioxide removal equipment may be an adsorbent that removes water, or an adsorbent that selectively removes carbon dioxide.

[0060] A heat exchanger (111) may be provided between the moisture removal facility (2) and the first nitrogen removal rectification tower (3). A refrigerant is supplied to the heat exchanger (111) from a refrigerant supply means (111a), and heat is exchanged between the refrigerant and the gas supplied from the moisture removal facility (2). For example, nitrogen gas may be used as the refrigerant. For example, the gas accumulated at the top of the container (31) described later may be used as the nitrogen gas. In this case, a path for discharging helium gas may be connected to the top of the container (31).

[0061] The first nitrogen removal rectification tower (3) is a single-stage rectification tower, and the gas introduced into the first nitrogen removal rectification tower (3) is separated by deep liquefaction using the difference in boiling points of each component, and the high-boiling point components (nitrogen and oxygen) in the gas are liquefied and collected at the bottom, while the low-boiling point components (neon and helium) are collected as gas at the top. The theoretical number of stages provided in the first nitrogen removal rectification tower (3) is not particularly limited, and, for example, may be 8 to 15 stages.

[0062] A reboiler (3a) is provided at the bottom of the first nitrogen removal rectification tower (3). A heat medium is supplied to the reboiler (3a) from a heat medium supply means (3b), and heat is exchanged between the heat medium and the liquid liquefied within the first nitrogen removal rectification tower (3). After heat exchange, the heat medium is discharged through a path (3c). For example, nitrogen gas may be used as the heat medium. As the nitrogen gas, the gas collected at the top of the container (31) described later may be used. The liquid of high boiling point components collected at the bottom of the first nitrogen removal rectification tower (3) may be discharged out of the system through a path (not shown) installed at the bottom of the first nitrogen removal rectification tower (3). The discharged liquid may be supplied to a container (31) equipped with a condenser (31a) described later, for example, and used as a refrigerant.

[0063] Typically, a container (31) equipped with a condenser (31a) is provided in the first nitrogen removal rectification tower (3). In FIG. 1, the container (31) is provided at the top of the first nitrogen removal rectification tower (3). Gas of low-boiling point components collected at the top of the first nitrogen removal rectification tower (3) is supplied from the first nitrogen removal rectification tower (3) to the condenser (31a) provided in the container (31) via a path (3d).

[0064] A refrigerant is supplied to the container (31) from a refrigerant supply means (31d), and heat is exchanged between the refrigerant and the gas supplied to the condenser (31a). As the refrigerant, for example, a liquid discharged from a path (not shown) installed at the bottom of the first nitrogen removal rectification tower (3) may be used. The gas supplied to the condenser (31a) undergoes heat exchange with the refrigerant, and liquid and gas are generated. The generated liquid may be returned from the condenser (31a) to the first nitrogen removal rectification tower (3) via path (31c). Meanwhile, the generated gas is supplied from the condenser (31a) to a heat exchanger (4a) provided in the container (4) via path (31b). Since nitrogen gas accumulates at the top of the container (31), a path for discharging nitrogen gas out of the system may be connected to the top of the container (31).

[0065] A refrigerant is supplied to the container (4) from a refrigerant supply means (4b), and heat is exchanged between the refrigerant and the gas supplied to the heat exchanger (4a). As the refrigerant, a fluid with a temperature of -196°C to -210°C is used. The fluid obtained by heat exchange in the heat exchanger (4a) is supplied to a gas-liquid separator (5) and separated into liquid and gas. In this way, the gas obtained by passing through the first nitrogen removal rectification tower (3) is heat-exchanged with the refrigerant with a temperature of -196°C to -210°C in the heat exchanger (4a), and then the liquid is removed and the gas is separated by gas-liquid separation in the gas-liquid separator (5), thereby further reducing the nitrogen contained in the gas. The liquid obtained by gas-liquid separation may be discharged out of the system through a path (5b) installed at the bottom of the gas-liquid separator (5). The discharged liquid may be used as a refrigerant. Additionally, the discharged liquid may be returned to the first nitrogen removal rectification tower (3). The gas obtained by gas-liquid separation is supplied from the gas-liquid separator (5) to the temperature swing adsorption towers (6a, 6b). The temperature swing adsorption towers (6a, 6b) are equipped with an adsorbent that adsorbs impurity gases. The temperature swing adsorption towers (6a, 6b) may be filled with an adsorbent capable of removing at least nitrogen, and may additionally be filled with an adsorbent capable of removing hydrogen or water in addition to nitrogen. If the raw material mixed gas contains carbon monoxide, the adsorbent capable of removing carbon monoxide or carbon dioxide may also be additionally filled. Known adsorbents may be used. A valve (not shown) may be placed on the upstream side of the temperature swing adsorption towers (6a, 6b) and configured to be switchable.

[0066] In the temperature swing adsorption towers (6a, 6b), impurity gases contained in the gas supplied from the gas-liquid separator (5) are adsorbed by the temperature swing adsorption method. The temperature at which impurity gases are removed by the temperature swing adsorption method can be, for example, a low temperature of -100°C or lower. By removing impurity gases by the temperature swing adsorption method at -100°C or lower, the concentration of impurity gases can be reduced to several ppb, thereby enabling the production of high-purity neon. Although FIG. 1 shows an example configuration equipped with two temperature swing adsorption towers, the number of temperature swing adsorption towers is not limited to two and may be three or more. The gas from which impurity gases have been removed in the temperature swing adsorption towers (6a, 6b) is supplied from the temperature swing adsorption towers (6a, 6b) to the neon purification rectification tower (7).

[0067] In the neon purification rectification tower (7), the gas supplied from the temperature swing adsorption towers (6a, 6b) is rectified to remove helium gas and purify neon. The neon purification rectification tower (7) is a single-stage rectification tower, and the gas introduced into the neon purification rectification tower (7) is separated by deep liquefaction using the difference in boiling points of each component, and the high-boiling point component (neon) in the gas is liquefied and collected at the bottom, while the low-boiling point component (helium) is collected as gas at the top. The theoretical number of stages provided in the neon purification rectification tower (7) is not particularly limited and, for example, may be 5 to 10 stages.

[0068] Typically, a container (71) equipped with a condenser (71a) is provided in the neon purification rectification tower (7). In FIG. 1, the container (71) is provided at the top of the neon purification rectification tower (7). The low-boiling point component gas accumulated at the top of the neon purification rectification tower (7) is helium, and it is supplied from the neon purification rectification tower (7) to the condenser (71a) provided in the container (71) via a path (7e). A refrigerant is supplied to the container (71) from a refrigerant supply means (71b), and heat is exchanged between the refrigerant and the gas supplied to the condenser (71a). As the refrigerant, for example, a fluid with a temperature of -259°C to -253°C may be used, and liquid hydrogen may be used as the fluid with a temperature of -259°C to -253°C. The gas supplied to the condenser (71a) undergoes heat exchange with the refrigerant to produce liquid and gas. The generated gas may be discharged out of the system through path (71d) from the condenser (71a) and may be recovered as helium gas (71c). Meanwhile, the generated liquid may be returned from the condenser (71a) through path (71e) to the neon purification rectification tower (7). Also, although FIG. 1 shows an example configuration in which a refrigerant is supplied to the container (71) for heat exchange, heat exchange may also be performed by cooling the inside of the container (71) to -270°C to -253°C by means of a cooling means (not shown), for example.

[0069] A reboiler (7a) is provided at the bottom of the neon purification rectification tower (7). Heat is supplied to the reboiler (7a) from a heat supply means (7b), and heat is exchanged between the heat and the liquid liquefied within the neon purification rectification tower (7). After heat exchange, the heat is discharged through a path (7c). For example, helium gas may be used as the heat. For example, helium gas (71c) recovered from a condenser (71a) may be used as the helium gas.

[0070] The liquid of the high boiling point component collected at the bottom of the neon purification rectification tower (7) is neon, and is discharged out of the system through the path (7d) installed at the bottom of the neon purification rectification tower (7) and recovered as liquefied neon (201).

[0071] Also, although Figure 1 shows an example of a configuration in which neon in a liquid state is recovered, neon in a gaseous state can also be recovered.

[0072] A heat exchanger (112) may be provided between the temperature swing adsorption towers (6a, 6b) and the neon purification rectification tower (7). A refrigerant is supplied to the heat exchanger (112) from a refrigerant supply means (112a), and heat is exchanged between the refrigerant and the gas supplied from the temperature swing adsorption towers (6a, 6b). For example, helium gas may be used as the refrigerant. For example, helium gas (71c) recovered from a condenser (71a) may be used, or helium gas collected at the top of a container (71) may be used. When helium gas collected at the top of the container (71) is used as the refrigerant, a path for discharging helium gas may be connected to the top of the container (71).

[0073] (Example 2)

[0074] FIG. 2 is a schematic diagram illustrating Example 2 of a neon manufacturing apparatus according to the present invention. As shown in FIG. 2, the neon manufacturing apparatus in Example 2 comprises a catalyst tower (1), a moisture removal facility (2), a first nitrogen removal rectification tower (3), a pressure swing adsorption tower (8a, 8b), a second nitrogen removal rectification tower (9), and a neon purification rectification tower (7).

[0075] In Example 2, the gas of low-boiling point components (neon and helium) collected at the top of the first nitrogen removal rectification tower (3) is supplied from the first nitrogen removal rectification tower (3) to the condenser (31a) via path (3d). The gas generated in the condenser (31a) is supplied from the condenser (31a) to the pressure swing adsorption towers (8a, 8b) via path (31b). The pressure swing adsorption towers (8a, 8b) are equipped with an adsorbent that adsorbs impurity gases. The pressure swing adsorption towers (8a, 8b) may be filled with an adsorbent capable of removing at least nitrogen, and may additionally be filled with an adsorbent capable of removing hydrogen or water in addition to nitrogen. If the raw material mixed gas contains carbon monoxide, an adsorbent capable of removing carbon monoxide or carbon dioxide may also be additionally filled. Known adsorbents may be used. A valve (not shown) may be placed on the upstream side of the pressure swing adsorption tower (8a, 8b) and configured to be switchable.

[0076] In the pressure swing adsorption towers (8a, 8b), impurity gases contained in the gas supplied from the condenser (31a) are adsorbed by the pressure swing adsorption method. The temperature at which impurity gases are removed by the pressure swing adsorption method may be, for example, room temperature (20°C ± 15°C). By removing impurity gases by the pressure swing adsorption method at room temperature, the concentration of impurity gases can be reduced to several ppm, thereby enabling the production of high-purity neon. Although FIG. 2 shows an example configuration equipped with two pressure swing adsorption towers, the number of pressure swing adsorption towers is not limited to two and may be three or more. The gas from which impurity gases have been removed in the pressure swing adsorption towers (8a, 8b) is supplied from the pressure swing adsorption towers (8a, 8b) to the second nitrogen removal rectification tower (9).

[0077] The second nitrogen removal rectification tower (9) is a single-stage rectification tower, and the gas introduced into the second nitrogen removal rectification tower (9) is separated by deep liquefaction using the difference in boiling points of each component, and the high-boiling point components (nitrogen and oxygen) in the gas are liquefied and collected at the bottom, while the low-boiling point components (neon and helium) are collected as gas at the top. The theoretical number of stages provided in the second nitrogen removal rectification tower (9) is not specifically limited, and for example, it may be 8 to 15 stages. A reboiler (9a) is provided at the bottom of the second nitrogen removal rectification tower (9). Refrigerant is supplied to the reboiler (9a) from a heat supply means (9b), and heat is exchanged between the refrigerant and the liquid liquefied in the second nitrogen removal rectification tower (9). After heat exchange, the refrigerant is discharged from the path (9c). As a refrigerant, for example, a fluid at -259°C to -253°C may be used, and liquid hydrogen may be used as the fluid at -259°C to -253°C. Also, although FIG. 2 shows an example configuration in which heat exchange is performed by supplying a refrigerant to a reboiler (9a), heat exchange may also be performed by cooling the interior of the second nitrogen removal rectification tower (9) to -270°C to -253°C by means of a cooling means (not shown) inside the container (71). The liquid of high boiling point components collected at the bottom of the second nitrogen removal rectification tower (9) may be discharged out of the system through a path (9e) installed at the bottom of the second nitrogen removal rectification tower (9) and recovered as a liquid (301). The discharged liquid (301) may be supplied to a container (31) equipped with the above-mentioned condenser (31a) and used as a refrigerant supplied from a refrigerant supply means (31d).

[0078] Typically, a container (91) equipped with a condenser (91a) is provided in the second nitrogen removal rectification tower (9). In FIG. 2, the container (91) is provided at the top of the second nitrogen removal rectification tower (9). Gas of low-boiling point components collected at the top of the second nitrogen removal rectification tower (9) is supplied from the second nitrogen removal rectification tower (9) to the condenser (91a) provided in the container (91) via path (9d). Refrigerant is supplied to the container (91) from a refrigerant supply means (91e), and heat is exchanged between the refrigerant and the gas supplied to the condenser (91a). As the refrigerant, for example, a liquid discharged from a path (not shown) installed at the bottom of the first nitrogen removal rectification tower (3) may be used. The gas supplied to the condenser (91a) undergoes heat exchange with the refrigerant to produce liquid and gas. The generated liquid may be returned from the condenser (91a) to the second nitrogen removal rectification tower (9) via path (91c). Meanwhile, the generated gas is supplied from the container (91) to the neon purification rectification tower (7) via path (91b).

[0079] A heat exchanger (112) may be provided between the pressure swing adsorption towers (8a, 8b) and the second nitrogen removal rectification tower (9). A refrigerant is supplied to the heat exchanger (112) from a refrigerant supply means (112a), and heat is exchanged between the refrigerant and the gas supplied from the pressure swing adsorption towers (8a, 8b). For example, helium gas may be used as the refrigerant. For example, helium gas (71c) recovered from the condenser (71a) described later may be used, or helium gas collected at the top of the container (71) described later may be used. When helium gas collected at the top of the container (71) is used as the refrigerant, a path for discharging helium gas may be connected to the top of the container (71).

[0080] In the neon purification rectification tower (7), the gas supplied from the second nitrogen removal rectification tower (9) is rectified to remove helium gas and purify neon. The neon purification rectification tower (7) is a single-stage rectification tower, and the gas introduced into the neon purification rectification tower (7) is separated by deep liquefaction using the difference in boiling points of each component, and the high-boiling point component (neon) in the gas is liquefied and collected at the bottom, while the low-boiling point component (helium) is collected as gas at the top. The theoretical number of stages provided in the neon purification rectification tower (7) is not particularly limited, and, for example, may be 5 to 10 stages.

[0081] Typically, a container (71) equipped with a condenser (71a) is provided in the neon purification rectification tower (7). In FIG. 2, the container (71) is provided at the top of the neon purification rectification tower (7). The low-boiling point component gas collected at the top of the neon purification rectification tower (7) is helium, and it is supplied from the neon purification rectification tower (7) to the condenser (71a) provided in the container (71) via a path (7e). A refrigerant is supplied to the container (71) from a refrigerant supply means (71b), and heat is exchanged between the refrigerant and the gas supplied to the condenser (71a). As the refrigerant, for example, a fluid with a temperature of -259°C to -253°C may be used, and liquid hydrogen may be used as the fluid with a temperature of -259°C to -253°C. The gas supplied to the condenser (71a) undergoes heat exchange with the refrigerant to produce liquid and gas. The generated gas may be discharged out of the system through path (71d) from the condenser (71a) and may be recovered as helium gas (71c). Meanwhile, the generated liquid may be returned from the condenser (71a) through path (71e) to the neon purification rectification tower (7). Also, although FIG. 2 shows an example configuration in which a refrigerant is supplied to the container (71) for heat exchange, heat exchange may also be performed by cooling the inside of the container (71) to -270°C to -253°C by means of a cooling means (not shown).

[0082] A reboiler (7a) is provided at the bottom of the neon purification rectification tower (7). Heat is supplied to the reboiler (7a) from a heat supply means (7b), and heat is exchanged between the heat and the liquid liquefied within the neon purification rectification tower (7). After heat exchange, the heat is discharged through a path (7c). For example, helium gas may be used as the heat. For example, helium gas (71c) recovered from a condenser (71a) may be used as the helium gas. The liquid of high boiling point components collected at the bottom of the neon purification rectification tower (7) is neon, and is discharged out of the system through a path (7d) installed at the bottom of the neon purification rectification tower (7) and recovered as liquefied neon (201). Also, although FIG. 2 shows an example configuration in which neon in a liquid state is recovered, neon in a gaseous state may also be recovered.

[0083] According to Examples 1 and 2 of the neon manufacturing apparatus according to the present invention, high-purity neon with a purity of 99.999% or higher can be manufactured.

[0084] Thus, by using the apparatus and method disclosed in the present invention, it becomes possible to reduce the load on the adsorption tower and efficiently manufacture neon, and to reduce driving energy compared to conventional technology. Therefore, greenhouse gases can be reduced, and it can contribute to some activities of the Sustainable Development Goals (SDGs).

[0085] This application claims the benefit of priority based on Japanese Patent Application No. 2023-207754, filed on December 8, 2023. The entire contents of the specification of the above Japanese Patent Application No. 2023-207754 are incorporated herein by reference. Explanation of the symbols

[0086] 1: Catalytic tower 2: Moisture removal equipment 3: First Nitrogen Removal Rectification Tower 4: Courage 4a: Heat exchanger 5: Gas-liquid separator 6a, 6b: Temperature swing adsorption tower 7 Neon Refining Rectification Tower 8a, 8b: Pressure swing adsorption tower 9: Second Nitrogen Removal Stabilization Tower

Claims

Claim 1 A method for manufacturing neon from a raw material mixed gas comprising neon, helium, hydrogen, and nitrogen, comprising: a hydrogen gas conversion process in which hydrogen gas is converted into water by contacting the raw material mixed gas and an oxygen-containing gas with a catalyst; a moisture removal process in which water is removed from the gas obtained through the hydrogen gas conversion process; a first nitrogen rectification separation process in which nitrogen is removed by rectifying the gas obtained through the moisture removal process; an impurity gas adsorption separation process in which impurity gas is removed by contacting the gas obtained through the first nitrogen rectification separation process with an adsorbent; and a helium rectification separation process in which helium gas is removed by rectifying the gas obtained through the impurity gas adsorption separation process. Claim 2 A method for manufacturing according to claim 1, wherein between the first nitrogen rectification separation process and the impurity gas adsorption separation process, a gas separation process is performed to separate the gas by separating the gas obtained through the first nitrogen rectification separation process and the gas obtained through the first nitrogen rectification separation process by heat exchange with a refrigerant at -196℃ to -210℃, and then separating the gas by gas-liquid separation, wherein in the impurity gas adsorption separation process, the gas obtained through the gas separation process is brought into contact with an adsorbent. Claim 3 In claim 2, the manufacturing method for removing impurity gas by a temperature swing adsorption method at -100℃ or lower in the impurity gas adsorption separation process. Claim 4 A method for manufacturing according to claim 1, wherein between the impurity gas adsorption separation process and the helium rectification separation process, a second nitrogen rectification separation process is included to remove nitrogen by rectifying the gas obtained through the impurity gas adsorption separation process, and in the helium rectification separation process, the gas obtained through the second nitrogen rectification separation process is rectified to remove helium gas. Claim 5 In claim 4, the impurity gas adsorption separation process is a manufacturing method for removing impurity gas by a pressure swing adsorption method at room temperature. Claim 6 A manufacturing method according to claim 1, wherein the raw material mixed gas further comprises carbon monoxide, and the carbon monoxide included in the raw material mixed gas is converted into carbon dioxide through a carbon monoxide conversion process. Claim 7 A manufacturing method according to claim 1, wherein the raw material mixed gas further comprises carbon monoxide, a carbon monoxide conversion process for converting carbon monoxide contained in the raw material mixed gas into carbon dioxide, and a carbon dioxide removal process for removing carbon dioxide from the gas obtained through the carbon monoxide conversion process. Claim 8 A neon manufacturing apparatus comprising a raw material mixed gas containing neon, helium, hydrogen, and nitrogen, the apparatus comprising: a catalytic tower having a catalyst that contacts the raw material mixed gas and an oxygen-containing gas; a moisture removal facility that removes water contained in the gas from the catalytic tower; a first nitrogen removal rectification tower that rectifies the gas from the moisture removal facility to remove nitrogen; a heat exchanger that exchanges heat between the gas from the first nitrogen removal rectification tower and a refrigerant at -196°C to -210°C; a gas-liquid separator that separates the fluid from the heat exchanger into gas and liquid; a temperature swing adsorption tower that adsorbs impurity gas contained in the gas from the gas-liquid separator by a temperature swing adsorption method; and a neon purification rectification tower that rectifies the gas from the temperature swing adsorption tower to remove helium gas and purify neon. Claim 9 A neon manufacturing apparatus comprising a raw material mixed gas containing neon, helium, hydrogen, and nitrogen, the apparatus comprising: a catalytic tower having a catalyst that contacts the raw material mixed gas with an oxygen-containing gas; a moisture removal facility that removes water contained in the gas from the catalytic tower; a first nitrogen removal rectification tower that rectifies the gas from the moisture removal facility to remove nitrogen; a pressure swing adsorption tower that adsorbs impurity gas contained in the gas from the first nitrogen removal rectification tower by a pressure swing adsorption method; a second nitrogen removal rectification tower that rectifies the gas from the pressure swing adsorption tower to remove nitrogen; and a neon purification rectification tower that rectifies the gas from the second nitrogen removal rectification tower to remove helium gas and purify neon. Claim 10 A manufacturing apparatus according to claim 8 or 9, wherein the raw material mixed gas further comprises carbon monoxide and a second catalyst tower having a catalyst to which the raw material mixed gas contacts. Claim 11 A manufacturing apparatus according to claim 8 or 9, wherein the raw material mixed gas further comprises carbon monoxide, a second catalytic tower having a catalyst to which the raw material mixed gas contacts, and a carbon dioxide removal facility for removing carbon dioxide contained in the gas from the second catalytic tower.

Images