Gas treatment system and gas treatment method

Abstract

The present invention provides a gas treatment system and gas treatment method that can increase the amount of water vapor permeating through a gas separation membrane without relying on power, and that can suppress contact between water vapor and adsorbent, thereby stably immobilizing gas components that are not permitted to be discharged to the outside within the system. [Solution] The gas treatment system 100 comprises a membrane module 1 separated into a primary side 1a and a secondary side 1b by a gas separation membrane that selectively permeates water vapor, an adsorption container 5 containing an adsorbent capable of adsorbing gas components that do not permeate the gas separation membrane, a primary side discharge piping system 4 that discharges the gas from the primary side 1a to the adsorption container 5, a secondary side supply piping system 6 that supplies the gas treated by the adsorbent to the secondary side 1b, and a secondary side discharge piping system 7 that discharges the gas from the secondary side 1b. The gas treatment method involves contacting the gas separation membrane with the gas to separate water vapor and gas components, adsorbing the gas components onto the adsorbent, and supplying the treated gas to the secondary side to dilute the water vapor.

Description

TECHNICAL FIELD

[0001] The present invention relates to a gas processing system and a gas processing method for separating water vapor and other gas components contained in a mixed gas from each other using a gas separation membrane.

BACKGROUND ART

[0002] As a method for separating gas components contained in a mixed gas, there is a method using a gas separation membrane. The permeability to the gas separation membrane differs for each gas component. Therefore, when the mixed gas is brought into contact with the gas separation membrane, specific gas components can be selectively separated. A gas separation membrane that selectively separates water vapor is called a water vapor separation membrane. Examples of the gas separation membrane include a polar membrane that utilizes the difference in adsorption force according to polarity, and a molecular sieve membrane that utilizes the difference in molecular size.

[0003] The permeation amount of a gas component that permeates the gas separation membrane is proportional to the gas permeability coefficient for each gas component and the partial pressure difference for each gas component formed between the primary side and the secondary side of the gas separation membrane. The gas permeability coefficient corresponds to the permeation amount per unit thickness, per unit area, per unit time, and per unit pressure. It can be said that the gas separation membrane is a material that more easily permeates the gas component as the gas permeability coefficient is larger.

[0004] The permeation amount of a gas component that permeates the gas separation membrane decreases when the gas component permeates from the primary side to the secondary side and the partial pressure on the secondary side increases. In addition, gas components that are difficult to permeate through the gas separation membrane remain on the primary side, and the permeation amount decreases when the partial pressure of gas components that easily permeate through the gas separation membrane on the primary side becomes low. Therefore, in performing efficient gas separation, it is important to remove the gas components that have permeated to the secondary side and the gas components remaining on the primary side.

[0005] Patent Document 1 describes a carbon dioxide recovery device. This device separates carbon dioxide contained in the source gas from impurities and water vapor. Separation of gases is achieved by using separation membranes that selectively permeate carbon dioxide and separation membranes that selectively permeate water vapor. The second processed gas in the supply space of the second separation module is drawn in by a suction unit such as a compressor or pump. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2024-114783 [Overview of the project] [Problems that the invention aims to solve]

[0007] In recent years, systems for separating and capturing carbon dioxide have attracted attention as a means of achieving carbon neutrality. When fossil fuels are burned, water vapor and carbon dioxide are produced, resulting in combustion gas containing water vapor, carbon dioxide, nitrogen, unreacted oxygen, etc. Separating and capturing the carbon dioxide contained in the combustion gas from other gaseous components prevents its release into the environment, thus bringing us closer to achieving carbon neutrality.

[0008] When combustion gases are brought into contact with a polar membrane, polar water vapor easily permeates from the primary to the secondary side. On the other hand, nonpolar carbon dioxide, nitrogen, and oxygen do not easily permeate to the secondary side. Similarly, when combustion gases are brought into contact with a molecular sieve membrane, water vapor, which has a small molecular size, easily permeates from the primary to the secondary side. On the other hand, carbon dioxide, nitrogen, and oxygen, which have larger molecular sizes, do not easily permeate to the secondary side. Based on these differences in permeability, water vapor and carbon dioxide, etc., can be separated from each other. Separation of carbon dioxide is possible by adsorption or absorption.

[0009] In gas separation using a gas separation membrane, gas components that do not permeate the membrane remain on the primary side of the membrane. If the impermeable gas components remaining on the primary side are not removed, the partial pressure of the permeable gas components on the primary side decreases. This reduces the partial pressure difference of the permeable gas components formed between the primary and secondary sides of the gas separation membrane, leading to a problem where the amount of permeable gas components that permeate the gas separation membrane decreases.

[0010] To address these issues, Patent Document 1 describes a method in which the second processed gas in the supply space of the second separation module is drawn in by a suction unit such as a compressor or pump. However, from the perspective of achieving carbon neutrality, it is desirable to remove the gas components remaining on the primary side of the gas separation membrane without relying on power.

[0011] Furthermore, if the mixed gas used for gas separation contains gaseous components that cannot be released to the outside, such as carbon dioxide, it is desirable to immobilize these gaseous components within the system. One method for immobilizing gaseous components is to adsorb them onto an adsorbent. By flowing the gaseous components that cannot be released to the outside, which remain on the primary side of the gas separation membrane, into an adsorption container holding an adsorbent, it is possible to achieve both the immobilization of the gaseous components and the maintenance of a partial pressure difference.

[0012] However, adsorbents are often provided in powder form or as porous materials formed by sintering powder to ensure sufficient surface area. Such adsorbents experience reduced adsorption performance if moisture adheres to their surface. Furthermore, since adsorption efficiency improves at lower temperatures, cooling of the gas flowing through the adsorption container may be required. However, if the gas flowing through the adsorption container contains water vapor, which has a high latent heat, a high cooling capacity is required. Therefore, it is desirable to minimize the amount of moisture contained in the gas flowing through the adsorption container, i.e., the amount of water vapor remaining on the primary side of the gas separation membrane.

[0013] The amount of water vapor that permeates through a gas separation membrane is proportional to the partial pressure difference of water vapor formed between the primary and secondary sides of the membrane. Therefore, it is desirable not only to reduce gas components other than water vapor remaining on the primary side of the membrane, but also to continuously lower the partial pressure of water vapor on the secondary side of the membrane. It is also desirable to remove the water vapor on the secondary side of the membrane without relying on power.

[0014] Therefore, the present invention aims to provide a gas treatment system and a gas treatment method that can increase the amount of water vapor permeating through a gas separation membrane without relying on power, and that can suppress contact between water vapor and adsorbent, thereby stably immobilizing gas components that are not permitted to be discharged to the outside within the system. [Means for solving the problem]

[0015] To solve the aforementioned problems, the gas treatment system according to the present invention comprises: a membrane module having a gas separation membrane that selectively permeates water vapor, the interior of which is separated into a primary side and a secondary side by the gas separation membrane; an adsorption container containing an adsorbent capable of adsorbing one or more of the gas components that do not permeate the gas separation membrane; a primary side discharge piping system for discharging the gas from the primary side to the adsorption container; a secondary side supply piping system for supplying the gas treated by the adsorbent to the secondary side; and a secondary side discharge piping system for discharging the gas from the secondary side to the outside of the system.

[0016] Furthermore, the gas treatment method according to the present invention involves contacting a gas with a gas separation membrane that selectively permeates water vapor to separate the water vapor contained in the gas from gas components that do not permeate the gas separation membrane, adsorbing one or more of the separated gas components that do not permeate the gas separation membrane onto an adsorbent on the primary side of the gas separation membrane, supplying the gas treated by the adsorbent to the secondary side of the gas separation membrane to dilute the water vapor separated on the secondary side, and discharging the diluted gas on the secondary side of the gas separation membrane out of the system. [Effects of the Invention]

[0017] According to the present invention, it is possible to increase the permeation amount of water vapor permeating through a gas separation membrane without depending on power, suppress the contact between water vapor and an adsorbent, and provide a gas processing system and a gas processing method capable of stably fixing gas components that are not allowed to be discharged to the outside in the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] [Figure 1] It is a diagram schematically showing the configuration of the gas processing system according to the first embodiment. [Figure 2] It is a diagram for explaining a gas separation method using a polymer membrane. [Figure 3] It is a diagram for explaining a gas separation method using a ceramic membrane. [Figure 4] It is a diagram schematically showing the configuration of the gas processing system according to the second embodiment. [Figure 5] It is a diagram schematically showing the configuration of the gas processing system according to the third embodiment. [Figure 6] It is a diagram schematically showing the configuration of the gas processing system according to the fourth embodiment. [Figure 7] It is a diagram schematically showing the configuration of the gas processing system according to the fifth embodiment. [Figure 8] It is a diagram schematically showing the configuration of the gas processing system according to the sixth embodiment. DETAILED DESCRIPTION OF EMBODIMENTS FOR IMPLEMENTING THE INVENTION

[0019] Hereinafter, a gas processing system and a gas processing method according to an embodiment of the present invention will be described with reference to the drawings. In addition, in each of the following drawings, common configurations are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0020] The gas treatment system and gas treatment method according to this embodiment relate to a system and method for treating a mixed gas composed of multiple gas components. In this gas treatment system and gas treatment method, a mixed gas, which is a mixture of water vapor and other gas components, is treated. Other gas components include harmful gas components that are not permitted to be discharged into the environment, and harmless gas components other than water vapor that are permitted to be discharged into the environment.

[0021] In the gas treatment system and gas treatment method according to this embodiment, water vapor and other gas components contained in the mixed gas are separated from each other using a gas separation membrane. Then, the harmful gas components separated from the water vapor are adsorbed onto an adsorbent. The harmful gas components are immobilized, at least temporarily, within the gas treatment system by adsorption onto the adsorbent.

[0022] Harmful gas components that cannot be released into the environment are contained within the system by immobilization through adsorption onto an adsorbent, preventing their release into the environment. On the other hand, water vapor and harmless gas components that can be released into the environment are permitted to be released outside the system.

[0023] Harmful gas components that are not permitted to be released into the environment include components that have adverse effects on the environment and components that have adverse effects on the human body. Specific examples of harmful gas components include gases with a high global warming potential, such as carbon dioxide, chlorofluorocarbons (CFCs), methane, sulfur oxides such as sulfur dioxide, nitrogen oxides such as nitrogen dioxide, and radioactive materials.

[0024] Harmless gas components that are permitted to be released into the environment include those that have little impact on the environment or have little adverse effects on the human body. Specific examples of harmless gas components include gases that make up air, such as oxygen and nitrogen.

[0025] In the gas treatment system and gas treatment method according to this embodiment, harmful gas components and water vapor are separated from each other by a gas separation membrane before the harmful gas components come into contact with the adsorbent. In gas separation using a gas separation membrane, the amount of water vapor that permeates through the gas separation membrane is increased by diluting the water vapor that has permeated to the secondary side. Therefore, the decrease in the adsorption performance of the adsorbent due to the adhesion of moisture is suppressed. By suppressing the decrease in adsorption performance, harmful gas components are stably immobilized within the system.

[0026] <First Embodiment> Figure 1 is a schematic diagram showing the configuration of a gas treatment system according to the first embodiment. As shown in Figure 1, the gas treatment system 100 according to this embodiment comprises a membrane module 1, a primary supply piping system 2, a back pressure valve 3, a primary discharge piping system 4, an adsorption container 5, a secondary supply piping system 6, and a secondary discharge piping system 7.

[0027] The membrane module 1 is a module that incorporates a gas separation membrane that selectively permeates water vapor. The membrane module 1 separates water vapor and other gas components contained in the mixed gas using the gas separation membrane. The inside of the membrane module 1 is divided by the gas separation membrane into a primary side 1a, which is the inlet side, and a secondary side 1b, which is the outlet side.

[0028] One end of the primary side supply piping system 2 is connected to the primary side 1a of the membrane module 1. The other end of the primary side supply piping system 2 is connected to the mixed gas supply source. The primary side supply piping system 2 is a piping system that connects the mixed gas supply source to the primary side 1a of the membrane module 1, and is formed by pipes, fittings, valves, etc. The primary side supply piping system 2 supplies a mixed gas containing water vapor and harmful gas components from the supply source to the primary side 1a of the membrane module 1.

[0029] One example of a source of mixed gas is an exhaust system that discharges combustion gases from a combustion engine. The exhaust system of a combustion engine discharges combustion gases containing, for example, water vapor, carbon dioxide, nitrogen, and unreacted oxygen as a mixed gas. Carbon dioxide is a harmful gas component that cannot be emitted into the environment because of its high global warming potential.

[0030] Furthermore, one end of the primary side discharge piping system 4 is connected to the primary side 1a of the membrane module 1. The other end of the primary side discharge piping system 4 is connected to the inlet of the adsorption container 5. The primary side discharge piping system 4 is a piping system that discharges the gas from the primary side 1a of the membrane module 1 to the adsorption container 5, and is formed by pipes, fittings, valves, etc. In Figure 1, a back pressure valve 3 is installed upstream of the adsorption container 5 in the primary side discharge piping system 4.

[0031] One end of the secondary supply piping system 6 is connected to the outlet of the adsorption container 5. The other end of the secondary supply piping system 6 is connected to the secondary side 1b of the membrane module 1. The secondary supply piping system 6 is a piping system that supplies the gas treated by the adsorbent in the adsorption container 5 from the adsorption container 5 to the secondary side 1b of the membrane module 1, and is formed by pipes, fittings, valves, etc.

[0032] One end of the secondary discharge piping system 7 is connected to the secondary side 1b of the membrane module 1. The other end of the secondary discharge piping system 7 is connected to the outside of the gas treatment system 100. The secondary discharge piping system 7 is a piping system that discharges the gas from the secondary side 1b of the membrane module 1 to the outside of the system, and is formed by pipes, fittings, valves, etc.

[0033] Figures 2 and 3 illustrate gas separation methods using gas separation membranes. Figure 2 illustrates a gas separation method using polymer membranes. Figure 3 illustrates a gas separation method using ceramic membranes. Figures 2 and 3 schematically show the methods for separating combustion gases. Combustion gas is a mixed gas containing water vapor, carbon dioxide, nitrogen, unreacted oxygen, etc. Reference numeral 21 indicates a polymer membrane, and reference numeral 22 indicates a ceramic membrane.

[0034] As shown in Figure 2, polymer membranes are generally formed in the form of hollow fibers, which are porous tubular structures with a network structure. Examples of polymer membrane materials include fluororesins such as polyvinylidene fluoride, cellulose acetate, polysulfone, polyimide, polyamide, polyethylene, and polypropylene. Polymer membranes tend to be stronger under tensile force than compressive force. Therefore, gas separation using polymer membranes is performed by supplying a mixed gas to the inside of the hollow fibers and allowing the gas components contained in the mixed gas to permeate from the inside to the outside.

[0035] In gas separation using polymer membranes, the inside of the hollow fiber becomes the primary side, and the outside becomes the secondary side. When a mixed gas is supplied to the inside of the hollow fiber, gas components that easily permeate the polymer membrane permeate from the inside to the outside of the hollow fiber and are discharged to the outside of the module. On the other hand, gas components that do not easily permeate the polymer membrane remain inside the hollow fiber and are discharged to the outside of the module from the inside. When combustion gases are separated using a water vapor separation membrane, water vapor permeates to the outside, while carbon dioxide, nitrogen, and oxygen remain inside.

[0036] As shown in Figure 3, ceramic membranes are generally formed in a porous tubular shape. Examples of materials for ceramic membranes include silica, alumina, titania, zirconia, zeolite, silicon carbide, and silicon nitride. Ceramic membranes tend to be stronger under compressive forces than tensile forces. Therefore, gas separation using ceramic membranes is performed by supplying a mixed gas to the outside of a porous tube and allowing the gas components contained in the mixed gas to permeate from the outside to the inside.

[0037] In gas separation using ceramic membranes, the outside of the porous tube becomes the primary side, and the inside of the porous tube becomes the secondary side. When a mixed gas is supplied to the outside of the porous tube, gas components that easily permeate the ceramic membrane permeate from the outside to the inside of the porous tube and are discharged from the inside to the outside of the module. On the other hand, gas components that do not easily permeate the ceramic membrane remain on the outside of the porous tube and are discharged from the outside to the outside of the module. When combustion gases are separated using a water vapor separation membrane, water vapor permeates to the inside, while carbon dioxide, nitrogen, and oxygen remain on the outside.

[0038] As shown in Figures 2 and 3, the membrane module 1 can incorporate tubular gas separation membranes that form flow channels. The membrane module 1 can be formed by bundling multiple gas separation membranes that selectively permeate water vapor so that multiple flow channels are arranged in parallel. The multiple gas separation membranes are housed inside a casing so that space is formed around them. The outside of the gas separation membranes communicates with the inlet and outlet of the casing via flow channels. In addition, the inside of the gas separation membranes communicates with other inlets and outlets of the casing via different flow channels than those on the outside of the gas separation membranes.

[0039] The membrane module 1 may incorporate a polar membrane that utilizes differences in adsorption force according to polarity, or a molecular sieve membrane that utilizes differences in molecular size, as the gas separation membrane. As the polar membrane, a gas separation membrane having polarity with hydrophilic groups or the like bonded to it is used. As the molecular sieve membrane, it is preferable to use a mesoporous or microporous gas separation membrane having pores larger than water molecules.

[0040] The membrane module 1 may incorporate either a polymer membrane or a ceramic membrane as the gas separation membrane. Polymer membranes are easy to mold and allow for easy securing of membrane area. Furthermore, while polymer membranes readily permeate hydrogen, they are less affected by water vapor, making it easy to obtain high water vapor permeability. Ceramic membranes readily absorb hydrogen and are susceptible to the effects of water vapor adsorption and durability, but they offer higher durability, pressure resistance, and heat resistance compared to polymer membranes.

[0041] In gas separation using a gas separation membrane that selectively permeates water vapor, the amount of water vapor that permeates through the gas separation membrane is proportional to the partial pressure difference of water vapor formed between the primary and secondary sides. When water vapor permeates to the secondary side, the partial pressure of water vapor on the primary side decreases, while the partial pressure of water vapor on the secondary side increases. As the partial pressure difference between the primary and secondary sides decreases, the amount of water vapor permeated decreases. Therefore, the gas components that remain on the primary side are discharged to the outside.

[0042] In the case of the polymer membrane shown in Figure 2, gaseous components that remain inside the polymer membrane hinder contact between the polymer membrane and water vapor, so it is preferable to continuously discharge the gaseous components from the inside of the polymer membrane to the outside of the casing. In the case of the ceramic membrane shown in Figure 3, gaseous components that remain outside the ceramic membrane hinder contact between the ceramic membrane and water vapor, so it is preferable to continuously discharge the gaseous components from the outside of the ceramic membrane to the outside of the casing.

[0043] The gas treatment performed by the gas treatment system 100 shown in Figure 1 is carried out by transferring a mixed gas composed of multiple gas components using the pressure at which it is supplied to the membrane module 1, without inputting power from an external source such as electricity. By introducing a high-temperature and high-pressure mixed gas into the membrane module 1, gas separation using a gas separation membrane and immobilization by an adsorbent are performed without the use of pumps or blowers.

[0044] The gas treatment method according to this embodiment involves contacting a gas with a gas separation membrane that selectively permeates water vapor to separate the water vapor contained in the gas from gas components that do not permeate the gas separation membrane, adsorbing one or more of the separated gas components that do not permeate the gas separation membrane onto an adsorbent on the primary side of the gas separation membrane, supplying the gas treated by the adsorbent to the secondary side of the gas separation membrane to dilute the water vapor separated on the secondary side, and discharging the diluted gas on the secondary side of the gas separation membrane out of the system. While discharging the gas from the primary side of the gas separation membrane to the adsorption container, the flow rate of the gas flowing into the adsorption container is restricted to pressurize the upstream side where the gas separation membrane is located.

[0045] In Figure 1, a mixed gas containing water vapor and harmful gas components is supplied to the primary side 1a of the membrane module 1 through the primary side supply piping system 2. Preferably, the primary side supply piping system 2 does not have pumps, blowers, or other equipment installed to transfer the gas. The mixed gas can be transferred by the pressure at the supply source.

[0046] In membrane module 1, water vapor and other gaseous components are separated from each other by gas separation using a gas separation membrane. Water vapor permeates from the primary side 1a to the secondary side 1b of membrane module 1. On the other hand, the other gaseous components do not permeate from the primary side 1a to the secondary side 1b and remain on the primary side 1a of membrane module 1.

[0047] On the other hand, the gas component on the primary side 1a of the membrane module 1 is discharged from the primary side 1a of the membrane module 1. Then, it flows from the primary side 1a of the membrane module 1 to the adsorption container 5 through the primary side discharge piping system 4. It is preferable that the primary side discharge piping system 4 does not have pumps, blowers, or other devices installed to transfer the gas. The gas on the primary side 1a can be transferred by the pressure when it is supplied to the membrane module 1.

[0048] In Figure 1, a back pressure valve 3 is installed in the primary side discharge piping system 4. The back pressure valve 3 is a valve that allows gas exceeding a set pressure to flow from the primary side to the secondary side, and is designed so that the pressure on the primary side can be adjusted by adjusting the degree of opening. Before the gas discharged from the primary side 1a of the membrane module 1 flows into the adsorption container 5, the flow rate is limited by the back pressure valve 3, pressurizing the upstream side of the primary side discharge piping system 4 and the primary side 1a of the membrane module 1.

[0049] The back pressure valve 3 pressurizes the gas upstream of the back pressure valve 3 in the primary side discharge piping system 4, thereby increasing the pressure on the primary side 1a of the membrane module 1. As the partial pressure difference of water vapor formed between the primary side 1a and the secondary side 1b of the membrane module 1 increases, the amount of water vapor permeating through the gas separation membrane can be increased.

[0050] The adsorption container 5 contains an adsorbent capable of adsorbing one or more gas components that do not permeate the gas separation membrane of the membrane module 1. In the adsorption container 5, an adsorption treatment is performed in which the gas discharged from the primary side 1a of the membrane module 1 is brought into contact with the adsorbent. Through the adsorption treatment, harmful gas components that did not permeate the gas separation membrane are immobilized by adsorption onto the adsorbent. When combustion gas is separated using a water vapor separation membrane, carbon dioxide can be adsorbed onto the adsorbent.

[0051] As the adsorbent, a solid porous material with a predetermined pore size distribution can be used, depending on the type of gas component to be immobilized. Specific examples of adsorbents include zeolite, activated carbon, mesoporous silica, mesoporous carbon, and silica gel. The adsorbent may be in any material form, such as powder, porous material obtained by sintering powder, particulate, pelletized, or fibrous. Using a solid adsorbent makes re-release after chemical adsorption and de-absorption after absorption into a liquid less likely, allowing for relatively stable immobilization.

[0052] Generally, adsorbents are often provided in powder form or as porous materials formed by sintering powder in order to ensure a sufficient surface area. Such adsorbents experience a decrease in adsorption performance when moisture adheres to their surface. Furthermore, the adsorption performance of adsorbents tends to decrease as the ambient temperature increases. However, if sufficient water vapor is removed from the gas flowing into the adsorption container 5, additional moisture removal or active cooling upstream of the adsorption container 5 is not necessary.

[0053] The gas treated in the adsorption container 5 is discharged from the adsorption container 5. It then flows from the adsorption container 5 to the secondary side 1b of the membrane module 1 through the secondary supply piping system 6. Preferably, the secondary supply piping system 6 does not have pumps, blowers, or other equipment for transferring the gas. The gas treated in the adsorption container 5 can be transferred by the pressure at which it is supplied to the membrane module 1.

[0054] On the secondary side 1b of the membrane module 1, the water vapor separated on the secondary side 1b is diluted by the inflow of gas treated in the adsorption container 5. This dilution lowers the partial pressure of water vapor on the secondary side 1b. Because the partial pressure difference of water vapor between the primary side 1a and the secondary side 1b increases, the amount of water vapor permeating through the gas separation membrane can be increased.

[0055] When the amount of water vapor permeating through the gas separation membrane increases, the amount of water vapor flowing to the adsorption container 5 through the primary side discharge piping system 4 decreases. As a result, moisture is less likely to adhere to the adsorbent contained in the adsorption container 5, and the adsorption efficiency of harmful gas components by the adsorbent is increased. In addition, when cooling is required for the gas flowing into the adsorption container 5, the amount of water vapor, which has a large latent heat, flowing into the adsorption container 5 decreases, making it easier to secure cooling capacity.

[0056] The water vapor separated on the secondary side 1b of the membrane module 1 is diluted by the gas treated in the adsorption container 5 and then discharged from the secondary side 1b of the membrane module 1. It then flows from the secondary side 1b of the membrane module 1 to the outside of the gas treatment system 100 through the secondary side discharge piping system 7. It is preferable that the secondary side discharge piping system 7 does not have pumps, blowers, or other equipment for transferring the gas. The gas on the secondary side 1b can be transferred by the pressure at which it is supplied to the membrane module 1. The gas that has flowed through the secondary side discharge piping system 7 is released into the environment, for example, through a chimney, duct, etc.

[0057] The number of membrane modules 1 installed is not particularly limited. Multiple membrane modules 1 may be connected in parallel, in series, or both in parallel and in series. The gas from the primary side 1a of each membrane module 1 is flowed to the adsorption container 5, and the gas treated in the adsorption container 5 is supplied to the secondary side 1b of each membrane module 1 to dilute the water vapor. If the amount of water vapor contained in the mixed gas is known, the number of membrane modules 1 installed can be reduced based on the effect of water vapor dilution.

[0058] Furthermore, the number of adsorption containers 5 is not particularly limited. Multiple adsorption containers 5 may be connected in parallel, multiple may be connected in series, or multiple may be connected in both parallel and series configurations. The gas processed in each adsorption container 5 can be supplied to the secondary side 1b of each membrane module 1 to dilute the water vapor.

[0059] According to this gas treatment system 100 and gas treatment method, the gas discharged from the primary side of the gas separation membrane is supplied to the secondary side of the gas separation membrane after harmful gas components have been removed by adsorption. As the gas on the primary side of the gas separation membrane is discharged and the water vapor on the secondary side of the gas separation membrane is diluted, the partial pressure difference of water vapor formed between the primary and secondary sides of the gas separation membrane can be increased. Therefore, the amount of water vapor permeating through the gas separation membrane can be increased. Furthermore, since the gas discharged from the primary side of the gas separation membrane is pressurized by the back pressure valve, the partial pressure difference of water vapor formed between the primary and secondary sides of the gas separation membrane can be increased even further. Gas transfer in each piping system can be performed by the pressure at the time of supplying the mixed gas, without using pumps or blowers. Therefore, it is possible to increase the amount of water vapor permeating through the gas separation membrane without depending on power. By increasing the amount of water vapor permeation, contact between water vapor and the adsorbent is suppressed, and gas components that are not permitted to be discharged to the outside by adsorption to the adsorbent can be stably fixed within the system.

[0060] <Second Embodiment> Figure 4 is a schematic diagram showing the configuration of a gas treatment system according to the second embodiment. As shown in Figure 4, the gas treatment system 200 according to this embodiment comprises a membrane module 1, a primary supply piping system 2, a back pressure valve 3, a primary discharge piping system 4, an adsorption container 5, a secondary supply piping system 6, a secondary discharge piping system 7, and an orifice 8.

[0061] The gas treatment system 200 according to this embodiment differs from the gas treatment system 100 in that it is equipped with an orifice 8 on the primary side discharge piping system 4. The other main components of the gas treatment system 200 are the same as those of the gas treatment system 100.

[0062] Orifice 8 is a throttling mechanism that reduces the cross-sectional area of ​​the flow path through which the gas passes. Orifice 8 corresponds to a structure that reduces the pressure of the gas flowing through the primary side discharge piping system 4 by reducing the flow rate. Orifice 8 can be an orifice plate, orifice flange, orifice ring, etc. Orifice 8 is installed downstream of the back pressure valve 3 of the primary side discharge piping system 4 and upstream of the adsorption container 5, such that the cross-sectional area of ​​the flow path is smaller than that of the inlet side of the adsorption container 5.

[0063] When the orifice 8 is installed, the pressure loss in the gas flow path increases, and the flow rate of gas flowing through the primary discharge piping system 4 is restricted. As a result, the gas flowing into the adsorption container 5 is depressurized. If the gas flowing into the adsorption container 5 contains water vapor, the degree of superheating of the water vapor increases. As a result, even if water vapor remains on the primary side 1a of the membrane module 1, it becomes difficult for the water vapor to condense in the adsorption container 5. Thus, the decrease in the adsorption performance of the adsorbent due to moisture adhesion can be suppressed.

[0064] Furthermore, as a structure for reducing the pressure of the gas by decreasing the flow rate, in addition to the orifice 8, welded flow nozzles, pipe-type flow nozzles, conical venturi tubes, nozzle-type venturi tubes, etc., may be installed, as long as they can reduce the pressure of the gas flowing through the primary side discharge piping system 4.

[0065] The gas treatment performed by the gas treatment system 200 shown in Figure 4 is carried out by transferring a mixed gas composed of multiple gas components using the pressure at which it is supplied to the membrane module 1, without inputting power from an external source such as electricity. By introducing a high-temperature, high-pressure mixed gas into the membrane module 1, gas separation using a gas separation membrane and immobilization using an adsorbent are performed without the use of pumps or blowers.

[0066] The gas treatment method according to this embodiment involves contacting a gas with a gas separation membrane that selectively permeates water vapor to separate the water vapor contained in the gas from gas components that do not permeate the gas separation membrane, adsorbing one or more of the separated gas components that do not permeate the gas separation membrane onto an adsorbent on the primary side of the gas separation membrane, supplying the gas treated by the adsorbent to the secondary side of the gas separation membrane to dilute the water vapor separated on the secondary side, and discharging the diluted gas on the secondary side of the gas separation membrane out of the system. While discharging the gas from the primary side of the gas separation membrane to the adsorption container, the flow rate of the gas flowing into the adsorption container is restricted to pressurize the primary side of the gas separation membrane, and then the gas flowing into the adsorption container is depressurized by reducing the flow rate.

[0067] In Figure 4, after gas separation is performed using a gas separation membrane in membrane module 1, the gas component on the primary side 1a of membrane module 1 is discharged from the primary side 1a of membrane module 1. Then, it flows from the primary side 1a of membrane module 1 through the primary side discharge piping system 4, via the back pressure valve 3 and the orifice 8, to the adsorption container 5. The flow rate of the gas flowing through the primary side discharge piping system 4 is limited by the back pressure valve 3, pressurizing the upstream side of the primary side discharge piping system 4 and the primary side 1a of membrane module 1. Subsequently, the flow rate of the gas flowing through the primary side discharge piping system 4 is limited by the orifice 8, reducing the pressure of the gas flowing to the adsorption container 5. As the degree of superheating of the water vapor increases, it becomes more difficult for the water vapor to condense in the adsorption container 5.

[0068] With such a gas treatment system 200 and gas treatment method, similar to the gas treatment system 100 and gas treatment method described above, the partial pressure difference of water vapor formed between the primary and secondary sides of the gas separation membrane can be increased. Therefore, the amount of water vapor permeating through the gas separation membrane can be increased. In addition, since the gas discharged from the primary side of the gas separation membrane is depressurized before it comes into contact with the adsorbent, the increased superheating of the water vapor makes it difficult for the water vapor to condense, thus suppressing the decrease in the adsorption performance of the adsorbent due to moisture adhesion. Furthermore, there is no need to input power for the transfer of gas in each piping system or for the structure that depressurizes the gas by reducing the flow rate. Therefore, it is possible to increase the amount of water vapor permeating through the gas separation membrane without relying on power. By increasing the amount of water vapor permeation, contact between water vapor and the adsorbent is suppressed, and gas components that cannot be discharged to the outside by adsorption to the adsorbent can be stably fixed within the system.

[0069] <Third Embodiment> Figure 5 is a schematic diagram showing the configuration of a gas treatment system according to the third embodiment. As shown in Figure 5, the gas treatment system 300 according to this embodiment comprises a membrane module 1, a primary supply piping system 2, a primary discharge piping system 4, an adsorption container 5, a secondary supply piping system 6, a secondary discharge piping system 7, and an orifice 8.

[0070] The gas treatment system 300 according to this embodiment differs from the gas treatment system 100 in that it is equipped with an orifice 8 on the primary side discharge piping system 4 and does not have a back pressure valve 3 for adjusting the pressure on the upstream side of the primary side discharge piping system 4. The other main components of the gas treatment system 300 are the same as those of the gas treatment system 100.

[0071] Orifice 8 is a throttling mechanism that reduces the cross-sectional area of ​​the flow path through which the gas passes. Orifice 8 corresponds to a structure that reduces the pressure of the gas flowing through the primary side discharge piping system 4 by decreasing the flow rate. Orifice 8 can be an orifice plate, orifice flange, orifice ring, etc. Orifice 8 is installed upstream of the adsorption container 5 in the primary side discharge piping system 4, such that the cross-sectional area of ​​the flow path is smaller than that of the inlet side of the adsorption container 5.

[0072] When orifice 8 is installed, the pressure loss in the gas flow path increases, and the flow rate of gas through the primary discharge piping system 4 is restricted. As a result, the gas flowing into the adsorption container 5 is depressurized. If the gas flowing into the adsorption container 5 contains water vapor, the degree of superheating of the water vapor increases. Consequently, even if water vapor remains on the primary side 1a of the membrane module 1, it becomes difficult for the water vapor to condense in the adsorption container 5. Therefore, the decrease in the adsorption performance of the adsorbent due to moisture adhesion can be suppressed.

[0073] However, depending on the length and structure of the upstream side of the primary discharge piping system 4, the flow rate restriction by the orifice 8 may cause a pressure increase on the primary side 1a of the membrane module 1. Due to the action of the orifice 8, the partial pressure difference of water vapor formed between the primary side 1a and the secondary side 1b of the membrane module 1 may increase, and the amount of water vapor permeating through the gas separation membrane may increase. In such cases, the installation of the back pressure valve 3 can be omitted.

[0074] Furthermore, as a structure for reducing the pressure of the gas by decreasing the flow rate, in addition to the orifice 8, welded flow nozzles, pipe-type flow nozzles, conical venturi tubes, nozzle-type venturi tubes, etc., may be installed, as long as they can reduce the pressure of the gas flowing through the primary side discharge piping system 4.

[0075] The gas treatment performed by the gas treatment system 300 shown in Figure 5 is carried out by transferring a mixed gas composed of multiple gas components using the pressure at which it is supplied to the membrane module 1, without inputting power from an external source such as electricity. By introducing a high-temperature, high-pressure mixed gas into the membrane module 1, gas separation using a gas separation membrane and immobilization by an adsorbent are performed without the use of pumps or blowers.

[0076] The gas treatment method according to this embodiment involves contacting a gas with a gas separation membrane that selectively permeates water vapor to separate the water vapor contained in the gas from gas components that do not permeate the gas separation membrane, adsorbing one or more of the separated gas components that do not permeate the gas separation membrane onto an adsorbent on the primary side of the gas separation membrane, supplying the gas treated by the adsorbent to the secondary side of the gas separation membrane to dilute the water vapor separated on the secondary side, and discharging the diluted gas on the secondary side of the gas separation membrane out of the system. While discharging the gas on the primary side of the gas separation membrane to the adsorption container, the gas flowing into the adsorption container is depressurized by reducing the flow rate.

[0077] In Figure 5, after gas separation is performed using the gas separation membrane in the membrane module 1, the gas component on the primary side 1a of the membrane module 1 is discharged from the primary side 1a of the membrane module 1. Then, it flows from the primary side 1a of the membrane module 1 through the primary side discharge piping system 4, via the orifice 8, to the adsorption container 5. The flow rate of the gas flowing through the primary side discharge piping system 4 is restricted by the orifice 8, which reduces the pressure of the gas flowing to the adsorption container 5. As the degree of superheating of the water vapor increases, it becomes more difficult for the water vapor to condense in the adsorption container 5.

[0078] With such a gas treatment system 300 and gas treatment method, similar to the gas treatment system 100 and gas treatment method described above, the partial pressure difference of water vapor formed between the primary and secondary sides of the gas separation membrane can be increased. Therefore, the amount of water vapor permeating through the gas separation membrane can be increased. In addition, since the gas discharged from the primary side of the gas separation membrane is depressurized before it comes into contact with the adsorbent, the increased superheating of the water vapor makes it difficult for the water vapor to condense, thus suppressing the decrease in the adsorption performance of the adsorbent due to moisture adhesion. Furthermore, there is no need to supply power for the transfer of gas in each piping system or for the structure that depressurizes the gas by reducing the flow rate. In addition, the installation of back pressure valves is omitted, simplifying the system configuration. Therefore, with a simple system configuration, it is possible to increase the amount of water vapor permeating through the gas separation membrane without relying on power. By increasing the amount of water vapor permeation, contact between water vapor and the adsorbent is suppressed, and gas components that cannot be discharged to the outside by adsorption to the adsorbent can be stably fixed within the system.

[0079] <Fourth Embodiment> Figure 6 is a schematic diagram showing the configuration of the gas treatment system according to the fourth embodiment. As shown in Figure 6, the gas treatment system 400 according to this embodiment comprises a membrane module 1, a primary supply piping system 2, a back pressure valve 3, a primary discharge piping system 4, an adsorption container 5, a secondary supply piping system 6, a secondary discharge piping system 7, an air-cooled heat exchanger 9, and an air guide 10.

[0080] The gas treatment system 400 according to this embodiment differs from the gas treatment system 100 in that it is equipped with an air-cooled heat exchanger 9 on the primary side discharge piping system 4, and the air-cooled heat exchanger 9 is installed on the air guide 10. The other main components of the gas treatment system 400 are the same as those of the gas treatment system 100.

[0081] The heat exchanger 9 is an air-cooled heat exchanger that uses air as a heat transfer medium, and performs heat exchange between the gas flowing through the primary side discharge piping system 4, which is discharged from the primary side 1a of the membrane module 1, and the outside air. The heat exchanger 9 is installed downstream of the back pressure valve 3 and upstream of the adsorption container 5 in the primary side discharge piping system 4. The heat transfer tubes of the heat exchanger 9 form part of the primary side discharge piping system 4 and are installed on the air guide 10.

[0082] The air guide passage 10 is a passage through which air can flow, and it guides outside air from outside the gas processing system 400 to the heat transfer tubes of the heat exchanger 9. The air guide passage 10 may be formed by laying the heat transfer tubes of the heat exchanger 9 outside the gas processing system 400, or it may be formed as a structure that connects the outside and inside of the gas processing system 400. It is preferable that no pumps, blowers, or the like for supplying outside air are installed in the air guide passage 10.

[0083] By installing an air-cooled heat exchanger 9, the gas flowing through the primary side discharge piping system 4 can be cooled by heat exchange with outside air supplied through the air guide 10. If the gas flowing through the primary side discharge piping system 4 contains water vapor, the gas can be cooled and the water vapor condensed before it flows into the adsorption container 5. As a result, even if water vapor remains on the primary side 1a of the membrane module 1, it becomes difficult for the water vapor to condense in the adsorption container 5. Therefore, the decrease in the adsorption performance of the adsorbent due to moisture adhesion can be suppressed. In addition, since the gas flowing into the adsorption container 5 is cooled, the adsorption efficiency of the adsorbent can be improved.

[0084] Furthermore, by installing the air guide 10, outside air is guided to the heat exchanger 9 inside the gas processing system 400, thereby enhancing the cooling effect of the heat exchanger 9. With an air-cooled heat exchanger 9, moisture contained in the gas flowing through the primary side discharge piping system 4 and the gas flowing through the primary side discharge piping system 4 can be removed and the gas flowing through the primary side discharge piping system 4 cooled without the need for power input.

[0085] A drain for discharging condensed water from water vapor may be installed on the primary side discharge piping system 4, downstream of the heat exchanger 9 and upstream of the adsorption container 5. Alternatively, the drain for discharging condensed water may be installed on the inlet side of the adsorption container 5. The condensed water discharged from the primary side discharge piping system 4 can be discharged to the outside of the gas treatment system 400.

[0086] Furthermore, a structure that reduces the gas pressure by decreasing the flow rate may be installed on the primary side discharge piping system 4. Examples of such structures include orifices, welded flow nozzles, pipe-type flow nozzles, conical venturi tubes, and nozzle-type venturi tubes. Such a structure may be installed upstream of the heat exchanger 9 in the primary side discharge piping system 4, or downstream of the heat exchanger 9 and upstream of the adsorption container 5. From the viewpoint of effectively obtaining the effect of pressure reduction, it is preferable to install it downstream of the heat exchanger 9 in the primary side discharge piping system 4.

[0087] The gas treatment performed by the gas treatment system 400 shown in Figure 6 is carried out by transferring a mixed gas composed of multiple gas components using the pressure at which it is supplied to the membrane module 1, without inputting power from an external source such as electricity. By introducing a high-temperature, high-pressure mixed gas into the membrane module 1, gas separation using a gas separation membrane and immobilization by an adsorbent are performed without the use of pumps or blowers.

[0088] The gas treatment method according to this embodiment involves contacting a gas with a gas separation membrane that selectively permeates water vapor to separate the water vapor contained in the gas from gas components that do not permeate the gas separation membrane, adsorbing one or more of the separated gas components that do not permeate the gas separation membrane onto an adsorbent on the primary side of the gas separation membrane, supplying the gas treated by the adsorbent to the secondary side of the gas separation membrane to dilute the water vapor separated on the secondary side, and discharging the diluted gas on the secondary side of the gas separation membrane out of the system. While discharging the gas from the primary side of the gas separation membrane to the adsorption container, the flow rate of the gas flowing into the adsorption container is restricted to pressurize the primary side of the gas separation membrane, and then the gas flowing into the adsorption container is cooled by heat exchange with the outside air.

[0089] In Figure 6, after gas separation is performed using a gas separation membrane in the membrane module 1, the gas component on the primary side 1a of the membrane module 1 is discharged from the primary side 1a of the membrane module 1. Then, it flows from the primary side 1a of the membrane module 1 through the primary side discharge piping system 4, via the back pressure valve 3 and the air-cooled heat exchanger 9 to the adsorption container 5. The flow rate of the gas flowing through the primary side discharge piping system 4 is limited by the back pressure valve 3, pressurizing the upstream side of the primary side discharge piping system 4 and the primary side 1a of the membrane module 1. Subsequently, the gas flowing through the primary side discharge piping system 4 is cooled by heat exchange with the outside air guided to the air guide passage 10 by the air-cooled heat exchanger 9.

[0090] With such a gas treatment system 400 and gas treatment method, similar to the gas treatment system 100 and gas treatment method described above, the partial pressure difference of water vapor formed between the primary and secondary sides of the gas separation membrane can be increased. Therefore, the amount of water vapor permeating through the gas separation membrane can be increased. In addition, since the gas discharged from the primary side of the gas separation membrane is cooled by air cooling, the amount of moisture adhering to the surface of the adsorbent is reduced, and the temperature of the gas in contact with the adsorbent is lowered, thereby improving the adsorption efficiency. Furthermore, air-cooled heat exchangers do not require power input. Because the amount of water vapor permeating through the gas separation membrane increases, air-cooled heat exchangers and air ducts can be miniaturized to the minimum necessary size. Therefore, in a system suitable for miniaturization, it is possible to increase the amount of water vapor permeating through the gas separation membrane without relying on power, while improving the adsorption efficiency of the adsorbent. By increasing the amount of water vapor permeation, contact between water vapor and the adsorbent is suppressed, and gas components that cannot be discharged to the outside by adsorption to the adsorbent can be stably fixed within the system.

[0091] <Fifth Embodiment> Figure 7 is a schematic diagram showing the configuration of the gas treatment system according to the fifth embodiment. As shown in Figure 7, the gas treatment system 500 according to this embodiment comprises a membrane module 1, a primary supply piping system 2, a back pressure valve 3, a primary discharge piping system 4, an adsorption container 5, a secondary supply piping system 6, a secondary discharge piping system 7, a water-cooled heat exchanger 11, and a cooling tank 12.

[0092] The gas treatment system 500 according to this embodiment differs from the gas treatment system 100 in that it is equipped with a water-cooled heat exchanger 11 on the primary side discharge piping system 4, and the water-cooled heat exchanger 11 is installed in a cooling tank 12. Cooling water 13 is stored in the cooling tank 12. Other main components of the gas treatment system 500 are the same as those of the gas treatment system 100.

[0093] The heat exchanger 11 is a water-cooled heat exchanger that uses cooling water 13 as a heat transfer medium, and performs heat exchange between the gas flowing through the primary side discharge piping system 4 discharged from the primary side 1a of the membrane module 1 and the cooling water 13 stored in the cooling tank 12. The heat exchanger 11 is installed downstream of the back pressure valve 3 of the primary side discharge piping system 4 and upstream of the adsorption container 5. The heat transfer tubes of the heat exchanger 11 form part of the primary side discharge piping system 4 and are installed inside the cooling tank 12.

[0094] The cooling tank 12 is an open-type tank, and cooling water 13 is prepared before processing the mixed gas. The cooling tank 12 can be installed outdoors or elsewhere outside the gas processing system 500. With an open-type cooling tank 12, heat dissipation and pressure release from the gas processing system 500 to the outside can be performed efficiently without power. It is preferable that the cooling tank 12 does not have a pump or the like installed to circulate the cooling water 13.

[0095] By installing a water-cooled heat exchanger 11, the gas flowing through the primary side discharge piping system 4 can be cooled by heat exchange with the cooling water 13 stored in the cooling tank 12. If the gas flowing through the primary side discharge piping system 4 contains water vapor, the gas can be cooled and the water vapor condensed before it flows into the adsorption container 5. As a result, even if water vapor remains on the primary side 1a of the membrane module 1, it becomes less likely for the water vapor to condense in the adsorption container 5. Therefore, the decrease in the adsorption performance of the adsorbent due to moisture adhesion can be suppressed. In addition, since the gas flowing into the adsorption container 5 is cooled, the adsorption efficiency of the adsorbent can be improved.

[0096] Furthermore, by installing the cooling tank 12, the required amount of cooling water 13 can be stored in advance, so that moisture contained in the gas flowing through the primary side discharge piping system 4 can be removed and the gas flowing through the primary side discharge piping system 4 can be cooled without supplying power. Water, brine, etc. can be used as the cooling water 13.

[0097] Furthermore, a structure that reduces the gas pressure by decreasing the flow rate may be installed on the primary side discharge piping system 4. Examples of such structures include orifices, welded flow nozzles, pipe-type flow nozzles, conical venturi tubes, and nozzle-type venturi tubes. Such a structure may be installed upstream of the heat exchanger 11 in the primary side discharge piping system 4, or downstream of the heat exchanger 11 and upstream of the adsorption container 5. From the viewpoint of effectively obtaining the effect of pressure reduction, it is preferable to install it downstream of the heat exchanger 11 in the primary side discharge piping system 4.

[0098] The gas treatment performed by the gas treatment system 500 shown in Figure 7 is carried out by transferring a mixed gas composed of multiple gas components using the pressure at which it is supplied to the membrane module 1, without inputting power from an external source such as electricity. By introducing a high-temperature, high-pressure mixed gas into the membrane module 1, gas separation using a gas separation membrane and immobilization by an adsorbent are performed without the use of pumps or blowers.

[0099] The gas treatment method according to this embodiment involves contacting a gas with a gas separation membrane that selectively permeates water vapor to separate the water vapor contained in the gas from gas components that do not permeate the gas separation membrane, adsorbing one or more of the separated gas components that do not permeate the gas separation membrane onto an adsorbent on the primary side of the gas separation membrane, supplying the gas treated by the adsorbent to the secondary side of the gas separation membrane to dilute the water vapor separated on the secondary side, and discharging the diluted gas on the secondary side of the gas separation membrane out of the system. While discharging the gas from the primary side of the gas separation membrane to the adsorption container, the flow rate of the gas flowing into the adsorption container is restricted to pressurize the primary side of the gas separation membrane, and then the gas flowing into the adsorption container is cooled by heat exchange with cooling water.

[0100] In Figure 7, after gas separation is performed using a gas separation membrane in the membrane module 1, the gas component on the primary side 1a of the membrane module 1 is discharged from the primary side 1a of the membrane module 1. Then, it flows from the primary side 1a of the membrane module 1 through the primary side discharge piping system 4, via the back pressure valve 3 and the water-cooled heat exchanger 11 to the adsorption container 5. The flow rate of the gas flowing through the primary side discharge piping system 4 is limited by the back pressure valve 3, pressurizing the upstream side of the primary side discharge piping system 4 and the primary side 1a of the membrane module 1. Subsequently, the gas flowing through the primary side discharge piping system 4 is cooled by heat exchange with the cooling water 13 stored in the cooling tank 12 by the water-cooled heat exchanger 11.

[0101] With such a gas treatment system 500 and gas treatment method, similar to the gas treatment system 100 and gas treatment method described above, the partial pressure difference of water vapor formed between the primary and secondary sides of the gas separation membrane can be increased. Therefore, the amount of water vapor permeating through the gas separation membrane can be increased. In addition, since the gas discharged from the primary side of the gas separation membrane is cooled by water cooling, the amount of moisture adhering to the surface of the adsorbent is reduced, and the temperature of the gas in contact with the adsorbent is lowered, thereby improving the adsorption efficiency. With the water-cooled method, a higher cooling capacity can be obtained compared to the air-cooled method. Also, there is no need to supply power to the water-cooled heat exchanger. Because the amount of water vapor permeating through the gas separation membrane is increased, the water-cooled heat exchanger and cooling tank can be miniaturized to the minimum necessary size. Therefore, in a system suitable for miniaturization, it is possible to increase the amount of water vapor permeating through the gas separation membrane without relying on power, while improving the adsorption efficiency of the adsorbent. By increasing the amount of water vapor permeate, contact between water vapor and the adsorbent is suppressed, and gaseous components that cannot be released to the outside by adsorption onto the adsorbent can be stably fixed within the system.

[0102] <Sixth Embodiment> Figure 8 is a schematic diagram showing the configuration of the gas treatment system according to the sixth embodiment. As shown in Figure 8, the gas treatment system 600 according to this embodiment comprises a membrane module 1, a primary supply piping system 2, a back pressure valve 3, a primary discharge piping system 4, an adsorption container 5, a secondary supply piping system 6, a secondary discharge piping system 7, and a combustible gas treatment device 14.

[0103] The gas treatment system 600 according to this embodiment differs from the gas treatment system 100 described above in that it is equipped with a gas treatment device 14 on the primary side discharge piping system 4. The other main components of the gas treatment system 600 are the same as those of the gas treatment system 100 described above.

[0104] The gas treatment device 14 is equipped with a reactor that performs gas reactions and removes one or more of the gas components flowing through the primary side discharge piping system 4 by material conversion through reaction. The gas treatment device 14 is installed downstream of the back pressure valve 3 and upstream of the adsorption container 5 in the primary side discharge piping system 4. The reactor of the gas treatment device 14 is installed to communicate with the primary side discharge piping system 4.

[0105] In the gas treatment device 14, for example, gases that inhibit the adsorption process, discharged from the primary side 1a of the membrane module 1, are removed. Examples of gases that inhibit the adsorption process include flammable gases that pose a risk of combustion. Examples of flammable gases include hydrogen, hydrocarbons, carbon monoxide, and some chlorofluorocarbons (CFCs). Reactions that convert flammable gases into different substances can include combustion reactions, catalytic oxidation reactions, partial oxidation reactions, hydrocracking reactions, direct decomposition reactions, and combinations thereof.

[0106] The gas treatment device 14 can include a catalytic tower for holding a catalyst, an inline catalytic tube for holding a catalyst, a combustor equipped with a spark plug for generating a spark, a red-hot heating element, an inline combustor equipped with these, or a combination thereof. The combustor preferably includes a battery that enables ignition without power supply, and an ignition coil that converts the power supply voltage to a high voltage.

[0107] By installing the gas treatment device 14, even if the gas flowing through the primary side discharge piping system 4 contains gas components that hinder adsorption treatment, these gas components can be decomposed or flammable gases converted into non-flammable gases through combustion reactions or catalytic reactions. For example, burning unreacted fuel gases contained in the combustion gas converts hydrogen and hydrocarbons into carbon dioxide and water vapor. This prevents flammable gases from flowing to the downstream adsorption container 5, thus reducing the risk of hindering adsorption treatment and combustion downstream.

[0108] Furthermore, a structure that reduces the gas pressure by decreasing the flow rate may be installed on the primary side discharge piping system 4. Examples of such structures include orifices, welded flow nozzles, pipe-type flow nozzles, conical venturi tubes, and nozzle-type venturi tubes. Such a structure may be installed upstream of the gas treatment device 14 on the primary side discharge piping system 4, or downstream of the gas treatment device 14 on the primary side discharge piping system 4 and upstream of the adsorption container 5. From the viewpoint of effectively obtaining the effect of pressure reduction, it is preferable to install it downstream of the gas treatment device 14 on the primary side discharge piping system 4.

[0109] Furthermore, an air-cooled heat exchanger 9 or a water-cooled heat exchanger 11 may be installed on the primary side discharge piping system 4. The air-cooled heat exchanger 9 or the water-cooled heat exchanger 11 may be installed upstream of the gas treatment device 14 in the primary side discharge piping system 4, or downstream of the gas treatment device 14 and upstream of the adsorption container 5 in the primary side discharge piping system 4. From the viewpoint of cooling after combustion and depending on the optimal temperature of the catalytic reaction, it is preferable to install it downstream of the gas treatment device 14 in the primary side discharge piping system 4.

[0110] The gas treatment performed by the gas treatment system 600 shown in Figure 8 is carried out by transferring a mixed gas composed of multiple gas components using the pressure at which it is supplied to the membrane module 1, without inputting power from an external source such as electricity. By introducing a high-temperature, high-pressure mixed gas into the membrane module 1, gas separation using a gas separation membrane and immobilization by an adsorbent are performed without the use of pumps or blowers.

[0111] The gas treatment method according to this embodiment involves contacting a gas with a gas separation membrane that selectively permeates water vapor to separate the water vapor contained in the gas from gas components that do not permeate the gas separation membrane, adsorbing one or more of the separated gas components that do not permeate the gas separation membrane onto an adsorbent on the primary side of the gas separation membrane, supplying the gas treated by the adsorbent to the secondary side of the gas separation membrane to dilute the water vapor separated on the secondary side, and discharging the diluted gas on the secondary side of the gas separation membrane out of the system. While discharging the gas from the primary side of the gas separation membrane to the adsorption vessel, the flow rate of the gas flowing into the adsorption vessel is restricted to pressurize the primary side of the gas separation membrane, and then one or more of the gas components that do not permeate the gas separation membrane flowing into the adsorption vessel are removed by reaction.

[0112] In Figure 8, after gas separation is performed using the gas separation membrane in the membrane module 1, the gas components on the primary side 1a of the membrane module 1 are discharged from the primary side 1a of the membrane module 1. Then, the gas flows from the primary side 1a of the membrane module 1 through the primary side discharge piping system 4, via the back pressure valve 3 and the gas treatment device 14, to the adsorption container 5. The flow rate of the gas flowing through the primary side discharge piping system 4 is limited by the back pressure valve 3, pressurizing the upstream side of the primary side discharge piping system 4 and the primary side 1a of the membrane module 1. Subsequently, gas components that interfere with the adsorption process flowing through the primary side discharge piping system 4 are removed by the gas treatment device 14.

[0113] With such a gas treatment system 600 and gas treatment method, similar to the gas treatment system 100 and gas treatment method described above, the partial pressure difference of water vapor formed between the primary and secondary sides of the gas separation membrane can be increased. Therefore, the amount of water vapor permeating through the gas separation membrane can be increased. In addition, since gases that inhibit the adsorption treatment, such as flammable gases discharged from the primary side of the gas separation membrane, are removed by material conversion through reaction, the risk of inhibition of the adsorption treatment or combustion downstream can be reduced. Furthermore, since batteries or catalysts can be used to remove gases that inhibit the adsorption treatment, there is no need to input power. Thus, it is possible to reduce the risk of inhibition of the adsorption treatment or combustion, improve the adsorption efficiency of the adsorbent, and increase the amount of water vapor permeating through the gas separation membrane without relying on power. By increasing the amount of water vapor permeation, contact between water vapor and the adsorbent is suppressed, and gas components that are not permitted to be discharged to the outside by adsorption to the adsorbent can be stably fixed within the system.

[0114] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. For example, the present invention is not necessarily limited to having all the configurations of the embodiments described above. Some configurations of one embodiment can be replaced with other configurations, some configurations of one embodiment can be added to other forms, and some configurations of one embodiment can be omitted. [Explanation of Symbols]

[0115] 1. Membrane module 1a Primary side 1b Secondary side 2 Primary side supply piping system 3. Back pressure valve 4 Primary side discharge piping system 5 Adsorption container 6 Secondary supply piping system 7 Secondary discharge piping system 8 Orifice 9. Air-cooled heat exchanger 10 Air guide path 11. Water-cooled heat exchanger 12 Cooling tank 13 Cooling water 14 Gas treatment equipment 21 Polymer membrane 22 Ceramic film 100 Gas Processing Systems 200 Gas Processing Systems 300 Gas Processing Systems 400 Gas Processing System 500 Gas Processing Systems 600 Gas Processing System

Claims

1. A gas treatment system comprising: a membrane module having a gas separation membrane that selectively permeates water vapor, the membrane separating the interior into a primary side and a secondary side; an adsorption container containing an adsorbent capable of adsorbing one or more gas components that do not permeate the gas separation membrane; a primary side discharge piping system for discharging the gas from the primary side to the adsorption container; a secondary side supply piping system for supplying the gas treated by the adsorbent to the secondary side; and a secondary side discharge piping system for discharging the gas from the secondary side to the outside of the system.

2. A gas processing system according to claim 1, A gas treatment system comprising a structure on the primary side discharge piping system that reduces the pressure of the gas by decreasing its flow rate.

3. A gas processing system according to claim 2, A gas processing system in which the structure that reduces the pressure of the aforementioned gas by decreasing its flow rate is an orifice.

4. A gas processing system according to claim 1, A gas treatment system comprising a heat exchanger on the primary side discharge piping system for performing heat exchange of the gas discharged from the primary side.

5. A gas processing system according to claim 4, A gas processing system in which the heat exchanger is air-cooled and performs heat exchange between the gas and the outside air.

6. A gas processing system according to claim 4, A gas processing system in which the heat exchanger is a water-cooled type that performs heat exchange between the gas and cooling water.

7. A gas processing system according to claim 1, A gas treatment system comprising a gas treatment device on the primary side discharge piping system that removes one or more gas components that do not permeate the gas separation membrane by reaction.

8. A gas processing system according to claim 1, A gas treatment system in which the gas separation membrane is a polymer membrane.

9. A gas processing system according to claim 1, A gas processing system in which the gas separation membrane is a ceramic membrane.

10. By bringing a gas into contact with a gas separation membrane that selectively permeates water vapor, the water vapor contained in the gas and the gas components contained in the gas that do not permeate the gas separation membrane are separated. One or more of the gas components that do not permeate the gas separation membrane, separated on the primary side of the gas separation membrane, are adsorbed onto an adsorbent. The gas treated with the adsorbent is supplied to the secondary side of the gas separation membrane to dilute the water vapor separated on the secondary side. A gas treatment method for discharging the diluted gas from the secondary side of the gas separation membrane to the outside of the system.

Images