Gas purification apparatus and purified gas

Abstract

The present invention aims to provide a gas purification apparatus that can improve and maintain gas processing capacity while suppressing increases in purification costs. [Means of achievement] A gas purification apparatus comprising a heating mechanism, a gas separation membrane element, and a heat exchange mechanism configured to exchange heat between the supply gas and the non-permeable gas of the gas separation membrane element.

Description

[Technical Field]

[0001] This invention relates to a gas purification apparatus and purified gas. [Background technology]

[0002] Membrane separation is a known method for selectively separating and purifying specific gas components from a mixture containing multiple gas components. Because membrane separation utilizes a pressure difference, it has the advantage of consuming less energy compared to other separation and purification methods.

[0003] Gas separation membranes used in membrane separation methods separate permeable gases from non-permeable gases by having higher gas permeability for specific gas components (permeate gases) compared to gas permeability for other gas components (non-permeate gases). Gas separation membranes are housed in partitioned spaces and used as gas separation membrane elements that increase the gas processing capacity per unit volume.

[0004] When a mixed gas is separated using a gas separation membrane element, the temperature inside the element decreases due to the Joule-Thomson effect as the permeate gas passes through the membrane. This temperature decrease could lead to a decrease in gas permeability, as condensed low-boiling point components could adsorb onto the membrane if the gas being separated contains low-boiling point components. As a gas separation device that suppresses clogging of inorganic membranes caused by the liquefaction or solidification of heavy hydrocarbons, a gas separation device that maintains the temperature inside the gas separation membrane module above the dew point of heavy hydrocarbons is known (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] WO2017 / 056134 publication [Overview of the project] [Problems that the invention aims to solve]

[0006] Patent Document 1 discloses a non-hydrocarbon gas separation apparatus for separating non-hydrocarbon gases from natural gas containing non-hydrocarbon gases, comprising: a supply line to which natural gas containing heavy hydrocarbons, which are hydrocarbons with 5 or more carbon atoms, is supplied; an outlet line from which the natural gas separated from the non-hydrocarbon gases flows out; and an outlet line from which the non-hydrocarbon gases separated from the natural gas are discharged; a separation module connected to these lines; an inorganic membrane made of an inorganic material housed within the separation module, which allows the non-hydrocarbon gases contained in the natural gas supplied from the supply line to permeate to the outlet line and allows the natural gas from which the non-hydrocarbon gases have been separated to flow to the outlet line; and a heating unit positioned on the supply line side for heating the natural gas, wherein the heating unit heats the natural gas supplied to the separation module in response to the temperature drop caused by the permeation of the inorganic membrane by the non-hydrocarbon gases, so that the temperature inside the separation module is maintained at a temperature higher than the dew point temperature of the heavy hydrocarbons. However, the method described in Patent Document 1 has the problem that the purification cost is high because a lot of energy is required to heat the inorganic membrane.

[0007] Therefore, the present invention aims to provide a gas purification apparatus that can improve and maintain gas processing capacity while suppressing an increase in purification costs. [Means for solving the problem]

[0008] To solve the above problems, the present invention has the following configuration.

[0009] In other words, the present invention is a gas purification apparatus comprising a gas separation membrane and a housing for housing the gas separation membrane, wherein the housing contains a gas separation membrane element having a non-permeable side through which a supply gas is introduced with the gas separation membrane in between, and a permeable side through which the permeable gas that has permeated the gas separation membrane is discharged; a heating mechanism for heating the supply gas; and a heat exchange mechanism disposed upstream of the heating mechanism and configured to exchange heat between the non-permeable gas discharged from the non-permeable side of the gas separation membrane element and the supply gas. [Effects of the Invention]

[0010] The gas purification apparatus of the present invention performs heat exchange between the supply gas before it is heated by the heating mechanism and the non-permeable gas discharged from the non-permeable side of the gas separation membrane element. By preheating the supply gas, the energy required for heating in the heating mechanism can be reduced, and the gas processing capacity of the gas separation membrane element can be improved and maintained while suppressing an increase in purification costs. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram showing one embodiment of the gas purification apparatus of the present invention. [Figure 2] This is a schematic diagram showing another embodiment of the gas purification apparatus of the present invention. [Modes for carrying out the invention]

[0012] The present invention will be described below with reference to the drawings, but the present invention is not limited to these examples.

[0013] The gas purification apparatus of the present invention comprises a gas separation membrane and a housing that houses the gas separation membrane, wherein the housing contains a gas separation membrane element having a non-permeable side through which a supply gas is introduced and a permeable side through which permeable gas that has permeated the gas separation membrane is discharged, a heating mechanism for heating the supply gas, and a heat exchange mechanism disposed upstream of the heating mechanism and configured to exchange heat between the non-permeable gas discharged from the non-permeable side of the gas separation membrane element and the supply gas. As described above, in conventional technology, clogging of the inorganic membrane caused by the liquefaction or solidification of heavy hydrocarbons is suppressed by heating above the dew point temperature of the heavy hydrocarbons, but there was a problem that the purification cost increased due to heating. By using the gas purification apparatus of the present invention, heat exchange is performed between the relatively high temperature non-permeable gas discharged from the non-permeable side of the gas separation membrane element and the relatively low temperature supply gas before heating, so that the supply gas is preheated, and the energy required to heat the supply gas in the heating mechanism can be suppressed.

[0014] Figure 1 shows a gas purification apparatus 1 having a heating mechanism 2, a gas separation membrane element 5, and a heat exchange mechanism 4, as one embodiment of the present invention.

[0015] The gas separation membrane element 5 has a non-permeable side through which the supply gas is introduced, and a permeable side through which the permeated gas that has permeated the gas separation membrane 3 is discharged, with the gas separation membrane 3 housed inside the casing. The supply gas to be separated (pathways 11 and 12) is supplied to the non-permeable side of the gas separation membrane element 5 via the heat exchange mechanism 4 and the heating mechanism 2, and is separated into non-permeable gas (pathway 13) and permeable gas that has permeated the gas separation membrane 3 (pathway 15).

[0016] The heat exchange mechanism 4 performs heat exchange between the non-permeate gas before heat exchange (path 13) discharged from the non-permeate side of the gas separation membrane element 5 and the supply gas before heat exchange (path 11). Since the non-permeate gas before heat exchange (path 13) is at a higher temperature than the supply gas before heat exchange (path 11), the temperature of the supply gas increases and the temperature of the non-permeate gas decreases after passing through the heat exchange mechanism 4. Examples of the heat exchange mechanism 4 include a recuperator, a plate heat exchanger, a shell and tube heat exchanger, a finned tube heat exchanger, a spiral heat exchanger, etc. However, a simple mechanism in which the high-temperature side piping and the low-temperature side piping are adjacent directly or via a heat medium may also be used.

[0017] The heating mechanism 2 heats the supply gas after heat exchange (path 12) and controls the temperature. Examples of the heating mechanism include an oil bath, a water bath, a mantle heater, an electric heater, a hot air heater, an infrared heater, an induction heating device, a microwave heating device, etc. Note that the heating mechanism 2 may be located in front of the gas separation membrane element 5 as shown in FIG. 1, or may be a mechanism that covers and heats the entire gas separation membrane element 5. Further, it is preferable to provide a heat preservation mechanism that prevents the temperature of the heated gas from decreasing.

[0018] In one aspect of the present invention, the non-permeate gas after heat exchange (path 14) is recovered as a product through an additional purification process etc. not shown in the figure. Further, the permeate gas that has passed through the gas separation membrane 3 is recovered from path 15 and discharged or utilized after post-treatment not shown in the figure.

[0019] The heating mechanism of the gas purification device of the present invention preferably has a function of controlling the temperature of the supplied gas to 50°C or higher and 300°C or lower. By controlling the temperature of the supplied gas to 50°C or higher, the gas permeability of the gas separation membrane is improved, so that the required membrane area of the gas separation membrane can be reduced. In addition, since the heat exchange efficiency in the heat exchange mechanism is improved, the temperature of the supplied gas is more preferably controlled to 120°C or higher, further preferably 150°C or higher, and even more preferably 200°C or higher. On the other hand, by controlling the temperature of the supplied gas to 300°C or lower, it is possible to prevent excessive energy consumption for heating the gas separation membrane. As described above, the heating of the supplied gas by the heating mechanism may be performed before being introduced into the gas separation membrane element, or may be in a mode where the gas separation membrane element is included and heated. From the viewpoint of suppressing the influence of temperature drop accompanying gas separation, it is more preferable to be in a mode of heating including the gas separation membrane element. Further, when the supplied gas contains liquid water, the latent heat becomes large and the energy required for heating becomes large, so it is preferable that the supplied gas is heated after passing through a wet process or after drain removal.

[0020] In addition, in one aspect of the present invention, the heat exchange mechanism is preferably configured to perform heat exchange using both the non-permeating gas discharged from the non-permeating side of the gas separation membrane element and the permeating gas discharged from the permeating side as heat sources and the supplied gas as a non-heat source. By doing so, it becomes possible to more efficiently reuse the thermal energy added to the supplied gas by the heating mechanism.

[0021] The supplied gas of the present invention is a mixed gas containing at least a pair of highly permeable gas and low-permeable gas as main components. By the gas purification device of the present invention, the low-permeable gas is concentrated as the non-permeating gas of the gas separation membrane element, and the highly permeable gas is concentrated as the permeating gas. Examples of the highly permeable gas include H2, He, H2O, CO2, etc., and examples of the low-permeable gas include N2, CH4, fluorine-containing gas, etc. The supplied gas may contain impurity components other than the main components.

[0022] The gas purification apparatus of the present invention can be suitably used for purifying supply gases containing aromatic compounds. That is, it is preferable that the supply gas is a gas containing aromatic compounds. Aromatic compounds are highly condensable and tend to adsorb onto gas separation membranes, reducing gas permeability. However, by supplying them to the gas separation membrane module at a high temperature using the gas purification apparatus of the present invention, it is possible to shift the adsorption / desorption equilibrium to the desorption side while suppressing an increase in purification costs, thereby maintaining the gas processing rate.

[0023] Examples of aromatic compounds include benzene, toluene, xylene, phenol, styrene, benzoic acid, benzenesulfonic acid, and benzenephosphonic acid. Aromatic compounds may also be polycyclic aromatic compounds.

[0024] In embodiments where the supply gas contains aromatic compounds, the partial pressure of the aromatic compounds in the supply gas is preferably 0.1 kPa or more and 30 kPa or less. A partial pressure of 0.1 kPa or more in the supply gas increases the operating temperature required to maintain gas permeability, thus increasing the cost reduction effect of supply gas preheating. A partial pressure of 0.5 kPa or more in the supply gas is more preferable, and even more preferable, is 1 kPa or more. On the other hand, a partial pressure of 30 kPa or less in the supply gas reduces the temperature required to maintain gas permeability to 300°C or less, thereby reducing the energy required for heating. Note that when the supply gas contains multiple aromatic compounds, the partial pressure of the aromatic compounds in the supply gas can be expressed as the sum of the partial pressures of the individual aromatic compounds. For example, if the partial pressure of benzene is 1 kPa and the partial pressure of toluene is 1 kPa in the supply gas, the partial pressure of the aromatic compounds will be 2 kPa.

[0025] The partial pressure of aromatic compounds in the supply gas can be calculated from the product of the concentration of aromatic compounds in the supply gas and the total pressure of the supply gas. The concentration of aromatic compounds in the supply gas can be measured by gas chromatography-mass spectrometry (GC-MS) after sampling the supply gas at atmospheric pressure.

[0026] A gas separation membrane is a membrane in which the permeability of highly permeable gases and low permeable gases differs. Examples of gas separation membranes include zeolite membranes, metal-organic frame (MOF) membranes, inorganic membranes such as carbon membranes, and polymer membranes. When the gas separation membrane element is heated to 100°C or higher, or when the supply gas contains reactive components, it is preferable to use an inorganic membrane, and more preferable to use a carbon membrane, due to their excellent heat resistance and chemical resistance.

[0027] A zeolite membrane is a gas separation membrane having a separation functional layer made of zeolite. Examples of zeolite membranes include membranes made of aluminosilicate, such as NaX type (FAU), ZSM-5, MOR, silicalite, and type A. It is more preferable to use a medium-pore zeolite with a 10-membered ring, as the pore size is between the size of the carrier gas and the size of the gas to be purified. An example of a medium-pore zeolite with a 10-membered ring is ZSM-5. Two or more of these may be used.

[0028] MOF membranes are gas separation membranes having a separation functional layer made of MOF. Examples of MOF membranes include membranes made of Cu-BTC, MOF-5, IRMOF-3, MIL-47, MIL-53, MIL-96, MMOF, SIM-1, ZIF-7, ZIF-8, ZIF-22, ZIF-69, ZIF-90, etc. Two or more of these may be used.

[0029] A carbon membrane is a gas separation membrane having a separation functional layer made of carbon. Examples of carbon membranes include membranes made by carbonizing polyphenylene oxide, polyvinyl alcohol, polyacrylonitrile, phenolic resin, fully aromatic polyester, unsaturated polyester resin, alkyd resin, melamine resin, urea resin, polyimide resin, diallyl phthalate resin, lignin resin, urethane resin, etc. Two or more of these may be used. When separating a supply gas containing aromatic compounds using a gas separation membrane that is a carbon membrane, aromatic compounds are easily adsorbed onto the highly hydrophobic carbon membrane, so it is necessary to operate at a temperature sufficiently higher than the dew point temperature in order to maintain the gas processing rate. The gas purification apparatus of the present invention can be used particularly suitably in this embodiment.

[0030] Examples of gas separation membrane shapes include flat membranes, hollow fiber membranes, and solid fiber membranes. Hollow fiber membranes are preferred for gas separation membranes because they allow for a larger membrane area per unit volume.

[0031] Gas separation membranes, which are hollow fiber membranes, are preferably used as gas separation membrane modules (hereinafter sometimes simply referred to as "modules") in which the gas separation membranes are filled inside a housing. A gas separation membrane module is a module in which gas separation membrane elements, each consisting of hollow fiber membranes bundled in a substantially straight line and fixed at least one end with a potting material, are fixed to the inner surface of a vessel.

[0032] Methods for fixing the gas separation membrane element to the inner surface of the vessel include, for example, directly fixing it to the inner surface of the vessel using the potting material itself, or fixing it inside the vessel via an adapter (for example, an O-ring) that can ensure liquid-tightness or airtightness. It is preferable to fix it inside the vessel via an adapter or the like, as this allows only the gas separation membrane element to be replaced when the performance of the gas separation membrane deteriorates over time.

[0033] Furthermore, in one aspect of the present invention, the gas separation membrane element may have a casing separate from the vessel (hereinafter referred to as "element casing"). Examples of materials for the element casing include metal, resin, fiber-reinforced plastic (FRP), etc., which can be appropriately selected depending on the situation in which it is used. Resin is preferred because it has high adaptability to the curing shrinkage of the potting material, and polyphenylene sulfide, polytetrafluoroethylene, polyethylene, polypropylene, polyetheretherketone, polyphenylene ether, polyetherimide, polyamideimide, and polysulfone are more preferred because they combine moldability and chemical resistance.

[0034] The potting portion of the gas separation membrane element may be one or multiple locations, but from the viewpoint of sufficiently fixing the position of the gas separation membrane and ensuring the effective surface area of ​​the gas separation membrane, it is preferable to fix both ends of multiple gas separation membranes bundled in a substantially straight line with potting material. Alternatively, the bundled multiple gas separation membranes may be bent into a U-shape and both ends of the gas separation membrane may be fixed at one location with potting material, or only one end of the gas separation membrane may be fixed with potting material and the other end sealed by means other than potting material.

[0035] Potting materials include, for example, thermoplastic resins and thermosetting resins. Furthermore, other additives may also be included.

[0036] The gas purification apparatus of the present invention preferably includes a plurality of gas separation membrane elements, depending on the composition and processing volume of the supplied gas. The plurality of gas separation membrane elements may be connected in series or in parallel. From the viewpoint of increasing the gas processing volume, they are preferably arranged in parallel, and from the viewpoint of improving the degree of purification and recovery rate, they are preferably arranged in series.

[0037] Furthermore, in an embodiment having multiple gas separation membrane elements, it is preferable to circulate the permeate gas discharged from the permeate side of at least some of the gas separation membrane elements as a supply gas.

[0038] Figure 2 shows a gas purification apparatus 1 having a heating mechanism 2, a plurality of gas separation membrane elements, and a heat exchange mechanism 4 as one embodiment of the present invention. In Figure 2, the non-permeable sides of the first gas separation membrane element 6 and the second gas separation membrane element 7 are arranged in series. That is, the supply gas supplied to the non-permeable side of the first gas separation membrane element 6 is separated into a first permeable gas (path 16) and a first non-permeable gas (path 17), and the first non-permeable gas (path 17) is supplied to the non-permeable side of the second gas separation membrane element 7, where it is separated into a second permeable gas (path 18) and a second non-permeable gas (path 19).

[0039] In Figure 2, the heating mechanism 2 covers and heats the entirety of the two gas separation membrane elements, and the heat exchange mechanism 4 is configured to exchange heat using the second non-permeable gas (path 19) as a heat source and the supply gas before heat exchange (path 11) as a non-heat source. The heat exchange mechanism 4 may also use both the second non-permeable gas (path 19) and the first permeable gas (path 16) as heat sources.

[0040] Furthermore, the second permeate gas (path 18) merges with the heat-exchanged supply gas (path 12) downstream of the heat exchange mechanism 4 via the pressurization mechanism 8. Since the second permeate gas, having passed through the heating mechanism 2 and the pressurization mechanism 8, is relatively hotter, circulating and mixing it with the supply gas allows for direct heat exchange, thereby increasing the temperature of the supply gas. It is preferable that the confluence point of the supply gas and the second permeate gas be downstream of the heat exchange mechanism 4. This ensures a temperature difference between the second non-permeate gas (path 19) in the heat exchange mechanism 4 and the supply gas before heat exchange (path 11), while the heat-exchanged supply gas (path 12) can receive further heat through mixing with the circulated permeate gas, thereby improving the overall heat recovery efficiency of the gas purification system.

[0041] In the case where a portion of the permeate gas is circulated as the supply gas, when discussing the partial pressure of aromatic compounds and the concentration of directional compounds in the supply gas, the supply gas refers to the supply gas after the circulated permeate gas has been mixed.

[0042] The supply gas to be separated by the gas purification apparatus of the present invention is not particularly limited. For example, it includes a carbon dioxide separation and storage system from exhaust gas of a power plant, a blast furnace, etc., removal of sulfur components from gasified fuel gas in integrated gasification combined cycle power generation, purification of biogas and natural gas, hydrogen purification from organic hydrides, and the like.

[0043] The purified gas of the present invention is the gas purified by the gas purification apparatus of the present invention. Since the purified gas of the present invention is purified by a purification apparatus capable of improving and maintaining the gas treatment amount while suppressing an increase in purification cost, it is possible to produce at low cost and with energy savings. Note that the purified gas may be purified including additional processes before and after the purification process in the gas purification apparatus of the present invention. Examples of the additional processes include purification such as distillation, adsorption, absorption, and component adjustment for mixing with another gas.

[0044] In one aspect of the present invention, it is preferable that the purified gas satisfies the following formula (1). 1.0 ≦ C 芳香族化合物、精製ガス / C 芳香族化合物、供給ガス ≦ 2.0 ··· Formula (1) [In the formula, C 芳香族化合物、精製ガス represents the concentration of aromatic compounds in the purified gas, and C 芳香族化合物、供給ガス represents the concentration of aromatic compounds in the supply gas.] C 芳香族化合物、精製ガス / C 芳香族化合物、供給ガス being 1 or more causes the aromatic compounds in the supply gas to be concentrated in the purified gas, so the calorific value per unit volume increases, and the value as energy improves when the purified gas is burned. On the other hand, C 芳香族化合物、精製ガス / C 芳香族化合物、供給ガス being 2 or less can suppress the adsorption of the concentrated aromatic compounds to the gas separation membrane, making it easier to maintain the equipment. C 芳香族化合物、精製ガス and C 芳香族化合物、供給ガス can be measured by gas chromatography-mass spectrometry (GC-MS) of the purified gas and the supply gas sampled at atmospheric pressure.

Example

[0045] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these. Evaluations in each example and comparative example were carried out by the following methods.

[0046] (Gas processing volume and energy required for heating) In the gas purification apparatuses of the examples and comparative examples, test gas 1 (CH4: 80 vol%, CO2: 20 vol%) was supplied at a total pressure of 4 MPa, and the gas was continuously separated while controlling the flow rate of the non-permeable gas so that the CH4 concentration in the non-permeable gas of the gas separation membrane element was 95%. The gas processing volume was expressed as a ratio to the non-permeable gas flow rate during room temperature operation. Furthermore, the energy required for heating in the gas purification apparatus of the examples was expressed as a ratio to the energy required for heating in the gas purification apparatus of the corresponding comparative example.

[0047] (Gas separation performance in the presence of aromatic compounds) Test gas 2 (CH4: 80 vol%, CO2: 20 vol%, benzene: 450 ppm) was supplied to the gas purification apparatus of the examples and comparative examples at a total pressure of 4 MPa. Gas separation was continuously performed at the non-permeable gas flow rate at which the CH4 concentration in the non-permeable gas of the gas separation membrane element reached 95% when test gas 1 was supplied. The gas separation performance in the presence of aromatic compounds was rated as "Excellent" if the CH4 concentration in the non-permeable gas when test gas 2 was supplied was 92.5% or more and 95% or less, "Good" if it was 90% or more and less than 92.5%, "Acceptable" if it was 85% or more and less than 90%, and "Poor" if it was less than 85%.

[0048] (Manufacturing Example 1: Fabrication of a gas separation membrane element containing a carbon film) Ten parts by weight of polyacrylonitrile (weight-average molecular weight 150,000) manufactured by Polyscience, Inc., ten parts by weight of polyvinylpyrrolidone (weight-average molecular weight 40,000) manufactured by Sigma-Aldrich, Inc., and eighty parts by weight of dimethyl sulfoxide (hereinafter referred to as DMSO) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. were mixed and stirred at 100°C to prepare a spinning stock.

[0049] After cooling the obtained spinning stock to 25°C, using a concentric triple-ended nozzle, an 80 wt% DMSO aqueous solution was simultaneously discharged from the inner tube, the spinning stock from the middle tube, and a 90 wt% DMSO aqueous solution from the outer tube. The discharged material was then guided into a coagulation bath consisting of pure water at 25°C and wound onto rollers to obtain the yarn. After washing the obtained yarn with water, it was dried at 25°C for 24 hours using a circulating dryer to produce a precursor for a hollow fiber porous carbon membrane.

[0050] The resulting porous carbon film precursor was passed through an electric furnace at 250°C and heated in an air atmosphere for 1 hour to perform an infusibility treatment, thereby obtaining infusible yarn. Subsequently, the infusible yarn was carbonized at a carbonization temperature of 650°C to obtain a carbon film with an outer diameter of 300 μm and an inner diameter of 100 μm.

[0051] 700 of the obtained carbon membranes were bundled together and placed inside a PEEK pipe (12 mm inner diameter) having an inlet and outlet for the fluid to be separated. Both ends of the PEEK pipe were then potted one at a time using epoxy resin. After the epoxy resin cured, the potted portion at one end was cut with a rotary saw to open the fluid separation membrane, obtaining the gas separation membrane element of Production Example 1.

[0052] (Example 1) The gas separation membrane element of Manufacturing Example 1 was housed in a pressure vessel, and the supply gas, non-permeable gas, and permeable gas channels were piped. Next, a high-temperature brazed plate heat exchanger (manufactured by KAORI, Taiwan) was placed so that the non-permeable gas of the gas separation membrane element and the supply gas before heating could exchange heat. The pressure vessel and the upstream piping were covered with a mantle heater and heated so that the gas temperature inside the pressure vessel reached 150°C. A mass flow controller was connected to the non-permeable gas piping downstream of the heat exchanger to obtain the gas purification apparatus of Example 1. As a result of evaluation using the method described above, the gas processing capacity of the gas purification apparatus of Example 1 was 5.3, the energy required for heating was 0.62, and the gas separation performance in the presence of aromatic compounds was "excellent".

[0053] (Example 2) The gas purification apparatus of Example 2 was obtained in the same manner as in Example 1, except that the gas temperature inside the pressure vessel was set to 50°C. As a result of evaluation using the method described above, the gas processing capacity of the gas purification apparatus of Example 2 was 1.5, the energy required for heating was 0.75, and the gas separation performance in the presence of aromatic compounds was "acceptable".

[0054] (Comparative Example 1) The gas separation membrane element of Manufacturing Example 1 was housed in a pressure vessel, and the supply gas, non-permeable gas, and permeable gas channels were piped. The pressure vessel and the upstream piping were covered with a mantle heater to heat the gas temperature inside the pressure vessel to 150°C, and a mass flow controller was connected to the non-permeable gas piping to obtain the gas purification apparatus of Comparative Example 1. As a result of evaluation using the method described above, the gas processing capacity of the purification apparatus of Comparative Example 1 was 5.3, and the gas separation performance in the presence of aromatic compounds was "excellent".

[0055] (Comparative Example 2) A gas purification apparatus for Comparative Example 2 was obtained in the same manner as for Comparative Example 1, except that the gas temperature inside the pressure vessel was set to 50°C. As a result of evaluation using the method described above, the gas processing capacity of the gas purification apparatus for Comparative Example 2 was 1.5, and the gas separation performance in the presence of aromatic compounds was "acceptable".

[0056] (Comparative Example 3) A gas purification apparatus for Comparative Example 3 was obtained in the same manner as for Comparative Example 1, except that the gas temperature inside the pressure vessel was set to 25°C. As a result of evaluation using the method described above, the gas processing capacity of the gas purification apparatus for Comparative Example 3 was 1.0, and the gas separation performance in the presence of aromatic compounds was "unacceptable". [Industrial applicability]

[0057] The gas purification apparatus of the present invention can be suitably used in carbon dioxide separation and storage systems from exhaust gases of power plants and blast furnaces, removal of sulfur components from gasified fuel gas in coal gasification combined cycle power generation, purification of biogas and natural gas, and hydrogen purification from organic hydrides. [Explanation of symbols]

[0058] 1: Gas purification equipment 2:Heating mechanism 3: Gas separation membrane 4: Heat exchange mechanism 5: Gas separation membrane element 6: First gas separation membrane element 7: Second gas separation membrane element 8: Boost Mechanism 11: Pathway (supply gas before heat exchange) 12: Pathway (supply gas after heat exchange) 13: Pathway (impermeable gas before heat exchange) 14: Pathway (impermeable gas after heat exchange) 15: Pathway (Permeation Gas) 16: Pathway (First Permeation Gas) 17: Pathway (First non-permeable gas) 18: Pathway (Second Permeation Gas) 19: Pathway (Second non-permeable gas)

Claims

1. A gas separation membrane element comprising a gas separation membrane and a housing that houses the gas separation membrane, wherein the housing has a non-permeable side through which the supply gas is introduced with the gas separation membrane in between, and a permeable side through which the permeated gas that has passed through the gas separation membrane is discharged, A heating mechanism for heating the supply gas, A gas purification apparatus comprising a heat exchange mechanism located upstream of the heating mechanism and configured to exchange heat between the non-permeable gas discharged from the non-permeable side of the gas separation membrane element and the supply gas.

2. The gas purification apparatus according to claim 1, characterized in that the heating mechanism has a function to control the temperature of the supply gas to 50°C or more and 300°C or less.

3. The gas purification apparatus according to claim 1, characterized in that the supply gas contains an aromatic compound.

4. The gas purification apparatus according to claim 3, characterized in that the partial pressure of aromatic compounds in the supply gas is 0.1 kPa or more and 30 kPa or less.

5. The gas purification apparatus according to claim 1, characterized in that the gas separation membrane is a carbon membrane.

6. Purified gas purified by a gas purification apparatus according to any one of claims 1 to 5.

7. The purified gas according to claim 6, characterized in that the aromatic compound concentration satisfies the following formula 1. 1.0 ≤ C 芳香族化合物、精製ガス / C 芳香族化合物、供給ガス ≦ 2.0 ・・・Form 1 [In the formula, C 芳香族化合物、精製ガス This represents the concentration of aromatic compounds in the purified gas, C 芳香族化合物、供給ガス This represents the concentration of aromatic compounds in the supply gas.

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