Gas separation apparatus, method for managing gas separation apparatus, gas separation method, and method for producing purified gas

Abstract

Provided is a gas separation apparatus for separating carbon dioxide from a mixed gas containing the carbon dioxide, the apparatus being provided with: an adsorption tower in which an adsorbent capable of adsorbing carbon dioxide is filled; a mixed gas supply line through which the mixed gas is introduced into the adsorption tower; a carbon dioxide recovery line through which carbon dioxide is removed from the adsorption tower; a pressure-reducing device which is connected to the carbon dioxide recovery line; and a pressure difference measurement unit which measures a pressure loss ΔP due to the adsorption tower.

Description

Gas separation apparatus, gas separation apparatus management method, gas separation method, and method for producing purified gas

[0001] The present invention relates to a gas separation apparatus, a method for managing a gas separation apparatus, a gas separation method, and a method for producing purified gas.

[0002] In recent years, there has been an increasing need for carbon dioxide separation in order to reduce carbon dioxide emissions. There are several carbon dioxide separation methods, one of which is a separation method using an adsorbent. Separation methods using an adsorbent include pressure swing adsorption (PSA), in which the pressure during desorption is lowered below the pressure during gas adsorption, and gas separation is performed by utilizing the difference between the amount of adsorption at high pressure and the amount of adsorption at low pressure. Thermal swing adsorption (TSA), in which the temperature during desorption is increased above the temperature during gas adsorption, and gas separation is performed by utilizing the difference between the amount of adsorption at low temperature and the amount of adsorption at high temperature. Furthermore, there is a pressure and temperature swing adsorption / desorption method (PTSA), which is a combination of these methods.

[0003] For example, a carbon dioxide production method capable of extracting high-purity methane and high-purity carbon dioxide from biogas has been disclosed, in which carbon dioxide is separated from biogas together with methane by pressure swing adsorption using an adsorption tower filled with an adsorbent (Patent Document 1).

[0004] JP 2015-67504 A

[0005] To reduce carbon dioxide emissions, there is a need to separate and capture carbon dioxide from mixed gases such as biogas. One proposed method for separating and capturing carbon dioxide is to use an adsorbent that adsorbs carbon dioxide. In this method, carbon dioxide is adsorbed using an adsorbent molded from a material that adsorbs carbon dioxide, from the perspective of ease of handling. It has been found that when an adsorbent is actually manufactured and used to adsorb carbon dioxide, the adsorbent becomes brittle and powder is generated. This powder leads to pressure loss within the device, increasing the ultimate pressure during decompression and reducing the efficiency of carbon dioxide separation and capture. Another issue is that the generated powder flows into the pressure-reducing device, increasing the burden on maintenance and management of the device.

[0006] Therefore, the present invention provides a gas separation apparatus capable of managing an adsorbent, a method for managing a gas separation apparatus, a gas separation method, and a method for producing a purified gas.

[0007] The present invention includes the following embodiments. <1> A gas separation apparatus for separating carbon dioxide from a mixed gas containing carbon dioxide, comprising: an adsorption tower filled with an adsorbent that adsorbs carbon dioxide; a mixed gas supply line for introducing the mixed gas into the adsorption tower; a carbon dioxide capture line for extracting carbon dioxide from the adsorption tower; a pressure reduction device connected to the carbon dioxide capture line; and a pressure difference measurement unit for measuring a pressure loss ΔP across the adsorption tower. <2> The gas separation apparatus according to <1>, wherein the carbon dioxide capture line has a powder removal unit between the adsorption tower and the pressure reduction device. <3> The gas separation apparatus according to <1> or <2>, further comprising a management unit, wherein the management unit has: a determination unit for determining whether the pressure loss ΔP exceeds a predetermined value; and an output unit for outputting status information of the adsorbent when the determination unit determines that the pressure loss ΔP exceeds the predetermined value. <4> The gas separation apparatus according to <3>, wherein the pressure loss ΔP is the pressure loss ΔPf when the mixed gas is introduced. <5> The pressure difference measuring unit measures the pressure P １ and the pressure P of the adsorption tower on the opposite side of the mixed gas supply line. ２The gas separation apparatus according to <4>, wherein the pressure loss ΔPf is measured from a pressure difference between the pressure P of the adsorption tower on the carbon dioxide capture line side and the pressure P of the adsorption tower on the carbon dioxide capture line side. <6> The gas separation apparatus according to <4> or <5>, wherein the predetermined value is 50 kPa or less. <7> The gas separation apparatus according to <3>, wherein the pressure loss ΔP is a pressure loss ΔPr during decompression. <8> The pressure difference measuring unit is ３ and the pressure P of the adsorption tower on the opposite side of the carbon dioxide recovery line ４ The gas separation apparatus according to <7>, wherein the pressure loss ΔPr is measured from a pressure difference between the pressure P of the adsorption tower on the mixed gas supply line side and the pressure P of the adsorption tower on the mixed gas supply line side. <9> The gas separation apparatus according to <7> or <8>, wherein the predetermined value is 10 kPa or less. <10> The gas separation apparatus according to <3>, wherein the pressure loss ΔP is a pressure loss ΔPf when the mixed gas is introduced and a pressure loss ΔPr when the mixed gas is reduced. <11> The pressure difference measuring unit is １ and the pressure P of the adsorption tower on the opposite side of the mixed gas supply line. ２ The pressure loss ΔPf is measured from the pressure difference between the pressure P of the adsorption tower on the carbon dioxide recovery line side and the pressure P ３ and the pressure P of the adsorption tower on the opposite side of the carbon dioxide recovery line ４<10>, wherein the pressure loss ΔPr is measured from the pressure difference between the adsorption tower and the mixed gas. <12> The gas separation apparatus according to <10> or <11>, wherein the pressure loss ΔP is a pressure loss ΔPf when the mixed gas is introduced and a pressure loss ΔPr when the mixed gas is reduced in pressure, and the output outputs state information about the adsorbent when the pressure loss ΔPf or the pressure loss ΔPr exceeds a predetermined value. <13> The gas separation apparatus according to any of <1> to <12>, wherein the mixed gas contains a gaseous substance A other than carbon dioxide, and a gaseous substance A recovery line for extracting gaseous substance A from the adsorption tower, and wherein the carbon dioxide and the gaseous substance A are separated. <14> The gas separation apparatus according to any of <1> to <13>, wherein the adsorbent contains zeolite. <15> The gas separation apparatus according to <14>, wherein the zeolite is FAU-type zeolite or GIS-type zeolite. <16> The gas separation apparatus according to any one of <1> to <15>, wherein the adsorption selectivity of the adsorbent for carbon dioxide / gaseous substance A is 8 or more. <17> A management method for a gas separation apparatus that separates carbon dioxide from a mixed gas containing carbon dioxide, wherein the gas separation apparatus comprises: an adsorption tower filled with an adsorbent that adsorbs carbon dioxide, a mixed gas supply line that introduces the mixed gas into the adsorption tower, a carbon dioxide capture line that extracts carbon dioxide from the adsorption tower, a pressure reduction device connected to the carbon dioxide capture line, a pressure difference measurement unit that measures a pressure loss ΔP across the adsorption tower, and a management unit, wherein the management unit comprises: a determination step of determining whether the pressure loss ΔP exceeds a predetermined value, and an output step of outputting status information of the adsorbent if the determination step determines that the pressure loss ΔP exceeds the predetermined value. <18> The management method for a gas separation apparatus, wherein the pressure loss ΔP is equal to or greater than the pressure loss ΔP ｆ <19> The method for managing a gas separation apparatus according to <18>, wherein the predetermined value is 10 kPa or less. <20> The method for managing a gas separation apparatus according to <17>, wherein the predetermined value is 10 kPa or less. <21> The method for managing a gas separation apparatus according to <18>, wherein the pressure loss ΔP is a pressure loss ΔP ｒ<21> The method for managing a gas separation apparatus according to <17>. <21> The method for managing a gas separation apparatus according to <20>, wherein the predetermined value is 5 kPa or less. <22> The pressure loss ΔP is a pressure loss ΔP when introducing a mixed gas ｆ and pressure loss ΔP during decompression ｒ <23> The method for managing a gas separation apparatus according to <17>, wherein the pressure loss ΔP is a pressure loss ΔP ｆ and pressure loss ΔP during decompression ｒ and the output is the pressure loss ΔP ｆ Or the pressure loss ΔP ｒ <24> A gas separation method for separating carbon dioxide from a mixed gas containing carbon dioxide using an adsorption tower filled with an adsorbent, comprising: an adsorption step of introducing the mixed gas into the adsorption tower and adsorbing the carbon dioxide onto the adsorbent; and a desorption step of removing the carbon dioxide from the adsorbent by depressurizing and evacuating the carbon dioxide from the adsorption tower, wherein the adsorption step and / or the desorption step are performed while measuring a pressure drop ΔP across the adsorption tower. <25> The gas separation method according to <24>, wherein the mixed gas contains a gaseous substance A other than carbon dioxide, and the gaseous substance A is removed in the adsorption step. <26> A method for producing a purified gas, in which purified carbon dioxide is obtained by the gas separation method according to <24> or <25>. <27> A method for producing a purified gas, in which a purified gas substance A is obtained by the gas separation method according to <25>.

[0008] According to the present invention, it is possible to provide a gas separation apparatus capable of managing an adsorbent, a method for managing a gas separation apparatus, a gas separation method, and a method for producing a purified gas.

[0009] FIG. 1 is a diagram showing a schematic configuration of the gas separation apparatus 100. FIG. 2 is a diagram showing a schematic configuration of the powder removal unit 6. FIG. 3 is a conceptual diagram showing changes over time in pressure fluctuations in the carbon dioxide adsorption towers 3a and 3b due to the operation of the gas separation apparatus 100. FIG. 4 is a block diagram showing a schematic configuration of the management unit 45. FIG. 5 is a block diagram showing an example of the hardware configuration of the management unit 45. FIG. 6 is a flowchart showing an example of a processing flow in the management method according to the present embodiment. FIG. 7 is a flowchart showing an example of a processing flow in the management method according to the present embodiment. FIG. 8 is a flowchart showing an example of a processing flow in the management method according to the present embodiment. FIG. 9 is a flowchart showing an example of a processing flow in the management method according to the present embodiment. FIG. 10 is a diagram showing a schematic configuration of a biogas purification system 1000 in which the gas separation apparatus 100 is applied to biogas purification.

[0010] Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail. The present invention is not limited to the following description, and various modifications can be made within the scope of the present invention.

[0011] The gas separation apparatus according to this embodiment is a gas separation apparatus for separating carbon dioxide from a mixed gas containing carbon dioxide, and includes: an adsorption tower filled with an adsorbent that adsorbs carbon dioxide; a mixed gas supply line for introducing the mixed gas into the adsorption tower; a carbon dioxide capture line for extracting carbon dioxide from the adsorption tower; a pressure reduction device connected to the carbon dioxide capture line; and a pressure difference measurement unit for measuring the pressure loss ΔP across the adsorption tower. The above-described configuration provides a gas separation apparatus, a gas separation apparatus management method, a gas separation method, and a method for producing purified gas that are capable of managing the adsorbent. It has been revealed that physical wear due to the flow of the adsorbent during gas adsorption / desorption, and the adsorbent becomes brittle during the process of adsorbing carbon dioxide onto the adsorbent, resulting in the generation of powder. It has been found that the generation of this powder gradually increases the pressure loss in the adsorption tower when the mixed gas is circulated or depressurized. Therefore, by providing a pressure difference measurement unit for measuring the pressure loss ΔP across the adsorption tower, it is possible to manage the condition of the adsorbent, such as determining whether it is time to replace it.

[0012] Below, we will explain the adsorbent molded article used in the gas separation apparatus and the mixed gas containing carbon dioxide and gaseous substance A to be treated by the gas separation apparatus, and then we will explain the gas separation apparatus and the method for managing the gas separation apparatus according to this embodiment.

[0013] <Adsorbent Molded Body> The carbon dioxide adsorption tower is filled with an adsorbent. The adsorbent used in this embodiment adsorbs carbon dioxide. It is preferable to use a solid adsorbent as the adsorbent. More specifically, examples of the adsorbent include solid adsorbents such as zeolite, metal organic frameworks (MOFs), carbonaceous char, activated carbon, carbon black, graphite, silica, silica gel, alumina clay, and metal oxides. Among these, it is preferable that the adsorbent contains zeolite. It is preferable that the adsorbent is a zeolite molded body.

[0014] Examples of zeolites include CHA type zeolite, GIS type zeolite, FAU type zeolite, MWF type zeolite, LTA type zeolite, etc. Among these, FAU type zeolite or GIS type zeolite is preferred, and GIS type zeolite is more preferred.

[0015] The GIS zeolite may contain silica and alumina. The aluminum content in the GIS zeolite is preferably 1 mass% or more, more preferably 3 mass% or more, and even more preferably 5 mass% or more. The silicon content in the GIS zeolite is preferably 3 mass% or more, and more preferably 5 mass% or more. The upper limit of the aluminum and silicon contents is preferably such that the SAR described below satisfies a predetermined range, and is determined by the SAR value.

[0016] The GIS zeolite preferably contains silica and alumina as its main components, which are components that account for 51 mass % or more.

[0017] The silica-alumina ratio (SiO ２ / Al ２ O ３ The SAR (representing the molar ratio of silica to alumina, hereinafter also referred to as "SAR") is preferably 3.40 or more. The lower the SAR of a GIS-type zeolite, the more hydrophilic it becomes, and the stronger its adsorption power for polar molecules such as carbon dioxide. If the SAR is low, the adsorption power is too strong, and the energy required for desorption by heating or vacuuming becomes large, so a high SAR is preferable, but if the SAR is too high, the interaction with the adsorbate becomes weak. The SAR is more preferably 4.40 to 3000, even more preferably 4.60 to 500, and even more preferably 4.80 to 100.

[0018] The phosphorus content in GIS zeolite is preferably 4% by mass or less. The lower limit of the phosphorus content is not particularly limited and may be 0% by mass or more. The Zr content in GIS zeolite is preferably 8% by mass or less. The lower limit of the Zr content is not particularly limited and may be 0% by mass or more. The Ti content in GIS zeolite is preferably 8% by mass or less. The lower limit of the Ti content is not particularly limited and may be 0% by mass or more. From the viewpoint of further improving the selective adsorption ability of carbon dioxide, the content of phosphorus atoms in the zeolite is more preferably 1.5% by mass or less, and particularly preferably 0% by mass. The contents of aluminum, silicon, phosphorus, Zr, and Ti can be measured by the method described in the examples described later. The contents of aluminum, silicon, phosphorus, Zr, and Ti can be adjusted to the above-mentioned ranges, for example, by adjusting the composition ratio of the mixed gel used in synthesizing GIS zeolite to the preferred ranges described later.

[0019] From the viewpoint of improving the selective adsorption capacity of carbon dioxide, the GIS zeolite preferably contains potassium or lithium as a cation species, and more preferably contains potassium. The total content of potassium and lithium in the zeolite is calculated as the ratio (Z / T) of the total amount of substance of potassium and lithium (Z) to the total amount of substance of alkali metals (T) in the GIS zeolite. Z / T is preferably 0.05 or more, more preferably 0.10 or more, and even more preferably 0.15 or more. There is no particular upper limit for Z / T, but Z / T may be 1.00 or less. Z / T can be measured by thermally dissolving the zeolite in a sodium hydroxide aqueous solution or aqua regia and then performing ICP-emission spectroscopy using an appropriately diluted solution. More specifically, Z / T can be measured by the method described in the Examples below. Z / T can be adjusted by changing the ratio of potassium and lithium as cation species in the GIS zeolite. The ratio (K / T) of the total amount of potassium (K) to the total amount of each alkali metal (T) in the GIS zeolite is preferably 0.05 or more, more preferably 0.10 or more, and even more preferably 0.15 or more. There is no particular upper limit to K / T, but K / T may be 1.00 or less.

[0020] From the viewpoint of the energy required for desorption, a higher SAR is preferable, but it has been confirmed that when the SAR in GIS zeolite becomes high, adsorption / desorption hysteresis in the carbon dioxide adsorption / desorption isotherm becomes apparent. In GIS zeolite, the adsorption / desorption hysteresis in the carbon dioxide adsorption / desorption isotherm can be eliminated by controlling the bonding mode of Si and Al in the zeolite framework. Specifically, ２９ When the peak area intensities assigned to Q4(3Al), Q4(2Al), Q4(1Al), and Q4(0Al) observed in the Si-MAS-NMR spectrum are a, b, c, and d, respectively, it is preferable that (a+d) / (b+c)≧0.192 is satisfied, more preferably 0.913≧(a+d) / (b+c)≧0.195, and even more preferably 0.519≧(a+d) / (b+c)≧0.199. ２９Peaks such as Q4(3Al), Q4(2Al), Q4(1Al), and Q4(0Al) observed in the Si-MAS-NMR spectrum represent the bonding modes of Si and Al in the zeolite framework, and the sums of the area intensities, X and Y, represent the sum of the abundances of these bonding modes, and Z represents the abundance ratio. The abundance ratio of Si and Al bonding modes affects the structural changes in the zeolite framework itself during adsorption and desorption, so by setting Z, the abundance ratio of Si and Al bonding modes in the zeolite framework, within an appropriate range, adsorption / desorption hysteresis in the adsorption / desorption isotherm can be eliminated.

[0021] ２９ For Si-MAS-NMR spectroscopy, a desiccator filled with water is prepared, and a sample tube containing zeolite is placed in the desiccator at the top and kept at room temperature (25°C) for 48 hours to perform humidity control. After that, measurements are performed using a solid-state NMR measurement device. Examples of the solid-state NMR measurement device include a JEOL "RESONANCE ECA700" (magnetic field strength: 16.44 T ( １ The resonant frequency at H is 700 MHz.

[0022] The GIS zeolite of this embodiment is ２９ In a Si-MAS-NMR spectrum, the following five peaks are generally observed: (1) Q4(0Al): a peak of Si that is not bonded to any Al atoms via oxygen; (2) Q4(1Al): a peak of Si that is bonded to one Al atom via oxygen; (3) Q4(2Al): a peak of Si that is bonded to two Al atoms via oxygen; (4) Q4(3Al): a peak of Si that is bonded to three Al atoms via oxygen; (5) Q4(4Al): a peak of Si that is bonded to four Al atoms via oxygen.

[0023] Also, ２９ ​In the Si-MAS-NMR spectrum, the peak positions are generally located between -112 ppm and -80 ppm, and can be assigned to Q4(0Al), Q4(1Al), Q4(2Al), Q4(3Al), and Q4(4Al) from the upfield side. The peak positions may vary depending on the cation species present in the zeolite framework, but generally, the peak positions are located in the following ranges: (1) Q4(0Al): -105 ppm to -112 ppm (2) Q4(1Al): -100 ppm to -105 ppm (3) Q4(2Al): -95 ppm to -100 ppm (4) Q4(3Al): -87 ppm to -95 ppm (5) Q4(4Al): -80 ppm to -87 ppm

[0024] ２９ The peak area intensity of the Si-MAS-NMR spectrum is analyzed using the analysis program dmfit (version #202000113) with Gaussian and Lorentzian functions, and the four parameters, amplitude (height of the maximum value of the spectrum), position (spectral position, ppm), width (full width at half maximum of the spectrum, ppm), and Gaussian / Lorentzian ratio (xG / (1−x)L), are calculated by optimizing them using a least-squares algorithm.

[0025] Using the area intensities of the peaks obtained by this calculation, the area intensities a, b, c, and d of the peaks assigned to Q4(3Al), Q4(2Al), Q4(1Al), and Q4(0Al) can be determined. ２９ More specifically, the Si-MAS-NMR spectrum can be measured by the method described in the Examples below. In order to set (a+d) / (b+c) within a predetermined range, it is possible to add a salt compound containing an alkali metal and / or an alkaline earth metal and adjust the quantitative ratio of the cation provided by the addition of the salt compound to the aluminum source, etc.

[0026] (Binder) The adsorbent molded body may contain a binder, such as an inorganic binder or an organic binder.

[0027] ​Examples of inorganic binders include inorganic oxides such as alumina, silica, magnesia, zirconia, and titania, clay minerals such as bentonite and kaolin, calcium silicate, and calcium aluminate. Examples of alumina include α-alumina, γ-alumina, boehmite, pseudo-boehmite, bayerite, gibbsite, and diaspore. Examples of silica include colloidal silica, water glass, fumed silica, silica sol, wet-process silica, dry-process silica, and natural silica. These inorganic binders may be used alone or in combination. Among these inorganic binders, alumina, silica, magnesia, zirconia, and titania are preferred, with silica and alumina being more preferred, from the viewpoint of increasing the strength of the zeolite molded body.

[0028] The content of the inorganic binder is preferably 1 to 99 mass %, more preferably 5 to 90 mass %, and even more preferably 8 to 80 mass %, relative to the total amount (100 mass %) of the adsorbent shaped article.

[0029] Examples of organic binders include cellulose, methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, latex, polyvinyl alcohol, vinyl acetate, polyvinyl acetal, vinyl chloride, acrylic, polyamide, urea, melamine, phenolic resin, polyester, polyurethane, polyamide, polybenzimidazole, chloroprene rubber, nitrile rubber, styrene-butadiene rubber, polysulfide, butyl rubber, silicone rubber, acrylic rubber, and urethane rubber. These organic binders may be used alone or in combination. Among these organic binders, cellulose, methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, and polyvinyl alcohol are preferred from the viewpoint of surface bonding with GIS-type zeolite, and cellulose, methyl cellulose, and polyvinyl alcohol are more preferred.

[0030] The content of the organic binder is preferably 1 to 99 mass %, more preferably 5 to 90 mass %, and even more preferably 8 to 80 mass %, relative to the total amount (100 mass %) of the adsorbent shaped article.

[0031] It is preferable that the binder contains one or more types of inorganic binder and one or more types of organic binder.

[0032] The total binder content is preferably 1 to 99 mass%, more preferably 5 to 90 mass%, and even more preferably 8 to 80 mass%, based on the total amount (100 mass%) of the adsorbent shaped body. Increasing the carrier content tends to increase the strength of the shaped body, but tends to decrease the zeolite content itself. Therefore, the binder content may be adjusted taking into account the strength and performance required for each application.

[0033] The shape of the adsorbent shaped body is not particularly limited, but examples include spherical, cylindrical, elliptical, bale-shaped, trefoil-shaped, ring-shaped, and powder-shaped bodies. Of these, spherical and cylindrical shapes are more preferred. The size of the shaped body is not particularly limited, but will vary depending on the conditions under which the shaped body is used. For example, when using the shaped body in a process that uses a shaped body in a non-fluidized state, such as a fixed bed or moving bed, a cylindrical shape with a length of 3 mm to 30 mm and a diameter of 1 mm to 30 mm is preferred. The length of the cylinder is more preferably 3 mm to 10 mm, and even more preferably 3 mm to 8 mm. The diameter of the cylinder is more preferably 2 mm to 4 mm.

[0034] The length and diameter can be determined by measuring the length and diameter of three pellet samples using a caliper with a minimum readout of 0.1 mm or less, and averaging the measurements to determine the length and diameter. The length and diameter can be adjusted to fall within the above-mentioned ranges by, for example, classification or other operations.

[0035] The adsorption selectivity of the adsorbent for carbon dioxide / gaseous substance A is preferably 5 or more. By using an adsorbent with such a high adsorption selectivity for carbon dioxide / gaseous substance A, it is possible to increase the recovery rate of gaseous substance A extracted in one adsorption step and the purity of carbon dioxide extracted in one desorption step. The adsorption selectivity of the adsorbent is calculated by the equilibrium adsorption amount (cm) of carbon dioxide and gaseous substance A at 760 mmHg obtained by measuring the adsorption isotherm. ３ / gSTP) and q(CO ２), q(GMA), q(CO2) / q(GMA) is the adsorption selectivity. The adsorption selectivity of the adsorbent for carbon dioxide / gaseous substance A is preferably 8 or more, more preferably 13 or more, even more preferably 15 or more, and still more preferably 20 or more. The adsorption selectivity of the adsorbent for carbon dioxide / gaseous substance A is measured by the method described in the Examples.

[0036] [Method for Producing Adsorbent Molded Body] (Preparation Step) The above-mentioned GIS-type zeolite can be obtained by a production method including a preparation step of a mixed gel containing, for example, a silica source containing silicon, an aluminum source containing aluminum, an alkali source containing at least one selected from alkali metals (M1) and alkaline earth metals (M2), a salt compound containing at least one selected from alkali metals (M1) and alkaline earth metals (M2), a phosphorus source containing phosphorus, an organic structure-directing agent, and water.

[0037] (Hydrothermal synthesis step) The method for producing GIS zeolite preferably further includes a hydrothermal synthesis step in which the hydrothermal synthesis temperature is 80°C to 200°C. The hydrothermal synthesis temperature is preferably 100°C to 180°C. The mixed gel obtained in the preparation step is held at a predetermined temperature for a predetermined time, either stirred or left to stand, to perform hydrothermal synthesis. The hydrothermal synthesis time is not particularly limited as long as it is a commonly used time, and is preferably 3 hours to 30 days, more preferably 10 hours to 20 days, and even more preferably 24 hours to 10 days.

[0038] (Separation and drying process) After the hydrothermal synthesis process, the solid product and the aqueous liquid are separated. The separation method is not particularly limited as long as it is a common method, and examples that can be used include filtration, decantation, spray drying (rotary spraying, nozzle spraying, ultrasonic spraying, etc.), drying using a rotary evaporator, vacuum drying, freeze drying, and natural drying. Separation is usually achieved by filtration or decantation.

[0039] (Caustic Step) The method for producing GIS zeolite preferably further includes a calcination step in which the calcination temperature is 300°C to 450°C. The calcination temperature is more preferably 350°C to 420°C, and even more preferably 360°C to 400°C. The calcination time may be 0.5 hours to 10 days, 1 hour to 7 days, or 3 hours to 5 days. The calcination atmosphere is not particularly limited as long as it is a commonly used atmosphere, but typically, an air atmosphere, an inert gas such as nitrogen or argon, or an atmosphere containing oxygen is used.

[0040] (Cation Exchange Step) The method for producing GIS zeolite preferably further includes a cation exchange step. The cation exchange may be performed using, but is not limited to, carbonates such as sodium carbonate, potassium carbonate, lithium carbonate, rubidium carbonate, cesium carbonate, magnesium carbonate, calcium carbonate, strontium carbonate, barium carbonate, or ammonium carbonate; nitrates such as sodium nitrate, potassium nitrate, lithium nitrate, rubidium nitrate, cesium nitrate, magnesium nitrate, calcium nitrate, strontium nitrate, barium nitrate, or ammonium nitrate; salts in which the carbonate ion or nitrate ion contained in the carbonate or nitrate salt is replaced with a halide ion, sulfate ion, carbonate ion, bicarbonate ion, acetate ion, phosphate ion, or hydrogen phosphate ion; or acids such as nitric acid or hydrochloric acid. The temperature for the cation exchange may be any common cation exchange temperature, but is typically from room temperature to 100° C. or less.

[0041] When separating the zeolite after cation exchange, the separation method is not particularly limited as long as it is a common method, and methods such as filtration, decantation, spray drying (rotary spraying, nozzle spraying, ultrasonic spraying, etc.), drying using a rotary evaporator, vacuum drying, freeze drying, and natural drying can be used, and separation can usually be performed by filtration or decantation.

[0042] [Method for Producing Molded Adsorbent Body] The method for producing the molded adsorbent body is not particularly limited, and may include a raw material mixing step (X) of mixing a zeolite with other optional components (e.g., a binder) to prepare the molded adsorbent body, a molding step (Y) of subjecting the prepared raw material to a molding process to obtain a precursor, and a firing step (Z) of calcining the precursor to obtain a molded zeolite body. Other methods for producing the molded adsorbent body that can obtain the desired molded adsorbent body include, for example, extrusion molding, injection molding, injection / casting, tumbling granulation, compression molding, spray drying, or a combination of two or more of these methods.

[0043] (Raw material mixing step (X)) In the raw material mixing step (X), the raw materials used may be used in a state suited to the manufacturing method, such as powder, solvent dispersion, sol, or liquid. Among the raw materials used, for example, when an inorganic binder is used, it is used in a state suited to the manufacturing method, such as powder, solvent dispersion, sol, or liquid, but from the viewpoint of ease of handling, powder or sol is preferred. These inorganic binders may be used alone or in combination.

[0044] The temperature at which the raw materials are mixed is not particularly limited, but is preferably 10°C to 80°C, and more preferably 15°C to 60°C.

[0045] Any stirring means can be used when preparing the raw materials. For example, when the state after mixing the raw materials is a slurry, as in the case of a spray drying process, stirring blades are preferred. Specific examples of blades used for stirring include propeller-type, paddle-type, flat paddle-type, turbine-type, and cone-type. Furthermore, baffles or the like may be installed in the vessel for efficient stirring. The number of stirrers can be selected based on optimal conditions such as the size of the catalyst raw material liquid vessel and the shape of the stirring blades.

[0046] Furthermore, when the raw materials are mixed and then become clay-like in the funicular to capillary range, as in extrusion molding, it is preferable to select a mixer or kneader in accordance with the state of the raw materials.

[0047] [Molding Step (Y)] Examples of the molding step (Y) include extrusion molding, compression molding, and spray drying.

[0048] The extrusion molding process is not particularly limited, but for example, the temperature during extrusion molding is preferably 10°C to 80°C, more preferably 15°C to 75°C, depending on the properties of the raw material used (also called "raw clay" in the extrusion molding process).

[0049] The water content in the raw clay is preferably 35% to 50% by mass, more preferably 38% to 45% by mass. When the water content is 50% by mass or less, excessive improvement in the flexibility of the raw clay can be prevented, and moldability tends to be improved. When the water content is 35% by mass or more, a moderate decrease in the flexibility of the raw clay can be prevented, and moldability tends to be improved.

[0050] When extrusion molding is used as the molding step (Y), the extrusion molding machine is not particularly limited, and examples thereof include screw type, roll type, blade type, self-molding type, ram type, disk pelleter type, etc. Among these, it is particularly preferable to carry out extrusion molding using a roll type, screw type, or disk pelleter type extruder.

[0051] When compression molding is used as the molding step (Y), the compression molding machine is not particularly limited, but examples thereof include uniaxial press molding and hot press molding.

[0052] In the spray drying process, for example, the atomization of the slurry can be carried out by methods usually practiced industrially, such as a rotating disk method, a two-fluid nozzle method, and a high-pressure nozzle method, but the rotating disk method is particularly preferred. As a drying heat source for drying the sprayed droplets, it is preferred to use air heated by steam, an electric heater, or the like.

[0053] The temperature at the inlet of the dryer can be about 100°C to 400°C, preferably 150°C to 300°C. The temperature at the outlet of the dryer can be about 40°C to 150°C, preferably 50°C to 130°C.

[0054] [Caking step (Z)] The calcination temperature in the calcination step (Z) is not particularly limited as long as it is a commonly used temperature, but since this tends to ensure strength while maintaining the crystallinity of the zeolite, it is preferably less than 550° C., more preferably 530° C. or less, and even more preferably 500° C. or less. In addition, the calcination temperature is preferably 110° C. or more, more preferably 120° C. or more.

[0055] The calcination time in the calcination step (Z) is not particularly limited as long as the carrier is sufficiently dried and sintered, and can be appropriately selected depending on the calcination temperature. However, since there is a tendency to ensure strength while maintaining the crystallinity of the zeolite, the calcination time is preferably 20 days or less, more preferably 10 days or less, and even more preferably 7 days or less.

[0056] The firing atmosphere in the firing step (Y) is not particularly limited as long as it is a commonly used atmosphere, but typically, an air atmosphere, an inert gas atmosphere such as nitrogen or argon, or an atmosphere containing oxygen is used.

[0057] The firing in the firing step (Z) can be carried out using a firing furnace such as a rotary furnace, a tunnel furnace, or a muffle furnace.

[0058] <Gaseous substance A> The gaseous substance A may be any gaseous substance other than carbon dioxide. The term "gaseous substance" refers to a substance that is gaseous at room temperature (25°C) and normal pressure. Examples of the gaseous substance A include methane, ethane, nitrogen, carbon monoxide, hydrogen, argon, and dimethyl ether. Among these gaseous substances A, methane, ethane, and nitrogen are preferred, methane and ethane are more preferred, and methane is even more preferred.

[0059] <Mixed Gas> The mixed gas used as a raw material contains carbon dioxide and gaseous substance A. The content of carbon dioxide in the mixed gas may be 1 vol% to 99 vol%, 5 vol% to 90 vol%, 10 vol% to 80 vol%, 20 vol% to 70 vol%, or 30 vol% to 70 vol%.

[0060] The content of gaseous substance A in the mixed gas may be 1 vol% to 99 vol%, 5 vol% to 90 vol%, 10 vol% to 80 vol%, 20 vol% to 70 vol%, or 30 vol% to 70 vol%.

[0061] The moisture content of the mixed gas is preferably 10% by volume or less, more preferably 1000 ppm by volume or less, even more preferably 500 ppm by volume or less, and even more preferably 100 ppm by volume or less. By setting the moisture content within this range, it is possible to enhance the adsorption performance of the adsorbent. The moisture content of the mixed gas can be measured, for example, using a dew point meter and converted to moisture content using the method described in JIS Z8806:2001.

[0062] [Gas Separation Apparatus] The schematic configuration of a gas separation apparatus 100 according to the first embodiment will be described with reference to Fig. 1. The gas separation apparatus 100 includes a mixed gas supply line 1, carbon dioxide adsorption towers 3a and 3b, pressure difference measurement units 41a, 42a, 41b, and 42b, a management unit 45, a carbon dioxide capture line 5, a gaseous substance A capture line 7, and a pressure reduction device 9.

[0063] <Carbon dioxide adsorption tower> The carbon dioxide adsorption tower 3a is configured to allow a mixed gas to be introduced and to bring the mixed gas into contact with the adsorbent shaped bodies. In the adsorption step described below, the mixed gas is brought into contact with the adsorbent, causing carbon dioxide in the mixed gas to be adsorbed onto the adsorbent. Because carbon dioxide is adsorbed in the mixed gas, gaseous substance A can be extracted. Furthermore, after the adsorption step, the adsorption tower is depressurized in the desorption step, allowing carbon dioxide to be extracted. In this way, a purified gas of gaseous substance A and a purified gas of carbon dioxide are obtained in the adsorption step and the desorption step. The adsorption tower may be equipped with a heater to increase the temperature inside the adsorption tower.

[0064] 1 , the carbon dioxide adsorption tower 3a has a fixed bed 31a packed with adsorbent molded bodies configured to be able to come into contact with the mixed gas introduced therein. One end of the carbon dioxide adsorption tower 3a is connected to the mixed gas supply line 1, and the other end is connected to a gaseous substance A recovery line 7. The gaseous substance A recovery line 7 is equipped with an automatic valve AV3. The gaseous substance A recovery line 7 is also equipped with a flow meter 71, a moisture meter 72, and a component analyzer 73. The component analyzer 73 may be an analyzer capable of measuring the concentrations of carbon dioxide and gaseous substance A.

[0065] The carbon dioxide adsorption tower 3a is connected to the carbon dioxide capture line 5 at an end thereof on the same side as the end connected to the mixed gas supply line 1. The mixed gas supply line 1 is equipped with a flow meter 11, a moisture meter 12, and a component analyzer 13. An automatic valve AV1 is provided at the inlet of the carbon dioxide adsorption tower 3a. Meanwhile, a pressure reducing device 9 is connected to the carbon dioxide capture line 5, which is configured to be able to reduce the pressure inside the carbon dioxide adsorption tower 3a. The pressure reducing device 9 may be a vacuum pump. The carbon dioxide capture line 5 connected to the carbon dioxide adsorption tower 3a is equipped with an automatic valve AV5 and a pressure gauge 53a. Furthermore, the carbon dioxide capture line 5 is equipped with a flow meter 51, a moisture meter 52, and a component analyzer 54. An analyzer capable of measuring the concentration of carbon dioxide and the concentration of gaseous substance A may be used as the component analyzer 54.

[0066] The carbon dioxide adsorption tower 3b has a fixed bed 31b including adsorbent molded bodies configured to be able to come into contact with the mixed gas introduced therein. An automatic valve AV2 is provided at the inlet of the carbon dioxide adsorption tower 3b. One end of the carbon dioxide adsorption tower 3b is connected to the mixed gas supply line 1, and the other end is connected to the gaseous substance A recovery line 7. An automatic valve AV4 is provided on the gaseous substance A recovery line 7. The carbon dioxide adsorption tower 3b is also connected to the carbon dioxide recovery line 5 at an end on the same side as the end connected to the mixed gas supply line 1. In addition, the carbon dioxide recovery line 5 connected to the carbon dioxide adsorption tower 3b is provided with an automatic valve AV6 and a pressure gauge 53b.

[0067] The pressure difference measuring unit 41a may be connected to the mixed gas supply line 1 and the gaseous substance A recovery line 7, and measures the pressure P1 of the carbon dioxide adsorption tower 3a on the mixed gas supply line 1 side and the pressure P ２ The pressure loss ΔPf can be measured from the pressure difference between the pressure loss ΔPf and the pressure loss ΔPf.

[0068] The pressure difference measuring unit 42a may be connected to the gaseous substance A recovery line 7 and the carbon dioxide recovery line 5, and the pressure P ３ and the pressure P of the adsorption tower on the opposite side of the carbon dioxide recovery line ４ The pressure loss ΔPr can be measured from the pressure difference between the pressure loss ΔPr and the pressure loss ΔPr.

[0069] The pressure difference measuring units 41b and 42b are installed in the same manner as the pressure difference measuring units 41a and 41b described above.

[0070] The pressure difference measuring units 41 a, 42 a, 41 b, and 42 b may be differential pressure gauges. The differential pressure gauges are not particularly limited, but examples thereof include U-tube pressure gauges and digital differential pressure gauges.

[0071] Although not shown, instead of the pressure difference measuring unit 41a, a first pressure gauge that measures the pressure P1 on the mixed gas supply line 1 side of the carbon dioxide adsorption tower 3a and a pressure P ２ The pressure difference measuring unit may be a pressure difference measuring unit using a second pressure gauge that measures the pressure difference between the first pressure gauge and the second pressure gauge. The same applies to the pressure difference measuring units 42a, 41b, and 42b. Examples of pressure gauges that can be used as the first pressure gauge and the second pressure gauge include a liquid-type pressure gauge, a deadweight pressure gauge, a Bourdon tube pressure gauge, a bellows pressure gauge, a chamber pressure gauge, and a diaphragm pressure gauge.

[0072] The management unit 45 is electrically connected to the pressure difference measurement units 41a, 42a, 41b, and 42b as shown by the dashed lines in FIG.

[0073] <Powder Removal Section> The carbon dioxide capture line 5 has a powder removal section 6 between the carbon dioxide adsorption tower 3a and the pressure reduction device 9. The adsorbent molded bodies packed inside the carbon dioxide adsorption tower 3a become embrittled by adsorbing carbon dioxide, generating powder. The powder removal section 6 removes the powder generated from inside the carbon dioxide adsorption tower 3a.

[0074] The powder removing device used in the powder removing unit 6 may be, for example, a gravity type, an inertia type, a centrifugal type, a washing type, a filtration type, or an electrical type. Of these powder removing devices, the powder removing unit 6 is preferably a filtration type powder removing device.

[0075] The filtering type powder removing device may be of either a strainer type or a filter type, but is preferably of the strainer type.

[0076] 2 is a diagram showing a schematic configuration of the powder removal unit 6. The powder removal unit 6 has a strainer 61a and a strainer 62b. The strainer 61a has a strainer housing 611a and a filter 612a. Similarly, the strainer 61b has a strainer housing 611b and a filter 612b. The switch valves 63 and 64 control the flow of gas introduced from the carbon dioxide adsorption tower 3a or 3b, and powder is removed by either or both of the strainer 61a and the strainer 62b. Here, the switch valves 62 and 63 may be operated to operate only the strainer 61a, allowing maintenance such as cleaning the filter of the strainer 61b to be performed.

[0077] Each strainer 61a and strainer 62b may be provided with a differential pressure gauge 65 that measures the pressure difference between the upstream and downstream sides, and the pressure loss across the strainers 61a and 62b may be measured. A management unit 66 may be electronically connected to the differential pressure gauge 65 and capable of acquiring differential pressure information from the differential pressure gauge. The management unit 66 displays maintenance information for the powder removal unit 6, such as the strainers 61a and 62b, on a display unit (not shown) based on the pressure loss measurement results. When two strainers are provided, such as the powder removal unit 6 shown in FIG. 2 , these strainers can be switched by operating the selector valves 62 and 63. Alternatively, the management unit 66 may be configured to measure the pressure loss across each strainer and automatically operate the selector valves 62 and 63 when the pressure loss exceeds a predetermined value, thereby automatically switching between the strainers 61a and 62b.

[0078] The carbon dioxide adsorption tower 3b has a fixed bed 31b including adsorbent molded bodies configured to be able to come into contact with the mixed gas introduced therein. An automatic valve AV2 is provided at the inlet of the carbon dioxide adsorption tower 3b. One end of the carbon dioxide adsorption tower 3b is connected to the mixed gas supply line 1, and the other end is connected to the gaseous substance A recovery line 7. An automatic valve AV4 is provided on the gaseous substance A recovery line 7. The carbon dioxide adsorption tower 3b is also connected to the carbon dioxide recovery line 5 at an end on the same side as the end connected to the mixed gas supply line 1. In addition, the carbon dioxide recovery line 5 connected to the carbon dioxide adsorption tower 3b is provided with an automatic valve AV6 and a pressure gauge 53b.

[0079] Next, with reference to FIG. 1 , the operation of the gas separation apparatus 100 of this embodiment will be described. The gas separation apparatus 100 of this embodiment implements a gas separation method for separating carbon dioxide and a gaseous substance A different from carbon dioxide from a mixed gas containing the carbon dioxide and the gaseous substance A using an adsorption tower filled with an adsorbent. The gas separation method includes an adsorption step of introducing the mixed gas into the adsorption tower, adsorbing carbon dioxide onto the adsorbent, and extracting the gaseous substance A, and a desorption step of removing the carbon dioxide from the adsorption tower by depressurizing and evacuating the carbon dioxide from the adsorption tower. This gas separation method allows carbon dioxide and the gaseous substance A to be separated efficiently with little power. In the gas separation method of this embodiment, carbon dioxide and the gaseous substance A are obtained as purified gas. In the gas separation method of this embodiment, the adsorption step and the desorption step may be repeated depending on the amount of mixed gas to be treated and the purity of the target purified gas. Repeating these steps produces a highly pure purified gas.

[0080] It is preferable that the recovery rate of gaseous substance A extracted in one adsorption step be 90% or more, thereby enabling high-purity gaseous substance A to be obtained in fewer steps. Furthermore, if the purity of carbon dioxide extracted in one desorption step is 90% or more, high-purity carbon dioxide can be obtained in fewer steps. The above configuration enables efficient purification with little power, making it possible to simultaneously produce high-purity carbon dioxide and high-purity gaseous substance A. The recovery rate of gaseous substance A extracted in one adsorption step refers to the recovery rate from the second cycle onwards in a pressure fluctuation cycle. At the first pressure fluctuation cycle (startup), the adsorbent is in a state where almost no carbon dioxide is adsorbed, but from the second cycle onwards in a pressure fluctuation cycle, the adsorption step begins with a predetermined amount of carbon dioxide adsorbed from the previous cycle. Therefore, the recovery rate from the second cycle onwards is defined as the recovery rate of gaseous substance A extracted in one adsorption step. "One adsorption step" and "one desorption step" refer to one pressure fluctuation cycle of the carbon dioxide adsorption tower in the adsorption step and desorption step.

[0081] The carbon dioxide adsorption tower 3a is supplied with a mixed gas through a mixed gas supply line 1. Then, carbon dioxide (CO ２ ) is adsorbed by the adsorbent packed in the carbon dioxide adsorption tower 3a, and methane (CH ４ That is, in the carbon dioxide adsorption tower 3a, an adsorption step is carried out in which the mixed gas is introduced into the adsorption tower, the carbon dioxide is adsorbed by the adsorbent, and the gaseous substance A is extracted.

[0082] Adsorption pressure P in the adsorption process ａ is preferably 50 to 3000 kPa, more preferably 60 to 500 kPa or less, and even more preferably 70 to 350 kPa or less. ａ means the pressure near the inlet of the adsorption tower where the mixed gas is introduced.

[0083] The average temperature in the adsorption step is preferably 0°C or higher, preferably 10°C to 400°C, more preferably 25°C to 300°C, and even more preferably 25°C to 200°C, from the viewpoint of increasing the efficiency of carbon dioxide desorption in the subsequent desorption step and reducing the power required per mixed gas to be treated. The average temperature in the adsorption step means the average temperature of the gas near the outlet of the adsorption tower in the adsorption step. Note that in the adsorption step, the temperature may change gradually due to the generation of heat by adsorption of carbon dioxide onto the adsorbent.

[0084] The carbon dioxide adsorption tower 3a containing the adsorbent that has adsorbed carbon dioxide is depressurized and evacuated by the pressure reducing device 9, thereby regenerating the adsorbent in the carbon dioxide adsorption tower 3a and extracting purified carbon dioxide. In other words, the carbon dioxide desorption step of extracting carbon dioxide is performed by depressurizing and evacuating carbon dioxide from the adsorption tower.

[0085] The ultimate pressure P in the desorption process ｂ is preferably 50 kPa or less, more preferably 30 kPa or less, even more preferably 20 kPa or less, even more preferably 15 kPa or less, even more preferably 10 kPa or less, even more preferably 5 kPa or less, and even more preferably 3 kPa or less.ｂ means the pressure near the exhaust outlet of an adsorption tower filled with an adsorbent, which is evacuated under reduced pressure, and refers to the pressure at which the pressure in the adsorption tower gradually decreases due to reduced pressure evacuation and finally becomes constant.

[0086] The average temperature in the desorption step is preferably 0°C or higher, preferably 10°C to 400°C, more preferably 25°C to 300°C, and even more preferably 25°C to 200°C, from the viewpoint of increasing the efficiency of carbon dioxide desorption and reducing the power required per mixed gas to be treated. The average temperature in the desorption step refers to the average temperature of the desorbed gas (carbon dioxide) near the outlet of the adsorption tower in the desorption step. Note that in the desorption step, the temperature may change gradually because heat is absorbed by the desorption of carbon dioxide from the adsorbent.

[0087] In the gas separation method according to this embodiment, the purity of the carbon dioxide extracted in one desorption step is preferably 90% by volume or more, more preferably 92% by volume or more, and even more preferably 94% by volume or more. The carbon dioxide that has undergone the desorption step may be further subjected to an adsorption step and a desorption step to further increase its purity.

[0088] As described above, the carbon dioxide adsorption towers 3a and 3b repeatedly adsorb carbon dioxide by introducing the mixed gas and desorb carbon dioxide by reducing the pressure. Therefore, while the carbon dioxide adsorption tower 3a is desorbing carbon dioxide, the mixed gas is introduced into the carbon dioxide adsorption tower 3b to adsorb the carbon dioxide. After the carbon dioxide adsorption tower 3a has completed desorption of carbon dioxide, the mixed gas is again introduced into the carbon dioxide adsorption tower 3a, and the carbon dioxide adsorption tower 3b is reduced in pressure to desorb the carbon dioxide, thereby repeatedly adsorbing and desorbing carbon dioxide in each tower, allowing the mixed gas to be treated continuously.

[0089] More specifically, the gas separation apparatus 100 can be operated in the following manner. Fig. 3 is a conceptual diagram showing the time-dependent changes in pressure fluctuations in the carbon dioxide adsorption towers 3a and 3b due to the operation of the gas separation apparatus 100. At time T １ａThen, with all the automatic valves AV1 to AV6 closed, the automatic valves AV1 and AV3 are opened, and the mixed gas is supplied to the carbon dioxide adsorption tower 3a at an adsorption pressure P ａ When the carbon dioxide concentration in the component analyzer 73 exceeds 5% by volume (for example, at time T １ｂ ), the automatic valves AV1 and AV3 may be closed and the automatic valves AV2 and AV4 may be opened at the same time to switch the supply of the mixed gas from the carbon dioxide adsorption tower 3a to the carbon dioxide adsorption tower 3b. By switching, the mixed gas is supplied to the carbon dioxide adsorption tower 3b at an adsorption pressure P ａ The carbon dioxide adsorption tower 3a is supplied at a pressure of 105 kPa (for example, 105 kPa). When the automatic valve AV5 is opened with the automatic valve AV3 closed and the pressure is reduced by the pressure reducing device 9, the pressure in the carbon dioxide adsorption tower 3a is reduced, and the pressure in the carbon dioxide adsorption tower is reduced to the ultimate pressure P ｂ (for example, 2 kPa) to recover carbon dioxide from the carbon dioxide adsorption tower 3a. ｂ The arrival time to １ｃ The carbon dioxide adsorbed by the adsorbent in the carbon dioxide adsorption tower 3a is desorbed, so that the carbon dioxide is recovered and the adsorbent is regenerated.

[0090] Subsequently, when the carbon dioxide concentration of the gas flowing out from the carbon dioxide adsorption tower 3b exceeds 5% by volume, the automatic valves AV2 and AV4 may be closed, and at the same time, the automatic valves AV1 and AV3 may be opened to switch the supply of the mixed gas from the carbon dioxide adsorption tower 3b to 3a (this time is referred to as T １ｄ The carbon dioxide adsorption tower 3b is desorbed by opening the automatic valve AV6 and reducing the pressure with the pressure reducing device 9, thereby setting the pressure in the carbon dioxide adsorption tower 3b to 2 kPa and performing a desorption operation. Thereafter, when the carbon dioxide concentration in the component analyzer 73 exceeds 5% by volume (for example, at time T １ｅ ), the automatic valves AV1 and AV3 may be closed and the automatic valves AV2 and AV4 may be opened at the same time, and the supply of the mixed gas may be switched again from the carbon dioxide adsorption tower 3a to the carbon dioxide adsorption tower 3b.

[0091] The time T １ａ ~T １ｄ The series of operations up to this point is one cycle C of pressure fluctuation in the carbon dioxide adsorption tower 3a. １ The operation is as follows. １ｂ ~T １ｅ The series of operations up to this point is one cycle C of pressure fluctuation in the carbon dioxide adsorption tower 3b. １ That is, cycle C １ The second cycle C of pressure fluctuation is performed by repeating the same operation. ２ , 3rd cycle C ３ The adsorption and desorption steps may be repeated.

[0092] In the gas separation method according to this embodiment, the purity of the gaseous substance A extracted after one adsorption step is preferably 90% by volume or more, more preferably 93% by volume or more, and even more preferably 95% by volume or more. The carbon dioxide that has undergone the desorption step may be further subjected to an adsorption step and a desorption step to further increase its purity.

[0093] In the gas separation method according to this embodiment, the recovery rate of carbon dioxide extracted by one adsorption step and one desorption step is preferably 90% or more, more preferably 93% or more, and even more preferably 95% or more, relative to the total amount of carbon dioxide in the mixed gas introduced into the adsorption tower in one adsorption step. The recovery rate of carbon dioxide extracted by one adsorption step and one desorption step refers to the recovery rate from the second cycle onward in a pressure fluctuation cycle. At the first pressure fluctuation cycle (startup), the adsorbent is in a state where almost no carbon dioxide is adsorbed, but from the second cycle onward in a pressure fluctuation cycle, the adsorption step begins with a predetermined amount of carbon dioxide adsorbed from the previous cycle. Therefore, the recovery rate from the second cycle onward is taken as the recovery rate of carbon dioxide extracted by one adsorption step and one desorption step.

[0094] The gas separation method according to this embodiment preferably includes an activation step in which the temperature and pressure inside the adsorption tower are increased to desorb moisture from the adsorbent. The activation step activates the adsorbent, allowing it to adsorb moisture in the gas to be treated and reduce the moisture in the resulting carbon dioxide and gaseous substance A. The activation step is preferably carried out before the above-mentioned adsorption step and desorption step. Alternatively, the adsorption step and desorption step may be repeated, and the activation step may be carried out when the adsorbent has adsorbed a large amount of moisture.

[0095] The ultimate pressure P in the activation process ｅ is preferably 50 kPa or less, more preferably 30 kPa or less, even more preferably 20 kPa or less, even more preferably 15 kPa or less, even more preferably 10 kPa or less, even more preferably 5 kPa or less, and even more preferably 3 kPa or less. ｅ means the pressure near the exhaust outlet of an adsorption tower filled with an adsorbent, which is evacuated under reduced pressure, and refers to the pressure at which the pressure in the adsorption tower gradually decreases due to reduced pressure evacuation and finally becomes constant.

[0096] The temperature inside the adsorption tower in the activation step is preferably 150°C or higher, more preferably 180°C to 300°C, and even more preferably 200°C to 280°C.

[0097] The gas separation device 100 may be applied to, for example, purification of industrial exhaust gas containing carbon dioxide, biogas obtained by fermentation of organic matter, etc. Among these, it is preferable to use it for purification of biogas.

[0098] In the gas separation method according to this embodiment, the total recovery rate of carbon dioxide from the mixed gas is preferably 90% or more, more preferably 93% or more, and even more preferably 95% or more. The total recovery rate here means the total amount of carbon dioxide recovered relative to the total amount of carbon dioxide in the mixed gas introduced into the adsorption tower.

[0099] In the gas separation method according to this embodiment, the recovery rate of the gaseous substance A extracted in one cycle of the adsorption step and the desorption step is preferably 90% or more, more preferably 93% or more, and even more preferably 95% or more, relative to the total amount of the gaseous substance A in the mixed gas introduced into the adsorption tower in one cycle of the adsorption step.

[0100] In the gas separation method according to this embodiment, the total recovery rate of gaseous substance A from the mixed gas is 90% or more, more preferably 93% or more, and even more preferably 95% or more. The total recovery rate here means the total amount of gaseous substance A recovered relative to the total amount of gaseous substance A in the mixed gas introduced into the adsorption tower.

[0101] In the gas separation method according to this embodiment, it is preferable that the total recovery rate of carbon dioxide from the mixed gas is 90% by volume or more and the total recovery rate of gaseous substance A from the mixed gas is 90% or more; it is more preferable that the total recovery rate of carbon dioxide from the mixed gas is 93% or more and the total recovery rate of gaseous substance A from the mixed gas is 93% or more; it is even more preferable that the total recovery rate of carbon dioxide from the mixed gas is 95% or more and the total recovery rate of gaseous substance A from the mixed gas is 95% or more.

[0102] The purity of the gaseous substance A obtained by the gas separation method according to this embodiment is preferably 90% by volume or more, more preferably 93% by volume or more, and even more preferably 95% by volume or more.

[0103] The purity of the carbon dioxide obtained by the gas separation method according to this embodiment is preferably 90% by volume or more, more preferably 92% by volume or more, and even more preferably 95% by volume or more.

[0104] The water content in the carbon dioxide obtained by the gas separation method according to this embodiment is preferably 500 ppm by volume or less, more preferably 300 ppm by volume or less, and even more preferably 100 ppm by volume or less. The water content in the carbon dioxide can be measured, for example, using a dew point meter. By using zeolite as an adsorbent in the gas separation method, the water content in the carbon dioxide can be reduced below the above-mentioned value.

[0105] In the method for producing a purified gas according to this embodiment, a purified gas substance A or purified carbon dioxide is obtained by the gas separation method according to this embodiment described above.

[0106] [Management Method] The management method for the gas separation apparatus is to obtain the pressure loss ΔP of the carbon dioxide adsorption towers 3 a and 3 b by the management unit 45 and manage the adsorbent.

[0107] 4, the management unit 45 includes a pressure loss ΔPr acquisition unit 451, a pressure loss ΔPf acquisition unit 452, a determination unit 454, an information generation unit 455, and an output unit 456. The management unit 45 is configured to be able to acquire the pressure loss ΔP from the pressure difference measurement units 41 a, 42 a, 41 b, and 42 b.

[0108] The functions of the management unit can also be realized by a plurality of computers 800. As shown in Fig. 5, the computer 800 includes a processor 801, a memory 803, a storage device 805, an input I / F 807, a communication I / F 809, and a display device 811. The computer 800 may not include some of the above components, or may include other components in addition to the above components.

[0109] The processor 801 is a control unit that executes various processes in the computer 800 by executing programs stored in the memory 803 and controls each component in the computer 800 .

[0110] The memory 803 is a storage medium such as a RAM (Random Access Memory), etc. The memory 803 temporarily stores the program code of the program executed by the processor 801 and data required when the program is executed.

[0111] The storage device 805 is a non-volatile storage medium such as a hard disk drive (HDD), flash memory, etc. The storage device 805 stores an operating system and various programs for realizing the above-mentioned components.

[0112] The input I / F 807 is a device for receiving input from a user. Specific examples of the input I / F 807 include a keyboard, a mouse, a touch panel, various sensors, and a wearable device. The input I / F 807 may be connected to the computer 800 via an interface such as a USB (Universal Serial Bus).

[0113] The communication I / F 809 is a device for performing wired or wireless data communication with an external device of the computer 800 via the Internet N. The communication I / F 809 is realized by, for example, a network interface card (NIC).

[0114] The display device 811 is a device for displaying various types of information. Specific examples of the display device 811 include a liquid crystal display, an organic EL (Electro-Luminescence) display, and a display of a wearable device. The display device 811 may be provided outside the computer 800. In this case, the display device 811 is connected to the computer 800 via, for example, a display cable. Furthermore, when a touch panel is used as the input I / F 807, the display device 811 can be configured as an integral part of the input I / F 807.

[0115] The following description will be given taking an example of managing the carbon dioxide adsorption tower 3a, but the carbon dioxide adsorption tower 3b may also be managed in a similar manner.

[0116] As shown in FIG. 6 , when the carbon dioxide adsorption tower 3 a is depressurized to recover carbon dioxide, the management method for the gas separation apparatus includes a pressure loss ΔPr acquisition step S101, a determination step S102 of determining whether the pressure loss ΔPr exceeds a predetermined value, and an output step S103 of outputting state information of the adsorbent if the pressure loss ΔPr exceeds the predetermined value.

[0117] In the pressure loss ΔPr acquisition step S101, the pressure loss ΔPr acquisition unit 451 acquires the pressure loss ΔPr by acquiring the pressure difference caused by the carbon dioxide adsorption tower 3a from the pressure difference measurement unit 42a when the carbon dioxide adsorption tower 3a is depressurized to recover carbon dioxide.

[0118] In determination step S102, the determination unit 454 determines whether the pressure loss ΔPr exceeds a predetermined value. The predetermined value of the pressure loss ΔPr can be set, for example, to a value indicating when the adsorbent should be replaced. The adsorbent becomes embrittled by adsorbing carbon dioxide, generating powder. This powder may flow into the pressure reducing device 9, making the maintenance of the device more difficult. On the other hand, it has been revealed that continuous and repeated carbon dioxide adsorption processing using the carbon dioxide adsorption tower generates powder within the carbon dioxide adsorption tower, causing an increase in pressure loss. In other words, measuring the pressure loss of the carbon dioxide adsorption tower makes it possible to check the state of embrittlement of the adsorbent. Therefore, if the pressure loss ΔPr exceeds a predetermined value, it becomes possible to manage the adsorbent, such as when to replace the adsorbent, before the generation of powder from the adsorbent requires complicated maintenance, such as cleaning the pressure reducing device.

[0119] The predetermined value of the pressure drop ΔPr can be set based on a target value in gas separation, which can be set from the viewpoints of the purity and recovery rate of the gaseous substance A, the purity and recovery rate of carbon dioxide, the power required for the raw material supply device and the pressure reducing device, and protection of the pressure reducing device.

[0120] For example, when setting a predetermined value as the target purity of gaseous substance A, the predetermined value ΔPrs of the pressure drop ΔPr can be expressed as (Pa + ΔPf) × (1 − X) − Pd + Z (Formula A) using the required purity of gaseous substance A expressed as a volume fraction as X, the pressure Pa (absolute pressure) during adsorption (when the mixed gas is supplied), the pressure Pd (absolute pressure) during desorption (decompression), and an arbitrarily set coefficient Z. In other words, this means controlling the pressure drop ΔPr in the decompression step so that it does not exceed the predetermined value ΔPrs, thereby ensuring that the partial pressure of carbon dioxide in gaseous substance A does not exceed the predetermined value ΔPrs and that the purity of gaseous substance A is X or higher. Z can be set arbitrarily depending on the expected replacement time of the adsorbent, and is set by estimating the time required for replacement preparation using data on the change in ΔPr over time during gas separation.

[0121] Furthermore, for example, when setting a predetermined value as the target recovery rate of gaseous substance A, since an increase in pressure loss leads to a decrease in the recovery rate, the pressure loss ΔPf when the mixed gas is introduced, the pressure loss ΔPr when depressurized, and the gaseous substance A can be measured over time, and the pressure loss ΔPf and the pressure loss ΔPr that do not fall below any desired target values ​​can be set as the set values. Similarly, since the required power of the raw material supply device and the pressure reducer increases with an increase in pressure loss, the set values ​​can be set by determining the correlation with the pressure loss ΔPf and the pressure loss ΔPr that do not fall below any desired target values.

[0122] The predetermined value of the pressure loss ΔPr may be, for example, 10 kPa or less, 5 kPa or less, or 2 kPa or less.

[0123] If the pressure loss ΔPr exceeds the predetermined value in the determination step S102, the process proceeds to the next output step S103. On the other hand, if the pressure loss ΔPr is equal to or less than the predetermined value in the determination step S102, the process returns to the pressure loss ΔPr acquisition step S101.

[0124] In the output step S103, if the determination unit 454 determines that the absorbent concentration exceeds a predetermined value, the absorbent status information is output. Examples of the status information include information indicating that the absorbent needs to be replaced. The status information may be output, for example, as a display device 811 or transmitted from the communication I / F 809 to an external device.

[0125] 7, when the carbon dioxide adsorption tower 3a is depressurized to recover carbon dioxide, the management method for the gas separation apparatus includes a pressure loss ΔPr acquisition step S201, a determination step S202 of determining whether the pressure loss ΔPr exceeds a predetermined value, a generation step S203 of generating status information of the adsorbent if the pressure loss ΔPr exceeds the predetermined value, and an output step S204 of outputting the status information of the adsorbent. The pressure loss ΔPr acquisition step S201 is similar to the pressure loss ΔPr acquisition step S101 described above, and therefore a description thereof will be omitted.

[0126] In the determination step S202, the determination unit 454 determines whether the pressure loss ΔPr exceeds a predetermined value. The predetermined value is as described above.

[0127] In the generating step S203, status information is generated according to the value of the pressure loss ΔPr. Examples of the information to be generated include information indicating that the time for replacement is approaching, information indicating that the adsorbent needs to be replaced, etc. The above-mentioned information may be displayed according to the value of the pressure loss ΔPr.

[0128] In the output step S203, status information of the adsorbent is output based on the information generated by the information generating unit 455. Examples of the status information include information indicating that the adsorbent needs to be replaced. The status information may be output, for example, by being displayed on the display device 811 or by being transmitted from the communication I / F 809 to an external device.

[0129] As shown in FIG. 8 , when a mixed gas is supplied to the carbon dioxide adsorption tower 3 a, the management method for the gas separation apparatus includes a pressure loss ΔPf acquisition step S301, a determination step S302 of determining whether the pressure loss ΔPf exceeds a predetermined value, and an output step S303 of outputting status information of the adsorbent if the pressure loss ΔPf exceeds the predetermined value.

[0130] In the pressure loss ΔPf acquisition step S301, the pressure loss ΔPf acquisition unit 452 acquires the pressure loss ΔPf by acquiring the pressure difference caused by the carbon dioxide adsorption tower 3a from the pressure difference measurement unit 41a when the mixed gas is supplied to the carbon dioxide adsorption tower 3a and carbon dioxide is adsorbed.

[0131] In determination step S302, determination unit 452 determines whether the pressure loss ΔPf exceeds a predetermined value. The predetermined value of the pressure loss ΔPf can be set, for example, to a value indicating when to replace the adsorbent. As described above, it has been revealed that the pressure loss increases in the carbon dioxide adsorption tower when the carbon dioxide adsorption process is continuously and repeatedly performed using an adsorbent (especially an adsorbent containing zeolite). Similarly, information about the adsorbent can also be managed using the value of the pressure loss ΔPf when the mixed gas is supplied.

[0132] The predetermined value of the pressure loss ΔPf may be, for example, 50 kPa or less, 30 kPa or less, or 10 kPa or less.

[0133] If the pressure loss ΔPf exceeds the predetermined value in the determination step S302, the process proceeds to the next output step S303. On the other hand, if the pressure loss ΔPf is equal to or less than the predetermined value in the determination step S302, the process returns to the pressure loss ΔPf acquisition step S301.

[0134] In the output step S303, if the determination unit 454 determines that the absorbent concentration exceeds a predetermined value, the absorbent status information is output. Examples of the status information include information indicating that the absorbent needs to be replaced. The status information may be output, for example, as a display device 811 or transmitted from the communication I / F 809 to an external device.

[0135] 9 , when the carbon dioxide adsorption tower 3a is depressurized to recover carbon dioxide, the management method for the gas separation apparatus includes a pressure loss ΔPf acquisition step S401, a determination step S402 of determining whether the pressure loss ΔPf exceeds a predetermined value, a generation step S403 of generating status information of the adsorbent if the pressure loss ΔPf exceeds the predetermined value, and an output step S404 of outputting the status information of the adsorbent. The pressure loss ΔPf acquisition step S401 is similar to the pressure loss ΔPf acquisition step S401 described above, and therefore a description thereof will be omitted.

[0136] In the determination step S402, the determination unit 454 determines whether the pressure loss ΔPf exceeds a predetermined value. The predetermined value is as described above.

[0137] In the generating step S403, status information is generated according to the value of the pressure loss ΔPf. Examples of the information to be generated include information indicating that the time for replacement is approaching, information indicating that the adsorbent needs to be replaced, etc. The above-mentioned information may be displayed according to the value of the pressure loss ΔPf.

[0138] In the output step S403, status information of the adsorbent is output based on the information generated by the information generating unit 455. Examples of the status information include information indicating that the adsorbent needs to be replaced. The status information may be output, for example, by being displayed on the display device 811 or by being transmitted from the communication I / F 809 to an external device.

[0139] [Biogas Refining System 1000: Example of Application to Biogas Refining] Fig. 10 is a diagram showing a schematic configuration of a biogas refining system 1000 in which the gas separation device 100 is applied to biogas refining. In this example of application to biogas refining, methane, which is the main component of biogas, and carbon dioxide are separated and recovered. In the case of biogas refining, the gaseous substance A is usually methane (CH ４ 10 shows an example in which the gas separation apparatus 100 is applied, the gas separation apparatus 110 or the gas separation apparatus 120 described above may also be applied.

[0140] The biogas purification system 1000 of this embodiment includes a fermenter 200, a desulfurization tower 300, a siloxane removal device 400, an oxygen removal device 500, a cooling device 600, a dehydration device 700, and a gas separation device 100.

[0141] The fermenter 200 is a tank that generates biogas (hereinafter also referred to as "mixed gas") by anaerobic fermentation of sewage sludge generated from sewage treatment plants, food waste generated from food factories and restaurants, and manure generated by dairy farms, etc. The fermenter 200 is connected to a blower 201 so that the generated biogas can be supplied to other devices.

[0142] The fermenter 200 may be connected to a desulfurization tower 300 before the biogas is introduced into the gas separation apparatus 100. The desulfurization tower 300 is an adsorption tower for removing hydrogen sulfide contained in the biogas. An example of a desulfurization agent filled in the desulfurization tower 300 is iron oxide. The iron oxide reacts with the hydrogen sulfide contained in the biogas to produce iron sulfide.

[0143] The fermenter 200 may be connected to a siloxane removal device 400 before the biogas is introduced into the gas separation device 100. The siloxane removal device 400 removes siloxanes contained in the biogas. These siloxanes are silicon oxide-containing substances contained in sewage sludge.

[0144] The fermenter 200 may be connected to an oxygen remover 500 before the biogas is introduced into the gas separation apparatus 100. The oxygen remover 500 removes oxygen contained in the biogas. By removing this oxygen, the purified methane gas can be safely transported.

[0145] The fermenter 200 may be connected to a cooling device 600 before the biogas is introduced into the gas separation device 100. The cooling device 600 removes moisture contained in the biogas by cooling the supplied biogas, thereby lowering the dew point of the biogas. As the cooling device 600, for example, a water-cooled cooler, an air-cooled cooler, an electric cooler, or the like can be used.

[0146] The fermenter 200 may be connected to a dehydration device 700 before the biogas is introduced into the gas separation device 100. The dehydration device 700 further removes moisture from the biogas from which moisture has been removed by the cooling device 600. This can further lower the dew point of the biogas. As the dehydration device 700, for example, a device filled with a dehydrating agent can be used.

[0147] Next, the operation of the biogas purification system 1000 of this embodiment will be described with reference to Figure 10. First, biogas is generated by anaerobic fermentation of sewage sludge generated from sewage treatment plants, food waste from food factories and restaurants, and manure from dairy farms, etc., in the fermenter 200. The biogas at this stage contains hydrogen sulfide, moisture, etc.

[0148] The biogas generated in the fermenter 200 is sent to the desulfurization tower 300. In the desulfurization tower 300, hydrogen sulfide is removed so that the concentration of hydrogen sulfide contained in the biogas is at the level of several ppm by volume.

[0149] Thereafter, the biogas from which hydrogen sulfide has been removed is sent to the siloxane removal device 400. In the siloxane removal device 400, the concentration of siloxane contained in the biogas is reduced to several mg / Nm3. ３ Siloxane is removed to a level.

[0150] The biogas from which siloxane has been removed is then sent to the oxygen remover 500. In the oxygen remover 500, oxygen is removed so that the concentration of oxygen contained in the biogas is at the level of several ppm by volume.

[0151] The biogas is then sent to a cooling device 600. The cooling device 600 cools the biogas and removes moisture contained in the biogas, thereby lowering the dew point of the biogas. The biogas is then sent to a dehydration device 700. In the dehydration device 700, moisture in the biogas is further removed, reducing the moisture content to 1000 ppm by volume or less.

[0152] The biogas from which hydrogen sulfide, siloxane, and moisture have been removed is sent to the gas separation apparatus 100. The operation of the gas separation apparatus 100 is as described above for the gas separation apparatus.

[0153] According to the present embodiment, it is possible to provide a gas separation apparatus capable of managing an adsorbent, a method for managing a gas separation apparatus, a gas separation method, and a method for producing a purified gas.

[0154] The present embodiment will be described in more detail below with reference to examples, but these are merely illustrative and the present embodiment is not limited to the following examples.

[0155] <Adsorption Selectivity> The adsorption selectivity was determined by the following procedure. (1) 0.2 g of the adsorbent was placed in a 12 mm cell (manufactured by Micro Meritics). (2) The sample placed in the cell in (1) above was placed in a gas adsorption measurement device "3-Flex" (trade name) manufactured by Micro Meritics, and subjected to a heating and vacuum degassing treatment at 250°C and 0.001 mmHg or less for 12 hours. (3) The sample placed in the cell after the treatment in (2) above was placed in constant-temperature circulating water at 25°C. After the sample temperature reached 25±0.2°C, absolute pressures of 0.25 to 760 mmHg were measured using liquefied carbon dioxide gas (manufactured by Sumitomo Seika Chemicals Co., Ltd., purity 99.9% by mass or more). Note that during the measurement, the pressure was measured over time, and it was determined that the saturated adsorption amount had been reached when the pressure fluctuation reached 0.001% by volume / 10 sec or less. Similarly, gaseous substance A was measured at absolute pressures of 0.25 to 760 mmHg using a gas with a purity of 99.9% by volume or higher. The adsorption selectivity was calculated by measuring the equilibrium adsorption amounts (cc / g) of carbon dioxide and gaseous substance A at 760 mmHg obtained by measuring the adsorption isotherm, and these were defined as q(CO ２ ), q(GMA), then q(CO ２ ) / q(GMA) is the adsorption selectivity.

[0156] <Moisture Content of Mixed Gas> The moisture content of the mixed gas was measured using a dew point meter (DMP74B probe, manufactured by VAISALA).

[0157] <Atomic Concentrations of Silicon, Aluminum, Phosphorus, and Potassium, and the Contents of Potassium and Lithium in Zeolite> Zeolite was thermally dissolved in aqueous sodium hydroxide or aqua regia, and the solution was appropriately diluted to measure the concentration of alkali metals in the zeolite by ICP-AES (hereinafter also referred to as "ICP-AES", SPS3520UV-DD: instrument name, manufactured by Hitachi High-Tech Science Corporation). The contents of potassium and lithium in the zeolite were calculated as the ratio (Z / T) of the total amount of potassium and lithium (Z) to the total amount of alkali metals (T) in the zeolite. The ratio (K / T) of the total amount of potassium (K) to the total amount of alkali metals (T) in the zeolite was also calculated in the same manner.

[0158] < ２９ Measurement of Si-MAS-NMR spectrum and SAR> The SAR of the zeolite in the zeolite molded body is ２９ It can be determined by measuring Si-MAS-NMR. First, to condition the moisture of the zeolite, water was placed at the bottom of a desiccator, and the zeolite placed in a sample tube was kept above the water for 48 hours. After the moisture conditioning treatment, the zeolite was measured under the following conditions: ２９ Si-MAS-NMR measurement was carried out. Apparatus: JEOL RESONANCE ECA700 Magnetic field strength: 16.44 T ( １ H resonance frequency 700MHz) Measurement nucleus: ２９ Si Resonance frequency: 139.08 MHz NMR tube: 4 mmφ (zirconia rotor) Measurement method: DD / MAS (dipolar decoupling magic angle spinning) Pulse width: 45° Waiting time: 50 sec Number of accumulations: 800 (measurement time: approximately 22 hours) MAS: 10,000 Hz Chemical shift reference: silicone rubber (-22.34 ppm) external reference For the molded body containing GIS-type zeolite, ２９ The Si-MAS-NMR spectrum shows the following five peaks: (1) Q4(0Al): a peak of Si that is not bonded to any Al atoms via oxygen; (2) Q4(1Al): a peak of Si that is bonded to one Al atom via oxygen; (3) Q4(2Al): a peak of Si that is bonded to two Al atoms via oxygen; (4) Q4(3Al): a peak of Si that is bonded to three Al atoms via oxygen; and (5) Q4(4Al): a peak of Si that is bonded to four Al atoms via oxygen. ２９In the Si-MAS-NMR spectrum, the peak positions are generally located between -112 ppm and -80 ppm, and can be assigned to Q4(0Al), Q4(1Al), Q4(2Al), Q4(3Al), and Q4(4Al) from the upfield side. The peak positions may vary depending on the cation species present in the zeolite framework, but generally, the peak positions are located in the following ranges: (1) Q4(0Al): -105 ppm to -112 ppm (2) Q4(1Al): -100 ppm to -105 ppm (3) Q4(2Al): -95 ppm to -100 ppm (4) Q4(3Al): -87 ppm to -95 ppm (5) Q4(4Al): -80 ppm to -87 ppm ２９ The peak area intensity of the Si-MAS-NMR spectrum is analyzed using the analysis program dmfit (version #202000113) with Gaussian and Lorentzian functions, and the four parameters, amplitude (height of the maximum value of the spectrum), position (spectral position, ppm), width (full width at half maximum of the spectrum, ppm), and Gaussian / Lorentzian ratio (xG / (1−x)L), are calculated by optimizing them using a least-squares algorithm. The peak areas of Q4(0Al), Q4(1Al), Q4(2Al), Q4(3Al), and Q4(4Al) thus determined are designated as A_Q4(0Al), A_Q4(1Al), A_Q4(2Al), A_Q4(3Al), and A_Q4(4Al), and the total value of A_Q4(0Al), A_Q4(1Al), A_Q4(2Al), A_Q4(3Al), and A_Q4(4Al) is designated as A_total, and the SAR can be calculated as follows: SAR = 100 / [A_Q4(1Al) / 4 + 2 x A_Q4(2Al) / 4 + 3 x A_Q4(3Al) / 4 + 4 x A_Q4(4Al) / 4] x 2

[0159] <X-ray diffraction; crystal structure analysis> X-ray diffraction was performed according to the following procedure. (1) The zeolite (dried product) obtained in each production example was used as a sample and pulverized in an agate mortar. 10% by mass of crystalline silicon (manufactured by Rare Metallic Co., Ltd.) was then added, and the mixture was mixed in the agate mortar until uniform, to prepare a sample for structural analysis. (2) The sample (1) above was uniformly fixed on a non-reflective powder sample plate, and crystal structure analysis was performed by X-ray diffraction under the following conditions. X-ray diffractometer (XRD): Rigaku Corporation, powder X-ray diffractometer "RINT2500" (product name) X-ray source: Cu tube (40 kV, 200 mA) Measurement temperature: 25°C Measurement range: 5 to 60° (0.02° / step) Measurement speed: 0.2° / min Slit width (scattering, divergence, receiving light): 1°, 1°, 0.15 mm

[0160] Production Example 1: Method for producing GIS-type zeolite molded body 61.93 g of water, 0.403 g of sodium hydroxide (NaOH, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and sodium nitrate (NaNO ３ , manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 3.39 g, and sodium aluminate (NaAlO ２ A mixed gel was prepared by mixing 1.64 g of PEG-400 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and 10.82 g of colloidal silica (Ludox AS-40, solid content concentration 40 mass%, manufactured by Grace Chemicals) and stirring for 30 minutes. The composition of the mixed gel was α = E / Al ２ O ３ =4.53, β=SiO ２ / Al ２ O ３ = 8.17, γ = Na ２ O / Al ２ O ３ = 3.99, δ = P ２ O ５ / Al ２ O ３ = 0.00, ε = H ２ O / Al ２ O ３ = 431.0, ζ = H ２ O / OH － =376.7, η=R / Al ２ O ３= 0.00. The mixed gel was placed in a 200 mL stainless steel micro-bomb (manufactured by HIRO COMPANY) containing a fluororesin inner cylinder, and hydrothermal synthesis was carried out for 4 days at a stirring speed of 30 rpm and 135°C using a stirring thermostatic chamber (manufactured by HIRO COMPANY) that can rotate the micro-bomb up and down. The product was filtered and dried at 120°C, and then powdered zeolite was obtained. 1 g of the obtained zeolite was dissolved in potassium carbonate (K ２ CO ３ The resulting mixture was placed in 500 mL of a 0.05 N aqueous potassium carbonate solution prepared using a zeolite ion exchanger (manufactured by Nippon Soda Co., Ltd.) and stirred at 500 rpm at room temperature for 3 hours. The product was filtered and dried at 120°C to obtain a powdered zeolite in which some of the cations had been exchanged with potassium. The XRD spectrum confirmed that the resulting zeolite was a GIS-type zeolite. Furthermore, since no peaks attributable to other zeolites or amorphous silica-alumina were observed, the zeolite was evaluated as a high-purity GIS-type zeolite.

[0161] The obtained zeolite was ２９ The silica-alumina ratio was calculated from the Si-MAS-NMR spectrum, and as a result, SAR was 6.90, and (a+d) / (b+c) was 0.305. The contents of potassium and lithium in the zeolite were Z / T=0.99 (=K / T). ２ The adsorption and desorption isotherms of CH were measured, and the adsorption amount at 760 mmHg was 82.2 cc / g, and q(Ad) / q(De)=0.984. ４ The adsorption isotherm was measured and the adsorption amount at 760 mmHg was 2.2 cc / g.

[0162] 40 parts by mass of GIS type zeolite powder, 48.2 parts by mass of alumina sol (manufactured by Nissan Chemical Industries, Ltd., alumina content: 10.5% by mass), and 11.8 parts by mass of powdered alumina hydrate were mixed. The mixture was extruded into a cylindrical shape with a diameter of 3 mm using a wet extrusion granulator MG-55 (manufactured by Dalton Co., Ltd.), and then fired in an electric furnace at 350°C for 24 hours in an air atmosphere to produce a GIS type zeolite molded body.

[0163] Example 1: Gas Separation Method Using the gas separation apparatus shown in Figure 1, a mixed gas containing nitrogen and carbon dioxide was separated into Gas 1 (nitrogen) and Gas 2 (carbon dioxide) and separated and recovered. The carbon dioxide adsorption towers 3a and 3b each had a volume of 1 L, and were filled with molecular sieves 13X 1 / 16 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.). A mixed gas containing 30% by volume of nitrogen and 70% by volume of carbon dioxide was used. The moisture content of the mixed gas was 120 ppm by volume. The carbon dioxide adsorption towers 3a and 3b were depressurized to 20 kPa and heated to 250°C using a heater to perform an activation step.

[0164] (Operation 1) With all of the automatic valves AV1 to AV6 closed, automatic valves AV1 and AV3 were opened, and a 25°C mixed gas was supplied to the carbon dioxide adsorption tower 3a through pipe 1 at a flow rate of 10.0 NL / min while being monitored with flow meter 11, and the pressure loss in 3a was measured using the pressure difference measurement unit 41a. After continuing the gas flow for 3 minutes, automatic valves AV1 and AV3 were closed, and at the same time, automatic valves AV2 and AV4 were opened, the supply of raw material gas was switched from the carbon dioxide adsorption tower 3a to 3b, and the pressure loss in 3b was measured using the pressure difference measurement unit 41b. Furthermore, automatic valve AV5 was opened and the carbon dioxide adsorption tower 3a was depressurized with the pressure reducing device 9, thereby performing a desorption operation with the carbon dioxide adsorption tower pressure gauge 43a at 5 kPa. The operations up to this point were designated as Operation 1.

[0165] (Operation 2) Subsequently, gas flow through the carbon dioxide adsorption tower 3b was continued for 3 minutes, and then the automatic valves AV2 and AV4 were closed and the automatic valves AV1 and AV3 were opened at the same time to switch the supply of raw material gas from the carbon dioxide adsorption tower 3b to the carbon dioxide adsorption tower 3a. Furthermore, the automatic valve AV6 was opened and the pressure in the carbon dioxide adsorption tower 3b was reduced by the pressure reducing device 9, thereby setting the pressure gauge 43b of the carbon dioxide adsorption tower 3b to 2 kPa and performing a desorption operation. The operations up to this point were referred to as Operation 2.

[0166] (Operation 3) Operations 1 and 2 were repeated 300 times, and then operation 1 was performed again. The pressure losses measured by pressure difference measuring units 41a, 41b, 42a, and 42b were 1.5 kPaA, 1.5 kPaA, 0.5 kPaA, and 0.5 kPaA, respectively. After that, the apparatus was stopped, and pressure reducing device 9 was opened, but no powdery substance was observed.

[0167] (Operation 4) Operations 1 and 2 were repeated 2000 times, and then operation 1 was performed again. The pressure losses measured by pressure difference measuring units 41a, 41b, 42a, and 42b were 4.5 kPaA, 4.5 kPaA, 1.8 kPaA, and 1.8 kPaA, respectively. After that, the apparatus was stopped, and pressure reducing device 9 was opened, whereupon a powdery substance was observed.

[0168] (Operation 5) In order to prevent powdery substances from being observed, the judgment value of the control unit is set to 0.45 kPa, which is the value at which the pressure loss during decompression is lower than that of Operation 3, based on the results of Operations 3 and 4, and the pressure loss during decompression ΔP is output as the state information of the adsorbent at the output unit. ｒ If the pressure loss ΔP is less than 0.45 kPa, it outputs and displays "Normal" and ｒ When the pressure reached 0.45 kPa or higher, a message indicating that it was time to replace the adsorbent was output and displayed. After the "adsorbent replacement time" message was output, the molecular sieves were removed and replaced, an activation step was performed, and operations 1 and 2 were then repeated. While performing this management, operations 1 and 2 were repeated a total of 2,000 times. The pressure losses measured by the pressure difference measuring units 41a, 41b, 42a, and 42b at the 2,000th measurement were 1.3 kPaA, 1.3 kPaA, 0.4 kPaA, and 0.4 kPaA, respectively. After that, the apparatus was stopped and the pressure reducing device 9 was opened, and no powdery material was found.

[0169] Example 2: Gas separation method Using the gas separation apparatus shown in FIG. 1, a mixed gas containing methane and carbon dioxide was separated and separated and recovered into Gas 1 (methane) and Gas 2 (carbon dioxide). The carbon dioxide adsorption towers 3a and 3b each had a volume of 1 L, and were filled with GIS-type zeolite shaped bodies. A mixed gas containing 60 vol% methane and 40 vol% carbon dioxide was used. The water content in the mixed gas was 98 vol ppm. Before the following operation 1, the carbon dioxide removal towers 3a and 3b were depressurized to 50 kPa and heated to 200°C using a heater, and an activation step was carried out.

[0170] (Operation 1) With all automatic valves AV1 to AV6 closed, automatic valves AV1 and AV3 were opened, and a 25°C mixed gas was supplied to the carbon dioxide adsorption tower 3a through pipe 1 at a flow rate of 8.0 NL / min, while being monitored by flowmeter 11. The pressure loss in 3a was measured using the pressure difference measurement unit 41a. After continuing the gas flow for 3 minutes, automatic valves AV1 and AV3 were closed, and automatic valves AV2 and AV4 were simultaneously opened to switch the supply of raw material gas from the carbon dioxide removal tower 3a to 3b. The pressure loss in 3b was measured using the pressure difference measurement unit 41b. All of the gas that had flowed out of the carbon dioxide adsorption tower 3a up until the switchover was recovered. (The resulting gas was designated gas 1 (methane).) Furthermore, automatic valve AV5 was opened, and the carbon dioxide adsorption tower 3a was depressurized using pressure reduction device 9, and a desorption operation was performed with the carbon dioxide adsorption tower pressure gauge 43a at 2 kPa, thereby recovering gas from the carbon dioxide adsorption tower 3a. (The gas obtained is referred to as Gas 2 (carbon dioxide).) The temperature of the desorbed gas was 35° C. on average. The operations up to this point are referred to as Operation 1.

[0171] (Operation 2) Subsequently, after continuing to pass the gas through the carbon dioxide adsorption tower 3b for 3 minutes, automatic valves AV2 and AV4 were closed and automatic valves AV1 and AV3 were opened at the same time, and the supply of the raw material gas was switched from the carbon dioxide adsorption tower 3b to the carbon dioxide adsorption tower 3a. Furthermore, automatic valve AV6 was opened and the pressure was reduced by pressure reducing device 9, so that the pressure gauge 43b of the carbon dioxide adsorption tower 3b was set to 2 kPa and a desorption operation was performed, thereby recovering gas from the carbon dioxide adsorption tower 3b. The operations up to this point were defined as operation 2.

[0172] (Operation 3) Operations 1 and 2 were repeated 100 times, and then operation 1 was performed again. The pressure losses measured by pressure difference measuring units 41 a, 41 b, 42 a, and 42 b were 0.5 kPaA, 0.5 kPaA, 1.0 kPaA, and 1.0 kPaA, respectively. The methane concentration in the resulting gas 1 was 97.0 vol% (purity of gaseous substance A extracted in one adsorption step: 97.0 vol%), and the carbon dioxide concentration in gas 2 was 94.5 vol% (purity of carbon dioxide extracted in one desorption step: 94.5 vol%). With regard to the recovery rates, from the second adsorption and desorption steps onwards, the recovery rate of methane in gas 1 obtained in one adsorption step was 96.3%, and the recovery rate of carbon dioxide in gas 2 obtained in one desorption step from the second desorption step onwards was 95.5%.

[0173] All of the gas 1 (methane) and gas 2 (carbon dioxide) obtained after repeating operations 1 and 2 100 times were recovered, and the methane and carbon dioxide concentrations were similarly measured to be 97.0% by volume and 94.5% by volume, respectively. The recovery rate was calculated from the amount of methane V2 (NL) recovered in gas 1 from the amount of methane V1 (NL) supplied during this period by V2 / V1, which was 96%. Similarly, the recovery rate was calculated from the amount of methane V4 (NL) recovered in gas 2 from the amount of carbon dioxide V3 (NL) supplied during this period by V4 / V3, which was 96.3%. Furthermore, when the powder removal section 6 was checked, powder was found to have been collected in strainer 61a. Switching valves 62 and 63 were operated to switch to powder collection in strainer 61b, and operations 1 and 2 were repeated 100 times. Furthermore, the ultimate pressure during subsequent depressurization did not change from the initial pressure.

[0174] [Evaluation of Embrittlement Rate of Adsorbent] After the operation was completed, the adsorbent was extracted, and in order to confirm the state of the adsorbent, an embrittlement rate evaluation was performed using the following procedure. (1) The mass W1 of the extracted adsorbent was measured under an N2 atmosphere, and then it was passed through a sieve with a published main opening dimension of 2.8 mm as specified in JIS Z8801-1, and the mass W2 of the adsorbent that passed through the sieve was measured. The embrittlement rate of the adsorbent extracted after operation 3, calculated using formula (1), was 0%.

[0175] (Operation 4) After repeating operations 1 and 2 1,000 times, operation 1 was performed again. The pressure losses measured by pressure difference measuring units 41a, 41b, 42a, and 42b were 5.0 kPaA, 5.0 kPaA, 10 kPaA, and 10 kPaA, respectively. The methane concentration in gas 1 was 88.6 vol% (purity of gaseous substance A extracted in one adsorption step: 88.6 vol%), and the carbon dioxide concentration in gas 2 was 88.2 vol% (purity of carbon dioxide extracted in one desorption step: 88.2 vol%). From the second adsorption and desorption steps onwards, the methane recovery rate in gas 1 obtained in one adsorption step was 92.7%, and the carbon dioxide recovery rate in gas 2 obtained in one desorption step from the second desorption step onwards was 82.0%. After completion of the operations, the adsorbent was extracted.

[0176] After operation 4, all of the gas 1 (methane) and gas 2 (carbon dioxide) obtained when operations 1 and 2 were repeated 10 times were recovered, and the methane concentration and carbon dioxide concentration were measured in the same manner, and were 88.6% by volume and 88.2% by volume, respectively. The recovery rate was calculated from the amount of methane V2 (NL) recovered in gas 1 from the amount of methane V1 (NL) supplied during this period by V2 / V1, which was 92.7%. Similarly, the recovery rate was calculated from the amount of methane V4 (NL) recovered in gas 2 from the amount of carbon dioxide V3 (NL) supplied during this period by V4 / V3, which was 82.0%. In addition, the embrittlement rate evaluation of the extracted adsorbent was measured, and the embrittlement rate was 22%, confirming the embrittlement of the adsorbent.

[0177] (Operation 5) A predetermined value was calculated with a target methane purity of 95%. The predetermined value was calculated using Formula A, where Pa = 101.3 kPaA, Pd = 2.0 kPaA, ΔPf = 0.5, X = 0.95, and Z = 0.01. The predetermined value for the pressure loss ΔPr during depressurization was set to 3.1 kPa, and the control unit determined the pressure loss. After repeating Operations 1 and 2 for a total of 391 times, the pressure loss during depressurization exceeded 3 kPa, and the adsorbent molded body status information was output, indicating that it was time to replace the adsorbent. After removing and replacing the adsorbent and performing the activation step, Operations 1 and 2 were repeated again. After removing and replacing the adsorbent and performing the activation step, Operations 1 and 2 were repeated for a total of 802 times, the pressure loss during depressurization again exceeded 3 kPa, and the adsorbent molded body status information was output, indicating that it was time to replace the adsorbent. After removing and replacing the adsorbent and performing the activation step, Operations 1 and 2 were repeated until a total of 1,000 times. The methane concentrations in Gas 1 in the 391st, 802nd, and 1001st runs were 95.1 vol% (purity of gaseous substance A extracted by one adsorption step: 95.1 vol%), 95.1 vol% (purity of gaseous substance A extracted by one adsorption step: 95.1 vol%), and 96.3 vol% (purity of gaseous substance A extracted by one adsorption step: 96.3 vol%), respectively, and the carbon dioxide concentrations in Gas 2 were 93.0 vol% (purity of carbon dioxide extracted by one desorption step: 93.0 vol%), 93.0 vol% (purity of carbon dioxide extracted by one desorption step: 94.5 vol%), and 94.3 vol% (purity of carbon dioxide extracted by one desorption step: 94.3 vol%), respectively. The methane recovery rates in gas 1 obtained by a single adsorption step in the 391st, 802nd, and 1001st repetitions of operations 1 and 2 were 95.4%, 95.4%, and 96.3%, respectively, and the carbon dioxide recovery rates in gas 2 obtained by a single desorption step from the second desorption step onwards were 93.0%, 93.0%, and 94.1%, respectively.

[0178] In operation 5, after operations 1 and 2 were repeated 391 times, 802 times, and 1001 times in total, operations 1 and 2 were similarly repeated 10 times, and the methane concentrations of all the gases 1 (methane) obtained were measured and found to be 95.1 vol%, 95.1 vol%, and 96.3 vol%, respectively. After the operations were completed, the adsorbent was extracted and the embrittlement rate of the extracted adsorbent was measured. The embrittlement rates were 9%, 9%, and 5%, respectively, confirming embrittlement of the adsorbent.

[0179] (Operation 6) Set the target value to CO ２ The predetermined value was calculated based on the recovery rate of 90% or more. The predetermined value was determined by measuring the time-dependent changes in the data on the methane recovery rate and pressure loss during depressurization when operations 1 and 2 were repeated, and after confirming that the methane recovery rate was less than 90% when the pressure loss during depressurization exceeded 5.0 kPa, the judgment value of the control unit was set to a pressure loss during depressurization of 5.0 kPa, and the output unit was caused to output, as adsorbent status information, a message indicating that the adsorbent needed to be replaced. After output, the adsorbent was removed and replaced, an activation step was performed, and operations 1 and 2 were repeated again. Operations 1 and 2 were repeated a total of 1,000 times while performing this management. It was the 677th repetition of operations 1 and 2 that the pressure loss during depressurization exceeded 5 kPa. The methane concentrations in Gas 1 in the 677th and 1001st repetitions were 93.1 vol% (purity of gaseous substance A extracted by a single adsorption step: 95.1 vol%) and 96.3 vol% (purity of gaseous substance A extracted by a single adsorption step: 96.3 vol%), respectively. The carbon dioxide concentrations in Gas 2 were 92.9 vol% (purity of carbon dioxide extracted by a single desorption step: 92.9 vol%) and 94.3 vol% (purity of carbon dioxide extracted by a single desorption step: 94.3 vol%), respectively. The methane recovery rates in Gas 1 obtained by a single adsorption step in the 677th and 1001st repetitions of Operations 1 and 2 were 94.5% and 96.3%, respectively. The carbon dioxide recovery rates in Gas 2 obtained by a single desorption step were 90.0% and 94.1%, respectively.

[0180] In operation 6, after the 677th and 1001st repetitions of operations 1 and 2, all of the gas 2 obtained when operations 1 and 2 were similarly repeated 10 times was recovered, and the amount of carbon dioxide V4 (NL) recovered in gas 2 from the amount of carbon dioxide V3 (NL) supplied during this time was calculated, and the recovery rates, based on V4 / V3, were 90.0% and 94.1%, respectively. After completion of the operation, the adsorbent was extracted and the embrittlement rate of the extracted adsorbent was measured. The embrittlement rates were 12% and 5%, respectively, confirming embrittlement of the adsorbent.

[0181] The gas separation method, purified gas production method, and gas separation apparatus of the present invention make it possible to produce purified methane gas from biogas while recovering carbon dioxide, for example, and have industrial applicability.

[0182] DESCRIPTION OF SYMBOLS 1...mixed gas supply line, 3a, 3b...carbon dioxide adsorption tower, 5...carbon dioxide recovery line, 6...powder removal section, 7...gaseous substance A recovery line, 9...pressure reducing device, 11...flow meter, 12...moisture meter, 13...component analyzer, 31a, 31b...fixed bed, 40...solid concentration, 41a, 41b, 42a, 42b...pressure difference measuring section, 43a, 43b...pressure gauge, 45...management section, 51...flow meter, 52...moisture meter, 53a, 53b...pressure gauge, 54...component analyzer, 61a, 61b...strainer, 611a, 611b...strainer housing, 612a, 612b... Filter, 62, 63, 64...switching valve, 65...differential pressure gauge, 66...control unit, 71...flow meter, 72...moisture meter, 73...component analyzer, 100, 110, 120...gas separation device, 200...fermenter, 201...blower, 300...desulfurization tower, 400...siloxane removal device, 500...oxygen removal device, 600...cooling device, 700...dehydration device, 800...computer, 801...processor, 803...memory, 805...storage device, 811...display device, 1000...biogas purification system, AV1, AV2, AV3, AV4, AV5, AV6...automatic valve

Claims

1. A gas separation apparatus for separating carbon dioxide from a mixed gas containing carbon dioxide, an adsorption tower filled with an adsorbent that adsorbs carbon dioxide; a mixed gas supply line for introducing the mixed gas into the adsorption tower; a carbon dioxide recovery line that extracts carbon dioxide from the adsorption tower; a pressure reducing device connected to the carbon dioxide recovery line; a pressure difference measuring unit for measuring a pressure loss ΔP caused by the adsorption tower; Equipped with Gas separation equipment.

2. The gas separation apparatus according to claim 1 , wherein the carbon dioxide recovery line has a powder removal section between the adsorption tower and the pressure reducing device.

3. Further comprising a management department, The management unit: a determination unit that determines whether the pressure loss ΔP exceeds a predetermined value; an output unit that outputs state information of the adsorbent when the determination unit determines that the value exceeds the predetermined value; having The gas separation apparatus of claim 1 .

4. The pressure loss ΔP is the pressure loss ΔPf when the mixed gas is introduced. The gas separation apparatus according to claim 3 .

5. The pressure difference measuring unit The pressure P of the adsorption tower on the mixed gas supply line side １ and the pressure P of the adsorption tower on the opposite side of the mixed gas supply line. ２ Measure the pressure loss ΔPf from the pressure difference between The gas separation apparatus according to claim 4.

6. The predetermined value is 50 kPa or less. The gas separation apparatus according to claim 4.

7. The pressure loss ΔP is the pressure loss ΔPr during pressure reduction. The gas separation apparatus according to claim 3 .

8. The pressure difference measuring unit The pressure P of the adsorption tower on the carbon dioxide recovery line side ３ and the pressure P of the adsorption tower on the opposite side of the carbon dioxide recovery line ４ The pressure loss ΔPr is measured from the pressure difference between The gas separation apparatus of claim 7.

9. The predetermined value is 10 kPa or less. The gas separation apparatus of claim 7.

10. The pressure loss ΔP is a pressure loss ΔPf when the mixed gas is introduced and a pressure loss ΔPr when the mixed gas is reduced in pressure. The gas separation apparatus according to claim 3 .

11. The pressure difference measuring unit The pressure P of the adsorption tower on the mixed gas supply line side １ and the pressure P of the adsorption tower on the opposite side of the mixed gas supply line. ２ Measure the pressure loss ΔPf from the pressure difference between The pressure P of the adsorption tower on the carbon dioxide recovery line side ３ and the pressure P of the adsorption tower on the opposite side of the carbon dioxide recovery line ４ The pressure loss ΔPr is measured from the pressure difference between The gas separation apparatus of claim 10.

12. the pressure loss ΔP is a pressure loss ΔPf when the mixed gas is introduced and a pressure loss ΔPr when the mixed gas is reduced in pressure, the output unit outputs state information of the adsorbent when the pressure loss ΔPf or the pressure loss ΔPr exceeds a predetermined value. The gas separation apparatus of claim 10.

13. The mixed gas contains a gaseous substance A other than carbon dioxide, a gaseous substance A recovery line for extracting the gaseous substance A from the adsorption tower; Equipped with Separating the carbon dioxide from the gaseous substance A; The gas separation apparatus of claim 1 .

14. the adsorbent comprises a zeolite; The gas separation apparatus of claim 1 .

15. The gas separation apparatus according to claim 14, wherein the zeolite is an FAU-type zeolite or a GIS-type zeolite.

16. 2. The gas separation apparatus according to claim 1, wherein the adsorbent has an adsorption selectivity of carbon dioxide / gaseous substance A of 8 or more.

17. A method for managing a gas separation apparatus that separates carbon dioxide from a mixed gas containing the carbon dioxide, comprising: The gas separation device an adsorption tower filled with an adsorbent that adsorbs carbon dioxide; a mixed gas supply line for introducing the mixed gas into the adsorption tower; a carbon dioxide recovery line that extracts carbon dioxide from the adsorption tower; a pressure reducing device connected to the carbon dioxide recovery line; a pressure difference measuring unit for measuring a pressure loss ΔP caused by the adsorption tower; The management department and Equipped with The management method comprises: a determination step of determining whether the pressure loss ΔP exceeds a predetermined value; an output step of outputting state information of the adsorbent when the predetermined value is exceeded in the determination step; having Methods for managing gas separation equipment.

18. The pressure loss ΔP is the pressure loss ΔP when the mixed gas is introduced. ｆ That is, The method for managing a gas separation apparatus according to claim 17.

19. The predetermined value is 10 kPa or less. The method for managing a gas separation apparatus according to claim 18.

20. The pressure loss ΔP is the pressure loss ΔP during pressure reduction. ｒ That is, The method for managing a gas separation apparatus according to claim 17.

21. The predetermined value is 5 kPa or less. The method for managing a gas separation apparatus according to claim 20.

22. The pressure loss ΔP is the pressure loss ΔP when the mixed gas is introduced. ｆ and pressure loss ΔP during decompression ｒ That is, The method for managing a gas separation apparatus according to claim 17.

23. The pressure loss ΔP is the pressure loss ΔP when the mixed gas is introduced. ｆ and pressure loss ΔP during decompression ｒ and The output step is ｆ Or the pressure loss ΔP ｒ If the value exceeds a predetermined value, output the status information of the adsorbent. The method for managing a gas separation apparatus according to claim 17.

24. A gas separation method for separating carbon dioxide from a mixed gas containing carbon dioxide using an adsorption tower filled with an adsorbent, an adsorption step of introducing the mixed gas into the adsorption tower and adsorbing carbon dioxide onto the adsorbent; a desorption step of removing the carbon dioxide from the adsorbent by decompressing and evacuating the carbon dioxide from the adsorption tower; Including, The adsorption step and / or the desorption step is performed while measuring the pressure drop ΔP in the adsorption tower. Gas separation methods.

25. The mixed gas contains a gaseous substance A other than carbon dioxide, In the adsorption step, a gaseous substance A is extracted.

25. The gas separation method of claim 24.

26. A method for producing a purified gas, comprising obtaining purified carbon dioxide by the gas separation method according to claim 24.

27. A method for producing a purified gas, comprising obtaining a purified gas substance A by the gas separation method according to claim 25.