Zeolite molded body, adsorption apparatus, method for producing purified gas, and method for producing zeolite molded body

Abstract

This zeolite molded article contains a zeolite capable of adsorbing carbon dioxide, and has an apparent density d of 0.75 or greater.

Description

[Technical Field]

[0001] The present invention relates to a shaped zeolite body, an adsorption apparatus, a method for producing a purified gas, and a method for producing a shaped zeolite body. [Background technology]

[0002] Zeolites can be used as adsorbents, desiccants, separating agents, catalysts, catalyst carriers, detergent aids, ion exchange agents, wastewater treatment agents, fertilizers, food additives, cosmetic additives, etc., and are particularly useful for gas separation applications.

[0003] For example, among zeolites, those with a GIS structure, a code for specifying the structure of zeolites established by the IZA (International Zeolite Association), are called GIS-type zeolites. GIS-type zeolites have pores composed of eight-membered oxygen rings. Regarding such GIS-type zeolites, for example, Patent Document 1 discloses that GIS-type zeolites having the ability to adsorb carbon dioxide are synthesized, and that when GIS-type zeolites are used as adsorbents, they can be used for separating, capturing, and purifying carbon dioxide. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. WO2019 / 202933 Summary of the Invention [Problem to be solved by the invention]

[0005] When separating, capturing, and purifying carbon dioxide using an adsorbent, methods such as pressure swing adsorption separation, temperature swing adsorption separation, and pressure-temperature swing adsorption separation are used. In these methods, zeolite is packed into a column or the like. To prevent fine powdered zeolite from accumulating and clogging the flow channels within the device, the zeolite is shaped into pellet-shaped zeolite compacts. The performance of these zeolite compacts requires sufficient durability under the conditions of use.

[0006] We have found that when a large amount of carbon dioxide is adsorbed into a zeolite molded body, the molded body becomes brittle, and in the case of a pellet-shaped zeolite molded body, it breaks down into powder. This embrittlement generates fine powder inside the adsorption device, which makes it difficult to operate the device continuously due to pressure loss, etc.

[0007] An object of the present invention is to provide a zeolite molded body that is excellent in resistance to embrittlement due to carbon dioxide adsorption, an adsorption apparatus including the same, a method for producing a purified gas using the same, and a method for producing a zeolite molded body. [Means for solving the problem]

[0008] As a result of extensive research into solving the above-mentioned problems, the inventors have found that the problems can be solved when the density of a zeolite-containing shaped body is within a predetermined range, and have thus completed the present invention.

[0009] That is, the present invention includes the following embodiments. <1> A zeolite molded body containing zeolite capable of adsorbing carbon dioxide, The apparent density d of the zeolite molded body a A zeolite molded body having a β-dispersion constant of 0.75 or more. <2> The zeolite is 10 cm 3 / g or more of carbon dioxide adsorption capacity, <1> The zeolite molded body according to claim 1. <3> The apparent density d of the zeolite molded body a / true density d t The ratio is 0.36 or more. <1> or <2> The zeolite molded body according to claim 1. <4> The bulk density d of the zeolite molded body b / true density d t The ratio is 0.25 or more. <1> ~ <3> The zeolite molded body according to any one of the preceding claims. <5> The zeolite has an adsorption selectivity of carbon dioxide adsorption amount / second component gas adsorption amount of 10 or more. <1> ~ <4> The zeolite molded body according to any one of the preceding claims. <6> The zeolite is a GIS-type zeolite. <1> ~ <5> The zeolite molded body according to any one of the preceding claims. <7> The silica-alumina ratio of the GIS-type zeolite is 3.40 or more. <6> The zeolite molded body according to claim 1. <8> Contains potassium or lithium as a cation species in GIS-type zeolite, <6> or <7> The zeolite molded body according to claim 1. <9> 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-type zeolite is 0.05 or more; <6> ~ <8> The zeolite molded body according to any one of the preceding claims. <10> 29 The peak area intensities attributable to Q4(3Al), Q4(2Al), Q4(1Al), and Q4(0Al) observed in the Si-MAS-NMR spectrum are designated as a, b, c, and d, respectively, and the GIS-type zeolite satisfies (a+d) / (b+c)≧0.192. <6> ~ <9> The zeolite molded body according to any one of the preceding claims. <11> including a carrier, <1> ~ <10> The zeolite molded body according to any one of the preceding claims. <12> The carrier comprises an inorganic binder and an organic binder. <11> The zeolite molded body according to claim 1. <13> The total content of the carrier is 1 to 99% by mass relative to the total amount (100% by mass) of the zeolite shaped body. <11> or <12> The zeolite molded body according to claim 1. <14> The weight loss rate per 1.2g when heated at 300℃ for 2 hours is 1.0 or less. <1> ~ <13> The zeolite molded body according to any one of the preceding claims. <15> The aspect ratio is between 1 and 10. <1> ~ <14> The zeolite molded body according to any one of the preceding claims. <16> having a cylindrical shape, <1> ~ <15> The zeolite molded body according to any one of the preceding claims. <17> The length is 3 mm or more and 30 mm or less, and the diameter is 1 mm or more and 30 mm or less. <16> The zeolite molded body according to claim 1. <18> having a spherical shape, <1> ~ <15> The zeolite molded body according to any one of the preceding claims. <19> The diameter is between 3mm and 10mm. <18> The zeolite molded body according to claim 1. <20> <1> ~ <19> An adsorption device comprising the zeolite shaped body according to any one of the preceding items. <21> <20> A method for producing a purified gas, comprising a separation step of separating one or more gases selected from the group consisting of CO2, H2O, He, Ne, Cl2, NH3, and HCl from a mixture containing two or more gases selected from the group consisting of H2, N2, O2, Ar, CO, and hydrocarbons, using the adsorption apparatus described in the above. <22> In the separation step, the gas is separated by a pressure swing adsorption separation method, a temperature swing adsorption separation method, or a pressure-temperature swing adsorption separation method. <21> A method for producing the purified gas described in claim 1. <23> A method for producing a purified gas, comprising: separating carbon dioxide and a second component gas different from carbon dioxide from a mixed gas containing the carbon dioxide and the second component gas using an adsorption tower; an adsorption step of introducing the mixed gas into the adsorption tower, causing the adsorbent to adsorb carbon dioxide, and extracting a second component gas; 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 tower <1> ~ <22> 10. A method for producing a purified gas, wherein an adsorbent containing the zeolite shaped article according to any one of claims 1 to 9 is packed. <24> The adsorption step and the desorption step are repeated multiple times. <23> A method for producing the purified gas described in claim 1. <25> A raw material mixing step (X) of mixing a zeolite capable of adsorbing carbon dioxide with a carrier containing an inorganic binder and an organic binder; a molding process step (Y) in which the prepared raw material is subjected to a molding process to obtain a precursor; a calcination step (Z) of calcining the precursor to obtain a zeolite shaped body; A method for producing a zeolite molded body, comprising: [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a shaped zeolite body having excellent resistance to embrittlement due to adsorption of carbon dioxide, an adsorption apparatus including the same, a method for producing a purified gas using the same, and a method for producing a shaped zeolite body. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating an example of the suction device according to this embodiment. [Figure 2] FIG. 2 is a diagram illustrating a schematic configuration of a purified gas production apparatus 100 according to this embodiment. [Figure 3] FIG. 3 is a conceptual diagram showing the carbon dioxide adsorption tower and the pressure fluctuations in the carbon dioxide adsorption tower over time due to the operation of the purified gas production system 100. [Figure 4] FIG. 4 is a diagram illustrating an example of the gas separation performance evaluation device of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] 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 can be practiced with various modifications within the scope of the gist thereof. In this specification, for example, when a numerical range is expressed as "1 to 100," it is intended to include both the lower limit "1" and the upper limit "100." The same applies to other numerical ranges.

[0013] [Zeolite Molded Body] The zeolite molded body according to this embodiment contains zeolite capable of adsorbing carbon dioxide, and the apparent density d a is 0.75 or more. The zeolite shaped body according to this embodiment has excellent resistance to embrittlement due to the adsorption of carbon dioxide. According to this embodiment, by increasing the density of the zeolite shaped body and controlling the amount of voids present in the zeolite shaped body to densify it, it is possible to reduce the maximum stress generated in response to the expansion and contraction of the zeolite itself, and it is believed that it is possible to provide a zeolite shaped body that is resistant to deterioration due to expansion and contraction, an adsorption apparatus including the zeolite shaped body, a method for producing a purified gas using the zeolite shaped body, and a method for producing a zeolite shaped body.

[0014] Apparent density of zeolite compact d a (g / cm 3 ) is 0.75 or more, preferably 0.78 or more, and more preferably 0.80 or more, from the viewpoint of improving resistance to embrittlement due to adsorption of carbon dioxide. a The upper limit of the apparent density d is not particularly limited, but may be, for example, 3.20 or less, 2.80 or less, or 2.50 or less. a In order to keep the value within the predetermined range, it may be adjusted by selecting the type of carrier as described below.

[0015] Bulk density of zeolite compact d b (g / cm 3From the viewpoint of enabling gas separation using a smaller device, the bulk density d is preferably 0.20 or more, more preferably 0.40 or more, and even more preferably 0.50 or more. b The upper limit of the bulk density d is not particularly limited, but may be, for example, 3.00 or less, 2.50 or less, or 1.50 or less. b In order to set the value within the predetermined range, it may be adjusted by adjusting the size of the molded body as described later.

[0016] True density of zeolite compact d t (g / cm 3 ) may be, for example, 1.00 to 4.00, 1.50 to 3.50, or 2.00 to 3.00. t In order to keep the value within the predetermined range, it may be adjusted by selecting the type of carrier or adjusting the amount of carrier added, as described below.

[0017] Apparent density d of zeolite molded body a / true density d t From the viewpoint of increasing the recovery purity of carbon dioxide and the recovery rate of the second component gas, the apparent density d is preferably 0.36 or more, more preferably 0.42 or more, and even more preferably 0.50 or more. a / true density d tis less than 1.0, preferably 0.90 or less, more preferably 0.80 or less, and even more preferably 0.70 or less. When carbon dioxide is separated using a zeolite shaped body, for example, carbon dioxide is circulated through the zeolite shaped body to adsorb the carbon dioxide, and then the carbon dioxide is desorbed by reducing the pressure. It has been found that in this separation method, the recovery purity of carbon dioxide and the recovery rate of the second component gas cannot exceed a certain level, resulting in low values. If the recovery purity of carbon dioxide and the recovery rate of the second component gas are low, the gas must be repeatedly treated to increase the recovery purity of carbon dioxide and the recovery rate of the second component gas, which increases the cost of gas purification. To address this issue, it has been found that if voids exist within the zeolite shaped body passing through during carbon dioxide adsorption and desorption, the second component gas remains unadsorbed in the adsorption tower, making it impossible to increase the recovery purity of carbon dioxide. Furthermore, it has been found that the second component gas remaining in the voids cannot be recovered as purified gas, making it impossible to increase the recovery rate of the second component gas. Therefore, it has been found that the apparent density d of the zeolite shaped body a / true density d t By setting the apparent density d in the above range, it is possible to reduce the proportion of voids in the zeolite formed body, which leads to a reduction in the amount of residual gas, and it is thought that as a result, it is possible to increase the recovery purity of carbon dioxide and the recovery rate of the second component gas. a / true density d t In order to keep the value within the predetermined range, it is only necessary to adjust the value by selecting the carrier and the granulation method, which will be described later.

[0018] The term "second component gas" refers to a gaseous substance other than carbon dioxide at a temperature of 25°C and a pressure of 0.10 MPa. Examples of second component gases include H2, N2, O2, Ar, CO, and hydrocarbons. Hydrocarbons include, but are not limited to, methane, ethane, ethylene, propane, propylene, 1-butene, 2-butene, 2-methylpropene, dimethyl ether, and acetylene.

[0019] Bulk density d of zeolite molded body b / true density dt From the viewpoint of increasing the recovery purity of carbon dioxide and the recovery rate of the second component gas, the bulk density d is preferably 0.25 or more, more preferably 0.30 or more, and even more preferably 0.35 or more. b / true density d t Although the upper limit of d is not particularly limited, it is less than 1.0, preferably 0.90 or less, more preferably 0.70 or less, and even more preferably 0.60 or less. It has been found that the purity of recovered carbon dioxide cannot be increased because unadsorbed gas remains in the adsorption tower even in the gaps present between the zeolite shaped bodies that pass through during adsorption and desorption of carbon dioxide. Furthermore, it has been found that the recovery rate of the second component gas cannot be increased because the second component gas remaining in the gaps between the shaped bodies cannot be recovered as purified gas. Therefore, the bulk density d of the zeolite shaped bodies b / true density d t By setting the bulk density d in the above range, it is possible to reduce the proportion of voids between the zeolite molded bodies, which leads to a reduction in the amount of residual gas, and it is thought that as a result, it is possible to increase the recovery purity of carbon dioxide and the recovery rate of the second component gas. b / true density d t In order to set the value within the predetermined range, it may be adjusted by selecting the carrier, adjusting the size of the compact, selecting the granulation method, etc., as will be described later.

[0020] The apparent density d a , bulk density d b , and true density d t The measurement method is the same as that described in the Examples.

[0021] (Zeolite) Zeolite is 10cm 3 The carbon dioxide adsorption capacity of the zeolite is preferably 20 cm / g or more. 3 / g or more, more preferably 40 cm 3 / g or more, more preferably 50 cm 3 The upper limit of the carbon dioxide adsorption capacity of zeolite is not particularly limited, but for example, it is 100 cm 3 / g or less.

[0022] From the viewpoint of further improving the recovery purity of carbon dioxide, the adsorption selectivity of the zeolite, i.e., the carbon dioxide adsorption amount / second component gas adsorption amount, is preferably 10 or more, more preferably 13 or more, and even more preferably 15 or more. The upper limit of the adsorption selectivity of the zeolite, i.e., the carbon dioxide adsorption amount / second component gas adsorption amount, is not particularly limited, but is, for example, 100 or less. The adsorption amounts of carbon dioxide and the second component gas, etc., are expressed as the carbon dioxide adsorption capacity (cm) per 1 g of zeolite at 25°C. 3 ) More specifically, it is measured by the method described in the Examples.

[0023] From the viewpoint of further improving the recovery purity of carbon dioxide, the zeolite preferably has an adsorption selectivity of carbon dioxide adsorption amount / methane adsorption amount of 10 or more, more preferably 13 or more, and even more preferably 15 or more. The upper limit of the adsorption selectivity of carbon dioxide adsorption amount / methane adsorption amount of the zeolite is not particularly limited, but is, for example, 100 or less.

[0024] From the viewpoint of further improving the recovery purity of carbon dioxide, the zeolite has an adsorption selectivity of carbon dioxide adsorption amount / nitrogen adsorption amount of preferably 10 or more, more preferably 13 or more, and even more preferably 15 or more. The upper limit of the adsorption selectivity of carbon dioxide adsorption amount / nitrogen adsorption amount of the zeolite is not particularly limited, but is, for example, 100 or less.

[0025] Zeolites capable of adsorbing carbon dioxide include, for example, GIS-type zeolites, FAU-type zeolites, MWF-type zeolites, etc. Among these, GIS-type zeolites are preferred.

[0026] The lower the silica-alumina ratio (representing the molar ratio of silica to alumina expressed as SiO2 / Al2O3, hereinafter also referred to simply as "SAR") of the GIS zeolite according to this embodiment, the more hydrophilic it is, and the stronger its adsorption power for polar molecules such as carbon dioxide. If the SAR is low, the adsorption power will be too strong, and the energy required for desorption by heating or vacuuming will be large, so a higher SAR is preferable. The SAR of the GIS zeolite is preferably 3.40 or more, more preferably 4.40 or more, more preferably 4.50 or more, even more preferably 4.69 or more, even more preferably 4.90 or more, even more preferably 5.40 or more, and even more preferably 6.01 or more. There is no particular upper limit for the SAR, but if the SAR is too high, the interaction with the adsorbate will be reduced, so the SAR of the GIS zeolite is preferably 3000 or less, more preferably 500 or less, and even more preferably 100 or less. The SAR of the zeolite in the zeolite molded body is 29 The SAR is determined by measuring Si-MAS-NMR. More specifically, the SAR can be measured by the method described in the Examples below. The SAR is determined by the ratio of water and OH in the mixed gel. - The amount of the saturation agent can be adjusted by adjusting the ratio of the saturation agent and the like.

[0027] From the viewpoint of the energy required for desorption, a high SAR is preferable. However, it has been confirmed that when the SAR of a GIS zeolite increases, adsorption / desorption hysteresis becomes apparent in the carbon dioxide adsorption / desorption isotherm. In the GIS zeolite according to this embodiment, 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 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, and it is preferable that (a+d) / (b+c)≧0.192, 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 Si-MAS-NMR spectra represent the bonding modes of Si and Al in the zeolite framework. The sum of the area intensities (a + d) and (b + c) represents the sum of the abundances of these bonding modes, and (a + d) / (b + c) represents the abundance ratio. The abundance ratio of Si and Al bonding modes affects the structural changes of the zeolite framework itself during adsorption and desorption. Therefore, by adjusting the abundance ratio of Si and Al bonding modes in the zeolite framework, (a + d) / (b + c), within an appropriate range, adsorption / desorption hysteresis in the adsorption / desorption isotherm can be eliminated. (a + d) / (b + c) can be measured using the method described in the Examples below. To achieve a desired range for (a + d) / (b + c), salt compounds containing alkali metals and / or alkaline earth metals can be added and adjusted by adjusting the amount ratio of the cations and aluminum source provided by the addition of the salt compounds.

[0028] 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 potassium and lithium (Z) to the total amount 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 subjecting the appropriately diluted solution to ICP-emission spectroscopy. 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.

[0029] The GIS zeolite preferably has a weight loss rate of 1.0 or less per 1.2 g under conditions of 300°C for 2 hours. A weight loss rate of 1.0 or less improves high-temperature durability. The weight loss rate is preferably 0.5 or less, more preferably 0.2 or less, and even more preferably 0.1 or less. The degree of weight loss was measured by the method described in the Examples. The degree of weight loss can be adjusted to the above range by reducing the amount of organic binder or by sintering the zeolite molded body at a temperature above 300°C.

[0030] The zeolite content may be preferably 50% by mass or more, 60% by mass or more, 70% by mass or more, or 80% by mass or more, based on 100% by mass of the total amount of the zeolite shaped body, and may be 98% by mass or less, or 95% by mass or less, based on 100% by mass of the total amount of the zeolite shaped body.

[0031] (Method for synthesizing GIS-type zeolite) The method for producing a GIS-type zeolite according to this embodiment can include, for example, a step of preparing a mixed gel containing 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. The mixed gel and each component contained therein will be described below.

[0032] [Mixed gel] The mixed gel in this embodiment refers to a mixture containing a silica source, an aluminum source, a salt compound, and water as components, and optionally containing a phosphorus source, an alkali source, and an organic structure-directing agent.

[0033] The silica source refers to a component in the mixed gel that serves as a source of silicon contained in the zeolite produced from the mixed gel, the aluminum source refers to a component in the mixed gel that serves as a source of aluminum contained in the zeolite produced from the mixed gel, the salt compound refers to a component that serves as a source of alkali metals and / or alkaline earth metals contained in the zeolite produced from the mixed gel, the alkali source refers to a component that adjusts the alkalinity of the mixed gel, and the phosphorus source refers to a component in the mixed gel that serves as a source of phosphorus contained in the zeolite produced from the mixed gel.

[0034] [Silica Source] The silica source is not particularly limited as long as it is a commonly used one, and examples thereof include crystalline silica, amorphous silica, silicic acid, silicates, organic silicate compounds, etc. More specific examples include sodium silicate, potassium silicate, calcium silicate, magnesium silicate, fumed silica, precipitated silica, silica gel, colloidal silica, aluminosilicate, tetraethoxysilane (TEOS), trimethylethoxysilane, etc. These compounds may be used alone or in combination. Here, the aluminosilicate serves as both a silica source and an aluminum source.

[0035] Among these, fumed silica, colloidal silica, and precipitated silica are preferred because they tend to produce zeolites with a high degree of crystallinity.

[0036] [Aluminum source] The aluminum source is not particularly limited as long as it is a commonly used one, and specific examples include sodium aluminate, aluminum sulfate, aluminum nitrate, aluminum acetate, aluminum hydroxide, aluminum oxide, aluminum chloride, aluminum alkoxide, metallic aluminum, amorphous aluminosilicate gel, etc. These compounds may be used alone or in combination.

[0037] Among these, sodium aluminate, aluminum sulfate, aluminum nitrate, aluminum acetate, aluminum hydroxide, aluminum chloride, and aluminum alkoxides are preferred because they tend to produce zeolites with a high degree of crystallinity. From the same viewpoint, sodium aluminate and aluminum hydroxide are more preferred, and sodium aluminate is even more preferred.

[0038] [Salt compounds] The salt compound is a compound containing an alkali metal such as Li, Na, K, Rb, or Cs, or an alkaline earth metal such as Ca, Mg, Sr, or Ba, which promotes crystallization into a zeolite structure when producing zeolite. The alkali metal and alkaline earth metal contained in the salt compound to be added are preferably Na and K, and more preferably Na, from the viewpoint of facilitating the formation of crystals of a GIS-type framework. The salt compounds may be used alone or in combination.

[0039] Specific examples of salt compounds include, but are not limited to, sodium sulfate, sodium sulfite, sodium thiosulfate, sodium nitrite, sodium nitrate, sodium carbonate, sodium hydrogencarbonate, sodium phosphate, sodium acetate, sodium formate, sodium citrate, sodium oxalate, sodium fluoride, sodium chloride, sodium bromide, sodium iodide, sodium thiosodium, sodium silicate, sodium metasilicate, sodium tetraborate, sodium chlorate, sodium perchlorate, sodium cyanide, sodium metastannate, sodium hexahydroxide stannate (IV), sodium hexacyanilide ferrate (II), sodium permanganate, sodium chromate, sodium dichromate, Potassium sulfate, potassium sulfite, potassium thiosulfate, potassium nitrite, potassium nitrate, potassium carbonate, potassium bicarbonate, potassium phosphate, potassium acetate, potassium formate, potassium citrate, potassium oxalate, potassium fluoride, potassium chloride, potassium bromide, potassium iodide, potassium thio, potassium silicate, potassium metasilicate, potassium tetraborate, potassium chlorate, potassium perchlorate, potassium cyanide, potassium metastannate, potassium hexahydroxide stannate(IV), potassium hexacyanilide ferrate(II), potassium permanganate, potassium chromate, potassium dichromate, Lithium sulfate, lithium sulfite, lithium thiosulfate, lithium nitrite, lithium nitrate, lithium carbonate, lithium bicarbonate, lithium phosphate, lithium acetate, lithium formate, lithium citrate, lithium oxalate, lithium fluoride, lithium chloride, lithium bromide, lithium iodide, lithium thiolithium, lithium silicate, lithium metasilicate, lithium tetraborate, lithium chlorate, lithium perchlorate, lithium cyanide, lithium metastannate, lithium hexahydroxide stannate(IV), lithium hexacyanilide ferrate(II), lithium permanganate, lithium chromate, lithium dichromate, Rubidium sulfate, rubidium sulfite, rubidium thiosulfate, rubidium nitrite, rubidium nitrate, rubidium carbonate, rubidium bicarbonate, rubidium phosphate, rubidium acetate, rubidium formate, rubidium citrate, rubidium oxalate, rubidium fluoride, rubidium chloride, rubidium bromide, rubidium iodide, rubidium thiol, rubidium silicate, rubidium metasilicate, rubidium tetraborate, rubidium chlorate, rubidium perchlorate, rubidium cyanide, rubidium metastannate, rubidium hexahydroxide stannate(IV), rubidium hexacyanidoferrate(II), rubidium permanganate, rubidium chromate, rubidium dichromate Cesium sulfate, Cesium sulfite, Cesium thiosulfate, Cesium nitrite, Cesium nitrate, Cesium carbonate, Cesium bicarbonate, Cesium phosphate, Cesium acetate, Cesium formate, Cesium citrate, Cesium oxalate, Cesium fluoride, Cesium chloride, Cesium bromide, Cesium iodide, Cesium thiocesium, Cesium silicate, Cesium metasilicate, Cesium tetraborate, Cesium chlorate, Cesium perchlorate, Cesium cyanide, Cesium metastannate, Cesium hexahydroxide stannate(IV), Cesium hexacyanilide ferrate(II), Cesium permanganate, Cesium chromate, Cesium dichromate, Magnesium sulfate, magnesium sulfite, magnesium thiosulfate, magnesium nitrite, magnesium nitrate, magnesium carbonate, magnesium bicarbonate, magnesium phosphate, magnesium acetate, magnesium formate, magnesium citrate, magnesium oxalate, magnesium fluoride, magnesium chloride, magnesium bromide, magnesium iodide, magnesium thiomagnesium, magnesium silicate, magnesium metasilicate, magnesium tetraborate, magnesium chlorate, magnesium perchlorate, magnesium cyanide, magnesium metastannate, magnesium hexahydroxide stannate(IV), magnesium hexacyanilide ferrate(II), magnesium permanganate, magnesium chromate, magnesium dichromate, Calcium sulfate, calcium sulfite, calcium thiosulfate, calcium nitrite, calcium nitrate, calcium carbonate, calcium bicarbonate, calcium phosphate, calcium acetate, calcium formate, calcium citrate, calcium oxalate, calcium fluoride, calcium chloride, calcium bromide, calcium iodide, calcium thiocalcium, calcium silicate, calcium metasilicate, calcium tetraborate, calcium chlorate, calcium perchlorate, calcium cyanide, calcium metastannate, calcium hexahydroxide stannate(IV), calcium hexacyanilide ferrate(II), calcium permanganate, calcium chromate, calcium dichromate, Strontium sulfate, strontium sulfite, strontium thiosulfate, strontium nitrite, strontium nitrate, strontium carbonate, strontium bicarbonate, strontium phosphate, strontium acetate, strontium formate, strontium citrate, strontium oxalate, strontium fluoride, strontium chloride, strontium bromide, strontium iodide, strontium thiostrontium, strontium silicate, strontium metasilicate, strontium tetraborate, strontium chlorate, strontium perchlorate, strontium cyanide, strontium metastannate, strontium hexahydroxide stannate(IV), strontium hexacyanidoferrate(II), strontium permanganate, strontium chromate, strontium dichromate, Examples of suitable cations include barium sulfate, barium sulfite, barium thiosulfate, barium nitrite, barium nitrate, barium carbonate, barium bicarbonate, barium phosphate, barium acetate, barium formate, barium citrate, barium oxalate, barium fluoride, barium chloride, barium bromide, barium iodide, barium thiosulfate, barium silicate, barium metasilicate, barium tetraborate, barium chlorate, barium perchlorate, barium cyanide, barium metastannate, barium hexahydroxide stannate(IV), barium hexacyanilide ferrate(II), barium permanganate, barium chromate, and barium dichromate.

[0040] [Alkaline source] When producing zeolite, an alkali source is used for the purpose of adjusting the alkalinity (pH) of the mixed gel in order to promote crystallization into a zeolite structure. The alkali used may be any compound that exhibits alkalinity, and may be either an inorganic or organic compound. However, from the standpoint of cost, inorganic compounds are preferred, and alkali metal hydroxides are more preferred. Examples of alkali metal hydroxides include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide. Sodium hydroxide and potassium hydroxide are preferred, and sodium hydroxide is more preferred. These compounds may be used alone or in combination.

[0041] The phosphorus source is not particularly limited as long as it is a commonly used one, and specific examples include an aqueous phosphoric acid solution, sodium phosphate, aluminum phosphate, potassium phosphate, lithium phosphate, calcium phosphate, barium phosphate, etc. These compounds may be used alone or in combination.

[0042] Among these, phosphoric acid aqueous solution, sodium phosphate, and aluminum phosphate are preferred because they tend to produce zeolites with a high degree of crystallinity. From the same viewpoint, phosphoric acid aqueous solution and sodium phosphate are more preferred, and phosphoric acid aqueous solution is even more preferred.

[0043] [Organic structure directing agent] When producing a zeolite by hydrothermal synthesis of a mixed gel, the organic structure-directing agent is a compound that acts to promote crystallization into a zeolite structure. In the crystallization of zeolite, an organic structure-directing agent can be used as needed.

[0044] The organic structure-directing agent may be of any type as long as it can form the desired GIS zeolite. The organic structure-directing agents may be used alone or in combination.

[0045] Examples of organic structure-directing agents that can be used include, but are not limited to, amines, quaternary ammonium salts, alcohols, ethers, amides, alkyl ureas, alkyl thioureas, cyanoalkanes, and alicyclic heterocyclic compounds containing nitrogen as a heteroatom. Preferably, alkyl amines are used, and more preferably isopropylamine is used.

[0046] Such salts may include anions, such as, but not limited to, Cl. - , Br - , I - These include halogen ions such as halogen ions, hydroxide ions, acetate ions, sulfate ions, nitrate ions, carbonate ions, and hydrogen carbonate ions. Among these, halogen ions and hydroxide ions are preferred, with halogen ions being more preferred, from the viewpoint of facilitating the formation of GIS-type framework crystals.

[0047] [Composition ratio of mixed gel] In this embodiment, the addition of a salt compound containing an alkali metal and / or alkaline earth metal is the most important factor for synthesizing a GIS-type zeolite with an appropriate structure. Zeolite is produced by reacting and crystallizing a silica source and an aluminum source dissolved in an aqueous solvent while dissolving. The addition of a salt compound makes it possible to adjust the bonding pattern and abundance ratio of Si and Al in the zeolite framework, making it possible to synthesize a GIS with an ideal crystal structure.

[0048] The ratio of the cations provided by the addition of the salt compound to the aluminum source is particularly important. The ratio of the cations provided by the salt compound to the aluminum source in the mixed gel is expressed as the sum molar ratio of the amount of cations E to Al2O3, that is, E / Al2O3. Here, E represents the molar amount of cations provided by the salt compound. For example, when sodium nitrate is added, Na is added as the cationic species. + is produced, and in the case of sodium carbonate, 2Na +is generated, and the sum of the molar amounts of cation species generated by the addition of the salt compound is represented by E. The aggregation state of Al in the mixed gel can be changed by E / Al2O3, which leads to control of the randomness of Al during zeolite crystal formation, making it possible to synthesize GIS-type zeolite with an ideal crystal structure. From the above perspectives, it is necessary to optimally control E / Al2O3, and E / Al2O3 is preferably 0.1 or more and 100.0 or less, more preferably 0.5 or more and 80.0 or less, and even more preferably 0.8 or more and 50.0 or less.

[0049] In addition, water and OH in the mixed gel - The ratio (H2O / OH - ) is important for synthesizing GIS-type zeolites with appropriate SAR. - is the OH derived from inorganic hydroxides such as NaOH and Ca(OH)2, or organic hydroxides such as tetraethylammonium hydroxide, used as an alkali source. - and the OH released when oxides such as sodium aluminate and sodium silicate or their hydrates are dissolved in water. - Zeolite is produced by a reaction in which the silica source, aluminum source, and alkali source dissolved in the aqueous solvent crystallize, and some of them dissolve in the alkaline solvent, creating an equilibrium between crystallization and re-dissolution. OH derived from inorganic hydroxides such as NaOH and Ca(OH)2 and organic hydroxides such as tetraethylammonium hydroxide. - Adding OH to the mixed gel means shifting the balance between crystallization and re-dissolution to the re-dissolution side. Re-dissolution proceeds from the amorphous or low-crystalline parts. Therefore, adding OH to the mixed gel moderately - By increasing the amount of OH, the imperfect crystals can be redissolved and recrystallized repeatedly, increasing the formation of the ideal crystal structure. - If the amount of OH increases too much, excessive dissolution will occur, and crystals will not be obtained, or other crystal phases, such as ANA-type zeolite, which has a more stable structure, will be formed. Also, dissolved alumina is more reactive than silica, and alumina is more easily incorporated into crystals. Therefore, -By appropriately adjusting the ratio of silica to alumina incorporated into the crystals, it is possible to adjust the crystallization and redissolution rates and optimize the SAR of the synthesized GIS-type zeolite.

[0050] A high water to alumina ratio (H2O / Al2O3) makes it easier for the components in the mixed gel to be dispersed more uniformly, but if it is too high, it significantly reduces the crystallization rate. Therefore, in order to synthesize GIS-type zeolite with the optimal SAR and optimal crystal structure, it is necessary to select a high H2O / Al2O3 ratio, which affects the equilibrium between crystallization and redissolution. - It is necessary to optimally control H2O / Al2O3 along with the control of

[0051] From the above viewpoints, H2O / Al2O3 and H2O / OH - is preferably 100≦H2O / Al2O3≦780 and 50≦H2O / OH - ≦1000, more preferably 120≦H2O / Al2O3≦778 and 60≦H2O / OH - ≦800, and more preferably 150≦H2O / Al2O3≦775 and 70≦H2O / OH - ≦700.

[0052] The ratio of the silica source to the aluminum source in the mixed gel is expressed as the molar ratio of the oxides of each element, i.e., SiO2 / Al2O3. (Note that the ratio in the synthesized zeolite and the silica-alumina ratio in the mixed gel do not match. The silica-alumina ratio of the synthesized zeolite is determined by other components and synthesis conditions.)

[0053] The SiO2 / Al2O3 ratio in this mixed gel is not particularly limited as long as it allows the formation of zeolite, but since this tends to suppress the formation of zeolite having a skeleton different from the GIS-type skeleton, it is preferably 3.0 or more and 70.0 or less, more preferably 3.5 or more and 65.0 or less, and even more preferably 4.0 or more and 60.0 or less.

[0054] The ratio of the aluminum source to the alkali metal and alkaline earth metal in the mixed gel is expressed as the sum molar ratio of MO and MO to Al2O3, i.e., (MO + MO) / Al2O3 (where M1 represents an alkali metal and M2 represents an alkaline earth metal. These are calculated as oxides). Note that, from the viewpoint of facilitating the formation of GIS-type framework crystals, this (MO + MO) / Al2O3 is preferably 1.5 or more, more preferably 1.6 or more, and even more preferably 1.65. From the viewpoint of suppressing the formation of zeolites having frameworks different from the GIS-type framework, (MO + MO) / Al2O3 is preferably 15.0 or less, more preferably 12.0 or less, and even more preferably 10.0 or less.

[0055] The ratio of the phosphorus source to the aluminum source in the mixed gel is expressed as the molar ratio of the oxides of the respective elements, i.e., P2O5 / Al2O3. This P2O5 / Al2O3 is not particularly limited as long as it is a ratio that allows zeolite to be formed, but since this tends to suppress the formation of zeolite having a framework different from the GIS-type framework, it is preferably less than 1.0, more preferably 0.6 or less, even more preferably 0.4 or less, and particularly preferably 0.

[0056] When an organic structure-directing agent is contained in the mixed gel, the ratio of the aluminum source to the organic structure-directing agent in the mixed gel is expressed as the molar ratio of the organic structure-directing agent to Al2O3, i.e., R / Al2O3 (where R represents the organic structure-directing agent). From the viewpoint of easier crystal formation of the GIS framework and / or shorter synthesis time, resulting in superior economics when producing zeolite, the ratio is preferably less than 7.0, more preferably 6.0 or less, and even more preferably 5.0 or less. When an organic structure-directing agent is used, the organic structure-directing agent remains in the zeolite pores, preventing carbon dioxide from entering the pores and reducing the amount of adsorption. Heating to at least 400°C or higher is necessary to remove the organic structure-directing agent. However, since GIS zeolite crystals collapse and become amorphous at temperatures above 350°C, it is preferable to use less organic structure-directing agent. From this viewpoint, the preferred R / Al2O3 is 4.0 or less, more preferably 3.5 or less, and even more preferably 3.0 or less.

[0057] As described above, the method for producing GIS-type zeolite according to the present embodiment includes a step of preparing a mixed gel that contains: a silica source that contains silicon; an aluminum source that contains aluminum; an alkali source that contains at least one selected from alkali metals (M1) and alkaline earth metals (M2); a salt compound that contains at least one selected from alkali metals (M1) and alkaline earth metals (M2); a phosphorus source; and water; and the molar ratio of each component in the mixed gel, when calculated as an oxide of each element for the silicon, aluminum, alkali metal (M1), alkaline earth metal (M2), and phosphorus source, is expressed by the following formula (1): The molar ratios α, β, γ, δ, ε, and ζ represented by (2), (3), (4), (5), and (6) preferably satisfy 0.1≦α≦100.0, 3.0≦β≦70.0, 1.5≦γ≦15.0, 0≦δ<1.0, 100≦ε≦780, and 50≦ζ≦1000, more preferably satisfy 0.5≦α≦80.0, 3.5≦β≦65.0, 1.6≦γ≦12.0, 0≦δ≦0.6, 120≦ε≦778, and 60≦ζ≦800, and even more preferably satisfy 0.8≦α≦50, 4.0≦β≦60.0, 1.65≦γ≦10.0, 0≦δ≦0.4, 150≦ε≦775, and 70≦ζ≦700. The GIS zeolite according to this embodiment is particularly preferably obtained by the above-described method for producing GIS zeolite according to this embodiment. α = E / Al2O3(1) β = SiO2 / Al2O3(2) γ = (MO + MO) / AlO(3) δ = P2O5 / Al2O3(4) ε = H2O / Al2O3(5) ζ=H2O / OH- (6)

[0058] Furthermore, in the method for producing a GIS-type zeolite according to this embodiment, when the molar ratios α, β, γ, δ, ε, and ζ satisfy the above ranges and the mixed gel further contains an organic structure-directing agent R, it is preferable that the molar ratio η represented by the following formula (7) satisfies η≦4. η = R / Al2O3(7)

[0059] It is not necessarily required that seed crystals be present in the mixed gel, but the GIS zeolite according to this embodiment can also be obtained by adding pre-produced GIS zeolite as seed crystals to the mixed gel.

[0060] [Preparation process of mixed gel] The process for preparing the mixed gel is not particularly limited, and may include, for example, a mixing step of mixing a silica source, an aluminum source, a salt compound, water, and, if necessary, a phosphorus source, an alkali source, and an organic structure-directing agent all at once or in multiple stages, and an aging step of the mixture obtained in this mixing step.

[0061] In the mixing step, the silica source, aluminum source, salt compound, water, and, if necessary, the components including the phosphorus source, alkali source and organic structure directing agent can be mixed all at once or in multiple stages.

[0062] The order of mixing in multiple stages is not limited and may be appropriately selected depending on the conditions used. When mixing in multiple stages, the mixture may be mixed with or without stirring. When mixing, any commonly used stirring method may be used without any particular limitation, and specific examples include impeller stirring, vibration stirring, rocking stirring, centrifugal stirring, etc.

[0063] The rotation speed of stirring is not particularly limited as long as it is a commonly used stirring speed, and may be, for example, 1 rpm or more and less than 2000 rpm.

[0064] The temperature in the mixing step is not particularly limited as long as it is a commonly used temperature, and examples thereof include temperatures of -20°C or higher and lower than 80°C.

[0065] The time for the mixing step is not particularly limited and can be appropriately selected depending on the temperature of the mixing step, but may be, for example, more than 0 minutes and not more than 1000 hours.

[0066] The aging step may be carried out by standing or stirring. The stirring method used in the aging step is not particularly limited as long as it is a commonly used stirring method, and specific examples include methods using blade stirring, vibration stirring, swing stirring, centrifugal stirring, etc.

[0067] The rotation speed of stirring is not particularly limited as long as it is a commonly used stirring speed, and may be, for example, 1 rpm or more and less than 2000 rpm.

[0068] The temperature in the aging step is not particularly limited as long as it is a commonly used temperature, and examples thereof include a temperature of -20°C or higher and lower than 80°C.

[0069] The time for the aging step is not particularly limited and can be appropriately selected depending on the temperature for the aging step, but may be, for example, more than 0 minutes and not more than 1000 hours.

[0070] It is believed that the dissolution of raw materials, the generation of zeolite precursors, and their re-dissolution occur during the raw material mixing and aging processes. To form a large periodic structure containing eight-membered rings without defects, it is preferable that the formation of the zeolite precursor does not proceed excessively. Furthermore, excessive aging is also preferable because excessive formation of the zeolite precursor tends to increase the formation of ANA zeolite, which has a more stable structure. On the other hand, it is preferable that the raw materials are thoroughly mixed and the raw material gel is in a homogeneous state. The combined time for the mixing and aging processes is not particularly limited and can be adjusted appropriately based on the raw material composition, etc., to obtain a zeolite with the appropriate structure. The above time is typically preferably from 1 minute to less than 24 hours, more preferably from 3 minutes to less than 23 hours, even more preferably from 10 minutes to 18 hours, even more preferably from 12 minutes to 15 hours, and even more preferably from 20 minutes to 6 hours.

[0071] [Hydrothermal synthesis process] The method for producing a GIS-type zeolite according to this embodiment preferably further includes a hydrothermal synthesis step in which the hydrothermal synthesis temperature is 80° C. to 200° C., and more preferably the hydrothermal synthesis temperature is 100° C. to 180° C. That is, preferably, the mixed gel obtained in the preparation step is subjected to hydrothermal synthesis by being stirred or left to stand for a predetermined time at a predetermined temperature.

[0072] The temperature for the hydrothermal synthesis is not particularly limited as long as it is a commonly used temperature, but is preferably 80°C or higher from the viewpoint of shortening the synthesis time and being economical when producing zeolite. From the viewpoint of being able to suppress the formation of zeolite having a skeleton different from the GIS-type skeleton, it is more preferably 90°C or higher, and even more preferably 100°C or higher. From the viewpoint of being able to suppress the formation of zeolite having a skeleton different from the GIS-type skeleton, it is more preferably 200°C or lower, even more preferably 180°C or lower, and even more preferably 170°C or lower. The temperature for the hydrothermal synthesis may be constant or may be changed stepwise.

[0073] The time for hydrothermal synthesis is not particularly limited as long as it is a commonly used time, and can be appropriately selected depending on the temperature of the hydrothermal synthesis. The time for hydrothermal synthesis is preferably 3 hours or more, more preferably 10 hours or more, from the viewpoint of forming a GIS skeleton. From the viewpoint of obtaining a highly crystalline GIS-type zeolite, it is even more preferably 24 hours or more. From the viewpoint of excellent economic efficiency in producing zeolite, the time for hydrothermal synthesis is preferably 30 days or less, more preferably 20 days or less, and even more preferably 10 days or less.

[0074] In the hydrothermal synthesis step, the container into which the mixed gel is placed is not particularly limited as long as it is a commonly used container, but if the pressure inside the container increases at a predetermined temperature or if the mixed gel is placed under gas pressure that does not inhibit crystallization, it is preferable to place the mixed gel in a pressure-resistant container and perform hydrothermal synthesis. The pressure-resistant container is not particularly limited, and various shapes such as a spherical shape, a vertically elongated shape, or a horizontally elongated shape can be used.

[0075] When stirring the mixed gel in the pressure-resistant vessel, the pressure-resistant vessel is rotated vertically and / or horizontally, preferably vertically. When rotating the pressure-resistant vessel vertically, the rotation speed is not particularly limited as long as it is within a commonly used range, but is preferably 1 to 50 rpm, more preferably 10 to 40 rpm.

[0076] In the hydrothermal synthesis step, the mixed gel can be preferably stirred by using a vertically long pressure-resistant vessel and rotating it vertically.

[0077] [Separation / drying process] After the hydrothermal synthesis step, 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.

[0078] The separated product may be used as is or washed with water or a predetermined solvent. If necessary, the separated product may be dried. The temperature at which the separated product is dried is not particularly limited as long as it is a general drying temperature, but is usually from room temperature to 150°C or lower. The atmosphere during drying is not particularly limited as long as it is a commonly used atmosphere, but usually, an air atmosphere, an inert gas such as nitrogen or argon, or an atmosphere containing oxygen is used.

[0079] [Firing process] If necessary, the GIS zeolite can be calcined before use. The calcination temperature is not particularly limited as long as it is a commonly used temperature, but when it is desired to remove the organic structure-directing agent, the calcination temperature is preferably 300°C or higher, and more preferably 350°C or higher, since the remaining proportion of the organic structure-directing agent can be reduced. From the viewpoint of shortening the calcination time and being economical when producing zeolite, the calcination temperature is even more preferably 360°C or higher. Since the crystallinity of the zeolite tends to be maintained, the calcination temperature is preferably less than 450°C, more preferably 420°C or lower, and even more preferably 400°C or lower.

[0080] The calcination time is not particularly limited as long as it is a time that allows the organic structure-directing agent to be sufficiently removed, and can be appropriately selected depending on the calcination temperature, but since this tends to reduce the proportion of remaining organic structure-directing agent, it is preferably 0.5 hours or more, more preferably 1 hour or more, and even more preferably 3 hours or more.Since the crystallinity of the zeolite tends to be maintained, it is preferably 10 days or less, more preferably 7 days or less, and even more preferably 5 days or less.

[0081] The firing atmosphere 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.

[0082] [Cation Exchange] If necessary, GIS-type zeolite can be subjected to cation exchange to obtain a desired cation type. For the cation exchange, for example, but not limited to, carbonates such as sodium carbonate, potassium carbonate, lithium carbonate, rubidium carbonate, cesium carbonate, magnesium carbonate, calcium carbonate, strontium carbonate, barium carbonate, and ammonium carbonate, nitrates such as sodium nitrate, potassium nitrate, lithium nitrate, rubidium nitrate, cesium nitrate, magnesium nitrate, calcium nitrate, strontium nitrate, barium nitrate, and 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 and hydrochloric acid can be used.

[0083] The temperature for cation exchange is not particularly limited as long as it is a general temperature for cation exchange, but is usually from room temperature to 100°C or less.

[0084] 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.

[0085] The separated product may be used as it is or may be washed with water or a predetermined solvent. If necessary, the separated product may be dried.

[0086] The temperature at which the separated product is dried is not particularly limited as long as it is a general drying temperature, but is usually from room temperature to 150°C or less.

[0087] The atmosphere used for drying 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.

[0088] Furthermore, the ammonium type zeolite can be converted into a proton type zeolite by calcining the zeolite.

[0089] (Carrier) The zeolite molded body according to this embodiment preferably contains a carrier, such as an inorganic binder or an organic binder.

[0090] 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, pseudoboehmite, 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. 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 zeolite molded body.

[0091] 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. 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 zeolite molded body.

[0092] From the viewpoint of obtaining a desired density, the carrier preferably contains an inorganic binder and an organic binder, that is, it preferably contains one or more types of the inorganic binders and one or more types of the organic binders described above.

[0093] The total content of the carrier is preferably 1 to 99% by mass, more preferably 5 to 90% by mass, and even more preferably 8 to 80% by mass, relative to the total amount (100% by mass) of the zeolite shaped body. Increasing the content of the carrier tends to increase the strength of the shaped body, but tends to decrease the content of the zeolite itself. Therefore, the content of the carrier may be adjusted taking into account the strength and performance required depending on the application.

[0094] The shape of the zeolite shaped body is not particularly limited, but examples thereof include a spherical shape, a cylindrical shape, an elliptical shape, a bale shape, a trefoil shape, a ring shape, a powder shape, etc. Among these, a spherical shape and a cylindrical shape are more preferred.

[0095] The term "spherical" means that the aspect ratio of a molded product is in the range of 1 to 1.1. The aspect ratio of a molded product is the ratio of the major axis to the minor axis when the molded product is stably stationary on a horizontal surface, a vertical projection of the molded product is taken, and the projection is sandwiched between two parallel lines tangent to the projection, with the longest distance between the parallel lines being the major axis and the smallest distance being the minor axis. The roundness mentioned above means the difference between the maximum and minimum diameters of any three points measured with a micrometer with a minimum reading of 0.01 mm or less, divided by 2.

[0096] The cross section of the molded body cut along a plane passing through any two points on the outer periphery of the molded body is preferably a single circle with a circularity of 0.5 or less, more preferably a single circle with a circularity of 0.4 or less, and even more preferably a single circle with a circularity of 0.3 or less.

[0097] The size of the molded body is not particularly limited, but varies depending on the conditions under which the molded body is used. For example, when the molded body is used in a process that is not in a fluidized state, such as a fixed bed or a moving bed, it is preferably spherical with a diameter of 3 mm to 10 mm or cylindrical with a length of 3 mm to 30 mm and a diameter of 1 mm to 30 mm.

[0098] The diameter of the sphere is more preferably 5 mm or more and 8 mm or less. The diameter of the sphere is the average value of the major axis and the minor axis used to calculate the aspect ratio of the molded body, and can be adjusted to the above-mentioned range by, for example, dividing the sphere.

[0099] The length of the cylinder is more preferably 3 mm to 10 mm, and even more preferably 3 mm to 8 mm, and the diameter of the cylinder is more preferably 2 mm to 4 mm. The length and diameter can be determined by measuring the length and diameter of three pellet samples using a vernier caliper with a minimum reading of 0.1 mm or less, and then calculating the average length and diameter. The length and diameter can be adjusted to fall within the above-mentioned ranges by, for example, classification or other operations.

[0100] When used in a process in which the compact is fluidized, such as a fluidized bed, the particle diameter is preferably 20 μm or more and 300 μm or less. The particle diameter is more preferably 20 μm or more and 200 μm or less, and even more preferably 30 μm or more and 100 μm or less. The particle diameter is determined by measuring the median diameter (D) using a laser diffraction / scattering particle size analyzer (MT3000 manufactured by Microtrac) according to the attached manual. 50 ) can be measured as

[0101] The compressive strength of the zeolite shaped article according to the present embodiment is preferably 1.0 MPa or more, more preferably 2.2 MPa or more, and even more preferably 3.4 MPa or more. In particular, when the zeolite shaped article according to the present embodiment is in powder form, it is preferable that the compressive strength satisfies the above range. The above-mentioned compressive strength can be measured as the average value of 20 measurements using a micro-compression tester (Shimadzu Corporation MCT-W500, compressive strength measurement), and can be adjusted to the above-mentioned range by, for example, adjusting the firing temperature and firing time.

[0102] The breaking strength of the zeolite shaped article according to this embodiment is preferably 5 N or more, more preferably 10 N or more, and even more preferably 20 N or more. In particular, when the zeolite shaped article according to this embodiment is in the form of pellets, it is preferable that the breaking strength satisfies the above range. The above-mentioned breaking strength can be measured as the average value of the values ​​obtained by measuring 20 times using a digital hardness meter (KHT-40N manufactured by Fujiwara Seisakusho Co., Ltd., indenter 3 mm, breaking strength measurement), and can be adjusted to fall within the above-mentioned range by, for example, adjusting the firing temperature and firing time.

[0103] [Method of manufacturing zeolite molded body] The method for producing the zeolite molded body according to this embodiment is not particularly limited, but may include a raw material mixing step (X) of mixing the zeolite according to this embodiment with other optional components (e.g., a carrier) to prepare the zeolite molded body, a molding step (Y) of subjecting the prepared raw material to a molding process to obtain a precursor, and a calcination step (Z) of calcining the precursor to obtain the zeolite molded body. Other methods for producing zeolite shaped bodies 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, as long as the desired zeolite shaped body can be obtained.

[0104] In the zeolite molded body according to this embodiment, the apparent density d a , true density d t , apparent density d / true density d t , bulk density d b , bulk density d b / true density d t The apparent density d is adjusted by selecting the carrier and the granulation method. a There is no particular limitation on the method for keeping the apparent density d of the compact within the predetermined range. For example, a method of selecting a carrier with high affinity for zeolite is available. By selecting a carrier with high affinity, the mixture of zeolite and carrier exhibits excellent shape retention, and the apparent density d of the compact is a will improve.

[0105] true density d t There is no particular limitation on the method for keeping the value within the predetermined range, but one method is to adjust the type and amount of the carrier, for example.

[0106] Apparent density d a / true density d t The method for keeping the apparent density d in the predetermined range is not particularly limited, but for example, there is a method of selecting a carrier that can be granulated into any shape with a smaller amount of water when mixed with the zeolite of this embodiment, or a method of selecting a granulation method that can granulate with a smaller amount of water. The smaller the amount of water during granulation, the smaller the distance between particles of the zeolite or carrier, and the smaller the voids inside the molded body.a / true density d t will improve.

[0107] Bulk density d b The method for keeping the bulk density d within the predetermined range is not particularly limited, but for example, there is a method of adjusting the size of the compact. By adjusting the size of the compact so that it is sufficiently small compared to the size of the container to be filled, the compact can be densely packed into the container, and the bulk density d b will improve.

[0108] Bulk density d b / true density d t The method for achieving a predetermined range is not particularly limited, but for example, there is a method of granulating compacts that are sufficiently small relative to the size of the container to be filled with a smaller amount of water. Granulation with a small amount of water reduces the voids inside the compacts, and by making the compacts sufficiently small relative to the size of the container to be filled with, they can be densely filled into the container, and the bulk density d b / true density d t will improve.

[0109] [Raw material mixing process (X)] In the raw material mixing step (X), the raw materials may be used in a state suited to the manufacturing method, such as powder, solvent dispersion, sol, or liquid. For example, when an inorganic binder is used, the raw materials are used in a state suited to the manufacturing method, such as powder, solvent dispersion, sol, or liquid, with powder or sol being preferred from the viewpoint of ease of handling. These inorganic binders may be used alone or in combination. The temperature at which the raw materials are mixed is not particularly limited, but is preferably, for example, 10°C to 80°C, and more preferably 15°C to 60°C. For example, as in a spray drying process, when the raw materials are mixed in a slurry state, evaporation of water from the raw materials tends to be suppressed when the raw material temperature is 80°C or lower, and freezing of the slurry tends to be suppressed when the raw material temperature is 10°C or higher. Furthermore, for example, in an extrusion molding process, when the raw materials are mixed and the clay is in a funicular to capillary clay state, evaporation of water from the clay is suppressed and the moisture content in the clay tends to be maintained at a constant level if the raw material temperature is 80°C or lower, while freezing of water in the clay tends to be suppressed if the raw material temperature is 10°C or higher. Any stirring means can be used when preparing the raw materials. For example, when the raw materials are mixed in a slurry state, as in a spray drying process, stirring blades are preferred. Specific examples of blades used for stirring include propellers, paddles, flat paddles, turbines, and cones. For efficient stirring, baffles or the like may be installed in the vessel. The number of stirrers can be optimized depending on the size of the catalyst raw material vessel, the shape of the stirring blades, and other factors. In this embodiment, the total stirring time of the raw materials is preferably 1 minute to 24 hours, more preferably 10 minutes to 5 hours, and even more preferably 15 minutes to 3 hours. When the mixing time of the mixed liquid is 1 minute or more, the composition of the raw materials tends to become uniform, and when it is 24 hours or less, the influence of water evaporation in the raw materials tends to be small. Furthermore, for example, in the case of extrusion molding, when the raw materials are mixed and then become clay-like in the funicular to capillary region, it is preferable to select a mixer or kneader according to the state of the raw materials. In this embodiment, the total time for mixing and kneading the raw materials is preferably 1 minute to 24 hours, more preferably 2 minutes to 5 hours, and even more preferably 3 minutes to 3 hours.If the mixing time of the mixed liquid is 1 minute or longer, the composition of the raw material tends to become uniform, and if it is 24 hours or shorter, the effect of water evaporation from the raw material tends to be small. Furthermore, if an organic binder that easily gels when heated, such as methyl cellulose, is blended, gelation of the organic binder can be suppressed by maintaining the internal temperature of the mixer or kneader at a value lower than the thermal gelation temperature of the organic binder, and raw materials with a uniform composition tend to be obtained. Furthermore, the clay-like raw material can be left to stand and mature. By maturing, moisture becomes more easily distributed among the raw zeolite, which tends to improve moldability, and also tends to replace gases such as air present among the zeolite, resulting in a denser molded product.

[0110] [Molding process step (Y)] Examples of the molding process in the molding process step (Y) include extrusion molding, compression molding, and spray drying.

[0111] The extrusion molding process is not particularly limited, but for example, depending on the properties of the raw material used (also referred to as "raw clay" in the extrusion molding process), the temperature during extrusion molding is preferably 10°C to 80°C, more preferably 15°C to 75°C. 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, while when the water content is 35% by mass or more, an appropriate decrease in the flexibility of the raw clay can be prevented, and moldability tends to be improved.

[0112] When extrusion molding is used as the molding step (Y), the extruder 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.

[0113] 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.

[0114] In the spray drying process, for example, the atomization of the slurry can be carried out by methods such as the rotating disk method, the two-fluid nozzle method, and the high-pressure nozzle method, which are commonly used industrially, but the rotating disk method is particularly preferable. As a drying heat source for drying the sprayed droplets, it is preferable to use air heated by steam, an electric heater, or the like. 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.

[0115] [Firing process (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. The calcination time in the calcination step (Z) is not particularly limited as long as it is a time that allows the carrier to be sufficiently dried and sintered, and can be appropriately selected depending on the calcination temperature. However, since this tends 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. 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 such as nitrogen or argon, or an atmosphere containing oxygen is used. 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.

[0116] The uses of the zeolite shaped article according to the present embodiment are not particularly limited, and can be used, for example, as a separating agent or separation membrane for various gases and liquids, an electrolyte membrane for fuel cells and the like, a filler for various resin shaped articles, a membrane reactor, a catalyst for hydrocracking, alkylation, etc., a catalyst carrier for supporting metals, metal oxides, etc., an adsorbent, a desiccant, a detergent aid, an ion exchange agent, a wastewater treatment agent, a fertilizer, a food additive, a cosmetic additive, and the like. Among the above, the zeolite molded body according to this embodiment can be suitably used as an adsorbent.

[0117] [Adsorption device] The adsorption device according to the present embodiment includes the zeolite shaped article according to the present embodiment. Because the adsorption device according to the present embodiment is configured in this manner, it can sufficiently adsorb carbon dioxide and has high selectivity for carbon dioxide adsorption relative to the amount of methane adsorbed. Therefore, it can be particularly preferably used for the purpose of selectively removing carbon dioxide from natural gas, for example.

[0118] The adsorption apparatus according to the present embodiment includes zeolite shaped bodies containing the zeolite according to the present embodiment, and may have the configuration shown in FIG. 1 . The adsorption apparatus 2 according to the present embodiment illustrated in FIG. 1 includes filters 23 arranged at two locations, one on the inlet side and one on the outlet side, inside a container 21, and a plurality of zeolite shaped bodies 24 packed between the two filters 23. The filters 23 may be made of, for example, quartz. For example, when the adsorption apparatus 2 is used to separate carbon dioxide from natural gas, natural gas is introduced through an upper line, impurities are removed by the filter 23, and carbon dioxide is selectively adsorbed and removed by the zeolite shaped bodies 24, and methane-rich gas is extracted through a lower line. However, the target to be fed to the adsorption apparatus is not limited to natural gas, and the internal structure of the adsorption apparatus is not limited to the example shown in FIG. 1 . The adsorption apparatus 2 according to the present embodiment may also be a purified gas production apparatus 100, which will be described later.

[0119] [Method of producing purified gas] The method for producing a purified gas according to this embodiment uses an adsorption apparatus containing the zeolite according to this embodiment to separate one or more species selected from the group consisting of CO, HO, He, Ne, Cl, NH, and HCl from a mixture containing two or more gases selected from the group consisting of H, N, O, CO, and hydrocarbons. In this embodiment, it is preferable to separate one or more species selected from the group consisting of CO and HO from one or more gases selected from the group consisting of N, O, CO, and hydrocarbons. Examples of hydrocarbons include, but are not limited to, methane, ethane, ethylene, propane, propylene, 1-butene, 2-butene, 2-methylpropene, dimethyl ether, and acetylene.

[0120] The GIS-type zeolite according to this embodiment has a particularly high CO2 adsorption capacity, and physical adsorption without chemical bonding is observed. Separation methods using the zeolite according to this embodiment are not particularly limited, but a method that requires low energy for regenerating the adsorbent and is economical is preferred. Specific examples of such methods are not particularly limited, but it is preferable to use one of pressure swing adsorption, temperature swing adsorption, or pressure-temperature swing adsorption. Pressure swing adsorption (PSA) is a method in which the pressure during desorption is lower than the pressure during gas adsorption, and gas is separated by utilizing the difference in the amount of adsorption at high pressure and the amount of adsorption at low pressure. Thermal swing adsorption (TSA) is a method in which the temperature during desorption is higher than the temperature during gas adsorption, and gas is separated by utilizing the difference in the amount of adsorption at low pressure and the amount of adsorption at high temperature. Furthermore, a combination of these methods is called pressure-temperature swing adsorption / desorption (PTSA). These methods can be carried out under various known conditions.

[0121] A method for producing a purified gas according to the present embodiment is a method for producing a purified gas, which comprises separating carbon dioxide and a second component gas different from carbon dioxide from a mixed gas containing the carbon dioxide and the second component gas using an adsorption tower filled with an adsorbent containing zeolite, an adsorption step of introducing the mixed gas into the adsorption tower, causing the adsorbent to adsorb carbon dioxide, and extracting a second component gas; a desorption step of removing the carbon dioxide from the adsorbent by decompressing and evacuating the carbon dioxide from the adsorption tower; Includes. In the method for producing a purified gas according to this embodiment, the above-described shaped zeolite is used as an adsorbent. By using the shaped zeolite, which has excellent resistance to embrittlement due to carbon dioxide adsorption, the method for producing a purified gas according to this embodiment can reduce the frequency of replacing the shaped zeolite, thereby facilitating the maintenance and management of the equipment.

[0122] In the method for producing purified gas according to this embodiment, the adsorbent having the apparent density d a / true density d t A zeolite molded body having a bulk density d b / true density d t It is preferable to use a zeolite molded body in which the ratio of is 0.25 or more. With the above configuration, the second component gas can be obtained in high yield, and high-purity CO2 can be recovered.

[0123] The apparent density d a , bulk density d b , and true density d t , apparent density d a / true density d t Ratio of bulk density d b / true density d t The ratio is preferably in the same range as that explained for the zeolite molded body.

[0124] <Second component gas> The second component gas may be any gaseous substance other than carbon dioxide. "Gaseous substance" refers to a substance that is gaseous at room temperature (25°C) and atmospheric pressure. Examples of the second component gas include methane, ethane, nitrogen, carbon monoxide, hydrogen, argon, and dimethyl ether. Among these second component gases, methane, ethane, and nitrogen are preferred, methane and ethane are more preferred, and methane is even more preferred.

[0125] <Mixed gas> The mixed gas used as the raw material contains carbon dioxide and a second component gas. The carbon dioxide content in the mixed gas may be 1% to 99% by volume, 5% to 90% by volume, 10% to 80% by volume, 20% to 70% by volume, or 30% to 70% by volume.

[0126] The content of the second component gas in the mixed gas may be 1% to 99% by volume, 5% to 90% by volume, 10% to 80% by volume, 20% to 70% by volume, or 30% to 70% by volume.

[0127] The moisture content of the mixed gas is preferably 1000 ppm by volume or less, 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.

[0128] <Adsorption tower> The adsorption tower is filled with an adsorbent. The adsorption tower is configured to allow the mixed gas to be introduced and the mixed gas to come into contact with the adsorbent. In the adsorption process, the mixed gas is brought into contact with the adsorbent, causing carbon dioxide in the mixed gas to be adsorbed onto the adsorbent. Since carbon dioxide is adsorbed in the mixed gas, the second component gas can be extracted. Furthermore, after the adsorption process, the adsorption tower is depressurized in the desorption process, allowing carbon dioxide to be extracted. In this way, a purified gas of the second component gas and a purified gas of carbon dioxide are obtained in the adsorption process and desorption process. The adsorption tower may be equipped with a heater to increase the temperature inside the adsorption tower.

[0129] <Conditions for the adsorption and desorption steps> The adsorption step and the desorption step may be repeated multiple times. The mixed gas is circulated through the adsorption tower to perform the carbon dioxide adsorption step at a pressure close to atmospheric pressure. Subsequently, the pressure inside the adsorption tower is reduced and a desorption step is performed to desorb the carbon dioxide from the adsorbent. By repeatedly performing the adsorption step and the desorption step in this manner, the carbon dioxide and the second component gas are separated, and by using the zeolite molded body according to this embodiment, the recovery purity of the carbon dioxide and the recovery rate of the second component gas can be increased.

[0130] 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, where the pressure is reduced and exhausted, and means the pressure at which the pressure in the adsorption tower gradually decreases due to reduced pressure exhaust and finally becomes constant.

[0131] From the viewpoint of increasing the efficiency of carbon dioxide desorption and reducing the power required per unit of mixed gas to be treated, 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. 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 due to endothermic heat caused by the desorption of carbon dioxide from the adsorbent.

[0132] Adsorption pressure P in the adsorption process a The adsorption pressure P is preferably 50 to 3000 kPa, more preferably 60 to 500 kPa or less, and even more preferably 70 to 200 kPa or less. a means the pressure near the inlet of the adsorption tower where the mixed gas is introduced.

[0133] 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 refers to 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.

[0134] In the method for producing a purified gas according to this embodiment, the total recovery rate of carbon dioxide from a 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.

[0135] In the method for producing a purified gas according to this embodiment, the total recovery rate of the second component gas 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 recovered second component gas relative to the total amount of second component gas in the mixed gas introduced into the adsorption tower.

[0136] In the method for producing a purified gas according to this embodiment, it is preferable that the total recovery rate from the carbon dioxide mixed gas is 90% or more and that the total recovery rate from the second component gas mixed gas is 90% or more; it is more preferable that the total recovery rate from the carbon dioxide mixed gas is 93% or more and that the total recovery rate from the second component gas mixed gas is 93% or more; and it is even more preferable that the total recovery rate from the carbon dioxide mixed gas is 95% or more and that the total recovery rate from the second component gas mixed gas is 95% or more.

[0137] The purity of the second component gas obtained by the method for producing a purified gas 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.

[0138] The purity of carbon dioxide obtained by the method for producing a purified gas 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.

[0139] The water content in the carbon dioxide obtained by the method for producing a purified gas 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, with a dew point meter. By using zeolite as an adsorbent in the method for producing a purified gas, the water content in the carbon dioxide can be reduced below the above-mentioned value.

[0140] The method for producing a purified gas according to this embodiment produces a purified second component gas or purified carbon dioxide.

[0141] <Activation process> The method for producing a purified gas 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 being treated and reduce the moisture content in the resulting carbon dioxide and second component gas. The activation step is preferably carried out before the above-described 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.

[0142] Ultimate pressure P in the activation process e However, the ultimate pressure P 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, where the pressure is reduced and exhausted, and means the pressure at which the pressure in the adsorption tower gradually decreases due to reduced pressure exhaust and finally becomes constant.

[0143] 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.

[0144] [Purified gas production equipment] The schematic configuration of a purified gas production apparatus 100 according to this embodiment will be described with reference to Fig. 2. The purified gas production apparatus 100 includes a mixed gas supply line 1, a carbon dioxide adsorption tower 3a and a carbon dioxide adsorption tower 3b, a carbon dioxide recovery line 5, a second component gas recovery line 7, and a pressure reducing device 9.

[0145] The carbon dioxide adsorption tower 3a has a fixed bed 31a packed with an adsorbent 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 second component gas recovery line 7. The second component gas recovery line 7 is equipped with an automatic valve AV3. The second component gas 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 concentration of carbon dioxide and the concentration of the second component gas.

[0146] The carbon dioxide adsorption tower 3a is connected to a carbon dioxide capture line 5 at an end thereof that is 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, so that the inside of the carbon dioxide adsorption tower 3a can be reduced in pressure. 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. The carbon dioxide capture line 5 is further 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 the second component gas may be used as the component analyzer 54.

[0147] The carbon dioxide adsorption tower 3b has a fixed bed 31b containing an adsorbent 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 second component gas recovery line 7. An automatic valve AV4 is provided on the second component gas 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.

[0148] Next, the operation of the purified gas production apparatus 100 of this embodiment will be described with reference to Fig. 2. A mixed gas is supplied to the carbon dioxide adsorption tower 3a via a mixed gas supply line 1. Carbon dioxide (CO2) contained in the mixed gas is adsorbed by the adsorbent packed in the carbon dioxide adsorption tower 3a, and a second component gas such as methane (CH4) is recovered through a second component gas recovery line 7. That is, an adsorption step is performed in the carbon dioxide adsorption tower 3a, in which the mixed gas is introduced into the adsorption tower, the adsorbent adsorbs the carbon dioxide, and the second component gas is extracted.

[0149] The carbon dioxide adsorption tower 3a containing the adsorbent that has adsorbed carbon dioxide is depressurized and evacuated by the decompression 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.

[0150] 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 absorption tower 3b is reduced in pressure to desorb the carbon dioxide. This allows the adsorption and desorption of carbon dioxide to be repeated in each tower, enabling continuous treatment of the mixed gas.

[0151] More specifically, the purified gas production system 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 purified gas production system 100. At time T 1a Then, 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 by checking the flow meter 11 so that the mixed gas supply line 1 has a predetermined flow rate. aWhen the carbon dioxide concentration in the component analyzer 73 exceeds 5% by volume (for example, time T 1b ), the automatic valves AV1 and AV3 are closed and the automatic valves AV2 and AV4 are opened at the same time, and the supply of the mixed gas may be switched 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 (for example, 105 kPa). In addition, the carbon dioxide adsorption tower 3a is depressurized by the pressure reducing device 9 by opening the automatic valve AV5 while keeping the automatic valve AV3 closed, and the pressure in the carbon dioxide adsorption tower 3a is reduced, and the pressure in the carbon dioxide adsorption tower is increased 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.

[0152] 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 the automatic valves AV1 and AV3 may be opened at the same time, 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 3 ) In addition, 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 to recover carbon dioxide from the carbon dioxide adsorption tower 3b. 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.

[0153] The time T 1a ~T 1d The series of operations from time T1b ~T 1e The series of operations up to this point constitutes one cycle C1 of pressure fluctuation in the carbon dioxide adsorption tower 3b. In other words, cycle C1 includes one adsorption step and one desorption step. By repeating similar operations, the adsorption step and desorption step may be repeated in a second cycle C2 and a third cycle C3 of pressure fluctuation.

[0154] The purified gas production apparatus 100 may be applied to, for example, the purification of industrial exhaust gas containing carbon dioxide, biogas obtained by fermentation of organic matter, etc. Among these, it is suitable for use in the purification of biogas. [Example]

[0155] 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.

[0156] [Apparent density d a Measurement of Apparent density of zeolite compact d a was carried out in the following steps: (1) 100 mL of liquid paraffin was placed in a 250 mL measuring cylinder, and the initial liquid level was measured. (2) The mass W (g) of approximately 80 mL of the zeolite molded body was measured. (3) The moisture content u (unit: mass %) of the zeolite molded body was measured using an infrared moisture meter "FD-660" (trade name) manufactured by Kett Electric Laboratory. (4) The weighed zeolite shaped body is placed in liquid paraffin in a measuring cylinder, and the volume V of the zeolite shaped body added is determined from the amount by which the liquid level of the liquid paraffin rises after 10 minutes. a (cm 3 The mass W (g) and volume V of the zeolite pellets were calculated. a (cm 3 ) and calculate the apparent density d a was calculated. d a =(WW×u / 100) / V a (g / cm3 )

[0157] [Bulk density d b Measurement of Bulk density of zeolite compact d b The measurement was carried out according to the following procedure. (1) Approximately 800 mL of zeolite molded body was filled into a 1000 mL measuring cylinder. During filling, the zeolite molded body was hammered with a rubber hammer every time approximately 50 mL of the zeolite molded body was added until the filling height of the molded body did not change. (2) Packing volume of zeolite molded body Vb (cm 3 ) was read from the graduated line on the measuring cylinder. (3) The mass W (g) of the packed zeolite molded body was measured using an electronic balance with a minimum weighing value of 0.01 g. (4) The moisture content u (unit: mass %) of the zeolite molded body was measured using an infrared moisture meter "FD-660" (trade name) manufactured by Kett Electric Laboratory. (5) The mass W and moisture content u measured in (3) and (4) above and the filling volume V read in (2) above b Therefore, the bulk density d b (g / cm 3 ) was decided. d b =(WW×u / 100) / V b (g / cm 3 )

[0158] [True density d t Measurement of True density of zeolite compact d t The measurement was carried out according to the following procedure. (1) Using a Microtrac-Bel high-precision gas adsorption measurement device "BELSORP MAX II" (product name), measure the volume V1 (cm) of an empty measurement cell using high-purity helium gas with a purity of 99.9% or higher in a water tank controlled at 25°C. 3 ) was measured. (2) Approximately 0.2 g of zeolite molded body was filled into the measurement cell whose volume was measured in (1) above, and vacuum dried at 250°C for more than 3 hours using a pretreatment device "BELPREP-VACIII" (product name) manufactured by Microtrac-Bell. (3) After drying the cell while still in a vacuum state, cool it to room temperature, and measure the volume V2 (cm) of the measurement cell when filled with the zeolite molded body in the same manner as in (1) above. 3 ) was measured. (4) After measuring the volume V2, the mass W (g) of the zeolite molded body in the cell was measured using a precision balance with a minimum weighing value of 0.0001 g. (5) Cell volume V1 (cm 3 ), V2(cm 3 ) and the packed mass W (g) of the zeolite molded body, the true density d of the zeolite molded body is calculated from the following formula: t (g / cm 3 ) was calculated. true density d t =W / (V1-V2)

[0159] [X-ray diffraction; crystal structure analysis] X-ray diffraction was carried out according to the following procedure. (1) The zeolite molded body (dried after treatment at 350°C for 24 hours) obtained in each example and comparative example was used as a sample and pulverized in an agate mortar. Furthermore, crystalline silicon (manufactured by Rare Metallic Co., Ltd.) was added to the zeolite molded body (dried product) in an amount of 10% by mass, and the mixture was mixed in the agate mortar until homogeneous, to prepare a sample for structural analysis. (2) The sample (1) above was uniformly fixed on a non-reflective sample plate for powders, and the crystal structure was analyzed by X-ray diffraction under the following conditions. X-ray diffractometer (XRD): Rigaku powder X-ray diffractometer "RINT2500" (product name) X-ray source: Cu tube (40kV, 200mA) Measurement temperature: 25℃ Measurement range: 5 to 60° (0.02° / step) Measurement speed: 0.2° / min Slit width (scattering, diverging, receiving): 1°, 1°, 0.15mm

[0160] [ 29 Si-MAS-NMR spectrum, SAR measurement The SAR of zeolite in the zeolite molded body is 29This 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 it for 48 hours. After the moisture conditioning process, the following conditions were met: 29 Si-MAS-NMR measurements were carried out. Equipment: JEOL RESONANCE ECA700 Magnetic field strength: 16.44 T( 1 H resonance frequency 700MHz) Measurement nuclei: 29 Si Resonance frequency: 139.08MHz NMR tube: 4mmφ (zirconia rotor) Measurement method: DD / MAS (dipolar decoupling angle magic spinning) Pulse width: 45° Waiting time: 50 seconds Accumulation count: 800 times (measurement time: approx. 22 hours) MAS: 10,000Hz Chemical shift reference: Silicone rubber (-22.34 ppm) external reference In the molded body containing GIS-type zeolite, 29 The Si-MAS-NMR spectrum shows the following five peaks: (1) Q4(0Al): Si peak that is not bonded to Al at all via oxygen (2) Q4(1Al): Peak of Si bonded to one Al atom via oxygen. (3) Q4(2Al): Peak of Si bonded to two Al atoms via oxygen atoms (4) Q4(3Al): Peak of Si bonded to three Al atoms via oxygen atoms (5) Q4(4Al): Peak of Si bonded to four Al atoms via oxygen atoms Also, 29In the Si-MAS-NMR spectrum, these peak positions generally exist 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 exist in the following range: (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 was analyzed using the analysis program dmfit (Version #202000113) with Gaussian and Lorentzian functions, and the four parameters of 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) were 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 of A_Q4(0Al), A_Q4(1Al), A_Q4(2Al), A_Q4(3Al), and A_Q4(4Al) is designated as A_total. The SAR can be calculated as follows: SAR=100 / 〔A_Q4(1Al) / 4+2×A_Q4(2Al) / 4 +3×A_Q4(3Al) / 4+4×A_Q4(4Al) / 4〕×2

[0161] [Evaluation of embrittlement resistance of zeolite molded body in a CO2 atmosphere] The embrittlement resistance of the zeolite molded bodies obtained in the Examples and Comparative Examples in a CO2 atmosphere was evaluated according to the following procedure. (1) 100 g of zeolite compacts were weighed, and the minor axes of the zeolite compacts were measured. The average minor axis value of the zeolite compacts was designated as ds. A sieve having the largest opening smaller than ds and the largest mesh size was selected and prepared from the published mesh sizes specified in JIS Z8801-1. The zeolite compacts remaining on the sieve were used as test samples for evaluating embrittlement resistance in a CO2 atmosphere. (2) The test sample was dried in a N2 atmosphere at 200°C for 3 hours, cooled to room temperature in a N2 atmosphere, and then exposed to CO2 at room temperature for 30 minutes. (3) After the CO2 exposure, the mass W1 of the test sample was measured, and then the sample was passed through a sieve with the same opening size, and the mass W2 of the zeolite molded body that passed through the sieve was measured. The value calculated using formula (1) was defined as the powdering rate [mass%] of the zeolite molded body, and the lower the powdering rate, the more resistant the zeolite molded body was to embrittlement in a CO2 atmosphere.

number

[0162] [Alkali metal content] Zeolite was thermally dissolved in aqueous sodium hydroxide or aqua regia, and the solution was diluted appropriately to measure the alkali metal concentrations in the zeolite using ICP-AES (hereinafter also referred to as "ICP-AES", Hitachi High-Tech Science Corporation, SPS3520UV-DD: instrument name). The potassium and lithium contents in the zeolite were calculated as the ratio (Z / T) of the total amount of potassium and lithium (Z) to the total amount of each alkali metal (T) in the zeolite. K / T was calculated in the same way.

[0163] [CO2 adsorption amount and hysteresis amount; gas adsorption / desorption isotherm measurement] Gas adsorption / desorption isotherm measurements were carried out in the following manner. (1) The dried product obtained in each example and comparative example was used as a sample, and 0.2 g of the sample was placed in a 12 mm cell (manufactured by Micro Meritics). (2) The sample placed in the cell (1) above was placed in a gas adsorption measuring device "3-Flex" (trade name) manufactured by Micro Meritics, and heated and vacuum degassed 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, and after the temperature of the sample reached 25±0.2°C, liquefied carbon dioxide gas (manufactured by Sumitomo Seika Chemicals Co., Ltd., purity 99.9% by mass or more) was used to measure absolute pressures from 0.25 to 760 mmHg. During the measurement, the pressure was measured over time, and when the pressure fluctuation became 0.001% / 10 sec or less, it was determined that the saturated adsorption amount had been reached. The CO2 adsorption amount at 25°C (unit: cm 3 / g). (4) Following the measurement in (3) above, the pressure was gradually reduced from 760 to 0.25 mmHg absolute, and the carbon dioxide desorption isotherm was measured. Note that, as in (3), the equilibrium was determined by measuring the pressure fluctuation of 0.001% / 10 sec or less. (5) As an index showing the amount of hysteresis in the carbon dioxide adsorption / desorption isotherm, q(Ad) / q(De) was used as an index showing the amount of hysteresis, where q(Ad) and q(De) are the equilibrium adsorption amount at 75 mmHg of the adsorption isotherm measured in (3) and the equilibrium adsorption amount at 75 mmHg of the desorption isotherm measured in (4). q(Ad) / q(De) = 1.00 indicates no hysteresis, and the smaller q(Ad) / q(De) indicates a state with greater hysteresis.

[0164] [CH4 adsorption amount; gas adsorption isotherm measurement] Gas adsorption isotherm measurements were carried out according to the following procedure. (1) The dried product obtained in each example and comparative example was used as a sample, and 0.2 g of the sample was placed in a 12 mm cell (manufactured by Micro Meritics). (2) The sample placed in the cell (1) above was placed in a gas adsorption measuring device "3-Flex" (trade name) manufactured by Micro Meritics, and heated and vacuum degassed 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 35°C, and after the temperature of the sample reached 25±0.2°C, absolute pressures of 0.25 to 760 mmHg were measured using methane gas (manufactured by Fujii Shoji Co., Ltd., purity 99.99% by mass or higher). 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 was 0.001% / 10 sec or less. The CH4 adsorption amount at 25°C (unit: cm 3 / g).

[0165] [N2 adsorption amount; gas adsorption isotherm measurement] Gas adsorption isotherm measurements were carried out according to the following procedure. (1) The dried product obtained in each example and comparative example was used as a sample, and 0.2 g of the sample was placed in a 12 mm cell (manufactured by Micro Meritics). (2) The sample placed in the cell (1) above was placed in a gas adsorption measuring device "3-Flex" (trade name) manufactured by Micro Meritics, and heated and vacuum degassed 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 35°C, and after the temperature of the sample reached 25±0.2°C, the absolute pressure was measured from 0.25 to 760 mmHg using nitrogen gas (manufactured by Taiyo Nippon Sanso Corporation, purity 99.99% by mass or more). 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 became 0.001% / 10 sec or less. The N adsorption amount at 25°C (unit: cm) was calculated. 3 / g).

[0166] [Gas separation performance evaluation: CO2 recovery purity and CH4 recovery rate] The CO2 recovery purity and CH4 recovery rate of the zeolite shaped bodies produced in the Examples and Comparative Examples were measured using the gas separation performance evaluation device 1000 shown in FIG. 4 in the following manner. (1) Container 1008 was filled with 2500 cm of zeolite molded body produced in the Examples or Comparative Examples. 3 The container was filled with the above and placed in a thermostatic chamber 1007. (2) The thermostatic chamber (1) was maintained at 250°C for 12 hours or more to desorb the water and gas molecules adsorbed in the zeolite molded body, and then the temperature of the thermostatic chamber was lowered to 35°C and maintained there. (3) The raw material gas to be separated was filled into the raw material gas tank 1005. The composition of this raw material gas was 40% by volume of CO2 and 60% by volume of CH4. (4) The flow rate of the raw material gas was adjusted to 15 NL / min using a mass flow controller 1006, and the raw material gas was allowed to flow so as to come into contact with the zeolite molded bodies packed in a container 1008. The ratio of the amount of CH4 gas measured by a mass flow meter 1009 to the amount of CH4 gas flowing through the container 1008 until the CO2 concentration measured by a CO2 concentration meter 1010 reached 40% by volume was defined as the CH4 recovery rate (unit: vol%). (5) When the CO2 concentration measured by the CO2 concentration meter 1010 reached 40% by mass, the introduction of the raw material gas into the container 1008 was stopped, and the pressure in the container 1008 was reduced by the pressure reducing device 1011 to 2 kPa, and the gas was recovered from the container 1008 by performing a desorption operation. (6) The volume of the collected gas (unit: L) was measured using an integrating flow meter. (7) The amounts of CO2 and CH4 contained in the recovered gas in (5) were measured under the following conditions using a gas chromatograph "GC-2014" (trade name) manufactured by Shimadzu Corporation. Carrier gas: He (purity 99.9% or higher) Column: Agilent Technologies "CarboBOND" (trade name) Column temperature: 40℃ Detector:TCD The amounts of CO2 and CH4 were calculated from the peak areas and calibration curves. (8) The volume of CO2 contained in the recovered gas was calculated from the ratio of the volume of the recovered gas measured in (6) above to the mass of CO2 and CH4 measured in (7) above. The ratio of the volume of CO2 contained in the recovered gas to the volume of the recovered gas was taken as the CO2 recovery purity (unit: volume %).

[0167] [Pressure loss] The pressure loss of the zeolite molded body was evaluated according to the following procedure. (1) A 52 mm diameter, 1.5 m high polyvinyl chloride pipe with a 1.5 mm mesh fixed to the bottom was filled with zeolite molded bodies to a height of 1 m. During filling, the polyvinyl chloride pipe was hammered with a rubber hammer every 10 cm until the filling height no longer changed. (2) A gas distribution line was connected to each of the upper and lower ends of the polyvinyl chloride pipe (1) above. (3) A digital differential pressure gauge was connected at a position where the pressure difference between the upper and lower ends of the polyvinyl chloride pipe (2) above could be measured. (4) The reading on the digital differential pressure gauge when compressed air was introduced from the gas distribution line connected to the upper end in (2) above so that the superficial velocity was 1 m / s was taken as the pressure loss (unit: kPa).

[0168] [Length and diameter measurement of zeolite compacts] For cylindrical zeolite molded bodies, the length and diameter of the pellets were measured by the vernier caliper method. In this measurement, a vernier caliper with a minimum readable value of 0.1 mm or less was used, and measurements were taken for three samples, and the average values ​​were used as the length and diameter. For spherical zeolite compacts, the compact was placed stably on a horizontal surface and aligned with a precision straightedge with a minimum reading of 0.5 mm or less, and a vertical projection image of the compact was taken. The projected image of the compact was sandwiched between two parallel lines tangent to the projected image, and the largest distance between the parallel lines was taken as the major axis, and the smallest distance was taken as the minor axis. The actual major and minor axes of the compact were calculated from the length of the scale marks on the straightedge in the image. Measurements were performed on three samples, and the average of the six calculated diameters was taken as the diameter of the spherical compact.

[0169] [Weight loss measurement] The weight loss (unit: g) per 1.2 g of the zeolite shaped bodies obtained in the Examples and Comparative Examples after heating at 300° C. for 2 hours was measured by the following procedure. (1) 1.2 g of the zeolite molded body was weighed and dried at 180°C in a N2 atmosphere for 3 hours. (2) The dried zeolite molded body was weighed in a glove box. (3) The weighed zeolite molded body was heated in an air atmosphere at 300°C for 2 hours. (4) The container was sealed to prevent moisture absorption and cooled to room temperature, and then the zeolite molded body was weighed in the glove box. The difference between the weight of the zeolite molded body measured in step (2) and the weight of the zeolite molded body measured in step (4) was defined as the weight loss degree, and the closer this value was to 0, the smaller the weight loss degree was, and the more durable the zeolite molded body was evaluated to be.

[0170] [Measurement of powdering rate after high temperature exposure] The powdering rate of the zeolite molded body after the weight loss measurement was measured using the same procedure as in the "Evaluation of durability of zeolite molded body under CO2 atmosphere" described above. The powdering rate measured in this manner was defined as the powdering rate [mass%] after high-temperature exposure, and the closer this value was to 0, the more durable the zeolite molded body was.

[0171] Hereinafter, the zeolite molding containing the zeolite capable of adsorbing carbon dioxide has an apparent density d a The following examples are illustrative only, and the present embodiment is not limited to the following examples.

[0172] [Production Example 1] A mixed gel was prepared by mixing 61.93 g of water, 0.403 g of sodium hydroxide (NaOH, Fujifilm Wako Pure Chemical Industries, Ltd.), 3.39 g of sodium nitrate (NaNO3, Fujifilm Wako Pure Chemical Industries, Ltd.), 1.64 g of sodium aluminate (NaAlO2, Fujifilm Wako Pure Chemical Industries, Ltd.), and 10.82 g of colloidal silica (Ludox AS-40, solids concentration 40 wt%, Grace Chemical Industries, Ltd.) and stirring for 30 minutes. The composition of the mixed gel was: α = E / Al2O3 = 4.53, β = SiO2 / Al2O3 = 8.17, γ = Na2O / Al2O3 = 3.99, δ = P2O5 / Al2O3 = 0.00, ε = H2O / Al2O3 = 431.0, ζ = H2O / OH. -= 376.7, and η = R / Al2O3 = 0.00. The mixed gel was placed in a 200 mL stainless steel microbomb (manufactured by HIRO COMPANY) with a fluororesin inner cylinder, and hydrothermal synthesis was carried out for 4 days at 135°C and a stirring speed of 30 rpm in a thermostatically controlled stirring bath (manufactured by HIRO COMPANY) that could rotate the microbomb up and down. The product was filtered and dried at 120°C to obtain powdered zeolite. X-ray diffraction spectroscopy confirmed that the obtained zeolite was GIS-type zeolite. Furthermore, since no peaks derived from other zeolites or amorphous silica-alumina were observed, it was evaluated as a high-purity GIS-type zeolite.

[0173] The obtained zeolite was 29 The silica-alumina ratio was calculated from the Si-MAS-NMR spectrum to be SAR = 6.90, and (a + d) / (b + c) = 0.305. The potassium and lithium contents in the zeolite were Z / T = 0.00 (= K / T). Measurement of the CO2 adsorption and desorption isotherms of the obtained GIS-type zeolite revealed that the adsorption amount at 760 mmHg was 82.2 cm3. 3 / g, and q(Ad) / q(De) = 0.984. Similarly, when the adsorption isotherm of CH4 was measured, the adsorption amount at 760 mmHg was 6.2 cm 3 / g.

[0174] [Production Example 2] A mixed gel was prepared by mixing 61.65 g of water, 0.60 g of sodium hydroxide solution (NaOH, 48% by mass, manufactured by Tokuyama Soda Co.), 2.27 g of sodium carbonate (NaCO3, manufactured by Tokuyama Soda Co.), 1.64 g of sodium aluminate (NaAlO2, manufactured by Hokuriku Chemical Industry Co.), and 10.82 g of colloidal silica (Ludox AS-40 (trade name), 40% solids by mass, manufactured by Grace Chemicals) and stirring for 30 minutes. The composition of the mixed gel was: α = E / AlO3 = 4.86, β = SiO2 / AlO3 = 8.17, γ = Na2O / AlO3 = 3.99, δ = P2O5 / AlO3 = 0.00, ε = H2O / AlO3 = 431.2, ζ = H2O / OH. -= 527.8, and η = R / Al2O3 = 0.00. The mixed gel was placed in a 200 mL stainless steel microbomb (HIRO COMPANY) with a fluororesin inner cylinder and subjected to hydrothermal synthesis at 130 °C for 5 days at a stirring speed of 30 rpm using a thermostatically controlled stirring bath (HIRO COMPANY) that could rotate the microbomb vertically. The product was filtered and dried at 120 °C to obtain powdered zeolite. 1 g of the obtained zeolite was added to 500 mL of 0.05 N potassium carbonate aqueous solution prepared using potassium carbonate (K2CO3, Nippon Soda Co., Ltd.) and stirred at 500 rpm for 3 hours at room temperature. The product was filtered and dried at 120 °C to obtain powdered zeolite in which some of the cations had been exchanged with potassium. XRD spectrum confirmed that the obtained zeolite was GIS-type zeolite. Furthermore, since no peaks derived from other zeolites or amorphous silica alumina were observed, it was evaluated as a high-purity GIS-type zeolite.

[0175] The obtained zeolite was 29 The silica-alumina ratio was calculated from the Si-MAS-NMR spectrum, and the SAR was 6.90, with (a+d) / (b+c) = 0.220. The potassium and lithium contents in the zeolite were Z / T = 0.98 (= K / T). Measurement of the CO2 adsorption and desorption isotherms revealed that the adsorption amount at 760 mmHg was 84.0 cm 3 / g, and q(Ad) / q(De) = 1.000. Similarly, when the adsorption isotherm of CH4 was measured, the adsorption amount at 760 mmHg was 0.0 cm 3 / g.

[0176] [Production Example 3] A mixed gel was prepared by mixing 141.41 g of water, 2.62 g of sodium hydroxide (NaOH, Fujifilm Wako Pure Chemical Industries, Ltd.), 8.53 g of sodium nitrate (NaNO3, Fujifilm Wako Pure Chemical Industries, Ltd.), 3.85 g of sodium aluminate (NaAlO2, Fujifilm Wako Pure Chemical Industries, Ltd.), and 17.41 g of amorphous silica (Perkasil SM500, Grace Chemical Industries, Ltd.) and stirring for 1 hour. The composition of the mixed gel was: α = E / Al2O3 = 4.85, β = SiO2 / Al2O3 = 14.00, γ = Na2O / Al2O3 = 5.16, δ = P2O5 / Al2O3 = 0.00, ε = H2O / Al2O3 = 379.3, ζ = H2O / OH. - = 120.0, and η = R / Al2O3 = 0.00. The mixed gel was placed in a 300 mL stainless steel micro-bomb (manufactured by HIRO COMPANY) with a fluororesin inner cylinder, and hydrothermal synthesis was carried out for 4 days at 130°C and a stirring speed of 30 rpm in a stirring thermostatic bath (manufactured by HIRO COMPANY) that could rotate the micro-bomb up and down. The product was filtered and dried at 120°C to obtain powdered zeolite. XRD spectrum confirmed that the obtained zeolite was GIS-type zeolite. Furthermore, since no peaks derived from other zeolites or amorphous silica-alumina were observed, it was evaluated as high-purity GIS-type zeolite.

[0177] The obtained zeolite was 29 The silica-alumina ratio was calculated from the Si-MAS-NMR spectrum, and the SAR was 10.1, with (a+d) / (b+c) = 0.519. The potassium and lithium contents in the zeolite were Z / T = 0.00 (= K / T). Measurement of the CO2 adsorption and desorption isotherms revealed that the adsorption amount at 760 mmHg was 80.0 cm 3 / g, and q(Ad) / q(De) = 1.000. Similarly, when the adsorption isotherm of CH4 was measured, the adsorption amount at 760 mmHg was 7.2 cm 3 / g.

[0178] [Production Example 4] A mixed gel was prepared by mixing 141.41 g of water, 2.62 g of sodium hydroxide (NaOH, Fujifilm Wako Pure Chemical Industries, Ltd.), 2.43 g of sodium nitrate (NaNO3, Fujifilm Wako Pure Chemical Industries, Ltd.), 0.55 g of sodium aluminate (NaAlO2, Fujifilm Wako Pure Chemical Industries, Ltd.), and 35.33 g of aluminosilicate (SIPERNAT 820A, Evonik) and stirring for 1 hour. The composition of the mixed gel was: α = E / Al2O3 = 0.88, β = SiO2 / Al2O3 = 14.00, γ = Na2O / Al2O3 = 2.62, δ = P2O5 / Al2O3 = 0.00, ε = H2O / Al2O3 = 242.4, ζ = H2O / OH. - = 120.0, and η = R / Al2O3 = 0.00. The mixed gel was placed in a 300 mL stainless steel microbomb (HIRO COMPANY) with a fluororesin inner cylinder and hydrothermally synthesized at 130 °C for 5 days using a stirring thermostatic chamber (HIRO COMPANY) that could rotate the microbomb up and down. The product was filtered and dried at 120 °C to obtain powdered zeolite. 1 g of the obtained zeolite was added to 500 mL of 0.005 N potassium carbonate aqueous solution prepared using potassium carbonate (K2CO3, Nippon Soda Co., Ltd.) and stirred at 500 rpm for 3 hours at room temperature. The product was filtered and dried at 120 °C to obtain powdered zeolite in which some of the cations had been exchanged with potassium. XRD spectrum confirmed that the obtained zeolite was GIS-type zeolite. Furthermore, since no peaks derived from other zeolites or amorphous silica alumina were observed, it was evaluated as a high-purity GIS-type zeolite.

[0179] The obtained zeolite was 29 The silica-alumina ratio was calculated from the Si-MAS-NMR spectrum, and the SAR was 8.20, with (a+d) / (b+c) = 0.356. The potassium and lithium contents in the zeolite were Z / T = 0.16 (= K / T). Measurement of the CO2 adsorption and desorption isotherms revealed that the adsorption amount at 760 mmHg was 72.7 cm 3 / g, and q(Ad) / q(De) = 0.991. Similarly, when the adsorption isotherm of CH4 was measured, the adsorption amount at 760 mmHg was 0.5 cm 3 / g.

[0180] [Production Example 5] A mixed gel was prepared by mixing 21.05 g of water, 0.53 g of sodium hydroxide (NaOH, Junsei Chemical Co., Ltd.), 1.37 g of sodium nitrate (NaNO3, Fujifilm Wako Pure Chemical Co., Ltd.), 1.13 g of sodium aluminate (NaAlO2, Fujifilm Wako Pure Chemical Co., Ltd.), and 15.5 g of water glass No. 3 (Kishida Chemical Co., Ltd.) and stirring for 1 hour. The composition of the mixed gel was: α = E / Al2O3 = 2.66, β = SiO2 / Al2O3 = 12.39, γ = Na2O / Al2O3 = 6.10, δ = P2O5 / Al2O3 = 0.00, ε = H2O / Al2O3 = 197.9, ζ = H2O / OH - = 90.2, and η = R / Al2O3 = 0.00. The mixed gel was placed in a 100 mL stainless steel microbomb (HIRO COMPANY) with a fluororesin inner cylinder and hydrothermally synthesized at 130 °C for 5 days at a stirring speed of 30 rpm using a thermostatically controlled stirring bath (HIRO COMPANY) that could rotate the microbomb vertically. The product was filtered and dried at 120 °C to obtain powdered zeolite. 1 g of the obtained zeolite was added to 500 mL of a 0.006 N lithium carbonate aqueous solution prepared using lithium nitrate (LiNO3, Fujifilm Corporation) and stirred at 500 rpm for 3 hours at room temperature. The product was filtered and dried at 120 °C to obtain powdered zeolite in which some of the cations had been exchanged with lithium. XRD spectra confirmed that the obtained zeolite was GIS-type zeolite. Furthermore, since no peaks derived from other zeolites or amorphous silica alumina were observed, it was evaluated as a high-purity GIS-type zeolite.

[0181] The obtained zeolite was 29The silica-alumina ratio was calculated from the Si-MAS-NMR spectrum, and the SAR was 3.40, with (a+d) / (b+c) = 0.192. The potassium and lithium contents in the zeolite were Z / T = 0.11. Measurement of the CO2 adsorption and desorption isotherms revealed that the adsorption amount at 760 mmHg was 51.2 cm 3 / g, and q(Ad) / q(De) = 0.978. Similarly, when the adsorption isotherm of CH4 was measured, the adsorption amount at 760 mmHg was 0.8 cm 3 / g.

[0182] Example 1 40 parts by mass of the GIS-type zeolite powder obtained in Production Example 1, 43 parts by mass of powdered alumina hydrate (manufactured by JGC Catalysts and Chemicals, alumina content: 70% by mass), and 17 parts by mass of ion-exchanged water 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. The zeolite molded body thus obtained was subjected to various evaluations, and the results are shown in Table 1. Apparent density d a is 1.4g / cm 3 , bulk density d b is 0.882g / cm 3 , true density d t is 2.48g / cm 3 and the apparent density d a / true density d t is 0.56, bulk density d b / true density d t The weight loss was 0.02 g. The zeolite compact was evaluated for embrittlement resistance in a CO2 atmosphere, and the powdering rate was measured to be 0% by mass. The powdering rate after exposure to high temperatures was also 0% by mass.

[0183] When measuring the adsorption isotherms of CO2, CH4 and N2 on the zeolite compact, the adsorption amounts at 760 mmHg were CO2: 46.9 cm3, respectively. 3 / g, CH4:3.5cm 3 / g, N2:4.0cm 3 / g, the CO2 / CH4 adsorption selectivity was 13.4, and the CO2 / N2 adsorption selectivity was 11.7. The recovery purity of CO2 measured using a gas separation performance evaluation device was 98.5 vol%, the recovery rate of CH4 was 99.0 vol%, and the pressure drop at a packing height of 1 m was 10.8 kPa.

[0184] Example 2 Using the zeolite synthesized in Production Example 2, a zeolite molded body was obtained in the same manner as in Example 1. The apparent density of the zeolite molded body thus obtained is d a is 1.4g / cm 3 , bulk density d b is 0.882g / cm 3 , true density d t is 2.48g / cm 3 and the apparent density d a / true density d t is 0.56, bulk density d b / true density d t The weight loss was 0.02 g. The zeolite compact was evaluated for embrittlement resistance in a CO2 atmosphere, and the powdering rate was measured to be 2% by mass. Furthermore, the powdering rate after exposure to high temperatures was 1% by mass. When measuring the adsorption isotherms of CO2, CH4 and N2 for the zeolite compact, the adsorption amounts at 760 mmHg were CO2: 48.0 cm3, respectively. 3 / g, CH4: 0.9 cm 3 / g, N2:1.3cm 3 / g, the adsorption selectivity for CO2 / CH4 was 53.3, and the adsorption selectivity for CO2 / N2 was 36.9. The recovery purity of CO2 measured by a gas separation performance evaluation device was 98.5% by volume, and the recovery rate of CH4 was 99.0% by volume. The pressure drop at a packed height of 1 m was measured to be 10.6 kPa.

[0185] Example 3 Using the zeolite synthesized in Production Example 3, a zeolite molded body was obtained in the same manner as in Example 1. The apparent density of the zeolite molded body thus obtained is d a is 1.4g / cm 3 , bulk density d b is 0.882g / cm 3 , true density d t is 2.48g / cm 3 and the apparent density d a / true density d t is 0.56, bulk density d b / true density d t The weight loss was 0.02 g. The zeolite compact was evaluated for embrittlement resistance in a CO2 atmosphere, and the powdering rate was measured to be 2% by mass. Furthermore, the powdering rate after exposure to high temperatures was 1% by mass. When measuring the adsorption isotherms of CO2, CH4 and N2 on the zeolite compact, the adsorption amounts at 760 mmHg were CO2: 46.2 cm3, respectively. 3 / g, CH4: 4.1 cm 3 / g, N2:4.5cm 3 / g, the adsorption selectivity of CO2 / CH4 was 11.3, and the adsorption selectivity of CO2 / N2 was 10.3. The recovery purity of CO2 measured using a gas separation performance evaluation device was 98.5% by volume, and the recovery rate of CH4 was 99.0% by volume. The pressure drop at a packed height of 1 m was measured to be 10.9 kPa.

[0186] Example 4 A zeolite molded body was obtained in the same manner as in Example 1, except that 40 parts by mass of the GIS-type zeolite powder obtained in Production Example 1, 10.4 parts by mass of powdered alumina hydrate (manufactured by JGC Catalysts and Chemicals Co., Ltd., alumina content: 70% by mass), 1.2 parts by mass of methyl cellulose (Celander YB-132A manufactured by HighChem Co., Ltd.), 0.2 parts by mass of polyvinyl alcohol (Gohsenol N-300 manufactured by Mitsubishi Chemical Corporation), and 48.2 parts by mass of alumina sol (manufactured by Nissan Chemical Industries, Ltd., alumina content: 10.5% by mass) were mixed and molded using a wet extrusion granulator. The apparent density of the zeolite molded body thus obtained is d a is 1.3g / cm 3 , bulk density d b is 0.819g / cm3 , true density d t is 2.31g / cm 3 and the apparent density d a / true density d t is 0.56, bulk density d b / true density d t The weight loss was 0.02 g. The zeolite compact was evaluated for embrittlement resistance in a CO2 atmosphere, and the powdering rate was measured to be 2% by mass. Furthermore, the powdering rate after exposure to high temperatures was 1% by mass. When the adsorption isotherms of CO and CH of the zeolite molded body of Example 4 were measured, the adsorption amounts at 760 mmHg were CO: 62.6 cm 3 / g, CH4: 4.9 cm 3 / g, and the CO2 / CH4 adsorption selectivity was 12.8. The recovery purity of CO2 measured using a gas separation performance evaluation device was 98.3% by volume, and the recovery rate of CH4 was 98.8% by volume. The pressure drop at a packed height of 1 m was measured to be 10.8 kPa.

[0187] Example 5 A zeolite molded body was obtained in the same manner as in Example 1 using the zeolite synthesized in Production Example 4. The apparent density of the zeolite molded body thus obtained is d a is 1.3g / cm 3 , bulk density d b is 0.819g / cm 3 , true density d t is 2.48g / cm 3 and the apparent density d a / true density d t is 0.52, bulk density d b / true density d t The weight loss was 0.02 g. The zeolite compact was evaluated for embrittlement resistance in a CO2 atmosphere, and the powdering rate was measured to be 2% by mass. Furthermore, the powdering rate after exposure to high temperatures was 1% by mass. When measuring the adsorption isotherms of CO2, CH4 and N2 for the zeolite compact, the adsorption amounts at 760 mmHg were CO2: 41.6 cm3, respectively.3 / g, CH4: 1.2 cm 3 / g, N2:1.5cm 3 / g, the adsorption selectivity for CO2 / CH4 was 34.7, and the adsorption selectivity for CO2 / N2 was 27.7. The recovery purity of CO2 measured using a gas separation performance evaluation device was 98.3% by volume, and the recovery rate of CH4 was 98.8% by volume. The pressure drop at a packed height of 1 m was measured to be 10.6 kPa.

[0188] Example 6 Using the zeolite synthesized in Production Example 5, a zeolite molded body was obtained in the same manner as in Example 1. The apparent density of the zeolite molded body thus obtained is d a is 1.3g / cm 3 , bulk density d b is 0.819g / cm 3 , true density d t is 2.48g / cm 3 and the apparent density d a / true density d t is 0.52, bulk density d a / true density d t The weight loss was 0.02 g. The zeolite compact was evaluated for embrittlement resistance in a CO2 atmosphere, and the powdering rate was measured to be 2% by mass. Furthermore, the powdering rate after exposure to high temperatures was 1% by mass. When measuring the adsorption isotherms of CO2, CH4 and N2 for the zeolite compact, the adsorption amounts at 760 mmHg were CO2: 29.3 cm3, respectively. 3 / g, CH4: 1.4 cm 3 / g, N2:1.8cm 3 / g, the adsorption selectivity for CO2 / CH4 was 20.9, and the adsorption selectivity for CO2 / N2 was 16.2. The recovery purity of CO2 measured using a gas separation performance evaluation device was 98.3% by volume, and the recovery rate of CH4 was 98.8% by volume. The pressure drop at a packed height of 1 m was measured to be 10.9 kPa.

[0189] Example 7 A zeolite molded body was obtained in the same manner as in Example 4, except that 49.4 parts by mass of alumina sol (manufactured by Taki Chemical Co., Ltd.) with an alumina content of 7.2% by mass was used instead of the alumina sol with an alumina content of 10.5% by mass, and 9.2 parts by mass of powdered alumina hydrate was used. The apparent density of the zeolite molded body thus obtained is d a is 0.92g / cm 3 , bulk density d b is 0.580g / cm 3 , true density d t is 2.31g / cm 3 and the apparent density d a / true density d t is 0.40, bulk density d b / true density d t The weight loss was 0.02 g. The zeolite compact was evaluated for embrittlement resistance in a CO2 atmosphere, and the powdering rate was measured to be 5% by mass. Furthermore, the powdering rate after exposure to high temperatures was 3% by mass. When measuring the adsorption isotherms of CO2 and CH4 on the zeolite compact, the adsorption amounts at 760 mmHg were CO2: 65.8 cm3, respectively. 3 / g, CH4: 5.0 cm 3 / g, and the CO2 / CH4 adsorption selectivity was 13.2. The recovery purity of CO2 measured using a gas separation performance evaluation device was 96.9% by volume, and the recovery rate of CH4 was 97.9% by volume. The pressure drop at a packed height of 1 m was measured to be 10.5 kPa.

[0190] Example 8 A zeolite shaped product was obtained in the same manner as in Example 4, except that polyvinyl alcohol was not used. The apparent density of the zeolite molded body thus obtained is d a is 0.91g / cm 3 , bulk density d b is 0.573g / cm 3 , true density d t is 2.31g / cm 3 and the apparent density d a / true density d t is 0.39, bulk density db / true density d t The weight loss was 0.03 g. The zeolite compact was evaluated for embrittlement resistance in a CO2 atmosphere, and the powdering rate was measured to be 8% by mass. Furthermore, the powdering rate after exposure to high temperatures was 7% by mass. When measuring the adsorption isotherms of CO2 and CH4 on the zeolite compact, the adsorption amounts at 760 mmHg were CO2: 62.5 cm3, respectively. 3 / g, CH4: 4.8 cm 3 / g, and the CO2 / CH4 adsorption selectivity was 13.0. The recovery purity of CO2 measured using a gas separation performance evaluation device was 96.9% by volume, and the recovery rate of CH4 was 97.9% by volume. The pressure drop at a packed height of 1 m was measured to be 10.8 kPa.

[0191] Example 9 A molded article was obtained in the same manner as in Example 4, except that methyl cellulose was not used. The apparent density of the zeolite molded body thus obtained is d a is 1.0g / cm 3 , bulk density is d b 0.630g / cm 3 , true density d t is 2.31g / cm 3 and the apparent density d a / true density d t is 0.43, bulk density d a / true density d t The weight loss was 0.1 g. The zeolite compact was evaluated for embrittlement resistance in a CO2 atmosphere, and the powdering rate was measured to be 6% by mass. The powdering rate after exposure to high temperatures was also 6% by mass. When measuring the adsorption isotherms of CO2 and CH4 on the zeolite compact, the adsorption amounts at 760 mmHg were CO2: 62.5 cm3, respectively. 3 / g, CH4: 4.7 cm 3 / g, and the CO2 / CH4 adsorption selectivity was 13.3. The recovery purity of CO2 measured using a gas separation performance evaluation device was 97.3% by volume, and the recovery rate of CH4 was 98.1% by volume. The pressure drop at a packed height of 1 m was measured to be 10.9 kPa.

[0192] Example 10 A zeolite molded body was obtained in the same manner as in Example 4, except that manual extrusion molding was performed using a clay gun instead of the wet extrusion granulator "MG-55." The apparent density of the zeolite molded body thus obtained is d a is 0.77g / cm 3 , bulk density d b is 0.485g / cm 3 , true density d t is 2.31g / cm 3 and the apparent density d a / true density d t is 0.33, bulk density d a / true density d t The weight loss was 0.04 g. The zeolite compact was evaluated for embrittlement resistance in a CO2 atmosphere, and the powdering rate was measured to be 10% by mass. After exposure to high temperatures, the powdering rate was 8% by mass. When measuring the adsorption isotherms of CO2 and CH4 on the zeolite compact, the adsorption amounts at 760 mmHg were CO2: 62.6 cm3, respectively. 3 / g, CH4: 4.8 cm 3 / g, and the CO2 / CH4 adsorption selectivity was 13.0. The recovery purity of CO2 measured using a gas separation performance evaluation device was 96.1% by volume, and the recovery rate of CH4 was 97.3% by volume. The pressure drop at a packed height of 1 m was measured to be 10.7 kPa.

[0193] Example 11 A molded body was obtained in the same manner as in Example 4, except that an alumina sol (alumina content: 10 mass %) manufactured by Kawaken Fine Chemicals Co., Ltd. was used instead of the alumina sol manufactured by Nissan Chemical Industries, Ltd. The apparent density of the zeolite molded body thus obtained is d a is 0.77g / cm 3 , bulk density d bis 0.485g / cm 3 , true density d t is 2.31g / cm 3 and the apparent density d a / true density d t is 0.33, bulk density d b / true density d t The weight loss was 0.03 g. The zeolite compact was evaluated for embrittlement resistance in a CO2 atmosphere, and the powdering rate was measured to be 10% by mass. After exposure to high temperatures, the powdering rate was 8% by mass. When measuring the adsorption isotherms of CO2 and CH4 on the zeolite compact, the adsorption amounts at 760 mmHg were CO2: 62.4 cm3, respectively. 3 / g, CH4: 4.8 cm 3 / g, and the CO2 / CH4 adsorption selectivity was 13.0. The recovery purity of CO2 measured using a gas separation performance evaluation device was 96.1% by volume, and the recovery rate of CH4 was 97.3% by volume. The pressure drop at a packed height of 1 m was measured to be 10.8 kPa.

[0194] Example 12 A compact was obtained in the same manner as in Example 4, except that a pressure treatment of 12 MPa was carried out for 20 seconds using a tablet molding compression machine "BRE-32" (manufactured by Maekawa Testing Machinery Manufacturing Co., Ltd.) instead of the wet extrusion granulator "MG-55," and a disk-shaped compact with a diameter of 32 mm and a thickness of 5 mm was obtained. The apparent density of the zeolite molded body thus obtained is d a is 1.4g / cm 3 , bulk density d b is 1.092g / cm 3 , true density d t is 2.31g / cm 3 and the apparent density d a / true density d t is 0.61, bulk density d a / true density d t The weight loss was 0.01 g. The embrittlement resistance of the zeolite molded body was evaluated in a CO2 atmosphere, and the powdering rate was measured, which was 0% by mass. The powdering rate after exposure to high temperatures was also 0% by mass. When measuring the adsorption isotherms of CO2 and CH4 on the zeolite compact, the adsorption amounts at 760 mmHg were CO2: 62.4 cm3, respectively. 3 / g, CH4: 4.9 cm 3 / g, and the CO2 / CH4 adsorption selectivity was 12.7. The recovery purity of CO2 measured using a gas separation performance evaluation device was 99.1% by volume, and the recovery rate of CH4 was 99.4% by volume. The pressure drop at a packed height of 1 m was measured to be 11.0 kPa.

[0195] Example 13 After extrusion to a diameter of 8 mm instead of 3 mm, the mixture was granulated at 200 rpm for 10 minutes using a Marumerizer (manufactured by Dalton Co., Ltd.) to obtain spherical molded bodies with a diameter of 8 mm, in the same manner as in Example 7. The apparent density of the zeolite molded body thus obtained is d a is 1.2g / cm 3 , bulk density d b is 0.744g / cm 3 , true density is 2.31g / cm 3 The apparent density / true density is 0.52, and the bulk density d b / true density d t The weight loss was 0.03 g. The zeolite compact was evaluated for embrittlement resistance in a CO2 atmosphere, and the powdering rate was measured to be 2% by mass. The powdering rate after exposure to high temperatures was also 2% by mass. When measuring the adsorption isotherms of CO2 and CH4 on the zeolite compact, the adsorption amounts at 760 mmHg were CO2: 62.6 cm3, respectively. 3 / g, CH4: 4.9 cm 3 / g, and the CO2 / CH4 adsorption selectivity was 12.8. The recovery purity of CO2 measured using a gas separation performance evaluation device was 97.9% by volume, and the recovery rate of CH4 was 98.6% by volume. The pressure drop at a packed height of 1 m was measured to be 3.06 kPa.

[0196] Example 14 40 parts by mass of the GIS-type zeolite powder obtained in Production Example 1, 10 parts by mass of bentonite (manufactured by Kunimine Industries Co., Ltd.), 0.4 parts by mass of carboxymethyl cellulose (manufactured by Nippon Paper Industries Co., Ltd.), and 40.6 parts by mass of ion-exchanged water 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 600°C for 10 hours in an air atmosphere. The apparent density of the zeolite molded body thus obtained is d a is 0.97g / cm 3 , bulk density d b is 0.631g / cm 3 , true density d t is 2.40g / cm 3 and the apparent density d a / true density d t is 0.40, bulk density d a / true density d t The weight loss was 0.03 g. The zeolite compact was evaluated for embrittlement resistance in a CO2 atmosphere, and the powdering rate was measured to be 0% by mass. The powdering rate after exposure to high temperatures was also 0% by mass. When measuring the adsorption isotherms of CO2 and CH4 on the zeolite compact, the adsorption amounts at 760 mmHg were CO2: 65.6 cm3, respectively. 3 / g, CH4: 5.02 cm 3 / g, and the CO2 / CH4 adsorption selectivity was 13.1. The recovery purity of CO2 measured using a gas separation performance evaluation device was 98.1% by volume, and the recovery rate of CH4 was 97.3% by volume. The pressure drop at a packed height of 1 m was measured to be 10.9 kPa.

[0197] Example 15 After extruding to a diameter of 8 mm instead of 3 mm, the mixture was granulated at 200 rpm for 10 minutes using a Marumerizer (manufactured by Dalton Co., Ltd.) to obtain spherical molded bodies with a diameter of 8 mm, in the same manner as in Example 14. The apparent density of the zeolite molded body thus obtained is d a is 1.1g / cm 3 , bulk density db is 0.693g / cm 3 , true density d t is 2.40g / cm 3 and the apparent density d a / true density d t is 0.46, bulk density d a / true density d t The weight loss was 0.03 g. The zeolite compact was evaluated for embrittlement resistance in a CO2 atmosphere, and the powdering rate was measured to be 0% by mass. The powdering rate after exposure to high temperatures was also 0% by mass. When measuring the adsorption isotherms of CO2 and CH4 on the zeolite compact, the adsorption amounts at 760 mmHg were CO2: 65.9 cm3, respectively. 3 / g, CH4: 5.00 cm 3 / g, and the CO2 / CH4 adsorption selectivity was 13.2. The recovery purity of CO2 measured using a gas separation performance evaluation device was 97.6% by volume, and the recovery rate of CH4 was 98.4% by volume. The pressure drop at a packed height of 1 m was measured to be 3.10 kPa.

[0198] Comparative Example 1 49.5 parts by mass of the GIS zeolite powder obtained in Production Example 1 was dispersed in 50.5 parts by mass of ion-exchanged water to prepare a raw material slurry. The obtained raw material slurry was stirred at 25°C for 1 hour. The raw material slurry was supplied to a spray dryer (OC-16 spray dryer manufactured by Okawara Kakoki Co., Ltd.) with the fluid temperature at the spray dryer inlet set to 230°C and the fluid temperature at the spray dryer outlet set to 120°C, and spray-dried using a rotating disk method to obtain a spray-dried powder. A molded body was obtained in the same manner as in Example 4, except that the spray-dried powder was used instead of the GIS zeolite of Production Example 1. The apparent density of the zeolite molded body thus obtained is d a is 0.70g / cm 3 , bulk density d b is 0.441g / cm 3 , true density d t is 2.31g / cm 3 and the apparent density d a / true density d t is 0.30, bulk density db / true density d t The weight loss was 0.09 g. The embrittlement resistance of the zeolite compact was evaluated in a CO2 atmosphere, and the powdering rate was measured to be 90% by mass. After exposure to high temperatures, the powdering rate was 95% by mass. When the adsorption isotherms of CO and CH of the zeolite molded body of Comparative Example 1 were measured, the adsorption amounts at 760 mmHg were CO: 62.5 cm 3 / g, CH4: 4.8 cm 3 / g, and the CO2 / CH4 adsorption selectivity was 13.0. The recovery purity of CO2 measured using a gas separation performance evaluation device was 95.6% by volume, and the recovery rate of CH4 was 96.9% by volume. The pressure drop at a packed height of 1 m was measured to be 11.0 kPa.

[0199] Comparative Example 2 A molded article was obtained in the same manner as in Comparative Example 1, except that methyl cellulose and polyvinyl alcohol were not used. The apparent density of the zeolite molded body thus obtained is d a is 0.74g / cm 3 , bulk density d b is 0.466g / cm 3 , true density d t is 2.31g / cm 3 and the apparent density d a / true density d t is 0.32, bulk density d a / true density d t The weight loss was 0.03 g. The embrittlement resistance of the zeolite molded body was evaluated in a CO2 atmosphere, and the powdering rate was measured and found to be 100% by mass. The powdering rate after exposure to high temperatures was also 100% by mass. When measuring the adsorption isotherms of CO2 and CH4 on the zeolite compact, the adsorption amounts at 760 mmHg were CO2: 62.6 cm3, respectively. 3 / g, CH4: 4.9 cm 3 / g, and the CO2 / CH4 adsorption selectivity was 12.8. The recovery purity of CO2 measured using a gas separation performance evaluation device was 95.9% by volume, and the recovery rate of CH4 was 97.1% by volume. The pressure drop at a packed height of 1 m was measured to be 10.9 kPa.

[0200] Comparative Example 3 A composite was obtained by melt-kneading 70 parts by mass of the GIS-type zeolite powder obtained in Production Example 1 and 30 parts by mass of a polyamide resin (Zytel 101L manufactured by DuPont Co., Ltd.) in a twin-screw extruder (TEM48-SS manufactured by Toshiba Machine Co., Ltd.) at 285°C and 400 rpm. The composite was then used in an injection molding machine (EC75NII manufactured by Toshiba Machine Co., Ltd.) set at a cylinder temperature of 285°C and a mold temperature of 70°C to obtain a zeolite molded product having a length of 80 mm, a width of 10 mm, and a thickness of 4 mm. The apparent density of the zeolite molded body thus obtained is d a is 0.74g / cm 3 , bulk density d b is 0.385g / cm 3 , true density d t is 2.31g / cm 3 and the apparent density d a / true density d t is 0.32, bulk density d b / true density d t The weight loss was 0.65g. The embrittlement resistance of the zeolite compact was evaluated in a CO2 atmosphere, and the powdering rate was measured to be 12% by mass. After exposure to high temperatures, the powdering rate was 100% by mass. When the adsorption isotherms of CO and CH of the zeolite molded body of Comparative Example 3 were measured, the adsorption amounts at 760 mmHg were CO: 57.5 cm 3 / g, CH4: 4.5 cm 3 / g, and the CO2 / CH4 adsorption selectivity was 12.8. The recovery purity of CO2 measured using a gas separation performance evaluation device was 94.8% by volume, and the recovery rate of CH4 was 96.3% by volume. The pressure drop at a packed height of 1 m was measured to be 6.29 kPa.

[0201] Comparative Example 4 90 parts by mass of the GIS-type zeolite powder obtained in Production Example 1 was mixed with 10 parts by mass of γ-alumina powder (manufactured by Kanto Chemical Co., Ltd.), and the mixture was molded into tablets with a diameter of 3 mm and a height of 2 mm using a tablet molding machine (manufactured by Labnect Co., Ltd.) The tablet-molded product was heated at 335°C for 4 hours to obtain a zeolite molded product. The apparent density of the zeolite molded body thus obtained is d a is 0.70g / cm 3 , bulk density d b is 0.455g / cm 3 , true density d t is 2.42g / cm 3 and the apparent density d a / true density d t is 0.29, bulk density d a / true density d t The weight loss was 0.03g. The embrittlement resistance of the zeolite molded body was evaluated in a CO2 atmosphere, and the powdering rate was measured and found to be 100% by mass. The powdering rate after exposure to high temperatures was also 100% by mass. When measuring the adsorption isotherms of CO2 and CH4 on the zeolite compact, the adsorption amounts at 760 mmHg were CO2: 74.0 cm3, respectively. 3 / g, CH4: 5.6 cm 3 / g, and the CO2 / CH4 adsorption selectivity was 13.2. The recovery purity of CO2 measured using a gas separation performance evaluation device was 95.7% by volume, and the recovery rate of CH4 was 97.0% by volume. The pressure drop at a packed height of 1 m was measured to be 18.5 kPa.

[0202] The above results are summarized in Table 1.

[0203] [Table 1-1]

[0204] [Table 1-2]

[0205] [Table 1-3]

[0206] [Table 1-4] [Industrial Applicability]

[0207] The zeolite shaped article according to the present invention has industrial applicability as a separating agent and separation membrane for various gases and liquids, an electrolyte membrane for fuel cells and the like, a filler for various resin shaped articles, a membrane reactor, a catalyst for hydrocracking, alkylation, etc., a catalyst support for supporting metals, metal oxides, etc., an adsorbent, a desiccant, a detergent aid, an ion exchange agent, a wastewater treatment agent, a fertilizer, a food additive, a cosmetic additive, etc. [Explanation of symbols]

[0208] 2 Adsorption device 21 Container 23 filters 24 Zeolite molding 100 Purified gas production equipment 1. Mixed gas supply line 11 Flowmeter 12 Moisture meter 13 Component analyzer 3a,3b Carbon dioxide adsorption tower 31a,31b Fixed floor 5 Carbon dioxide capture line 53a, 53b Pressure gauge 51 Flow meter 52 Moisture meter 54 Component analyzer 7 Second component gas recovery line 71 Flow meter 72 Moisture meter 73 Component analyzer 9. Pressure reducing device AV1, AV2, AV3, AV4 Automatic valves 1000 Gas separation performance evaluation device 1005 Raw gas tank 1006 Mass Flow Controller 1007 Constant temperature bath 1008 Container 1009 Mass flow meter 1010 CO2 concentration meter 1011 Pressure reducing device

Claims

1. A zeolite molded body containing zeolite capable of adsorbing carbon dioxide, The apparent density d of the zeolite molded body a A zeolite molded body having a β-dispersion constant of 0.75 or more.

2. The zeolite is 10 cm 3 The zeolite formed body according to claim 1, having a carbon dioxide adsorption capacity of 1000 ppm or more.

3. The apparent density d of the zeolite molded body a / true density d t The zeolite molded body according to claim 1, wherein the ratio of

4. The bulk density d of the zeolite molded body b / true density d t The zeolite molded body according to claim 1, wherein the ratio of is 0.25 or more.

5. 2. The zeolite formed body according to claim 1, wherein the zeolite has an adsorption selectivity of carbon dioxide adsorption amount / second component gas adsorption amount of 10 or more.

6. The zeolite molded body according to claim 1, wherein the zeolite is a GIS-type zeolite.

7. The zeolite formed body according to claim 6, wherein the GIS-type zeolite has a silica-alumina ratio of 3.40 or more.

8. The zeolite shaped body according to claim 6, wherein the GIS zeolite contains potassium or lithium as a cation species.

9. 9. The zeolite molded body according to claim 8, wherein the ratio (Z / T) of the total amount of substance (Z) of potassium and lithium to the total amount of substance (T) of alkali metals in the GIS zeolite is 0.05 or more.

10. 29 The zeolite shaped body according to claim 6, comprising a GIS zeolite satisfying (a + d) / (b + c) ≧ 0.192, where a, b, c, and d are the peak area intensities assigned to Q4(3Al), Q4(2Al), Q4(1Al), and Q4(0Al) observed in a Si-MAS-NMR spectrum, respectively.

11. The zeolite shaped body according to claim 1 , which comprises a carrier.

12. 12. The zeolite formed body according to claim 11, wherein the support comprises an inorganic binder and an organic binder.

13. The zeolite shaped body according to claim 11, wherein the total content of the carrier is 1 to 99 mass% with respect to the total amount (100 mass%) of the zeolite shaped body.

14. 2. The zeolite molded body according to claim 1, which has a weight loss rate of 1.0 or less per 1.2 g when heated at 300°C for 2 hours.

15. 2. The zeolite molded body according to claim 1, having an aspect ratio of 1 to 10.

16. The zeolite molded body according to claim 1 , which has a cylindrical shape.

17. 17. The zeolite molded body according to claim 16, having a length of 3 mm or more and 30 mm or less and a diameter of 1 mm or more and 30 mm or less.

18. The zeolite shaped body according to claim 1 , which has a spherical shape.

19. The zeolite molded body according to claim 18, having a diameter of 3 mm or more and 10 mm or less.

20. An adsorption device comprising the zeolite shaped body according to any one of claims 1 to 19.

21. The adsorption device according to claim 20 is used to 2 , N 2 , O 2 , Ar, CO, and a hydrocarbon from a mixture containing two or more gases selected from the group consisting of 2 , H 2 O, He, Ne, Cl 2 , N.H. 3 and HCl.

22. 22. The method for producing a purified gas according to claim 21, wherein in the separation step, the gas is separated by pressure swing adsorption separation, temperature swing adsorption separation, or pressure-temperature swing adsorption separation.

23. A method for producing a purified gas, comprising: separating carbon dioxide and a second component gas different from carbon dioxide from a mixed gas containing the carbon dioxide and the second component gas using an adsorption tower; an adsorption step of introducing the mixed gas into the adsorption tower, causing the adsorbent to adsorb carbon dioxide, and extracting a second component gas; a desorption step of removing the carbon dioxide from the adsorbent by decompressing and evacuating the carbon dioxide from the adsorption tower; Including, A method for producing a purified gas, wherein the adsorption tower is filled with an adsorbent comprising the zeolite shaped article according to any one of claims 1 to 22.

24. The method for producing a purified gas according to claim 23, wherein the adsorption step and the desorption step are repeated multiple times or more.

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