JP5752485B2 - Method for producing CO adsorption / desorption agent - Google Patents

Description

  The present invention relates to a method for producing a CO adsorbing / desorbing agent, and more particularly to a technique for producing an adsorbing / desorbing agent for CO separation and recovery having high CO adsorption performance.

Conventionally, carbon monoxide (CO) is useful for the reduction of organic compounds and synthetic raw materials such as formic acid and acetic acid. Therefore, it is separated and recovered from CO-containing gases such as converter gas obtained from converters in steelworks. Has been. In the recovery of CO, for example, an absorption method such as the COSORB method or a cryogenic separation method is adopted for equipment having a CO-containing gas throughput of 2000 m ³ / h or more, and pressure swing is used for equipment less than 2000 m ³ / h. Adsorption methods such as adsorption method (PSA) or temperature swing adsorption method (TSA) are employed. The adsorption method is characterized in that the recovered CO is less likely to contain impurities than the absorption method, and a purified gas with high purity can be obtained.

  Various CO adsorbents that can be used in such adsorption methods have been proposed. For example, Patent Document 1 proposes a CO adsorbent in which copper is supported on a carrier made of aluminum oxide and zinc oxide. This adsorbent is a technique for improving the reversible adsorption ability by controlling the copper density and the zinc / copper ratio to specific ranges (see Patent Document 1 (paragraph [0050])). Patent Documents 2 to 5 propose a CO adsorbent in which a complex composed of pyridine, a diamine compound, or the like and copper (I) halide is supported on silica gel.

  As a method for producing a CO adsorbent, Patent Document 6 proposes a method of removing a solvent by bringing a liquid containing a copper (II) salt and a reducing agent into contact with an alumina support. Patent Document 7 describes a method in which copper (II) chloride and copper (II) carboxylate are supported on a carrier and heat-treated in an inert or reducing gas atmosphere under reduced pressure. Patent Document 8 discloses a method in which an alumina carrier is impregnated with an inorganic acid and then contacted with a liquid containing a copper (II) salt and a reducing agent to remove the solvent; There has been proposed a method of contacting a liquid containing a reducing agent and an inorganic acid to remove the solvent.

By the way, in an on-site hydrogen station for a fuel cell vehicle, hydrogen produced through city steam or liquefied petroleum gas (LPG) as a raw material through steam reforming and CO modification processes is further purified (impurity concentration 10 ppm). Below) In particular, removal of CO, which is a catalyst poison of the fuel cell catalyst, is important. Conventionally, CO removal from CO in hydrogen gas has been performed by CO selective oxidation in which oxygen or air is added to the gas and CO is converted to CO ₂ using an oxidation catalyst. However, CO selective oxidation requires an expensive noble metal catalyst, and has the disadvantages that hydrogen is consumed by the added oxygen. Therefore, a method for efficiently removing CO is desired.

JP 11-179197 A JP-A-9-290149 JP-A-9-290150 JP-A-9-290152 JP-A-9-290153 JP-A-1-155945 JP 2005-289761 A JP 2010-269264 A

  In the adsorption method such as PSA and TSA, the CO adsorbent needs to be regenerated under reduced pressure and heated, so that the size of the adsorbent packed column is limited from the viewpoint of facilitating reduced pressure and heating. For this reason, a CO adsorbent having a more reversible adsorption capacity is demanded in order to increase CO recovery efficiency without expanding the adsorbent packed tower. In addition, in a hydrogen station, a method capable of efficiently removing CO with simple equipment is required.

  The present invention has been made in view of the above circumstances, and is a CO adsorbing / desorbing agent having excellent CO adsorbing / desorbing performance, particularly a hydrogen station capable of efficiently separating and recovering high-purity CO from a mixed gas containing CO. However, an object is to provide a practical CO adsorption / desorption agent.

  The method for producing a CO adsorbing / desorbing agent of the present invention that has solved the above-described problems is obtained by using at least one metal selected from the group consisting of Group 3 and Group 13 metal elements of the long-period periodic table. It is characterized by contacting a liquid containing a carrier precursor, which is a salt, a copper (II) compound, a reducing agent and a solvent, with a porous carrier, then removing the solvent and baking. Examples of the carrier precursor include a water-soluble aluminum salt that decomposes by heating at 120 ° C. to 300 ° C. and / or a water-soluble cerium salt that decomposes by heating at 120 ° C. and 330 ° C. to generate cerium oxide. Is more preferable, and at least one selected from the group consisting of aluminum nitrate, cerium nitrate, and cerium acetate is more preferable. The amount of the carrier precursor used is preferably 0.1 mmol to 0.7 mmol with respect to a volume of 1 ml of the porous carrier. The reducing agent is preferably at least one selected from the group consisting of saccharides, aldehydes, carboxylic acids and low-valent metal salts. The porous carrier is preferably a carrier made of alumina and / or a carrier made of silica-alumina composite.

  According to the production method of the present invention, a CO adsorption / desorption agent having high CO adsorption / desorption performance can be obtained.

  The method for producing a CO adsorption / desorption agent of the present invention is characterized in that a solvent containing a specific carrier precursor, a copper (II) compound, a reducing agent and a solvent is contacted with a porous carrier, and then the solvent is removed. And In the present invention, the copper (II) compound supported on the porous carrier is efficiently reduced by the reducing agent simultaneously supported, and a mixture of the copper (I) compound and the copper (II) compound, or It is presumed that it will have an intermediate valence of II. In addition, when a copper (II) compound is supported on a porous carrier, a specific carrier precursor is allowed to coexist so that the copper (II) compound is supported on the porous carrier in a state of being mixed with the carrier precursor. Become so. Therefore, the copper (II) compound is supported in a more dispersed state on the porous carrier surface. Therefore, the contact area between the copper (II) compound and CO is increased, and the CO adsorption / desorption performance is improved.

  Any carrier precursor can be used as long as it can form a carrier by firing. Examples of the carrier precursor include a salt of at least one metal selected from the group consisting of Group 3 and Group 13 metal elements of the long-period periodic table. Specifically, nitrates and acetates of Group 3 metal elements such as scandium, yttrium, and lanthanoids (lanthanum, cerium, etc.) and Group 13 metal elements such as aluminum, gallium, indium, and thallium are included. These carrier precursors may be used alone or in combination of two or more. Among these, as the carrier precursor, a water-soluble aluminum salt that decomposes by heating at 120 ° C. or higher and 300 ° C. or lower and / or water solution that decomposes by heating at 120 ° C. or higher and 330 ° C. or lower to generate cerium oxide. Cerium salt is preferred. Examples of such a water-soluble aluminum salt include aluminum nitrate, and examples of the water-soluble cerium salt include cerium nitrate and cerium acetate.

  The amount of the carrier precursor used is preferably 0.1 mmol or more, more preferably 0.15 mmol or more, further preferably 0.2 mmol or more, and preferably 0.7 mmol or less with respect to 1 ml of the volume of the porous support. More preferably, it is 0.6 mmol or less, and further preferably 0.5 mmol or less. Here, the usage amount of the carrier precursor with respect to 1 ml of the volume of the porous carrier is determined by the following formula from the bulk density of the porous carrier. The bulk density of the porous carrier can be measured using a commercially available measuring instrument or can be determined as follows. Specifically, a measurement sample is filled into a 100 ml (or 1000 ml) measuring cylinder, and the surface is smoothed while vibrating using a vibrator, and vibration is applied until the volume change disappears. The volume of the carrier when the volume change disappears is confirmed, and the mass (bulk density) per reference volume is calculated by dividing the mass of the porous carrier filled with this volume value.

  Examples of the copper (II) compounds include copper (II) halides such as copper (II) chloride, copper (II) fluoride, and copper (II) bromide; copper (II) oxide; copper cyanide (II). ); Copper (II) such as copper (II) formate, copper (II) acetate, copper (II) oxalate, copper (II) sulfate, copper (II) nitrate, copper (II) phosphate, copper (II) carbonate ) Oxygenate or organic acid salt; Copper hydroxide (II); Copper sulfide (II); Trifluoro copper (II) acid salt, Tetrafluoro copper (II) acid salt, Trichloro copper (II) acid salt, Tetra Examples include chlorocopper (II) acid salt, tetracyano copper (II) acid salt, tetrahydrooxo copper (II) acid salt, hexahydrooxo copper (II) acid salt, and complex salts such as ammine complex salt. You may use the said copper (II) compound individually or in combination of 2 or more types. Among these, copper (II) halide is preferable, and copper (II) chloride is the most practical.

  The concentration of the copper (II) compound in the liquid in contact with the porous carrier is preferably 2 mol / l or more, more preferably 3 mol / l or more, still more preferably 3.5 mol / l or more, and 9 mol / l or less. More preferably, it is 8 mol / l or less, More preferably, it is 6 mol / l or less. By setting the concentration of the copper (II) compound to 2 mol / l or more, the energy required for removing the solvent can be further reduced. By setting the concentration to 9 mol / l or less, the copper (II) compound is added to the solvent. The heating (heating) energy at the time of dissolving can be further reduced.

The supported amount of the copper (II) compound with respect to the porous carrier is preferably 0.5 mmol / g or more, more preferably 1 mmol / g or more, further preferably 2 mmol / g or more, preferably 10 mmol / g or less, more preferably. Is 7 mmol / g or less, more preferably 5 mmol / g or less. If the supported amount of the copper (II) compound is too small, the CO adsorption capacity is insufficient. On the other hand, if the supported amount is too large, the separation efficiency decreases. Here, the loading amount of the copper (II) compound on the porous carrier is determined by the following formula from the charged amounts of the porous carrier and the copper (II) compound.
The amount of copper (II) compound supported on the porous carrier = the amount of copper (II) compound charged / the amount of porous carrier charged

  The molar ratio (carrier precursor / copper (II) compound) between the carrier precursor and the copper (II) compound in the liquid in contact with the porous carrier is preferably 0.05 or more, more preferably 0.1 or more. More preferably, it is 0.2 or more, 0.6 or less is preferable, More preferably, it is 0.5 or less, More preferably, it is 0.4 or less. When the molar ratio of the carrier precursor to the copper (II) compound is within the above range, the adsorption / desorption performance of the obtained CO adsorption / desorption agent is further improved.

  As the reducing agent used in the present invention, a metal salt in a low valence state or an organic compound having a low oxidation stage is used. Examples of the metal salt in the low valence state include iron (II), tin (II), titanium (III), and chromium (II) salts. Examples of the organic compound having a low oxidation stage include sucrose, glucose, fructose, galactose, psicose, mannose, allose, tagatose, ribose, deoxyribose, xylose, arabinose, maltose, lactose and other saccharides; formaldehyde and other aldehydes; formic acid And carboxylic acids such as oxalic acid; In addition, since sucrose also hydrolyzes and expresses reducibility, it can be used as a reducing agent. These reducing agents may be used alone or in combination of two or more. Among these, saccharides are preferable and sucrose is more preferable.

  The amount of the reducing agent used is preferably 0.01 mol or more, more preferably 0.03 mol or more, still more preferably 0.05 mol or more, with respect to 1 mol of the copper (II) compound supported on the porous carrier. The amount is preferably 0.25 mol or less, more preferably 0.20 mol or less, still more preferably 0.18 mol or less. If the amount of the reducing organic substance used is within the above range, the copper (II) compound can be efficiently converted to the copper (I) compound.

  As the liquid containing the carrier precursor and the copper (II) compound, a solution in which the carrier precursor and the copper (II) compound are dissolved in a solvent, and the carrier precursor and / or the copper (II) compound are dispersed in the solvent. Any dispersion may be used, but a solution is preferred. Examples of the solvent include water; ammonia water; halogen-containing solvents such as chloroform, carbon tetrachloride, ethylene dichloride, trichloroethane, tetrachloroethane, tetrachloroethylene, methylene chloride, and fluorinated solvents; hexane, benzene, toluene, xylene, and ethylbenzene. , Hydrocarbons such as cyclohexane and decalin; alcohols such as methanol, ethanol, propanol, butanol, amyl alcohol, cyclohexanol, ethylene glycol and propylene glycol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, isophorone and cyclohexanone Esters such as methyl acetate, ethyl acetate, amyl acetate, methyl propionate, amyl propionate; isopropyl ether, dioxane Ethers; cellosolve, ethyl cellosolve, butyl cellosolve, cellosolve such as cellosolve Sol acetate; carbitol; and the like. Among these, water can be preferably used.

  Examples of the material for the porous carrier include a porous carrier made of a metal oxide such as alumina, silica, or a composite thereof, activated carbon, and the like. These porous carriers may be used alone or in combination of two or more. Among these, a porous carrier made of a metal oxide is preferable, and a porous carrier made of alumina or a silica-alumina composite is preferable.

  The porous carrier made of alumina can be obtained, for example, by precipitating aluminum hydroxide from an aqueous solution of a soluble aluminum salt, removing it by filtration, and igniting it. As a method for producing a porous carrier composed of a silica-alumina composite, a method of simply mixing silica and alumina; a method of kneading silica gel and alumina gel in a wet state; a method of immersing an aluminum salt in silica gel; Examples thereof include a method of gelling silica and alumina simultaneously from an aqueous solution; a method of depositing alumina gel on silica gel; and the like. Both the porous carrier made of alumina and the porous carrier made of a silica-alumina composite are commercially available, and in the present invention, it is preferable to use them after drying if necessary.

  The particle diameter of the porous carrier is preferably 0.3 mm or more, more preferably 1 mm or more, further preferably 2 mm or more, preferably 10 mm or less, more preferably 6 mm or less, and further preferably 4 mm or less. By using a porous carrier having a particle diameter within the above range, the pressure loss of the adsorbent / desorbent packed bed can be easily adjusted to an allowable range, and a desired adsorption / desorption rate can be easily obtained. The particle diameter can be confirmed using an optical microscope or the like.

Pore volume of the porous carrier is preferably at least 0.1 cm ³ / g, more preferably 0.2 cm ³ / g or more, more preferably 0.3 cm ³ / g or more, 0.7 cm ³ / g or less Is preferred. If the pore volume of the porous carrier is 0.1 cm ³ / g or more, it is advantageous to hold the solution or dispersion containing a copper (II) compounds, also equal to or less than 0.7 cm ³ / g The physical strength of the porous carrier becomes better.

The specific surface area of the porous carrier is preferably at least 150 meters ² / g, more preferably 250 meters ² / g or more, still more preferably 300 meters ² / g or more, preferably 1800 m ² / g or less, more preferably 1600 m ² / g or less, more preferably 1300 m ² / g or less. By using a porous carrier having a specific surface area within the above range, retention and dispersion of the copper (II) compound become better.

As a method of bringing the liquid containing the carrier precursor etc. into contact with the porous carrier, a method of impregnating the porous carrier with the liquid containing the carrier precursor etc .; spraying the liquid containing the carrier precursor etc. onto the porous carrier Method; and the like. In this case, in order to completely replace the gas present in the pores of the porous carrier with the liquid, the liquid is brought into contact with the porous carrier which has been degassed under vacuum, or the liquid is brought into contact with the porous carrier, and then the pressure is reduced You may deaerate.
When the porous carrier is impregnated with a liquid containing a carrier precursor or the like, the impregnation time is preferably 5 minutes or more, more preferably 10 minutes or more, still more preferably 30 minutes or more, and preferably 100 minutes or less. Is 80 minutes or less, more preferably 60 minutes or less.

After contacting the porous carrier with the liquid, the solvent is removed. By removing the solvent, the support precursor and the copper (II) compound can be supported on the porous support.
The method for removing the solvent is not particularly limited, and examples thereof include heat drying and vacuum drying. Among these, it is preferable to distill and remove the solvent by heating and drying in an inert gas atmosphere such as nitrogen, argon or helium without lowering the temperature of the porous carrier in contact with the liquid. The drying temperature is preferably 50 ° C. or higher, more preferably 100 ° C. or higher, further preferably 120 ° C. or higher, 330 ° C. or lower, more preferably 250 ° C. or lower, still more preferably 200 ° C. or lower. The drying time is preferably 1 hour or longer, more preferably 1.5 hours or longer, preferably 10 hours or shorter, more preferably 5 hours or shorter. Drying is preferably performed in an inert gas atmosphere such as nitrogen, argon, or helium.

  Finally, the porous carrier carrying the carrier precursor, the copper (II) compound, and the reducing agent is fired. The firing temperature is preferably 100 ° C. or higher, more preferably 150 ° C. or higher, further preferably 180 ° C. or higher, preferably 500 ° C. or lower, more preferably 350 ° C. or lower, still more preferably 330 ° C. or lower. The firing time is preferably 1 hour or longer, more preferably 2 hours or longer, further preferably 3 hours or longer, preferably 12 hours or shorter, more preferably 10 hours or shorter, still more preferably 8 hours or shorter.

Firing is preferably performed in an inert gas such as nitrogen, argon or helium or in a reducing gas atmosphere such as CO or H ₂ . By baking in such an atmosphere, the copper (II) compound that has not been reduced by the reducing agent can be converted into a copper (I) compound, and the CO adsorption capacity is further improved. Note that the drying treatment for removing the solvent and the heat treatment for the adsorbent after drying may use different heat treatment apparatuses, or the drying treatment and the heat treatment may be continuously performed using the same heat treatment apparatus. You may go.

The adsorption / desorption agent obtained as described above is packed in an adsorption tower, and separation and recovery of CO from a mixed gas containing CO are performed by the PSA method or the TSA method. Processing amount of CO containing gas mixture is not particularly limited, is preferably from 2000 m ³ / h, more preferably at most 1000 m ³ / h.

  When CO is separated and recovered by the PSA method, the adsorption pressure in the adsorption process is preferably atmospheric pressure or higher, for example, 0 kPa [gage] to 600 kPa [gage], and the degassing pressure in the deaeration process is less than atmospheric pressure. For example, the degree of vacuum is desirably 30 kPa [abs] to 1.0 kPa [abs]. When CO is separated and recovered by the TSA method, it is desirable that the adsorption temperature in the adsorption step is, for example, about 0 ° C. to 40 ° C., and the deaeration temperature in the deaeration step is, for example, about 60 ° C. to 180 ° C. Further, the PSA method and the TSA method can be used in combination, and the adsorption can be performed at a low temperature under atmospheric pressure and the deaeration can be performed under a high temperature under atmospheric pressure. Since the TSA method is disadvantageous in terms of energy consumption compared to the PSA method, it is desirable to employ the PSA method industrially or the PSA-TSA combined method.

  As the mixed gas containing CO that can be applied, for example, CO-containing hydrogen gas produced through steam reforming using city gas or liquefied petroleum gas (LPG) as a raw material; converter gas generated from a converter at a steelworks Used.

The CO adsorption / desorption phenomenon by the solid adsorbent / desorbent obtained by the method of the present invention is mainly caused by a reversible chemical reaction (complex formation reaction) between a copper compound obtained by reducing a copper (II) compound supported on a carrier and CO. Dissociation reaction) (no chemical reaction with N ₂ and CO ₂ takes place), and secondarily based on physical adsorption and desorption from CO on the pore surface of the support It is thought to be a thing.

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to the following examples, and may be appropriately modified and implemented within a range that can meet the purpose described above and below. All of which are within the scope of the present invention.

Method for Measuring Cu Content in CO Adsorbent / Desorbent After the CO adsorbent was finely pulverized, a mixed solution of sulfuric acid and nitric acid was added to thermally decompose carbon at 350 ° C. and to dissolve the copper compound. This solution was diluted with water and filtered, and the filtrate was subjected to quantitative analysis by ICP (inductively coupled plasma) emission analysis to determine the Cu content of the CO adsorbent.

Evaluation Method of Reversible CO Adsorption Performance The amount of reversible CO adsorption was measured using a high-accuracy specific surface area / pore distribution measuring device (“BELSORP-max” manufactured by Nippon Bell Co., Ltd.). In the measurement, a dedicated cell of the apparatus is filled with an adsorption / desorption agent, and after evacuation (10 ⁻⁶ Pa) at 200 ° C. for 1 hour, CO is adsorbed at 40 ° C. and 10 kPa, and then the exhaust pressure is reduced (about 10 ⁻² kPa). ) Was repeated, and two kinds of CO reversible adsorption amounts between 80 kPa and 0.02 kPa and between 7 kPa and 0.02 kPa were measured. In these measurements, the CO concentration in the raw material gas is assumed to be 80% by volume between 80 kPa and 0.02 kPa, and the CO concentration in the raw material gas is assumed to be 7% by volume between 7 kPa and 0.02 kPa. is there.

Production Example 1
In a 200 mL Erlenmeyer flask, 44.0 g of copper (II) chloride dihydrate (manufactured by Kishida Chemical Co., Ltd., special grade reagent), 22.8 g of aluminum nitrate nonahydrate (manufactured by Kishida Chemical Co., Ltd., special grade reagent), sucrose (Kishida Chemical Co., Ltd.) A solution was prepared by dissolving 10.4 g (special grade reagent, manufactured by Kagakusha) in 32 g of demineralized water heated to 40 ° C. To this solution, a porous carrier made of activated alumina previously dried at 120 ° C. for 4 hours or more (manufactured by Sumitomo Chemical Co., Ltd., activated alumina (product name “NKHD-24”, particle diameter: 2 mm to 4 mm, pore volume: 0.35 cm) ³ / g, was placed a specific surface area of 300m ² / g)) and 80.0 g (volume 122 ml), was impregnated with 60 minutes with occasional swirling liquid. The flask was put in a 1 L eggplant-shaped flask, attached to a rotary evaporator, and rotated by 30 rpm, and the flask was dried by heating in an oil bath under a flow of N ₂ -400 mL / min. The temperature condition of the oil bath was raised to 140 ° C. (flask internal temperature 120 ° C.) over 1 hour, held at 140 ° C. for 5 hours, and then naturally cooled. The cooled adsorbent is transferred to a magnetic dish, placed in an externally heated tube furnace, heated to 230 ° C. at 5 ° C./min under an N ₂ -400 mL / min air flow, held for 10 hours, and then naturally cooled to absorb CO A desorbent was obtained.

Production Example 2
The same procedure as in Production Example 1 except that the amount of aluminum nitrate nonahydrate was changed to 11.4 g, the amount of sucrose was changed to 5.2 g, and the amount of demineralized water was changed to 36 g. A CO adsorption / desorption agent was produced.

Production Example 3
Aluminum nitrate 9hydrate 22.8 g was changed to cerium nitrate hexahydrate (Kishida Chemical Co., Ltd., special grade reagent) 13.2 g, sucrose usage 5.2 g, demineralized water usage 39 g A CO adsorbent / desorbent was produced in the same manner as in Production Example 1 except that

Production Example 4
In a 200 mL Erlenmeyer flask, 44.0 g of copper (II) chloride dihydrate (special grade reagent manufactured by Kishida Chemical Co., Ltd.) and 10.4 g of sucrose (special grade reagent manufactured by Kishida Chemical Co., Ltd.) were heated to 40 ° C. A solution dissolved in 2 g was prepared. To this solution, a porous carrier made of activated alumina previously dried at 120 ° C. for 4 hours or more (manufactured by Sumitomo Chemical Co., Ltd., activated alumina (product name “NKHD-24”, particle diameter: 2 mm to 4 mm, pore volume: 0.35 cm) ³ / g, were placed 80.0g specific surface area 300m ² / g)), impregnated with 60 minutes with occasional swirling liquid. The flask was placed in a 1 L eggplant-shaped flask, attached to a rotary evaporator, and rotated at 30 rpm, and the flask was dried by heating in an oil bath under a flow of N ₂ -200 mL / min. The temperature condition of the oil bath was raised to 140 ° C. (flask internal temperature 120 ° C.) over 1 hour, held at 140 ° C. for 5 hours, and then naturally cooled. The cooled adsorbent is transferred to a magnetic dish, placed in an externally heated tube furnace, heated to 230 ° C. at 5 ° C./min under an N ₂ -400 mL / min air flow, held for 10 hours, and then naturally cooled to absorb CO A desorbent was obtained.

Production Example 5
Aluminum nitrate 9hydrate 22.8g was changed to zirconium nitrate dihydrate (special grade reagent manufactured by Kishida Chemical Co., Ltd.) 8.1g, sucrose usage 5.2g, demineralized water usage 41g A CO adsorbent / desorbent was produced in the same manner as in Production Example 1 except that

As shown in Table 1, the adsorption / desorption agent obtained in Production Examples 2 and 3 is assumed to have a CO concentration of 7% by volume as compared with the adsorption / desorption agent obtained in Production Example 4 in which no carrier precursor is used. In both the reversible CO adsorption test and the CO reversible adsorption test assuming a CO concentration of 80% by volume, the adsorption amount per 1 mol of copper is increased. From these results, it is understood that the dispersion of the copper salt is promoted by using the carrier precursor, and the copper adsorption performance is further exhibited.
In the adsorption / desorption agent obtained in Production Example 1, the amount of adsorption per 1 mol of copper is higher than that in Production Example 4 in the CO reversible adsorption amount test assuming a CO concentration of 80% by volume. In the CO reversible adsorption amount test assuming a CO concentration of 7% by volume, the adsorption amount per 1 mol of copper was almost the same as in Production Example 4. This is presumably because the use of the support precursor promoted the dispersion of the reducing agent as well as the copper salt, and as a result, the surface of the copper salt was coated with the thermal decomposition product of the reducing agent.
Production Example 5 is a case where zirconium nitrate was used as the carrier precursor. However, in the CO reversible adsorption amount test assuming a CO concentration of 80% by volume, the adsorption amount per 1 mol of copper was greatly inferior to that of Production Example 4. It was. This is presumably because the carrier precursor is not sufficiently dispersed in the porous carrier.

  The present invention is suitable as a method for producing a CO separation recovery adsorption / desorption agent.

Claims (4)

Aluminum nitrate, support precursor is at least one selected from the group consisting of cerium nitrate and cerium acetate, copper (II) compound, a liquid containing a reducing agent and a solvent, after contacting the porous support, a solvent A method for producing a CO adsorbing and desorbing agent, characterized by removing the carbon and baking. The method for producing a CO adsorption / desorption agent according to claim 1, wherein the amount of the carrier precursor used is 0.1 mmol to 0.7 mmol with respect to 1 ml of the volume of the porous carrier. The method for producing a CO adsorption / desorption agent according to claim 1 or 2 , wherein the reducing agent is at least one selected from the group consisting of sugars, aldehydes, carboxylic acids, and metal salts in a low valence state. The method for producing a CO adsorption / desorption agent according to any one of claims 1 to 3 , wherein the porous carrier is a carrier made of alumina and / or a carrier made of a silica-alumina composite.