TW202308940A - Method and apparatus for producing carbon monoxide - Google Patents

Abstract

A method for producing carbon monoxide, the method comprising a step in which carbon monoxide is produced by a decomposition reaction of at least one of formic acid and a formic acid alkyl ester in the presence of a solid acid catalyst, wherein the total pore volume of pores having a pore diameter of 2 nm or less in the solid acid catalyst is 0.23 cm3/g or less.

Description

Carbon monoxide production method and production device

The invention relates to a method and device for producing carbon monoxide.

Conventionally, methods for producing carbon monoxide include a method of producing carbon monoxide by steam reforming natural gas, a method of producing carbon monoxide by contacting oxygen with light hydrocarbons in the presence of a partial oxidation catalyst, and decomposing formic acid to produce carbon monoxide. A method for producing carbon monoxide, etc. Among them, carbon monoxide is obtained with a high selectivity, so a method of decomposing formic acid to produce carbon monoxide is advantageous. As a method of decomposing formic acid to produce carbon monoxide, a method using mineral acid, a method using a solid acid catalyst, and the like are known. Among them, a method using a solid acid catalyst is expected as a method capable of producing carbon monoxide at a high conversion rate. For example, Patent Document 1 below discloses a method of reducing the concentration of hydrogen in carbon monoxide by decomposing formic acid using a solid acid catalyst to generate carbon monoxide and performing a purification step using a palladium catalyst or the like on the generated carbon monoxide.

[Patent Document 1] Korean Laid-Open Patent No. 2016-0173781

However, the method described in the above-mentioned Patent Document 1 has the following problems. That is, in the method described in the above-mentioned Patent Document 1, in order to reduce the hydrogen concentration, a purification step using a palladium catalyst or the like is performed on carbon monoxide generated by the decomposition of formic acid. Therefore, the method described in the above-mentioned Patent Document 1 has room for improvement in terms of efficiently producing high-purity carbon monoxide with low components. Therefore, there is a demand for a carbon monoxide production method and production apparatus capable of sufficiently reducing the hydrogen concentration in the produced carbon monoxide without performing a purification step for removing hydrogen.

Therefore, an object of the present invention is to provide a carbon monoxide production method and production apparatus capable of sufficiently reducing the hydrogen concentration in the produced carbon monoxide without performing a purification step for removing hydrogen.

The inventors of the present invention conducted intensive studies in order to solve the above-mentioned problems. Specifically, the study focused on the total pore volume of the solid acid catalyst. Generally, solid acids have fine pores for adsorbing molecules. For example, zeolite is a solid acid having pores having a pore diameter of 2 nm or less, that is, micropores, and adsorbs molecules smaller than the diameter. In addition, since the catalyst has a porous structure, most of the active points exist in the pores, and react with the raw material molecules through the contact between the active points and the raw material molecules. Therefore, generally, the larger the total pore volume, the greater the amount of raw material molecules adsorbed to the solid acid, so the total pore volume becomes larger, thereby effectively decomposing the raw material. The selectivity in carbon monoxide does not decrease the concentration of hydrogen, an impurity in the production of carbon monoxide. Surprisingly, however, it was found that the concentration of hydrogen in the production of carbon monoxide decreased when the total pore volume of the solid acid catalyst was small. Therefore, as a result of intensive research based on such knowledge, the present inventors have found that the above-mentioned problems can be solved by the following disclosure.

That is, one aspect of the present invention is a method for producing carbon monoxide, which includes the step of generating carbon monoxide by decomposing at least one raw material of formic acid or alkyl formate in the presence of a solid acid catalyst. In the acid catalyst, the total pore volume of pores having a pore diameter of 2 nm or less is 0.23 cm ³ /g or less. According to the present invention, in a solid acid catalyst, compared with the case where the total pore volume of the pores having a pore diameter of 2 nm or less exceeds 0.23 cm ³ /g, it can be sufficiently reduced without performing a purification step for removing hydrogen. Manufactures the concentration of hydrogen in carbon monoxide. Therefore, according to the method for producing carbon monoxide of the present invention, high-purity carbon monoxide can be produced efficiently and at low cost. Alternatively, according to the present invention, in the solid acid catalyst, the conversion rate of the raw material can be increased compared to the case where the total pore volume of the pores having a pore diameter of 2 nm or less exceeds 0.23 cm ³ /g. Therefore, according to the manufacturing method of carbon monoxide of this invention, carbon monoxide can be manufactured efficiently.

In the above method for producing carbon monoxide, in the solid acid catalyst, the total pore volume of pores having a pore diameter of 2 nm or less is preferably 0.20 cm ³ /g or less. In this case, the conversion rate of the raw material can be further increased, and the hydrogen concentration in the production of carbon monoxide can be reduced more sufficiently without performing a purification step for removing hydrogen.

In the above-mentioned method for producing carbon monoxide, in the above-mentioned solid acid catalyst, the total pore volume of pores having a pore diameter of 2 nm or less is more preferably 0.19 cm ³ /g or less. In this case, the conversion rate of the raw material can be increased, and the hydrogen concentration in the production of carbon monoxide can be reduced more sufficiently without performing a purification step for removing hydrogen.

In the above method for producing carbon monoxide, the solid acid catalyst is, for example, a proton-type zeolite.

In the above method for producing carbon monoxide, it is preferable that the Si/Al atomic ratio of the proton type zeolite is 1-200. In this case, the catalytic activity of the zeolite can be further increased, and the conversion rate of the raw material can be further increased.

In the above-mentioned production method of carbon monoxide, it is preferable to carry out the decomposition reaction of the above-mentioned raw materials at 100-300°C. In this case, there is a tendency that the hydrogen concentration in the produced carbon monoxide can be further sufficiently reduced and the decomposition reaction can be efficiently performed.

Another aspect of the present invention is a production device for carbon monoxide, which generates carbon monoxide through the decomposition reaction of at least one raw material of formic acid or alkyl formate in the presence of a solid acid catalyst, and is equipped with accommodating the solid acid catalyst and A reactor for generating carbon monoxide by the decomposition reaction of the aforementioned raw material in the presence of the aforementioned solid acid catalyst, wherein the total pore volume of pores having a pore diameter of 2 nm or less in the aforementioned solid acid catalyst is 0.23 cm ³ / below g. According to this carbon monoxide production device, if carbon monoxide is generated by the decomposition reaction of at least one raw material of formic acid or alkyl formate in the presence of a solid acid catalyst in a reactor, then it has a pore diameter of 2 nm or less Compared with the case where the total pore volume of the pores exceeds 0.23 cm ³ /g, the hydrogen concentration in the production of carbon monoxide can be sufficiently reduced without performing a purification step for removing hydrogen. Therefore, according to the carbon monoxide production apparatus of the present invention, high-purity carbon monoxide can be produced efficiently and at low cost. Or, according to the above-mentioned production device of carbon monoxide, if carbon monoxide is generated by the decomposition reaction of at least one raw material in formic acid or alkyl formate in the presence of a solid acid catalyst in the reactor, then in the solid acid catalyst , compared with the case where the total pore volume of pores having a pore diameter of 2 nm or less exceeds 0.23 cm ³ /g, the conversion rate of the raw material can be increased. Therefore, according to the manufacturing apparatus of carbon monoxide of this invention, carbon monoxide can be manufactured efficiently.

In the above carbon monoxide production apparatus, in the solid acid catalyst, the total pore volume of pores having a pore diameter of 2 nm or less is preferably 0.20 cm ³ /g or less. In this case, the conversion rate of the raw material can be further increased, and the hydrogen concentration in the production of carbon monoxide can be reduced more sufficiently without performing a purification step for removing hydrogen. [Invention effect]

According to the present invention, it is possible to provide a carbon monoxide production method and production apparatus capable of sufficiently reducing the hydrogen concentration in the produced carbon monoxide without performing a purification step for removing hydrogen.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

A method for producing carbon dioxide according to the present invention includes the step of generating carbon monoxide by decomposing at least one raw material of formic acid or alkyl formate in the presence of a solid acid catalyst. As the solid acid catalyst, a solid acid catalyst having pores having a pore diameter of 2 nm or less (hereinafter also referred to as “micropores”) and a total pore volume of 0.23 cm ³ /g or less can be used. The method for producing carbon monoxide according to the present invention can be carried out, for example, by a carbon monoxide producing apparatus equipped with a reactor that accommodates the above-mentioned solid acid catalyst and generates carbon monoxide by decomposition reaction of raw materials in the presence of the solid acid catalyst.

(solid acid catalyst) The solid acid catalyst is not particularly limited, and as the solid acid catalyst, for example, a proton type zeolite is preferably used. Examples of proton-type zeolites include zeolites such as mordenite, ZSM-5, β-type, Y-type, and US-Y-type. As the proton type zeolite catalyst, for example, a high silica zeolite catalyst manufactured by TOSOH CORPORATION, etc. can be used.

In the solid acid catalyst, the total pore volume of micropores is 0.23 cm ³ /g or less. In the solid acid catalyst, if the total pore volume of the micropores is 0.23 cm ³ /g or less, then compared with the case of using a solid acid catalyst whose total pore volume exceeds 0.23 cm ³ /g, it is not Performing a purification step to remove hydrogen can substantially reduce the hydrogen concentration in the carbon monoxide produced. Alternatively, in the solid acid catalyst, the conversion rate of the raw material can be increased compared to the case where the total pore volume of the pores having a pore diameter of 2 nm or less exceeds 0.23 cm ³ /g. Therefore, according to the manufacturing method of carbon monoxide of this invention, carbon monoxide can be manufactured efficiently. From the standpoint of improving the conversion rate of the raw material and further reducing the hydrogen concentration in the production of carbon monoxide without performing a purification step for removing hydrogen, the total pore volume of the micropores of the solid acid catalyst is preferably 0.20 cm ³ /g or less , more preferably 0.19 cm ³ /g or less, still more preferably 0.18 cm ³ /g or less, particularly preferably 0.15 cm ³ /g or less. However, in the solid acid catalyst, the total pore volume of the micropores is preferably at least 0.10 cm ³ /g, more preferably at least 0.12 cm ³ /g. In the solid acid catalyst, when the total pore volume of the micropores is 0.10 cm ³ /g or more, the decomposition reaction of the raw material proceeds more easily, and as a result, the conversion rate of the raw material tends to further increase.

The pore diameter refers to one of the measurement results obtained by using BELSORP-MAX (manufactured by MicrotracBEL Corp.) as an analysis device and BELMaster (manufactured by MicrotracBEL Corp.) as an analysis software and analyzed by the SF method under the following conditions The value dp. (Conditions) Measurement temperature: -196°C Adsorbent: Nitrogen equilibrium Adsorption time: 300 seconds Pretreatment conditions for solid acid catalyst: Heat treatment ( ³⁵⁰ °C , 5h)

The total pore volume of pores having a pore diameter of 2 nm or less is the integrated value ΣVp of the pore volume that can be analyzed and calculated by the SF method in the same manner as the aforementioned pore diameter, and the pore diameter dp calculated as above is 2 nm The following values.

The Si/Al atomic ratio of the proton-type zeolite used as a solid acid catalyst is not particularly limited, but is preferably 1 or more, more preferably 5 or more. When the Si/Al atomic ratio is 1 or more, the catalytic activity of the zeolite tends to be further improved and the conversion rate of the raw material tends to be improved. The Si/Al atom ratio is preferably 200 or less, more preferably 150 or less, still more preferably 100 or less, particularly preferably 50 or less. When the Si/Al atomic ratio is 200 or less, the catalytic activity of the zeolite tends to be further improved and the conversion rate of the raw material tends to be improved. Therefore, the Si/Al atomic ratio of the proton type zeolite is preferably 1 to 200 from the viewpoint of improving the conversion rate of the raw material. In particular, in solid acid catalysts, when the total pore volume of micropores is less than 0.19 cm ³ /g, the Si/Al atomic ratio is preferably 5-100, more preferably 5-50, and 5-50. 30 is still more preferable, and 5-20 is especially preferable. In solid acid catalysts, when the total pore volume of micropores is less than 0.19 cm ³ /g, if the Si/Al atomic ratio is 5 to 100, the conversion rate of the raw material is significantly improved. In addition, Si/Al atomic ratio can be calculated|required by the measurement by the solid-state NMR method.

(raw material) Examples of raw materials include formic acid and alkyl formate. These can be used alone or can also be used as a mixture. Examples of the alkyl formate include methyl formate and ethyl formate.

(decomposition reaction) The decomposition reaction of the raw material is carried out by bringing the raw material into contact with a solid acid catalyst and heating to decompose it. Alternatively, the decomposition reaction of the raw material can also be carried out by bringing the raw material into contact with a solid acid catalyst previously modified with mineral acid and heating to decompose it. The contact between the raw material and the solid acid catalyst can be performed, for example, by bringing gas or liquid containing the raw material into contact with the solid acid catalyst. When the gas containing the raw material is brought into contact with the solid acid catalyst, the gas containing the vapor of the raw material is generated from the solution containing the raw material using a vaporizer or the like, and supplied to the solid acid catalyst for contact. The contact of the raw material and the solid acid catalyst is preferably performed by bringing the gas containing the raw material into contact with the solid acid catalyst. In this case, there exists a tendency for the efficiency of a decomposition reaction to improve. Furthermore, in the case of using a liquid containing raw materials, the concentration of the raw materials in the liquid is not particularly limited, but from the viewpoint of energy efficiency, based on the mass of the solution (100% by mass), preferably 40% by mass or more . As a liquid containing a raw material, formic acid aqueous solution is mentioned, for example.

As the reactor, a reaction tank or a reaction tower filled with a catalyst can be used. In the case of using a reactor as the reactor, the catalyst and raw materials may be put into the reactor and heated to generate carbon monoxide. In the case of using a reaction tower filled with a catalyst as the reactor, for example, carbon monoxide may be generated by passing steam of a raw material to the catalyst filled in the reaction tower and heating. In consideration of reaction efficiency, it is preferable to use a reaction tower filled with a catalyst as a reactor. One reaction tower may be used, or a plurality of reaction towers may be connected. A reactor composed of a plurality of reaction towers is advantageous in suppressing variation in flow velocity distribution in the reactor and securing a heat transfer area for heating. Furthermore, in the case of continuously supplying gas or liquid including raw materials to a reactor, generally, the reactor has an inlet and an outlet for supplying or discharging the gas or liquid, and these are connected to an external flow path.

The reactor is made of, for example, non-metallic materials such as carbon. Reactors made of non-metallic materials are less likely to be corroded by raw materials and carbon monoxide, and less likely to affect the reaction. When the temperature (reaction temperature) at which the decomposition reaction of the raw material proceeds is relatively low (for example, 100 to 200° C.), a reactor having a surface treated with a glass lining can also be used as the reactor.

The space velocity (SV: SpaceVelocity) of the gas containing the raw material (hereinafter referred to as "raw material gas") is not particularly limited, but is preferably 1000 [1/h] or less. From the viewpoint of further improving the conversion rate of the raw material, the SV is more preferably 280 [1/h] or less, and particularly preferably 240 [1/h] or less. However, the SV is preferably at least 0.1 [1/h], more preferably at least 100 [1/h], and particularly preferably at least 200 [1/h]. The space velocity of the raw material gas is a value measured by a standard conversion standard. The space velocity of the source gas can be calculated, for example, from the supply rate (g/h) of the source gas, the volume of the solid acid catalyst, and the like according to the following formula. Space velocity of raw gas [1/h] = Supply rate of raw material gas (g/h) × 0.01 × Concentration of at least one of formic acid or alkyl formate in the raw material gas (% by weight) ÷Molecular weight of formic acid or alkyl formate (raw material) (g/mol) × standard state volume 22.4 (NL/mol) ÷Volume of solid acid catalyst (L) Furthermore, when the raw material gas is a gas obtained by vaporizing a liquid containing raw materials (hereinafter referred to as "raw material liquid"), "at least one of formic acid or alkyl formate in the raw material liquid" The concentration of "is set as "the concentration of at least one of formic acid or alkyl formate in the raw material gas".

The reaction temperature should just be a temperature at which the raw materials can be decomposed, and is preferably 100 to 300°C, more preferably 100 to 200°C. By setting the reaction temperature to 100 to 300° C., there is a tendency that the reaction can be efficiently performed while reducing the hydrogen concentration in the produced carbon monoxide more sufficiently and suppressing the generation of by-products such as hydrogen. As a reactor, for example, a reaction tower filled with a catalyst is used, and when a heater is provided around the solid acid catalyst, the set temperature of the heater is set as the reaction temperature. The decomposition reaction of the raw material is generally carried out in a state where the catalyst, the raw material or both are heated to the above-mentioned temperature.

The generated carbon monoxide sometimes contains trace amounts of hydrogen, carbon dioxide and methane as by-products besides water. Therefore, the production method of carbon monoxide may further include a step of removing unreacted raw materials and by-products from the carbon monoxide taken out from the reactor and a step of removing water from the carbon monoxide. Raw materials and by-products can be removed by general cleaning methods, so that high-purity carbon monoxide can be obtained. Raw materials and carbon dioxide can be easily removed, for example, by caustic soda. Water can be removed, for example, by cooling and adsorption to a dehydrating material. Through these steps, the purity of carbon monoxide after removal of water, raw materials, and by-products can also be set to 99.99% or more. Such high-purity carbon monoxide can be used in various applications including the semiconductor manufacturing field.

Fig. 1 is a schematic diagram showing an embodiment of the carbon monoxide production apparatus of the present invention. As shown in FIG. 1 , a carbon monoxide production device 10 of the present invention includes a reactor 1 and a solid acid catalyst 2 accommodated in the reactor 1 . As the reactor 1, the above-mentioned reactor can be used, and as the solid acid catalyst 2, the above-mentioned solid acid catalyst can be used. The reactor 1 has an inlet 1a and an outlet 1b for supplying or discharging gas or liquid. Outside the reactor 1, a flow path 3 for supplying at least one of formic acid or an alkyl formate is connected to the inlet 1a, and a flow path 4 for discharging gas or liquid is connected to the outlet 1b. The production device 10 of carbon monoxide may also be equipped with a heating device (not shown) for heating the solid acid catalyst 2, the raw material, or both, and a device for removing unreacted raw materials and by-products from the product containing carbon monoxide (not shown). shown) and means for removing water from the product (not shown).

In the production apparatus 10 of carbon monoxide, the raw material is supplied to the reactor 1 through the inlet 1a through the flow path 3, and the solid acid catalyst 2 is passed therethrough. At this time, carbon monoxide is generated by the decomposition reaction of the raw material in the presence of the solid acid catalyst. The product comprising carbon monoxide is discharged from the outlet 1 b of the reactor 1 through the flow path 4 . Carbon monoxide is thus produced.

In addition, the summary of this invention is as follows. [1] A method for producing carbon monoxide, comprising a step of generating carbon monoxide by decomposition reaction of at least one raw material of formic acid or alkyl formate in the presence of a solid acid catalyst, and in the solid acid catalyst , the total pore volume of pores having a pore diameter of 2 nm or less is 0.23 cm ³ /g or less. [2] The method for producing carbon dioxide according to [1], wherein in the solid acid catalyst, the total pore volume of the pores is 0.20 cm ³ /g or less. [3] The method for producing carbon monoxide according to [2], wherein in the solid acid catalyst, the total pore volume of the pores is 0.19 cm ³ /g or less. [4] The method for producing carbon dioxide according to any one of [1] to [3], wherein the solid acid catalyst is a proton-type zeolite. [5] The method for producing carbon monoxide according to [4], wherein the Si/Al atomic ratio of the proton-type zeolite is 1-200. [6] The method for producing carbon dioxide according to any one of [1] to [5], wherein the decomposition reaction of the raw material is carried out at 100 to 300°C. [7] A production device for carbon monoxide, which generates carbon monoxide by decomposition reaction of at least one raw material of formic acid or alkyl formate in the presence of a solid acid catalyst, and has a device for accommodating the solid acid catalyst and in the aforementioned A reactor for generating carbon monoxide by decomposition reaction of the aforementioned raw material in the presence of a solid acid catalyst, in which the total pore volume of pores having a pore diameter of 2 nm or less is 0.23 cm ³ /g or less . [8] The apparatus for producing carbon dioxide according to [7], wherein in the solid acid catalyst, the total pore volume of the pores is 0.20 cm ³ /g or less. [Example]

Hereinafter, an Example is given and this invention is demonstrated further concretely. However, the present invention is not limited to the following examples.

(Example 1) A zeolite catalyst (manufactured by TOSOH CORPORATION, Si/Al atomic ratio: 12, micro Total pore volume of pores: 0.15 cm ³ /g). The amount of the zeolite catalyst used was set at 40 g (49 mL). The column filled with the catalyst was heated from the outside with a heater set at 175°C, and was fed from one end of the column at a feed rate of 31g/h through the gasifier with an aqueous formic acid solution with a concentration of 76% by weight. To generate the vapor of formic acid at 120°C. In this way, the vapor of formic acid is brought into contact with the solid acid catalyst to carry out a decomposition reaction, thereby generating carbon monoxide gas. At this time, the space velocity of the vapor (raw material gas) of formic acid was 234 [1/h] on the standard conversion basis. Then, carbon dioxide discharged from the other end of the column was passed through in this order of a caustic soda aqueous solution having a concentration of 20% by weight and water. The trace amount of carbon dioxide contained in carbon monoxide is removed by caustic soda aqueous solution. After cooling and drying the carbon monoxide passed through the caustic soda aqueous solution and water, the amount of hydrogen in the carbon monoxide was quantified by gas chromatography with a PDD (Pulsed Discharge Detector) as a detector, and calculated From the obtained amount of hydrogen and the flow rate of carbon monoxide, the conversion rate of formic acid (raw material), the selectivity to carbon monoxide and the concentration of hydrogen were obtained. Moreover, the improvement rate of the conversion rate based on Example 3 was calculated. The results are shown in Table 1. As shown in Table 1, the conversion rate of formic acid (raw material) was 89%, and the improvement rate of the conversion rate based on Example 3 was 178%. Also, the selectivity to carbon monoxide was 99.99% or higher, and the hydrogen concentration was 1.8 ppm. In addition, the total pore volume of the pores of the solid acid catalyst was measured under the following conditions using BELSORP-MAX (manufactured by MicrotracBEL Corp.) as an analyzer. (Conditions) Measurement temperature: -196°C Adsorbent: Nitrogen equilibrium Adsorption time: 300 seconds Pretreatment conditions for solid acid catalyst: Heat treatment ( ³⁵⁰ °C , 5h)

(Example 2) As a solid acid catalyst packed in a column, 39 g (49 mL) of a zeolite catalyst (manufactured by TOSOH CORPORATION, Si/Al atomic ratio: 110, total pore volume of micropores: 0.19 cm ³ ) was used /g), except that, the reaction was carried out in the same manner as in Example 1 to generate carbon monoxide. Furthermore, in the same manner as in Example 1, the conversion rate of formic acid (raw material), the selectivity rate to carbon monoxide, and the hydrogen concentration were obtained. Moreover, the improvement rate of the conversion rate based on Example 3 was calculated. The results are shown in Table 1. As shown in Table 1, the conversion rate of formic acid (raw material) is 60%, and the improvement rate of the conversion rate based on Example 3 is 88%. Also, the selectivity to carbon monoxide was 99.99% or higher, and the hydrogen concentration was 4.9 ppm.

(Example 3) As the solid acid catalyst packed in the column, 34 g (49 mL) of a zeolite catalyst (manufactured by TOSOH CORPORATION, Si/Al atomic ratio: 15, total pore volume of micropores: 0.23 cm ³ was used /g), except that, the reaction was carried out in the same manner as in Example 1 to generate carbon monoxide. Furthermore, in the same manner as in Example 1, the conversion rate of formic acid (raw material), the selectivity rate to carbon monoxide, and the hydrogen concentration were obtained. Moreover, the improvement rate of the conversion rate based on Example 3 was calculated. The results are shown in Table 1. As shown in Table 1, the conversion rate of formic acid (raw material) was 32%, and the improvement rate of the conversion rate based on Example 3 was 0%. Also, the selectivity to carbon monoxide was 99.99% or higher, and the hydrogen concentration was 11 ppm.

(Comparative Example 1) As the solid acid catalyst packed in the column, 35 g (49 mL) of zeolite catalyst (manufactured by TOSOH CORPORATION, Si/Al atomic ratio: 3, total pore volume of micropores: 0.25 cm ³ was used. /g), except that, the reaction was carried out in the same manner as in Example 1 to generate carbon monoxide. Furthermore, in the same manner as in Example 1, the conversion rate of formic acid (raw material), the selectivity rate to carbon monoxide, and the hydrogen concentration were obtained. Moreover, the improvement rate of the conversion rate based on Example 3 was calculated. The results are shown in Table 1. As shown in Table 1, the conversion rate of formic acid (raw material) was 21%, and the improvement rate of the conversion rate based on Example 3 was -34%. Also, the selectivity to carbon monoxide was 99.93% or higher, and the hydrogen concentration was 644 ppm.

(Comparative Example 2) As the solid acid catalyst packed in the column, 32 g (49 mL) of zeolite catalyst (manufactured by TOSOH CORPORATION, Si/Al atomic ratio: 3, total pore volume of micropores: 0.24 cm ³ was used. /g), except that, the reaction was carried out in the same manner as in Example 1 to generate carbon monoxide. Furthermore, in the same manner as in Example 1, the conversion rate of formic acid (raw material), the selectivity rate to carbon monoxide, and the hydrogen concentration were obtained. Moreover, the improvement rate of the conversion rate based on Example 3 was calculated. The results are shown in Table 1. As shown in Table 1, the conversion rate of formic acid (raw material) was 22%, and the improvement rate of the conversion rate based on Example 3 was -31%. Also, the selectivity to carbon monoxide was 99.99% or higher, and the hydrogen concentration was 90 ppm.

[Table 1] solid acid catalyst Raw material conversion rate Ratio of improvement in the conversion rate of raw materials (based on Example 3) selectivity hydrogen concentration Total pore volume of micropores (cm ³ /g) Si/Al atomic ratio % % % ppm Example 1 0.15 12 89 178 99.99 or more 1.8 Example 2 0.19 110 60 88 99.99 or more 4.9 Example 3 0.23 15 32 0 99.99 or more 11 Comparative example 1 0.25 3 twenty one -34 99.99 or more 644 Comparative example 2 0.24 3 twenty two -31 99.99 or more 90

FIG. 2 shows the relationship between the total pore volume of the micropores and the hydrogen concentration in the solid acid catalyst of Examples 1 to 3 or Comparative Example 1. FIG. From the results shown in Table 1 and FIG. 2 , it can be seen that, compared with Examples 1-3 and Comparative Example 1, the concentration of hydrogen in carbon monoxide was significantly reduced. Therefore, it has been confirmed that if the total pore volume of the micropores in the solid acid catalyst is set to be 0.23 cm ³ /g or less, the total pore volume of the micropores in the solid acid catalyst exceeds 0.23 cm ³ /g. In contrast, the hydrogen concentration in the production of carbon monoxide can be substantially reduced without the purification step for removing hydrogen.

3 shows the relationship between the total pore volume of the micropores and the conversion rate of the raw material in the solid acid catalysts of Examples 1-3 or Comparative Examples 1-2. From the results shown in Table 1 and FIG. 3 , it can be seen that the conversion rate of the raw material was significantly higher than that of Examples 1-3 and Comparative Examples 1-2. Therefore, it has been confirmed that if the total pore volume of the micropores in the solid acid catalyst is 0.20 cm ³ /g or less, the total pore volume of the micropores in the solid acid catalyst exceeds 0.20 cm ³ /g. Compared with the situation, the conversion rate of raw materials can be further improved.

1: Reactor 1a: entrance 1b: Export 2: Solid acid catalyst 3,4: flow path 10: Manufacturing device of carbon monoxide

[ Fig. 1 ] is a schematic diagram showing one embodiment of the production apparatus of carbon monoxide of the present invention. [ Fig. 2 ] is a graph showing the relationship between the hydrogen concentration and the total pore volume of pores having a pore diameter of 2 nm or less in Examples 1 to 3 and Comparative Example 1. [ Fig. 3 ] is a graph showing the relationship between the conversion rate of raw materials and the total pore volume of pores having a pore diameter of 2 nm or less in Examples 1 to 3 and Comparative Example 1.

1: Reactor

1a: entrance

1b: Export

2: Solid acid catalyst

3: flow path

4: flow path

10: Manufacturing device of carbon monoxide

Claims (8)

A method for producing carbon monoxide, which includes the step of generating carbon monoxide through the decomposition reaction of at least one raw material of formic acid or alkyl formate in the presence of a solid acid catalyst, and in the aforementioned solid acid catalyst, having 2nm The total pore volume of pores having a pore diameter of not more than 0.23 cm ³ /g is not more than 0.23 cm 3 /g. The method for producing carbon monoxide according to claim 1, wherein in the solid acid catalyst, the total pore volume of the pores is 0.20 cm ³ /g or less. The method for producing carbon monoxide according to claim 2, wherein in the solid acid catalyst, the total pore volume of the pores is 0.19 cm ³ /g or less. The method for producing carbon monoxide according to claim 1, wherein, The aforementioned solid acid catalyst is a proton type zeolite. The method for producing carbon monoxide as described in Claim 4, wherein, The Si/Al atomic ratio of the proton type zeolite is 1-200. A method for producing carbon dioxide as described in any one of claim 1 to claim 5, wherein, The decomposition reaction of the aforementioned raw materials is carried out at 100-300°C. A production device for carbon monoxide, which generates carbon monoxide by decomposing at least one raw material of formic acid or alkyl formate in the presence of a solid acid catalyst, and has a device that accommodates the solid acid catalyst and acts on the solid acid catalyst In the solid acid catalyst, the total pore volume of pores having a pore diameter of 2 nm or less is 0.23 cm ³ /g or less. The apparatus for producing carbon dioxide according to claim 7, wherein in the solid acid catalyst, the total pore volume of the pores is 0.20 cm ³ /g or less.

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