JP2002274809A - Chemical reaction apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chemical reaction apparatus which is capable of recovering hydrogen with a high recovery rate from gaseous raw material and is decreased in the consumption of carbon dioxide absorptive materials and the heating quantity necessary for regeneration of the same. SOLUTION: This apparatus includes a first reaction region where solid catalysts are housed, a second reaction region which is arranged behind this first reaction region and where chemical absorbents for selectively absorbing carbon dioxide and the solid catalysts are housed and heating means for heating the second reaction region. In the first reaction region, hydrogen which is main formed gas and the carbon dioxide which is by-product gas are formed by causing the chemical reaction of the gaseous raw material. The gases generated in the first reaction region are introduced into the second reaction region, where the chemical reaction and the absorption of the carbon dioxide are effected. The weight of the solid catalysts housed into the first reaction region is >=0.4 to <=2.0 times.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical reaction apparatus, and more particularly, to a chemical reaction apparatus that separates carbon dioxide generated as a by-product in a chemical reaction to increase the recovery of hydrogen generated as a main component. About.

[0002]

2. Description of the Related Art There are many well-known reactions in which hydrogen is produced as a main product gas and carbon dioxide is produced as a by-product gas. Are being considered. For example, fossil fuels used in thermal power generation systems are mainly composed of hydrocarbons, and most of the carbon components become carbon dioxide with combustion. As such a method of recovering carbon dioxide,
It has been studied to separate fossil fuels by reacting fossil fuels before combustion to produce hydrogen and the by-product carbon dioxide or carbon monoxide. (See, for example, JP-A-11-26398
No. 8). Alternatively, in a chemical industry process, a process using a shift reaction in which carbon monoxide and water are reacted to generate hydrogen as a main product and carbon dioxide as a by-product is used. In these, hydrogen, which is the main product gas, is used as fuel or raw material,
It is required to increase the recovery rate.

In a reaction in which carbon dioxide is generated as a by-product, such as a reforming reaction and a shift reaction, the chemical equilibrium shifts to a side where a main product is generated by removing carbon dioxide from a reaction field. This makes it possible to increase the recovery rate of the gas as the main product. In order to separate carbon dioxide from gas, a chemical absorption process using an alkanolamine-based solvent or the like, a method such as a pressure swing method, a cryogenic separation method, and a membrane separation method are used. However, the upper limit of the introduced gas temperature needs to be suppressed to about 200 ° C. or less in any of the methods because of the heat resistance of a material such as a membrane and a solvent used for carbon dioxide separation. Since the reforming reaction and the shift reaction are performed at a temperature of 400 ° C. or higher, it has been difficult to remove carbon dioxide from the reaction field by the conventional method.

[0004] In such a situation, by filling a reactor for performing a reforming reaction or a shift reaction with an inorganic absorbent,
There is disclosed a method for efficiently obtaining a main product by removing carbon dioxide from a high-temperature reaction field exceeding 400 ° C. (for example, JP-A-10-152302). For example, steam reforming of methane is represented by the following reaction formula (1):
It is an endothermic reaction.

[0005]

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At this time, by removing carbon dioxide from the reaction field using the inorganic absorbent, the reaction equilibrium of the reaction formula (1) is shifted to the rightward reaction, and the recovery rate of hydrogen is improved. Usually, this reaction is carried out at 800 ° C. or higher, but it is possible to proceed at a lower temperature by shifting this chemical equilibrium.
Recently, research has been conducted on lithium silicate as an inorganic filler (Japanese Patent Application No. 2000-262).
89 etc.). This material has a high carbon dioxide absorption rate and is used as a material particularly suitable for such an application. Lithium silicate is decomposed into lithium carbonate and a compound containing silicon as shown in the following reaction formula (2) or (3) in the presence of carbon dioxide.

[0007]

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[0008]

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In any of the reaction formulas, if a rightward reaction occurs, carbon dioxide reacts with lithium silicate and becomes absorbed. The reaction of absorbing carbon dioxide is the fastest at about 600 ° C. Since these reactions are exothermic, as described above, when a source gas that generates hydrogen by an endothermic reaction and a chemical absorber containing lithium silicate as a main component are used, heat required to generate hydrogen is generated. It can be supplemented by the heat generated during carbon dioxide absorption.
In addition, lithium silicate that absorbed carbon dioxide was 7
By heating to 50 ° C. or more, a leftward reaction shown in the reaction formula (2) or (3) is caused. Therefore,
Lithium silicate can be regenerated.

However, a reactor filled with an inorganic absorbent has a larger volume than a conventional reactor filled only with a solid catalyst, and requires a large amount of absorbent. Furthermore, in order to perform heating to regenerate the absorbent material that has absorbed carbon dioxide, heat must be supplied to the entire reactor containing the absorbent material, and unnecessary parts such as a catalyst used for the reaction are required. Until heated. Therefore, there has been a demand for a chemical reaction device in which a carbon dioxide absorbent is efficiently filled.

[0011]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a chemical reaction apparatus capable of recovering hydrogen from a raw material gas at a high recovery rate, and reducing the amount of carbon dioxide absorbent used and the amount of heating required for its regeneration. The purpose is to provide.

[0012]

According to the present invention, there is provided a chemical reaction apparatus for generating hydrogen from a raw material gas, comprising: a first reaction zone containing a solid catalyst;
A second reaction region that is disposed at a stage subsequent to the first reaction region and contains a chemical absorber and a solid catalyst that selectively absorbs carbon dioxide, and heating means for heating the second reaction region. In the first reaction region, the source gas is subjected to a chemical reaction to generate hydrogen as a main product gas and carbon dioxide as a by-product gas, and the second reaction region includes the second The gas generated in one reaction zone is introduced,
The chemical reaction and the absorption of the carbon dioxide are performed, and the weight of the solid catalyst accommodated in the second reaction region is:
There is provided a chemical reaction apparatus characterized in that the weight is 0.4 times or more and 2.0 times or less the weight of the solid catalyst accommodated in the first reaction zone.

In the present invention, the volume of the second reaction zone is at least 0.8 times the volume of the first reaction zone.
It is preferably 5 times or less.

In the chemical reaction apparatus according to the present invention, the first reaction region is a reactor containing the solid catalyst, and the second reaction region is a reactor containing the chemical absorber and the solid catalyst. can do.

Further, the chemical reaction apparatus of the present invention has a reactor divided into a source gas introduction side containing the solid catalyst and a final product gas exhaust side containing the chemical absorber and the solid catalyst. The first reaction zone may be on the source gas introduction side, and the second reaction zone may be on the final product gas discharge side.

Alternatively, in the chemical reaction apparatus according to the present invention, the first reaction region is a reactor containing the solid catalyst, and the second reaction region is a reactor containing the chemical absorber. And a reactor that is disposed at the subsequent stage and contains the solid catalyst.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the drawings.

FIG. 1 is a schematic diagram showing the configuration of an example of the chemical reaction apparatus according to the present invention.

The illustrated chemical reaction apparatus includes a first reactor 1
And a second reactor 2 connected downstream of the first reactor by a connecting pipe 6. These first and second reactors correspond to a first reaction zone and a second reaction zone, respectively.

The reactor 1 has a raw material gas introduction pipe 5 and is filled with a solid catalyst 3. The raw material gas introduced into the first reactor 1 reacts in the reactor 1 to generate a first product gas containing hydrogen as a main product gas and carbon dioxide as a by-product gas. As the raw material gas, hydrocarbon, oxygen-containing hydrocarbon, alcohols, or a mixed gas of carbon monoxide and water vapor can be used.

The first product gas is introduced into the second reactor 2 via the connecting pipe 6. This connection pipe 6 can reduce heat loss by winding a heat insulating material. Alternatively, the temperature may be raised by providing a heating member.

The second reactor 2 is filled with a solid catalyst 3 and a carbon dioxide absorber 4. The filling ratio of the solid catalyst 3 and the carbon dioxide absorber 4 can be appropriately determined depending on the operation time of the apparatus, and does not need to be completely mixed. In the second reactor 2, the reaction of generating hydrogen of the main product gas is promoted by the solid catalyst 3, and at the same time, carbon dioxide as the by-product gas is removed from the gas by the carbon dioxide absorber 4. Is done. here,
The heat generated when the carbon dioxide absorber 4 absorbs carbon dioxide can be used as reaction heat for generating hydrogen. The first product gas introduced into the second reactor 2 reacts in the reactor 2 in this way, and a final product gas containing hydrogen as a main product gas and carbon dioxide as a by-product gas is generated. Is discharged from

Further, a heating section 8 may be provided around the second reaction vessel 2. As shown, the heating section 8 can be installed only around the reactor 2. The heating unit 8 serves to regenerate the carbon dioxide absorber 4 by heating and raising the temperature of the carbon dioxide absorber 4 that has absorbed carbon dioxide to a saturated state, thereby releasing carbon dioxide.

In the chemical reaction apparatus of the present invention, the solid catalyst 3 contained in the second reactor 2 which is the second reaction zone
Must be set within a predetermined range.
Specifically, the weight of the solid catalyst 3 accommodated in the second reactor 2 which is the second reaction zone is equal to the weight of the solid catalyst 3 accommodated in the first reactor 1 which is the first reaction zone. It is necessary that the weight be 0.4 times or more and 2.0 times the weight. This is for the following reason. If the second reaction zone is filled with the solid catalyst at the same density as the first reaction zone, at least the lower limit of the relative catalyst amount is set to 0 in order to obtain the effect of filling the carbon dioxide absorber and increasing the recovery rate of hydrogen. This is because the solid catalyst needs to be distributed to the second reaction zone at a ratio of .4. Further, in order to obtain the effect of setting the first reaction region containing only the solid catalyst, the volume of the second reaction region heated during regeneration is 2.0 times the volume of the first reaction region. It must be: Therefore,
In the present invention, the weight of the catalyst in the second reaction zone is specified to be 0.4 to 2.0 times the weight of the catalyst in the first reaction zone.

When lithium silicate is used as the carbon dioxide absorber, the volume of the second reactor 2 as the second reaction zone is equal to that of the first reactor 1 as the first reaction zone.
It is desired that the value be 0.8 times or more and 5.5 times or less. Within this range, the packing density of the solid catalyst becomes excessively or excessively small, and it is possible to satisfy the relative catalyst amount range of the second reaction region as described above without inconvenience of obstructing the gas flow. is there.

FIG. 2 is a schematic diagram showing another example of the chemical reaction apparatus according to the present invention.

The illustrated chemical reaction apparatus has one reactor 9 having a raw material gas introduction pipe 13 and a discharge pipe 14, and the inside of the reactor 9 is formed by a porous inner wall 12 in a first reaction zone 1.
0 and a second reaction region 11.

The first reaction zone 10 is filled with the solid catalyst 3. The raw material gas introduced into the first reaction region 10 reacts in the first reaction region 10 to generate a first product gas containing hydrogen as a main product gas and carbon dioxide as a by-product gas. I do.

The first product gas passes through the porous inner wall 12 and is introduced into the second reaction zone 11. Second reaction zone 1
1 is filled with a solid catalyst 3 and a carbon dioxide absorber 4, and the filling ratio of these can be appropriately determined according to the operation time of the apparatus. In the second reaction zone 11, the reaction of generating hydrogen of the main product gas is promoted by the solid catalyst 3, and at the same time, carbon dioxide as the by-product gas is removed from the gas by the carbon dioxide absorber 4. You. The first product gas introduced into the second reaction zone 11 reacts in this manner, and a final product gas containing hydrogen as the main product gas and carbon dioxide as the by-product gas is generated and discharged from the discharge pipe 14.

Further, around the second reaction zone 11,
A heating unit 15 may be provided. As shown
The heating unit 15 can be installed only around the second reaction area 11. The heating unit 15 serves to regenerate the carbon dioxide absorber 4 by heating and raising the temperature of the carbon dioxide absorber 4 that has absorbed carbon dioxide to a saturated state, thereby releasing carbon dioxide.

The pore diameter of the porous inner wall 12 dividing the first and second reaction zones is determined by the size of the solid catalyst 3 and the carbon dioxide absorber 4 filled in the reaction zones 10 and 11.
Is preferably smaller than the particle size. Further, the pressure difference on both sides of the porous inner wall 12 is desirably 5.0 kg / cm ³ or less. This is to reduce the energy required for pressurization performed to flow the source gas during operation of the apparatus.

For the reasons described above, in the chemical reaction apparatus of the present invention, the weight of the solid catalyst 3 accommodated in the second reaction zone 11 is reduced by the weight of the solid catalyst 3 accommodated in the first reaction zone 10. It is necessary that the weight of the catalyst 3 is 0.4 times or more and 2.0 times or more. Further, when lithium silicate is used as the carbon dioxide absorber, the volume of the second reaction region 11 is 0.8 times or more of the first reaction region 10.
It is desired that it be 5 times or less.

FIG. 3 is a schematic diagram showing another example of the chemical reaction apparatus according to the present invention.

In the illustrated chemical reactor, the reactor 16 filled with the solid catalyst 3 corresponds to a first reaction zone, and the reactor 17 containing the carbon dioxide absorber 4 and the reaction containing the solid catalyst 3 The two with the vessel 18 constitute a second reaction zone.

The reactor 16 has the same structure as the first reactor 1 described with reference to FIG. A raw material gas is introduced into the reactor 16 through a raw gas introduction pipe 19. The raw material gas reacts in the reactor 16 and reacts with hydrogen of the main product gas,
A first product gas containing a by-product gas such as carbon dioxide is generated.

The first product gas is filled into the carbon dioxide absorber 4 through the connecting pipe 20 and introduced into the reactor 17. The volume of the reactor 17 can be appropriately determined according to the operation time of the apparatus.

In the reactor 17, carbon dioxide is removed from the first product gas by the carbon dioxide absorber 4. The second product gas obtained here contains a smaller amount of carbon dioxide than the first product gas and hydrogen as the main component, and is filled with the solid catalyst 3 through the connecting pipe 21. To the reactor 18.

A heating unit 23 is provided around the reactor 17.
May be provided. As shown in FIG.
Can be installed only around the reactor 17. The heating unit 23 plays a role of heating and raising the temperature of the carbon dioxide absorber 4 that has absorbed the carbon dioxide to a saturated state to release carbon dioxide, thereby regenerating the carbon dioxide absorber 4.

The reactor 18 into which the second product gas is introduced is filled with the solid catalyst 3. The second product gas reacts in the reactor 18 to produce a final product gas containing hydrogen as a main product gas and carbon dioxide as a by-product gas, and is discharged from the discharge pipe 22.

For the reasons described above, in the chemical reaction apparatus of the present invention, the weight of the solid catalyst 3 contained in the reactor 18 constituting the second reaction zone is the first reaction zone. It is necessary that the weight be 0.4 times or more and 2.0 times the weight of the solid catalyst 3 accommodated in the reactor 16. Further, when lithium silicate is used as the carbon dioxide absorber, it is desired that the volume of the second reaction region is 0.8 times or more and 5.5 times or less of the first reaction region.

In the present invention, a solid catalyst for chemically reacting a raw material gas to obtain hydrogen as a main product gas and carbon dioxide as a by-product gas includes a solid catalyst in the case where the raw material gas contains methane and water vapor. A nickel-based catalyst such as metallic nickel is desirable. Alternatively, an iron-based oxide such as iron oxide or an iron-chromium composite oxide can be mixed in the rear part of the gas flow path. When the raw material gas contains carbon monoxide and water vapor, iron oxides such as iron oxide and iron-chromium composite oxide are preferably used as the solid catalyst.

As a carbon dioxide absorber for selectively absorbing carbon dioxide as a by-product gas, an inorganic compound can be used. Among them, lithium silicate is particularly preferable.

When lithium silicate is used as the carbon dioxide absorber, this lithium silicate can be regenerated for the following reasons. That is, as shown in the above-mentioned reaction formulas (2) and (3), the reaction with carbon dioxide is a reversible reaction. Therefore, by heating the lithium silicate that has absorbed carbon dioxide, carbon dioxide can be released and regenerated. By utilizing such properties of lithium silicate, it is also possible to generate hydrogen almost continuously. For example, a chemical reaction device in which only a second reaction region or a plurality of two of the first reaction region and the second reaction region is arranged. Hydrogen is generated almost continuously by alternately performing the operation of generating hydrogen in one of the systems and regenerating lithium silicate in the other system.

A case where this is applied to the apparatus shown in FIG. 1 will be described with reference to FIG.

The illustrated chemical reaction apparatus comprises a first reactor 24 corresponding to a first reaction region and two second reactors 25a and 25b corresponding to a second reaction region. The reactor packing and structure used in each reaction zone are the same as those described with reference to FIG.

The first reactor 24 has a raw material gas introduction pipe 26
And filled with a solid catalyst (not shown). The second reactors 25a and 25b are connected to regeneration gas introduction pipes 27a and 27b, respectively, and are filled with a solid catalyst (not shown) and a carbon dioxide absorber (not shown).

First, the case where carbon dioxide is removed in the reactor 25a to purify hydrogen and the carbon dioxide absorbent is regenerated in the reactor 25b will be described. At this time, the valves 31a are closed, 32a is open, 31b is open,
b is closed.

The raw material gas introduction pipe 26 is connected to the first reactor 24
The raw material gas introduced therein reacts in the reactor 24 to generate a first product gas. The first product gas is introduced into the reactor 25a through the connecting pipe 28, the valve 32a, and the gas introducing pipe 29a. The first product gas is supplied to the reactor 2
5a, a final product gas is generated, and the exhaust pipe 3
0a.

During the removal of carbon dioxide in the reactor 25a, the reactor 25b is connected to the regeneration gas introduction pipe 27.
b, the valve 31b, and the regeneration gas are introduced through the gas introduction pipe 29b. In the reactor 25b, a heater (not shown) is used until the carbon dioxide absorber emits carbon dioxide.
, The regeneration of the carbon dioxide absorber is performed. As a result, the regeneration gas containing carbon dioxide at a high concentration is discharged from the discharge pipe 30b.

Next, a case where carbon dioxide is removed in the reactor 25b to purify hydrogen and the carbon dioxide absorber is regenerated in the reactor 25a will be described. At this time, the valves 31a are open, 32a is closed, 31b is closed, 32
b is open.

The first reactor 24 is connected to the raw material gas introduction pipe 26 through the first reactor 24.
The raw material gas introduced therein reacts in the reactor 24 to generate a first product gas. The first product gas is introduced into the reactor 25b through the connection pipe 28, the valve 32b, and the gas introduction pipe 29b. The first product gas is supplied to the reactor 2
5b, a final product gas is generated, and the exhaust pipe 3
0b.

During the removal of carbon dioxide in the reactor 25b, the reactor 25a is connected to the regeneration gas introduction pipe 27.
The regeneration gas is introduced through a, the valve 31a, and the gas introduction pipe 29a. In the reactor 25a, a heater (not shown) is used until the carbon dioxide absorber emits carbon dioxide.
, The regeneration of the carbon dioxide absorber is performed. As a result, the regeneration gas containing carbon dioxide at a high concentration is discharged from the discharge pipe 30a.

The regeneration gas introduced into the regeneration reactor is a carrier gas for discharging carbon dioxide generated in the reactor through an exhaust pipe. The type is not particularly limited. In regeneration of lithium silicate which is a carbon dioxide absorber, supply of regeneration gas is not indispensable. However, when the concentration of carbon dioxide in the reactor becomes high, the leftward reactions of the above-mentioned reaction formulas (2) and (3) become slow, and it becomes necessary to set the regeneration temperature to a high temperature such as 950 ° C. or higher. .
Therefore, in order to regenerate the lithium silicate to an almost initial state at a temperature of 900 ° C. or less, it is desirable to supply a regeneration gas into the reactor as described above.

As described above, in the chemical reaction apparatus of the present invention, in the first reaction zone, although the reaction for producing hydrogen as the main product gas proceeds, the reaction has not reached equilibrium and the carbon dioxide concentration is low. . When a carbon dioxide absorber is accommodated in such a first reaction region, its absorption rate is low, and the effect of absorbing carbon dioxide cannot be sufficiently obtained. In order to sufficiently exert the effect of the carbon dioxide absorber, in the present invention, the first reaction region and the second reaction region are divided, and the carbon dioxide absorbent is used only in the second reaction region. Even with such a configuration, the recovery rate of hydrogen, which is the main product gas, can be approximately the same as in the conventional case where a carbon dioxide absorbent is used in the entire reaction region.

In the chemical reaction device of the present invention, since the carbon dioxide absorbing material is efficiently disposed, the amount of the carbon dioxide absorbing material used is reduced while maintaining the recovery rate of hydrogen as the main product gas at the same level. It became possible to do. In addition, the heating section serving to regenerate the carbon dioxide absorbent can be provided only at the portion where the carbon dioxide absorbent is disposed. For this reason, the advantage that the loss by heating the solid catalyst can be reduced as compared with the conventional case where the entire reactor is heated is obtained.

[0056]

Now, the present invention will be described in further detail with reference to specific examples.

Example 1 Hydrogen was produced using a chemical reaction apparatus having the structure shown in FIG.

The reactor 1 has a tubular shape having an inner diameter of 0.03 m and a length of 1.6 m, and the reactor 2 has an inner diameter of 0.03 m,
The tube was 2.9 m in length. The reactor 1 was filled with 1.5 kg of alumina particles having an average particle diameter of 10 μm and carrying about 20% by weight of metallic nickel as the reforming catalyst 3. In the reactor 2, the carbon dioxide absorber 4 has an average particle diameter of 10 μm.
Then, 0.90 kg of lithium silicate granulated to m and 0.90 kg of the same reforming catalyst as described above were sufficiently mixed and then charged.

Example 2 Hydrogen was generated using a chemical reaction apparatus having the structure shown in FIG.

The reactor 1 has a tubular shape having an inner diameter of 0.03 m and a length of 1.2 m, and the reactor 2 has an inner diameter of 0.03 m,
The length was 4.7 m. The reactor 1 was charged with 1.1 kg of alumina particles having an average particle size of 10 μm and supporting about 20% by weight of metallic nickel as the reforming catalyst 3. In the reactor 2, the carbon dioxide absorber 4 has an average particle diameter of 10 μm.
Then, 1.3 kg of lithium silicate granulated into m and 1.3 kg of the same reforming catalyst as described above were sufficiently mixed and then charged.

(Comparative Example 1) Hydrogen was generated using a chemical reaction apparatus having the structure shown in FIG.

The reactor 1 has a tubular shape having an inner diameter of 0.03 m and a length of 2.1 m, and the reactor 2 has an inner diameter of 0.03 m,
The length was 1.3 m. The reactor 1 was charged with 2.0 kg of alumina particles having an average particle size of 10 μm and supporting about 20% by weight of metallic nickel as the reforming catalyst 3. In the reactor 2, the carbon dioxide absorber 4 has an average particle diameter of 10 μm.
Then, 0.40 kg of lithium silicate granulated into m and 0.40 kg of the same reforming catalyst as described above were sufficiently mixed and then charged.

(Comparative Example 2) Hydrogen was generated using a chemical reaction apparatus having the structure shown in FIG.

The reactor 1 has a tubular shape having an inner diameter of 0.03 m and a length of 0.74 m, and the reactor 2 has an inner diameter of 0.03 m.
m and a length of 5.6 m. The reactor 1 was filled with 0.69 kg of alumina particles having an average particle size of 10 μm and carrying about 20% by weight of metallic nickel as the reforming catalyst 3. 1.7 kg of lithium silicate granulated to have an average particle size of 10 μm as a carbon dioxide absorber 4 in the reactor 2
And 1.7 kg of the same reforming catalyst as described above, and then charged.

A raw material gas is prepared by mixing H ₂ O and CH ₄ at a ratio of H ₂ O / CH ₄ = 4, and this raw material gas is heated in advance to 500 ° C. The gas was introduced from the gas introduction pipe 5 into the reactor 1 of each device. At this time, the entire reactor was heated to 500 ° C. by a heater (not shown). The pressure in the reactor was 1.7 × 10 ⁶ Pa. The methane reforming rate of each device 30 minutes after the operation of the reactor was started was calculated based on the following equation.

[0066] reforming conversion ratio of methane = 1 - {(CH ₄ moles of final product gas discharged per 1s) / (CH ₄ moles of the raw material gas to be introduced per 1s)} obtained The results are shown in Table 1 below, together with the relative catalyst amount, the relative volume, the amount of lithium silicate used, and the heating volume during regeneration. Note that the relative catalyst amount and the relative volume are the respective values of the second reaction region when the catalyst amount and the volume of the first reaction region are set to 1. That is, the relative catalyst amount is
The ratio of the weight of the solid catalyst contained in the second reaction area to the weight of the solid catalyst contained in the first reaction area, and the relative volume is the volume of the second reaction area, relative to the volume of the first reaction area. Ratio.

[0067]

[Table 1]

In Comparative Example 1, the amount of lithium silicate used and the heating volume during regeneration were different from those of the present invention (Examples 1 and 2).
Although smaller, the performance as a chemical reactor for producing hydrogen is inferior due to the low methane reforming rate. This is because the reaction in the second reaction zone is less likely to proceed as compared with the first reaction zone because the relative catalyst amount in the second reaction zone is too low at 0.2. When the relative catalyst amount is such a low value, the effect of accelerating the reaction cannot be sufficiently obtained by simultaneously using lithium silicate as the carbon dioxide absorber and the catalyst in the second reaction region.

In Comparative Example 2, the methane reforming ratio is higher than that of the present invention (Examples 1 and 2). However, due to the large amount of lithium silicate used and the large heating volume during regeneration, the initial equipment cost and operation cost are large. This is due to the relative catalyst amount in the second reaction zone being as large as 2.5. This is because the effect of installing the first reaction region containing only the catalyst before the second reaction region in which the reaction is promoted by simultaneously using lithium silicate as the carbon dioxide absorber and the catalyst is not sufficiently obtained.

As shown in the above results, the relative catalyst amount in the second reaction zone is desirably 0.4 or more and 2.0 or less.

[0071]

As described above in detail, according to the present invention, it is possible to recover hydrogen from a raw material gas at a high recovery rate, and to reduce the amount of carbon dioxide absorbent used and the amount of heating required for its regeneration. A reactor is provided.

The chemical reaction apparatus of the present invention is advantageous in terms of both economy and operability since the amount of carbon dioxide absorbent used is small and the amount of heating required for regeneration is small.
It can be applied to hydrogen production processes in various plants, and its industrial value is enormous.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of an example of a chemical reaction device according to the present invention.

FIG. 2 is a schematic diagram showing a configuration of another example of the chemical reaction device according to the present invention.

FIG. 3 is a schematic diagram illustrating a configuration of another example of the chemical reaction device according to the present invention.

FIG. 4 is a schematic diagram illustrating a configuration of another example of the chemical reaction device according to the present invention.

[Explanation of symbols]

 1, 24 ... first reactor 2, 25a, 25b ... second reactor 3 ... solid catalyst 4 ... carbon dioxide absorber 5, 13, 19, 26 ... source gas introduction pipe 6, 20, 21 ... reaction area Connecting pipes 7, 14, 22, 30a, 30b ... Discharge pipes 8, 15, 23 ... Heating unit for regenerating carbon dioxide absorbent 9 ... Reactor 10 ... First reaction area 11 ... Second reaction area 12 ... Porous Inner walls 16, 17, 18 ... Reactors 27a, 27b ... Regeneration gas introduction pipes 28, 29a, 29b ... Connection pipes 31a, 31b, 32a, 32b ... Valves

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Masareu Kato 1st address, Komukai Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture Inside Toshiba R & D Center (72) Inventor Sawako Yoshikawa Komukai, Sai-ku, Kawasaki-shi, Kanagawa No. 1 Toshiba-cho Toshiba R & D Center F term (reference) 4G040 EA03 EA06 EB31 EC07 FA02 FB04 FC02 FE02 4G070 AA01 AB04 BA08 BB02 BB08 CA25 CB11 CB17 CC07 CC11 DA14 DA21 4G140 EA03 EA06 EB31 EC02 FA02 FB04

Claims (5)

[Claims] 1. A chemical reactor for generating hydrogen from a raw material gas, comprising: a first reaction zone containing a solid catalyst;
A second reaction region that is disposed at a stage subsequent to the first reaction region and contains a chemical absorber and a solid catalyst that selectively absorbs carbon dioxide, and heating means for heating the second reaction region. In the first reaction region, the source gas is subjected to a chemical reaction to generate hydrogen as a main product gas and carbon dioxide as a by-product gas, and the second reaction region includes the second The gas generated in one reaction zone is introduced, the chemical reaction and the absorption of carbon dioxide are performed, and the weight of the solid catalyst contained in the second reaction zone is reduced to the first reaction zone. A chemical reaction apparatus characterized in that the weight is 0.4 times or more and 2.0 times or less the weight of the contained solid catalyst. 2. The chemical reaction apparatus according to claim 1, wherein the volume of the second reaction region is 0.8 times or more and 5.5 times or less of the volume of the first reaction region. . 3. The first reaction zone comprises a reactor containing the solid catalyst, and the second reaction zone comprises a reactor containing the chemical absorber and the solid catalyst. The chemical reaction device according to claim 1 or 2, wherein: 4. A source gas introduction side containing the solid catalyst,
A reactor divided into a final product gas discharge side including the chemical absorber and the solid catalyst, the first reaction region is the raw material gas introduction side, and the second reaction region is The chemical reaction device according to claim 1, wherein the chemical reaction device is a product gas discharge side. 5. The first reaction zone comprises a reactor containing the solid catalyst, and the second reaction zone comprises a reactor containing the chemical absorber, and a solid catalyst disposed downstream of the reactor. 3. The chemical reaction apparatus according to claim 1, comprising a reactor containing a catalyst.