JP4822937B2 - Hydrogen production system - Google Patents

Description

  The present invention relates to a hydrogen production system, and more particularly to a hydrogen production system that produces hydrogen using natural gas generated by decomposing natural gas hydrate (NGH) as a raw material.

In recent years, global warming has become a problem as one of the causes of environmental destruction. The cause of this warming is mainly the greenhouse effect caused by carbon dioxide emitted from automobiles and the like. Therefore, each automobile manufacturer is attracting attention as an electric vehicle that does not emit carbon dioxide as a next-generation power engine replacing a gasoline engine. However, electricity, that is, storage batteries are required as fuel for electric vehicles, and the current storage batteries are mainly lead storage batteries. Therefore, they are heavy and have a large volume in order to maintain the required power. Since most of the batteries are occupied by the storage battery, it is difficult to put it to practical use, and the reduction in size and weight of the storage battery is a major issue.
Therefore, fuel cells are attracting attention as one means for solving the drawbacks of lead-acid batteries. A fuel cell is a power generation device that takes out electric energy by chemically reacting hydrogen and oxygen, and this chemical reaction is generally said to be a reverse reaction of water electrolysis. And it is said that it will become one of the pillars of clean energy in the future because the only waste generated by chemical reaction is water.

Hydrogen used in fuel cells is made from various raw materials, but is generally produced by reacting methane with water. And since methane is abundant on the earth, there is no particular problem as a raw material, but it is of interest in terms of manufacturing technology, such as how cheaply hydrogen can be produced from methane and stably supplied. Is growing. In other words, when electric vehicles equipped with fuel cells become popular in the future, and hydrogen gas stations that supply hydrogen fuel to each site (which corresponds to the current gas station) are required, hydrogen can be produced at low cost. In addition, whether or not equipment that can be efficiently manufactured can be constructed at a low cost is a factor that affects the spread of future electric vehicles and fuel cells.
In addition, methane used for producing hydrogen contains carbon monoxide. In particular, high purity carbon monoxide is a resource used as a raw material for polyurethane and polycarbonate. It is taken out by adsorbing carbon monoxide in the generated gas with a chemical adsorbent. On the other hand, it has been proposed to obtain methane and water as raw materials for hydrogen from methane gas hydrate.

Patent Document 1 discloses that hydrogen is added to a hydrogen storage medium, the hydrogen storage medium to which hydrogen is added is transported to a hydrogen use place, and hydrogen is generated from the hydrogen storage medium to which the hydrogen is added at the hydrogen use place. A supply system is disclosed.
JP 2006-83000 A

However, in the conventional hydrogen production method, usually, methane and water are separately supplied and the reaction is performed, so that there is a problem that a great deal of cost is required for the procurement of the raw materials. Further, even carbon monoxide obtained using a chemical adsorbent was not 100% pure.
In addition, the conventional technique disclosed in Patent Document 1 needs to add and transport hydrogen to a known hydrogen storage medium and recover the dehydrogenated hydrogen storage medium remaining after obtaining hydrogen. Therefore, there is a problem that a great deal of cost is required.

In view of such problems, an object of the present invention is to provide a hydrogen production system that efficiently produces hydrogen from natural gas and water obtained by decomposing NGH.
Another object is to efficiently recover carbon monoxide and carbon dioxide from off gas and combustion exhaust gas generated during hydrogen decomposition.
Another object is to cool carbon monoxide or carbon dioxide gas with cold water derived from NGH and the cold heat of NGH itself, and stir with water under high pressure, so that carbon monoxide hydrate or carbon dioxide hydrate can be obtained. Is to produce rates.

In order to solve the above problems, the present invention provides a natural gas hydrate decomposition apparatus for generating water and natural gas by applying heat to natural gas hydrate and decomposing it, and the natural gas hydrate decomposition apparatus. A hydrogen production device that produces hydrogen using water and natural gas produced as raw materials, and a recovery device that collects carbon monoxide and carbon dioxide using off-gas and combustion exhaust gas generated by the hydrogen production device as raw materials. It is characterized by that.
The main object of the present invention is to produce hydrogen from natural gas obtained by decomposing NGH. However, off-gas and combustion exhaust gas are generated from the hydrogen production apparatus during this production process. Originally, if only hydrogen is produced, these gases are discharged and discarded, but these gases contain a large amount of carbon monoxide and carbon dioxide. It is a resource used as a raw material for polyurethane and polycarbonate. Therefore, the present invention also includes a recovery device that recovers carbon monoxide and carbon dioxide with high purity in addition to hydrogen.

According to a second aspect of the present invention, the hydrogen production apparatus mixes water generated by the natural gas hydrate decomposition apparatus and natural gas to generate a mixed liquid, and heats the mixed liquid generated by the mixer. A heater to be vaporized, a reformer to introduce a water vapor vaporized by the heater and a natural gas contained in the mixed solution to perform a reforming reaction, and to heat the heater and the reformer A heating chamber, a reformer that denatures carbon monoxide contained in the reformed gas generated by the reformer into hydrogen, and a component other than hydrogen contained in the modified gas sent from the reformer. And a PSA device that adsorbs to the substrate.
The hydrogen production apparatus of the present invention mixes cold water and natural gas obtained by the NGH decomposition apparatus with a mixer. The mixture is reformed by using a heater to convert cold water into steam along with natural gas and introducing it into the reformer. The reformed reformed gas is further sent to a denaturer, and carbon monoxide is denatured into hydrogen. Further, it is sent to the PSA apparatus to remove other components containing hydrogen, and adsorbs other components to increase the purity of hydrogen. The PSA (Pressure Swing Adsorption) device uses the difference in the adsorption characteristics of the adsorbent to the gas, and continuously repeats the operation of pressurization and depressurization while continuously supplying the target gas. It is a device to separate.

According to a third aspect of the present invention, the hydrogen production apparatus comprises: a mixer that mixes water and natural gas produced by the natural gas hydrate decomposition apparatus; a heater that heats a mixed liquid mixed by the mixer; A reformer that introduces steam vaporized by a heater and natural gas contained in the mixed solution to perform a reforming reaction, a heating chamber that heats the heater and the reformer, and the reformer And a PSA device that selectively adsorbs components other than hydrogen contained in the reformed gas sent from the reactor.
In the present invention, hydrogen is purified by a PSA apparatus without performing a modification reaction after the reforming reaction. That is, at this time, compared with the case where there is a denaturer, although the amount of hydrogen produced is reduced, there is an advantage that the amount of carbon monoxide produced is increased.

According to a fourth aspect of the present invention, the hydrogen production apparatus includes a mixer that mixes water and natural gas generated by the natural gas hydrate decomposition apparatus, and a heater that heats and vaporizes the liquid mixture generated by the mixer. A reformer that introduces steam vaporized by the heater and natural gas contained in the mixed solution to perform a reforming reaction, a heating chamber that heats the heater and the reformer, and And a PSA device that selectively adsorbs components other than hydrogen contained in the reformed gas sent from the reformer.
The recovery device recovers carbon monoxide and carbon dioxide individually. That is, carbon monoxide is recovered from the off-gas generated after the hydrogen is purified by the PSA apparatus by an adsorption method or a method of generating a hydrate and separating it from other components. Carbon dioxide is recovered from the combustion exhaust gas discharged from the heating chamber by an adsorption method or a method of generating a hydrate and separating it from other components.

The present invention reacts the reformer with a reformed gas cooler provided at the outlet of the reformer in order to cool the reformed gas heated to a temperature necessary for reacting the reformer. A modified gas cooler provided at an outlet of the reformer to cool the modified gas heated to a temperature required for the reforming gas, and the reformed gas cooler and / or the modified gas cooler includes the natural gas hydrate. It cools using the water produced | generated by the decomposition device.
In the reformer, the reforming reaction is performed at about 800 ° C. On the other hand, a denaturing reaction is performed at 200 to 500 ° C. in the denaturing device. Therefore, since the temperature of the reformed gas coming out of the reformer needs to be cooled before being introduced into the reformer, a reformed gas cooler is required. In addition, since the denatured gas coming out of the denaturer needs to be lowered in temperature before being introduced into the PSA apparatus, a denatured gas cooler is required. And water produced | generated by the natural gas hydrate decomposition | disassembly apparatus is utilized for these coolers.

A sixth aspect of the present invention is characterized in that the hot water heat-exchanged by the reformed gas cooler and / or the modified gas cooler is used to promote the reforming reaction of the reformer.
When water cools the heat, it naturally becomes hot water. Since the reformer needs to be heated at a high temperature of about 800 ° C., it effectively uses the hot water heat-exchanged by the reformed gas cooler and the modified gas cooler.

According to a seventh aspect of the present invention, the heating chamber generates a heat source using the natural gas obtained by the natural gas hydrate decomposition apparatus and the off-gas discharged from the carbon monoxide recovery apparatus as fuel.
Since the heating chamber heats the heater and the reformer at a high temperature, it is necessary to heat the heating chamber from the outside with, for example, a burner. Natural gas and off-gas are effectively used as fuel for the burner.

According to an eighth aspect of the present invention, the carbon monoxide recovery device includes a gas cooling unit that cools off-gas generated after hydrogen is purified by the PSA device, and a pressurizing unit that pressurizes the off-gas cooled by the gas cooling unit. And an agitation means for agitating the off gas pressurized by the pressurizing means and the water, and the gas cooling means penetrates at least a pipe for passing the off gas into the natural gas hydrate decomposition apparatus. Thus, the off-gas is cooled to produce the carbon monoxide hydrate.
Hydrate is obtained by stirring the cooled gas with water under high pressure. The carbon monoxide recovery apparatus of the present invention basically produces hydrates by this procedure. By utilizing the low temperature inside the natural gas hydrate decomposition apparatus as the gas cooling means, the off-gas piping is penetrated. The off gas is cooled.

According to a ninth aspect of the present invention, the carbon dioxide recovery device includes a gas cooling unit that cools the combustion exhaust gas discharged from the heating chamber, a pressurization unit that pressurizes the combustion exhaust gas cooled by the gas cooling unit, and the pressurization And a stirring means that stirs the combustion exhaust gas pressurized by the means and water, and the gas cooling means penetrates at least a pipe for passing the combustion exhaust gas into the natural gas hydrate decomposition apparatus. The combustion exhaust gas is cooled to generate the carbon dioxide hydrate.
Hydrate is obtained by stirring the cooled gas with water under high pressure. The carbon dioxide recovery device of the present invention basically produces hydrates by this procedure. By utilizing the low temperature in the natural gas hydrate decomposition device as the gas cooling means, the combustion exhaust gas pipe is penetrated. The combustion exhaust gas is cooled.

  According to the present invention, natural gas hydrate decomposes by applying heat to natural gas hydrate to produce water and natural gas, and water and natural gas produced by the natural gas hydrate decomposer as raw materials. Equipped with a hydrogen production device that produces hydrogen, and a recovery device that collects carbon monoxide and carbon dioxide using off-gas and combustion exhaust gas generated by the hydrogen production device as raw materials. The exhaust gas that is sometimes generated can be used effectively.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the components, types, combinations, shapes, relative arrangements, and the like described in this embodiment are merely illustrative examples and not intended to limit the scope of the present invention only unless otherwise specified. .
FIG. 1 is a schematic configuration diagram of a hydrogen production system according to an embodiment of the present invention. This hydrogen production system 100 includes an NGH decomposition apparatus 7 that generates heat 4 and natural gas 5 by applying heat to the NGH 2 supplied from a natural gas hydrate (hereinafter referred to as NGH) tank 1 to decompose it. As described later, hydrogen production apparatus 20 that produces hydrogen 21 using water 4 and natural gas 5 produced by NGH decomposition apparatus 7 as raw materials, and off-gas 22 and combustion exhaust gas 23 generated by hydrogen production apparatus 20 are used as raw materials for oxidation. And a recovery device 24 that recovers carbon 25 and carbon dioxide 26. Note that NGH 2 is supplied from the NGH tank 1 to the NGH decomposition apparatus 7 as necessary.

  The main purpose of this embodiment is to produce hydrogen 21 from natural gas 5 obtained by decomposing NGH 2 by the NGH decomposition apparatus 7. However, off-gas 22 and combustion exhaust gas 23 are generated from the hydrogen production apparatus 20 during this production process. Originally, if only hydrogen 21 is produced, these gases are discharged and discarded, but these gases contain a large amount of carbon monoxide and carbon dioxide, and particularly high-purity carbon monoxide. Is a resource used as a raw material for polyurethane and polycarbonate. Therefore, in this embodiment, in addition to the hydrogen 21, a recovery device 24 that recovers the carbon monoxide 25 and the carbon dioxide 26 with high purity is also provided.

FIG. 2 is a diagram schematically illustrating the configuration of the NGH decomposition apparatus. The NGH decomposition apparatus 7 includes a decomposition tank 11 constituted by a sealed cylindrical member, and a net 12 that is disposed inside the decomposition tank 11 so as to partition the inside of the decomposition tank 11 up and down and supports NGH 2 supplied from the NGH tank 1. And the sprinkling pipe which decomposes | disassembles NGH2 mounted on the net | network 12 by sprinkling the hot water 13 from the upper part in the decomposition tank 11, and isolate | separates it into the water (decomposed water) 4 and the natural gas 5 with high pressure 14, a high-pressure water (cracked water) 4 stored in the lower part of the cracking tank 11, and a water supply pipe (watering mechanism) 15 for taking the water out of the cracking tank 11 and leading it to the hydrogen production device 20; A pump 16 for pumping the water (decomposed water) 4 stored in the tank, a heat exchanger 17 for heating the water 4 pumped by the pump 16 to warm water 13 and injecting it into the decomposition tank 11 from the water spray pipe 14; Store in the upper part of the decomposition tank 11 Remove the natural gas 5 high pressure Tsu configured to include a gas supply pipe 18 for supplying the hydrogen production system 20.
In addition, since NGH2 decomposes | disassembles by applying a heat | fever, it is also possible to comprise so that it may decompose naturally with external temperature, without promoting the decomposition | disassembly by warm water. In this case, the apparatus configuration can be further simplified.

  FIG. 3 is a diagram showing the configuration of the hydrogen production apparatus according to the first embodiment of the present invention. The hydrogen production apparatus 20 includes a mixer 30 that mixes the water 4 generated by the NGH decomposition apparatus 7 and the natural gas 5, a heater 32 that heats the mixed liquid 30 a mixed by the mixer 30, and a heater 32. The reformer 34 that introduces the steam vaporized by the natural gas and the natural gas contained in the mixed solution 30a to perform the reforming reaction, and the reformed gas heated to the temperature necessary for reacting the reformer 34 Included in the reformed gas cooler 35 provided at the outlet of the reformer 34, the heater 32 and the heating chamber 31 for heating the reformer 34, and the reformed gas generated by the reformer 34 for cooling. A denaturing device 36 for denaturing carbon monoxide to hydrogen, and a denaturing gas cooler 37 provided at the outlet of the denaturing device 36 for cooling the denaturing gas heated to a temperature necessary for reacting the denaturing device 36. , Sent from the denaturing device 36 PSA device 40 that selectively adsorbs components other than hydrogen contained in the modified gas, and a method of selectively adsorbing carbon monoxide from off-gas 41 generated after hydrogen is purified by PSA device 40 Or a carbon monoxide recovery device 42 that recovers carbon monoxide 25 by any method of generating carbon monoxide hydrate (details will be described later) and separating it from other gases, and discharged from the heating chamber 31. The carbon dioxide 26 is recovered by either a method of selectively adsorbing carbon dioxide from the combustion exhaust gas 45 or a method of separating it from other gases by generating carbon dioxide hydrate (details will be described later). And a carbon dioxide recovery device 46.

  The heating chamber 31 generates a heat source using the natural gas 5 obtained by the NGH decomposition device 7 and the offgas 44 discharged from the carbon monoxide recovery device 42 as fuel for the burner 33. Further, the heater 32 does not have a mechanism for heating itself, and the heating chamber is heated when the mixed solution passes through the pipe by the heat heated by the burner 33. Therefore, in order to increase the heating efficiency, the shape of the tube is formed in a spiral shape so that the heating area is as wide as possible. Further, the hot waters 39 and 38 exchanged by the reformed gas cooler 35 and the modified gas cooler 37 are used to warm the water 4 of the mixer 30 in order to promote the reforming reaction of the reformer 34. Further, the reformed gas cooler 35 and the modified gas cooler 37 are configured to be cooled using the water 4 generated by the NGH decomposition apparatus 7. As described above, in the present embodiment, not only carbon monoxide and carbon dioxide are recovered by effectively using off gas and combustion exhaust gas that are originally discarded, but also the energy necessary for heating and cooling is procured from within the apparatus. Thus, a hydrogen production apparatus that efficiently uses each energy without waste is realized.

  Next, a hydrogen production process by the hydrogen production apparatus 20 of the present embodiment will be described. The natural gas 5 obtained by the NGH decomposition apparatus 7 is mixed with the water 4 obtained by the NGH decomposition apparatus 7 by the mixer 30 and introduced into the heater 32. In the heater 32, the water 4 becomes steam, and the natural gas 5 and steam are introduced into the reformer 34. Natural gas is composed of 80 to 90% methane, 2 to 10% ethane, 2 to 4% propane, and 1 to 2% butane.

In the reformer 34, the reforming reaction is performed at about 800 ° C. The reaction formula at this time is
CH ₄ + H ₂ O-> 3H ₂ + CO
C ₂ H ₆ + 2H ₂ O-> 5H ₂ + 2CO
_{C 3 H 8 + 3H 2 O} -> 7H 2 + 3CO
_{C 4 H 10 + 4H 2 O} -> 9H 2 + 4CO
The reformed gas generated by performing the reforming reaction is mainly composed of hydrogen but contains carbon monoxide. Examples of the steam reforming medium for reforming include Ni-based catalysts.
The reformed gas is then sent to a denaturing device 36 that denatures carbon monoxide into hydrogen. Since the temperature of the denaturation reaction in the denaturing device 36 is performed at 200 to 500 ° C., it is cooled by the reformed gas cooler 35. In the reformed gas cooler 35, the water 4 obtained by the NGH decomposition apparatus 7 is used. As the modification catalyst, an iron-chromium catalyst is used when the temperature in the modifier 36 is 300 to 500 ° C, and a copper-zinc catalyst is used when the temperature is 200 to 300 ° C. The reaction formula at this time is
CO + H ₂ O-> H ₂ + CO ₂
It is.

The PSA device 40 is provided with a plurality of adsorption towers filled with an adsorbent that selectively adsorbs components other than hydrogen under high pressure and desorbs under reduced pressure. The operation consisting of adsorption-desorption-substitution-pressure increase is performed in each adsorption tower, and the cycle between the adsorption towers is shifted in time so that the PSA apparatus 40 as a whole operates as an automatic continuous adsorption apparatus.
Then, after the hydrogen is purified by the PSA device 40, the offgas 41 is supplied to the carbon monoxide recovery device 42. The off gas 41 contains hydrogen, water vapor, unreacted methane, and carbon monoxide, and only carbon monoxide is recovered. Examples of the recovery method include a method using an adsorbent and a method in which carbon monoxide hydrate is generated and separated from other gases.
Further, the combustion exhaust gas 45 generated by burning methane or the like in the combustion chamber 31 with the burner 33 contains carbon dioxide and is recovered by the carbon dioxide recovery device 46. Examples of the recovery method include a method using an adsorbent and a method of separating carbon dioxide hydrate from other gases by generating carbon dioxide.

The hot water heat-exchanged by the reformed gas cooler 35 and the modified gas cooler 37 is used as water for the reforming reaction. Thereby, effective utilization of water resources can be aimed at. Further, since heat energy for vaporization can be obtained by the reformed gas cooler 35 and the modified gas cooler 37, high efficiency can be achieved.
The heater 32 and the reformer 34 are heated by the burner 33 in the heating chamber 31. As the fuel source, the natural gas 5 obtained by the NGH decomposition device 7 and the off-gas 44 from the carbon monoxide recovery device 42 are used. The off gas 44 includes hydrogen, water vapor, and unreacted methane. The burner 33 consumes a large amount of natural gas 5 in the initial stage of operation of the hydrogen production apparatus 20, but the amount of natural gas 5 used can be reduced by using off-gas 44, and more natural gas 5 is used for hydrogen production. Can be used as raw material.
The hydrogen production apparatus 20 is used for various applications such as fuel cells, semiconductor production, optical fiber production, glass production, and metal heat treatment.

  FIG. 4 is a diagram showing a configuration of a hydrogen production apparatus according to the second embodiment of the present invention. The same components will be described with the same reference numerals as in FIG. This hydrogen production apparatus 70 is different from the hydrogen production apparatus 20 of the first embodiment in that the denaturing device 36 is omitted and the hydrogen purification is performed by the PSA apparatus 40 without performing the modification reaction after the reforming reaction. It is. That is, at this time, there is an advantage that the amount of carbon monoxide 25 generated is increased, although the amount of hydrogen generated is smaller than when the denaturing device 36 is provided. The hydrogen production process is the same as that shown in FIG. 3 except for the operation of the denaturing device 36, and a description thereof will be omitted.

  FIG. 5 is a diagram showing the configuration of a carbon monoxide recovery device using carbon monoxide hydrate. (A) is a structural block diagram, (b) is a figure explaining the method to cool offgas in a NGH decomposition | disassembly apparatus. The same components will be described with the same reference numerals as in FIG. 5A, the carbon monoxide recovery device 80 includes a cooler (gas cooling means) 50 that cools off-gas 41 generated after the hydrogen 21 is purified by the PSA device 40, and an off-gas cooled by the cooler 50. NGH decomposition device 7 for further cooling 52, pressurizer (pressurizing means) 56 for pressurizing offgas 55 cooled by NGH decomposition device 7, offgas 57 and water 54 pressurized by pressurizer 56 Stirring means (not shown) for stirring. The cooler 50 and the water 54 to be stirred are supplied from the NGH decomposition device 7.

As shown in FIG. 5B, the off gas 52 is passed through the NGH decomposition device 7 through the pipe 58, whereby the off gas 52 is cooled by NGH 2 and supplied to the pressurizer 56 as the off gas 55.
Thus, the gas hydrate can be obtained by stirring the cooled gas with water under high pressure. The carbon monoxide recovery device 80 of this embodiment basically produces hydrates by this procedure, but the gas cooling means uses the low temperature inside the NGH decomposition device 7 to penetrate the off-gas pipe 58. This cools off-gas.
Carbon dioxide hydrate can also be produced in the same manner by using the combustion exhaust gas 45 discharged from the heating chamber 31 instead of off-gas, in the same configuration.

As described above, according to the present invention, NGH 2 is decomposed by applying heat to produce water 4 and natural gas 5, and water 4 and natural gas 5 produced by NGH decomposition device 7 are used as raw materials. Since the hydrogen production apparatus 20 for producing hydrogen and the recovery apparatus 24 for collecting the carbon monoxide 25 and the carbon dioxide 26 using the off-gas 22 and the combustion exhaust gas 23 generated by the hydrogen production apparatus 20 as raw materials are provided, the hydrogen 21 Can be efficiently produced, and exhaust gas generated during production can be used effectively.
In addition, the hydrogen production apparatus 20 mixes the cold water 4 obtained by the NGH decomposition apparatus 7 and the natural gas 5 with a mixer 30, and modifies the mixed solution 30 a together with the natural gas 5 by using the heater 32 to convert the cold water 4 into water vapor. The reformed gas is introduced into the reformer 34 and reformed. The reformed gas is further sent to a reformer 36, where carbon monoxide is denatured into hydrogen and further other components including hydrogen are removed. Since it is sent to the PSA device 40, other components can be adsorbed to increase the purity of the hydrogen 21.

In addition, since the hydrogen 21 is purified by the PSA device 40 without performing the denaturing reaction after the reforming reaction, the amount of hydrogen 21 generated is smaller than when the denaturing device 36 is present, but the carbon monoxide 25 The production amount of can be increased.
The carbon monoxide 25 is recovered from the off-gas 41 generated after the hydrogen 21 is purified by the PSA device 40 by an adsorption method or a method of generating a hydrate and separating it from other components. The carbon dioxide 26 is recovered from the combustion exhaust gas 45 discharged from the heating chamber 31 by an adsorption method or a method of generating a hydrate and separating it from other components. Either method can be selected depending on the balance.

Further, since the reformed gas cooler 35 and the modified gas cooler 37 are cooled using the water 4 generated by the NGH decomposition apparatus 7, it is not necessary to separately prepare water for cooling the cooler, and water should be used effectively. Can do.
Moreover, since the hot waters 39 and 38 heat-exchanged by the reformed gas cooler 35 and the modified gas cooler 37 are used to promote the reforming reaction of the reformer 34, the fuel used for heating can be saved. Can do.
Moreover, since the heating chamber 31 produces | generates a heat source using the off gas 44 discharged | emitted from the natural gas 5 and the carbon monoxide collection | recovery apparatus 42 obtained by the NGH decomposition | disassembly apparatus 7, the fuel for a heating is used effectively. be able to.

Further, since the gas cooling means of the carbon monoxide recovery device 42 cools off gas by penetrating the piping of the off gas 52 by utilizing the low temperature inside the NGH decomposition device 7, other cooling means are required. Therefore, the equipment cost can be saved.
Further, since the gas cooling means of the carbon dioxide recovery device 46 cools the combustion exhaust gas 45 through the piping of the combustion exhaust gas 45 by utilizing the low temperature inside the NGH decomposition device 7, other cooling means are used. It is not necessary, and the equipment cost can be saved.

1 is a schematic configuration diagram of a hydrogen production system according to an embodiment of the present invention. It is a figure which represents typically the structure of the NGH decomposition | disassembly apparatus of this invention. It is a figure which shows the structure of the hydrogen production apparatus which concerns on the 1st Embodiment of this invention. It is a figure which shows the structure of the hydrogen production apparatus which concerns on the 2nd Embodiment of this invention. It is a figure which shows the structure of the carbon monoxide collection | recovery apparatus by carbon monoxide hydrate, (a) is a block diagram, (b) is a figure explaining the method of cooling offgas in a NGH decomposition | disassembly apparatus.

Explanation of symbols

  1 NGH tank, 2 NGH, 4 water, 5 natural gas, 7 NGH decomposition device, 20, 70 Hydrogen production device, 21 Hydrogen, 22 Off-gas, 23 Combustion exhaust gas, 24 Recovery device, 25 Carbon monoxide, 26 Carbon dioxide, 30 Mixer, 31 heating chamber, 32 heater, 33 burner, 34 reformer, 35 reformed gas cooler, 36 reformer, 37 modified gas cooler, 40 PSA device, 42 carbon monoxide recovery device, 44 off gas, 45 combustion exhaust gas, 46 Carbon dioxide recovery device, 56 Pressurizer, 100 Hydrogen production system

Claims (9)

A natural gas hydrate decomposition device that decomposes natural gas hydrate by applying heat to produce water and natural gas;
A hydrogen production apparatus for producing hydrogen using water produced by the natural gas hydrate decomposition apparatus and natural gas as raw materials;
A recovery device that recovers carbon monoxide and carbon dioxide using off-gas and combustion exhaust gas generated by the hydrogen production device as raw materials;
A hydrogen production system comprising: The hydrogen production apparatus includes a mixer that mixes water produced by the natural gas hydrate decomposition apparatus and natural gas to produce a mixed liquid;
A heater that heats and vaporizes the mixture produced by the mixer;
A reformer that introduces steam vaporized by the heater and a natural gas contained in the mixed solution to perform a reforming reaction;
A heating chamber for heating the heater and the reformer;
A denaturer that denatures carbon monoxide contained in the reformed gas generated by the reformer into hydrogen;
A PSA device that selectively adsorbs components other than hydrogen contained in the denatured gas sent from the denaturer;
The hydrogen production system according to claim 1, comprising: The hydrogen production apparatus comprises a mixer for mixing water and natural gas generated by the natural gas hydrate decomposition apparatus;
A heater that heats and vaporizes the mixture produced by the mixer;
A reformer that introduces steam vaporized by the heater and a natural gas contained in the mixed solution to perform a reforming reaction;
A heating chamber for heating the heater and the reformer;
A PSA device that selectively adsorbs components other than hydrogen contained in the reformed gas sent from the reformer;
The hydrogen production system according to claim 1, comprising: The recovery device selectively separates carbon monoxide from other gases by generating carbon monoxide hydrate from the off-gas generated after the hydrogen is purified by the PSA device. A carbon monoxide recovery device for recovering the carbon monoxide by any of the methods;
The carbon dioxide is recovered by either selectively adsorbing carbon dioxide from the combustion exhaust gas discharged from the heating chamber or by separating it from other gases by generating carbon dioxide hydrate. The hydrogen production system according to claim 1, 2 or 3, further comprising a carbon dioxide recovery device. A reformed gas cooler provided at the outlet of the reformer to cool the reformed gas heated to a temperature necessary for reacting the reformer;
A denaturing gas cooler provided at the outlet of the denaturing device in order to cool the denaturing gas heated to a temperature necessary for reacting the denaturing unit,
4. The hydrogen production system according to claim 1, wherein the reformed gas cooler and / or the modified gas cooler is cooled using water generated by the natural gas hydrate decomposition apparatus.   The hot water exchanged by the reformed gas cooler and / or the modified gas cooler is used to promote a reforming reaction of the reformer. Hydrogen production system.   The said heating chamber produces | generates a heat source using the off gas discharged | emitted from the said natural gas obtained by the said natural gas hydrate decomposition | disassembly apparatus and the said carbon monoxide collection | recovery apparatus as fuel. The hydrogen production system described in 1. The carbon monoxide recovery device includes a gas cooling means for cooling off-gas generated after hydrogen is purified by the PSA device;
Pressurizing means for pressurizing the off-gas cooled by the gas cooling means;
A stirring means for stirring the off-gas pressurized by the pressurizing means and water;
The gas cooling means cools the off-gas to generate the carbon monoxide hydrate by penetrating at least a pipe for passing the off-gas into the natural gas hydrate decomposition apparatus. Item 5. The hydrogen production system according to Item 4. The carbon dioxide recovery device includes gas cooling means for cooling the combustion exhaust gas discharged from the heating chamber,
Pressurizing means for pressurizing the combustion exhaust gas cooled by the gas cooling means; and stirring means for stirring the combustion exhaust gas pressurized by the pressurization means and water,
The gas cooling means cools the combustion exhaust gas to generate the carbon dioxide hydrate by penetrating at least a pipe for passing the combustion exhaust gas into the natural gas hydrate decomposition apparatus. The hydrogen production system according to claim 4.

Images