JP6989820B2 - Hydrogen generation system and fuel cell system - Google Patents

Description

The present disclosure relates to hydrogen generation systems and fuel cell systems.

Methanol, which is a clean energy source, is attracting attention as a hydrogen supply source because of the large amount of hydrogen produced by the reforming reaction. Fuel cells, which have been attracting attention in recent years as one of the uses of hydrogen supply sources, are required to have a method for producing high-purity hydrogen in order to put them into practical use.

A steam reforming method by vapor phase contact is generally known for reforming methanol. In the steam reforming method, a copper catalyst or a composite catalyst in which a secondary metal such as zinc is added to copper is used.
However, since the steam reforming method is a solid air contact method, it is necessary to prepare heat of vaporization for converting methanol and water into gas in advance and a wide solid air contact area in the endothermic reactor, which saves energy. It is not preferable from the viewpoint of energy saving and compactness of the system.

On the other hand, a method for producing hydrogen in which an aqueous methanol solution is reformed with a liquid phase in the presence of a solid catalyst is disclosed (see, for example, Patent Document 1).
Further, it is also disclosed that a superheated liquid film type dehydrogenation reaction utilizing a superheated liquid film state is applied as a reforming reaction of an aqueous methanol solution (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 11-157803 Japanese Patent No. 4213952

As described above, a method of reforming an aqueous methanol solution in a liquid phase has been disclosed, but even if a simple catalyst is used to reform methanol in the liquid phase, a high hydrogen conversion rate cannot be expected. Unless a large reaction field is secured, it is difficult to secure a desired amount of hydrogen in a temperature range of about 250 ° C to 350 ° C.

Further, in order to increase the hydrogen conversion rate while suppressing the generation of CO to a low level by performing the reforming reaction in a temperature range of about 250 ° C. to 350 ° C., it is desirable to form a superheated liquid film state in the liquid phase catalytic reaction. , It is difficult to maintain the superheated liquid film state in the actual reaction field.

The present disclosure has been made in view of the above.
An object of the present disclosure is to provide a hydrogen generation system that is compact and stably generates hydrogen in a medium temperature region (250 ° C to 350 ° C), and a fuel cell system that can supply electric power according to demand. do.

In order to achieve the above object, the hydrogen generation system according to the first aspect of the present disclosure is
<1> A hydrogen generator that reforms an aqueous solution of methanol to generate hydrogen gas and a mixed gas containing hydrogen discharged from the hydrogen generator are supplied, and the supplied mixed gas is condensed into at least hydrogen gas. It is provided with a condensate separation device for separating the condensate and a resupply means for resupplying at least unreacted methanol in the condensate separated by the condensate separation device to the hydrogen generation device for reforming the aqueous solution.
The hydrogen generator is
A substrate having a tubular structure with at least one end open and a heating chamber disposed inside the tubular structure.
A catalyst arranged so as to cover at least a part of the outer peripheral surface of the tubular structure of the substrate and having a catalyst metal supported on a carbon sheet.
An exterior material that houses the substrate on which the catalyst is placed, and
A discharge port arranged on the side of one end of the substrate in the length direction of the cylinder and discharging hydrogen gas.
A supply port arranged on the other end side in the length direction of the cylinder of the substrate and supplying an aqueous methanol solution between the substrate and the exterior material.
The supplied methanol aqueous solution is reformed with the catalyst to generate hydrogen gas.

In the hydrogen generation system according to the first aspect, an aqueous methanol solution is reformed by a hydrogen generator equipped with a sheet-shaped catalyst, and the mixed gas containing the reformed and generated hydrogen is condensed by a condensation separation device. At least separated into hydrogen gas and condensate, and the separated hydrogen gas (preferably hydrogen gas purified from a gas phase component other than hydrogen gas by a hydrogen separation membrane or the like) is supplied to an external hydrogen-using device. .. On the other hand, the separated condensate contains an unreacted aqueous methanol solution that has not been subjected to the aqueous solution reforming reaction, and at least unreacted methanol among the liquid phase condensates discharged from the condensation separation apparatus. Will be supplied to the same or another hydrogen generator by the resupply means and will be subjected to aqueous solution reforming in the hydrogen generator.
At this time, the hydrogen generator has a tubular structure of the substrate forming the reaction chamber, with the space formed between the substrate responsible for the heating function of the catalyst and the inner wall of the exterior material accommodating the substrate as the reaction chamber. A sheet-like catalyst in which a catalyst metal is supported on a heat-transmitting sheet-like carrier is arranged, for example, by winding (preferably multiple times) so as to cover at least a part of the periphery of the tubular structure. Then, the aqueous methanol supplied to the reaction chamber is reformed using a sheet-shaped catalyst.
That is, a sheet-shaped catalyst in which a catalyst metal is supported on a sheet-shaped carrier is arranged, for example, by winding (preferably multiple times) around the tubular structure of the substrate provided with the heating chamber. In addition, a methanol aqueous solution at room temperature is sent from a supply port to a carbon-based sheet-like carrier having heat transfer properties to condense and store the methanol solution in the micropores, where the methanol aqueous solution is preheated until it exceeds the boiling point. Set the flow line velocity. The superheated aqueous solution of methanol diffuses and moves on the carbon surface while maintaining an appropriate wet state, and reaches the metal particles of the catalyst at the nucleate boiling point. The hydrogen, carbon dioxide, and carbon monoxide vapor phase products generated on the surface of the catalyst metal and the unreacted aqueous solution of methanol frequently form isolated bubbles by taking advantage of the heating source temperature well above the boiling point and the good heat flux. However, as soon as the bubbles are separated, they are covered with the superheated liquid, and the reforming reaction of the aqueous methanol solution proceeds irreversibly. Therefore, endothermic reaction heat and product desorption heat can be effectively donated to the catalyst as a result of the densification of vacant active sites under steep temperature gradients and large amounts of heat transfer.
As a result, hydrogen gas can be reformed and generated in the medium temperature region (250 ° C to 350 ° C) while achieving miniaturization, and the reforming reaction can be converted by circulating and reusing agglomerates containing an unreacted aqueous solution of methanol. The rate improves dramatically. Further, by adjusting the supply rate of the aqueous methanol solution, the flow line velocity of the aqueous methanol solution forming a superheated liquid film state is controlled, and the amount of hydrogen corresponding to the amount of hydrogen required by the fuel cell (external hydrogen demand) is met. Along with achieving supply, complete conversion of methanol can be achieved throughout the system. As a result, the amount of hydrogen produced can be dramatically improved.

<2> In the hydrogen generation system according to the first aspect of the above <1>, it is preferable that the catalyst is wound around the outer peripheral surface of the substrate to have a laminated structure.
When the catalyst has a laminated structure wound so as to cover the outer periphery of the substrate heated from the inside of the substrate, bubbles generated in the aqueous methanol solution forming a superheated liquid film state while increasing the amount of the catalyst metal supported. Can be efficiently escaped. As a result, the contact between the catalyst and the gas-liquid mixed phase is minimized, solid-liquid contact is ensured, and the heat transfer coefficient can be kept high. Can be generated.

<3> In the hydrogen generation system according to the first aspect of <1> or <2>, the catalyst has a catalyst metal supported on the carbon sheet of 15 g / L to 150 g / L. Is preferable.
When the amount of the catalyst metal supported on the carbon sheet is within the above range, the foaming points in the liquid phase catalytic reaction increase, the nucleate boiling state with a large heat transfer coefficient tends to occur, and the hydrogen gas generation efficiency is excellent. Will be.

<4> In the hydrogen generation system according to the first aspect according to any one of <1> to <3>, the catalyst reforms the supplied methanol aqueous solution in a superheated liquid film state. It is preferable that it is a thing.

By performing a dehydrogenation reaction utilizing the superheated liquid film state, the amount of hydrogen gas generated can be further increased.
Here, the "superheated liquid film state" means a state in which the surface of the catalyst is slightly moistened with an aqueous solution of methanol in a superheated state (heating at a temperature exceeding the boiling point of methanol).

<5> In the hydrogen generation system according to the first aspect according to any one of <1> to <4>, the aqueous methanol solution supplied from the supply port is in the length direction of the cylinder of the substrate. It is preferable that the aqueous solution is reformed by the catalyst in a state where it is preheated while being distributed in the water and superheated to a temperature exceeding the boiling point.
Since the catalyst temperature is in a high temperature state exceeding the boiling point of methanol, the temperature of the reaction system is kept low and the hydrogen production efficiency is excellent.

<6> In the hydrogen generation system according to the first aspect according to any one of <1> to <5>, the carbon sheet is preferably carbon cloth or carbon felt.
Since both the carbon cloth and the carbon felt are sheets using fibrous carbon, they have micropores and have a large surface area. Therefore, it is easy to hold an aqueous solution of methanol in a superheated state, and it is easy to support a catalyst metal.

<7> In the hydrogen generation system according to the first aspect according to any one of <1> to <6>, the catalyst metal is platinum, palladium, ruthenium, nickel or copper, or platinum. It is preferably a composite of at least one selected from the metal group consisting of palladium, ruthenium, nickel and copper and another metal different from the metal of the metal group.
<8> In the hydrogen generation system according to the first aspect of the above <7>, the other metal preferably contains at least one of manganese and zinc.
As described above, by selecting the above metal as the catalyst metal, the aqueous solution modifying activity becomes more excellent.

<9> In the hydrogen generation system according to the first aspect according to any one of <1> to <8>, the catalyst metal is a solid solution containing at least one of platinum, ruthenium, and nickel. Is preferable.
As described above, by selecting the above metal as the catalyst metal, the aqueous solution modifying activity becomes more excellent.

<10> In the hydrogen generation system according to the first aspect according to any one of <1> to <9>, the catalyst is supported by metal particles containing the catalyst metal, and the metal particles are supported. The average primary particle size is preferably 10 nm or less.
When the catalyst metal is supported as metal particles and the supported metal particles have a small particle size, the number of foaming points in the liquid phase catalytic reaction is increased, the heat transfer property is further improved, and the reforming of the aqueous solution is further promoted. It will be easier.

The fuel cell system according to the second aspect of the present disclosure is
<11> The hydrogen generation system according to any one of the above <1> to the above <10>, and a fuel cell that generates electricity by hydrogen gas generated by the hydrogen generation system are provided.

Since the fuel cell system according to the second aspect includes the hydrogen generation system according to the first aspect, the system can be miniaturized, and the outside can be maintained while maintaining a medium temperature range of 250 ° C to 350 ° C. It is possible to supply electric power according to the demand of hydrogen-using equipment.

According to the present disclosure, a hydrogen generation system that is small in size and stably generates hydrogen in a medium temperature region (250 ° C to 350 ° C) and a fuel cell system capable of supplying electric power according to demand are provided.

It is a schematic block diagram which shows an example of the fuel cell system of this disclosure. It is a schematic perspective view which shows an example of the hydrogen generation apparatus of this disclosure. It is an exploded view which shows by disassembling the hydrogen generation apparatus of FIG. FIG. 2 is a cross-sectional view taken along the line AA of the hydrogen generator of FIG. It is a schematic perspective view which shows the state which the catalyst is arranged so as to cover the periphery of the tubular structure of a substrate. It is a schematic perspective view which shows the circular catalyst of a single-layer structure, a two-layer structure or a three-layer structure in which platinum particles are supported on a carbon cloth. It is a graph which shows the relationship between the supply amount of an aqueous methanol solution, and the hydrogen generation rate at the time of hydrogen generation using the three kinds of circular catalysts of FIG. (A) shows a state in which the supply amount of the methanol aqueous solution is too small to dry, (b) shows a superheated liquid film state, and (c) shows a suspension state in which the supply amount of the methanol aqueous solution is too large. It is a schematic block diagram which shows another example of the fuel cell system of this disclosure.

Hereinafter, embodiments of the hydrogen generation system and the fuel cell system of the present disclosure will be specifically described with reference to FIGS. 1 to 8. However, the present disclosure is not limited to the embodiments shown below.

In one embodiment of the present disclosure, the supplied methanol aqueous solution is reformed into an aqueous solution to generate hydrogen gas by using a sheet-shaped catalyst in which platinum particles as a catalyst metal are supported on a sheet-shaped carbon cloth as a catalyst. The embodiment will be described in detail as an example.

As shown in FIG. 1, the fuel cell system 100 of the embodiment of the present disclosure is a condensation separator which is a condensation separator which is connected to a hydrogen generator 10 and a hydrogen generator and a mixed gas containing hydrogen gas is sent. 20 and a hydrogen storage tank 30 for storing hydrogen-containing gas separated from condensable methanol and water by a condensation separator 20, and a solid polymer fuel cell (PEFC) which is an example of a fuel cell to which hydrogen gas is supplied. ) 60 and a control device 40 for controlling system operation.

In the fuel cell system 100 according to the embodiment of the present disclosure, the hydrogen-containing gas is separated from the hydrogen-containing mixed gas generated by the hydrogen generation device 10 by the aqueous solution reforming by the condensation separator 20 and hydrogen-containing through the hydrogen permeation film. By supplying hydrogen gas purified from the gas to PEFC, a system is constructed in which PEFC supplies electric power according to demand to an external hydrogen-using device. The hydrogen supply according to the PEFC's requirement based on external demand can be adjusted by adjusting the flow rate of the aqueous methanol solution.
When carbon monoxide is generated by a hydrogen generator, carbon monoxide is temporarily stored as a hydrogen-containing gas together with hydrogen, but as hydrogen is selectively purified from the hydrogen-containing gas, the stored carbon monoxide is stored. Carbon increases. Then, when combustion heat is required, carbon monoxide is used for combustion and is effectively used as heat energy.

The hydrogen generation device 10 reforms an aqueous solution of methanol supplied from the outside with a catalyst to generate hydrogen gas. The generated hydrogen gas is sent to the condensation separator 20 as a mixed gas mixed with other gas components via the gas discharge pipe 12 connected to the hydrogen generation device 10.
Here, the mixed gas discharged from the hydrogen generator includes, in addition to hydrogen generated by the aqueous solution reforming reaction, other gas components such as carbon dioxide, carbon monoxide, steam, and unreacted methanol. Therefore, the mixed gas containing hydrogen flows through the gas discharge pipe 12 connected to the hydrogen generator.

The hydrogen generation apparatus of the present disclosure will be further described in detail with reference to FIGS. 2 to 4.
One embodiment of the present disclosure comprises the hydrogen generator 10 shown in FIG. As shown in FIG. 3, the hydrogen generation device 10 includes a substrate 13 having a cylindrical structure in which one end is open and the other end is closed, and an exterior material 11 for accommodating the substrate 13. It is a cylindrical reforming reactor.
FIG. 2 is a schematic perspective view showing a hydrogen generation device according to an embodiment of the present disclosure, and FIG. 3 is an exploded view showing the hydrogen generation device 10 of FIG. 2 in an exploded manner.

The exterior material 11 has a tubular structure that is hollow inside and has one end open, a discharge port 12a that discharges hydrogen gas provided on the tubular structure, and a supply port 14a that supplies a methanol aqueous solution to a hydrogen generator. One end of the gas discharge pipe 12 for discharging the generated gas is connected to the discharge port 12a, and one end of the raw material supply pipe 14 is connected to the supply port 14a.

The gas discharge pipe 12 is a pipe for discharging the gas generated in the reaction chamber of the hydrogen generation device 10 to the outside. As shown in FIG. 1, the other end of the gas discharge pipe 12 is connected to a condensing separator 20 that separates hydrogen gas from the mixed gas containing the reformed and generated hydrogen gas, and operates the mixed gas pump P1. Then, the mixed gas is sent from the hydrogen generator 10 to the condensation separator 20 through the gas discharge pipe 12.

The raw material supply pipe 14 is provided with a raw material supply pump P2, and is a pipe for supplying an aqueous methanol solution, which is a raw material for reforming, to the reaction chamber of the hydrogen generation device 10 from the outside. As shown in FIG. 1, the other end of the raw material supply pipe 14 is connected to the raw material supply device 50 which is a supply source of the aqueous methanol solution, and by operating the raw material supply pump P2, the raw material is supplied from the raw material supply device 50. An aqueous solution of methanol is supplied to the reaction chamber of the hydrogen generator through the tube 14.

Although not shown, the raw material supply pipe 14 is preferably configured in such a manner that a heater for preheating the aqueous methanol solution is provided in the middle of the pipe.
A heater is arranged in the middle of the raw material supply pipe 14, and when the aqueous methanol solution is supplied from the raw material supply pipe 14 to the reaction chamber of the hydrogen generator 10, the aqueous methanol is preheated to the boiling point before being supplied to the reaction chamber. It is preferable to be done. By supplying the aqueous methanol solution to the reaction chamber in a state of being preheated to the boiling point in advance, a superheated liquid film state is likely to be formed, which is advantageous in increasing the efficiency of hydrogen production.
The heat required for preheating may be applied using an electric heater as described later, but for the heat required for preheating, for example, combustion heat obtained from a combustion device such as a burner or a boiler should be used. You can also. Of the combustion heat, it is preferable to use heat in, for example, a medium temperature range (about 250 ° C. to 350 ° C.) other than the heat in the target temperature range.

The substrate 13 has a cylindrical tubular structure 16 having one end open and the other end closed, and an exterior material when the open other end of the tubular structure is closed and housed in the exterior material 11. A lid material 17 for closing the other end of the cylinder 11 is provided, and a catalyst (not shown) is arranged on the outer peripheral surface of the cylinder structure 16 so as to cover the periphery of the cylinder structure 16. It has become.

Here, FIG. 4 shows a cross-sectional structure of the hydrogen generating apparatus 10 in a state where the substrate 13 is housed in the exterior material 11. FIG. 4 is a sectional view taken along line AA of the hydrogen generator of FIG.
In a state where the substrate 13 is inserted and housed in the exterior material 11, a reaction chamber 18 in which a catalyst-based reforming reaction is performed is formed between the inner wall surface of the exterior material 11 and the surface of the tubular structure of the substrate 13. It is formed. In the reaction chamber 18, a catalyst 15 provided so as to cover the outer peripheral surface of the tubular structure is arranged along the peripheral direction of the tubular structure 16 of the substrate 13.

As shown in FIG. 5, the tubular structure 16 of the substrate 13 is formed with a triple laminated structure in which a sheet-shaped catalyst 15 is wound over the entire surface around the cylindrical shape. That is, on the substrate 13, a catalyst layer composed of three layers is arranged by winding a sheet-shaped catalyst 15 on a curved surface of a tubular structure 16 and winding the catalyst 15 three times.
In the present embodiment, the case where the catalyst layer composed of three layers in which the catalyst is wound three times is provided has been described, but the laminated structure of the catalyst is not particularly limited, and the scale and supply of the hydrogen generator are supplied. It can be appropriately selected according to various requirements such as the amount or flow rate or temperature of the aqueous methanol solution, the amount of hydrogen gas reformed and generated, the amount of catalyst supported or the type of catalyst metal.
Therefore, the number of turns of the catalyst to be wound is preferably 3 or more, and may be 5 or more or 10 or more, if necessary. The upper limit of the number of turns is not limited, but may be 20 or less, for example.

The catalyst 15 has a carbon cloth which is a carbon sheet and platinum particles which are catalyst metals supported on the carbon cloth.

Preferred examples of the catalyst metal include platinum (Pt), palladium (Pd), ruthenium (Ru), nickel (Ni), and copper (Cu), and the catalyst metal may be a composite containing these metals. .. Examples of the composite include a composite consisting of at least one selected from the metal group consisting of platinum, palladium, ruthenium, nickel and copper, and another metal different from the metal of the metal group. Other metals include zinc (Zn), manganese (Mn) and the like, preferably zinc or manganese, or zinc and manganese.
Examples of the catalyst metal as the complex include Ni-Ru (1: 1), Ni-Cu (1: 1), Cu-Ru (2: 1), Cu-Mn (12: 1) and the like. Can be done. The numbers in parentheses indicate the molar ratio of the elements.
As the composite, a solid solution is preferable because it can more efficiently modify the aqueous methanol solution by the superheated liquid film method, and a solid solution containing at least one of platinum, ruthenium, and nickel is preferable.

The carbon sheet is used as a carrier for supporting the catalyst metal. By using the sheet-shaped carrier, it is possible to cover the outer peripheral surface of the tubular structure and to stack and wind the cylinder structure as in the present embodiment. When the carbon sheets on which the catalyst metal is supported are stacked and wound, a superheated liquid film state is generated in the methanol aqueous solution while increasing the amount of the catalyst metal supported, and the gas phase in the gas-liquid mixed phase existing in the vicinity of the catalyst particles. Suitable for efficiently releasing ingredients. Therefore, since solid-liquid contact is secured and the heat transfer coefficient can be increased, efficient hydrogen generation is possible, and further, by increasing the supply flow rate of the methanol aqueous solution, the reaction opportunity by solid-liquid contact is further increased. Compared to a carbon-supported catalyst that does not have a wound structure, more efficient hydrogen generation becomes possible.
However, if the supply flow rate of the aqueous methanol solution becomes too large, liquid phase components that do not come into contact with the catalyst and pass through the gaps between the catalysts of the wound structure and do not contribute to the reaction are likely to occur (channeling), resulting in conversion rate. Will gradually decrease, and the hydrogen production rate will decrease. By increasing the temperature, the heat flux can be increased and the hydrogen production rate can be improved. When the temperature is raised, it is desirable to keep the temperature low in a temperature range that does not lead to film boiling so that nucleate boiling, which is advantageous for heat transfer, does not convert to film boiling, which is disadvantageous for heat transfer. By suppressing the temperature to a temperature range that does not lead to film boiling, it becomes possible to efficiently generate hydrogen gas.
That is, it is important that the relationship between the amount of catalyst and the amount of the aqueous methanol solution (raw material for reforming) that can maintain the superheated liquid film state is within the range of ensuring the solid-liquid contact state. This makes it possible to efficiently proceed with the reforming reaction of the reforming raw material while distributing the reforming raw material supplied from one end side to the other end side.

In order to maintain a state in which the catalyst is appropriately moistened with an aqueous methanol solution (superheated liquid film state), it is important to consider the following points.
(1) Since the reforming of an aqueous methanol solution is a reaction in which the liquid phase changes into a gas phase product in parallel with evaporation, the supplied amount of the aqueous methanol solution is such that the aqueous methanol solution does not evaporate completely and a superheated solution exists. However, it is preferable to adjust the amount to a range not too small compared to the amount of the catalyst, that is, a range in which the solid-liquid contact does not become a solid contact.
(2) Further, since the reaction rate is increased by the catalytically active site becoming an effervescent point and growing and releasing bubbles, the supply amount of the supplied methanol aqueous solution is adjusted within a range not too large compared to the catalytic amount. It is preferable to be done. As a result, when the carrier is a carbon sheet, an appropriate wet state can be maintained, and when the carrier is granular carbon, the carrier is in a suspended state and the temperature difference at the solid-liquid interface is suppressed from being lost.
(3) Therefore, when the catalyst is placed under the nucleate boiling condition while maintaining the state of being appropriately moistened with the aqueous methanol solution, the heat transferred from the external heating source to the superheated liquid film causes the growth and detachment of bubbles. Can be strongly encouraged.
From the above, the relationship between the amount of catalyst metal [V ¹ ; g] and the amount of methanol aqueous solution [V ² ; L (liter)] that can maintain the superheated liquid film state is as follows. The range shown is preferable, and the range shown by the following formula 2 is more preferable.
V ² / V ¹ = 10 g / L to 50 g / L ... Equation 1
V ² / V ¹ = 15 g / L to 20 g / L ... Equation 2

As the carbon sheet, carbon cloth or carbon felt can be used.
The carbon cloth refers to a cloth obtained by spinning carbon fiber obtained by firing and carbonizing carbon fiber such as acrylic fiber, and a commercially available product on the market (for example, carbon cloth manufactured by Kuraray Chemical Co., Ltd.) is used. Can be done.
Carbon felt refers to a sheet-shaped non-woven fabric in which short fibers of carbon fibers are entwined without weaving carbon fibers, and commercially available products on the market (for example, carbon cloth manufactured by Kuraray Chemical Co., Ltd.) can be used. ..

As the catalyst, it is preferable that the metal particles containing the catalyst metal are supported and the average primary particle diameter of the supported metal particles is 10 nm or less. That is, when the surface area is increased by being supported in the form of metal particles and the average primary particle diameter of the supported metal particles is a small particle size of 10 nm or less, the number of foaming points in the liquid phase catalytic reaction increases. , The heat flux increases and the reforming reactivity is further improved.
The smaller the average primary particle size is, the better from the viewpoint of the reforming reaction activity, and 5 nm or less is more preferable. The lower limit of the average primary particle diameter may be, for example, 2 nm.
The average primary particle size is a value obtained as an average value of the primary particle size measured by observing with a transmission electron microscope and arbitrarily selecting 20 arbitrary metal particles.

The amount of the catalyst metal supported on the catalyst depends on the type of metal, the temperature, and the like, but in the catalyst of the present disclosure, the amount of the catalyst metal supported on the carbon sheet is 15 g / L to 150 g / L. preferable.
When the amount of the catalyst metal supported on the carbon sheet is 15 g / L or more, the foaming points in the liquid phase catalytic reaction increase, it is easy to maintain the state of nucleate boiling with a large heat transfer coefficient, and the hydrogen gas generation efficiency is excellent. .. Further, when the amount of the catalyst metal supported on the carbon sheet is 150 g / L or less, it is advantageous in that the particle size of the metal particles of the catalyst can be adjusted to an appropriate range and long-term stability can be easily obtained. ..
The amount of the catalyst metal supported on the carbon sheet may be selected according to the type of catalyst. For example, in the case of a Pt-based catalyst, since it is highly active, 15 g / m ³ to 100 g from the viewpoint of securing the required amount. It may be set to / m ³ or, for example, in the case of a Cu—Mn-based catalyst, it may be set to 100 g / m ³ to 150 g / m ³ because it is inexpensive.

The method for producing the catalyst in which the catalyst metal is supported on the carbon sheet is not particularly limited, and any method may be used for producing the catalyst. The catalyst may be produced, for example, by an impregnation method in which a carrier is impregnated in a metal-containing liquid.
In the case of the impregnation method, for example, it can be produced by the following method. That is,
First, a carbon material (for example, a carbon sheet having a high surface area having pores) that has been pretreated with a base or the like is prepared. The carbon sheet is immersed in a stirring aqueous solution of potassium chloride (K ₂ PtCl ₄ ) for 24 hours and then heated and reduced with an aqueous solution of sodium borohydride (NaBH ₄ ) at 90 ° C. to form platinum metal. , Wash with 1000 ml of distilled water. By vacuum-drying the washed platinum metal at 70 ° C. for 10 hours, a platinum-supported catalyst in which platinum particles are supported on a carbon sheet can be produced.

The catalyst in the present disclosure modifies an aqueous solution of methanol in a superheated liquid film state. Aqueous solution reforming is a reforming reaction that produces hydrogen by catalytic reaction in a liquid phase, and is distinguished from a steam reforming reaction that produces hydrogen using steam.
When modifying an aqueous solution, the quantitative relationship between the amount of catalyst and the aqueous solution of methanol is important in the liquid-phase catalytic reaction that produces a gas.
In a reaction system in which the amount of the aqueous methanol solution is too large with respect to the amount of the catalyst, the catalyst particles supported on the granular carbon are present in a suspended state as shown in FIG. 8 (c). Since the temperature of the suspension is equal to the boiling point of the liquid phase, the dehydrogenation activity of this reaction system is small. On the other hand, in a reaction system in which the amount of catalyst is increased to form a state in which the catalyst is appropriately moistened with an aqueous methanol solution (wet state) as shown in FIG. 8B, the catalyst temperature is higher than the boiling point of the aqueous methanol solution. It becomes a high state (overheated state). The dehydrogenation activity is greatest when the catalyst is wet with an aqueous methanol solution. Such a state is called a "superheated liquid film state".
On the other hand, in a reaction system in which the amount of the aqueous methanol solution is too small with respect to the amount of the catalyst as shown in FIG. It becomes smaller. On the other hand, in general, when the temperature of the heat transfer surface is set too high, the generated bubbles coalesce to form a steam film and cover the heat transfer surface, resulting in film boiling. Therefore, good heat transfer from the heat transfer surface cannot be expected.
In the liquid phase catalytic reaction to generate a gas, it is preferable to use nucleate boiling, which has a large heat transfer coefficient. In the region of nucleate boiling, a superheated liquid is generated in the heat transfer boundary film at the solid-liquid interface, and the substance and heat are supplied from the liquid phase to the bubbles through gas phase generation and evaporation. At this time, if the catalyst particles are present, the catalyst particles play the role of a foaming point. In order to increase the surface area of the catalyst particles to be the foaming points, the catalyst particles are preferably small particles, and nano-order size particles are preferable. As a result, the number of foaming points increases, and the generation of isolated bubbles can be promoted.
In addition, since an endothermic reaction is added to the phase change, the heat transfer coefficient is improved, and the growth and desorption of bubbles are advantageous. Methanol molecules in the superheated liquid immediately adsorb to the catalytically active sites vacated by the separation of bubbles and begin to react.
A high bubble separation frequency can result in a large heat flux and empty site surface density, which can improve the reaction rate.

Here, a catalyst layer having a three-layer structure in which the sheet-shaped catalyst 15 is wound three times will be described.
In the liquid phase (methanol aqueous solution), the sheet-shaped catalyst 15 has nanoscale catalyst metal particles supported on the surface of the carbon sheet, and the micropores of the carbon sheet are methanol aqueous solution (methanol: water = 1: 1 [. Methanol ratio]) is stored and made wet.
The aqueous methanol solution preheated to near the boiling point condenses capillaries in the pores of the carbon sheet, and repeats pore condensation and surface movement from one end to the other end of the sheet, resulting in endothermic reforming reaction and evaporation. proceed. At that time, the reaction chamber 18 is heated from both sides of the substrate 13 side and the exterior material 11 side at a temperature higher than the boiling point of the aqueous methanol solution.
The methanol aqueous solution, which had only a liquid phase at one end of the sheet, changes to a gas-liquid mixed phase while moving in the reaction chamber. , The reaction rate inherent in the superheated liquid film state cannot be maintained.
In view of such a situation, in one embodiment of the present disclosure, the catalyst is arranged as a laminated structure in which a carbon sheet carrying a catalyst metal is wound a plurality of times, so that the gas phase component of the gas-liquid mixed phase is transferred between the sheets. It is easy to escape to the outside of the reaction system through the gap of. This facilitates stable nucleate boiling in the liquid phase, which is advantageous for satisfactorily advancing the reforming reaction with a catalyst.

Further, when a plurality of sheet-shaped catalysts 15 are stacked, the hydrogen production rate is approximately proportional to the number of laminated sheet-shaped catalysts when the supply rate of a substrate such as an aqueous methanol solution is changed. That is, by stacking the sheet-shaped catalysts, the bulk density of the metal particles of the catalyst in the reactor is increased while the superheated liquid film state is maintained. In this respect, it is meaningful to use the sheet-shaped catalysts in layers.
For example, as shown in FIG. 6, a single-layer structure, a two-layer structure, or a three-layer structure circular catalyst can be prepared by using a catalyst in which 12 mg of platinum particles are supported on a carbon cloth of φ4 cm as it is or by stacking a plurality of catalysts. Each was placed in contact with the heating surface. Then, 2-propanol (boiling point: 82.4 ° C.) heated to 150 ° C. was added dropwise to the concentric portion of the circular catalyst from the side farthest from the heating surface. As a result, as shown in FIG. 7, it was found that the hydrogen production rate is approximately proportional to the number of layers.
The dropped 2-propanol is surface-diffused and moves in the plane of the multi-layered circular catalyst, whereas the heat is transferred from the outside in the direction orthogonal to the plane of the circular catalyst, and it can be said that the superheated liquid film state. It is effective for maintaining the reforming reaction in.

Further, as shown in FIG. 4, inside the tubular structure 16, a heating chamber 19 for heating the catalyst arranged on the surface of the tubular structure 16 is provided. By controlling the heating temperature in the heating chamber 19, the catalyst can be heated and controlled in a desired temperature range via the wall material forming the curved surface of the tubular structure.
The heating chamber 19 may be configured as a combustion chamber that heats the tubular structure with the heat of combustion when the fuel is burned. In this case, a fuel supply system for supplying fuel to the heating chamber and an exhaust system for discharging combustion exhaust gas may be attached. Further, the heating chamber 19 may be a heating chamber in which an electric heater is arranged. As the electric heater, either a heat generating heater, a radiant heat heater, or the like may be used.

Further, a tape heater, which is a heater for heating the catalyst via the exterior material, is arranged on the outside of the exterior material 11 accommodating the tubular structure 16. As a result, as shown in FIG. 4, the catalyst 15 in the reaction chamber 18 is heated from both sides of the substrate 13 side and the exterior material 11 side.
As the heater, in addition to the tape heater, a combustion waste heat transfer device that heats by utilizing the combustion waste heat may be used.

It is preferable to use a part of the combustion heat obtained by the combustion device 70 such as a burner, for example, to apply the heat required for heating the catalyst. In the present disclosure, among the combustion heat obtained by the combustion equipment, the heat in the temperature range originally intended is used for the intended purpose, and the heat in the medium temperature range (about 250 ° C to 350 ° C) other than the heat in the target temperature range is used. The heat of the above can be used for heating the hydrogen generator. Specifically, a so-called combustion exhaust heat transfer device that heats with combustion exhaust heat is used, and the amount of heat required by the hydrogen generator at the start of the system is covered by the combustion exhaust heat obtained by the combustion device 70 such as a burner. preferable. In this case, the heat of combustion may be used for heating the reaction chamber, or may be used for preheating the aqueous methanol solution supplied to the reaction chamber.

The substrate 13 and the exterior material 11 are preferably made of a heat transferable material so that the catalyst can be heated to raise the temperature. As the heat transfer material, metal is preferable. The metal is not particularly limited, and for example, a stainless alloy (so-called SUS material) is preferable from the viewpoint of heat resistance, corrosion, and the like.

The heating temperature of the catalyst is preferably 150 ° C. to 350 ° C., more preferably 250 ° C. to 350 ° C.

The condensation separator 20 which is a condensation separator is connected to the hydrogen generator 10 by a gas discharge pipe 12.
When hydrogen is generated by the hydrogen generator 10, the hydrogen is discharged to the gas discharge pipe 12 as a mixed gas mixed with other gas components, and by operating the mixed gas pump P1 attached to the gas discharge pipe 12, the hydrogen is discharged. The mixed gas is sent to the condensing separator 20 via the gas discharge pipe 12. The mixed gas includes hydrogen gas, carbon dioxide, carbon monoxide, water vapor, and unreacted methanol.

The condensation separation device condenses a mixed gas containing hydrogen gas generated by the hydrogen generator, and utilizes the difference in boiling point to separate gas components such as hydrogen gas (hydrogen-containing gas) and condensable components (condensate). Separate and purify.
At this time, the gas component includes hydrogen, carbon dioxide and carbon monoxide. Therefore, the gas components of hydrogen, carbon dioxide and carbon monoxide can be separated from the mixed gas by condensation.
As the condensation separation device, an apparatus capable of separating a mixed gas of hydrogen and carbon dioxide or a mixed gas of hydrogen, carbon dioxide and carbon monoxide from unreacted methanol and water by condensation is arbitrarily selected and used. can do. As the condensation separation device, for example, a distillation device may be used.

One end of a return pipe 24, which is a resupply means for subjecting the agglomerate to the aqueous solution reforming reaction in the hydrogen generation device 10, is connected to the condensation separator 20. In the condensation separator 20, the agglomerates separated from the gas component such as hydrogen gas are discharged from the condensation separator 20 through the return pipe 24.

The return pipe 24 is connected to the upstream side of the raw material supply pipe 14 having the other end connected to the hydrogen generator in the flow direction of the methanol aqueous solution. As a result, the hydrogen generator 10 and the condensation separator 20 are communicated with each other by a return pipe. The condensate flowing through the return pipe 24 is returned to the raw material supply pipe 14, and is supplied to the reaction chamber of the hydrogen generator by operating the raw material supply pump P2. The condensed product supplied to the reaction chamber is reused for the aqueous solution reforming reaction. Then, the same amount of methanol and water as the methanol aqueous solution used in the aqueous solution reforming reaction is newly supplied from the raw material supply device 50 to the hydrogen generation device as a methanol aqueous solution.
In this way, the unreacted methanol and water remaining in the condensate after the hydrogen gas is separated are reused for the aqueous solution reforming reaction through the circulation path, so that the supplied methanol can be completely converted. Become.

Although not shown, the return pipe 24 may be provided with a drive pump for satisfactorily circulating the liquid phase condensate in the pipe, if necessary.

A hydrogen storage tank 30 is connected to the condensation separator 20 by a hydrogen flow pipe 22.
In the condensation separator 20, after the gas component (hydrogen-containing gas) is separated from the mixed gas generated by the hydrogen generator 10, the separated hydrogen-containing gas is temporarily stored in the hydrogen storage tank 30. The hydrogen-containing gas may contain carbon dioxide or the like in addition to hydrogen.
The hydrogen-containing gas generated by the hydrogen generator can be directly supplied to the fuel cell, but it is temporarily stored in the hydrogen storage tank 30 and the required amount is supplied to the fuel cell according to the operating condition of the fuel cell system. Is preferable.

The polymer electrolyte fuel cell (PEFC) 60 is connected to the hydrogen storage tank 30 by a hydrogen supply pipe 26. The PEFC 60 is a fuel cell using a polymer membrane (ion exchange membrane) having ionic conductivity as an electrolyte between the electrodes, and a general PEFC conventionally known can be used. Further, a fuel cell other than the polymer electrolyte fuel cell (PEFC) may be used.

The hydrogen supply pipe 26 includes a valve V1, and the opening degree of the valve V1 is controlled by receiving a signal from the control device 40, so that hydrogen (hydrogen-containing) corresponding to the required amount of PEFC 60 from the hydrogen storage tank 30 is controlled. Gas) is to be supplied.

Further, a hydrogen permeation membrane 28 is attached to the hydrogen supply pipe 26. The hydrogen permeation membrane 28 is a membrane through which hydrogen in a hydrogen-containing gas can be selectively passed, and for example, an alloy thin film containing palladium (Pd) or the like can be used. As a result, the hydrogen concentration in the gas flowing through the hydrogen supply pipe 26 is increased, and a hydrogen gas having a high hydrogen concentration (preferably pure hydrogen gas) can be supplied to the PEFC 60.

A combustible gas pipe 32 provided with a valve V2 is connected to the hydrogen storage tank 30.
As described above, when hydrogen is selectively separated from the hydrogen-containing gas by the hydrogen permeation film 28, the concentration of gas components other than hydrogen (particularly flammable gas such as carbon monoxide and hydrogen) in the hydrogen storage tank 30. Will be higher. Therefore, by operating the valve V2, a gas component (flammable gas) other than hydrogen can be discharged to the outside through the combustible gas pipe 32. The opening degree of the valve V2 is controlled by, for example, providing a hydrogen detection sensor for detecting, for example, the hydrogen concentration in the tank in the hydrogen storage tank 30, and receiving a signal from the control device 40 based on the detection value of the hydrogen detection sensor. May be good.
A burner 70, which is an example of a combustion device, is connected to the combustible gas pipe 32, and the combustible gas is supplied to the burner through the combustible gas pipe 32 and used for combustion. The combustion heat obtained by the burner can be used for heating the catalyst in the hydrogen generator and preheating the aqueous methanol solution supplied to the hydrogen generator. As a result, effective use of energy can be achieved.
As described above, by controlling the opening degree of the valve V2 by receiving the signal from the control device 40, the concentration of the gas component other than hydrogen in the hydrogen storage tank 30 is kept within the desired range, and hydrogen is also maintained. Other gas components can also be effectively used.
Although an example of using a burner as a combustion device has been described here, the same effect can be expected even if a combustion device other than the burner is connected.

As described above, the hydrogen-containing gas separated by the condensation separator 20 is once stored in the hydrogen storage tank 30, then purified through the hydrogen permeation membrane 28, and the hydrogen gas corresponding to the required amount of PEFC is supplied to the PEFC 60. Will be done.

The control device 40 controls the operation of the fuel cell system including the hydrogen generation system.
As shown in FIG. 1, the control device 40 is electrically connected to a mixing gas pump P1, a raw material supply pump P2, a condensation separation device, and the like, and operates a hydrogen generation system and a fuel cell system equipped with the hydrogen generation system. I'm in control.

Next, hydrogen generation and external supply of electric power in the fuel cell system according to the embodiment of the present disclosure will be briefly described.
First, when the raw material supply pump P2 is operated, the liquid reforming raw material (methanol aqueous solution) is supplied to the hydrogen generation device 10 from the supply port of the raw material supply device 50 through the raw material supply pipe 14. Specifically, as shown in FIG. 4, the reforming raw material supplied from the supply port 14a to the hydrogen generation device 10 has a tubular structure of the inner wall of the exterior material 11 and the substrate 13 housed in the exterior material. It is introduced into the reaction chamber 18 formed between the outer peripheral surface and the outer peripheral surface. In the reaction chamber 18, the catalyst 15 is arranged so as to cover the entire circumference of the tubular structure of the substrate 13.

The liquid methanol aqueous solution supplied from the supply port 14a to the reaction chamber 18 flows along the surface of the tubular structure in the longitudinal direction of the tubular structure of the substrate 13 and moves in the reaction chamber to the side where the discharge port 12a is provided. do. The aqueous methanol solution is preheated while moving in the reaction chamber, and is reformed by contacting with the metal particles of the catalyst in a state of being superheated to a temperature exceeding the boiling point.
At this time, the catalyst metal of the catalyst 15 is supported on a carbon sheet, and a state appropriately moistened with an aqueous methanol solution (wet state) is formed there. At this time, the catalyst metal is in the heat transfer boundary film, the temperature is higher than the boiling point of the aqueous methanol solution (superheated state), and the dehydrogenation activity is the highest. That is, at this time, it is in the "superheated liquid film state".

Further, as described above, nanoscale catalytic metal particles are supported on the high surface area activated carbon having excellent heat transfer properties, and the catalytic metal particles become foaming points in the liquid phase, so that nucleate boiling proceeds. In the region of nuclear boiling, a superheated liquid is generated in the heat transfer boundary film at the solid-liquid interface, and if the temperature difference between the heating temperature and the boiling point is appropriate, the substance and heat are supplied from the liquid phase to the bubbles. Since the endothermic reaction is added to the phase change, the heat transfer coefficient is improved, and the growth and desorption of bubbles are advantageous. Methanol molecules in the superheated liquid are immediately adsorbed on the catalytically active sites vacated by the desorption of bubbles and start to react, so that the reaction rate is improved.

In the catalyst 15, as shown in the reaction formula below, the aqueous solution reforming reaction (formula 3) of methanol proceeds to generate hydrogen. Further, depending on the catalyst, the aqueous solution reforming reaction of the formula 3 and the methanol decomposition reaction (formula 4) proceed to generate hydrogen.
CH ₃ OH + H ₂ O → 3H ₂ + CO ₂ ... Equation 3
CH ₃ OH → 2H ₂ + CO ・ ・ ・ Equation 4

The generated gaseous hydrogen moves in the reaction chamber together with carbon dioxide or carbon dioxide produced as a by-product and unreacted methanol with carbon monoxide, is discharged as a mixed gas from the discharge port 12a, and is attached to the gas discharge pipe 12. By operating the mixed gas pump P1, the mixed gas is sent to the condensing separator 20.
In the condensation separator 20, a hydrogen-containing gas containing methanol and water as condensable components, hydrogen and carbon dioxide as non-condensable components, and carbon monoxide as a by-product, contained in the supplied mixed gas. And, and the separated hydrogen-containing gas is stored in the hydrogen storage tank 30. Then, purified hydrogen is produced by passing a hydrogen-containing gas through a hydrogen permeation membrane. When the purpose of using purified hydrogen is as a fuel for power generation in PEFC, carbon monoxide cannot be used as a fuel for PEFC, so for example, combustion for obtaining heat required for reforming in a hydrogen production system. It is temporarily stored in the hydrogen storage tank 30 for use as fuel for equipment.
The hydrogen-containing gas separated by the condensation separator 20 is once sent to the hydrogen storage tank 30 through the hydrogen flow pipe 22 connected to one end of the condensation separator 20. After that, it is made into purified hydrogen containing no carbon monoxide and the like by the hydrogen permeation membrane 28 attached to the hydrogen supply pipe 26, and is sent to PEFC60. By supplying the purified hydrogen gas, the PEFC 60 can generate electricity.
On the other hand, the condensable component (condensate) after the hydrogen gas is separated by the condensation separator 20 can be discharged and removed through a discharge pipe connected to the other end of the condensation separator 20 and reused as an aqueous methanol solution. can.

Next, a modified example of the fuel cell system of the present disclosure will be described with reference to FIG.
In FIG. 9, the same components as those of the above-mentioned hydrogen generation system shown in FIGS. 1 to 8 are designated by the same reference numerals, and the description thereof will be omitted.

The fuel cell system 200 shown in FIG. 9 includes two hydrogen generation devices by including two hydrogen generation systems. In the fuel cell system 200, two hydrogen generators are connected and arranged in series, so that unreacted methanol remaining without being used for aqueous solution reforming in the hydrogen generator on the upstream side is discharged on the downstream side. This is an embodiment in which the hydrogen generation device is supplied to the hydrogen generator, thereby increasing the conversion efficiency of the aqueous methanol solution and improving the amount of hydrogen produced. In this embodiment, of the methanol aqueous solution supplied to the hydrogen generator, the unreacted methanol is returned to the same hydrogen generator at the point where the unreacted methanol is provided to another hydrogen generator to reform the aqueous solution. It is different from the above-mentioned hydrogen generation system shown in FIG.

As shown in FIG. 9, the hydrogen generation system of this embodiment includes two hydrogen generation devices 10 and 10A, and includes a hydrogen-containing gas and a condensate containing hydrogen gas generated by the hydrogen generation device 10 on the upstream side. Is separated by the condensation separator 20, and the unreacted aqueous methanol solution in the separated condensate is supplied to the hydrogen generation device 10A on the downstream side through the resupply pipe 34 which is a resupply means.

The resupply pipe 34 communicates the condensation separator 20 and the hydrogen generator 10A. A raw material supply pump P2A is attached to the resupply pipe 34, and by operating the raw material supply pump P2A, the condensed product discharged from the condensation separator 20 is supplied to the hydrogen generator and subjected to an aqueous solution reforming reaction. .. In this case, methanol and water may be separated from the condensate discharged from the condensation separator 20 and the methanol and water may be selectively distributed to the resupply pipe 34. In this case, for example, by analyzing the composition of the condensed product discharged from the condensation separator 20, methanol and water have a composition suitable for the reforming reaction (for example, methanol: water = 1: 1 (molar ratio)). After adjusting the mixing ratio as described above, methanol and water may be circulated to the resupply pipe 34. The mixing ratio may be adjusted by supplementing the deficient component such as methanol from the outside.
The methanol resupplied through the resupply pipe 34 is reformed in an aqueous solution by the hydrogen generator 10A to generate hydrogen, and the hydrogen is sent to the condensation separator 20A as a hydrogen-containing gas. In the condensation separator 20A, the hydrogen-containing gas and the condensed product are separated in the same manner as in the condensation separator 20. The hydrogen-containing gas is temporarily stored in the hydrogen storage tank 30 through the hydrogen flow pipe 22A. The hydrogen-containing gas may contain carbon dioxide or the like in addition to hydrogen.
The hydrogen-containing gas generated by the hydrogen generator can be directly supplied to the fuel cell, but it is temporarily stored in the hydrogen storage tank 30 and the required amount is supplied to the fuel cell according to the operating condition of the fuel cell system. Is preferable.
A hydrogen supply pipe 26 provided with a valve V1 is connected to the hydrogen storage tank 30, and is communicated with the PEFC 60 via the hydrogen supply pipe 26. Hydrogen (hydrogen-containing) according to the required amount of the PEFC 60 from the hydrogen storage tank 30. Gas) is to be supplied. The PEFC 60 supplied with hydrogen can generate electricity. Since the condensate separated by the condensation separator 20A has a small residual amount of methanol, it is discharged from the condensation separator 20A to the outside.

In the hydrogen generation system of this embodiment, the unreacted methanol remaining in the condensate is reformed in an aqueous solution (preferably after adjusting the composition of unreacted methanol and water) in the hydrogen generation device 10A on the downstream side. , It is possible to increase the conversion efficiency of the aqueous methanol solution in the entire system. This makes it possible to further improve the amount of hydrogen produced.

In the hydrogen generation system of this embodiment, the configuration in which two hydrogen generation devices and two condensation separation devices are arranged has been mainly described, but the hydrogen generation device is not limited to two units, depending on the residual ratio of unreacted methanol. 3 or more units may be arranged in series and / or in parallel.
As another modification, two hydrogen generators are arranged in parallel, and the condensate discharged from the two hydrogen generators and condensed and separated by the condensation separator is combined with both of the two hydrogen generators. The unreacted methanol may be reformed into an aqueous solution by supplying it to one hydrogen generator located downstream in series with respect to the hydrogen generator. This also makes it possible to increase the conversion efficiency of the aqueous methanol solution and improve the amount of hydrogen produced.
Further, the condensation separation device is not limited to two, and although not shown, for example, one condensation separation device is arranged for two hydrogen generation devices, and hydrogen-containing gas is collected in one place and collectively. It may be configured to be condensed and separated, or it may be configured to arrange three or more units according to the number of arrangements of the hydrogen generating apparatus.

In the above embodiment, a hydrogen generator in which a substrate having one end closed is housed in an exterior material has been described as an example. However, the substrate has a tubular shape in which both ends in the longitudinal direction of the substrate are opened and hot air flows, for example. It may be configured in.
Further, in the above, the case where platinum is used as the catalyst metal has been described, but the same or better effect can be obtained even when a catalyst metal other than platinum is used.
Further, in the above embodiment, the structure in which the catalyst layer composed of three layers is arranged by winding the carbon sheet on which the catalyst metal is supported three times has been described as an example, but the scale of the reaction chamber of the hydrogen generator and the like have been described. That is, the same effect can be obtained even in a structure in which a multi-layered catalyst layer is arranged by winding four or more times depending on the amount of hydrogen gas produced or the like.

10, 10A ... Hydrogen generator 11 ... Exterior material 12, 12A ... Gas discharge pipe 12a ... Discharge port 13 ... Base 14, 14A ... Raw material supply pipe 14a ... Supply port 15 ... Catalyst 16 ... Cylindrical structure 17 ... Cover material 18 ... Reaction chamber 19 ... Heating chamber 20, 20A ... Condensation separation device 22, 22A ... Hydrogen flow tube 24 ...・ Return pipe (resupply means)
26 ... Hydrogen supply pipe 28 ... Hydrogen permeation membrane 30 ... Hydrogen storage tank 32 ... Combustible gas pipe 34 ... Resupply pipe (resupply means)
40 ... Control device 50 ... Raw material supply device 60 ... Solid polymer electrolyte fuel cell (PEFC)
70 ... Burner (combustion equipment)
100,200 ... Fuel cell system P1, P1A ... Mixing gas pump P2, P2A ... Raw material supply pump V1, V2 ... Valve

Claims (11)

A hydrogen generator that reforms an aqueous solution of methanol to generate hydrogen gas,
A condensation separation device in which a mixed gas containing hydrogen discharged from the hydrogen generation device is supplied, and the supplied mixed gas is condensed to separate at least the hydrogen gas and the condensate.
A resupply means for resupplying at least unreacted methanol in the condensate separated by the condensation separation device to the hydrogen generation device to reform the aqueous solution.
The hydrogen generator is equipped with
A substrate having a tubular structure with at least one end open and a heating chamber disposed inside the tubular structure.
A catalyst arranged so as to cover at least a part of the outer peripheral surface of the tubular structure of the substrate and having a catalyst metal supported on a carbon sheet.
An exterior material that houses the substrate on which the catalyst is placed, and
A discharge port arranged on the side of one end of the substrate in the length direction of the cylinder and discharging hydrogen gas.
A supply port arranged on the other end side in the length direction of the cylinder of the substrate and supplying an aqueous methanol solution between the substrate and the exterior material.
A hydrogen generation system that reforms the supplied methanol aqueous solution with the catalyst to generate hydrogen gas. The hydrogen generation system according to claim 1, wherein the catalyst is wound around an outer peripheral surface of the substrate to form a laminated structure. The hydrogen generation system according to claim 1 or 2, wherein the catalyst is a catalyst metal supported on the carbon sheet in an amount of 15 g / L to 150 g / L. The hydrogen generation system according to any one of claims 1 to 3, wherein the catalyst is an aqueous solution reforming of the supplied methanol aqueous solution in a superheated liquid film state. Claims 1 to claim that the aqueous methanol solution supplied from the supply port is preheated while flowing in the length direction of the cylinder of the substrate, and is reformed by the catalyst in a state of being superheated to a temperature exceeding the boiling point. 4. The hydrogen generation system according to any one of 4. The hydrogen generation system according to any one of claims 1 to 5, wherein the carbon sheet is carbon cloth or carbon felt. The catalyst metal is a composite of at least one selected from the metal group consisting of platinum, palladium, ruthenium, nickel or copper, or platinum, palladium, ruthenium, nickel and copper and another metal different from the metal of the metal group. The hydrogen generation system according to any one of claims 1 to 6. The hydrogen generation system according to claim 7, wherein the other metal contains at least one of manganese and zinc. The hydrogen generation system according to any one of claims 1 to 8, wherein the catalyst metal is a solid solution containing at least one of platinum, ruthenium and nickel. The hydrogen generation system according to any one of claims 1 to 9, wherein the catalyst is supported by metal particles containing the catalyst metal, and the average primary particle diameter of the metal particles is 10 nm or less. The hydrogen generation system according to any one of claims 1 to 10.
A fuel cell that generates electricity from the hydrogen gas generated by the hydrogen generator,
Fuel cell system with.

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