JP6938186B2 - Ammonia fuel power generation system and ammonia fuel supply system - Google Patents

Description

The present invention relates to a fuel cell device that generates electricity by receiving the supply of ammonia, and an ammonia fuel power generation system including an ammonia fuel supply device that supplies ammonia as a fuel to the fuel cell device.

At present, a technique for obtaining electric power by directly using ammonia as a fuel is attracting attention (Patent Documents 1 and 2). These techniques are very useful in terms of _{CO 2} reduction because ammonia does not contain carbon. In addition, no carbon deposit is generated on the electrodes.

A typical fuel cell using ammonia as a direct fuel is a solid oxide fuel cell (a solid oxide fuel cell according to the present invention, also called SOFC), and today, mainly in a battery electrode (anode). , Development is progressing in the direction of decomposing ammonia into hydrogen to cause a battery reaction while avoiding a decrease in output (Patent Documents 3 and 4).

Further, as a fuel cell directly using ammonia as a fuel, an anion exchange membrane fuel cell has also been proposed (Patent Document 5).

In an attempt to obtain electric power from a fuel cell using ammonia as a fuel, it has been proposed to use a material (gas storage material) that adsorbs and desorbs the fuel under a predetermined temperature condition for fuel supply (Patent Document). 6). The gas storage / supply system disclosed in Patent Document 6 is a technique for supplying hydrogen, ammonia, methane, etc., and it is proposed to use a material composed of a metal halide and a metal sulfate as the ammonia storage material. Has been done. In addition, a chemical heat storage material is used to desorb ammonia from the ammonia storage material. A material that generates heat due to a hydration reaction, such as a metal oxide, is also shown in this chemical heat storage material.

In this type of gas storage and supply system (corresponding to the fuel supply device of the present invention), fuel filling is performed separately at a specific filling site, and a fuel-filled gas storage and supply system is used at the place of use. used.

Japanese Unexamined Patent Publication No. 2011-204416 Japanese Unexamined Patent Publication No. 2011-204418 Japanese Unexamined Patent Publication No. 2013-21117 Japanese Unexamined Patent Publication No. 2013-2111118 Japanese Unexamined Patent Publication No. 2011-34710 JP-A-2015-215125

As explained above, the power generation system using ammonia as fuel has various advantages, and as the adoption destination of such an ammonia fuel power generation system, a range extender, a fork list, and a golf course that increase the mileage of an electric vehicle are used. There are also power trains with relatively short mileage such as carts, luggage transport vehicles in factories and markets, and well-controlled fuel supply locations, and auxiliary power systems for moving objects powered by internal combustion engines.

However, today, an ammonia fuel power generation system that can be adopted in an in-vehicle form, has a relatively compact configuration, and is highly reliable has not yet been established.

For example, when the gas storage / supply system described in Patent Document 6 is adopted and a power generation system is constructed using ammonia as fuel, although ammonia can be supplied as fuel, there remains a problem in the amount of ammonia that can be supplied and its sustainability. In addition, when looking at the ammonia fuel power generation system as a whole, there is room for improvement in terms of its operation mode, heat utilization, and the like.

Hereinafter, the description of the present invention will be described in the form of being mounted on a vehicle, but the ammonia fuel power generation system according to the present invention can also be used as a small stationary ammonia fuel power generation system.

A main object of the present invention is to provide an ammonia fuel power generation system which has a relatively simple configuration, is compact and has excellent reliability, and is also excellent in terms of heat utilization, and this power generation system can be constructed. To provide an ammonia fuel supply system.

To achieve the above objectives,
The first characteristic configuration of the ammonia fuel power generation system of the present invention is
A fuel cell device that generates electricity by receiving the supply of ammonia,
An ammonia storage tank that houses an ammonia storage material that forms a complex with ammonia and adsorbs it, and receives heat to desorb the ammonia in the adsorbed state.
A hydration reaction storage tank containing oxides of alkali metals and / or alkaline earth metals, and
Equipped with an ammonia removal tank that oxidizes or adsorbs and removes ammonia
The hydration reaction storage tank and the ammonia removal tank are connected to the ammonia storage tank so as to be heat transferable.
A fuel supply path for supplying the fuel cell device with ammonia desorbed from the ammonia storage tank as fuel is provided.
It is provided with a gas-liquid separation device for gas-liquid separation of off-gas released from the fuel cell device, and a water storage tank for storing the water separated by the gas-liquid separation device.
A water introduction path for a hydration reaction that guides water from the water storage tank to the hydration reaction product storage tank is provided, and a gas introduction path that guides the gas separated by the gas-liquid separation device to the ammonia removal tank is provided. There is.

This ammonia fuel power generation system is configured with a fuel cell device as the core, an ammonia storage tank is provided on the fuel supply side, and when ammonia is supplied from this ammonia storage tank, it is transmitted from the hydration reaction product storage tank and the ammonia removal tank. Use the heat that is heated.

For example, when the system is started, ammonia can be supplied to the fuel cell apparatus simply by sending water from the water storage tank to the hydration reaction product storage tank via the water introduction path for the hydration reaction. Ammonia supplied in this way is used for power generation, but at the same time, ammonia may slip from the fuel cell device and be contained in off-gas and released. This ammonia is introduced into the ammonia removal tank via the gas introduction path and is removed in this tank. As a result, off-gas can be released to the outside.

The hydration reaction and the ammonia removal reaction in the removal tank are exothermic reactions, and the heat generated by such heat generation is transferred to the ammonia storage tank and used for the desorption of ammonia. As a result, it is sufficiently rational in terms of heat utilization as a power generation system.

The first characteristic configuration of the ammonia fuel supply device capable of constructing this ammonia fuel power generation system is
An ammonia storage tank that houses an ammonia storage material that forms a complex with ammonia and adsorbs it, and receives heat to desorb the ammonia in the adsorbed state.
A hydration reaction storage tank containing oxides of alkali metals and / or alkaline earth metals, and
Equipped with an ammonia removal tank that oxidizes or adsorbs and removes ammonia
The hydration reaction storage tank and the ammonia removal tank are provided so as to transfer heat to the ammonia storage tank.
A fuel supply path that supplies ammonia released from the ammonia storage tank as fuel, a water introduction path for hydration reaction that guides water to the hydration reaction product storage tank, and an ammonia-containing gas containing ammonia are introduced into the ammonia removal tank. It will be equipped with a guiding gas introduction path.

As a result, the ammonia fuel power generation system consists of a core fuel cell device, an ammonia fuel supply device unique to the present invention, and a gas-liquid separation system (mainly composed of a gas-liquid separation device and a water storage tank) connecting the two. Since it can be constructed, it has a relatively simple configuration, is compact and highly reliable, and is excellent in terms of heat utilization.

The second characteristic configuration of the ammonia fuel power generation system of the present invention is
The fuel cell apparatus includes a solid electrolyte (solid oxide electrolyte) and a solid electrolyte fuel cell having an anode electrode on one side of the solid electrolyte and a cathode electrode on the other side.
The present invention is a direct ammonia fuel cell that generates electricity from ammonia supplied as fuel to the solid electrolyte fuel cell.

A direct ammonia fuel cell means that ammonia reaches the fuel cell as it is, is reformed in the battery and used for power generation (the same applies hereinafter).

According to this configuration, ammonia can be supplied to a solid electrolyte fuel cell that directly uses ammonia as fuel to generate electricity.

The third characteristic configuration of the ammonia fuel power generation system according to the present invention including the solid electrolyte fuel cell is
Urea water storage tank for storing urea water and
It is provided with a hydrolysis reaction tank that receives the urea water supply from the urea water storage tank and is heated to hydrolyze the urea water.
The point is that it is provided with a heating means for heating the hydrolysis reaction tank with the off gas released from the fuel cell device.

According to this configuration, the heat possessed by the off-gas discharged from a solid electrolyte fuel cell that operates at a relatively high temperature is used for hydrolysis of urea water in a hydrolysis reaction tank, and ammonia as a fuel in a fuel cell device is used. Can be generated and supplied to the fuel cell device to generate power.
In this configuration, ammonia can be obtained as fuel from both the ammonia storage tank and the hydrolysis reaction tank, and the amount of ammonia that can be supplied can be increased. As a result, the amount of power generation can be increased, and the supply form can be appropriately adjusted according to the characteristics of the supply form (amount, supply timing, temperature condition, etc.) of ammonia supplied from both tanks.
For example, if the exhaust heat discharged from the engine can be used in its high temperature state, it is more efficient to use ammonia derived from urea water, but it is possible to switch the fuel origin according to this kind of usage condition. preferable.

The second feature configuration of the ammonia fuel supply device capable of constructing the ammonia fuel power generation system of this configuration is, in addition to the first feature, the first feature.
Urea water storage tank for storing urea water and
It is provided with a hydrolysis reaction tank that receives the urea water supply from the urea water storage tank and is heated to hydrolyze the urea water.
A heating means for heating the hydrolysis reaction tank with the off-gas released from the supply destination of the ammonia fuel is provided.

By the way, the fourth characteristic configuration of the ammonia fuel power generation system having a configuration in which ammonia is supplied as fuel by hydrolyzing urea water in this way is
The point is that a water reaction water introduction path for guiding the water separated by the gas-liquid separation device to the hydrolysis reaction tank is provided.

According to this configuration, the water vapor generated in the fuel cell device is restored in the hydrolysis reaction tank, and further separated into gas and liquid and used for the hydrolysis of urea water, so that water is supplied separately from the water in the urea water. This makes it possible to maintain a high concentration of urea water stored in the urea water storage tank, and to build an ammonia fuel power generation system in a compact urea water storage tank.

The third characteristic configuration of the ammonia fuel supply device that can construct an ammonia fuel power generation system with this configuration is
It is provided with a water reaction water introduction path for guiding the water separated by the gas-liquid separation device to the hydrolysis reaction tank.

The fifth characteristic configuration of the ammonia fuel power generation system according to the present invention is
The fuel cell device is an anion exchange membrane type fuel cell having an anion exchange membrane, an anode electrode on one side of the anion exchange membrane, and a cathode electrode on the other side.

An anion exchange membrane fuel cell is also a type of direct ammonia fuel cell in which ammonia reaches the fuel cell as it is and is reformed in the battery to generate power.

According to this configuration, ammonia can be supplied to an anion exchange membrane fuel cell that directly uses ammonia as fuel to generate electricity.

In addition to the above-mentioned fifth characteristic configuration, the sixth characteristic configuration of the ammonia fuel power generation system in which the fuel cell device is an anion exchange membrane fuel cell is
Carbonate that contains oxides of alkali metal, alkaline earth metal, or both, and removes carbon dioxide contained in the oxidant gas as a carbonate from the oxidant gas containing the oxidant supplied to the fuel cell apparatus. The point is that it is equipped with a reaction product storage tank.

In this configuration, the oxidant gas from which carbon dioxide has been removed is transferred to the anion exchange membrane fuel cell by passing an oxidant gas (for example, air) containing carbon dioxide through the carbon dioxide reaction product storage tank. By supplying the fuel cell, the operation of the anion exchange membrane fuel cell can be maintained satisfactorily.

In addition to the first characteristic configuration, the fourth characteristic configuration of the ammonia fuel supply device capable of constructing this ammonia fuel power generation system contains an alkali metal, an alkaline earth metal, or an oxide of both of them, and is composed of an oxidant gas. A carbonation reaction product storage tank that removes carbon dioxide contained in the oxidant gas as a carbonate is provided in the ammonia storage tank so that heat can be transferred to the ammonia storage tank.
An oxidant gas containing carbon dioxide is introduced into the carbonation reaction product storage tank, and an oxidant gas treatment path through _{which the CO 2 free gas sent out after removing the carbon dioxide from the carbonation reaction product storage tank flows is provided.} It will be kept.

By the way, in the ammonia fuel supply device described so far, the fuel cell device is different from the solid electrolyte type fuel cell and the anion exchange membrane type fuel cell, but it shall have the fifth characteristic configuration shown below. You can also do it.

The fifth characteristic configuration of the ammonia fuel supply device according to the present invention is
An ammonia storage tank that houses an ammonia storage material that forms a complex with ammonia and adsorbs it, and receives heat to desorb the ammonia in the adsorbed state.
A storage tank containing oxides of alkali metals and / or alkaline earth metals, and
Equipped with an ammonia removal tank that oxidizes or adsorbs and removes ammonia
The storage tank and the ammonia removal tank are provided so that heat can be transferred to the ammonia storage tank.
Provided as a fuel supply channel for supplying the ammonia released from the ammonia storage tank as fuel.
The storage tank is provided with at least a first storage tank and a second storage tank.
The first storage tank is provided with a water introduction path for hydration reaction to guide water, and the first storage tank is configured as a hydration reaction product storage tank.
Oxidation in which a water introduction path for a hydration reaction that guides water and an oxidant gas containing carbon dioxide are guided to the second storage tank, and the CO ₂ free gas that is sent out after removing the carbon dioxide from the second storage tank flows. The point is that the agent gas treatment path is switchable.

By adopting this configuration, oxides (oxides of alkali metal, alkaline earth metal, or both) that may cause both hydration reaction and carbonization reaction are stored in the first storage tank and the second storage tank. The ammonia fuel supply device according to the present invention can be commonly adopted for different types of fuel cells by accommodating them in both tanks and switching the ones to be supplied to the second storage tank.

The figure which shows the structure of the ammonia fuel power generation system which concerns on 1st Embodiment Schematic diagram of a vehicle equipped with an ammonia fuel power generation system according to the first embodiment. The figure which shows the structure of the ammonia fuel power generation system which concerns on 2nd Embodiment The figure which shows the switching state in the ammonia fuel power generation system which provided the ammonia fuel supply device which can be shared with 1st Embodiment and 2nd Embodiment, and is equipped with the solid electrolyte type fuel cell. The figure which shows the switching state in the ammonia fuel power generation system which provided the ammonia fuel supply device which can be shared with 1st Embodiment and 2nd Embodiment, and was equipped with an anion exchange membrane type fuel cell. The figure which shows the structure of the ammonia fuel power generation system which concerns on 4th Embodiment Schematic diagram of a vehicle equipped with an ammonia fuel power generation system according to a fourth embodiment. The figure which shows the structure of the system which uses the off gas of a solid electrolyte type fuel cell for the production of ammonia as a fuel.

The ammonia fuel power generation system according to the present invention will be described below with reference to the drawings.

In the present specification, the first to fourth embodiments will be described, but the first embodiment is an embodiment in which a solid electrolyte fuel cell is adopted as the fuel cell device 1, and the second embodiment is the fuel cell device 1. This is an embodiment in which an anion exchange membrane fuel cell is adopted as the fuel cell. The third embodiment is an embodiment in which an ammonia fuel supply device 203 that can be shared when either a solid electrolyte fuel cell or an anion exchange membrane fuel cell is used for the fuel cell device 1 is adopted. The fourth embodiment uses the solid electrolyte fuel cell as in the first embodiment, but is an embodiment in which the heat possessed by the off-gas from the solid electrolyte fuel cell is further utilized.

In each embodiment, the ammonia fuel power generation systems 101, 102, 103, 104 according to the present invention are constructed with the ammonia fuel supply devices 201, 202, 203, 204 unique to the present invention, respectively. In each figure, the former is shown by being surrounded by a chain line and the latter is shown by being surrounded by a broken line.

〔Common Items〕
_{Ammonia fuel supply devices 201, 202, 203, 204 are devices that supply ammonia (NH 3} ) am as fuel f to the fuel cell device 1 provided in the ammonia fuel power generation systems 101, 102, 103, 104. The start can be performed only by supplying water w to the hydration reaction storage tank 22 constituting the ammonia fuel supply devices 201, 202, 203 and 204. Then, when the fuel cell device 1 is started, the fuel f is continuously supplied by utilizing the generated water (water vapor) w and the ammonia am that may be contained in the discharged off-gas og.

The electric power generated by each of the ammonia fuel power generation systems 101, 102, 103, and 104 is sent to the power conditioner 2 and the storage battery 3 provided on the lower side of the electric power supply, and after a predetermined conversion process and storage are performed, the electric power is stored. Further, it is supposed to be sent to the electric motor 4 provided on the lower side. Therefore, the electric power generated by the ammonia fuel power generation system 100 is stored in the storage battery 3 and can be used as power by the motor 4 if necessary.

The ammonia fuel supply device 201 includes an ammonia storage tank 21, a hydration reaction product storage tank 22 thermally connected to the ammonia storage tank 21, and an ammonia removal tank 23.

[First Embodiment]
The ammonia fuel power generation system 101 of this embodiment is shown in FIG.

The ammonia fuel power generation system 101 includes a fuel cell device 1 and an ammonia fuel supply device 201 as main devices, and off-gas og discharged from the fuel cell device 1 is gas-liquid separated by the gas-liquid separation device 32, and each is predetermined. It is configured to be introduced into the tank (hydration reaction product storage tank 22, ammonia removal tank 23).

The fuel cell device 1 is a solid electrolyte type fuel cell. Briefly, it is a solid having a solid electrolyte 1a, an anode electrode 1b on one side of the solid electrolyte 1a, and a cathode electrode 1c on the other side. It is a direct ammonia fuel cell that is configured by forming a large number of electrolyte type fuel cells fc in a stack and generates power by ammonia supplied as fuel f to the solid electrolyte type fuel cell fc.

The material of the solid electrolyte 1a is a so-called oxygen ion conductive ceramic material, specifically, YSZ (yttria-stabilized zirconia), ScSZ (scandia-stabilized zirconia), and these zirconia are further doped with Ce, Al, etc. Zirconia-based powder, dope-based powder such as SDC (Samaria-doped ceria), GDC (Gadria-doped ceramic), LSGM (lantern gallate) -based powder, bismuth oxide-based powder, and the like are used.

As is well known, the anode electrode 1b is formed by an anode electrode catalyst and solid electrolyte particles.

Specifically, the material of such an anode electrode catalyst is an alloy of nickel (Ni) and cobalt (Co).
The cathode electrode 1c is also formed by the cathode electrode catalyst and the solid electrolyte particles.

Specifically, as the cathode electrode catalyst, oxides having a manganese-based, ferrite-based, cobalt-based or nickel-based perovskite-type structure are preferable, and for example, a Group 2 element of the periodic table such as strontium (Sr) is added. Lanternstrontium manganite (LaXSr1-XMnO ₃ ), lancetrontium cobaltite (LaXSr1-XCoO ₃ ), lancetrontium cobalt ferrite (LaXSr1-XCoYFe1-YO ₃ ), lanthanum nickel ferrite (LaNiYFe1-YO ₃ ).

In power generation, ammonia as fuel is supplied to the anode electrode 1b, and oxidant gas ocg (air) as an oxidant is supplied to the cathode electrode 1c.
FIG. 1 and the like show a thick middle-black arrow coming out of the fuel cell device 1, and this arrow indicates that heat removal (cooling of the fuel cell device 1) is required for power generation.

The ammonia fuel supply device 201 includes an ammonia storage tank 21, a hydration reaction product storage tank 22 thermally connected to the ammonia storage tank 21, and an ammonia removal tank 23.

As shown by the thick arrow in FIG. 1, the hydration reaction product storage tank 22 and the ammonia removal tank 23 are configured to heat and raise the temperature of the ammonia storage tank 21 (the mutual is via the heat transfer layer hex). (Structure to be connected) is adopted.

The ammonia storage tank 21 is a tank that houses an ammonia storage material that forms a complex with ammonia and adsorbs it, and also receives heat to desorb ammonia in an adsorbed state. Examples of the ammonia storage material include one or more selected from a halogenated Ba compound, a halogenated Ca compound, a halogenated Sr compound, a halogenated Fe compound, a halogenated Co compound, and a halogenated Mg compound. For example, strontium chloride (SrCl ₂ ), calcium chloride (CaCl ₂ ) and the like can be used.

The hydration reaction product storage tank 22 is a tank in which an alkali metal, an alkaline earth metal, or an oxide of both of them is stored. This kind of oxide generates heat when water w is supplied. Examples of these oxides include calcium oxide (CaO), magnesium oxide (MgO), calcium sulfate (CaSO ₄ ) and the like.

The ammonia removing tank 23 is a tank containing an ammonia removing agent capable of removing ammonia inside. Examples of this type of ammonia remover include metal catalysts such as nickel (Ni) and ruthenium (Ru), halogenated Ni compounds, and halogenated Mg compounds. The former is a material that oxidatively decomposes ammonia, and the latter adsorbs and removes ammonia. Heat is also generated during these oxidation and adsorption.

Therefore, in the ammonia fuel supply device 201 according to the present invention, the heat generated by the hydration reaction in the hydration reaction product storage tank 22 and the oxidation or adsorption reaction in the ammonia removal tank 23 is stored in the ammonia storage tank 21. The ammonia storage material is heated to separate and desorb ammonia.

Regeneration of the ammonia storage tank 21 (re-adsorbing ammonia to the ammonia storage material) returns the storage material to a predetermined temperature and pressure state for adsorbing ammonia, and at a separately provided ammonia fuel filling site (not shown), ammonia. This can be done for the storage tank 21.

The regeneration of the hydration reaction product storage tank 22 (regeneration of oxides) is carried out by heating the hydration reaction product storage tank 22 in an open state to dissipate water w.

Regarding the regeneration of the ammonia removing tank 23, when the ammonia removing agent is a metal oxidation catalyst, a substantial regeneration operation is not required. On the other hand, in the case of an ammonia storage material, it can be carried out by separating and desorbing ammonia from the storage material by heating.

Hereinafter, the connection relationship between the fuel cell device 1 and the tanks 21, 22, and 23 forming the ammonia fuel supply device 201 will be described.
The fuel cell device 1 and the ammonia storage tank 21 are connected to each other via the fuel supply path L1, and the ammonia am sent out from the ammonia storage tank 21 is supplied to the fuel cell device 1 as fuel f.

The off-gas passage L2 through which the off-gas og generated by power generation flows is provided with a gas-liquid separation device 32 for gas-liquid separation of the off-gas og, and a water storage tank for storing the water w separated by the gas-liquid separation device 32. 33 is provided. In order to appropriately secure the amount of water w to be stored in the water storage tank 33, water w can be separately replenished as shown by an arrow in FIG.

If necessary, the water storage tank 33 is provided with a hydration reaction water introduction path L3 that guides water w to the hydration reaction product storage tank 22, for example, at the start of power generation. Therefore, in this ammonia fuel power generation system 101, the water w generated by the power generation is used for supplying ammonia.

A gas introduction path L4 for guiding the gas og2 separated by the gas-liquid separation device 32 to the ammonia removal tank 23 is also provided. As a result, in the ammonia fuel power generation system 101, when the off-gas og generated by the power generation contains ammonia am, this ammonia am is also used for supplying the fuel f.

The exhaust gas exg made ammonia-free in the ammonia removal tank 23 can be discharged as it is.

The above is the configuration of the ammonia fuel power generation system 101, but the ammonia fuel supply device 201 has the following configuration.
An ammonia storage tank 21 that houses an ammonia storage material that forms a complex with ammonia and adsorbs it, and receives heat to desorb the ammonia in the adsorbed state.
A hydration reaction storage tank 22 containing oxides of alkali metals, alkaline earth metals, or both, and
Ammonia removing tank 23 containing an ammonia removing agent that oxidizes or adsorbs and removes ammonia is provided.
The hydration reaction product storage tank 22 and the ammonia removal tank 23 are provided in the ammonia storage tank 21 so that heat can be transferred.
A fuel supply path L1 that supplies ammonia released from the ammonia storage tank 21 as fuel f, a hydration reaction water introduction path L3 that guides water w to the hydration reaction product storage tank 22, and ammonia that may contain ammonia am. It is provided with a gas introduction path L4 that guides the contained gas (in the case of the present embodiment, the off-gas og2 of the fuel cell device 1 in which water is separated by the gas-liquid separation device 32) to the ammonia removal tank 23.

FIG. 2 shows a configuration when the ammonia fuel power generation system 100 described above is used for an in-vehicle use.
As can be seen from the figure, it can be seen that the system according to the present invention can be adopted as an auxiliary power source or the like with a relatively simple configuration.

[Second Embodiment]
The configuration of the ammonia fuel power generation system 102 and the ammonia fuel supply device 202 of this embodiment is shown in FIG. Regarding the figure, the same parts as those in the first embodiment will not be described.
The features of this embodiment are that the fuel cell device 1 is an anion exchange membrane fuel cell and that a carbonation reaction product storage tank 24 is added to the ammonia fuel supply device 202.

The anion exchange membrane type fuel cell is composed of an anion exchange membrane 1d, an anode electrode 1e on one side of the anion exchange membrane 1d, and a cathode electrode 1f on the other side, and is a solid described above. Similar to the electrolyte fuel cell, it is a direct ammonia fuel cell that generates power from ammonia supplied as fuel f.

The material of the anion exchange film 1d is a so-called hydrocarbon-based polymer material having anion conductivity, and specifically, a basic polymer film having a quaternary ammonium base or a pyridinium base as an ion exchange group. Etc. are used.

As is well known, the anode electrode 1e is composed of an anionic conductive polymer and an anode electrode catalyst. Specifically, as the anode electrode catalyst, a catalyst in which Pt, Ru, and Pt-Ru are supported on a carbon material is adopted.
The cathode electrode 1f is also formed by an anion conductive polymer and a cathode electrode catalyst.

Specifically, the cathode electrode catalyst is a catalyst in which Pt is supported on a carbon material.

In power generation, ammonia as a fuel is supplied to the anode electrode 1e, and oxidant gas ocg (air) as an oxidant is supplied to the cathode electrode 1f.

As is clear from FIG. 3, in this ammonia fuel power generation system 102, with respect to the battery reaction generated in the fuel cell device 1, gas ocg (for example, air, “oxidant gas” in the present invention) that acts as an oxidant is used. It is supplied as _{a CO 2} free gas from which carbon dioxide has been removed.
The reason for providing the carbonation reaction product storage tank 24 in this way is that the anion exchange membrane fuel cell is vulnerable to poisoning by carbon dioxide.

The carbonation reaction product storage tank 24 is also thermally connected to the ammonia storage tank 21, and the heat _{generated by the adsorption and removal of carbon dioxide (CO 2} ) is used to supply ammonia am as fuel.

The carbonated reaction product storage tank 24 contains an oxide of an alkali metal, an alkaline earth metal, or both of them, and is contained in the oxidant gas ocg containing oxygen such as air from the oxidant gas ocg. Removes carbon dioxide as carbonate. Examples of these oxides include calcium oxide (CaO), magnesium oxide (MgO), strontium oxide (SrO), and the like.

Regarding the regeneration of the carbonation reaction product storage tank 24, the regeneration can be completed by heating the tank 24 in an open state.

In relation to the hydration reaction product removing tank 22 described above, the substances contained therein may be the same or different in type and properties between the tanks 22 and 24. ..

Now, regarding the gas system to be provided in the carbonation reaction product storage tank 24, this is a gas system that introduces an oxidizing agent gas ocg that may contain carbon dioxide into the carbonation reaction product storage tank 24 and the carbonation reaction. It may be set as the oxidant gas treatment path L5 through _{which the CO 2} free gas sent out after removing carbon dioxide from the storage tank 24 flows.

Therefore, in addition to the configuration described above in the first embodiment, the ammonia fuel supply device 202 of the second embodiment contains an alkali metal, an alkaline earth metal, or an oxide of both of them, and contains an oxidant gas ocg. A carbonated reaction product storage tank 24 for removing carbon dioxide contained in the oxidant gas ocg as a carbonate is provided in the ammonia storage tank 21 so as to be heat transferable.
An oxidant gas treatment path L5 through which an oxidant gas containing carbon dioxide flows into the carbonation reaction product storage tank 24 and a CO _{2 free gas sent out after removing carbon dioxide from the carbonation reaction product storage tank 24 flows.} It is provided.

Also in this second embodiment, in the case of the vehicle-mounted type, the configuration shown in FIG. 2 described above is used.

[Third Embodiment]
In the first embodiment and the second embodiment, the fuel cell device 1 is of a different type.
As a result, in the first embodiment in which the fuel cell device 1 is a solid electrolyte fuel cell, an ammonia storage tank 21, a hydrate reaction storage tank 22, and an ammonia removal tank 23 are provided, and a fuel supply path L1 and water for a hydration reaction are introduced. In the second embodiment in which the fuel cell device 1 is an anion exchange film type fuel cell, while the passage L3 and the gas introduction passage L4 are provided, a carbonation reaction product storage tank 24 is provided, and the fuel cell is provided in this tank 24. An oxidant gas passage L5 for supplying the oxidant gas ocg is added to the device 1.

On the other hand, as described above, the substances (materials) stored inside the hydration reaction storage tank 22 and the carbonation reaction product storage tank 24 are basically alkali metals, alkaline earth metals, or both. As an oxide of.

Further, the ammonia fuel power generation systems 101 and 102 as in the present invention provided with the fuel cell device 1 have various start-up times, power supply amounts, and the like depending on the mounting destination and the application thereof. In other words, there are applications in which it is preferable to select a solid electrolyte fuel cell as in the first embodiment, and applications in which it is preferable to select an anion exchange membrane fuel cell as in the second embodiment. There is also. In this respect, when viewed as an ammonia fuel supply device, it is not preferable that each device has a dedicated configuration.

The ammonia fuel supply device 203 that meets the so-called standardization request is the third embodiment, and the switching state is shown in FIGS. 4 and 5. FIG. 4 shows a switching state when a solid electrolyte fuel cell is used as the fuel cell device 1, and FIG. 5 shows a switching state when an anion exchange membrane fuel cell is used.

The description of the same parts as those of the first and second embodiments as the embodiment of the ammonia fuel power generation system 103 will be omitted.

Regarding the ammonia fuel supply device 203, the hydration reaction product storage tank 22 and the carbonation reaction product storage tank 24 described so far are simply referred to as storage tanks 25, and will be described below.

The ammonia fuel supply device 203 forms a complex with ammonia and adsorbs it, and also receives heat to desorb the ammonia in the adsorbed state. The ammonia storage tank 21 and an alkali metal or alkaline earth metal. Alternatively, a storage tank 25 that houses both of these oxides and an ammonia removal tank 23 that oxidizes or adsorbs and removes ammonia are provided, and these storage tank 25 and the ammonia removal tank 23 are configured to be heat transferable to the ammonia storage tank 21. It is not different from the configuration described so far in that it is provided with a fuel supply path L1 for supplying the ammonia released from the ammonia storage tank 21 as the fuel f.

As shown in FIGS. 4 and 5, in this embodiment, at least the first storage tank 25a and the second storage tank 25b are provided as the storage tank 25, and hydration that guides water w to the first storage tank 25. A water introduction path for reaction is provided, and the first storage tank 25a is configured as a hydration reaction product storage tank.

On the other hand, regarding the second storage tank 25b, the water introduction path for the hydration reaction that guides the water w and the oxidant gas ocg containing carbon dioxide are guided to the second storage tank 25b, and carbon dioxide is removed from the second storage tank 25b. A switching valve mechanism V for switching between the oxidant gas treatment path through which the CO _{2 free gas to be sent out flows is provided.}

FIG. 4 shows a state in which a solid electrolyte fuel cell is adopted as the fuel cell device 1 and water is supplied to both the first and second storage tanks 25a and 25b, as shown in the first embodiment. .. In this usage pattern, the second storage tank 25b is also used as the hydration reaction product storage tank 22.

FIG. 5 shows that an anion exchange membrane fuel cell is adopted as the fuel cell device, water w is supplied to the first storage tank 25a, and the second storage tank 25b is used for an oxidant, as shown in the second embodiment. It is in a state where the fuel cell is introduced.
In this mode of use, the second storage tank 25b can be used as the carbonation reaction product storage tank 24.

As a result, by switching the introduction paths L2 and L5 connected to the second storage tank 25b, the same ammonia fuel supply device 203 can be commonly used by operations such as switching performed at the time of its installation.

[Fourth Embodiment]
In the embodiments described so far, the fuel cell device 1, the ammonia fuel supply devices 201, 202, 203, the gas-liquid separation device 32, and the water storage tank 33 are combined to realize the ammonia fuel power generation systems 101.102, 103. There is.

Here, the fuel cell device 1 is basically a heat source that generates heat with power generation, and the off-gas og discharged from the fuel cell device 1 has available heat.
For example, when the fuel cell device 1 is a solid electrolyte fuel cell, the off-gas og is at about 500 ° C. and contains water vapor. Therefore, it is preferable to utilize the sensible heat and latent heat possessed by the off-gas og. The fourth embodiment attempts to use such heat for supplying ammonia am as fuel f. The system configuration of this embodiment is shown in FIG.

Explaining by comparison with the first embodiment shown in FIG. 1, the following configuration is added to this embodiment. That is, it is provided with a urea water storage tank 40 for storing the urea water uwa, and a hydrolysis reaction tank 41 for receiving the supply of the urea water uwa from the urea water storage tank 40 and hydrolyzing the urea water uwa. Further, the heating means H for heating the hydrolysis reaction tank 41 with the off-gas og released from the fuel cell device 1 is provided.

With this configuration, the hydrolysis reaction tank 41 receives from the urea water storage tank 40 _{as a mixture of urea ((NH 2} ) ₂ CO) at room temperature and water (H ₂ O) ((NH ₂ ) ₂ CO + H ₂ O). By providing the heating means H, it is a decomposition device that _{receives heat from the off-gas og and hydrolyzes it into ammonia (NH 3} ) and carbon dioxide (CO _2). The temperature of the hydrolysis reaction tank 41 is maintained at a temperature (about 200 ° C.) at which the hydrolysis of urea water can be satisfactorily maintained. In this configuration, the temperature of the water vapor contained in the off-gas og can be effectively lowered.

A urea-side fuel supply path L6 is provided which connects the ammonia am generated by hydrolysis in the hydrolysis reaction tank 41 to the fuel supply path L1 which is sent to the fuel cell apparatus 1 as the fuel f. As a result, in this configuration, ammonia am can be obtained from urea water uwa and supplied to the fuel cell device 1.

In the above description, the water used for the hydrolysis of urea is the water w contained in the urea water uw stored in the urea water storage tank 40, but as shown by the two-point chain line in FIG. 6, the present ammonia fuel A water supply passage L7 for hydrolysis may be provided to supply the water w separated by the gas-liquid separation device 32 constituting the battery system 104 to the urea water storage tank 40 or the hydrolysis reaction tank 41. The illustration shows an example in which water w is supplied to the hydrolysis reaction tank 41. In this way, the capacity of the urea water storage tank 40 can be reduced.

In the ammonia fuel power generation system 104, the relatively high temperature heat generated from the fuel cell device 1 can be used for hydrolyzing the urea water uwa, and the load on the gas-liquid separation device 32 can be reduced. Therefore, in this ammonia fuel power generation system 204, the storage and supply of ammonia as fuel can also be performed from urea water uu.

Then, as shown in FIG. 7, the ammonia fuel supply device 204 transfers this exhaust heat (indicated by a hollow arrow) of the fuel cell device 1 in a vehicle having a hybrid configuration including an engine E using a hydrocarbon CH as a fuel. It can be effectively used in the system used for driving.

[System that uses only urea water to supply ammonia as fuel]
In the fourth embodiment shown in FIG. 6, the heat possessed by the off-gas og discharged from the high-temperature operating solid electrolyte fuel cell is used to supply ammonia as a fuel from the urea water uwa to the fuel cell device 1. An example has been described.

As shown in FIG. 7, when the above-mentioned solid electrolyte fuel cell is operated by utilizing the heat possessed by the exhaust gas discharged from the engine E using the hydrocarbon CH as fuel, the start-up is quick. However, in this system, the heat discharged together with the off-gas og of the fuel cell device 1 may also increase. For example, since the ambient temperature conditions of the fuel cell device 1 differ between summer and winter, the heat possessed by the engine exhaust gas cannot always be effectively used only by the fuel cell device 1.

As shown in FIG. 7, the configuration shown in FIG. 8 includes an engine E operated by a hydrocarbon CH and a fuel cell device 1 (specifically, a solid electrolyte fuel cell that directly uses ammonia as fuel). In a system in which the exhaust heat of the engine E is used for the operation of the fuel cell device 1, the fuel of the fuel cell device 1 is obtained from the urea water uu.

In this example as well, the urea water storage tank 40 and the hydrolysis reaction tank 41 are provided, and the hydrolysis reaction tank 41 is heated by the off-gas og of the fuel cell device 1. The point that the gas-liquid separation device 32 and the water storage tank 33 are provided is the same, and water w is supplied from the water storage tank 33 to the hydrolysis reaction tank 41 via the water supply channel L8 for hydrolysis. Of course, as shown by the alternate long and short dash line, the gas-liquid separation tank 32 may be directly guided to the hydrolysis reaction tank 41.

The ammonia fuel power generation system of this configuration is indicated by 301, and the corresponding ammonia fuel supply device is indicated by 401.

Also in this system 301, the exhaust heat of the engine E can be effectively used for the operation of the fuel cell device 1, and the heat that tends to be wasted without being used can be effectively used for fuel supply to the fuel cell device 1. The system configuration is compact and simple, and can be highly reliable.

〔Example〕
In line with the above-mentioned first embodiment, a case where it is actually adopted for an in-vehicle use was examined.
1. 1. The required amount of ammonia as fuel required to extend the mileage by 200 km is 12.53 m ³ N = 9.55 kg.
This amount of ammonia required is the amount of ammonia corresponding to the amount of hydrogen required to extend the mileage by the same distance in the current fuel cell vehicle.
2. Ammonia storage material When the ammonia storage material is strontium chloride, the required amount is 23.6 kg.
3. 3. Hydration reaction product When the hydration reaction product is calcium oxide, the amount required to desorb ammonia from strontium chloride is 14.9 kg. The thermal efficiency of the heat transfer layer hex is set to 80%.
4. Carbonation reaction product When calcium oxide is used to remove carbon dioxide in the air, the required oxygen amount is 20 m ³ N (air utilization rate is 50) for ^{200 m 3 N of hydrogen required as a fuel cell when traveling 200 km.} %), And the corresponding amount of carbon dioxide is 0.5 m ³ N.
As a result, the amount of calcium oxide is 1.25 kg, which is sufficiently compact.
Further, if 12.5 kg of calcium oxide is filled, 1000 running is possible.

5. Ammonia remover When the remover stored in the ammonia remover is nickel chloride (NiCl ₂ ), the fuel utilization rate of the fuel cell device 1 is 80%, the air utilization rate is 50%, and the safety factor is 200%. The amount of nickel chloride required for traveling 200 km is 380 g, which is sufficiently compact.

[Another Embodiment]
(1) In the above embodiment, an example of calcium oxide is shown as a specific example of the hydration reaction product and the carbonation reaction product, but as the hydration reaction product, calcium oxide and magnesium oxide are preferable from the reaction form. As the carbonated reaction product, in addition to the combination of calcium oxide and magnesium oxide, the combination of calcium oxide and strontium oxide is also practical because of its reaction form.

1 Fuel cell device (solid electrolyte fuel cell, anion exchange membrane fuel cell)
2 Power conditioner 3 Storage battery 4 Motor 21 Ammonia storage tank 22 Hydration reaction storage tank 23 Ammonia removal tank 24 Carbonation reaction product storage tank 25 Storage tank 25a First storage tank (hydration reaction storage tank)
25b Second storage tank (hydration reaction product storage tank / carbonation reaction product storage tank)
32 Gas-liquid separation device 33 Water storage tank 40 Urea water storage tank 41 Hydrolysis reaction tank 101 Ammonia fuel power generation system 102 Ammonia fuel power generation system 103 Ammonia fuel power generation system 104 Ammonia fuel power generation system 201 Ammonia fuel power supply device 202 Ammonia fuel supply device 203 Ammonia fuel supply device 204 Ammonia fuel supply device exg Exhaust gas f Fuel hex Heat transfer layer ocg Oxidizer gas og Off gas og2 Off gas w Water E Engine H Heating means V Switching valve mechanism

Claims (9)

A fuel cell device that generates electricity by receiving the supply of ammonia,
With adsorbed by forming complexes with ammonia, the ammonia storage tank housing the ammonia storage material capable of leaving the ammonia in the adsorption state by heat,
A hydration reaction storage tank containing oxides of alkali metals and / or alkaline earth metals, and
Equipped with an ammonia removal tank that oxidizes or adsorbs and removes ammonia
The hydration reaction storage tank and the ammonia removal tank are connected to the ammonia storage tank so as to be heat transferable.
A fuel supply path for supplying the ammonia released from the ammonia storage tank as fuel to the fuel cell device is provided.
It is provided with a gas-liquid separation device for gas-liquid separation of off-gas released from the fuel cell device, and a water storage tank for storing the water separated by the gas-liquid separation device.
A water introduction path for hydration reaction for guiding water from the water storage tank to the hydration reaction product storage tank is provided, and a gas introduction path for guiding the gas separated by the gas-liquid separation device to the ammonia removal tank is provided. Ammonia fuel power generation system. The fuel cell device includes a solid electrolyte and a solid electrolyte fuel cell having an anode electrode on one side of the solid electrolyte and a cathode electrode on the other side.
The ammonia fuel power generation system according to claim 1, which is a direct ammonia fuel cell that generates electricity from ammonia supplied as fuel to the solid electrolyte fuel cell. Urea water storage tank for storing urea water and
It is provided with a hydrolysis reaction tank that receives the urea water supply from the urea water storage tank and is heated to hydrolyze the urea water.
The ammonia fuel power generation system according to claim 2, further comprising a heating means for heating the hydrolysis reaction tank with off-gas released from the fuel cell device. The ammonia fuel power generation system according to claim 3, further comprising a water reaction water introduction path for guiding the water separated by the gas-liquid separation device to the hydrolysis reaction tank. The ammonia according to claim 1, wherein the fuel cell device is an anion exchange membrane type fuel cell having an anion exchange membrane, an anode electrode on one side of the anion exchange membrane, and a cathode electrode on the other side. Fuel power generation system. Carbonate that contains oxides of alkali metal, alkaline earth metal, or both, and removes carbon dioxide contained in the oxidant gas as a carbonate from the oxidant gas containing the oxidant supplied to the fuel cell apparatus. The ammonia fuel power generation system according to claim 5, further comprising a reaction product storage tank. With adsorbed by forming complexes with ammonia, the ammonia storage tank housing the ammonia storage material capable of leaving the ammonia in the adsorption state by heat,
A hydration reaction storage tank containing oxides of alkali metals and / or alkaline earth metals, and
Equipped with an ammonia removal tank that oxidizes or adsorbs and removes ammonia
The hydration reaction storage tank and the ammonia removal tank are provided so as to transfer heat to the ammonia storage tank.
A fuel supply path that supplies ammonia released from the ammonia storage tank as fuel, and
A water introduction path for hydration reaction that guides water to the hydration reaction storage tank,
An ammonia fuel supply device including a gas introduction path for guiding an ammonia-containing gas containing ammonia to the ammonia removal tank. A carbonated reaction product storage tank in which an alkali metal, an alkaline earth metal, or both oxides are contained and the carbon dioxide contained in the oxidant gas is removed as a carbonate from the oxidant gas is transmitted to the ammonia storage tank. To prepare for heating
An oxidant gas containing carbon dioxide is introduced into the carbonation reaction product storage tank, and an oxidant gas treatment path through _{which the CO 2 free gas sent out after removing the carbon dioxide from the carbonation reaction product storage tank flows is provided.} The ammonia fuel supply device according to claim 7. With adsorbed by forming complexes with ammonia, the ammonia storage tank housing the ammonia storage material capable of leaving the ammonia in the adsorption state by heat,
A storage tank containing oxides of alkali metals and / or alkaline earth metals, and
Equipped with an ammonia removal tank that oxidizes or adsorbs and removes ammonia
The storage tank and the ammonia removal tank are provided so that heat can be transferred to the ammonia storage tank.
Provided as a fuel supply channel for supplying the ammonia released from the ammonia storage tank as fuel.
The storage tank is provided with at least a first storage tank and a second storage tank.
The first storage tank is provided with a water introduction path for hydration reaction to guide water, and the first storage tank is configured as a hydration reaction product storage tank.
Oxidation in which a water introduction path for a hydration reaction that guides water and an oxidant gas containing carbon dioxide are guided to the second storage tank, and the CO ₂ free gas that is sent out after removing the carbon dioxide from the second storage tank flows. An ammonia fuel supply device that can be switched from the agent gas treatment path.

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