JP2005324584A - Intermediate and high pressure hydrogen supply method and its device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intermediate and high pressure hydrogen supply device that is small and can supply high pressure hydrogen and intermediate pressure hydrogen with one facility without waste. <P>SOLUTION: The intermediate and high pressure hydrogen supply device 10 essentially comprises a solid polymer water electrolysis device 20 that can extract intermediate pressure hydrogen by electrolyzing water, pressurizes the hydrogen, can obtain high pressure hydrogen, and hence plays a role as a compressor, and a storage tank 41 capable of storing the intermediate pressure hydrogen manufactured by the solid polymer water electrolysis device 20. Since the solid polymer water electrolysis device for generating the hydrogen works as a compressor for pressurizing the intermediate pressure hydrogen to the high pressure hydrogen, the intermediate pressure hydrogen and the high pressure hydrogen can be supplied with one device without waste. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a medium-pressure and high-pressure hydrogen supply technology for supplying hydrogen gas to a vehicle-mounted tank.

As vehicles equipped with fuel cells become widespread, a system for supplying fuel gas as fuel becomes important. For this purpose, a hydrogen gas supply method and apparatus have been proposed. (For example, refer to Patent Document 1).
JP 2002-373230 A (FIG. 6)

Patent document 1 is demonstrated based on the following figure.
FIG. 8 is a diagram for explaining the basic principle of the prior art, in which a hydrogen service station is provided with a hydrogen production device Hk, a hydrogen storage device St, and a hydrogen filling device Is, and supplies a hydrogen gas to the hydrogen automobile J2. Is disclosed.

  By the way, the system of Patent Document 1 is a hydrogen service station that supplies hydrogen to a plurality of hydrogen vehicles, and has a hydrogen gas generator, a storage tank, and a filling device of a corresponding size. You need to be ready to do it.

Such a full-scale hydrogen service station has the following drawbacks.
First, since it consists of a large hydrogen gas generator, a storage tank, and a filling device, the equipment becomes large and equipment costs increase. It is difficult to place it in the corner of a parking lot at home or small business.

Next, it is suitable for supplying high-pressure hydrogen because it always passes through a filling device, but it is excessive in equipment for supplying medium-pressure hydrogen, which increases operating costs.
Here, the medium pressure hydrogen is about 15 to 25 MPa, and the high pressure hydrogen is about 30 to 40 MPa. In order to produce high-pressure hydrogen, a large amount of energy is required in the pressurizing process, and the efficiency is also reduced due to leakage or the like. If the planned mileage is short, it is not necessary to load a large amount of hydrogen, so the medium pressure is sufficient for the hydrogen pressure.
Considering the effective use of energy, it is desired that high-pressure hydrogen and medium-pressure hydrogen can be produced as needed and can be supplied by one facility.

  An object of the present invention is to provide a medium-pressure and high-pressure hydrogen supply device that is small in size and can supply high-pressure hydrogen and medium-pressure hydrogen with a single facility without waste.

  The invention according to claim 1 is a process for producing medium-pressure hydrogen by electrolyzing water with a solid polymer water electrolyzer, a process for storing this hydrogen in a storage tank, and the stored hydrogen for the storage tank. And supplying the high-pressure hydrogen to the vehicle while pressurizing the hydrogen stored in the storage tank when necessary using the solid polymer water electrolyzer. .

  According to a second aspect of the present invention, there is provided a solid polymer water electrolyzer that can electrolyze water and take out medium-pressure hydrogen, pressurize the hydrogen, and act as a compressor to obtain high-pressure hydrogen, and the solid A storage tank capable of storing medium-pressure hydrogen produced by a polymer-type water electrolysis apparatus, and a pipe line including a return flow path for returning medium-pressure hydrogen from the storage tank to the inlet of the solid polymer-type water electrolysis apparatus And a plurality of valves interposed in the pipe line, and a middle / high hydrogen discharge port provided at the end of the pipe line.

  In the invention according to claim 1, by supplying hydrogen directly from the storage tank to the vehicle, the medium-pressure hydrogen can be filled into the vehicle-mounted tank, and when necessary, the medium-pressure hydrogen stored in the storage tank is solid. The high-pressure hydrogen can be filled into the vehicle-mounted tank by supplying high-pressure hydrogen to the vehicle while applying pressure using the polymer water electrolysis apparatus.

Therefore, when filling a little hydrogen for reasons such as a short planned traveling distance, it is filled with medium-pressure hydrogen, and when it is necessary to fill a sufficient amount of hydrogen, high-pressure hydrogen is filled.
Since the hydrogen supply device can be operated as required and energy is not wasted, operation costs can be greatly reduced compared to a full-scale hydrogen service station.

  In the invention according to claim 2, the solid polymer water electrolysis apparatus for generating hydrogen serves as a compressor for increasing the pressure of the medium pressure hydrogen to the pressure of the high pressure hydrogen, so that the medium pressure hydrogen and the high pressure hydrogen can be saved in one apparatus. It is possible to supply, achieve integration of equipment, and reduce the size of the hydrogen supply device.

In addition, when a piston compressor or a roots compressor is used for boosting, if foreign matter such as metal powder is mixed in the fluid, the piston is damaged or the roots are worn, so it is necessary to remove the foreign matter.
In this respect, the polymer electrolyte water electrolysis apparatus does not have to worry about mechanical wear because there is no mechanical contact portion.

Furthermore, a mechanical compressor such as a Roots compressor generates noise and has a large energy loss for operation.
In this respect, the solid polymer type water electrolysis apparatus is quiet because there is no mechanical contact portion, has high efficiency, and has low energy loss.
Therefore, diverting the polymer electrolyte water electrolyzer to the compressor has many advantages.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a configuration diagram of a medium-pressure and high-pressure hydrogen supply apparatus according to the present invention. A medium-pressure and high-pressure hydrogen supply apparatus 10 is a role of a hydrogen production apparatus that can electrolyze water and take out medium-pressure hydrogen. And a solid polymer water electrolyzer 20 that serves as a compressor that pressurizes hydrogen and obtains high-pressure hydrogen, and a storage tank that can store medium-pressure hydrogen produced by the solid polymer water electrolyzer 20 41, a pipe line 43 including a return flow path 42 for returning medium pressure hydrogen from the storage tank 41 to the inlet 27 of the polymer electrolyte water electrolysis device 20, and a plurality of valves 44 to 49, a purifier 50 interposed in the pipe line 43 for removing moisture contained in the hydrogen gas, a medium / high pressure hydrogen discharge port 51 provided at the end of the pipe line 43, and a solid polymer type water electrolysis apparatus It consists of an exhaust pump 60 that exhausts 20

  Then, a hydrogen supply hose 52 is connected to the medium / high pressure hydrogen discharge port 51, and the tip of the hydrogen supply hose 52 is connected to the vehicle-mounted tank 53, so that the vehicle-mounted tank 53 mounted on the vehicle 54 has medium-pressure hydrogen or high-pressure hydrogen. Can be filled.

Reference numeral 32 denotes a DC power source for the polymer electrolyte water electrolysis device 20, which is based on power from solar power generation or wind power generation, uses the shortage with commercial power, and converts the AC power into a predetermined DC power source. It has a function.
Reference numeral 55 denotes a pure water production device, which is a device capable of producing pure water from tap water, although its detailed structure is omitted.

  FIG. 2 is a cross-sectional view of a solid polymer type water electrolysis apparatus. The solid polymer type water electrolysis apparatus 20 has a thin catalyst layer on both sides of a solid polymer layer 21 that has properties of passing protons but not electrons. 22 and 23 are provided, and an anode 24 and a power feeding body 33 called an anode side gas diffusion electrode are arranged on one side with such a solid polymer layer 21 therebetween, and a cathode 25 called a cathode side gas diffusion electrode on the other side. In addition, the power supply body 34 is disposed, and the whole is surrounded by a sealed case 26, and an inlet 27, an outlet 28, and an oxygen outlet 29 are provided in the sealed case 26. The inlet 27 faces the anode 24, the outlet 28 faces the cathode 25 and is disposed opposite to the inlet 27, and the oxygen outlet 29 faces the anode 24 and is disposed opposite to the inlet 27.

31 is a circuit connecting the anode 24 and the cathode 25, and 32 is a DC power source.
Reference numerals 33 and 34 denote power feeding bodies that supply a current and promote a gas flow, and are made of a metal porous body.

FIG. 3 is a principle diagram of hydrogen production by the solid polymer type water electrolysis apparatus, and H ₂ O is supplied to the anode 24 side through the inlet 27. A DC voltage is applied between the anode 24 and the cathode 25 through a circuit 31.
The supplied H ₂ O is decomposed into (1 / 2O ₂ + 2H ⁺ + 2e) by the action of the catalyst 22. H ⁺ is a proton and e is an electron.

The separated H ⁺ passes through the solid polymer layer 21 and reaches the catalyst 23 on the cathode 25 side. By the action of the catalyst 23, a reaction of 2H ⁺ + 2e → H ₂ occurs, and hydrogen (H ₂ ) can be produced. The e associated with the reaction is opposite to the current through the circuit 31, that is, constantly flows from the cathode 25 to the anode 24 and plays a role of continuing the reaction on the anode 24 side and the cathode 25 side.

Based on the above principle, hydrogen (H ₂ ) can be continuously obtained from the outlet 28, and oxygen (O ₂ ) can be continuously obtained from the oxygen outlet 29.

FIG. 4 is an explanatory view of the compressor action by the solid polymer type water electrolysis apparatus. In the case where there is a difference between the two pressures, it is generally distinguished from low pressure and high pressure, but in the present invention, the names “medium pressure” and “high pressure” are adopted.
First, the oxygen outlet 29 is closed by a valve 49, supplies the intermediate pressure _{H 2} through the inlet 27 to the anode 24 side. A DC voltage is applied between the anode 24 and the cathode 25 through a circuit 31.

The supplied intermediate pressure H ₂ is decomposed into (2H ⁺ + 2e) by the action of the catalyst 22.
The separated H ⁺ passes through the solid polymer layer 21 and reaches the catalyst 23 on the cathode 25 side. By the action of the catalyst 23, a reaction of 2H ⁺ + 2e → high pressure H ₂ occurs, and medium pressure hydrogen (H ₂ ) can be increased in pressure.

The capacity of this compressor can be explained by the following equation. In (Ph / Pl) = (2F / RT) × (ΔE−ir). Here, ln is a natural logarithm symbol, Ph is a high-pressure side hydrogen partial pressure, Pl is a medium-pressure side hydrogen partial pressure, F is a Faraday constant, R is a gas constant, T is an absolute temperature of the cell, ΔE is an applied voltage, and i is a current. Density, r is the resistance of the cell.
The compressor capacity can be expressed as Ph / Pl. For example, the pressure of high-pressure hydrogen can be controlled by controlling the applied voltage (ΔE).

  The operation of the medium pressure and high pressure hydrogen supply apparatus of the present invention including the solid polymer type water electrolysis apparatus 20 described above will be described below. In the following drawings, a valve symbol filled in black indicates valve closing, and a white valve symbol indicates valve opening.

FIG. 5 is an operation diagram relating to hydrogen production by an intermediate-pressure and high-pressure hydrogen supply device. Valves 45 and 47 are closed, valves 44, 46, 48 and 49 are opened, and H ₂ O (water) is supplied from the valve 44 side. Supplied and decomposed into H ₂ (hydrogen) and O ₂ (oxygen) by the polymer electrolyte water electrolysis apparatus 20, and O ₂ (oxygen) is discharged through a valve 49 and an oxygen discharge port 56 or a container (not shown). Accumulate on.

On the other hand, H ₂ (hydrogen) is sent to the storage tank 41 through the valve 48, the purifier 50, and the valve 46 and stored there. In the purifier 50, unavoidable moisture contained in H ₂ (hydrogen) can be removed to obtain high-purity H ₂ (hydrogen).

FIG. 6 is an explanatory diagram of a procedure for supplying hydrogen to the on-vehicle tank, where (a) is a medium-pressure hydrogen supply diagram and (b) is a high-pressure hydrogen supply diagram.
In (a), the hydrogen supply hose 52 connects the middle / high pressure hydrogen discharge port 51 and the vehicle-mounted tank 53, the valves 44, 45, 48, 49 are closed, and the valves 46, 47 are opened. Then, the hydrogen accumulated in the storage tank 41 starts to flow into the on-vehicle tank 53 through the valves 46 and 47 and the hydrogen supply hose 52. The supply ends when the residual pressure in the storage tank 41 and the pressure in the in-vehicle tank 53 are in an equilibrium state, that is, the same pressure.
If the planned mileage is short, the hydrogen charge will be in time. If the planned travel distance is long, the following (b) is performed.

  Since (a) operates with a pressure difference, it cannot be applied when a considerable amount of hydrogen remains in the vehicle-mounted tank 53 and the residual pressure is higher than or not different from the internal pressure of the storage tank 41. In this case, the following (b) is used.

That is, (b) can be applied to the case where it is carried out following (a) and the case where the residual pressure in the vehicle tank is high.
In (b), the valves 44, 46 and 49 are closed, and the exhaust pump 60 is operated to discharge water and oxygen remaining in the polymer electrolyte water electrolysis device 20. Then, the valves 45, 47 and 48 are opened, and the polymer electrolyte water electrolysis device 20 is operated. Then, the polymer electrolyte water electrolysis apparatus 20 exhibits the compressor action described with reference to FIG. 4 and sucks the hydrogen in the storage tank 41 through the valve 45 to increase the pressure, and the high-pressure hydrogen is mounted on the vehicle through the valves 47 and 48 and the hydrogen supply hose 52. The tank 53 can be filled.

  It should be noted that (a) and (b) are based on factors such as the remaining amount (residual pressure) of the in-vehicle tank 53 and the planned travel distance, and only (a), only (b), or a combination of (a) and (b). Can be used. Such usage will be described with reference to the following figure.

FIG. 7 is a flowchart according to the intermediate pressure and high pressure hydrogen supply method according to the present invention, and STxx indicates a step number.
ST01: Hydrogen is produced in advance using a solid polymer type water electrolysis apparatus.
ST02: Hydrogen is stored in a storage tank.
ST03: When supplying hydrogen, the pressure P1 in the vehicle tank is read.
ST04: At the same time, the storage tank pressure P2 is read.

ST05: Check whether the pressure P2 of the storage tank exceeds the pressure P1 of the vehicle tank. If exceeded, the process proceeds to the next step. If not, the process proceeds to ST08.
ST06: Since the pressure P2 of the storage tank exceeds the pressure P1 of the in-vehicle tank, the differential pressure filling is performed as shown in FIG.
ST07: The on-board tank was filled with a considerable amount of hydrogen. If the filling amount is sufficient due to a short planned travel distance or the like, this flow is terminated. If it is still insufficient, go to the next.

ST08: By using the solid polymer type water electrolysis apparatus as a compressor, high-pressure hydrogen is filled in the vehicle-mounted tank as shown in FIG. 6B.
ST09: Filling is continued until the pressure in the on-vehicle tank reaches a predetermined pressure, and the filling is terminated when the predetermined pressure is reached.

The above flow is summarized as follows.
The present invention includes a step (ST01) of producing medium pressure hydrogen by electrolyzing water with a solid polymer type water electrolysis device;
A step of storing this hydrogen in a storage tank (ST02);
Supply the stored hydrogen directly from the storage tank to the vehicle (ST06), and supply high-pressure hydrogen to the vehicle while pressurizing the hydrogen stored in the storage tank using the polymer electrolyte water electrolyzer when necessary. And a step (ST08).

According to this method, when filling a little hydrogen for reasons such as the planned travel distance being short, the medium-pressure hydrogen is filled, and if it is necessary to fill a sufficient amount of hydrogen, the high-pressure hydrogen is filled.
The hydrogen supply device can be operated as necessary, and the energy used can be greatly reduced as compared with the conventional hydrogen production / supply device.

  The medium-pressure and high-pressure hydrogen supply apparatus of the present invention can be applied to a full-scale large-scale office or a hydrogen service station in addition to being installed in a corner of a parking lot at home or a small-scale office.

  The present invention is suitable for a medium-pressure and high-pressure hydrogen supply technology for supplying hydrogen gas to a vehicle-mounted tank.

It is a block diagram of the intermediate pressure and high pressure hydrogen supply apparatus which concerns on this invention. It is sectional drawing of a solid polymer type water electrolysis apparatus. It is a principle diagram of hydrogen production by a solid polymer type water electrolysis apparatus. It is explanatory drawing of the compressor effect | action by a solid polymer type water electrolysis apparatus. It is an effect | action figure which concerns on the hydrogen production by a medium pressure and high pressure hydrogen supply apparatus. It is explanatory drawing of the procedure which supplies hydrogen to a vehicle-mounted tank, (a) is a medium pressure hydrogen supply figure, (b) is a high pressure hydrogen supply figure. It is a flowchart concerning the intermediate pressure and high pressure hydrogen supply method according to the present invention. It is a figure explaining the basic principle of the prior art.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Medium pressure and high pressure hydrogen supply apparatus, 20 ... Solid polymer type water electrolysis apparatus, 41 ... Storage tank, 42 ... Return flow path, 43 ... Pipe line, 44-49 ... Valve, 50 ... Purifier, 51 ... Medium -High-pressure hydrogen discharge port, 53 ... vehicle tank, 54 ... vehicle.

Claims (2)

A process for producing medium pressure hydrogen by electrolyzing water in a solid polymer water electrolyzer;
Storing this hydrogen in a storage tank;
Supplying the stored hydrogen directly from the storage tank to the vehicle, and supplying high-pressure hydrogen to the vehicle while pressurizing the hydrogen stored in the storage tank using the solid polymer water electrolyzer when necessary; An intermediate-pressure and high-pressure hydrogen supply method comprising: Manufactured with a solid polymer water electrolyzer that can extract water of medium pressure by electrolyzing water and pressurize hydrogen to act as a compressor to obtain high pressure hydrogen, and this solid polymer water electrolyzer A storage tank capable of storing the intermediate pressure hydrogen, a conduit including a return passage for returning the intermediate pressure hydrogen from the storage tank to the inlet of the polymer electrolyte water electrolysis device, and an intervening in the conduit A medium-pressure and high-pressure hydrogen supply device comprising a plurality of valves and a medium- and high-pressure hydrogen discharge port provided at the end of the pipeline.

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