JP2011119050A - Fuel cell power generation system, and hydrogen production device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a closed-cycle fuel cell power generation system, in which high-purity hydrogen and benzene are produced with a simple construction by using cyclohexane, liquid at normal temperature, as a fuel, and then cyclohexane is reproduced by supplying them to a fuel cell, without supply of fuel from outside, and to provide a hydrogen production device capable of obtaining high-purity hydrogen. <P>SOLUTION: A fuel cell power generation system 10 is a closed-cycle type system and is equipped with a fuel container 11 storing cyclohexane, a hydrogen-separation container 14 providing a hydrogen-production unit producing hydrogen and benzene-rich liquid from cyclohexane, a hydrogen-separation unit separating the produced hydrogen from the benzene-rich liquid, and the fuel cell 15 in which the hydrogen is supplied to an anode 15a and the benzene-rich liquid is also supplied to a cathode 15b. And, the hydrogen-production unit is composed of a hydrogen-generation portion 12 having electrodes 12a, 12b arranged in opposition and a pulse power source 13 applying pulse voltage between the electrodes 12a, 12b. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fuel cell power generation system and a hydrogen production apparatus, and more particularly to a closed cycle fuel cell power generation system using hydrogen obtained by decomposing cyclohexane with pulse power and a hydrogen production apparatus using pulse power.

As is well known, a fuel cell includes an anode electrode to which hydrogen is supplied, a cathode electrode to which oxygen is supplied, and an electrolyte, and obtains electric energy by reacting hydrogen and oxygen. Since fuel cells themselves have good power generation efficiency and do not emit carbon dioxide (CO ₂ ), they are attracting attention from the global environmental viewpoint and are gradually being utilized.

  In order to generate electricity with a fuel cell, a large amount of hydrogen is required continuously. For this reason, a normal fuel cell is provided with a reformer and a fuel supply system in the vicinity thereof to obtain hydrogen from fuel such as natural gas and methanol. However, when the equipment of the reformer and the fuel supply system is provided, the entire fuel cell is increased in size.

  Therefore, it has been studied to make it possible to generate electricity without supplying a large amount of hydrogen to a fuel cell from another supply system. For example, as described in Patent Document 1, hydrogen is repeatedly used in a closed system. Thus, a fuel cell system that can continuously generate power without supplying hydrogen has been proposed. The fuel cell system of Patent Document 1 uses a dehydrogenation reactor having a dehydrogenation catalyst to dehydrogenate a compound to be dehydrogenated to produce a dehydrogenation compound and hydrogen, and dehydrogenation produced in the dehydrogenation reactor. The compound and hydrogen are separated by a hydrogen separator.

  Then, the separated hydrogen is supplied to the anode electrode of the fuel cell, and the dehydrogenation compound is supplied to the cathode electrode of the fuel cell to generate electric power. The hydrogen is repeatedly used in a closed cycle by regenerating the dehydrogenated compound from

In the fuel cell system described above, cyclohexane or isopropanol is used as the dehydrogenated compound. That is, cyclohexane (C ₆ H ₁₂ ) is dehydrogenated to produce benzene (C ₆ H ₆ ) and hydrogen, and cyclohexane is regenerated by a benzene hydrogenation reaction, and isopropanol (C ₃ H ₈ O). May be dehydrogenated to produce acetone (C ₃ H ₆ O) and hydrogen, and isopropanol may be regenerated by an acetone hydrogenation reaction.

  In order to supply hydrogen used in the fuel cell, for example, Patent Document 2 proposes a method for extracting a large amount of hydrogen from a hydrogenated aromatic compound. The hydrogen extraction method of Patent Document 2 uses a hydrogenated aromatic compound such as cyclohexane that is liquid at room temperature and stored in a storage tank.

  Then, the hydrogenated aromatic compound is supplied to the catalytic reactor filled with the dehydrogenation catalyst, and heated by a heater provided outside in the presence of the dehydrogenation catalyst while maintaining the inside of the catalytic reactor in a liquid phase state. Then, hydrogen gas is generated. The generated hydrogen gas is separated from unreacted hydrogenated aromatic compounds and dehydrogenated products using a hydrogen separation means such as a hydrogen separation membrane, and supplied to the fuel cell.

JP 2002-208430 A JP 2006-265065 A

  The fuel cell power generation system as described in Patent Document 1 has an advantage that hydrogen can be repeatedly used in a closed cycle of the fuel cell. However, since cyclohexane or the like is used as a dehydrogenated compound and this is reacted with a dehydrogenation catalyst in a dehydrogenation reactor to generate hydrogen, equipment for producing and separating high-purity hydrogen is expensive. . In addition, there is a problem that the entire fuel cell power generation system cannot be economically manufactured because it has to be heated to a predetermined temperature in order to improve the catalytic reaction.

  Further, the catalytic reaction apparatus is used also in the method of producing and taking out hydrogen used in the fuel cell by the method of taking out hydrogen as described in Patent Document 2. And while keeping the inside of the catalytic reaction apparatus in which a dehydrogenation catalyst exists in a liquid phase state, a dehydrogenation catalyst is heated with the heater provided outside, and hydrogen gas is produced | generated from hydrogenated aromatic compounds, such as a cyclohexane. As a result, there is a problem in that the structure of the entire equipment cannot be easily configured and cannot be manufactured economically.

  The object of the present invention is to use cyclohexane which is liquid at normal temperature as a fuel, generate high-purity hydrogen and benzene with a simple structure, supply these to the fuel cell to regenerate cyclohexane, and do not supply fuel from the outside The object is to provide a closed-cycle fuel cell power generation system.

  Another object of the present invention is to provide a hydrogen production apparatus that can easily obtain high-purity hydrogen without using an expensive catalyst by using cyclohexane that is liquid at room temperature as a fuel.

  The present invention provides a hydrogen generating means for generating a liquid rich in hydrogen and benzene from cyclohexane supplied from a fuel container, a hydrogen separating means for separating the liquid rich in hydrogen and benzene from the hydrogen generating means, and the hydrogen In a closed cycle type fuel cell power generation system comprising a fuel cell in which hydrogen separated by the separation means is supplied to the anode electrode and a liquid rich in benzene is supplied to the cathode electrode, the hydrogen generation means is The hydrogen generating part having electrodes arranged opposite to each other and a pulse power power source for supplying a pulse voltage between the electrodes are characterized in that it is characterized in that

  Further, the hydrogen production apparatus of the present invention is provided with a hydrogen container containing cyclohexane and a hydrogen generation part having electrodes arranged opposite to each other, and from the cyclohexane supplied from the fuel container in the hydrogen generation part to hydrogen and benzene. A hydrogen separation container that produces and separates a rich liquid, a pulse power power source that applies a pulse voltage between the electrodes of the hydrogen generation unit, a hydrogen recovery container that recovers hydrogen separated in the hydrogen separation container, and a benzene-rich material It is characterized by comprising a recovery container for recovering the liquid.

  If the fuel cell power generation system as in the present invention is used, a high-purity hydrogen generated from cyclohexane and benzene are supplied to the fuel cell in the hydrogen generator having electrodes connected to the pulse power source, and the cyclohexane is regenerated in the fuel cell. And can be recirculated. Further, since hydrogen can be generated without using a catalyst that must be heated, there is no need to supply fuel from the outside, and a closed cycle system with a small amount of exhaust heat can be obtained.

  Further, if a hydrogen production apparatus is configured as in the present invention, high-purity hydrogen and benzene can be easily generated from cyclohexane by pulse power without using an expensive catalyst, and the entire apparatus can be economically compared with the conventional apparatus. There is an advantage that can be manufactured.

It is a schematic block diagram which shows one Example of the fuel cell power generation system of this invention. It is a schematic block diagram which shows one Example of the hydrogen production apparatus of this invention. (A)-(f) is the schematic which shows the example of the electrode arrangement | positioning used for manufacture of hydrogen, respectively.

  A fuel cell power generation system according to the present invention includes a hydrogen generation unit that generates a liquid rich in hydrogen and benzene from cyclohexane supplied from a fuel container, and a hydrogen separation that separates the liquid rich in hydrogen and benzene from the hydrogen generation unit. And a fuel cell in which hydrogen separated by the hydrogen separation means is supplied to the anode electrode and a benzene-rich liquid is supplied to the cathode electrode. The hydrogen generation means includes a hydrogen generation unit having electrodes arranged opposite to each other and a pulse power power source that supplies a pulse voltage between the electrodes.

  Further, the hydrogen production apparatus of the present invention uses a hydrogen separation vessel provided with a hydrogen generation unit having electrodes arranged opposite to each other, and from a pulse power power source to a hydrogen and benzene from a cyclohexane by a pulse voltage applied between the electrodes. Produces a rich liquid.

Hereinafter, a fuel cell power generation system and a hydrogen production apparatus according to the present invention will be described with reference to FIGS. 1 to 3. In the fuel cell power generation system 10 of the present invention, which is a closed-cycle regeneration type shown in FIG. 1, cyclohexane (C ₆ H ₁₂ ) that is liquid at room temperature is used as the fuel for hydrogen generation. I store it.

  The cyclohexane stored in the fuel container 11 is sent to a hydrogen generation unit 12 used as a hydrogen generation means via a supply system having a valve V1 and a liquid pump P1. The hydrogen generator 12 has electrodes 12a and 12b as described later, and has a structure in which an expensive catalyst is not used at all.

The electrodes 12a and 12b of the hydrogen generator 12 are connected to a pulse power power supply 13 and applied with a predetermined pulse voltage. Utilizing this pulse power, in the hydrogen generation section 12, cyclohexane produces hydrogen and a benzene-rich liquid containing cyclohexane that has not been decomposed, such as C ₆ H ₁₂ → 3H ₂ + C ₆ H ₆ . The produced hydrogen and benzene-rich liquid is stored in a gas-liquid separated state in the hydrogen separation container 14 used as the hydrogen separation means. In the example of FIG. 1, the hydrogen generation unit 12 is provided in a part of the hydrogen separation vessel 14, but can be installed independently.

  As the electrodes 12a and 12b of the hydrogen generator 12 connected to the pulse power source 13, those illustrated in FIGS. 3A to 3F can be used. That is, a combination of a coaxial electrode and cylindrical electrode shown in FIG. 3A, a parallel arrangement of coaxial electrodes shown in FIG. 3B, a combination of a cylindrical electrode and cylindrical electrode shown in FIG. Both of the combinations shown in (d) can be a combination of rod-shaped electrodes, a combination of a rod-shaped electrode and a plate electrode shown in (e), a combination of a sword-shaped electrode and a plate electrode shown in (f), or the like.

  Hydrogen in the hydrogen separation vessel 14 is supplied from the supply system having the valve V2 to the anode 15a side of the fuel cell 15, and the benzene-rich liquid in the hydrogen separation vessel 14 has a valve V3 and a liquid pump P2. The fuel is supplied from the supply system to the cathode 15b side of the fuel cell 15. Note that hydrogen can be stored by providing a temporary storage container (not shown) in the supply system and supplied to the fuel cell 15 from the temporary storage container.

In the fuel cell 15, electricity is generated using hydrogen and a liquid rich in benzene and supplied to the external load 16, and cyclohexane is regenerated as C ₆ H ₆ + 6H ⁺ + 6e ⁻ → C ₆ H _12. Yes. This cyclohexane is recycled to the fuel container 11 and reused as a fuel for hydrogen generation.

  As in the above-described closed-cycle fuel cell power generation system, when the hydrogen generation means is configured and used by a hydrogen generator having electrodes arranged opposite to each other and a pulse power power source that supplies a pulse voltage between the electrodes, There are advantages like That is, when hydrogen-producing means is used to produce a liquid rich in hydrogen and benzene that is liquid at room temperature from cyclohexane that is liquid at room temperature, a heater is prepared and a catalyst is prepared like a reactor using a conventional catalyst. There is no need to heat to a predetermined temperature. For this reason, since the temperature does not increase during the hydrogen generation, the amount of exhaust heat is remarkably reduced, and high-purity hydrogen can be generated and used in the fuel cell.

  The fuel cell power generation system of the present invention can also be operated at all times. Naturally, hydrogen is generated and separated during a time period when the power demand is low, and stored during a time when the power demand is high or during a power failure. It is also possible to generate electricity with a fuel cell using hydrogen. Note that the pulse power power supply 13 can utilize not only normal power but also nighttime power or natural energy.

  Next, the hydrogen production apparatus 20 of the present invention shown in FIG. 2 will be described. The cyclohexane to be treated is accommodated in a fuel container 21, and the fuel container 21 is connected to a hydrogen separation container 24 provided with a leak valve VB by a supply system having a valve VA interposed therebetween.

  The hydrogen separation vessel 24 is provided with a hydrogen generator 22 having electrodes arranged oppositely to be present in the cyclohexane liquid supplied. The oppositely arranged electrodes of the hydrogen generator 22 are selected from the combinations shown in FIGS. 3A to 3F in the same manner as described above, and a pulse power source 23 for applying a pulse voltage is connected between the electrodes. ing.

  In this hydrogen generation part 22, the pulse power applied between the electrodes hardly affects the temperature rise in the hydrogen generation part 22 when the liquid cyclohexane is decomposed, and the decomposition reaction is promoted at room temperature. Can produce a benzene-rich liquid containing hydrogen and undecomposed cyclohexane.

  The hydrogen generated in the hydrogen separation container 24 and separated into gas and liquid is recovered and stored in the hydrogen recovery container 25 connected through the valve VC. The liquid rich in benzene is recovered and stored in a continuous recovery container 26 with a valve VE interposed, and supplied to a fuel cell or the like when necessary. The hydrogen recovery container 25 is provided with an exhaust system having a valve VD and a vacuum pump VP.

  In the hydrogen production apparatus 20 configured as described above, the hydrogen generation unit 22 having opposed electrodes is used for producing a liquid rich in hydrogen and benzene from cyclohexane, and an expensive catalyst is not used. Highly pure hydrogen and benzene can be easily generated by pulse power.

  Subsequently, an operation procedure of the above-described hydrogen production apparatus 20 will be described. First, the valve VA in the production system is closed, the valve VB is closed, the valve VC is opened, the valve VD is opened, and the valve VE is opened. Then, the vacuum pump VP is driven to recover the hydrogen separation vessel 24 and the hydrogen recovery The container 25 and the collection container 26 are evacuated.

  Thereafter, the valve VE, the valve VC, and the valve VD are closed in this order, then the valve VA is opened, a predetermined amount of cyclohexane is introduced into the hydrogen separation container 24, and at least the space between the electrodes of the hydrogen generator 22 is filled with liquid. Close VA. If necessary, cyclohexane is supplied to the fuel container 21 from another storage container (not shown).

  A pulse voltage is applied between the electrodes of the hydrogen generator 22 from a pulse power power source 23 to decompose liquid cyclohexane with pulse power to generate gaseous hydrogen and liquid benzene. After a certain amount of the gas-liquid separated hydrogen is accumulated in the hydrogen decomposition vessel 24, the valve VC is opened and the hydrogen is collected in the hydrogen collection vessel 25. After the hydrogen recovery is completed, the valve VC is closed and then the valve VB and the valve VE are opened, and the benzene-rich liquid in the hydrogen separation container 24 is recovered in another recovery container 26.

DESCRIPTION OF SYMBOLS 10 ... Fuel cell power generation system, 11, 21 ... Fuel container, 12, 22 ... Hydrogen generating part, 12a, 12b ... Electrode, 13, 23 ... Pulse power power supply, 14, 24 ... Hydrogen separation container, 15 ... Fuel cell, 20 ... hydrogen production apparatus, 25 ... hydrogen recovery container, 26 ... recovery container.

Claims (2)

  Separation by hydrogen generating means for generating a liquid rich in hydrogen and benzene from cyclohexane supplied from a fuel container, a hydrogen separating means for separating the liquid rich in hydrogen and benzene from the hydrogen generating means, and the hydrogen separating means In a closed-cycle fuel cell power generation system comprising a fuel cell in which the hydrogen is supplied to the anode electrode and a benzene-rich liquid is supplied to the cathode electrode, the hydrogen generating means has electrodes arranged opposite to each other A fuel cell power generation system comprising a hydrogen generator and a pulse power power source for supplying a pulse voltage between the electrodes.   A hydrogen separation container having a hydrogen container containing cyclohexane and a hydrogen generation part having electrodes arranged opposite to each other, and generating and separating a liquid rich in hydrogen and benzene from cyclohexane supplied from the fuel container in the hydrogen generation part And a pulse power power source that applies a pulse voltage between the electrodes of the hydrogen generation unit, a hydrogen recovery container that recovers hydrogen separated in the hydrogen separation container, and a recovery container that recovers a liquid rich in benzene A hydrogen production apparatus characterized by that.

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