JP3901139B2 - Solid electrolyte type hydrogen treatment system - Google Patents

Description

  The present invention relates to a solid electrolyte type hydrogen treatment apparatus, and particularly applicable to various industrial fields such as a hydrogen sensor, a fuel cell, an energy conversion material, and a hydrogen pump using a solid electrolyte having proton conductivity. The present invention relates to a solid electrolyte type hydrogen treatment apparatus using a simple proton electrolysis cell.

  Conventionally, solid electrolytes (generally referred to as “proton conductors”) having excellent proton (hydrogen ion) conductivity are known, particularly among ceramic materials having a perovskite structure. This proton conductor is expected to be applied to hydrogen sensors, hydrogen pumps, fuel cells, and the like, and has already been put into practical use in part.

Here, it is known that the proton conductor mainly has two characteristic functions of an electromotive function and a proton selective permeation function. More specifically, the electromotive function is the use of the proton conductor described above as a partition wall, and by flowing different concentrations of hydrogen gas into both spaces partitioned by the partition wall,
<Nernst equation>
E = (RT / 2F) ln (PH ₂ (1) / PH ₂ (2))
The electromotive force (EMF) is generated, and power is obtained from the electrodes attached to the front and back surfaces of the proton conductor. Here, “E: theoretical electromotive force”, “R: gas constant”, “F: Faraday constant”, “T: absolute temperature”, and “PH ₂ (1) · PH ₂ (2): hydrogen gas concentration ( Hydrogen gas partial pressure), * PH ₂ (1)> PH ₂ (2) ”. Thereby, application to the fuel cell field and the energy conversion material field becomes possible.

Furthermore, by applying the above-described Nernst equation, when one hydrogen gas concentration (for example, PH ₂ (1)) and the temperature (T) are known, the other hydrogen is generated from the generated electromotive force (E). The gas concentration (here, PH ₂ (2)) can be calculated. That is, the proton conductor can be applied as a sensor for detecting hydrogen gas, so-called “hydrogen sensor”.

  On the other hand, the proton permeation function is a proton electrolysis cell in which electrodes (anode electrode and cathode electrode) made of a metal material such as platinum or palladium having a catalytic function are formed on a proton conductor, and a current is passed between the electrodes. The proton conductor is selectively permeated through the proton conductor from the anode electrode to the cathode electrode by flowing the proton conductor into the energized state.

Thereby, it can be applied as a “hydrogen pump” that can selectively recover only hydrogen gas from the cathode electrode from various gases (such as water vapor gas, nitrogen gas, and methane gas) present in the anode electrode. Is. The reactions proceeding at the anode electrode and the cathode electrode are as shown below.
<Anode electrode side>
H ₂ → 2H ⁺ + 2e ⁻
<Cathode electrode side>
2H ⁺ + 2e ⁻ → H ₂

  At this time, it is known that the reactions that occur in the anode electrode and the cathode electrode described above generally proceed rapidly as the temperature rises. Therefore, when applying a proton electrolysis cell to a hydrogen pump or the like, for example, the processing conditions are adjusted to a high temperature of about 600 ° C. or more in the case of a perovskite oxide and about 1200 ° C. in the case of an alumina-based proton conductor. There was a need.

  By the way, in a fusion facility that performs fusion power generation, tritium (tritium) is generated by the fusion reaction. Since such tritium is a radioactive material, its emission is regulated by law. In addition, since tritium is used as a raw material for a fusion reaction, it has been required to collect tritium generated in the process of the fusion reaction and use it again as a fusion fuel.

  Therefore, water vapor tritiated by tritium generated during the fusion reaction (tritiated water vapor gas) or methane gas (tritiated methane gas) is passed through the reforming catalyst packed tower in advance and further permeated through the palladium alloy membrane. Thus, recovery as tritiated hydrogen gas is performed.

  The above prior art is naturally performed by those skilled in the art, and the applicant is not particularly aware of the literature or the like describing the prior art at the time of filing the present application.

  However, in order to increase the efficiency of the electromotive function and the proton selective permeation function by the proton conductor described above, it is necessary to optimize various parameters such as the concentration of hydrogen gas to be supplied and the current value to be energized. Furthermore, the type of metal material (platinum or palladium) having a catalytic function used for the anode and cathode electrodes attached to the proton electrolysis cell, the method of attachment (or coating), and the composition of the gas that acts on the anode electrode For example, it has been known that the recovery efficiency of hydrogen gas at the cathode electrode changes greatly.

  In particular, when used as a hydrogen pump, the conversion reaction (shift reaction) occurring on the anode electrode side is known to greatly depend on the type of metal used as a catalyst for promoting the reaction and the coating method, and the treatment is performed. In order to allow the reaction on the anode electrode side to proceed promptly, the temperature condition must be set to a high temperature of about 600 ° C. for the perovskite oxide and about 1200 ° C. for the alumina proton conductor. there were. For this reason, research has been conducted on a method for coating a metal material capable of efficiently recovering hydrogen gas and for reducing the processing temperature.

  In addition, the method of recovering tritium generated by the fusion reaction using the above-described palladium alloy film is obtained by previously generating carbon dioxide gas and hydrogen gas from water vapor gas and methane gas in a reforming catalyst packed tower. Further, a process of evacuating hydrogen gas through the palladium alloy film was performed. Therefore, equipment for vacuuming and processing operations are required, and the steam reforming reaction in the reforming catalyst packed tower proceeds reversibly, so that the steam gas that has not been recovered by the palladium alloy membrane is recycled again. It was necessary to pass through a reforming catalyst packed tower. In fusion research facilities, etc., it has been desired to efficiently recover tritium generated by the fusion reaction in the state of hydrogen gas with little risk of water pollution.

  Therefore, in view of the above circumstances, the present invention is to provide a solid electrolyte type hydrogen treatment apparatus having a proton electrolysis cell capable of efficiently operating an electromotive function and a proton selective permeation function at a low temperature. Furthermore, it is a second object to provide a solid electrolyte type hydrogen treatment apparatus that can use a hydrogen pump to which a proton electrolysis cell is applied for tritium gas recovery in the nuclear fusion field.

In order to solve the above-mentioned problems, the solid electrolyte type hydrogen treatment apparatus of the present invention uses a solid oxide type solid electrolyte having proton conductivity and a metal material on the surface of the solid electrolyte using an electroless plating method. Proton electrolysis cell comprising a porous anode electrode and a cathode electrode coated by plating with a catalyst electrode portion to which a mixed gas containing water vapor and methane gas is supplied. To do.

  Here, the metal material used for the catalyst electrode portion acts as a catalyst for promoting the conversion reaction such as the steam reforming reaction described above, and for example, platinum (Pt), palladium (Pd), silver (Ag) ) And nickel (Ni). Furthermore, the electroless plating method is also referred to as “chemical plating method”, and is a method in which a metal material is coated on a solid surface using a reduction reaction in an aqueous solution of a metal salt. In addition, as a reducing agent, formaldehyde aqueous solution (formalin), hypophosphorous acid, sodium borohydride etc. are used as a representative example. As a result, the catalyst electrode portion is formed in a thin and porous state on the surface of the solid electrolyte. Further, although it is possible to form a catalyst electrode having similar characteristics using a thin film forming apparatus such as CVD, there is a problem that the cost is increased as compared with electroless plating.

  Therefore, according to the solid electrolyte type hydrogen treatment apparatus of the present invention, a metal material is used for the catalyst electrode portion including the anode electrode and the cathode electrode of the proton electrolysis cell, and the metal material is applied to the surface of the solid electrolyte by an electroless plating method. It is formed by coating. Since the catalyst electrode portion having a dense porosity formed by the electroless plating method has an increased contact surface area with the gas to be treated, the catalytic activity of the above-described metal material such as platinum is further increased. Thereby, electrode resistance can be reduced, generation | occurrence | production of a proton is performed efficiently, and the performance of a proton electrolysis cell is improved.

  Furthermore, it is possible to form a thin film more uniformly than in the case where a catalyst material is formed by coating a metal material by a conventional paste method or the like. It is also possible to form a similar catalyst electrode by applying conventionally well-known thin film production techniques such as CVD, PVD, and ion sputtering. However, the equipment for producing the thin film becomes large-scale, and the cost for producing the catalyst electrode portion is remarkably increased as compared with electroless plating. As a result, application of electroless plating enables application in a wide range of fields such as a hydrogen pump and a hydrogen gas detection sensor using a proton electrolysis cell with reduced electrode resistance.

  Furthermore, the solid electrolyte type hydrogen treatment apparatus of the present invention includes: “a current supply means for electrically connecting the anode electrode and the cathode electrode to bring the solid electrolyte into an energized state; and the anode electrode of the proton electrolysis cell, A mixed gas supply means for supplying a mixed gas containing water vapor gas and methane gas, and a recovery means for recovering protons that pass through the solid electrolyte as hydrogen gas from the cathode electrode, with the conversion reaction being promoted by the anode electrode. May be provided.

Therefore, according to the solid electrolyte type hydrogen treatment apparatus of the present invention, the anode electrode and the cathode electrode attached to the proton electrolysis cell are electrically connected, and further, the current is passed to bring the proton electrolysis cell into an energized state. The above-described hydrogen pump can be achieved. Here, a mixed gas in which hydrogen gas and methane gas coexist (coexists) is supplied to the anode electrode attached to the solid electrolyte in an energized state by the mixed gas supply means. As a result, the steam reforming reaction (conversion reaction: see the following formula) that occurs on the surface of the catalyst electrode portion of the anode electrode becomes more prominent as compared with the atmosphere in which steam gas or methane gas is generally present alone. Thus, hydrogen gas is efficiently generated, and protons that permeate the solid electrolyte are selectively recovered as hydrogen gas from the cathode electrode.
<Conversion reaction>
CH ₄ + 2H ₂ O⇔CO ₂ + 4H ₂

  Further, the solid electrolyte type hydrogen treatment apparatus of the present invention is as follows: "The mixed gas contains at least one of tritiated water vapor gas and tritiated methane gas in which at least one hydrogen atom in the molecule is substituted with tritium. It does not matter.

Therefore, according to the solid electrolyte type hydrogen treatment apparatus of the present invention, the tritiated water vapor gas (T), which is a gaseous substance containing at least one tritiated hydrogen atom in the molecule in accordance with the conversion reaction described above. ₂ O or HTO) or tritiated hydrogen gas (HT or T ₂ ) containing tritium from a tritiated methane gas (CT ₄ , CTH ₃ , CT ₂ H ₂ , CT ₃ H) via a solid electrolyte It becomes possible to collect by. Here, “T” represents a tritiated hydrogen atom. As a result, it can be recovered from tritiated water vapor gas that is easily liquefiable at room temperature and highly likely to cause water pollution, etc., and converted to gaseous tritiated hydrogen gas that is difficult to liquefy at room temperature. It becomes possible. As a result, it is possible to efficiently recover tritium generated in the process of fusion reaction and to use the recovered tritiated hydrogen gas again as fuel for the fusion reaction. It is particularly preferred that it be adopted.

  Further, the solid electrolyte type hydrogen treatment apparatus of the present invention is as follows: “The mixed gas supply means includes methane gas addition means for adding the methane gas to at least one of the tritiated water vapor gas and the water vapor gas; and the tritiated methane gas. And / or a water vapor gas adding means for adding the water vapor gas to at least one of the methane gas.

  Therefore, according to the solid oxide hydrogen treatment apparatus of the present invention, at least one of methane gas addition means and water vapor gas addition means is included. As a result, when gas is allowed to act on the catalyst electrode portion of the anode electrode and the conversion reaction is promoted, water vapor gas (including tritiated water vapor gas) or methane gas (including tritiated methane gas) is supplied individually. In this case, it is possible to generate a mixed gas composed of “water vapor gas + methane gas” by using the methane gas addition means and the water vapor gas addition means. Thereby, as described above, it is possible to enjoy the effect of further promoting the conversion reaction by mixing each other. Thereby, the function as a hydrogen pump comes to be further improved.

  Furthermore, the solid electrolyte type hydrogen treatment apparatus of the present invention may be one in which “alumina compound is applied to the solid electrolyte”.

  Therefore, according to the solid electrolyte type hydrogen treatment apparatus of the present invention, an alumina compound is applied as the solid electrolyte. Examples of the alumina compound include α-alumina doped with an alkaline earth metal oxide (for example, magnesium oxide). As a result, when used as a hydrogen sensor, the operating temperature can be relaxed to about 700 ° C.

  As described above, the treatment apparatus (solid electrolyte gas hydrogen treatment apparatus) of the present invention is a proton electrolysis composed of a proton conductor (solid electrolyte) formed by coating an anode electrode and a cathode electrode on the surface by an electroless plating method. The cell can be used as a hydrogen pump capable of selectively permeating protons into the solid electrolyte and recovering as hydrogen gas from the cathode electrode. In particular, the conversion reaction can be efficiently performed by treating a mixed gas in which methane gas and water vapor gas are mixed. Further, since the tritium-containing gas (tritiated methane gas or the like) can be processed and the tritium gas can be recovered, it is particularly preferable to employ the processing apparatus of the present invention in a fusion research facility or the like. Further, the proton electrolysis cell is used as a partition wall, and an electromotive force is generated by a difference in hydrogen sensor or hydrogen gas concentration, so that application as a fuel cell or energy conversion material is possible.

  Hereinafter, a solid oxide hydrogen treatment apparatus 1 (hereinafter simply referred to as “treatment apparatus 1”) according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. Here, FIG. 1 is a schematic diagram showing a schematic configuration of the processing apparatus 1 of the first embodiment, and FIG. 2 is an explanatory diagram schematically showing an example of processing of mixed gas in the processing apparatus.

As shown in FIG. 1, the processing apparatus 1 of the first embodiment is composed mainly of a perovskite proton conductor (here, SrCeO ₃ is used), and a proton conductor 3 formed in a substantially flat plate shape. The front and back surfaces 4a and 4b of the proton conductor 3 are coated with platinum (Pt) having a catalytic function for promoting a conversion reaction such as a steam reforming reaction using an electroless plating method. A proton electrolysis cell 2 having a catalyst electrode portion 5 composed of the formed anode electrode 5a and cathode electrode 5c, and the anode electrode 5a and A DC power supply unit 6 electrically connected to the cathode electrode 5c and a mixed gas supply unit for supplying a mixed gas 7 (details will be described later) to the anode electrode 5a of the proton electrolysis cell 2 8 and a gas recovery unit 9 that recovers protons 16 selectively transmitted from the anode electrode 5a of the proton electrolysis cell 2 in an energized state as the hydrogen gas 10 from the cathode electrode 5c. It is applied as a “hydrogen pump”.

  Further, the mixed gas supply unit 8 is configured so that “normal” methane gas 13n is added to the tritiated water vapor gas 12t containing at least one tritiated hydrogen atom in the molecule (where “normal” means tritiated in the molecule). Normal water vapor in the methane gas addition section 11 for adding a hydrogen atom that is not contained above the natural concentration: the same applies hereinafter) and a tritiated methane gas 13t (including a tritiated hydrogen atom). A water vapor gas addition unit 14 for adding the gas 12n is included.

  Thereby, the mixed gas 7 supplied to the anode electrode 5a of the proton electrolysis cell 2 always contains the water vapor gases 12n and 12t and the methane gases 13n and 13a. Here, the proton conductor 3 corresponds to the solid electrolyte in the present invention, the DC power supply unit 6 corresponds to the energizing means in the present invention, the mixed gas supply unit 8 corresponds to the mixed gas supply means in the present invention, and the gas recovery The section 9 corresponds to the recovery means in the present invention, the methane gas addition section 11 corresponds to the methane gas addition means in the present invention, and the water vapor gas addition section 14 corresponds to the water vapor gas addition means in the present invention.

  Next, an example of processing of the tritiated water vapor gas 13t or the tritiated methane gas 13t in the processing apparatus 1 of the first embodiment will be described based on FIG. Here, the tritiated water vapor gas 12t or the tritiated methane gas 13t to be treated is such that at least one hydrogen atom in the molecule is generated by tritium (tritium) generated in the course of the fusion reaction in the nuclear fusion research facility. Has been replaced.

  First, the raw material gas SG containing at least one of the tritiated water vapor gas 12t and the tritiated methane gas 13t is sent into the mixed gas supply unit 8 of the processing apparatus 1 from the outside. At this time, when the raw material gas SG fed into the mixed gas supply unit 8 is composed only of the tritiated water vapor gas 12t, the above-described methane gas addition unit 11 in the mixed gas supply unit 8 is operated, and “normal” is set. Methane gas 13n is added to the tritiated water vapor gas 12t (corresponding to “Case 1” in FIG. 2). On the other hand, when the source gas SG is composed only of the tritiated methane gas 13t, the water vapor gas addition unit 14 is operated, and the “normal” water vapor gas 12n is added to the tritiated methane gas 13t (“Case 2” in FIG. 2). "Equivalent to").

  As a result, the mixed gas 7 supplied from the mixed gas supply unit 8 to the anode electrode 5a of the proton electrolysis cell 2 inevitably contains water vapor gases 12n and 12t and methane gases 13n and 13a. Note that when the raw material gas SG already has a configuration in which the water vapor gases 12n and 12t and the methane gas 13n and 13t are mixed, the methane gas addition unit 11 and the water vapor gas addition unit 13 do not operate, and the gas for the raw material gas SG In a state in which there is no addition (corresponding to “Case 3” in FIG. 2), the mixed gas 7 is supplied to the proton electrolysis cell 2 via the mixed gas supply unit 8. The mixing ratio of the water vapor gas 12n, 12t and the methane gas 13n, 13t adjusted by the mixed gas supply unit 8 can be appropriately changed depending on the component composition constituting the proton conductor 3, the current value to be energized, and the like. is there.

  Thereafter, the mixed gas 7 supplied from the mixed gas supply unit 8 reaches the surface of the anode electrode 5 a formed on the one surface 4 a of the proton electrolysis cell 2. Here, the catalyst electrode portion 5 composed of the anode electrode 5 a and the cathode electrode 5 c formed by the electroless plating method is formed in a thin film shape on each of the front and back surfaces 4 a and 4 b, and is further electrically connected by the DC power source portion 6. Connected. In addition, the direct current power supply unit 6 is in a state (energized state) in which a current is passed through the proton electrolysis cell 2. By the way, by observing with an electron microscope (SEM) or the like, it is confirmed that the surface of the catalyst electrode portion 5 is fine and formed in a porous shape. As a result, the contact surface area with the reached mixed gas 7 is increased, and the catalytic activity of platinum can be enhanced, and the permeability of protons 16 described later can be improved.

Then, the conversion reaction (described above) of the mixed gas 7 is promoted at the anode electrode 5a, and the carbon dioxide gas 18 and the hydrogen gas 10 are generated from the water vapor gas 12n and the like, the methane gas 13n and the like (see the formula a in FIG. 2). . Furthermore, protons 16 and electrons (e ⁻ ) are generated from the hydrogen gas 10 at the interface of the anode electrode 5a (see formula b in FIG. 2). Then, the generated proton 16 passes through the anode electrode 5a, moves inside the proton conductor 3 of the proton electrolysis cell 2 having proton conductivity, and is also electrolessly applied to the back surface 4b of the proton conductor 3. The cathode electrode 5c formed by coating by the plating method is reached.

At this time, the electrons (e ⁻ ) generated together with the protons 16 in the anode electrode 5a are electrons (e-) in the opposite direction to the current flow because the anode electrode 5a and the cathode electrode 5c are electrically connected by the DC power supply unit 6. e ⁻ ) moves and tries to move from the anode electrode 5a toward the cathode electrode 5c through the DC power source 6 to the cathode electrode 5c. Then, electrons (e ⁻ ) are supplied to the protons 16 that have reached the cathode electrode 5c from the cathode electrode 5c that is electrically connected to the DC power supply unit 6, and a reaction in which hydrogen gas 10 is generated at the interface of the cathode electrode 5c occurs. (See equation c in FIG. 2). At this time, the hydrogen gas 10 generated at the interface of the cathode electrode 5c contains at least part of the tritium contained in the source gas SG. That is, only the proton 16 is selectively permeated from the anode electrode 5 a side, and tritium can be recovered as hydrogen gas 10 by the gas recovery unit 9.

  In addition, in the vicinity of the anode electrode 5a after only the proton 16 generated by the conversion reaction permeates, the conversion reaction is performed together with the surplus gas component 17 (that is, normal water vapor gas 12n or methane gas 13n, etc.) that has not participated in the reaction. The carbon dioxide gas 18 generated in the process remains. Since the surplus gas component 17 and the carbon dioxide gas 18 have almost no influence on the human body, they are exhausted to the outside air as they are. On the other hand, the tritium recovered as the highly liquefiable hydrogen gas 10 by the gas recovery unit 9 is again taken up by the fusion research facility and reused again as a fuel for the fusion reaction.

  As described above, according to the processing apparatus 1 of the first embodiment, the proton conductor 3 is coated with the mixed gas 7 in which the water vapor gas 12n, 12t and the methane gas 13n, 13t are mixed by the electroless plating method. The hydrogen gas 10 (including tritium) can be selectively recovered using the proton electrolysis cell 2 including the catalyst electrode portion 5 having the anode electrode 5a and the cathode electrode 5c. Thereby, compared with the collection | recovery method (collection apparatus) using the conventional palladium alloy film | membrane, it does not have complicated structure, such as a vacuum installation, but can obtain the hydrogen gas 10 efficiently.

  Therefore, as described above, the treatment apparatus 1 of the present embodiment can exhibit particularly excellent effects in collecting tritium from the tritiated water vapor gas 12t and the tritiated methane gas 13t discharged from a fusion research facility or the like. In addition, the recovered tritium can be further used as a raw material for the fusion reaction, and the efficiency of fuel supply in the fusion reaction system can be improved.

  Furthermore, since the recovered tritium is recovered in the state of the hydrogen gas 10, in other words, a hardly liquefiable gas, the tritium is not easily liquefied at room temperature unlike the water vapor gas 12t. As a result, it is possible to avoid the risk of ingesting tritium, which is a radioactive substance, into the human body.

  Next, the processing apparatus 30 of 2nd embodiment of this invention is demonstrated based on FIG. Here, FIG. 3 is an explanatory view schematically showing a schematic configuration of the processing apparatus 30 of the second embodiment and a processing example of the mixed gas 7. In addition, the processing apparatus 30 of 2nd embodiment collect | recovers hydrogen gas 10 from methane gas 13n using the proton electrolysis cell 2, Unlike the example shown in 1st embodiment, any gas (methane gas) 13n, water vapor gas 12n, and hydrogen gas 10) also contain no tritium in the molecule. In addition, in the processing apparatus 30 of 2nd embodiment, what has the same function and structure as the processing apparatus 1 of 1st embodiment attaches | subjects the same number, and shall omit detailed description.

  As shown in FIG. 3, the processing apparatus 30 of the second embodiment uses methane gas 13n as the source gas SG and applies the proton electrolysis cell 2 as a hydrogen pump, as compared with the processing apparatus 1 shown in the first embodiment. Thus, it is configured for the purpose of recovering the hydrogen gas 10. That is, it is not intended to recover tritium in a fusion research facility or the like, but can, for example, efficiently produce high-purity hydrogen gas 10 that can be used as a raw material for a fuel cell from methane gas 13n.

  Accordingly, the basic configuration of the processing apparatus 30 is almost the same as that of the processing apparatus 1 of the first embodiment, and the methane gas shown in the first embodiment is provided with only the water vapor gas addition section 32 in the mixed gas supply section 31. The point which does not have the structure of the addition part 11 differs. Furthermore, in the processing apparatus 30 of the second embodiment, a reforming catalyst packed tower 33 that is conventionally used to promote the conversion reaction is disposed between the mixed gas supply unit 31 and the proton electrolysis cell 2. .

  Next, the collection | recovery of the hydrogen gas 10 from the methane gas 13n in the processing apparatus 30 of 2nd embodiment of this invention is demonstrated. First, methane gas 13n is sent from the outside to the mixed gas supply unit 31 of the processing apparatus 30 as the source gas SG. Then, the mixed gas supply unit 31 adds the water vapor gas 12n to the methane gas 13n. Thereby, the mixed gas 7 in which the water vapor gas 12n is mixed with the methane gas 13n at a predetermined ratio is generated and sent from the mixed gas supply unit 31 to the reforming catalyst packed tower 33.

  Here, as shown in FIG. 3, the reforming catalyst packed tower 33 is provided in the middle of being sent to the proton electrolysis cell 2, and from the methane gas 13n and the water vapor gas 12n, the carbon dioxide gas 18 and the hydrogen gas are catalyzed. 10 is generated (see equation a ′ in FIG. 3). However, in the reforming catalyst packed tower 33, it is difficult to completely convert the methane gas 13n and the water vapor gas 12n included in the mixed gas 7, and at least a part of the methane gas 13n and the steam gas 12n are sent to the proton electrolysis cell 2 in a remaining state. . Then, by flowing the methane gas 13n so as to contact the anode electrode 5a of the proton electrolysis cell 2, the conversion reaction of the mixed gas 7 including the methane gas 13n that has not been treated in the reforming catalyst packed tower 33 (formula a in FIG. 3). )) Is promoted, and carbon dioxide gas 18 and hydrogen gas 10 are generated at such locations.

Furthermore, protons 16 and electrons (e ⁻ ) are generated from the hydrogen gas 10 at the interface of the anode electrode 5a (see formula b in FIG. 3). As described above, only the proton 16 is selectively transmitted in the order of the anode electrode 5a → the proton conductor 3 → the cathode electrode 5c, and the anode electrode 5a and the cathode electrode 5c are electrically connected. As a result, the electrons (e ⁻ ) flowing in the direction opposite to the current react with the transmitted protons 16 to generate hydrogen gas 10 (see formula c in FIG. 3). Thereby, the recovered hydrogen gas 10 can be used as a raw material for an energy conversion material such as a fuel cell. That is, the treatment apparatus 30 of the present invention can produce the hydrogen gas 10 having a high purity more easily and efficiently than the conventional hydrogen gas production apparatus or production method.

  Next, the example which applies the processing apparatus 40 which concerns on this invention as a hydrogen sensor is demonstrated based on FIG. As shown in FIG. 4, the processing device 40 of the third embodiment is different from the processing devices 1 and 30 of the first embodiment and the second embodiment described above so as to block the pipe line 42 of the processing pipe portion 41. A proton electrolysis cell 43 mainly composed of a perovskite proton conductor 43a is attached. The proton electrolysis cell 43 has substantially the same configuration as that of the first embodiment and the second embodiment, and thus detailed description thereof is omitted here. Then, the mixed raw material gas MG (methane gas, water vapor gas, hydrogen gas, carbon monoxide gas, carbon dioxide gas, and argon gas) is supplied from one side (left side direction in FIG. 4) partitioned with the proton electrolysis cell 43 as a partition wall. And sent so as to be in contact with the catalyst electrode portion 44 a of the proton electrolysis cell 43.

  Argon gas Ar is supplied toward the catalyst electrode portion 44b from the other side (corresponding to the right side in FIG. 4) partitioned by the proton electrolysis cell 43 as a partition wall. That is, each region A and region B partitioned by the proton electrolysis cell 43 has different hydrogen concentrations. Here, when the temperature and one of the hydrogen concentrations (for example, the region B) are known, the other hydrogen concentration (in this case, corresponding to the region A) can be calculated according to the Nernst equation already described. . Thereby, the processing apparatus 40 of 1st embodiment can be used as a hydrogen sensor for hydrogen gas detection. At this time, since a potential difference is generated between the catalyst electrode portions 44a and 44b, it can be applied as a fuel cell.

  Here, the processing devices 1 and 30 (application as a hydrogen pump) of the first embodiment and the second embodiment described above and the processing device 40 of the third embodiment (adapted as a hydrogen sensor) can be used respectively. The temperature range is different. Furthermore, the usable temperature range varies greatly depending on the composition of the proton conductors 3 and 43a used in the proton electrolysis cells 2 and 43 and the manner of attachment to the catalyst electrode portions 5a, 5b, 44a and 44b.

  In the processing apparatuses 1, 30, and 40 of the first to third embodiments, the proton conductors 3, 43a are made of a perovskite oxide, and the catalyst electrode portions 5, 44a, 44b, etc. are made of platinum. Is formed by electroless plating. Thereby, the usable temperature of 200 ° C. or more as a hydrogen sensor and 400 ° C. or more as a hydrogen pump can be obtained. On the other hand, when an electrode is configured by electroless plating of platinum by applying an alumina-based conductor mainly composed of α-alumina as the proton conductor, 700 ° C. or more as a hydrogen sensor and 1000 as a hydrogen pump. It can be used at a temperature of 0 ° C. or higher. That is, it becomes possible to lower the operating temperature of the hydrogen sensor and the hydrogen pump as compared with the prior art, and the proton conductor can be applied in a wider field.

  Next, the effect of mixing the methane gas 13n and the water vapor gas 12n in the processing apparatus 1 of the first embodiment of the present invention will be described based on the graphs of FIGS. 5 (a) and 5 (b). Here, FIG. 5A shows the generation efficiency of the hydrogen gas 10 generated on the cathode electrode 5c side in accordance with the current value given by the DC power supply unit 6 with no steam gas added (Dry) and with the steam gas added ( On the other hand, FIG. 5 (b) shows the respective concentrations of water vapor gas 12n, methane gas 13n, etc., and hydrogen gas 10 in each of the anode electrode 5a and the cathode electrode 5c with respect to the current value. It is a thing.

  Thus, as clearly shown in FIG. 5 (a), the generation of the hydrogen gas 10 on the cathode electrode 5c side is generated in “Wet” in which water vapor gas 12n is added to “Dry” in which water vapor is not added. The efficiency was shown to be significantly higher. That is, by performing hydrogen treatment in a mixed atmosphere of methane gas 13n and the like and water vapor gas 12n and the like, unlike the conventional hydrogen pump, the hydrogen gas 10 can be recovered very efficiently on the cathode electrode 5c side. Further, FIG. 5B also shows that such a tendency is strong.

On the other hand, FIG. 6A and FIG. 6B show test examples by the processing apparatus 40 (applied as a hydrogen sensor) shown in the third embodiment. Here, FIG. 6A is a gas chromatography chart in which the gas composition in the vicinity of the inlet of the region A where the mixed raw material gas MG is introduced is measured, while FIG. 6B is the vicinity of the outlet through the region A. It is the chart of the gas chromatography which measured the gas composition (residual gas component). Thereby, it is shown that peaks of hydrogen gas, methane gas, etc. are remarkably observed in the introduced mixed raw material gas MG, whereas only a peak of hydrogen gas is observed in the residual gas. That is, the proton electrolysis cell 43 provided as a partition so as to partition the region A and the region B causes the conversion reaction of water vapor gas and methane gas to proceed, and only hydrogen gas is detected from the proton electrolysis cell 43. It is. That is, a peak corresponding to methane gas or oxygen (derived from water vapor gas) contained in the introduced mixed gas raw material MG is not detected. This shows that hydrogen gas is selectively recovered by the proton electrolysis cell.

The present invention has been described with reference to the preferred first to third embodiments. However, the present invention is not limited to these embodiments, and departs from the gist of the present invention as described below. Various improvements and design changes are possible without departing from the scope.

That is, in the processing apparatus 1 of the first embodiment, the mixed gas supply unit 8 is provided with both the methane gas addition unit 11 and the water vapor gas addition unit 14, but the present invention is not limited to this. You may provide only. That is, when it is known in advance that the raw material gas SG to be processed is either the tritiated water vapor gas 12t or the tritiated methane gas 13t, it corresponds to the raw material gas SG supplied to generate the mixed gas 7. Since it is sufficient to supply only (that is, the gas corresponding to the opposite), either one of the configurations can be omitted. Thereby, the whole structure of the processing apparatus 1 can be simplified.

Further, as shown in the processing apparatus 1,30,40 in the first embodiment to third embodiment, as a proton conductor 3 to be used for proton electrolytic cell 2, showed that the perovskite-type oxide, This is not limited, and as described above, a proton conductor such as α-alumina may be used. In this case, when each is applied to a hydrogen pump and a hydrogen sensor, there may be a difference in operating temperature compared to the perovskite oxide. Further, it is also possible to use a metal oxide having other proton conductivity, for example, a solid electrolyte such as CaZrO ₃ .

  Further, in the processing apparatuses 1 and 30 of the first embodiment and the second embodiment, the proton electrolysis cell 2 is energized and used as a hydrogen pump. However, the present invention is not limited to this. As shown in the embodiment, the proton electrolysis cell 43 may be used as a partition wall and used as a part of a hydrogen sensor or a fuel cell.

It is a schematic diagram which shows schematic structure of the processing apparatus of 1st embodiment. It is explanatory drawing which shows typically the example of a process of the mixed gas in the processing apparatus of 1st embodiment. It is explanatory drawing which shows typically the schematic structure of the processing apparatus of 2nd embodiment, and the process example of mixed gas. It is explanatory drawing which shows typically schematic structure of the processing apparatus of 3rd embodiment. It is a graph which shows (a) current-hydrogen gas generation efficiency and (b) current-gas concentration in a proton electrolysis cell. It is a chart of gas chromatography which shows gas composition of (a) mixed source gas and (b) residual gas.

Explanation of symbols

1,30,40 treatment equipment (solid electrolyte hydrogen treatment equipment)
2,43 proton electrolysis cell 3,43a proton conductor (solid electrolyte)
4a Front surface 4b Back surface 5, 44a, 44b Catalyst electrode portion 5a Anode electrode 5c Cathode electrode 6 DC power supply portion (energization means)
7 Mixed gas 8,31 Mixed gas supply section (mixed gas supply means)
9 Gas recovery unit (recovery means)
10 Hydrogen gas 11 Methane gas addition part (methane gas addition means)
12n water vapor gas 12t tritiated water vapor gas 13n methane gas 13t tritiated methane gas 14,32 water vapor gas addition section (water vapor gas addition means)
16 Proton 17 Excess gas component 18 Carbon dioxide gas 33 Reforming catalyst packed tower E Electromotive force SG Raw material gas MG Mixed raw material gas

Claims (5)

A solid oxide type solid electrolyte having proton conductivity, and a porous anode electrode and a cathode electrode formed by coating a metal material on the surface of the solid electrolyte by using an electroless plating method ; A solid electrolyte type hydrogen treatment apparatus comprising a proton electrolysis cell configured to include a catalyst electrode portion to which a mixed gas containing water vapor and methane gas is supplied to an anode electrode . An energization means for electrically connecting the anode electrode and the cathode electrode to bring the solid electrolyte into an energized state;
A mixed gas supply means for supplying a mixed gas of water vapor gas and methane gas to the anode electrode of the proton electrolysis cell;
The solid electrolyte hydrogen treatment according to claim 1, further comprising a recovery unit that promotes a conversion reaction by the anode electrode and recovers protons that pass through the solid electrolyte as hydrogen gas from the cathode electrode. apparatus. The mixed gas is
3. The solid electrolyte type hydrogen treatment apparatus according to claim 2, comprising at least one of tritiated water vapor gas and tritiated methane gas in which at least one hydrogen atom in the molecule is substituted with tritium. The mixed gas supply means includes
Methane gas addition means for adding the methane gas to at least one of the tritiated water vapor gas and the water vapor gas;
4. The solid electrolyte type according to claim 3, comprising at least one of the tritiated methane gas and the water vapor gas adding means for adding the water vapor gas to at least one of the methane gas. 5. Hydrogen treatment equipment. The solid electrolyte is
The solid electrolyte type hydrogen treatment apparatus according to any one of claims 1 to 4, wherein an alumina-based compound is applied.

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