Ammonia dehydrogenase

Abstract

1. A method for producing compressed hydrogen in a membrane reactor, the membrane reactor comprising a first region separated from a second region by a proton conducting membrane, the first region having a gas inlet and a product outlet, and the second region having a product outlet, the method comprising: a. supplying a gas comprising ammonia through the gas inlet to the first region and reacting in the first region to form hydrogen and nitrogen; b. applying an electric field to the proton conducting membrane; c. selectively passing hydrogen through the proton conducting membrane to the second region, where the protons and electrons recombine to form hydrogen in the second region. Including, The method wherein the membrane reactor is equipped with a pressure regulator at the product outlet from the second region such that during operation the partial pressure of hydrogen in the second region is higher than the partial pressure of hydrogen in the first region.

Description

[Technical Field]

[0001] The present invention relates to a method for obtaining hydrogen from ammonia, preferably by compression. In particular, the present invention uses a proton-conducting membrane for separating hydrogen generated from ammonia, wherein the membrane generates hydrogen pressure on the permeate side of the membrane. An electric field is applied to the membrane to promote proton transport across the membrane, and Joule heating can be used during the application of the electric field to supply heat for an endothermic ammonia dehydrogenation method. [Background technology]

[0002] Hydrogen can be extracted from hydrogen-containing molecules, for example, by the dehydrogenation of ammonia: 2NH3 (gas) = ​​N2 (gas) + 3H2 (gas) (1)

[0003] Reaction (1) is endothermic (ΔH 298K = 45.94 kJ mol -1 The reaction is typically carried out in the temperature range of 400-600°C using a dehydrogenation catalyst. The reaction proceeds spontaneously at temperatures >183°C at standard pressure; however, temperatures >400°C are required to overcome both thermodynamic and kinetic barriers in order to achieve high conversion rates. The hydrogen can be separated downstream from the nitrogen-hydrogen mixture, for example, using pressure swing absorption (PSA). Finally, the hydrogen can be compressed using available compressor technologies, such as piston or diaphragm mechanical compressors, or using electrochemical / chemical compressors.

[0004] Alternatively, hydrogen separation can be included in a dehydrogenation system using a hydrogen-selective membrane. Such a system consists of two method steps. The first step includes a dehydrogenation catalyst that converts ammonia to hydrogen and nitrogen at a temperature of >400°C according to Formula 1. The mixture of hydrogen and nitrogen is then supplied to a gas separation membrane.

[0005] The vast majority of such membranes utilize metallic hydrogen-selective permeable palladium (Pd) or palladium in combination with Ag and Cu. This allows for operation at lower temperatures while still maintaining high hydrogen recovery rates.

[0006] A drawback of this Pd-based membrane is the significant hydrogen partial pressure difference required across the membrane, i.e., pH2 (retainer) > pH2 (permeate). The driving force for hydrogen transport is the chemical potential gradient of hydrogen across the membrane. If the hydrogen partial pressure on the retainer side is low, high hydrogen recovery becomes difficult.

[0007] The final hydrogen pressure in the permeate is always low, and further pressurization of the hydrogen would require a large volume-based compressor. This is demanding, adds complexity to the overall method, and hinders high energy efficiency.

[0008] A further challenge in connecting the catalytic reactor to the Pd-based membrane is that thermal management becomes more complex because the heat required for both the endothermic dehydrogenation reaction and the high-temperature operation of the Pd-based membrane must be supplied from an external source.

[0009] Alternatively, electrochemical dehydrogenation of ammonia can produce high-purity hydrogen with a high conversion rate under near-ambient conditions. For this purpose, aqueous alkaline electrolytes have been demonstrated, however, they have the drawback of requiring a high operating potential, implying low energy efficiency. Another difficulty is the disadvantage of catalyst deactivation over time.

[0010] A combination of a solid-acid-based electrochemical cell and a bilayered anode containing a novel Ru-Cs / CNT thermal cracking catalyst layer and a Pt-based hydrogen electrolytic oxidation catalyst layer has also been used to separate hydrogen. Humidified dilute ammonia was supplied to the anode, and humidified hydrogen was supplied to the cathode. Although a novel thermal cracking catalyst was used, the conversion from ammonia to hydrogen reached a rate of only about 3.5% at the open-circuit voltage (OCV), and subsequently increased to <15% under an applied load (Joule 4, 2338-47). Ammonia has been used as a hydrogen source for direct fuel cell operation, where it decomposes according to equation (1).

[0011] Several metals have been investigated as ammonia dehydrogenation catalysts, with catalytic activity decreasing in the order Ru > Ni > Rh > Co > Ir > Fe > Pt > Cr > Pd > Cu >> Te, Se, Sb. Ru is clearly the most active metal catalyst, and most reports rely on the use of Ru-based catalysts. Furthermore, Ce-promoted Ru supported on graphite structures, e.g., carbon nanotubes, exhibits catalytic activity at temperatures starting from approximately 250°C. However, large-scale use of Ru is impractical due to its high cost and scarcity. Ni-based catalysts are more suitable for industrial applications. Ni is supported on oxides, e.g., Al2O3, Gd2O3, or Y2O3, and its catalytic activity can be further improved by CeO2 as an accelerator. Ni-based catalysts achieve complete ammonia conversion at >600°C (e.g., Okura et al. ChemCatChem 8, (2016)).

[0012] It is generally accepted that hydrogen compressor technology will not be able to meet future infrastructure demands in a cost-effective manner. Hydrogen compressors currently in use face considerable wear due to the use of technologies that utilize moving parts. Regarding piston pumps, studies have shown that piston sealing rings fail due to uneven pressure distribution, and that piston failure is caused by server impacts.

[0013] Diaphragm compressors tend to have shorter lifespans due to contaminants / debris in hydrogen gas and improper priming procedures when restarting the compressor after a shutdown. Their operating pressure is high enough to cause localized plastic deformation around trapped hard particles, leaving residual stress and thus shortening the fatigue life of the diaphragm.

[0014] Previously, International Publication No. 2018 / 069546 described electrochemical hydrogen separation in vapor reforming. However, it was not suggested that such a method could be effective for ammonia. It will be understood that ammonia is caustic and therefore a much more difficult reactant than carbohydrates. The said brochure 546 was not suggested that the membrane reactor described therein could dehydrogenate ammonia. [Overview of the project] [Problems that the invention aims to solve]

[0015] The inventors understood that electrochemical hydrogen compressors, because they operate without any moving parts, offer increased reliability and availability compared to mechanical compressors. However, challenges remain in the design of these electrochemical compressors, such as their energy efficiency.

[0016] This invention simultaneously solves three distinct difficulties that have hindered the commercial development of various chemical methods by introducing a galvanically driven proton membrane compressor. In particular, the proton membrane of this invention is 1. Remove hydrogen from the reaction chamber and shift the limited (thermodynamic and / or kinetic) methods to a higher conversion rate to the desired product. 2. Provide heat to the endothermic reaction process, 3. Simultaneously, hydrogen is compressed to the desired pressure on the permeate side of the membrane.

[0017] Furthermore, the high selectivity of the membrane allows only hydrogen to pass through. Therefore, the generated hydrogen is of high purity, and thus, a final purification step is not required.

[0018] The proton membrane of the present invention exhibits increased proton conductivity due to its high water content, and therefore its performance is enhanced, enabling operation in steam-reach environments, such as ammonia vapor mixtures.

[0019] The combination of these four (or optionally five) effects in a single method results in high energy efficiency. More specifically, this offers obvious advantages. The conversion rate and yield of the chemical method can be increased to commercially attractive levels, and the by-product hydrogen has attractive partial pressure and purity for further use. Finally, the generated Joule heat allows the entire method to operate in a self-thermal state. [Means for solving the problem]

[0020] Therefore, from one perspective, the present invention is a method for producing compressed hydrogen in a membrane reactor, wherein the membrane reactor comprises a first region separated from a second region by a proton-conducting membrane, the first region having a gas inlet and a product outlet, and the second region having a product outlet, and the method is a. A gas containing ammonia is supplied to the first region through the gas inlet, and a reaction occurs in the first region to form hydrogen and nitrogen. b. Applying an electric field to the proton-conducting film, c. Dissociating hydrogen into electrons and protons and selectively passing them through the proton-conducting film to the second region, where the protons and electrons recombine to form hydrogen in the second region. Includes, Herein, the membrane reactor is equipped with a pressure regulator at the product outlet from the second region, so that during operation, the partial pressure of hydrogen in the second region is higher than the partial pressure of hydrogen in the first region, thus providing the above method.

[0021] From another perspective, the present invention is a method for producing hydrogen in a membrane reactor, wherein the membrane reactor comprises a first region separated from a second region by a proton-conducting membrane, the first region having a gas inlet and a product outlet, and the second region having a product outlet, and the method is a. A gas containing ammonia is supplied to the first region, and a reaction occurs in the first region to form hydrogen and nitrogen. b. Applying an electric field to the proton-conducting film, c. Dissociating hydrogen into electrons and protons and selectively passing them through the proton-conducting film to the second region, where the protons and electrons recombine to form hydrogen in the second region. Includes, Herein, the method is provided wherein Joule heating occurring during the application of the electric field to the proton-conducting film is used to heat the first region.

[0022] From another perspective, the present invention is a method for producing compressed hydrogen in a membrane reactor, wherein the membrane reactor comprises a first region separated from a second region by a proton-conducting membrane, the first region having a gas inlet and a product outlet, and the second region having a product outlet, and the method is a. A gas containing ammonia is supplied to the first region, and a reaction occurs in the first region to form hydrogen and nitrogen. b. Applying an electric field to the proton-conducting film, c. Dissociating hydrogen into electrons and protons and selectively passing them through the proton-conducting film to the second region, where the protons and electrons recombine to form hydrogen in the second region. Includes, Here, the membrane reactor is equipped with a pressure regulator at the product outlet from the second region, and therefore, during operation, the partial pressure of hydrogen in the second region is higher than the partial pressure of hydrogen in the first region, The Joule heating that occurs during the application of the electric field to the proton-conducting film is used to heat the first region. The above method is provided.

[0023] In a preferred embodiment, the energy required to heat the first region to the reaction temperature is exclusively derived from Joule heating that occurs during the application of the electric field to the proton-conducting film. In a more preferred embodiment, the energy required for isothermal operation of the film reactor is exclusively derived from Joule heating.

[0024] In a preferred embodiment, the energy required to heat the first region to the reaction temperature is induced from Joule heating that occurs during the application of the electric field to the proton-conducting film and from the heat generated on the permeate side of the proton-conducting film during hydrogen compression.

[0025] The gas added to the first region contains ammonia, and consists of, for example, ammonia. In a further preferred embodiment, the gas added to the first region contains a mixture of ammonia and water (i.e., as vapor), and consists of, for example, the mixture.

[0026] From another perspective, the present invention relates to a membrane reactor comprising: a first region separated from a second region by a membrane electrode assembly, the first region having a gas inlet and a product outlet; and a second region having a product outlet, the second region having a pressure regulator provided at the product outlet of the second region. a power source adapted to pass an electric field through the membrane electrode assembly and comprising wherein the membrane electrode assembly comprises the following layers in the following order, namely 1) a support electrode layer comprising a metal-oxide composite of the following formula (I) Ni-AZr a Ce b Acc c O 3-y (I) wherein the volume or weight fraction of Ni is greater than 0 to 0.8, for example 0.2 to 0.8, for example 0.4, relative to the weight of the metal-oxide composite 2) a proton conductive membrane layer comprising the following formula (II) [[ID=​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​Preferably, the MEA is (I) Ni-BaCe 0.1 Zr 0.7 Y 0.1 Yb 0.1 O 3-y Support electrode layer containing Ni composite, (II)BaCe 0.1 Zr 0.7 Y 0.1 Yb 0.1 O 3-y A proton-conducting film layer containing (III) the following formula Ni-BaCe 0.1 Zr 0.7 Y 0.1 Yb 0.1 O 3-y This is a second electrode material containing a Ni composite. [Modes for carrying out the invention]

[0029] The present invention relates to a method for dehydrogenating ammonia to form hydrogen and nitrogen. In particular, the present invention uses a proton-conducting membrane to simultaneously remove hydrogen from a reaction mixture, for example, a mixture of ammonia, nitrogen, and hydrogen. The present invention also allows for the compression of the removed hydrogen and uses Joule heating in the proton-conducting membrane to heat the holding side of the membrane reactor in which the dehydrogenation reaction takes place. Preferably, the first region is provided with a dehydrogenation catalyst, which, in a more preferred embodiment, also forms an electrode on the proton-conducting membrane.

[0030] To produce hydrogen by dehydrogenating ammonia, the present inventors' method solves the problems of reaction, separation, compression, and heat management in a single step.

[0031] The method of the present invention is carried out in a membrane reactor in which the proton-conducting membrane separates a first region (the retaining side of the membrane) and a second region (the permeating side of the membrane).

[0032] In a preferred embodiment, the first region is provided with a catalyst to facilitate the dehydrogenation method. The second region is provided with an outlet for a gas passing through the proton-conducting membrane. The outlet is preferably provided with a pressure regulator that allows for the compression of hydrogen within the second region.

[0033] In the claimed method, ammonia (or ammonia and water) is introduced into a first region and an electric field is applied across the proton-conducting film. The ammonia is dehydrogenated within the first region, so the application of the electric field across the proton-conducting film promotes the dissociation of the formed hydrogen into protons and their passage through the proton-conducting film.

[0034] The heat generated by the current passing through the proton-conducting film is used to promote an endothermic reformation reaction in the first region.

[0035] Reactants Ammonia is added to the membrane reactor in the first step of the method of the present invention. In this specification, the term “reactants” is used to mean the ammonia gas that is dehydrogenated to hydrogen and nitrogen in the first region of the membrane reactor. Ammonia is given by the following formula: 2NH3 = 3H2 + N2 It is dehydrogenated accordingly.

[0036] The conversion rate of the reactants achieved in this type of dehydrogenation method is preferably at least 50% by weight, preferably at least 70% by weight, for example 80% by weight or more. Therefore, the yield of the product is preferably at least 50%, preferably at least 70%, for example 80% or more.

[0037] Furthermore, the selectivity is preferably at least 70% by weight, more preferably at least 90% by weight, for example, at least 95% by weight. This means that the decomposed product formed is at least 95% by weight pure, i.e., virtually no impurities are present. The only compounds present in the first region are the unconverted reactants, nitrogen, and hydrogen (and possibly water).

[0038] In another preferred embodiment, the gas supplied to the first region is a mixture of ammonia and water. Water is not considered a reactant, and rather ammonia is often supplied as an aqueous solution; therefore, it will be understood that it is important that the membrane reactor of the present invention can be operated using this common raw material. Ammonia or its decomposition products, i.e., nitrogen or hydrogen, do not react with water at all; however, water (vapor) increases the concentration of charge carriers through hydration, thus increasing the proton conductivity of the proton-conducting membrane. The presence of water can also enable coionic conductivity, which, if water is present on the permeate side, can lead some oxygen transport in the opposite direction to the protons on the electrolyte.

[0039] The concentration of water in the ammonia-water mixture supplied to the membrane reactor is preferably at least 1 volume%, preferably at least 10 volume%, for example 30 volume% or more, for example 70 volume% or 80 volume%.

[0040] In a preferred embodiment, the aqueous ammonia solution preferably contains less than 35% by volume of ammonia, for example, 10 to 35% by volume of ammonia. Ammonia solutions containing less than 35% by volume of ammonia are considered safe for transport and comply with international transport regulations. Therefore, it is advantageous that this material can be used directly in the membrane reactor of the present invention without requiring further steps.

[0041] In another preferred embodiment, the supply gas is a mixture of ammonia and water in a ratio of 1:0.01 to 1:5 moles.

[0042] When the method of the present invention involves supplying aqueous ammonia to the membrane reactor, the dehydrogenation reaction can still proceed with a high conversion rate. At least 95%, preferably at least 97%, for example 99% or more of the ammonia can be converted to nitrogen and hydrogen. This means that almost all of the ammonia supplied to the reactor is converted.

[0043] Proton-conducting film The proton-conducting membrane (which may also be called a hydrogen-conducting membrane or hydrogen transport membrane) is an important feature of the claimed method. It is very important that the membrane reactor is provided with a proton-conducting membrane that selectively allows hydrogen in the form of protons to leave the first region of the membrane reactor through the proton-conducting membrane, but does not allow ammonia, water, nitrogen or any by-products to pass through.

[0044] The proton-conducting membrane separates a first region where the dehydrogenation method is carried out (i.e., where the feed and, if present, the dehydrogenation catalyst are placed together) from a second region which will include hydrogen passing through the proton-conducting membrane and any means desirable for removing that hydrogen.

[0045] The proton-conducting membrane must be made of a material capable of selectively transporting hydrogen in ionic form as protons. Once the protons pass through the proton-conducting membrane, hydrogen is reformed on the permeate side of the membrane.

[0046] The proton-conducting film material is preferably chemically inert and stable at temperatures of 400 to 1000°C. The proton-conducting film should be chemically inert in an atmosphere containing gases, such as ammonia, water, nitrogen, and hydrogen. The proton-conducting film material should not promote nitride formation, which typically means that the material should be basic and also have a surface that does not catalytically promote nitride formation.

[0047] One group of materials that satisfy these requirements is a mixture of metal oxides, and it is preferable that the proton-conducting film material used in the proton-conducting film contains a mixture of metal oxides. Ideally, the transport film should have at least 1 × 10⁻¹⁶ -3 The proton conductivity of the proton-conducting film of the present invention is preferably at least 1.5 × 10⁻⁶. -3 S / cm, especially at least 5 × 10 -3 It is in S / cm. 40 × 10 -3 Proton conductivity up to S / cm is possible.

[0048] Various mixed metal oxides, including acceptor-doped perovskites (e.g., Y-doped BaZrO3 and Y-BaCeO3), can be suitable as proton-conducting films.

[0049] Therefore, preferred film materials include perovskites that conform to the following general formula (IV): A'B 1-q B' q O 3-z (IV) Here, A' is La, Ba, Sr, or Ca, or a combination thereof. B is Ce, Zr, Hf, Ti, In, Tb, Th, or Cr, or a combination thereof. B' is Y, Yb, Gd, Pr, Sc, Fe, Eu, In, or Sm, or a combination thereof. z is a sufficient number to neutralize the charge, 0.01 ≤ q ≤ 0.5. It will be understood that B and B' are different metals.

[0050] In one embodiment, element B can represent two or more elements, for example, Zr and Ce.

[0051] Therefore, the preferred formula is the following formula (IV): A'Zrp Ce r B' q O 3-z (IV) Here, A' is La, Ba, Sr, or Ca. B' is Y, Yb, Gd, Pr, Sc, Fe, Eu, In, or Sm, or a combination thereof. z is a sufficient number to neutralize the charge, p+q+r=1, 0.01 ≤ q ≤ 0.5.

[0052] The variables p and r are preferably between 0.01 and 0.9.

[0053] In one embodiment, element B' is Y.

[0054] In one embodiment, element B' can represent two or more elements, for example, Y and Yb.

[0055] Therefore, the preferred formula is the following formula (V): A'B 1-q (Y 1-w Yb w ) q O 3-z (V) Here, 0.01 ≤ w ≤ 0.99, and the other variables are as defined above in this specification.

[0056] The preferred formula is also the following formula (VI): AZr p Ce r (Y 1-w Yb w ) q O 3-z (VI) Here, A' is La, Ba, Sr, or Ca. w is such that 0.01 ≤ w ≤ 0.99, z is a sufficient number to neutralize the charge, p+q+r=1, 0.01 ≤ q ≤ 0.5.

[0057] The variables p and r are preferably between 0.01 and 0.9.

[0058] An ideal mixed metal oxide consists of the following components: Ln, Zr, Acc and O, More preferably, ions of Ln, Zr, Ce, Acc and O, This includes, where Ln is Ba, Sr, or Ca, or a combination thereof, and Acc is a trivalent transition metal or trivalent lanthanide metal, such as Y, Yb, Gd, Pr, Sc, Fe, Eu, In, or Sm, or a combination thereof.

[0059] More specifically, preferred oxides include mixed metal oxides of the following formula (I): AZr a Ce b Acc c O 3-y (I) Here, A is Ba, Sr, or Ca, or a combination thereof. The sum of a + b + c is equal to 1. b is between 0 and 0.75, for example, between 0.1 and 0.75. c is between 0.05 and 0.5.

[0060] Acc is a trivalent transition metal or lanthanide metal, such as Y, Yb, Gd, Pr, Sc, Fe, Eu, Pr, In, or Sm, or a combination thereof. y is the number for which equation (I) is uncharged, for example, 3-y is between 2.75 and 2.95.

[0061] In particular, it is preferable that A is Ba. Acc is preferably Y or Yb, or a combination thereof, especially Y or Y and Yb.

[0062] Therefore, in a more preferred embodiment, the film comprises a mixture of metal oxides of the following formula (II) or formula (II'): BaZr a Ceb Y c O 3-y (II') or SrZ ra Ce b Y c O 3-y (II'') Here, the sum of a + b + c is equal to 1. b is between 0 and 0.75, for example, between 0.1 and 0.75. c is between 0.05 and 0.5. y is the number for which equation (I) is uncharged, for example, 3-y is between 2.75 and 2.95.

[0063] When b is 0, no Ce ions are present, and the equation can be summarized as equation (III') or (III'') below: BaZr a Y c O 3-y (III') or SrZr a Y c O 3-y (III'') Here, the sum of a + c is equal to 1. c is between 0.05 and 0.5. y is the number for which equation (I) is uncharged, for example, 3-y is between 2.75 and 2.95.

[0064] Preferred ceramics contain ions selected from the group consisting of Ba, Ce, Zr, Y, Yb, and O. A metal oxide mixed with a very preferred ceramic is given by the formula BaZr 0.7 Ce 0.2 Y 0.1 O 3-δ Or BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-y It belongs to them.

[0065] b+c is preferably between 0.1 and 0.7, for example, between 0.2 and 0.4.

[0066] b is preferably between 0.1 and 0.75, for example, between 0.1 and 0.4.

[0067] c is preferably 0.05 to 0.4, for example, 0.1 to 0.2.

[0068] Another very preferred option is equation (X) below: BaZr a Ce b Y c Yb d O 3-y (X) Here, the sum of a+b+c+d is equal to 1. b is between 0.05 and 0.75. c is between 0.05 and 0.45. d is between 0.05 and 0.45. y is the number for which equation (I) is uncharged, for example, 3-y is between 2.75 and 2.95.

[0069] Another very preferred option is the following equation (X): BaZr a Ce b Y c Yb d O 3-y (X) Here, the sum of a+b+c+d is equal to 1. b is between 0.05 and 0.75. c is between 0.05 and 0.25. d is between 0.05 and 0.25. y is the number for which equation (I) is uncharged, for example, 3-y is between 2.75 and 2.95.

[0070] The ceramic material of the proton-conducting film preferably employs a perovskite crystal structure.

[0071] Membrane preparation The metal ions necessary to form the metal oxide mixed with the ceramic that forms the proton-conducting film can be supplied as any convenient salt of the ions. A sintering process is required to form the proton-conducting film. During the sintering process, the salt is converted to the oxide, and therefore any salt can be used. The amount of each component is carefully controlled depending on the target final mixed metal oxide.

[0072] Suitable salts include sulfates, nitrates, carbonates, and oxides of the ion. For alkaline earth metal components, sulfates, particularly BaSO4, are preferred. For cerium ion sources, CeO2 is preferred. For Zr sources, ZrO2 is preferred. For Acc ion sources, oxides are preferred. For Y ion sources, Y2O3 is preferred. For Yb ion sources, Yb2O3 is preferred.

[0073] The particles of the precursor material can be milled to form a powder mixture.

[0074] The reactants required to create the proton-conducting film layer are preferably prepared as a slurry in an aqueous or non-aqueous solvent (e.g., alcohol). Water is preferred. The relative amounts of the reactants can be carefully measured to ensure a stoichiometric amount of the desired mixed metal oxide. Essentially all metal oxides present become part of the sintered film body, and all other components are removed; therefore, the amount of each component required to produce the desired stoichiometric amount can be easily calculated by those skilled in the art.

[0075] As with the metal salts required to create the mixed metal oxide, the slurry used to create the proton-conducting film may contain other components present to ensure the formation of the proton-conducting film. Such components are well known in the art and include binders, rheological modifiers, dispersants and / or emulsifiers, or other additives to ensure that the proton-conducting film is formed and remains solid and intact until the sintering process. Thus, the additives act as adhesives of a kind, fixing the metal salt particles together to form a layer.

[0076] Suitable additive compounds include ammonium polyacrylate dispersants and acrylic emulsions. The content of additives, such as emulsifiers / dispersants, may be 0-10% by weight of the total mixture, for example, 1-5% by weight. Suitable binders may be methylcellulose, acrylic emulsions, and starch. The content of such binders may be 0-10% by weight of the total mixture, for example, 1-5% by weight.

[0077] Water is a preferred solvent and may constitute 5-20% by weight of the slurry used to form the proton-conducting film. The metal components necessary to form the composite may constitute 50-80% by weight of the slurry.

[0078] This slurry can be extruded and applied to a mold to form the proton-conducting film, and then dried to leave a solid, unsintered green body as a precursor to the proton-conducting film. Any additives present will preferably be organic, as they will decompose during the sintering process. The green layer described herein will be understood to be a precursor to the actual proton-conducting film, which is formed during sintering as detailed below.

[0079] The proton-conducting membrane used in the membrane reactor may have a thickness of 1 to 500 micrometers, for example, 10 to 150 micrometers. Therefore, the thickness of the proton-conducting membrane is the distance required for the proton to pass through the membrane.

[0080] Some proton-conducting films, particularly those with thicknesses at the lower end of the range, require a structural support, while films with thicknesses at the upper end of the indicated thickness range may be "self-supported."

[0081] support A support may be necessary to support the proton-conducting film. The support should be inert, porous, and able to withstand the conditions within the film reactor. In one embodiment, the support may form electrodes.

[0082] The following are important properties for the support: Being porous, The proton-conducting film is chemically compatible, that is, it does not react to form a secondary insulating phase. The proton-conducting film is mechanically compatible with the material, that is, its thermal expansion coefficient is preferably the same as that of the proton-conducting film.

[0083] In one embodiment, the support is an inert metal oxide, such as an alkali metal oxide, or silica or alumina. Such supports are well known in the art. Generally, the particle size in the support should be larger than the particle size in the film, for example, at least 200 nm larger. The support can be 2-300 μm to 1 mm or more in thickness.

[0084] The design of the support material depends on the overall design of the membrane reactor. Typically, the proton-conducting membrane, and therefore any support / electrode, is planar or tubular. The term “tubular” may be used herein to name a proton-conducting membrane that is a hollow cylinder with two open ends, or alternatively, a plurality of smaller channels forming a “honeycomb structure,” or a “test tube,” i.e., a cylinder with one end hemispherical and the other end open.

[0085] In a tubular embodiment, the porous support tube can be extruded. The support can then be heat-treated to obtain the desired mechanical strength. In a planar embodiment, the support material can be tape-cast and subsequently heat-treated to obtain the desired mechanical strength. In the tape-casting process, the slurry of the material is typically spread uniformly on a flat, horizontal surface by utilizing a doctor blade. After drying, the formed thin film can be removed, cut into the desired shape, and burned.

[0086] To manufacture the support structure as either a planar support or a tube, an ink of the desired support material can be produced using either water or an organic solvent as a solvent, and optionally a stabilizer. A pore filler material, such as carbon black, is often used to achieve controlled porosity. The ink can then be tape-cast or extruded. The support is then burned to a desired combustion temperature, for example, 600–1650°C, to obtain a mechanically robust support with the desired porosity.

[0087] In embodiments of complex designs, the porous support tube or porous electrode support can be prepared by gel casting. A mold of the desired structure is prepared. Next, a solution of the desired material is prepared and poured into the mold. After the solution gels, the mold is removed. The support is then burned to a desired combustion temperature, for example, 600-1650°C, to burn off any organic residue and obtain a mechanically robust support with the desired porosity.

[0088] electrode To apply an electric current across the proton-conducting film, the film needs to be provided with an anode and a cathode. Conveniently, a porous electrode is formed on either side of the proton-conducting film. Thus, a three-layer structure can be formed, comprising a first electrode layer, a proton-conducting film layer, and a second electrode layer.

[0089] In some embodiments, one or both electrodes can act as a support for the proton-conducting film. In some embodiments, the electrodes present in the first region can also act as a dehydrogenation catalyst.

[0090] The preferred electrode exposed to the first region of the reactor should have the following characteristics: Electronic percolation, Catalytic activity toward hydrogen dissociation, Catalytic activity toward the decomposition of ammonia into nitrogen and hydrogen, A porous microstructure to enable the diffusion of hydrogen gas into and from the triple phase boundary and to avoid concentration polarization due to the accumulation of larger nitrogen molecules or vapors. Chemical compatibility with catalysts (if applicable) under reactor operation.

[0091] A preferred structure is, Support electrode layer containing Ni and a metal-oxide composite, A proton-conducting film layer containing a metal-oxide composite, Second electrode layer containing Ni and a metal-oxide composite It has.

[0092] The electrode can be a single phase or a composite including a multi-phase. Some potential candidate materials include the following groups: Metals / metal alloys (e.g., Ni, Fe, Ru, Pt, and Pd alloys), Mixed metal oxides, such as La 1-x Sr x Cr 1-y Mn y O3 (where x and y are between 0 and 1), Mixed metal oxides, such as La x Sr 1-x TiO3 (where x and y are between 0 and 0.5).

[0093] The electrode preferably has catalytic properties for the ammonia dehydrogenation process. Such materials are Ni, Fe .

[0094] The second electrode is not exposed to the first region within the membrane reactor and is preferably positioned within the second region. The second electrode can be selected from a wider range of materials known to those skilled in the art.

[0095] In one embodiment, the electrodes are conveniently of the same composition.

[0096] In a preferred embodiment, the required electrodes form part of a membrane electrode assembly (MEA) comprising two electrode layers and the proton-conducting membrane (also referred to herein as the membrane layer or electrolyte layer).

[0097] The electrodes in this embodiment may be of the same composition, in particular, using a material that exhibits activity for both ammonia dehydrogenation and hydrogen dissociation / association. Such a material may include Ni. Most conveniently, the electrode is a Ni composite comprising Ni and the material used in the proton-conducting film. Even more conveniently, since Ni increases hydrogen activity, the catalytic activity toward ammonia dehydrogenation is improved when the proton-conducting film acts as a support for Ni.

[0098] The membrane electrode assembly (MEA) can be manufactured using techniques generally known to those skilled in the art of fuel cells and inorganic gas separation membranes.

[0099] First electrode The first electrode layer is preferably thicker than the electrolyte or the second electrode layer because it supports the MEA. Therefore, it is preferable that the MEA does not contain a separate support layer. The MEA should be supported by the first electrode layer.

[0100] The first electrode layer may have a thickness of 250 microns to 2.0 mm, for example, 500 microns to 1.5 mm, preferably 500 microns to 1.2 mm.

[0101] The first electrode layer is preferably produced in a green state, i.e., the first electrode layer is not sintered / densified before the electrolyte layer is applied to it.

[0102] The MEA may be cylindrical or planar (or any other layered structure as needed). However, ideally, the MEA is planar or cylindrical, particularly cylindrical. At the center of the cylinder, there may be either an anode or a cathode, and the first electrode layer may be either an anode or a cathode.

[0103] The method for preparing the first electrode layer is highly flexible. A mold or support may be used to prepare the first electrode layer. Thus, the first electrode layer may be deposited on a cylindrical or planar support mold. After the layer is formed, the mold may be removed, leaving the first electrode layer. Alternatively, the first electrode layer may be extruded to form a cylindrical or planar support.

[0104] The first electrode layer may be prepared by methods including extrusion, slip casting, injection molding, tape casting, wet and dry bag isopressing, and additive manufacturing.

[0105] The length / width of the first electrode layer is not particularly important, but can be 10 to 50 cm. In a tubular form, the inner diameter of the tube can be 2.0 mm to 50 mm, for example, 2.0 to 15.0 mm. The inner diameter of the tube means that the diameter is measured from the inside of the layer and excludes the actual thickness of the tube.

[0106] The mixture used to manufacture the support electrode material comprises ceramic powder and optional additives, such as emulsifiers, pore-forming agents, binders, and rheology modifiers, to enable the molding process. The first electrode is preferably produced from a slurry containing ceramic components, a binder, and a rheology modifier.

[0107] After sintering, the first electrode may contain a mixed metal oxide, and therefore the mixture used to prepare it should contain a precursor to the desired mixed metal oxide. A preferred mixed metal oxide is the same as that taught above for the proton-conducting film.

[0108] The first electrode material is a composite material in which a metal oxide, ideally the aforementioned mixed metal oxide, is combined with NiO. When sintered at a temperature of 500-1100°C and reduced by passing a reducing gas through it, the NiO is reduced to Ni, which creates a porous structure through which substances such as hydrogen can pass. Therefore, in a preferred embodiment, the first electrode material is a Ni composite of metal oxides, as described above in relation to the proton-conducting film.

[0109] Therefore, the compounds necessary to create the target mixed metal oxide of the first electrode can be combined with a nickel compound to form a composite structure. The nickel is preferably added in the form of its oxide.

[0110] The fractional amount of the Ni compound in the Ni:mixed metal oxide composite after sintering may be greater than 0 to 0.8, preferably 0.2 to 0.8, on a volume or weight basis (therefore, the mixed metal oxides form less than 1 to 0.2). The amount of the Ni compound in the composite after sintering may be greater than 0 to 80% by weight, preferably 20 to 80% by weight, for example 40 to 80% by weight or 55 to 80% by weight, relative to the weight of the composite. Ideally, one or more of the nickel compounds form at least 50% by weight, for example at least 60% by weight, of the green electrode layer. Ideally, the Ni components form at least 50% by weight, for example at least 60% by weight, of the sintered electrode.

[0111] The metal ions necessary to form the metal oxide mixed with the ceramic that forms the electrode layer can be supplied as any convenient salt of the ions, as described above in relation to the proton-conducting film.

[0112] The particles of the precursor material of the reactant can be milled to form a powder mixture. Once formed, this powder mixture can be combined with nickel oxide to form a powder mix.

[0113] The reactants and Ni oxide required to create the first electrode layer are preferably prepared as a slurry in an aqueous or non-aqueous solvent (e.g., alcohol). The use of water is preferred. The relative amounts of the reactants can be carefully measured to ensure that the desired stoichiometric amount of the mixed metal oxide and the desired Ni content are present in the final product after sintering. Essentially all of the metal oxide / NiO present becomes part of the sintered electrode body, and all other components are removed. Therefore, the amount of each component required to produce the desired stoichiometric amount can be easily calculated by those skilled in the art.

[0114] As with the metal salts required to create the mixed metal oxide and the nickel oxide composite, the slurry used to create the first electrode layer may contain other components present to ensure the formation of the electrode layer. Such components are well known in the art and include binders, rheological modifiers, dispersants and / or emulsifiers, or other additives to ensure that the electrode support is formed and remains solid and intact until the sintering process. Thus, the additives act as adhesives of a kind, fixing the metal salt particles together to form a layer.

[0115] Suitable additive compounds include ammonium polyacrylate dispersants and acrylic emulsions. The content of additives, such as emulsifiers / dispersants, may be 0-10% by weight of the total mixture, for example, 1-5% by weight. Suitable binders may be methylcellulose, acrylic emulsions, and starch. The content of such binders may be 0-10% by weight of the total mixture, for example, 1-5% by weight.

[0116] Water is a preferred solvent and may constitute 5-20% by weight of the slurry used to form the support electrode layer. The metal components necessary to form the composite may constitute 50-80% by weight of the slurry.

[0117] The first electrode, after sintering, is made of Ni=AZr a Ceb Acc c O 3-y The Ni fraction in the composite is 0.2 to 0.8 on a volume or weight basis, and the variable is as already defined herein (Equation (I)), the formula Ni-AZr a Ce b Acc c O 3-y is preferably a composite of.

[0118] Alternatively viewed, after sintering, the second electrode is the Ni-AZr a Ce b Acc c O 3-y The Ni fraction in the composite is 0.2 to 0.8 on a volume or weight basis, and the variable is as already defined herein (Equation (I)), the formula Ni-AZr a Ce b Acc c O 3-y is preferably a composite of.

[0119] Once the first electrode is formed, the proton-conductive membrane precursor material can be applied to the first electrode. Any method can be used to apply the proton-conductive membrane to the first electrode. It will be understood that these two layers should be adjacent without any intermediate layer.

[0120] Several thin-film techniques can be used to deposit the film on a support. These include, for example, screen printing, chemical vapor deposition techniques (CVD), spray deposition methods, such as ultrasonic spray deposition (USD), electrophoretic deposition, spin and dip coating, slurry coating, and impregnation are included.

[0121] Screen printing, spray deposition, and spin / dip coating are preferred techniques. Screen printing can be easily upscaled and thinning down to 10 μm can be easily achieved.

[0122] In planar embodiments, the film is preferably deposited on a porous support using screen printing technology.

[0123] Second electrode The second electrode typically has a structure similar to that of the first electrode. Therefore, the second electrode is ideally a composite of a mixed metal oxide and Ni oxide. Any method can be used to apply the second electrode layer to the electrolyte layer. It will be understood that these two layers should be adjacent without any intermediate layers. Methods include immersion coating, spray coating, hand washing, pulsed laser deposition, physical vapor deposition, and screen printing.

[0124] The second electrode layer may have a thickness of 10 to 400 microns, for example, 30 to 100 microns.

[0125] It will be understood that the second electrode layer does not need to cover the entire electrolyte layer. The dimensions of the second electrode layer can be controlled by those skilled in the art.

[0126] The second electrode layer is preferably provided as a green ceramic slurry. The weight fraction of metal powder for spraying the vehicle in the second electrode slurry is preferably 30-85% by weight, more preferably 40-76% by weight. The solvent for the second electrode slurry may be organic or aqueous, but is preferably aqueous to minimize redissolution and / or swelling of the electrolyte layer, which could lead to catastrophic failure of the film before further processing.

[0127] In this case as well, the ceramic compound used to form the second electrode layer is ideally mixed with additives including emulsifiers, rheological modifiers, binders, etc., to ensure good adhesion of the layer to the electrolyte layer. The viscosity of the slurry is controlled to aid in deposition. The required viscosity is a function of the characteristics of the applied technology. For spray coatings, the slurry may have a viscosity of 10-30 cP, measured using a Brookfield viscometer with an LV2 spindle at 60 rpm. In aqueous systems, the viscosity can be easily adjusted by the use of polyionic dispersants. Such dispersants can be polyacrylates, polymethacrylate salts, and lignosulfonates, with ammonium polyacrylate (e.g., Duramax D-3005 or Darvan 821A) being preferred. a) A mixture of approximately 50% by weight containing 75-95% by weight of electrode powder, 2-3% by weight of methylcellulose binder, up to 2% by weight of starch, up to 2% by weight of plasticizer, and up to 2% by weight of dispersant, b) Approximately 50% by weight of water An immersion coating slurry containing the above can be prepared.

[0128] The second electrode, after sintering, is made of Ni-AZr a Ce b Acc c O 3-y The Ni fraction in the composite is 0.2 to 0.8 by volume or weight, and this variable is as already defined herein (Equation (I)), Equation Ni-AZr a Ce b Acc c O 3-y It is preferable that it be a composite of the two.

[0129] Alternatively, the second electrode, after sintering, is made of Ni-AZr a Ce b Acc c O 3-y The Ni fraction in the composite is 0.2 to 0.8 by volume or weight, and this variable is as already defined herein (Equation (I)), Equation Ni-AZra Ce b Acc c O 3-y It is preferable that it be a composite of the two.

[0130] The porosity of the second electrode can be achieved in a manner similar to that of the first electrode. This porosity is achieved by reducing NiO to Ni under reducing conditions at 500-1100°C.

[0131] In one embodiment, the solvent used to deposit the second electrode is different from the solvent used to deposit the film layer. This is important because the subsequent electrode deposition step may dissolve any of the binders used in the film formation step.

[0132] For example, if the binder used in a film coating is water-soluble, the layer will dissolve in water if the outer electrode is coated by immersion using an aqueous solvent.

[0133] Even if dissolution is not an issue, the film layer can absorb the solvent and swell. Therefore, even if the green film layer does not dissolve, it can swell, crack, and delaminate.

[0134] In a preferred embodiment, water is used as the solvent for depositing the second electrode, and an ester is used as the solvent for spray coating the film. Additives can be added to the slurry used in the coating process to ensure that the solubility of the film layer / electrode layer in the organic / aqueous solvent is adjusted.

[0135] A current collector may also be applied to one or both of the electrodes. The current collector may be a metallic current collector, preferably Ni.

[0136] Sintering Once the three layers are formed, the whole assembly can be sintered. In this sintering process, the whole assembly is heat-treated to first remove organic components and any water, and then to increase its density. This heat treatment process may be carried out in steps.

[0137] An initial heat treatment process at a lower temperature can be used to remove any existing organic matter. This process can then be followed by a sintering process at a higher temperature to complete the densification process.

[0138] The initial heat treatment sintering can be carried out at a temperature of 200–500°C, for example, 250–400°C. The process starts at ambient temperature, and the rate of temperature increase can be 1–5°C per minute. The sintering can remain at the aforementioned temperature range for a period of time.

[0139] The sintering temperature to ensure the density of the MEA can be at least 1000°C, for example, 1100-2000°C, or for example, 1200-1900°C. Ideally, temperatures up to 1800°C are used, for example, 800-1700°C, preferably 1000-1650°C, or for example, 1200-1600°C. In this case as well, the rate of temperature increase can be 1-5°C per minute.

[0140] Sintering can be carried out in several different atmospheres, such as oxygen, hydrogen, inert gases, such as hydrogen, vapor, or mixtures, such as air or humidified oxygen. Ideally, air, such as atmosphere, is used. If NiO is present during the sintering of a film supported on the NiO-cermet, and the sintering is carried out in an atmosphere in which the NiO is retained in the material, a second reduction step is required. This step is preferably carried out under reducing conditions, such as hydrogen or diluted hydrogen. Furthermore, it is preferable that this be carried out at a temperature of 500 to 1200°C, more preferably 700 to 1100°C, and most preferably 800 to 1000°C. After sintering, it is preferable that each layer of the MEA is essentially free of any organic material.

[0141] The electrode layer is ideally porous, allowing compounds, such as hydrogen, to pass through without obstruction. The electrolyte layer is ideally dense.

[0142] Alternatively, the individual layers can be sintered separately, for example, in a first step the support is sintered, in a second step the electrolyte layer is deposited, then a second sintering step is performed, in a third step the second electrode is deposited, then a third sintering step is performed, where the temperature of each sintering step is adjusted to reach a desired density.

[0143] Alternatively, the film can be easily formed from the mixed metal oxide and an optional support using the dehydrogenation catalyst, for example, to form a matrix in a reactor through which the feed passes. Therefore, the catalyst can be provided as a particle bed.

[0144] Preferably, the membrane reactor has the following layers in the following order, namely, (I) The following formula Ni-AZr a Ce b Acc c O 3-y A support electrode layer containing a Ni composite, (II)AZr a Ce b Acc c O 3-y A proton-conducting film layer containing (III) The following formula Ni-AZr a Ce b Acc c O 3-y A second electrode layer containing a Ni composite, Here, independently for each layer, A is Ba, Sr, or Ca, or a combination thereof, and the sum of a+b+c is equal to 1. b is between 0 and 0.75. c is between 0.05 and 0.5. Acc is Y, Yb, Gd, Pr, Sc, Fe, Eu, In, or Sm, or a combination thereof, and y is the number for which equation (I) is uncharged, for example, 3-y is between 2.75 and 2.95. It is equipped with a membrane electrode assembly that includes the following features.

[0145] Preferably, the membrane reactor has the following layers in the following order, namely, (I) The following formula Ni-BaZr a Ce b Y c O 3-y A support electrode layer containing a Ni composite, (II)BaZr a Ce b Y c O 3-y A proton-conducting film layer containing (III) The following formula Ni-BaZr a Ce b Y c O 3-y Second electrode layer containing Ni composite Here, independently for each layer, the sum of a+b+c is equal to 1. b is between 0 and 0.75. c is between 0.05 and 0.5, and, y is the number for which equation (I) is uncharged, for example, 3-y is between 2.75 and 2.95. It is equipped with a membrane electrode assembly that includes the following features.

[0146] Preferably, the membrane reactor has the following layers in the following order, namely, (I) The following formula Ni-BaZr a Ce b Y c Yb d O 3-y A support electrode layer containing a Ni composite, (II)BaZr a Ce b Y c Yb d O 3-y A proton-conducting film layer containing (III) The following formula Ni-BaZr a Ce b Y c Yb d O 3-yA second electrode layer containing a Ni composite, Here, the sum of a+b+c+d is equal to 1. b is between 0.05 and 0.75. c is between 0.05 and 0.25. d is between 0.05 and 0.25, and, y is the number for which equation (I) is uncharged, for example, 3-y is between 2.75 and 2.95. It is equipped with a membrane electrode assembly that includes the following features.

[0147] Preferably, the membrane reactor has the following layers in the following order, namely, (I) The following formula Ni-BaCe 0.7 Zr 0.1 Y 0.1 Yb 0.1 O 3-y A support electrode layer containing a Ni composite, (II)BaCe 0.7 Zr 0.1 Y 0.1 Yb 0.1 O 3-y A proton-conducting film layer containing (III) The following formula Ni-BaCe 0.7 Zr 0.1 Y 0.1 Yb 0.1 O 3-y A second electrode layer containing a Ni composite, Here, y is the number for which equation (I) is uncharged, for example, 3-y is between 2.75 and 2.95. It is equipped with a membrane electrode assembly that includes the following features.

[0148] Method conditions The method of the present invention requires that starting materials be supplied to the reactor. The temperature of the supply is such that the material is supplied as a gas, but typically, the supply is preferably heated to the same temperature as the reactor.

[0149] The process within the first region is typically operated at a temperature of 300°C to 1000°C, preferably 400°C to 700°C. The pressure within the reactor can range from 0.5 to 50 bar, preferably 6 bar to 30 bar. The heat required to carry out the dehydrogenation reaction in the first region is preferably derived from the Joule heating process occurring in the proton-conductive membrane.

[0150] In one embodiment, liquid ammonia and optional water can be pressurized, for example, to a pressure of 5 to 50 bar before entering the first region. Heating the compressed liquid readily provides a feed of gaseous reactants at the starting temperature.

[0151] The proton membrane can remove hydrogen from the first region and promote nearly 100% conversion at a low temperature of 500°C.

[0152] The overall dehydrogenation reaction is endothermic, and conventionally heat can be supplied by heat transfer through the membrane from an exothermic reaction occurring on the permeate side of the membrane between the permeated hydrogen and sweep air. This is not attractive as it wastes hydrogen, which is a valuable resource and the core of the method.

[0153] In the present invention, heat is preferably supplied by ohmic losses and thus by Joule energy as further discussed below. There is no need to react the desired hydrogen product with oxygen to generate heat for the dehydrogenation reaction. This maximizes hydrogen production. Therefore, the proton-conductive membrane enables heat management within the system.

[0154] Furthermore, compared to the use of complex metal membranes or mechanically less stable membranes of the prior art, the proton-conductive membrane of the present invention is stable even under chemically harsh conditions at high temperatures. The basic properties of the Ba-based proton conductor utilized make it ideal for ammonia operation.

[0155] The reaction products at the outlet of the first region include nitrogen, any hydrogen that did not pass through the membrane, unreacted ammonia, and water, if present. The nitrogen does not pass through the proton-conducting membrane and can be extracted from the first region and separated from any other components present. Therefore, the nitrogen can be extracted and pressurized. This resource can be used in any useful application, or the nitrogen can be passed through a heat exchanger to recover heat, which can then be used to heat the first region.

[0156] Protons (and therefore hydrogen) passing through the proton-conducting film are electrochemically compressed, and this process also generates heat. Therefore, it is important that ammonia dehydrogenation is endothermic, as the reaction in the first region acts as a heat sink for the heat generated during hydrogen compression across the proton-conducting film.

[0157] Hydrogen is extracted from the permeate side of the proton membrane using an external bias that allows for the direct compression of hydrogen gas. The process involves a ΔP across the proton-conducting membrane, other than the overall potential increase due to the chemical Nernst potential. H2 It does not depend on [the substance]. Furthermore, the removal of hydrogen from the permeate side of the proton-conducting membrane shifts the reaction toward nitrogen, thus enabling a high hydrogen recovery rate.

[0158] As hydrogen passes through the membrane, the pressure in the second region increases. Therefore, once the process begins, the partial pressure of hydrogen in the second region becomes higher than the partial pressure of hydrogen in the first region. In particular, the partial pressure of hydrogen in the second region is at least twice, for example, at least five times, for example, at least 15 times, the pressure in the first region. Pressures up to 20 times or less are possible. The partial pressure of hydrogen in the first region can be 1 to 70 bar, more preferably 5 to 30 bar, or most preferably 10 to 20 bar.

[0159] The reactor may be provided with a pressure regulator at the gas outlet in the second region. This pressure regulator allows control of the pressure in the second region by preventing hydrogen that has passed through the membrane from escaping from the second region. Once the process is performed, the hydrogen pressure in the second region will be higher than the hydrogen pressure in the first region and can be controlled by the pressure regulator.

[0160] The pressure regulator can be used to ensure that a specific pressure is achieved within the second region. A suitable pressure within the second region is 2 to 700 bar, for example 10 to 350 bar, for example 20 to 100 bar.

[0161] Joule heating, also known as ohmic heating or resistance heating, is a process in which heat is released as an electric current passes through a conductor. In this invention, ohmic losses during the operation of the film will cause Joule heating. The heat generated in this process can be used to provide the heat necessary for the dehydrogenation.

[0162] dehydrogenation catalyst The membrane reactor used in the method of the present invention may utilize a separate dehydrogenation catalyst to promote the dehydrogenation reaction. Any dehydrogenation catalyst capable of achieving the desired method can be used.

[0163] In one embodiment, the dehydrogenation catalyst is preferably a porous catalyst that is freely present within the first region of the membrane reactor. The catalyst may be in the form of a powder having a particle size suited to the purpose. The catalyst is not adhered to the membrane. Therefore, in this embodiment, the catalyst can be easily replaced if it needs to be regenerated.

[0164] However, the dehydrogenation catalyst is preferably integrated into the MEA as an electrode. Preferably, a first electrode containing Ni as defined herein also acts as the dehydrogenation catalyst.

[0165] In some embodiments, no catalyst is used at all. In some embodiments, the material used in the film has sufficient catalytic activity so that no further catalyst is required.

[0166] membrane reactor In principle, any reactor design can be used, however, preferred reactor designs are flow-type fixed-bed, fluidized-bed, and wash-coated designs. Therefore, it is important that there is flow from the inlet to the outlet of the first region of the reactor. One advantageous design utilizes a reactor in which a tubular transport membrane is present. Between the wall of the reactor and the tubular membrane, there is a bed of an optional dehydrogenation catalyst. This forms the first region of the reactor. This bed does not need to extend the entire length of the reactor, but may. Alternatively, the first region of the reactor is located inside the tube, where the catalyst is preferably positioned.

[0167] Ammonia, optionally accompanied by vapor, is supplied to the first region. Dehydrogenation occurs upon contact between the reactants and an optional catalyst, thus forming hydrogen. The generated hydrogen gas passes through the membrane and enters the second region of the membrane reactor. Gas that does not pass through the membrane can be collected at the outlet of the first region.

[0168] The distance from the catalyst to the film is preferably as short as possible, preferably 5 cm or less, and more preferably less than 5 mm.

[0169] It is most preferable that the catalyst also serves as the electrode in the first region.

[0170] It is preferable that hydrogen is removed in the opposite direction to the flow of the reactant gases.

[0171] Optionally, sweep gas can be supplied to the second region which is the permeate side of the membrane. The sweep gas is preferably inert to hydrogen. Most preferably, the sweep gas is steam. The steam sweep gas contributes to the hydration of the membrane and will increase the proton conductivity.

[0172] Herein, the present invention is defined while referring to the following non-limiting examples and figures.

Brief Description of the Drawings

[0173] [Figure 1] Figure 1 is a micrograph of a fractured surface showing the structure resulting from the use of a single co-sintering process to produce the MEA structure. It also includes a porous current collector layer deposited on the cathode surface. [Figure 2] Figure 2 shows the conversion rate of anhydrous ammonia as a function of hydrogen recovery rate. Here, the hydrogen recovery rate is defined as the percentage of hydrogen measured at the outlet of the second region divided by the total hydrogen available from the NH3 supplied to the first region. A hydrogen recovery rate of zero results in open circuit conversion. It is observed that the ammonia conversion rate increases with increasing hydrogen recovery rate and reaches 100% at a hydrogen recovery rate of about 60%. [Figure 3] Figure 3 shows the conversion rate of aqueous ammonia as a function of hydrogen recovery rate. Here, the hydrogen recovery rate is defined as the percentage of hydrogen measured at the outlet of the second region divided by the total hydrogen available from the NH3 supplied to the first region. A hydrogen recovery rate of zero results in open circuit conversion. It is observed that the ammonia conversion rate increases with increasing hydrogen recovery rate and reaches >98% at a hydrogen recovery rate of >95%. [Figure 4] Figure 4 shows the increasing hydrogen partial pressure within the membrane reactor during ammonia dehydrogenation. [Figure 5] Figure 5 shows a process flow diagram for a 1 ton / day hydrogen production facility operation for anhydrous ammonia. [Figure 6]Figure 6 shows a process flow diagram for the operation of a hydrogen production facility using aqueous ammonia (35% NH3 solution) at a rate of 1 ton / day.

[0174] Examples Membrane preparation: 60 wt% Ni-BaZr containing a 30 μm high-density film 0.7 Ce 0.2 Y 0.1 O 3-δ A tubular asymmetric film support of (BCZY27) was synthesized using a reactive sintering method.

[0175] The precursors BaSO4, ZrO2, Y2O3, and CeO2 were placed together in stoichiometric amounts (metal-based) in a Nalgene bottle and mixed on a jar roller for 24 hours. The material was dried in air and sieved through a 40-mesh screen. This formed the initial precursor mixture.

[0176] The two precursor mixtures were further mixed with 64% by weight of NiO. Next, one of these parts (the first part) was blended with a water-soluble acrylic and cellulose ether plasticizer to prepare an extrusion batch.

[0177] Using the extrusion batch, green tubes were extruded in a Loomis extruder. The extruded tubes were then dried and spray-coated with the initial precursor mixture.

[0178] After a second drying process, the tube was immersion coated in the solution of the second portion (containing NiO). The tube was simultaneously combusted in air at 1600°C for 4 hours by hang-firing. This process creates an inner NiO-BCZY27 layer. Next, the sintered tube was treated at 1000°C in a hydrogen mixture (safety gas) to reduce NiO to Ni, obtaining the required porosity in the anode support structure and outer cathode. A Ni current collector was deposited on the outer cathode. A scanning electrode microscope image of the cell cross-section is shown in Figure 1.

[0179] catalyst: The anode support structure, consisting of 60% by weight of Ni-BCZY27, provides sufficient catalytic activity for ammonia dehydrogenation.

[0180] Cell assembly: The aforementioned ceramic cell was sealed in a ceramic alumina riser having an outer diameter of 1 / 2'' using a glass-ceramic seal designed to thermally match the thermal expansion coefficient of the cell assembly. The ceramic riser allowed the ceramic cell to be positioned within a uniform temperature range during the experiment. The other end of the tubular ceramic cell was capped using a similar glass-ceramic sealant material to obtain a leak-free cell assembly.

[0181] Reactor and setup: The tubular reactor apparatus consisted of an inner cell assembly and an outer steel reactor tube (Kanthal APMT, ID=20.93mm). The cell assembly was assembled on a 316SS Swagelok-based system, providing electrical contact and feedthrough for thermocouples and gas. Multiple thermocouples were placed inside the tubular cell and outside the reactor tube at the top and bottom of the ceramic cell. By utilizing these thermocouples, the heating region of the reactor furnace was adjusted so that the axial temperature difference was less than 10°C. A Ni tube (OD=4.6mm) acted as a gas supply and current probe for the inner first region. To ensure contact between the tubular cell and the Ni tube, Ni wool (American Elements) was inserted into the first region to ensure contact between the Ni tube and the first electrode. The outer second electrode was in contact with an Ag wire (diameter=0.25mm) wound around the tubular structure. Gas analysis was performed using an Agilent 7890 gas chromatograph, and the concentrations of He, H2, N2, and NH3 in the product line and sweep outlet gas line were measured. A Hameg HMP4040 power supply was used in constant current mode for hydrogen removal, compression, and heat generation.

[0182] Process 1: Dehydrogenation of anhydrous NH3 The cell assembly was mounted in the reactor apparatus (as described above). The active cell area was 32.4 cm². 2A gas stream consisting of 105 mL / min of N2 and 20 mg / min of H2O was supplied to the second region, while a gas stream consisting of 26.2 mL / min of He and 20 mg / min of NH3 was supplied to the first region, where a dehydrogenation reaction of NH3 occurred when an external bias was applied, and hydrogen was transported through the membrane. The reaction temperature was 600°C. Helium was used as an internal standard to identify potential leaks through the membrane. The ammonia conversion rate obtained at the open-circuit voltage (OCV) was equal to 99.5%. When an external electric field of 3.2 A was applied to the membrane, the ammonia conversion rate reached 100%. As shown in Figure 2, the ammonia conversion rate increased with the amount of hydrogen transported through the membrane, corresponding to the increase in current and the resulting hydrogen recovery rate.

[0183] Process 2: Dehydrogenation of aqueous NH3 The cell assembly was mounted in the reactor apparatus (as described above). The active cell area was 15.39 cm². 2 A gas stream consisting of 105 mL / min of N2 and 20 mg / min of H2O was supplied to the second region, while a gas stream consisting of 15.1 mL / min of He, 10 mg / min of NH3, and 32 mg / min of H2O (corresponding to an aqueous ammonia mixture of 75% H2O and 25% NH3) was supplied to the first region, where a dehydrogenation reaction of NH3 occurred when an external bias was applied, and hydrogen was transported through the membrane. The reaction temperature was 600°C. Helium was used as an internal standard to identify potential leaks through the membrane. The ammonia conversion rate obtained at the open-circuit voltage (OCV) was equal to 76%. When an external electric field of 3 A was applied to the membrane, the ammonia conversion rate reached 98%. As in the anhydrous case, as shown in Figure 3, the ammonia conversion rate increased with the amount of hydrogen transported through the membrane, corresponding to the increase in current and the resulting hydrogen recovery rate.

[0184] Electrochemical compression The cell assembly was mounted in the reactor apparatus (as described above). The active cell area was 14.45 cm². 2A gas flow consisting of 15.1 mL / min of He and 65 mg / min of NH3 was supplied to the first region, where a dehydrogenation reaction of NH3 occurred when an external bias was applied, and hydrogen was transported through the membrane. During the experiment, the gas flow in the second region was reduced in two steps from 105 mL / min of N2 and 20 mg / min of water to 10 mL / min of N2 and 20 mg / min of H2O, and then to 20 mg / min of H2O. The continuous transport of hydrogen through the membrane allowed for a corresponding increase in the partial pressure of hydrogen, as shown in Figure 4, and it was shown that the partial pressure of hydrogen in the second region (cathode pressure) was higher than the partial pressure of hydrogen in the first region (anode pressure).

[0185] Process flow diagram 5: Anhydrous ammonia A process flow diagram for the production of compressed hydrogen from anhydrous ammonia is shown in Figure 5.

[0186] Anhydrous ammonia is supplied to heat exchanger 1 by a pump via line (1). This heat exchanger 1 can be heated by hydrogen extracted from the membrane reactor to line (5). A second heat exchanger 2 can be used before ammonia passes through line (4) into the membrane reactor. Any unreacted starting material and retained nitrogen are recycled to heat exchanger 2 via line (10), and nitrogen can be extracted via line (11).

[0187] If necessary, water can be added to the permeate side of the reactor via heat exchanger 3, which can also be heated by hydrogen via line (6). The mixture of hydrogen and water from heat exchanger 3 can be removed and condensed via 7. The water can be recycled, and the hydrogen can be set aside for storage via line (9). If necessary, the water can also be further heated by lines 15 and 16, and heaters between them.

[0188] ASPEN software is used to simulate a facility producing 1 ton of H2 per day using the process flow diagram described above. The reaction conditions are 650°C and a reaction pressure of 27.9 bar (assuming complete conversion with a hydrogen partial pressure of 20.9 bar). The generated hydrogen is electrochemically compressed to 25.4 bar at 0.517 A / cm². 2 When operating at a current density of 214m 2 A certain film surface area is required. The heat generated by the operation of the film, i.e., Joule heating, is supplied for the endothermic ammonia dehydrogenation reaction and for heat exchange with the supplied anhydrous ammonia. The benefits of thermal integration result in an overall energy efficiency of 92.1%.

[0189] Process flow diagram 6: Aqueous ammonia A process flow diagram for the production of compressed hydrogen from aqueous ammonia is shown in Figure 6.

[0190] Aqueous ammonia is supplied to line (2) by a pump via line (1) and passes through a series of heat exchangers that form a so-called heat recovery loop. Line (3), containing the reaction mixture, is supplied to heat exchanger 1, which can be heated by line (11) from the retained material of the membrane reactor. A second heat exchanger 2 can be used before aqueous ammonia enters the membrane reactor via line (5). This heat exchanger 2 can be heated by hydrogen extracted from the permeate of the membrane reactor into line (6). Any unreacted starting material, as well as retained water and nitrogen, can be recycled to heat exchanger 1, heat exchanger 3 and the heat recovery loop via line (11), and residual water and nitrogen mixture are extracted via line (15).

[0191] If necessary, water can be added to the membrane via line (17) and first supplied to heat exchanger 3, which can be heated by retainer from line (11), followed by heat exchanger 4, which can be heated by line (6) containing a mixture of hydrogen and water from the permeate. The mixture of hydrogen and water from heat exchanger 4 can be removed and condensed via 7. The water can be recycled and the hydrogen can be set aside via line (9) for storage. If necessary, the water can also be further heated by lines (19) and (20) and heaters between them.

[0192] ASPEN software is used to simulate a facility producing 1 ton of H2 per day using the process flow diagram described above. The reaction conditions are 650°C and a reaction pressure of 27.9 bar (assuming complete conversion with a hydrogen partial pressure of 7.3 bar). The generated hydrogen is electrochemically compressed to 25.4 bar at 0.664 A / cm². 2 When operating at a current density of 167m 2 A certain film surface area is required. The heat generated by the operation of the film, i.e., Joule heating, is supplied for the endothermic ammonia dehydrogenation reaction and for heat exchange of the supplied aqueous ammonia (35% NH3 solution). The benefits of thermal integration result in an overall energy efficiency of 82.7%. In one embodiment, the present invention may be configured as follows. [Section 1] A method for producing compressed hydrogen in a membrane reactor, wherein the membrane reactor comprises a first region separated from a second region by a proton-conducting membrane, the first region having a gas inlet and a product outlet, and the second region having a product outlet, and the method is a. A gas containing ammonia is supplied to the first region through the gas inlet, and a reaction occurs in the first region to form hydrogen and nitrogen. b. Applying an electric field to the proton-conducting film, c. Dissociating hydrogen into electrons and protons and selectively passing them through the proton-conducting film to the second region, where the protons and electrons recombine to form hydrogen in the second region. Includes, The method wherein the membrane reactor is equipped with a pressure regulator at the outlet of the product from the second region, so that during operation the partial pressure of hydrogen in the second region is higher than the partial pressure of hydrogen in the first region. [Section 2] A method for producing hydrogen in a membrane reactor, wherein the membrane reactor comprises a first region separated from a second region by a proton-conducting membrane, the first region having a gas inlet and a product outlet, and the second region having a product outlet, and the method is a. A gas containing ammonia is supplied to the first region, and a reaction occurs in the first region to form hydrogen and nitrogen. b. Applying an electric field to the proton-conducting film, c. Dissociating hydrogen into electrons and protons and selectively passing them through the proton-conducting film to the second region, where the protons and electrons recombine to form hydrogen in the second region. Includes, The method wherein Joule heating occurring during the application of the electric field to the proton-conducting film is used to heat the first region. [Section 3] A method for producing compressed hydrogen in a membrane reactor, wherein the membrane reactor comprises a first region separated from a second region by a proton-conducting membrane, the first region having a gas inlet and a product outlet, and the second region having a product outlet, and the method is a. A gas containing ammonia is supplied to the first region, and a reaction occurs in the first region to form hydrogen and nitrogen. b. Applying an electric field to the proton-conducting film, c. Dissociating hydrogen into electrons and protons and selectively passing them through the proton-conducting film to the second region, where the protons and electrons recombine to form hydrogen in the second region. Includes, Here, the membrane reactor is equipped with a pressure regulator at the product outlet from the second region, and therefore, during operation, the partial pressure of hydrogen in the second region is higher than the partial pressure of hydrogen in the first region, The Joule heating that occurs during the application of the electric field to the proton-conducting film is used to heat the first region. The method. [Section 4] The method according to any one of claims 1 to 3, wherein the temperature in the first region is 400°C or higher, for example, 400 to 1000°C. [Section 5] The method according to any one of claims 1 to 4, wherein the proton-conducting film is self-supporting. [Section 6] The method according to any one of claims 1 to 5, wherein the first region includes a dehydrogenation catalyst. [Section 7] The method according to any one of claims 1 to 6, wherein the hydrogen in the second region is compressed and at a pressure of 2 bar or more. [Section 8] The method according to any one of claims 1 to 7, wherein the hydrogen in the second region is compressed and the heat generated thereby is used to heat the first region. [Section 9] The proton-conducting film comprises at least one mixed metal oxide of the following formula (I): AZr a Ce b Acc c O 3-y (I) Here, each layer operates independently. A is Ba, Sr, or Ca, or a combination thereof, and the sum of a+b+c is equal to 1. b is between 0 and 0.75. c is between 0.05 and 0.5. Acc is Y, Yb, Gd, Pr, Sc, Fe, Eu, In, or Sm, or a combination thereof, and, y is the number for which equation (I) is uncharged, for example, 3-y is between 2.75 and 2.95. The method according to any one of claims 1 to 8. [Section 10] The membrane reactor is equipped with a membrane electrode assembly, and the membrane electrode assembly has the following layers in the following order: (I) Ni-AZr a Ceb Acc c O 3-y A support electrode layer containing a Ni composite; (II)AZr a Ce b Acc c O 3-y A proton-conducting film layer containing [a specific component]; (III) Type Ni-AZr a Ce b Acc c O 3-y Second electrode layer containing Ni composite It is equipped with, Here, independently for each layer, A is Ba, Sr, or Ca, or a combination thereof, and the sum of a+b+c is equal to 1. b is between 0 and 0.75. c is between 0.05 and 0.5. Acc is Y, Yb, Gd, Pr, Sc, Fe, Eu, In, or Sm, or a combination thereof, and y is the number for which equation (I) is uncharged, for example, 3-y is between 2.75 and 2.95. The method according to any one of claims 1 to 9. [Section 11] The method according to any one of claims 1 to 10, wherein water is supplied to the first region together with ammonia. [Section 12] The method according to any one of claims 1 to 11, wherein the supply is aqueous ammonia. [Section 13] The proton-conducting film is part of a film electrode assembly, and the film electrode assembly has the following layers in the following order: (I) Formula Ni-BaZr a Ce b Y c O 3-y A support electrode layer containing a Ni composite, (II)BaZr a Ce b Y c O 3-y A proton-conducting film layer containing (III) Ni-BaZr a Ce b Y c O 3-y Second electrode layer containing Ni composite It is equipped with, Here, independently for each layer, the sum of a+b+c is equal to 1. b is between 0 and 0.75. c is between 0.05 and 0.5, and, y is the number for which equation (I) is uncharged, for example, 3-y is between 2.75 and 2.95. The method according to any one of claims 1 to 12. [Section 14] The proton-conducting film is part of a film electrode assembly, and the film electrode assembly has the following layers in the following order: (I) Formula Ni-BaZr a Ce b Y c Yb d O 3-y A support electrode layer containing a Ni composite, (II)BaZr a Ce b Y c Yb d O 3-y A proton-conducting film layer containing (III) Ni-BaZr a Ce b Y c Yb d O 3-y Second electrode layer containing Ni composite They are equipped, Here, the sum of a+b+c+d is equal to 1. b is between 0.05 and 0.75. c is between 0.05 and 0.25. d is between 0.05 and 0.25, and, y is the number for which equation (I) is uncharged, for example, 3-y is between 2.75 and 2.95. The method according to any one of claims 1 to 13. [Section 15] The proton-conducting film is part of a film electrode assembly, and the film electrode assembly has the following layers in the following order: (I) Formula Ni-BaCe 0.7 Zr 0.1 Y 0.1 Yb 0.1 O 3-y A support electrode layer containing a Ni composite, (II)BaCe 0.7 Zr 0.1 Y 0.1 Yb 0.1 O 3-y A proton-conducting film layer containing (III) Formula Ni-BaCe 0.7 Zr 0.1 Y 0.1 Yb 0.1 O 3-y Second electrode layer containing Ni composite It is equipped with, Here, y is the number for which equation (I) is uncharged, for example, 3-y is between 2.75 and 2.95. The method according to any one of claims 1 to 14. [Section 16] A method for producing hydrogen in a membrane reactor, wherein the membrane reactor comprises a first region separated from a second region by a proton-conducting membrane, the first region having a gas inlet and a product outlet, and the second region having a product outlet, and the method is a. A gas containing ammonia is supplied to the first region through the gas inlet, and a reaction occurs in the first region to form hydrogen and nitrogen. b. Applying an electric field to the proton-conducting film, c. Dissociating hydrogen into electrons and protons and selectively passing them through the proton-conducting film to the second region, where the protons and electrons recombine to form hydrogen in the second region. Includes, Here, the membrane reactor is equipped with a membrane electrode assembly, and the membrane electrode assembly has the following layers in the following order: (I) Ni-AZr a Ce b Acc c O 3-y A support electrode layer containing a Ni composite; (II)AZr a Ce b Acc c O 3-y A proton-conducting film layer containing [a specific component]; (III) Type Ni-AZr a Ce b Acc c O 3-y Second electrode layer containing Ni composite It is equipped with, Here, independently for each layer, A is Ba, Sr, or Ca, or a combination thereof, and the sum of a+b+c is equal to 1. b is between 0 and 0.75. c is between 0.05 and 0.5. Acc is Y, Yb, Gd, Pr, Sc, Fe, Eu, In, or Sm, or a combination thereof, and y is the number for which equation (I) is uncharged, for example, 3-y is between 2.75 and 2.95. The method. [Section 17] A membrane reactor comprising a first region separated from a second region by a membrane electrode assembly, and a power supply adapted to pass an electric field through the membrane electrode assembly, wherein the first region has a gas inlet and a product outlet, and the second region has a product outlet, and a pressure regulator is provided in the second region. Here, the film electrode assembly has the following layers in the following order: (I) Ni-AZr a Ce b Acc c O 3-y A support electrode layer containing a Ni composite, (II)AZr a Ce b Acc c O 3-y A proton-conducting film layer containing (III) Type Ni-AZr a Ce b Acc c O 3-y Second electrode layer containing Ni composite It is equipped with, where A is Ba, Sr, or Ca, or a combination thereof, and the sum of a+b+c is equal to 1. b is between 0 and 0.75. c is between 0.05 and 0.5. Acc is Y, Yb, Pr, Eu, Pr, Sc, or In, or a combination thereof, and y is the number for which equation (I) is uncharged, for example, 3-y is between 2.75 and 2.95. The membrane reactor.

Claims

1. A method for producing compressed hydrogen in a membrane reactor, wherein the membrane reactor comprises a first region separated from a second region by a proton-conducting membrane, the first region having a gas inlet and a product outlet, and the second region having a product outlet, and the method is a. A gas containing ammonia is supplied to the first region through the gas inlet, and a reaction occurs in the first region to form hydrogen and nitrogen. b. Applying an electric field to the proton-conducting film, c. Dissociating hydrogen into electrons and protons and selectively passing them through the proton-conducting film to the second region, where the protons and electrons recombine to form hydrogen in the second region. Includes, Here, the membrane reactor is equipped with a pressure regulator at the product outlet from the second region, and therefore, during operation, the partial pressure of hydrogen in the second region is higher than the partial pressure of hydrogen in the first region; The temperature in the first region is 400°C or higher; and, The proton-conducting film comprises at least one mixed metal oxide of the following formula (I), AZr a Ce b Acc c O 3-y (I) Here, A is Ba, Sr, or Ca, or a combination thereof; The sum of a + b + c is equal to 1; b is between 0 and 0.75; c is between 0.05 and 0.5; Acc is Y, Yb, Gd, Pr, Sc, Fe, Eu, In, or Sm, or a combination thereof; and, y is the number for which equation (I) is uncharged. The method.

2. A method for producing hydrogen in a membrane reactor, wherein the membrane reactor comprises a first region separated from a second region by a proton-conducting membrane, the first region having a gas inlet and a product outlet, and the second region having a product outlet, and the method is a. A gas containing ammonia is supplied to the first region, and a reaction occurs in the first region to form hydrogen and nitrogen. b. Applying an electric field to the proton-conducting film, c. Dissociating hydrogen into electrons and protons and selectively passing them through the proton-conducting film to the second region, where the protons and electrons recombine to form hydrogen in the second region. Includes, Here, the Joule heating that occurs during the application of the electric field to the proton-conducting film is used to heat the first region; The temperature in the first region is 400°C or higher; and, The proton-conducting film comprises at least one mixed metal oxide of the following formula (I), AZr a Ce b Acc c O 3-y (I) Here, A is Ba, Sr, or Ca, or a combination thereof; The sum of a + b + c is equal to 1; b is between 0 and 0.75; c is between 0.05 and 0.5; Acc is Y, Yb, Gd, Pr, Sc, Fe, Eu, In, or Sm, or a combination thereof; and, y is the number for which equation (I) is uncharged. The method.

3. A method for producing compressed hydrogen in a membrane reactor, wherein the membrane reactor comprises a first region separated from a second region by a proton-conducting membrane, the first region having a gas inlet and a product outlet, and the second region having a product outlet, and the method is a. A gas containing ammonia is supplied to the first region, and a reaction occurs in the first region to form hydrogen and nitrogen. b. Applying an electric field to the proton-conducting film, c. Dissociating hydrogen into electrons and protons and selectively passing them through the proton-conducting film to the second region, where the protons and electrons recombine to form hydrogen in the second region. Includes, Here, the membrane reactor is equipped with a pressure regulator at the product outlet from the second region, and therefore, during operation, the partial pressure of hydrogen in the second region is higher than the partial pressure of hydrogen in the first region. The Joule heating that occurs during the application of the electric field to the proton-conducting film is used to heat the first region; The temperature in the first region is 400°C or higher; and, The proton-conducting film comprises at least one mixed metal oxide of the following formula (I), AZr a Ce b Acc c O 3-y (I) Here, A is Ba, Sr, or Ca, or a combination thereof; The sum of a + b + c is equal to 1; b is between 0 and 0.75; c is between 0.05 and 0.5; Acc is Y, Yb, Gd, Pr, Sc, Fe, Eu, In, or Sm, or a combination thereof; and, y is the number for which equation (I) is uncharged. The method.

4. The method according to any one of claims 1 to 3, wherein the temperature in the first region is 400 to 1000°C.

5. The method according to any one of claims 1 to 4, wherein the proton-conducting film is self-supporting.

6. The method according to any one of claims 1 to 5, wherein the first region includes a dehydrogenation catalyst.

7. The method according to any one of claims 1 to 6, wherein the hydrogen in the second region is compressed to a pressure of 2 bar or more.

8. The method according to any one of claims 1 to 7, wherein the hydrogen in the second region is compressed and the heat generated thereby is used to heat the first region.

9. The membrane reactor is equipped with a membrane electrode assembly, and the membrane electrode assembly is arranged in the following order of layers: (I) Formula Ni-AZr ａ Ce ｂ Acc ｃ O ３－ｙ Support electrode layer containing Ni composite; (II) AZr ａ Ce ｂ Acc ｃ O ３－ｙ A proton-conducting film layer containing; (III) formula Ni - AZr ａ Ce ｂ Acc ｃ O ３－ｙ The second electrode layer containing the Ni composite of It is equipped with, Here, independently for each layer, A is Ba, Sr, or Ca, or a combination thereof, and the sum of a + b + c is equal to 1. b is between 0 and 0.

75. c is between 0.05 and 0.

5. Acc is Y, Yb, Gd, Pr, Sc, Fe, Eu, In, or Sm, or a combination thereof, and y is the number for which equation (I) is uncharged. The method according to any one of claims 1 to 8.

10. The method according to any one of claims 1 to 9, wherein water is supplied to the first region together with ammonia.

11. The method according to any one of claims 1 to 10, wherein the supply is aqueous ammonia.

12. The proton-conducting film is part of a film electrode assembly, and the film electrode assembly consists of the following layers in the order listed below: (I) Formula Ni-BaZr ａ Ce ｂ Y ｃ O ３－ｙ Support electrode layer containing Ni composite, (II) BaZr ａ Ce ｂ Y ｃ O ３－ｙ A proton-conducting film layer containing (III) Formula Ni-BaZr ａ Ce ｂ Y ｃ O ３－ｙ Second electrode layer containing Ni composite It is equipped with, Here, independently for each layer, the sum of a + b + c is equal to 1. b is between 0 and 0.

75. c is between 0.05 and 0.5, and, y is the number for which equation (I) is uncharged. The method according to any one of claims 1 to 11.

13. The proton-conducting film is part of a film electrode assembly, and the film electrode assembly consists of the following layers in the order listed below: (I) Formula Ni-BaZr ａ Ce ｂ Y ｃ Yb ｄ O ３－ｙ Support electrode layer containing Ni composite, (II) BaZr ａ Ce ｂ Y ｃ Yb ｄ O ３－ｙ A proton-conducting film layer containing (III) Formula Ni-BaZr ａ Ce ｂ Y ｃ Yb ｄ O ３－ｙ Second electrode layer containing Ni composite They are equipped, Here, the sum of a + b + c + d is equal to 1. b is between 0.05 and 0.

75. c is between 0.05 and 0.

25. d is between 0.05 and 0.25, and, y is the number for which equation (I) is uncharged. The method according to any one of claims 1 to 12.

14. The proton-conducting film is part of a film electrode assembly, and the film electrode assembly consists of the following layers in the order listed below: (I) Formula Ni-BaCe ０．７ Zr ０．１ Y ０．１ Yb ０．１ O ３－ｙ Support electrode layer containing Ni composite, (II) BaCe ０．７ Zr ０．１ Y ０．１ Yb ０．１ O ３－ｙ A proton-conducting film layer containing (III) Formula Ni-BaCe0.7Zr ０．１ Y ０．１ Yb ０．１ O ３－ｙ Second electrode layer containing Ni composite It is equipped with, Here, y is the number for which equation (I) is uncharged. The method according to any one of claims 1 to 13.

15. A method for producing hydrogen in a membrane reactor, wherein the membrane reactor comprises a first region separated from a second region by a proton-conducting membrane, the first region having a gas inlet and a product outlet, and the second region having a product outlet, and the method is a. A gas containing ammonia is supplied to the first region through the gas inlet, and a reaction occurs in the first region to form hydrogen and nitrogen. b. Applying an electric field to the proton-conducting film, c. Dissociating hydrogen into electrons and protons and selectively passing them through the proton-conducting film to the second region, where the protons and electrons recombine to form hydrogen in the second region. Includes, Here, the membrane reactor is equipped with a membrane electrode assembly, and the membrane electrode assembly is arranged in the following order of layers: (I) Formula Ni-AZr ａ Ce ｂ Acc ｃ O ３－ｙ Support electrode layer containing Ni composite; (II) AZr ａ Ce ｂ Acc ｃ O ３－ｙ A proton-conducting film layer containing; (III) Formula Ni-AZr ａ Ce ｂ Acc ｃ O ３－ｙ Second electrode layer containing Ni composite It is equipped with, Here, independently for each layer, A is Ba, Sr, or Ca, or a combination thereof, and the sum of a + b + c is equal to 1. b is between 0 and 0.

75. c is between 0.05 and 0.

5. Acc is Y, Yb, Gd, Pr, Sc, Fe, Eu, In, or Sm, or a combination thereof, and y is the number for which equation (I) is uncharged; and The temperature in the first region is 400°C or higher. The method.

16. The method according to any one of claims 1 to 15, wherein 3-y is 2.75 to 2.95.

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