Method for carrying out ammonia decomposition reaction in a fluidized bed reactor

Abstract

A method for conducting an ammonia decomposition reaction accompanied by the production of hydrogen, comprising the steps of: (a) providing an ammonia-containing feedstock and at least one fluidized bed reactor comprising a bed comprising at least two electrodes and particles; (b) fluidizing the particles in the bed to form a fluidized bed; and (c) heating the fluidized bed to a temperature of 250°C to 1000°C, wherein the particles in the bed comprise conductive particles and particles of a catalyst composition, at least 10% by weight of the particles are conductive particles and have a resistivity of 0.001 ohm·cm to 500 ohm·cm at 800°C, the catalyst composition comprises one or more metal compounds, and the step c) of heating the fluidized bed is performed by passing an electric current through the fluidized bed.

Description

[Technical field]

[0001] The present invention relates to a method for carrying out an ammonia decomposition reaction in a fluidized bed reactor, where the reaction takes place within the fluidized bed reactor without the need for an external heating device. The object of the invention is to contribute to replacing the use of fossil carbon-based fuel heating devices.The invention relates to the electrification of the chemical industry. [Background technology]

[0002] Replacing fossil carbon-based fuels in chemical production and recycling processes with greener, decarbonized energy sources is essential in light of climate change and the ongoing energy transition.

[0003] Ammonia decomposition (cracking) is the reverse of ammonia production (see Equation 1) and is an endothermic reaction. NH3(g)―> 1 / 2 N2(g)+3 / 2 H2(g)―> △H=+46kJ / mol [Formula 1]

[0004] The temperature required for efficient cracking varies with catalyst. There is a wide variety of effective materials, some of which (e.g. Ni-supported catalysts) require temperatures in excess of 700 °C to achieve attractive levels of conversion. Other catalysts (e.g. Ru-supported catalysts) show good conversion efficiency in the temperature range of 450-550 °C.

[0005] The resulting gas mixture from the above reaction is hydrogen and nitrogen (i.e., forming gas) in a ratio of 3:1 (75 vol% H2, 25 vol% N2) with small amounts (20-100 ppm) of undissociated ammonia remaining. The residual undissociated ammonia is a result of the thermodynamic limitations of the reaction. These residual traces must be removed as they may act as a poison in some downstream applications. The forming gas can be further purified, for example, using molecular sieves in pressure swing adsorption units or scrubbers to reduce the amount of undissociated ammonia to 1-3 ppm. Summary of the Invention [Problem to be solved by the invention]

[0006] It is an object of the present invention to provide a large scale solution to one or more problems encountered in the prior art that is suitable for application in industries such as the chemical industry. Another object of the present invention is to contribute to replacing the use of fossil carbon-based fuel heating devices in fluidized bed reactors. The present invention provides a solution for the pyrolysis of ammonia into forming gas using electrical power alone. [Means for solving the problem]

[0007] In accordance with a first aspect of the present invention, the present invention provides a method for producing a method for producing a film comprising the steps of: a) providing an ammonia-containing feedstock and at least one fluidized bed reactor comprising at least two electrodes and a bed comprising particles; b) Fluidizing the bed particles to form a fluidized bed; c) heating the fluidized bed to a temperature in the range of 250°C to 1000°C to carry out an ammonia decomposition reaction on the ammonia-containing raw material; d) optionally recovering the reaction product; 1. A method for carrying out an ammonia decomposition reaction with the production of hydrogen, comprising: The method is characterized in that the step c) of heating the fluidized bed is performed by passing an electric current through the fluidized bed, the particles of the fluidized bed comprise electrically conductive particles, at least 10% by weight of the particles, based on the total weight of the particles of the fluidized bed, are electrically conductive particles and have a resistivity in the range of 0.001 ohm·cm to 500 ohm·cm at 800°C, and the catalyst composition comprises one or more metal compounds and a catalyst support, the catalyst support being electrically conductive particles.

[0008] The catalyst composition preferably comprises one or more metal compounds selected from the following: 1) one or more non-noble metals selected from Ni, Fe, Co, Mo, Cu and any mixtures thereof; and / or 2) one or more precious metals selected from Ru, Rh, Pd, Ir, Pt and any mixtures thereof; and / or 3) One or more bimetallic compounds comprising a non-noble metal and a precious metal, wherein the non-noble metal is selected from Ni, Fe, Co, Mo and Cu, and the precious metal is selected from Ru, Rh, Pd, Ir and Pt.

[0009] Surprisingly, it has been found that the use of electrically conductive particles in one or more fluidized bed reactors can maintain temperatures sufficient to carry out ammonia decomposition reactions requiring high temperature conditions, such as temperature reactions in the range of 250°C to 1000°C, without the need for external heating devices. The use of at least 10% by weight of conductive particles within the bed particles can minimize heat losses when a voltage is applied. Thanks to the Joule effect, most, if not all, of the electrical energy is converted into heat that is used to heat the reactor medium. The conductive particles can perform a dual function, since at least a portion of them is used as a support for the catalyst.

[0010] Conductive Particles For example, the conductive particles are or include one or more selected from one or more metal alloys, one or more non-metallic resistors, one or more metal carbides, one or more metal nitrides, one or more metallic phosphides, one or more carbon-containing particles, one or more superionic conductors, one or more phosphate electrolytes, one or more mixed oxides doped with one or more low-valent cations, one or more mixed sulfides doped with one or more low-valent cations, and any mixtures thereof, and are preferably present in an amount of 50% to 100% by weight, preferably 60% to 100% by weight, more preferably 70% to 100% by weight, even more preferably 80% to 100% by weight, and most preferably 90% to 100% by weight based on the total weight of the conductive particles in the bed.

[0011] In a preferred embodiment, the conductive particles are or comprise one or more selected from one or more metal alloys, one or more non-metallic resistors, one or more metal carbides, one or more metal nitrides, one or more metal phosphides, graphite, carbon black, one or more superionic conductors, one or more phosphate electrolytes, one or more mixed oxides doped with one or more low-valent cations, one or more mixed sulfides doped with one or more low-valent cations, and any mixtures thereof, and are preferably present in an amount of 50% to 100% by weight, preferably 60% to 100% by weight, more preferably 70% to 100% by weight, even more preferably 80% to 100% by weight, and most preferably 90% to 100% by weight, based on the total weight of the conductive particles in the bed.

[0012] Preferably, the conductive particles of the bed are or contain one or more selected from one or more non-metallic resistors, one or more metal carbides, one or more metal nitrides, one or more metal phosphides, one or more superionic conductors, one or more phosphate electrolytes, one or more mixed oxides doped with one or more low-valent cations, one or more mixed sulfides doped with one or more low-valent cations, and any mixtures thereof, and the content of the conductive particles of the bed is 50% to 100% by weight, preferably 60% to 100% by weight, more preferably 70% to 100% by weight, even more preferably 80% to 100% by weight, and most preferably 90% to 100% by weight, based on the total weight of the conductive particles of the bed.

[0013] In one embodiment, the conductive particles of the bed include one or more carbon-containing particles that are graphite, the content of which is 10% to 100% by weight, or 10% to 90% by weight, or 10% to 80% by weight, preferably 15% to 70% by weight, more preferably 20% to 60% by weight, and even more preferably 30% to 50% by weight, based on the total weight of the conductive particles of the bed. For example, the conductive particles of the bed are a mixture of graphite and particles of a catalyst composition.

[0014] For example, the conductive particles of the bed do not include one or more carbon-containing particles selected from petroleum coke, carbon black, coke, or mixtures thereof.

[0015] In one embodiment, the conductive particles of the bed do not include one or more carbon-containing particles selected from graphite, petroleum coke, carbon black, coke, or mixtures thereof. For example, the conductive particles of the bed do not include graphite and / or carbon black. For example, the conductive particles of the bed do not include petroleum coke and / or coke.

[0016] Alternatively, the conductive particles of the bed are or comprise graphite and one or more selected from one or more metal alloys, one or more non-metallic resistors, one or more metal carbides, one or more metal nitrides, one or more metal phosphides, one or more superionic conductors, one or more phosphate electrolytes, one or more mixed oxides doped with one or more low valent cations, one or more mixed sulfides doped with one or more low valent cations and any mixtures thereof, preferably in a content of 50% to 100% by weight, preferably 60% to 100% by weight, more preferably 70% to 100% by weight, even more preferably 80% to 100% by weight and most preferably 90% to 100% by weight, based on the total weight of the conductive particles of the bed.

[0017] Alternatively, the conductive particles of the bed are one or more particles selected from one or more metal alloys, one or more non-metallic resistors (provided that the non-metallic resistor is not silicon carbide), one or more metal carbides, one or more metal nitrides, one or more metal phosphides, graphite, carbon black, one or more superionic conductors, one or more phosphate electrolytes, one or more mixed oxides doped with one or more low valent cations and / or one or more mixed sulfides doped with one or more low valent cations and any mixtures thereof, and the content thereof is preferably 50% to 100% by weight, more preferably 60% to 100% by weight, more preferably 70% to 100% by weight, even more preferably 80% to 100% by weight, and most preferably 90% to 100% by weight based on the total weight of the conductive particles of the bed.

[0018] For example, the conductive particles of the bed are one or more selected from one or more metal alloys, one or more non-metallic resistors, graphite, carbon black, one or more mixed oxides doped with one or more low-valent cations, one or more mixed sulfides doped with one or more low-valent cations, and any mixtures thereof, and are preferably present in an amount of 50% to 100% by weight, preferably 60% to 100% by weight, more preferably 70% to 100% by weight, even more preferably 80% to 100% by weight, and most preferably 90% to 100% by weight, based on the total weight of the conductive particles of the bed.

[0019] For example, the conductive particles of the bed are or contain graphite and one or more selected from one or more metal alloys, one or more non-metallic resistors, one or more mixed oxides doped with one or more low-valent cations, one or more mixed sulfides doped with one or more low-valent cations and mixtures thereof, in a content of 50% to 100% by weight, preferably 60% to 100% by weight, more preferably 70% to 100% by weight, even more preferably 80% to 100% by weight, and most preferably 90% to 100% by weight, based on the total weight of the conductive particles of the bed.

[0020] For example, the conductive particles of the bed are or contain one or more selected from one or more metal alloys, one or more non-metallic resistors, one or more mixed oxides doped with one or more low valent cations, one or more mixed sulfides doped with one or more low valent cations, and any mixtures thereof, and the content thereof is preferably 50% to 100% by weight, preferably 60% to 100% by weight, more preferably 70% to 100% by weight, even more preferably 80% to 100% by weight, and most preferably 90% to 100% by weight, based on the total weight of the conductive particles of the bed.

[0021] For example, the conductive particles of the bed are or contain one or more selected from one or more non-metallic resistors, one or more mixed oxides doped with one or more low-valent cations, one or more mixed sulfides doped with one or more low-valent cations, and any mixtures thereof, and the content thereof is preferably 50% to 100% by weight, preferably 60% to 100% by weight, more preferably 70% to 100% by weight, even more preferably 80% to 100% by weight, and most preferably 90% to 100% by weight, based on the total weight of the conductive particles of the bed.

[0022] Advantageously, a step d) of recovering the reaction product is carried out, said product consisting of a gaseous product being a mixture of H2 and N2. Step d) is carried out after step c).

[0023] In a preferred embodiment, the volumetric heat generation rate is greater than 0.1 MW / m of the fluidized bed. 3 More than 1 MW / m 3 Above 3 MW / m 3 Exceeds.

[0024] In a preferred embodiment, at least one fluidized bed reactor is free of heating means. For example, at least one fluidized bed reactor includes a vessel and no heating means are disposed around or within the vessel. For example, at least one fluidized bed reactor is free of heating means selected from an oven, a gas burner, a hot plate, or any combination thereof. For example, all fluidized bed reactors are free of heating means selected from an oven, a gas burner, a hot plate, or any combination thereof.

[0025] The solid particulate matter (i.e., particles) used in the fluidized bed reactor includes electrically conductive solid particles capable of generating heat and catalytic particulate matter that catalyzes the NH3 decomposition reaction. The catalytic particulate matter is also electrically conductive and therefore contributes to the heat generation of the endothermic ammonia decomposition reaction.

[0026] For example, the content of the conductive particles is in the range of 10% by weight to 100% by weight, preferably 15% by weight to 95% by weight, more preferably 20% by weight to 90% by weight, even more preferably 25% by weight to 80% by weight, and most preferably 30% by weight to 75% by weight. When the content of the conductive particles is 100% by weight, the conductive particles are also catalyst particles.

[0027] For example, the content of conductive particles relative to the total weight of the bed is at least 12% by weight, preferably at least 15% by weight, more preferably at least 20% by weight, even more preferably at least 25% by weight, and most preferably at least 30% by weight or at least 40% by weight or at least 50% by weight or at least 60% by weight, relative to the total weight of the particles in the bed.

[0028] For example, the resistivity of the conductive particles at 800°C is in the range of 0.005 to 400 ohm·cm, preferably in the range of 0.01 to 300 ohm·cm at 800°C, more preferably in the range of 0.05 to 150 ohm·cm at 800°C, and most preferably in the range of 0.1 to 100 ohm·cm at 800°C.

[0029] For example, the conductive particles have a resistivity of at least 0.005 ohm·cm at 800°C, preferably at least 0.01 ohm·cm at 800°C, more preferably at least 0.05 ohm·cm at 800°C, even more preferably at least 0.1 ohm·cm at 800°C, and most preferably at least 0.5 ohm·cm at 800°C.

[0030] For example, the conductive particles have a resistivity of at most 400 ohm·cm at 800°C, preferably at most 300 ohm·cm at 800°C, more preferably at most 200 ohm·cm at 800°C, more preferably at most 150 ohm·cm at 800°C, and most preferably at most 100 ohm·cm at 800°C. The content of conductive particles relative to the total weight of particles in the bed and the selection of conductive particles with a given resistivity influence the temperature reached by the fluidized bed. Thus, if the target temperature is not reached, the skilled person can increase the density of the particle bed, the content of conductive particles relative to the total weight of particles in the bed, and / or select conductive particles with a lower resistivity to increase the temperature reached by the fluidized bed.

[0031] For example, the density of a bed of particles is expressed as the void fraction. This void fraction, or bed porosity, is the volume of voids between the particles divided by the total volume of the bed. At the initiation velocity, the void fraction is usually 0.4-0.5. At fast fluidized beds, the void fraction increases to a maximum of 0.98, ranging from a low of about 0.5 at the bottom to greater than 0.9 at the top of the bed. The void fraction can be controlled by the linear velocity of the fluidizing gas and can be reduced by recycling the solid particles that are collected at the top and returned to the bottom of the bed, thus compensating for the entrainment of solid particles out of the bed.

[0032] The void fraction VF is defined as the volume fraction of voids in a particle bed and is determined according to the following formula: JPEG2025502090000001.jpg1364, where Vt is the total bed volume and is determined by: JPEG2025502090000002.jpg1254Here, A is the cross-sectional area of ​​the fluidized bed, H is the height of the fluidized bed, and Vp is the total volume of particles in the fluidized bed.

[0033] For example, the porosity of the bed is in the range of 0.5 to 0.8, preferably in the range of 0.5 to 0.7, and more preferably in the range of 0.5 to 0.6. In order to increase the density of the particle bed, it is necessary to decrease the porosity.

[0034] For example, the particles of the bed have an average particle size in the range of 5 to 300 μm, preferably in the range of 10 to 200 μm, more preferably in the range of 20 to 200 μm or 30 to 150 μm, as measured by sieving according to ASTM D4513-11.

[0035] It is preferably measured by sieving according to ASTM D4513-11. If the average size of the particles is less than 20 μm, the average size can also be measured by laser light scattering according to ASTM D4464-15.

[0036] For example, the conductive particles of the bed have an average particle size, as measured by sieving according to ASTM D4513-11, in the range of 5 to 300 μm, preferably in the range of 10 to 200 μm, and more preferably in the range of 30 to 150 μm.

[0037] For example, said one or more metal alloys are selected from Ni-Cr, Fe-Ni-Cr, Fe-Ni-Al or mixtures thereof. Preferably, when the metal alloy comprises at least chromium, the chromium content is at least 15 mol%, more preferably at least 20 mol%, even more preferably at least 25 mol%, most preferably at least 30 mol% of the total molar content of the metal alloy comprising at least chromium. Advantageously, furthermore, the iron content in the metal alloy is at most 2.0 mol%, preferably at most 1.5 mol%, more preferably at most 1.0 mol%, even more preferably at most 0.5 mol% relative to the total molar content of the metal alloy.

[0038] For example, the non-metallic resistor may be silicon carbide (SiC), molybdenum disilicide (MoSi2), nickel silicide (NiSi), sodium silicide (Na2Si), magnesium silicide (Mg2Si), platinum silicide (PtSi), titanium silicide (TiSi2), tungsten silicide (WSi2), or mixtures thereof, preferably silicon carbide.

[0039] For example, the one or more metal carbides are selected from iron carbide (Fe3C) and / or molybdenum carbide (such as a mixture of MoC and MO2C).

[0040] For example, the one or more metal nitrides are selected from zirconium nitride (ZrN), tungsten nitride (such as a mixture of WN, WN, and WN), vanadium nitride (VN), tantalum nitride (TaN), and / or niobium nitride (NbN).

[0041] For example, the one or more metal phosphides are selected from copper phosphide (Cu3P), indium phosphide (InP), gallium phosphide (GaP), sodium phosphide (Na3P), aluminum phosphide (AlP), zinc phosphide (Zn3P2) and / or calcium phosphide (Ca3P2).

[0042] For example, the one or more superionic conductors may be LiAlSiO4, LiGeP2Si2, Li 3.6 S O.6 P 0.4 O4, sodium superionic conductors (NaSICON), e.g., Na3Zr2PSi2O 12 , or sodium beta alumina, e.g., NaAl 11 O17, Na 1.6 Al 11 O 17.3 and / or Na 1.76 Li 0.38 Al1 0.62 O l7 is selected from.

[0043] For example, the one or more phosphate electrolytes are selected from UPO4 or LaPO4.

[0044] For example, said mixed oxide or oxides are ionic or mixed conductors doped with one or more low valent cations. Advantageously, said mixed oxides are chosen from oxides having a cubic pyrochlore structure, perovskite, pyrochlore, doped with one or more low valent cations.

[0045] For example, one or more of the mixed sulfides described above may be ionic or mixed conductors doped with one or more low valent cations.

[0046] For example, the conductive particles of the bed are or include a non-metallic resistive material such as silicon carbide.

[0047] For example, the conductive particles of the bed are or include a mixture of a non-metallic resistor that is silicon carbide and conductive particles different from silicon carbide. The presence of conductive particles different from silicon carbide in the bed is optional. It can be present as a starting material for heating the bed, since the resistivity of silicon carbide at room temperature was found to be too high to initiate heating of the bed. Alternatively, the presence of conductive particles different from silicon carbide makes it possible to apply heat to the reactor for a defined time to initiate the reaction.

[0048] For example, the silicon carbide is selected from sintered silicon carbide, nitride bonded silicon carbide, recrystallized silicon carbide, reaction bonded silicon carbide, and any mixture thereof.

[0049] For example, the conductive particles of the bed are or include a mixture of a non-metallic resistor that is silicon carbide and conductive particles other than silicon carbide, and the conductive particles of the bed include 10% to 99% by weight of silicon carbide, preferably 15% to 95% by weight, more preferably 20% to 90% by weight, even more preferably 25% to 80% by weight, and most preferably 30% to 75% by weight of silicon carbide, based on the total weight of the conductive particles of the bed.

[0050] For example, the conductive particles of the bed may be or include a mixture of a non-metallic resistive material that is silicon carbide and conductive particles other than silicon carbide, the conductive particles other than silicon carbide being graphite and / or one or more mixed oxides doped with one or more low valent cations and / or one or more mixed sulfides doped with one or more low valent cations.

[0051] For example, the conductive particles of the bed may be or include silicon carbide and molybdenum disilicide, with the silicon carbide being 10% to 90% by weight and the molybdenum disilicide being 90% to 10% by weight, based on the total weight of the conductive particles of the bed.

[0052] For example, the conductive particles of the bed are or contain ion conductors, i.e. one or more mixed oxides doped with one or more low valent cations, preferably selected from the following: - one or more oxides having a cubic fluorite structure at least partially substituted with one or more low-valent cations, preferably selected from Sm, Gd, Y, Sc, Yb, Mg, Ca, La, Dy, Er, Eu, and / or - one or more ABO3 perovskites comprising trivalent cations A and B, the A positions being at least partially substituted with one or more low-valent cations, preferably selected from Ca, Sr or Mg, and the B positions comprising at least one of Ni, Ga, Co, Cr, Mn, Sc, Fe and / or mixtures thereof, and / or - one or more ABO3-perovskites having a divalent cation A and a tetravalent cation B, with the B positions at least partially replaced by one or more low-valent cations, preferably selected from magnesium (Mg), scandium (Sc), yttrium (Y), neodymium (Nd) or ytterbium (Yb), or the B positions at least partially replaced by a mixture of different B elements, and / or - one or more A2B2O7-pyrochlores having a trivalent cation A and a tetravalent cation B, the A positions being at least partially substituted with one or more low-valent cations preferably selected from calcium or magnesium, and the B positions including at least one of Sn, Zr and Ti.

[0053] For example, the conductive particles of the bed are or contain ionic conductors, i.e. one or more mixed sulfides doped with one or more low-valent cations. The mixed sulfides are preferably selected from the following: - one or more sulfides having a cubic fluorite structure at least partially substituted with one or more low-valent cations, preferably selected from Sm, Gd, Y, Sc, Yb, Mg, Ca, La, Dy, Er, Eu, and / or - one or more ABS3 structures comprising trivalent cations A and B, at least partially substituted in A position with one or more low-valent cations, preferably selected from Ca, Sr or Mg, and comprising in B position at least one of Ni, Ga, Co, Cr, Mn, Sc, Fe and / or mixtures thereof; and / or - one or more ABS3 structures with divalent cations A and tetravalent cations B, where the B positions are at least partially substituted with one or more low-valent cations, preferably selected from Mg, Sc, Y, Nd or Yb, or the B positions are at least partially substituted with a mixture of different B elements, and / or - one or more A2B2S7 structures having a trivalent cation A and a tetravalent cation B in which the A positions are at least partially substituted with one or more low-valent cations, preferably selected from Ca or Mg, and the B positions include at least one of Sn, Zr and Ti.

[0054] Preferably, the degree of substitution in the mixed oxide(s) having a cubic fluorite structure doped with one or more low valent cations is 1 to 15 atomic %, preferably 3 to 12 atomic %, more preferably 5 to 10 atomic %, relative to the total number of atoms present in the oxide(s) having a cubic fluorite structure.

[0055] Preferably, the degree of substitution in the mixed oxide(s) doped with one or more low-valent cations is between 1 and 50 atomic %, preferably between 3 and 20 atomic %, more preferably between 5 and 15 atomic %, relative to the total number of atoms present in the ABO3 perovskites or perovskites with trivalent cations A and B, the ABO3 perovskites with divalent cation A and tetravalent cation B, or the A2B2O7 pyrochlore with trivalent cation A and tetravalent cation B, respectively.

[0056] Preferably, the degree of substitution in the one or more mixed sulfides having a cubic fluorite structure doped with one or more low valent cations is 1 to 15 atomic %, preferably 3 to 12 atomic %, more preferably 5 to 10 atomic %, based on the total number of atoms present in the one or more oxides having a cubic fluorite structure.

[0057] Preferably, the degree of substitution in the mixed sulfide(s) doped with one or more low-valent cations is 1 to 50 atomic %, preferably 3 to 20 atomic %, more preferably 5 to 15 atomic %, based on the total number of atoms present in the ABS3 structure(s) with trivalent cations A and B, the ABS3 structure(s) with divalent cation A and tetravalent cation B, or the A2B2S7 structure(s) with trivalent cation A and tetravalent cation B, respectively.

[0058] For example, the conductive particles of the bed are or include one or more metal alloys, preferably the one or more metal alloys are selected from Ni-Cr, Fe-Ni-Cr, Fe-Ni-Al or mixtures thereof.

[0059] Preferably, when said metal alloy comprises at least chromium, the chromium content is at least 15 mol%, more preferably at least 20 mol%, even more preferably at least 25 mol%, most preferably at least 30 mol% of the total molar content of said metal alloy comprising at least chromium. Advantageously, furthermore, the iron content in the metal alloy is at most 2.0 mol%, preferably at most 1.5 mol%, more preferably at most 1.0 mol%, even more preferably at most 0.5 mol% relative to the total molar content of said metal alloy.

[0060] For example, the conductive particles of the bed are or comprise a mixture of a non-metallic resistor which is silicon carbide and particles other than silicon carbide, the particles other than silicon carbide being or comprise graphite, preferably the graphite particles having an average particle size in the range of 5 to 300 μm, more preferably in the range of 10 to 200 μm, most preferably in the range of 30 to 150 μm, as determined by sieving according to ASTM D4513-11.

[0061] Particles of the catalyst composition For example, the content of the catalyst composition particles is in the range of 30% by weight to 100% by weight, preferably in the range of 32% by weight to 95% by weight, more preferably in the range of 35% by weight to 90% by weight, even more preferably in the range of 37% by weight to 85% by weight, most preferably in the range of 40% by weight to 80% by weight, and even more preferably in the range of 45% by weight to 75% by weight or in the range of 50% by weight to 70% by weight, based on the total weight of the particles in the bed. When the content of the catalyst composition particles is 100% by weight based on the total weight of the particles in the bed, the catalyst composition particles are also conductive particles.

[0062] For example, the particles of the catalyst composition have an average particle size, measured by sieving according to ASTM D4513-11, in the range of 5 to 300 μm, preferably in the range of 10 to 200 μm, more preferably in the range of 20 to 200 μm or 30 to 150 μm.

[0063] Preferably, the average size is measured by sieving according to ASTM D4513-11, but if the average size of the particles is less than 20 μm, the average size can also be measured by laser light scattering according to ASTM D4464-15.

[0064] The catalyst composition comprises one or more metal compounds. Preferably, the catalyst composition comprises one or more metal compounds selected from the following: - one or more non-noble metals selected from Ni, Fe, Co, Mo, Cu and any mixtures thereof; and / or - one or more noble metals selected from Ru, Rh, Pd, Ir, Pt and mixtures thereof, and / or - one or more bimetallic compounds comprising a non-noble metal and a precious metal, where the non-noble metal is selected from Ni, Fe, Co, Mo and Cu, and the precious metal is selected from Ru, Rh, Pd, Ir and Pt.

[0065] For example, the one or more non-noble metals selected from Ni, Fe, Co, Mo, Cu and mixtures thereof are present in an amount ranging from 0.05 wt % to 20.00 wt %, preferably from 0.10 wt % to 15.00 wt %, more preferably from 0.50 wt % to 10.00 wt %, and even more preferably from 1.00 wt % to 5.00 wt %, based on the total weight of the catalyst composition.

[0066] For example, the one or more non-noble metals is or includes Ni.

[0067] For example, the one or more precious metals selected from Ru, Rh, Pd, Ir, Pt and mixtures thereof are present in an amount of 0.05 wt % to 10.00 wt %, preferably 0.10 wt % to 5.00 wt %, more preferably 1.00 wt % to 3.00 wt %, and even more preferably 1.50 wt % to 2.50 wt %, based on the total weight of the catalyst composition.

[0068] For example, the one or more noble metals is or includes Ru.

[0069] For example, the noble metal in the bimetallic compound(s) is present in an amount from 10 ppm to 500 ppm, preferably from 50 ppm to 400 ppm, and more preferably from 100 ppm to 250 ppm.

[0070] Advantageously, the catalytic composition further comprises one or more elements selected from alkali metals, alkaline earth metals and rare earth elements. For example, the one or more alkali metals are one or more selected from Li, Na, K, Cs and mixtures thereof. For example, the one or more alkaline earth metals are one or more selected from Mg and / or Ca. For example, the one or more rare earth elements are one or more selected from Ce, La, Sc, Y and mixtures thereof.

[0071] In the present invention, the catalyst composition further comprises a catalyst support which is a conductive particle. Preferably, the conductive particle is silicon carbide and / or graphite and / or carbon nanotube, or a conductive particle other than silicon carbide. This allows the catalytically active material and the conductive material to be in intimate contact with each other.

[0072] Preferably, the catalyst composition has a specific surface area of ​​10 m2 as measured by N2 adsorption measurement. 2 / g~1000m 2 / g, more preferably in the range of 50m 2 / g~900m 2 / g, more preferably 100m 2 / g~800m 2 / g, most preferably 200m 2 / g~700m 2 / g range.

[0073] Ammonia decomposition reaction For example, the ammonia decomposition reaction is carried out at a temperature of 300°C to 950°C, preferably 350°C to 900°C, more preferably 400°C to 850°C, and most preferably 450°C to 800°C or 480°C to 950°C.

[0074] The present invention further provides a method for the partial decomposition of ammonia, i.e. the conversion rate of ammonia to forming gas is less than 50%, preferably in the range of 20% to 50% or 20% to 30%. The method of the present invention is advantageous for smooth combustion of the produced hydrogen in the following cases: - the catalyst composition comprises one or more non-noble metals (e.g. Ni or supported Ni) and the temperature provided in step (c) is in the range of 250°C to 800°C, preferably 300°C to 750°C, more preferably 350°C to 700°C, even more preferably 400°C to 650°C, or - when the catalyst composition comprises one or more precious metals (e.g. Ru or supported Ru) and the temperature provided in step (c) is between 250°C and 450°C, preferably between 275°C and 425°C, more preferably between 300°C and 400°C.

[0075] The conversion rate was determined by calculating the ratio of the difference between the amount of NH3 in the ammonia-containing feedstock and the amount of NH3 in the product recovered in step (d), divided by the amount of NH3 in the ammonia-containing feedstock, and multiplying this ratio by 100 to express it as a percentage.

[0076] For example, the ammonia decomposition reaction is carried out at a pressure in the range of 0.01 MPa to 10.0 MPa, preferably in the range of 0.1 MPa to 5.0 MPa.

[0077] In one embodiment, the process further comprises pre-heating the fluidized bed reactor with a gas stream prior to carrying out the ammonia decomposition reaction in the fluidized bed reactor. Preferably, the gas stream is an inert gas stream and / or has a temperature between 250° C. and 800° C. This embodiment is important when bed particles such as graphite and / or electrically resistive materials have such high resistivity at room temperature that electrical heating of the bed cannot be initiated.

[0078] For example, the ammonia decomposition reaction is carried out in the presence of a diluent stream, and the weight hourly space velocity of the reaction stream is 0.1 h -1 ~100h -1Preferably for 1.0 h -1 ~50h -1 Weight hourly space velocity is defined as the ratio of the mass flow rate of the reactant stream to the mass of solid particulate material in the fluidized bed.

[0079] The ammonia-containing feedstock for the process of the present invention is selected from ammonia-containing feedstocks provided by the Haber-Bosch process, any biological process for the production of ammonia, any electrochemical process for the production of ammonia, or any combination thereof.

[0080] Optionally, the ammonia-containing feedstock can be diluted with one or more diluent gases. When one or more diluent gases are present, they can be one or more selected from steam, hydrogen, carbon dioxide, argon, helium, nitrogen, and one or more hydrocarbons, such as methane. The one or more diluent gases can be, for example, one or more fluidizing gases. Preferably, the one or more diluent gases can be one or more selected from steam, hydrogen, carbon dioxide, nitrogen, and one or more hydrocarbons, such as methane. In one embodiment, the diluent gas is a mixture of at least steam and one or more hydrocarbons, such as methane. In this case, the synthesis gas is produced by endothermic steam reforming of hydrocarbons and the ammonia decomposition reaction with the production of hydrogen is carried out simultaneously. In another embodiment, the diluent gas is a mixture of at least carbon dioxide and one or more hydrocarbons, such as methane. In this case, the synthesis gas is produced by endothermic dry reforming of hydrocarbons and the ammonia decomposition reaction with the production of hydrogen is carried out simultaneously.

[0081] For example, in step (b) the particles of the bed are fluidized by passing a gas stream upwardly through the bed. Preferably the gas stream is or comprises an ammonia-containing feedstock.

[0082] In particular, the products obtained from the process of the present invention include hydrogen and / or nitrogen.

[0083] In a preferred embodiment, the outlet temperature of the reactor is in the range of 300 to 1100°C, preferably 350 to 1050°C, more preferably 400 to 1000°C, more preferably 450 to 950°C.

[0084] In a preferred embodiment, the residence time of the ammonia-containing feedstock in the fluidized bed section of the reactor, where the temperature is between 450 and 900° C., is in the range of 0.005 to 5.00 seconds, preferably 0.10 to 1.20 seconds.

[0085] For example, the step of heating the fluidized bed may be performed by passing an electric current through the fluidized bed, the voltage being at most 300V, preferably at most 200V, more preferably at most 150V, even more preferably at most 120V, most preferably at most 100V, and even most preferably at most 90V.

[0086] For example, the at least one fluidized bed reactor used in step a) comprises a heating zone and a reaction zone, and step c) of heating the fluidized bed comprises the following substeps: - heating the fluidized bed to a temperature in the range of 250°C to 1000°C by passing an electric current through the heating zone of at least one fluidized bed reactor; - transporting the heated particles from the heating zone to the reaction zone; - in a reaction zone, fluidizing the heated particles to form a fluidized bed by flowing a fluid stream comprising the ammonia-containing feedstock and any re-dilution gas upwardly through the bed in the reaction zone, thereby carrying out an ammonia decomposition reaction on the ammonia-containing feedstock; - Optionally, the particles are recovered from the reaction zone and recycled to the heating zone.

[0087] For example, the at least one fluidized bed reactor used in step a) comprises a heating zone and a reaction zone, and the step c) of heating the fluidized bed comprises the following substeps: - preheating the bed to a temperature of 250°C to 800°C by passing a fluidizing stream, which is a gas stream having a temperature of 250°C to 800°C, upward through the particles in the fluidized bed; - heating the fluidized bed to a temperature in the range of 250°C to 1000°C by passing an electric current through a heating zone of at least one fluidized bed reactor, - transporting the heated particles from the heating zone to the reaction zone; - carrying out an ammonia decomposition reaction on the ammonia-containing feedstock in a reaction zone by passing a fluid stream comprising the ammonia-containing feedstock and optional diluent gas upwardly through the bed in the reaction zone to fluidize the heated particles to form a fluidized bed; - Optionally, particles are recovered from the reaction zone and recycled to the heating zone.

[0088] Thus, preferably, the particles are preheated and / or heated in a preheating zone and / or heating zone prior to step c), so that at least one fluidized bed reactor used in step a) is equipped with a preheating zone, this preheating step being carried out by passing a gas stream upwards through the bed, the gas stream being fed to the preheating zone, the temperature of the gas stream used being in the range of 250°C to 800°C, and / or - at least one fluidized bed reactor used in step a) comprises a heating zone and a reaction zone, the heating zone being brought into a fluidized state by passing a gas stream having a temperature in the range of 250°C to 800°C upwards through the bed to cause the particles of the bed to flow, and the fluidized bed being heated to a temperature in the range of 250°C to 1000°C by passing an electric current through the heating zone.

[0089] The fluidizing stream can be a gas stream containing one or more diluents, for example, one or more inert gases.

[0090] For example, in step b), when a gas stream is passed upwardly through the bed to fluidize the particles in the bed, and the heating zone and the reaction zone are mixed (i.e., in the same zone), the gas stream (i.e., the fluidizing stream) can be or contain an ammonia-containing feedstock.

[0091] For example, in step b), the particles of the bed are fluidized by passing a gas stream upward through the bed, and if the heating zone and the reaction zone are separate zones, the gas stream (i.e., the fluidization stream) fed to the heating zone may be free of ammonia-containing feedstock. For example, in step b), the particles of the bed are fluidized by passing a gas stream upward through said bed, the process employs at least one fluidized bed reactor which is the heating zone and at least one fluidized bed reactor which is the reaction zone, and in step b), the gas stream provided to the heating zone is free of ammonia-containing feedstock and the gas stream provided to the reaction zone is or comprises the ammonia-containing feedstock.

[0092] It will be appreciated that an ammonia-containing feedstock is provided to the reaction zone, and that if the heating zone and reaction zone are separate, an ammonia-containing feedstock is not provided to the heating zone.

[0093] Simultaneous process of ammonia decomposition with hydrogen production and steam methane reforming to produce synthesis gas Advantageously, in step (c) endothermic steam reforming of hydrocarbons to produce synthesis gas is carried out simultaneously with the ammonia decomposition reaction with hydrogen production by selecting one or more of the following: - step (a) further comprises providing one or more hydrocarbons and water vapor; or - the ammonia-containing feedstock provided in step (a) comprises at least a diluent gas which is a mixture of water vapor and one or more hydrocarbons (e.g. methane).

[0094] Alternatively, one or more of the following are selected to carry out endothermic dry reforming of hydrocarbons to produce synthesis gas simultaneously with the ammonia decomposition reaction with hydrogen production in step (c): - step (a) further comprises providing one or more hydrocarbons and carbon dioxide; or - the ammonia-containing feedstock provided in step (a) comprises at least a diluent gas which is a mixture of carbon dioxide and one or more hydrocarbons (such as methane).

[0095] For example, the one or more hydrocarbons are part of the hydrocarbon-containing feedstock and / or the one or more hydrocarbons have one or more carbon atoms, such as methane or a mixture of light hydrocarbons containing 1-5 carbon atoms. Advantageously, the hydrocarbon-containing feedstock also includes carbon dioxide. The hydrocarbon-containing feedstock is preferably natural gas, biogas, or refinery gas, each of which may include varying amounts of carbon dioxide.

[0096] Preferably, the molar ratio of steam to carbon in the hydrocarbon-containing feedstock is in the range of 2.0-5.0 moles of steam per mole of carbon in the hydrocarbon feedstock, preferably 2.2-4.0, more preferably 2.5-3.0.

[0097] Advantageously, when step (d) is performed, the products include at least the product gas (e.g., a mixture of H2 and N2) and unreacted ammonia. When step (c) is performed to perform the ammonia decomposition reaction and steam reforming of hydrocarbons simultaneously, when step (d) is performed, the products further include carbon monoxide, carbon dioxide, unreacted hydrocarbons and unreacted steam.

[0098] In one embodiment, step (c) is carried out to carry out only the ammonia decomposition reaction accompanied by hydrogen production. In this case, the process further comprises step (j) of carrying out a combustion reaction on the products recovered in step (d), i.e. products comprising at least the formed gas and unreacted ammonia. Preferably, this step (j) is carried out immediately after step (d). Preferably, the combustion reaction is carried out at a temperature in the range of 1000° C. to 3000° C. This embodiment is preferably carried out when the conversion of the ammonia decomposition reaction is partial.

[0099] In another embodiment, the process further comprises step (e) of removing unreacted ammonia from the product recovered in step (d). This embodiment is preferably carried out when the conversion of the ammonia decomposition reaction is completed since unreacted ammonia occurs in the forming gas formed during decomposition in an amount of about 20 ppm to 100 ppm. Step (e) is preferably one or more steps selected from the following: - one step of washing the forming gas with an acid or alkaline solution, - one step of adsorbing the unreacted ammonia on an adsorbent which is one or more zeolites selected from zeolite 4A, zeolite 5A or zeolite 13X; One condensation step carried out at a pressure of -0.1 MPa to 15 MPa, preferably 1 MPa to 10 MPa, and at a temperature of -20°C to 20°C, preferably -15°C to 15°C.

[0100] When step (c) is carried out in order to carry out an endothermic steam reforming of hydrocarbons to produce synthesis gas or an endothermic dry reforming of hydrocarbons to produce synthesis gas simultaneously with an ammonia decomposition reaction with the production of hydrogen, the process of the invention advantageously further comprises, after step (e) of removing unreacted ammonia from the product recovered in step (d), the following step: f) Water gas shift (WGS) reaction of the carbon monoxide obtained in step (d) (CO+H2O <=> CO2+H2△Hー298= ― 41.09 kJ / mol) with steam to produce a stream comprising carbon dioxide, hydrogen, unreacted carbon monoxide and unreacted hydrocarbons; g) separating a CO2-rich stream comprising carbon dioxide, hydrogen, unreacted carbon monoxide and unreacted hydrocarbons from said stream to produce a CO2-lean stream comprising hydrogen, unreacted carbon monoxide and unreacted hydrocarbons, and separating from said CO2-lean stream a purified hydrogen stream and a purge stream comprising unrecovered hydrogen, unreacted carbon monoxide and unreacted hydrocarbons; i) Optionally, in step (a), recovering said O2-enriched stream, said purified hydrogen stream, and / or providing said purge stream comprising unrecovered hydrogen, unreacted carbon monoxide and unreacted hydrocarbons.

[0101] For example, step (f) is carried out in the presence of a water gas shift catalyst, preferably the water gas shift catalyst is selected from copper or iron based catalysts.

[0102] From a second aspect, the present invention provides an installation for carrying out at least an ammonia decomposition reaction and producing hydrogen according to the first aspect, comprising: i) a current-carrying fluidized bed unit having at least one fluidized bed reactor comprising: at least two electrodes, preferably one of which is a submerged central electrode or two of which are submerged electrodes, - a reaction vessel, - one or more fluid nozzles for introducing into at least one fluidized bed reactor an ammonia-containing feedstock and, optionally, one or more dilution gases; and - Bed containing particles ii) a separation unit and / or a combustion unit downstream of the current-carrying moving bed unit, and if both a separation unit and a combustion unit are present, the separation unit is downstream of the current-carrying moving bed unit and upstream of the combustion unit; iii) An optional current-carrying moving bed unit or water gas shift unit, if present, downstream of the separation unit. The equipment of the present invention is characterized in that the bed particles include conductive particles and particles of a catalyst composition, at least 10% by weight of the bed particles based on the total weight of the bed particles are conductive and have a resistivity in the range of 0.001 ohm·cm to 500 ohm·cm at a temperature of 800°C, and the catalyst composition includes one or more metal compounds.

[0103] Preferably, at least two of the electrodes comprise or are made of tantalum.

[0104] Advantageously, at least one fluidized bed reactor is devoid of heating means. For example, at least one fluidized bed reactor is devoid of heating means arranged around or inside the reaction vessel. For example, all fluidized bed reactors are devoid of heating means. When it is said that at least one fluidized bed reactor is devoid of "heating means", it refers to "classical" heating means such as ovens, gas burners, hot plates, etc. There are no heating means other than at least two electrodes on the fluidized bed reactor itself. For example, at least one fluidized bed reactor is devoid of heating means selected from ovens, gas burners, hot plates, or any combination thereof. For example, all fluidized bed reactors are devoid of heating means selected from ovens, gas burners, hot plates, or any combination thereof.

[0105] In a preferred embodiment, at least one fluidized bed reactor having at least two electrodes and a bed containing particles is free of structured packing such as honeycomb monoliths or crossed plates.

[0106] For example, the one or more dilution gases are used as one or more fluidization gases. Preferably, the one or more dilution gases are one or more selected from steam, hydrogen, carbon dioxide, argon, helium, nitrogen, and one or more hydrocarbons such as methane. More preferably, the one or more dilution gases are one or more selected from steam, hydrogen, carbon dioxide, nitrogen, and one or more hydrocarbons such as methane. In one embodiment, when the dilution gas is a mixture of at least steam and one or more hydrocarbons such as methane, the synthesis gas is produced by endothermic steam reforming of hydrocarbons and the ammonia decomposition reaction accompanied by the production of hydrogen is carried out simultaneously. In another embodiment, when the dilution gas is a mixture of at least carbon dioxide and one or more hydrocarbons such as methane, the synthesis gas is produced by endothermic dry reforming of hydrocarbons and the ammonia decomposition reaction accompanied by the production of hydrogen is carried out simultaneously.

[0107] For example, the internal diameter of at least one reaction vessel is at least 100 cm, preferably at least 200 cm, more preferably at least 300 cm.

[0108] Preferably, the reactor vessel comprises a reactor vessel wall made of a corrosion resistant material, advantageously the reactor vessel wall material comprises nickel (Ni), SiAION ceramic, yttria stabilized zirconia (YSZ), tetragonal polycrystalline zirconia (TZP) and / or tetragonal polycrystalline zirconia (TPZ).

[0109] Preferably, one of the electrodes is the reaction vessel or the gas distributor and / or at least two of the electrodes are made of a stainless steel material or a nickel-chromium alloy or a nickel-chromium-iron alloy.

[0110] For example, at least one fluidized bed reactor includes a heating zone, a reaction zone, one or more fluid nozzles that supply an ammonia-containing feedstock to the reaction zone, and, optionally, a means for transporting particles from the reaction zone to the heating zone.

[0111] For example, the present invention includes at least two fluidized bed reactors connected to each other, at least one of the at least two fluidized bed reactors being a heating zone and at least another of the at least two fluidized bed reactors being a reaction zone. Preferably, the present invention includes one or more fluid nozzles arranged to inject ammonia-containing feedstock into at least one fluidized bed reactor that is a reaction zone, and means for transporting particles from the heating zone to the reaction zone as required, and means for transporting particles from the reaction zone to the heating zone (optional). This configuration is noteworthy in that one particle bed is common to at least two fluidized bed reactors.

[0112] For example, at least one fluidized bed reactor is a single fluidized bed reactor, with a heating zone at the bottom of the fluidized bed reactor and a reaction zone at the top of the fluidized bed reactor. Preferably, the inventive system comprises one or more fluid nozzles for injecting ammonia-containing feedstock between the two zones. The diameters of the heating zone and the reaction zone may be different to achieve optimal conditions for heating in the bottom zone and optimal conditions for methane conversion in the top zone. Particles can move from the heating zone to the reaction zone by entrainment and vice versa by gravity from the reaction zone back to the heating zone. Optionally, particles can be collected from the top heating zone and transported back to the bottom heating zone by another transport line.

[0113] For example, at least one fluidized bed comprises at least two lateral zones, an outer zone and an inner zone, the outer zone surrounding the inner zone, the outer zone being the heating zone and the inner zone being the reaction zone. Less preferred is a configuration in which the outer zone is the reaction zone and the inner zone is the heating zone. Preferably, the system comprises one or more fluid nozzles for injecting the ammonia-containing feedstock into the reaction zone.

[0114] Advantageously, the installation further comprises a line fluidly connecting the current-carrying moving bed unit to the separation unit and / or the combustion unit, the installation further comprising a heat exchanger on the line.

[0115] Preferably, the separation unit is or comprises a pressure swing adsorption (PSA) unit and / or a scrubber and / or a condenser.

[0116] Preferably, the combustion unit is or comprises an oven and / or a furnace and / or a burner.

[0117] If there is a water gas shift (WGS) unit downstream of the current-flow moving bed unit or separation unit, the WGS unit comprises at least one water gas shift reactor for performing a water gas shift reaction on carbon monoxide, which is part of the synthesis gas, when the endothermic steam reforming or dry reforming of hydrocarbons reaction is performed simultaneously with the ammonia decomposition reaction with hydrogen production. Additional separation units can be present downstream of the WGS unit, for example a first additional separation unit for separating a CO2-rich stream from the effluent discharged from the WGS unit, and / or a second additional separation unit, preferably downstream of the first additional separation unit, for separating a purified hydrogen stream, the second additional separation unit preferably comprising a pressure swing adsorption (PSA) device. The second additional separation unit can also remove a purge stream comprising unrecovered hydrogen, unreacted carbon monoxide and unreacted hydrocarbons, and the inventive installation advantageously comprises a line for providing such a purge stream in step (a).

[0118] From a third aspect of the invention, the invention provides the use of a bed comprising particles for carrying out at least one ammonia decomposition reaction and hydrogen production according to the first aspect in at least one fluidized bed reactor, the use being notable in that the particles of the bed comprise electrically conductive particles and particles of a catalytic composition, at least 10% by weight of the particles of the bed relative to the total weight of the particles of the bed being electrically conductive and having a resistivity in the range of 0.001 ohm·cm to 500 ohm·cm at a temperature of 800°C, and the catalytic composition comprises one or more metal compounds.

[0119] For example, the use of the present invention includes heating a bed containing particles in a first reactor to a temperature in the range of 250°C to 1000°C, transporting the heated particle bed from the first reactor to a second reactor, and feeding an ammonia-containing feedstock to the second reactor. Preferably, at least the second reactor is a fluidized bed reactor, and / or at least the second reactor does not have a heating means. More preferably, the first reactor and the second reactor are fluidized bed reactors, and / or the first reactor and the second reactor do not have a heating means. For example, the second reactor does not have an electrode.

[0120] From a fourth aspect of the invention, the invention provides the use of an installation comprising at least one fluidized bed reactor, which is notable in that the installation is according to the second aspect, preferably comprising at least one fluidized bed reactor for carrying out at least one ammonia decomposition reaction to produce hydrogen in a process according to the first aspect.

[0121] It will be apparent to one of ordinary skill in the art from the above disclosure that the particular features, structures, characteristics or embodiments of the invention in one or more embodiments may be combined in any suitable manner. [Brief description of the drawings]

[0122] [Figure 1] FIG. 1 shows a prior art installation. [Diagram 2] FIG. 1 shows an installation of the invention with one reactor in which the heating zone and the reaction zone are the same. [Diagram 3] FIG. 1 shows an installation according to the invention with one reactor in which the heating zone and the reaction zone are arranged one above the other. [Figure 4] FIG. 1 shows an installation according to the invention with one reactor in which the heating zone and the reaction zone are arranged side by side. [Diagram 5] FIG. 1 shows an installation according to the invention with two reactors. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0123] For the purposes of the present invention, the following definitions are provided: As used herein, the terms "comprises," "having," and "comprising" are synonymous with "includes," "containing," or "contains," and are not inclusive or open-ended, and do not exclude additional, unrecited components, elements, or methods or steps. These terms "comprises" and "comprising" also include the meanings "comprises," "comprised of," and "consisting only of."

[0124] Recitation of numerical ranges by endpoints includes all integers and, where appropriate, fractions subsumed within the range (e.g., 1 to 5 includes 1, 2, 3, 4, 5, e.g., when referring to the number of elements, and also includes 1.5, 2, 2.75, 3.80, e.g., when referring to measurements). Recitation of endpoints also includes the recited endpoint values ​​themselves (e.g., 1.0 to 5.0 includes both 1.0 and 5.0). Recited numerical ranges also include all subranges subsumed therein.

[0125] The term "transition metal" refers to elements whose atoms have a partially filled d subshell or can form cations with an incomplete d subshell (IIIPAC definition). Transition metals by this definition are Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, La, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Ac, Rf, Db, Sg, Bh, Hs, Mt, Ds, Rg, and Cn.

[0126] Ga, In, Sn, Ti, Pb, and Bi are considered "post-transition" metals.

[0127] Au, Ag, Ru, Rh, Pd, Os, Ir, and Pt exhibit good oxidation resistance and are considered "noble" metals. The other metals can be considered "non-noble".

[0128] The term "alkali metal" refers to any element classified as being in Group 1 (or Group IA) of the Periodic Table of the Elements, excluding hydrogen. Alkali metals by this definition are Li, Na, K, Rb, Cs, and Fr.

[0129] The term "alkaline earth metals" refers to those elements classified as Group 2 (or Group IIA) elements of the Periodic Table of the Elements. The alkaline earth metals by this definition are Be, Mg, Ca, Sr, Ba, and Ra.

[0130] The term "rare earth elements" refers to the 15 lanthanides as well as scandium and yttrium. The 17 rare earth elements are cerium (Ce), dysprosium (Dy), erbium (Er), europium (Eu), gadolinium (Gd), holmium (Ho), lanthanum (La), lutetium (Lu), neodymium (Nd), praseodymium (Pr), promethium (Pm), samarium (Sm), scandium (Sc), terbium (Tb), thulium (Tm), ytterbium (Yb) and yttrium (Y).

[0131] The present invention relates to a method for producing a method for manufacturing a semiconductor device comprising the steps of: a) providing an ammonia-containing feedstock and at least one fluidized bed reactor comprising at least two electrodes and a bed comprising particles; b) fluidizing the particles in the bed, for example by passing a fluid stream upwardly through said bed to form a fluidized bed; c) heating the fluidized bed to a temperature in the range of 250°C to 1000°C to carry out an ammonia decomposition reaction on the ammonia-containing raw material; d) optionally recovering the reaction product; 1. A process for carrying out an ammonia decomposition reaction with the production of hydrogen comprising: The process is notable in that step c) of heating the fluidized bed is effected by passing an electric current through the fluidized bed; the particles of the bed comprise electrically conductive particles and particles of a catalyst composition, at least 10% by weight of the particles based on the total weight of the particles of the bed are electrically conductive and have a resistivity in the range of 0.001 ohm·cm to 500 ohm·cm at 800°C; and the catalyst composition comprises one or more metal compounds and a catalyst support, the catalyst support being electrically conductive particles.

[0132] Preferably, the catalyst composition comprises one or more metal compounds selected from: - one or more non-noble metals selected from Ni, Fe, Co, Mo, Cu and mixtures thereof; and / or - one or more precious metals selected from Ru, Rh, Pd, Ir, Pt and mixtures thereof; and / or one or more bimetallic compounds comprising a non-precious metal and a precious metal, where the non-precious metals are selected from Ni, Fe, Co, Mo and Cu, and the precious metals are selected from Ru, Rh, Pd, Ir and Pt.

[0133] For example, the ammonia-containing feedstock of the method of the present invention is selected from ammonia-containing feedstocks provided by the Haber-Bosch process, any biological process that produces ammonia, any electrochemical process that produces ammonia, or any combination thereof.

[0134] For example, the conductive particles of the bed are or comprise one or more selected from carbon-containing particles, metal alloys, non-metallic resistors, metal carbides, metal nitrides, metal phosphides, superionic conductors, phosphate electrolytes, mixed oxides doped with low valent cations, mixed sulfides doped with low valent cations and any mixtures thereof, preferably in a content of 50% to 100% by weight, preferably 60% to 100% by weight, more preferably 70% to 100% by weight, even more preferably 80% to 100% by weight, most preferably 90% to 100% by weight, based on the total weight of the conductive particles of the bed.

[0135] For example, the conductive particles of the bed are or include one or more selected from graphite, carbon black, one or more metal alloys, one or more non-metallic resistors, one or more metal carbides, one or more metal nitrides, one or more metal phosphides, one or more superionic conductors, one or more phosphate electrolytes, one or more mixed oxides doped with one or more low valent cations, one or more mixed sulfides doped with one or more low valent cations and any mixtures thereof, preferably in a content of 50% to 100% by weight, preferably 60% to 100% by weight, more preferably 70% to 100% by weight, even more preferably 80% to 100% by weight, and most preferably 90% to 100% by weight, based on the total weight of the conductive particles of the bed.

[0136] For example, the step of heating the fluidized bed is carried out by passing a current through the fluidized bed at a voltage of 300 V or less, preferably 200 V or less, more preferably 150 V or less, even more preferably 120 V or less, most preferably 100 V or less, and even most preferably 90 V or less.

[0137] The solid particulate material in a fluidized bed reactor is usually supported by a perforated plate, called a distributor, or a plate equipped with nozzles or chimneys. Fluid is forced up through the distributor and passes through the voids between the solid particulate material. At low fluid velocities, the solids remain settled while the fluid passes through the voids in the material. This is called a packed bed reactor. As the fluid velocity increases, the particulate solids reach a stage where the force of the fluid on the solids is sufficient to counterbalance the weight of the solid particulate material. This stage is called incipient fluidization and occurs at this minimum fluidization velocity. Above this minimum velocity, the contents of the reactor bed begin to expand and become fluidized. Various fluidization regimes are observed in such reactors depending on the operating conditions and the properties of the solid phase. The minimum fluidization velocity required for bed expansion depends on the size, shape, porosity, and density of the particles and the density and viscosity of the rising fluid.

[0138] In Non-Patent Document 1 (PR Gunjal, VV Ranade, "Industrial Catalytic Processes for Fine and Specialty Chemicals", 2016), Geldart distinguishes four different fluidization categories for average particles, which determine the fluidization regime: Type A, aerable fluidized (medium size, medium density particles that are easy to fluidize. Usually 30-100μm particles, density about 1500kg / m 3 ) Type B, sand-like fluidization (heavy particles that are difficult to fluidize. Usually particles of 100-800 μm, density 1500-4000 kg / m 3 ) Type C, agglomerated fluidization (fluidization of solid particles, typically powder-like, fine particles (approximately 20 μm) where intraparticle or cohesive forces predominate), and Type D, jettable fluidization (high density, large particles of about 1–4 mm, high density, jettable).

[0139] [Non-Patent Document 1] “Industrial Catalytic Processes for Fine and Specialty Chemicals” by PR Gunjal and VV Ranade (2016)

[0140] Fluidization can be broadly classified into two regimes: homogeneous and heterogeneous (Fluid Bed Technology in Materials Processing, 1999, CRC Press). In homogeneous or particulate fluidization, the particles are uniformly fluidized without any distinct voids. In heterogeneous or bubbling fluidization, gas bubbles without solids are clearly observable. These voids behave like bubbles in a gas-liquid flow, changing size and shape as they rise in the medium and exchange gas with the surrounding homogeneous medium. In particulate fluidization, the bed expands smoothly with large particle displacements and the bed surface is clearly defined. Particle fluidization is observed only with Geldart-A type particles. At a much higher rate than homogeneous fluidization, a bubbling fluidization state is observed. In this state, identifiable gas bubbles grow from the distributors, coalesce with other bubbles, and finally burst at the surface of the bed. These bubbles enhance the mixing of the solids and gas, and the size of the bubbles tends to become even larger with increasing fluidization rate. A slug condition is observed when the bubble diameter increases to that of the reactor. Under turbulent conditions, the bubbles grow and begin to break down as the bed expands. Under these conditions, the upper surface of the bed becomes indistinguishable. With fast or air fluidization, the particles are transported out of the bed and must be recycled back to the reactor. No distinct bed surface is observed. [Non-Patent Document 2] Fluid Bed Technology in Materials Processing, 1999, CRC Press

[0141] A fluidized bed reactor has the following advantages: Uniform particle mixing : In a fluidized bed, the solid particulate matter behaves essentially like a fluid, eliminating the poor mixing that occurs in packed beds. The elimination of radial and axial concentration gradients improves fluid-solid contact, which is essential for reaction efficiency and quality. Uniform temperature gradient : Many chemical reactions require the addition or removal of heat, and fluidized conditions avoid localized hot or cold spots within the reaction bed. Ability to operate reactors continuously : The fluidized bed characteristics of the reactor allow the product to be continuously removed and new reactants to be introduced into the reactor. In addition to the continuous operation of chemical reactions, the fluidized bed allows the solid material to be removed continuously or at a specific frequency, and new fresh solid material to be added continuously or at a specific frequency, since the solid material is a fluidizable solid particulate material.

[0142] Heat is produced by passing an electric current through a conductive material (resistor) that has a resistivity high enough to convert electricity into heat. Electrical resistivity (also called specific electrical resistance or volume resistivity; it is an intrinsic property independent of shape and size) and its reciprocal, conductivity, are fundamental properties of a material that quantify its ability to resist or conduct electric current (the SI units of electrical resistivity are the ohm-meter (Q m) and conductivity is the siemens per meter (S / m)).

[0143] When an electric current is passed through a fixed bed of conductive particulate solids with sufficient resistivity, the bed offers resistance to the flow of electric current. This resistance depends on many parameters, such as the type of solid, the nature of the bonds between the particles in the bed, the porosity of the bed, the height of the bed, and the shape of the electrodes. If the same fixed bed is fluidized by passing a gas through it, the resistance of the bed increases. The resistance offered by the conductive particles generates heat within the bed, allowing the bed to be kept isothermal (called an electrothermal fluidized bed or electrofluid reactor). For many high-temperature reactions, electrothermal fluidized beds are particularly useful for operating endothermic reactions, as they provide heat in situ during the reaction, saving energy by eliminating the need for external heating or heat transfer. A prerequisite is that at least a portion of the solid particle material is electrically conductive, but sufficient heat can be generated even when non-conductive solid particles are mixed. Such non-conductive or very highly resistive solids can act as catalysts in chemical transformations. Heat generation is of the charge-resistance type, and the inherent resistivity of the particles affects the bed resistance, so the properties of the bed material determine the resistance of the electrothermal fluidized bed reactor. The size, shape, composition and size distribution of the particles also affect the magnitude of the bed resistance. Also, when the bed is fluidized, voids appear between the particles, which increases the bed resistance. The total bed resistance is the sum of two components: the electrode contact resistance (i.e. the resistance between the electrode and the bed) and the bed resistance. A high contact resistance will result in widespread localized heating near the electrode while the rest of the bed will remain rather cold. This contact resistance is determined by factors such as the current density, the fluidization rate, the type of bed material, the size of the electrode and the type of material used for the electrode. Advantageously, the electrode composition is metal such as iron, cast iron, other steel alloys, copper, copper-based alloys, nickel, nickel-based alloys, refractory metals, intermetallic compounds or carbon-based such as alloys of Zr, Hf, V, Nb, Ta, Cr, Mo, W, ceramics, carbides, nitrides or graphite. The contact area between the fluidized bed material and the electrode can be adjusted depending on the submergence of the electrode and the amount of particulate material in the fluidized bed. It is therefore advantageous to be able to manipulate the electrical resistance and power levels by adjusting these variables.To prevent overheating of the electrodes compared to the fluidized bed, the electrodes should have a lower resistivity (and therefore lower Joule heating) than the particulate material of the fluidized bed. In a preferred embodiment, the electrodes can be cooled by passing a cooler fluid inside or outside the electrodes. Such a fluid can be any liquid that will evaporate in the heated gas stream, or it can be part of a cold feedstock that initially cools the electrodes before entering the fluidized bed.

[0144] Bed resistance can be predicted by Ohm's law . The mechanism of current transfer in fluidized beds is believed to occur at low operating voltages by current flow along continuous chains of conductive particles. At higher voltages, current transfer occurs by a combination of arcing between the conductive particle chains and the electrode and bed, and arcing between particles that may ionize the gas and lower the bed resistance. Arcing inside the bed reduces electrical and thermal efficiency and is therefore undesirable in principle. Gas velocity strongly influences bed resistance, with increasing gas flow rate the resistance increases sharply from a settled bed, reaching a maximum value near the initial fluidization velocity and then decreasing with increasing velocity. Resistance increases again at gas flow rates sufficient to initiate slugging. The average particle size and shape are important as they affect the resistance and thus the contact points between particles. In general, bed resistance increases 2-5 times from a settled bed (e.g., 20 ohm·cm for graphite) to initial fluidization (60 ohm·cm for graphite) and 10-40 times from a settled bed. Twice the initial fluidization velocity (300 ohm·cm for graphite). Nonconductive or less conductive particles can be added to the conductive particles. A low conductive solid fraction breaks the bonds in the chains of conductive solids between the electrodes, increasing the bed resistivity. Finer dimensions of the nonconductive solid components fill the gaps or voids of the larger conductive solids, increasing the bed resistivity.

[0145] Generally, low voltage and high current are desirable to obtain the required high heating power. The power supply can be either AC or DC. The voltage applied to an electrothermal fluidized bed to achieve sufficient heating power is usually less than 100V. An electrothermal fluidized bed can be controlled in three ways: 1.Gas flow adjustment: Since the electrical conductivity of the fluidized bed depends on the degree of voids or bubbles in the bed, changing the gas flow rate will change the power level. Therefore, the temperature can be controlled by adjusting the fluidization gas flow rate. The flow rate required for optimal performance corresponds to a velocity equal to or slightly greater than the minimum fluidization velocity. 2. Adjustment of electrode immersion depth: Since the conductivity of the fluidized bed depends on the contact area between the conductive particles and the electrodes, the power level can also be controlled by varying the immersion level of the electrodes in the fluidized bed: the surface area of ​​the electrode through which current flows increases with electrode immersion, decreasing the overall resistance. 3. Adjustment of applied voltage: Although it is often more affordable and economical to vary the power level using the two methods above rather than increasing the applied voltage, in an electrically heated fluidized bed three variables can be used to control the heating power produced:

[0146] The reactor walls are typically made of graphite, ceramics (e.g., SiC), or refractory metals or alloys, making them versatile and compatible with many high-temperature reactions of industrial importance. The reaction atmosphere is often restricted to neutral or reducing; an oxidizing atmosphere may result in combustion of carbon materials or the formation of a non-conducting metal oxide layer on the metal or alloy. The walls and / or distribution plate themselves act as the reactor electrodes. The fluidizing solid is graphite or other high-melting conductive particles. The electrodes are typically immersed in the bed and are graphite or refractory metals, intermetallics or alloys.

[0147] In the case where little or substantially no ammonia-containing feedstock is present and only a diluent gas (such as a fluidization gas) is present, it may be advantageous to heat the conductive particles and / or catalyst particles in a separate zone of the reactor to generate the required heat of reaction. The advantage then is that suitable fluidization conditions for heat generation can be optimized by passing an electric current through a bed of conductive particles, and optimal reaction conditions during hydrocarbon conversion can be selected for the other zones of the reactor. Optimal porosity and linear velocity conditions may be different for heating and chemical conversion purposes.

[0148] In one embodiment of the invention, the apparatus comprises two zones arranged in series, the first being a heating zone and the second being a reaction zone, and the conductive particles and catalyst particles are continuously moved or transported from the first zone to the second zone or vice versa. The first and second zones may be different parts of one fluidized bed or may be located in separate fluidized bed reactors connected to each other.

[0149] In the above embodiment, the process for carrying out an ammonia decomposition reaction with the production of hydrogen includes the following steps. a) providing at least one fluidized bed reactor containing an ammonia-containing feedstock and at least two electrodes and a bed containing particles; b) fluidizing the particles, for example by passing a fluid stream upwardly through said bed to form a fluidized bed; c) heating the fluidized bed to a temperature in the range of 250°C to 1000°C to carry out an ammonia decomposition reaction of the ammonia-containing raw material; d) optionally recovering the reaction product; The step c) of heating the fluidized bed is carried out by passing an electric current through the fluidized bed, the particles in the fluidized bed include conductive particles and particles of a catalyst composition, at least 10% by weight of the particles based on the total weight of the particles in the fluidized bed are conductive particles and have a resistivity in the range of 0.001 ohm·cm to 500 ohm·cm at 800°C, and the catalyst composition includes one or more metal compounds; The at least one fluidized bed reactor provided in step a) comprises a heating zone and a reaction zone, and step c) of heating the fluidized bed comprises the following substeps: - heating the fluidized bed to a temperature in the range of 250°C to 1000°C by passing an electric current through a heating zone of at least one fluidized bed reactor, - transporting the heated particles from the heating zone to the reaction zone; - carrying out an endothermic ammonia decomposition reaction on the ammonia-containing feedstock in a reaction zone by passing a fluid stream comprising the ammonia-containing feedstock and optionally one or more diluent gases upwardly through the bed in the reaction zone to fluidize the heated particles to form a fluidized bed; - Optionally, the particles are recovered from the reaction zone and recycled to the heating zone.

[0150] For example, the one or more dilution gases can be one or more selected from steam, hydrogen, carbon dioxide, argon, helium, nitrogen, and one or more hydrocarbons, such as methane. The one or more dilution gases are used, for example, as one or more fluidization gases. Preferably, one or more dilution gases are used, for example, as one or more fluidization gases. The dilution gas is one or more selected from steam, hydrogen, carbon dioxide, nitrogen, and one or more hydrocarbons, such as methane. In one embodiment, the dilution gas is a mixture of at least steam and one or more hydrocarbons, such as methane. In this case, the synthesis gas is produced by endothermic steam reforming of hydrocarbons and the ammonia decomposition reaction accompanied by the production of hydrogen is carried out simultaneously. In another embodiment, the dilution gas is a mixture of at least carbon dioxide and one or more hydrocarbons, such as methane. In this case, the synthesis gas is produced by endothermic dry reforming of hydrocarbons and the ammonia decomposition reaction accompanied by the production of hydrogen is carried out simultaneously.

[0151] For example, at least one fluidized bed reactor is connected to at least two fluidized bed reactors, at least one fluidized bed reactor being a heating zone and at least another fluidized bed reactor being a reaction zone. Preferably, at least one fluidized bed reactor being a heating zone is equipped with a gravity or pneumatic transport means for transporting particles from the heating zone to the reaction zone, and / or the inventive installation is equipped with a means configured to inject an ammonia-containing feedstock into at least one fluidized bed reactor being a reaction zone. In the inventive installation, there is no means for injecting an ammonia-containing feedstock into at least one fluidized bed reactor being a heating zone.

[0152] For example, the at least one fluidized bed reactor is a single fluidized bed reactor, the heating zone being at the bottom of the fluidized bed reactor and the reaction zone being at the top of the fluidized bed reactor. Preferably, the inventive system comprises means for injecting the ammonia-containing feedstock and any one or more dilution gases between the two zones. The diameters of the heating zone and the reaction zone may be different to achieve optimal conditions for heating in the lower zone and optimal conditions for hydrocarbon conversion in the upper zone. The particles may move from the heating zone to the reaction zone by entrainment and vice versa, by gravity from the reaction zone back to the heating zone. Optionally, the particles can be collected from the upper heating zone and transferred to the lower heating zone by a separate transfer line.

[0153] In step c), an ammonia decomposition reaction is carried out on an ammonia-containing feedstock. This means that an ammonia-containing feedstock is provided. It will be understood that if an ammonia-containing feedstock is provided to the reaction zone and the heating zone is separated from the reaction zone, preferably the ammonia-containing feedstock comprising at least two carbons is not provided to the heating zone. If the heating zone and the reaction zone are mixed (i.e. in the same zone), the fluid stream provided in step b) comprises an ammonia-containing feedstock.

[0154] Bed containing particles To achieve the temperatures required to carry out the ammonia decomposition reaction, at least 10% by weight of the particles, based on the total weight of the particles in the bed, must be electrically conductive, with a resistivity in the range of 0.001 ohm·cm to 500 ohm·cm at 800 °C.

[0155] For example, the conductive particles of the bed are or include one or more selected from one or more metal alloys, one or more non-metallic resistors, one or more metal carbides, one or more metal nitrides, one or more metal phosphides, one or more carbon-containing particles, one or more superionic conductors, one or more phosphate electrolytes, one or more mixed oxides doped with one or more low-valent cations, one or more mixed sulfides doped with one or more low-valent cations and any mixtures thereof, and preferably have a content of 50% to 100% by weight, preferably 60% to 100% by weight, more preferably 70% to 100% by weight, even more preferably 80% to 100% by weight, and most preferably 90% to 100% by weight, based on the total weight of the conductive particles of the bed.

[0156] For example, the conductive particles of the bed are one or more selected from one or more metal alloys, one or more non-metallic resistors, one or more metal carbides, one or more metal nitrides, one or more metal phosphides, graphite, carbon black, one or more superionic conductors, one or more phosphate electrolytes, one or more mixed oxides doped with one or more low valent cations, one or more mixed sulfides doped with one or more low valent cations, and any mixtures thereof, and are preferably present in an amount of 50% to 100% by weight, preferably 60% to 100% by weight, more preferably 70% to 100% by weight, even more preferably 80% to 100% by weight, and most preferably 90% to 100% by weight, based on the total weight of the conductive particles of the bed.

[0157] In one embodiment of the invention, the conductive particles of the bed comprise one or more carbon-containing particles that are graphite, preferably in a content of 10% to 100% by weight, or 10% to 90% by weight, or 10% to 80% by weight, preferably 15% to 70% by weight, more preferably 20% to 60% by weight, and even more preferably 30% to 50% by weight, based on the total weight of the conductive particles of the bed. For example, the conductive particles of the bed are a mixture of graphite and particles of a catalyst composition.

[0158] In one embodiment of the present invention, 50% to 100% by weight of the conductive particles in the bed do not contain graphite and / or carbon black, preferably 60% to 95% by weight, more preferably 70% to 90% by weight, and even more preferably 75% to 85% by weight of the conductive particles in the bed do not contain graphite and / or carbon black, based on the total weight of the conductive particles in the bed.

[0159] For example, the content of the conductive particles is in the range of 10% by weight to 100% by weight, preferably 15% by weight to 95% by weight, more preferably 20% by weight to 90% by weight, even more preferably 25% by weight to 80% by weight, and most preferably 30% by weight to 5% by weight, based on the total weight of the particles in the bed.

[0160] For example, the content of conductive particles relative to the total weight of the bed is at least 12% by weight, preferably at least 15% by weight, more preferably at least 20% by weight, even more preferably at least 25% by weight, and most preferably at least 30% by weight, or at least 40% by weight, or at least 50% by weight, or at least 60% by weight, relative to the total weight of the particles in the bed.

[0161] For example, the conductive particles have a resistivity in the range of 0.005 to 400 ohm·cm at 800°C, preferably in the range of 0.01 to 300 ohm·cm at 800°C, more preferably in the range of 0.05 to 150 ohm·cm at 800°C, and most preferably in the range of 0.1 to 100 ohm·cm at 800°C.

[0162] For example, the conductive particles have a resistivity of at least 0.005 ohm-cm at 800°C, preferably at least 0.01 ohm-cm at 800°C, more preferably at least 0.05 ohm-cm at 800°C, even more preferably at least 0.1 ohm-cm at 800°C, and most preferably at least 0.5 ohm-cm at 800°C.

[0163] For example, the conductive particles have a resistivity of at most 400 ohm·cm at 800°C, preferably at most 300 ohm·cm at 800°C, more preferably at most 200 ohm·cm at 800°C, even more preferably at most 150 ohm·cm at 800°C, and most preferably at most 100 ohm·cm at 800°C.

[0164] For example, the particles of the bed have an average particle size in the range of 5 to 300 μm, preferably in the range of 10 to 200 μm, more preferably in the range of 30 to 150 μm, as measured by sieving according to ASTM D4513-11.

[0165] For example, the conductive particles of the bed have an average particle size, as measured by sieving according to ASTM D4513-11, in the range of 5 to 300 μm, preferably in the range of 10 to 200 μm, and more preferably in the range of 30 to 150 μm.

[0166] Electrical resistance is measured by a four-probe DC method using an ohmmeter. The densified powder sample is formed into a cylindrical pellet and placed between the probe electrodes. The resistivity is determined from the measured resistance R by applying the known formula ρ=RxA / L, where L is the distance between the probe electrodes, usually a few millimeters, and A is the electrode area.

[0167] The conductive particles of the bed can exhibit electronic, ionic or mixed electronic-ionic conductivity. Ionic bonds in many sparingly soluble compounds allow ionic diffusion and, accordingly, ionic conduction occurs under the influence of an electric field and suitable temperature conditions.

[0168] The electrical conductivity σ, i.e. the proportionality constant between the current density j and the electric field E, is given by: σ=j / E=Σci x Ziq x μi (where ci is the carrier density (number / cm 3 ), μi is the mobility (cm 2 / Vs), Ziq is the charge of the ith charge carrier (q=1.6x10 -19 C) is

[0169] The large order of magnitude differences in σ between metals, semiconductors, and insulators are usually due to differences in c rather than μ, while electronic conductors have higher conductivity than ionic conductors because the mobility of electronic species is usually much higher than that of ionic species.

[0170] The most common materials available for resistance heating can be divided into nine groups: (1) Metal alloys that can withstand temperatures up to 1200-1400°C; (2) Non-metallic resistors such as silicon carbide (SiC), molybdenum disilicide (MoSi2), nickel silicide (NiSi), sodium silicide (Na2Si), magnesium silicide (Mg2Si), platinum silicide (PtSi), titanium silicide (TiSi2), and tungsten silicide (WSi2) up to 1600-1900°C; (3) mixed oxides and / or mixed sulfides doped with one or more low valent cations (temperature optima vary); (4) Graphite up to 2000°C; (5) Metal carbides, (6) metal nitrides, (7) metal phosphides, (8) superionic conductors, (9) Phosphate electrolyte.

[0171] The first group of metal alloys that can be used at temperatures up to 1150-1250 °C can consist of Ni-Cr alloys with low Fe content (0.5-2.0%), preferably Ni-Cr alloys (Ni 80%, Cr 20%) and (Ni 70%, Cr 30%). Increasing the Cr content improves the oxidation resistance of the material at high temperatures. The second group of metal alloys consisting of three components are Fe-Ni-Cr alloys or Fe-Cr-AI, the former have a maximum operating temperature of 1050-1150 °C in oxidizing atmospheres but can also be used in reducing atmospheres, and the latter (chemical composition 15-30% Cr, 2-6% Al, the rest Fe) can be used in oxidizing atmospheres up to 1300-1400 °C, protected from corrosion by a surface layer of Cr and Al oxides. Silicon carbide as a nonmetallic resistor can exhibit a wide range of resistivity, which can be controlled by the synthesis method and the presence of impurities such as aluminum, iron, oxides, nitrogen, excess carbon and silicon, resulting in non-stoichiometric silicon carbide. Generally, silicon carbide has high resistivity at low temperatures, but exhibits good resistivity in the range of 500-1200° C. In alternative embodiments, the non-metallic resistor does not include silicon carbide and / or can include molybdenum disilicide (MoSi2), nickel silicide (NiSi), sodium silicide (Na2Si), magnesium silicide (Mg2Si), platinum silicide (PtSi), titanium silicide (TiSi2), tungsten silicide (WSi2), or mixtures thereof.

[0172] Graphite has a relatively low resistivity and a negative temperature coefficient up to about 600°C, above which the resistivity begins to increase.

[0173] Many mixed oxides and / or mixed sulfides doped with one or more low-valent cations generally have too high resistivity at low temperatures but become ionic conductors or mixed conductors at high temperatures. In the following situations, the oxides or sulfides may become conductors sufficient for heating purposes. Ionic conduction in solids is explained by the generation and movement of atomic defects, especially vacancies and interstitial atoms, and their generation and mobility depend very positively on temperature. Such mixed oxides or sulfides are ionic conductors or mixed conductors, that is, doped with one or more low-valent cations. The following three mechanisms for the formation of ionic defects in oxides are known. (1) Thermally induced intrinsic ionic disorder (such as Schottky and Frenkel defect pairs, becoming non-stoichiometric), (2) Redox-induced defects, and (3) Impurity-induced defects. The defects in the first two categories are predicted from statistical thermodynamics, and the latter are formed to satisfy electrical neutrality. In the latter case, a high charge carrier density can be induced by replacing host cations with low-valent cations. Mixed oxides and / or mixed sulfides having a fluorite, pyrochlore or perovskite structure are very suitable for substitution by one or more low-valent cations.

[0174] Some lattice-disordered oxides or sulfides have high ionic transport capabilities upon temperature increase. These are superionic conductors such as LiAlSiO4, Li 10 GeP2S 12 , Li 3.6 Si 0.6 P 0.4 O4, NaSICON (sodium (Na) superionic conductor), etc., and the general formula is Na i+x Zr2P 3-x Si x Oi2, where 0 < x < 3, for example, Na3Zr2PSi2O 12 (x = 2), or sodium beta-alumina (NaAl 11 O 17 , Na 1.6 Al 11 O 17.3 , and / or, Na1.76 Li 0.38 Al 10.62 O 17 And so on.

[0175] A high concentration of ionic carriers can be induced in the essentially insulating solid, resulting in a highly defective solid, i.e. the conductive particles of the bed are or comprise ionic or mixed conductors, one or more mixed oxides doped with one or more low-valent cations, and / or ionic or mixed conductors, one or more mixed oxides doped with one or more low-valent cations, and / or ionic or mixed conductors, i.e. one or more mixed sulfides doped with one or more low-valent cations. Preferably, the mixed oxide is one or more oxides having a cubic fluorite structure at least partially substituted with one or more low-valent cations selected from Sm, Gd, Y, Sc, Yb, Mg, Ca, La, Dy, Er, Eu, and / or one or more ABOs perovskites having trivalent cations A and B at A-positions at least partially substituted with one or more low-valent cations selected from Ca, Sr or Mg and at B-positions containing at least one of Ni, Ga, Co, Cr, Mn, Sc, Fe and / or mixtures thereof, and / or one or more ABOs perovskites having trivalent cations A and B at B-positions at least partially substituted with one or more low-valent cations selected from Ca, Sr or Mg and at B-positions containing at least one of Ni, Ga, Co, Cr, Mn, Sc, Fe and / or mixtures thereof. one or more ABO3-perovskites having a divalent cation A and a tetravalent cation B, which are at least partially substituted in the A position with one or more low-valent cations, preferably selected from among g, Sc, Y, Nd or Yb, or also partially substituted in the B position with different mixtures of the B elements, and / or one or more A2B2O7-pyrochlores having a trivalent cation A and a tetravalent cation B, which are at least partially substituted in the A position with one or more low-valent cations, preferably selected from among Ca or Mg, and which include at least one of Sn, Zr and Ti in the B position.

[0176] Preferably, the one or more mixed sulfides are one or more sulfides having a cubic fluorite structure at least partially substituted with one or more low-valent cations selected from Sm, Gd, Y, Sc, Yb, Mg, Ca, La, Dy, Er, Eu, and / or one or more ABS3 structures with trivalent cations A and B at the A position at least partially substituted with one or more low-valent cations selected from Ca, Sr, or Mg, and at the B position containing at least one of Ni, Ga, Co, Cr, Mn, Sc, Fe, and / or mixtures thereof, and / or one or more ABS3 structures with trivalent cations A and B at the B position containing at least one of Mg, Sc, one or more ABS3 structures having a divalent cation A and a tetravalent cation B, at least partially substituted with one or more low-valent cations, preferably selected from Y, Nd or Yb, or at least partially substituted in the B position with a mixture different from the B element, and / or one or more A2B2S7 structures having a trivalent cation A and a tetravalent cation B, at least partially substituted in the A position with one or more low-valent cations, preferably selected from Ca or Mg, and at least one of Sn, Zr and Ti in the B position.

[0177] Preferably, the degree of substitution in the one or more mixed oxides having a cubic fluorite structure doped with one or more low-valent cations is 1 to 15 atomic %, preferably 3 to 12 atomic %, more preferably 5 to 10 atomic %, based on the total number of atoms present in the one or more oxides or sulfides having a cubic fluorite structure, one or more ABO3 perovskites having trivalent cations A and B, one or more ABO3 perovskites having divalent cation A and tetravalent cation B, or one or more A2B2O7 pyrochlores having trivalent cation A and tetravalent cation B.

[0178] Preferably, the degree of substitution in said mixed oxide(s) doped with said low valent cation(s) is / are 1-50 at. %, preferably 3-20 at. %, more preferably 5-15 at. %, based on the total number of atoms present in said ABO3 perovskites with trivalent cations A and B, said ABO3 perovskites with divalent cation A and tetravalent cation B or said A2B2O7 pyrochlore with trivalent cation A and tetravalent cation B, respectively.

[0179] Preferably, the degree of substitution in the one or more mixed sulfides having a cubic fluorite structure doped with one or more low-valent cations is 1 to 15 atomic %, preferably 3 to 12 atomic %, more preferably 5 to 10 atomic %, based on the total number of atoms present in one or more ABS3 structures having trivalent cations A and B, one or more ABS3 structures having divalent cation A and tetravalent cation B, or one or more A2B2S7 structures having trivalent cation A and tetravalent cation B.

[0180] Preferably, the degree of substitution in the mixed sulfide(s) doped with one or more low-valent cations is 1 to 50 atomic %, preferably 3 to 20 atomic %, more preferably 5 to 15 atomic %, based on the total number of atoms present in the ABS3 structure(s) with trivalent cations A and B, the ABS3 structure(s) with divalent cation A and tetravalent cation B or the A2B2S7 structure(s) with trivalent cation A and tetravalent cation B, respectively.

[0181] The one or more oxides have a cubic fluorite structure, one or more ABC3-perovskites having the trivalent cations A and B, one or more ABO3-perovskites having the divalent cation A and the tetravalent cation B, one or more A2B2O7-pyrochlores having the trivalent cation A and the tetravalent cation B at least partially substituted with a lower valent cation, one or more A2B2O7-pyrochlores having the cubic fluorite structure, one or more ABS3 structures having the trivalent cations A and B, one or more ABS3 structures having the divalent cation A and the tetravalent cation B, one or more A2B2S7 structures having the trivalent cation A and the tetravalent cation B at least partially substituted with a lower valent cation, This also means that Ti(IV) can be reduced to Ti(III), and / or Co(III) to Co(II), and / or Fe(III) to Fe(II), and / or Cu(II) to Cu(I).

[0182] Phosphate electrolytes, such as LiPO4 or LaPO4, can also be used as the conductive particles.

[0183] Metal carbides, metal nitrides and metal phosphides can also be selected as conductive particles. For example, the metal carbides can be selected from iron carbide (FesC), molybdenum carbide (e.g., a mixture of MoC and MO2C). For example, the one or more metal nitrides can be selected from zirconium nitride (ZrN), tungsten nitride (e.g., a mixture of W2N, WN and WN2), vanadium nitride (VN), tantalum nitride (TaN) and / or niobium nitride (NbN). For example, the one or more metal phosphides can be selected from copper phosphide (Cu3P), indium phosphide (InP), gallium phosphide (GaP), sodium phosphide (Na3P), aluminum phosphide (AlP), zinc phosphide (Zn3P2) and / or calcium phosphide (Ca3P2).

[0184] It is also a preferred embodiment of the invention that conductive particles that exhibit sufficiently low resistivity at high temperatures are heated by external means or mixed with a solid that has a sufficiently low resistivity at low temperatures before they reach a high enough temperature for electrical resistive heating to catch up, and the resistivity of the resulting mixture heats the fluidized bed to the desired reaction temperature.

[0185] For example, the conductive particles of the bed are or include silicon carbide, e.g., at least 10 weight percent of the conductive particles, based on the total weight of the conductive particles of the bed, are silicon carbide particles and have a resistivity in the range of .001 ohm·cm to 500 ohm·cm at 800°C.

[0186] In an embodiment in which the conductive particles of the bed are or comprise silicon carbide, the skilled person has the advantage that before carrying out the endothermic reaction in the fluidized bed reactor, a step of preheating the fluidized bed reactor with a gas stream can be carried out. Advantageously, this gas stream is a stream of an inert gas, i.e. nitrogen, argon, helium, methane, carbon dioxide, hydrogen or steam. The temperature of the gas stream can be at least 250°C or at least 300°C or at least 350°C or at least 400°C or at least 450°C or at least 500°C or at least 550°C or at least 600°C or at least 650°C or at least 700°C or at least 750°C or at least 800°C. Advantageously, the temperature of the gas stream can be between 250°C and 800°C, for example between 300°C and 750°C or between 350°C and 700°C. The above-mentioned gas stream of inert gas can also be used as a fluidizing gas. Preheating of the gas stream of inert gas is carried out by conventional means, including the use of electrical energy. The temperature of the gas stream used to preheat the bed does not have to reach the reaction temperature.

[0187] Because of the high resistivity of silicon carbide at ambient temperatures, it is useful to heat the fluidized bed by external means to facilitate initiation of the reaction, but preferably the fluidized bed reactor does not have a heating means. Once the bed is heated to the desired temperature, the use of hot gas streams is unnecessary.

[0188] However, in one embodiment, the conductive particles of the bed are or include a mixture of silicon carbide particles and conductive particles different from the silicon carbide particles.

[0189] The preheating step can also be used when conductive particles other than silicon carbide particles are present in the bed. For example, the preheating step can be used when the content of silicon carbide in the conductive particles of the bed is 80% by weight or more, such as 85% by weight or more, for example 90% by weight or more, for example 95% by weight or more, for example 98% by weight or more, for example 99% by weight or more, based on the total weight of the particles of the bed. However, the preheating step can be used regardless of the content of silicon carbide particles in the bed.

[0190] In embodiments in which the conductive particles of the bed are or include a mixture of silicon carbide particles and conductive particles different from silicon carbide particles, the conductive particles of the bed may comprise 10% to 99% by weight of silicon carbide particles, preferably 15% to 95% by weight, more preferably 20% to 90% by weight, even more preferably 25% to 80% by weight, and most preferably 30% to 75% by weight, based on the total weight of the conductive particles of the bed.

[0191] For example, the conductive particles of the bed may be or include a mixture of silicon carbide particles and conductive particles different from the silicon carbide particles, and the conductive particles of the bed may include at least 40% by weight of silicon carbide particles based on the total weight of the conductive particles of the bed, preferably at least 50% by weight, more preferably at least 60% by weight, even more preferably at least 70% by weight, and most preferably at least 80% by weight.

[0192] In one embodiment, the conductive particles of the bed may contain 10% to 90% by weight of conductive particles other than silicon carbide particles, preferably 15% to 95% by weight, more preferably 20% to 90% by weight, even more preferably 25% to 80% by weight, and most preferably 30% to 75% by weight, based on the total weight of the conductive particles of the bed.

[0193] However, it may be important to keep the content of conductive particles other than silicon carbide particles in the mixture very low.Thus, in one embodiment, the conductive particles of the bed are or comprise a mixture of silicon carbide particles and conductive particles other than silicon carbide particles, and the conductive particles of the bed comprise 1% to 20% by weight of conductive particles other than silicon carbide based on the total weight of the conductive particles of the bed, preferably 2% to 15% by weight, more preferably 3% to 10% by weight, even more preferably 4% to 8% by weight.

[0194] For example, the conductive particles of the bed may be or include a mixture of silicon carbide particles and particles other than silicon carbide particles, and the particles other than silicon carbide particles may be or include graphite particles.

[0195] Thus, in one embodiment, the conductive particles are a combination of silicon carbide particles and graphite particles. The conductive particles heat up when an electrical current is applied to the fluidized bed reactor, and contribute to increasing and / or maintaining the temperature within the reactor by fluidization. The Joule heating of the graphite can accelerate the heating of the reactants and / or other particles present in the fluidized bed reactor.

[0196] For example, the graphite can be flake graphite, the average particle size of which is preferably in the range of 1 to 400 μm, more preferably in the range of 5 to 300 μm, more preferably in the range of 10 to 200 μm, and most preferably in the range of 30 to 150 μm, as measured by sieving according to ASTM D4513-11.

[0197] The presence of graphite particles in the bed allows the process of the invention to be applied with or without a preheating step, preferably without a preheating step. In fact, the graphite particles heat up when the electric current is passed through the fluidized bed reactor and contribute to increasing and / or maintaining the desired temperature in the reactor by fluidization.

[0198] Silicon Carbide Particles For example, the silicon carbide may be selected from sintered silicon carbide, nitride bonded silicon carbide, recrystallized silicon carbide, reaction bonded silicon carbide, and mixtures thereof.

[0199] Sintered SiC (SSiC) is a self-bonding material that contains less than 1% by weight of a sintering aid, usually boron.

[0200] Recrystallized silicon carbide (RSiC) is a high-purity SiC material sintered by an evaporation-condensation process without any additives.

[0201] Nitride-bonded silicon carbide (NBSC) is made by adding fine silicon powder along with silicon carbide particles, and finally sintering in a nitrogen furnace in the presence of mineral additives. The silicon carbide is bonded by the silicon nitride phase (Si3N4) that forms during nitridation.

[0202] Reaction bonded silicon carbide (RBSC), also known as siliconized silicon carbide or SiSiC, is a type of silicon carbide produced by the chemical reaction of porous carbon or graphite with molten silicon. The silicon reacts with the carbon to form silicon carbide, bonding the silicon carbide particles together. The excess silicon fills the remaining pores in the body, producing a dense SiC-Si composite. Because traces of silicon remain, reaction bonded silicon carbide is often referred to as siliconized silicon carbide. This process is known by various names, including reaction bonding, reaction sintering, self-bonding or melt infiltration.

[0203] Generally, the resistivity of high-purity iC particles exceeds 1000 ohm cm, but sintered, reaction-bonded, and nitrided SiC ceramics can exhibit resistivities of about 100–1000 depending on the impurities in the SiC phase. The electrical resistivity of bulk polycrystalline SiC ceramics shows a wide range of resistivity depending on the sintering additives and heat treatment conditions (Non-Patent Document 3 (Journal of the European Ceramic Society, Vol. 35, No. 15, December 2015, p. 4137), Non-Patent Document 4 (Ceramics International, Vol. 46, No. 4, March 2020, p. 5454)). High-purity SiC polytypes have high band gap energy and therefore high electrical resistivity (>10 6Q.cm). However, the electrical resistivity of SiC is affected by doping impurities. N and P act as n-type dopants and reduce the resistivity of SiC, while Al, B, Ga, and Sc act as p-type dopants. SiC doped with Be, O, and V becomes highly insulating. N is considered the most efficient dopant to improve the electrical conductivity of SiC. For N-doping of SiC (to reduce resistivity), Y2O3 and Y2O3-REMO3 (REM = rare earth metals = Sm, Gd, Lu) are used as sintering additives to efficiently grow conductive SiC grains with N donors. N-doping of SiC grains is promoted by the addition of nitrides (AIN, BN, Si3N4, TiN, ZrN) or a combination of nitrides with Re2O3 (AIN-REM2O3 (REM = Sc, Nd, Eu, Gd, Ho, Er) or TiN-Y2O3). [Non-Patent Document 3] Journal of the European Ceramic Society, Volume 35, Issue 15, December 2015, Page 4137, [Non-Patent Document 4] Ceramics International, Volume 46, Issue 4, March 2020, Page 5454

[0204] catalyst composition For example, the content of the catalyst composition particles is in the range of 30% by weight to 100% by weight, preferably 32% by weight to 95% by weight, more preferably 35% by weight to 90% by weight, even more preferably 37% by weight to 85% by weight, most preferably 40% by weight to 80% by weight, and even most preferably 45% by weight to 75% by weight or 50% by weight to 70% by weight, based on the total weight of the particles in the bed. When the content of the catalyst composition particles is 100% by weight based on the total weight of the particles in the bed, the particles of the catalyst composition are also conductive particles.

[0205] For example, the particles of the catalyst composition have an average particle size in the range of 5 to 300 μm, preferably in the range of 10 to 200 μm, more preferably in the range of 20 to 200 μm or 30 to 150 μm, as measured by sieving according to ASTM D4513-11.

[0206] Measurement by sieving according to ASTM D4513-11 is recommended, and if the average particle size is less than 20 μm, the average size can also be measured by laser light scattering according to ASTM D4464-15.

[0207] The catalyst composition comprises one or more metal compounds. Preferably, the catalyst composition comprises one or more metal compounds selected from the following: one or more non-noble metals selected from Ni, Fe, Co, Mo, Cu and mixtures thereof; and / or one or more precious metals selected from Ru, Rh, Pd, Ir, Pt and mixtures thereof; and / or - one or more bimetallic compounds comprising a non-noble metal and a noble metal, where the non-noble metal is selected from Ni, Fe, Co, Mo and Cu, and the noble metal is selected from Ru, Rh, Pd, Ir and Pt.

[0208] For example, one or more non-noble metals selected from Ni, Fe, Co, Mo, Cu and mixtures thereof are present in an amount ranging from 0.05 wt.% to 20.00 wt.%, preferably from 0.10 wt.% to 15.00 wt.%, more preferably from 0.50 wt.% to 10.00 wt.%, and even more preferably from 1.00 wt.% to 5.00 wt.%, based on the total weight of the catalyst composition.

[0209] For example, the one or more non-noble metals is or includes Ni.

[0210] For example, one or more precious metals selected from Ru, Rh, Pd, Ir, Pt and mixtures thereof are present in an amount ranging from 0.05 wt % to 10.00 wt %, preferably from 0.10 wt % to 5.00 wt %, more preferably from 1.00 wt % to 3.00 wt %, and even more preferably from 1.50 wt % to 2.50 wt %, based on the total weight of the catalyst composition.

[0211] For example, the one or more precious metals preferably is or includes Ru in an amount ranging from 0.05 wt % to 10.00 wt %, based on the total weight of the catalyst composition.

[0212] Commercially available catalysts that can be used to carry out the ammonia decomposition reaction are ACTA Hypermec 10010 Ru catalyst, KATALCO® 27-2 series for high temperature decomposition (Johnson Matthey), KATALCO® 27-612 series for high temperature decomposition (Johnson Matthey), R-87 HEAT X® (Haldor Topsoe).

[0213] Advantageously, the catalyst composition further comprises one or more elements selected from one or more selected from alkali metals, alkaline earth metals and rare earth elements.For example, the one or more alkali metals are one or more selected from Li, Na, K, Cs and any mixture thereof.For example, the one or more alkaline earth metals are one or more selected from Mg and / or Ca.For example, the one or more rare earth elements are one or more selected from Ce, La, Sc, Y and mixtures thereof.

[0214] Preferably, the catalyst composition further comprises a catalyst support. Advantageously, the catalyst support is a conductive particle, preferably silicon carbide and / or graphite and / or carbon nanotubes, or alternatively a conductive particle different from silicon carbide. This allows an intimate contact between the catalytically active material and the conductive material.

[0215] Preferably, the catalyst composition further has a viscosity of 10 m as measured by N2 adsorption measurement. 2 / g~1000m 2 / g, more preferably 50m 2 / g~900m 2 / g, more preferably 100m 2 / g~800m 2 / g, most preferably 200m 2 / g~700m 2 / g.

[0216] equipment The terms "bottom" and "top" are to be understood in the general direction of the installation or fluidized bed reactor, i.e. "bottom" means closer to the ground than "top" along the vertical axis. The same reference numbers in different figures refer to the same or similar elements.

[0217] FIG. 1 shows a conventional fluidized bed reactor 1, which includes a reaction vessel 3, a bottom fluid nozzle 5 for introducing a fluidizing gas and feedstock, an optional inlet 7 for material input, an optional outlet 9 for material discharge, a gas outlet 11 and a bed 15. In the fluidized bed reactor 1 of FIG. 1, heat is provided by preheating the feedstock, for example by combustion of a fossil fuel, using heating means 17 located at the level of the lines supplying the fluidizing gas and ammonia-containing feedstock to the reactor.

[0218] The equipment of the present invention will now be described with reference to Figures 2 to 5. For simplicity, internal devices used in fluidized bed reactors known to those skilled in the art, such as bubble breakers, deflectors, particle termination devices, cyclones, ceramic wall coatings, thermocouples, etc., are not shown.

[0219] FIG. 2 shows a first installation with a fluidized bed reactor 19 with the same heating and reaction zones, which has a reaction vessel 3, a bottom fluid nozzle 21 for introducing a fluidizing gas and ammonia-containing feedstock and optionally one or more dilution gases, an optional inlet 7 for the input of materials, an optional outlet 9 for the discharge of materials and a gas outlet 11. The fluidized bed reactor 19 in FIG. 2 shows two electrodes 13 submerged in the bed 25.

[0220] FIG. 3 illustrates an embodiment in which at least one fluidized bed reactor 19 includes a heating zone 27 and a reaction zone 29, with the heating zone 27 being the bottom zone and the reaction zone 29 being on top of the heating zone 27. One or more fluid nozzles 23 deliver an ammonia-containing feedstock and optional one or more dilution gases from a distributor 33 to the reaction zone. As can be seen in FIG. 3, the one or more fluid nozzles 23 can be connected to the distributor 33 to distribute the ammonia-containing feedstock within the bed 25.

[0221] FIG. 4 shows an installation in which at least one fluidized bed reactor 18 has at least two zones in the lateral (radial) direction, an outer zone being a heating zone 27 and an inner zone being a reaction zone 29. The heated particles in the bed 25 are passed from the outer zone to the inner zone by one or more openings 41 and mixed with the ammonia-containing feedstock. At the end of the reaction zone the particles are separated from the reaction products and transferred to the heating zone.

[0222] FIG. 5 shows an installation in which at least two fluidized bed reactors (37, 39) are connected to each other, where at least one fluidized bed reactor is a heating zone 27 and at least one fluidized bed reactor is a reaction zone 29.

[0223] The present invention provides an equipment for use in a process for carrying out an ammonia decomposition reaction accompanied by the production of hydrogen. The equipment of the present invention includes the following i) to iii): i) a current-carrying fluidized bed unit with at least one fluidized bed reactor (18, 19, 37, 39), which unit comprises: - at least two electrodes 13, - reaction vessel 3, - one or more fluid nozzles (21, 23) for introducing an ammonia-containing feedstock and optionally one or more dilution gases into at least one fluidized bed reactor (18, 19, 37, 39); and - 25 beds containing particles, ii) a separation unit and / or a combustion unit, the separation unit or the combustion unit being downstream of said current-carrying moving bed unit, and if both a separation unit and a combustion unit are present, the separation unit being downstream of the current-carrying moving bed unit and upstream of the combustion unit; iii) optionally, a water gas shift unit downstream of the current-carrying moving bed unit or the separation unit; The bed particles include conductive particles and particles of a catalyst composition, at least 10 weight percent of the bed particles based on the total weight of the bed particles are conductive and have a resistivity in the range of 0.001 ohm·cm to 500 ohm·cm at 800°C, and the catalyst composition includes one or more metal compounds.

[0224] Preferably, at least two of the electrodes comprise or are made of tantalum.

[0225] For any chemical and / or physical process requiring heating, the required heat can potentially be obtained by burning hydrogen. However, the flame speed of hydrogen (which is the measured speed of the flame front in a combustion reaction) is generally fast. Flame speed is an important consideration in determining how fast a flame can move through a combustible mixture and subsequently disperse throughout the system. If it is desired to reduce the flame speed, the hydrogen to be burned can be diluted with one or more combustible components to form a mixture that favors a lower flame speed.

[0226] In the case of partial decomposition of ammonia, i.e. when the conversion of ammonia to forming gas is less than 50%, preferably in the range of 20%-50% or 20%-30%, a mixture of forming gas (i.e. N2+H2) and ammonia is burned in a combustion unit (preferably including an oven, furnace, burner or a combination thereof) downstream of the current-carrying moving bed unit. The flame speed of this mixture is slower than that of hydrogen but faster than that of ammonia. By carrying out partial decomposition, an ammonia / hydrogen mixture can be produced that has a flame speed higher than that of pure ammonia and slower than that of pure hydrogen. This allows for a more stable and controllable combustion.

[0227] In the case of complete cracking of ammonia, a separation unit, preferably comprising a pressure swing adsorption (PSA) device and / or a scrubber and / or a condenser, is provided downstream of the current-flowing moving bed unit to recover a purified hydrogen stream. In practice, the separation unit can remove unreacted ammonia present in the forming gas during cracking at about 20 ppm to 100 ppm. It is also possible to remove a nitrogen-containing purge stream in the separation unit, so that a purified hydrogen stream can be recovered.

[0228] When cracking ammonia to recover hydrogen for further use, it is necessary to remove as much unreacted ammonia as possible. If unreacted ammonia is still present, it can interfere with the chemical process when hydrogen is used. For example, a PSA unit contains one or more adsorbents that are one or more zeolites selected from Zeolite 4A, Zeolite 5A, or Zeolite 13X. For example, a scrubber uses an acidic and / or alkaline solution to remove the unreacted ammonia. The amount of unconverted ammonia in the product stream after passing through the separation unit falls to the range of 1 ppm to 3 ppm. To remove the ammonia, the mixture must be further cleaned up using a membrane or temperature swing adsorption (TSA) unit, depending on the desired application. This stream can then be conveyed to one or more storage tanks for further use.

[0229] For example, one electrode is a submerged central electrode, or alternatively, two electrodes 13 are submerged in the reaction vessel 3 of at least one reactor (18, 19, 37).

[0230] For example, the one or more diluent gases are one or more fluidizing gases selected from steam, hydrogen, carbon dioxide, argon, helium, nitrogen, and one or more hydrocarbons, such as methane. Preferably, the one or more diluent gases are one or more selected from steam, hydrogen, carbon dioxide, nitrogen, and one or more hydrocarbons, such as methane. In one embodiment, when the diluent gas is a mixture of at least steam and one or more hydrocarbons, such as methane, synthesis gas is produced by endothermic steam reforming of hydrocarbons simultaneously with the ammonia decomposition reaction accompanied by the production of hydrogen. In another embodiment, when the diluent gas is a mixture of at least carbon dioxide and one or more hydrocarbons, such as methane, synthesis gas is produced by endothermic dry reforming of hydrocarbons simultaneously with the ammonia decomposition reaction accompanied by the production of hydrogen.

[0231] In a preferred embodiment, at least one fluidized bed reactor (18, 19, 37, 39) is devoid of heating means. For example, at least one fluidized bed reactor is devoid of heating means selected from ovens, gas burners, hot plates or any combination thereof. For example, all fluidized bed reactors are devoid of heating means selected from ovens, gas burners, hot plates or any combination thereof. In a preferred embodiment, at least one fluidized bed reactor comprising at least two electrodes and a bed comprising particles is devoid of structured packing such as honeycomb monoliths or crossed plates.

[0232] For example, the inner diameter of the reaction vessel 3 is at least 100 cm, or at least 200 cm, or at least 400 cm. Such large diameters allow chemical reactions to be carried out on an industrial scale. For example, the weight hourly space velocity of the reaction flow is 0.1 h -1 ~100h -1 Preferably for 1.0 h -1 ~50h -1 The weight hourly space velocity is defined as the ratio of the mass flow rate of the reactant stream to the mass of the solid particulate matter in the fluidized bed.

[0233] At least one fluidized bed reactor (18, 19, 37) comprises at least two electrodes 13. For example, one electrode is electrically connected to the outer wall of the fluidized bed reactor and one additional electrode is submerged in the fluidized bed 25, or both electrodes 13 are submerged in the fluidized bed 25. The at least two electrodes 13 are electrically connected and can be connected to a power source (not shown). Advantageously, the at least two electrodes 13 are made of graphite. The skilled person will appreciate that the electrodes 13 have the advantage of being more electrically conductive than the particle bed 25.

[0234] For example, at least one electrode 13 is made of or includes graphite. Preferably, all or two electrodes 13 are made of graphite. For example, one of the electrodes is a reaction vessel, the reaction vessel comprising two electrodes, one of which is an immersed central electrode and the other of which is a reaction vessel 3.

[0235] For example, at least one fluidized bed reactor comprises at least one cooling device arranged to cool at least one electrode.

[0236] When using a fluidized bed reactor, a potential of up to 300V, preferably up to 250V, more preferably up to 200V, even more preferably up to 150V, most preferably up to 100V, and even most preferably up to 90V or up to 80V is applied.

[0237] Since the power of the current is adjustable, it is easy to adjust the temperature inside the reaction vessel.

[0238] The reaction vessel 3 may be made of graphite. In one embodiment, the reaction vessel 3 may be made of an electrically resistive material that is silicon carbide or a mixture of silicon carbide and graphite.

[0239] Preferably, the reactor vessel 3 comprises a reactor vessel wall made of a corrosion resistant material, advantageously the reactor vessel wall material comprises nickel (Ni), SiAION ceramic, yttria stabilized zirconia (YSZ), tetragonal polycrystalline zirconia (TZP) and / or tetragonal polycrystalline zirconia (TPZ). SiAION ceramic is a ceramic based on the elements silicon (Si), aluminum (Al), oxygen (O) and nitrogen (N). It is a solid solution of silicon nitride (Si3N4 with the Si-N bonds partially replaced by Al-N and Al-O bonds).

[0240] For example, the reaction vessel 3 is made of an electrically resistive material that is a mixture of silicon carbide and graphite. The electrically resistive material of the reaction vessel 3 contains 10% by weight to 99% by weight, preferably 15% by weight to 95% by weight, more preferably 20% by weight to 90% by weight, even more preferably 25% by weight to 80% by weight, and most preferably 30% by weight to 75% by weight of silicon carbide based on the total weight of the electrically resistive material.

[0241] For example, the reaction vessel 3 is made from an electrically resistive material that is a mixture of silicon carbide and graphite.

[0242] For example, the reaction vessel 3 is not conductive. For example, the reaction vessel 3 is made of ceramic.

[0243] For example, at least one fluidized bed reactor (18, 19, 37, 39) includes a heating zone 27 and a reaction zone 29, one or more fluid nozzles 21 for supplying a fluidizing gas from a distributor 31 to at least the heating zone, one or more fluid nozzles 23 for supplying an ammonia-containing feedstock and optional diluent gas(es) from a distributor 33 to the reaction zone, and optionally a means 41 for transporting particles from the heating zone 27 to the reaction zone 29 and an optional means 35 for transporting particles from the reaction zone 29 to the heating zone 27.

[0244] For example, as shown in FIG. 3, the at least one fluidized bed reactor is a single fluidized bed reactor 19, with a heating zone 27 at the bottom of the fluidized bed reactor 19 and a reaction zone 29 at the top of the fluidized bed reactor 19. Preferably, the installation comprises one or more fluid nozzles 23 for injecting ammonia-containing feedstock between the two zones (27, 29) or into the reaction zone 29. The fluidized bed reactor 19 further comprises an optional inlet 7 for the input of material, an optional outlet 9 for the discharge of material and a gas outlet 11. Preferably, the fluidized bed reactor 19 does not comprise a heating means. For example, the electrode 13 is located at the bottom of the fluidized bed reactor 19, i.e., in the heating zone 27. For example, there is no electrode at the top of the fluidized bed reactor 19, i.e., in the reaction zone 29. The fluidized bed reactor 19 comprises an optional means 35 for returning particles from the reaction zone 29 to the heating zone 27, for example, by using a line located between the top and bottom of the fluidized bed reactor 19.

[0245] For example, as shown in FIG. 4, the inventive installation comprises at least two transverse fluidized bed zones (27, 29) connected to each other, at least one fluidized bed zone 27 being a heating zone and at least one fluidized bed zone 29 being a reaction zone. For example, the heating zone 27 surrounds the reaction zone 29. Preferably, the installation comprises one or more fluid nozzles 23 arranged to inject the ammonia-containing feedstock and optionally one or more dilution gases into the at least one reaction zone 29 using a distributor 33. The fluidized bed zones (27, 29) further comprise an optional inlet 7 for material input and a gas outlet 11. Preferably, at least one fluidized bed zone, which is the heating zone 27, and / or at least one fluidized bed zone, which is the reaction zone 29, is devoid of heating means. For example, at least one fluidized bed zone, which is the reaction zone 29, is optionally equipped with an outlet 9 for material discharge. The one or more fluid nozzles 21 feed fluidizing gas from the distributor 31 to at least the heating zone. The heated particles are transported from the heating zone 27 to the reaction zone 29 by one or more inlet devices 41, and the separated particles are returned from the reaction zone 29 to the heating zone 27 by one or more means 35 including a downcomer. The fluidizing gas in the heating zone 27 can be one or more inert diluents selected from steam, hydrogen, carbon dioxide, methane, argon, helium, and nitrogen. In this configuration, the fluidizing gas in the heating zone can also include air or oxygen for burning coke deposited on the particles.

[0246] For example, as shown in FIG. 5, the facility of the present invention comprises at least two fluidized bed reactors (37, 39) connected to each other, of which at least one fluidized bed reactor 37 is the heating zone 27 and at least one fluidized bed reactor 39 is the reaction zone 29. Preferably, the facility comprises one or more fluid nozzles 23 arranged to inject the ammonia-containing feedstock and optional one or more dilution gases into the at least one fluidized bed reactor 39 that is the reaction zone 29. The fluidized bed reactors (37, 39) further comprise optional inlets 7 for material input and gas outlets 11. Preferably, at least one fluidized bed reactor 37 that is the heating zone 27 and / or at least one fluidized bed reactor 39 that is the reaction zone 29 does not have a heating means. For example, at least one fluidized bed reactor 39 that is the reaction zone 29 is provided with an outlet 9 for material discharge as required. The heated particles are transported from the heating zone 27 to the reaction zone 29 as required via inlet device 41, and particles separated after the reaction zone are returned from the reaction zone to the heating zone by device 35. The fluidizing gas in the heating zone can be one or more inert diluents selected from steam, hydrogen, carbon dioxide, argon, helium, nitrogen, one or more hydrocarbons such as methane. Preferably, the one or more diluents / fluidizing gases can be one or more diluents / fluidizing gases selected from steam, hydrogen, carbon dioxide, nitrogen and one or more hydrocarbons such as methane. In one embodiment, the diluent gas is a mixture of at least steam and one or more hydrocarbons such as methane, in which case the endothermic steam reforming of hydrocarbons to produce synthesis gas is carried out simultaneously with the ammonia decomposition reaction with the production of hydrogen. In this configuration, the fluidizing gas in the heating zone can include air or oxygen to combust coke deposited on the particles. In another embodiment, the diluent gas is a mixture of at least carbon dioxide and one or more hydrocarbons such as methane. In this case, the production of synthesis gas by endothermic dry reforming of hydrocarbons is carried out simultaneously with the ammonia decomposition reaction with accompanying hydrogen production.

[0247] For example, at least one fluidized bed reactor 37 that is a heating zone 27 includes at least two electrodes 13, while at least one fluidized bed reactor 39 that is a reaction zone 29 is devoid of electrodes.

[0248] For example, at least two fluidized bed reactors (37, 39) are connected to each other by suitable means 41, such as one or more lines, for transporting particles from the heating zone 27 to the reaction zone 29.

[0249] For example, at least two fluidized bed reactors (37, 39) are connected to each other by suitable means 35, such as one or more lines, for transporting particles from the reaction zone 29 to the heating zone 27.

[0250] Advantageously, the installation further comprises a line fluidly connecting the current-carrying moving bed unit to the separation unit and / or the combustion unit, and the installation further comprises a heat exchanger on the line, for example for use in cooling the forming gas before it enters the separation unit or for adjusting the temperature of the forming gas before it enters the combustion unit.

[0251] Ammonia decomposition reaction For example, the ammonia decomposition reaction is carried out at a temperature of 300°C to 950°C, preferably 350°C to 900°C, more preferably 400°C to 850°C, and most preferably 450°C to 800°C or 480°C to 950°C.

[0252] Advantageously, when the partial decomposition of ammonia, i.e. the conversion rate of ammonia to forming gas is less than 50%, preferably in the range of 20% to 50% or 20% to 30%, in order to smoothly combust the hydrogen produced, the partial decomposition of ammonia is carried out in one of the following cases: - the catalyst composition comprises one or more non-noble metals (e.g. Ni or supported Ni) and the temperature applied in step (c) is in the range of 250°C to 800°C, preferably in the range of 300°C to 750°C, more preferably in the range of 350°C to 700°C, even more preferably in the range of 400°C to 650°C, or - when the catalyst composition comprises one or more precious metals (e.g. Ru or supported Ru) and the temperature applied in step (c) is in the range of 250°C to 450°C, preferably in the range of 275°C to 425°C, more preferably in the range of 300°C to 400°C.

[0253] For example, the ammonia decomposition reaction is carried out at a pressure in the range of 0.01 MPa to 10.0 MPa, preferably 0.1 MPa to 5.0 MPa.

[0254] For example, the ammonia decomposition reaction is carried out in the presence of a reaction stream, and the weight hourly space velocity of the reaction stream is 0.1 h -1 ~100h -1 Preferably for 1.0 h -1 ~50h -1 It is carried out in a state between.

[0255] The residence time of the ammonia-containing feedstock in the fluidized bed zone of the reactor is advantageously in the range of 0.005 to 5.0 seconds, preferably 0.001 to 1.2 seconds, more preferably 0.01 to 1.0 seconds, even more preferably 0.1 to 0.6 seconds, or even 0.1 to 0.3 seconds, when the temperature is between 450 and 900° C.

[0256] Simultaneous process of ammonia decomposition with hydrogen production and steam methane reforming to produce synthesis gas Advantageously, when carrying out in step (c) an ammonia decomposition reaction with hydrogen production and simultaneously an endothermic steam reforming of hydrocarbons to produce synthesis gas, one or more of the following are selected: - providing in step (a) one or more hydrocarbons and water vapor, or - the ammonia-containing feedstock provided in step (a) comprises at least a diluent gas which is a mixture of water vapor and one or more hydrocarbons (e.g. methane).

[0257] Alternatively, when carrying out endothermic dry reforming of hydrocarbons to produce synthesis gas simultaneously with the ammonia decomposition reaction with hydrogen production in step (c), one or more of the following are selected: - providing in step (a) one or more hydrocarbons and carbon dioxide, or - the ammonia-containing feedstock provided in step (a) comprises at least a diluent gas which is a mixture of carbon dioxide and one or more hydrocarbons (such as methane).

[0258] For example, the one or more hydrocarbons are part of a hydrocarbon-containing feedstock and / or the one or more hydrocarbons have one or more carbon atoms, such as methane or a mixture of light hydrocarbons containing 1-5 carbon atoms. Advantageously, the hydrocarbon-containing feedstock also includes carbon dioxide. The hydrocarbon-containing feedstock is preferably natural gas, biogas or refinery gas, each of which may include varying amounts of carbon dioxide.

[0259] Preferably, the molar ratio of steam to carbon in the hydrocarbon-containing feedstock is in the range of 2.0-5.0 moles of steam per mole of carbon in the hydrocarbon feedstock, preferably 2.2-4.0, more preferably 2.5-3.0.

[0260] Advantageously, when step (d) is carried out, the products comprise at least forming gas (i.e. a mixture of H2 and N2) and unreacted ammonia. When step (c) comprises endothermic steam reforming of hydrocarbons to produce synthesis gas simultaneously with the ammonia decomposition reaction with production of hydrogen, when step (d) is carried out, the products further comprise carbon monoxide, carbon dioxide, unreacted hydrocarbons and unreacted water vapor.

[0261] In one embodiment, when step (c) is an ammonia decomposition reaction accompanied by hydrogen production, the process further comprises step (j) of performing a combustion reaction on the products recovered in step (d), i.e., products comprising at least forming gas and unreacted ammonia. Preferably, step (j) is performed immediately after step (d). This embodiment is preferably performed when the conversion of the ammonia decomposition reaction is partial.

[0262] In another embodiment, the process further comprises step (e) of removing unreacted ammonia from the product recovered in step (d). This embodiment is preferably carried out when the conversion of the ammonia decomposition reaction is partial. Preferably, said step (e) is one or more steps selected from the following: - one step of washing the formed gas with an acid or alkaline solution: - one step of adsorbing the unreacted ammonia with an adsorbent which is one or more zeolites selected from zeolite 4A, zeolite 5A or zeolite 13X; - one condensation step carried out at a pressure between 0.1 MPa and 15 MPa, preferably between 1 MPa and 10 MPa, and at a temperature between -20°C and 20°C, preferably between -15°C and 15°C.

[0263] When step (c) is carried out in order to carry out the endothermic steam reforming of hydrocarbons to produce synthesis gas or the endothermic dry reforming of hydrocarbons to produce synthesis gas simultaneously with the abovementioned ammonia decomposition reaction with the production of hydrogen, the process of the invention advantageously further comprises the following step, carried out after step (e) of removing unreacted ammonia from the product recovered in step (d): f) performing a water gas shift (WGS) reaction on the carbon monoxide obtained in step (d) using water steam (CO+H2O<=>CO2+H2△H298=-41.09 kJ / mol) to produce a stream containing carbon dioxide, hydrogen, unreacted carbon monoxide and unreacted hydrocarbons; g) separating the CO2-enriched stream from said stream containing carbon dioxide, hydrogen, unreacted carbon monoxide and unreacted hydrocarbons to produce a CO2-lean stream containing hydrogen, unreacted carbon monoxide and unreacted hydrocarbons; h) separating a purified hydrogen stream and a purge stream comprising unrecovered hydrogen, unreacted carbon monoxide, and unreacted hydrocarbons from said CO2-lean stream in a pressure swing adsorption (PSA) process; i) Optionally, recovering said CO2-enriched stream, said purified hydrogen stream, and / or providing said purge stream comprising unrecovered hydrogen, unreacted carbon monoxide and unreacted hydrocarbons in step (a).

[0264] It is advantageous to utilize the water gas shift reaction described in detail in the following [Non-Patent Document 5] and [Non-Patent Document 6]. [Non-Patent Document 5] ``The water-gas shift reaction: from conventional catalytic systems to Pd-based membrane reactors _ a review'' from Mendes D. et al. (Asia-Pacific J. Chem. Engineering, 2010, 5, 111-137) [Non-Patent Document 6] ``Performance of water-gas shift reaction catalysts: A review'' from Pal DB et al. (Renewable and Sustainable Energy Reviews, 2018, 93, 549-565)

[0265] For example, step (f) above is carried out in the presence of a water gas shift catalyst, preferably selected from copper or iron based catalysts.

[0266] The reaction is moderately exothermic and its equilibrium constant decreases with increasing temperature. The reaction is thermodynamically favored at low temperatures and kinetically favored at high temperatures and is insensitive to pressure changes. The WGS process can be operated at high temperatures and can be run at high temperature (HTS) or low temperature (LTS) or a combination of both depending on the desired amount of CO remaining in the product.

[0267] HTS catalysts, called ferrochrome catalysts, contain both iron and chromium and generally operate in the temperature range of 310°C to 450°C. The inlet temperature is kept as low as possible, about 350°C, to prevent excessive temperature rise in the reactor, and the maximum outlet temperature is kept at about 550°C. The typical composition of HTS catalysts is reported to be about 70-75% Fe2O3, about 5-15% Cr2O3, and some alkali or alkaline earth oxides. The Cr2O3 also acts as a stabilizer, preventing sintering of the Fe2O3. The outlet concentration of a conventional Fe / Cr HTS WGS reactor can be as low as 3% CO, which is the equilibrium concentration at 450°C.

[0268] The low temperature shift (LTS) reaction is carried out at 200-250 °C using a catalyst containing a mixture of CuO, ZnO, Cr2O3 and Al2O3. The typical composition of this catalyst is 20-75% ZnO, 15-35% CuO, 5-15% Cr2O3, 1-5% Mn, Al and the remainder magnesium oxide. The active species in this catalyst is copper metal crystallites. ZnO and Cr2O provide structural support for the catalyst, while Al2O3 is the carrier that provides surface area for dispersion and mechanical strength of the catalyst particles. WGS reactions are traditionally carried out in two- or three-stage catalytic converters to reduce the adiabatic temperature rise and improve steam management. The first stage is characterized by operating at a high temperature to speed up CO consumption and minimize the catalyst bed volume. Subsequent stages carry out the reaction at progressively lower temperatures to achieve higher conversions limited by the reaction equilibrium. Interstage cooling systems are used to run the subsequent WGS reactions at lower temperatures and to expedite the approach to equilibrium conversion.

[0269] The pressure of WGS varies from 1 to 6 MPa for HTS and from 1 to 4 MPa for LTS.

[0270] The above step (g) of separating a CO2-rich stream from said stream containing carbon dioxide, hydrogen, unreacted carbon monoxide and unreacted hydrocarbons is advantageously carried out by treating the stream containing carbon dioxide, hydrogen, unreacted carbon monoxide and unreacted hydrocarbons obtained in step (f) with a separation process for hydrogen production with CO2 capture, such as adsorption, absorption, membrane, cryogenic / low temperature process, see [Non-Patent Document 7]. [Non-Patent Document 7] ``Hydrogen production with CO2 capture'' from Voldsund M. et al. (International Journal of Hydrogen Energy, 2016, 4969-4992)

[0271] The hydrogen purification technology currently most commonly used to obtain very pure hydrogen is Pressure Swing Adsorption (PSA), see [8]. [Non-Patent Document 8] Pressure swing adsorption technology for hydrogen production, K. Liu, C. Song, V. Subramani (Eds.), Hydrogen and syngas production and purification technologies (2010), p. 414

[0272] In a PSA unit, synthesis gas is pumped at high pressure into an adsorbent column where impurities are adsorbed and hydrogen passes through largely unadsorbed. When the adsorbent becomes saturated, it is regenerated by lowering the pressure and purging. Common adsorbents include silica gel, alumina, activated carbon, and zeolites, which have different relative strengths of adsorption for each component. PSA units are typically run at ambient temperature (lower temperatures promote adsorption) and at a feed pressure of 2-6 MPa. Hydrogen product is produced at a pressure slightly lower than the feed pressure by pressure drop, and PSA off-gas is delivered at low pressure (usually 0.1-0.3 MPa). In standard plants without CO2 capture, CO2-rich off-gas is often used as fuel because it contains combustible components. Such CO2-rich off-gas is not suitable for CO2 transport and storage.

[0273] Adsorption using CO2-selective adsorbents can be used to capture and purify CO2 from other gases. See [9]. The process consists of two purification steps, first a carbon-based adsorbent bed to selectively remove wet CO2, then a zeolite-based adsorbent bed to remove CH4, CO, N2 and residual CO2 from the hydrogen. Optionally, the first pressure swing adsorption is a vacuum swing adsorption unit (VSA), which captures wet CO2 between the existing SMR and PSA units. The majority of the CO2 (>90%) is captured from the syngas (after compression and drying) at a purity of >97%. [Non-Patent Document 9] Sep Sci Technol, 35 (5) (2000), pp. 667; CO2 capture from SMRs: a demonstration project Hydrocarbon Process (September) (2012), pp. 63)

[0274] Gas separation by absorption is achieved by contacting the gas with a liquid solvent in which the acid gases are dissolved in a scrubber column. The rich solvent is sent to a regeneration / stripping column where it is heated and / or reduced pressure to produce an overhead stream containing the desorbed components and an overhead stream containing lean solvent, the latter of which is sent back to the scrubber column. Liquid solvents can be divided into chemical and physical solvents. Chemical solvents react with CO2 (CO2 is a weak acid and reacts with bases) and require significant heat for regeneration, but the reaction rate is fast, which allows for smaller plant size. Common chemical solvents are aqueous solutions of amines such as MEA, TEA, MDEA, etc. or hot potassium carbonate (e.g. Benfield process). Physical solvents dissolve CO2 and are regenerated by reduced pressure and / or increased temperature, so they require less heat than chemical solvents. Common technologies using physical solvents are the Rectisol®, Selexol® and Purisol® technologies.

[0275] The absorption capacity of chemical solvents increases with decreasing partial pressure of CO2. The absorption capacity of physical solvents is lower than that of chemical solvents at low partial pressure of CO2, but increases linearly with the partial pressure of CO2 according to Henry's law. Therefore, chemical solvents are suitable when the partial pressure of CO2 is low, and physical solvents are suitable when the partial pressure of CO2 is high.

[0276] Membranes are selective barriers that allow some components to pass more easily than others (the feed component that passes through the membrane is called the permeate, the component that does not pass through is called the retentate). Transport of molecules across a membrane is driven by the partial pressure difference across the membrane.

[0277] Both hydrogen-selective and CO2-selective membranes can be used for hydrogen production with CO2 capture. Hydrogen-selective membranes produce a permeate consisting of pure hydrogen at low pressure and a retentate consisting of impure CO2 at high pressure. Typically, CO2-selective membranes produce a CO2-rich permeate at low pressure and a CO2-poor retentate at high pressure. Hydrogen-selective membranes operating at low temperatures below 100 °C are polymeric membranes and are used for hydrogen capture from low-temperature process streams. High-temperature hydrogen-selective membranes can be classified as metallic membranes (300-700 °C), microporous ceramic membranes (200-600 °C), porous carbon membranes (500-900 °C), and dense ceramic membranes (600-900 °C). They can operate at high temperatures, making them suitable for steam reforming / water gas shift processes. A variety of CO2 membranes exist and include several types, including polymeric CO2-selective membranes based on solution-diffusion mechanisms (which must dominate over diffusion) or facilitated transport mechanisms, mixed-matrix membranes consisting of inorganic particles uniformly dispersed in a polymer matrix, and porous inorganic membranes that selectively separate CO2 by surface diffusion or capillary condensation.

[0278] In cryogenic or low-temperature separation, gases are cooled to separate the various chemical components using the difference in boiling points. In hydrogen separation, the gas mixture is cooled to cryogenic temperatures (<150°C). The polluting gases are condensed at various temperature levels, while the hydrogen remains in the gas phase. In CO2 separation, the gas mixture is cooled below the boiling point of CO2 at a given pressure (above the triple point of CO2 at 5.2 bar and -56.6°C), causing the CO2 to condense out of the lighter gases. The advantage of cryogenic separation is that the captured CO2 is in a liquid state and can be pressurized for pumping at low energy cost.

[0279] Step (h) above is the separation of the hydrogen stream purified from the CO2-lean stream in a pressure swing adsorption (PSA) process from a purge stream containing unrecovered hydrogen, unreacted carbon monoxide and unreacted hydrocarbons. In this PSA unit, the gas is pumped at high pressure to an adsorbent column where impurities are adsorbed and most of the hydrogen passes through unadsorbed. When the adsorbent becomes saturated, it is regenerated by reducing the pressure and purging. Typical adsorbents include silica gel, alumina, activated carbon and zeolites, which have different relative adsorption strengths for each component. Typically, PSA units are operated at ambient temperature (lower temperatures promote adsorption) and at a feed pressure of 2-6 MPa. Hydrogen product is produced at a pressure slightly lower than the feed pressure due to pressure reduction, and the PSA off-gas is typically fed at a low pressure of 0.1-0.3 MPa.

[0280] The process may further include feeding the product stream comprising hydrogen to an upgrading unit, where an upgraded hydrogen stream and an off-gas stream are separated. The upgrading unit may be arranged such that the off-gas stream is recycled and mixed with the feed gas before passing through the structured catalyst. The upgrading unit may include a pressure swing adsorption unit (PSA), a temperature swing adsorption unit (TSA) or a membrane or combination thereof. A PSA or TSA configuration separates hydrogen as a high pressure stream leaving the upgrading unit, while the off-gas is at low pressure, which is the preferred solution. In a preferred embodiment, the upgrading unit is configured to produce an upgraded stream of substantially pure H2 and an off-gas of substantially pure N2. In one aspect, the process may further include feeding the upgraded hydrogen stream from the upgrading unit to a downstream power production plant. In one embodiment, the power production plant may be a solid oxide fuel cell or gas engine plant. This allows the technology to be used in energy storage when using ammonia as an energy vector.

[0281] Test and Measurement Methods Nitrogen adsorption / desorption isotherms were measured using N2 adsorption analysis using a Micrometrics ASAP 2020 volumetric adsorption analyzer. Dried samples were degassed overnight at 523 K (249.85 °C) under vacuum prior to measurement. The specific surface area of ​​the catalyst composition was calculated from this measurement.

Claims

1. The following steps: a) providing an ammonia-containing feedstock and at least one fluidized bed reactor (18, 19, 37, 39) containing at least two electrodes (13) and a bed containing particles; b) fluidizing the particles of said bed to obtain a fluidized bed (25); c) heating the fluidized bed (25) to a temperature in the range of 250° C. to 1000° C. to carry out the ammonia decomposition reaction of the ammonia-containing feedstock; d) optionally recovering the reaction product; 1. A method for carrying out an ammonia decomposition reaction to produce hydrogen comprising:

1. The method of claim 1, wherein the step c) of heating the fluidized bed (25) is carried out by passing an electric current through the fluidized bed (25), and wherein the particles of the fluidized bed (25) comprise electrically conductive particles and particles of a catalyst composition, at least 10% by weight of said particles, based on the total weight of the particles of the fluidized bed (25), are electrically conductive particles and have a resistivity in the range of 0.001 ohm-cm to 500 ohm-cm at 800° C., and wherein said catalyst composition comprises one or more metal compounds and a catalyst support, said catalyst support being electrically conductive particles.

2. 2. The method of claim 1, wherein the conductive particles of the fluidized bed (25) comprise one or more selected from one or more metal alloys, one or more non-metallic resistors, one or more metal carbides, one or more metal nitrides, one or more metal phosphides, one or more carbon-containing particles, one or more superionic conductors, one or more phosphate electrolytes, one or more mixed oxides doped with one or more low-valent cations, one or more mixed sulfides doped with one or more low-valent cations, and / or any mixture thereof.

3. 3. The method according to claim 1 or 2, characterized in that the conductive particles of the fluidized bed (25) comprise one or more carbon-containing particles with a graphite content of 10% by weight to 100% by weight relative to the total weight of the conductive particles of the fluidized bed.

4. 3. The method according to claim 1 or 2, characterized in that the conductive particles of the fluidized bed do not contain graphite and / or carbon black.

5. 5. The method according to claim 1, wherein the conductive particles of the fluidized bed (25) comprise one or more non-metallic resistive elements selected from silicon carbide, molybdenum disilicide or mixtures thereof.

6. 6. The method according to claim 1, wherein the conductive particles of the fluidized bed (25) comprise a mixture of non-metallic resistors which are silicon carbide and conductive particles different from silicon carbide.

7. 7. The method of claim 6, wherein the conductive particles of the fluidized bed comprise between 10% and 100% by weight of silicon carbide based on the total weight of the conductive particles of the fluidized bed (25).

8. 8. The method according to claim 6 or 7, characterized in that the conductive particles different from silicon carbide are one or more carbon-containing particles and / or one or more mixed oxides doped with one or more low-valent cations and / or one or more mixed sulfides doped with one or more low-valent cations.

9. 9. The method according to any one of the preceding claims, characterized in that the conductive particles of the fluidized bed (25) comprise one or more mixed oxides doped with one or more low-valent cations.

10. 10. The method according to claim 9, characterized in that the mixed oxide is selected from the following: one or more oxides having a cubic fluorite structure at least partially substituted with one or more low-valent cations, preferably selected from Sm, Gd, Y, Sc, Yb, Mg, Ca, La, Dy, Er, Eu, and / or one or more ABOs with trivalent cations A and B, in which the A positions are at least partially substituted with one or more low-valent cations, preferably selected from Ca, Sr or Mg, and the B positions contain at least one of Ni, Ga, Co, Cr, Mn, Sc, Fe and / or mixtures thereof; 3 - Perovskites, and / or - one or more ABOs having a divalent cation A and a tetravalent cation B, in which the B positions are at least partially replaced by one or more low-valent cations, preferably selected from Mg, Sc, Y, Nd or Yb, or the B positions are at least partially replaced by a mixture of different B elements; 3 Perovskite, and / or one or more AaBaOs having a trivalent cation A and a tetravalent cation B, the A positions of which are at least partially substituted with one or more low-valent cations, preferably selected from Ca or Mg, and the B positions of which contain at least one of Sn, Zr and Ti; 7 - Pyrochlore.

11. 11. The method according to claim 1, wherein the conductive particles of the fluidized bed (25) comprise one or more metal alloys and / or one or more superionic conductors.

12. The conductive particles in the fluidized bed (25) are LiAlSiO 4 , Li 10 GeP 2 S 12 , Li 3.6 S 0.6 P 0.4 O 4 12. The method according to claim 1, further comprising one or more superionic conductors selected from among sodium superionic conductor, sodium beta alumina or sodium beta alumina.

13. 13. The method according to any one of claims 1 to 12, characterized in that in step (b) the particles of the fluidized bed (25) are brought into a fluidized state by passing a gas stream upwardly through the bed, the gas stream being or comprising an ammonia-containing feedstock and / or comprising preheating the fluidized bed reactor (18, 19, 37, 39) with the gas stream prior to carrying out the ammonia decomposition reaction therein.

14. 14. The method of claim 13, wherein the gas flow is an inert gas flow.

15. 15. The method according to claim 13 or 14, wherein the temperature of the gas stream is between 250°C and 800°C.

16. 16. The method according to any one of claims 1 to 15, wherein the catalyst composition comprises one or more of the following: one or more non-noble metals selected from Ni, Fe, Co, Mo, Cu and mixtures thereof; and / or one or more precious metals selected from Ru, Rh, Pd, Ir, Pt and mixtures thereof; and / or - one or more bimetallic compounds comprising a non-noble metal and a precious metal, the non-noble metal being selected from Ni, Fe, Co, Mo and Cu, and the precious metal being selected from Ru, Rh, Pd, Ir and Pt.

17. 17. The method according to any one of claims 1 to 16, characterized in that the at least one fluidized bed reactor (18, 19, 37, 39) provided in step a) comprises a heating zone (27) and a reaction zone (29), and the step c) of heating the fluidized bed (25) comprises the following substeps: - heating the fluidized bed (25) to a temperature in the range of 250°C to 1000°C by passing an electric current through a heating zone (27) of at least one fluidized bed reactor (18, 19, 37, 39); - transporting the heated particles from the heating zone (27) to the reaction zone (29); in a reaction zone (29), passing a fluid stream comprising the ammonia-containing feedstock upwardly through the fluidized bed (25) in the reaction zone (29) to fluidize the heated particles to form a fluidized bed (25) and carry out an ammonia decomposition reaction on the ammonia-containing feedstock; - Optionally, recover the particles from the reaction zone (29) and recycle them to the heating zone (27).

18. 18. The method according to any one of claims 1 to 17, characterized in that the at least one fluidized bed reactor (18, 19, 37, 39) provided in step a) comprises a heating zone (27) and a reaction zone (29), and the step c) of heating the fluidized bed (25) comprises the following substeps: - passing a fluidized stream, which is a gas stream at between 250°C and 800°C, upwardly through the particles (25) of the fluidized bed (25) to preheat the fluidized bed (25) to a temperature of between 250°C and 800°C; - heating the fluidized bed (25) to a temperature in the range of 250°C to 1000°C by passing an electric current through a heating zone (27) of at least one fluidized bed reactor (18, 19, 37, 39); - transporting the heated particles from the heating zone (27) to the reaction zone (29); - in a reaction zone (29), passing a fluid stream comprising the ammonia-containing feedstock upwardly through the fluidized bed (25) of the reaction zone (29) to fluidize the heated particles to form a fluidized bed (25) and carry out an ammonia decomposition reaction on the ammonia-containing feedstock; - Optionally, the particles are recovered from the reaction zone (29) and recycled to the heating zone (27).

19. 19. The method according to any one of claims 1 to 18, wherein step (a) further comprises providing one or more hydrocarbons and steam, and step (c) comprises endothermic steam reforming of hydrocarbons or dry reforming of hydrocarbons to produce synthesis gas, simultaneously with an ammonia decomposition reaction with production of hydrogen.

20. 20. The method according to any one of claims 1 to 19, characterized in that the ammonia-containing feedstock provided in step (a) comprises a diluent gas which is a mixture of at least steam and one or more hydrocarbons, and in step (c), an endothermic steam reforming of a hydrocarbon or a dry reforming of a hydrocarbon is carried out simultaneously with an ammonia decomposition reaction with production of hydrogen to produce a synthesis gas, preferably the hydrocarbon is methane.

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