Classifications

• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
  • C25B1/00—Electrolytic production of inorganic compounds or non-metals
  • C25B1/01—Products
  • C25B1/02—Hydrogen or oxygen
  • C25B1/04—Hydrogen or oxygen by electrolysis of water
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
  • B01D53/32—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by electrical effects other than those provided for in group B01D61/00
  • B01D53/326—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by electrical effects other than those provided for in group B01D61/00 in electrochemical cells
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G45/00—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds
  • C10G45/44—Hydrogenation of the aromatic hydrocarbons
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G47/00—Cracking of hydrocarbon oils, in the presence of hydrogen or hydrogen- generating compounds, to obtain lower boiling fractions
  • C10G47/22—Non-catalytic cracking in the presence of hydrogen
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G49/00—Treatment of hydrocarbon oils, in the presence of hydrogen or hydrogen-generating compounds, not provided for in a single one of groups C10G45/02, C10G45/32, C10G45/44, C10G45/58 or C10G47/00
  • C10G49/007—Treatment of hydrocarbon oils, in the presence of hydrogen or hydrogen-generating compounds, not provided for in a single one of groups C10G45/02, C10G45/32, C10G45/44, C10G45/58 or C10G47/00 in the presence of hydrogen from a special source or of a special composition or having been purified by a special treatment
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
  • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
  • C25B11/02—Electrodes; Manufacture thereof not otherwise provided for characterised by shape or form
  • C25B11/03—Electrodes; Manufacture thereof not otherwise provided for characterised by shape or form perforated or foraminous
  • C25B11/031—Porous electrodes
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
  • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
  • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
  • C25B15/00—Operating or servicing cells
  • C25B15/08—Supplying or removing reactants or electrolytes; Regeneration of electrolytes
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
  • C25B3/00—Electrolytic production of organic compounds
  • C25B3/20—Processes
  • C25B3/25—Reduction
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
  • C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
  • C25B9/17—Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof
  • C25B9/19—Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof with diaphragms
  • C25B9/23—Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof with diaphragms comprising ion-exchange membranes in or on which electrode material is embedded
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2257/00—Components to be removed
  • B01D2257/30—Sulfur compounds
  • B01D2257/302—Sulfur oxides
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2257/00—Components to be removed
  • B01D2257/40—Nitrogen compounds
  • B01D2257/404—Nitrogen oxides other than dinitrogen oxide
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2257/00—Components to be removed
  • B01D2257/50—Carbon oxides
  • B01D2257/502—Carbon monoxide
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2257/00—Components to be removed
  • B01D2257/50—Carbon oxides
  • B01D2257/504—Carbon dioxide
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/30—Hydrogen technology
  • Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P20/00—Technologies relating to chemical industry
  • Y02P20/151—Reduction of greenhouse gas [GHG] emissions, e.g. CO2

Definitions

• the present invention relates to a method of generating highly reactive hydrogen and oxygen by electrolysis of water vapor using a proton conduction membrane.
• Conductive ceramic membranes are now the subject of much research to increase their performance; in particular, these membranes find particularly interesting applications in fields such as the electrolysis of water at high temperature for the production of hydrogen or the treatment of carbonaceous gases (CO 2 , CO) by electrochemical hydrogenation.
• Patent applications WO2008152317 and WO2009150352 describe examples of such methods.
• Hydrogen (H 2 ) appears today as a very interesting energy vector, which will become increasingly important for processing petroleum products, among other things, and which could, in the long term, be a good substitute for oil. and fossil fuels, whose reserves will decline sharply in the coming decades. In this perspective, however, it is necessary to develop efficient processes for producing hydrogen.
• a promising route for the industrial production of hydrogen is the technique known as electrolysis of water vapor, for example at high temperature (EHT), at an average temperature, typically above 200 ° C., or at intermediate temperature. between 200 ° C and 1000 ° C.
• EHT high temperature
• an electrolyte capable of conducting the O 2 - ions and operating at temperatures generally of between 750 ° C. and 1000 ° C. is used.
• FIG. 1 schematically represents an electrolyser 1 comprising a ceramic membrane 2, conducting O 2 " ions, providing the electrolyte function separating an anode 3 and a cathode 4.
• this first method makes it possible to generate at the outlet of the electrolyser 1 oxygen - anode compartment - and hydrogen mixed with water vapor - cathode compartment.
• an electrolyte capable of driving the protons and operating at temperatures lower than those required by the first method described above, generally between 200 ° C. and 800 ° C., is used.
• FIG. 2 schematically represents an electrolyzer 10 comprising a proton-conducting ceramic membrane 1 1 providing the electrolyte function separating an anode 12 and a cathode 13.
• this process provides at the outlet of the electrolyzer 10 pure hydrogen - cathode compartment - and oxygen mixed with water vapor - anodic compartment.
• H 2 passes through the formation of intermediate compounds which are hydrogen atoms adsorbed on the surface of the cathode with varying energies and degrees of interaction and / or radical hydrogen atoms . (or H ode in the notation of Kröger-Vink). These species being highly reactive, they usually recombine to form hydrogen H 2 according to the equation:
• Patent application WO2008152317 has shown that the insertion of pressurized water vapor makes it possible to remain at moderate operating temperatures (of the order of 500 to 600 ° C.) while obtaining conductivity values ensured by the displacement. relatively high H + protons.
• the charge carriers are not intrinsic to the structure of the membrane and are therefore more limited in the structure than the charge carriers of anionic conduction which are formed by the gaps in the structure.
• the present invention aims to provide a method of generating highly reactive hydrogen and oxygen adsorbates by electrolysis of water vapor by means of an electrolysis cell comprising both a solid electrolyte proton conduction, said process being industrializable by limiting the risk of delamination of the electrodes.
• the invention proposes a process for generating adsorbates of hydrogen and oxygen by electrolysis of water vapor between 200 ° C. and 800 ° C. by means of an electrolysis cell comprising a solid electrolyte. made in a proton-conductive ceramic, said electrolyte being disposed between an anode and a cathode, said anode and cathode each comprising a proton-conduction ceramic and each having a ratio between their electroactive surface and their geometric surface at least equal to 10, said process comprising the following steps:
• the current can be continuous or pulsed; in the case of a pulsed current, the term current density means the current density corresponding to the maximum value of the current intensity reached during the tap.
• the generation of the current can be obtained by various means:
• a generator imposing a voltage across the terminals of the assembly can be used (ie a potential difference between the electrodes); a source of current imposing a current between the electrodes can be used; it is also possible to use operation in potentiostatic mode; in other words, in addition to the two cathode and anode electrodes, at least one third so-called reference electrode is used.
• the working electrode preferably the cathode
• the generator for automatically maintaining the potential of the working electrode, even under current, is called potentiostat.
• reactive hydrogen atoms means hydrogen atoms adsorbed on the surface of the cathode and / or radical hydrogen atoms H ' (or H electrode in the Kröger-Vink notation).
• geometric surface of an electrode is meant its plane outer surface and electroactive surface, the surface formed by the inner surface of the pores of the electrode in which the electrochemical reaction occurs; in other words, it is the internal surface on which the reaction occurs: 2e + 20H Q - 20 + H 2 .
• the electrodes according to the invention therefore have a large number of triple points, namely points or contact surfaces between an ion conductor, an electronic conductor and a gas phase.
• electrodes comprising a proton-conductive ceramic (typically electrodes formed by a cermet including a mixture of said perovskite type ceramic and a metal alloy and / or perovskite doped with a lanthanide at one or more degrees of oxidation) surrounding a proton-conductive electrolyte and having a ratio electroactive surface / geometric surface sufficiently high allows to work at much higher current densities than those provided in the state of the art without risk of delamination of said electrodes.
• the consequent increase in the ratio between the electrostatic surface and the geometrical surface of the electrodes compared to the ratio of the electrodes of the state of the art makes it possible to reduce the local overvoltages which are responsible for the delamination phenomena of the electrodes. .
• the process according to the invention generates highly reactive hydrogen at the cathode of the electrolyser (in particular hydrogen atoms adsorbed at the surface of the electrode and / or radical).
• the method according to the invention may also have one or more of the following characteristics, considered individually or in any technically possible combination:
• said ratio between the electroactive surface and the geometrical surface of said cathode and anode is greater than or equal to 100; such a ratio makes it possible to further improve the resistance of the electrodes at high current densities without the risk of delamination;
• said current density is greater than or equal to 1 A / cm 2 ;
• the partial and relative pressure of water vapor is advantageously greater than or equal to 1 bar and preferably greater than or equal to 10 bar;
• the flow of current is between an anode and a cathode each made in a cermet consisting of a mixture of a proton conductive ceramic and a conductive material;
• said conductive material is a passivable material with a high melting point which may comprise at least 40% of chromium; the flow of current is between an anode and a cathode each comprising a proton-conductive ceramic formed by a perovskite doped with a lanthanide at one or more oxidation states, said ceramic being doped by a complementary doping element taken from the following group : niobium, tantalum, vanadium, phosphorus, arsenic, antimony, bismuth;
• the method according to the invention comprises the following steps:
• the method according to the invention comprises the following steps:
• said nitrogenous compounds are compounds of the type NO x with x> 1, said process comprising a step of forming compounds of the NtOyHz type, with t greater than or equal to 1, y greater than or equal to 0 and z greater than or equal to zero, following the reduction of NO x ;
• said nitrogenous compounds are N 2 compounds, said process comprising a step of forming N x H y compounds with x> 1 and y> 0 to result in the formation of NH 3 following reduction of N 2 ; said reactive hydrogen atoms are used to carry out a hydrocracking step at the cathode;
• said reactive hydrogen atoms are used to convert aromatic compounds to the cathode, for example saturated alkanes (paraffins) or cycloalkanes (naphthenes);
• the method according to the invention comprises a step of reacting said highly reactive oxygen with a compound introduced to the anode so that the latter undergoes oxygenation.
• the present invention also relates to an electrolysis cell for implementing the method according to the invention comprising:
• an anode comprising a proton-conduction ceramic, each of said anodes and cathode having a ratio of its electroactive surface to its geometrical surface of at least 10;
• a cathode comprising a proton-conduction ceramic, said electrolyte being disposed between said anode and said cathode;
• Said means for inducing a current flowing between the anode and the cathode may be a voltage, current or potentios generator (in this case, the cell will also include at least one cathodic or anodic reference electrode).
• the cell may also comprise means for introducing and evacuating pressurized gas into the cathode compartment and / or means for introducing and evacuating pressurized gas into the anode compartment.
• FIGS. 1 and 2 already described, are simplified schematic representations of steam electrolyzers
• FIG. 3 is a general simplified schematic representation of an electrolysis cell for implementing the method according to the invention.
• FIGS. 4 to 6 are illustrations of applications using the cell of FIG. FIG. 3 generally shows, schematically and simplified, an electrolysis cell 30, also called an elementary assembly, implementing the electrolysis method according to the invention.
• This electrolysis cell 30 has a structure similar to that of the device 20 of FIG. 2.
• the cell 30 comprises:
• partial and relative pressure refers to the insertion pressure relative to the atmospheric pressure.
• partial pressure denotes either the total pressure of the gas stream in the case where the latter consists solely of water vapor or the partial pressure of water vapor in the case where the gas stream includes other gases than water vapor.
• the anode 32 and the cathode 33 are preferably formed by a cermet constituted by the mixture of a proton-conductive ceramic and an electrically conductive passivable alloy which is capable of forming a passive protection layer in order to protect it in an oxidizing environment (ie at the anode of an electrolyser).
• This passivable alloy is preferably a metal alloy
• the passivable alloy comprises, for example, chromium (and preferably at least 40% of chromium) so as to have a cermet present both the special feature of not oxidizing temperature.
• the chromium content of the alloy is determined so that the melting point of the alloy is greater than the sintering temperature of the ceramic.
• sintering temperature is meant the sintering temperature necessary to sinter the electrolyte membrane so as to make it gas tight.
• the chromium alloy may also include a transition metal so as to maintain an electronic conductive character of the passive layer.
• the chromium alloy is an alloy of chromium and one of the following transition metals: cobalt, nickel, iron, titanium, niobium, molybdenum, tantalum, tungsten, etc.
• the ceramic of the anode and cathode electrodes 32 and 33 is advantageously the same ceramic as that used for producing the electrolyte membrane of the electrolyte 31.
• the proton-conducting ceramic used for producing the cermet of the electrodes 32 and 33 and of the electrolyte 31 is a zirconate perovskite of formula of general formula AZrO 3 which can advantageously be doped with an element A selected from lanthanides.
• the use of this type of ceramic for the production of the membrane therefore requires the use of a high sintering temperature in order to obtain a densification sufficient to be gastight.
• the sintering temperature of the electrolyte 31 is more particularly defined according to the nature of the ceramic but also according to the desired porosity level. Conventionally, it is estimated that to be gas-tight, the electrolyte 31 must have a porosity of less than 6% (or a density greater than 94%).
• the sintering of the ceramic is carried out under a reducing atmosphere so as to avoid the oxidation of the metal at high temperature, that is to say under an atmosphere of hydrogen (H 2 ) and argon (Ar) or even carbon monoxide (CO) if there is no risk of carburation.
• the electrodes 32 and 33 of the cell 30 are also sintered at a temperature above 1500 ° C (according to the example of sintering a zirconate type ceramic).
• the anode 32 and the cathode 33 may also be formed by a ceramic material which is a perovskite doped with a lanthanide.
• Perovskite can be a zirconate of formula AZr0 3 .
• the zirconate is doped with a lanthanide which is, for example, erbium.
• the lanthanide-doped perovskite is doped with a doping element taken from the following group: niobium, tantalum, vanadium, phosphorus, arsenic, antimony, bismuth.
• doping elements are chosen to dope the ceramic since they can go from an oxidation degree of 5 to an oxidation degree of 3, which allows to release oxygen during sintering. More specifically, the doping element is preferably niobium or tantalum.
• Each electrode may also comprise a metal mixed with the ceramic so as to form a cermet.
• the ceramic comprises for example between 0.1% and 0.5% by weight of niobium, between 4 and 4.5% by weight of erbium and the remainder of zirconate. Boosting the ceramic with niobium, tantalum, vanadium, phosphorus, arsenic, antimony or bismuth makes the ceramic conductive electrons.
• the ceramic is then a mixed conduction ceramic; in other words, it is conductive to both electrons and protons, whereas in the absence of these doping elements, the perovskite doped with a lanthanide with a single oxidation state is not electron conducting. .
• Such a configuration makes it possible to have electrodes made of a material of the same nature as the solid electrolyte which has good conductivity of both protons and electrons, even when the ceramic is not mixed. to a metal (as is the case of the first embodiment).
• the electrodes 32 and 33 of the cell 30 are designed to have a ratio between their electroactive surface and their geometric surface at least equal to 10 and preferably greater than or equal to 100.
• geometric surface is meant the plane outer surface of the electrode, that is to say the surface receiving the flow of electrons.
• specific (or developed) surface is meant the surface accessible to a gas within the electrode: it is therefore essentially constituted by the inner surface of the pores.
• electroactive surface is meant that part of the specific surface on which the electrochemical reaction occurs; in other words, it is the internal surface on which the reaction occurs:
• the means 34 make it possible to inject a current flowing between the anode 32 and the cathode 33 whose density is greater than or equal to 500 mA / cm 2 and preferably greater than or equal to 2 A / cm 2 without risk. of current drop or delamination of the electrodes
• the applicant has advantageously found that the fact of using electrodes made of a proton-conduction material and having a sufficient electroactive surface (advantageously greater than or equal to 100) makes it possible to increase significantly the usable current density without the risk of delamination of the electrodes. .
• the determination of the ratio between the electroactive surface and the geometrical surface is carried out for example by means of a method for characterizing the porous surface of a cermet electrode detailed in the publication "Characterization of porous texture of cermet electrode for steam electrolysis". At Intermediate Temperature, C. Deslouis, M. Keddam, K. Rahmouni, H. Takenouti, F. Grasset, O. Lacroix, B. Sala, Electrochimica Acta 56 (201 1) 7890-7898.
• H + ions or OH 0 in the Kröger-Vink notation migrate through the electrolyte 31, to form hydrogen H 2 on the surface of the cathode 33 according to the equation:
• this process provides at the outlet of the cell 30 pure hydrogen - cathode compartment - and oxygen mixed with water vapor - anodic compartment.
• H 2 passes through the formation of intermediate compounds which are hydrogen atoms adsorbed on the surface of the cathode 33 and / or radical hydrogen atoms H ' (or H j Lctrode in the notation of Kröger-Vink). These species being highly re-active,
• the oxygen atoms adsorbed on the surface of the anode 32 can advantageously be used to produce the oxygen adsorbate C> E electrode that can be used in an anode oxygenation reaction, by for example by injecting SO 2 sulfur dioxide or SOx into the anode which reacts with oxygen to form sulfuric acid H 2 SO 4 or to make oxygen for oxyfuel combustion.
• SO 2 sulfur dioxide or SOx into the anode which reacts with oxygen to form sulfuric acid H 2 SO 4 or to make oxygen for oxyfuel combustion.
• the latter depends on the type of material used for the membrane 31; in any case, this temperature is greater than 200 ° C and generally less than 800 ° C, or even lower than 600 ° C. This operating temperature corresponds to a conduction provided by H + protons.
• Figures 4 and following each illustrate a particular use of the cell of Figure 3 wherein the highly reactive hydrogen is used to recombine with other compounds at the cathode
• FIG. 4 illustrates a first example in which the electrolysis cell 30 is used to form compounds of the CxH y Oz type, (with x ⁇ 1, 0 ⁇ y ⁇ (2x + 2) and 0 ⁇ z ⁇ 2x). to the reduction of C0 2 and / or CO.
• the cell 30 of FIG. 3 further comprises means 36 for inserting gas (pCO 2 or / and CO) into the cathode compartment 33 under pressure.
• gas pCO 2 or / and CO
• the water is oxidized by releasing electrons while H + ions (in OH G form) are generated.
• H + ions migrate through the electrolyte 31 and are therefore capable of reacting with various compounds that would be injected at the cathode 33, the carbon compounds of the CO 2 and / or CO type reacting at the cathode 33 with these H + ions for form compounds of type C x H y O z (with x> 1, 0 ⁇ y ⁇ (2x + 2) and 0 ⁇ z ⁇ 2x) and water at the cathode.
• the nature of the compounds C x H y O z synthesized at the cathode depends on many operating parameters such as, for example, the pressure of the cathode compartment, the partial pressure of the gases, the operating temperature T1, the potential / current torque applied to the cathode, the residence time of the gas and the nature of the electrodes.
• the relative pressure of CO 2 and / or CO is greater than or equal to 1 bar and less than or equal to the rupture pressure of the assembly.
• the total pressure imposed in one compartment - catalytic or anodic - can be compensated in the other compartment so as to have a pressure difference between the two compartments to prevent the rupture of the membrane assembly, the support electrode if the one - Ci at a breaking strength too low.
• the temperature T1 of operation of the device 30 also depends, in the range between 200 and 800 ° C, of the nature of the carbon compounds CxH y Oz that it is desired to generate.
• FIG. 5 illustrates a second example in which the electrolytic cell 30 is used for reducing compounds of the type NO x (x ⁇ 2) to form compounds of the type N t O y H z, (with t> 1, y > 0 and z> 0).
• the cell 30 of FIG. 3 further comprises means 36 for inserting under pressure NO x (x ⁇ 2) type compounds into the cathode compartment 33.
• the problem consists in allowing the reduction by electro-catalytic hydrogenation of the NO x content of the effluents produced for example during the combustion of hydrocarbons or gases.
• the production of these molecules is made up to 60% by urban transport and 40% by boilers and thermal power plants. These molecules easily penetrate the bronchioles and affect breathing, causing hyperreactivity bronchial tubes in asthmatics; and increased susceptibility of bronchial tubes to microbes, at least in children.
• current regulations require industries to limit their releases to ⁇ .
• the method of using the cell 30 according to FIG. 5 is based on the following principle: pressurized water vapor is introduced at the level of the anode compartment 32 and the NO x is introduced under pressure at the cathode compartment 33.
• pressurized water vapor will cause an oxidation of this water in the form of steam on the surface of the anode so as to generate protonated species in the membrane which, after migration within the membrane, are reduced on the surface of the cathode very reactive hydrogen capable of reducing by hydrogenation NO x introduced into the cathode compartment such that the NO x are reduced to NO y (with y x x ) less oxidized then nitrogen and ammonia.
• Adsorbates monatomic hydrogen are formed at the cathode surface 33 according to the reaction: e '+ OH ⁇ 0 Q 0 x + H electrode.
• the highly reactive electrolyte adsorbates H react with the nitrogen compounds at the cathode 33 to give reduced compounds of nitrogen oxides of the type N t O y H z.
• these compounds are either NO and less oxidized than the NO x compounds introduced under pressure, N 2 nitrogen, or NH 3 ammonia.
• the solution according to the invention makes it possible to reduce the number of reactors required for the reduction of NOx to a single and only reactor seat of the electro-hydrogenation.
• Figure 6 illustrates a third example in which the electrolysis cell 30 is used to produce ammonia by electro-catalytic hydrogenation of N 2 . It should be noted that, according to this embodiment, it is also possible to produce other N x H y compounds with x> 1 and y> 0 before leading to the formation of NH 3 .
• the cell 30 of FIG. 3 further comprises means 36 for inserting pressurized nitrogen N 2 under pressure into the cathode compartment 33.
• the problem here is to produce in massive quantity, at low cost and without emission of CO 2 of the ammonia, by electro-catalytic hydrogenation of N 2 .
• ammonia is produced by catalytic reaction of hydrogenation of N 2 during the steam reforming of hydrocarbons.
• the synthesis of this product is therefore indirectly emitting CO 2 .
• the method of synthesis induces a very high volatility of the production price of
• the solution implemented in cell 30 of Figure 6 is to produce ammonia using a single reactor.
• the monoatomic hydrogenated compounds are formed on the cathode surface according to the reaction: e + OH 0 ⁇ 0 0 x + 3 ⁇ 4 atod ,
• the hydrogen needed to reduce nitrogen is no longer produced from fossil fuels; the process according to the invention is "cleaner" insofar as it does not generate C0 2 .
• the highly reactive hydrogen produced by the cell 30 of FIG. 3 can be used industrially for very different applications.
• the invention is not limited to the embodiments which have just been described.
• hydrogenation by highly reactive hydrogen atoms can also be used in the petrochemical industry, for example to convert aromatic compounds to saturated alkanes (paraffins) and cycloalkanes (naphthenes).
• the process according to the invention can also be used for hydrocracking for converting heavy petroleum products into light products under hydrogen pressure and at a sufficiently high temperature: typically, hydrocracking makes it possible to obtain products such as diesel or kerosene from heavy residues.

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• Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
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• 2011
  • 2011-10-12 FR FR1159221A patent/FR2981368B1/fr not_active Expired - Fee Related
• 2012
  • 2012-10-11 WO PCT/EP2012/070214 patent/WO2013053858A1/fr not_active Ceased
  • 2012-10-11 CN CN201280057387.3A patent/CN103987878A/zh active Pending
  • 2012-10-11 US US14/350,844 patent/US20140284220A1/en not_active Abandoned
  • 2012-10-11 BR BR112014008732A patent/BR112014008732A2/pt not_active Application Discontinuation
  • 2012-10-11 EP EP12773302.0A patent/EP2766512A1/fr not_active Withdrawn
  • 2012-10-11 JP JP2014535087A patent/JP2014532119A/ja active Pending
  • 2012-10-11 RU RU2014118792/04A patent/RU2014118792A/ru not_active Application Discontinuation
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