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
  • C25B15/00—Operating or servicing cells
• • 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
• • 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
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2251/00—Reactants
  • B01D2251/20—Reductants
  • B01D2251/202—Hydrogen
• • 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
• • 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
• • 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 and a system for treating carbonaceous gases - carbon dioxide (CO 2) and / or carbon monoxide (CO) - from highly reactive hydrogen generated by electrolysis of water to produce water. obtaining a compound of the type CxH y O z , in particular with x>1; 0 ⁇ y ⁇ (2x + 2) and 0 ⁇ z ⁇ 2x.
• the production method uses an electrolyte capable of driving the protons and operating at temperatures generally between 200 ° C and 800 ° C.
• FIG. 1 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 tectrode in the Kröger-Vink notation). These species being highly reactive, they usually recombine to form hydrogen H 2 according to the equation:
• the object of the invention is to promote the carbonaceous gases resulting for example from the production of heating from carbon products (coal, wood, oil), or the incineration of waste, and to optimally reduce the production of gas. greenhouse effect for carrying out the hydrogenation treatment.
• the invention proposes a method for treating CO 2 and / or CO by electrochemical hydrogenation to obtain a compound of type C x H y O z, with x>1; 0 ⁇ y ⁇ (2x + 2) and z between 0 and 2x, said CO 2 and / or CO being obtained by the combustion of carbonaceous products via heating means (160), said method comprising:
• reactive hydrogen atoms are meant atoms absorbed on the surface of the cathode and / or radical hydrogen atoms H (or Hf ieci: rode in the Kröger-Vink notation).
• the process according to the invention makes it possible to recover the carbon dioxide produced by heating means resulting from the combustion of carbonaceous products by jointly using the electrolysis of water vapor, which generates highly reactive hydrogen at the cathode.
• the electrolyser with electrocatalyzed hydrogenation of the carbonaceous products injected cathode level of the electrolyzer by reaction with highly reactive hydrogen.
• these compounds of the C x H y O z type are paraffins C n H 2n + 2 , olefins C 2n H 2 n, alcohols C n H 2 n + 2 0H or ⁇ ⁇ ⁇ 2 ⁇ - ⁇ , aldehydes and ketones C n H 2n O.
• the compounds C x H y O z produced are components for feeding the combustion of the heating means so as to reduce the external input of carbon products.
• the compounds formed are combustible carbonaceous products, such as for example aliphatics or aromatics belonging to the family of alkanes, alkenes or alkynes, substituted or unsubstituted, which may include one or more functions alcohol, aldehyde, ketone, acetal, ether, peroxide, ester, anhydride.
• the invention also makes it possible to advantageously use the heat produced by the heating means (resulting from the combustion of carbonaceous products) to bring the proton conducting electrolyser into temperature, the setting of the temperature of the electrolyser being necessary for the production of the electrolysis reaction and the electrocatalyzed hydrogenation reaction.
• the electrolyser does not require the use of expensive specific heating means and greenhouse gas generator.
• the method according to the invention may also have one or more of the following characteristics, considered individually or in any technically possible combination:
• the process comprises a step of using the compounds of the type
• said method comprises a phase separation step for injecting into the heating means the compounds of the type C x H y O z only in gaseous form: prior to said step of introducing CO 2 and / or CO produced by said heating means into the cathode compartment of the electrolyser, said method comprises a step of purifying the CO 2 and / or CO produced by said means of heating to obtain pure CO 2 and / or CO;
• step of oxidizing the water vapor at the anode generates oxygen at the outlet of the anode compartment
• said method comprises a step of phase separation of the oxygen produced by said electrolyser
• said method comprises a step of reinjection of oxygen in gaseous form into said heating means
• the method comprises a step of controlling the nature of the CxH y Oz type compounds formed as a function of the potential and / or the current applied to the cathode or to the terminals of the electrolyser;
• the compounds of the type C x H y O z formed belong to the family of alkanes or alkenes or alkynes, substituted or unsubstituted, which may include one or more functions alcohol or aldehyde or ketone or acetal or ether or peroxide or ester or anhydride;
• the compounds of the type C x H y O z are formed carbonaceous combustibles
• said step of transferring heat from the heating means to said electrolyser is carried out by means of a heat exchanger: said step of transferring heat from the heating means to said electrolyser is carried out by direct heat transfer, said electrolyser being positioned in said a heat zone in the vicinity of said heat means;
• the heat transfer from the heating means to a proton-conductive electrolyser is carried out so that said electrolyser reaches a temperature greater than or equal to 200 ° C. and less than or equal to 800 ° C., advantageously lying in the range 350 ° C. to 650 ° C. ° C; the heat transfer from the heating means to a proton-conductive electrolyser is carried out in such a way that said electrolyser reaches a temperature of between 500 ° C. and 600 ° C.
• the subject of the invention is also a system for treating carbonaceous gases by electrochemical hydrogenation for implementing the method according to the invention, said system comprising:
• heating means emitting CO 2 and / or CO by the combustion of carbonaceous products
• a proton conductive electrolyser comprising an electrolyte in the form of a proton conducting membrane, an anode and a cathode; said electrolyser being positioned near the heating means;
• the heating means are formed by a boiler.
• FIG. 1 is a simplified schematic representation of a proton-conductive water vapor electrolyser
• FIG. 2 is a schematic representation of a system for treating carbonaceous gases produced by a boiler during the combustion of carbonaceous products
• FIG. 3 is a general simplified schematic representation of an electrolysis cell for implementing the method according to the invention.
• FIG. 2 schematically represents a carbonaceous gas treatment system 100 for implementing the method according to the invention.
• the treatment system 100 comprises:
• heating means 160 such as a boiler, discharging CO 2 and / or CO and other gases resulting from the combustion of carbonaceous products used for the production of heat;
• a purifier 120 making it possible to purify gases discharged by the boiler 160 so as to isolate the CO 2 and / or CO;
• a proton conduction electrolyser 1 10 comprising an electrolyte 31 in the form of a proton conducting membrane, an anode 32 and a cathode 33 (FIG. 3);
• the means 34 for inducing a current flowing between the anode 32 and the cathode 34 may be a voltage generator, a current generator or a potentiostat (in this case, the cell will also comprise at least one cathodic or anodic reference electrode). .
• FIG. 3 illustrates in more detail an exemplary embodiment of an electrolysis cell 30 of the electrolyser 1 used to form compounds of the CxH y Oz type, (with x> 1, 0 ⁇ y ⁇ (2x + 2) and 0 ⁇ z ⁇ 2x) following the reduction of CO 2 and / or CO.
• the water is oxidized by releasing electrons while H + ions (in OH 0 form) are generated.
• H + ions migrate through the electrolyte 31 and are therefore likely to react with various compounds that would be injected at the cathode 33, the carbon compounds of the type C0 2 and / or CO reacting at the cathode 33 with these H + ions to form compounds of type C x H y O z (with x> 1, 0 ⁇ y ⁇ (2x + 2) and 0 ⁇ z ⁇ 2x) and water at cathode 33.
• the nature of the compounds C x H y O z synthesized at the cathode 33 depends on numerous 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. voltage applied to the cathode 33 or the terminals of the electrolyzer, the residence time of the gas and the nature of the electrodes.
• the operating temperature T1 of the electrolyser is in the range between 200 and 800 ° C, preferably between 350 ° C and 650 ° C.
• the operating temperature T1 in this temperature range will also depend on the nature of the CxHyO 2 carbon compounds that it is desired to generate. These operating parameters are defined so as to form at the outlet of the cathode 33 of the electrolyser 1 10 a combustible compound capable of supplying the combustion of the boiler 160.
• the hydrogen / compound mixture C x H y O z has the advantage of aiding the combustion of the compound C x H y O z in the heating means.
• the operating parameters are defined so as to obtain a mixture formed by 90% of CxHyO 2 compound and 10% of hydrogen.
• 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 an oxide layer protection so as 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 having the particularity 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 electrodes 32 and 33 and electrolyte 31 is a zirconate perovskite of formula of general formula AZrO 3 that 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 as a function of 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.
• 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. Ceramic 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 conducting both electrons and protons while in the absence of these doping elements, the perovskite doped with a lanthanide with a single degree of oxidation 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 with a metal ( as is the case of the first embodiment).
• the system 100 further comprises a condenser 130 receiving as input the compound C x H y O z synthesized at the cathode 33 of the electrolyser 1 10.
• the condenser 130 makes it possible to separate the compound C x H y O z in the state gas and water that are produced by the hydrogenation reaction.
• the condenser 130 traps the water in liquid form making it possible to obtain, at the outlet of the condenser 130, only the compound C x H y O z synthesized in the gaseous state (combustible carbon compounds in the embodiment shown in FIG. Figure 2).
• the compound CxH y O z is then injected into the carbonaceous feed system of the boiler 160 after dehydration in a desiccant cartridge 170.
• the addition of the synthesized compound C x H y O z reduces the specific carbon products.
• the system according to the invention therefore makes it possible to operate in a semi-closed circuit, the external supply of fuel being reduced by supplying the boiler with the compound C x H y O z synthesized.
• the water recovered in the condenser 130 is then reinjected into the water supply circuit so as to limit the external influx of water.
• the system 100 also comprises a condenser 140 receiving as input the oxygen produced by electrolysis of the water vapor at the anode 31.
• the condenser 140 makes it possible to separate the oxygen from the water.
• the oxygen is then reinjected into the boiler 160 to feed the combustion of the carbonaceous products, and the water is reinjected into the water supply circuit.
• the oxygen thus injected makes it possible to carry out an oxy-combustion by directly using the oxygen leaving the electrolyser as an oxidizer instead of air.
• the condensers 130 and 140 also have the function of cooling the compounds entering the condensers so as to reinject into the various circuits of the system 100 compounds cooled to a temperature between 80 and 85 ° C.
• the electrolyser 1 10 is brought to temperature by heat transfer from the boiler 160 to the electrolyser 1 10 so that the electrolyser reaches the temperature T1 greater than or equal to 200 ° C. and less than or equal to 800 ° C, advantageously between 350 ° C and 650 ° C.
• the temperature T1 of the electrolyser must advantageously be between 500 ° C. and 600 ° C.
• the heat transfer is carried out by positioning the electrolyser 1 10 in a heat zone 150 around the boiler 160.
• the heat transfer is carried out by means of a heat exchanger (not shown) making it possible to transfer the thermal energy produced by the boiler to the electrolyser.
• the system further comprises a turbine positioned at the outlet of the electrolyser, and more specifically at the anode outlet (steam) and / or cathode of the electrolyser.
• a turbine is illustrated as a dashed example by reference numeral 50.
• the turbine is positioned in the path of the output gas stream at the anode of the electrolyser .
• Such a turbine is adapted to generate electricity by passing the gas stream.
• the electricity produced then makes it possible to feed the electrolyser electrically.
• this particular embodiment makes it possible to reduce the power consumption of a specific generator in order to generate a potential difference across the electrolyser.
• the system according to the invention comprises thermoelectric devices advantageously placed so as to recover the heat of the products formed by the electrolysis reaction of the water.
• the system comprises a heat exchanger adapted to cool the oxygen / water mixture generated at the anode by the electrolysis reaction and to heat the water entering the electrolyzer so as to forming the water vapor capable of being inserted into the electrolyte via the anode.
• the invention finds a particularly advantageous application for upgrading carbonaceous gases resulting for example from the production of heating from carbon products (coal, wood, oil), or the incineration of waste.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Inorganic Chemistry (AREA)
• Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
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• 2011
  • 2011-10-12 FR FR1159223A patent/FR2981369B1/fr not_active Expired - Fee Related
• 2012
  • 2012-10-11 WO PCT/FR2012/052319 patent/WO2013054053A2/fr not_active Ceased
  • 2012-10-11 EP EP12780242.9A patent/EP2766514A2/fr not_active Withdrawn
  • 2012-10-11 BR BR112014008751A patent/BR112014008751A2/pt not_active Application Discontinuation
  • 2012-10-11 IN IN3032DEN2014 patent/IN2014DN03032A/en unknown
  • 2012-10-11 JP JP2014535150A patent/JP2014528519A/ja active Pending
  • 2012-10-11 RU RU2014118837/04A patent/RU2014118837A/ru not_active Application Discontinuation
  • 2012-10-11 CN CN201280058046.8A patent/CN104024479A/zh active Pending
  • 2012-10-11 US US14/350,837 patent/US20140291162A1/en not_active Abandoned

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