Classifications

• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
  • C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
  • C01B3/32—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
  • C01B3/34—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents
  • C01B3/38—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents using catalysts
  • C01B3/42—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents using catalysts using moving solid particles
  • C01B3/44—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents using catalysts using moving solid particles using the fluidised bed technique
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
  • C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
  • C01B3/32—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
  • C01B3/34—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents
  • C01B3/38—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents using catalysts
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
  • C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
  • C01B3/32—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
  • C01B3/34—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents
  • C01B3/38—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents using catalysts
  • C01B3/42—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents using catalysts using moving solid particles
• • 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
  • Y02P20/10—Process efficiency
  • Y02P20/129—Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines

Definitions

• the present invention relates to a process for producing synthesis gas, in particular with capture of CO 2 , in a chemical loop.
• the process commonly used for the production of hydrogen is therefore the SMR process.
• the heat required for the steam reforming reaction is provided by the combustion that is carried in the furnace (in the presence of air). In this furnace, CO 2 emissions are therefore necessarily diluted.
• Another process is also used: it is the self-thermal reforming.
• the heat required for the steam reforming reaction is supplied to the reactor by the combustion of a part of the methane using a pure oxygen injection or air.
• the CO 2 must then be separated from the synthesis gas if it is desired to produce hydrogen.
• this process requires a large amount of oxygen.
• WO-A-96/33794 discloses a process using a fixed bed reactor successively exposed to a reducing gas such as methane and an oxygen-containing gas such as air.
• the catalyst is selected from Ag / AgO, Cu / CuO, Fe / FeO, CO / CoO, W / WO, Mn / MnO, Mo / MoO, SrSO4 / SrS, BaSO4 / BaS and mixtures thereof.
• the transfer of heat by the oxygen carrier is mentioned, the heat released during the oxidation of the metal can thus be used for endothermic reactions such as oxidation of the reducing gas.
• the hydrogen produced during the reduction phase of the solid is diluted with the other products of the reactions occurring in the reactor and in particular CO, CO 2 and H 2 O.
• a second reactor in series containing CaO can react with CO 2 to form CaCO3 that can be regenerated to CaO during the oxidation phase.
• the CO 2 is then diluted with the depleted air.
• WO-A-99/1591 discloses an autothermal reforming process for methane using 2 fluidized bed reactors interconnected between which circulates a metal oxide.
• the heat generated during the oxidation reaction of the metal is used in the second reactor to allow the partial oxidation reaction of methane: CH 4 + 2MO x + 1 -> H 2 + CO + 2MOx + H 2 O but also the steam reforming reaction: CH + H 2 O-> CO + 2H 2 in the case where steam is co-injected with methane into the reactor.
• all the 2 interconnected reactors must be at the same pressure, which forces the air to be compressed at the inlet of the first reactor.
• WO-A-2008/036902 describes a process similar to the preceding process implementing a fixed-bed reactor successively subjected to an oxidation step and then a reduction step with the objective of converting a hydrocarbon into a gaseous mixture containing CO + H 2 .
• the document also proposes a variant implementing circulating fluidized bed reactors.
• the document US6797253 proposes an adaptation of the process described in the document WO-A-96/33794 in order to be able to convert gases containing high concentrations of H 2 S.
• the method described implements a fixed-bed reactor undergoing several successive stages. during which the reaction fronts progress along the reactor. During the reforming phase, the sulfur is fixed on the nickel forming NiS, the nickel being regenerated during the regeneration phase by air oxidation producing N1O + SO 2 .
• WO-A-00/00427 discloses a process producing synthesis gas from methane and using a metal oxide bed successively undergoing a reduction phase and an oxidation phase. The beginning of the solid reduction cycle does not produce instantaneously CO + H 2 , it is proposed in this document to recirculate the gases initially produced at the inlet of the reactor in a mixture with methane until CO + H 2 is obtained in the gaseous exit mixture.
• the object of the invention is to remedy this drawback by providing a process for preparing hydrogen (or synthesis gas) with an intrinsic capture of CO2 by the production of effluents concentrated in CO2.
• the subject of the invention is a cyclic process for the production of synthesis gas comprising the following successive steps:
• the synthesis gas production step is a steam reforming step and the oxygen-carrying solid is a catalyst for the steam reforming reaction.
• the combustion and / or steam reforming step is carried out with methane.
• the synthesis gas production step is a gasification step.
• the combustion and / or gasification step is carried out with coal.
• the method is implemented in a fluidized bed, preferably in batch mode.
• the solid is associated with a thermally stable support or in mixture with such a support.
• the solid contains a metal selected from the group consisting of Ni, W, Mn, Rh, Co, Sr, Ba, Pt, Fe, Cu, Mo, Pd, Ag, and mixtures thereof, preferably Ni .
• the oxidation step is conducted to a degree of oxidation greater than 0.8, preferably less than 0.99, advantageously between 0.9 and 0.98.
• the combustion step is conducted to a degree of oxidation of between 0.4 and 0.2, preferably between 0.35 and 0.25, advantageously about 0.3.
• the method further comprises a carbon gas shift reaction step of carbon monoxide from the fourth stage of production of synthesis gas in a mixture of CO2 and H 2 .
• the method further comprises a step of purifying H 2 , in particular by pressure swing adsorption.
• the method further comprises recycling the CO2 to the combustion step; the combustion step preferably having the same duration as the synthesis gas production step.
• the method further comprises a step of drying the gases from the combustion step.
• the process steps are carried out at substantially the same pressure, preferably at a pressure of from 1 to 150 bar, advantageously from 20 to 100 bar.
• the method further comprises at least one step of recovering heat from the effluents from the reactor.
• the method is implemented continuously in a plurality of reactors in parallel.
• the process according to the invention makes it possible to produce hydrogen, in particular from methane, with an intrinsic capture of CO2. Once dried, if necessary, the gas resulting from the combustion phase consists solely of CO2; this can then be com pressed and sent to a storage facility for further capture.
• the complete oxidation reaction is separated from the steam reforming reaction.
• the invention is based on the use of the same solid as carrier of oxygen, as a thermal vector and, in the case of steam reforming, as a catalyst.
• the oxidation phase is highly exothermic, generating the heat necessary for the highly endothermic SMR reaction (phase 4). This heat is carried directly by the solid which will act as a catalyst in phase 4.
• This same solid also makes it possible to transport the oxygen necessary for phase 3 (combustion), which makes it possible to produce a combustion without the presence of nitrogen ( N2) and therefore produce concentrated CO2.
• the invention is distinguished from the state of the art by the division of the reduction phase into two stages: a step during which the complete combustion reaction is favored and a step during which the steam reforming reaction is favored.
• This division makes it possible to obtain, on the one hand, a synthesis gas that is not polluted by CO 2 and on the other hand concentrated CO 2 .
• the reactions are not controlled and therefore are found during the reduction with a mixture of CO2 / H2O / CO / H2.
• Figure 1 schematically shows a method according to the state of the art.
• FIG. 2 schematically shows an embodiment of the method according to the invention.
• FIG. 1 schematically shows the reactor used in Example 1.
• Figure 4 shows the effluent profiles obtained in Example 1.
• Figure 5 schematically shows the reactor used in Example 2.
• Figure 6 shows the effluent profiles obtained in Example 2.
• FIG. 7 shows the arrangement of the reactors used in Example 3.
• Figure 8 is a timing diagram of the use of the reactors for a 1500 second cycle used in Example 3.
• synthesis gas any mixture of CO and H 2 , especially in ratios ranging from 1: 1 to 1: 3.
• This method according to the invention comprises the following steps.
• the first step is the oxidation step.
• the solid is oxidized.
• the oxygen-carrying solid may in particular contain a metal, the oxide of which is reducible, or a sulfur-containing derivative of this metal, this metal being in particular a catalyst for the steam reforming reaction.
• the metal may be present alone in the phase, or possibly mixed with another species (another metal or sulfur for example) in this phase, such as FeTiO5.
• metals are: Ni, W, Mn, Rh, Co, Sr, Ba, Pt, Fe, Cu, Mo, Pd and Ag, especially Ni.
• Ni / NiO Ni / NiO
• Ag / AgO Cu / CuO
• Fe / FeO Co / CoO
• W / WO Mn / MnO
• Mo / MoO moly stable inert carrier
• a thermally stable inert carrier can be used in a mixture to increase the heat capacity.
• thermally stable inert support is alumina or a nickel-Alumina spinel (NiAl 2 O 4 ), or else silica.
• NiAl 2 O 4 nickel-Alumina spinel
• silica silica
• thermal ballast solid may be silica, alumina, or sand.
• the oxygen-carrying solid may represent from 100% to 1%, preferably from 60 to 5%, preferably from 30 to 10%, of the final mixture (whether the oxygen carrier solid is supported or simply as a mixture).
• the solid is preferably fluidized by the gas in the reactor in order to advantageously benefit from the properties of solid homogeneities in fluidized bed reactors.
• fluidized beds are preferred, fixed beds are also possible, as well as transported beds.
• the size and particle distribution of the solid particles are chosen so known to those skilled in the art to have a fluidized bed under the reaction conditions.
• the dv50 of the Ni / NiO particles is between 50 ⁇ and 400 ⁇ , preferably between 50 ⁇ and 200 ⁇ , in particular between 70 and 150 ⁇ . Fluidized bed conditions are bullous or turbulent.
• the reactors operating in a fluidized bed are equipped with conventional means for distributing the incoming gas, conventional means for removing dust from the gaseous effluents, and a conduit for adding or withdrawing particles.
• the superficial velocity of the gas during the various cycles will always be kept below the minimum transport speed of all the catalytic particles, in order to avoid driving them.
• the metal is oxidized according to the following reaction:
• Ni + 1 ⁇ 2 O 2 NiO.
• This reaction is, in known manner, exothermic.
• the temperature of the oxidation reaction is typically between 700 ° C and 1000 ° C.
• the solid stores heat which will be necessary later during the endothermic steam reforming reaction.
• X is the degree of oxidation of the solid at a given instant t, defined as follows:
• m actual is the mass at time t of the oxygen carrier in its partially oxidized form
• m ox and m red are respectively the masses of the oxygen carrier in its completely oxidized and completely reduced forms.
• the oxidation phase makes it possible to obtain an oxidation degree such that preferably X> 0.8.
• X is not equal to 1, in order to avoid a period of activation of the solid at the beginning of the combustion phase.
• X at the end of the oxidation phase is less than 0.99, advantageously less than 0.98.
• the degree of oxidation can be measured in different ways. TGA (ThermoGravimetric Analysis) can be weighed or the oxygen content can be determined by mass balance. This last technique is the preferred one; we know what is fed and we know what comes out of the reactor. It is then possible to deduce the quantity of oxygen which is fixed or, on the contrary, released by the solid into the reactor and to deduce then its degree of oxidation. Physical samples from time to time may also be considered.
• This oxidation phase may be carried out at any industrially compatible pressure, in particular a pressure of between 1 and 150 bar, preferably of 20 to 100 bar.
• this step is carried out at a pressure substantially identical to that of the anterior and posterior stages.
• the mass of solid, the flow rate and the duration are adapted to obtain oxidation to the desired degree.
• the mass of solid oxygen carrier is fixed, the flow rate (which corresponds to the industrial needs) is fixed and the duration of the phase is then calculated.
• the oxidant is typically air; but it is possible to use oxygen possibly produced by another method available on site.
• the air which has been used for this oxidation phase therefore leaves the reactor in depleted form and is discharged into the atmosphere or used elsewhere in the process or in another process. Purge phase
• the second step is a purge step. Before the combustion phase, a purge phase is indeed required to avoid any direct contact between the air and the fuel gas.
• water vapor as inert or else nitrogen (air depleted) that could for example be produced by another reactor in phase oxidation or CO 2 which could for example be produced by another reactor in the combustion phase or from storage.
• nitrogen air depleted
• CO 2 which could for example be produced by another reactor in the combustion phase or from storage.
• This purge gas is characterized by its substantially zero O 2 content.
• This purge phase can be carried out at any pressure compatible industrially, including a pressure between 1 and 150 bar, preferably from 20 to 100 bar.
• this step is carried out at a pressure substantially identical to that of the anterior and posterior stages.
• the third step is the combustion phase.
• a fuel is sent into the reactor and it will be oxidized substantially completely with the oxygen carried by the oxygen-carrying solid.
• the fuel may be methane or another hydrocarbon (preferably gaseous under the reaction conditions), optionally mixed with the waste gas from the purification of the synthesis gas by pressure swing adsorption. In this configuration, it is then possible to capture 100% of the CO 2 of the installation.
• the duration is adapted to obtain combustion to the desired degree.
• the mass of oxygen carrier solid is fixed (see above for the oxidation phase for example)
• the flow rate (which corresponds to the industrial needs) is fixed and the duration of the phase is then calculated. This time is such that at the end of this step, the degree of oxidation of the solid is in general between 0.4 and 0.2, preferably between 0.35 and 0.25, advantageously about 0.3.
• This step is (slightly) endothermic or exothermic (for example in the case of Cu) depending on the nature of the oxygen-carrying solid.
• this phase is slightly endothermic.
• the product gas contains mainly H 2 O and CO 2 . After condensation of the water, the CO 2 can be compressed and then stored.
• the fuel gas can be co-injected with a small amount of steam to mimic carbon deposition on the solid (a phenomenon known as coking, which may result in at least partial deactivation of the carrier of O 2 ) .
• This combustion phase can be carried out at any commercially compatible pressure, in particular a pressure of between 1 and 150 bar, preferably of 20 to 100 bar.
• this step is carried out at a pressure substantially identical to that of the anterior and posterior stages.
• the fourth phase is the synthesis gas production phase.
• the methane is co-injected with water vapor.
• the main reaction is then the reforming reaction with steam:
• the synthesis gas produced can pass through a WGS reactor (Water
• the synthesis gas can be purified in a conventional manner in a PSA system (Pressure Swing Adsorption) which will produce purified hydrogen and a waste gas containing CO 2 , H 2 , CO and CH (in general such a gas contains about 50% CO 2 , about 25% H 2 , about 25% CO and traces of CH 4 ).
• PSA system Pressure Swing Adsorption
• Such a gas called "off-gas”, after purification to remove the desired hydrogen, may be used in mixture with the fuel (including methane) for phase 3.
• a minority reaction may also exist, the solid not being at a zero oxidation state; this reaction is however very minor.
• the duration of the phase (and the other operating parameters) is adapted so that the final temperature of the solid is substantially equal to the starting temperature during the first phase of the process.
• the duration of this phase is adapted to be identical to the duration of the combustion phase to allow easy return of the tail gas from the purification system of the synthesis gas to another reactor in the combustion phase.
• This synthesis gas production phase can be carried out at any industrially compatible pressure, in particular a pressure of between 1 and 150 bar, preferably of 20 to 100 bar.
• this step is carried out at a pressure substantially identical to that of the anterior and posterior stages.
• the duration of the combustion and synthesis gas production phases are substantially identical; in this embodiment, the gas resulting from the purification containing CO 2 is reinjected into the combustion phase. This purification gas then contains CO 2 , and optionally CO, which can also be converted into CO 2 . Purge phase
• the fifth phase is a purge step. Before returning to the oxidation phase, a purge phase is indeed required to avoid any direct contact between the air and the fuel gas.
• water vapor as inert or else nitrogen (air depleted) which could for example be produced by another reactor in the oxidation phase or CO2 which could for example be produced by another reactor in the combustion phase or from storage.
• nitrogen air depleted
• CO2 which could for example be produced by another reactor in the combustion phase or from storage.
• This purge gas is characterized by its substantially zero O2 content.
• This purge phase can be carried out at any industrially compatible pressure, in particular a pressure of between 1 and 150 bar, preferably of 20 to 100 bar.
• this step is carried out at a pressure substantially identical to that of the anterior and posterior stages.
• a heat exchanger can be positioned on the reactor effluent outlet (for all stages) to produce steam (needed by the system) and / or to preheat the reactor inlets.
• the gaseous hydrocarbon is replaced by a solid, coal.
• Steps 1, 2 and 5 are identical. Change steps 3 and 4, now burning and gasifying respectively.
• the CO2 at the end of this reaction is often mixed with water which is used as a fluidization vector.
• the gasification step is carried out according to the following main reaction:
• the reactive metal of the solid does not need to have catalytic properties of the steam reforming reaction (which is not implemented), but only to have a reducible oxide.
• the soil is driven in pulverulent form in the soil of the soil, especially since the fl uid isation can be carried out by the injection of little water (possibly mixed with CO2).
• the particle size distribution of coal is not critical because coal, when exposed to a high temperature, explodes into small particles that are easily fluidized. For reasons of kinetics, particles of small size, preferably less than 5 mm and preferably less than 500 ⁇ m, are preferred.
• the ash produced is managed according to conventional techniques in the art of gasification.
• synthesis gas can be produced according to the following reaction:
• the pressure is in particular about 80 bar.
• the CO produced can be converted to CO2 by the WGS reaction according to:
• Hydrogen production is therefore generally carried out by reforming methane rather than with coal which leads to less hydrogen, the hydrogen-to-carbon ratio being in favor of methane reforming.
• the pressure is in particular about 30 bars.
• the invention therefore allows the production of synthesis gas which can then be purified to lead to hydrogen, optionally with an intermediate step of WGS and a purification step.
• FIG. 7 represents such a valve system using 8 reactors. Given the different durations during the different stages, it is possible to provide several reactors assigned to a particular stage, with an offset of the inputs / outputs to level of the different reactors. Figure 8 shows the shift of the reactors for a complete cycle.
• the invention offers many advantages over the state of the art, in addition to those already mentioned above.
• the invention offers one or more of the following advantages:
• the reactor in batch mode allows easy pressurization, which the use of circulating fluidized bed reactors does not allow. This makes it possible to operate the various phases and in particular that of steam reforming at high pressure, which makes it possible to produce a synthesis gas (or hydrogen) at high pressure that can be used directly in the industrial unit.
• a reactor containing 200 g of solid compound, in% by weight, 60% of active NiO and 40% of NiAl 2 O 4 powder support with an average diameter of 200 ⁇ is used.
• the reactor consists of a quartz tube of 4.6 cm internal diameter where the solid is fluidized by a gas distributor located in the lower part of the reactor and consisting of a porous matrix of sintered quartz.
• the temperature of the reactor is measured using a thermocouple immersed directly in the bed of fluidizing solid. This temperature was regulated at 800 ° C in the example by heating shells around the reactor. The solid is then exposed to oxidation-reduction cycles.
• the fuel used for the reductions is a mixture of 10% methane diluted in argon (inert gas) and the re-oxidation is carried out with a 21.1% mixture of oxygen diluted in argon. Between each cycle, argon is sent to the reactor to purge it.
• the flow rates of the gases are regulated by flow regulators and the water is injected by means of a pump.
• the gases are preheated using an exchanger consisting of a fluidized sand bed whose temperature is controlled and through which passes the reactor feed tube.
• the water injected upstream is then vaporized before entering the reactor.
• the device is represented in FIG.
• composition of the gases (in% VO i) at the outlet of the reactor during a reduction phase measured using a mass spectrometer.
• the reduction phase has been divided into 2 stages:
• % VO i CH 4 + 90% VO i Ar is sent to the reactor.
• the initial oxidation state is 0.95, at the end of this stage it is 0.3. This is the combustion stage producing CO2 and H 2 O
• the majority reaction products are CO2 and H 2 O.
• the majority reaction products are H 2 and CO.
• a micro-reactor containing 200 mg of solid compound (in% by mass) of 60% of active NiO and 40% of NiAl 2 O 4 support in powder with an average diameter of 200 ⁇ is used.
• the reactor consists of a quartz tube of 4 mm internal diameter where the solid is based on a glass wool plug placed in the middle of the reactor.
• the solid bed is traversed by gas so descending and therefore behaves like a fixed bed.
• the tube is placed in an oven whose temperature is regulated at 800 ° C using a thermocouple placed 10 mm above the catalyst powder. The solid is then exposed to oxidation-reduction cycles.
• the fuel used for the reductions is a mixture of 10% methane diluted in argon (inert gas) and the re-oxidation is carried out with a 21.1% mixture of oxygen diluted in argon. Between each cycle, argon is sent to the reactor to purge it.
• the device is represented in FIG.
• FIG. 6 shows the composition of the gases (in% VO i) at the outlet of the reactor during a reduction phase measured using a mass spectrometer.
• the reducing gas flow rate (90% Ar + 10% CH) is controlled at 50 Nml / min.
• this gas is bubbled through a water container at controlled temperature in order to saturate the water up to 8% VO i-
• the degree of oxidation of the solid, as defined above, is calculated using mass balance output gas analysis and is also shown in FIG. 6.
• the reactors are supplied with an inlet pressure of 32 bar.
• the duration of the combustion phase is set at 375 seconds.
• each reactor is fed with a mixture containing 25% of CH, 14% H 2 , 12% CO and 49% CO 2 , for a flow rate of 2876 kmol / h.
• This mixture consists of the recycling of the gases resulting from the purification of hydrogen and a supply of fresh methane.
• the supply temperature is 435 ° C.
• the initial solid temperature of 1100 ° C and its degree of oxidation is 0.95.
• the solid temperature is 975 ° C and its oxidation degree 0.3.
• the gases contain only H 2 O and CO 2 . These gases are cooled through a recovery boiler producing steam, then dried and CO2 produced (2476 kmol / h per reactor) can be directed to a geological storage.
• the reforming phase therefore starts with an initial solid temperature of 975 ° C. and an oxidation degree of 0.3.
• the duration of this phase is also set at 375 seconds in order to have constantly 2 reactors in reforming phases and 2 reactors in combustion phases.
• the reactors are fed with a mixture containing 47% of CH and 53% of H 2 O, for a flow rate of 7525 kmol / h per reactor.
• the supply temperature is 223 ° C.
• the solid temperature is 721 ° C.
• the synthesis gas produced is cooled through a recovery boiler producing steam, then saturated with steam before being sent to a CO-Shift reactor.
• the H 2 -rich gas leaving this reactor will be dried and purified.
• the resulting hydrogen production is 6298 kmol / h per reactor or 1 2596 kmol / h continuously because only two reactors are in reforming phases simultaneously.
• the degree of oxidation remains at 0.3.
• the reactors are purged with steam at 250 ° C. for 50 seconds at a flow rate of 7000 kmol / h per reactor.
• the temperature of the solid then drops to 713 ° C.
• the purge gas produced is cooled through a steam-producing recovery boiler, then the water is condensed and the non-condensable gases are sent to the purification of the synthesis gas.
• the reactors are supplied with compressed air at 32 bar and a temperature of 529 ° C. Each reactor is fed with a flow rate of 4956 kmol / h of air for 650 seconds.
• the initial solid temperature of 713 ° C and its degree of oxidation is 0.3.
• the solid temperature is 1113 ° C and its oxidation degree 0.95.
• the depleted air is cooled through a recovery boiler producing steam, then expanded through a turbine to produce the electricity necessary for the compression of air upstream of the reactors .
• the reactors are purged with steam at 250 ° C. for 50 seconds for a flow rate of 6000 kmol / h per reactor.
• the temperature of the solid then falls to 1100 ° C, the initial temperature of the next combustion phase.
• the purge gas produced is cooled through a recovery boiler producing steam and then sent to the atmosphere.
• the arrangement of these 8 reactors according to the described cycle makes it possible to continuously produce 25.39 t / h of H 2 (12596 kmol / h) by capturing 100% of the CO2 emissions linked to the process, ie 217.98 t / h CO 2 (4952 kmol / h).
• the use of recovery boilers makes it possible to produce the steam necessary for the process and to be in addition surplus on average 55 t / h of steam at 32 bar and 250 ° C.

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