Method and system for the production of synthesis gas, by means of an oxy-hydrogen flame, from various sources of carbon and hydrogen

Abstract

The invention relates to a method for producing a synthesis gas comprising CO and H2, comprising: supplying an oxidising flow comprising O2 and a first reducing flow comprising H2 to a first reaction zone of a reactor, the oxidising flow and / or the first reducing flow comprising CO2; generating an oxy-hydrogen flame in the first zone by reacting O2 and H2, and producing a first gas comprising CO and H2Ovapour by bringing the oxidising flow and the first reducing flow into contact with the oxy-hydrogen flame; supplying a second reducing flow to the reactor, said second reducing flow comprising a source of carbon comprising a hydrocarbon; and generating, in a second reaction zone of the reactor, a second gas that comprises the synthesis gas, from the first gas originating from the first reaction zone and the second reducing flow, by means of a reaction involving the hydrocarbon.

Description

[0001] METHOD AND SYSTEM FOR THE PRODUCTION OF SYNTHESIS GAS BY AN OXYFLAME FROM VARIOUS CARBON AND HYDROGEN SOURCES

[0002] TECHNICAL FIELD

[0003] The present application relates to a method and system for producing a synthesis or reducing gas comprising carbon monoxide (CO) and hydrogen (H2) from various carbon and hydrogen (H2) sources. More particularly, the method for producing the synthesis or reducing gas uses at least a first carbon source which is CO2 and at least a second carbon source comprising a hydrocarbon.

[0004] STATE OF THE ART

[0005] Gas mixtures of carbon monoxide and hydrogen—commonly referred to as synthesis gas or reductant gas—are used in the manufacture of a wide range of commodity products such as synthetic liquid hydrocarbons and alcohols. They can also be used to produce reducing gases in the metallurgical industry (e.g., direct reduction of iron oxides). To produce such gases, including carbon monoxide (CO), a carbon source is required to fuel the process. The carbon source can be derived from fossil resources such as natural gas or coal. By using a carbon source and water vapor, a mixture of carbon monoxide and hydrogen can be produced. Well-known approaches to this include natural gas reforming techniques and steam gasification of coal.

[0006] The fight against climate change will have to involve, among other things, a substantial reduction in greenhouse gas (GHG) emissions, particularly CO2 and methane. Currently, considerable efforts are being made to minimize the consumption of fossil resources as an energy source and also as a basic ingredient for several chemical syntheses. The use of CO2 as a carbon source in the production of synthesis gas is one approach considered to reduce these GHG emissions. CO2 is found in ambient air, but also in atmospheric emissions from industrial processes that emit CO2 (e.g., cement plants, aluminum smelters, steel mills, etc.). The process of capturing CO2 from ambient air, from biogenic sources, or released by industrial processes to recycle it for later use is also known as "Carbon Capture Utilization" (CCU).The captured CO2 can be used as a carbon source for the production of synthesis gas for the production of a wide spectrum of products with improved carbon neutrality, i.e., whose production and use cycle involves little net GHG emissions, when the CO2 comes from biogenic sources or ambient air. It is thus possible to produce synthetic fuels with increased carbon neutrality, which can be used in existing infrastructures. It is also possible to produce synthesis gases that can be used for the formulation of reducing gases for the metallurgical industry (e.g., for the direct reduction of metal oxides).

[0007] There are several ways to use CO2 as a basic reactant to provide carbon for syngas production. The most practical way is to convert CO2 into carbon monoxide (CO) using reaction (A) called "Reverse Water Gas Shift" or RWGS.

[0008] (A) CO2+ H2-> CO + H2O (steam)

[0009] By reacting CO2 with excess hydrogen (H2), mixtures of hydrogen and CO can be produced.

[0010] Catalytic bed reactors are generally used to carry out the RWGS reaction (A). However, the use of conventional catalysts to carry out reaction (A) is not without certain limitations related to the desired CO2 conversion rate. Indeed, to obtain high conversion rates, it is necessary to proceed at a high temperature (for example, more than 1200°C), but the use of conventional catalysts proves problematic at high temperature levels.

[0011] Another method for producing syngas relies on the combustion of hydrogen with pure oxygen in the presence of an oxy-flame. The oxy-flame generates heat and water vapor, following reaction (B). (B) (steam) + HEAT

[0012] The water vapor generated by the oxy-flame following reaction (B) and also by the RWGS reaction (A), during the production of syngas, can be considered as a "loss" of hydrogen and have an impact on operating costs. A method that can take advantage of this generated water vapor, by using it to produce syngas, would be desirable.

[0013] SUMMARY

[0014] According to a first aspect, the present technology relates to a method for producing synthesis gas comprising carbon monoxide (CO) and hydrogen (H2), the method comprising: feeding an oxidizing stream comprising oxygen (O2) and a first reducing stream comprising hydrogen (H2) into at least a first zone of at least one reactor, wherein the oxidizing stream and / or the first reducing stream further comprises a first carbon source which is CO2; generating an oxy-flame in the first zone by reaction between the oxygen of the oxidizing stream and the hydrogen of the first reducing stream, and producing a first gas comprising at least carbon monoxide (CO) and water vapor (H2O) by contacting the oxidizing stream and the first reducing stream with the oxy-flame; feeding into the reactor a second reducing stream comprising a second carbon source comprising at least one hydrocarbon;generation in a second reaction zone of the reactor of a second gas comprising the synthesis gas, from the first gas from the first reaction zone and the second reducing stream by a reaction involving the hydrocarbon.;

[0015] According to one embodiment, the production of the first gas comprising at least carbon monoxide (CO) and water vapor (H2O), in the first zone, is carried out at a temperature of at least 1000°C and at most 2400°C.

[0016] According to another embodiment, the production of the first gas comprising at least carbon monoxide (CO) and water vapor (H2O), in the first zone, is carried out at a temperature of between approximately 1000°C and approximately 1900°C. According to another embodiment, the generation of the synthesis gas, in the second zone, is carried out at a temperature of at least 700°C and at most 1500°C.

[0017] According to another embodiment, the generation of the synthesis gas, in the second zone, is carried out at a temperature between approximately 700°C and approximately 1000°C.

[0018] According to another embodiment, the generation of the synthesis gas, in the second zone, is carried out at a temperature lower than a temperature in the first zone.

[0019] According to another embodiment, the oxidizing flow is supplied in a lower and central part of the first zone and the first reducing flow is supplied in the lower part of the first zone on the periphery of the oxidizing flow.

[0020] According to another embodiment, the second gas generated in the second zone comprises the synthesis gas and residual CO2 and the method further comprises recycling a portion of the second gas into the first zone.

[0021] According to another embodiment, a portion of the second gas is recycled into the first reducing flow.

[0022] According to another embodiment, the method further comprises cooling the portion of the second gas to be recycled, before recycling.

[0023] According to another embodiment, the method is carried out in a plurality of reactors in parallel, each reactor having the first zone which receives the oxidizing flow and the first reducing flow and where the first gas is produced, and the second zone which receives the second reducing flow and where the second gas is generated.

[0024] According to another embodiment, the reactor comprises a plurality of first zones and a second common zone, and wherein: the oxidizing stream and the first reducing stream are supplied to each first zone of the plurality of first zones and the first gas is produced in each first zone, the second reducing stream is supplied to the second common zone which receives the first gas produced in each first zone and the second gas is generated in the second common zone. According to another aspect, the present technology relates to a system for producing a synthesis gas comprising carbon monoxide (CO) and hydrogen (H2), the system comprising at least one reactor and said reactor comprising at least one first reaction zone and at least one second reaction zone, wherein: the first reaction zone is supplied with an oxidizing stream comprising oxygen (O2) and a first reducing stream comprising hydrogen (H2),where the oxidizing stream and / or the first reducing stream further comprises a first carbon source which is CO2, and in the first zone an oxy-flame is generated by reaction between the oxygen of the oxidizing stream and the hydrogen of the first reducing stream, to produce a first gas comprising at least carbon monoxide (CO) and water vapor (H2O) by bringing the oxidizing stream and the first reducing stream into contact with the oxy-flame; the second reaction zone is supplied with a second reducing stream comprising a second carbon source comprising at least one hydrocarbon, to generate in the second reaction zone a second gas comprising the synthesis gas from the first gas from the first reaction zone and the second reducing stream by a reaction involving the hydrocarbon.,

[0025] According to one embodiment, the first zone is at a temperature of at least 1000°C and at most 2400°C during the production of the first gas comprising at least carbon monoxide (CO) and water vapor (H2O).

[0026] According to another embodiment, the first zone is at a temperature between approximately 1000°C and approximately 1900°C during the production of the first gas comprising at least carbon monoxide (CO) and water vapor (H2O).

[0027] According to another embodiment, the second zone is at a temperature of at least 700°C and at most 1500°C during the generation of the synthesis gas.

[0028] According to another embodiment, the second zone is at a temperature between approximately 700°C and approximately 1000°C during the generation of the synthesis gas.

[0029] According to another embodiment, the generation of the synthesis gas, in the second zone, is carried out at a temperature lower than a temperature in the first zone. According to another embodiment, the second gas generated in the second zone comprises the synthesis gas and residual CO2 and the system further comprises a means for recycling a portion of the second gas into the first zone.

[0030] According to another embodiment, the recycling means comprises a conduit conveying the portion of the second gas to be mixed with the first reducing flow.

[0031] According to another embodiment, the system further comprises a device for cooling the part of the second gas to be recycled, before recycling.

[0032] According to another embodiment, the first zone and the second zone are each cylindrical in shape.

[0033] According to another embodiment, the system comprises a first means for supplying the oxidizing flow into a lower and central part of the first zone and a second means for supplying the first reducing flow into the lower part of the first zone on the periphery of the oxidizing flow.

[0034] According to another embodiment, the first means consists of a first central tube and the second means consists of an annular space extending perpendicularly between an outer wall of the central tube and an inner wall of the first zone.

[0035] According to another embodiment, the system comprises a third means for supplying the second reducing flow into the second zone.

[0036] According to another embodiment, the first zone and the second zone are each cylindrical in shape and the third means consists of an opening formed by an annular space extending between an outer wall of the first zone and an inner wall of the second zone, optionally in an upper region of the first zone and a lower region of the second zone.

[0037] According to another embodiment, the system comprises a plurality of reactors in parallel, each reactor having the first zone receiving the oxidizing stream and the first reducing stream and where the first gas is produced, and the second zone receiving the second reducing stream and where the second gas is generated. According to another embodiment, the reactor comprises a plurality of first zones and a second common zone, and wherein: each first zone of the plurality of first zones is supplied with the oxidizing stream and the first reducing stream to produce the first gas in each first zone, and the second common zone is supplied with the second reducing stream and receives the first gas produced in each first zone to generate the second gas in the second common zone.

[0038] In some aspects, the method and / or system according to the present technology may comprise the following embodiments.

[0039] According to one embodiment, the oxidizing flow comprises oxygen and CO2.

[0040] According to another embodiment, the first reducing stream comprises hydrogen (H2) and CO2, and optionally water vapor in an H2O / H2 ratio ranging from 0 to 1, preferably in an H2O / H2 ratio ranging from 0 to 0.5.

[0041] According to another embodiment, the oxidizing stream and the first reducing stream each comprise CO2.

[0042] According to another embodiment, only the oxidizing flow comprises CO2.

[0043] According to another embodiment, the CO2 comes from an industrial discharge, is biogenic CO2 from a biogas, is CO2 captured directly from the ambient air or a mixture of these.

[0044] According to another embodiment, the hydrogen present in the first reducing flow results from a water electrolysis reaction.

[0045] According to another embodiment, the hydrogen present in the first reducing stream results from a water electrolysis reaction in an electrolyzer which is powered by electricity produced from a renewable source (e.g., produced from solar energy, wind energy, hydraulic energy, biomass or geothermal energy) or nuclear energy. According to another embodiment, the hydrogen present in the first reducing stream results from a steam reforming reaction of natural gas or methane in a process for which the CO2 generated is at least partly captured and sequestered.

[0046] According to another embodiment, the hydrogen present in the first reducing stream comprises hydrogen resulting from a water electrolysis reaction in an electrolyzer which is powered by electricity produced from a renewable source (e.g., produced from solar energy, wind energy, hydraulic energy, biomass or geothermal energy) or nuclear energy, and hydrogen resulting from a steam reforming reaction of natural gas or methane in a process for which the CO2 generated is at least partly captured and sequestered.

[0047] According to another embodiment, the hydrogen present in the first reducing stream further comprises hydrogen resulting from a methane pyrolysis reaction.

[0048] According to another embodiment, hydrogen, oxygen and CO2 are supplied to the first zone in a H2 / O2 molar ratio of at least 2, and a H2 / CO2 molar ratio of at least 1.8.

[0049] According to another embodiment, hydrogen, oxygen and CO2 are supplied to the first zone in a molar ratio H2 / O2 of between 2 and 10, and a molar ratio H2 / CO2 of between 1.8 and 9.

[0050] According to another embodiment, oxygen and CO2 are supplied to the first zone in an O2 / CO2 molar ratio of at least 0.5.

[0051] According to another embodiment, oxygen and CO2 are supplied to the first zone in an O2 / CO2 molar ratio of between 0.5 and 6.

[0052] According to another embodiment, the generation of the synthesis gas comprises steam reforming of the hydrocarbon(s) with the water vapor included in the first gas.

[0053] According to another embodiment, the second reducing stream further comprises water vapor and the generation of the synthesis gas comprises steam reforming of the hydrocarbon(s) with the water vapor included in the first gas and the water vapor included in the second reducing stream.

[0054] According to another embodiment, the second carbon source comprises a fossil or renewable hydrocarbon.

[0055] In another embodiment, the second carbon source comprises fossil or renewable natural gas.

[0056] In another embodiment, the second carbon source comprises methane.

[0057] In another embodiment, the second carbon source comprises methane from biogas.

[0058] According to another embodiment, the second reducing flow further comprises an organic compound derived from biomass.

[0059] According to another embodiment, the second reducing flow further comprises a compound of formula C a HpO Y with a varying from 1 to 5, p varying from 2 to 10 and y varying from 1 to 4.

[0060] According to another embodiment, the second reducing flow comprises methane (CH4) and optionally hydrogen (H2) in a molar ratio H2 / CH4 between 0 and 2.5.

[0061] According to another embodiment, the second reducing flow comprises methane (CH4) and optionally hydrogen (H2) and a molar ratio between the CH4 supplied and a total quantity of H2 supplied in the two zones is between 0.1 and 1.

[0062] According to another embodiment, the second reducing flow further comprises hydrogen (H2).

[0063] According to another embodiment, the hydrogen present in the second reducing stream results from a steam reforming reaction of natural gas or methane in a process for which the CO2 generated is at least partly captured and sequestered.

[0064] According to another embodiment, the second reducing stream comprises a quantity of hydrogen to balance the molar composition of the synthesis gas to have H2 / CO > 2 and (H2-CO2) / (CO+CO2) > 2. According to another embodiment, the second reducing stream comprises methane (CH4) and optionally water vapor (H2O) and a molar ratio between water vapor (H2O) and CH4 is between 0 and 2.

[0065] According to another embodiment, the second reducing flow further comprises water vapor.

[0066] According to another embodiment, the production of carbon monoxide and water vapor in the first zone is carried out in the absence of a catalyst.

[0067] According to another embodiment, the generation of the second gas comprising the synthesis gas in the second zone of the reactor is carried out in the absence of catalyst.

[0068] According to another embodiment, the oxygen (O2) present in the oxidizing flow results from a water electrolysis reaction.

[0069] According to another embodiment, the oxygen (O2) present in the oxidizing flow comes from an air separation unit (ASU).

[0070] In yet another aspect, the present technology relates to the use of a synthesis gas produced by the method as defined in the present description or by the system as defined in the present description, for the manufacture of chemicals or fuels.

[0071] According to one embodiment, the use allows the manufacture of synthetic hydrocarbons.

[0072] According to yet another aspect, the present technology relates to the use of a synthesis gas produced by the method as defined in the present description or by the system as defined in the present description, as a reducing agent for the metallurgical industry.

[0073] According to yet another aspect, the present technology relates to the use of a system as defined in the present description for the treatment of gaseous industrial effluents containing CO2. BRIEF DESCRIPTION OF THE FIGURES

[0074] Figure 1 represents a schematic sectional view along the vertical of a reactor which can be used to carry out the method according to one embodiment.

[0075] Figure 2 represents a schematic sectional view along the vertical of a reactor which can be used to carry out the method according to an embodiment where the oxy-flame extends towards the second zone.

[0076] Figure 3 represents a schematic sectional view along the vertical of a reactor which can be used to carry out the method according to another embodiment.

[0077] Figure 4 represents a schematic view in section along the vertical of a system comprising several reactors in parallel, which can be used to carry out the method according to another embodiment.

[0078] Figure 5 represents a schematic sectional view along the vertical of a reactor comprising several first reaction zones and a second common zone, which can be used to carry out the method according to yet another embodiment.

[0079] Figure 6 shows a bottom view of the reactor of Figure 5.

[0080] Figure 7 shows a schematic vertical sectional view of a reactor that can be used to carry out the present method and which is used for the examples. The figure shows the general arrangement of the tubes for this reactor.

[0081] DETAILED DESCRIPTION

[0082] All technical and scientific terms and expressions used herein have the same meaning as generally understood by a person skilled in the art of the present technology. Definitions of certain terms and expressions used are nevertheless provided below.

[0083] The term "about" as used in this document means approximately, in the region of, and around. When the term "about" is used in connection with a numerical value, it modifies it, for example, above and below by a variation of 10% from the nominal value. This term may also take into account, for example, the experimental error of a measuring device or the rounding of a value.

[0084] Where a range of values ​​is referred to in this application, the lower and upper bounds of the range are, unless otherwise indicated, always included in the definition.

[0085] In this disclosure, the terms "synthesis gas", "reducing gas", and "syngas" are used interchangeably to identify a gas mixture comprising at least carbon monoxide (CO) and hydrogen (H2). In some embodiments, the synthesis gas, reducing gas, or syngas may comprise CO2.

[0086] The term "flow" is used to describe the different gas flows that are used for the production of synthesis gas, in the different zones, inside the reactor.

[0087] The term "carbon source" describes the chemical compound(s) that are used to provide the carbon that is found in the produced syngas. Thus, the carbon source provides at least the carbon that is found in the produced carbon monoxide (CO). Different chemical compounds can be used as the carbon source. The present method uses at least CO2 and at least one hydrocarbon (Le., compound based primarily on carbon and hydrogen) as the carbon source to produce the syngas. In some embodiments, the hydrocarbon used as one of the carbon sources is methane (CH4) or fossil or renewable natural gas (RNG). In some embodiments, other carbon sources such as organic compounds comprising carbon, hydrogen and oxygen, can be used, as will be explained below.

[0088] The terms "electricity from a renewable source" or "electricity produced from a renewable source" mean electricity produced from solar energy, wind energy, hydropower, biomass or geothermal energy.

[0089] The term "fossil natural gas" as used in this specification means a mixture of gaseous hydrocarbons (primarily methane) derived from the natural transformation of organic matter from underground deposits. The term "renewable natural gas" (RNG) as used in this specification means a gaseous fuel also known as biomethane or first-generation RNG, which may generally contain between 55 and 99% methane, produced from biogas resulting from the anaerobic digestion of organic matter.

[0090] The present document therefore presents an innovative method for the production of synthesis gas from at least CO2 as a carbon source and involving an oxy-flame generated by reaction between oxygen and hydrogen. More specifically, the method for producing synthesis gas comprises: feeding an oxidizing stream comprising oxygen (O2) and a first reducing stream comprising hydrogen into at least a first reaction zone of at least one reactor, wherein the oxidizing stream and / or the first reducing stream further comprises a first carbon source which is CO2; generating an oxy-flame in the first zone by reaction between the oxygen of the oxidizing stream and the hydrogen of the first reducing stream, and producing a first gas comprising at least carbon monoxide (CO) and water vapor (H2O) by bringing the oxidizing stream and the first reducing stream into contact with the oxy-flame;feeding the reactor with a second reducing stream comprising a second carbon source comprising at least one hydrocarbon; and generating in a second zone of the reactor a second gas comprising the synthesis gas, from the first gas from the first zone and the second reducing stream using a reaction involving the hydrocarbon.;

[0091] As indicated above, the method uses at least CO2 as a carbon source to produce the synthesis gas. The CO2 can have various origins. Thus, the method can use CO2 from an industrial discharge, biogenic CO2 from a biogas, or CO2 captured directly from the ambient air, e.g., according to the process called "Direct Air Capture" (DAC). In certain embodiments, the carbon source comprises CO2 captured from the ambient air or CO2 from biomass, this carbon is then described as "carbon neutral" or "biogenic".

[0092] Figure 1 illustrates the general principle of operation of the method. According to certain embodiments, the method can therefore be carried out in at least one reactor 10 having two reaction zones 12 and 14. According to certain embodiments, the reactor is provided with thermal insulation (not shown in the figures). The second reaction zone can be referred to as a zone downstream of the first reaction zone since the products resulting from the reaction(s) involved in the first zone can serve as inputs for the reaction(s) occurring in the second reaction zone. As will be explained in more detail below, the reactions occurring in the second reaction zone are different from those occurring in the first reaction zone.In the first zone, the reaction(s) involve(s) at least CO2 as the first carbon source and in the second zone, a second carbon source comprising a hydrocarbon is used. Several sources and types of carbon and / or hydrogen can be used at strategic locations in the reactor. According to certain embodiments, the choice of the carbon and / or hydrogen source and the location where these gases are fed into the reactor can reduce operating costs. According to certain embodiments, the method can be carried out in at least one reactor provided with two reaction zones 12 and 14, an inlet zone 20 and an outlet zone 28. The first reaction zone 12 is fed by at least two gas streams. The stream 16 which is fed into the first reaction zone 12 is an oxidizing stream which comprises at least oxygen (O2).The gas stream 18 which is fed into the first reaction zone 12 is a first reducing stream which comprises at least hydrogen (H2). According to the present method, at least one of the oxidizing stream 16 and the first reducing stream 18 further comprises a first carbon source which is CO2.

[0093] In the first reaction zone 12, the oxy-flame 22 is produced by the combustion of hydrogen (H2) from the first reducing stream 18 in the presence of oxygen (O2) from the oxidizing stream 16 according to the reaction (B) mentioned above. This flame is lively and radiant and makes it possible to provide the heat required to support the reaction which will produce a first gas comprising carbon monoxide (CO) produced from the first carbon source comprising at least CO2, and also comprising water vapor, according to the reaction (A) of the RWGS. Thus, the first gas comprising at least carbon monoxide (CO) and water vapor (H2O) is obtained by “bringing into contact” the oxidizing stream and the first reducing stream with the oxy-flame. The expression "contacting" according to the present method is understood to mean a distance "d" between the oxidizing flow and the reducing flow which can range from 0 to 50 mm, and preferably from 0 to 30 mm.The distance "d" between the oxidizing stream and the reducing stream in may be 0 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, or any value therebetween. For example, the distance "d" may range from 0 to 50 mm, 0 to 40 mm, 0 to 30 mm, 0 to 20 mm, or 0 to 10 mm. In addition, the oxy-flame may generate ionic species and free radicals that may promote the conversion of the carbon source to CO. Thus, it is also noted that the production of carbon monoxide and water vapor in the first reaction zone 12 may be carried out in the absence of a catalyst such as conventionally used solid catalysts. The combustion of hydrogen (H2) in the presence of oxygen (O2) which makes it possible to produce the oxy-flame can be initiated using an ignition device. According to certain embodiments, the oxy-flame can make it possible to reach a temperature, in the first reaction zone, of at least 600°C.According to other embodiments, the temperature reached in the first zone 12 is at least 1000°C and at most 2400°C. According to some embodiments, the reactor may be provided with thermal insulation around the reactive zones to minimize heat loss and thus maintain the temperature in the reactor at a level high enough to support the reactions. According to some embodiments, the production of the first gas comprising at least carbon monoxide (CO) and water vapor (H2O) in the first zone 12 may be carried out at a temperature between about 1000°C and about 2300°C, or between about 1000°C and about 2200°C, or between about 1000°C and about 2100°C, or between about 1000°C and about 2000°C, or between about 1000°C and about 1900°C.The temperature in the first zone 12 may also vary between approximately 1000°C and approximately 1800°C, between approximately 1000°C and approximately 1700°C, between approximately 1000°C and approximately 1600°C, or between approximately 1000°C and approximately 1500°C. In certain embodiments, as shown in Figure 2, the oxy-flame that is generated in the first zone 12 may extend into the second zone 14 of the reactor. Figures 1 and 2 generally show a reactor where the reaction zones 12 and 14 appear one above the other (zones in series), but other configurations are conceivable. Thus, according to certain embodiments, the two reaction zones 12 and 14 may be at least partially adjacent to each other (zones in parallel). In one embodiment, the oxygen (O2) used in the oxidizing stream is pure oxygen.By "pure" oxygen, it is understood that this does not necessarily mean 100% purity, but that the oxygen-based mixture substantially comprises O2 and may be accompanied by certain impurities such as N2, H2O for example. According to certain embodiments, the oxygen present in the oxidizing stream 16 results from a water electrolysis reaction. According to certain other embodiments, the oxygen (O2) present in the oxidizing stream 16 may come from an air separation unit (ASU). It would also be possible to use oxygen which would be a mixture of oxygen resulting from a water electrolysis reaction and coming from an air separation unit.

[0094] In some embodiments, the first carbon source, which comprises CO2, is fed into the first zone of the reactor with oxygen from the oxidizing stream. In another embodiment, the first carbon source, which comprises CO2, is fed into the first zone of the reactor with hydrogen from the first reducing stream. In some cases, a portion of the first carbon source, which comprises CO2, is fed into the first zone of the reactor with oxygen from the oxidizing stream and another portion of the first carbon source is fed into the first zone of the reactor with hydrogen from the first reducing stream. In a preferred embodiment, the first carbon source, which comprises CO2, is fed into the first zone only with oxygen from the oxidizing stream.

[0095] As mentioned previously, CO2 may have various origins. In some embodiments, the CO2 comes from an industrial discharge, is biogenic CO2 from a biogas, or is CO2 captured directly from ambient air. In some preferred embodiments, the CO2 that is used as the primary carbon source is biogenic CO2 from a biogas.

[0096] According to one embodiment, the hydrogen required in the present method may be hydrogen qualified as low carbon hydrogen. According to one embodiment, the hydrogen required in the present method to produce the oxy-flame in the first zone, i.e. the hydrogen present in the first reducing stream 18, may, at least in part, result from a water electrolysis reaction. This hydrogen is qualified as “green hydrogen” if the electrolyzer in which the water electrolysis is carried out is powered by electricity produced from a renewable source, such as for example from solar energy, wind energy, hydraulic energy, biomass or geothermal energy.In some embodiments, the electricity used for water electrolysis may come from nuclear energy which is an energy source that does not emit greenhouse gases, and this hydrogen may also be referred to as "pink hydrogen" in the context of the present technology.

[0097] According to another embodiment, the hydrogen present in the first reducing stream 18 fed into the first zone of the reactor may be “blue hydrogen”, i.e. hydrogen resulting from a steam reforming reaction of natural gas or methane in a process for which the CO2 generated is at least partly captured and sequestered.

[0098] According to yet another embodiment, the hydrogen present in the first reducing stream 18 fed into the first zone of the reactor may be “turquoise hydrogen”, i.e. hydrogen resulting from a methane pyrolysis reaction.

[0099] According to yet another embodiment, the hydrogen present in the first reducing flow 18 supplied to the first zone of the reactor may be “pink hydrogen”, that is to say hydrogen resulting from a water electrolysis reaction supplied by nuclear energy.

[0100] It is also possible to use hydrogen mixtures from various sources to supply the first zone, to produce the oxy-flame and form the first gas comprising carbon monoxide (CO) and water vapor (H2O). Thus, in certain embodiments, the first reducing stream 18 may comprise a mixture of green hydrogen and blue hydrogen, or a mixture of green hydrogen and turquoise hydrogen, a mixture of blue hydrogen and turquoise hydrogen, a mixture of green hydrogen, blue hydrogen and turquoise hydrogen.

[0101] In certain embodiments, the quantities of hydrogen supplied in the first zone 12 (eg, green, blue, pink and / or turquoise hydrogen) are metered so as to reduce operating costs as much as possible while ensuring that at the outlet of the reactor, the molar composition of the synthesis gas satisfies the following equations (C) and (D):

[0102] (C) H2 / CO > 2

[0103] (D) (H2-CO2) / (CO+CO2) > 2 These equations also take into account the fact that additional hydrogen can be introduced into the second zone 14 of the reactor via stream 24, as will be discussed below, to balance the composition of the synthesis gas.

[0104] In some embodiments in particular, the hydrogen, oxygen, and CO2 are supplied to the first zone 12 in an H2 / O2 molar ratio of at least 2, and an H2 / CO2 molar ratio of at least 1.8. In another embodiment, the hydrogen, oxygen, and CO2 may be supplied to the first zone in an H2 / O2 molar ratio of between 2 and 10, and an H2 / CO2 molar ratio of between 1.8 and 9. Thus, the hydrogen and oxygen may be supplied to the first zone 12 with an H2 / O2 molar ratio of about 2, about 3, about 4, about 5, about 6, about 7, about 8, about 9, or about 10, or any value in between.Additionally, the amount of hydrogen and the amount of CO2 supplied to the first zone may be adjusted such that the H2 / CO2 molar ratio is about 1.8, or about 2, or about 3, or about 4, or about 5, or about 6, or about 7, or about 8, or about 9, or any value in between. In some embodiments, the oxygen and CO2 may be supplied to the first zone in an O2 / CO2 molar ratio of at least 0.5. For example, oxygen and CO2 may be supplied to the first zone in an O2 / CO2 molar ratio of between 0.5 and 6. Thus, the amount of oxygen and the amount of CO2 supplied to the first zone may be adjusted such that the O2 / CO2 molar ratio is about 0.5, or about 1, or about 2, or about 3, or about 4, or about 6, or any value in between.The molar ratios H2 / O2, H2 / O2 and O2 / CO2 can be adjusted according to the quantity of other gases sent into the reactor if applicable, and according to the ratio of CO and H2 desired in the final synthesis gas.

[0105] It should be noted that in certain embodiments, the oxidizing stream 16 and / or the reducing stream 18 may contain, in addition to the inputs described above, a certain quantity of impurities and water vapor. According to certain embodiments, the reducing stream 18 may contain water vapor up to a H2O / H2 molar ratio of 0.5.

[0106] Still referring to Figures 1 and 2, the reactor 10 comprises a second reaction zone 14 generally configured in series with respect to the first zone 12. In certain embodiments, as mentioned previously and illustrated in Figure 2 in particular, the oxy-flame 22 which is generated in the first zone may extend into the second zone 14. Thus, the two zones 12 and 14 may also be at least partly parallel to each other. In Figures 1 and 2, the streams are fed into each of the reaction zones in a substantially parallel manner. Thus, the first reducing stream and the second reducing stream are substantially parallel in the reactor. However, in other embodiments, it could be envisaged to have a feed of the streams "at an angle", that is to say that the first reducing stream and the second reducing stream could be fed at a certain angle to each other.In some embodiments, the first reducing stream and the second reducing stream could be fed at a substantially perpendicular angle to each other.

[0107] The second reaction zone receives the gas formed in the first reaction zone which comprises at least CO and water vapor generated by reactions (A) and (B) and possibly a certain quantity of residual CO2 and / or hydrogen H2. This second reaction zone 14 is further supplied with a second reducing stream 24 comprising a second carbon source comprising at least one hydrocarbon. Furthermore, the reducing stream 24 may comprise water vapor. After reaction of the second reducing stream with the first gas in the second reaction zone of the reactor, a second gas 26 comprising the synthesis gas is recovered at the outlet of the reactor 28.

[0108] The second reducing stream 24 comprises at least one hydrocarbon as a second carbon source, and the generation of the synthesis gas, in the second reaction zone 14, is carried out in part by steam reforming the hydrocarbon(s) with the water vapor included in the first gas and / or water vapor possibly present in the reducing stream 24 as mentioned above. This carbon source may be a fossil or renewable hydrocarbon, preferably methane or fossil or renewable natural gas (RNG). In certain embodiments, the second carbon source is methane which comes from biogas. In the case where a hydrocarbon which is methane is used, the reaction (E), and the reaction (F) in the presence of residual CO2, occur in the second zone 14.

[0109] (F) CH4+ CO2-> 2 CO + 2H2

[0110] By steam reforming the hydrocarbon(s) fed into the second zone, a synthesis gas meeting the criteria presented by equations (C) and (D) can be obtained.

[0111] As explained above, hydrogen can also be supplied to the second zone 14 to produce the synthesis gas. When additional hydrogen is supplied to the zone 14 by the reducing stream 24, on the one hand, the composition of the synthesis gas can be balanced to comply with equations (C) and (D) as mentioned above and, on the other hand, the water vapor and residual CO2 in this zone can be reduced.

[0112] Furthermore, the molar proportions of CO and H2 in the synthesis gas can also be varied by feeding the second zone 14 with both one or more hydrocarbons and hydrogen.

[0113] According to certain embodiments, the hydrogen which is supplied via the second reducing flow 24 in the second zone 14 may be blue hydrogen as described above, that is to say hydrogen resulting from a steam reforming reaction of natural gas or methane in a process for which the CO2 generated is at least partly captured and sequestered.

[0114] According to certain embodiments, the second reducing flow 24 may comprise methane (CH4) and optionally hydrogen (H2) in a molar ratio H2 / CH4 between 0 and 2.5.

[0115] According to another embodiment, the second zone can be supplied with a second reducing flow 24 comprising methane (CH4) and optionally hydrogen (H2), such that the molar ratio between the CH4 supplied and a total quantity of H2 supplied in the two zones is between 0.1 and 1.

[0116] It should be noted that in certain embodiments, the second reducing stream 24 may contain, in addition to the inputs described above, water vapor and a small quantity of impurities. According to certain embodiments, the reducing stream 24 fed into the second zone 14 may comprise methane (CH4) and optionally water vapor (H2O) with a molar ratio of water vapor (H2O) relative to CH4 which may be between 0 and 2.

[0117] According to certain embodiments, the reducing flow 24 fed into the second zone 14 may further comprise organic compounds derived from biomass, i.e. comprising biogenic carbon. These organic compounds comprising biogenic carbon may have the formula CJHpOy with a varying from 1 to 5, p varying from 2 to 10 and y varying from 1 to 4.

[0118] In some embodiments, the reaction in the second zone 14 of the reactor is carried out at a temperature that is lower than the temperature in the first zone 12. In some embodiments, the generation of the synthesis gas, in the second zone 12, may be carried out at a temperature of at least 700°C and at most 1500°C. In some cases, the temperature in the second reaction zone may be between about 700°C and about 1000°C. Thus, the temperature in the second reaction zone may also be between about 700°C and about 1400°C, between about 700°C and about 1300°C, between about 700°C and about 1200°C, between about 700°C and about 1100°C, between about 700°C and about 1000°C, between about 700°C and about 900°C, or between about 700°C and about 800°C.It is possible to achieve a lower temperature in the second zone 14 in various ways, such as by adjusting the insulation and / or the heating or cooling system of the reactor. In some embodiments, the desired temperature in the second reaction zone 14 can be achieved by using a less insulated wall than, for example, the reactor wall in the first zone. It is also possible, in some cases, to use a cooling system to achieve the desired temperature in the second zone of the reactor.

[0119] According to certain embodiments, the production of the synthesis gas in the second zone 14 of the reactor can be carried out in the absence of a catalyst such as solid catalysts (eg, metal catalysts) as conventionally used.

[0120] With the use of the second reaction zone 14, the amount of water vapor that results from the reaction that takes place in the first zone 12 and the amount of water vapor possibly present in the stream 24 fed into this second zone, are reduced substantially. This presents an important advantage. In addition, in certain embodiments, if CO2 persists in the zone 14 as a result of the reactions that occur there, and it is preferable to reduce it further, a return loop 30 as shown in Figure 3, can be activated to return a portion of the gas generated in the second zone 14 to the first zone 12 of the reactor. According to certain embodiments, the portion of the second gas that is recycled can be mixed with the first reducing stream 18 before feeding into the first zone 12. Furthermore, the portion of the second gas that is recycled can be cooled at the outlet 28 of the reactor before being returned to the first zone.According to some embodiments, the cooling must allow over-pressurization of the gas at outlet 28 using a fan.

[0121] In a particular embodiment, the production of syngas according to the present method may comprise feeding into the first zone 12, an oxidizing stream 16 comprising oxygen and a renewable carbon source and a first reducing stream 18 comprising green hydrogen, and, in the second zone 14, feeding blue hydrogen as well as a fossil carbon source. If the renewable carbon source is CO2 and the fossil carbon source is methane, the reactions involved may allow the efficient and low-cost production of syngas. Equation (G) below presents a typical overall reaction scheme that may be carried out:

[0122] (G) 1 / 202 + H2(green) + CO2(renewable) + 2CH4(fossil) + H2(blue) 3 (CO+ 2H2)

[0123] Considering that the method, although it can use fossil carbon sources as inputs, also uses CO2 as input, the net GHG emission of the reactor can be zero or very close to zero; this method can be considered as a carbon capture and utilization (CCU) method.

[0124] A schematic representation of a reactor that can be used for the implementation of the present method is shown in Figures 1 to 3. However, the design of the reactor may vary and / or a system comprising several reactors may be used. Other examples of designs are shown in Figures 4 to 7 which will be discussed below. However, the design of the reactor or system is not limited to the representations of Figures 1 to 7, and this design can be adjusted as long as it allows the reactions involved in the production of the syngas to be carried out, according to the parameters described above.

[0125] In some embodiments, a cylindrically shaped reactor may be used that includes two reaction zones, as described above. In some embodiments, each of the two zones may itself be cylindrical.

[0126] The reactor 10 may comprise a first means for supplying the oxidizing stream 16 into a lower and central portion of the first zone 12 and a second means for supplying the first reducing stream 18 into the lower portion of the first zone at the periphery of the oxidizing stream. In some embodiments, the reactor may comprise a first central tube through which the oxidizing stream 16 is supplied into the first zone 12 and an annular space extending perpendicularly between an outer wall of the central tube and an inner wall of the first zone 12 for supplying the first reducing stream 18. In addition, the reactor may comprise a third means for supplying the second reducing stream 24 into the second zone 14. In some embodiments, this third means may consist of an opening formed by an annular space extending between an outer wall of the first zone 12 and an inner wall of the second zone 14.In some embodiments, the annular space through which the second reducing stream 24 is fed into the reactor may extend between the outer wall of the first zone 12 and the inner wall of the second zone 14 in an upper region of the first zone and a lower region of the second zone. In some embodiments, the inlets of each of the streams 16, 18 and 24 may be at the same level as shown in Figure 7 for example. The reactor may also include an outlet 28 in an upper portion of the second zone 14 for recovering the gas formed in the second zone which comprises the synthesis gas. Furthermore, as mentioned above, the reactor may be provided with a return loop 30 (Figure 3) for possibly returning a portion of the gas formed in the second zone 14.According to another embodiment, the production of the synthesis gas can be carried out using a plurality of reactors positioned in parallel, as shown in Figure 4. Each of the reactors can correspond to one of the reactors shown in Figures 1 to 3 for example. However, the reactors of Figure 4 can have a different design as long as each reactor has a first zone where the oxidizing stream and the first reducing stream are fed to produce the first gas, and a second zone where the second reducing stream is fed to generate the second gas comprising the synthesis gas, according to the parameters and conditions described previously.

[0127] According to yet another embodiment, the production of the synthesis gas can be carried out using a reactor comprising a plurality of first zones 12 and a second common zone 14 (Figures 5 and 6). More particularly, in this embodiment, each first zone 12 of the reactor is supplied with the oxidizing stream and the first reducing stream to produce the first gas in each first zone, and the second common zone 14 is supplied with the second reducing stream 24 and receives the first gas produced in each first zone to generate the second gas in the second common zone. Thus, the first zones 12 operate in parallel and each comprises an oxy-flame. According to certain embodiments, the second reducing stream 24 can be supplied into the second common zone 14 by at least one inlet which can be located in a peripheral zone of the second zone.However, several inlets may be provided to feed the second reducing flow 24 into the second zone. For example, inlets may be provided at several locations in a peripheral zone of the second zone and near the lower portion of its inner wall.

[0128] The synthesis gas obtained at the reactor outlet is generally cooled to then be used in a subsequent chemical synthesis. The method described in this document can make it possible to produce synthesis gases based on CO and H2 which are balanced, i.e., with appropriate proportions of CO and H2, to then allow the production of a variety of products by conventional chemical syntheses. Thus, it is possible by controlling the nature and quantity of reactants used (e.g., the flow rate of the gas streams), to produce a synthesis gas where the proportion of CO and H2 is adapted so that the mixture can be used in a subsequent chemical synthesis. It is also possible to adjust the proportion of CO and H2 in the synthesis gas by controlling the temperature and possibly the pressure in each reaction zone of the reactor.This pressure is generally around atmospheric pressure and can typically vary between 1 and 5 bar (absolute pressure), for each zone. In some embodiments, the absolute pressure in the first zone can range from 1 to 5 bar, or from 1 to 4 bar, or from 1 to 3 bar, or from 1 to 2 bar. The absolute pressure in the first zone can be about 1 bar, about 2 bar, about 3 bar, about 4 bar, about 5 bar, or any pressure value between these values. In some embodiments, the absolute pressure in the second zone can range from 1 to 5 bar, or from 1 to 4 bar, or from 1 to 3 bar, or from 1 to 2 bar. The absolute pressure in the second zone can be about 1 bar, about 2 bar, about 3 bar, about 4 bar, about 5 bar, or any pressure value between these values. According to some realizations, the pressure in the first zone and the pressure in the second zone are very close, or even the same.

[0129] In some embodiments, the synthesis gas produced by the present method can be used to produce a wide variety of basic chemicals and fuels. These products include methanol and hydrocarbons such as those found in motor gasoline, diesel, and kerosene, to name a few examples. In some embodiments, the synthesis gas produced by the present method is used as a reducing agent for the metallurgical industry, among other things, for the direct reduction of metal oxides, including iron oxides.

[0130] The synthesis gas production method described above and the reactor that can be used to carry out this method therefore have several advantages. The reactants are easily accessible and can be derived from renewable sources and the method is simple to implement. There is no need to resort to the use of solid catalysts. It is possible to use hydrogen from various sources and it is therefore possible to reduce costs by using hydrogen produced at a lower cost. It is possible to use hydrogen with a low carbon footprint (e.g., green, blue, turquoise and / or pink hydrogen). Thus, if green hydrogen is produced at a higher cost than blue hydrogen for example, the amount of green hydrogen used in the method can be reduced by using blue hydrogen in addition to green hydrogen, or simply by using only blue hydrogen.The method also takes advantage of the water vapor generated during CO2 reduction, using it to produce syngas. This avoids the need to condense a significant amount of water as is done in other known methods and avoids indirect loss of hydrogen via water vapor. The method has a beneficial environmental effect by recycling CO2 while allowing the efficient conversion of other carbon sources such as fossil hydrocarbons, such as methane for example. Finally, the method allows for a significant overall conversion of the carbon entering the reactor to CO while being flexible through relative and in situ conversions of CO2 and hydrocarbon(s).

[0131] EXAMPLES

[0132] As examples, laboratory tests have been carried out to demonstrate the concept proposed in the present application. These examples are based on an arrangement similar to that shown in Figure 7. The inlets of each of the streams 16, 18 and 24 are physically at the same level. Streams 16 and 18 define the first reaction zone while stream 24 defines the second reaction zone, the latter on the periphery of the first reaction zone.

[0133] The reactor consists of an external alumina tube (99.8% AI2O3) with 13.54 mm internal diameter and 19.05 mm external diameter over a length of 212 mm. The reaction volume is 33 cm 3The gas inlet is achieved by means of three spaces, a central space and two annular spaces defined by the end of two concentric alumina tubes: a central tube and a middle tube. These two concentric tubes have the following dimensions respectively: an internal diameter of 6.31 mm with an external diameter of 4.11 mm for the central tube, and an internal diameter of 8.48 mm with an external diameter of 12.34 mm for the middle tube. The end of the central tube defines the passage of the oxidizing flow 16 of the first zone of the reactor, while the annular space between the external diameter of the central tube and the internal diameter of the middle tube is found to define the passage of the reducing flow 18 of the first reaction zone. Finally, the annular space between the internal diameter of the external tube and the external diameter of the middle tube is found to define the passage of the second reducing flow of the second reaction zone 24.

[0134] The external alumina tube, which defines the wall of the reaction chamber, is itself surrounded - along the entire length of the reactor - by an insulating jacket based on calcium silicate (thermal conductivity of 0.3 W / mK, density of 1.36 g / cm 3 ) cylindrical in shape with an external diameter of 132 mm and an internal diameter of 20 mm (not shown in Figure 7). The purpose of the insulating jacket is to provide some thermal insulation of the reactor so as to minimize heat losses.

[0135] For each of these examples, oxygen is mixed with CO2 and this mixture constitutes the oxidizing stream 16 of the first reaction zone. In the examples, the supplied hydrogen constitutes the reducing stream 18 of the first zone. For the first and third examples, methane is supplied to constitute the reducing stream 24 of the second zone while for the second example, it is a mixture of methane and water vapor which constitutes the reducing stream 24 of the second zone. The methane-water vapor mixture is produced by a device for hot saturation of the methane flow in the presence of a controlled flow of water.

[0136] Each of the examples is presented in Table 1. In this table, for each of the gases fed, the number of the gas stream in question (16, 18 or 24) is indicated in parentheses, next to the volume flow rate of this gas (sL / min, i.e. the flow rate at 25°C, 1 atm). A sample of the gas leaving the reactor is dried by rapid cooling (to -1°C) before being sent to a mass spectrometry analysis system. The gas analysis is therefore given on a dry basis.

[0137] The table provides the analysis of the gas leaving the reactor as determined by mass spectrometry. From the volume composition of the gas, the ratio S equal to (H2-CO2) / (CO+CO2) is calculated on the basis of the respective volume fraction of each of the gases H2, CO2 and CO of the dry gas obtained. The conversion rate of methane and that of CO2 are calculated from the atomic balances and from the composition of the gas (dry basis) as obtained by gas analysis by mass spectrometry. The table also presents the conversion rate to CO of the total carbon entering the reactor, i.e. the carbon contained in the CO2 fed plus the carbon contained in the CH4 fed.

[0138] The table also shows the temperature as measured using a thermocouple located 25 mm from outlet 28 of the reactor. The measured temperature value is used to calculate the average residence time of the reactants (i.e. all the gases fed) in the reactor, based on the reaction volume as described above and assuming that the reactor operates at atmospheric pressure.

[0139] It should be noted that no measurable carbon was observed in the reactor after the tests. Table 1 presents the results obtained for each of the two examples.

[0140] Table 1

[0141] The results of Examples 1, 2 and 3 as presented in Table 1 demonstrate the flexibility of the method and system according to the present description. This flexibility results essentially from the geometric distinction of the reactive zones in the reactor. In particular, the configuration used in these examples (see Fig. 7) offers the advantage of obtaining a fairly broad and flexible range of relative and in situ conversions of CH4 and CO2 while ensuring an overall and significant conversion of the carbon entering the reactor (of at least 70%). The results of Examples 1 and 2 show that the supply of water vapor is not critical to achieve a high conversion of methane. Indeed, an addition of water in the second zone only slightly increases the conversion of methane (from 79% to 83%) (by reaction (E)) but promotes a decrease in the conversion of CO2 probably by promoting the reverse of reaction (A).The results of Example 3 show that a high and equivalent conversion of CH4 and CO2 is achievable by adding a certain amount of excess hydrogen in the first zone (9 vs. 6 sL / min). Indeed, this excess hydrogen seems to help convert CO2 more efficiently in the first zone by reaction (A)). In this same Example 3, we see that the conversion of CH4 is not significantly affected by the increase in CO2 conversion due to the fact that this CH4 is fed separately into the second zone.

[0142] Although certain embodiments of the technology have been described above, the technology is not limited to these embodiments alone. Several modifications could be made to any of the embodiments described above, without departing from the scope of the present technology as contemplated.

Claims

DEMANDS 1- A method for producing synthesis gas comprising carbon monoxide (CO) and hydrogen (H2), the method comprising: feeding an oxidizing stream comprising oxygen (O2) and a first reducing stream comprising hydrogen (H2) into at least a first reaction zone of at least one reactor, wherein the oxidizing stream and / or the first reducing stream further comprises a first carbon source which is CO2; generation of an oxy-flame in the first zone by reaction between the oxygen of the oxidizing stream and the hydrogen of the first reducing stream, and production of a first gas comprising at least carbon monoxide (CO) and water vapor (H2O) by contacting the oxidizing stream and the first reducing stream with the oxy-flame; feeding into the reactor a second reducing stream comprising a second carbon source comprising at least one hydrocarbon;generation in a second reaction zone of the reactor of a second gas comprising the synthesis gas, from the first gas from the first reaction zone and the second reducing flow by a reaction involving the hydrocarbon.; 2- The method according to claim 1, wherein the oxidizing flux comprises oxygen and CO2. 3- The method according to claim 1, wherein the first reducing flux comprises hydrogen (H2) and CO2, and optionally water vapor in an H2O / H2 ratio of 0 to 1, preferably in an H2O / H2 ratio of 0 to 0.

5. 4- The method according to claim 1, wherein the oxidizing flux and the first reducing flux each comprise CO2. 5- The method according to claim 1, wherein only the oxidizing flux comprises CO2. 6- The method according to any one of claims 1 to 5, wherein the CO2 originates from an industrial discharge, is biogenic CO2 from a biogas, is CO2 captured directly from ambient air or a mixture of these. 7- The method according to any one of claims 1 to 6, wherein the hydrogen present in the first reducing flux results from an electrolysis reaction of water. 8- The method according to any one of claims 1 to 6, wherein the hydrogen present in the first reducing stream results from an electrolysis reaction of water in an electrolyzer which is powered by electricity produced from a renewable source (e.g., produced from solar energy, wind energy, hydropower, biomass or geothermal energy) or from nuclear energy. 9- The method according to any one of claims 1 to 6, wherein the hydrogen present in the first reducing stream results from a steam reforming reaction of natural gas or methane in a process for which the CO2 generated is at least partly captured and sequestered. 10- The method according to any one of claims 1 to 6, wherein the hydrogen present in the first reducing stream comprises hydrogen resulting from a pyrolysis reaction of methane. 11- The method according to any one of claims 1 to 6, wherein the hydrogen present in the first reducing stream comprises hydrogen resulting from a water electrolysis reaction in an electrolyzer which is powered by electricity produced from a renewable source (e.g., produced from solar energy, wind energy, hydropower, biomass or geothermal energy) or nuclear energy, and hydrogen resulting from a steam reforming reaction of natural gas or methane in a process for which the generated CO2 is at least partly captured and sequestered. 12- The method according to any one of claims 8, 9 and 11, wherein the hydrogen present in the first reducing stream further comprises hydrogen resulting from a pyrolysis reaction of methane.

13. The method according to any one of claims 1 to 12, wherein hydrogen, oxygen, and CO2 are supplied to the first zone in a ratio molar H2 / O2 of at least 2, and a molar H2 / CO2 ratio of at least 1.

8. 14- The method according to any one of claims 1 to 12, wherein hydrogen, oxygen and CO2 are supplied to the first zone in an H2 / O2 molar ratio of between 2 and 10, and an H2 / CO2 molar ratio of between 1.8 and 9. 15- The method according to any one of claims 1 to 14, wherein oxygen and CO2 are supplied to the first zone in an O2 / CO2 molar ratio of at least 0.

5. 16- The method according to any one of claims 1 to 14, wherein oxygen and CO2 are supplied to the first zone in an O2 / CO2 molar ratio between 0.5 and 6. 17- The method according to any one of claims 1 to 16, wherein the generation of the synthesis gas comprises steam reforming of the hydrocarbon(s) with the water vapor included in the first gas. 18- The method according to any one of claims 1 to 17, wherein the second reducing stream further comprises water vapor and the generation of the synthesis gas comprises steam reforming of the hydrocarbon(s) with the water vapor included in the first gas and the water vapor included in the second reducing stream. 19- The method according to any one of claims 1 to 18, wherein the second carbon source comprises a fossil or renewable hydrocarbon. 20- The method according to any one of claims 1 to 18, wherein the second carbon source comprises fossil or renewable natural gas. 21- The method according to any one of claims 1 to 18, wherein the second carbon source comprises methane. 22- The method according to any one of claims 1 to 18, wherein the second carbon source comprises methane from a biogas. 23- The method according to any one of claims 1 to 22, wherein the second reducing flux further comprises an organic compound derived from biomass. 24- The method according to any one of claims 1 to 23, wherein the second reducing flux further comprises a compound of formula C a HpO Y with a ranging from 1 to 5, p ranging from 2 to 10 and y ranging from 1 to 4. 25- The method according to any one of claims 1 to 24, wherein the second reducing flux comprises methane (CH4) and optionally hydrogen (H2) in an H2 / CH4 molar ratio between 0 and 2.

5. 26- The method according to any one of claims 1 to 25, wherein the second reducing flux comprises methane (CH4) and optionally hydrogen (H2) and a molar ratio between the CH4 fed and a total amount of H2 fed in the two zones is between 0.1 and 1. 27- The method according to any one of claims 1 to 26, wherein the second reducing flux further comprises hydrogen (H2). 28- The method according to claim 27, wherein the hydrogen present in the second reducing stream results from a steam reforming reaction of natural gas or methane in a process in which the CO2 generated is at least partly captured and sequestered. 29- The method according to claim 27 or 28, wherein the second reducing flux comprises an amount of hydrogen to balance the molar composition of the synthesis gas to have H2 / CO > 2 and (H2-CO2) / (CO+CO2) > 2. 30- The method according to any one of claims 1 to 29, wherein the second reducing flux comprises methane (CH4) and optionally water vapor (H2O) and a molar ratio between water vapor (H2O) and CH4 is between 0 and 2. 31- The method according to any one of claims 1 to 30, wherein the second reducing flux further comprises water vapor. 32- The method according to any one of claims 1 to 31, wherein the production of the first gas comprising at least carbon monoxide (CO) and water vapor (H2O), in the first zone, is carried out at a temperature of at least 1000°C and at most 2400°C. 33- The method according to any one of claims 1 to 32, wherein the production of the first gas comprising at least carbon monoxide (CO) and water vapor (H2O), in the first zone, is carried out at a temperature between about 1000°C and about 1900°C. 34- The method according to any one of claims 1 to 33, wherein the generation of the synthesis gas, in the second zone, is carried out at a temperature of at least 700°C and at most 1500°C. 35- The method according to any one of claims 1 to 34, wherein the generation of the synthesis gas, in the second zone, is carried out at a temperature between about 700°C and about 1000°C. 36- The method according to any one of claims 1 to 35, wherein the generation of the synthesis gas, in the second zone, is carried out at a temperature lower than a temperature in the first zone. 37- The method according to any one of claims 1 to 36, wherein the production of carbon monoxide and water vapor in the first zone is carried out in the absence of a catalyst. 38- The method according to any one of claims 1 to 37, wherein the generation of the second gas comprising the synthesis gas in the second zone of the reactor is carried out in the absence of a catalyst. 39- The method according to any one of claims 1 to 38, wherein the oxygen (O2) present in the oxidizing stream results from an electrolysis reaction of water. 40- The method according to any one of claims 1 to 39, wherein the oxygen (O2) present in the oxidizing stream comes from an air separation unit (ASU). 41- The method according to any one of claims 1 to 40, wherein the oxidizing flux is fed into a lower and central part of the first zone and the first reducing flux is fed into the lower part of the first zone at the periphery of the oxidizing flux. 42- The method according to any one of claims 1 to 41, wherein the second gas generated in the second zone comprises synthesis gas and residual CO2 and the method further comprises recycling a portion of the second gas into the first zone. 43- The method according to claim 42, wherein the part of the second gas is recycled into the first reducing stream. 44- The method according to claim 42 or 43, further comprising cooling of the part of the second gas to be recycled, before recycling. 45- The method according to any one of claims 1 to 44, wherein the method is carried out in a plurality of reactors in parallel, each reactor having the first zone which receives the oxidizing flux and the first reducing flux and where the first gas is produced, and the second zone which receives the second reducing flux and where the second gas is generated. 46- The method according to any one of claims 1 to 44, wherein the reactor comprises a plurality of first zones and a second common zone, and wherein: the oxidizing flux and the first reducing flux are fed into each first zone of the plurality of first zones and the first gas is produced in each first zone, the second reducing flux is fed into the second common zone which receives the first gas produced in each first zone and the second gas is generated in the second common zone. 47- A system for producing a synthesis gas comprising carbon monoxide (CO) and hydrogen (H2), the system comprising at least one reactor and said reactor comprising at least a first reaction zone and at least a second reaction zone, wherein: the first reaction zone is supplied by an oxidizing flux comprising oxygen (O2) and a first reducing flux comprising hydrogen (H2), wherein the oxidizing flux and / or the first reducing flux further comprises a first carbon source which is CO2, and in the first zone an oxy-flame is generated by reaction between the oxygen of the oxidizing flux and the hydrogen of the first reducing flux, to produce a first gas comprising at least carbon monoxide (CO) and water vapor (H2O) by contacting the oxidizing flux and the first reducing flux with the oxy-flame;the second reaction zone is fed by a second reducing flux comprising a second carbon source including at least one hydrocarbon, to generate in the second reaction zone a second gas comprising the synthesis gas from the first gas from the first reaction zone and the second reducing flux by reaction with the hydrocarbon. 48- The system according to claim 47, wherein the oxidizing flux comprises oxygen and CO2. 49- The system according to claim 47, wherein the first reducing flux comprises hydrogen (H2) and CO2, and optionally water vapor in an H2O / H2 ratio of 0 to 1, preferably in an H2O / H2 ratio of 0 to 0.

5. 50- The system according to claim 47, wherein the oxidizing flux and the first reducing flux each comprise CO2. 51- The system according to claim 47, wherein only the oxidizing flux comprises CO2. 52- The system according to any one of claims 47 to 51, wherein the CO2 is from an industrial discharge, is biogenic CO2 from a biogas, is CO2 captured directly from the ambient air, or a mixture of these. 53- The system according to any one of claims 47 to 52, wherein the hydrogen present in the first reducing flow results from an electrolysis reaction of water. 54- The system according to any one of claims 47 to 52, wherein the hydrogen present in the first reducing stream results from an electrolysis reaction of water in an electrolyzer which is powered by electricity produced from a renewable source (e.g., produced from solar energy, wind energy, hydropower, biomass or geothermal energy) or from nuclear energy. 55- The system according to any one of claims 47 to 52, wherein the hydrogen present in the first reducing stream results from a steam reforming reaction of natural gas or methane in a process in which the CO2 generated is at least partly captured and sequestered. 56- The system according to any one of claims 47 to 52, wherein the hydrogen present in the first reducing stream comprises hydrogen resulting from a pyrolysis reaction of methane. 57- The system according to any one of claims 47 to 52, wherein the hydrogen present in the first reducing stream comprises hydrogen resulting from a water electrolysis reaction in an electrolyzer which is powered by electricity produced from a renewable source (e.g., produced from solar energy, wind energy, hydropower, biomass or geothermal energy) or nuclear energy, and hydrogen resulting from a steam reforming reaction of natural gas or methane in a process for which the generated CO2 is at least partly captured and sequestered. 58- The system according to any one of claims 54, 55 and 57, wherein the hydrogen present in the first reducing stream further comprises hydrogen resulting from a pyrolysis reaction of methane. 59- The system according to any one of claims 47 to 58, wherein hydrogen, oxygen and CO2 are supplied in the first zone in an H2 / O2 molar ratio of at least 2, and an H2 / CO2 molar ratio of at least 1.

8. 60- The system according to any one of claims 47 to 58, wherein hydrogen, oxygen and CO2 are supplied in the first zone in an H2 / O2 molar ratio of between 2 and 10, and an H2 / CO2 molar ratio of between 1.8 and 9. 61- The system according to any one of claims 47 to 60, wherein oxygen and CO2 are supplied to the first zone in an O2 / CO2 molar ratio of at least 0.

5. 62- The system according to any one of claims 47 to 60, wherein oxygen and CO2 are supplied to the first zone in an O2 / CO2 molar ratio between 0.5 and 6. 63- The system according to any one of claims 47 to 62, wherein the generation of the synthesis gas comprises steam reforming of the hydrocarbon(s) with the water vapor included in the first gas. 64- The system according to any one of claims 47 to 63, wherein the second reducing stream further comprises water vapor and the generation of the synthesis gas comprises steam reforming of the hydrocarbon(s) with the water vapor included in the first gas and the water vapor included in the second reducing stream. 65- The system according to any one of claims 47 to 64, wherein the second carbon source comprises a fossil or renewable hydrocarbon. 66- The system according to any one of claims 47 to 64, wherein the second carbon source comprises fossil or renewable natural gas. 67- The system according to any one of claims 47 to 64, wherein the second carbon source comprises methane. 68- The system according to any one of claims 47 to 64, wherein the second carbon source comprises methane from a biogas. 69- The system according to any one of claims 47 to 68, wherein the second reducing flux further comprises an organic compound derived from biomass. 70- The system according to any one of claims 47 to 69, wherein the second reducing flux further comprises a compound of formula C a HpO Y with a ranging from 1 to 5, p ranging from 2 to 10 and y ranging from 1 to 4. 71- The system according to any one of claims 47 to 70, wherein the second reducing flux comprises methane (CH4) and optionally hydrogen (H2) in an H2 / CH4 molar ratio between 0 and 2.

5. 72- The system according to any one of claims 47 to 71, wherein the second reducing flux comprises methane (CH4) and optionally hydrogen (H2) and a molar ratio between the CH4 fed and a total amount of H2 fed in the two zones is between 0.1 and 1. 73- The system according to any one of claims 47 to 72, wherein the second reducing flux further comprises hydrogen (H2). 74- The system according to claim 73, wherein the second reducing flux comprises hydrogen resulting from a steam reforming reaction of natural gas or methane in a process for which the CO2 generated is at least partly captured and sequestered. 75- The system according to claim 73 or 74, wherein the second reducing flux comprises an amount of hydrogen to balance the molar composition of the synthesis gas to have H2 / CO > 2 and (H2-CO2) / (CO+CO2) > 2. 76- The system according to any one of claims 47 to 75, wherein the second reducing flux comprises methane (CH4) and optionally water vapor (H2O) and a molar ratio between water vapor (H2O) and CH4 is between 0 and 2. 77- The system according to any one of claims 47 to 76, wherein the second reducing flow further comprises water vapor. 78- The system according to any one of claims 47 to 77, wherein the first zone is at a temperature of at least 1000°C and at most 2400°C during the production of the first gas comprising at least carbon monoxide (CO) and water vapor (H2O). 79- The system according to any one of claims 47 to 77, wherein the first zone is at a temperature between about 1000°C and about 1900°C during the production of the first gas comprising at least carbon monoxide (CO) and water vapor (H2O). 80- The system according to any one of claims 47 to 79, wherein the second zone is at a temperature of at least 700°C and at most 1500°C during the generation of the synthesis gas. 81- The system according to any one of claims 47 to 79, wherein the second zone is at a temperature between about 700°C and about 1000°C during the generation of the synthesis gas. 82- The system according to any one of claims 47 to 81, wherein the generation of the synthesis gas, in the second zone, is carried out at a temperature lower than a temperature in the first zone. 83- The system according to any one of claims 47 to 82, wherein the production of carbon monoxide and water vapor in the first zone is carried out in the absence of a catalyst. 84- The system according to any one of claims 47 to 83, wherein the generation of the second gas comprising the synthesis gas in the second zone of the reactor is carried out in the absence of a catalyst. 85- The system according to any one of claims 47 to 84, wherein the oxygen (O2) present in the oxidizing stream results from an electrolysis reaction of water. 86- The system according to any one of claims 47 to 85, wherein the oxygen (O2) present in the oxidizing stream comes from an air separation unit (ASU). 87- The system according to any one of claims 47 to 86, wherein the second gas generated in the second zone comprises synthesis gas and residual CO2 and the system further comprises a means for recycling a portion of the second gas into the first zone. 88- The system according to claim 87, wherein the recycling means comprises a conduit conveying the portion of the second gas to be mixed with the first reducing stream. 89- The system according to claim 87 or 88, further comprising a device for cooling the part of the second gas to be recycled, before recycling. 90- The system according to any one of claims 47 to 89, wherein the first zone and the second zone are each cylindrical in shape. 91- The system according to any one of claims 47 to 90, comprising a first means for supplying the oxidizing flow in a lower and central part of the first zone and a second means for supplying the first reducing flow in the lower part of the first zone at the periphery of the oxidizing flow. 92- The system according to claim 91, wherein the first means consists of a first central tube and the second means consists of an annular space extending perpendicularly between an external wall of the central tube and an internal wall of the first zone. 93- The system according to any one of claims 47 to 92, comprising a third means for supplying the second reducing flow in the second zone. 94- The system according to claim 93, wherein the first zone and the second zone are each cylindrical in shape and the third means consists of an opening formed by an annular space extending between an outer wall of the first zone and an internal wall of the second zone, optionally in an upper region of the first zone and a lower region of the second zone. 95- The system according to any one of claims 47 to 94, comprising a plurality of reactors in parallel, each reactor having the first zone receiving the oxidizing flux and the first reducing flux and where the first gas is produced, and the second zone receiving the second reducing flux and where the second gas is generated. 96- The system according to any one of claims 47 to 92, wherein the reactor comprises a plurality of first zones and a second common zone, and wherein: each first zone of the plurality of first zones is fed by the oxidizing flow and the first reducing flow to produce the first gas in each first zone, and the second common zone is fed by the second reducing flow and receives the first gas produced in each first zone to generate the second gas in the second common zone. 97- Use of a synthesis gas produced by the method as defined according to any one of claims 1 to 46 or by the system as defined according to any one of claims 47 to 96, for the manufacture of chemical products or fuels. 98- Use according to claim 97, for the manufacture of synthetic hydrocarbons. 99- Use of a synthesis gas produced by the method as defined according to any one of claims 1 to 46 or by the system as defined according to any one of claims 47 to 96, as a reducing agent in the metallurgical industry. 100- Use of a system as defined according to any one of the claims 47 to 96 for the treatment of gaseous industrial effluents containing CO2.

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