Method and reactor for producing synthesis gas from a carbon and hydrogen source in the presence of an oxy flame

Abstract

The technology relates to a method for producing synthesis gas comprising carbon monoxide (CO) and hydrogen (H2), in which method the synthesis gas is produced by a reduction reaction of a first flow comprising a carbon source and an excess of hydrogen in contact with an oxy flame. The hydrogen originates from a reducing stream a first portion of which is located in the first flow and a second portion of which is used to generate the oxy flame by combusting the hydrogen in the presence of a second flow comprising oxygen (O2), the second flow originating from an oxidising stream. The first flow and the second flow are at a distance from each other such that the oxy flame supports the reaction between the carbon source and the hydrogen. A reactor which can have different configurations is also proposed for implementing the method.

Description

[0001] METHOD AND REACTOR FOR THE PRODUCTION OF SYNTHETIC GAS FROM A CARBON AND HYDROGEN SOURCE IN THE PRESENCE OF AN OXY-FLAME

[0002] PRIORITY REQUEST

[0003] This application claims priority from Canadian application CA 3.081.971, filed on June 4, 2020, which is incorporated herein by reference.

[0004] TECHNICAL FIELD

[0005] This application relates to a method and reactor for producing synthesis gas from a carbon and hydrogen (H2) source. More specifically, the synthesis gas production method is carried out in the direct presence of an oxy-flame to transform a stream comprising a carbon source and hydrogen into synthesis gas.

[0006] STATE OF THE ART

[0007] The fight against climate change will require, among other things, a substantial reduction in greenhouse gas (GHG) emissions, particularly CO2 and methane. To achieve this, beyond any incremental improvements, drastic measures will be necessary to reach the targeted GHG emission reductions. Currently, considerable efforts are being made to minimize the consumption of fossil fuels as an energy source and as a basic ingredient in many chemical syntheses. For the manufacture of products containing carbon in their atomic composition, using CO2 as a basic reagent to provide the carbon source is a promising solution. 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 or emissions from industrial processes for recycling and later use is also known as Carbon Capture Utilization (CCU). The captured CO2 can be used as a carbon source for the production of a wide range of products that can be considered carbon neutral, i.e., whose production and use cycle involves virtually no net greenhouse gas emissions. This makes it possible to produce carbon-neutral synthetic fuels that can be used in existing infrastructure.

[0008] There are several ways to use CO2 as a basic reagent to provide carbon. The most practical way is to convert CO2 to carbon monoxide (CO) according to reaction (A) called "Reverse Water Gas Shift" or RWGS. (steam) (A)

[0009] By reacting CO2 with an excess of hydrogen (H2), mixtures of hydrogen and CO can be produced. Such mixtures are called "synthesis gas" or "syngas." These synthesis gases may also contain some residual CO2.

[0010] Synthesis gases can be used to produce a range of basic chemicals. These include methanol and hydrocarbons such as those found in motor gasoline, diesel, and kerosene.

[0011] Methanol is a platform molecule that can serve as a raw material for many other basic products, such as formaldehyde. Methanol is also known for its use in windshield washer fluid and as an industrial solvent. It can also be used as a fuel. Methanol can even be converted into synthetic hydrocarbons. Finally, methanol can be transformed into dimethyl ether (DME), itself a chemical intermediate. DME is used, among other things, as a propellant for aerosols. DME can serve as a fuel for diesel engines or as a substitute for propane.

[0012] A known basic reaction for the production of methanol from synthesis gas is the following reaction (B):

[0013] CO + 2 H2^ CH3OH (B) Synthetic hydrocarbons can be produced from synthesis gas, according to the Fischer-Tropsch reaction (C):

[0014] Depending on the chemicals to be manufactured, the CO / H2 mixtures used as synthesis gas for these products must be balanced, i.e., they must contain the correct proportions of H2 and CO. Considering reactions (B) and (C), we observe that, theoretically, the synthesis gas (syngas) should contain primarily H2 and CO in an H2 / CO molar ratio close to 2. More precisely, taking into account the possible presence of residual CO2 in the synthesis gas, the molar proportions of the gases required to carry out reactions (B) or (C) generally correspond to the ratios R1 or R2 of the following equations (D) and (E):

[0015] (D) R1 = H2 / CO > 2

[0016] (E) R2 = (H2-CO2) / (CO + CO2) > 2

[0017] A very large number of chemical and hydrocarbon syntheses can be carried out using syngas that meet the molar composition criteria R1 or R2. It should also be noted that it is possible to produce methane (CPU) from synthesis gas. One mole of methane can be formed from 1 mole of CO and 3 moles of H2.

[0018] The RWGS (A) reaction is endothermic (enthalpy of reaction of 41 kJ / mol at room temperature). According to the stoichiometry of this reaction, producing 1 kg of CO requires 1.57 kg of CO2 and 0.07 kg of H2, and 1465 kJ, or 0.4 kWh, of thermal energy. This reaction is generally carried out using catalytic bed reactors. However, the use of conventional catalysts for reaction (A) does not allow for high conversion rates. This means that the conversion per pass, i.e., the conversion during the passage of CO2 through a catalytic bed, is rather low. The reason is that the operating temperature of catalytic bed reactors is quite limited—often below 600°C. However, it is known that, from a thermodynamic point of view, reaction (A) becomes rather favourable at higher temperature levels.This is illustrated by Table 1 which shows the value of the equilibrium constant as a function of temperature (at atmospheric pressure).

[0019] Table 1: Variation of the equilibrium constant of the RWGS reaction with temperature

[0020] T DH K

[0021] °C kJ / mol

[0022] 0 41.20 0.0000021

[0023] 100 40.78 0.0002704

[0024] 200 40.08 0.0043

[0025] 300 39.22 0.0248

[0026] 400 38.25 0.0830

[0027] 500 37.22 0.1987

[0028] 600 36.18 0.3822

[0029] 700 35.14 0.6334

[0030] 800 34.12 0.9439

[0031] 900 33.13 1.3017

[0032] 1000 32.19 1.6935

[0033] 1100 31.30 2.1071

[0034] 1200 30.46 2.5319

[0035] 1300 29.65 2.9595

[0036] 1400 28.89 3.3831

[0037] 1500 28.16 3.7980

[0038] A method for producing synthesis gas from a carbon and hydrogen source is particularly interesting. A method for producing synthesis gas from, for example, CO2 and hydrogen, without using conventional solid catalysts, is also particularly interesting. A method for preparing synthesis gases useful for manufacturing various chemicals is also attractive. Such a method will be described below.

[0039] SUMMARY

[0040] According to a first aspect, the present technology relates to a method of producing synthesis gas comprising carbon monoxide (CO) and hydrogen (hte), in which the synthesis gas is produced by a reduction reaction of a first stream comprising a carbon source and an excess of hydrogen in contact with an Oxy-flame, and in which: the hydrogen comes from a reducing stream, a first part of which is found in the first stream and a second part is used to generate the Oxy-flame by combustion of the hydrogen in the presence of a second stream comprising oxygen (O2), the second stream coming from an oxidizing stream, the first and second streams are at a distance from each other such that the Oxy-flame supports the reaction between the carbon source and the hydrogen.

[0041] According to one embodiment, the method is such that the reduction reaction is carried out in the absence of a solid catalyst.

[0042] According to another embodiment, the method is such that the Oxy-flame generates ionic species and free radicals which promote the conversion of the carbon source into CO.

[0043] According to another embodiment, the method is such that the carbon source comprises:

[0044] - CO2; or

[0045] - at least one type of oxygenated molecules with the formula CaHpO Y where a is between 1 and 5, b is between 2 and 10, and y is between 1 and 4; or

[0046] - one or more hydrocarbons; or

[0047] - a mixture of at least two of these carbon sources. According to another embodiment, the carbon source includes CO2 and the reduction reaction includes a reverse gas-to-water or "Reverse Water Gas Shift".

[0048] In another embodiment, the method is such that the reducing current is hydrogen. In another embodiment, the reducing current comprises hydrogen and the carbon source. In yet another embodiment, the reducing current comprises hydrogen and CO2.

[0049] According to another embodiment, the method is such that the reducing current comprises hydrogen, CO2, and at least one type of oxygenated molecule with the formula CaHpO Y where a is between 1 and 5, b is between 2 and 10 and y is between 1 and 4.

[0050] In another embodiment, the method is such that the oxidizing current is oxygen. In another embodiment, the oxidizing current comprises oxygen and CO2.

[0051] In another embodiment, the method is such that the reducing current comprises only hydrogen, the oxidizing current comprises only oxygen, and the carbon source is supplied by a separate current. In another embodiment, the separate current comprises CO2. In yet another embodiment, the separate current comprises both CO2 and methane.

[0052] According to another embodiment, the method is such that the oxygen comes from an electrolysis reaction of water.

[0053] According to another embodiment, the method is such that the hydrogen comes from an electrolysis reaction of water.

[0054] In another embodiment, the method is such that the carbon source is a gaseous mixture resulting from a biomass gasification or pyrolysis process. In another embodiment, the method is such that the reduction reaction is carried out at an average temperature of at least 600°C. In another embodiment, the reduction reaction is carried out at an average temperature of at least 1200°C. In yet another embodiment, the reduction reaction is carried out at an average temperature of at most 2200°C.

[0055] In another embodiment, the method is such that the first and second streams are separated by a distance of between 0.1 mm and 100 mm. In another embodiment, the first and second streams are separated by a distance of between 0.3 mm and 50 mm. In yet another embodiment, the first and second streams are separated by a distance of between 0.6 mm and 30 mm.

[0056] According to another embodiment, the method is such that the carbon source includes CO2 and the reduction reaction is carried out using an H2 / CO2 molar ratio between 2 and 7.

[0057] According to another embodiment, the method is such that the carbon source includes CO2 and the reduction reaction is carried out using an O2 / CO2 molar ratio between 0.35 and 0.9.

[0058] According to another embodiment, the method is such that the reduction reaction is carried out using an O2 / H2 molar ratio between 0.1 and 0.3.

[0059] According to another embodiment, the method is such that the synthesis gas produced has an H2 / CO molar ratio of at least 1.8. According to another embodiment, the synthesis gas produced has an H2 / CO molar ratio of at least 2. According to another embodiment, the synthesis gas produced has an H2 / CO molar ratio between 1.8 and 5.0.

[0060] According to another embodiment, the method is such that the synthesis gas produced further comprises CO2. According to another embodiment, the method is such that the synthesis gas produced has a molar ratio of H2, CO and CO2 such that (H2 - CO2) / (CO + CO2) ≥ 2.

[0061] According to another embodiment, the method further includes cooling the synthesis gas to form a cooled synthesis gas.

[0062] In another embodiment, the method further comprises condensation of water contained in the cooled syngas and recovery of the water. In another embodiment, at least some of the recovered water is recycled during the cooling stage.

[0063] In another aspect, the present technology relates to the use of a synthesis gas produced by the method according to the present technology, for the manufacture of chemicals or fuels.

[0064] In another aspect, the present technology relates to the use of a synthesis gas produced by the method according to the present technology, for the manufacture of methanol or synthetic hydrocarbons.

[0065] According to another aspect, the present technology relates to a reactor for producing a synthesis gas comprising carbon monoxide (CO) and hydrogen (H2), said reactor comprising: a reaction chamber in which the synthesis gas is produced by a reduction reaction of a first stream comprising a carbon source and an excess of hydrogen in contact with an oxy-flame, at least one first means for supplying the reaction chamber with a reducing stream comprising hydrogen, a first part of the reducing stream being found in the first stream and a second part being used to generate the oxy-flame in the combustion chamber, by combustion of the hydrogen in the presence of a second stream comprising oxygen (O2), at least one second means for supplying the reaction chamber with an oxidizing stream forming the second stream,the first and second flows being at a distance from each other such that the Oxy-flame sustains the reaction between the carbon source and hydrogen.

[0066] According to one embodiment, the reactor is such that the reduction reaction is carried out in the absence of a solid catalyst.

[0067] According to another embodiment, the reactor is such that the Oxy-flame generates ionic species and free radicals which promote the conversion of the carbon source into CO.

[0068] According to another embodiment, the reactor is such that the carbon source comprises:

[0069] - CO2; or

[0070] - at least one type of oxygenated molecules with the formula CaHpO Y where a is between 1 and 5, b is between 2 and 10, and y is between 1 and 4; or

[0071] - one or more hydrocarbons; or

[0072] - a mixture of at least two of these carbon sources.

[0073] According to another embodiment, the reactor is such that the carbon source includes CO2 and the reduction reaction is the reverse gas-to-water or "Reverse Water Gas Shift".

[0074] In another embodiment, the reactor is such that the reducing current is hydrogen. In another embodiment, the reducing current comprises hydrogen and a carbon source. In yet another embodiment, the reducing current comprises hydrogen and CO2.

[0075] According to another embodiment, the reactor is such that the reducing current comprises hydrogen, CO2, and at least one type of oxygenated molecule with the formula CaHpO Ywhere a is between 1 and 5, b is between 2 and 10, and g is between 1 and 4. In another embodiment, the reactor is such that the oxidizing stream is oxygen. In another embodiment, the oxidizing stream comprises oxygen and CO2.

[0076] According to another embodiment, the reactor is such that the first means for supplying the reducing current and the second means for supplying the oxidizing current are tubes.

[0077] In another embodiment, the reactor comprises a plurality of secondary means consisting of a plurality of tubes for injecting the oxidizing current into the reaction chamber, and a plurality of primary means consisting of a plurality of openings for injecting the reducing current into the reaction chamber. In another embodiment, each opening is defined by an annular space bounded by the outer diameter of one tube from the plurality of tubes and extending perpendicularly from the outer wall of the tube. In yet another embodiment, the reactor further comprises a reducing current distribution chamber separated from the reaction chamber by a separating wall, said distribution chamber and said separating wall being traversed by the plurality of tubes, the annular space extending perpendicularly from the outer wall of each tube also traversing the separating wall.

[0078] In another embodiment, the reactor is such that the reducing current is hydrogen, which is fed into the reaction chamber by means consisting of a first tube; the oxidizing current is oxygen, which is fed into the reaction chamber by means consisting of a second tube; and the carbon source is fed by an independent current, which is injected into the reaction chamber through at least one opening located in a wall of the reaction chamber. In another embodiment, the opening is formed by a third tube concentric with the first and second tubes, the second tube forming the inner tube, the first tube forming an intermediate tube, and the third tube forming an outer tube. In yet another embodiment, the opening is formed by an annular space delimited by an inner diameter of the third tube and an outer diameter of the first tube.In another embodiment, the reactor further comprises a distribution chamber separated from the reaction chamber by a partition wall, said distribution chamber serving to supply the independent stream comprising the carbon source and being traversed by the first tube and the second tube. In another embodiment, the reactor is such that the independent stream comprises CO2. In yet another embodiment, the reactor is such that the independent stream comprises carbon dioxide and methane.

[0079] According to another embodiment, the reactor is such that the oxygen comes from an electrolysis reaction of water.

[0080] According to another embodiment, the reactor is such that the hydrogen comes from an electrolysis reaction of water.

[0081] According to another embodiment, the reactor is such that the carbon source comes from a gaseous mixture resulting from a gasification or pyrolysis process of biomass.

[0082] In another embodiment, the reactor is such that the reaction chamber reaches a temperature of at least 600°C during the reduction reaction. In another embodiment, the reaction chamber reaches a temperature of at least 1200°C during the reduction reaction. In yet another embodiment, the reaction chamber reaches a temperature of at most 2200°C during the reduction reaction.

[0083] In another embodiment, the reactor is such that the first and second streams are separated by a distance of between 0.1 mm and 100 mm. In another embodiment, the first and second streams are separated by a distance of between 0.3 mm and 50 mm. In another embodiment, the first and second streams are separated by a distance of between 0.6 mm and 30 mm. In another embodiment, the reactor is such that the carbon source comprises CO2 and the reduction reaction is carried out using an H2 / CO2 molar ratio of between 2 and 7. In another embodiment, the carbon source comprises CC and the reduction reaction is carried out using an O2 / CO2 molar ratio of between 0.35 and 0.9.

[0084] According to another embodiment, the reactor is such that the reduction reaction is carried out using an O2 / H2 molar ratio between 0.1 and 0.3.

[0085] According to another embodiment, the reactor is such that the synthesis gas produced has an H2 / CO molar ratio of at least 1.8. According to another embodiment, the synthesis gas produced has an H2 / CO molar ratio of at least 2. According to another embodiment, the synthesis gas produced has an H2 / CO molar ratio between 1.8 and 5.0.

[0086] According to another embodiment, the reactor is such that the synthesis gas produced also includes CO2.

[0087] According to another embodiment, the reactor is such that the synthesis gas produced has a molar ratio in H2, CO and CO2 such that (H2 - CO2) / (CO + CO2) ³ 2.

[0088] According to yet another aspect, the present technology relates to a system comprising the reactor as defined according to the present technology, coupled to a syngas cooling device to form a cooled syngas.

[0089] According to one embodiment, the system is such that the cooling device is a direct contact cooler.

[0090] According to another embodiment, the system further includes a water condensation device to recover water from the cooled synthesis gas.

[0091] In another embodiment, the system is such that the condensing unit is a condenser-cooler. In yet another embodiment, the system further comprises equipment for recycling at least a portion of the recovered water back to the cooling device.

[0092] BRIEF DESCRIPTION OF THE FIGURES

[0093] Figure 1 represents a diagram of the general operating principle of the present method for producing syngas.

[0094] Figure 2 represents a vertical cross-sectional view of a reactor that can be used to carry out the syngas production method according to a first embodiment.

[0095] Figure 3 shows some distance parameters between the different flows and / or between different elements of the reactor according to an implementation of the syngas production method.

[0096] Figure 4 represents a vertical cross-sectional view of a reactor which can be used to carry out the syngas production method according to another embodiment.

[0097] Figure 5 represents a vertical cross-sectional view of a reactor which can be used to carry out the syngas production method according to another embodiment.

[0098] Figure 6a shows a vertical cross-sectional view of a reactor that can be used to implement the syngas production method according to another embodiment. Figure 6b shows a top-down cross-sectional view of the reactor of Figure 6a. An enlarged view of two concentric tubes is also shown in Figure 6b to illustrate the distance parameter in this embodiment.

[0099] Figure 7 shows a diagram of the syngas production process according to yet another embodiment. Figure 8 shows a schematic cross-sectional view along the vertical axis of a mini-reactor used for the examples. The figure illustrates the general arrangement of the tubes for this mini-reactor.

[0100] DETAILED DESCRIPTION

[0101] All technical and scientific terms and expressions used herein have the same meaning as that generally understood by a person versed in the art of this technology. The definitions of certain terms and expressions used are nevertheless provided below.

[0102] The term "approximately" as used in this document means roughly, in the region of, and around. When the term "approximately" is used in connection with a numerical value, it modifies that value, for example, above or below it by a variation of 10% from the nominal value. This term can also take into account, for example, the experimental error of a measuring instrument or the rounding of a value.

[0103] Where a range of values ​​is mentioned in this application, the lower and upper bounds of the range are, unless otherwise indicated, always included in the definition.

[0104] The chemical structures described here are drawn according to the conventions of the field. Therefore, when an atom, such as a carbon atom, as drawn appears to include an incomplete valence, then it will be assumed that the valence is satisfied by one or more hydrogen atoms even if they are not explicitly drawn.

[0105] In this description, the terms "syngas" and "syngas" are used interchangeably to identify a gaseous mixture comprising at least carbon monoxide (CO) and hydrogen (H2). In some embodiments, the syngas may include CO2. According to one embodiment, the H2 / CO molar ratio in the syngas is greater than or equal to 1. In other embodiments, the syngas may have an H2 / CO molar ratio of at least 1.8, for example, between 1.8 and 5.0. According to another embodiment, the H2 / CO molar ratio in the syngas is greater than or equal to

[0106] 2. Thus, the H2 / CO molar ratio in syngas can be 1.8 or 1.9 or 2.0 or 2.1 or 2.2 or 2.3 or 2.4 or 2.5 or 2.6 or 2.7 or 2.8 or 2.9 or 3.0 or 3.1 or 3.2 or 3.3 or 3.4 or 3.5 or 3.6 or 3.7 or 3.8 or 3.9 or 4.0 or 4.1 or 4.2 or 4.3 or 4.4 or 4.5 or 4.6 or 4.7 or 4.8 or 4.9 or 5.0. However, syngas with different and varied H2 / CO molar ratios can be obtained.

[0107] The term "stream" is used to describe the various gas streams that feed the reaction chamber where synthesis gas is formed. As will be described in more detail below, the method uses at least one stream containing hydrogen (H₂) and at least one stream containing oxygen (O₂). The carbon source used in the method, depending on its nature, can be supplied either by an independent stream, by the stream containing GO₂, or by the stream containing I₂. The streams entering the reaction chamber are in a gaseous state. If necessary, the reactants in liquid form can be vaporized so that they enter the reaction chamber in gaseous form.

[0108] The term "flow" is used to describe the different gas flows involved in the synthesis gas production reaction within the reaction chamber. As will be described in more detail below, the reaction involves a reducing flow containing hydrogen (H2) and the carbon source, which react to form synthesis gas, and an oxidizing flow containing oxygen (O2), which reacts with hydrogen (H2) to form an oxy-flame.

[0109] The term "carbon source" describes the chemical compound(s) used to provide the carbon found in the produced synthesis gas. Thus, the carbon source provides at least the carbon found in the produced carbon monoxide (CO). Various chemical compounds can be used as carbon sources. In one embodiment, the carbon source may include CO2. In another embodiment, the carbon source may include one or more types of carbon-based oxygenated molecules with the formula CaHpO2. Ywhere a is between 1 and 5, b is between 2 and 10, and y is between 1 and 4. The carbon source may also include one or more hydrocarbons such as alkanes, alkenes, and / or aromatics. It is also possible that the carbon source used to produce the synthesis gas is a combination of two or more of the different sources described above. Thus, in some embodiments, the carbon source may include CO2 and one or more oxygenated molecules of the CaHpO type. Y.In other embodiments, the carbon source may consist of CO2 and one or more hydrocarbons, for example, CO2 and methane. If the carbon source consists solely of hydrocarbons, an oxygen supply will be required. This oxygen can be provided by CO2, but it can also be supplied in the form of water vapor. In some embodiments, the carbon source may consist of one or more hydrocarbons, CO2, and water vapor. The water vapor, when required, can originate from the reaction that generates the Oxy-flame (see reaction (G) below) and / or can be supplied to the reaction chamber.

[0110] This document therefore presents an innovative method for the production of synthesis gas from a carbon source. As previously mentioned, the carbon source can vary. In some embodiments, the carbon source includes CO2, which can generally come from two main categories of sources: anthropogenic sources, linked to human activities, and natural, or biogenic, sources. The present method can use CO2 from both types of sources and can also use pure CO2. According to another embodiment, a gaseous mixture comprising CO2 and one or more types of oxygenated molecules with the formula CaHpO2 is used. Y where a is between 1 and 5, b is between 2 and 10, and g is between 1 and 4 can be used. Alternatively, the carbon source can simply consist of one or more types of CaHpO molecules Y.In another embodiment, a gaseous mixture comprising CO2 and hydrocarbons, such as alkanes (e.g., methane), alkenes, and / or aromatic molecules, can also be used. However, it is also possible to use only hydrocarbons as the carbon source. In some embodiments, the carbon source can include CO2, one or more types of CaHpO molecules Y and one or more types of hydrocarbons. A wide range of organic molecules, including products of fossil source, possibly containing sulfur, may be present in the gaseous mixture providing the carbon source.

[0111] More specifically, the syngas production method is carried out by reacting the carbon source with an excess of hydrogen in contact with an oxy-flame. According to the present technology, an "oxy-flame" is understood to be a flame produced by the combustion of hydrogen in the presence of an oxidant such as oxygen (O2) according to the following reaction (F):

[0112] H2 + I / 2 O2 -> H2O (vapor) + Heat (F)

[0113] This flame is bright and radiant, providing the heat required to support the reaction that produces synthesis gas from the carbon source. This flame can generate ionic species and free radicals that can catalyze the conversion of the carbon source to CO. In some designs, the Oxy-flame can achieve an average temperature of at least 600°C in the reaction chamber. In other designs, the average temperature reached in the reaction chamber is at least 1200°C. The temperature reached in the reaction chamber can reach up to approximately 2200°C. Thus, the synthesis gas production reaction in the reaction chamber can be carried out at an average temperature of at least 600°C, up to approximately 2200°C.The Oxy-flame can be described as a "reduction Oxy-flame" because the combustion reaction between hydrogen and oxygen occurs in the presence of excess hydrogen. In one embodiment, the oxidant used to produce the Oxy-flame can be an oxygen-based mixture (O2), preferably pure oxygen. "Pure" oxygen is understood not to mean necessarily 100% purity, but rather that the oxygen-based mixture contains a substantial amount of GO2 and may be accompanied by certain impurities such as N2 and H2O, for example.

[0114] As mentioned above, the reaction to form synthesis gas is carried out in the presence of excess hydrogen. By "excess hydrogen," we mean that the quantity of hydrogen (H2) must be sufficient to both enable the combustion reaction (F) to produce the oxy-flame and to carry out the reaction converting the carbon source into synthesis gas. The required quantity of hydrogen can be determined based on the carbon source used and taking into account the stoichiometry of the reactions involved.

[0115] According to another embodiment, which will be explained in more detail below, the hydrogen required in this method, as well as the oxygen used to produce the Oxy-flame, can, at least in part, result from a water electrolysis reaction. This can be particularly advantageous if the water electrolysis system is powered by electricity from a renewable source. The combustion that produces the Oxy-flame can be initiated using an ignition device, such as an electric arc, a glowing wire, or any other known energy source.

[0116] According to some embodiments, the present method can produce a syngas containing essentially H2 and CO with an H2 / CO molar ratio close to 2. In one particular embodiment, the present method is adapted for the production of syngas whose composition meets the conditions presented by equations (D) and (E) shown above. This is made possible by varying the proportions of the different gas streams producing the oxidizing and reducing fluxes. Figure 1 illustrates the general operating principle of the method. A reducing flux (on the right of the figure) comprising at least hydrogen and the carbon source is placed in a reaction chamber (10). The heat required to convert the carbon source to CO is supplied by means of a hot flame, called an Oxy-flame, which is produced by the combustion of hydrogen in the presence of an oxidant such as oxygen (left side of the figure).Part of the hydrogen fed into the reaction chamber can be used to produce the oxy-flame (bottom arrow in the figure). Another part of the hydrogen fed into the reaction chamber is used directly for the production of syngas. The oxy-flame, in addition to providing the heat required for the carbon-CO conversion reaction, can generate ionic species and free radicals that can further this conversion. Hydrogen is introduced in excess into the reaction chamber, and some of it is removed with the CO to form syngas. Overall, the entire process can be described as an "autothermal" process.

[0117] In the reaction chamber (10), there are two distinct flows: one originating from a pure oxygen-based oxidizing gas, called the oxidizing flow, and another flow, called the reducing flow, originating from a hydrogen-based reducing gas mixture containing the carbon source. These two flows are in close proximity to each other. In one embodiment, the two flows can be separated by a distance "d" such that 0.1 mm < d < 100 mm. In another embodiment, the distance d separating the two flows can be such that 0.3 mm < d < 50 mm. Preferably, this distance can be such that 0.6 mm < d < 30 mm. Thus, the distance d separating the two flows can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm, 80 mm, 85 mm, 90 mm, 95 mm, 100 mm, or any distance between these values.It should be noted that the reducing and oxidizing fluxes in the reaction chamber can originate from various streams. The reducing flux comes from a reducing stream containing at least H2, while the oxidizing flux comes from an oxidizing stream containing at least oxygen. However, the carbon source in the reducing flux within the reaction chamber can be supplied by the reducing stream, an independent stream, or the oxidizing stream if this carbon source consists solely of CO2.

[0118] A first implementation of the syngas production method is shown on the [Error! Reference source not found]. This implementation is particularly suited to the production of syngas from CO2 as a carbon source. A stream containing oxygen (1) is mixed with a stream containing CO2 (2) to produce an oxidizing stream (3) comprising a mixture of O2 and CO2. The oxidizing stream (3) is routed through a tube (4) allowing the injection of the O2 and CO2 mixture into the reaction chamber (10) of a reactor. Inside the reaction chamber (10), the O2 and CO2 mixture forms an oxidizing stream (6) from which GO2 will be used to produce the Oxy-flame (9). A stream including hydrogen (5) is injected into the reaction chamber, through an annular space defined between the outer wall of the tube (4) and the circumference of an opening (7) at the entrance of the reaction chamber.The hydrogen stream (5) constitutes a reducing stream, which, once inside the chamber, will form a reducing flow which itself divides into two parts: a first part (8a) of the reducing flow will react with the oxidizing flow (6) according to the combustion reaction of hydrogen (F) to produce the Oxy-flame (9).

[0119] The second part (8b) of the hydrogen stream serves as a reactant ingredient for the RWGS reaction (A). The heat required for this reaction comes from the Oxy-flame (9).

[0120] Reactions (F) and (A) occur inside the reaction chamber (10) to form a gaseous mixture (12) consisting of hydrogen, carbon monoxide, carbon dioxide, and water vapor. This gaseous mixture (12) is also called wet syngas. The gaseous mixture (12) is discharged through the reactor opening (13). The reactor used in this embodiment includes a wall (14) that can be lined with refractory and insulating materials (11). The volume of the reaction chamber (10) is determined by the cylindrical space defined by the length L and the diameter D. Combustion in the reactor can be initiated using a conventional ignition device such as an electric arc or a glowing wire (not shown in the figure). In one embodiment, the reactor can be equipped with a device for measuring the temperature inside the reaction chamber. Such a device could be, for example, a thermocouple (not shown in the figure).The injection tube (4) for the oxidizing current (3) can be secured by means of a device (15). In some embodiments, the securing device (15) can serve both as a guide for the injection tube (4) and as a sealing system. The securing device (15) may, for example, include clamping flanges with cable glands.

[0121] In some designs, the length L of the reaction chamber can range from 1 cm to 300 cm, preferably from 10 cm to 100 cm. The diameter D of the reaction chamber can, for example, range from 0.3 cm to 100 cm, preferably from 1 cm to 50 cm. In some designs, these values ​​for the length and diameter of the reaction chamber can also be applied to the reactors shown in Figures 2 to 5.

[0122] According to certain designs, the different gas flows can be characterized by certain parameters, which will be defined below. Some of these parameters depend on different distances, as shown, for example, in Figure 3.

[0123] The oxidizing flux (6) can be characterized by a rate parameter v1 according to the following equation (G): v1 = nΐ / ((p / 4)·ϋi L 2) (G) where V1 corresponds to the volumetric flow rate of the oxidizing stream (3) at the temperature and pressure conditions in the reaction chamber, and Di is the inside diameter of the inlet tube (4) of the oxidizing stream (3). In the equations, the symbol “·” means “multiplied” and the symbol “ L 2 means "squared".

[0124] The diameter Di is such that the velocity v1 characterizing the oxidizing flux (6) is at least 1 m / s, based on the volumetric flow rate V1. According to another embodiment, the diameter Di is such that the velocity v1 is between 5 m / s and 150 m / s, preferably between 5 and 100 m / s. The velocity v1 can therefore be, for example, between 5 m / s and 90 m / s, between 5 m / s and 80 m / s, between 5 m / s and 70 m / s, between 5 m / s and 60 m / s, between 5 m / s and 50 m / s, between 5 m / s and 40 m / s, between 5 m / s and 30 m / s, between 5 m / s and 20 m / s, or between 5 m / s and 10 m / s.

[0125] The flux of the reducing current (8a, 8b) is characterized by a velocity parameter v2 according to the following equation (H): v2 = V2 / ((p / 4)·(ϋ L 2-ϋ'i L 2)) (H) where V2 is the volumetric flow rate of the reducing stream (8a, 8b) at the temperature and pressure conditions in the reaction chamber, D is the internal diameter of the reactor and D'i is the external diameter of the inlet tube (4) of the oxidizing stream (3).

[0126] The aperture (7) characterized by (D / 2-DV2) can be such that the velocity v2 of the reducing current flowing in the annular space defined between the outer wall of the tube (4) and the circumference of the aperture (7) will be at least 1 m / s, based on the volumetric flow rate V2. According to another embodiment, the aperture (7) (D / 2-DV2) is such that the velocity v2 is between 5 m / s and 150 m / s, preferably between 10 and 100 m / s. The velocity v2 can therefore be, for example, between 10 m / s and 90 m / s, between 10 m / s and 80 m / s, between 10 m / s and 70 m / s, between 10 m / s and 60 m / s, between 10 m / s and 50 m / s, or between 10 m / s and 40 m / s.

[0127] According to some implementations, it is possible to define a parameter to characterize the level of proximity between the reducing flux (8a, 8b) and the flux producing the Oxy-flame (9). This parameter can be defined by the distance d according to the following equation (I): d = (D - D'i) / 4 (I)

[0128] As previously stated, the distance d can be between 0.1 mm and 100 mm, preferably between 0.3 mm and 50 mm, and preferably between 0.6 mm and 30 mm. The distance d can also be any distance within these ranges of values.

[0129] According to one embodiment, the volume of the reaction chamber (10) of the reactor allows a residence time of at least 0.01 seconds for all reactants within the reaction chamber (10). This residence time can be defined by the following equation (J): t = ((p / 4)·ϋ L 2··ί) / (nΐ + V2) (J) where L is the length of the reaction chamber (10), i.e., the length of the internal volume of the reactor as shown for example on the Error! Reference source not found..

[0130] According to some designs, V1 can be between 2 L / min (3.33E-5 m 3 / s) and 100,000 L / min (1.67 m 3 / s), preferably between 5 L / min (8.33E-05 m 3 / s) and 50000 L / min (0.84 m 3 / s). Depending on the specific design, V2 can be between 10 L / min (1.67E-04 m 3 / s) and 300,000 L / min (5 m 3 / s), preferably between 25 L / min (4.17E-04 m 3 / s) and 200,000 L / min (3.33 m 3 / s).

[0131] According to some embodiments, the method for producing syngas can be carried out using an H2 / CO2 molar ratio between 2 and 7. The O2 / CO2 molar ratio can, for example, be between 0.35 and 0.9. Syngas production can be carried out using, for example, an O2 / H2 molar ratio between 0.1 and 0.3. According to some embodiments, the method for producing syngas can be carried out using the following molar proportions of the different reactants:

[0132] • H2 / CO2 molar ratio between 2 and 7; and

[0133] • O2 / CO2 molar ratio between 0.35 and 0.9; and

[0134] • O2 / H2 molar ratio between 0.1 and 0.3.

[0135] The temperature reached inside the reaction chamber during syngas production can be at least 600°C and at most 2200°C. It is understood that the temperature can therefore vary between 600°C and 2200°C, and could thus be, for example, 1000°C, 1100°C, 1200°C, 1300°C, 1400°C, 1500°C, 1600°C, 1700°C, 1800°C, 1900°C, 2000°C, 2100°C, and 2200°C, or any temperature between these values. It is understood that a temperature profile is established inside the reaction chamber during the reaction. Therefore, the temperature is not necessarily the same at one specific point as at another point within the reaction chamber. In other words, there are warmer and cooler areas inside the reaction chamber. When we talk about the temperature reached in the reaction chamber, we are therefore referring to a representative average temperature.

[0136] The temperature can vary depending on the pressure in the reaction chamber during the syngas production reaction. The pressure required to carry out the syngas production reaction can be as low as 0.5 atm. In some embodiments, syngas production can be performed at a pressure of up to 3 atm. Therefore, in some embodiments, the pressure can be 0.5 atm, 1 atm, 1.5 atm, 2 atm, 2.5 atm, or 3 atm, or any pressure between these values. For example, the pressure can be between 1 atm and 3 atm. In some embodiments, for a given flow rate of CO2 and H2, the Û2 feed rate can be adjusted to achieve a desired temperature and heat level inside the reactor to operate the RWGS reaction.On the other hand, the H2 flow rate can be adjusted to obtain the H2 / CO ratio or the R2 ratio defined by equation (E) that one wishes to have for the gaseous mixture (12) evacuated through the opening (13).

[0137] The error! Reference source not found, presents another possible embodiment of the syngas production method and a reactor that can be used for this production. This embodiment is suitable for producing syngas from any possible carbon source. In this case, a stream containing a carbon source (2) is mixed with a hydrogen stream (5a) to form a reducing stream (5b), which is then sent to the reactor. Even if the carbon source contains CO2, which is an oxidant, the mixture (5b) formed by mixing the gas containing CO2 and hydrogen is nevertheless a reducing mixture since it is predominantly composed of hydrogen. According to some embodiments, the carbon source is CO2, and the H2 / CO2 molar ratio in the reducing stream can be at least approximately 2, and preferably at least 3. Once in the reaction chamber (10), the reducing stream (5b) becomes the reducing flux (8a, 8b).An oxidizing stream containing GO2 (1) is fed into the reactor via tube (4) to form the oxidizing stream (6). A first portion (8a) of the reducing stream reacts with the oxidizing stream (6) to produce the Oxy-flame (9). The second portion (8b) of the hydrogen stream, which also contains the carbon source, reacts using the heat from the Oxy-flame (9). Since stream (8b) contains an excess of hydrogen, the gas mixture (12) formed at the reactor outlet consists of hydrogen, carbon monoxide, carbon dioxide, and water vapor. This gas stream, or wet syngas, is discharged through the reactor opening (13). In one embodiment, the carbon source forming stream (2) can consist primarily of CO2, and the reaction occurring in the reaction chamber is the RWGS reaction (A).

[0138] According to another embodiment, the carbon source forming stream (2) can include organic molecules with the chemical formula CaHpOy, where a can vary between 1 and 5, b can vary between 2 and 10, and g can vary between 1 and 4. Other types of organic molecules can also form stream (2), such as hydrocarbons like alkanes (e.g., methane), alkenes, and aromatics. These organic molecules may also be mixed with CO2 in stream (2).

[0139] When the carbon source includes organic molecules of the CaHpOy type, the following reactions can occur in the reaction chamber:

[0140] • Syngas formation according to equation (K):

[0141] • Combustion of hydrogen according to equation (L): where a', a”, b, c, d, e', e” and f are stoichiometric coefficients whose values ​​depend on the molecules involved and the operating conditions considered to achieve the production of synthesis gas, and Q is the heat involved in the process.

[0142] With a = a' + a” and e = e'+ e”, the sum of equations (K) and (L) therefore gives the following stoichiometric equation (M):

[0143] The stoichiometric coefficients can be determined from the chemical formula of the organic compound used as the carbon source. For example, for a = 1, the coefficients can have the following values:

[0144] • a between 1 and 5

[0145] • a” between 0.5 and 2

[0146] • b between 0.25 and 1

[0147] • c between 2 and 3

[0148] • d between 0.5 and 1

[0149] • e between 0.5 and 2.5

[0150] • e” between 0.5 and 2

[0151] • f between 0.15 and 0.75.

[0152] As mentioned above, stream (2) may comprise a mixture of CO2 and organic molecules of formula CaHpO Y In this case, both reactions (A) and (M) can occur in the reaction chamber to form syngas.

[0153] When the carbon source is a hydrocarbon, syngas production can take place in the reaction chamber in the presence of an oxidant to enable the hydrocarbon's oxidation. Such an oxidant can include water vapor and / or CO2. The water vapor can be generated by the combustion reaction (F) of Fh during the formation of the Oxy-flame and / or can be supplied independently to the reaction chamber.

[0154] If the carbon source includes methane as a hydrocarbon, the following reactions can occur in the reaction chamber, depending on the oxidant involved (water vapor, CO2):

[0155] CH4 + H2O -> CO + 3 H2(N)

[0156] If the carbon source includes a hydrocarbon with formula C n H m The following reaction can occur in the reaction chamber:

[0157] CnHm + n H2O = n CO + (n + 1 / 2 m) H2(P) Thus, the present method for producing syngas offers the possibility of using various carbon sources. For example, the carbon source can be a gaseous mixture produced by industrial processes such as gasification or biomass pyrolysis.

[0158] It should be noted that the various reaction parameters mentioned above in relation to Figure 3 (pressure, temperature, distance, diameters, velocities, volumetric flow rates, residence time, etc.) can also be applied to the embodiment involving the different carbon sources which has just been presented in relation to Figure 4.

[0159] Figure 5 shows another embodiment of the syngas production method and a reactor that can be used, among other things, for this purpose. As with the embodiment shown in Figure 4, the one in Figure 5 is adapted for the production of syngas from any possible carbon source (e.g., CO2, molecules of the formula CaHpO2). Y(hydrocarbons or mixtures thereof). As shown in Figure 5, the Oxy-flame (9) can be produced by injecting oxygen and hydrogen through two separate concentric tubes (4a and 4b), as will be explained in more detail below. In this embodiment, the reactor comprises in its lower part a central tube (4a) which fits into a second tube of larger diameter (4b). The central tube (4a) can be attached to the larger tube (4b) by means of a fastening device (15b), such as a sealing device. The second, larger tube (4b) can itself be attached to the wall (14) of the reactor by means of a fastening device (15a), which is preferably similar to the fastening device (15b). The interior of the reactor is divided into two compartments (10a and 10b). The two compartments (10a, 10b) are separated by a wall (16) with an opening (7b). The first compartment (10a) constitutes the reaction chamber of the reactor.

[0160] As can be seen in Figure 5, an oxygen-based oxidizing stream (1) is injected into the central tube (4a), while a stream containing hydrogen (5) is injected into the second tube (4b). The hydrogen stream (5) passes through an opening defined by the annular space (7a) between the inner wall of the middle tube (4b) and the outer wall of the central tube (4a). A stream (2) containing a carbon source is injected into the compartment (10b), which can be described as a distribution chamber, and then passes through the opening (7b) to enter the reaction chamber (10a). In the reactor, the O2 stream (1) becomes an oxidizing stream (6), the H2 stream (5) becomes a hydrogen stream (8c), and the stream (2) containing the carbon source becomes a third stream (8d). The oxygen flow (6) and part of the hydrogen flow (8c) are used to produce the Oxy-flame (9), while the excess hydrogen, i.e.which is not burned, reacts with the stream including the carbon source (8d). It is understood that, even if directly at the entrance of the reaction chamber, there will indeed be a stream (8c) of Fte distinct from a stream (8d) including the carbon source, these two streams (8c) and (8d) no longer constitute totally separate streams once they enter the reaction chamber, and that they can then each include both H2 and the carbon source once in the reaction chamber.

[0161] In the embodiment illustrated in Figure 5, the stream comprising the carbon source (2) can be CO2. However, the stream (2) can also comprise other compounds such as organic molecules and / or hydrocarbons as described above, while being free of CO2. Furthermore, according to some embodiments, the stream (2) can also comprise hydrogen. Thus, a certain quantity of hydrogen can be fed into the middle tube (4b) to form the hydrogen stream (8c), while another portion of hydrogen can be mixed with CO2 and / or organic and / or hydrocarbon vapors to form the stream (8d).

[0162] It should be noted that the various reaction parameters mentioned above in relation to Figure 3 (pressure, temperature, velocities, diameters, volumetric flow rates, residence time, etc.) can also be applied to the embodiment involving the different carbon sources just presented in relation to Figure 5. Figures 6a and 6b present an embodiment of the syngas production method using a large-capacity reactor. As with the embodiment presented in relation to Figure 2, the embodiment of Figures 6a and 6b is particularly suited to the production of syngas from CO2 as a carbon source. According to this embodiment, the reactor may include a wall (14) and an insulating and refractory material (11) to protect the reaction chamber (10a). A distribution chamber (10b) is located in the lower part of the reactor and is connected to the reaction chamber (10a).The distribution chamber receives the reducing current (5) containing hydrogen before it enters the reaction chamber. The reaction chamber (10a) is separated from the reducing current distribution chamber (10b) by a wall. The wall may be made of refractory material with insulation and supported by a plate (16). The plate (16) may, for example, be a metal plate. The compartment (10b) may be traversed by a multitude of concentric tubes (4) which may be fixed to the wall (14) of the reactor in the lower part of the compartment (10b). The tubes (4) may be fixed to the wall (14) by means of a sealing device (15). The fixing and sealing devices (15) may also serve as guides to maintain the position of the tubes (4).The concentric tubes (4) extend through the distribution chamber (10b) into the lower part of the reaction chamber (10a) to form a multitude of inlet ports (7b) through which the oxidizing current (3) is injected into the reaction chamber. Furthermore, the wall between the distribution chamber and the reaction chamber has openings forming a multitude of inlet ports (7a) of radius n through which the reducing current (5) can enter the reaction chamber. In a preferred embodiment, the openings (7a) form a ring around the tubes (4) as shown in Figure 6b. The inlet ports (7b) of radius G2 can be concentric with respect to the inlet ports (7a). The reducing current (5) can be injected into the distribution chamber (10b) through more than one inlet port. Figure 6b shows that the reactor can be equipped with at least 4 input ports for the reducing current (5).Furthermore, as shown in Figure 6a, the reactor can include a multitude of tubes (4) for injecting the oxidizing current (3) into the reaction chamber (10a). Finally, the reactor according to this embodiment also includes an outlet (13) to allow the syngas produced in the reaction chamber to be evacuated.

[0163] According to this embodiment, several oxy-flames can form in the reaction chamber. The distance parameter between the reducing flux and the oxidizing flux (oxy-flame) for this embodiment can be defined as follows: d = (n - r²) / 2 (Q)

[0164] As with all designs, the distance d can preferably be between 0.1 mm and 100 mm. According to another design, the distance d separating the two flows can be between 0.3 mm and 50 mm, or preferably between 0.6 mm and 30 mm. The distance d can also be any distance within these ranges.

[0165] As mentioned above, according to some applications, the hydrogen required in the reducing current, which is used to obtain syngas, can be produced from renewable resources. Specifically, hydrogen can be produced from a water electrolysis system powered by electricity from renewable sources. The current, which includes the carbon source (e.g., CO2) also required as a reactant, can itself be a gaseous mixture produced by biomass gasification or pyrolysis techniques, as mentioned above. Thus, overall, it is possible to produce syngas from a captured carbon source, water, and electricity from renewable sources.

[0166] This implementation of the method for producing syngas from renewable resources is shown in part of Figure 7. Figure 7 also shows additional steps, including, for example, the recovery of water formed during the syngas production reaction. Thus, Figure 7 presents the following steps: • electrolysis (20) of the fed water (FteO-a) by electricity from a renewable source (E);

[0167] • production of syngas (30) according to one of the implementations described above;

[0168] • cooling of the produced gases (40), for example by means of direct contact cooling;

[0169] • water recovery (FteO-c) by condensation (50).

[0170] More specifically, as can be seen in Figure 7, the electrolysis system (20) is supplied with water (FteO-a) to produce hydrogen (Fte) and oxygen. The hydrogen (H2) produced by electrolysis is mixed with a gas comprising CO2 and / or another carbon source, preferably CO2. This gas, comprising CO2 and / or another carbon source, may originate, at least in part, from a biomass gasification or pyrolysis process. The resulting mixture (G0) forms a reducing current that can then be used for syngas production (30). Some of the oxygen (U2-a) produced by electrolysis (20) is sent to the syngas production unit (30), where it can be used to generate the Oxy-flame. The remaining oxygen (U2-b) produced by electrolysis (20) can be discharged.

[0171] The gas (G1) resulting from the production of syngas (30) is then rapidly cooled (40) to limit / prevent the reverse reaction of reaction (A). The cooling can be carried out using a conventional method. In a preferred embodiment, the cooling (40) can be achieved using a cooler in direct contact with a stream of water (H2O-). In one embodiment, the gas (G1) is cooled to a temperature above the dew point of the hot gas and not exceeding 250°C. In some embodiments, the dew point of the hot gas (G1) is below 90°C at atmospheric pressure. For example, the dew point of the hot gas (G1) is between 60°C and 90°C at atmospheric pressure. In some embodiments, the gas (G1) can be cooled to a temperature between 90°C and 250°C.

[0172] The cooled gas (G2) obtained after cooling (40) is a humid gas. This gas (G2) can then undergo a second cooling, which can be carried out by condensation (50). In some embodiments, this condensation can be achieved using a condenser-cooler. In a preferred embodiment, the condensation step (50) can be carried out in such a way that the gas (G2) is cooled to a temperature of 35 °C or less. At the outlet of the condenser-cooler, syngas (G3) and condensed water (hhO-c) are obtained. Part of the condensed water (hteO-c) can be recycled (hteO-b flow) to the cooling step (40), while the other part of the condensed water can be discharged (hhO-d flow). According to some designs, the hteO-d flow can be used, at least in part, to supply water to the electrolysis system (20).

[0173] As previously mentioned, the syngas production method described in this document can produce balanced CO-hte gas mixtures (syngas), i.e., with appropriate CO and hte proportions, enabling the subsequent production of a variety of products through conventional chemical syntheses. Thus, by controlling the nature and quantity of reagents used (e.g., the gas flow rate), it is possible to produce a syngas where the CO and hte ratio is tailored for direct use in subsequent chemical synthesis. It is also possible to manipulate the CO and hte ratio in the syngas by controlling the temperature, pressure, and Û2 feed rate in the reaction chamber. Furthermore, the temperature in the reactor can be controlled by the oxygen feed rate.According to one embodiment, the syngas produced contains H₂ and CO in an H₂ / CO molar ratio > 2. The syngas produced by the described method may also contain CO₂. In this case, the molar ratios of H₂, CO, and CO₂ in the syngas can be such that (H₂-CO₂) / (CO + CO₂) > 2. By respecting these molar ratios, the syngas produced by the present method can be used to produce a large number of basic chemicals. These products include, in particular, methanol and hydrocarbons such as those found in motor gasoline, diesel, and kerosene, to name a few examples.

[0174] The syngas production method described above, and the reactor used to implement it, offer several advantages. The reactants are readily available and can be derived from renewable sources. Solid catalysts are not required. The reactant conversion rate can also be higher than that observed in a conventional RWGS reaction using a catalyst. Finally, this method is robust, versatile, and easy to implement. These advantages reduce production costs and provide the beneficial environmental impact of recycling carbon sources such as CO2.

[0175] EXAMPLES

[0176] Example 1

[0177] This example is based on a small-scale reactor as schematically represented in Figure 8. This mini-reactor operates according to a scenario involving the co-injection of premixed O2 and CO2 inside the inner tube, i.e., in space A, and the injection of H2 into the annular space B. The reactor was constructed from small Inconel 600™ tubes. The following dimensions are used to characterize the geometry of the mini-reactor (Dl = internal diameter; ED = external diameter) where L corresponds to a length from the beginning of the reaction zone (dimensions in mm):

[0178] • External tube: Dl = 10.41; ED = 12.7; L = 371.83

[0179] • Median tube: Δl = 7.752; ΔE = 9.53; L < 0 (beginning of the reaction zone) Inner tube: Δl = 3.048; ΔE = 6.35; L < 0 (beginning of the reaction zone)

[0180] An ignition system for igniting a pulsejet, i.e., a spark plug with 20 kV ignition, was inserted inside the reactor, very close to the upper end of the inner and middle tubes. A hole was drilled to allow the spark plug to be inserted (not shown in the figure for clarity). The temperature within the reactor is monitored using thermocouples. The temperature is measured in both the lower and upper parts of the reaction zone inside the mini-reactor. Specifically, a temperature reading is taken near the base of the reaction zone (where the gases are injected), precisely 13 mm above the start line of the reaction zone (see Figure 8), and another reading is taken 89 mm above the start line of the reaction zone (see Figure 8). The thermocouples were installed using T-fittings (not shown in the figure).

[0181] The experimental setup includes the following: the reactor itself, a jacketed tube heat exchanger for rapid cooling of the reactor exiting gases, a condensate recovery tank, a relative humidity (RH) gas analysis system, and finally, a CO2 / CO2 / CxH analysis system. y / 02) allowing the measurement of CO, CO2, hydrocarbon (CxH) levels y ) as well as the oxygen content of the gas produced, at the outlet of the gas cooling system.

[0182] A mass flow meter system with automated control valves is also installed. The system includes software for programming changes to the composition of the gas mixture introduced into the reactor. Finally, manual valves are used to direct each gas into the desired reactor tube.

[0183] To prevent backfires during ignition, the ignition is carried out in stages (of approximately 1 second each). The main steps of the ignition sequence include: 1) starting the injection of high-temperature fuel, 2) after a few seconds, injecting oxygen in successive stages up to the desired flow rate, each stage lasting a few seconds, 3) starting the injection of CO2.

[0184] Once ignition occurs, the analysis steps can be performed. Each step lasts 60 seconds. After this time, the various measurements are taken. The input flow rates (standard liters (SL) at 25 °C, 1 atm per min) are as follows:

[0185] • CO2: 1.3 SL / min

[0186] • O2: 0.93 SL / min

[0187] • H2: 6.1 SL / min

[0188] The CO2 and O2 flow rates are pre-mixed. The operating pressure is approximately 1 atm.

[0189] The following results were obtained:

[0190] • Molar concentration of CO in the gas: 22.2%

[0191] • Molar concentration of CO2 in the gas: 8.1%

[0192] • Molar concentration of hydrocarbon: trace

[0193] • Molar ratio of CO / CO2 of the gas produced: 2.74

[0194] • CO2 to CO conversion rate: 73%

[0195] • Average temperature in the reaction chamber: 686°C

[0196] • Velocity at the inlet of the O2 / CO2 mixture (at average temperature, 1 atm): 16.4 m / s

[0197] • Velocity at the H2 inlet (at average temperature): 21.1 m / s

[0198] • Residence time in the reactor (s): < 0.06 s

[0199] • R2 ratio = (H2-CO2) / (CO+CO2): 2.26

[0200] To calculate the R2 ratio, the H2 concentration is determined using an atomic balance. This atomic balance is performed by considering all inputs (CO2, H2, O2) and the composition of the outgoing gas (CO and CO2 levels, hydrocarbon content expressed as CH4 equivalent, gas moisture content, and residual oxygen content). The atomic balance for hydrogen atoms allows for the calculation of the hydrogen composition of the gas exiting the reactor.

[0201] Example 2

[0202] In this example, the same setup as in Example 1 is used, but with O2 injected into the inner tube (space A), H2 injected into the annular space between the middle tube and the inner tube (space B), and an equimolar CO2 / CH4 mixture injected into the annular space between the outer tube and the middle tube (space C). The input flow rates (standard liters at 25 °C, 1 atm per min) are as follows:

[0203] • CO2: 0.40 SL / min

[0204] • Ch 0.40 SL / min

[0205] • O2: 0.9 SL / min

[0206] • H2: 3.3 SL / min

[0207] These three flows are injected separately into the mini-reactor. The following results were obtained:

[0208] • CO concentration of dry gas: 13.3%

[0209] • Molar concentration of CO2 in the gas: 10.2%

[0210] • Molar hydrocarbon concentration of the gas: 2135 ppm

[0211] • CO / CO2 ratio of the gas produced: 1.30

[0212] • CO2 conversion rate: 13.1%

[0213] • CH4 conversion rate: 98.2%

[0214] • Average temperature: 855 °C

[0215] • O2 inlet velocity (at average temperature, 1 atm): 7.77 m / s

[0216] • Velocity at the H2 inlet (at average temperature, 1 atm): 13.4 m / s

[0217] • Velocity at the inlet of the CO2 / CH4 mixture (at average temperature, 1 atm): 7.46 m / s

[0218] • Reagent residence time: < 0.07 s

[0219] • R2 = (H2-CO2) / (CO+CO2) : 2.87 For the calculation of the ratio R2, the concentration of hte is calculated from an atomic balance.

[0220] Example 3

[0221] In this example, the same reactor as in Example 1 is used, but the outer Inconel™ tube is replaced with a quartz tube. The reaction chamber length is the same. For this example, the CO2 and O2 flow rates are premixed. The resulting mixture is injected into the inner tube (space A), while hydrogen is injected into space B. The operating pressure is approximately 1 atm. Since the temperature cannot be measured directly, the temperature used is a thermodynamic equilibrium temperature calculated to obtain a gas with the same CO / CO2 ratio as the measured value.

[0222] The input flow rates (standard liters at 25°C, 1 atm per min) are as follows:

[0223] • CO2: 1.3 SL / min

[0224] • O2: 0.93 SL / min

[0225] • H2: 6.2 SL / min

[0226] The following results were obtained:

[0227] • CO concentration of the gas: 22.9%

[0228] • CO2 concentration of the gas: 7.30%

[0229] • Molar concentration of hydrocarbon: trace

[0230] • CO / CO2 ratio of the gas produced: 3.14

[0231] • CO2 to CO conversion rate: 75.8%

[0232] • Equilibrium temperature T: 1230 °C

[0233] • Velocity at the inlet of the O2 / CO2 mixture (at temperature T, 1 atm): 25.6 m / s

[0234] • Velocity at the H2 inlet (at temperature T and 1 atm): 33.7 m / s

[0235] • Reagent residence time: < 0.04 s

[0236] • R2 = (H2-CO2) / (CO+CO2) : 2.34 For the calculation of the R2 ratio, the high concentration of the gas exiting the reactor is calculated from an atomic balance. Comparison of the results of Example 1 with those of Example 3 shows that the nature of the reactor materials (Inconel™ versus quartz) has no significant influence on the CO2 conversion rate.

[0237] Example 4

[0238] This example uses the same equipment as Example 3, i.e., based on the use of a quartz tube as the external tube. In this example, O2 is injected into space A, H2 is injected into space B, and CO2 into space C. Since the temperature cannot be measured directly, the temperature used is a thermodynamic equilibrium temperature calculated to obtain a gas with the same CO / CO2 ratio as that which was measured. The input flow rates (standard liters (SL) at 25 °C, 1 atm per min) are as follows:

[0239] • CO2: 1.3 SL / min

[0240] • O2: 0.93 SL / min

[0241] • H2: 6.1 SL / min

[0242] The following results were obtained:

[0243] • CO concentration of the gas: 18.21%

[0244] • Gas CO2 concentration: 11.5%

[0245] • Hydrocarbon concentration: trace

[0246] • Gas CO / CO2 ratio: 1.58

[0247] • CO2 to CO conversion rate: 61.2%

[0248] • Equilibrium temperature T: 877 °C

[0249] • O2 velocity (at temperature T): 8.20 m / s

[0250] • Velocity of H2 (at temperature T, 1 atm): 25.4 m / s

[0251] • CO2 velocity (at temperature T, 1 atm): 9.02 m / s

[0252] • Residence time in the reactor: < 0.05 s

[0253] • R2 = (H2-CO2) / (CO+CO2) : 2.26 For the calculation of the ratio R2, the concentration of H2 in the gas exiting the reactor is calculated from an atomic balance.

[0254] The applicability of the synthesis gas production process has been demonstrated in the examples above, among others, based on the use of CO2 as a carbon source. CO2 is a very chemically stable molecule, and much more stable than a CaHpO molecule. Y where a is between 1 and 5. Since the examples above have demonstrated that the process is applicable to CO2, which is more difficult to chemically transform than a CaHpO-type molecule Y It is reasonable to conclude that the process is also applicable to CaHpO type molecules Y as a source of carbon.

[0255] Although some embodiments of the present method, and of the reactor that can be used to implement this method, have been described above, the method and the reactor are 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 envisaged.

Claims

DEMANDS 1- A method for producing synthesis gas comprising carbon monoxide (CO) and hydrogen (hte), wherein the synthesis gas is produced by a reduction reaction of a first stream comprising a carbon source and an excess of hydrogen in contact with an Oxy-flame, and wherein: the hydrogen comes from a reducing stream, a first part of which is found in the first stream and a second part is used to generate the Oxy-flame by combustion of the hydrogen in the presence of a second stream comprising oxygen (O2), the second stream coming from an oxidizing stream, the first and second streams are at a distance from each other such that the Oxy-flame supports the reaction between the carbon source and the hydrogen. 2- The method according to claim 1, in which the reduction reaction is carried out in the absence of a solid catalyst. 3- The method according to claim 1 or 2, wherein the Oxy-flame generates ionic species and free radicals which promote the conversion of the carbon source into CO. 4- The method according to any one of claims 1 to 3, wherein the carbon source comprises: - CO2; or - at least one type of oxygenated molecules with the formula C a HpO Y where a is between 1 and 5, b is between 2 and 10, and y is between 1 and 4; or - one or more hydrocarbons; or - a mixture of at least two of these carbon sources. 5- The method according to any one of claims 1 to 4, wherein the carbon source comprises CO2 and the reduction reaction comprises a reverse gas-to-water or "Reverse Water Gas Shift". 6- The method according to any one of claims 1 to 5, wherein the reducing current is hydrogen. 7- The method according to any one of claims 1 to 5, wherein the reducing current comprises hydrogen and the carbon source.

8. The method according to any one of claims 1 to 5, wherein the reducing current comprises hydrogen and CO2.

9. The method according to any one of claims 1 to 5, wherein the reducing current comprises hydrogen, CO2, and at least one type of oxygenated molecule of the formula CaHpO2. Y where a is between 1 and 5, b is between 2 and 10 and y is between 1 and 4. 10- The method according to any one of claims 1 to 9, wherein the oxidizing current is oxygen. 11- The method according to any one of claims 1 to 10, wherein the oxidizing stream comprises oxygen and CO2. 12- The method according to any one of claims 1 to 6, wherein the reducing current comprises only hydrogen, the oxidizing current comprises only oxygen and the carbon source is supplied by an independent current. 13- The method according to claim 12, wherein the independent current comprises CO2. 14- The method according to claim 12, wherein the independent stream comprises CO2 and methane. 15- The method according to any one of claims 1 to 14, wherein the oxygen is obtained from an electrolysis reaction of water. 16- The method according to any one of claims 1 to 15, wherein the hydrogen is obtained from an electrolysis reaction of water. 17- The method according to any one of claims 1 to 16, wherein the carbon source is from a gaseous mixture resulting from a gasification or pyrolysis process of biomass. 18- The method according to any one of claims 1 to 17, wherein the reduction reaction is carried out at an average temperature of at least 600°C. 19- The method according to any one of claims 1 to 18, wherein the reduction reaction is carried out at an average temperature of at least 1200°C. 20- The method according to any one of claims 1 to 19, wherein the reduction reaction is carried out at an average temperature of at most 2200°C. 21- The method according to any one of claims 1 to 20, wherein the first flow and the second flow are at a distance from each other of between 0.1 mm and 100 mm. 22- The method according to any one of claims 1 to 21, wherein the first flow and the second flow are at a distance from each other of between 0.3 mm and 50 mm. 23- The method according to any one of claims 1 to 22, wherein the first flow and the second flow are at a distance from each other of between 0.6 mm and 30 mm. 24- The method according to any one of claims 1 to 23, wherein the carbon source comprises CO2 and the reduction reaction is carried out using an H2 / CO2 molar ratio between 2 and 7. 25- The method according to any one of claims 1 to 24, wherein the carbon source comprises CO2 and the reduction reaction is carried out using an O2 / CO2 molar ratio between 0.35 and 0.

9. 26- The method according to any one of claims 1 to 25, wherein the reduction reaction is carried out using an O2 / H2 molar ratio between 0.1 and 0.

3. 27- The method according to any one of claims 1 to 26, wherein the synthesis gas produced has an H2 / CO molar ratio of at least 1.

8. 28- The method according to any one of claims 1 to 27, wherein the synthesis gas produced has an H2 / CO molar ratio of at least 2. 29- The method according to any one of claims 1 to 27, wherein the synthesis gas produced has an H2 / CO molar ratio between 1.8 and 5.

0. 30- The method according to any one of claims 1 to 29, wherein the synthesis gas produced further comprises CO2. 31- The method according to claim 30, wherein the synthesis gas produced has a molar ratio in H2, CO and CO2 such that (H2 - CO2) / (CO + CO2) ³ 2. 32- The method according to any one of claims 1 to 31, further comprising cooling the synthesis gas to form a cooled synthesis gas.

33. The method according to claim 32, further comprising condensation of water contained in the cooled syngas and recovery of the water.

34. The method according to claim 33, wherein at least a portion of the recovered water is recycled in the cooling step. 35- Use of a synthesis gas produced by the method as defined according to any one of claims 1 to 34, for the manufacture of chemical products or fuels. 36- Use of a synthesis gas produced by the method as defined according to any one of claims 1 to 34, for the manufacture of methanol or synthetic hydrocarbons. 37- A reactor for producing a synthesis gas comprising carbon monoxide (CO) and hydrogen (hte), said reactor comprising: a reaction chamber in which the synthesis gas is produced by a reduction reaction of a first stream comprising a carbon source and an excess of hydrogen in contact with an Oxy-flame, at least one first means for supplying the reaction chamber with a reducing stream comprising hydrogen, a first part of the reducing stream being found in the first stream and a second part being used to generate the Oxy-flame in the combustion chamber, by combustion of hydrogen in the presence of a second stream comprising oxygen (O2), at least one second means for supplying the reaction chamber with an oxidizing stream forming the second stream, the first stream and the second stream being at a distance from each other such that the Oxy-flame sustains the reaction between the carbon source and the hydrogen. 38- The reactor according to claim 37, in which the reduction reaction is carried out in the absence of a solid catalyst. 39- The reactor according to claim 37 or 38 in which the Oxy-flame generates ionic species and free radicals which promote the conversion of the carbon source into CO. 40- The reactor according to any one of claims 37 to 39, wherein the carbon source comprises: - CO2; or - at least one type of oxygenated molecules with the formula CaHpO Y where a is between 1 and 5, b is between 2 and 10, and y is between 1 and 4; or - one or more hydrocarbons; or - a mixture of at least two of these carbon sources. 41- The reactor according to any one of claims 37 to 40, wherein the carbon source comprises CO2 and the reduction reaction is the reverse gas-to-water or "Reverse Water Gas Shift". 42- The reactor according to any one of claims 37 to 41, wherein the reducing current is hydrogen. 43- The reactor according to any one of claims 37 to 41, wherein the reducing current comprises hydrogen and the carbon source. 44- The reactor according to any one of claims 37 to 41, wherein the reducing current comprises hydrogen and CO2.

45. The reactor according to any one of claims 37 to 41, wherein the reducing current comprises hydrogen, CO2 and at least one type of oxygenated molecules of formula CaHpO Y where a is between 1 and 5, b is between 2 and 10 and y is between 1 and 4. 46- The reactor according to any one of claims 37 to 45, wherein the oxidizing stream is oxygen. 47- The reactor according to any one of claims 37 to 45, wherein the oxidizing stream comprises oxygen and CO2. 48- The reactor according to any one of claims 37 to 47, wherein the first means for supplying the reducing current and the second means for supplying the oxidizing current are tubes. 49- The reactor according to any one of claims 37 to 47, comprising a plurality of second means consisting of a plurality of tubes allowing the injection of the oxidizing current into the reaction chamber, and a plurality of first means consisting of a plurality of openings allowing the injection of the reducing current into the reaction chamber. 50- The reactor according to claim 49, in which each opening is defined by an annular space delimited by the external diameter of a tube of the plurality of tubes and extending perpendicularly from the external wall of the tube. 51- The reactor according to claim 50, further comprising a reducing current distribution chamber separated from the reaction chamber by a separating wall, said distribution chamber and said separating wall being traversed by the plurality of tubes, the annular space extending perpendicularly from the outer wall of each tube also traversing the separating wall. 52- The reactor according to any one of claims 37 to 42, wherein the reducing stream is hydrogen which is supplied into the reaction chamber by the first means consisting of a first tube, the oxidizing stream is oxygen which is supplied into the reaction chamber by the second means consisting of a second tube, and the carbon source is supplied by an independent stream which is injected into the reaction chamber through at least one opening located in a wall of the reaction chamber. 53- The reactor according to claim 52, in which the opening is formed by a third tube concentric with the first tube and the second tube, the second tube forming the inner tube, the first tube forming an intermediate tube and the third tube forming an outer tube. 54- The reactor according to claim 53, in which the opening is formed by an annular space delimited by an internal diameter of the third tube and an external diameter of the first tube. 55- The reactor according to any one of claims 52 to 54, further comprising a distribution chamber separated from the reaction chamber by a separating wall, said distribution chamber serving to supply the independent current comprising the carbon source and being traversed by the first tube and the second tube. 56- The reactor according to any one of claims 52 to 55, wherein the independent current comprises CO2. 57- The reactor according to any one of claims 52 to 56, wherein the independent stream comprises CO2 and methane. 58- The reactor according to any one of claims 37 to 57, in which the oxygen is obtained from an electrolysis reaction of water. 59- The reactor according to any one of claims 37 to 58, in which the hydrogen is obtained from an electrolysis reaction of water. 60- The reactor according to any one of claims 37 to 59, wherein the carbon source is from a gaseous mixture resulting from a gasification or pyrolysis process of biomass. 61- The reactor according to any one of claims 37 to 60, in which the reaction chamber reaches an average temperature of at least 600°C during the reduction reaction. 62- The reactor according to any one of claims 37 to 61, in which the reaction chamber reaches an average temperature of at least 1200°C during the reduction reaction. 63- The reactor according to any one of claims 37 to 62, in which the reaction chamber reaches an average temperature of at most 2200°C during the reduction reaction. 64- The reactor according to any one of claims 37 to 63, in which the first flow and the second flow are at a distance from each other of between 0.1 mm and 100 mm. 65- The reactor according to any one of claims 37 to 64, in which the first flow and the second flow are at a distance from each other of between 0.3 mm and 50 mm. 66- The reactor according to any one of claims 37 to 65, in which the first flow and the second flow are at a distance from each other of between 0.6 mm and 30 mm. 67- The reactor according to any one of claims 37 to 66, wherein the carbon source comprises CC and the reduction reaction is carried out using an H2 / CO2 molar ratio between 2 and 7. 68- The reactor according to any one of claims 37 to 67, wherein the carbon source comprises CC and the reduction reaction is carried out using an O2 / CO2 molar ratio between 0.35 and 0.

9. 69- The reactor according to any one of claims 37 to 68, in which the reduction reaction is carried out using an O2 / H2 molar ratio between 0.1 and 0.

3. 70- The reactor according to any one of claims 37 to 69, in which the synthesis gas produced has an H2 / CO molar ratio of at least 1.

8. 71- The reactor according to any one of claims 37 to 70, in which the synthesis gas produced has an H2 / CO molar ratio of at least 2. 72- The reactor according to any one of claims 37 to 69, in which the synthesis gas produced has an H2 / CO molar ratio between 1.8 and 5.

0. 73- The reactor according to any one of claims 37 to 72, wherein the synthesis gas produced further comprises CO2. 74- The reactor according to claim 73, in which the synthesis gas produced has a molar ratio in H2, CO and CO2 such that (H2 - CO2) / (CO + CO2) ³ 2. 75- A system comprising the reactor as defined according to any one of claims 37 to 74, coupled to a synthesis gas cooling device to form a cooled synthesis gas. 76- The system according to claim 75, wherein the cooling device is a direct contact cooler. The system according to claim 75 or 76, further comprising a water condensation apparatus for recovering water from the cooled synthesis gas. 77- The system according to claim 77, wherein the condensing unit is a condenser-cooler. 78- The system according to claim 77 or 78, further comprising equipment for recycling at least a portion of the recovered water back to the cooling device.

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