Method and reactor for producing synthesis gas from a carbon source and a hydrogen source in the presence of an oxygen flame - Patents.com

Abstract

The present technology relates to a method for producing synthesis gas containing carbon monoxide (CO) and hydrogen (H2), where the synthesis gas is produced by a reduction reaction of a first flow containing a carbon source and excess hydrogen in contact with an oxygen flame. The hydrogen comes from the reduction stream, a first portion of which ultimately becomes the first flow, and a second portion of which is used to generate the oxygen flame by burning the hydrogen in the presence of a second flow containing oxygen (O2), which comes from the oxidation stream. The first and second flows are spaced apart from each other so that the oxygen flame supports the reaction between the carbon source and the hydrogen. A reactor, which may have various configurations, has also been proposed for implementing the method.

Description

[Technical Field]

[0001] [Priority Application] This application claims priority to Canadian application CA3.081.971, filed June 4, 2020, which is incorporated herein by reference.

[0002] This application relates to a method and reactor for producing synthesis gas from a source of carbon and hydrogen (H2). More specifically, the synthesis gas production method is carried out in the direct presence of an oxygen flame to convert a flow containing a source of carbon and hydrogen into synthesis gas. [Background technology]

[0003] The fight against climate change requires, among other things, significant reductions in greenhouse gas (GHG) emissions, particularly CO2 and methane emissions. This requires radical measures that can achieve the goal of reducing GHG emissions, going beyond all measures related to incremental improvements. Currently, significant efforts are being made to minimize the consumption of fossil fuels as energy sources and as building blocks for several chemical syntheses. For the production of products containing carbon in their atomic composition, using CO2 as a basic reagent to provide a carbon source is a promising solution. CO2 is found in the atmosphere and in air emissions from CO2-emitting industrial processes (e.g., cement plants, aluminum plants, and steel mills). The process of capturing CO2 from ambient air or CO2 emitted by industrial processes and recycling it for later use is also known as "carbon capture and utilization" (CCU). Such 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., their production and use cycles involve virtually no net greenhouse gas emissions). It is therefore possible to produce carbon-neutral synthetic fuels that can be used in existing infrastructure.

[0004] There are several ways to use CO2 as a basic reagent to provide carbon, the most practical being to convert CO2 to carbon monoxide (CO) according to a reaction (A) called the "Reverse Water Gas Shift," or RWGS. CO2+ H2a CO + H2O (vapor) (A)

[0005] CO2 can be reacted with excess hydrogen (H2) to produce a hydrogen and CO2-based mixture. Such a mixture is called "syngas" or "syngas." These synthesis gases may also contain residual CO2.

[0006] Syngas can be used to produce a variety of commodity chemicals, notably methanol and hydrocarbons found in automobile gasoline, diesel, and kerosene.

[0007] Methanol is a platform molecule that can be used as a raw material for many other base 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 converted into dimethyl ether (DME), itself a chemical intermediate. DME is used, among other things, as a propellant in aerosols. DME can be used as a fuel for diesel engines or as a propane replacement.

[0008] The basic reaction known for producing methanol from synthesis gas is the following reaction (B): CO + 2 H2a CH3OH (B)

[0009] Synthetic hydrocarbons can be produced from synthesis gas according to the Fischer-Tropsch reaction (C): n CO + 2n H2a -(CH2) n - + n H2O (C)

[0010] Depending on the chemical products produced, a CO / H2-based mixture useful as synthesis gas for these products must be balanced, i.e., contain H2 and CO in the appropriate ratio. Considering reactions (B) and (C), it should be noted that, theoretically, synthesis gas (syngas) must essentially contain H2 and CO according to a H2 / CO molar ratio close to 2. More precisely, taking into account the possible presence of residual CO2 in the synthesis gas, the molar ratio of gases capable of carrying out reactions (B) or (C) generally corresponds to the ratio R1 or R2 in equations (D) and (E) below: (D) R1 = H2 / CO ≥ 2 (E) R2 = (H2-CO2) / (CO + CO2) ≧ 2

[0011] A great many chemical and hydrocarbon syntheses can be performed using syngas that can meet the R1 or R2 molar composition criteria. Note that methane (CH4) can also be produced from syngas. One mole of methane can be produced from one mole of CO and three moles of H2.

[0012] The RWGS (A) reaction is endothermic (41 kJ / mol reaction enthalpy at room temperature). According to the stoichiometry of this reaction, 1.57 kg of CO2 and 0.07 kg of H2 are required to produce 1 kg of CO2, providing 1465 kJ or 0.4 kWh of thermal energy. A catalytic bed reactor is typically used to carry out this reaction. However, the use of conventional catalysts to carry out reaction (A) does not result in high conversion rates. This means that the per-pass conversion rate, i.e., the conversion rate while CO2 passes through the catalyst bed, is quite low. This is because the operating temperature of catalytic bed reactors is quite limited, often below 600 °C. However, thermodynamically, reaction (A) is significantly favored at higher temperature levels. This is shown in Table 1, which presents the equilibrium constant values ​​as a function of temperature (at atmospheric pressure).

[0013] [Table 1]

[0014] Of particular interest are methods for producing synthesis gas from carbon and hydrogen sources. Also of particular interest are methods for producing synthesis gas, for example, from CO and from hydrogen, without requiring the use of conventional solid catalysts. Also attractive are methods that allow for the preparation of synthesis gas useful for the production of various chemical products. Such methods are described below. Summary of the Invention [Means for solving the problem]

[0015] According to a first aspect, the present technology provides a method for producing a synthesis gas comprising carbon monoxide (CO) and hydrogen (H), wherein the synthesis gas is produced by a reduction reaction of a first flow comprising a carbon source and excess hydrogen in contact with an oxygen flame; The hydrogen is derived from the reducing stream, a first portion of which ultimately becomes the first flow, and a second portion of which is used to generate an oxygen flame by combustion of the hydrogen in the presence of a second flow containing oxygen (O2), the second flow being derived from the oxidizing stream; The first flow and the second flow are spaced apart from each other so that the oxygen flame supports the reaction between the carbon source and the hydrogen. Regarding the method.

[0016] According to one embodiment, the method is such that the reduction reaction is carried out in the absence of a solid catalyst.

[0017] According to another embodiment, the method is such that the oxygen flame generates ionic species and free radicals that promote the conversion of the carbon source to CO.

[0018] According to another embodiment, the method further comprises the step of: CO2, or ·Formula C α H β O γ At least one oxygen-containing molecule represented by the formula (wherein α is 1 to 5, β is 2 to 10, and γ is 1 to 4), or one or more hydrocarbons, or a mixture of at least two of the above carbon sources, This is a method that includes the following.

[0019] According to another embodiment, the carbon source comprises CO2 and the reduction reaction comprises the reverse reaction of gas to water, i.e., the "reverse water gas shift."

[0020] In another embodiment, the method is such that the reduced stream is hydrogen. In another embodiment, the reduced stream comprises hydrogen and a carbon source. In another embodiment, the reduced stream comprises hydrogen and CO.

[0021] According to another embodiment, the method further comprises the step of: the reducing stream comprising hydrogen, CO, and a catalyst of formula C α H β O γ(wherein α is 1 to 5, β is 2 to 10, and γ is 1 to 4).

[0022] According to another embodiment, the method is such that the oxidizing stream is oxygen. In another embodiment, the oxidizing stream comprises oxygen and CO2.

[0023] According to another embodiment, the method is such that the reduced stream contains only hydrogen, the oxidized stream contains only oxygen, and the carbon source is provided by an independent stream. According to another embodiment, the independent stream contains CO. According to another embodiment, the independent stream contains CO and methane.

[0024] According to another embodiment, the method is such that the oxygen comes from a water electrolysis reaction.

[0025] According to another embodiment, the method is such that the hydrogen is derived from a water electrolysis reaction.

[0026] According to another embodiment, the method is such that the carbon source is derived from a gas mixture resulting from a biomass gasification or pyrolysis process.

[0027] According to another embodiment, the method is such that the reduction reaction is carried out at an average temperature of at least 600° C. According to another embodiment, the method is such that the reduction reaction is carried out at an average temperature of at least 1200° C. According to another embodiment, the method is such that the reduction reaction is carried out at an average temperature of at most 2200° C.

[0028] According to another embodiment, the method is such that the first flow and the second flow are spaced from each other by a distance of between 0.1 mm and 100 mm. According to another embodiment, the first flow and the second flow are spaced from each other by a distance of between 0.3 mm and 50 mm. According to another embodiment, the first flow and the second flow are spaced from each other by a distance of between 0.6 mm and 30 mm.

[0029] According to another embodiment, the method is such that the carbon source comprises CO2 and the reduction reaction is carried out using a H2 / CO2 molar ratio of 2-7.

[0030] According to another embodiment, the method is such that the carbon source comprises CO2 and the reduction reaction is carried out using an O2 / CO2 molar ratio of 0.35 to 0.9.

[0031] According to another embodiment, the method is such that the reduction reaction is carried out using an O2 / H2 molar ratio of 0.1 to 0.3.

[0032] According to another embodiment, the method is such that the synthesis gas produced has a H2 / CO molar ratio of at least 1.8. According to another embodiment, the synthesis gas produced has a H2 / CO molar ratio of at least 2. According to another embodiment, the synthesis gas produced has a H2 / CO molar ratio of 1.8 to 5.0.

[0033] According to another embodiment, the method is such that the synthesis gas produced further comprises CO2.

[0034] 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.

[0035] According to another embodiment, the method further comprises cooling the syngas to form a cooled syngas.

[0036] According to another embodiment, the method further comprises the step of condensing water contained in the cooled syngas and recovering the water, wherein at least a portion of the recovered water is recycled to the cooling step.

[0037] According to another aspect, the present technology relates to the use of synthesis gas produced by the methods of the present technology for the production of chemicals or fuels.

[0038] According to another aspect, the present technology relates to the use of synthesis gas produced by the methods of the present technology for the production of methanol or synthetic hydrocarbons.

[0039] According to another aspect, the present technology provides a reactor for producing a synthesis gas comprising carbon monoxide (CO) and hydrogen (H), comprising: a reaction chamber in which synthesis gas is produced by a reduction reaction of a first flow comprising a carbon source and excess hydrogen in contact with an oxygen flame; at least one first means for supplying a reducing stream comprising hydrogen to a reaction chamber, a first portion of the reducing stream ultimately becoming a first flow, and a second portion of the reducing stream being used to generate an oxygen flame within the chamber that combusts by combustion of hydrogen in the presence of a second flow comprising oxygen (O); at least one second means for supplying an oxidizing stream to the reaction chamber forming a second flow; Equipped with The first and second flows are related to reactors at a distance from each other so that the oxygen flame supports the reaction between the carbon source and hydrogen.

[0040] According to one embodiment, the reactor is such that the reduction reaction is carried out in the absence of a solid catalyst.

[0041] According to another embodiment, the reactor is such that the oxygen flame generates ionic species and free radicals that promote the conversion of the carbon source to CO.

[0042] According to another embodiment, the reactor is configured such that the carbon source is: CO2, or ·Formula C α H β O γ At least one oxygen-containing molecule represented by the formula (wherein α is 1 to 5, β is 2 to 10, and γ is 1 to 4), or one or more hydrocarbons, or a mixture of at least two of the above carbon sources, The reactor comprises:

[0043] According to another embodiment, the reactor is one in which the carbon source comprises CO2 and the reduction reaction is the reverse reaction of gas to water, i.e., the "reverse water gas shift."

[0044] In another embodiment, the reactor is a reactor in which the reduced stream is hydrogen. In another embodiment, the reduced stream comprises hydrogen and a carbon source. In another embodiment, the reduced stream comprises hydrogen and CO2.

[0045] According to another embodiment, the reactor comprises a reducing stream of hydrogen, CO, and a catalyst of formula C α H β O γ (wherein α is 1 to 5, β is 2 to 10, and γ is 1 to 4).

[0046] According to another embodiment, the reactor is a reactor in which the oxidation stream is oxygen. According to another embodiment, the oxidation stream comprises oxygen and CO2.

[0047] According to another embodiment, the reactor is such that the first means for feeding a reduction stream and the second means for feeding an oxidation stream are tubes.

[0048] According to another embodiment, the reactor includes a plurality of second means, consisting of a plurality of tubes, for allowing injection of an oxidizing stream into the reaction chamber, and a plurality of first means, consisting of a plurality of openings, for allowing injection of a reducing stream into the reaction chamber. According to another embodiment, each opening is delimited by the outer diameter of one of the plurality of tubes and is defined by an annular space extending perpendicularly from the outer wall of the tube. According to another embodiment, the reactor further includes a reducing stream distribution chamber separated from the reaction chamber by a separation wall, the distribution chamber and the separation wall being traversed by a plurality of tubes, and the annular space extending perpendicularly from the outer wall of each tube also traversing the separation wall.

[0049] According to another embodiment, the reactor is such that the reduction stream is hydrogen supplied to the reaction chamber by a first means consisting of a first tube, the oxidation stream is oxygen supplied to the reaction chamber by a second means consisting of a second tube, and the carbon source is supplied by an independent stream injected into the reaction chamber through at least one opening arranged in the wall of the reaction chamber. According to 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 the middle tube, and the third tube forming the outer tube. According to another embodiment, the opening is formed by an annular space bounded by the inner diameter of the third tube and the outer diameter of the first tube. According to another embodiment, the reactor further comprises a distribution chamber separated from the reaction chamber by a partition wall, the distribution chamber serving to supply an independent stream containing the carbon source and traversed by the first and second tubes. According to another embodiment, the reactor is such that the independent stream contains CO2. According to another embodiment, the reactor is such that the independent streams comprise CO2 and methane.

[0050] According to another embodiment, the reactor is one in which the oxygen comes from a water electrolysis reaction.

[0051] According to another embodiment, the reactor is one in which the hydrogen comes from a water electrolysis reaction.

[0052] According to another embodiment, the reactor is such that the carbon source comes from a gas mixture resulting from a biomass gasification or pyrolysis process.

[0053] 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 another embodiment, the reaction chamber reaches a temperature of at most 2200° C. during the reduction reaction.

[0054] In another embodiment, the reactor is such that the first flow and the second flow are spaced from each other by a distance of 0.1 mm to 100 mm. According to another embodiment, the first flow and the second flow are spaced from each other by a distance of 0.3 mm to 50 mm. According to another embodiment, the first flow and the second flow are spaced from each other by a distance of 0.6 mm to 30 mm.

[0055] In another embodiment, the reactor is such that the carbon source comprises CO2 and the reduction reaction is carried out using a H2 / CO2 molar ratio of 2 to 7. According to another embodiment, the carbon source comprises CO2 and the reduction reaction is carried out using an O2 / CO2 molar ratio of 0.35 to 0.9.

[0056] According to another embodiment, the reactor is such that the reduction reaction is carried out using an O2 / H2 molar ratio of 0.1 to 0.3.

[0057] According to another embodiment, the reactor is such that the synthesis gas produced has a H2 / CO molar ratio of at least 1.8. According to another embodiment, the synthesis gas produced has a H2 / CO molar ratio of at least 2. According to another embodiment, the synthesis gas produced has a H2 / CO molar ratio of 1.8 to 5.0.

[0058] According to another embodiment, the reactor is such that the synthesis gas produced further comprises CO2.

[0059] According to another embodiment, the reactor is such that the synthesis gas produced has a molar ratio of H2, CO and CO2 such that (H2-CO2) / (CO+CO2) > 2.

[0060] According to yet another embodiment, the present technology relates to a system comprising a reactor as defined in accordance with the present technology coupled to a syngas cooling device for forming a cooled syngas.

[0061] According to one embodiment, the system is such that the cooling device is a direct contact cooler.

[0062] According to another embodiment, the system further comprises a water condenser for recovering water from the cooled syngas.

[0063] According to another embodiment, the system is such that the condensing device is a refrigerating-condenser.

[0064] According to another embodiment, the system further comprises an apparatus for recirculating at least a portion of the recovered water to the cooling device. [Brief explanation of the drawings]

[0065] [Figure 1] 1 is a schematic diagram of the general operating principle of the present method for producing synthesis gas. [Figure 2] 1 shows a cross-sectional view along a vertical plane of a reactor that can be used to carry out the method for producing synthesis gas according to a first embodiment. [Figure 3] 1 illustrates certain distance parameters between different flows and / or different elements of the reactor according to one embodiment of the synthesis gas production method. [Figure 4] 1 shows a cross-sectional view along a vertical plane of a reactor that can be used to carry out a synthesis gas production method according to another embodiment. [Figure 5] 1 shows a cross-sectional view along a vertical plane of a reactor that can be used to carry out a method for producing synthesis gas according to another embodiment. [Figure 6a] 1 shows a cross-sectional view along a vertical plane of a reactor that can be used to carry out a synthesis gas production method according to another embodiment. [Figure 6b]6a shows a cross-sectional top view of the reactor of FIG. 6a (a close-up of two concentric tubes is also shown to illustrate the distance parameters according to this embodiment). [Figure 7] FIG. 1 shows a diagram of a synthesis gas production process according to yet another embodiment. [Figure 8] FIG. 1 shows a schematic cross-section along a vertical plane of a typical tube configuration mini-reactor used in the examples. DETAILED DESCRIPTION OF THE INVENTION

[0066] All technical and scientific terms and phrases used herein have the same meaning as commonly understood by one of ordinary skill in the art. Nevertheless, definitions of certain terms and phrases used are provided below.

[0067] The term "about" as used herein means approximately, within, and around the range. When the term "about" is used in connection with a numerical value, it is modified up or down, for example, by a variance of 10% compared to the nominal value. This term can also take into account, for example, experimental error of a measuring device or rounding of values.

[0068] Whenever an interval of values ​​is mentioned in this application, the lower and upper limits of the interval are always included in the definition, unless otherwise stated.

[0069] The chemical structures described herein are drawn according to the conventions of the art, and where a drawn atom, such as a carbon atom, appears to have incomplete valences, the valences are assumed to be satisfied by one or more hydrogen atoms, even if not explicitly drawn.

[0070] As used herein, the terms "synthesis gas" and "syngas" are used interchangeably to identify a gas mixture containing at least carbon monoxide (CO) and hydrogen (H). In some embodiments, synthesis gas or syngas can include CO. According to one embodiment, the H / CO molar ratio in synthesis gas is 1 or greater. In other embodiments, synthesis gas can have an H / CO molar ratio of at least 1.8, e.g., between 1.8 and 5.0. According to another embodiment, the H / CO molar ratio in synthesis gas is 2 or greater. Thus, the H2 / CO molar ratio in the synthesis gas 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, synthesis gases with different H2 / CO molar ratios can be obtained.

[0071] The term "stream" is used to refer to the various gas streams that are fed to the reaction chamber where synthesis gas formation takes place. As explained in more detail below, the method uses at least one stream containing hydrogen (H) and at least one stream containing oxygen (O). Depending on its nature, the carbon source used in the method can be fed by an independent stream, by an O-containing stream, or by an H-containing stream. The streams entering the reaction chamber are in gaseous state. If necessary, reagents in liquid state can be evaporated to reach the reaction chamber in gaseous form.

[0072] The term "flow" is used to describe the various gas flows involved in carrying out the synthesis gas production reaction within the reaction chamber. As explained in more detail below, the reaction involves a reducing stream comprising hydrogen (H) and a carbon source, which react with each other to form synthesis gas, and an oxidizing stream comprising oxygen (O) which reacts with the hydrogen (H) to form an oxygen flame.

[0073] The term "carbon source" refers to a compound used to provide the carbon that ultimately becomes the synthesis gas produced. Thus, the carbon source provides at least the carbon that ultimately leads to the carbon monoxide (CO) that is produced. A variety of compounds can be used as the carbon source. According to one embodiment, the carbon source can include CO. According to another embodiment, the carbon source can be a compound of formula C α H β O γ where α is 1-5, β is 2-10, and γ is 1-4. The carbon source may also include one or more hydrocarbons, such as, for example, alkanes, alkenes, and / or aromatics. The carbon source used to produce synthesis gas can also be a combination of two or more of the different sources listed above. Thus, according to certain embodiments, the carbon source may be CO2 and C α H β O γ According to other embodiments, the carbon source may include CO and one or more hydrocarbons, such as CO and methane. If the carbon source contains only hydrocarbons, the intake of oxygen atoms is required. This oxygen is provided by CO, but may also be provided in the form of water vapor. According to some embodiments, the carbon source may include one or more hydrocarbons, CO, and water vapor. The water vapor may optionally be derived from a reaction generating an oxygen flame (see reaction (G) below) and / or may be fed to the reaction chamber.

[0074] Thus, the present specification presents an innovative method for producing syngas from a carbon source. As mentioned above, the carbon source can be varied. In some embodiments, the carbon source generally comprises CO2, which can be derived from two major source categories: anthropogenic sources associated with human activities, and so-called biogenic natural sources. The method can use CO2 derived from both types of sources, and can also use pure CO2. According to another embodiment, CO2 and a carbon source of formula C are used. α H β O γ (wherein α is 1 to 5, β is 2 to 10, and γ is 1 to 4) can be used. Alternatively, the carbon source can simply be one or more C α H β O γ According to another embodiment, a gas mixture containing CO and hydrocarbons such as alkanes (e.g., methane), alkenes, and / or aromatic molecules can be used. However, it is also possible to use hydrocarbons alone as the carbon source. According to some embodiments, the carbon source can be CO, one or more C α H β O γ A wide range of organic molecules may be present in the gas mixture providing the carbon source, including products from fossil sources that may optionally contain sulfur.

[0075] More specifically, the method for producing synthesis gas is carried out by reacting a carbon source with an excess of hydrogen in contact with an oxygen flame. According to the present technology, "oxy-flame" means a flame produced by the combustion of hydrogen in the presence of an oxidizer, such as oxygen (O2), according to the following reaction (F): H2+ 1 / 2 O2a H2O (vapor) + Heat (F)

[0076] The flame is bright and luminous and provides the heat necessary to support the reaction that produces synthesis gas from the carbon source. The flame can generate ionic species and free radicals that can catalyze the conversion of the carbon source to CO. According to certain embodiments, the oxygen flame can be capable of reaching an average temperature of at least about 600°C within the reaction chamber. According to other embodiments, the average temperature reached within the reaction chamber is at least about 1200°C. The temperature reached within the reaction chamber can increase to about 2200°C. Thus, the reaction that produces synthesis gas within the reaction chamber can be carried out at an average temperature of at least 600°C up to about 2200°C. The oxygen flame can be considered a "reducing oxygen flame" because the combustion reaction between hydrogen and oxygen occurs in the presence of excess hydrogen. In one embodiment, the oxidant used to generate the oxygen flame can be an oxygen (O2)-based mixture, preferably pure oxygen. It should be understood that "pure" oxygen does not necessarily mean 100% purity; the oxygen-based mixture can contain substantially O2, along with certain impurities, such as N2, HO, etc.

[0077] As mentioned above, the reaction to form synthesis gas is carried out in the presence of excess hydrogen. By "excess of hydrogen," it is understood that the amount of hydrogen (H) must be sufficient to generate an oxygen flame by the combustion reaction (F) on the one hand, and to be able to carry out the reaction of converting the carbon source to synthesis gas on the other hand. The amount of hydrogen required can be determined depending on the carbon source used and taking into account the stoichiometry of the reactions involved.

[0078] According to another embodiment, described in more detail below, the hydrogen required in the method, as well as the oxygen used to generate the oxygen flame, can be derived at least in part from a water electrolysis reaction. This can be even more advantageous if the water electrolysis system is powered by renewable electricity. The combustion that generates the oxygen flame can be initiated using an ignition device, such as an electric arc, an incandescent wire, or other known energy source.

[0079] According to certain embodiments, the method is capable of producing a synthesis gas containing essentially H and CO with a H / CO molar ratio close to 2. According to certain embodiments, the method is suitable for producing a synthesis gas having a composition that satisfies the conditions set forth by equations (D) and (E) above. This is possible by varying the proportions of the different gas streams that produce the oxidizing and reducing streams.

[0080] Figure 1 illustrates the general principle of operation of the method. The reduction stream (right side of the diagram), containing at least hydrogen and a carbon source, ultimately enters a reaction chamber (10). The heat required to convert the carbon source to CO is provided by a high-temperature flame, called an oxy-flame, which is generated by burning hydrogen in the presence of an oxidizer such as oxygen (left side of the diagram). A portion of the hydrogen fed to the reaction chamber can be used to generate the oxy-flame (arrow at the bottom of the diagram). Another portion of the hydrogen fed to the reaction chamber is used directly to generate synthesis gas. In addition to providing the heat required for the carbon source to CO conversion reaction, the oxy-flame can generate ionic species and free radicals that can accelerate this conversion. Hydrogen is introduced into the reaction chamber in excess and is partially vented along with CO to form synthesis gas. Overall, the entire process can be characterized as an "autothermal" process.

[0081] Thus, there are two separate flows in the reaction chamber (10): one flow originating from an oxidizing gas with pure oxygen, called the oxidizing flow, and the other flow, called the reducing flow, originating from a hydrogen-based reducing gas mixture and containing a carbon source. The two flows are in close proximity. According to one embodiment, the two flows may be separated from each other by a distance "d" such that 0.1 mm≦d≦100 mm. According to another embodiment, the distance d separating the two flows may be 0.3 mm≦d≦50 mm. This distance may preferably be 0.6 mm≦d≦30 mm. Thus, the distance d separating the two streams 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 the above values. Note that the reducing and oxidizing flows ultimately entering the reaction chamber can originate from various streams. In practice, the reducing flow originates from a reducing flow containing at least H2, and the oxidizing flow originates from an oxidizing flow containing at least oxygen. However, the carbon source ultimately entering the reducing flow in the reaction chamber can be provided by either the reducing flow or an independent stream, or the oxidizing flow if this carbon source contains only CO2.

[0082] A first embodiment of a synthesis gas production method is shown in FIG. 2. This embodiment is particularly suitable for producing synthesis gas from CO as a carbon source. An oxygen-containing stream (1) is mixed with a CO-containing stream (2) to produce an oxidation stream (3) containing a mixture of O and CO. The oxidation stream (3) is conveyed through a tube (4) that can inject the O and CO mixture into the reaction chamber (10) of the reactor. Inside the reaction chamber (10), the O and CO mixture forms an oxidation stream (6), of which O is used to generate an oxygen flame (9). A hydrogen-containing stream (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 to the reaction chamber. The hydrogen stream (5) constitutes a reduction stream, which, upon entering the chamber, forms a reduction stream that splits into two parts. The first part (8a) of the reduction stream reacts with the oxidation stream (6) according to the hydrogen combustion reaction (F) to generate an oxygen flame (9).

[0083] A second portion of the hydrogen flow (8b) is used as a reagent component in the RWGS reaction (A). The heat required for this reaction comes from an oxygen flame (9).

[0084] Reactions (F) and (A) occur in the reaction chamber (10) to form a gas mixture (12) consisting of hydrogen, carbon monoxide, carbon dioxide, and water vapor. This gas mixture (12) is also called wet synthesis gas. This gas mixture (12) is discharged through an opening (13) in the reactor.

[0085] The reactor used in this embodiment includes a wall (14) that can be filled with a refractory material and an insulating material (11). The volume of the reaction chamber (10) is determined by a cylindrical space defined by a length L and a diameter D. A conventional ignition device, such as an electric arc or an incandescent wire (not shown), can be used to initiate combustion within the reactor. According to one embodiment, the reactor can include a device that allows for measuring the temperature within the reaction chamber. Such a device can be, for example, a thermocouple (not shown). The injection tube (4) of the oxidation stream (3) can be secured by a device (15). According to some embodiments, the securing device (15) can be used as a guide for the injection tube (4) and as a sealing system. The securing device (15) can include, for example, a clamp with a cable gland packing.

[0086] According to some embodiments, the length L of the reaction chamber can be between 1 cm and 300 cm, preferably between 10 cm and 100 cm. The diameter D of the reaction chamber can be, for example, between 0.3 cm and 100 cm, preferably between 1 cm and 50 cm. According to some embodiments, the above values ​​of the length and diameter of the reaction chamber can also be applied to the reactors shown in Figures 2 to 5.

[0087] According to certain embodiments, the different gas flows can be characterized by certain parameters defined below, some of which depend on various distances, for example as shown in FIG.

[0088] The oxidation flow (6) can be characterized by a rate parameter v1 according to the following equation (G): v1 = V1 / ((π / 4)●D1^2) (G) where V1 corresponds to the volumetric flow rate of the oxidation stream (3) at the temperature and pressure conditions in the reaction chamber, and D1 is the inner diameter of the inlet tube (4) of the oxidation stream (3). The symbol "●" in the formula means "multiplication" and the symbol "^2" means "squaring."

[0089] The diameter D1 is such that the velocity v1 characterizing the oxidation flow (6) is at least 1 m / s based on the volumetric flow rate V1. According to another embodiment, the diameter D1 is such that the velocity v1 is between 5 m / s and 150 m / s, preferably between 5 m / s and 100 m / s. Thus, the velocity v1 can 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.

[0090] The flow of the reduction flows (8a, 8b) is characterized by a rate parameter v2 according to the following equation (H): v2 = V2 / ((π / 4)●(D^2-D'1^2)) (H) where V2 is the volumetric flow rate of the reduction flow (8a, 8b) at the temperature and pressure conditions in the reaction chamber, D is the inner diameter of the reactor, and D'1 is the outer diameter of the inlet tube (4) of the oxidation stream (3).

[0091] The opening (7) characterized by (D / 2-D'1 / 2) can be configured so that the velocity v2 of the return flow through the annular space defined between the outer wall of the tube (4) and the circumference of the opening (7) is at least 1 m / s based on the volumetric flow rate V2. According to another embodiment, the opening (7) (D / 2-D'1 / 2) is configured so that the velocity v2 is between 5 m / s and 150 m / s, preferably between 10 and 100 m / s. Thus, the velocity v2 can 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.

[0092] According to some embodiments, it is possible to define a parameter that characterizes the level of proximity between the reducing flows (8a, 8b) and the flow generating the oxygen flame (9), said parameter being defined by the distance d according to the following formula (I): d = (D - D'1) / 4 (I)

[0093] As indicated above, 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.

[0094] According to one embodiment, the volume of the reaction chamber (10) of the reactor is capable of providing a specific residence time of at least 0.01 seconds for all reactants within the reaction chamber (10), which residence time can be defined according to the following equation (J): t = ((π / 4)●D^2●L) / (V1 + 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 in the example of FIG.

[0095] According to certain embodiments, V1 is 2 L / min (3.33E-5 m 3 / sec)~100000L / min(1.67m 3 / sec), preferably 5 L / min (8.33E-05 m 3 / sec)~50000L / min(0.84m 3 / sec). According to some embodiments, V2 can be between 10 L / min (1.67E-04 m 3 / sec)~300000L / min(5m 3 / sec), preferably 25 L / min (4.17E-04 m 3 / sec)~200000L / min(3.33m 3 / sec).

[0096] According to certain embodiments, the method for producing synthesis gas can be carried out using an H2 / CO2 molar ratio between 2 and 7. The O2 / CO2 molar ratio can be, for example, between 0.35 and 0.9. Synthesis gas production can be carried out using an O2 / H2 molar ratio between 0.1 and 0.3, for example.

[0097] According to certain embodiments, the method for producing synthesis gas comprises the steps of: H2 / CO2 molar ratio between 2 and 7 O2 / CO2 molar ratio between 0.35 and 0.9 O2 / H2 molar ratio between 0.1 and 0.3 It can be performed using:

[0098] The temperature reached within the reaction chamber during synthesis gas production can be at least 600°C. This temperature can be as high as 2200°C. It will be understood, therefore, that the temperature can vary between values ​​of 600°C and 2200°C, such as 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 in between these values. It will be understood that a temperature profile is established within the reaction chamber during the reaction. Thus, the temperature will not necessarily be the same at one spot relative to another spot within the reaction chamber. In other words, there will be hotter and cooler regions within the reaction chamber. Therefore, when referring to temperatures reached within the reaction chamber, reference is being made to a representative average temperature.

[0099] The temperature may vary depending on the pressure in the reaction chamber during the synthesis gas production reaction. The pressure for conducting the synthesis gas production reaction may be at least 0.5 atmospheres. According to some embodiments, synthesis gas production may be carried out at a pressure of 3 atmospheres or less. Thus, according to some embodiments, the pressure may be 0.5 atmospheres, 1 atmosphere, 1.5 atmospheres, 2 atmospheres, 2.5 atmospheres, or even 3 atmospheres, or any pressure between these values. For example, the pressure may be between 1 atmosphere and 3 atmospheres.

[0100] In some embodiments, for a given flow rate of CO and H, the O feed rate can be adjusted to obtain a desired level of temperature and heat in the reactor for operating the RWGS reaction. Additionally, the flow rate of H can be adjusted to obtain a suitable H / CO ratio or R ratio, as defined by equation (E), for the gas mixture (12) exiting through opening (13).

[0101] FIG. 4 shows another possible embodiment of a synthesis gas production method and a reactor that can be used for this production. This embodiment is suitable for producing synthesis gas from any possible carbon source. In this case, a stream containing the carbon source (2) mixes with a hydrogen stream (5a) to form a reduction stream (5b) that is then sent to the reactor. However, even if the carbon source contains the oxidizing agent CO, the mixture (5b) formed by mixing the CO-containing gas with hydrogen is primarily composed of hydrogen and is therefore a reducible mixture. In some embodiments, the carbon source is CO, and the H / CO molar ratio in the reduction stream can be at least about 2, preferably at least 3. Upon entering the reaction chamber (10), the reduction stream (5b) becomes a reduction flow (8a, 8b). An oxidation stream (1) containing O is delivered to the reactor by a tube (4) to form an oxidation flow (6). A first portion (8a) of the reduction flow reacts with the oxidation flow (6) to generate an oxygen flame (9). A second portion (8b) of the hydrogen flow, which also contains a carbon source, is reacted with heat from the oxygen flame (9). If the flow (8b) contains excess hydrogen, a gas mixture (12) is formed at the outlet of the reactor, consisting of hydrogen, carbon monoxide, carbon dioxide, and water vapor. This gas stream, or wet synthesis gas, is discharged through the opening (13) of the reactor.

[0102] According to one embodiment, the carbon source forming stream (2) may essentially comprise CO2, and the reaction occurring in the reaction chamber is the RWGS reaction (A).

[0103] According to another embodiment, the carbon source forming stream (2) is of formula C α H β O γ (where α can vary from 1 to 5, β can vary from 2 to 10, and γ can vary from 1 to 4). Other types of organic molecules can also form stream (2), such as hydrocarbons, such as alkanes (e.g., methane), alkenes, and aromatics. These organic molecules can optionally be mixed with CO2 in stream (2).

[0104] Carbon source is Cα H β O γ When the reaction chamber contains organic molecules of the type: · Synthesis gas production according to equation (K); C α H β O γ + a' H2+ Q ac H2+ d CO + e' H2O + f CO2 (K) · Hydrogen combustion according to equation (L); a'' H2+ b O2a e'' H2O + Q (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 synthesis gas production, and Q is the heat involved in the process.

[0105] Thus, when a = a' + a'' and e = e' + e'' the sum of equations (K) and (L) gives the following stoichiometric equation (M): C α H β O γ + a H2+ bO2a c H2+ d CO + e H2O + f CO2(M)

[0106] The stoichiometric coefficients can be determined from the chemical formula of the organic compound used as the carbon source.

[0107] For example, when α=1, the coefficients are: a is between 1 and 5 a'' is between 0.5 and 2 b is between 0.25 and 1 c is between 2 and 3 d is between 0.5 and 1 e is between 0.5 and 2.5 e'' is between 0.5 and 2 f is between 0.15 and 0.75 may have:

[0108] As mentioned above, stream (2) is a mixture of CO2 and the reaction mixture of formula C α H β O γ In this case, both reactions (A) and (M) can occur within the reaction chamber to form synthesis gas.

[0109] When the carbon source comprises a hydrocarbon, synthesis gas production can occur in the presence of an oxidant that allows for the oxidation of the hydrocarbon within the reaction chamber. Such an oxidant can include water vapor and / or CO. Water vapor can be generated by the H combustion reaction (F) during the formation of the oxygen flame and / or can be fed to the reaction chamber independently.

[0110] If the carbon source contains methane as the hydrocarbon, the following reactions can occur in the reaction chamber depending on the oxidant involved (water vapor, CO): CH4 + H2O a CO + 3 H2(N) CH4 + CO2a 2 CO + 2 H2(O)

[0111] The carbon source is of formula C n H m In the case of hydrocarbons containing 1,0 ... sulphuric acid, the following reactions can occur in the reaction chamber: C n H m + n H2O → n CO + (n + 1 / 2 m) H2(P)

[0112] Thus, the present method for producing synthesis gas offers the possibility of using a variety of carbon sources, for example, the carbon source can be a gas mixture produced by an industrial process such as biomass gasification or pyrolysis process.

[0113] It should be noted that the various reaction parameters (pressure, temperature, distance, diameter, velocity, volumetric flow rate, residence time, etc.) discussed above with respect to FIG. 3 are also applicable to the embodiments incorporating various carbon sources presented in connection with FIG. 4.

[0114] 5 illustrates another embodiment of a method for producing synthesis gas, and in particular another embodiment of a reactor that can be used in this embodiment. As with the embodiment shown in FIG. 4, the embodiment of FIG. 5 can be used with any conceivable carbon source (e.g., CO, α H β O γ The reactor is adapted for the production of synthesis gas from oxygen molecules, hydrocarbons or mixtures thereof. As shown in FIG. 5, the oxygen flame (9) can be generated by injecting oxygen and hydrogen by means of two separate concentric tubes (4a and 4b), which will be described in more detail below. In this embodiment, the reactor comprises a central tube (4a) in the lower part of which fits a second tube (4b) of larger diameter. The central tube (4a) can be attached to the larger tube (4b) by a fixing device (15b), such as a sealing device. The second, wider tube (4b) can itself be attached to the reactor wall (14) by a fixing device (15a), preferably similar to the fixing 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) equipped with an opening (7b). The first compartment (10a) constitutes the reaction chamber of the reactor.

[0115] As shown in Figure 5, an oxygen-based oxidation stream (1) is injected into the central tube (4a), and a hydrogen-containing stream (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 median tube (4b) and the outer wall of the central tube (4a). The carbon source-containing stream (2) is injected into a section (10b) that can be considered a distribution chamber and then passes through opening (7b) into the reaction chamber (10a). Within the reactor, the O2 stream (1) becomes the oxidation stream (6), the H2 stream (5) becomes the hydrogen flow (8c), and the carbon source-containing stream (2) ultimately becomes the third flow (8d). The oxygen flow (6) and a portion of the hydrogen flow (8c) are used to generate an oxygen flame (9), and excess, i.e., unburned, hydrogen reacts with the carbon source-containing stream (8d). Even if there is a H2 flow (8c) that is different from the flow (8d) containing the carbon source just at the entrance to the reaction chamber, these two flows (8c) and (8d) do not constitute completely separate flows as soon as they enter the reaction chamber, and each flow can contain both H2 and a carbon source upon entering the reaction chamber.

[0116] In the embodiment shown in Figure 5, the stream containing the carbon source (2) may be CO2. However, the stream (2) may also contain other compounds, such as the organic molecules and / or hydrocarbons mentioned above, without CO2. Furthermore, according to some embodiments, the stream (2) may also contain hydrogen. Thus, a certain amount of hydrogen may be fed into the central tube (4b) used to form the hydrogen flow (8c), while another portion of the hydrogen may be mixed with CO2 and / or organic and / or hydrocarbon vapors to form the flow (8c).

[0117] It should be noted that the various reaction parameters (pressure, temperature, velocity, diameter, volumetric flow rate, residence time, etc.) discussed above with respect to FIG. 3 are also applicable to the embodiments encompassing the various carbon sources just presented in connection with FIG. 5.

[0118] 6a and 6b illustrate an embodiment of a method for producing syngas using a large-volume reactor. In relation to the embodiment presented in connection with FIG. 2, the embodiment of FIGS. 6a and 6b is particularly suitable for producing syngas from CO as a carbon source. According to this embodiment, the reactor may include a wall (14) and insulating and refractory materials (11) to protect the reaction chamber (10a). A distribution chamber (10b) is located at the bottom of the reactor and communicates with the reaction chamber (10a). The distribution chamber receives the hydrogen-containing reduction stream (5) before it enters the reaction chamber. The reaction chamber (10a) is separated from the reduction stream distribution chamber (10b) by a wall. The wall may be made of a refractory material with thermal insulation and may be supported by a plate (16). The plate (16) may be, for example, a metal plate. The compartment (10b) may be traversed by a number of concentric tubes (4), which may be fixed to the reactor wall (14) at the bottom of the compartment (10b). The tube (4) can be fixed to the wall (14) by a sealing device (15). The fixing and sealing device (15) can also serve as a guide to maintain the position of the tube (4). The concentric tube (4) extends through the distribution chamber (10b) to the bottom of the reaction chamber (10a) and forms multiple inlet ports (7b), through which the oxidation stream (3) is injected into the reaction chamber. Furthermore, the wall between the distribution chamber and the reaction chamber is provided with openings forming multiple inlet ports (7a) with a radius r1, through which the reduction stream (5) can enter the reaction chamber. According to a preferred embodiment, the openings (7a) form an annular space around the tube (4), as can be seen in FIG. 6b. The inlet port (7b) with a radius r2 can be concentric with the inlet port (7a). The reduction stream (5) can be injected into the distribution chamber (10b) through two or more inlet ports. In FIG. 6b, it can be seen that the reactor can be provided with at least four inlet ports for the reduction stream (5). Additionally, as shown in Figure 6a, the reactor may include multiple tubes (4) for injecting the oxidation stream (3) into the reaction chamber (10a).Finally, the reactor according to this embodiment also comprises an outlet (13) making it possible to vent the synthesis gas produced in the reaction chamber.

[0119] According to this embodiment, multiple oxygen flames can be formed in the reaction chamber. The distance parameter between the reducing flow and the oxidizing flow (oxygen flame) in this embodiment can be defined as follows: d = (r1- r2) / 2 (Q)

[0120] For all embodiments, the distance d may preferably be between 0.1 mm and 100 mm. According to other embodiments, the distance d separating the two flows may be between 0.3 mm and 50 mm, or preferably between 0.6 mm and 30 mm. The distance d may also be any distance within these ranges.

[0121] As mentioned above, according to some embodiments, the hydrogen required in the reduction stream and used to obtain syngas can be produced from renewable resources. In particular, hydrogen can be produced from a water electrolysis system powered by electricity from a renewable energy source. The stream containing the carbon source (e.g., CO), which is also required as a reagent, can itself be a gas mixture resulting from the biomass gasification or pyrolysis techniques described above. Thus, overall, it is possible to produce syngas from a captured carbon source, water, and electricity derived from renewable resources.

[0122] This embodiment of a method for producing syngas from renewable resources is shown in part in Figure 7. Figure 7 also shows additional steps, including, for example, recovery of water formed during the syngas production reaction. Thus, Figure 7 illustrates the following steps: · Electrolysis step (20) of water (H2O-a) supplied by electricity from renewable sources (E); a synthesis gas generation step (30) according to one of the above-described embodiments; a step of cooling the produced gas (40), for example by direct contact cooling; Recovery of water (H2O-c) by condensation step (50); This shows:

[0123] Specifically, as shown in FIG. 7, water (H2O-a) is fed to an electrolysis system (20) to produce hydrogen (H2) and oxygen. The hydrogen (H2) produced by electrolysis is mixed with a gas containing CO2 and / or another carbon source, preferably CO2. This gas containing CO2 and / or another carbon source can be derived, at least in part, from a biomass gasification or pyrolysis process. The resulting mixture (GO) forms a reduced stream that can then be used in the synthesis gas production step (30). A portion of the oxygen produced by electrolysis (20) (O2-a) is sent to the synthesis gas production step (30) where it can be used to generate an oxygen flame. The remaining portion of the oxygen produced by electrolysis (20) (O2-b) can be vented.

[0124] The gas (G1) resulting from the synthesis gas generation step (30) is then rapidly cooled (40) to limit / prevent the occurrence of the reverse reaction of reaction (A). Cooling can be carried out by conventional methods. According to a preferred embodiment, the cooling step (40) can be carried out by a direct contact cooler with a water stream (H2O-b). According to one embodiment, the gas (G1) is cooled to a temperature above the dew point of the hot gas but not exceeding 250°C. According to 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. According to some embodiments, the gas (G1) can be cooled to a temperature between 90°C and 250°C.

[0125] The cooled gas (G2) obtained after cooling (40) is a wet gas. This gas (G2) can then undergo a second cooling, which can be carried out by a condensation step (50). According to some embodiments, this condensation step can be carried out using a cooling-condenser. According to a preferred embodiment, the condensation step (50) can be carried out so that the gas (G2) is cooled to a temperature of 35°C or less. At the outlet of the cooling-condenser, synthesis gas (G3) is obtained on the one hand, and condensed water (H2O-c) is obtained on the other hand. Part of the condensed water (H2O-c) can be recycled to the cooling stage (40) (H2O-b flow), while the remaining part of the condensed water can be discharged (H2O-d flow). According to some embodiments, the H2O-b flow can be used, at least in part, to supply water to the electrolysis system (20).

[0126] As mentioned above, the synthesis gas generation method described herein may enable the production of a gas mixture (syngas) that is balanced based on CO and H, i.e., has an appropriate ratio of CO and H, allowing the subsequent production of various products by conventional chemical synthesis. Thus, by controlling the nature and amount of the reagents used (e.g., the flow rate of the gas stream), it is possible to produce synthesis gas with a CO and H ratio tailored to allow the mixture to be directly used in subsequent chemical synthesis. It is also possible to manipulate the ratio of CO and H in the synthesis gas by controlling the temperature, pressure, and O supply rate in the reaction chamber. The temperature in the reactor can also be controlled by the flow rate of the oxygen supplied. According to one embodiment, the synthesis gas produced contains H and CO in a molar ratio of H / CO ≥ 2. The synthesis gas produced by the described method may also contain CO. In this case, the molar ratio of H, CO, and CO in the synthesis gas may be (H - CO) / (CO + CO) ≥ 2.

[0127] By adhering to these molar ratios, the synthesis gas produced by this method can be used to produce a number of commodity chemicals, among which can be found methanol and hydrocarbons found in automotive gasoline, diesel, kerosene, to name a few.

[0128] The synthesis gas production method described above and the reactor that can be used to carry it out therefore have several advantages. The reagents are readily available and can be obtained from renewable resources. There is no need to resort to the use of solid catalysts. The conversion of reactants can be greater than that observed in conventional RWGS reactions carried out in the presence of a catalyst. Finally, the method is characterized by its robustness, in that it is versatile and easy to implement. These advantages therefore make it possible to reduce production costs, in addition to the beneficial environmental effect of recycling carbon sources, such as CO2. [Example]

[0129] [Example 1] This example is based on a small reactor, which is shown schematically in Figure 8. This mini-reactor operates according to the scenario of simultaneous injection of premixed O2 and CO2 into the interior of the inner tube, i.e., into space A, and H2 into the annular space B. The reactor was constructed from small tubes of Inconel 600™. The following dimensions are used to characterize the geometry of the mini-reactor (ID = inner diameter, ED = outer diameter), where L corresponds to the length from the start of the reaction zone (dimensions in mm): Outer tube: ID = 10.41, OD = 12.7, L = 371.83 Center tube: ID = 7.752, OD = 9.53, L ≒ 0 (beginning of reaction zone) Inner tube: ID = 3.048, OD = 6.35, L ≒ 0 (beginning of reaction zone)

[0130] The ignition system used to ignite the pulse reactor (pulsoreactor), i.e., spark plugs firing at 20 kV, was inserted into the reactor very close to the top of the inner and central tubes. Holes were drilled to allow for the insertion of the spark plugs (not shown in the figure for clarity). The temperature level change within the reactor was monitored using thermocouples. Temperature was measured at the bottom and top of the reaction zone within the mini-reactor: one temperature reading was taken near the base of the reaction zone (where the gas was injected) specifically at a position 13 mm above the line at the beginning of the reaction zone (see Figure 8), and another reading was taken at a position 89 mm above the line at the beginning of the reaction zone (see Figure 8). The thermocouples were attached by T-connectors (not shown in the figure).

[0131] The experimental setup included the reactor itself, a tube and jacket heat exchanger allowing rapid cooling of the gas leaving the reactor, a condensate collection tank, a gas relative humidity (RH) analysis system and finally, at the outlet of the gas cooling system, an analysis system (CO2 / CO / CxHy / O2) capable of measuring the CO, CO2, hydrocarbon (CxHy) content as well as the oxygen content of the produced gas.

[0132] A mass flow meter system with automatic control valves is also set up. The system is equipped with software for programming the composition of the gas mixture introduced into the reactor. Finally, manual valves are used to direct each gas to the desired reaction tube.

[0133] To avoid flashback during ignition, ignition is performed in stages (lasting approximately 1 second). The main stages of the ignition sequence include: 1) starting H injection; 2) after a few seconds, injecting oxygen in successive stages, each lasting a few seconds, up to the desired flow rate; and 3) starting CO injection.

[0134] Once ignited, the analytical steps can proceed. Each of these steps lasts for 60 seconds. After this period, various measurements are performed. The input flow rate (standard liters (SL) at 25°C and 1 atmosphere per minute) is: ·CO2:1.3SL / min ·O2:0.93SL / min ·H2:6.1SL / min is.

[0135] The CO2 and O2 flows are premixed and the operating pressure is approximately 1 atmosphere.

[0136] As a result of the following: Molar concentration of CO in gas: 22.2% Molar concentration of CO2 in gas: 8.1% Molar concentration of hydrocarbons: trace CO / CO2 molar ratio in produced gas: 2.74 CO2 to CO conversion rate: 73% Average temperature in the reaction chamber: 686°C Inlet velocity of O2 / CO2 mixture (average temperature, 1 atmosphere): 16.4 m / s H2 velocity at inlet (average temperature): 21.1 m / s Residence time in reactor (seconds): <0.06 seconds ·Ratio R2=(H2-CO2) / (CO+CO2):2.26 was obtained.

[0137] For the calculation of the R2 ratio, the H2 concentration was calculated from an atomic balance. The atomic balance itself was performed taking into account all inputs (CO2, H2, O2) and also the composition of the exit gas (CO and CO2 content, hydrocarbon content expressed in CH4 equivalents, gas humidity, residual oxygen content). The atomic balance of hydrogen atoms allows the calculation of the hydrogen composition of the gas at the reactor outlet.

[0138] [Example 2] In this example, the same device as in Example 1 is used, but with O injected into the inner tube (space A), H injected into the annular space between the middle and inner tubes (space B), and an equimolar mixture of CO / CH injected into the annular space between the outer and middle tubes (space C). The input flow rates (standard liters per minute at 1 atmosphere at 25° C.) are: ·CO2:0.40SL / min ·CH4:0.40SL / min O2: 0.9SL / min ·H2:3.3SL / min is.

[0139] The above three flows are injected separately into the mini-reactor. The following results are obtained: CO concentration in dry gas: 13.3% Molar concentration of CO2 in gas: 10.2% Molar concentration of hydrocarbons in gas: 2135 ppm CO / CO2 ratio in produced gas: 1.30 CO2 conversion rate: 13.1% CH4 conversion rate: 98.2% ·Average temperature: 855℃ Inlet O2 velocity (average temperature, 1 atmosphere): 7.77 m / s Inlet H2 velocity (average temperature, 1 atmosphere): 13.4 m / s Inlet velocity of CO2 / CH4 mixture (average temperature, 1 atmosphere): 7.46 m / s Reagent residence time: <0.07 seconds R2=(H2-CO2) / (CO+CO2):2.87 was obtained.

[0140] In calculating the ratio R2, the H2 concentration was calculated from the atomic balance.

[0141] [Example 3] In this example, the same reactor as in Example 1 is used, but the outer Inconel™ tube is replaced by a quartz tube. The length of the reaction chamber is the same. In this example, the CO2 and O2 flows are premixed. The resulting mixture is injected into the inner tube (space A), and hydrogen is injected into space B. The operating pressure is approximately 1 atmosphere. Since the temperature cannot be measured directly, the temperature used is the thermodynamic equilibrium temperature value calculated to obtain a gas with the same CO / CO2 ratio as the one measured.

[0142] The input flow rate (standard liters per minute at 25°C and 1 atmosphere) is: ·CO2:1.3SL / min ·O2:0.93SL / min ·H2:6.2SL / min is.

[0143] The input flow rate (standard liters per minute at 25°C and 1 atmosphere) is: CO concentration in gas: 22.9% CO2 concentration in gas: 7.30% Molar concentration of hydrocarbons: trace CO / CO2 ratio in produced gas: 3.14 CO2 to CO conversion rate: 75.8% ·Equilibrium temperature T: 1230℃ Velocity of O2 / CO2 mixture at inlet (temperature T, 1 atmosphere): 25.6 m / s Inlet H2 velocity (at temperature T and 1 atm): 33.7 m / s Reagent residence time: <0.04 seconds R2=(H2-CO2) / (CO+CO2):2.34 is.

[0144] For the calculation of the ratio R2, the H2 concentration in the gas exiting the reactor is calculated from an atomic balance. A comparison of the results of Example 1 with those of Example 3 shows that the nature of the reactor material (Inconel™ vs. quartz) does not significantly affect the CO2 conversion.

[0145] [Example 4] This example uses the same equipment as in Example 3, i.e., it is based on using a quartz tube as the outer tube. In this example, O2 is injected into space A, H2 into space B, and CO2 into space C. Since the temperature cannot be measured directly, the temperature used is the thermodynamic equilibrium temperature value calculated to obtain a gas with the same CO / CO2 ratio as that measured. The input flow rate (standard liters (SL) at 25°C and 1 atmosphere pressure / minute) is: ·CO2:1.3SL / min ·O2:0.93SL / min ·H2:6.1SL / min is.

[0146] As a result of the following: CO concentration in gas: 18.21% CO2 concentration in gas: 11.5% Hydrocarbon concentration: trace CO / CO2 ratio in gas: 1.58 CO2 to CO conversion rate: 61.2% ·Equilibrium temperature T: 877℃ ·O2 speed (temperature T): 8.20m / sec ·Velocity of H2 (temperature T, 1 atm): 25.4m / sec CO2 velocity (temperature T, 1 atmosphere): 9.02 m / s Residence time in reactor: <0.05 seconds R2=(H2-CO2) / (CO+CO2):2.26 was obtained.

[0147] To calculate the ratio R2, the H2 concentration in the gas exiting the reactor is calculated from the atomic balance.

[0148] The applicability of the synthesis gas production process has been demonstrated in the above examples, inter alia, based on the use of CO2 as a carbon source. CO2 is a chemically very stable molecule, with α between 1 and 5. α H β O γThe above example is much more stable than the C α H β O γ This method demonstrates the applicability of the process to CO2, which has proven more difficult to chemically convert than molecules of the C type. α H β O γ It is reasonable to conclude that this method is also applicable to molecules of this type.

[0149] Although several embodiments of the method and reactor that can be used to carry out the method have been described above, the method and reactor are not limited to these only embodiments. Multiple modifications can be made to one or other of the above embodiments without departing from the scope of the technology as contemplated.

Claims

1. Carbon monoxide (CO) and hydrogen (H ２ 1. A method for producing a synthesis gas comprising: The hydrogen comes from a reduction stream, a first portion of which ends up in the first flow, and a second portion of which is oxygen (O ２ to generate the oxygen flame by combustion of hydrogen in the presence of a second flow comprising: the first flow and the second flow are spaced apart from each other such that the oxygen flame supports a reaction between the carbon source and the hydrogen; the distance between the first flow and the second flow is 0.1 mm to 100 mm; The carbon source is at least CO ２ and The reduction reaction is carried out in the absence of a solid catalyst. method.

2. 10. The method of claim 1, wherein the oxygen flame generates ionic species and free radicals that promote the conversion of the carbon source to CO.

3. 3. The method according to claim 1 or 2, wherein the carbon source is CO ２ or CO ２ and, ・Formula C α H β O γ wherein α is 1 to 5, β is 2 to 10, and γ is 1 to 4; or one or more hydrocarbons, or A mixture of the above carbon sources and a combination of

4. 4. The method according to claim 1, wherein the reduction reaction comprises the reverse reaction of gas to water, i.e., the "reverse water-gas shift."

5. The method according to any one of claims 1 to 4, wherein the carbon source is CO ２ or CO ２ and at least one hydrocarbon.

6. The method according to any one of claims 1 to 4, wherein the carbon source is CO ２ That's the method.

7. The method according to any one of claims 1 to 4, wherein the carbon source is CO ２ and methane.

8. The method according to any one of claims 1 to 7, wherein the reduced stream is hydrogen, or the reduced stream comprises hydrogen and the carbon source, or the reduced stream comprises hydrogen and CO ２ or the reduced stream comprises hydrogen, CO ２ and formula C α H β O γ wherein α is 1 to 5, β is 2 to 10, and γ is 1 to 4.

9. The method according to any one of claims 1 to 8, wherein the oxidizing stream is oxygen or the oxidizing stream is oxygen and CO ２ A method comprising:

10. 8. The method of claim 1, wherein the reducing stream contains only hydrogen, the oxidizing stream contains only oxygen, and the carbon source is provided by an independent stream.

11. 11. The method of claim 10, wherein the independent stream is CO ２ or the independent stream comprises CO ２ and methane.

12. 12. The method according to any one of claims 1 to 11, wherein the oxygen is derived from a water electrolysis reaction, and / or the hydrogen is derived from a water electrolysis reaction, and / or the carbon source is derived from a gas mixture resulting from a biomass gasification or pyrolysis process.

13. The method according to any one of claims 1 to 12, wherein the reduction reaction is carried out at an average temperature of at least 600°C.

14. The method according to any one of claims 1 to 13, wherein the distance between the first flow and the second flow is between 0.3 mm and 50 mm.

15. 15. The method according to any one of claims 1 to 14, wherein the carbon source is CO ２ and the synthesis gas contains 2 to 7 H ２ / CO ２ and / or the synthesis gas is produced using a molar ratio of 0.35 to 0.9 O ２ / CO ２ and / or the synthesis gas is produced using a molar ratio of 0.1 to 0.3 O ２ / H ２ The method is produced using a molar ratio.

16. 16. Use of synthesis gas produced by the method of any one of claims 1 to 15 for the production of chemicals or fuels and / or for the production of methanol or synthetic hydrocarbons.

17. Carbon monoxide (CO) and hydrogen (H ２ 1. A reactor for producing a synthesis gas comprising: a reaction chamber in which synthesis gas is produced by a reduction reaction of a first flow comprising a carbon source and excess hydrogen in contact with an oxygen flame; At least one first means for supplying a reducing stream comprising hydrogen to the reaction chamber, a first portion of the reducing stream ultimately becoming a first flow, and a second portion of the reducing stream ultimately becoming a first flow, and ２ a first means used to generate the oxygen flame in the reaction chamber by combustion of hydrogen in the presence of a second flow comprising: at least one second means for supplying an oxidizing stream to said reaction chamber, said oxidizing stream forming said second flow; Equipped with the first flow and the second flow are spaced apart from each other such that the oxygen flame supports a reaction between the carbon source and the hydrogen; the distance between the first flow and the second flow is 0.1 mm to 100 mm; The carbon source is at least CO ２ and The reduction reaction is carried out in the absence of a solid catalyst. Reactor.

18. 18. The reactor of claim 17, wherein the oxygen flame generates ionic species and free radicals that promote the conversion of the carbon source to CO.

19. 19. The reactor of claim 17 or 18, wherein the carbon source is CO ２ or CO ２ and, ・Formula C α H β O γ wherein α is 1 to 5, β is 2 to 10, and γ is 1 to 4; or one or more hydrocarbons, or A mixture of the above carbon sources and a combination of

20. 20. The reactor according to claim 17, wherein the reduction stream is hydrogen, or the reduction stream contains hydrogen and the carbon source, or the reduction stream contains hydrogen and CO ２ or the reducing stream comprises hydrogen, CO ２ and formula C α H β O γ wherein α is 1 to 5, β is 2 to 10, and γ is 1 to 4, and wherein the oxidizing stream is oxygen or the oxidizing stream is a mixture of oxygen and CO ２ a reactor comprising:

21. 20. The reactor of any one of claims 17-19, comprising a plurality of second means comprising a plurality of tubes to allow injection of the oxidizing stream into the reaction chamber, and a plurality of first means comprising a plurality of openings to allow injection of the reducing stream into the reaction chamber, wherein each opening is bounded by the outer diameter of one of the plurality of tubes and is defined by an annular space extending perpendicularly from the outer wall of the tube.

22. 22. The reactor of claim 21, further comprising a reduction stream distribution chamber separated from the reaction chamber by a separation wall, the distribution chamber and the separation wall being traversed by the plurality of tubes, and the annular space extending perpendicularly from the outer wall of each tube also traversing the separation wall.

23. 20. The reactor according to any one of claims 17 to 19, wherein the reducing stream is hydrogen supplied to the reaction chamber by the first means comprising a first tube, the oxidizing stream is oxygen supplied to the reaction chamber by the second means comprising a second tube, and the carbon source is supplied by an independent stream injected into the reaction chamber through at least one opening disposed in a wall of the reaction chamber.

24. 24. The reactor of claim 23, wherein said opening is defined by a third tube concentric with said first tube and said second tube, said second tube forming an inner tube, said first tube forming a middle tube, and said third tube forming an outer tube, and wherein said opening is defined by an annular space bounded by an inner diameter of said third tube and an outer diameter of said first tube.

25. 25. The reactor of claim 23 or 24, wherein the independent stream is CO ２ or CO ２ and methane.

26. 26. The reactor of any one of claims 17 to 25, wherein the reaction chamber reaches a temperature of at least 600°C during the reduction reaction.

27. 27. The reactor according to any one of claims 17 to 26, wherein the distance between the first flow and the second flow is between 0.3 mm and 50 mm.

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