Fischer-Tropsch synthesis method

Abstract

In particular, the present disclosure relates to a Fischer-Tropsch process for producing hydrocarbons and their oxygenates from a renewable carbon dioxide source. The disclosure relates generally to methods for the Fischer-Tropsch production of hydrocarbons from methane. In particular, the disclosure provides a method for producing hydrocarbons and / or oxygenates comprising the steps of reforming a reforming feedstock comprising methane with water and / or oxygen to produce a reformed product stream comprising carbon monoxide and hydrogen, and contacting a hydrocarbon synthesis mixture comprising hydrogen and carbon monoxide with a Fischer-Tropsch hydrocarbon synthesis catalyst, wherein the hydrocarbon synthesis mixture comprises at least a portion of the reformed product stream and produces a hydrocarbon product stream having a selectivity for C5+ hydrocarbons of at least 50% and / or a selectivity for oxygenates of at least 20%.

Description

[Technical Field]

[0001] This disclosure relates particularly to a Fischer-Tropsch process for producing hydrocarbons and their oxygenates from renewable carbon dioxide sources. [Background technology]

[0002] The conversion of synthesis gas to hydrocarbons via the Fischer-Tropsch process has been known for many years. The increasing importance of alternative energy sources has led to renewed interest in the Fischer-Tropsch (FT) process, as it enables a direct and environmentally acceptable route to high-quality fuels and feedstock chemicals through the use of bio-derived carbon sources.

[0003] The FT process is typically used to produce linear hydrocarbons for use in fuels, as well as oxygenates that are also useful in fuels and can otherwise serve as valuable feedstock chemicals. Hydrocarbon fuels derived from the FT process can better meet increasingly stringent environmental regulations compared to conventional refinery-produced fuels because FT-derived fuels typically contain lower amounts of sulfur, nitrogen, and aromatic compounds, which contribute to the emission of potent pollutants such as SO2, NOx, and particulates. Alcohols derived from the FT process often have higher octane numbers than hydrocarbons and therefore burn more completely, thereby reducing the environmental impact of such fuels. The resulting alcohols and other oxygenates can also be used as feedstocks for other processes, such as the synthesis of lubricants.

[0004] Various transition metals have been identified as catalytically active in the conversion of synthesis gas to hydrocarbons and their oxygenated derivatives. In particular, cobalt, nickel, and iron have been investigated, often in combination with support materials, the most common of which are alumina, silica, and carbon. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent No. 4,312,720 [Patent Document 2] U.S. Patent No. 4,021,323 [Patent Document 3] U.S. Patent No. 4,094,751 [Patent Document 4] International Patent Application Publication No. 2004 / 022480 Pamphlet [Patent Document 5] U.S. Patent No. 6,749,829 [Patent Document 6] International Patent Application No. 2019 / 154885 Brochure [Non-patent literature]

[0006] [Non-Patent Document 1] British Standard methods BS7591:Part 1:1984'Recommendations for gas adsorption(BET)methods' [Non-patent document 2] BS4359:Part 2:1992'Porosity and pore size distribution of materials'-Method of evaluation by gas adsorption [Non-patent document 3] Brunauer, S, Emmett, PH, & Teller, E, J. Amer. Chem. Soc. 60, 309, (1938) [Non-patent document 4] Barrett, EP, Joyner, LG & Halenda P, J. Am Chem. Soc., 1951 73 373-380 Summary of the Invention [Problem to be solved by the invention]

[0007] Typically, Fischer-Tropsch reactions utilize carbon monoxide as a carbon source due to its higher reactivity compared to carbon dioxide. However, the use of carbon dioxide is of great interest due to its widespread availability as a waste gas and its low cost. One way to utilize carbon dioxide in the Fischer-Tropsch process is through the so-called "reverse water-gas shift reaction," in which carbon dioxide is reacted with hydrogen to produce carbon monoxide and water. The produced carbon monoxide can then be subjected to Fischer-Tropsch synthesis. However, this conversion must be carried out at exceptionally high temperatures, often exceeding 900 °C, and is therefore energetically unfavorable.

[0008] Therefore, there remains a need to develop processes for more efficient utilization of carbon dioxide in the production of hydrocarbons. [Means for solving the problem]

[0009] The present inventors have discovered a method for efficiently converting carbon dioxide and hydrogen to methane using a Fischer-Tropsch catalyst.

[0010] Accordingly, one aspect of the present disclosure is a process for the production of hydrocarbons and / or oxygenates, comprising reforming a reforming feedstock comprising methane with water and / or oxygen to produce a reformed product stream comprising carbon monoxide and hydrogen. 1. A process comprising contacting a hydrocarbon synthesis mixture comprising hydrogen and carbon monoxide with a Fischer-Tropsch hydrocarbon synthesis catalyst to produce a hydrocarbon product stream comprising C5+ hydrocarbons and / or oxygenates, e.g., with a selectivity to C5+ hydrocarbons of at least 50% and / or a selectivity to oxygenates of at least 20%.

[0011] Another aspect of the present disclosure is a process for producing a reformed feedstock comprising: contacting a methane synthesis mixture comprising hydrogen and carbon dioxide with a supported methane synthesis catalyst to form a methane product stream, wherein the supported methane synthesis catalyst comprises cobalt in the range of 1 wt.% to 35 wt.%, wherein the method provides a methane product stream having a selectivity for methane of at least 75%.

[0012] Other aspects of the present disclosure will be apparent to those skilled in the art in view of the following description. The present invention will now be described with reference to the drawings. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a process schematic according to one embodiment of the present disclosure. [Figure 2] FIG. 1 is a process schematic according to one embodiment of the present disclosure. [Figure 3] FIG. 1 is a process schematic according to one embodiment of the present disclosure. [Figure 4] FIG. 1 is a process schematic according to one embodiment of the present disclosure. [Figure 5] 1 is a graph illustrating CO2 conversion as a function of H2:CO2 ratio according to an exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] This disclosure describes a method for efficiently producing methane from a mixture of carbon dioxide and hydrogen. Carbon dioxide is an attractive starting material due to its widespread availability and low cost, particularly because it can be conveniently produced from renewable sources, for example, as a by-product of fermentation or combustion or via biomass gasification. Converting carbon dioxide into hydrocarbons that can be used as fuels and lubricants is particularly attractive due to environmental concerns. However, due to its non-polar nature and thermodynamic stability, carbon dioxide is typically less reactive than carbon monoxide and therefore less favorable for use in the Fischer-Tropsch process. To overcome this challenge, carbon dioxide can be reacted with hydrogen in a reverse water-gas shift reaction to produce carbon monoxide and water. However, because reverse water-gas shift reactors typically operate at temperatures exceeding 900 °C, this extra step is energy-intensive, leading to high operating costs and expensive reactor designs.

[0015] In contrast, the present inventors have determined that methane can be produced from carbon dioxide without relying on the reverse water-gas shift reaction. Surprisingly, contact of carbon dioxide and hydrogen with a cobalt-containing Fischer-Tropsch synthesis catalyst is carried out at temperatures much lower than those used for the reverse water-gas shift reaction. This allows for lower energy consumption and lower capital costs associated with operating a reverse water-gas shift reactor.

[0016] Accordingly, one aspect of the present disclosure is a process for the production of hydrocarbons and / or oxygenates, comprising: reforming a reforming feedstock comprising methane with water and / or oxygen to produce a reformed product stream comprising carbon monoxide and hydrogen; and contacting a hydrocarbon synthesis mixture comprising hydrogen and carbon monoxide with a Fischer-Tropsch hydrocarbon synthesis catalyst, wherein the hydrocarbon synthesis mixture comprises at least a portion of the reformed product stream, to produce a hydrocarbon product stream having a selectivity for C5+ hydrocarbons of at least 50 wt% and / or a selectivity for oxygenates of at least 20 wt%.

[0017] Advantageously, the present inventors have discovered that methane can be produced by the surprisingly efficient reaction of carbon dioxide with hydrogen in the presence of a catalyst similar to that used in the Fischer-Tropsch process. This methane can then be reformed as otherwise described herein. Accordingly, in certain embodiments described elsewhere herein, at least a portion of the methane reforming feedstock is produced by a process comprising contacting a methane synthesis mixture containing hydrogen and carbon dioxide with a supported methane synthesis catalyst to form a methane product stream, the supported methane synthesis catalyst comprising cobalt in the range of 1 wt% to 35 wt% and providing a methane product stream having a selectivity of at least 75%.

[0018] In certain embodiments, at least 50% (e.g., at least 60%, or 70%, or 80%, or 90%, or 95%, or 99%, or 99.9%) of the methane provided in the reforming feed is derived from a methane product stream produced as described herein.

[0019] An advantage of certain processes of the present disclosure is the ability to produce methane from a methane synthesis mixture having low amounts (or substantially no carbon monoxide). In certain embodiments, as described elsewhere herein, the methane synthesis mixture contains 10% or less by weight of carbon monoxide. For example, in certain embodiments, the methane synthesis mixture contains 8% or less by weight of carbon monoxide (e.g., 5% or less by weight, or 4% or less by weight, or 3% or less by weight, or 2% or less by weight, or 1% or less by weight). In certain embodiments, the methane synthesis mixture contains 0.5% or less by weight of carbon monoxide (e.g., 0.2% or less by weight, or 0.1% or less by weight, 500 ppm or less, or 100 pm or less of carbon monoxide, or is substantially free of carbon monoxide).

[0020] The methane synthesis mixture used as a feedstock for the production of methane can advantageously contain more carbon dioxide than carbon monoxide. Notably, carbon monoxide has been found to reduce the effectiveness of conversion to methane. Thus, in certain embodiments as described elsewhere herein, the gas has a weight ratio of carbon dioxide to carbon monoxide of at least 5:1, e.g., at least 10:1. For example, in certain embodiments, the methane synthesis mixture has a weight ratio of carbon dioxide to carbon monoxide of at least 15:1, e.g., 20:1, or 50:1, or 100:1, or 200:1, or 500:1. Of course, this ratio can be much higher if carbon monoxide is substantially absent.

[0021] In certain advantageous processes disclosed herein, carbon dioxide is reacted with hydrogen to produce methane. Thus, the methane synthesis mixture includes both carbon dioxide and hydrogen. The carbon dioxide and hydrogen can be fed to the reactor as a combined stream, or can be fed separately to the reactor and the mixture fed therein. In certain embodiments as described elsewhere herein, the molar ratio of hydrogen to carbon dioxide (H2:CO2) in the methane synthesis mixture is at least 0.5:1, e.g., at least 1:1, at least 1.5:1, at least 2:1, or at least 3:1. In certain embodiments as described elsewhere herein, the volumetric ratio of hydrogen to carbon dioxide in the methane synthesis mixture is at most 10:1, e.g., at most 7:1, or at most 5:1, or at most 4:1. Examples of suitable molar ratios of hydrogen to carbon dioxide in the methane synthesis mixture include ranges of from 0.5:1 to 10:1, for example, from 0.5:1 to 7:1; or from 0.5:1 to 5:1; or from 0.5:1 to 4:1; or from 1:1 to 10:1; or from 1:1 to 7:1; or from 1:1 to 5:1; or from 2:1 to 10:1; or from 2:1 to 7:1; or from 2:1 to 5:1; or from 3:1 to 10:1; or from 3:1 to 7:1; or from 3:1 to 5:1. In certain desirable embodiments, the molar ratio of hydrogen to carbon dioxide is in the range of 1:1 to 4:1, for example, 1:1 to 3.5:1, or 1:1 to 3:1, or 1.5:1 to 4:1, or 1.5:1 to 3.5:1, or 1.5:1 to 3:1, or 2:1 to 3:1, or 2:1 to 3.5:1, or 2:1 to 3:1.

[0022] The gaseous reactant stream may also include other gaseous components such as nitrogen, water, methane, carbon dioxide, and other saturated and / or unsaturated light hydrocarbons (i.e., C4 and below), each preferably present at a concentration of less than 30% by volume. In certain embodiments as otherwise described herein, at least 20% by volume, e.g., at least 30%, at least 40%, or at least 50% by volume of the methane synthesis mixture is hydrogen and carbon dioxide. In certain embodiments as otherwise described herein, at least 50% by volume, e.g., at least 60%, at least 70%, at least 80%, or at least 90% by volume of the methane synthesis mixture is hydrogen, carbon dioxide, and nitrogen. In certain embodiments as otherwise described herein, at least 50% by volume, e.g., at least 60%, at least 70%, at least 80%, or at least 90% by volume of the methane synthesis mixture is hydrogen, carbon dioxide, nitrogen, water, and methane.

[0023] As noted above, the supported methane synthesis catalyst used in certain processes of the present disclosure contains cobalt in an amount ranging from 1% to 35% by weight on an elemental basis. In particular, many catalysts traditionally used in Fischer-Tropsch processes are surprisingly suitable for the methane synthesis processes described herein. One of ordinary skill in the art will select an appropriate amount of cobalt based on the disclosure herein. For example, in certain embodiments, the supported methane synthesis catalyst contains cobalt in an amount ranging from 1% to 30% by weight, or from 1% to 25% by weight, or from 1% to 20% by weight, or from 2% to 35% by weight, or from 2% to 30% by weight, or from 2% to 25% by weight, or from 2% to 20% by weight, or from 5% to 35% by weight, or from 5% to 30% by weight, or from 5% to 25% by weight, or from 10% to 35% by weight, or from 10% to 30% by weight, or from 10% to 25% by weight. In certain embodiments, the supported methane synthesis catalyst comprises cobalt in an amount ranging from 2 to 20 wt %, e.g., from 2 to 15 wt %, or from 2 to 10 wt %, or from 5 to 20 wt %, or from 5 to 15 wt %, or from 5 to 10 wt %, or from 7 to 20 wt %, or from 7 to 15 wt %, or from 7 to 12 wt %, or from 10 to 20 wt %, or from 10 to 15 wt % on an elemental basis.

[0024] In certain desirable embodiments as described elsewhere herein, the supported methane synthesis catalyst comprises at least 0.5 wt. % manganese on an elemental basis. In certain embodiments, the supported methane synthesis catalyst comprises no more than 20 wt. % manganese on an elemental basis. For example, the supported methane synthesis catalyst may comprise manganese in the range of 0.5 to 20 wt % on an elemental basis, for example, 0.5 to 15 wt %, or 0.5 to 10 wt %, or 0.5 to 7 wt %, or 0.5 to 5 wt %, or 1 to 20 wt %, or 1 to 15 wt %, or 1 to 10 wt %, or 1 to 5 wt %, or 2 to 20 wt %, or 2 to 15 wt %, or 2 to 10 wt %, or 2 to 5 wt %, or 5 to 20 wt %, or 5 to 15 wt %, or 5 to 12 wt %, or 5 to 10 wt %, or 7 to 20 wt %, or 7 to 15 wt %, or 7 to 12 wt %.

[0025] Without being bound by any particular theory, it is believed that the presence of manganese contributes to a surface effect on the solid support that affects the development and surface dispersibility of cobalt oxide crystallites. This may result from the mobility of the cobalt-containing precursor compound(s) in the presence of the manganese-containing precursor compound(s), for example, suspended or dissolved in an impregnation solution, that is applied to the support material during catalyst preparation. Thus, a catalyst particularly suitable for use herein can include one in which the cobalt-containing precursor compound(s) and the manganese-containing precursor compound(s) are applied to the support material during its preparation so as to form a mobile mixture at the surface of the support.

[0026] In certain embodiments as described elsewhere herein, the total amount of cobalt and manganese in the synthesis catalyst is 40 wt% or less, on an elemental basis, based on the total weight of the synthesis catalyst. For example, in certain embodiments, the total amount of cobalt and manganese in the methane synthesis catalyst is 30 wt% or less, or 25 wt% or less, or 22 wt% or less, or 20 wt% or less. In certain embodiments, the total amount of cobalt and manganese in the synthesis catalyst is 15 wt% or less. In certain embodiments as described elsewhere herein, the total amount of cobalt and manganese in the methane synthesis catalyst is at least 2 wt% on an elemental basis, based on the total weight of the methane synthesis catalyst. For example, in certain embodiments, the total amount of cobalt and manganese in the methane synthesis catalyst is at least 5 wt%, or at least 8 wt%, or at least 10 wt%.

[0027] Those skilled in the art will appreciate that suitable supported methane synthesis catalysts can also contain a wide variety of other transition metals. Various promoters can be included, such as one or more of ruthenium, palladium, platinum, rhodium, rhenium, chromium, nickel, iron, molybdenum, tungsten, zirconium, gallium, thorium, lanthanum, cerium, copper, and mixtures thereof. Promoters are typically used at cobalt-to-promoter atomic ratios of up to 250:1, e.g., up to 125:1, or up to 25:1, or up to 10:1. In certain such embodiments, one or more promoters are present in the resulting cobalt-containing methane synthesis catalyst in an amount of 0.1 wt % to 3 wt %, on an elemental basis, based on the total weight of the supported synthesis catalyst. In other embodiments, the cobalt-containing methane synthesis catalyst does not contain such promoters.

[0028] A particular active cobalt surface area has been found to improve catalytic performance. In certain embodiments as described elsewhere herein, the supported methane synthesis catalyst has a surface area of ​​2 m 2 / g~15 m 2 / g (e.g., 3 to 12 m 2 / g, or 4 m 2 / g~10 m 2 / g) as determined by hydrogen chemisorption.

[0029] In certain embodiments as otherwise described herein, the supported methane synthesis catalyst comprises 5 m 2 / g~350 m 2The BET surface area, pore volume, pore size distribution, and average pore radius are determined from nitrogen adsorption isotherms determined at 77 K using a Micromeritics TRISTAR 3000 static volumetric adsorption analyzer, according to the application of [1] and [2]. The resulting data are reduced using the BET method (over a pressure range of 0.05 to 0.20 P / Po) and the Barrett, Joyner & Halenda (BJH) method (for pore diameters of 20 to 1000 Å) to obtain the surface area and pore size distribution, respectively. References suitable for the above data reduction methods are given in [3] and [4].

[0030] The supported methane synthesis catalyst includes a support material. The support material serves to bind the catalyst particles together and may also affect catalytic activity. In certain embodiments, as described elsewhere herein, the support material includes at least one of alumina, zirconia, titania, silica, zinc oxide, ceria, or a combination thereof. In certain embodiments, the support material includes one of alumina, zirconia, zinc oxide, ceria, silica, and titania. For example, the support material is one of alumina, zirconia, zinc oxide, ceria, silica, and titania. In other certain embodiments, the support material includes one of alumina, zirconia, zinc oxide, ceria, and titania. For example, the support material is one of alumina, zirconia, zinc oxide, ceria, and titania. In other certain embodiments, the support material includes one of zirconia, zinc oxide, ceria, and titania. For example, the support material is one of zirconia, zinc oxide, ceria, and titania. In yet other particular embodiments, the support material comprises titania, eg, the support material is titania.

[0031] The supported methane synthesis catalysts used in accordance with certain embodiments of the present disclosure may be prepared by any suitable method capable of providing the required manganese to cobalt weight ratio and the required concentration of manganese on the support. Preferably, the supported methane synthesis catalysts used in accordance with certain embodiments of the present disclosure are prepared by a process in which cobalt and manganese are impregnated onto the support material.

[0032] Suitable impregnation methods include, for example, impregnating the support material with a cobalt- and manganese-containing compound that is thermally decomposable to its oxide form. Impregnation of the support material with the cobalt- and manganese-containing compound can be accomplished by any suitable method recognized by those skilled in the art, such as by vacuum impregnation, incipient wetness, or immersion in excess liquid.

[0033] The incipient wetness technique is so named because it requires that the volume of impregnation solution be predetermined to provide the minimum volume of solution necessary to just wet the entire surface of the support without excess liquid. The excess solution method, as the name suggests, requires an excess of impregnation solution, after which the solvent is removed, usually by evaporation.

[0034] The support material may be in the form of a powder, granules, shaped particles, such as preformed spheres or microspheres, or extrudates. References herein to powders or granules of support material are understood to refer to free-flowing particles of the support material, or particles of the support material that have been granulated and / or sieved to a particular shape (e.g., spherical) and size range. References herein to "extrudates" are intended to mean support materials that can be subjected to an extrusion process and thus shaped. In the context of the present disclosure, the powders or granules are in a form suitable for impregnation with a solution of the cobalt-containing compound and the manganese-containing compound, and subsequent extrusion or shaping into other shaped particles.

[0035] It will be understood that the support material may be in any form suitable for use as a support for a methane synthesis catalyst, and preferably is not pre-impregnated with a source of metals (i.e., other than cobalt and / or manganese) that could adversely affect the performance of the active catalyst and interfere with the benefits of the methane synthesis process described herein. Thus, support materials pre-loaded with cobalt and / or manganese metals or precursors thereof may be used in accordance with the present disclosure, but other pretreatments that provide sources of other metals should preferably be avoided. Preferred support materials are substantially free of extraneous components that could adversely affect the catalytic activity of the system. Accordingly, preferred support materials are at least 95% w / w pure, more preferably at least 98% w / w pure, and most preferably at least 99% w / w pure. Impurities are preferably present in amounts less than 1% w / w, more preferably less than 0.50% w / w, and most preferably less than 0.25% w / w. The pore volume of the support is preferably greater than 0.150 ml / g, preferably greater than 0.30 ml / g. The support material has an average pore radius (before impregnation) of 10 to 500 Å, preferably 15 to 100 Å, more preferably 20 to 80 Å, most preferably 25 to 60 Å. The BET surface area is suitably 2 to 1000 m 2 / g, preferably 10 to 600 m 2 / g, more preferably 15 to 300 m 2 / g, most preferably 30-150 m 2 / g.

[0036] When in powder form, the median particle size (d50) is preferably less than 50 μm, more preferably less than 25 μm. When the carrier material is in granular form, the median particle size (d50) is preferably 300-600 μm. The particle size (d50) may suitably be determined by a particle size analyzer (e.g., a Microtrac S3500 particle size analyzer).

[0037] It is known that using shaped particles such as extrudates to perform Fischer-Tropsch catalysis is beneficial, particularly in fixed-bed reactor systems, and such catalysts are similarly useful in the methane synthesis process described herein. For example, it is known that for a given catalyst particle shape, a decrease in catalyst particle size in a fixed bed causes a corresponding increase in pressure drop through the bed. Thus, particles with relatively large shapes cause less pressure drop through the catalyst bed in a reactor compared to corresponding powdered or granular supported catalysts. Shaped particles such as extrudates also generally have greater strength and experience less attrition, which is particularly valuable in fixed-bed configurations where bulk crush strength must be very high.

[0038] References herein to "impregnation" or "impregnating" are intended to refer to contacting the support material with, for example, one or more solutions of cobalt- and manganese-containing compounds prior to drying to achieve precipitation of the cobalt- and manganese-containing compounds. Impregnation with a fully dissolved solution or solutions of the cobalt- and manganese-containing compounds ensures good dispersion of the cobalt- and manganese-containing compounds on the support material and is therefore preferred. This contrasts with, for example, the use of partially dissolved cobalt- and / or manganese-containing compounds in a "solid solution" or suspension, where the level of dispersion of the cobalt- and manganese-containing compounds throughout the surface and within the pores of the support material may vary depending on the nature of the precipitation on the support material. Furthermore, the use of a fully dissolved solution(s) of the cobalt- and manganese-containing compounds also has less of an effect on the resulting morphology and bulk crush strength of the subsequently formed extrudates compared to a solid solution. Nevertheless, the advantages of certain processes of the present disclosure can also be realized when a solid solution or solution of a partially undissolved cobalt-containing compound and / or manganese-containing compound is used.

[0039] When the powder or granules of the support material are contacted with the solution(s) of the cobalt-containing compound and the manganese-containing compound, the amount of solution used preferably corresponds to an amount of liquid suitable for obtaining a mixture of a consistency suitable for further processing, for example, shaping by extrusion, in which case complete removal of the solvent of the impregnation solution can be carried out after the formation of shaped particles, such as extrudates.

[0040] Suitable cobalt-containing compounds are those that can be thermally decomposed to cobalt oxide after calcination and are preferably completely soluble in the impregnation solution. Preferred cobalt-containing compounds are cobalt nitrates, acetates, or acetylacetonates, most preferably cobalt nitrates, such as cobalt nitrate hexahydrate. It is preferable to avoid the use of halides, as they are known to be harmful.

[0041] Suitable manganese-containing compounds are those that are thermally decomposable after calcination and preferably completely soluble in the impregnation solution. Preferred manganese-containing compounds are manganese nitrates, acetates, or acetylacetonates, most preferably manganese acetates.

[0042] The solvent of the impregnation solution may be either an aqueous solvent or a non-aqueous organic solvent. Suitable non-aqueous organic solvents include, for example, alcohols (e.g., methanol, ethanol, and / or propanol), ketones (e.g., acetone), liquid paraffinic hydrocarbons, and ethers. Alternatively, an aqueous organic solvent, such as an aqueous alcoholic solvent, may be used. Preferably, the solvent of the impregnation solution is an aqueous solvent.

[0043] In a preferred embodiment, the impregnation of the support material with the cobalt-containing compound and the manganese-containing compound is carried out in a single step, without intermediate drying or calcination steps to separate the loadings of the different components. As one skilled in the art will appreciate, the cobalt-containing compound and the manganese-containing compound may be applied to the support material sequentially or simultaneously in separate impregnation solutions or suspensions, or preferably, an impregnation solution or suspension containing both the cobalt-containing compound and the manganese-containing compound is used.

[0044] The concentrations of the cobalt-containing compound and the manganese-containing compound in the impregnation solution(s) are not particularly limited, but preferably the cobalt-containing compound and the manganese-containing compound are completely dissolved as described above. When the powder or granules of the support material are impregnated and immediately followed by the extrusion step, the amount of the impregnation solution(s) is preferably suitable to form an extrudable paste.

[0045] A suitable concentration of the cobalt-containing compound and / or the manganese-containing compound is, for example, 0.1 to 15 mol / liter.

[0046] It will be appreciated that if the support material is in powder or granular form, once impregnated with the cobalt-containing compound and manganese-containing compound, the impregnated support material may be extruded or formed into shaped particles at any suitable stage, before or after drying and calcination.

[0047] Impregnation of the support material is typically followed by drying of the impregnation solution to effect precipitation of the cobalt- and manganese-containing compounds onto the support material and preferably to remove the impregnation solution's binding solvent (e.g., water). Thus, drying does not, for example, result in complete decomposition of the cobalt-containing compound or otherwise result in a change in the oxidation state of the cobalt-containing compound. As will be appreciated, in embodiments in which extrusion is performed, complete drying and removal of the impregnation solution's solvent (e.g., binding solvent) can occur after formation of the shaped particles, for example, by extrusion. Drying is suitably carried out at temperatures between 50°C and 150°C, preferably between 75°C and 125°C. Suitable drying times are, for example, 5 minutes to 72 hours. Drying can be suitably carried out in a drying oven or box furnace, for example, at elevated temperatures under a stream of inert gas.

[0048] It will be appreciated that where shaped particles such as extrudates are being impregnated, the carrier may be contacted with the impregnation solution by any suitable means including, for example, vacuum impregnation, incipient wetness, or immersion in excess liquid, as previously described. Where powders or granules of carrier material are being impregnated, the powder or granules may be mixed with the impregnation solution by any suitable means recognized by those skilled in the art, such as by adding the powder or granules to a container of the impregnation solution and stirring.

[0049] If a process for forming shaped particles, such as an extrusion process, immediately follows the impregnation of the powder or granules, the mixture of powder or granules and impregnation solution may be further processed, e.g., by extrusion, if it is not in a form suitable for forming shaped particles. For example, the mixture may be milled to reduce the presence of larger particles that may not be easily extruded or otherwise formed into shaped particles, or whose presence may otherwise impair the physical properties of the resulting shaped particles, e.g., extrudates. Kneading typically involves forming a paste suitable for shaping, such as by extrusion. Any suitable kneading or blending device known to those skilled in the art can be used for kneading in the context of the present disclosure. For example, a pestle and mortar may be suitably used in some applications, or a Simpson muller may be suitably used. Kneading is typically carried out for 3 to 90 minutes, preferably 5 to 30 minutes. Kneading can be carried out over a range of temperatures, including ambient temperature. A preferred temperature range for kneading is 15°C to 50°C. Kneading is preferably carried out at ambient pressure. As previously mentioned, it will be appreciated that complete removal of the binding solvent from the impregnation solution may be carried out to effect complete precipitation after formation of the shaped particles, such as by extrusion.

[0050] In embodiments where a calcination step is performed on the impregnated powder or granules, thereby completely removing the solvent of the impregnation solution, the calcined powder or granules may also be further processed, for example by extrusion, to form a mixture suitable for formation into shaped particles. For example, an extrudable paste may be formed by combining the calcined powder or granules with a suitable solvent, such as the solvent used for impregnation, preferably an aqueous solvent, and kneaded as described above.

[0051] The preparation of the supported methane synthesis catalyst can include a calcination step. As will be appreciated, calcination is necessary to convert the cobalt-containing compound impregnated on the support material to an oxide of cobalt. Calcination therefore results in thermal decomposition of the cobalt-containing compound and not simply removal of the binding solvent of the impregnation solution, as occurs, for example, in drying.

[0052] Calcination may be carried out by any method known to those skilled in the art, for example, in a fluidized bed or rotary kiln at a temperature of at least 250°C, preferably 275°C to 500°C. In some embodiments, calcination may be carried out as part of an integrated process in which calcination and reductive activation of the synthesis catalyst to obtain a reduced Fischer-Tropsch synthesis catalyst occur in the same reactor. In particularly preferred embodiments, the supported methane synthesis catalyst used in certain methods of the present disclosure is obtained or is obtainable from a process comprising the following steps:

[0053] (a) impregnating a support material with a cobalt-containing compound and a manganese-containing compound in a single impregnation step to form an impregnated support material.

[0054] (b) drying and calcining the impregnated support material to form the supported methane synthesis catalyst.

[0055] A particular advantage of this embodiment is the convenience of being able to modify and convert the support material into a supported methane synthesis catalyst using only a single impregnation step followed by drying and calcination steps. Thus, in a preferred embodiment, the support material used in the methane synthesis catalyst is not pre-modified, for example, by the addition of promoters, dispersing aids, strength aids and / or binders, or precursors thereof, prior to impregnation in step (a) of the method.

[0056] Those skilled in the art will be able to carry out the processes described herein using any desired reaction system. For example, a wide variety of reactors can be used, such as fixed-bed reactors, slurry-bed reactors, or fluidized-bed reactors. Advantageously, so-called CAN reactor systems can be used.

[0057] Advantageously, the methane synthesis processes described herein can be carried out at relatively low temperatures compared to conventional processes for converting carbon dioxide to hydrocarbons. In certain embodiments, as described elsewhere herein, contacting the methane synthesis mixture comprising hydrogen and carbon dioxide with the supported methane synthesis catalyst is carried out at a temperature in the range of 150°C to 325°C (e.g., 150°C to 300°C, or 150°C to 275°C, or 150°C to 270°C, or 150°C to 260°C, or 150°C to 250°C, or 175°C to 325°C, or 175°C to 275°C, or 175°C to 270°C, or 175°C to 260°C, or 175°C to 250°C, or 200°C to 325°C, or 200°C to 275°C, or 200°C to 270°C, or 200°C to 260°C, or 200°C to 250°C). In certain embodiments, as described elsewhere herein, contacting of the methane synthesis mixture comprising hydrogen and carbon dioxide with the supported methane synthesis catalyst occurs at a pressure in the range of 10 to 100 bar (1 to 10 MPa). For example, in certain embodiments, contacting occurs at a pressure in the range of 20 barg to 80 barg, e.g., 20 barg to 60 barg, or 20 barg to 50 barg, or 20 barg to 40 barg.

[0058] The supported methane synthesis catalyst can be conveniently converted to a reduced supported methane synthesis catalyst by reductive activation by any known means recognized by those skilled in the art that can convert cobalt oxide to active cobalt metal. Furthermore, the inventors have discovered that reductive activation of the catalyst at relatively low temperatures provides comparable or improved catalytic performance compared to high-temperature reduction. This surprising result allows for improved catalyst yields as well as energy savings. Thus, in one embodiment, the methane synthesis method of the present disclosure further comprises a prior step of activating the methane synthesis catalyst by a process comprising reducing the catalyst with a reducing gas at a temperature of 350°C or less to form a supported methane synthesis catalyst comprising cobalt(0). In certain embodiments, the reducing gas comprises hydrogen gas. The step of forming the reduced synthesis catalyst can be carried out batchwise or continuously in a fixed-bed, fluidized-bed, or slurry-phase reactor, or in situ in the same reactor subsequently used for the methane synthesis reaction. The reduction is carried out at a temperature of 150°C to 350°C, for example, 150°C to 325°C, or 200°C to 325°C.

[0059] Activation conditions, including low temperatures, can be designed to limit the amount of cobalt converted to cobalt metal. For example, the catalyst may be impregnated with the catalyst in its oxidized cationic form. Subsequent calcination can be used to convert the metal to an oxide. Catalytic reduction can then be used to convert at least a portion of the metal to the zero-valent form of the metal (e.g., cobalt(0)). Thus, in certain embodiments described elsewhere herein, at least 70% (e.g., greater than 80%, or greater than 90%) of the cobalt in the supported methane synthesis catalyst is cobalt(0) on an atomic basis after reduction.

[0060] Advantageously, the supported methane synthesis catalyst may be passivated to prevent deactivation due to exposure to air. Passivation may be desirable for storing, transporting, loading, and / or unloading the catalyst. Once installed in the reactor, the catalyst may be reactivated. Thus, in certain embodiments as described elsewhere herein, the process further includes passivating the supported methane synthesis catalyst by contacting the supported methane synthesis catalyst with a passivating agent (e.g., a passivating agent comprising oxygen) to form a passivated methane synthesis catalyst, and reactivating the supported methane synthesis catalyst by contacting the supported methane synthesis catalyst with a reducing agent at a temperature of 350°C or less. In certain embodiments, the passivating agent is oxygen, optionally mixed with one or more of water, nitrogen, and carbon dioxide. In certain embodiments, as described elsewhere herein, the method further includes transporting the passivated methane synthesis catalyst and loading the passivated methane synthesis catalyst into a reactor bed prior to the reactivation step.

[0061] As will be appreciated, the gaseous reactant mixture fed to the methane synthesis reaction may also be suitable for reducing a supported methane synthesis catalyst to form a reduced supported methane synthesis catalyst in situ, without the need for any preceding or separate reductive activation step.

[0062] One potential source of green hydrogen is through the electrolysis of water. In certain embodiments, hydrogen may be formed by the electrolysis of water. Numerous methods of electrolysis are known in the art. For example, electrolysis may be performed on pure water to produce hydrogen gas and oxygen gas, or on other solutions, such as saline, to produce hydrogen gas and another product (e.g., chlorine gas). In certain embodiments, hydrogen is formed by the electrolysis of saline. Water electrolysis is further described in U.S. Patent Nos. 5,629,999; 5,629,999; and 5,629,999, each of which is incorporated by reference in its entirety.

[0063] To be considered green hydrogen, the electricity used in the electrolysis of water must come from a renewable source, i.e., a source that does not depend on the combustion of fossil fuels. Examples of renewable electricity sources include solar power through photovoltaic capture or solar thermal technologies, wind power, geothermal energy capture, hydroelectric energy, or other renewable electricity sources. Suitable renewable energy sources are known to those skilled in the art and can optionally be selected through certification by an appropriate authority.

[0064] Blue hydrogen is defined as hydrogen gas produced in a process that relies somewhat on fossil fuels but is entirely carbon-neutral (i.e., does not result in the net introduction of carbon dioxide into the atmosphere). In certain embodiments described elsewhere herein, the hydrogen utilized in the processes described elsewhere herein includes blue hydrogen. One example of blue hydrogen is hydrogen gas produced from fossil-fuel-derived hydrocarbons, such as methane gas, with the resulting carbon product being captured or otherwise utilized. For example, steam reforming of methane can be performed to produce 3 moles of hydrogen gas and 1 mole of carbon monoxide per mole of methane. Methane steam reforming is highly endothermic and requires a significant energy input. Of course, the energy required to carry out these processes must be sourced from renewable sources or sources with appropriate carbon capture technology. Thus, in certain embodiments as described elsewhere herein, at least a portion (e.g., at least 50%, at least 75%, at least 90%, or at least 95%) of the hydrogen is formed by steam reforming of methane. Steam reforming of methane to produce hydrogen is discussed in US Pat. No. 6,223,999, the entirety of which is incorporated herein by reference.

[0065] Advantageously, the carbon dioxide utilized in the processes described herein may be carbon dioxide collected from the atmosphere or may be carbon dioxide that would otherwise be released into the atmosphere, for example, from combustion or other industrial processes. The carbon dioxide may be captured, collected or absorbed after being released from an industrial process, or absorbed directly from the atmosphere. Methods of carbon capture are known to those skilled in the art. In certain embodiments, the carbon dioxide comprises captured carbon dioxide, e.g., at least 50%, at least 75%, at least 90%, or at least 95% of the carbon dioxide is captured carbon dioxide.

[0066] Alternatively, biomass is an attractive source of renewable carbon dioxide for use in the processes described herein. One source of biomass is agricultural products in the form of dedicated energy crops such as switchgrass, miscanthus, bamboo, sorghum, tall fescue, broom, wheatgrass, poplar, willow, silver maple, East cottonwood, green ash, black walnut, sweetgum, and sycamore. Another source of biomass is agricultural waste or crop residues. Conventional agricultural activities, including the production of food, feed, fiber, and forest products, generate large amounts of waste plant material. Examples of such materials include corn stover, wheat straw, oat straw, barley straw, soghum stubble, and rice straw. A third source of biomass comes from forest residues left after timber operations. Biomass can also be in the form of municipal waste, including commercial and residential garbage, including yard trimmings, paper and paperboard, plastics, rubber, leather, textiles, and food waste. Thus, in certain embodiments described elsewhere herein, the crude syngas is derived from biomass, e.g., agricultural biomass or municipal waste biomass. Additional sources of agricultural biomass will be apparent to those skilled in the art, as determined by local availability, economics, and process suitability.

[0067] To generate carbon dioxide from carbon-containing materials such as biomass, the material must be subjected to gasification. Gasification involves heating the material under controlled conditions to generate a gaseous stream of carbon monoxide, hydrogen, and carbon dioxide. Controlled amounts of other reactants (e.g., oxygen and / or steam) can be used to modify the process. Gasification conditions are adjusted according to the carbon-containing material being gasified to efficiently produce gaseous products. In certain embodiments, as described elsewhere herein, the carbon dioxide comprises carbon dioxide from the gasification of biomass. The biomass may be from any source, as described above, or may be a combination of sources. In certain embodiments, the carbon dioxide comprises carbon dioxide from the gasification of biomass, e.g., at least 50%, at least 75%, at least 90%, or at least 95% of the carbon dioxide is from the gasification of biomass.

[0068] As used herein, "selectivity" for a given component is measured as the mole fraction of a particular reactant that reacts in the process (i.e., not including any unreacted portion of that particular reactant) and is converted to that product. For example, in the reaction of carbon dioxide with hydrogen to provide a product component that includes methane, "selectivity" for a given component is defined as the mole fraction of carbon dioxide that reacts in the process and is converted to the product of interest, not including any unreacted carbon dioxide. Fischer-Tropsch selectivity is calculated with respect to CO and CO2 in the feedstock.

[0069] Advantageously, the processes described herein can produce a methane product stream with high selectivity to methane. In certain embodiments as described elsewhere herein, the selectivity to methane is at least 80% (e.g., at least 85%, or at least 90%, or at least 95%). It may be desirable to limit the selectivity to C5+ hydrocarbons. In certain embodiments as described elsewhere herein, carbon dioxide is reacted with a C5+ selectivity of 10% or less, e.g., 8% or less, or 7% or less, or 5% or less, or 4% or less, or 3% or less. In certain embodiments as described elsewhere herein, carbon dioxide is reacted with a C2+ selectivity of 25% or less, e.g., 20% or less, or 15% or less, or 10% or less, or 5% or less. It may also be desirable to limit the selectivity to oxygenates. Oxygenates are oxygen-containing molecules such as alcohols, ethers, esters, carboxylic acids, etc. (but do not include carbon dioxide or carbon monoxide). In certain embodiments, as described elsewhere herein, the carbon dioxide reacts with an oxygenate selectivity of 10% or less, e.g., 8% or less, or 7% or less, or 5% or less, or 4% or less, or 3% or less.

[0070] The methane synthesis method described herein advantageously and efficiently converts carbon dioxide to methane. Because carbon dioxide is often relatively inert except under extreme temperature and / or pressure conditions, high carbon dioxide conversion rates are a major challenge in the art. The inventors have developed a method that enables high carbon dioxide conversion rates under relatively mild conditions. Thus, in certain embodiments, as described elsewhere herein, a methane product stream is provided with a carbon dioxide conversion rate of at least 25%, e.g., at least 30%, or at least 35%, or at least 40%, or at least 45%, or at least 50%. As used herein, "conversion" of carbon dioxide is the mole fraction of carbon dioxide that is converted to other species in the reaction. Of course, those skilled in the art will understand that any unreacted carbon dioxide can be separated and recycled for use as part of the carbon dioxide feed.

[0071] The carbon dioxide-utilizing method is the reverse water gas shift reaction, in which carbon dioxide and hydrogen are converted into carbon monoxide and water. CO2+H2ProductCO+H2O

[0072] However, the reverse water gas shift reaction has typically been carried out under extreme conditions, with reaction temperatures exceeding 900°C. Therefore, the reaction is costly from an energy perspective and requires the use of specialized equipment. Furthermore, the process consumes hydrogen, which is often expensive in process economics. An advantage of the methane synthesis methods described herein is the ability to convert carbon dioxide into usable hydrocarbons, including methane, without using the reverse water gas shift reaction. Thus, in certain embodiments, as described elsewhere herein, the process does not include the reverse water gas shift reaction. Small amounts of carbon dioxide may be converted to carbon monoxide as a reaction by-product by the reverse water gas shift reaction during normal operation of the processes described herein. Therefore, the absence of the reverse water gas shift reaction is understood to mean the absence of a separate reaction zone dedicated to the reverse water gas shift reaction. Desirably, the processes described herein have a selectivity for carbon monoxide of less than 1%, e.g., less than 1000 ppm or even less than 100 ppm.

[0073] While the inventors have determined that the methane synthesis method described herein is a desirable method for providing methane to the remainder of the process, other sources of methane are contemplated. For example, in certain embodiments as described elsewhere herein, the methane in the reforming feed is provided from another source, such as captured methane or biogenic methane. The captured methane can be derived from industrial processes, agricultural processes (e.g., cattle), or methane from natural gas that would otherwise be flared. The biomethane can be derived from agricultural processes or the digestion of biomass (e.g., the digestion of agricultural or municipal waste, including landfill gas). Other suitable methane sources will be apparent to those skilled in the art.

[0074] Methane reforming is commonly utilized to produce carbon monoxide and hydrogen. In various processes of the present disclosure, a reforming feed comprising methane (e.g., whatever the source, as described above) is reformed with water and / or oxygen to produce a reformed product stream comprising carbon monoxide and hydrogen.

[0075] The reforming of methane can occur in a reforming zone separate from the zone where conversion to methane occurs. Indeed, methane can be produced at a different location and then transported to the location where reforming occurs. Several reforming techniques are known in the art. In certain embodiments, the reforming is at least one of steam reforming, autothermal reforming, gas-heat reforming, and partial oxidation reforming. For example, the reforming can be steam reforming. In a steam reforming process, methane is contacted with steam at elevated temperature and pressure. For example, steam reforming can be carried out at a reaction temperature of at least 1000°C and a pressure ranging from 10 barg to 45 barg in certain embodiments. In certain embodiments, the reforming is steam reforming, as otherwise described herein, using a steam reforming catalyst comprising at least one of nickel, rhodium, copper, and cobalt, either alternatively or in combination with a precious metal such as platinum, palladium, rhodium, ruthenium, and iridium. The catalyst may be supported by a composition comprising magnesia, magnesium aluminate, alumina, silica, zirconia, or a combination thereof. For example, in certain embodiments, the steam reforming catalyst is a single metal (e.g., nickel) supported on a refractory support. The catalyst may also include a promoter. Examples of suitable promoters include alkali metals (e.g., potassium). Methods for methane reforming are described, for example, in U.S. Patent No. 6,239,999, the entire contents of which are incorporated herein.

[0076] The reformed product stream contains carbon monoxide and hydrogen. However, this reformed product stream may not have an ideal H:CO ratio for an efficient Fischer-Tropsch hydrocarbon synthesis reaction. Furthermore, those skilled in the art will appreciate that the H:CO ratio may be advantageously adjusted (e.g., to adjust product selectivity or operating efficiency) depending on specific process requirements. Thus, in certain embodiments, as described elsewhere herein, the method further includes subjecting the reformed product stream to a shift reaction (e.g., a water gas shift reaction) to increase the hydrogen to carbon monoxide ratio. In other embodiments, the method further includes subjecting the reformed product stream to a reverse water gas shift reaction to decrease the hydrogen to carbon monoxide ratio.

[0077] The reforming product stream may optionally have its H:CO ratio adjusted by a water-gas shift reaction (to increase the H:CO ratio) or a reverse water-gas shift reaction (to decrease the H:CO ratio) and be suitable for the synthesis of long-chain hydrocarbons in a Fischer-Tropsch reaction. Accordingly, various processes of the present disclosure include contacting a hydrocarbon synthesis mixture containing carbon monoxide and hydrogen with a Fischer-Tropsch hydrocarbon synthesis catalyst to produce a hydrocarbon composition containing C5+ hydrocarbons and / or oxygenates with a selectivity to C5+ hydrocarbons of at least 50% and / or a selectivity to oxygenates of at least 20%, wherein at least a portion of the carbon monoxide and / or hydrogen is produced by a process as otherwise described herein, e.g., by the reforming process described above. In certain such embodiments, the hydrocarbon synthesis feed has a hydrogen to carbon monoxide molar ratio in the range of 0.5:1 to 5:1 (e.g., 0.5:1 to 4:1, or 0.5:1 to 3:1, or 1:1 to 5:1, or 1:1 to 4:1, or 1:1 to 3:1).

[0078] In certain embodiments described elsewhere herein, the Fischer-Tropsch hydrocarbon synthesis catalyst used in the Fischer-Tropsch process may have a composition similar to the methane synthesis catalyst generally described elsewhere herein, e.g., the Fischer-Tropsch hydrocarbon synthesis catalyst may be the same as the methane synthesis catalyst utilized in the production of methane.

[0079] Those skilled in the art will be able to select appropriate Fischer-Tropsch hydrocarbon synthesis parameters in light of this disclosure and taking into account the existing state of the art. Suitable techniques for hydrocarbon synthesis, particularly for the synthesis of C5+ hydrocarbons and / or oxygenates, are described in U.S. Patent No. 6,275,999, which is incorporated herein by reference in its entirety. For example, in certain embodiments as described elsewhere herein, contacting the hydrocarbon synthesis feedstock is carried out at a temperature in the range of 150°C to 325°C (e.g., in the range of 150°C to 300°C, or 150°C to 275°C, or 150°C to 250°C, or 175°C to 325°C, or 175°C to 275°C, or 175°C to 250°C, or 200°C to 325°C, or 200°C to 275°C, or 200°C to 250°C). In certain embodiments as described elsewhere herein, the contacting of the hydrocarbon synthesis feedstock is carried out at a pressure in the range of from 10 barg to 100 barg, e.g., from 20 barg to 80 barg, or from 20 barg to 60 barg, or from 20 barg to 50 barg, or from 20 barg to 40 barg.

[0080] Because long-chain hydrocarbons are often more valuable, it may be desirable to limit methane production in hydrocarbon synthesis. In certain embodiments as described elsewhere herein, contacting the hydrocarbon synthesis feedstock to provide a hydrocarbon product stream has a selectivity to methane of 25% or less (e.g., 20% or less, or 15% or less, or 10% or less). In certain embodiments as described elsewhere herein, contacting the hydrocarbon synthesis feedstock to provide a hydrocarbon product stream has a selectivity to C5+ hydrocarbons of at least 50% (e.g., at least 60%, or at least 70%, or at least 80%, or at least 90%). In some embodiments, hydrocarbon synthesis conditions can be adjusted as known in the art to favor the production of oxygenates (see, e.g., WO 2019 / 154885). In certain embodiments, as described elsewhere herein, the hydrocarbon product stream comprises oxygenates, and contacting the hydrocarbon synthesis feedstock to provide the hydrocarbon product stream has an oxygenate selectivity of at least 20% (e.g., at least 30%, or at least 40%, or at least 50%).

[0081] Following formation of the hydrocarbon product stream, it may be desirable to purify the product stream. Accordingly, in certain embodiments as described elsewhere herein, the hydrocarbon product stream is separated to produce a C5+ hydrocarbon product stream and / or an oxygenated product stream, and a C1-4 hydrocarbon product stream. In certain embodiments, the method further includes recycling the C1-4 product stream to provide at least a portion of the reforming feed.

[0082] One embodiment of the disclosed method is shown in the schematic diagram of FIG. 1. In process 100, a reforming feedstock 112 is reformed, for example, in a reforming zone 120 (e.g., a reforming reactor). Water and / or oxygen are also supplied to the reforming zone 120 via stream 114. The reforming provides a reformed product stream 122 containing carbon monoxide and hydrogen. This hydrogen- and carbon monoxide-containing stream (after optional water-gas shift or reverse water-gas shift, not shown) is then contacted with a Fischer-Tropsch hydrocarbon synthesis catalyst in a Fischer-Tropsch reaction zone 130 (e.g., a reactor having a catalyst bed therein). The contact produces a hydrocarbon product stream 132 containing C5+ hydrocarbons and / or oxygenates. Advantageously, the two catalysts can be provided in the same reactor, for example, in beds arranged in parallel. This can enable a high degree of process integration, as the temperature and pressure conditions of the methane synthesis reaction are similar to those of the Fischer-Tropsch reaction. As mentioned above, this product stream 132 may now be separated in separator 140 to provide a C5+ product stream 147 and a stream 142 comprising light hydrocarbons and water, which may be separated from each other in separator 150 to provide a light hydrocarbon stream 152 and a water stream 157. The light hydrocarbon stream 152 may be recycled to the reforming reaction zone 120, for example.

[0083] As noted above, methane can be supplied from many sources. Thus, in the embodiment of FIG. 1, methane can be supplied by pipeline from another location. Such pipeline methane can be provided from a conventional source or from a renewable source. For example, such pipeline methane can be provided using the methane synthesis techniques described herein. In such an embodiment, methane can advantageously act as a carrier for renewable hydrogen and / or carbon.

[0084] Another embodiment of the present disclosure is shown in Figure 2. Here, in an integrated process 200, a carbon dioxide and hydrogen-containing feed 202 is contacted with a methane synthesis catalyst, for example, in a methane synthesis zone 210 (e.g., a reactor having a catalyst bed therein) to provide a methane product stream 212. The methane in this methane product stream 212 is reformed, for example, in a reforming zone 220 (e.g., a reforming reactor). Water and / or oxygen are also supplied to the reforming zone 220 via stream 214. Reforming provides a reformed product stream 222 comprising carbon monoxide and hydrogen. This hydrogen and carbon monoxide-containing stream (after optional water-gas shift or reverse water-gas shift, not shown) is then contacted with a Fischer-Tropsch hydrocarbon synthesis catalyst, this time in a Fischer-Tropsch reaction zone 230 (e.g., a reactor having a catalyst bed therein). The contacting produces a hydrocarbon product stream 232 comprising C5+ hydrocarbons and / or oxygenates. As mentioned above, this product stream 232 may now be separated in separator 240 to provide a C5+ product stream 247 and a stream 242 comprising light hydrocarbons and water, which may be separated from each other in separator 250 to provide a light hydrocarbon stream 252 and a water stream 257. The light hydrocarbon stream 252 may be recycled to the reforming reaction zone 220, for example.

[0085] The present inventors have developed a process architecture that advantageously enables more efficient hydrocarbon synthesis and processing. For example, it may be desirable to combine at least a portion of the hydrocarbon product stream with a methane synthesis mixture to achieve process efficiencies for subsequent separation and recycling steps, if any. In certain embodiments, as otherwise described herein, the process comprises: combining the hydrocarbon product stream with the methane synthesis mixture to provide a combined product stream, wherein the conversion of the methane synthesis mixture to the methane product stream occurs in the presence of the hydrocarbon product stream; separating the resulting mixed product stream into a C5+ and / or oxygenated product stream and a C1-4 product stream; recirculating the C1-4 product vapor to provide at least a portion of the reforming feed; The mixing can occur prior to entering the methane synthesis reaction zone or can occur in the methane synthesis reaction zone itself.

[0086] An example of such an embodiment is shown in the schematic diagram of Figure 3. Here, a hydrogen- and carbon monoxide-containing stream (after optional water-gas shift or reverse water-gas shift, not shown) 322 is contacted with a Fischer-Tropsch hydrocarbon synthesis catalyst, here in a Fischer-Tropsch reaction zone 330 (e.g., a reactor having a bed of catalyst therein). The contacting produces a hydrocarbon product stream 332 comprising C5+ hydrocarbons and / or oxygenates. This hydrocarbon product stream 332 is mixed with a methane synthesis mixture 302 containing carbon dioxide and hydrogen, which is then contacted with a methane synthesis catalyst, here in a methane synthesis reaction zone 310 (e.g., a reactor having a bed of catalyst therein) to provide a mixed product stream 334 (i.e., a combination of the methane product stream of the methane synthesis reaction and the hydrocarbon product stream of the Fischer-Tropsch reaction). Advantageously, the two catalysts can be provided within the same reactor, e.g., in beds arranged in series. Because the temperature and pressure conditions of the methane synthesis reaction are similar to those of the Fischer-Tropsch reaction, this can enable a high degree of process integration. This combined product stream 334 can then be separated in separator 340 to provide a C5+ product stream 347 and a stream 342 containing light hydrocarbons and water, which can be separated from each other in separator 350 to provide a light hydrocarbon stream 352 and a water stream 357. In particular, light hydrocarbon stream 352 carries methane produced by the methane synthesis reaction and is recycled to provide methane to a reforming reaction zone 320 (e.g., a reforming reactor). Water and / or oxygen are also supplied to reforming zone 320 via stream 314. Reforming provides a reformed product stream 322 containing carbon monoxide and hydrogen. As described above, this reformed product stream 322 provides carbon monoxide and hydrogen for the Fischer-Tropsch reaction in reaction zone 330.

[0087] In other embodiments, it may be desirable to combine at least a portion of the hydrocarbon product stream with the methane product stream, if present, to achieve process efficiencies with respect to subsequent separation and recycling steps. In certain embodiments, the process, as otherwise described herein, comprises: mixing the methane product stream with the hydrocarbon product to form a mixed product stream; separating the mixed product stream into a C5+ product stream and / or an oxygenated product stream and a C1-4 product stream; The C1-4 product stream is recycled to provide at least a portion of the reforming feed.

[0088] An example of such an embodiment is shown in the schematic diagram of Figure 4. Here, a hydrogen- and carbon monoxide-containing stream 422 (after optional water-gas shift or reverse water-gas shift, not shown) is contacted with a Fischer-Tropsch hydrocarbon synthesis catalyst, here in a Fischer-Tropsch reaction zone 430 (e.g., a reactor having a catalyst bed therein). The contacting produces a hydrocarbon product stream 432 containing C5+ hydrocarbons and / or oxygenates. In a parallel pathway, a methane synthesis mixture 402 containing carbon dioxide and hydrogen, and a methane synthesis mixture, here in a methane synthesis reaction zone 410 (e.g., a reactor having a catalyst bed therein), are contacted with a methane synthesis catalyst to provide a methane product stream 412. Advantageously, the two catalysts can be provided in the same reactor, e.g., in beds arranged in parallel. Because the temperature and pressure conditions of the methane synthesis reaction are similar to those of the Fischer-Tropsch reaction, this can enable a high degree of process integration. The methane product stream 412 is mixed with the hydrocarbon product stream 432 to provide a mixed product stream 434. This combined product stream 434 can then be separated in separator 440 to provide a C5+ product stream 447 and a stream 442 comprising light hydrocarbons and water, which can be separated from each other in separator 450 to provide a light hydrocarbon stream 452 and a water stream 457. In particular, light hydrocarbon stream 452 carries methane produced by the methane synthesis reaction and is recycled to provide methane to a reforming reaction zone 420 (e.g., a reforming reactor). Water and / or oxygen are also supplied to reforming zone 420 via stream 414. Reforming provides a reformed product stream 422 comprising carbon monoxide and hydrogen. As described above, this reformed product stream 422 provides the carbon monoxide and hydrogen for the Fischer-Tropsch reaction in reaction zone 430.

[0089] As described elsewhere herein, the C1-4 product stream may be recycled to an earlier stage of the process. However, in certain embodiments, it may be desirable to remove contaminants or by-products from the C1-4 product stream during the recycle step. Thus, in certain embodiments as described elsewhere herein, the C1-4 product stream comprises water, and the process further comprises removing at least a portion of the water from the C1-4 product stream.

[0090] The process of the present disclosure will now be further described by reference to the following examples, which are merely illustrative. In the examples, CO conversion is defined as moles of CO used / moles of CO fed x 100, and carbon selectivity is defined as moles of CO attributed to a particular product / moles of CO converted x 100. Unless otherwise specified, temperatures referred to in the examples are application temperatures, not catalyst / bed temperatures. Unless otherwise specified, pressures referred to in the examples are absolute pressures. Example

[0091] The following examples illustrate specific embodiments of the disclosed method and various uses thereof. They are provided for illustrative purposes only and should not be construed as limiting the scope of the disclosure. Example 1: Conversion of hydrogen and carbon dioxide to methane

[0092] Several catalysts with various compositions similar to conventional Fischer-Tropsch catalysts were prepared and loaded into a 16-channel reactor with a common feedstock, temperature, and pressure across the catalyst channels, with online analysis of C1–C8. The catalysts were activated in the 16-channel reactor at atmospheric pressure and a gas hourly space velocity of 5000 hr-1 by heating from 25 °C to 150 °C at 2 °C / min, then from 150 °C to 300 °C at 1 °C / min under 100% H2. The catalysts were run at the GHSV indicated in the table with 51% N2 at CO2:CO2 ratios of 2:1, 1:1, 3:1, 1.8:1, 4:1, :1, :1, 4:1, and 2:1 (see Tables 1, 2, 3, 4, 6, and 7, respectively). No carbon monoxide was present in the feed. Table 1: H2:CO2 ratio of 2:1.

[0093] [Table 1] Table 2: 1:1 H2:CO2 ratio.

[0094] [Table 2] Table 3: H2:CO2 ratio of 3:1.

[0095] [Table 3] Table 4: H2:CO2 ratio of 1.8:1.

[0096] [Table 4] Table 5: Summary of test conditions for the results shown in Tables 1-4

[0097] [Table 5]

[0098] As shown in Tables 1-5 and the summary in Figure 5, we surprisingly discovered conditions that allow for the efficient conversion of hydrogen and carbon dioxide to methane. Importantly, the observed carbon dioxide conversion is advantageously high, given the typically low reactivity of carbon dioxide. This result is particularly surprising considering the moderate reaction temperatures, ranging from 215 to 245 °C. Furthermore, the method exhibits high selectivity, with specific parameters resulting in approximately 95% methane selectivity. This extremely high selectivity allows for efficient processing of the product stream with minimal required purification. Furthermore, this activity is not expected for typical Co / Mn catalysts, since they are typically used in the Fischer-Tropsch synthesis of much larger molecular weight materials. Table 6: H2:CO2 ratio of 4:1.

[0099] [Table 6] Table 7: H2:CO2 ratio of 2:1.

[0100] [Table 7]

[0101] As shown in Tables 6 and 7, high methane selectivity over titania supported catalysts is maintained at high temperatures. Example 2: Steam reforming of methane to produce carbon monoxide and hydrogen

[0102] The methane is then transferred to a steam reformer having an outlet temperature of 1065°C and a pressure of 32 bara. Within the steam reformer, the methane is contacted with a combination of oxygen and steam to produce a reformer product stream comprising carbon monoxide and hydrogen. Example 3: Hydrocarbon synthesis using steam reforming product stream

[0103] As described in Example 2, the methane produced in Example 1 can be sent to a steam reformer to produce a reformer product stream containing carbon monoxide and hydrogen. This product stream can be subjected to washing or product separation to purify the carbon monoxide and hydrogen mixture. Other processes can be used to adjust the hydrogen-to-carbon monoxide ratio. The hydrogen and carbon monoxide are then introduced into a Fischer-Tropsch hydrocarbon synthesis reactor. The Fischer-Tropsch hydrocarbon synthesis reactor operates in the range of 200-300°C and 10-50 bara. The catalyst provided may have the same or generally the same composition as that utilized in Example 1, or may have a different composition. This process produces a Fischer-Tropsch hydrocarbon composition with high selectivity for C5+ hydrocarbons and / or C1-C24 oxygenates. Example 4: Use of green hydrogen and captured carbon dioxide

[0104] Processes similar to those of Examples 1-3 can be performed using only green hydrogen, such as hydrogen produced from solar- and / or wind-driven water electrolysis. Similarly, the carbon dioxide in such processes can be provided from carbon capture processes, such as power generation or carbon capture from chemical synthesis or manufacturing. Optionally, any power required to operate the processes of Examples 1-3 can be supplied from renewable sources. Overall, the result can be a renewable, carbon-neutral, or even carbon-negative process for producing valuable hydrocarbons.

[0105] Various exemplary embodiments of the present disclosure include, but are not limited to, the enumerated embodiments listed below, which can be combined in any number and in any combination that is not technically or logically consistent.

[0106] Embodiment 1: A method for producing hydrocarbons and / or oxygenates, comprising: reforming a reforming feedstock comprising methane with water and / or oxygen to produce a reformed product stream comprising carbon monoxide and hydrogen; 1. A process comprising contacting a hydrocarbon synthesis mixture comprising hydrogen and carbon monoxide with a Fischer-Tropsch hydrocarbon synthesis catalyst to produce a hydrocarbon product stream comprising C5+ hydrocarbons and / or oxygenates, e.g., with a selectivity to C5+ hydrocarbons of at least 50% and / or a selectivity to oxygenates of at least 20%.

[0107] Embodiment 2: The method of embodiment 1, wherein at least a portion of the methane in the reforming feed is contacting a methane synthesis mixture comprising hydrogen and carbon dioxide with a supported methane synthesis catalyst to form a methane product stream, wherein the supported methane synthesis catalyst comprises cobalt in the range of 1 wt % to 35 wt %; and providing a methane product stream having a selectivity for methane of at least 75%.

[0108] Embodiment 3: The method of embodiment 2, wherein at least 50% (e.g., at least 60%, 70%, 80%, 90%, 95%, or 99%) of the methane provided in the reforming feed is produced by contacting the methane synthesis mixture with a supported methane synthesis catalyst.

[0109] Embodiment 4: The method of embodiment 2 or embodiment 3, wherein the methane synthesis mixture comprises 10% by weight or less carbon monoxide (e.g., 5% by weight or less, or 3% by weight or less, or 2% by weight or less, or 1% by weight or less carbon monoxide).

[0110] Embodiment 5: The method of any of embodiments 2-4, wherein the methane synthesis mixture contains 0.5% by weight or less of carbon monoxide (e.g., 0.2% by weight or less, or 0.1% by weight or less, 500 ppm or less, or 100 pm or less, or substantially no carbon monoxide).

[0111] Embodiment 6: The method of any of embodiments 2-5, wherein the methane synthesis mixture has a weight ratio of carbon dioxide to carbon monoxide of at least 10:1 (e.g., at least 15:1, or 20:1, or 50:1, or 100:1).

[0112] Embodiment 7: The process of any of embodiments 2-6, wherein the hydrogen and carbon dioxide are present in a molar ratio ranging from 0.5:1 to 10:1, for example, from 0.5:1 to 7:1; or from 0.5:1 to 5:1; or from 0.5:1 to 4:1; or from 1:1 to 10:1; or from 1:1 to 7:1; or from 1:1 to 5:1; or from 2:1 to 10:1; or from 2:1 to 7:1; or from 2:1 to 5:1; or from 3:1 to 10:1; or from 3:1 to 7:1; or from 3:1 to 5:1.

[0113] Embodiment 8: The method of any of embodiments 2-7, wherein the hydrogen and carbon dioxide are present in a molar ratio ranging from 1:1 to 4:1, for example, from 1:1 to 3.5:1, or from 1:1 to 3:1, or from 1.5:1 to 4:1, or from 1.5:1 to 3.5:1, or from 1.5:1 to 3:1, or from 2:1 to 3:1, or from 2:1 to 3.5:1, or from 2:1 to 3:1.

[0114] Embodiment 9: The method of any of Embodiments 2-8, wherein at least 20% by volume, e.g., at least 30% by volume, at least 40% by volume, or at least 50% by volume, of the methane synthesis mixture is hydrogen and carbon dioxide.

[0115] Embodiment 10: The method of any of Embodiments 2-9, wherein at least 50% by volume, e.g., at least 60% by volume, at least 70% by volume, at least 80% by volume, or at least 90% by volume, of the methane synthesis mixture is hydrogen, carbon dioxide, and nitrogen.

[0116] Embodiment 11: The method of any of Embodiments 2-10, wherein at least 50% by volume, e.g., at least 60% by volume, at least 70% by volume, at least 80% by volume, or at least 90% by volume, of the methane synthesis mixture is hydrogen, carbon dioxide, nitrogen, water, and methane.

[0117] Embodiment 12: The method of any of Embodiments 2-11, wherein the supported methane synthesis catalyst comprises cobalt in an amount ranging from 1 to 30 wt%, or 1 to 25 wt%, or 1 to 20 wt%, or 2 to 35 wt%, or 2 to 25 wt%, or 2 to 20 wt%, or 5 to 35 wt%, or 5 to 30 wt%, or 5 to 25 wt%, or 10 to 35 wt%, or 10 to 30 wt%, or 10 to 25 wt% on an elemental basis.

[0118] Embodiment 13: The method of any of Embodiments 2-12, wherein the supported methane synthesis catalyst comprises cobalt in an amount ranging from 2 to 20 wt%, e.g., 2 to 15 wt%, or 2 to 10 wt%, or 5 to 20 wt%, or 5 to 15 wt%, or 5 to 10 wt%, or 7 to 20 wt%, or 7 to 15 wt%, or 7 to 12 wt%, or 10 to 20 wt%, or 10 to 15 wt%, on an elemental basis.

[0119] Embodiment 14: The method of any of Embodiments 2-13, wherein the supported methane synthesis catalyst further comprises manganese, and the manganese is present in the range of 0.5 to 15 wt%, or 0.5 to 10 wt%, or 0.5 to 7 wt%, or 0.5 to 5 wt%, or 1 to 20 wt%, or 1 to 15 wt%, or 1 to 10 wt%, or 1 to 5 wt%, or 2 to 20 wt%, or 2 to 15 wt%, or 5 to 20 wt%, or 5 to 15 wt%, or 5 to 12 wt%, or 5 to 10 wt%, or 7 to 20 wt%, or 7 to 15 wt%, or 7 to 12 wt%.

[0120] Embodiment 15: The supported methane synthesis catalyst is 4 m 2 / g~8 m 2 The method of any of embodiments 2-14, wherein the active cobalt surface area is in the range of / g.

[0121] Embodiment 16: The supported methane synthesis catalyst is 2 / g~350 m 2 16. The method of any of embodiments 2-15, wherein the surface area is in the range of 1 / g.

[0122] Embodiment 17: The method of any of Embodiments 2-16, wherein the supported methane synthesis catalyst comprises a support material comprising at least one of alumina, zirconia, titania, silica, zinc oxide, ceria, or a combination thereof.

[0123] Embodiment 18: The method of any of Embodiments 2-17, wherein the contacting is performed at a temperature in the range of 150°C to 325°C (e.g., in the range of 150°C to 300°C, or 150°C to 275°C, or 150°C to 250°C, or 175°C to 325°C, or 175°C to 275°C, or 175°C to 250°C, or 200°C to 325°C, or 200°C to 275°C, or 200°C to 250°C).

[0124] Embodiment 19: The method of any of embodiments 2 to 18, wherein the contacting is carried out at a pressure in the range of from 10 barg to 100 barg, e.g., from 20 barg to 80 barg, or from 20 barg to 60 barg, or from 20 barg to 50 barg, or from 20 barg to 40 barg.

[0125] Embodiment 20: The method of any of Embodiments 2-19, wherein the selectivity to methane is at least 80% (e.g., at least 85%, or at least 90%, or at least 95%).

[0126] Embodiment 21: The method of any of Embodiments 2-20, wherein the carbon dioxide is reacted with a C5+ selectivity of 10% or less, e.g., 8% or less, or 7% or less, or 5% or less, or 4% or less, or 3% or less.

[0127] Embodiment 22: The method of any of Embodiments 2-21, wherein the carbon dioxide is reacted with a C2+ selectivity of 25% or less, e.g., 20% or less, or 15% or less, or 10% or less, or 5% or less.

[0128] Embodiment 23: The method of any of Embodiments 2-22, wherein the methane product stream is provided at a carbon dioxide conversion of at least 5%, e.g., at least 10%, or at least 15%, or at least 20%. Embodiment 24: The method of any of Embodiments 2-23, wherein the carbon dioxide is reacted to a carbon dioxide conversion of at least 25%, such as at least 30%, or at least 35%, or at least 40%.

[0129] Embodiment 25: The method of any of Embodiments 2-24, wherein the supported methane synthesis catalyst is activated by a process comprising reducing the catalyst with a reducing gas at a temperature of 350° C. or less to form a supported methane synthesis catalyst comprising cobalt(0).

[0130] Embodiment 26: The method of any of Embodiments 2-25, wherein 95% or less of the cobalt in the methane synthesis catalyst is cobalt(0).

[0131] Embodiment 27: The method of any one of embodiments 2 to 26, comprising: passivating the supported methane synthesis catalyst by contacting the supported methane synthesis catalyst with a passivating agent (e.g., an oxygen-containing passivating agent) to form a passivated methane synthesis catalyst; reactivating the supported methane synthesis catalyst by contacting the supported methane synthesis catalyst with a reducing agent at a temperature of 350°C or less.

[0132] Embodiment 28: The method of embodiment 27, further comprising, prior to the reactivation step, transporting the passivated methane synthesis catalyst and loading the passivated methane synthesis catalyst into a reactor bed.

[0133] Embodiment 29: The method of any of embodiments 2-28, wherein the hydrogen comprises green hydrogen (e.g., hydrogen produced by electrolysis, where the electrolysis is powered, at least in part, by renewable energy).

[0134] Embodiment 30: The method of embodiment 29, wherein the hydrogen in the methane synthesis mixture is at least 50% by weight green hydrogen.

[0135] Embodiment 31: The method of any of Embodiments 2-30, wherein the carbon dioxide comprises captured carbon dioxide or carbon dioxide from biomass gasification.

[0136] Embodiment 32: The method of embodiment 31, wherein at least 50 wt.% of the carbon dioxide in the methane synthesis mixture is derived from biomass gasification.

[0137] Embodiment 33: The method of embodiment 31, wherein the carbon dioxide of the methane synthesis mixture is at least 50% by weight of captured carbon dioxide.

[0138] Embodiment 34: The method of any of Embodiments 1-33, wherein the methane in the reforming feed is captured methane or biogenic methane.

[0139] Embodiment 35: The method of any of Embodiments 1-34, wherein the reforming is at least one of steam reforming, autothermal reforming, gas-heat reforming, and partial oxidation reforming.

[0140] Embodiment 36: The method of any of Embodiments 1-34, wherein the reforming is steam reforming, comprising contacting the methane and water with a steam reforming catalyst comprising at least one of nickel, rhodium, copper, and cobalt.

[0141] Embodiment 37: The method of embodiment 36, wherein the steam reforming is carried out at a temperature of at least 1000°C and a pressure in the range of 10 barg to 45 barg.

[0142] Embodiment 38: The method of any of Embodiments 1-37, wherein the reformed product stream is subjected to a water gas shift reaction to increase the ratio of hydrogen to carbon monoxide.

[0143] Embodiment 39: The method of any of Embodiments 1-38, wherein the reformed product stream is subjected to a reverse water gas shift reaction to reduce the ratio of hydrogen to carbon monoxide.

[0144] Embodiment 40: The method of any of Embodiments 1 to 38, wherein the method does not include a reverse water gas shift reaction.

[0145] Embodiment 41: The method of any of Embodiments 1-40, wherein the hydrocarbon synthesis feed has a hydrogen to carbon monoxide molar ratio in the range of 0.5:1 to 5:1 (e.g., 0.5:1 to 4:1, or 0.5:1 to 3:1, or 1:1 to 5:1, or 1:1 to 4:1, or 1:1 to 3:1).

[0146] Embodiment 42: The method of any of Embodiments 1 to 41, wherein the Fischer-Tropsch hydrocarbon synthesis catalyst is provided according to any preceding claim.

[0147] Embodiment 43: The method of any of embodiments 1 to 42, wherein the contacting of the hydrocarbon synthesis feedstock is carried out at a temperature in the range of 150°C to 325°C (e.g., in the range of 150°C to 300°C, or 150°C to 275°C, or 150°C to 250°C, or 175°C to 325°C, or 175°C to 275°C, or 175°C to 250°C, or 200°C to 325°C, or 200°C to 275°C, or 200°C to 250°C).

[0148] Example 44: The process of any of embodiments 1-43, wherein the contacting of the hydrocarbon synthesis feedstock is carried out at a pressure in the range of from 10 barg to 100 barg, e.g., from 20 barg to 80 barg, or from 20 barg to 60 barg, or from 20 barg to 50 barg, or from 20 barg to 40 barg.

[0149] Embodiment 45: The method of any of Embodiments 1-44, wherein the contacting of the hydrocarbon synthesis feedstock to provide the hydrocarbon product stream has a selectivity to methane of 25% or less (e.g., 2% or less, or 15% or less, or 10% or less).

[0150] Embodiment 46: The method of any of Embodiments 1-45, wherein the contacting of the hydrocarbon synthesis feedstock to provide the hydrocarbon product stream has a selectivity for C5+ hydrocarbons of at least 50 wt% (e.g., at least 60 wt%, or at least 70 wt%, or at least 80 wt%, or at least 90 wt%).

[0151] Embodiment 47: The method of any of Embodiments 1-45, wherein the hydrocarbon product stream comprises oxygenates, and wherein the contacting of the hydrocarbon synthesis feedstock to provide the hydrocarbon product stream has an oxygenate selectivity of at least 20% (e.g., at least 30%, or at least 40%, or at least 50%).

[0152] Embodiment 48: The method of any of Embodiments 1-47, wherein the hydrocarbon product stream is separated to produce a C5+ product stream and / or an oxygenated product stream, and a C1-4 hydrocarbon product stream.

[0153] Embodiment 49: The method of Embodiment 48, further comprising recycling the C1-4 product stream to provide at least a portion of the reforming feed.

[0154] Embodiment 50: The method of any of embodiments 2 to 49, further comprising: combining the hydrocarbon product stream with the methane synthesis mixture to provide a combined product stream, wherein the conversion of the methane synthesis mixture to the methane product stream occurs in the presence of the hydrocarbon product stream; separating the resulting mixed product stream into a C5+ and / or oxygenated product stream and a C1-4 product stream; Recirculating the C1-4 product vapor to provide at least a portion of the reforming feed.

[0155] Embodiment 51: The method of any one of embodiments 2 to 49 further comprises: mixing the methane product stream with the hydrocarbon product to form a mixed product stream; separating the mixed product stream into a C5+ and / or oxygenated product stream and a C1-4 product stream; and recycling the C1-4 product stream to provide at least a portion of said reforming feed.

[0156] Embodiment 52: The method of any of Embodiments 49-51, wherein the C1-4 product stream comprises water, further comprising removing at least a portion of the water from the C1-4 product stream prior to recycling.

[0157] Embodiment 53: The method of any one of Embodiments 2 to 52, wherein the Fischer-Tropsch hydrocarbon synthesis catalyst is the same as the methane synthesis catalyst utilized in the production of methane.

[0158] The details set forth herein are by way of example and are intended solely for the purpose of illustratively describing certain embodiments of the present disclosure, and are presented to provide what is believed to be the most useful and readily understood explanation of the principles and conceptual aspects of various embodiments of the present disclosure. In this regard, no attempt is made to show details relating to the methods of the present disclosure in more detail than is necessary for a fundamental understanding of the methods described herein, and the description provided together with the examples will make clear to those skilled in the art how some forms of the methods of the present disclosure can be embodied in practice. Therefore, before the disclosed processes and devices are described, it should be understood that the aspects described herein are not limited to specific embodiments, apparatus, or configurations, which may, of course, vary. It should also be understood that the terms used herein are for the purpose of describing particular aspects only, and are not intended to be limiting unless specifically defined herein.

[0159] As used in the context of describing the methods of the present disclosure (particularly in the context of the embodiments and claims that follow), the terms "a," "an," "the," and similar referents should be construed to encompass both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context.

[0160] All methods described herein can be performed in any suitable order of steps, unless otherwise indicated herein or clearly contradicted by context. Any and all examples provided herein, or the use of exemplary language (e.g., "etc."), are intended merely to better describe the methods of the present disclosure and do not impose limitations on the scope of the present disclosure. No language in this specification should be construed as indicating any non-claimed element essential to the practice of the methods of the present disclosure.

[0161] Unless the context requires otherwise, throughout the specification and claims, words like "comprises," "including," and the like should be construed in an inclusive sense, i.e., "including, but not limited to," rather than an exclusive or exhaustive sense. Words using the singular or plural also include the plural and singular, respectively. In addition, the words "herein," "above," and "below," and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application.

[0162] As will be understood by one of ordinary skill in the art, each embodiment disclosed herein can comprise, consist essentially of, or consist of its specified stated elements, steps, ingredients, or components. As used herein, the transitional terms "comprise" or "comprises" mean and allow for the inclusion of, but not limited to, any unspecified elements, steps, ingredients, or components, even in large amounts. The transitional phrase "consisting of" excludes any unspecified element, step, ingredient, or component. The transitional phrase "consisting essentially of" limits the scope of the embodiment to the specified elements, steps, ingredients, or components, and those that do not materially affect the embodiment.

[0163] All percentages, ratios and proportions herein are by weight unless otherwise specified.

[0164] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the present disclosure are approximations, the numerical values ​​set forth in the specific examples are reported as precisely as possible, however, any numerical value inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0165] Grouping of alternative elements or embodiments of the present disclosure should not be construed as limiting. Each group member may be referred to and claimed individually or in any combination with other members of the group or other elements found herein. It is anticipated that one or more members of a group may be included in, or deleted from, a group for reasons of convenience and / or patentability. When any such inclusion or deletion occurs, the specification includes the modified group and is therefore deemed to satisfy the written description of all Markush groups used in the appended claims.

[0166] As used herein, the phrase "at least a portion" is used to indicate that at least a partial amount up to the total possible amount is required.

[0167] Finally, it should be understood that the various embodiments herein are illustrative of the methods of the present disclosure. Other modifications that may be employed are within the scope of the present disclosure. Thus, by way of example, and not of limitation, alternative configurations of the methods may be utilized in accordance with the teachings herein. Thus, the methods of the present disclosure are not limited to that precisely as shown and described.

Claims

1. 1. A method for producing hydrocarbons and / or oxygenates, comprising: reforming a reforming feed comprising methane with water and / or oxygen to produce a reformed product stream comprising carbon monoxide and hydrogen; A process for producing a hydrocarbon product stream comprising C5+ hydrocarbons and / or oxygenates, e.g., with a selectivity for C5+ hydrocarbons of at least 50% and / or a selectivity for oxygenates of at least 20%, by contacting a hydrocarbon synthesis mixture comprising hydrogen and carbon monoxide with a Fischer-Tropsch hydrocarbon synthesis catalyst, wherein said hydrocarbon synthesis mixture comprises at least a portion of said reformed product stream.

2. At least a portion of the methane in the reforming feedstock is 10. The method of claim 1 produced by contacting a methane synthesis mixture comprising hydrogen and carbon dioxide with a supported methane synthesis catalyst to form a methane product stream, the supported methane synthesis catalyst comprising cobalt in the range of 1 wt. % to 35 wt. % and providing a methane product stream having a selectivity for methane of at least 75%.

3. 3. The method of claim 2, wherein at least 50% (e.g., at least 60%, 70%, 80%, 90%, 95%, or 99%) of the methane provided in the reforming feed is produced by contacting the methane synthesis mixture with a supported methane synthesis catalyst.

4. The method of claim 2, wherein the methane synthesis mixture contains less than 2% by weight of carbon monoxide.

5. The method of claim 2, wherein at least 50% by volume, for example at least 60%, at least 70%, at least 80%, or at least 90% by volume of the methane synthesis mixture is hydrogen, carbon dioxide, and nitrogen.

6. The method of claim 2, wherein the supported methane synthesis catalyst further comprises manganese, and the manganese is present in the range, on an elemental basis, of 0.5 to 15 wt%, or 0.5 to 10 wt%, or 0.5 to 7 wt%, or 0.5 to 5 wt%, or 1 to 20 wt%, or 1 to 15 wt%, or 1 to 10 wt%, or 1 to 5 wt%, or 2 to 20 wt%, or 2 to 15 wt%, or 2 to 10 wt%, or 2 to 5 wt%, or 5 to 20 wt%, or 5 to 15 wt%, or 5 to 12 wt%, or 5 to 10 wt%, or 7 to 20 wt%, or 7 to 15 wt%, or 7 to 12 wt%.

7. The method of claim 2, wherein the contacting is carried out at a temperature within the range of 150°C to 325°C (e.g., within the range of 150°C to 300°C, or 150°C to 275°C, or 150°C to 250°C, or 175°C to 325°C, or 175°C to 275°C, or 175°C to 250°C, or 200°C to 325°C, or 200°C to 275°C, or 200°C to 250°C).

8. 3. The process of claim 2, wherein the selectivity for methane is at least 80% (e.g., at least 85%, or at least 90%, or at least 95%) and the methane product stream is provided at a carbon dioxide conversion of at least 5%, e.g., at least 25%.

9. The method of claim 2, wherein the hydrogen comprises green hydrogen (e.g., hydrogen produced by electrolysis, the electrolysis being at least partially powered by renewable energy), and / or the carbon dioxide comprises captured carbon dioxide or carbon dioxide from biomass gasification.

10. The method of claim 1, wherein the contacting of the hydrocarbon synthesis feedstock to provide the hydrocarbon product stream has a selectivity for C5+ hydrocarbons of at least 50 wt% (e.g., at least 60 wt%, or at least 70 wt%, or at least 80 wt%, or at least 90 wt%).

11. The method of claim 1, wherein the hydrocarbon product stream comprises oxygenates and the contacting of the hydrocarbon synthesis feedstock to provide the hydrocarbon product stream has an oxygenate selectivity of at least 20% (e.g., at least 30%, or at least 40%, or at least 50%).

12. The method of claim 1, wherein the hydrocarbon product stream is separated to produce a C5+ product stream and / or an oxygenated product stream and a C1-4 hydrocarbon product stream.

13. The method of claim 12, further comprising recycling the C1-4 product stream to provide at least a portion of the reforming feed.

14. The method of claim 13, wherein the hydrocarbon product stream is mixed with a methane synthesis mixture, wherein conversion of the methane synthesis mixture to a methane product stream is carried out in the presence of the hydrocarbon product stream to provide a mixed product stream; separating the resulting mixed product stream into a C5+ and / or oxygenated product stream and a C1-4 product stream; 3. The method of claim 2, further comprising recycling the C1-4 product stream to provide at least a portion of the reforming feed.

15. The method of claim 1, further comprising: mixing the methane product stream with a hydrocarbon product to form a mixed product stream; separating the mixed product stream into a C5+ product stream and / or an oxygenate product stream and a C1-4 product stream; 3. The method of claim 2, further comprising recycling the C1-4 product stream to provide at least a portion of the reforming feed.

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