Nickel Catalysts for Reverse Water Gas Shift and Integrated Fischer-Tropsch Processes

Abstract

The present disclosure generally relates to a reverse water gas shift process, an integrated Fischer-Tropsch process, and a supported reverse water gas shift catalyst for performing these processes. The catalysts described herein include a support that is a cerium oxide support, a titanium oxide support, an aluminum oxide support, a zirconium oxide support, or a mixed oxide support comprising a mixture of two or more of cerium oxide, titanium oxide, aluminum oxide, and zirconium oxide, nickel present in an amount in the range of 0.05 to 10 wt% of the catalyst based on the total weight of the catalyst, and manganese present in an amount in the range of 0.5 to 20 wt% of the catalyst based on the total weight of the catalyst.

Description

Cross - reference to related applications

[0001] This application claims the benefit of priority of International Patent Application PCT / CN2022 / 102630 filed on June 30, 2022, and International Patent Application PCT / CN2022 / 102799 filed on June 30, 2022, each of which is hereby incorporated by reference in its entirety.

Technical field

[0002] The present disclosure generally relates to a reverse water - gas shift catalyst, a method for manufacturing the same, and a method for carrying out a reverse water - gas shift reaction. The present disclosure also relates to integrating a process for carrying out a reverse water - gas shift reaction with a process for carrying out a Fischer - Tropsch reaction.

Background art

[0003] The reverse water - gas shift reaction (rWGS) is an advantageous route for obtaining carbon monoxide from carbon dioxide for further chemical processing. The rWGS converts carbon dioxide and hydrogen into carbon monoxide and water, as shown in Equation (1).

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[0004] However, the rWGS reaction is not advantageous in all situations. For example, the competing reaction is the Sabatier reaction (Equation (3)), which advantageously reduces the carbon monoxide yield for methane formation, which is not an active feedstock for FT.

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[0005] Similarly, carbon monoxide products from rWGS can be hydrogenated to methane, as shown in Equation (4).

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[0006] In combination with Equations (3) and (4), further undesirable side reactions can occur. These side reactions can potentially form undesirable carbon deposits on the surface of the catalyst used to promote rWGS. Examples of these carbon-forming side reactions are shown in Equations (5), (6), and (7). All three of these reactions are endothermic and, like the rWGS reaction, are favorable at higher temperatures.

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[0007] Considering that multiple reactions and competing thermodynamics are at play, there is still a need in the art for new rWGS catalysts and methods, particularly for integration with the Fischer-Tropsch process. SUMMARY OF THE INVENTION

[0008] In one aspect, the present disclosure provides a supported reverse water gas shift catalyst, the catalyst comprising a support that is a cerium oxide support, a titanium oxide support, an aluminum oxide support, a zirconium oxide support, or a mixed oxide support comprising a mixture of two or more of cerium oxide, titanium oxide, aluminum oxide, and zirconium oxide, and nickel present in an amount in the range of 0.05 to 10 wt% of the catalyst, based on the total weight of the catalyst, and manganese present in an amount in the range of 0.5 to 20 wt% of the catalyst, based on the total weight of the catalyst.

[0009] In another aspect, the present disclosure provides a method of making a catalyst described herein, the method comprising providing a support that is a cerium oxide support, a titanium oxide support, an aluminum oxide support, a zirconium oxide support, or a mixed oxide support comprising a mixture of two or more of cerium oxide, titanium oxide, aluminum oxide, and zirconium oxide, contacting the support with a liquid comprising one or more nickel-containing compounds and one or more manganese-containing compounds dispersed in a solvent, evaporating the solvent to provide a catalyst precursor, and calcining the catalyst precursor.

[0010] In another aspect, the present disclosure provides a catalyst described herein made by the method described herein.

[0011] In another aspect, the present disclosure is a method for carrying out the reverse water gas shift reaction, which comprises contacting a catalyst described herein with a feed stream consisting of CO2 and H2 at a temperature in the range of 500 to 900 °C to provide a product stream containing CO2 and H2, and the product stream has a lower concentration of CO2 and a higher concentration of CO than the feed stream.

[0012] In one aspect, the present disclosure provides a process for carrying out an integrated Fischer-Tropsch process, the process comprising providing a first feed stream containing H2 and CO2, carrying out a reverse water gas shift reaction by contacting a reverse water gas shift catalyst with the first feed stream at a first temperature in the range of 500 to 900 °C and a first pressure to provide a first product stream containing CO and H2, wherein the first product stream has a lower CO2 concentration and a higher CO concentration than the first feed stream, contacting a Fischer-Tropsch catalyst with a second feed stream containing H2 and at least a portion of the CO of the first product stream at a second temperature and a second pressure to provide a second product stream containing C5+ hydrocarbons, wherein the reverse water gas shift catalyst is a supported reverse water gas shift catalyst, a support which is a cerium oxide support, a titanium oxide support, an aluminum oxide support, a zirconium oxide support, or a mixed oxide support containing a mixture of two or more of cerium oxide, titanium oxide, aluminum oxide, and zirconium oxide, nickel present in an amount in the range of 0.05 to 10 wt% of the catalyst based on the total weight of the catalyst, and manganese present in an amount in the range of 0.5 to 20 wt% of the catalyst based on the total weight of the catalyst.

[0013] The accompanying drawings are included to provide a further understanding of the method of the present disclosure, are incorporated in and constitute a part of this specification. The drawings are not necessarily to scale, and the sizes of various elements may be distorted for clarity. The drawings show one or more embodiments of the present disclosure and, together with the description, serve to explain the principles and operations of the present disclosure.

Brief Description of the Drawings

[0014]

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Modes for Carrying Out the Invention

[0015] As described above, the reverse water-gas shift reaction is useful for providing a feedstock containing carbon monoxide and hydrogen, often referred to as "synthesis gas", which reacts carbon dioxide with hydrogen to produce carbon monoxide and water for use in processes such as the Fischer-Tropsch process. However, the Sabatier reaction, carbon monoxide methanation, and carbon formation side reactions can interfere with the rWGS reaction. The Sabatier reaction and CO methanation are exothermic and favored at low temperatures, while the rWGS and carbon formation side reactions are endothermic and favored at high temperatures. Therefore, despite these complex factors, there is still a need for an rWGS catalyst that can provide good performance. Here, the inventors provide a supported reverse water-gas shift catalyst comprising a metal oxide support, nickel, and manganese that can meet the requirements necessary for a commercially useful rWGS process. Furthermore, the inventors have found an rWGS process that is particularly advantageous for integration with the Fischer-Tropsch process by using a supported reverse water-gas shift catalyst comprising a metal oxide support, nickel, and manganese.

[0016] Reverse water-gas shift catalyst In one aspect, the present disclosure provides a supported reverse water-gas shift catalyst. The supported reverse water-gas shift catalyst comprises a support that is a cerium oxide support, a titanium oxide support, an aluminum oxide support, a zirconium oxide support, or a mixed oxide support comprising a mixture of two or more of cerium oxide, titanium oxide, aluminum oxide, and zirconium oxide, and at least one of nickel present in an amount in the range of 0.05 to 10 wt% of the catalyst, based on the total weight of the catalyst, and manganese present in an amount in the range of 0.5 to 20 wt% of the catalyst, based on the total weight of the catalyst.

[0017] As described above, the reverse water-gas shift catalyst of the present disclosure is a supported catalyst. In various embodiments described herein separately, the support constitutes at least 70 wt%, for example, at least 75 wt%, or 80 wt%, or 85 wt%, or 90 wt% of the catalyst on an oxide basis.

[0018] In various embodiments described elsewhere herein, the carrier is a cerium oxide carrier. As used herein, a "cerium oxide" carrier is a carrier that exhibits at least a surface layer (e.g., 50 microns thick) that is at least 50 wt% cerium oxide on an oxide basis. In various embodiments of the disclosure described herein, at least the surface layer of the cerium oxide support comprises at least 60 wt% cerium oxide, e.g., at least 70 wt% cerium oxide, or at least 80 wt% cerium oxide. In some such embodiments, at least the surface layer of the cerium oxide support comprises at least 90 wt% cerium oxide. For example, in some embodiments, at least the surface layer of the cerium oxide support comprises at least 95 wt% cerium oxide or at least 98 wt% cerium oxide. In various examples, the cerium oxide support contains cerium oxide substantially throughout, e.g., at least 50 wt% of the cerium oxide support is cerium oxide on an oxide basis. For example, in various embodiments, the cerium oxide support comprises at least 60 wt% cerium oxide, e.g., at least 70 wt% cerium oxide, or at least 80 wt% cerium oxide. In various embodiments, the cerium oxide support comprises at least 90 wt% cerium oxide, e.g., at least 95 wt% cerium oxide, or at least 98 wt% cerium oxide. In some embodiments, the cerium oxide carrier may further comprise additional metals or metal oxides.

[0019] In various embodiments described elsewhere herein, the carrier is a titanium oxide carrier. As used herein, a "titanium oxide" carrier is a carrier that exhibits at least a surface layer (e.g., 50 microns thick) that is at least 50 wt% titanium oxide on an oxide basis. In various embodiments of the disclosure described herein, at least the surface layer of the titanium oxide carrier contains at least 60 wt% titanium oxide, e.g., at least 70 wt% titanium oxide, or at least 80 wt% titanium oxide. In some such embodiments, at least the surface layer of the titanium oxide carrier contains at least 90 wt% titanium oxide. For example, in some embodiments, at least the surface layer of the titanium oxide carrier contains at least 95 wt% titanium oxide or at least 98 wt% titanium oxide. In various examples, the titanium oxide carrier contains titanium oxide substantially throughout, e.g., at least 50 wt% of the titanium oxide carrier is titanium oxide on an oxide basis. For example, in various embodiments, the titanium oxide carrier contains at least 60 wt% titanium oxide, e.g., at least 70 wt% titanium oxide, or at least 80 wt% titanium oxide. In various embodiments, the titanium oxide carrier contains at least 90 wt% titanium oxide, e.g., at least 95 wt% titanium oxide, or at least 98 wt% titanium oxide. In some embodiments, the titanium oxide carrier may further contain additional metals or metal oxides.

[0020] In various embodiments described elsewhere herein, the carrier is an aluminum oxide carrier. As used herein, an "aluminum oxide" carrier is a carrier that exhibits at least a surface layer (e.g., 50 microns thick) that is at least 50 weight percent aluminum oxide on an oxide basis. In various embodiments of the disclosure described herein, at least the surface layer of the aluminum oxide support comprises at least 60 weight percent aluminum oxide, e.g., at least 70 weight percent aluminum oxide, or at least 80 weight percent aluminum oxide. In some such embodiments, at least the surface layer of the aluminum oxide support comprises at least 90 weight percent aluminum oxide. For example, in some embodiments, at least the surface layer of the aluminum oxide support comprises at least 95 weight percent aluminum oxide or at least 98 weight percent aluminum oxide. In various examples, the aluminum oxide support contains aluminum oxide substantially throughout, e.g., at least 50 weight percent of the aluminum oxide support is aluminum oxide on an oxide basis. For example, in various embodiments, the aluminum oxide support comprises at least 60 weight percent aluminum oxide, e.g., at least 70 weight percent aluminum oxide, or at least 80 weight percent aluminum oxide. In various embodiments, the aluminum oxide support comprises at least 90 weight percent aluminum oxide, e.g., at least 95 weight percent aluminum oxide, or at least 98 weight percent aluminum oxide. In some embodiments, the aluminum oxide support may further comprise additional metals or metal oxides.

[0021] In various embodiments described elsewhere herein, the carrier is a zirconium oxide carrier. As used herein, a "zirconium oxide" carrier is a carrier that exhibits at least a surface layer (e.g., 50 microns thick) that is at least 50 wt% zirconium oxide on an oxide basis. In various embodiments of the disclosure described herein, at least the surface layer of the zirconium oxide support comprises at least 60 wt% zirconium oxide, e.g., at least 70 wt% zirconium oxide, or at least 80 wt% zirconium oxide. In some such embodiments, at least the surface layer of the zirconium oxide support comprises at least 90 wt% zirconium oxide. For example, in some embodiments, at least the surface layer of the zirconium oxide support comprises at least 95 wt% zirconium oxide or at least 98 wt% zirconium oxide. In various examples, the zirconium oxide support contains zirconium oxide substantially throughout, e.g., at least 50 wt% of the zirconium oxide support is zirconium oxide on an oxide basis. For example, in various embodiments, the zirconium oxide carrier comprises at least 60 wt% zirconium oxide, e.g., at least 70 wt% zirconium oxide, or at least 80 wt% zirconium oxide. In various embodiments, the zirconium oxide carrier comprises at least 90 wt% zirconium oxide, e.g., at least 95 wt% zirconium oxide, or at least 98 wt% zirconium oxide. In some embodiments, the zirconium oxide carrier may further comprise additional metals or metal oxides.

[0022] In various embodiments described elsewhere herein, the carrier is a mixed oxide carrier. These can be provided, for example, by a plurality of mixtures of the above oxides and formation onto carriers containing both. For example, in some embodiments, the mixed oxide carrier is a mixture of two or more metal oxides such as cerium oxide, titanium oxide, aluminum oxide, and zirconium oxide. In some embodiments, at least the surface layer of the carrier contains, on an oxide basis, at least 50 wt% in total of two or more of cerium oxide, titanium oxide, aluminum oxide, and zirconium oxide. In some embodiments, at least the surface layer of the mixed oxide support contains, in total, at least 60 wt%, for example, at least 70 wt% or at least 80 wt% of two or more of cerium oxide, titanium oxide, aluminum oxide, and zirconium oxide. In some embodiments, at least the surface layer of the mixed oxide support contains at least 90 wt%, for example, at least 95 wt% or at least 98 wt% of two or more of cerium oxide, titanium oxide, aluminum oxide, and zirconium oxide. In various examples, the mixed oxide carrier contains oxides substantially throughout, for example, at least 50 wt% of the mixed oxide carrier is two or more of cerium oxide, titanium oxide, aluminum oxide, and zirconium oxide. In various embodiments, the mixed oxide carrier contains, in total, at least 60 wt%, for example, at least 70 wt% or at least 80 wt% of two or more of cerium oxide, titanium oxide, aluminum oxide, and zirconium oxide. In various embodiments, the mixed oxide carrier contains, in total, at least 90 wt%, for example, at least 95 wt% or at least 98 wt% of two or more of cerium oxide, titanium oxide, aluminum oxide, and zirconium oxide. In some embodiments, the mixed oxide carrier may further contain additional metals or metal oxides.

[0023] The inventors have found that cerium oxide, titanium oxide, aluminum oxide, and zirconium oxide can provide good performance when there is no substantial amount of other metals present in the support. For example, in various embodiments of the present disclosure described separately herein, the support does not contain additional metals in a total amount of more than 2 wt%, for example, more than 1 wt%, or more than 0.5 wt% on an oxide basis.

[0024] However, the inventors have noted that in many cases, the performance can be favorably affected by including other metals in the support. Thus, in other embodiments described separately herein, the support contains at least one additional metal. In various embodiments, the total amount of at least one additional metal is in the range of 0.5 to 20 wt%, for example, 1 to 20 wt%, or 2 to 20 wt%, or 0.5 to 15 wt%, or 1 to 15 wt%, or 2 to 15 wt%, or 0.5 to 10 wt%, or 1 to 10 wt%, or 2 to 10 wt%, or 0.5 to 5 wt%, or 1 to 5 wt% on an oxide basis.

[0025] The supports suitable for use herein can have a range of pore volumes. One of ordinary skill in the art will select a pore volume appropriate for the desired catalytic process. For example, in various embodiments described separately herein, the pore volume is at least 0.05 mL / g, for example, at least 0.1 mL / g. In various embodiments described separately herein, the pore volume is at most 1.5 mL / g, for example, at most 1 mL / g. In various embodiments of the present disclosure described herein, the pore volume is in the range of 0.05 to 1.5 mL / g, for example, 0.1 mL / g to 1 mL / g. The pore volume is measured by mercury porosimetry, for example, as measured in accordance with ASTM D4284 - 12.

[0026] As described above, the supported water-reverse gas shift catalyst of the present disclosure contains nickel. For example, in various embodiments described separately herein, nickel is present in the catalyst. For the purposes of the present disclosure, the amount of nickel present is calculated as the weight percentage of nickel atoms in the catalyst based on the total weight of the catalyst, regardless of the form in which the nickel may be present. Nickel may be present in various forms in the catalyst. Most commonly, nickel is present mainly as a metal, a metal oxide, or a combination thereof. In some embodiments of the present disclosure described herein, nickel is present in the catalyst in an amount in the range of 0.05 to 10 wt%, for example, 0.1 to 10 wt%, or 0.5 to 10 wt%, 1 to 10 wt%, or 2 to 10 wt%, or 5 to 10 wt% based on the total weight of the catalyst. For example, in some embodiments, nickel is present in the catalyst in an amount in the range of 0.05 to 7 wt%, for example, 0.1 to 7 wt%, or 0.5 to 7 wt%, or 1 to 7 wt%, or 2 to 7 wt% based on the total weight of the catalyst. In some embodiments, nickel is present in the catalyst in an amount in the range of 0.05 to 5 wt%, for example, 0.1 to 5 wt%, or 0.5 to 5 wt%, or 1 to 5 wt%, or 2 to 5 wt% based on the total weight of the catalyst. For example, in some embodiments of the present disclosure described herein, nickel is present in the catalyst in an amount in the range of 0.05 to 2 wt%, for example, 0.1 to 2 wt%, or 0.3 to 2 wt%, or 0.5 to 2 wt% based on the total weight of the catalyst. In some embodiments, nickel is present in the catalyst in an amount in the range of 0.05 to 1.5 wt%, for example, 0.1 to 1.5 wt%, or 0.3 to 1.5 wt%, or 0.5 to 1.5 wt% based on the total weight of the catalyst. In some embodiments, nickel is present in an amount in the range of 0.05 to 1 wt%, for example, 0.1 to 1 wt%, or 0.3 to 1 wt%, or 0.5 to 1 wt% based on the total weight of the catalyst. In some embodiments, nickel is present in the catalyst in an amount in the range of 0.05 to 0.8 wt%, for example, 0.1 to 0.8 wt%, or 0.3 to 0.8 wt%, or 0.5 to 0.8 wt% based on the total weight of the catalyst.

[0027] As described above, the supported water-reverse gas shift catalyst of the present disclosure also contains manganese. The inventors have determined that, as described in the following examples, including manganese in the catalyst can bring about performance improvement. For the purposes of the present disclosure, the amount of manganese present is calculated as the weight percentage of manganese atoms in the catalyst based on the total weight of the catalyst, regardless of the form in which the manganese may exist. Manganese may exist in various forms in the catalyst, and most commonly, manganese exists mainly as metal oxides, metals, or combinations thereof. In various embodiments of the present disclosure described separately herein, manganese is present in the catalyst in an amount in the range of 0.5 to 20% by weight based on the total weight of the catalyst. For example, in various embodiments, manganese is present in the catalyst in an amount in the range of 0.5 to 15% by weight, or 0.5 to 12% by weight, or 0.5 to 10% by weight based on the total weight of the catalyst. In various embodiments of the present disclosure described herein, manganese is present in the catalyst in an amount in the range of 1 to 20% by weight, for example, 1 to 15% by weight, or 1 to 12% by weight, or 1 to 10% by weight based on the total weight of the catalyst. In various embodiments of the present disclosure described herein, manganese is present in an amount in the range of 2 to 20% by weight, for example, 2 to 15% by weight, or 2 to 12% by weight, or 2 to 10% by weight based on the total weight of the catalyst. In various embodiments of the present disclosure described herein, manganese is present in an amount in the range of 4 to 20% by weight, for example, 4 to 15% by weight, or 4 to 12% by weight, or 4 to 10% by weight.

[0028] Nickel and manganese can be provided in various weight ratios. For example, in some embodiments of the present disclosure described herein, the weight ratio of nickel to manganese present in the catalyst is at least 0.05:1. For example, in various embodiments, the weight ratio of nickel to manganese is at least 0.1:1. In various embodiments of the present disclosure described herein, the weight ratio of nickel to manganese present in the catalyst is at most 5:1. For example, the weight ratio of nickel to manganese is at most 2:1, or 1:1, or 0.5:1. For example, in various embodiments, the weight ratio of nickel to manganese present in the catalyst ranges from 0.05:1 to 5:1. For example, the weight ratio of nickel to manganese is in the range of 0.05:1 to 2:1, or 0.05:1 to 1:1, or 0.05:1 to 0.5:1, or 0.05:1 to 0.3:1, or 0.07:1 to 5:1, or 0.07:1 to 2:1, or 0.07:1 to 1:1, or 0.07:1 to 0.5:1, or 0.07:1 to 0.3:1, or 0.1:1 to 5:1, or 0.1:1 to 2:1, or 0.1:1 to 1:1, or 0.1:1 to 0.5:1, or 0.1:1 to 0.3:1.

[0029] The inventors have determined that a suitable reverse water gas shift catalyst is formed from one or more of cerium oxide, titanium oxide, aluminum oxide, and zirconium oxide as carriers, and nickel can be included in / on the catalyst in combination with manganese. As will be understood by those skilled in the art, the amounts of cerium, titanium, aluminum, zirconium, nickel, and manganese can be quantified on a metal basis, regardless of the form in which these metals may exist. For example, the amounts of these metals can be expressed as weight percentages based on the total weight of the metals in the catalyst (i.e., on a metal basis), that is, calculated without including oxygen or non-metal counterions in the calculation. Thus, in various embodiments of the present disclosure described herein, the total amount of cerium, titanium, aluminum, zirconium, manganese, and nickel in the catalyst is at least 90 wt%, for example, at least 95 wt%, or at least 98 wt% on a metal basis. For example, in some specific embodiments, the total amount of cerium, manganese, and nickel in the catalyst is at least 90 wt%, for example, at least 95 wt%, or at least 98 wt% on a metal basis. In other embodiments, the total amount of titanium, manganese, and nickel in the catalyst is at least 90 wt%, for example, at least 95 wt%, or at least 98 wt% on a metal basis. In other embodiments, the total amount of aluminum, manganese, and nickel in the catalyst is at least 90 wt%, for example, at least 95 wt%, or at least 98 wt% on a metal basis. In other embodiments, the total amount of zirconium, manganese, and nickel in the catalyst is at least 90 wt%, for example, at least 95 wt%, or at least 98 wt% on a metal basis.

[0030] As described above, the catalyst described in this specification is mostly composed of cerium, titanium, aluminum, zirconium, manganese, and nickel. In some embodiments described in this specification, the catalyst has an additional metal content of 10% by weight or less based on the total weight of the catalyst. The additional metal may be any metal other than nickel, manganese, cerium, titanium, aluminum, or zirconium. For example, the additional metal may be selected from alkali metals, alkaline earth metals, rare earth metals, other coinage metals, noble metals, or other transition metals. For example, in various embodiments, the catalyst has an additional metal content of 5% by weight or less, or 2% by weight or less, or 2% by weight or less based on the total weight of the catalyst. In some embodiments described in this specification, the catalyst has a copper content of 10% by weight or less based on the total weight of the catalyst. For example, in various embodiments, the catalyst has a copper content of 5% by weight or less, or 2% by weight or less, or 1% by weight or less based on the total weight of the catalyst. In some embodiments described in this specification, the catalyst has an alkali metal content of 10% by weight or less based on the total weight of the catalyst. For example, in various embodiments, the catalyst has an alkali metal content of 5% by weight or less, or 2% by weight or less, or 1% by weight or less based on the total weight of the catalyst. In some embodiments described in this specification, the catalyst has an alkaline earth metal content of 10% by weight or less based on the total weight of the catalyst. For example, in various embodiments, the catalyst has an alkaline earth metal content of 5% by weight or less, or 2% by weight or less, or 1% by weight or less based on the total weight of (a) and (b).

[0031] As described above, the supported catalyst contains manganese and nickel. Depending on the synthesis method, these species typically exist mainly in the metallic and / or oxide forms and can be located at various different sites on the support. For example, they can be found in the pores of the support and on the outer surface of the support. They can be found, for example, substantially throughout the support as in the case where a large amount of impregnation liquid is used, or only in the surface layer of the support when the impregnation liquid does not penetrate throughout the support, as in the case where the incipient wetness technique is used.

[0032] Although not bound by theory, the active form of nickel is typically considered to be substantially in the metallic form. As described below, since nickel can exist substantially in the oxide form after catalyst preparation and during transport and storage, it is typically desirable to activate the catalyst by contacting it with a reducing agent, such as hydrogen gas, to convert a substantial portion of such oxides to the metallic form. However, those skilled in the art will understand that the present disclosure contemplates the usefulness of the various nickel forms in the catalyst, because these can be active or can be conveniently converted to an active form.

[0033] Manganese is typically provided in the oxide form after catalyst preparation and during transport and storage. Although not bound by theory, the inventors believe that manganese acts to improve the catalytic activity of the supported nickel catalyst by reducing CO methanation that can occur over a typical reverse water-gas shift reaction temperature range that affects CO selectivity. The inventors believe that the improved activity can be attributed to manganese in contact with the interface of both nickel and the support (e.g., cerium oxide, titanium oxide, aluminum oxide, zirconium oxide, or mixed oxides). However, those skilled in the art will understand that the present disclosure contemplates the usefulness of the various manganese forms in the catalyst, because these can provide a promoting effect or can be conveniently converted to a form that provides a promoting effect.

[0034] Those skilled in the art will understand that the catalysts of the present disclosure can be provided in many forms, especially depending on the specific form of the reactor system in which they are used, for example, in a fixed bed or as a fluidized bed. The carrier itself can be provided as a discrete body of material, for example, as porous particles, pellets, or shaped extrudates, with nickel and manganese provided thereon to provide the catalyst. However, in other embodiments, the catalysts of the present disclosure can be formed as a layer on a substrate below. The underlying substrate is not particularly limited. It can be formed, for example, from a metal or metal oxide and can itself be provided in many forms such as particles, pellets, shaped extrudates, or monoliths. Of course, as will be understood by those skilled in the art, other embodiments may be possible.

[0035] Another aspect of the present disclosure provides a method for producing the catalysts described herein. As described above, the method includes providing a carrier that is a cerium oxide carrier, a titanium oxide carrier, an aluminum oxide carrier, a zirconium oxide carrier, or a mixed oxide carrier containing two or more of cerium oxide, titanium oxide, aluminum oxide, and zirconium oxide, contacting the carrier with one or more liquids each containing one or more nickel-containing compounds and / or one or more manganese-containing compounds dispersed in a solvent, evaporating the solvent to provide a catalyst precursor, and calcining the catalyst precursor. Those skilled in the art will of course understand that other methods can be used to produce the catalysts described herein.

[0036] In some embodiments of the present disclosure described herein, contacting the support with the liquid includes adding the liquid in an amount approximately equal to the pore volume of the support (i.e., within 25% or within 10%). In other embodiments, contacting the support with the liquid includes adding the liquid in an amount greater than the pore volume of the support. For example, in some embodiments, the ratio of the amount of the liquid to the amount of the support is in the range of 0.75:1 to 5:1, for example, in the range of 0.9:1 to 3:1 on a mass basis. In some embodiments, a slurry is obtained by contacting the support with the liquid.

[0037] In various embodiments of the present disclosure described herein, evaporating the solvent is carried out at ambient temperature. In various embodiments, evaporating the solvent is carried out at an elevated temperature during the drying time. One skilled in the art can select an appropriate apparatus or equipment for evaporating the solvent, and such an apparatus or equipment is not particularly limited. Further, one skilled in the art will understand that the elevated temperature for evaporating the solvent depends on the boiling point of the solvent. Thus, one skilled in the art will be able to select an appropriate elevated temperature. For example, in some embodiments, the elevated temperature ranges from 50 to 150 °C, such as from 50 to 120 °C, or from 50 to 100 °C, or from 100 to 150 °C, or from 100 to 120 °C. In some embodiments, the drying time ranges from 1 to 48 hours, such as from 10 to 36 hours, or from 12 to 24 hours. For example, in certain embodiments, the drying time is about 24 hours. In some embodiments, evaporating the solvent is carried out under vacuum and at an elevated temperature over the drying time as described herein. In some embodiments, evaporating the solvent is carried out in a stirred drying bath at an elevated temperature, such as in the range of 30 to 100 °C.

[0038] In some embodiments of the present disclosure described herein, firing the catalyst precursor is carried out in a furnace at a firing time and a firing temperature. For example, in some embodiments, the firing time ranges from 0.5 to 24 hours, or from 0.5 to 15 hours, or from 0.5 to 10 hours, or from 0.5 to 5 hours. In some embodiments, the firing temperature ranges from 100 to 600 °C, such as in the range of 120 to 500 °C.

[0039] As described above, the method for preparing the catalyst described herein includes contacting a support with one or more liquids each containing one or more nickel-containing compounds and / or one or more manganese-containing compounds dispersed in a solvent. The nickel and manganese-containing compounds are not particularly limited, and those skilled in the art can select appropriate compounds that are soluble in the solvent. For example, in some embodiments of the present disclosure described herein, the nickel and manganese-containing compounds can be selected from salts (such as nitrates and acetates). The solvent is also not particularly limited, and those skilled in the art can select an appropriate solvent that can be absorbed by the support. For example, in some embodiments of the present disclosure described herein, the solvent is water. As will be understood by those skilled in the art, these metal species are conveniently provided in the same liquid, and as a result, only one step of contacting the support with the liquid is required. However, other schemes are also possible.

[0040] In another aspect, the present disclosure provides a catalyst described herein prepared by the method described herein.

[0041] Reverse water gas shift reaction Another aspect of the present disclosure provides a method for carrying out the reverse water gas shift reaction. As described above, the method includes contacting the catalyst described herein with a feed stream containing CO2 and H2 at a temperature in the range of 500 to 900 °C to provide a product stream containing CO and H2, wherein the product stream has a lower CO2 concentration and a higher CO concentration than the feed stream. An example of such a method is schematically shown in FIG. 1. In FIG. 1, method 100 includes performing the reverse water gas shift reaction by feeding a feed stream 111 consisting of H2 and CO2 to a reaction zone, such as a reactor 110 here. The reverse water gas shift catalyst 113 described herein contacts the feed stream 111 at a temperature in the range of 500 to 900 °C to provide a product stream 112 containing CO and H2. The product stream has a lower concentration of CO2 and a higher concentration of CO than the feed stream.

[0042] As used herein, "feed stream" is used to mean all of the materials introduced into a process step, whether provided in a single physical stream or multiple physical streams, and whether through a single inlet or multiple inlets. For example, the H2 and CO of the feed stream can be provided to the reverse water gas shift catalyst in a single physical stream (e.g., a single pipe to reactor 110), or in multiple physical streams (e.g., separate inlets for CO and H2, or one inlet for fresh CO and H2 and another inlet for recycled CO and / or H2). Similarly, "product stream" is used to mean all of the materials output from a process step, whether provided in a single physical stream or multiple physical streams, and whether through a single outlet or multiple outlets.

[0043] In various embodiments of the disclosure described herein, the reverse water gas shift reaction has a CO selectivity of at least 50%, such as at least 60%, or 70%, or 80%, or 90%. As used herein, the "selectivity" of a given reaction product is the mole fraction of the feed (here CO2) that is converted to the product (with respect to "CO selectivity", for CO). The inventors have determined that the present catalyst can provide excellent selectivity for CO, even when operating at a lower temperature than many conventional reverse water gas shift catalysts and despite the potential for competition by the Sabatier reaction and the methanation of CO. For example, in various embodiments of the disclosure described herein, the reverse water gas shift reaction has a CO selectivity in the range of 50 to 99 wt%. For example, in various embodiments, the reverse water gas shift reaction has a CO selectivity in the range of 50 to 90 wt%, or 50 to 80 wt%, or 50 to 70 wt%, or 50 to 60 wt%, or 60 to 99 wt%, or 60 to 90 wt%, or 60 to 80 wt%, or 60 to 70 wt%, or 70 to 99 wt%, or 70 to 90 wt%, or 70 to 80 wt%.

[0044] In particular, the catalysts described herein can be operated to provide carbon monoxide with only a very small degree of methane formation. For example, in various embodiments of the present disclosure described herein, the reverse water gas shift reaction has a methane selectivity of 40% or less, such as 35% or less, or 30% or less, or 25% or less, or 20% or less. For example, in various embodiments of the present disclosure described herein, the reverse water gas shift reaction has a methane selectivity of 10% or less, such as 8% or less. For example, in various embodiments of the present disclosure described herein, the reverse water gas shift reaction has a methane selectivity of 5% or less, such as 4% or less. For example, in some embodiments, the reverse water gas shift reaction has a methane selectivity of 2% or less, such as 1% or less. In some embodiments, the reverse water gas shift reaction has a methane selectivity of 0.5% or less, such as 0.4% or less.

[0045] The inventors have determined that the catalysts described herein can provide commercially relevant conversion rates with desirably high CO selectivity and desirably low methane selectivity. As used herein, "conversion" is the mole fraction of feedstock that is reacted (to either the desired product or an undesired species). In various embodiments of the disclosure described herein, the reverse water gas shift reaction has a CO2 conversion of at least 5%, for example, at least 10% or 20%. For example, in some embodiments, the reverse water gas shift reaction has a CO2 conversion of at least 30%, for example, at least 40% or 50% or 60%. In various embodiments of the disclosure described herein, the reverse water gas shift reaction has a CO2 conversion of 90% or less, for example, 80% or less or 70% or less. For example, in some embodiments, the reverse water gas shift reaction has a CO2 conversion of 65% or less, for example, 60% or less. For example, in various embodiments separately described herein, the CO2 conversion is in the range of 10 - 90%, for example, 10 - 80% or 10 - 70% or 10 - 60% or 10 - 65% or 20 - 90% or 20 - 80% or 20 - 70% or 20 - 60% or 20 - 65% or 30 - 90% or 30 - 80% or 30 - 70% or 30 - 60% or 30 - 65% or 40 - 90% or 40 - 80% or 40 - 70% or 40 - 60% or 40 - 65%. One of ordinary skill in the art will operate at a degree of conversion that provides the desired product based on the disclosure herein. Of course, in other embodiments, for example, when in a packed bed or mixed bed system, the CO2 conversion can be even higher than that described herein.

[0046] Advantageously, the processes described herein can be carried out at temperatures lower than those used in many conventional reverse water gas shift processes. As described above, the various processes of the present disclosure can be carried out in the temperature range of 500 to 900 °C. For example, in the various embodiments of the present disclosure described herein, the method for carrying out the reverse water gas shift reaction is in the range of 500 to 850 °C, for example, 500 to 800 °C, or 500 to 750 °C, or 500 to 700 °C, or 500 to 650 °C, or 500 to 600 °C. In some embodiments, the method for carrying out the reverse water gas shift reaction is in the range of 550 to 900 °C, for example, 550 to 850 °C, or 550 to 800 °C, or 550 to 750 °C, or 550 to 700 °C, or 550 to 650 °C, or 550 to 600 °C. In some embodiments, the method for carrying out the reverse water gas shift reaction is in the range of 600 to 900 °C, for example, 600 to 850 °C, or 600 to 800 °C, or 600 to 750 °C, or 600 to 700 °C, or 600 to 650 °C. In some embodiments, the method for carrying out the reverse water gas shift reaction is in the range of 650 to 900 °C, for example, 650 to 850 °C, or 650 to 800 °C, or 650 to 750 °C, or 650 to 700 °C. In some embodiments, the method for carrying out the reverse water gas shift reaction is in the range of 700 to 900 °C, for example, 700 to 850 °C, or 700 to 800 °C, or 700 to 750 °C.

[0047] In some embodiments, the reverse water gas shift reaction is carried out at a temperature in the range of 200 to 500 °C, for example, 200 to 450 °C, or 200 to 400 °C, or 200 to 350 °C, or 250 to 500 °C, or 250 to 450 °C, or 250 to 400 °C, or 250 to 350 °C. The inventors have noted that operation at these temperatures can provide a lower energy requirement.

[0048] As described above, the feed stream contains CO2 and H2. Advantageously, the inventors have recognized that both of these can be derived from renewable or other environmentally responsible sources. For example, at least a portion of the H2 can be so-called "green" hydrogen generated, for example, from the electrolysis of water operated using renewable electricity (such as wind, solar, or hydroelectric power). In other embodiments, at least a portion of the H2 can be from a so-called "blue" source, such as from a natural gas reforming process with carbon capture. Of course, other hydrogen sources can be used in part or in whole. For example, in some embodiments, at least a portion of the H2 in the feed stream is gray hydrogen, black hydrogen, brown hydrogen, pink hydrogen, turquoise hydrogen, yellow hydrogen, and / or white hydrogen. CO2 can generally be captured from the environment or more directly from processes that form CO2 (especially in sectors where it is difficult to remove), and at least carbon-neutral CO can be used to produce products made later. For example, in some embodiments, at least a portion of the CO2 is from direct air capture or from manufacturing plants such as bioethanol plants (e.g., CO2-producing fermentation), steel mills, or cement factories. Thus, the rWGS reaction can not only be carbon-neutral but can also, in some cases, be a net consumer of carbon dioxide. These advantages make the rWGS reaction very attractive for decarbonizing transportation fuels for both the automotive and aircraft sectors, especially since the carbon monoxide produced in the reaction can be readily utilized by well-established technologies for synthesizing liquid hydrocarbon fuels.

[0049] The feed stream contains both H2 and CO2 (e.g., provided to the reaction zone in a single physical stream or multiple physical streams). As used herein, the feed stream includes all feeds to the process, whether provided as a mixture of gases or as gases provided individually to the reaction zone. In various embodiments described herein, the molar ratio of H2 to CO2 in the feed stream is at least 0.1:1, e.g., at least 0.5:1. In some embodiments, the molar ratio of H2 to CO2 in the feed stream is at least 0.9:1, e.g., 1:1 or at least 1.5:1. In some embodiments, the molar ratio of H2 to CO2 in the feed stream is at least 2:1, e.g., at least 2.5:1. In some embodiments, the molar ratio of H2 to CO2 in the feed stream is 100:1 or less, e.g., 75:1 or less, or 50:1 or less. In some embodiments, the molar ratio of H2 to CO2 in the feed stream is 20:1 or less, e.g., 15:1 or less, or 10:1 or less. For example, in some embodiments, the molar ratio of H2 to CO2 in the feed stream is in the range of 0.5:1 to 10:1. One of ordinary skill in the art, based on the disclosure herein, will be able to provide the desired ratio of H2:CO2 in the feed stream that provides the desired conversion and selectivity, and, when consistent with the desired conversion and selectivity, provide an excess of H2 to flow through the system and provide a product stream having the desired ratio of H2 to CO for downstream processes.

[0050] Other gases may also be included in the feed stream. For example, in some embodiments, the feed stream further includes CO. In some embodiments of the present disclosure described herein, the feed stream further includes one or more inert gases. For example, in some embodiments, the feed stream further includes nitrogen and / or methane.

[0051] The processes described herein can be carried out at various pressures, as will be understood by those skilled in the art. In various embodiments of the present disclosure, the method for performing the reverse water gas shift reaction is carried out at a pressure in the range of 1 to 100 barg. For example, the method can be carried out at a pressure in the range of 1 to 70 barg, or 1 to 50 barg, or 1 to 40 barg, or 1 to 35 barg, or 5 to 70 barg, or 5 to 50 barg, or 5 to 40 barg, or 5 to 35 barg, or 10 to 70 barg, 10 to 50 barg, or 10 to 40 barg, or 10 to 35 barg, or 20 to 70 barg, 20 to 50 barg, or 20 to 40 barg, or 20 to 35 barg, or 25 to 70 barg, 25 to 50 barg, or 25 to 40 barg, or 25 to 35 barg.

[0052] The processes described herein can be carried out at various GHSVs (gas hourly space velocities), as will be understood by those skilled in the art. Thus, the GHSV for carrying out the reverse water gas shift reaction is not particularly limited. For example, in some embodiments of the present disclosure, the method for carrying out the reverse water gas shift reaction is carried out at a GHSV in the range of 1,000 to 2,000,000 h-1. In various embodiments, the method for carrying out the reverse water gas shift reaction is 1,000 to 1,200,000 h-1, or 1,000 to 500,000 h-1, or 1,000 to 100,000 h-1, or 5,000 to 1,200,000 h-1, or 5,000 to 500,000 h-1, or 5,000 to 100,000 h-1, or 10,000 to 1,200,000 h-1, or 10,000 to 500,000 h-1, or 10,000 to 100,000 h-1. In various embodiments of the present disclosure, the method for carrying out the reverse water gas shift reaction is 1,000 to 50,000 h-1, or 2,000 to 50,000 h-1, or 5,000 to 50,000 h-1, or 10,000 to 50,000, or 1,000 to 40,000 h-1, or 2,000 to 40,000 h-1, or 5,000 to 40,000 h-1, or 10,000 to 40,000 h-1, or 1,000 to 30,000 h-1, or 2,000 to 30,000 h-1, or 5,000 to 30,000 h-1, or 10,000 to 30,000 h-1, and is carried out at a GHSV in this range.

[0053] The rWGS catalysts described herein are partially nickel-based. Typically, it is desirable to activate the rWGS catalyst, for example, before contacting it with a feed stream. Thus, in some embodiments of the present disclosure described herein, the method includes activating the rWGS catalyst before contacting the catalyst with a feed stream. For example, in some embodiments, activating the catalyst includes contacting the catalyst with a reducing gas, such as a reducing stream containing hydrogen. In various embodiments of the present disclosure, the reducing stream contains hydrogen in an amount of at least 25 mol%, for example, at least 50 mol%, or 75 mol%, or 90 mol%. Those skilled in the art will determine the conditions suitable for the reductive activation of the rWGS catalyst. Thus, those skilled in the art will be able to select the appropriate temperature, pressure, and time for activating the rWGS catalyst. For example, in various embodiments, the activation of the catalyst is carried out at a temperature in the range of 200 °C to 800 °C. In some embodiments, activating the catalyst is carried out at a temperature in the range of 250 °C to 800 °C, or 300 °C to 800 °C, or 200 °C to 700 °C, or 250 °C to 800 °C, or 300 °C to 700 °C. In some embodiments of the present disclosure described herein, activating the catalyst provides a catalyst that is reduced by at least 10% (for example, at least 25%, or at least 50% reduced).

[0054] The inventors have found that by contacting an rWGS catalyst as described herein with a feed stream, a product stream having advantageously high CO selectivity and low methane selectivity can be provided. The amount of CO in the product stream can be further controlled by the rWGS reaction conditions as described above. However, generally, methods for performing an rWGS reaction as described herein provide a product stream comprising H2 and CO, and the product stream has a lower concentration of CO2 and a higher concentration of CO than the feed stream, so as to match the degree of conversion described herein. For example, in various embodiments, the product stream comprises 95 mol% or less of CO2, or 90 mol% or less of CO2. In some embodiments, the product stream comprises 85 mol% or less of CO2, or 80 mol% or less of CO2. In other examples, the product stream comprises 75 mol% or less, or 70 mol% or less of CO2. However, as described above, the inventors have determined that it may be desirable to operate the process at an intermediate degree of conversion in order to provide the desired high CO selectivity and the desired low methane selectivity. Thus, in various embodiments described separately herein, the product stream comprises a certain amount of CO2 together with CO.

[0055] Other gases may also be included in the product stream. In some embodiments of the disclosure described separately herein, the product stream further comprises one or more inert gases. These inert gases may be included from the feed stream or may be provided from a source other than the feed stream. For example, in some embodiments, the product stream further comprises nitrogen and / or methane.

[0056] In particular, depending on the conversion degree, CO selectivity, relative amounts of H2 and CO2 in the feed stream, and reaction conditions, the product stream can contain H2 in various ratios in combination with CO. For example, in some embodiments, the H2:CO ratio in the product stream ranges from 0.1:1 to 100:1 (e.g., from 0.1:1 to 50:1, or from 0.1:1 to 25:1, or from 0.1:1 to 10:1, or from 0.1:1 to 5:1, or from 1:1 to 100:1, or from 1:1 to 50:1, or from 1:1 to 25:1, or from 1:1 to 10:1, or from 1:1 to 5:1).

[0057] One of ordinary skill in the art will understand that, based on the methods described herein, the product stream can contain various amounts of H2, CO, and CO2, as well as other components. The components of the product stream can be separated and used for various purposes in the rWGS process.

[0058] For example, in various embodiments of the present disclosure described herein, the method further includes separating the product stream and recycling at least a portion (e.g., at least 5 mol%, at least 10 mol%, at least 25 mol%, at least 50 mol%, at least 75 mol%, or at least 90 mol%) of one or more components of the product stream to the feed stream. For example, if the product stream contains CO2, the method can include recycling at least a portion (e.g., at least 5 mol%, at least 10 mol%, at least 25 mol%, at least 50 mol%, at least 75 mol%, or at least 90 mol%) of the CO2 in the product stream to the feed stream. The product stream may also contain H2, and in some embodiments, the method further includes recycling at least a portion (e.g., at least 5 mol%, at least 10 mol%, at least 25 mol%, at least 50 mol%, at least 75 mol%, or at least 90 mol%) of the H2 in the product stream to the feed stream.

[0059] Such recycling is shown in process 100 of FIG. 1 (and FIG. 2). Here, process 100 includes separating at least a portion (stream 114) of CO2 from product stream 112 for recycling to feed stream 111. Similarly, process 100 includes separating at least a portion (stream 115) of H2 from product stream 112 and recycling it to product stream 111. Stream 115 is shown as entering reactor 110 through an inlet different from the remainder of feed stream 111, but since it is part of the material input to the process steps, it is considered to be part of the feed stream.

[0060] As described above, one competing reaction in the reverse water gas shift reaction is the Sabatier reaction that produces methane. In various embodiments, the reverse water gas shift process described herein can be carried out without forming large amounts of methane, although in some embodiments some methane can be formed. Thus, in various embodiments of the methods described herein, the product stream comprises one or more light hydrocarbons. For example, in some embodiments, the product stream can comprise one or more of methane, ethane, propane, or combinations thereof. As will be appreciated by those skilled in the art, it may be desirable to operate the reverse water gas shift reaction to provide a greater amount of light hydrocarbons in the product feed. For example, such light hydrocarbons can be inert in further processing of the product stream and can therefore be tolerated in higher amounts. Those skilled in the art will be able to select appropriate reaction conditions (e.g., temperature, pressure, feed stream composition) to provide a product stream containing methane in the desired amount. Thus, in various embodiments described elsewhere herein, the product stream comprises 40 mol% or less, or 35 mol% or less, or 30 mol% or less, or 25 mol% or less, or 20 mol% or less, or 15 mol% or less, or 10 mol% or less methane. As described above, when it is desirable to have a lower amount of methane in the product stream, the catalysts of the present disclosure can provide very low methane selectivity. For example, in various embodiments, the product stream comprises 5 mol% or less, or 1 mol% or less, or 0.5 mol% or less methane. Generally, light hydrocarbons (e.g., C1-C5 hydrocarbons) can be present in the product stream. For example, in various embodiments described elsewhere herein, the product stream comprises 20 mol% or less light hydrocarbons (e.g., 15 mol% or less, 10 mol% or less, 5 mol% or less, 1 mol% or less, 0.5 mol% or less, or 0.1 mol% or less light hydrocarbons).

[0061] The light hydrocarbons (e.g., C1-C5 hydrocarbons) in the product stream can be separated and used for other purposes. For example, in various embodiments, the method further comprises separating at least a portion of one or more light hydrocarbons from the product stream to provide a light hydrocarbon stream. For example, in method 100 of FIG. 1, at least a portion of one or more light hydrocarbons is separated from product stream 112 to provide light hydrocarbon stream 116. The light hydrocarbon stream can be used, for example, to provide other products, can be partially oxidized to form CO, can be steam reformed to provide hydrogen, and / or can be combusted to provide heat or other energy (e.g., electricity for electrolysis) for use in the rWGS process or other processes.

[0062] Of course, as will be understood by those skilled in the art, the light hydrocarbon stream can be used in other processes as well. For example, as will be understood by those skilled in the art, some rWGS catalysts can have reforming capabilities. Without being bound by theory, the inventors hypothesize that one explanation for the low methane production observed using the rWGS catalysts described herein is that methane is formed but is then immediately reformed to CO and H2. Thus, in some embodiments described herein, the light hydrocarbons in the process stream are recycled to the feed stream for the rWGS reaction. These light hydrocarbons can be separated and used for other purposes. For example, in various embodiments, the method further comprises separating at least a portion of one or more light hydrocarbons from the first product stream to provide a light hydrocarbon stream. For example, in process 100 of FIG. 2, at least a portion of one or more light hydrocarbons is separated from the first product stream 112 to provide a light hydrocarbon stream 118. The light hydrocarbon stream can be used, for example, to provide other products, can be partially oxidized to form CO, can be steam reformed to provide hydrogen, and / or can be combusted to provide heat or other energy (e.g., electricity for electrolysis) for use in an integrated process or other method. Of course, as will be understood by those skilled in the art, the light hydrocarbon stream can be used in other processes as well.

[0063] Integrated Fischer-Tropsch process In some embodiments described herein, the supported reverse water gas can be used in an rWGS process integrated with an FT process. Embodiments related to the reverse water gas shift portion of the integrated FT process are as described above in the previous section. For example, the feed stream of the rWGS process corresponds to the first feed stream in the integrated FT process, and the product stream of the rWGS process corresponds to the first product stream in the integrated FT process.

[0064] Another aspect of the present disclosure provides a process for carrying out an integrated Fischer-Tropsch process (i.e., integrated with the rWGS process). The method includes providing a first feed stream comprising H2 and CO2, and contacting the reverse water gas shift catalyst described herein with the first feed stream at a first temperature in the range of 500 to 900 °C and a first pressure to carry out a reverse water gas shift reaction to provide a first product stream comprising CO and H2, the first product stream having a lower CO2 concentration and a higher CO concentration than the first feed stream. An example of such a process is schematically shown in FIG. 2. In FIG. 2, process 100 includes carrying out a reverse water gas shift reaction by feeding a first feed stream 111 consisting of H2 and CO2, here to a first reaction zone, for example, reactor 110. The reverse water gas shift catalyst 113 described herein contacts the feed stream 111 at a first temperature in the range of 500 to 900 °C and a first pressure to provide a first product stream 112 comprising CO and H2. The first product stream has a lower concentration of CO2 and a higher concentration of CO than the first feed stream. The method of this aspect of the present disclosure also includes contacting a Fischer-Tropsch catalyst with a second feed stream comprising H2 and at least a portion of the CO of the first product stream at a second temperature and a second pressure to provide a second product stream comprising C5+ hydrocarbons. In the method 100 of FIG. 2, at least a portion of the CO of the first product stream 112 is included in the second feed stream 121, which is here contacted with a Fischer-Tropsch catalyst 123 in a second reaction zone (e.g., reactor 120). This provides a second product stream 122 comprising C5+ hydrocarbons.

[0065] The inventors have found that by contacting an rWGS catalyst as described herein with a first feed stream, a first product stream having advantageously high CO selectivity and low methane selectivity can be provided. The amount of CO in the first product stream can be further controlled by the rWGS reaction conditions as described above.

[0066] However, as described above, the inventors have determined that it may be desirable to operate the process at an intermediate conversion in order to provide desirably high CO selectivity and desirably low methane selectivity. Further, the inventors have noted that it may be advantageous to operate a downstream Fischer-Tropsch process with a relatively high level of inert, and thus believe that it may be beneficial to pass a significant amount of CO2 through the Fischer-Tropsch process step. Accordingly, in various embodiments described herein, the first product stream contains a certain amount of CO2 along with CO. In various embodiments, the first product stream contains from 5 to 95 mole % CO2, such as from 5 to 90 mole %, or from 5 to 85 mole %, or from 5 to 80 mole %, or from 5 to 75 mole %, or from 5 to 70 mole %, or from 10 to 95 mole %, or from 10 to 90 mole %, or from 10 to 85 mole %, or from 10 to 80 mole %, or from 10 to 75 mole %, or from 10 to 70 mole %, or from 20 to 95 mole %, or from 20 to 90 mole %, or from 20 to 85 mole %, or from 20 to 80 mole %, or from 20 to 75 mole %, or from 20 to 70 mole %, or from 30 to 95 mole %, or from 30 to 90 mole %, or from 30 to 85 mole %, or from 30 to 80 mole %, or from 30 to 75 mole %, or from 30 to 70 mole % CO2.

[0067] Furthermore, as described below, Fischer-Tropsch catalysts typically require activation by a reducing gas. As will be understood by those skilled in the art, different Fischer-Tropsch catalysts require different activation conditions (e.g., gas composition, temperature, pressure, time). For example, iron-based Fischer-Tropsch catalysts require activation by both H2 and CO, while cobalt-based Fischer-Tropsch catalysts require activation by H2 only. Thus, this activation can be carried out using H2 and CO or H2 only from the first product stream. Thus, in various embodiments described elsewhere herein, the method comprises separating at least a portion of H2 and CO (preferably in a ratio of at least 1:1 or at least 3:1) from the first product stream, and contacting it with a Fischer-Tropsch catalyst to activate the Fischer-Tropsch catalyst. In various other embodiments described elsewhere herein, the method comprises separating at least a portion of H2 from the first product stream, and contacting it with a Fischer-Tropsch catalyst to activate the Fischer-Tropsch catalyst. For example, in the process of Figure 2, stream 125 separates H2 or H2 and CO and directs it to reactor 120. This separation does not need to be continuous; rather, it may be carried out for only as long as desired to supply the reducing gas to the Fischer-Tropsch catalyst for activation. Of course, as will be understood by those skilled in the art, other sources of H2 or CO may be used to supply the reducing gas to the Fischer-Tropsch catalyst for activation.

[0068] As shown above, water is a product of the reverse water gas shift reaction. Thus, the first product stream generally contains water. In many cases, it is desirable to reduce the amount of water fed to the Fischer-Tropsch process step. Accordingly, in various embodiments described elsewhere herein, the process further includes removing at least a portion (e.g., at least 25%, at least 50%, or at least 75%) of the water from the first product stream. In the embodiment of FIG. 2, a water removal zone 116 is used to remove water and provide a water-containing stream 117. Those skilled in the art will understand that various processes can be used to remove water from the first product stream. For example, the first product stream can be contacted with a water scavenger to remove water therefrom. For example, a molecular sieve guard bed can be used to remove water from the first product stream, and the water can be recovered from the molecular sieve of the guard bed, for example, by heating and vacuum. In other embodiments, a knockout vessel can be used. However, the use of a knockout vessel may, in some cases, be able to sufficiently cool the first product stream so that it is desirably reheated for introduction into the Fischer-Tropsch process step. The water removed from the first product stream can be used, for example, as feed water for the electrolysis process described herein.

[0069] As described above, the reverse water gas shift process can be provided at a variety of temperatures. In some cases, these temperatures may be relatively close to the temperatures of subsequent Fischer-Tropsch process steps (often 150-400 °C, e.g., 200-350 °C, or other temperatures described below). In other cases, the reverse water gas shift process can be carried out at temperatures significantly higher than the temperatures of the Fischer-Tropsch process. The inventors have noted that it may be desirable to provide heat exchange with a relatively hot first product stream to cool the first product stream to an appropriate temperature by the Fischer-Tropsch process and provide heat elsewhere in the integrated process. For example, in various embodiments of the processes described elsewhere herein, the process further includes exchanging heat between at least a portion of the first product stream and at least a portion of the first feed stream, thereby cooling at least a portion of the first product stream and heating at least a portion of the first feed stream. An example of such a process is schematically shown in FIG. 3. In FIG. 3, process 200, first reactor 210, first feed stream 211, first product stream 212, reverse water gas shift catalyst 213, second reactor 220, second feed stream 221, second product stream 222, and Fischer-Tropsch catalyst 223 are generally as described above. Here, process 200 includes exchanging heat between at least a portion of the first product stream 212 and at least a portion of the first feed stream 211 in a first heat exchange zone 230, thereby cooling at least a portion of the first product stream 212 and heating at least a portion of the first feed stream 211. Those skilled in the art will understand that a variety of heat exchangers can be used for this purpose.

[0070] Of course, any excess heat in the first product stream can additionally or alternatively be used for other purposes. For example, in various embodiments, the process further includes exchanging heat between at least a portion of the first product stream and a steam generation zone, thereby cooling at least a portion of the first product stream and providing heat to the steam generation zone. This is shown in FIG. 3. Here, after heat exchange with the first feed stream 211, the first product stream 212 is directed to the steam generation zone 232, cooling the first product stream 212 and providing heat to the steam generation zone 232. Steam can be generated from the supplied heat, and electricity can be generated from the steam. For example, in the embodiment of FIG. 3, the electric current 264 is provided by generating electricity using the steam generated in the steam generation zone 232. Of course, as will be understood by those skilled in the art, the steam generated in the steam generation zone may be used in other processes. In various embodiments, the steam may be used to heat the first feed stream. For example, in the embodiment of FIG. 3, the steam stream 266 generated in the steam generation zone 232 is directed to the heat exchange zone 290 to heat the first feed stream 211.

[0071] As described above, at least a portion of the CO in the first product stream is included in the second feed stream for use in the reaction in the Fischer-Tropsch process. For example, in various embodiments described elsewhere herein, at least 25% of the CO in the first product stream, such as at least 50%, at least 75%, or at least 90% of the CO in the first product stream, is included in the second feed stream. Of course, as described above, a portion of the CO in the first product stream can be used for other purposes, such as for catalyst activation as described herein.

[0072] In some embodiments, substantially all of the CO in the second feed stream comes from the first product stream. However, in other embodiments, the CO can be provided to the second feed stream from a fossil-derived or other alternative source. For example, in various embodiments, the CO is provided to the second feed stream from a CO source other than the first product stream. In FIG. 3, the flow of CO 226a from other sources is included in the second feed stream 221. One of ordinary skill in the art will understand that the CO can be provided from various sources, such as gasification, reforming, or electrochemical CO2 reduction. Further, as described in more detail below, the CO can be recycled from the second product stream to the second feed stream; and / or provided by reaction of a light hydrocarbon stream, for example, by partial oxidation or reforming (e.g., steam reforming and / or autothermal reforming).

[0073] As described above, the second feed stream contains H2. In particular, the first product stream often contains, for example, unreacted H2 from the first feed stream. In various embodiments, the first product stream contains H2 and the second feed stream contains at least a portion of the H2 in the first product stream. For example, in various embodiments as described elsewhere herein, at least 25% of the H2 in the first product stream, such as at least 50% of the H2 in the first product stream, at least 75% of the H2, or at least 90% of the H2, is included in the second feed stream. Of course, as described above, a portion of the H2 in the first product stream can be used for other purposes, such as for catalyst activation as described herein.

[0074] In some embodiments, substantially all of the H2 of the second feed stream is derived from the first product stream. In fact, one of ordinary skill in the art can supply more H2 than is required for the water gas shift reaction in the first feed stream, supply excess H2 in the first product stream, and then supply the desired amount of H2 to the second feed stream for the Fischer-Tropsch process step. However, in other embodiments, H2 can be provided to the second feed stream from other sources. For example, in various embodiments, H2 is provided to the second feed stream from an H2 source other than the first product stream. In FIG. 3, the H2 stream 226b from another source is included in the second feed stream 221. One of ordinary skill in the art will understand that H2 can be supplied from various sources, such as gasification, reforming, or H2O electrolysis (including the electrolysis described herein). Further, as described in more detail below, H2 can be recycled from the second product stream to the second feed stream.

[0075] Based on the disclosure herein, one of ordinary skill in the art can adjust the relative amounts of H2 and CO in the second feed stream to provide the desired ratio. For example, more or less H2 from the first feed stream and / or more or less H2 from electrolysis can be included in the second feed stream. Similarly, more or less CO from the first feed stream and more or less CO from other sources (such as partial oxidation and reforming as described below) can be included in the second feed stream.

[0076] As described above, the Fischer-Tropsch process steps may desirably be carried out in the presence of significant levels of inert substances. One such inert substance, CO2, can be provided from the reverse water gas shift, for example, via a first product stream. Thus, in various embodiments described herein, the second feed stream comprises at least a portion of the CO2 of the first product stream. For example, in various embodiments, at least 10% of the CO2 of the first product stream, such as at least 25% of the CO2 of the first product stream, at least 50% of the CO2, at least 75% of the CO2, or at least 90% of the CO2 of the first product stream, is included in the second feed stream. Of course, in other embodiments, the second feed stream may contain no substantial amount of the CO2 of the first product stream. Thus, in various embodiments, the second feed stream contains no substantial amount of the CO2 of the first product stream. Generally, it may be desirable to recycle CO2 to the first feed stream for use in the reverse water gas shift reaction, but as will be described in more detail below, unreacted CO2 can be recycled from the second product stream to the first feed stream.

[0077] However, additionally or alternatively, it may be desirable for the second feed stream to contain additional inert components, which may be CO2 or other inert substances such as nitrogen and methane. For example, in various embodiments, one or more inert substances (e.g., CO2, nitrogen, and / or methane) are provided to the second feed stream from a source other than the first product stream. In FIG. 3, the flow of inert substance 226c from another source is included in the second feed stream 221. Those skilled in the art will understand that the inert substances can be provided from various sources. Further, as will be described in more detail below, the inert substances can be recycled from the second product stream to the second feed stream.

[0078] As described above, it may be desirable to carry out the Fischer-Tropsch process steps in the presence of an inert substance. Thus, in various embodiments described separately herein, a portion of the first product stream contained in the second feed stream has a CO2 content in the range of 10 to 95 mol% CO2, such as 10 to 90 mol%, or 10 to 85 mol%, or 10 to 80 mol%, or 10 to 75 mol%, or 10 to 70 mol%, or 20 to 95 mol%, or 20 to 90 mol%, or 20 to 85 mol%, or 20 to 80 mol%, or 20 to 70 mol%, or 30 to 95 mol%, or 30 to 90 mol%, or 30 to 85 mol%, or 30 to 80 mol%, or 30 to 75 mol%, or 30 to 70 mol% CO2.

[0079] Other gases may also be included in the second feed stream as described above. For example, as described above, it may be desirable to carry out the Fischer-Tropsch process step in the presence of a significant amount of an inert substance (i.e., a component other than H2 or CO). For example, in various embodiments, the second feed stream contains up to 80 mol% of one or more inert substances, such as one or more inert substances in the range of 3 to 80 mol%, or 5 to 80 mol%, or 10 to 80 mol%, or 15 to 80 mol%, or 30 to 80 mol%. In various embodiments, the second feed stream contains up to 70 mol% of an inert substance, up to 60 mol% of an inert substance, or up to 50 mol% of an inert substance, such as 3 to 70 mol%, or 5 to 70 mol%, or 10 to 70 mol%, or 15 to 70 mol%, or 30 to 70 mol%, or 3 to 60 mol%, or 5 to 60 mol%, or 10 to 60 mol%, or 30 to 60 mol%, or 3 to 50 mol%, or 5 to 50 mol%, or 10 to 50 mol%, or 15 to 50 mol%, or 30 to 50 mol% of an inert substance. In various embodiments, the second feed stream contains up to 80%, such as up to 70 mol%, up to 60 mol%, or up to 50 mol%, or 15 to 70 mol%, or 30 to 70 mol%, or 15 to 60 mol%, or 30 to 60 mol%, or 15 to 50 mol%, or 30 to 50 mol% of one or more inert substances selected from CO2, methane, and nitrogen. In various embodiments, the second feed stream contains up to 80 mol%, such as up to 70 mol%, up to 60 mol%, or up to 50 mol%, or 15 to 70 mol%, or 30 to 70 mol%, or 15 to 60 mol%, or 30 to 60 mol%, or 15 to 50 mol%, or 30 to 50 mol% of CO2.

[0080] One skilled in the art can adjust the portion of the first product stream included in the second feed stream to provide a desired H2:CO ratio. For example, in various embodiments, a portion of the first product stream included in the second feed stream has an H2:CO ratio in the range of 0.5:1 to 10:1, such as in the range of 1:1 to 2.5:1. Of course, no matter what the H2:CO ratio of a portion of the first product stream included in the second feed stream is, one skilled in the art can add H2 or CO as described above as needed to provide the desired ratio in the entire second feed stream.

[0081] As described above, the second feed stream contains both H2 and CO, and regardless of whether the second feed stream is provided as a mixture of feeds or as feeds provided separately to the reaction zone, the second feed stream includes all feeds to the Fischer-Tropsch reactor. In various embodiments of the present disclosure described herein, the second feed stream has an H2:CO ratio in the range of 0.5:1 to 6:1. In some embodiments, the second feed stream has an H2:CO ratio in the range of 1:1 to 3:1, or 1:1 to 2.5:1. In some embodiments, the second feed stream has an H2:CO ratio of at least 1.4:1. For example, in some embodiments, the second feed stream has an H2:CO ratio in the range of 1.4:1 to 3:1, or 1.4:1 to 2:1. One skilled in the art will provide the desired ratio of H2:CO in the second feed stream based on the disclosure herein that provides the desired conversion rate and selectivity in the Fischer-Tropsch process.

[0082] As described above, it may be desirable to reduce the amount of water sent to the Fischer-Tropsch process step. Thus, in various embodiments described separately herein, a portion of the first product stream included in the second feed stream has a water content of 10 mol% or less, such as, or 2 mol% or less, or 0.5 mol% or less.

[0083] Also, as described above, it may be desirable to carry out the Fischer-Tropsch process in the presence of a relatively small amount of water. Thus, in various embodiments, the second feed stream has a water content of 10 mol% or less, for example, or 2 mol% or less, or 0.5 mol% or less.

[0084] The methods described herein include contacting a Fischer-Tropsch catalyst with a second feed stream as described herein. The Fischer-Tropsch catalyst for use in the methods described herein is not particularly limited, and one of ordinary skill in the art will be able to select a catalyst appropriate for the desired Fischer-Tropsch product. In some embodiments, the Fischer-Tropsch catalyst comprises cobalt, iron, rhodium, ruthenium, or combinations thereof.

[0085] For example, in some embodiments of the present disclosure described herein, the Fischer-Tropsch catalyst comprises cobalt in an amount in the range of 5 to 25 wt%, calculated as Co(0). The terms "calculated as Co(0)" and similar terms mean that the weight of the cobalt atoms / ions themselves is used in the calculation and not the total amount of any compound or polynuclear ion to which those cobalt atoms / ions may be bound. For example, in various embodiments, the Fischer-Tropsch catalyst comprises cobalt in an amount in the range of 7 to 25 wt%, or 10 to 25 wt%, or 5 to 20 wt%, or 7 to 20 wt%, or 10 to 20 wt%, calculated as Co(0). As will be appreciated by those skilled in the art, cobalt-based catalysts are often provided to the reaction zone in the form of cobalt oxide on a support, and the cobalt can be reductively activated in situ (e.g., with H2) to provide an active catalyst species having a significant concentration of Co(0).

[0086] In some embodiments, the Fischer-Tropsch catalyst comprises iron in an amount in the range of 5 to 95 weight percent, calculated as Fe(0). For example, in various embodiments, the Fischer-Tropsch catalyst comprises iron in an amount in the range of 10 to 95 weight percent, or 25 to 95 weight percent, or 50 to 95 weight percent, or 5 to 85 weight percent, or 10 to 85 weight percent, or 25 to 85 weight percent, or 50 to 85 weight percent, or 5 to 75 weight percent, or 10 to 75 weight percent, or 25 to 75 weight percent, calculated as Fe(0). As will be understood by those skilled in the art, iron-based catalysts are often supplied to the reaction zone, optionally on a support, in the form of metallic iron or iron oxide, and the iron is activated (e.g., by reaction with H2 and CO) to provide active catalyst species having a significant concentration of iron carbide.

[0087] In various embodiments described herein, particularly when the catalyst is a cobalt-based catalyst, the Fischer-Tropsch catalyst further comprises manganese. For example, in various embodiments, the Fischer-Tropsch catalyst comprises manganese in an amount up to 15 weight percent, for example, up to 12 weight percent, or up to 10 weight percent, or up to 7 weight percent, calculated as Mn(0). In certain such embodiments, the catalyst material comprises manganese in an amount in the range of 0.1 to 15 weight percent, for example, 0.1 to 10 weight percent, or 0.1 to 5 weight percent, 0.5 to 15 weight percent, or 0.5 to 10 weight percent, or 0.5 to 5 weight percent, or calculated as Mn(0). Of course, in other embodiments, manganese is substantially absent (e.g., less than 0.1 weight percent or less than 0.5 weight percent of manganese is present).

[0088] The Fischer-Tropsch catalysts suitable for use in the methods described herein can be in various forms and are not particularly limited. For example, the Fischer-Tropsch catalyst can be a supported catalyst or an unsupported catalyst. The form of the catalyst is not particularly limited, but in various desirable embodiments, the Fischer-Tropsch catalyst is a supported catalyst, and the support includes at least one of titanium oxide, zirconium oxide, cerium oxide, aluminum oxide, silicon oxide, and zinc oxide. For example, in various embodiments, the support includes at least one of titanium oxide, aluminum oxide, and silicon oxide. In some embodiments of the present disclosure described herein, the support is a titanium dioxide support.

[0089] One of ordinary skill in the art will understand that the Fischer-Tropsch catalysts of the present disclosure can be provided in many forms, depending, for example, on the particular form of the reactor system in which they are used, such as in a fixed bed or as a fluidized bed. The support of the Fischer-Tropsch catalyst can itself be provided as a discrete body of material, such as porous particles, pellets, or shaped extrudates, on which a metal is provided to provide the Fischer-Tropsch catalyst. However, in other embodiments, the Fischer-Tropsch catalysts of the present disclosure can themselves be formed as a layer on a underlying substrate. The underlying substrate is not particularly limited. It can be formed, for example, from a metal or metal oxide and can itself be provided in many forms, such as particles, pellets, shaped extrudates, or monoliths. One of ordinary skill in the art will select the Fischer-Tropsch catalyst appropriate for a particular reactor system.

[0090] Similar to the rWGS catalyst, the Fischer-Tropsch catalyst is typically activated prior to use to provide, for example, cobalt(0) species on a cobalt-based catalyst or iron carbide species on an iron-based catalyst. Such activation can be performed before contacting the Fischer-Tropsch catalyst with a second feed stream.

[0091] For example, in some embodiments, the Fischer-Tropsch catalyst is activated by contact with a reducing gas. For example, hydrogen can be a particularly suitable gas for activating the Fischer-Tropsch catalyst, such as in the case of many cobalt-based catalysts, for example, when the activation is a reduction to metal(0) species. In various embodiments of the present disclosure described elsewhere herein, the reducing gas comprises at least a portion of the H2 from the first product stream. For example, in some embodiments, the method further comprises separating at least a portion of the H2 of the first product stream and contacting it with the Fischer-Tropsch catalyst to activate the Fischer-Tropsch catalyst. In process 100 schematically shown in FIG. 2, at least a portion of hydrogen stream 125 is separated from the first product stream 112 and contacted with the Fischer-Tropsch catalyst 123 to activate it. In other embodiments, the H2 present in the second feed stream can be used to activate the catalyst. As will be understood by those skilled in the art, the activation temperature can vary depending on the Fischer-Tropsch catalyst used. Thus, those skilled in the art will be able to select an appropriate temperature for activating the catalyst, for example, in the range of 200-400 °C.

[0092] In various embodiments, the Fischer-Tropsch catalyst is activated by contact with H2 and CO. This can be particularly appropriate when the activation results in conversion to carbide, for example, in the case of many iron-based catalysts. In various embodiments of the present disclosure described herein, the reducing gas comprises at least a portion of H2 and CO from the first product stream. For example, in some embodiments, the method further comprises separating at least a portion of the H2 and at least a portion of the CO of the first product stream and contacting it with the Fischer-Tropsch catalyst to activate the Fischer-Tropsch catalyst. In process 200 schematically shown in FIG. 3, at least a portion of the H2 and CO stream 227 is separated from the first product stream 212 and contacted with the Fischer-Tropsch catalyst 223 to activate it. In other embodiments, the catalyst can be activated using H2 and CO present in a second feed stream. The activation temperature can vary, for example, in the range of 200 to 400 °C.

[0093] As described above, the method comprises contacting the Fischer-Tropsch catalyst with a second feed stream at a second temperature and a second pressure. One of ordinary skill in the art will select the appropriate reaction conditions in relation to the specific feedstock and catalyst used to provide the desired Fischer-Tropsch process. In some embodiments of the present disclosure described herein, the second temperature is in the range of 150 to 400 °C. For example, in various embodiments, the second temperature is in the range of 150 to 350 °C, or 150 to 300 °C, or 150 to 250 °C, or 150 to 200 °C, or 200 to 400 °C, or 200 to 350 °C, or 200 to 300 °C, or 200 to 250 °C, or 250 to 400 °C, or 250 to 350 °C, or 250 to 300 °C, or 300 to 400 °C. In some specific embodiments, the second temperature is in the range of 200 to 350 °C.

[0094] In particular, in many embodiments, the first temperature and the second temperature can be relatively close to each other. The inventors have noted that the reverse water gas shift catalysts described herein can provide suitable activity and CO selectivity even at relatively low temperatures. Thus, the first product stream can be provided at a temperature close to, or at least suitable for, the Fischer-Tropsch reaction process. This can desirably provide an increase in process integration. For example, in various embodiments, the first temperature is within 100 °C of the second temperature, such as within 50 °C of the second temperature, or within 25 °C of the second temperature.

[0095] However, in other embodiments, the first temperature and the second temperature are not so close to each other. The inventors have noted that in many cases, the desired reverse water gas shift process temperature is significantly higher than the desired Fischer-Tropsch process temperature. For example, in various embodiments, the first temperature is at least 100 °C higher than the second temperature, such as at least 150 °C higher than the second temperature, or at least 200 °C higher than the second temperature. The excess heat in the first product stream can be used for many purposes, such as to preheat at least a portion of the first feed stream, or as described above, to generate steam for use in power generation.

[0096] In some embodiments of the disclosure described herein, the second pressure ranges from 10 to 50 barg. For example, in various embodiments, the second pressure ranges from 20 to 50 barg, or 25 to 50 barg, or 10 to 40 barg, or 20 to 40 barg, or 25 to 40 barg, or 10 to 35 barg, or 20 to 35 barg, or 25 to 35 barg. In some embodiments, the second pressure ranges from 20 to 50 barg.

[0097] The Fischer-Tropsch process described in this specification can be carried out at various GHSV (gas hourly space velocity) values, as will be understood by those skilled in the art. Thus, the GHSV for carrying out the Fischer-Tropsch reaction is not particularly limited. For example, in some embodiments of the present disclosure, the method for carrying out the Fischer-Tropsch reaction is carried out at a GHSV in the range of 1,000 to 2,000,000 h-1. In various embodiments, the method for carrying out the reverse water gas shift reaction is carried out at a GHSV in the range of 1,000 to 1,200,000 h-1, or 1,000 to 500,000 h-1, or 1,000 to 100,000 h-1, or 5,000 to 1,200,000 h-1, or 5,000 to 500,000 h-1, or 5,000 to 100,000 h-1, or 10,000 to 1,200,000 h-1, or 10,000 to 500,000 h-1, or 10,000 to 100,000 h-1. In various embodiments of the present disclosure, the method for carrying out the Fischer-Tropsch reaction is carried out at a GHSV in the range of 1,000 to 50,000 h-1, or 2,000 to 50,000 h-1, or 5,000 to 50,000 h-1, or 10,000 to 50,000, or 1,000 to 40,000 h-1, or 2,000 to 40,000 h-1, or 5,000 to 40,000 h-1, or 10,000 to 40,000 h-1, or 1,000 to 30,000 h-1, or 2,000 to 30,000 h-1, or 5,000 to 30,000 h-1, or 10,000 to 30,000 h-1.

[0098] The Fischer-Tropsch process is typically used to produce C5+ hydrocarbons, such as unsubstituted C5+ hydrocarbons (e.g., alkanes and alkenes) and oxygenated C5+ hydrocarbons (e.g., C5+ alcohols, aldehydes, ketones, carboxylic acids). In various embodiments of the present disclosure described herein, contacting a Fischer-Tropsch catalyst with a second feed stream to provide a second product stream is performed with at least 30%, for example, at least 50%, or at least 70% C5+ selectivity (i.e., with respect to all C5+ species). For example, in some embodiments, the selectivity to C5+ alkanes is at least 30%, for example, at least 50%, or at least 70%. In some embodiments, the selectivity to C5+ alkanes and C5+ alcohols is at least 30%, for example, at least 50%, or at least 70%.

[0099] Additional components may be present in the second product stream. For example, in some embodiments, the second product stream contains water, which is another product of the Fischer-Tropsch reaction. Also, one or more light hydrocarbons (i.e., C1-C4) may be present as by-products. CO and / or H2 may be present, for example, as unreacted materials from the second feed stream. CO2 or other inert substances described herein may also be present. Such components of the second product stream can be separated and / or recycled in various ways.

[0100] For example, in various embodiments, the method further includes separating at least a portion of the water from the second product stream. This is schematically illustrated in FIG. 4. In the embodiment of FIG. 4, the reverse water gas shift catalyst 313 and the Fischer-Tropsch catalyst 323 are provided in separate beds within the same reactor. Thus, the first reaction zone 310 is the volume of the reactor 305 that includes the bed 314 containing the reverse water gas shift catalyst 313, and the second reaction zone 320 is the volume of the reactor 305 that includes the bed 324 containing the Fischer-Tropsch catalyst 323. The first feed stream 311 contacts the reverse water gas shift catalyst 313 to provide a first product stream 312, which is sent directly to the Fischer-Tropsch catalyst 323 as the second feed stream 321 to provide a second product stream 322. Here, the method also optionally includes separating at least a portion (e.g., at least 50%, at least 75%, or at least 90%) of the water from the second product stream 322 to provide a water-containing stream 334.

[0101] Light hydrocarbons are often not the desired portion of the Fischer-Tropsch products used as fuels or lubricants, but are useful in themselves for many purposes. Thus, in various embodiments, the method further includes separating at least a portion of the C1-C4 hydrocarbons from the second product stream to provide a light hydrocarbon stream. The light hydrocarbon stream can be recycled, for example, to the first feed stream or the second feed stream. For example, in the process 200 of FIG. 3, the light hydrocarbons can be provided as part of a recycle stream 236 that is part of the second feed stream 221. In the process 300 of FIG. 4, the light hydrocarbons can be provided as part of a recycle stream 336 that is part of the first feed stream 311. In the process 400 of FIG. 5, the light hydrocarbons are recycled to the first feed stream 411 via a recycle stream 442.

[0102] The light hydrocarbon stream has other uses. For example, in some embodiments, the method further includes oxidizing at least a portion of the light hydrocarbon stream to provide a CO and / or CO2-containing partial oxidation (pOX) stream, and including at least a portion of the pOX stream in the first feed stream and / or the second feed stream. An example of such a process is schematically shown in FIG. 5, where process 400, first feed stream 411, first product stream 412, reverse water gas shift catalyst 413, second feed stream 421, second product stream 422, and Fischer-Tropsch catalyst 423 may be as described elsewhere herein. Here, the process includes oxidizing at least a portion of the light hydrocarbon stream 450 in the partial oxidation reaction zone 452 to provide a pOX stream containing CO and / or CO2, and including at least a portion of the pOX stream 454 in the first feed stream 411 and / or the second feed stream 421.

[0103] Other methods can be used to provide CO and / or CO2 from the light hydrocarbon stream. For example, reforming techniques such as steam reforming and autothermal reforming can be used to provide CO by reacting hydrocarbons with water. Thus, in various embodiments, the method further includes reforming (e.g., steam reforming and / or autothermal reforming) at least a portion of the light hydrocarbon stream to provide a reformed stream containing CO and / or CO2, and including at least a portion of the reformed stream in the first feed stream and / or the second feed stream. Water separated from the first and / or second product streams can be provided as part of the feed to the reforming described herein.

[0104] Furthermore, a light hydrocarbon stream can be combusted to provide thermal energy, which can be used to heat various process streams or generate electricity. Thus, in various embodiments, the process includes combusting at least a portion of the light hydrocarbon stream to provide energy, such as thermal energy or electrical energy. For example, in process 400 of FIG. 5, a portion of light hydrocarbon stream 450 is combusted in a power generation zone (here, generator 470) to produce an electric current 472. In various embodiments, the thermal energy may be used to provide the heat load required for the reverse water gas shift process. For example, in process 400 of FIG. 5, a portion of light hydrocarbon stream 450 is combusted in a heat generation zone (here, heat generator 480) to produce a heat stream 482. Heat stream 482 is directed to heat exchange zone 490 to heat a first feed stream 411. Thermal energy can similarly be supplied to the Fischer-Tropsch reaction. Also, as will be understood by those skilled in the art, other processing of the light hydrocarbon stream (e.g., partial oxidation) can provide energy, which can be used, for example, as described herein.

[0105] Similar to the first product stream, heat can be exchanged from the second product stream to supply heat, for example, to a feed stream or a steam generation zone. For example, in various embodiments, the method further includes exchanging heat between at least a portion of the second product stream and at least a portion of the first feed stream, thereby cooling at least a portion of the second product stream and heating at least a portion of the first feed stream. In process 300 of FIG. 4, heat is exchanged between at least a portion of the second product stream 322 and the first feed stream 311 within the second heat exchange zone 330, thereby cooling the second product stream 322 and heating the first feed stream 311. Of course, heat can also be exchanged from the second product stream to the second feed stream. For example, in various embodiments, the method further includes exchanging heat between at least a portion of the second product stream and at least a portion of the second feed stream, thereby cooling at least a portion of the second product stream and heating at least a portion of the second feed stream. In process 400 of FIG. 5, heat is exchanged between at least a portion of the second product stream 422 and the second feed stream 421 within the second heat exchange zone 430, thereby cooling the second product stream 422 and heating the second feed stream 421. Those skilled in the art will understand that a wide variety of heat exchangers can be used for this purpose.

[0106] Of course, any excess heat in the second product stream can be additionally or alternatively used for other purposes. For example, in various embodiments, the process further includes exchanging heat between at least a portion of the second product stream and a steam generation zone, thereby cooling at least a portion of the second product stream and providing heat to the steam generation zone. This is shown in FIG. 4. Here, after heat exchange with the first feed stream 311, the second product stream 322 is directed to the steam generation zone 332 to cool the second product stream 322 and provide heat to the steam generation zone 332. Steam can be generated from the supplied heat, and electricity can be generated from the steam (not shown here).

[0107] It may be desirable to recycle hydrogen from the second product stream to, for example, the first feed stream and / or the second feed stream. For example, in various embodiments, the process includes recycling at least a portion of the H2 in the second product stream to the second feed stream. For example, in the process of FIG. 3, at least a portion (e.g., at least 25%, at least 50%, or at least 75%) of the H2 in the second product stream can be recycled to the second feed stream 221 via recycle stream 236. In various embodiments, the method includes recycling at least a portion of the H2 in the second product stream to the first feed stream. For example, in the process of FIG. 4, at least a portion (e.g., at least 25%, at least 50%, or at least 75%) of the H2 in the second product stream can be recycled to the first feed stream 311 via recycle stream 336. In various embodiments, at least 25%, for example, at least 50% of the H2 in the second product stream is recycled to the first feed stream or the second feed stream. In various embodiments, at least 75%, for example, at least 90% of the H2 in the second product stream is recycled to the first feed stream or the second feed stream.

[0108] In some cases, for example, when H2 is provided to the second feed stream from an H2 source other than the first product stream, the H2 from the second product stream can constitute a majority, e.g., at least 90%, at least 95%, or at least 98% of the H2 in the first feed stream. This is shown, for example, in FIG. 5. Here, the primary H2 input to the process passes through a stream 440 that is part of the second feed stream 421. The H2 in the second product stream is included in recycle stream 442, which becomes part of the first feed stream 411.

[0109] Similarly, it may be desirable to recycle the CO of the second product stream, for example, to the first feed stream and / or the second feed stream. For example, in various embodiments, the process includes recycling at least a portion of the CO of the second product stream to the second feed stream. For example, in the process of FIG. 3, at least a portion (e.g., at least 25%, at least 50%, or at least 75%) of the CO of the second product stream can be recycled to the second feed stream 221 via recycle stream 236. In various embodiments, the method includes recycling at least a portion of the CO of the second product stream to the first feed stream. For example, in the process of FIG. 4, at least a portion (e.g., at least 25%, at least 50%, or at least 75%) of the CO of the second product stream can be recycled to the first feed stream 311 via recycle stream 336. In various embodiments, at least 25%, for example, at least 50% of the CO of the second product stream is recycled to the first feed stream or the second feed stream. In various embodiments, at least 75%, for example, at least 90% of the CO of the second product stream is recycled to the first feed stream or the second feed stream.

[0110] Often, both the CO and H2 of the second product stream are recycled.

[0111] Furthermore, when using one or more inert substances in the Fischer-Tropsch process step, it may be desirable to recycle them. For example, in various embodiments, the process includes recycling at least a portion of the inert substances of the second product stream to the second feed stream. For example, in the process of FIG. 3, at least a portion (e.g., at least 25%, at least 50%, or at least 75%) of the inert substances of the second product stream can be recycled to the second feed stream 221 via the recycle stream 236. In various embodiments, the process includes recycling at least a portion of the inert substances of the second product stream to the first feed stream. For example, in the process of FIG. 4, at least a portion (e.g., at least 25%, at least 50%, or at least 75%) of the inert substances of the second product stream can be recycled to the first feed stream 311 via the recycle stream 336. In various embodiments, at least 25%, e.g., at least 50% of the inert substances of the second product stream are recycled to the first feed stream or the second feed stream. In various embodiments, at least 75%, e.g., at least 90% of the inert substances of the second product stream are recycled to the first feed stream or the second feed stream. In various embodiments, the purge stream can be incorporated with the recycle stream to prevent uncontrolled accumulation of inert substances in the recycle stream (not shown here).

[0112] Specifically, since CO2 is the carbon source in the reverse water gas shift process step, it may be particularly desirable to recycle CO2 to the first feed stream. Thus, in various embodiments, the process includes recycling at least a portion (e.g., at least 50%, at least 75%, or at least 90%) of the CO2 of the second product stream to the first feed stream. For example, in the process of FIG. 4, at least a portion (e.g., at least 50%, at least 75%, or at least 90%) of the CO2 of the second product stream can be recycled to the first feed stream 311 via the recycle stream 336.

[0113] In some cases, for example, when CO2 is provided from a CO2 source other than the first product stream to the second feed stream, the CO2 from the second product stream can constitute a majority of the CO2 in the first feed stream, for example, at least 90%, at least 95%, or at least 98% of the CO2 in the first feed stream. This is shown, for example, in FIG. 5. Here, the primary CO2 input to the process passes through a stream 440 that is part of the second feed stream 421. The CO2 in the second product stream is included in the recycle stream 442, which becomes part of the first feed stream 411.

[0114] As described above, the Fischer-Tropsch process step provides a second product stream that includes C5+ hydrocarbons (e.g., unsubstituted hydrocarbons such as alkanes and alkenes, and / or oxygenated hydrocarbons such as alcohols). Thus, in various embodiments, one or more products are provided from at least a portion of the C5+ hydrocarbons in the second product stream. The C5+ hydrocarbons can be used as a basis for various fuels such as gasoline, diesel, and aviation fuel. Other products such as waxes and lubricants can also be manufactured. Also, alkenes and oxygenates can be used as feedstocks in various other processes.

[0115] One of ordinary skill in the art will use conventional post-treatment techniques to convert the C5+ hydrocarbon-containing product into a desired product such as a desired fuel. For example, in various embodiments, the method further includes hydrotreating at least a portion of the C5+ hydrocarbons in the second product stream. As will be understood by one of ordinary skill in the art, hydrotreating is the treatment of a hydrocarbon stream with hydrogen in the presence of a suitable catalyst. A wide variety of hydrotreating techniques are known, and one of ordinary skill in the art will apply them here. For example, in the process 300 of FIG. 4, the second product stream 322 is hydrotreated in a hydrotreating reactor 350 to provide a hydrotreated product stream 352.

[0116] As described above, CO2 and H2 are substantial inputs to the claimed process. Advantageously, the inventors recognize that each of these can be provided from renewable or other environmentally responsible sources.

[0117] CO2 can generally be captured from the environment or more directly from processes that form CO2 (particularly in sectors where it is difficult to remove). This can make the final hydrocarbon product substantially carbon neutral or of lower carbon intensity. Thus, in some embodiments of the disclosure described herein, at least a portion of the CO2 in the first feed stream and / or the second feed stream is from a renewable source. In some embodiments, at least a portion (e.g., at least 25%, at least 50%, or at least 75%) of the CO2 in the first feed stream and / or the second feed stream is from direct air capture. In some embodiments, at least a portion (e.g., at least 25%, at least 50%, or at least 75%) of the CO2 in the first feed stream and / or the second feed stream is from a manufacturing plant such as a bioethanol plant (e.g., CO2-producing fermentation), a steel mill, or a cement factory. Thus, the rWGS-Fischer Tropsch integrated process of the disclosure described herein is not only carbon neutral but, in some cases, can be a net consumer of carbon dioxide. These advantages make an integrated approach very attractive for decarbonizing transportation fuels for both the automotive and aviation sectors, since the carbon monoxide produced in the rWGS reaction can be readily utilized by established techniques for synthesizing liquid hydrocarbon fuels by the Fischer Tropsch process.

[0118] Similarly, H2 can be provided from environmentally responsible sources. In some embodiments, at least a portion of the H2 in the first feed stream and / or the second feed stream is from renewable sources. For example, in various embodiments, at least a portion (e.g., at least 25%, at least 50%, or at least 75%) of the H2 in the first feed stream and / or the second feed stream can be so-called "green" hydrogen produced, for example, from the electrolysis of water operated using renewable electricity (such as wind, solar, or hydroelectric power). In some embodiments, at least a portion (e.g., at least 25%, at least 50%, or at least 75%) of the H2 in the first feed stream and / or the second feed stream can be from so-called "blue" sources, for example, from natural gas reforming processes with carbon capture. Of course, other H2 sources can be used in part or in whole. For example, in some embodiments, at least a portion (e.g., at least 25%, at least 50%, or at least 75%) of the H2 in the first feed stream and / or the second feed stream is grey hydrogen, black hydrogen, brown hydrogen, pink hydrogen, turquoise hydrogen, yellow hydrogen, and / or white hydrogen.

[0119] The inventors have noted that the electrolysis of water is a desirable method for providing hydrogen to the claimed process. Thus, in some embodiments, the method includes providing at least a portion of the H2 to the first feed stream and / or the second feed stream by electrolysis of water. However, the inventors have noted that electricity can be generated as part of the claimed process, for example, using heat exchange from the first or second product stream or by burning light hydrocarbons as described above. In some embodiments, the electrolysis of water is performed using at least partially electricity generated according to the process described herein. For example, in process 200 of FIG. 3, water 262 separated from the first product stream is electrolyzed in electrolyzer 260 using electricity 264 generated from steam created in steam generation zone 232 by heat exchange from the first product stream. The H2 generated by electrolysis is supplied to the first feed stream via stream 265. In some embodiments, at least a portion of the O2 generated by electrolysis is provided to the partial oxidation reaction zone as described herein and shown in the embodiment of FIG. 7. Hydrogen from electrolysis can also be burned to provide thermal energy, for example, this can be used to heat the first feed stream.

[0120] The processes described herein can be operated in a wide variety of reactor systems. In some embodiments, a first reaction zone (i.e., where the reverse water gas shift process step is performed) includes a first reactor in which a reverse water gas shift catalyst is disposed, and a second reaction zone (i.e., where the Fischer-Tropsch process step is performed) includes a second reactor in which a Fischer-Tropsch catalyst is disposed. Examples of such processes are schematically shown in FIGS. 1, 2, and 4. In these examples, the processes (100, 200, 400) are carried out in a reactor system that includes a first reactor (110, 210, 410) in which a reverse water gas shift catalyst (113, 213, 413) is disposed and a second reactor (120, 220, 420) in which a Fischer-Tropsch catalyst (123, 223, 423) is disposed. The reactors used in the integrated processes of the present disclosure described herein are not particularly limited, and those skilled in the art can select appropriate reactors.

[0121] However, other embodiments are possible. For example, in some embodiments, the process is carried out in a reactor system that includes a first catalyst bed in which a reverse water gas shift catalyst is disposed, and the second reaction zone includes a second catalyst bed in which a Fischer-Tropsch catalyst is disposed. In some embodiments, the first reactor bed and the second reactor bed are disposed within the same reactor. Such a configuration is shown in FIG. 4, where the reverse water gas shift catalyst 313 is disposed in the first catalyst bed 314 and the Fischer-Tropsch catalyst 323 is disposed in the second catalyst bed 324. Here, the catalyst beds 314 and 324 are within the same reactor 305 and process gas flows between them. Such a configuration is particularly desirable when the first temperature and the second temperature are relatively close to each other.

[0122] In various embodiments, the method is carried out in a reactor system that includes one or more first catalyst vessels in which a reverse water gas shift catalyst is disposed, and the second reaction zone includes one or more second catalyst vessels in which a Fischer-Tropsch catalyst is disposed. These can be provided within the same reactor as described above with respect to the catalyst beds.

[0123] As described above, the reverse water gas shift process step and the Fischer-Tropsch process step using the nickel catalyst described in this specification can be carried out under similar conditions. Therefore, in various embodiments, the reverse water gas shift catalyst and the Fischer-Tropsch catalyst can be provided together in the same catalyst bed, for example, can be mixed together. Such an embodiment is shown in FIG. 6. Here, the process 500 is carried out in a reactor system including a reactor 505, in which the reverse water gas shift catalyst 513 and the Fischer-Tropsch catalyst 523 are mixed together in a single catalyst bed 524. Here, the first feed stream 511 and the second product stream 522 can be substantially as described in this specification. The first product stream and the second feed stream are understood to be a mixture of process gases in the mixed catalyst.

[0124] Particularly in the above-described embodiments, separate rWGS catalysts and Fischer-Tropsch catalysts can be used, for example, in separate reactors, in separate regions of the same reactor, or even mixed in the same region of the reactor.

[0125] However, the inventors also note that there are certain commonalities between the rWGS catalysts described in this specification and certain Fischer-Tropsch catalysts. For example, as will be understood by those skilled in the art, manganese is a common modifier used in Fischer-Tropsch catalysts, particularly cobalt-based catalysts. The inventors also note that similar supports can be used for each.

[0126] Accordingly, in addition to the above configurations, the present inventors contemplate providing a single bifunctional catalyst having both reverse water gas shift activity and Fischer-Tropsch activity. Such a bifunctional catalyst contains both an rWGS-active catalyst metal and a Fischer-Tropsch-active catalyst metal in the same body. Those skilled in the art will understand that both the rWGS catalyst and the Fischer-Tropsch catalyst are supported catalysts, e.g., metal oxide-supported catalysts. Thus, in various embodiments of the present disclosure, the rWGS-active catalyst metal and the Fischer-Tropsch-active catalyst metal can be provided together on the same support to provide a bifunctional catalyst. For example, in some embodiments, the support of the bifunctional catalyst is itself provided as an individual body of material such as, e.g., porous particles, pellets, or shaped extrudates, and the rWGS-active catalyst metal and the FT-active catalyst metal are provided thereon to provide a bifunctional catalyst. The rWGS-active catalyst metal and the FT-active catalyst metal may be uniformly distributed throughout the support or may be distributed in discrete regions throughout the support. However, in other embodiments, the bifunctional catalyst of the present disclosure can itself be formed as a layer on a underlying substrate. For example, in some embodiments, the bifunctional catalyst is formed from a layer of the rWGS-active catalyst metal and a layer of the FT-active catalyst metal on a underlying substrate. The rWGS-active catalyst metal and the FT-active catalyst metal may be uniformly distributed on the underlying substrate. In other embodiments, the rWGS-active catalyst metal and the FT-active catalyst metal may be in separate regions on the underlying substrate. The underlying substrate is not particularly limited. It can be formed, e.g., from a metal or a metal oxide and can itself be provided in many forms such as, e.g., particles, pellets, shaped extrudates, or monoliths.

[0127] The dual-functional catalyst includes a support material, an rWGS active catalyst metal described herein, and a Fischer-Tropsch active catalyst metal described herein. For example, the dual-functional catalyst includes a support which is a metal oxide support described herein, nickel, manganese, and at least one of cobalt, iron, rhodium, and ruthenium. In some embodiments of the present disclosure, the dual-functional catalyst includes a support which is a metal oxide support described herein, nickel, manganese, and cobalt. In some embodiments of the present disclosure, the dual-functional catalyst includes a support including at least one of titanium oxide, zirconium oxide, cerium oxide, or aluminum oxide, nickel, manganese, and cobalt. In some embodiments, the dual-functional catalyst includes a titanium oxide support, nickel, manganese, and cobalt. For example, in some embodiments, the dual-functional catalyst includes a titanium oxide support, nickel present in an amount in the range of 0.05 to 10% by weight, manganese present in an amount in the range of 0.5 to 20% by weight, and cobalt present in an amount in the range of 7 to 25% by weight. The ratio of the rWGS active catalyst metal to the FT active catalyst metal in the dual-functional catalyst is not particularly limited, and those skilled in the art can select an appropriate ratio. For example, in some embodiments, the ratio of the rWGS active catalyst metal to the FT active catalyst metal in the dual-functional catalyst is at least 0.1:1. In various embodiments, the ratio of the rWGS active catalyst metal to the FT active catalyst metal in the dual-functional catalyst is at least 0.2:1, or 0.5, or 1:1.

[0128] Such catalysts can be used in embodiments such as those described with respect to FIG. 6. Those skilled in the art will select reaction conditions that provide an appropriate balance between the reverse water-gas shift activity and the Fischer-Tropsch activity.

[0129] Figure 7 is a schematic diagram of another integration process according to the present disclosure. Here, the reverse water gas shift and Fischer-Tropsch process steps are integrated with the partial oxidation of light hydrocarbons to provide CO and H2 to the Fischer-Tropsch process step, as described throughout this specification; electrolysis to provide H2 for the reverse water gas shift process step and O2 for partial oxidation; and various recycles and any feeds.

[0130] Based on the above general disclosure, those skilled in the art will provide the materials described herein and implement the processes with reference to the following examples.

Examples

[0131] The following examples illustrate specific embodiments of the catalysts and processes of the present disclosure, as well as their various uses. They are described for illustrative purposes only and should not be construed as limiting the scope of the present disclosure.

[0132] Example 1. Modeling The inventors modeled various equilibrium conditions of the reverse water gas shift reaction. The predicted carbon dioxide conversion and product composition of the rWGS reaction (Equation 1) competing with the Sabatier reaction (Equation 3) and the CO methanation reaction (Equation 4) were calculated based on thermodynamic equilibrium over a temperature range of 400 to 800 °C. From the modeling, the carbon monoxide selectivity increased at temperatures higher than 600 °C, while the methane selectivity decreased at higher temperatures.

[0133] From these results, it is clear that the Sabatier reaction (Equation (3)) and the CO methanation (Equation (4)) side reactions are exothermic and favorable at low temperatures, while the rWGS reaction (Equation (1)) is endothermic and favorable at high temperatures. However, other carbon-forming side reactions not described in this example can occur at high temperatures. Therefore, the inventors investigated catalysts operating at medium to high temperatures. These catalysts are discussed in more detail below.

[0134] Example 2. Preparation of Catalysts For the preparation of the catalyst, a conventional impregnation method was used before testing the effectiveness of the catalyst for the reverse water gas shift reaction. The supports used are shown in Table 1.

[0135]

Table 1

[0136] To prepare the catalyst, solutions of nickel(II) nitrate hexahydrate (purity 99.9985%, VWR) and manganese(II) acetate tetrahydrate (purity 99.9%, Fisher Chemicals) were prepared in deionized water. The nickel and manganese solutions were added to the support powder. The amount of support added was based on the amount of water on a mass basis, with a water:support ratio of 3:1. The slurry was then stirred at room temperature for 4 hours. Excess water was then evaporated using a stirring hotplate at a temperature of 60 °C. The resulting catalyst precursor powder was then dried in a drying oven at 90 °C for 24 hours.

[0137] This catalyst precursor powder was then subjected to calcination by spreading the powder evenly in a crucible. The crucible was placed in a firing furnace and the temperature was raised from ambient temperature to 120 °C at a rate of 10 °C per minute. The temperature was then held at 120 °C for 1 hour and then raised from 120 °C to 500 °C at a rate of 2 °C / min. The temperature was held at 500 °C for 4 hours and then cooled to ambient temperature. The resulting catalyst was then tested for its feasibility for the reverse water gas shift reaction.

[0138] Example 3. Performance of the nickel catalyst The catalysts prepared by the method described herein were then tested for their catalytic performance in the reverse water gas shift reaction. The catalysts tested were titania-supported catalysts containing 5 wt% nickel with 0 wt% or 5 wt% manganese. To test the catalytic performance of these catalysts, 20 μL of the catalyst diluted with SiC F100 to provide a ratio of 1:10 was loaded into a 3 mm ID ceramic tube reactor to obtain a 0.22 mL catalyst bed with a zone height of 31.1 mm. Prior to performing the rWGS reaction, the catalyst was activated at 590 °C for 5 h in a 97% hydrogen and 3% argon atmosphere. The catalyst was then contacted with a feed stream containing two different ratios of H2 and CO2 at two different temperatures. The total pressure was maintained at 10 barg. The GHSV for Tests 1 and 2 was 100,000 h-1, and the GHSV for Tests 3 - 6 was 120,000 h-1. Catalyst performance was analyzed by detecting the gas composition of the reactor outlet feed using a multi-detector gas chromatograph. The catalytic performance of these catalysts is shown in Table 2. In Table 2 and Tables 3 - 8 below, the amounts of nickel and / or manganese present in the catalyst are shown in parentheses. These values are in weight percent and are based on the total weight of the catalyst. For example, CeO2Ni(5)Mn(5) corresponds to a catalyst having 5 wt% Ni, 5 wt% Mn, and 90 wt% CeO2.

[0139]

Table 2

[0140] The addition of 5 wt% manganese to 5 wt% nickel supported on titania resulted in a loss of catalytic activity as indicated by a decrease in CO2 conversion, but an increase in CO selectivity.

[0141] Catalysts having nickel present at 0.5 wt%, 1 wt%, or 5 wt% and manganese present at 5 wt% on a titania or ceria support were tested at 600 °C, a H2:CO2 ratio of 2:1, a pressure of 30 barg, and a GHSV of 1,200,000 h-1. These results are reported in Table 3.

[0142]

Table 3

[0143] The results in Table 3 show that increasing the nickel content does not improve the selectivity of CO, but the CO2 conversion rate is improved.

[0144] Example 4. Influence of the carrier on the catalyst performance In addition, the influence of the carrier was investigated by evaluating nickel and manganese supported catalysts on various catalyst carriers (ceria, alumina, titania, and zirconia). The catalysts contained 5 wt% nickel and 5 wt% manganese. These catalysts were prepared by the method described herein, and the reactor setup and catalyst activation were used as described in Example 3. These catalysts were contacted at two different temperatures, a pressure of 10 barg, a GHSV of 800,000 h-1, and two different H2:CO2 ratios. The catalyst performance was analyzed by detecting the gas composition of the reactor outlet feed using a multi-detector gas chromatograph. The results are shown in Table 4.

[0145]

Table 4

[0146] Furthermore, these catalysts were contacted with a feed stream at a temperature of 700 °C, a ratio of H2 to CO2 of 2:1, a pressure of 20 barg, and a GHSV of 800,000 h-1. The results are shown in Table 5.

[0147]

Table 5

[0148] Tables 4 and 5 show that the performance of the nickel-manganese supported catalysts is reproduced with various support materials having a higher CO selectivity than that observed at 10 barg and a 1:1 H2:CO2 ratio. The methane selectivity increased as the temperature decreased from 760 °C to 700 °C. A further increase in methane selectivity was observed when the reaction pressure was doubled to 20 barg at 700 °C. Among all the supports tested in this study, the titania-supported nickel-manganese catalyst showed the lowest activity among all the supports but the highest CO selectivity under the tested conditions.

[0149] The high selectivity of the nickel-manganese supported catalysts makes them desirable candidates for medium- to high-temperature reverse water gas shift. The high yields and selectivities to CO demonstrated in the above tests provide an effluent stream suitable for integration with other processes.

[0150] Example 6. Influence of Catalyst Activation on Catalyst Performance The catalysts prepared as described in this specification were evaluated for the effect of catalyst activation on catalytic performance. The catalysts used in this study were a titania-supported catalyst with 5 wt% nickel and 5 wt% manganese, an alumina-supported catalyst with 5 wt% nickel and 5 wt% manganese, and a ceria-supported catalyst with 5 wt% nickel and 5 wt% manganese. These supported catalysts were activated at three different temperatures (400 °C, 590 °C, and 760 °C) in a hydrogen atmosphere and then used in the rWGS process. A ceramic tube reactor with an inner diameter of 3 mm was filled with 20 μL of the catalyst diluted with SiC F100 at a ratio of 1:10 to obtain a 0.22 mL catalyst bed with a zone height of 31.1 mm. The activation of the catalyst was carried out using pure H2 at a GHSV of 200,000 h-1. The reactor pressure was set to 10 barg, and then the reactor was heated to the desired activation temperature at a rate of 1 K / min and held at that temperature for 5 hours. After activation, the reactor was cooled to the temperature for the rWGS process. Four rWGS reaction temperatures, 400 °C, 500 °C, 600 °C, and 700 °C, were evaluated. When the rWGS reaction temperature was reached, the feed stream was introduced, and then the reaction pressure was set. The activated catalyst was contacted with a feed stream of H2 and CO2, with a molar ratio of 2:1, a pressure of 30 barg, and a GHSV of 1,200,000 h-1. The catalytic performance was analyzed by detecting the gas composition of the reactor outlet feed using a multi-detector gas chromatograph. The results are shown in Tables 6, 7, and 8.

[0151]

Table 6

[0152]

Table 7

[0153]

Table 8

[0154] For the titania-supported nickel and manganese catalyst, the alumina-supported nickel and manganese catalyst, and the ceria-supported nickel and manganese catalyst, the CO2 conversion rate increases as the reaction temperature rises and is constant over all activation temperatures.

[0155] The results in Tables 6 to 8 show that the activation temperature, reaction temperature, and type of support affect CO selectivity. The CO selectivity of the titania-supported nickel and manganese catalyst increases as the reaction temperature for activation increases at both 400 °C and 560 °C. However, when activated at 760 °C, the CO selectivity generally decreases as the reaction temperature rises. For the alumina-supported nickel and manganese catalyst, the CO selectivity peaks at a reaction temperature of 500 °C for all activation temperatures, and higher activation temperatures have higher CO selectivity over all measured reaction temperatures. Similarly, for the ceria-supported nickel and manganese catalyst, the CO selectivity peaks at a reaction temperature of 500 - 600 °C for all activation temperatures, and higher activation temperatures have higher CO selectivity over all measured reaction temperatures. Overall, the results in Tables 6 - 8 show that the activation temperature is another variable for tuning the resulting product stream.

[0156] Further aspects of the present disclosure are provided by the embodiments listed below, which may be combined in any number and in any combination that is not logically or technically inconsistent.

[0157] Embodiment 1. A supported reverse water gas shift catalyst, a support that is a cerium oxide support, a titanium oxide support, an aluminum oxide support, a zirconium oxide support, or a mixed oxide support comprising a mixture of two or more of cerium oxide, titanium oxide, aluminum oxide, and zirconium oxide, nickel present in an amount in the range of 0.05 to 10 wt% of the catalyst based on the total weight of the catalyst, manganese present in an amount in the range of 0.5 to 20 wt% of the catalyst based on the total weight of the catalyst A catalyst comprising Embodiment 2. The catalyst according to Embodiment 1, wherein the carrier constitutes at least 70% by weight (for example, at least 75% by weight, or 80% by weight, or 85% by weight, or 90% by weight) of the catalyst based on oxides. Embodiment 3. The catalyst according to Embodiment 1 or Embodiment 2, wherein the carrier is a cerium oxide carrier. Embodiment 4. The catalyst according to Embodiment 3, wherein at least one surface layer of the cerium oxide carrier contains at least 60% by weight of cerium oxide, for example, at least 70% by weight of cerium oxide or at least 80% by weight of cerium oxide based on oxides. Embodiment 5. The catalyst according to Embodiment 3, wherein at least the surface layer of the cerium oxide support contains at least 90% by weight of cerium oxide, for example, at least 95% by weight of cerium oxide, or at least 98% by weight of cerium oxide based on oxides. Embodiment 6. The catalyst according to any one of Embodiments 3 to 5, wherein the cerium oxide carrier contains at least 50% by weight of cerium oxide, for example, at least 60% by weight of cerium oxide, or at least 70% by weight of cerium oxide, or at least 80% by weight of cerium oxide based on oxides. Embodiment 7. The catalyst according to any one of Embodiments 3 to 5, wherein the cerium oxide carrier contains at least 90% by weight of cerium oxide, for example, at least 95% by weight of cerium oxide, or at least 98% by weight of cerium oxide based on oxides. Embodiment 8. The catalyst according to Embodiment 1 or Embodiment 2, wherein the carrier is a titanium oxide carrier. Embodiment 9. The catalyst according to Embodiment 8, wherein at least the surface layer of the titanium oxide carrier contains at least 60% by weight of titanium oxide, for example, at least 70% by weight of titanium oxide, or at least 80% by weight of titanium oxide based on oxides. Embodiment 10. The catalyst according to Embodiment 8, wherein at least one surface layer of the titanium oxide support contains at least 90% by weight of titanium oxide, for example, at least 95% by weight of titanium oxide, or at least 98% by weight of titanium oxide. Embodiment 11. The catalyst according to any one of Embodiments 8 to 10, wherein the titanium oxide support contains at least 50% by weight of titanium oxide, for example, at least 60% by weight of titanium oxide, or at least 70% by weight of titanium oxide, or at least 80% by weight of titanium oxide on an oxide basis. Embodiment 12. The catalyst according to any one of Embodiments 8 to 10, wherein the titanium oxide support contains at least 90% by weight of titanium oxide, for example, at least 95% by weight of titanium oxide, or at least 98% by weight of titanium oxide on an oxide basis. Embodiment 13. The catalyst according to Embodiment 1 or Embodiment 2, wherein the support is an aluminum oxide support. Embodiment 14. The catalyst according to Embodiment 13, wherein at least the surface layer of the aluminum oxide support contains at least 60% by weight of aluminum oxide, for example, at least 70% by weight of aluminum oxide or at least 80% by weight of aluminum oxide on an oxide basis. Embodiment 15. The catalyst according to Embodiment 13, wherein at least the surface layer of the aluminum oxide support contains at least 90% by weight of aluminum oxide, for example, at least 95% by weight of aluminum oxide, or at least 98% by weight of aluminum oxide on an oxide basis. Embodiment 16. The catalyst according to any one of Embodiments 13 to 15, wherein the aluminum oxide support contains at least 50% by weight of aluminum oxide, for example, at least 60% by weight of aluminum oxide, or at least 70% by weight of aluminum oxide, or at least 80% by weight of aluminum oxide on an oxide basis. Embodiment 17. The catalyst according to any one of Embodiments 13 to 15, wherein the aluminum oxide support contains at least 90% by weight of aluminum oxide, for example, at least 95% by weight of aluminum oxide, or at least 98% by weight of aluminum oxide, based on the oxide. Embodiment 18. The catalyst according to Embodiment 1 or Embodiment 2, wherein the support is a zirconium oxide support. Embodiment 19. The catalyst according to Embodiment 18, wherein at least the surface layer of the zirconium oxide support contains at least 60% by weight of zirconium oxide, for example, at least 70% by weight of zirconium oxide or at least 80% by weight of zirconium oxide, based on the oxide. Embodiment 20. The catalyst according to Embodiment 18, wherein at least the surface layer of the zirconium oxide support contains at least 90% by weight of zirconium oxide, for example, at least 95% by weight of zirconium oxide, or at least 98% by weight of zirconium oxide, based on the oxide. Embodiment 21. The catalyst according to any one of Embodiments 18 to 20, wherein the zirconium oxide support contains at least 50% by weight of zirconium oxide, for example, at least 60% by weight of zirconium oxide, or at least 70% by weight of zirconium oxide, or at least 80% by weight of zirconium oxide, based on the oxide. Embodiment 22. The catalyst according to any one of Embodiments 18 to 20, wherein the zirconium oxide support contains at least 90% by weight of zirconium oxide, for example, at least 95% by weight of zirconium oxide, or at least 98% by weight of zirconium oxide, based on the oxide. Embodiment 23. The catalyst according to Embodiment 1 or Embodiment 2, wherein the support is a mixed oxide support having at least one surface layer containing at least two of cerium oxide, titanium oxide, aluminum oxide, and zirconium oxide in an amount of at least 50% by weight based on the oxide. Embodiment 24. The catalyst according to any one of Embodiments 1 to 23, wherein the carrier contains no additional metal in a total amount of additional metal exceeding 2% by weight, for example, exceeding 1% by weight, or exceeding 0.5% by weight based on the oxide. Embodiment 25. The catalyst according to any one of Embodiments 1 to 23, wherein the carrier contains at least one additional metal. Embodiment 26. The catalyst according to Embodiment 25, wherein the total amount of at least one additional metal is in the range of 0.5 to 20% by weight, for example, 1 to 20% by weight, or 2 to 20% by weight, or 0.5 to 15% by weight, or 1 to 15% by weight, or 2 to 15% by weight, or 0.5 to 10% by weight, or 1 to 10% by weight, or 2 to 10% by weight, or 0.5 to 5% by weight, or 1 to 5% by weight based on the oxide. Embodiment 27. The catalyst according to any one of Embodiments 1 to 26, wherein the carrier has a pore volume of at least 0.05 mL / g. Embodiment 28. The catalyst according to any one of Embodiments 1 to 27, wherein the carrier has a pore volume of at most 1.5 mL / g. Embodiment 29. The catalyst according to any one of Embodiments 1 to 28, wherein the carrier has a pore volume in the range of 0.05 to 1.5 mL / g. Embodiment 30. The catalyst according to any one of Embodiments 1 to 29, wherein nickel is present in the catalyst in an amount in the range of 0.1 to 10% by weight, for example, 0.5 to 10% by weight, or 1 to 10% by weight, or 2 to 10% by weight, or 5 to 10% by weight based on the total weight of the catalyst. Embodiment 31. The catalyst according to any one of Embodiments 1 to 29, wherein nickel is present in the catalyst in an amount in the range of 0.05 to 7% by weight, for example, 0.1 to 7% by weight, or 0.5 to 7% by weight, or 1 to 7% by weight, or 2 to 7% by weight based on the total weight of the catalyst. Embodiment 32. The catalyst according to any one of Embodiments 1 to 29, wherein nickel is present in the catalyst in an amount in the range of 0.05 to 5% by weight, for example, in the range of 0.1 to 5% by weight, or 0.5 to 5% by weight, or 1 to 5% by weight, or 2 to 5% by weight, based on the total weight of the catalyst. Embodiment 33. The catalyst according to any one of Embodiments 1 to 29, wherein nickel is present in the catalyst in an amount in the range of 0.05 to 2% by weight, for example, in the range of 0.1 to 2% by weight, or 0.3 to 2% by weight, or 0.5 to 2% by weight, or 1 to 2% by weight, based on the total weight of the catalyst. Embodiment 34. The catalyst according to any one of Embodiments 1 to 29, wherein nickel is present in the catalyst in an amount in the range of 0.05 to 1.5% by weight, for example, in the range of 0.1 to 1.5% by weight, or 0.3 to 1.5% by weight, or 0.5 to 1.5% by weight, based on the total weight of the catalyst. Embodiment 35. The catalyst according to any one of Embodiments 1 to 29, wherein nickel is present in the catalyst in an amount in the range of 0.05 to 1% by weight, for example, in the range of 0.1 to 1% by weight, or 0.3 to 1% by weight, or 0.5 to 1% by weight, based on the total weight of the catalyst. Embodiment 36. The catalyst according to any one of Embodiments 1 to 29, wherein nickel is present in the catalyst in an amount in the range of 0.05 to 0.8% by weight, for example, in the range of 0.1 to 0.8% by weight, or 0.3 to 0.8% by weight, or 0.5 to 0.8% by weight, based on the total weight of the catalyst. Embodiment 37. The catalyst according to any one of Embodiments 1 to 36, wherein manganese is present in the catalyst in an amount in the range of 0.5 to 15% by weight, for example, in the range of 0.5 to 12% by weight or 0.5 to 10% by weight, based on the total weight of the catalyst. Embodiment 38. The catalyst according to any one of Embodiments 1 to 36, wherein manganese is present in the catalyst in an amount in the range of 1 to 20% by weight, for example, in the range of 1 to 15% by weight, or 1 to 12% by weight, or 1 to 10% by weight, based on the total weight of the catalyst. Embodiment 39. The catalyst according to any one of Embodiments 1 to 36, wherein manganese is present in the catalyst in an amount in the range of 2 to 20% by weight, for example, in the range of 2 to 15% by weight, or 2 to 12% by weight, or 2 to 10% by weight, based on the total weight of the catalyst. Embodiment 40. The catalyst according to any one of Embodiments 1 to 36, wherein manganese is present in the catalyst in an amount in the range of 4 to 20% by weight, for example, in the range of 4 to 15% by weight, or 4 to 12% by weight, or 4 to 10% by weight, based on the total weight of the catalyst. Embodiment 41. The catalyst according to any one of Embodiments 1 to 40, wherein the weight ratio of nickel to manganese is at least 0.05:1, for example, at least 0.1:1. Embodiment 42. The catalyst according to any one of Embodiments 1 to 41, wherein the weight ratio of nickel to manganese is at most 5:1, for example, at most 2:1, or 1:1, or 0.5:1. Embodiment 43. The catalyst according to any one of Embodiments 1 to 42, wherein the ratio of nickel to manganese is in the range of 0.05:1 to 5:1 (for example, in the range of 0.05:1 to 2:1, or 0.05:1 to 1:1, or 0.05:1 to 0.5:1, or 0.05:1 to 0.3:1, or 0.07:1 to 5:1, or 0.07:1 to 2:1, or 0.07:1 to 1:1, or 0.07:1 to 0.5:1, or 0.07:1 to 0.3:1, or 0.1:1 to 5:1, or 0.1:1 to 2:1, or 0.1:1 to 1:1, or 0.1:1 to 0.5:1, or 0.1:1 to 0.3:1). Embodiment 44. The catalyst according to any one of Embodiments 1 to 43, wherein the total amount of cerium, titanium, aluminum, zirconium, manganese and nickel in the catalyst is at least 90% by weight, for example, at least 95% by weight or at least 98% by weight, based on a metal basis. Embodiment 45. The catalyst according to any one of Embodiments 1 to 44, having an additional metal content (i.e., not Mn, Ni, Ce, Ti, Al, or Zr) of 10% by weight or less (for example, 5% by weight or less, or 2% by weight or less, or 1% by weight or less) based on the total weight of the catalyst. Embodiment 46. The catalyst according to any one of Embodiments 1 to 45, having a Cu content of 10% by weight or less (for example, 5% by weight or less, or 2% by weight or less, or 1% by weight or less) based on the total weight of the catalyst. Embodiment 47. The catalyst according to any one of Embodiments 1 to 46, having an alkali metal content of 10% by weight or less (for example, 5% by weight or less, or 2% by weight or less, or 1% by weight or less) based on the total weight of the catalyst. Embodiment 48. The catalyst according to any one of Embodiments 1 to 47, having an alkaline earth metal content of 10% by weight or less (for example, 5% by weight or less, or 2% by weight or less, or 1% by weight or less) based on the total weight of the catalyst. Embodiment 49. A method for preparing the catalyst according to any one of Embodiments 1 to 48, comprising: preparing a carrier which is a cerium oxide carrier, a titanium oxide carrier, an aluminum oxide carrier, a zirconium oxide carrier, or a mixed oxide carrier containing two or more of cerium oxide, titanium oxide, aluminum oxide, and zirconium oxide; contacting the carrier with one or more liquids each containing one or more nickel-containing compounds and / or one or more manganese-containing compounds dispersed in a solvent; evaporating the solvent to form a catalyst precursor; and calcining the catalyst precursor. Embodiment 50. The method according to Embodiment 49, wherein contacting the carrier with the liquid comprises adding an amount of the liquid equal to the pore volume of the carrier. Embodiment 51. The method according to embodiment 49, wherein contacting the carrier with the liquid comprises adding the liquid in an amount greater than the pore volume of the carrier. Embodiment 52. The method according to any one of embodiments 49 to 51, wherein the ratio of the amount of the liquid to the amount of the carrier on a mass basis is in the range of 1:1 to 5:1 (for example, in the range of 1:1 to 3:1). Embodiment 53. The method according to any one of embodiments 49 to 52, wherein a slurry is obtained by contacting the carrier with the liquid. Embodiment 54. The method according to any one of embodiments 49 to 53, wherein the evaporation of the solvent is carried out at ambient temperature. Embodiment 55. The method according to embodiments 49 to 53, wherein the evaporation of the solvent is carried out at a high temperature (for example, in the range of 50 to 150 °C) over a drying time (for example, 24 hours). Embodiment 56. The method according to embodiments 49 to 53, wherein the evaporation of the solvent is carried out under vacuum and at a high temperature (for example, in the range of 50 to 150 °C) over a drying time (for example, 24 hours). Embodiment 57. The method according to any one of embodiments 49 to 53, wherein the evaporation of the solvent is carried out at a high temperature (for example, in the range of 30 to 100 °C) in a stirred drying bath. Embodiment 58. The method according to any one of embodiments 49 to 53, wherein the calcination of the catalyst precursor is carried out over a calcination time in the range of 0.5 to 24 hours (for example, 0.5 to 15 hours, or 0.5 to 10 hours, or 0.5 to 5 hours). Embodiment 59. The method according to any one of embodiments 49 to 58, wherein the step of calcining the catalyst precursor is carried out for calcination in the range of 100 to 600 °C (for example, in the range of 120 to 500 °C). Embodiment 60. The catalyst according to any one of embodiments 1 to 48, produced by the method according to embodiments 49 to 59. A method for carrying out the reverse water gas shift reaction, comprising: contacting the catalyst according to any one of Embodiments 1 to 48 and 60 with a feed stream containing CO2 and H2 at a temperature in the range of 500 to 900 °C to form a product stream containing CO and H2, wherein the product stream has a lower concentration of CO2 and a higher concentration of CO than the feed stream. Embodiment 62. The method according to Embodiment 61, wherein the reverse water gas shift reaction has a CO selectivity of at least 50%, for example, at least 60%, or 70%, or 80%, or 90%. Embodiment 63. The method according to Embodiment 61, wherein the reverse water gas shift reaction has a CO selectivity in the range of 50 to 99% by weight (for example, in the range of 50 to 90% by weight, or 50 to 80% by weight, or 50 to 70% by weight, or 50 to 60% by weight, or 60 to 99% by weight, or 60 to 90% by weight, or 60 to 80% by weight, or 60 to 70% by weight, or 70 to 99% by weight, or 70 to 90% by weight, or 70 to 80% by weight). Embodiment 64. The method according to any one of Embodiments 61 to 63, wherein the reverse water gas shift reaction has a methane selectivity of 40% or less, for example, 35% or less, or 30% or less, or 25% or less, or 20% or less. Embodiment 65. The method according to any one of Embodiments 61 to 63, wherein the reverse water gas shift reaction has a methane selectivity of 10% or less, for example, 8% or less. Embodiment 66. The method according to any one of Embodiments 61 to 63, wherein the reverse water gas shift reaction has a methane selectivity of 5% or less, for example, 4% or less. Embodiment 67. The method according to any one of Embodiments 61 to 63, wherein the reverse water gas shift reaction has a methane selectivity of 2% or less, for example, 1% or less. Embodiment 68. The method according to any one of Embodiments 61 to 63, wherein the reverse water gas shift reaction has a methane selectivity of 0.5% or less, for example, 0.4% or less. Embodiment 69. The method according to any one of Embodiments 61 to 68, having at least 5% CO2 conversion, for example, at least 10% or 20% CO2 conversion. Embodiment 70. The method according to any one of Embodiments 61 to 68, having a CO2 conversion rate of at least 30%, for example, at least 40%. Embodiment 71. The method according to any one of Embodiments 61 to 70, having a CO2 conversion of 90% or less, for example, 80% or less or 70% or less. Embodiment 72. The method according to any one of Embodiments 61 to 70, having a CO2 conversion of 65% or less, for example, 60% or less. Embodiment 73. The method according to any one of Embodiments 61 to 72, which is carried out at a temperature in the range of 500 to 850 °C, for example, in the range of 500 to 800 °C, or 500 to 750 °C, or 500 to 700 °C, or 500 to 650 °C, or 500 to 600 °C. Embodiment 74. The method according to any one of Embodiments 61 to 72, which is carried out at a temperature in the range of 550 to 900 °C, for example, in the range of 550 to 850 °C, or 550 to 800 °C, or 550 to 750 °C, or 550 to 700 °C, or 550 to 650 °C, or 550 to 600 °C. Embodiment 75. The method according to any one of Embodiments 61 to 72, which is carried out at a temperature in the range of 600 to 900 °C, for example, in the range of 600 to 850 °C, or 600 to 800 °C, or 600 to 750 °C, or 600 to 700 °C, or 600 to 650 °C. Embodiment 76. The method according to any one of Embodiments 61 to 72, which is carried out at a temperature in the range of 650 to 900 °C, for example, in the range of 650 to 850 °C, or 650 to 800 °C, or 650 to 750 °C, or 650 to 700 °C. Embodiment 77. The method according to any one of Embodiments 61 to 72, which is carried out at a temperature in the range of 700 to 900 °C, for example, in the range of 700 to 850 °C, or 700 to 800 °C, or 700 to 750 °C. Embodiment 78. The method according to any one of Embodiments 61 to 77, wherein at least a part of the H2 in the feed stream is derived from a renewable source. Embodiment 79. The method according to any one of Embodiments 61 to 78, wherein at least a part of the H2 in the feed stream is green hydrogen. Embodiment 80. The method according to any one of Embodiments 61 to 78, wherein at least a part of the H2 in the feed stream is blue hydrogen. Embodiment 81. The method according to any one of Embodiments 61 to 78, wherein at least a part of the H2 in the feed stream is gray hydrogen, black hydrogen, brown hydrogen, pink hydrogen, turquoise hydrogen, yellow hydrogen, and / or white hydrogen. Embodiment 82. The method according to any one of Embodiments 61 to 81, wherein at least a part of the CO2 in the feed stream is from a renewable source. Embodiment 83. The method according to any one of Embodiments 61 to 81, wherein at least a part of the CO2 in the feed stream is from direct air capture. Embodiment 84. The method according to any one of Embodiments 61 to 81, wherein at least a part of the CO2 in the feed stream is captured from a manufacturing plant, for example, a bioethanol plant, a steel mill, or a cement factory. Embodiment 85. The method according to any one of Embodiments 61 to 84, wherein the molar ratio of H2 to CO2 in the feed stream is at least 0.1:1, for example, at least 0.5:1. Embodiment 86. The method according to any one of Embodiments 61 to 84, wherein the molar ratio of H2 to CO2 in the feed stream is at least 0.9:1, for example, at least 1:1 or at least 1.5:1. Embodiment 87. The method according to any one of Embodiments 61 to 84, wherein the molar ratio of H2 to CO2 in the feed stream is at least 2:1, for example, at least 2.5:1. Embodiment 88. The method according to any one of Embodiments 61 to 87, wherein the molar ratio of H2 to CO2 in the feed stream is 100:1 or less, for example, 75:1 or less, or 50:1 or less. Embodiment 89. The method according to any one of Embodiments 61 to 87, wherein the molar ratio of H2 to CO2 in the feed stream is 20:1 or less, for example, 15:1 or less, or 10:1 or less. Embodiment 90. The method according to any one of Embodiments 61 to 87, wherein the molar ratio of H2 to CO2 in the feed stream is in the range of 0.5:1 to 10:1. Embodiment 91. The method according to any one of Embodiments 61 to 90, which is carried out at a pressure in the range of 1 to 100 barg (for example, in the range of 1 to 70 barg, or 1 to 50 barg, or 1 to 40 barg, or 1 to 35 barg, or 5 to 80 barg, or 5 to 50 barg, or 5 to 40 barg, or 5 to 35 barg, or 10 to 70 barg, 10 to 50 barg, or 10 to 40 barg, or 10 to 35 barg, or 20 to 70 barg, 20 to 50 barg, or 20 to 40 barg, or 20 to 35 barg, or 25 to 70 barg, 25 to 50 barg, or 25 to 40 barg, or 25 to 35 barg). Embodiment 92. The method according to any one of Embodiments 61 to 91, carried out at a GHSV in the range of 1,000 to 2,000,000 h-1 (for example, in the range of 1,000 to 1,200,000 h-1, or 1,000 to 500,000 h-1, or 1,000 to 100,000 h-1, or 5,000 to 1,200,000 h-1, or 5,000 to 500,000 h-1, or 5,000 to 100,000 h-1, or 10,000 to 1,200,000 h-1, or 10,000 to 500,000 h-1, or 10,000 to 100,000 h-1). Embodiment 93. The method according to any one of Embodiments 61 to 92, wherein the product stream contains 95 mol% or less of CO2 (for example, 90 mol% or less of CO2). Embodiment 94. The method according to any one of Embodiments 61 to 92, wherein the product stream contains 85 mol% or less of CO2 (for example, 80 mol% or less of CO2). Embodiment 95. The method according to any one of Embodiments 61 to 92, wherein the product stream contains 75 mol% or less of CO2 (for example, 70 mol% or less of CO2). Embodiment 96. The method according to any one of Embodiments 61 to 95, wherein the product stream further contains CO2, and the method further includes recycling at least a part of the CO2 in the product stream to the feed stream. Embodiment 97. The method according to any one of Embodiments 61 to 96, wherein the product stream further contains hydrogen, and the method further includes recycling at least a part of the hydrogen in the product stream to the feed stream. Embodiment 98. The method according to any one of Embodiments 61 to 97, wherein the ratio of H2:CO in the product stream is in the range of 0.1:1 to 100:1 (for example, in the range of 0.1:1 to 50:1, or 0.1:1 to 25:1, or 0.1:1 to 10:1, or 0.1:1 to 5:1, or 1:1 to 100:1, or 1:1 to 50:1, or 1:1 to 25:1, or 1:1 to 10:1, or 1:1 to 5:1). Embodiment 99. The method according to any one of Embodiments 61 to 98, wherein the product stream contains 40 mol% or less of methane, for example, 35 mol% or less, or 30 mol% or less, or 25 mol% or less, or 20 mol% or less, or 15 mol% or less of methane. Embodiment 100. The method according to any one of Embodiments 61 to 98, wherein the product stream contains 10 mol% or less of methane, for example, 5 mol% or less, or 1 mol% or less, or 0.5 mol% or less, or 0.1 mol% or less of methane. Embodiment 101. The method according to any one of Embodiments 61 to 100, comprising activating the catalyst before contacting the catalyst with the feed stream. Embodiment 102. The method according to Embodiment 101, wherein activating the catalyst comprises contacting the catalyst with a reducing stream containing a reducing gas (e.g., hydrogen). Embodiment 103. The method according to Embodiment 101 or Embodiment 102, wherein the reducing stream contains hydrogen in an amount of at least 25 mol% (e.g., at least 50 mol%, or 75 mol%, or 90 mol%). Embodiment 104. The method according to any one of Embodiments 101 to 103, wherein activating the catalyst is carried out at a temperature in the range of 300 to 800 °C (e.g., in the range of 400 to 700 °C). Embodiment 105. The method according to any one of Embodiments 101 to 104, wherein the step of activating the catalyst feeds a catalyst that has been reduced by at least 10% (e.g., at least 25%, or 50%). Embodiment 106. A process for carrying out an integrated Fischer-Tropsch process, forming a first feed stream containing H2 and CO2, Contacting a reverse water gas shift catalyst with the first feed stream at a first temperature and a first pressure in the range of 500 to 900 °C to carry out a reverse water gas shift reaction to form a first product stream containing CO and H2, the first product stream having a lower CO2 concentration and a higher CO concentration than the first feed stream, Consisting of contacting a Fischer-Tropsch catalyst with a second feed stream containing H2 and at least a portion of the CO in the first product stream at a second temperature and a second pressure to form a second product stream containing C5+ hydrocarbons, wherein the reverse water gas shift catalyst is a supported reverse water gas shift catalyst, a carrier that is a cerium oxide carrier, a titanium oxide carrier, an aluminum oxide carrier, a zirconium oxide carrier, or a mixed oxide carrier containing a mixture of two or more of cerium oxide, titanium oxide, aluminum oxide, and zirconium oxide, nickel present in an amount in the range of 0.05 to 10% by weight of the catalyst based on the total weight of the catalyst, manganese present in an amount in the range of 0.5 to 20% by weight of the catalyst based on the total weight of the catalyst and a process comprising the same. Embodiment 107. The process according to embodiment 106, wherein the molar ratio of H2 to CO2 in the first feed stream is at least 0.1:1, for example, at least 0.5:1. Embodiment 108. The process according to any one of embodiments 106, wherein the molar ratio of H2 to CO2 in the first feed stream is at least 0.9:1, for example, at least 1:1 or at least 1.5:1. Embodiment 109. The process according to embodiment 106, wherein the molar ratio of H2 to CO2 in the first feed stream is at least 2:1, for example, at least 2.5:1. Embodiment 110. The process according to any one of embodiments 106 to 109, wherein the molar ratio of H2 to CO2 in the first feed stream is 100:1 or less, for example, 75:1 or less, or 50:1 or less. Process according to any one of Embodiments 106 to 109, wherein the molar ratio of H2 to CO2 in the first feed stream is 20:1 or less, for example 15:1 or less, or 10:1 or less. Process according to any one of Embodiments 106 to 109, wherein the molar ratio of H2 to CO2 in the first feed stream is in the range of 0.5:1 to 10:1. Process according to any one of Embodiments 106 to 112, wherein the first feed stream further contains CO. Process according to any one of Embodiments 106 to 113, wherein the first feed stream further contains one or more inert gases (for example, nitrogen and / or methane). Process according to any one of Embodiments 106 to 114, wherein the reverse water gas shift reaction has a CO selectivity of at least 50%, for example at least 60%, or 70%, or 80%, or 90%. Process according to any one of Embodiments 106 to 114, wherein the reverse water gas shift reaction has a CO selectivity in the range of 50 to 99 w% (for example, 50 to 90 wt%, or 50 to 80 wt%, or 50 to 70 wt%, or 50 to 60 wt%, or 60 to 99 wt%, or 60 to 90 wt%, or 60 to 80 wt%, or 60 to 70 wt%, or 70 to 99 wt%, or 70 to 90 wt%, or 70 to 80 wt%). Process according to any one of Embodiments 106 to 116, wherein the reverse water gas shift reaction has a methane selectivity of 40% or less, for example 35% or less, or 30% or less, or 25% or less, or 20% or less. Process according to any one of Embodiments 106 to 116, wherein the reverse water gas shift reaction has a methane selectivity of 10% or less, for example 8% or less. Embodiment 119. The process according to any one of Embodiments 106 to 116, wherein the reverse water gas shift reaction has a methane selectivity of 5% or less, for example, 4% or less. Embodiment 120. The process according to any one of Embodiments 106 to 116, wherein the reverse water gas shift reaction has a methane selectivity of 2% or less, for example, 1% or less. Embodiment 121. The process according to any one of Embodiments 106 to 116, wherein the reverse water gas shift reaction has a methane selectivity of 0.5% or less, for example, 0.2% or less. Embodiment 122. The process according to any one of Embodiments 106 to 121, wherein the reverse water gas shift reaction has a CO2 conversion rate of at least 5%, for example, at least 10% or 20%. Embodiment 123. The process according to any one of Embodiments 106 to 121, wherein the reverse water gas shift reaction has a CO2 conversion rate of at least 30%, for example, at least 40%. Embodiment 124. The process according to any one of Embodiments 106 to 123, wherein the reverse water gas shift reaction has a CO2 conversion rate of 90% or less, for example, 80% or less or 70% or less. Embodiment 125. The process according to any one of Embodiments 106 to 123, wherein the reverse water gas shift reaction has a CO2 conversion rate of 65% or less, for example, 60% or less. Embodiment 126. The process according to any one of Embodiments 106 to 125, which is carried out at a first temperature in the range of 500 to 850 °C, for example, in the range of 500 to 800 °C, or 500 to 750 °C, or 500 to 700 °C, or 500 to 650 °C, or 500 to 600 °C. Embodiment 127. The process according to any one of Embodiments 106 to 125, which is carried out at a first temperature in the range of 550 to 900 °C, for example, in the range of 550 to 850 °C, or 550 to 800 °C, or 550 to 750 °C, or 550 to 700 °C, or 550 to 650 °C, or 550 to 600 °C. Embodiment 128. The process according to any one of Embodiments 106 to 125, which is carried out at a first temperature in the range of 600 to 900 °C, for example, in the range of 600 to 850 °C, or 600 to 800 °C, or 600 to 750 °C, or 600 to 700 °C, or 600 to 650 °C. Embodiment 129. The process according to any one of Embodiments 106 to 125, which is carried out at a first temperature in the range of 650 to 900 °C, for example, in the range of 650 to 850 °C, or 650 to 800 °C, or 650 to 750 °C, or 650 to 700 °C. Embodiment 130. The process according to any one of Embodiments 106 to 125, which is carried out at a first temperature in the range of 700 to 900 °C, for example, in the range of 700 to 850 °C, or 700 to 800 °C, or 700 to 750 °C. Embodiment 131. The process according to any one of Embodiments 106 to 130, in which the reverse water gas shift reaction is carried out at a pressure in the range of 1 to 100 barg (for example, in the range of 1 to 70 barg, or 1 to 50 barg, or 1 to 40 barg, or 1 to 35 barg, or 5 to 80 barg, or 5 to 50 barg, or 5 to 40 barg, or 5 to 35 barg, or 10 to 70 barg, 10 to 50 barg, or 10 to 40 barg, or 10 to 35 barg, or 20 to 70 barg, 20 to 50 barg, or 20 to 40 barg, or 20 to 35 barg, or 25 to 70 barg, 25 to 50 barg, or 25 to 40 barg, or 25 to 35 barg). Embodiment 132. The process according to any one of Embodiments 106 to 131, wherein the reverse water gas shift reaction is carried out at a GHSV in the range of 1,000 to 2,000,000 h-1 (for example, in the range of 1,000 to 1,200,000 h-1, or 1,000 to 500,000 h-1, or 1,000 to 100,000 h-1, or 5,000 to 1,200,000 h-1, or 5,000 to 500,000 h-1, or 5,000 to 100,000 h-1, or 10,000 to 1,200,000 h-1, or 10,000 to 500,000 h-1, or 10,000 to 100,000 h-1). Embodiment 133. The process according to any one of Embodiments 106 to 132, wherein the process includes, for example, activating the reverse water gas shift catalyst before contacting the reverse water gas shift catalyst with the first feed stream. Embodiment 134. The process according to Embodiment 133, wherein activating the rWGS catalyst includes contacting the rWGS catalyst with a reducing stream containing a reducing gas (for example, hydrogen). Embodiment 135. The process according to Embodiment 133 or Embodiment 134, wherein the reducing stream contains hydrogen in an amount of at least 25 mol% (for example, at least 50 mol%, or 75 mol%, or 90 mol%). Embodiment 136. The process according to any one of Embodiments 133 to 135, wherein the activation of the rWGS catalyst is carried out at a temperature in the range of 200°C to 800°C (for example, in the range of 250°C to 800°C, or 300°C to 800°C, or 200°C to 700°C, or 250°C to 700°C, or 300°C to 700°C). Embodiment 137. The process according to any one of Embodiments 133 to 136, wherein activating the rWGS catalyst results in a catalyst that is reduced by at least 10% (for example, at least 25%, or 50%). Embodiment 138. The process according to any one of Embodiments 106 to 137, wherein the first product stream contains 95 mol% or less of CO2 (for example, 90 mol% or less of CO2). Embodiment 139. The process according to any one of Embodiments 106 to 137, wherein the first product stream contains 85 mol% or less of CO2 (for example, 80 mol% or less of CO2). Embodiment 140. The process according to any one of Embodiments 106 to 137, wherein the first product stream contains 75 mol% or less of CO2 (for example, 70 mol% or less of CO2). Embodiment 141. The process according to any one of Embodiments 106 to 137, wherein the first product stream contains CO2 in the range of 5 to 95 mol%, for example, 5 to 90 mol%, or 5 to 85 mol%, or 5 to 80 mol%, or 5 to 75 mol%, or 5 to 70 mol%, or 10 to 95 mol%, or 10 to 90 mol%, or 10 to 85 mol%, or 10 to 80 mol%, or 10 to 75 mol%, or 10 to 70 mol%, or 20 to 95 mol%, or 20 to 90 mol%, or 20 to 80 mol%, or 20 to 70 mol%, or 30 to 95 mol%, or 30 to 90 mol%, or 30 to 85 mol%, or 30 to 80 mol%, or 30 to 75 mol%, or 30 to 70 mol%. Embodiment 142. The process according to any one of Embodiments 106 to 141, wherein the first product stream contains 40 mol% or less of methane, for example, 35 mol% or less, or 30 mol% or less, or 25 mol% or less, or 20 mol% or less, or 15 mol% or less, or 10 mol% or less of methane. Embodiment 143. The process according to any one of Embodiments 106 to 141, wherein the first product stream contains 10 mol% or less of methane, for example, 5 mol% or less, or 1 mol% or less, or 0.5 mol% or less, or 0.1 mol% or less of methane. Embodiment 144. The process according to any one of Embodiments 106 to 143, wherein the ratio of H2:CO in the first product stream is at most 100:1, for example, at most 50:1, or at most 25:1, or at most 10:1. Embodiment 145. The process according to any one of Embodiments 106 to 143, wherein the ratio of H2:CO in the first product stream is in the range of 0.1:1 to 100:1 (for example, in the range of 0.1:1 to 50:1, or 0.1:1 to 25:1, or 0.1:1 to 10:1, or 0.1:1 to 5:1, or 1:1 to 100:1, or 1:1 to 50:1, or 1:1 to 25:1, or 1:1 to 10:1, or 1:1 to 5:1). Embodiment 146. The process according to any one of Embodiments 106 to 145, further comprising separating the first product stream and recycling at least a portion of one or more components of the first product stream to the first feed stream. Embodiment 147. The process according to any one of Embodiments 106 to 146, further comprising separating the first product stream and recycling at least a portion (for example, at least 5 mol%, at least 10 mol%, at least 25 mol%, at least 50 mol%, at least 75 mol%, or at least 90 mol%) of the CO2 of the first product stream to the first feed stream. Embodiment 148. The process according to any one of Embodiments 106 to 147, further comprising separating the first product stream and recycling at least a portion (for example, at least 5 mol%, at least 10 mol%, at least 25 mol%, at least 50 mol%, at least 75 mol%, or at least 90 mol%) of the H2 of the first product stream to the first feed stream. Embodiment 149. The process according to any one of Embodiments 106 to 148, further comprising separating at least a portion of H2 and / or CO from the first product stream and contacting it with the Fischer-Tropsch catalyst to activate the Fischer-Tropsch catalyst. Embodiment 150. The process according to any one of Embodiments 106 to 149, further comprising removing at least a portion (e.g., at least 25%, at least 50%, or at least 75%) of water from the first product stream. Embodiment 151. The process according to any one of Embodiments 106 to 150, wherein the first product stream contains one or more light hydrocarbons (e.g., methane, ethane, propane). Embodiment 152. The process according to Embodiment 151, further comprising separating at least a portion of the one or more light hydrocarbons from the first product stream to provide a light hydrocarbon stream. Embodiment 153. The process according to any one of Embodiments 106 to 152, further comprising exchanging heat between at least a portion of the first product stream and at least a portion of the first feed stream, thereby cooling at least a portion of the first product stream and heating at least a portion of the first feed stream. Embodiment 154. The process according to any one of Embodiments 106 to 153, further comprising exchanging heat between at least a portion of the first product stream and a steam generation zone, thereby cooling at least a portion of the first product stream and providing heat to the steam generation zone. Embodiment 155. The process according to Embodiment 154, further comprising generating steam from the heat provided to the steam generation zone and generating electricity from the steam. Embodiment 156. The process according to Embodiment 154 or 155, wherein the steam is used to heat the first feed stream and / or the second feed stream. Embodiment 157. The process according to any one of Embodiments 106 to 156, wherein at least 25% of the CO in the first product stream, e.g., at least 50%, at least 75%, or at least 90% of the CO in the first product stream, is contained in the second feed stream. Process according to any one of Embodiments 106 to 157, wherein CO is provided to a second feed stream from a CO source other than the first product stream. Process according to any one of Embodiments 106 to 159, wherein the first product stream contains H2 and the second feed stream contains at least a part of the H2 in the first product stream. Process according to any one of Embodiments 106 to 159, wherein at least 25% of the H2 in the first product stream, for example, at least 50% of the H2 in the first product stream, at least 75% of the H2, or at least 90% of the H2 is contained in the second feed stream. Process according to any one of Embodiments 106 to 160, wherein H2 is provided to the second feed stream from a hydrogen source other than the first product stream. Process according to any one of Embodiments 106 to 161, wherein the second feed stream contains at least a part of the CO2 in the first product stream. Process according to any one of Embodiments 106 to 162, wherein at least 10% of the CO2 in the first product stream, for example, at least 25% of the CO2 in the first product stream, at least 50% of the CO2, at least 75% of the CO2, or at least 90% of the CO2 is contained in the second feed stream. Process according to any one of Embodiments 106 to 162, wherein the feed stream does not contain a substantial amount of CO2 from the first product stream. Process according to any one of Embodiments 106 to 164, wherein a part of the first product stream contained in the second feed stream has an H2:CO ratio in the range of 0.5:1 to 10:1, for example, in the range of 1:1 to 3:1. Embodiment 166. The process according to any one of Embodiments 106 to 165, wherein a part of the first product stream contained in the second feed stream has a water content of 10 mol% or less, for example, or 2 mol% or less, or 0.5 mol% or less. Embodiment 167. The process according to any one of Embodiments 106 to 166, wherein the portion of the first product stream contained in the second feed stream has a CO₂ content in the range of 10 to 95 mol% CO₂, for example, 10 to 90 mol%, or 10 to 85 mol%, or 10 to 80 mol%, or 10 to 75 mol%, or 10 to 70 mol%, or 20 to 95 mol%, or 20 to 90 mol%, or 20 to 85 mol%, or 20 to 80 mol%, or 20 to 70 mol%, or 30 to 95 mol%, or 30 to 90 mol%, or 30 to 85 mol%, or 30 to 80 mol%, or 30 to 75 mol%, or 30 to 70 mol%. Embodiment 168. The process according to any one of Embodiments 106 to 167, wherein the second feed stream has an H₂:CO ratio in the range of 0.5:1 to 6:1. Embodiment 169. The process according to any one of Embodiments 106 to 167, wherein the second feed stream has an H₂:CO ratio in the range of 1:1 to 3:1, for example, 1:1 to 2.5:1. Embodiment 170. The process according to any one of Embodiments 106 to 167, wherein the second feed stream has an H₂:CO ratio in the range of at least 1.4:1, for example, 1.4:1 to 3:1, or 1.4:1 to 2.5:1. Embodiment 171. The process according to any one of Embodiments 106 to 170, wherein the second feed stream contains one or more inert substances at a maximum of 80%, for example, a maximum of 70 mol%, a maximum of 60 mol%, or a maximum of 50 mol%, or 15 to 70 mol%, or 30 to 70 mol%, or 15 to 60 mol%, or 30 to 60 mol%, or 15 to 50 mol%, or 30 to 50 mol%. Embodiment 172. The process according to any one of embodiments 106 to 170, wherein the second feed stream contains up to 80%, for example up to 70 mol%, up to 60 mol%, or up to 50 mol%, or 15 - 70 mol%, or 30 - 70 mol%, or 15 - 60 mol%, or 30 - 60 mol%, or 15 - 50 mol%, or 30 - 50 mol% of one or more inert substances selected from CO2, methane, and nitrogen. Embodiment 173. The process according to any one of embodiments 106 to 172, wherein the second feed stream contains up to 80%, for example up to 70 mol%, up to 60 mol%, or up to 50 mol%, or 15 - 70 mol%, or 30 - 70 mol%, or 15 - 60 mol%, or 30 - 60 mol%, or 15 - 50 mol%, or 30 - 50 mol% of CO2. Embodiment 174. The process according to any one of embodiments 106 to 173, wherein the second feed stream has a water content of 10 mol% or less, for example or 2 mol% or less, or 0.5 mol% or less. Embodiment 175. The process according to any one of embodiments 106 to 174, wherein the Fischer - Tropsch catalyst contains cobalt, iron, rhodium, ruthenium, or a combination thereof. Embodiment 176. The process according to any one of embodiments 106 to 174, wherein the Fischer - Tropsch catalyst contains cobalt in an amount in the range of 5 - 25 wt%, for example 7 - 25 wt%, or 10 - 25 wt%, or 5 - 20 wt%, or 7 - 20 wt%, or 10 - 20 wt%, calculated as Co(0). Embodiment 177. The process according to any one of embodiments 106 to 174, wherein the Fischer - Tropsch catalyst contains iron in an amount in the range of, for example 5 - 95 wt%, for example 10 - 95 wt%, or 25 - 95 wt%, or 50 - 95 wt%, or 5 - 85 wt%, or 10 - 85 wt%, or 25 - 85 wt%, or 50 - 85 wt%, or 5 - 75 wt%, or 10 - 75 wt%, or 25 - 75 wt%, calculated as Fe(0). Embodiment 178. The process according to any one of Embodiments 175 to 178, wherein the Fischer-Tropsch catalyst further contains manganese. Embodiment 179. The process according to Embodiment 178, wherein manganese is present in an amount in the range of up to 15 wt%, for example up to 12 wt%, or up to 10 wt%, or up to 7 wt%, or 0.1 to 15 wt%, for example 0.1 to 10 wt%, or 0.1 to 5 wt%, 0.5 to 15 wt%, or 0.5 to 10 wt%, or 0.5 to 5 wt%, calculated as Mn(0). Embodiment 180. The process according to any one of Embodiments 106 to 179, wherein the Fischer-Tropsch catalyst is a supported catalyst, and the carrier contains at least one of titanium oxide, zirconium oxide, cerium oxide, aluminum oxide, silicon oxide, and zinc oxide. Embodiment 181. The process according to any one of Embodiments 106 to 179, wherein the Fischer-Tropsch catalyst is a supported catalyst, and the carrier contains at least one of titanium oxide, aluminum oxide, and silicon oxide. Embodiment 182. The process according to any one of Embodiments 106 to 179, wherein the Fischer-Tropsch catalyst is a supported catalyst, and the carrier is a titanium dioxide carrier. Embodiment 183. The process according to any one of Embodiments 106 to 182, wherein the Fischer-Tropsch catalyst is activated by contact with a reducing gas, for example hydrogen. Embodiment 184. The process according to Embodiment 183, wherein the reducing gas contains at least a part of the hydrogen from the first product stream. Embodiment 185. The process according to any one of Embodiments 106 to 182, wherein the Fischer-Tropsch catalyst is activated by contact with H2 and CO. Embodiment 186. The process according to embodiment 185, wherein the reducing gas contains at least a part of H2 and CO from the first product stream. Embodiment 187. The process according to any one of embodiments 183 to 185, wherein the activation is carried out at a temperature in the range of 200 to 400 °C. Embodiment 188. The process according to any one of embodiments 106 to 187, wherein the second temperature is in the range of 150 to 400 °C (for example, in the range of 150 to 350 °C, or 150 to 300 °C, or 150 to 250 °C, or 150 to 200 °C, or 200 to 400 °C, or 200 to 350 °C, or 200 to 300 °C, or 200 to 250 °C, or 250 to 400 °C, or 250 to 350 °C, or 250 to 300 °C, or 300 to 400 °C). Embodiment 189. The process according to any one of embodiments 106 to 188, wherein the second temperature is in the range of 200 to 350 °C. Embodiment 190. The process according to any one of embodiments 106 to 189, wherein the first temperature is within 100 °C of the second temperature, for example, within 50 °C of the second temperature, or within 25 °C of the second temperature. Embodiment 191. The process according to any one of embodiments 106 to 189, wherein the first temperature is at least 100 °C higher than the second temperature, for example, at least 150 °C higher than the second temperature, or at least 200 °C higher than the second temperature. Embodiment 192. The process according to any one of embodiments 106 to 191, wherein the second pressure is in the range of 10 to 50 barg (for example, in the range of 20 to 50 barg, or 25 to 50 barg, or 10 to 40 barg, or 20 to 40 barg, or 25 to 40 barg, or 10 to 35 barg, or 20 to 35 barg, or 25 to 35 barg). Embodiment 193. The process according to any one of embodiments 106 to 192, wherein the second pressure is in the range of 20 to 50 barg. Embodiment 194. The process according to any one of Embodiments 106 to 193, wherein the Fischer-Tropsch reaction is carried out at a GHSV in the range of 1,000 to 2,000,000 h-1 (for example, in the range of 1,000 to 1,200,000 h-1, or 1,000 to 500,000 h-1, or 1,000 to 100,000 h-1, or 5,000 to 1,200,000 h-1, or 5,000 to 500,000 h-1, or 5,000 to 100,000 h-1, or 10,000 to 1,200,000 h-1, or 10,000 to 500,000 h-1, or 10,000 to 100,000 h-1). Embodiment 195. The process according to any one of Embodiments 106 to 194, wherein contacting the Fischer-Tropsch catalyst with a second feed stream to provide a second product stream is carried out at a C5+ selectivity of at least 30%, for example, at least 50% or at least 70%. Embodiment 196. The process according to any one of Embodiments 106 to 195, wherein contacting the Fischer-Tropsch catalyst with a second feed stream to provide a second product stream is carried out at a selectivity for C5+ alkanes of at least 30%, for example, at least 50% or at least 70%. Embodiment 197. The process according to any one of Embodiments 106 to 196, wherein contacting the Fischer-Tropsch catalyst with a second feed stream to provide a second product stream is carried out at a selectivity for C5+ alkanes and C5+ alcohols of at least 30%, for example, at least 50% or at least 70%. Embodiment 198. The process according to any one of Embodiments 106 to 197, further comprising separating at least a portion of the water from the second product stream. Embodiment 199. The process according to any one of Embodiments 106 to 198, further comprising separating at least a portion of the C1-C4 hydrocarbons from the second product stream to provide a light hydrocarbon stream. Embodiment 200. The process according to embodiment 199, further comprising including at least a portion of the light hydrocarbon stream in the first feed stream and / or the second feed stream. Embodiment 201. The process according to embodiment 199 or embodiment 200, further comprising oxidizing at least a portion of the light hydrocarbon stream to provide a pOX stream containing CO and / or CO2, and including at least a portion of the pOX stream in the first feed stream and / or the second stream. Embodiment 202. The process according to any one of embodiments 199 to 201, further comprising reforming (e.g., steam reforming and / or autothermal reforming) at least a portion of the light hydrocarbon stream to provide a reformed stream containing CO and / or CO2, and including at least a portion of the reformed stream in the first feed stream and / or the second feed stream. Embodiment 203. The process according to embodiment 201 or embodiment 202, wherein the oxidation or reforming provides energy, thermal energy or electrical energy. Embodiment 204. The process according to any one of embodiments 199 to 203, further comprising burning at least a portion of the light hydrocarbon stream to provide energy, such as thermal energy or electrical energy. Embodiment 205. The process according to embodiment 204, wherein thermal energy is provided and the thermal energy is used to heat the first feed stream. Embodiment 206. The process according to any one of embodiments 106 to 205, further comprising exchanging heat between at least a portion of the second product stream and the steam generation zone, thereby cooling at least a portion of the first feed stream and providing heat to the steam generation zone. Embodiment 207. The process according to embodiment 206, further comprising generating steam from the heat provided to the steam generation zone and generating electricity from the steam. Embodiment 208. The process according to embodiment 206 or 207, wherein steam is used to heat the first feed stream and / or the second feed stream. Embodiment 209. The process according to any one of embodiments 106 - 208, further comprising exchanging heat between at least a portion of the second product stream and at least a portion of the second feed stream, thereby cooling at least a portion of the second product stream and heating at least a portion of the second feed stream. Embodiment 210. The process according to any one of embodiments 106 - 209, further comprising recycling at least a portion of the H2 in the second product stream to the second feed stream. Embodiment 211. The process according to any one of embodiments 106 - 210, further comprising recycling at least a portion of the H2 in the second product stream to the first feed stream. Embodiment 212. The process according to embodiment 211, further comprising providing H2 from an H2 source other than the first product stream to the second feed stream. Embodiment 213. The process according to embodiment 212, wherein the H2 from the second product stream constitutes a majority of the H2 in the first feed stream, for example, at least 90%, at least 95%, or at least 98% of the H2 in the first feed stream. Embodiment 214. The process according to any one of embodiments 106 - 213, further comprising recycling at least a portion of the CO in the second product stream to the second feed stream. Embodiment 215. The process according to any one of embodiments 106 - 214, further comprising recycling at least a portion of the CO in the second product stream to the first feed stream. Embodiment 216. The process according to any one of embodiments 106 - 215, further comprising recycling at least a portion of the inert substance in the second product stream to the second feed stream. Process according to any one of embodiments 106 - 216, further comprising recycling at least a portion of the inert substances of the second product stream to the first feed stream. Process according to any one of embodiments 106 - 217, further comprising recycling at least a portion of the CO2 of the second product stream to the first feed stream. Process according to embodiment 218, further comprising providing CO2 from a CO2 source other than the first product stream to the second feed stream. Process according to embodiment 219, wherein the CO2 from the second product stream constitutes a majority of the CO2 of the first feed stream, for example, at least 90%, at least 95%, or at least 98% of the CO2 of the first product stream. Process according to any one of embodiments 106 - 220, wherein one or more products are provided from at least a portion of the C5+ hydrocarbons of the second product stream. Process according to embodiment 221, wherein one or more products include fuels (e.g., gasoline, diesel fuel, aviation fuel), lubricants, and waxes. Process according to any one of embodiments 106 - 222, further comprising hydrotreating at least a portion of the C5+ hydrocarbons of the second product stream. Process according to any one of embodiments 106 - 223, wherein at least a portion of the CO2 of the first feed stream and / or the second feed stream is derived from a renewable source. Process according to any one of embodiments 106 - 224, wherein at least a portion of the CO2 of the first feed stream and / or the second feed stream is from direct air capture. Embodiment 226. The process according to any one of Embodiments 106 to 225, wherein at least a part of the CO2 in the first feed stream and / or the second feed stream is captured from a manufacturing plant, such as a bioethanol plant, a steel mill, or a cement factory. Embodiment 227. The process according to any one of Embodiments 106 to 226, wherein at least a part of the H2 in the first feed stream or the second feed stream is derived from a renewable source. Embodiment 228. The process according to any one of Embodiments 106 to 227, wherein at least a part of the hydrogen in the first feed stream or the second feed stream is green hydrogen. Embodiment 229. The process according to any one of Embodiments 106 to 228, wherein at least a part of the hydrogen in the first feed stream or the second feed stream is blue hydrogen. Embodiment 230. The process according to any one of Embodiments 106 to 229, wherein at least a part of the hydrogen in the first feed stream or the second feed stream is grey hydrogen, black hydrogen, brown hydrogen, pink hydrogen, turquoise hydrogen, yellow hydrogen, and / or white hydrogen. Embodiment 231. The process according to any one of Embodiments 106 to 230, further comprising providing at least a part of the H2 to the first feed stream and / or the second feed stream by electrolysis of water. Embodiment 232. The method according to Embodiment 231, wherein the electrolysis of water is carried out using at least partially electricity from renewable resources. Embodiment 233. The process according to Embodiment 231 or Embodiment 232, wherein the electrolysis of water is carried out using at least partially electricity generated from heat exchange from the first product stream and / or the second product stream, or from steam generated by burning a light hydrocarbon stream. Process according to any of embodiments 232 to 233, further comprising providing at least a portion of the O2 generated in the electrolysis for partial oxidation. Embodiment 235. A process according to any of embodiments 106 to 234, which is carried out in a reactor system comprising a first reactor in which a reverse water gas shift catalyst is arranged and a second reactor in which a Fischer-Tropsch catalyst is arranged. Embodiment 236. A method according to any of embodiments 106 to 234, wherein the process is carried out in a reactor system comprising a first catalyst bed in which a reverse water gas shift catalyst is arranged, and a second reaction zone comprises a second catalyst bed in which the Fischer-Tropsch catalyst is arranged. Embodiment 237. The process according to embodiment 236, wherein the first reactor bed and the second reactor bed are arranged in the same reactor. Embodiment 238. A process according to any of embodiments 106 to 234, wherein the process is carried out in a reactor system comprising one or more first catalyst vessels in which a reverse water gas shift catalyst is arranged, and a second reaction zone comprises one or more second catalyst vessels in which the Fischer-Tropsch catalyst is arranged. Embodiment 239. The process according to embodiment 238, wherein the one or more first catalyst vessels and the one or more second catalyst vessels are arranged in the same reactor. Embodiment 240. A process according to any of embodiments 106 to 239, which is carried out in a reactor system comprising a reactor in which the reverse water gas shift catalyst and the Fischer-Tropsch catalyst are arranged, for example, in a mixture.

[0158] The details presented herein are for illustrative purposes only, for the purpose of an exemplary discussion of the preferred embodiments of the present invention, and are provided to offer what is considered to be the most useful and readily understood description of the principles and conceptual aspects of the various embodiments of the present invention. In this regard, no attempt is made to show the structural details of the present invention in more detail than is necessary for a basic understanding of the present invention, and the description made together with the drawings and / or examples will clarify to those skilled in the art how some forms of the present invention can be actually implemented. Therefore, before the disclosed processes and devices are described, it should be understood that the aspects described herein are not limited to specific embodiments, devices, or configurations, and thus, of course, can vary. It should also be understood that the terms used herein are for the purpose of describing only specific aspects and are not intended to be limiting unless specifically defined herein.

[0159] The terms "a", "an", "the" and similar referents used in the context of describing the present invention (in particular, in the context of the following claims) should be construed to include both the singular and the plural unless otherwise indicated herein or clearly contradicted by the context. The recitation of a range of values herein is intended merely to serve as a shorthand method of referring individually to each separate value falling within that range. Unless specifically indicated herein, each individual value is incorporated herein as if it were individually recited herein. Furthermore, it will be understood that the endpoints of each range are significant both in relation to the other endpoint and independently of the other endpoint.

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

[0161] Unless the context clearly requires otherwise, throughout this specification and the claims, words such as "comprise", "comprising", etc. shall be construed in an inclusive sense, i.e., in the sense of "including, but not limited to", rather than in an exclusive or exhaustive sense. Words using the singular or plural number shall also include the plural and the singular respectively. Further, the words "herein", "above", and "below", and words of similar import, when used in this application, refer to the whole of this application and not to any particular part of this application.

[0162] As will be understood by those skilled in the art, each embodiment disclosed herein can include, consist essentially of, or consist of its particular recited elements, steps, components, or ingredients. As used herein, the transitional phrase "comprise" or "comprises" means including, but not limited to, and allows for the inclusion of elements, steps, components, or ingredients not specifically recited, even in large quantities. The transitional phrase "consisting of" excludes any element, step, component, or ingredient not specifically recited. The transitional phrase "consisting essentially of" limits the scope of an embodiment to the specified elements, steps, components, or ingredients, and those that do not materially affect the embodiment.

[0163] Unless otherwise indicated, the numerical parameters set forth in this specification and the appended claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0164] Numerical ranges and parameters setting forth broad ranges of the invention are approximations although they are reported as precisely as possible in the specific examples. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0165] The grouping of alternative elements or embodiments of the invention disclosed herein should not be construed as a limitation. Members of each group may be referred to individually, or in any combination with other members of the group or other elements found herein, and may be claimed. It is anticipated that one or more members of a group may be included in, or deleted from, the group for convenience and / or patentability reasons. In the event of any such inclusion or deletion, the specification is to be considered as including the modified group and thus to satisfy the written description of all Markush groups used in the appended claims.

[0166] Some embodiments of the invention are described herein, including the best mode known to the inventors for carrying out the invention. It will of course be apparent to those skilled in the art that variations of these described embodiments will become apparent upon reading the foregoing description. The inventors expect those skilled in the art to employ such variations as appropriate, and the inventors intend the invention to be practiced otherwise than as specifically described herein. Accordingly, the invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Further, unless otherwise indicated herein or clearly contradicted by context, any combination of the above-described elements in all possible variations thereof is encompassed by the invention.

[0167] Furthermore, it is to be understood that the embodiments of the invention disclosed herein are illustrative of the principles of the invention. Other modifications that may be used are within the scope of the invention. Thus, by way of example and not limitation, alternative configurations of the invention may be utilized in accordance with the teachings herein. Accordingly, the invention is not strictly limited to that which is shown and described.

Claims

1. A method for performing a reverse water gas shift reaction, comprising: contacting a supported reverse water gas shift catalyst with a feed stream containing CO2 and H2 at a temperature in the range of 500 to 900 °C to form a product stream containing CO and H2, the product stream having a lower CO2 concentration and a higher CO concentration than the feed stream; the catalyst comprising a support that is a cerium oxide support, a titanium oxide support, an aluminum oxide support, a zirconium oxide support, or a mixed oxide support comprising a mixture of two or more of cerium oxide, titanium oxide, aluminum oxide, and zirconium oxide; nickel present in an amount in the range of 0.05 to 10% by weight of the catalyst based on the total weight of the catalyst; and manganese present in an amount in the range of 0.5 to 20% by weight of the catalyst based on the total weight of the catalyst.

2. The method according to claim 1, wherein the reverse water gas shift reaction has a CO selectivity of at least 50%.

3. The method according to claim 1, wherein the reverse water gas shift reaction has a methane selectivity of 40% or less.

4. The method according to claim 1, having a CO2 conversion rate of at least 30%.

5. The method according to claim 1, wherein the CO2 conversion rate is 90% or less.

6. The method according to claim 1, carried out at a temperature in the range of 600 to 800 °C.

7. The method according to claim 1, wherein the molar ratio of H2 to CO2 in the feed stream is in the range of 0.5:1 to 10:

1.

8. The method according to claim 1, wherein the product stream contains 75 mol% or less of CO2.

9. The method according to claim 1, wherein the product stream further contains CO2, and further comprising recycling at least a portion of the CO2 in the product stream to the feed stream.

10. The method according to claim 1, wherein the product stream further contains hydrogen, and further comprising recycling at least a portion of the hydrogen in the product stream to the feed stream.

11. The method according to claim 1, wherein the product stream contains 40 mol% or less of methane.

12. The method according to claim 1, wherein the product stream contains 10 mol% or less of methane.

13. A method for carrying out an integrated Fischer-Tropsch process, comprising: forming a first feed stream containing H2 and CO2; contacting a reverse water gas shift catalyst with the first feed stream at a first temperature and a first pressure in the range of 500 to 900 °C to carry out a reverse water gas shift reaction and form a first product stream containing CO and H2, the first product stream having a lower CO2 concentration and a higher CO concentration than the first feed stream; Contacting a Fischer-Tropsch catalyst with a second feed stream comprising H2 and at least a portion of the CO of the first product stream at a second temperature and a second pressure to form a second product stream comprising C5+ hydrocarbons, The reverse water gas shift catalyst is a supported reverse water gas shift catalyst, A carrier that is a cerium oxide carrier, a titanium oxide carrier, an aluminum oxide carrier, a zirconium oxide carrier, or a mixed oxide carrier comprising a mixture of two or more of cerium oxide, titanium oxide, aluminum oxide, and zirconium oxide, Nickel present in an amount in the range of 0.05 to 10% by weight of the catalyst based on the total weight of the catalyst, A method consisting of manganese present in an amount in the range of 0.5 to 20% by weight of the catalyst based on the total weight of the catalyst.

14. The method according to claim 13, wherein the carrier constitutes at least 70% by weight of the catalyst on an oxide basis.

15. The method according to claim 13, wherein nickel is present in the catalyst in an amount in the range of 0.1 to 10% by weight.

16. The method according to claim 13, wherein manganese is present in the catalyst in an amount in the range of 2 to 20% by weight.

17. The method according to claim 13, wherein the nickel to manganese ratio is in the range of 0.05:1 to 1:

1.

18. The method according to claim 13, wherein the molar ratio of H2 to CO2 in the first feed stream is in the range of 0.5:1 to 10:

1.

19. The method according to claim 13, wherein the reverse water gas shift reaction has a methane selectivity of 10% or less.

20. The method according to claim 13, comprising activating the reverse water gas shift catalyst with a reducing stream comprising a reducing gas.

21. The method according to claim 13, wherein the first product stream contains 75 mol% or less of CO2.

22. The method according to claim 13, wherein the first product stream contains 40 mol% or less of methane.

23. The method according to claim 13, wherein at least 25% of the CO in the first product stream is contained in the second feed stream.

24. The method according to claim 13, wherein the first product stream contains H2 and at least 25% of the H2 in the first product stream is contained in the second feed stream.

25. The method according to claim 13, wherein at least 10% of the CO2 in the first product stream is contained in the second feed stream.

26. The method according to claim 13, wherein the second feed stream does not contain a substantial amount of the CO2 of the first product stream.

27. The method according to claim 13, wherein the second feed stream has an H2:CO ratio in the range of 0.5:1 to 6:

1.

28. The method according to claim 13, wherein the second temperature is in the range of 200 to 350 °C.

29. The method according to claim 13, wherein the first temperature is at least 100 °C higher than the second temperature.

30. The method according to claim 13, wherein contacting the Fischer-Tropsch catalyst with the second feed stream to form a second product stream is carried out with a selectivity for C5+ alkanes of at least 30%.

31. The method according to claim 13, further comprising separating at least a portion of C1-C4 hydrocarbons from the second product stream to provide a light hydrocarbon stream.

32. The method according to claim 13, further comprising cooling at least a portion of the second product stream and heating at least a portion of the second feed stream by heat exchange between at least a portion of the second product stream and at least a portion of the second feed stream.

33. The method according to claim 13, further comprising recycling at least a portion of the H2 in the second product stream to the second feed stream.

34. The method according to claim 13, wherein at least a portion of the H2 in the second product stream is recycled to the first feed stream such that H2 < H1, and the H2 from the second product stream constitutes at least 90% of the H2 in the first feed stream.

35. The process according to claim 13, further comprising recycling at least a portion of the CO in the second product stream to the second feed stream or the first feed stream.

36. The method according to claim 13, wherein at least a portion of the CO2 in the second product stream is recycled to the first feed stream such that the CO2 from the second product stream constitutes at least 90% of the CO2 in the first feed stream.

37. A supported inverse water gas shift catalyst comprising: a support that is a cerium oxide support, a titanium oxide support, an aluminum oxide support, a zirconium oxide support, or a mixed oxide support comprising a mixture of two or more of cerium oxide, titanium oxide, aluminum oxide, and zirconium oxide; nickel present in an amount in the range of 0.05 to 10% by weight of the catalyst based on the total weight of the catalyst; and manganese present in an amount in the range of 0.5 to 20% by weight of the catalyst based on the total weight of the catalyst.

38. The catalyst according to claim 37, wherein at least the surface layer of the cerium oxide support contains at least 90% by weight of cerium oxide, for example, at least 95% by weight of cerium oxide, or at least 98% by weight of cerium oxide, based on the oxide.

39. The catalyst according to claim 37, wherein the total amount of cerium, titanium, aluminum, zirconium, manganese, and nickel in the catalyst is at least 90% by weight of the catalyst, for example, at least 95% by weight or at least 98% by weight, based on the metal.

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