Liquid hydrocarbon production in combination with hydrogen or hydrogen source

Abstract

Disclosed are pathways for producing liquid hydrocarbon products, including gasoline and / or diesel boiling range hydrocarbons, and in some cases renewable products having non-petroleum-derived carbons. In a representative process, a gaseous feed mixture comprising a combination of CO2 and H2 and / or CH4 (or other hydrocarbon sources of H2) is converted by reforming and / or reverse water gas shift (RWGS) reactions, optionally further in combination with Fischer-Tropsch (FT) synthesis and / or cracking. Preferred gaseous feed mixtures include biogas or other mixtures of CO2 and H2 that are not readily upgraded using conventional processes. The catalysts described herein have high activity for catalyzing the reforming (including dry reforming) of CH4 and other light hydrocarbons (e.g., those that have been produced by FT synthesis and recycled back to the process as a light end fraction) and simultaneously catalyzing the RWGS reaction. These attributes allow flexibility in the composition that may be efficiently translated. The use of an electrically heated reforming reactor in the first or initial reforming stage or the RWGS stage may improve the economy of small scale operation if desired.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application No. 63 / 344,599, filed on May 22, 2022, which is incorporated by reference in its entirety. Technical Field

[0003] Aspects of the present invention relate to processes and associated catalysts for producing liquid hydrocarbons, including naphtha boiling range hydrocarbons, jet fuel boiling range hydrocarbons, and / or diesel boiling range hydrocarbons, from a gaseous feed mixture including carbon dioxide (CO2). The process utilizes one or more reactions of reforming (including CO2 and / or steam reforming), reverse water gas shift (RWGS), and Fischer-Tropsch (FT) synthesis, optionally in combination with wax cracking and / or isomerization. Background Art

[0004] The search for alternatives to crude oil as a conventional carbon source for hydrocarbon products is increasingly driven by several factors. These include reduced petroleum reserves, higher expected energy requirements, and heightened concern about greenhouse gas (GHG) emissions from non-renewable carbon (herein, fossil carbon) sources. Hydrocarbon products of greatest industrial significance and interest include precursors for transportation and heating fuels and specialty chemicals in terms of replacing their carbon content with non-petroleum derived carbon. Liquid hydrocarbons, i.e., hydrocarbons that are liquid at room temperature, are representative of these hydrocarbon products.

[0005] Carbon dioxide (CO2) is the main contributor to GHG emissions and is found in the gases generated by combustion in engines, electricity production, and commercial and residential heating. Typically, a large number of small-scale and large-scale processes produce waste gases containing CO2, which are derived from the above-mentioned hydrocarbon products based on crude oil. In some cases, CO2 can be obtained as a component of a gas mixture including hydrogen (H2) and / or methane (CH4), wherein CO2 may or may not be a combustion product. Examples of such mixtures include industrial waste gases obtained from the production of H2 by reforming of CH4, wherein CO2 is used as a reactant (in the case of dry reforming) and / or is generated by a water-gas shift reaction. In addition, natural gas sources (although mainly methane) may also include a large amount of CO2 extracted in this resource. Other gaseous feed mixtures of CO2 and CH4 include those in which the latter component is a renewable resource, such as in the following specific cases: (i) biogas obtained from anaerobic bacterial digestion of biological waste or from wastewater treatment, (ii) gaseous products of biomass conversion (e.g., biomass gasification, pyrolysis or hydropyrolysis, such as in the case of supercritical water gasification of biomass), (iii) landfill gas, or (iv) gaseous products of electrochemical reduction of carbon dioxide.

[0006] In view of its abundance in natural gas reserves and petroleum-related gases, methane has become the focus of many possible synthetic routes. At present, natural gas is the most underutilized of fossil resources, and it is often flared / combusted in large quantities, especially in the case of "stranded" natural gas or other sources that are too isolated and / or insufficient in quantity, making them transported to large-scale processing facilities uneconomical propositions. In addition, fracking technology has led to a reduction in the price of natural gas in the United States, and the supply of this resource has increased globally. In addition, methane is one of the most common products that can be obtained from renewable resources, and in particular from those obtained from the processing of biological waste and biomass and the above-mentioned other resources. Therefore, methane, and especially the conversion of methane obtained from "renewable carbon" (referring to non-fossil carbon (including, for example, atmospheric CO2 and carbon derived from biomass), including sources such as biogas) represents a considerable area of ​​interest for development on an industrial scale with favorable economics.

[0007] The key commercial process for converting methane into fuel involves a first conversion step to produce synthesis gas (syngas), followed by a second downstream Fischer-Tropsch (FT) conversion step. With respect to the first conversion step upstream of the FT, known processes for producing synthesis gas from methane include partial oxidation reforming based on the highly exothermic oxidation of methane with oxygen, and autothermal reforming (ATR) based on a combination of highly exothermic oxidation of methane with oxygen and highly endothermic reforming of steam and methane and moderately endothermic water-gas shift to produce a process with a net enthalpy close to zero. In contrast, steam methane reforming (SMR) uses steam as an oxidant, making the thermodynamics significantly different, not only because the generation of steam itself may require energy input, but also because the reaction involving methane and water is highly endothermic. The SMR reaction proceeds according to the following:

[0008] CH4+H2O→CO+3H2.

[0009] Recently, it has also been proposed to use carbon dioxide as an oxidant for methane, so that the desired synthesis gas is formed by reacting carbon in its most oxidized form with carbon in its most reduced form, according to:

[0010] CH4+CO2→2CO+2H2.

[0011] This reaction is known as methane "dry reforming", and because it is highly endothermic, the thermodynamics of methane dry reforming are less favorable than those of an ATR or even an SMR. However, the stoichiometric consumption of 1 mole of carbon dioxide per mole of methane has the potential to reduce the overall carbon footprint of liquid fuel production, providing a "greener" consumption of methane. In the case of reforming higher hydrocarbons (e.g., C2-C6 alkanes), this rate of CO2 consumption per mole of feed increases, which may be desirable, for example, if hydrogen production (e.g., for refining processes) is a goal. In any case, the thermal barrier remains the primary challenge and is related to the fact that CO2 is fully oxidized and very stable, so that its activation as an oxidant requires significant energy. In view of this, many catalyst systems have been investigated for overcoming the activation barrier for methane dry reforming, and these are summarized in, for example, the review by Lavoie (Frontiers in Chemistry (November 2014), Vol. 2 (81): 1-17), which identifies heterogeneous catalyst systems as the most popular in terms of the catalytic approach used to carry out this reaction.

[0012] Although nickel-based catalysts have shown effectiveness in reducing the activation energy of the above-mentioned dry reforming reactions, high carbon deposition rates (coking) of these catalysts are also reported in Lavoie. Undesirable conversion of methane to elemental carbon can be carried out by methane cracking (CH4→C+2H2) or Bodo reaction (2CO→C+CO2) at the reaction temperatures generally required for methane dry reforming. Recently, other types of catalysts, including those including precious metals on a support containing ceria, have been described in US10,738,247, US10,906,808, US2020 / 0087144, and US 2020 / 0087576, which were transferred to the American Gas Technology Research Institute (Des Plaines, IL). Such catalysts have been shown to exhibit high activity and stability (low coking rates) in reforming based on a combination of CO2 alone or CO2 and steam. Additionally, the high tolerance to sulfur-containing contaminants (eg, H2S) exhibited by these catalysts can further improve process economics in terms of reducing costs typically associated with feed pretreatment.

[0013] Regarding the second step involving FT conversion, the synthesis gas containing a mixture of hydrogen and carbon monoxide (CO) is subjected to the continuous cracking of C–O bonds and the formation of C–C bonds with the incorporation of hydrogen. This mechanism provides the formation of hydrocarbons, and in particular linear alkanes, wherein the molecular weight distribution can be controlled to some extent by varying the FT reaction conditions (temperature and feed CO:H2 ratio) and the catalyst properties. Such properties include the pore size and other characteristics of the support material. The choice of catalyst can affect the FT product yield in other ways. For example, iron-based FT catalysts tend to produce more oxygenates, while ruthenium as the active metal tends to produce only paraffins. The reaction pathway of FT synthesis follows a statistical kinetic model, which results in hydrocarbons having an Anderson-Schultz-Flory distribution of their carbon numbers. The conversion level can be appropriately adjusted to favor the production of hydrocarbons with the desired molecular weight, although lower and higher carbon number hydrocarbons always constitute a part of the FT product composition. In summary, the prior art would benefit from technology that can efficiently convert industrially available gaseous mixtures containing CO2 with other beneficial reactants such as H2 and / or CH4 into products including liquid hydrocarbons, such as those that can be characterized as naphtha boiling range hydrocarbons, jet fuel boiling range hydrocarbons, or diesel boiling range hydrocarbons. Summary of the invention

[0014] Aspects of the present invention are associated with the discovery of a process in which CO2, an undesirable atmospheric pollutant that is considered to contribute to climate change, can be effectively used to produce valuable hydrocarbons, including liquid hydrocarbons used as transportation fuels, due to its carbon content. In this way, CO2 can be advantageously used to replace hydrocarbon fuels refined from petroleum and other fossil-derived sources. Although technologies for concentrating CO2 from air are available, such as via direct air capture routes, the present invention provides a viable option for producing hydrocarbons using air-extracted CO2 that can be implemented on an industrial scale. This is in contrast to, for example, CO2 sequestration, which is relatively expensive and limited in its capacity.

[0015] In this regard, the present invention relates to a method for producing C4 + The invention relates to novel pathways for producing hydrocarbons (e.g., comprising or consisting of naphtha-range, jet-range, and / or diesel-range hydrocarbons, separated and optionally recovered fractions of naphtha-range, jet-range, and / or diesel-range hydrocarbons), i.e., wherein some or all (e.g., at least about 70%) of their carbon content (expressed on a weight % or mole %) is not derived from petroleum, such as where the carbon content is renewable. Advantageously, regardless of whether the carbon content is renewable carbon, the representative liquid hydrocarbon products described herein (or the C4 hydrocarbons contained in these products) are not derived from petroleum. +At least a portion (e.g., at least about 20%, at least about 30%, or at least about 40%) of the total carbon content of the crude oil (e.g., hydrocarbons, or specific boiling range fractions separated and optionally recovered from these products) can be derived from CO2, e.g., initially present in the gaseous feed mixture and optionally extracted from air (e.g., via direct air capture). In the case where the renewable carbon content is also derived from CO2, such CO2 can be obtained, for example, from biogas (i.e., such CO2 was originally contained in biogas) or from gases produced by the decomposition, combustion, or gasification of biomass. In the case of non-renewable carbon content derived from CO2, such CO2 can be obtained, for example, as a fossil fuel combustion product. In any of these cases, and generally, regardless of whether the CO2 is obtained from (i) air, (ii) a renewable carbon source such as biomass (e.g., biomass that produces biogas), and / or (iii) an industrial waste gas such as a combustion product, it will be appreciated that the CO2 used to provide at least a portion of the carbon content is advantageously used for C4 + The production of hydrocarbons, rather than retaining them in the atmosphere or releasing them into the atmosphere.

[0016] Optionally combined with carbon content derived from CO2 (including renewable CO2), to the extent described above, the representative liquid hydrocarbon products described herein (including C4 + The hydrocarbons and specific boiling range fractions separated and optionally recovered from these products) can have a hydrogen content at least partially derived from: (a) "electrolysis hydrogen", which refers herein to hydrogen produced via electrolysis, optionally using renewable electricity such as derived from solar, wind, nuclear or hydropower, (b) "fossil hydrogen with carbon capture and storage (CCS)", which refers herein to hydrogen produced via coal gasification or natural gas reforming in combination with carbon capture and storage, (c) "biomass gasification hydrogen", which refers herein to hydrogen produced via biomass gasification, and (d) "methane pyrolysis hydrogen", which refers herein to hydrogen produced via methane pyrolysis. For example, the processes described herein and utilizing electrolysis hydrogen, fossil hydrogen with CCS, biomass gasification hydrogen, or methane pyrolysis hydrogen in a fresh supplemental H2-containing feed can be used to produce the products described herein, including such C4 + Hydrocarbons and such specific boiling range fractions. Thus, at least a portion of the total hydrogen content of these products may be derived from electrolytic hydrogen, fossil hydrogen with CCS, biomass gasification hydrogen or methane pyrolysis hydrogen.

[0017] Therefore, representative embodiments of the present invention relate to C4 + Hydrocarbon fractions, including those separated and optionally recovered C4 + A hydrocarbon fraction, such as a liquid fraction separated and optionally recovered in a process as described herein. Such C4 +The hydrocarbon fractions may include naphtha boiling range hydrocarbons, jet fuel boiling range hydrocarbons, and / or diesel boiling range hydrocarbons, for example, a given C4 + The hydrocarbon fraction may include substantially all (e.g., greater than about 95% by weight) of any of naphtha boiling range hydrocarbons, jet fuel boiling range hydrocarbons, or diesel boiling range hydrocarbons, or may consist of or consist essentially of hydrocarbons within such boiling ranges. According to specific embodiments, (i) any such liquid hydrocarbon product or C4 + At least about 20%, at least about 50%, at least about 80%, or at least about 95% of the total carbon content of the hydrocarbon fraction can be derived from atmospheric CO2 and / or biogas CO2 and / or CO2 in gases produced by decomposition, combustion, or gasification of biomass and / or (ii) any such liquid hydrocarbon product or C4 hydrocarbon product described herein. + At least about 20%, at least about 50%, at least about 80%, or at least about 95% of the total hydrogen content of the hydrocarbon product can be derived from electrolytic hydrogen, fossil hydrogen with CCS, biomass gasification hydrogen, or methane pyrolysis hydrogen. Importantly, the liquid hydrocarbon products produced by the processes described herein, as well as the C4 + The hydrocarbon fraction can have (i) a carbon content that is at least partially derived, and possibly substantially entirely derived, from atmospheric CO2 (e.g., obtained from direct air capture) and / or biogas CO2 and / or CO2 in gases produced by the decomposition, combustion or gasification of biomass and / or (ii) a hydrogen content that is at least partially derived, and possibly substantially entirely derived, from electrolytic hydrogen (e.g., obtained from solar and / or wind power generation), fossil hydrogen with CCS, biomass gasification hydrogen, or methane pyrolysis hydrogen. Thus, these products and fractions may be associated with processes as described herein, wherein atmospheric CO2 and / or biogas CO2 and / or CO2 from gases produced by decomposition, combustion or gasification of biomass may be present in a fresh supplemental CO2 and / or CH4-containing feed (e.g., such feed may include, essentially include, consist of, or consist essentially of atmospheric CO2 and / or biogas CO2 and / or CO2 from gases produced by decomposition, combustion or gasification of biomass) as an input to such processes; and / or electrolytic hydrogen, fossil hydrogen with CCS, biomass gasification hydrogen, or methane pyrolysis hydrogen may be present in a fresh supplemental H2-containing feed (e.g., such feed may include, essentially include, consist of, or consist essentially of electrolytic hydrogen, fossil hydrogen with CCS, biomass gasification hydrogen, or methane pyrolysis hydrogen) as an input to such processes. Any C4 + The hydrocarbon fractions, and in particular any recovered C4 + A hydrocarbon fraction may be an output of such a process.

[0018] Other aspects of the invention are associated with the discovery that common sources of CO2, and in particular gaseous mixtures of CO2, combined with H2 and / or a source of H2 (i.e., a hydrogen source such as CH4, C2H6, C3H8 and / or H2O) can be effectively used as a feedstock for producing liquid hydrocarbon products. Importantly, the entire feedstock and therefore all of these components can be used to obtain C4 + The reactants in one or more reactions of reforming of hydrocarbons (including CO2 and / or steam reforming), reverse water gas shift (RWGS) and Fischer-Tropsch (FT) synthesis, optionally in combination with wax cracking and / or isomerization. In the case of a gaseous feed mixture comprising both CH4 (as a hydrogen source) and CO2 (e.g., a gaseous feed mixture of biogas or comprising biogas), these components can be reacted in a reforming stage according to the above-mentioned dry reforming reaction to produce a synthesis gas intermediate comprising H2 and CO (i.e., a H2 / CO mixture). The intermediate can in turn be at least partially converted into a liquid hydrocarbon product via FT synthesis, and optionally via a combination of FT synthesis and wax cracking. The latter reaction can be used to adjust the carbon number distribution of hydrocarbons otherwise obtained from a separate FT synthesis, and is particularly useful for converting a wax fraction (e.g., comprising normal C2) otherwise contained in an FT synthesis effluent (in the absence of cracking) to a liquid hydrocarbon product. 20 + hydrocarbons) into normal or branched C4-C 19 hydrocarbons that contribute to the yield of liquid hydrocarbons from the process (e.g., present in the recovered C4 + liquid hydrocarbons in the hydrocarbon fraction).

[0019] In the case of a gaseous feed mixture comprising both H2 and CO2, for example, the gaseous feed mixture is or comprises an industrial waste gas, such as the tail gas of a pressure swing adsorber (PSA) used to purify H2 produced by steam methane reforming (or equivalent waste gas), or is or comprises a combination of atmospheric CO2 and / or biogas CO2 and / or CO2 in gases produced by decomposition, combustion or gasification of biomass with a mixture of electrolytic hydrogen, fossil hydrogen with CCS, biomass gasification hydrogen or methane pyrolysis hydrogen, H2 and CO2 can be reacted according to the RWGS reaction to produce a synthesis gas intermediate for conversion to liquid hydrocarbon products as described above, at least in part via FT synthesis, and optionally via a combination of FT synthesis and wax cracking. As is known in the art, the PSA tail gas used to purify H2 produced by steam methane reforming is a by-product obtained by producing H2 by reforming CH4 and steam. Simultaneously with the RWGS reaction, in the presence of CH4 in the H2 and CO2 gas mixture, CH4 and CO2 may react according to the above-described dry reforming reaction, thereby increasing the yield of H2 and CO in the syngas intermediate, wherein CO is obtained from the combination of RWGS and dry reforming.

[0020] Thus, other aspects of the invention are associated with the discovery that the catalysts described herein having high activity for catalyzing the reforming (including dry reforming) of CH4 and / or other hydrogen sources such as C2H6 and / or C3H8 are equally effective for catalyzing RWGS reactions under the same conditions. Thus, these properties of such catalysts are advantageous in producing liquid hydrocarbon products, particularly gaseous feed mixtures as described herein that include CO2 together with a source of H2 and / or H2 (i.e., a hydrogen source such as CH4, C2H6, C3H8, and / or H2O), all of which components can be advantageously used as reactants in these reactions. Otherwise such gaseous mixtures may be difficult to monetize and / or may typically be burned to obtain their calorific value. According to some embodiments, such as those involving processing gaseous mixtures on a relatively small scale, the use of an electrically heated reforming reactor in a first or initial stage (e.g., a reforming stage or an RWGS stage) to carry out one or both of these reactions can further improve processing efficiency and equipment compactness, thereby resulting in reduced costs. Small-scale operations may involve, for example, processing a gaseous feed mixture obtained from a low-capacity biogas production facility or a stranded gas reserve. The electrically heated reforming reactor may include one or more resistive or inductive heating elements for internal and / or external heating of the reforming reactor, and thereby effectively controlling the local and overall heat input into the reforming / RWGS catalyst bed described herein. Therefore, a representative electrically heated reforming reactor provides precise (e.g., axial and / or radial) and responsive bed temperature control, and examples of these bed temperature controls are described in co-pending U.S. Application No. 17 / 402,865 (published as US2022 / 0134298), and are incorporated herein by reference in their entirety.

[0021] Particular embodiments of the invention relate to processes for producing liquid hydrocarbon products (e.g., including naphtha boiling range hydrocarbons, jet fuel boiling range hydrocarbons, and / or diesel boiling range hydrocarbons), and liquid hydrocarbon products obtained from such processes, including within the process (e.g., present in a process stream, such as in an FT synthesis effluent or a refining effluent as described herein) or outside the process (e.g., a recovered C4 + The process comprises a first stage for reforming and / or RWGS reaction of the gaseous feed mixture, i.e., in a reforming stage, in an RWGS stage, or in a reforming / RWGS stage. This is followed by a second stage, i.e., a Fischer-Tropsch (FT) synthesis stage, of converting the synthesis gas intermediate (i.e., an H2 / CO mixture) produced in the first stage and comprising both H2 and CO. In particular, the intermediate is converted into C4 +The conversion step is at least partly carried out via FT synthesis, and optionally the step comprises a combination of both FT synthesis and wax cracking, optionally further combined with isomerization, wherein the wax cracking reaction is used to reduce the molecular weight of hydrocarbons that would otherwise be obtained from FT synthesis alone (in the absence of wax cracking), and preferably the combination of wax cracking and isomerization reactions is used to reduce the molecular weight of hydrocarbons that contain or additionally contain (in the absence of wax cracking and isomerization) normal C 20 + That is, in the case where a refining reactor is used in the FT synthesis stage, wax cracking combined with FT synthesis, and preferably wax cracking and isomerization combined with FT synthesis can be used to effectively reduce or eliminate such normal C ions that are otherwise contained in the FT synthesis effluent and / or the refining effluent. 20 + As described above, this is accomplished by adding the wax fraction (e.g., including normal C 20 + hydrocarbons) into normal or branched C4-C 19 hydrocarbons that contribute to the yield of liquid hydrocarbons from the process (e.g., C4 + The yield of such hydrocarbons in the hydrocarbon fraction).

[0022] Wax cracking, optionally in combination with isomerization, may be performed after FT synthesis, such as in a separate downstream wax cracking reactor, or may be performed simultaneously with FT synthesis, such as in the case of a mixture of FT catalyst and cracking catalyst used in the FT reactor, or in the case of a bifunctional FT / cracking catalyst having both FT functional components and cracking functional components. In the case of a separate wax cracking reactor or a FT reactor in which at least some wax cracking is performed, the effluent obtained from continuous wax cracking or simultaneous wax cracking in the FT synthesis stage may be referred to as FT synthesis effluent. According to a more specific embodiment, the FT synthesis stage may include (i) a FT reactor for performing wax cracking simultaneously with FT synthesis, optionally in combination with isomerization (e.g., using a catalyst mixture or a bifunctional catalyst), and (ii) a finishing reactor downstream of the FT reactor for performing further wax cracking separately from the FT synthesis, optionally in combination with further isomerization. The finishing reactor may contain one or more finishing catalysts (e.g., wherein at least one such finishing catalyst has the same composition and / or the same form as the cracking catalyst contained in the FT reactor, but no FT catalyst is present, or has the same composition as the cracking functional component of the bifunctional catalyst contained in the FT reactor, such as having the same composition as the bifunctional catalyst, but excluding the FT functional component), such that the FT reactor can provide a FT synthesis effluent and the finishing reactor can provide a finishing effluent.

[0023] According to a specific embodiment, in the first stage, a gaseous feed mixture comprising mainly (i) H2 and CO2 or (ii) a hydrogen source and CO2 is contacted with a catalyst as described herein (e.g., a reforming / RWGS catalyst) to produce a synthesis gas intermediate. Other specific embodiments relate to the above process, according to which biogas is converted into a liquid hydrocarbon product, that is, the gaseous feed mixture is or comprises biogas. Advantageously, biogas provides a readily available gaseous feed mixture or a portion thereof, which gaseous feed mixture or a portion thereof comprises mainly CH4 and CO2. Importantly, the C4 of the liquid hydrocarbon product prepared in this manner is +The carbon content of the hydrocarbons is derived from CH4 and CO2 originating from organic waste, i.e., the carbon content is renewable. Other specific embodiments relate to the above-mentioned process, according to which gases derived from decomposition, combustion or gasification or biomass (optionally mixed with supplemental H2, including CO, H2, CO2 and optionally CH4) are converted into liquid hydrocarbon products, i.e., the gaseous feed mixture is or includes gases derived from decomposition, combustion or gasification of biomass (optionally mixed with supplemental H2). Representative processes according to these specific embodiments include contacting a gas mixture including a combination of CO2 and H2 and / or a hydrogen source, biogas (or a gaseous feed mixture including biogas) and / or gases derived from decomposition, combustion or gasification of biomass with a reforming / RWGS catalyst in a reforming stage (and possibly but not necessarily a reforming / RWGS stage) to produce a synthesis gas intermediate including a H2 / CO mixture, which gas mixture is optionally mixed with supplemental H2, including CO, H2, CO2 and optionally CH4. The process may further comprise converting the synthesis gas intermediate into liquid hydrocarbon products in a FT synthesis stage, at least partly via FT synthesis and possibly a combination of both FT synthesis and wax cracking, optionally further combined with isomerization, as described above.

[0024] Other aspects relate to the ability to recycle fractions of the FT synthesis effluent or the refining effluent obtained from the FT synthesis stage, whether or not, in the case of the FT synthesis effluent, the effluent is obtained after optional wax cracking and / or optional isomerization. In particular, together with the liquid hydrocarbon product, the FT synthesis effluent or the refining effluent may include a fraction rich in (i) H2 and CO2 or (ii) a hydrogen source and CO2, the components (i) or (ii) of the fraction may include unconverted substances and / or light hydrocarbon by-products (e.g., CH4, C2H6, C3H8) leaving the FT synthesis stage (e.g., the FT reactor used in the stage or the refining reactor used in the stage). The representative process may further include separating (A) from the FT synthesis effluent (whether or not obtained after optional wax cracking and / or optional isomerization) or the refining effluent a fraction comprising C4 +A liquid hydrocarbon product of hydrocarbons, and (B) a fraction rich in (i) H2 and CO2 or (ii) a hydrogen source and CO2. Fraction (B) can be recycled to the reforming stage, the RWGS stage or the reforming / RWGS stage, or can be recycled to the FT synthesis stage. Otherwise, part of fraction (B) can be recycled to these respective stages. The ability to recycle in this manner lies in the effectiveness of the reforming / RWGS catalyst described herein: H2 and CO in the synthesis gas intermediate are produced by (i) CO2 together with H2 (via RWGS reaction) and by (ii) CO2 together with a hydrogen source (via dry reforming reaction). For example, in the case of a hydrogen source comprising light alkanes (e.g., one or more of CH4, C2H6, C3H8), the dry reforming reaction can be carried out according to the following general reaction:

[0025] C n H 2n+2 +nCO2→2nCO+(n+1)H2.

[0026] Operations utilizing recycled FT synthesis effluent or fractions of the refined effluent obtained by separating a liquid hydrocarbon fraction from such effluent can advantageously provide high overall conversions approaching 100% of the input carbon (including CO2) (or carbon present in CO2, combined with carbon from any hydrocarbons and any other carbon source) because all reactants (including CO2) of the RWGS and dry reforming reactions are recycled to extinction, as well as in the C4 + The process provides a high overall utilization of the input carbon (including CO2) in the formation of hydrocarbons. The recycled fraction can be enriched in (i) H2 and CO2, based on their combined amounts in the recycled fraction, or (ii) a hydrogen source and CO2, based on their combined amounts in the recycled fraction, relative to the FT synthesis effluent or the refining effluent and also relative to the synthesis gas intermediate, and is typically enriched in both (i) and (ii). In this regard, an important advantage associated with the present invention relates to the ability of the reforming / RWGS catalyst described herein to treat a "light tail" fraction of the FT synthesis effluent or the refining effluent enriched in (i) or (ii), which is recycled to the first stage of the process, thereby ultimately replacing substantially all or all of the carbon (including CO2) fed to the process. 2, ) (e.g., in a fresh supplementary feed or more specifically in a fresh supplementary feed containing CO2 and / or CH4) to C4 + The composition of the input feed can be preferentially controlled to produce a feed with the correct stoichiometry so that substantially all or all of the carbon (including CO2) fed to the process is converted to C4 +This provides a superior yield of liquid hydrocarbons based on the CO2 carbon fed or input to the process compared to processes in which the light ends fraction or a major portion thereof is not recycled. In the case of operation with recycle, for example, at least about 80%, at least about 90%, or even at least about 95% of the CO2 carbon fed to the process is converted to C4 hydrocarbons in the liquid hydrocarbon product and / or separated and optionally recovered. + C4 in hydrocarbon fraction + In the case of a recycle operation, for example, at least about 80%, at least about 90%, or even at least about 95% of the input carbon fed to the process is converted into liquid hydrocarbon products and / or C4 hydrocarbons that are separated and optionally recovered. + C4 in hydrocarbon fraction + hydrocarbon.

[0027] In other representative processes utilizing recycling, C4 + All or part of the separated fraction of hydrocarbons is recycled to the reforming stage or RWGS stage to increase the recovery of C4 + Control of the product composition of hydrocarbons. For example, one or more separated fractions of the process may include a naphtha boiling range hydrocarbon fraction. In the case of recycling all or a portion of this fraction to the first stage of the process for reforming naphtha boiling range hydrocarbons to provide additional synthesis gas, the product composition or product yield of the process can be converted to recover other types of hydrocarbons, such as jet fuel boiling range hydrocarbons and / or diesel boiling range hydrocarbons obtained in the corresponding separated and recovered fractions rich in these hydrocarbons. The flexibility of the reforming / RWGS catalyst in reforming a variety of hydrocarbons other than CH4 makes it possible to control the product composition or product yield in this way.

[0028] In summary, this paper describes a process for producing liquid hydrocarbon products from undesirable CO (including waste gases containing CO). In some cases, if CO is extracted from air, the process is effectively reversed by restoring atmospheric CO to hydrocarbons CO emissions from hydrocarbon combustion. In an embodiment, the H present in the gaseous feed mixture is produced by the electrolysis of water, and particularly using electricity from renewable sources such as solar and wind energy, fossil hydrogen with CCS, biomass gasification hydrogen or methane pyrolysis hydrogen to further achieve environmental benefits. It will be appreciated by those skilled in the art that the process described herein has the potential for replacing conventional liquid hydrocarbon products refined from fossil fuels (including gasoline and diesel fuel) with the recirculated CO removed from the atmosphere by the renewable hydrocarbon products made. These processes can also convert CO and renewable hydrocarbons, such as in biogas or those generally derived from biomass (e.g., from gasification or biomass hydropyrolysis).

[0029] These and other embodiments, aspects and advantages associated with the present invention will be apparent from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] A more complete understanding of exemplary embodiments of the present invention and its advantages may be obtained by referring to the following description in view of the accompanying drawings which provide a flow diagram of a process for producing a liquid hydrocarbon product, wherein like reference numerals are used to identify like or similar features.

[0031] Figure 1 Depicted is a diagram showing the use of two reaction stages (i.e., a reforming or RWGS stage and a FT synthesis stage) in combination with a separation stage to produce C4 + Flow chart of an embodiment of a process for producing a liquid hydrocarbon product from hydrocarbons. Advantageously, light tail fractions such as unconverted CO and H2, as well as CO2 and optionally light hydrocarbons (e.g., CH4, C2H6) separated downstream of the FT synthesis stage can be recycled. Figure 2 In a specific embodiment of the invention, the FT synthesis stage comprises both a FT reactor and a finishing reactor.

[0032] Figure 2 Depicted are diagrams for production including C4 + A flow chart of an embodiment of a process for producing a liquid hydrocarbon product from hydrocarbons, in which the FT synthesis stage more particularly comprises both a FT reactor and a finishing reactor, wherein optionally a portion of the fresh make-up H2-containing feed is fed directly to the finishing reactor. Figure 1 In addition to the recycling of the light ends fraction shown, the figure also shows the separation of C4 + Optional recycle of at least a portion of a hydrocarbon fraction such as a naphtha boiling range hydrocarbon fraction.

[0033] Figure 3 Depicted are the distillation curves obtained for the liquid hydrocarbon products recovered from the FT synthesis, with boundaries for gasoline, jet fuel and diesel boiling range hydrocarbons.

[0034] Figure 4 The performance of a reforming catalyst that is also active in catalyzing the reverse water gas shift (RWGS) reaction is depicted, expressed as total hydrocarbon conversion over an operating period of more than 500 hours.

[0035] Figure 5 Describes the method used to obtain Figure 4 The results shown are performance of the reforming catalyst but expressed as the H2:CO molar ratio of the syngas produced during the operating cycle.

[0036] Figure 6 Describes the method used to obtain Figure 4 and Figure 5 The results shown in FIG. 5 are based on the performance of the reformer catalyst, but are expressed in terms of the composition of the reformer product during the operating cycle.

[0037] Figure 1 and Figure 2 It should be understood as a diagrammatic representation of the processes and certain principles involved. To facilitate explanation and understanding, these drawings provide a simplified overview and it should be understood that the depicted elements are not necessarily drawn to scale. Figure 1 and Figure 2 The illustrated processes illustrate a number of possible features as described herein, which may be implemented individually or in any combination. That is, not all features (e.g., not all individual operations and their associated process flows and equipment) are required or necessary to practice the various inventive embodiments described herein, i.e., it is understood that various specific features may be implemented independently of other features. To further facilitate explanation and understanding, Figure 1 and Figure 2 An overview of various features implemented in reforming combined with FT synthesis is provided. Some associated equipment such as certain containers, heat exchangers, valves, instruments and utilities are not shown because their detailed description is not necessary for understanding or practicing various inventive embodiments. Such equipment is obvious to those skilled in the art with knowledge of the present disclosure. According to other embodiments within the scope of the present invention, other processes for producing liquid hydrocarbon products such as renewable fuels via reforming and / or RWGS reactions and having configurations and compositions determined in part according to specific processing purposes are also obvious. DETAILED DESCRIPTION

[0038] The expressions "wt%" and "mol%" are used herein to denote weight percent and mole percent, respectively. The expressions "wt-ppm" and "mol-ppm" denote parts by weight and parts by mole, respectively. For an ideal gas, "mol%" and "mol-ppm" are equal to a percentage by volume and parts by million by volume, respectively. In some cases, the percentage "%" is given relative to the same value, whether expressed as weight percent or mole percent. For example, (i) C4 + The percentage of feed carbon content of hydrocarbons, or (ii) the percentage of carbon content of renewable carbon or carbon derived from CO2 of the liquid hydrocarbon product have the same value whether expressed as a weight percentage or a mole percentage.

[0039] As used herein, the terms "substantially" and "substantially" refer to a degree of at least 95 mol% in the case of reference to a gas, and at least 95 wt% in the case of reference to a liquid or solid. For example, the phrase "substantially all" may be replaced by "at least 95 mol%" or "at least 95 wt%", as the case may be. With respect to a reference to an item being "substantially absent" or "substantially absent", this should be understood to mean that the item is present in an amount of at most 5 mol%, or at most 5 wt%, of the total amount mentioned, as the case may be. In a preferred embodiment, "substantially all" may be replaced by "all", "substantially absent" may be replaced by "absent", and "substantially absent" may be replaced by "absent".

[0040] The term "liquid hydrocarbon product" refers to a product comprising hydrocarbons that are liquid at room temperature. Examples of such hydrocarbons are hydrocarbons having 4 or more carbon atoms, referred to herein as "C4 + hydrocarbon".

[0041] "Hydrogen source" refers to one or more compounds that can generate hydrogen according to various reactions described herein and occurring in the reforming stage, the RWGS stage, or the reforming / RWGS stage. Examples of such compounds are CH4, C2H6, C3H8, and H2O, and the hydrogen source may include one or more of these compounds. According to a specific embodiment, the hydrogen source may include one or more of CH4, C2H6, and C3H8, which generate hydrogen according to a dry reforming reaction as described herein. According to a specific embodiment, the hydrogen source may include one or more of CH4, C2H6, and C3H8, which generate hydrogen according to a steam reforming reaction as described herein. For example, for any embodiment described herein, "hydrogen source" may refer to CH4, and the amount (e.g., concentration) of the hydrogen source may refer to methane alone. Alternatively, "hydrogen source" may refer to a combination of CH4 and C2H6, and the amount (e.g., concentration) of the hydrogen source may refer to the combined amount of methane and ethane. Alternatively, the "hydrogen source" may refer to a combination of CH4, C2H6, and C3H8, and the amount (e.g., concentration) of the hydrogen source may refer to a combined amount of methane, ethane, and propane. Alternatively, the "hydrogen source" may refer to a combination of CH4, C2H6, C3H8, and H2O, and the amount (e.g., concentration) of the hydrogen source may refer to a combined amount of methane, ethane, propane, and water (e.g., in the form of steam).

[0042] The term "naphtha boiling range hydrocarbons" is synonymous with and may be replaced by "gasoline boiling range hydrocarbons" and refers to a hydrocarbon fraction that includes hydrocarbons having boiling points within the initial ("front end") distillation temperature characteristic of C5 hydrocarbons, e.g., from about 30°C (86°F) to about 40°C (104°F), with a representative value of 35°C (95°F), and an end point distillation temperature generally from about 130°C (266°F) to about 169°C (336°F), and typically from about 141°C (286°F) to about 163°C (325°F), with a representative value of 155°C (311°F). The terms "jet fuel boiling range hydrocarbons" and "diesel boiling range hydrocarbons" refer to a hydrocarbon fraction that includes hydrocarbons having boiling points within the front end distillation temperature range of from about 135°C (275°F) to about 175°C (347°F), with a representative value of 155°C (311°F). The distillation endpoint temperatures for jet fuel boiling range hydrocarbons are generally from about 275°C (527°F) to about 300°C (572°F), with a typical value of 285°C (545°F), while the distillation endpoint temperatures for diesel fuel boiling range hydrocarbons are generally from about 300°C (572°F) to about 400°C (752°F), with a typical value of 370°C (698°F). These boiling point temperatures are also characteristic of the corresponding petroleum derived gasoline, jet fuel and diesel boiling range fractions, and can be measured according to ASTM D86, with the endpoint being the 95% recovery value. For the purpose of characterizing (i) naphtha boiling range hydrocarbons, (ii) jet fuel boiling range hydrocarbons, and (iii) diesel boiling range hydrocarbons, according to some embodiments, these can be considered to be hydrocarbon fractions comprising hydrocarbons having normal boiling points (i) between 35°C (95°F) and 135°C (275°F), (ii) between 135°C (275°F) and 300°C (572°F), and (iii) between 300°C (572°F) and 400°C (752°F), respectively. Such fractions can be readily determined, for example, from fractionation of the liquid hydrocarbon product obtained by the processes described herein (e.g., after separation of the liquid hydrocarbon product from a H2 / CO2-rich fraction or a hydrocarbon / CO2-rich fraction).

[0043] In the representative processes described herein, the first or initial stage may be referred to as the "reforming / RWGS stage" to indicate that reforming and reverse water gas shift (RWGS) reactions occur to some extent. As understood in the art and in the context of the present disclosure, reforming refers to the reaction of CH4 and / or possibly other hydrocarbons (e.g., those hydrocarbons that contribute to the hydrogen source as described above, such as C2H6 and / or C3H8) with an oxidant to produce H2 and CO (syngas), wherein the oxidant preferably includes CO2, but may include any one or more of CO2, H2O, and O2. The RWGS reaction is understood in the art as follows:

[0044] H2+CO2→H2O+CO.

[0045] In a wider range of embodiments, the first or initial stage may be a "reforming stage", in which reforming of CH4 and / or possible other hydrocarbons occurs as described above, without necessarily RWGS reactions. In other wider embodiments, the first or initial stage may be a "RWGS stage", in which RWGS reactions occur as described above, without necessarily reforming of CH4 and / or possible other hydrocarbons. For example, in the case of a gaseous feed mixture comprising CH4 and CO2, the first stage may be a reforming stage, in which these components react to produce synthesis gas. However, typically, according to the RWGS reaction, at least some of the H2 of the synthesis gas present in the reaction mixture reacts with the CO2 also present in the reaction mixture, so that the reforming stage can be more specifically characterized as a "reforming / RWGS stage". In the case of a gaseous feed mixture comprising H2 and CO2, the first stage may be a RWGS stage, in which these components react as described above. Therefore, it can be understood that in the case where the gaseous feed mixture together with CO2 includes CH4 (and / or possible other hydrocarbons such as C2H6 and / or C3H8) or H2, respectively, the first or initial stage may be a reforming stage or a RWGS stage. In the case of any gaseous feed mixture comprising CH4 (and / or possibly other hydrocarbons such as C2H6 and / or C3H8) together with CO2 (eg, comprising CH4, CO2 and H2), the first or initial stage may be a reforming / RWGS stage.

[0046] Gaseous feed mixture

[0047] For production including C4 +An exemplary process for producing a liquid hydrocarbon product of hydrocarbons comprises (a) contacting a gaseous feed mixture with a reforming / RWGS catalyst in a reforming stage or an RWGS stage to produce a synthesis gas intermediate comprising a H2 / CO mixture; and (b) converting the synthesis gas intermediate into a liquid hydrocarbon product at least in part via Fischer-Tropsch (FT) synthesis. Representative gaseous feed mixtures primarily comprise (i) H2 and CO2 or (ii) a hydrogen source and CO2, wherein the term "primarily" means that these gaseous feed mixtures comprise (i) at least 50 mol% of a combined amount of H2 and CO2, or (ii) at least 50 mol% of a combined amount of a hydrogen source (e.g., which may include one or more compounds as described above) and CO2. In more specific embodiments, the gaseous feed mixture comprises (i) at least 75 mol%, at least about 90 mol%, or at least about 95 mol% of a combined amount of H2 and CO2, or (ii) at least 75 mol%, at least about 90 mol%, or at least about 95 mol% of a combined amount of a hydrogen source and CO2. According to other embodiments, the representative gaseous feed mixture may include at least 50 mol%, at least about 75 mol%, at least about 90 mol%, or at least about 95 mol% of the combined amount of CH4, CO2, and H2. According to other embodiments, the representative gaseous feed mixture may include at least 50 mol%, at least about 75 mol%, at least about 90 mol%, or at least about 95 mol% of the combined amount of CO, CO2, and H2. Alternatively, or in combination with any of the features described herein, the representative gaseous feed mixture may include a small amount or no other components. For example, in the case where the gaseous feed mixture primarily includes (i) H2 and CO2, such a gaseous feed mixture may include a hydrogen source (e.g., may include CH4, optionally in combination with other hydrocarbons such as C2H6 and / or C3H8) in an amount less than about 25 mol%, less than about 10 mol%, less than about 5 mol%, or less than about 1 mol%. In the case where the gaseous feed mixture primarily includes (ii) a hydrogen source (e.g., which may include one or more compounds as described above) and CO2, such a gaseous feed mixture may include H2 in an amount of less than about 25 mol%, less than about 10 mol%, less than about 5 mol%, or less than about 1 mol%. In the case where the gaseous feed mixture primarily includes (i) H2, CO2, and CO, such a gaseous feed mixture may include a hydrogen source (e.g., may include CH4, optionally in combination with other hydrocarbons such as C2H6 and / or C3H8) in an amount of less than about 25 mol%, less than about 10 mol%, less than about 5 mol%, or less than about 1 mol%. Any gaseous feed mixture described herein may include oxygen-containing components other than CO2, such as one or more of CO, H2O, and O2, each in an amount (alone) or in a combined amount of less than about 35 mol%, less than about 15 mol%, less than about 10 mol%, less than about 5 mol%, or less than about 1 mol%.In this case, due to the limited presence or absence of oxidants other than CO 2 , any reforming of CH 4 occurring in the reforming stage or in the reforming / RWGS stage may be substantially or entirely dry reforming and / or may be substantially or entirely unaccompanied by partial oxidation.

[0048] In the case where the gaseous feed mixture mainly comprises (ii) a hydrogen source (e.g., CH4 alone or optionally in combination with other hydrocarbons such as C2H6 and / or C3H8) and CO2, step (a) may be a reforming stage as described above and an optional reforming / RWGS stage, according to which, in either case, the H2 and CO in the H2 / CO mixture of the synthesis gas intermediate may be produced by the reaction of CH4 and CO2. In the case where the gaseous feed mixture mainly comprises (i) H2 and CO2, step (a) may be an RWGS stage as described above and an optional reforming / RWGS stage. If step (a) is an RWGS stage, the H2 in the H2 / CO mixture of the synthesis gas intermediate may be the H2 that is unreacted or represents the equilibrium amount in the RWGS reaction of H2 and CO2 as described above, and the CO in the H2 / CO mixture may be the CO produced in the RWGS reaction or may alternatively be the unreacted CO. If step (a) is a reforming / RWGS stage, the gaseous feed mixture comprising primarily (i) H2 and CO2 may further comprise CH4, optionally in combination with other hydrocarbons such as C2H6 and / or C3H8. Thus, the H2 and CO in the H2 / CO mixture of the syngas intermediate may be produced by the reaction of CH4 (optionally in combination with other hydrocarbons such as C2H6 and / or C3H8) and CO2. It may be further appreciated that, regardless of whether the gaseous feed mixture comprises CH4 (optionally in combination with other hydrocarbons such as C2H6 and / or C3H8) such that H2 may be produced by reforming, the H2 and CO in the H2 / CO mixture of the syngas intermediate may represent the balance in the RWGS reaction. In a specific embodiment in which the gaseous feed mixture comprises CH4 (optionally in combination with other hydrocarbons such as C2H6 and / or C3H8), the H2 and CO in the H2 / CO mixture of the syngas intermediate may represent the balance in the combined reforming and RWGS reactions. To the extent that CH4 (optionally in combination with other hydrocarbons such as C2H6 and / or C3H8) and CO2 react in the reforming stage or reforming / RWGS stage according to the dry reforming reaction described above, the reaction of CH4 (optionally in combination with other hydrocarbons such as C2H6 and / or C3H8) with one or both of the other oxidants H2O and O2 may also produce H2 and / or CO in the H2 / CO mixture of the syngas intermediate. For example, these other oxidants may also be present in the gaseous feed mixture, or alternatively, H2O may be present in the reaction mixture as a product of the RWGS reaction (although not necessarily in the gaseous feed mixture).

[0049] The gaseous feed mixture or at least the compounds present in the mixture (e.g., CO2, CH4 and / or H2) can be obtained from a variety of sources. Advantageously, such sources include waste gases that are considered to have little or no economic value, or gases derived from wastes that are considered to have little or no economic value, and these waste gases may contribute to atmospheric CO2 levels in addition. For example, the gaseous feed mixture can be or can include industrial process waste gases obtained from a steel manufacturing process or a non-iron product manufacturing process. Other processes that can obtain all or part of the gaseous feed mixture include petroleum refining processes (e.g., processes that produce refinery waste gases), renewable hydrocarbon fuel (biofuel) production processes (e.g., pyrolysis processes, such as hydropyrolysis processes or fatty acid / triglyceride hydrogenation conversion processes), biomass and coal (e.g., lignocellulose and charcoal) gasification processes, power generation processes, carbon black production processes, ammonia production processes, other chemicals (e.g., methanol) production processes and coke manufacturing processes. In some cases, the gaseous feed mixture may be or may include (i) wellhead gas including methane or (ii) a gaseous product of the electrochemical reduction of carbon dioxide.

[0050] According to some embodiments, the gaseous feed mixture may include CO2 obtained from direct air capture (DAC) (i.e., CO2 extracted from the atmosphere). Alternatively or in combination, the gaseous feed mixture may include H2 obtained from the electrolysis of water, such as by using renewable electricity (e.g., generated by wind or solar power). For example, the gaseous feed mixture may include CO2 and H2 (e.g., in combined amounts as described above), wherein all or substantially all of the CO2 is obtained from direct air capture and / or all or substantially all of the H2 is electrolytic hydrogen (i.e., hydrogen obtained from the electrolysis of water). Alternatively, such hydrogen may be fossil hydrogen with carbon capture and storage (CCS), biomass gasification hydrogen, or methane pyrolysis hydrogen.

[0051] A specific gaseous feed mixture of interest is biogas, which is understood to include anaerobic bacterial digestion products of biogenic waste as well as landfill gas. Typically, biogas contains methane in an amount from about 35 mol % to about 90 mol % (e.g., about 40 mol % to about 80 mol % or about 50 mol % to about 75 mol %) and CO2 in an amount from about 10 mol % to about 60 mol % (e.g., about 15 mol % to about 55 mol % or about 25 mol % to about 50 mol %). The gases N2, H2, H2S, and O2 may be present in small amounts (e.g., in a combined amount of less than 20 mol %, or less than 10 mol %). Thus, in some embodiments, the gaseous feed mixture may be or may include biogas.

[0052] Another gaseous feed mixture of interest is natural gas including methane in an amount from about 65 mol % to about 98 mol % (e.g., from about 70 mol % to about 95 mol % or from about 75 mol % to about 90 mol %) and CO2 in an amount from about 3 mol % to about 35 mol % (e.g., from about 5 mol % to about 30 mol % or from about 10 mol % to about 25 mol %). Other hydrocarbons (e.g., ethane and propane) and nitrogen may be present in small amounts. Of particular interest is stranded natural gas, which is not easily converted into a synthesis gas intermediate in an economical manner using known processes. Therefore, in some embodiments, the gaseous feed mixture may be or may include natural gas, for example including a relatively high amount of CO2, such as at least about 10 mol % or even at least about 25 mol %.

[0053] Another gaseous feed mixture of interest is a hydrogen-depleted PSA tail gas, such as obtained from a hydrogen production process involving steam methane reforming (SMR) as described above. The mixture may include (i) methane in an amount from about 5 mol % to about 45 mol % (e.g., about 10 mol % to about 35 mol % or about 15 mol % to about 25 mol %), (ii) CO2 in an amount from about 20 mol % to about 75 mol % (e.g., about 25 mol % to about 70 mol % or about 35 mol % to about 60 mol %), and (iii) H2 in an amount from about 10 mol % to about 45 mol % (e.g., about 15 mol % to about 40 mol % or about 20 mol % to about 35 mol %). The remainder of the stream may primarily include water vapor and / or CO. Therefore, in some embodiments, the gaseous feed mixture may be or may include a hydrogen-depleted PSA tail gas.

[0054] Another gaseous feed mixture of interest is the gaseous effluent from biological (bacterial) fermentation integrated with a hydrogen production process. Such integrated fermentation processes are described in, for example, US 9,605,286; US 9,145,300; US2013 / 0210096; and US2014 / 0028598. This gaseous effluent can include (i) methane in an amount of from about 5 mol % to about 55 mol % (e.g., from about 5 mol % to about 45 mol % or from about 10 mol % to about 40 mol %), (ii) CO in an amount of from about 5 mol % to about 75 mol % (e.g., from about 5 mol % to about 60 mol % or from about 10 mol % to about 50 mol %), and (iii) H in an amount of from about 5 mol % to about 40 mol % (e.g., from about 5 mol % to about 30 mol % or from about 10 mol % to about 25 mol %). The remainder of the stream can primarily include water vapor and / or CO. Thus, in some embodiments, the gaseous feed mixture may be or may include such a gaseous effluent from fermentation.

[0055] Another gaseous feed mixture of interest is a gaseous effluent from biomass gasification, optionally supplemented with additional H2. Such a gaseous effluent may include (i) methane in an amount from about 0 mol% to about 15 mol% (e.g., about 0 mol% to about 10 mol% or about 0 mol% to about 5 mol%), (ii) CO2 in an amount from about 0 mol% to about 60 mol% (e.g., about 5 mol% to about 50 mol% or about 15 mol% to about 45 mol%), and (iii) H2 in an amount from about 5 mol% to about 40 mol% (e.g., about 5 mol% to about 30 mol% or about 10 mol% to about 25 mol%). The balance of the stream may consist primarily of water vapor and / or CO. Thus, in some embodiments, the gaseous feed mixture may be or may include such a gaseous effluent from biomass gasification, optionally supplemented with additional H2.

[0056] In some embodiments, the composition of the gaseous feed mixture as described herein can represent the combined composition of two or more streams fed to the reactor for the reforming stage or RWGS stage, respectively. A separate stream can include, for example, a recycle stream or a stream of a substance, or a stream rich in a substance relative to the gaseous feed mixture (e.g., a stream rich in CH4). In a specific embodiment utilizing recycling, as described herein, the gaseous feed mixture can be provided to such a reactor or reaction stage as a combination of (A) fresh supplementary feed and (B) a fraction rich in (i) H2 and CO2 or (ii) a hydrogen source and CO2. That is, the gaseous feed mixture can include (A) and (B), so that according to a specific embodiment associated with any "gaseous feed mixture" described herein, the fresh supplementary feed can be a part of such a gaseous feed mixture. Therefore, the components of the gaseous feed mixture can include (A) a fresh gaseous feed mixture component, i.e., the fresh gaseous feed mixture component is used as an input for the entire process, and (B) a recycled gaseous feed mixture component. Specific examples of (A) include fresh supplemental feed containing CO2 and / or CH4, the former of which may include CO2 obtained from DAC, exhaust gas associated with biomass combustion or biomass gasification, and fresh supplemental feed containing H2, the former of which may include H2 as electrolytic hydrogen, fossil hydrogen with carbon capture and storage (CCS), biomass gasification hydrogen, or methane pyrolysis hydrogen. Exemplary fresh supplemental feed containing CO2 and / or CH4 includes sustainable carbon such as from a biogenic source, and thus may include (a) CO2 obtained from DAC, (b) CO2 and / or CH4 obtained from biogas, and / or (c) CO2, CO and / or CH4 obtained from biomass gasification. Specific examples of (B) include fractions rich in (i) H2 and CO2 or (ii) a hydrogen source and CO2, and hydrocarbon recycle, i.e., rich in C4 + Recycling of at least a portion of a separated fraction of hydrocarbons, such as a fraction enriched in naphtha boiling range hydrocarbons.

[0057] To the extent that any components (A) and (B) of the gaseous mixture may be combined prior to (upstream) a reactor used in a reforming stage or RWGS stage, or may otherwise be added directly to the reactor as separate streams, it will be understood that a "gaseous feed mixture" may, in certain embodiments, refer to a composition formed within the reactor (e.g., in situ, such as at the reactor inlet) or a composition represented by at least a combination of components (A) and (B). With respect to the various fresh and recycled components of the gaseous feed mixture, and taking into account the various possible combinations of such components, typically, the gaseous feed mixture fed to the reactor used in the reforming stage or RWGS stage may include CO2, CO, H2, and a light tail fraction (e.g., CH4 and optionally other light hydrocarbons such as C2H6 and C3H8), with supplemental H2O (steam) added as needed to facilitate SMR and possibly adjust the H2:CO molar ratio of the syngas intermediate. To the extent that (A) the fresh gaseous feed mixture components may include light hydrocarbons (e.g., primarily CH4) in combination with CO2 and H2, and H2O (steam) may also be present in the gaseous feed mixture (e.g., due to the RWGS reaction and / or due to (B) recycled gaseous feed mixture components), the reforming / RWGS reactor used in the first stage of the process can be considered a "triple reforming" reactor in that the reactor is used to carry out (i) dry reforming, (ii) steam reforming, and (iii) RWGS reactions as needed to produce a syngas intermediate comprising a H2 / CO mixture.

[0058] According to alternative embodiments, any description of (i) a fraction rich in H2 and CO2 or (ii) a fraction rich in a source of hydrogen and CO2 may more specifically refer to "a portion" of such fraction (i) or (ii), such as a recycled portion of such fraction, or even a portion of such a recycled portion, consistent with the further disclosure below, including reference to Figure 1 and Figure 2 For example, a purge stream, a sampling stream, etc. may be removed from a fraction of the FT synthesis effluent enriched in (i) H2 and CO2 or (ii) a hydrogen source and CO2, leaving only a recycle portion of such fraction (i) or (ii) to be returned to the process, such as to the first stage (e.g., a reforming stage, such as a reforming / RWGS stage, or a RWGS stage) and / or the FT synthesis stage, optionally with different portions of such recycle portion of fraction (i) or (ii) being directed to different stages. In the same manner, any description of hydrocarbon recycling, such as a fraction enriched in C4 +Recycling of a separated fraction of hydrocarbons may more particularly refer to a portion of such a fraction. In view of the above description and the further description herein regarding the recycling operation, the gaseous feed mixture may include fresh make-up feed, optionally combined with a recycled portion of (i) a fraction rich in H2 and CO2 or (ii) a fraction rich in a source of hydrogen and CO2 (or even a portion of such fractions (i) or (ii)) separated from the FT synthesis effluent, and / or optionally combined with hydrocarbon recycling.

[0059] According to the above description, in some embodiments, the composition of the gaseous feed mixture as described herein can represent the combined composition of two or more streams fed or input into the reactor for the reforming stage or RWGS stage respectively. The separate streams may include, for example, fresh feed and / or recycle streams (e.g., fresh supplementary feed and / or (A) fraction (i) or (ii) as described herein, or a recycled portion of such fraction and / or (B) hydrocarbon recycle) or a stream of one component, or a stream enriched in one component relative to the gaseous feed mixture (e.g., a stream enriched in CH4). According to alternative embodiments, any of the composition characteristics described above for the gaseous feed mixture may be applicable to fresh supplementary feed, which may, for example, be a portion of a gaseous feed mixture that is fed or input into a reactor used in the reforming stage or RWGS stage, such as in the case of a recycle operation.

[0060] Reforming / RWGS Catalysts

[0061] As described above, an important aspect associated with the present invention is the discovery that the catalysts described herein can catalyze both the reforming (including dry reforming) and the RWGS reaction of hydrocarbons (e.g., CH4, C2H6 and / or C3H8) to various degrees, depending on the composition of the specific gaseous feed mixture as described above and the specific reforming / RWGS conditions used. This provides considerable flexibility relative to the composition of the gaseous feed mixture that can be processed into a synthesis gas intermediate using reforming and / or RWGS reactions. As used herein, the term "reforming / RWGS catalyst" refers to a catalyst that has at least some activity in catalyzing reforming and / or at least some activity in catalyzing RWGS in the initial stages of the process, whether this stage can be characterized as a reforming stage or an RWGS stage. In a preferred embodiment, given the gaseous feed mixture and the conditions used, such a catalyst will catalyze both reactions at least to some extent in the reforming / RWGS stage.

[0062] Representative embodiments include contacting a gaseous feed mixture as described herein with a reforming / RWGS catalyst in a reforming stage or RWGS stage. The contacting may be performed in batches, but is preferably performed continuously, wherein the gaseous feed mixture flows continuously to one or more reactors (and preferably a single reactor) containing a reforming / RWGS catalyst used in the stage (e.g., such that the catalyst is disposed in a catalyst bed volume within the reactor). Thus, the reforming stage or RWGS stage may also include continuously removing a synthesis gas intermediate comprising a H2 / CO mixture from the reactor, i.e., an intermediate product comprising H2 and CO, wherein such H2 and CO may be unreacted gases (present in the gaseous feed mixture) or may be produced by reforming and / or RWGS reactions as described above.

[0063] The catalysts described herein exhibit a number of important advantages over conventional reforming catalysts, particularly for certain components that may be present in the gaseous feed mixture, such as C2 + In terms of tolerance to olefins and / or H2S or other sulfur-containing components (e.g., mercaptans). Such properties reduce the significant pretreatment requirements of conventional processes and thereby increase flexibility, allowing economical production of synthesis gas intermediates from common process streams containing large concentrations of such components even on relatively small operating scales. In some embodiments, any of the gaseous feed mixtures described herein may include one or more C2 in addition to CO2, CH4, and / or H2. + Olefins such as ethylene, propylene, butene, pentene and / or C6 + In one embodiment, the gaseous feed mixture may include one or more C2 +Olefins, the olefins are selected from the group consisting of ethylene, propylene, butene, pentene and the combination of these. Any one of these olefins or the combination of olefins can be, for example, present in an amount of at least about 0.3 mol % (for example, from about 0.3 mol % to about 15 mol %), such as at least about 1 mol % (for example, from about 1 mol % to about 10 mol %) or a total (combination) amount. Typically, any one or more hydrocarbons except CH4 can be present in a gaseous feed mixture in an amount of at least about 3 mol % (for example, from about 3 mol % to about 45 mol %), such as at least about 5 mol % (for example, from about 5 mol % to about 30 mol %) or a total (combination) amount. With regard to their sulfur resistance, reforming / RWGS catalysts as described herein provide other advantages associated with the ability to process sulfur-containing gaseous feed mixtures, such as those including natural gas or derived from natural gas, depending on its source, the source can include sulfur or other sulfur-containing components in the form of H2S. Typically, the gaseous feed mixture can include at least about 1 mole-ppm (e.g., from about 1 mole-ppm to about 1 mole%) total sulfur (e.g., present as H2S and / or other sulfur-containing components), such as at least about 3 mole-ppm (e.g., from about 3 mole-ppm to about 5000 mole-ppm) total sulfur, at least about 10 mole-ppm (e.g., from about 10 mole-ppm to about 1000 mole-ppm) total sulfur, or at least about 100 mole-ppm (e.g., from about 100 mole-ppm to about 1000 mole-ppm) total sulfur.

[0064] The improvements in stability of the reforming / RWGS catalysts described herein, particularly with respect to gaseous feed mixtures including non-CH4 hydrocarbons and / or sulfur-containing components that typically promote catalyst deactivation as described herein, can be attributed at least in part to their high activity, which is manifested at lower operating (reactor or catalyst bed) temperatures. This in turn contributes to reduced rates of coke formation and deposition on the catalyst surface and extended stable operation. Given the ability of the reforming / RWGS catalysts described herein to achieve a given or target level of performance (e.g., in terms of CH4 conversion) at relatively low operating (or average catalyst bed) temperatures as reforming / RWGS conditions, such catalysts may alternatively be referred to as "cold" reforming catalysts, and the associated processes as "cold" reforming processes.

[0065] Representative reforming / RWGS catalysts suitable for catalyzing the reforming and / or RWGS reactions described herein include a noble metal and possibly two or even more than two noble metals on a solid support. The solid support may include cerium oxide, or more specifically, cerium oxide combined with a suitable binder (e.g., alumina) in a suitable amount (e.g., from about 5 wt % to about 35 wt %) to impart mechanical strength.

[0066] The phrase "on a solid support" is intended to encompass catalysts wherein the active metal is on the surface of the support and / or in the porous internal structure of the support. The solid support preferably includes a metal oxide, and cerium oxide is of particular interest. By the weight of the solid support (e.g., relative to the total amount of metal oxides in the solid support), cerium oxide can be present in an amount of at least about 60 wt %, and preferably at least about 75 wt %. Whether or not it is in oxide form, cerium can be present in an amount from about 30 wt % to about 80 wt % of the catalyst, and preferably from about 40 wt % to about 65 wt %. The solid support can include all or substantially all (e.g., greater than about 95 wt %) of cerium oxide, or in addition all or substantially all (e.g., greater than about 95 wt %) of the combined amount of cerium oxide and a second metal oxide (e.g., aluminum oxide) used as a binder. According to certain embodiments, the reforming / RWGS catalyst may include a precious metal such as Pt on a solid support including ceria in an amount as described above (e.g., at least about 60 wt%), wherein alumina represents all or substantially all of the balance of the solid support (e.g., ceria and alumina are present in a combined amount of at least about 95 wt% of the solid support), which amount of alumina may correspond to all or substantially all of the balance of the reforming / RWGS catalyst, excluding the metal (e.g., Pt) deposited on the solid support. A representative solid support may include at least about 70 wt% or at least about 75 wt% ceria, of which at least about 10 wt% or at least about 15 wt% is alumina, the latter component of the solid support being a relatively non-acidic metal oxide that increases mechanical strength.

[0067] In the solid support, one or more of the metal oxides other than cerium oxide, such as aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, magnesium oxide, calcium oxide, iron oxide, vanadium oxide, chromium oxide, nickel oxide, tungsten oxide, strontium oxide, etc., can also be present independently in a separate amount, or in the case of two or more such other metal oxides, in a combined amount accounting for a small portion of the solid support, such as less than about 50% by weight, less than about 30% by weight, less than about 10% by weight, or less than about 5% by weight. Preferably, one or more of silicon oxide, titanium oxide, zirconium oxide, magnesium oxide, calcium oxide, iron oxide, vanadium oxide, chromium oxide, nickel oxide, tungsten oxide, and strontium oxide are substantially absent in the solid support. For example, these metal oxides can be present independently in a separate amount, or in the case of two or more such other metal oxides, in a combined amount of less than about 3% by weight, less than about 0.5% by weight, or even less than about 0.1% by weight of the solid support. For the purpose of illustration, in a specific embodiment, (i) silicon oxide (silicon dioxide) can be present in an amount less than about 0.5 weight % of the solid support, (ii) nickel oxide can be present in an amount less than about 0.5 weight % of the solid support, or (iii) silicon oxide and nickel oxide can be present in a combined amount less than about 0.5 weight % of the solid support. In other embodiments, the solid support may include one or more of such other metal oxides, the metal oxide including aluminum oxide, independently in a separate amount, or in the case of two or more such other metal oxides, in an amount accounting for the combined amount of the major part of the solid support, such as greater than about 50 weight %, greater than about 70 weight %, or greater than about 90 weight %. In this case, the solid support may also optionally include a small portion of the solid support, such as less than about 50 weight %, less than about 30 weight % or less than about 10 weight % of the cerium oxide. This small portion of cerium oxide may also represent the entire or substantially entire remainder of the solid support, which is not represented by one or more of such other metal oxides.

[0068] According to a specific embodiment, in addition to cerium oxide, the solid support may include a second metal oxide used as a binder for cerium oxide. This second metal oxide may be selected from the group of other metal oxides mentioned above, i.e., aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, magnesium oxide, calcium oxide, iron oxide, vanadium oxide, chromium oxide, nickel oxide, tungsten oxide, and strontium oxide. This second metal oxide may generally be present in an amount from about 1% to about 45% by weight of the solid support, typically from about 5% to about 35% by weight, and often from about 10% to about 25% by weight. Preferably, the solid support includes a combined amount of cerium oxide and a second metal oxide of usually at least about 85% by weight, typically at least about 95% by weight, and often at least about 99% by weight of the solid support. The solid support may include a combined amount of cerium oxide and a second metal oxide of usually at least about 85% by weight, typically at least about 92% by weight, and often at least about 95% by weight of the reforming / RWGS catalyst. The preferred second metal oxide used as a cerium oxide binder is aluminum oxide.

[0069] A preferred characteristic of a solid support (e.g., comprising primarily ceria) and, therefore, a reforming / RWGS catalyst is low acidity. In this regard, it is believed that excess acid sites on the support or catalyst, and particularly strong Acid sites contribute to coking and catalyst deactivation during reforming and / or RWGS reactions. Importantly, while strong acid sites are known to promote activity in many important commercial reactions, low Acid site ratio or concentration still has advantages. Widely used methods for determining and quantifying the acid site intensity of solid materials are to use ammonia as the programmed temperature desorption of molecular probe (NH3-TPD). According to the method, a sample of solid material is prepared by degassing and activation under elevated temperature and inert environment to remove water and other combined substances. Then the sample is saturated with NH3, saturation temperature (e.g., 100°C), and subsequently purged with an inert gas (e.g., helium), providing conditions for removing any physically adsorbed NH3. The programmed temperature desorption of activated and saturated samples is initiated by raising the temperature to a final temperature (e.g., 400°C) at a predetermined rate (e.g., 10°C / minute) under an inert gas stream. The concentration of NH3 in the gas is continuously measured because it is driven from the acid sites of the solid material, which has an increased intensity corresponding to the increased desorption temperature. The determination of NH3 concentration in a flowing inert gas can be carried out, for example, using a gas chromatograph (GC-TCD) with a thermal conductivity detector.

[0070] Typically, the NH3 concentration versus temperature profile will include peaks at low and high temperatures corresponding to sites of the solid material having relatively low and high acid strengths, respectively. The areas under these peaks can then provide the relative concentrations of acid sites of different types of acid strength (e.g., expressed as a percentage of the total acid sites), or the areas can be used to determine the absolute concentrations of the different types (e.g., expressed in milliequivalents per gram of solid material). In the case where a solid support or reforming / RWGS catalyst produces two peaks in the NH3 concentration versus temperature profile over a relevant range (e.g., from 100°C to 400°C), the first low temperature peak can be associated with weak Lewis acid sites, while the second high temperature peak can be associated with strong Lewis acid sites. acid sites. For a representative solid support (e.g., primarily comprising cerium oxide) and a reforming / RWGS catalyst having such a support (in view of the relatively small or negligible effect of the catalytically active metals deposited on such a support on the NH3-TPD analysis), the NH3 concentration versus temperature distribution obtained by NH3-TPD analysis within a temperature range from 100°C to 400°C (wherein such a distribution has, for example, two identifiable peaks) may exhibit a maximum NH3 concentration at a temperature less than about 300°C (e.g., from about 150°C to about 300°C), and more typically at a temperature less than about 250°C (e.g., from about 150°C to about 250°C). Thus, this maximum NH3 concentration may be associated with a low temperature peak corresponding to a weak Lewis acid site, wherein the maximum NH3 concentration and the temperature at which this concentration is exhibited define a point on this low temperature peak. Based on the peak area of ​​the low temperature peak, relative to the temperature corresponding to the strong The peak area of ​​the higher temperature peak of the acid site, Lewis acid sites can account for the total acid sites (e.g., total Lewis acid and The maximum NH3 concentration may be, for example, at a temperature from about 300°C to about 350°C, or more typically from about 300°C to about 325°C. The maximum NH3 concentration associated with the low temperature peak is generally greater than the maximum NH3 concentration associated with the higher temperature peak, which further indicates that weak Lewis acid sites account for a majority of the total acid sites of the solid support or reforming / RWGS catalyst. In a representative embodiment, the solid support or reforming / RWGS catalyst may have a Lewis acid site concentration of at least about 0.25 milliequivalents per gram (meq / g) (e.g., from about 0.25 meq / g to about 1.5 meq / g), and more typically at least about 0.35 milliequivalents per gram (meq / g) (e.g., from about 0.35 meq / g to about 0.85 meq / g).

[0071] The solid support (e.g., consisting essentially of cerium oxide) and the reforming / RWGS catalyst comprising such a support may have a carbon content of from about 1 m 2 / g to about 100m2 / g, such as from about 10m 2 / g to about 50m 2 The surface area of ​​the carrier and / or catalyst can be from about 2 to about 75 nm, such as from about 5 to about 50 nm. The support and / or catalyst may have (i) from about 10% to about 80%, such as from about 30% to about 55%, of pore volume attributed to macropores of >50 nm, (ii) from about 20% to about 85%, such as from about 35% to about 60%, of pore volume attributed to mesopores of 2 to 50 nm, and / or (iii) less than about 2%, such as less than about 0.5%, of pore volume attributed to micropores of <2 nm. The pore size distribution may be obtained using the Barrett, Joyner, and Halenda methods.

[0072] Noble metals are understood to refer to a class of metallic elements that resist oxidation. In representative embodiments, the noble metals of the reforming / RWGS catalyst, and in some cases at least two of the noble metals, may be selected from the group consisting of platinum (Pt), rhodium (Rh), ruthenium (Ru), palladium (Pd), silver (Ag), osmium (Os), iridium (Ir) and gold (Au), according to specific embodiments, the term "consisting of" is only used to indicate that the group member is selected from the noble metal, but generally does not exclude the addition of other noble metals and / or other metals. Therefore, a catalyst comprising a noble metal encompasses a catalyst comprising at least two noble metals, as well as a catalyst comprising at least three noble metals, and likewise a catalyst comprising two noble metals and a third non-noble metal such as a promoter metal (e.g., a transition metal). According to preferred embodiments, the precious metal is present in an amount from about 0.05 wt % to about 5 wt %, from about 0.1 wt % to about 3 wt %, from about 0.3 wt % to about 1 wt %, or from about 0.5 wt % to about 2 wt %, or alternatively at least two precious metals are each independently present in such an amount, based on the weight of the catalyst. For example, a representative reforming / RWGS catalyst may include a precious metal Pt, a precious metal Rh, or a combination of two precious metals Pt and Rh, wherein such precious metals are independently present in an amount within any of these ranges (e.g., from about 0.05 wt % to about 5 wt %), or in a combined amount within any of these ranges. That is, Pt may be present in such an amount, Rh may be present in such an amount, or a combination of Pt and Rh may be present in such an amount. Preferred noble metal-containing reforming / RWGS catalysts include one or both of Pt and Rh, either alone or in combination, either of which may be present in an amount from about 0.3 wt % to about 1 wt % on a support that includes, substantially includes, or consists essentially of ceria and an optional metal oxide binder (e.g., alumina) as described above. Pt is particularly preferred as the noble metal. Regardless of the noble metal used or the specific amount used, it is preferred that these noble metals are in their elemental (metallic or zero oxidation state) form. For example, for the preferred noble metal-containing reforming / RWGS catalysts described above, such catalysts may include one or both of Pt and Rh, either alone or in combination, either of which may be present in their respective elemental form in an amount from about 0.3 wt % to about 1 wt % based on the weight of the catalyst. However, other (compound) forms of Pt and / or Rh may also be present, preferably non-elemental forms of Pt and / or Rh or generally non-elemental forms of the precious metals are present independently in individual amounts or in the case of two or more precious metals in a combined amount of less than about 1 wt. %, less than about 0.5 wt. %, or even less than about 0.1 wt. % of the reforming / RWGS catalyst.

[0073] In representative embodiments, one or two noble metals (e.g., Pt and / or Rh) may be substantially the only one or two noble metals present in the reforming / RWGS catalyst, such that, for example, any other noble metals are present in an amount or combined amount of less than about 0.1% by weight, or less than about 0.05% by weight, based on the weight of the catalyst. In other representative embodiments, one or two noble metals (e.g., Pt and / or Rh) are substantially the only metals present in the catalyst, except for metals present in the solid support (e.g., such as cerium present in the solid support as cerium oxide). For example, in addition to the one or two noble metals and the metal of the solid support, any other metals may be present in an amount or combined amount of less than about 0.1% by weight or less than about 0.05% by weight, based on the weight of the catalyst. In some embodiments, certain metals may be substantially absent from the catalyst, whether in elemental form or in compound form (e.g., in oxide form as a metal oxide component of the solid support). For example, certain metals may impart undesirable acidity, provide insubstantial catalytic activity, and / or catalyze undesirable reactions in the solid support. In specific embodiments, one or more of Si, Ti, Zr, Mg, Ca, Fe, V, Cr, Ni, W, and Sr are substantially absent from the solid support. For example, these metals may be present independently in separate amounts, or in the case of two or more such metals, in a combined amount of less than about 0.5 wt %, less than about 0.1 wt %, or even less than about 0.05 wt % of the reforming / RWGS catalyst or the solid support of the catalyst. For example, one or more of Si, Zr, Mg, and Ni may be present in these separate amounts or in combined amounts. Any metal present in the catalyst, including the noble metals, may have a metal particle size generally ranging from about 0.3 nanometers (nm) to about 20 nm, typically from about 0.5 nm to about 10 nm, and often from about 1 nm to about 5 nm.

[0074] Precious metals can be incorporated into solid supports according to known techniques for catalyst preparation, including sublimation, impregnation or dry mixing. In the case of impregnation, which is a preferred technique, one or more soluble compounds of the precious metals can be contacted with a solid support in an impregnation solution in a polar (aqueous) or non-polar (e.g., organic) solvent, preferably under an inert atmosphere. For example, the contact can preferably be carried out under stirring in an ambient atmosphere of nitrogen, argon and / or helium, or in a non-inert atmosphere such as air. The solvent can then be evaporated from the solid support, for example, using heating, flowing gas and / or vacuum conditions, leaving a dry precious metal-impregnated support. Precious metals can be impregnated in solid supports, such as in the case of impregnating a single precious metal (e.g., Pt), or in the case of two precious metals being impregnated simultaneously and both being dissolved in the same impregnation solution, or impregnated (e.g., sequentially) using different impregnation solutions and contact steps. In any case, the noble metal-impregnated support may undergo further preparation steps, such as washing with a solvent to remove excess noble metal and impurities, further drying, calcination, etc. to provide a reforming / RWGS catalyst.

[0075] The solid support itself can be prepared according to known methods, such as extrusion to form cylindrical particles (extrudates) or oil droplets or spray drying to form spherical particles. Regardless of the specific shape of the solid support and the resulting catalyst particles, as described above, the amount of the noble metal present in the catalyst refers to the average weight of such noble metals in a given catalyst particle (e.g., having any shape such as cylindrical or spherical), regardless of the specific distribution of the noble metal in the particle. In this regard, it is understood that different preparation methods can provide different distributions, such as noble metals are mainly deposited on or near the surface of the solid support, or noble metals are evenly distributed throughout the solid support. Typically, by the weight of the solid support or by the weight of the catalyst, the weight percentage described herein can refer to the weight percentage in a single catalyst particle, but more generally refers to the average weight percentage on a large number of catalyst particles, such as the number of catalyst beds in a reactor used in the first or initial stage for reforming and / or RWGS.

[0076] Restructuring / RWGS conditions

[0077] In the first or initial stage, reforming and / or RWGS reaction is carried out by contacting the gaseous feed mixture with a reforming / RWGS catalyst as described herein, and preferably reforming and / or RWGS reaction is carried out simultaneously, preferably using a flow stream of the gaseous feed mixture continuously to improve process efficiency. For example, contact can be carried out by continuously flowing the gaseous feed mixture through a reactor (which may be referred to as a reforming / RWGS reactor) containing a reforming / RWGS catalyst containing a precious metal as described herein. The reactor is maintained under reforming / RWGS conditions, i.e., conditions within the reactor vessel, and more specifically, conditions within the reforming / RWGS catalyst bed contained in the vessel. In the case of such conditions for carrying out reforming, these conditions include temperatures, pressures, and flow rates for effectively converting methane and optionally other hydrocarbons into hydrogen. Alternatively, but preferably in combination, these conditions are effective for converting CO2 into CO and thereby carrying out the RWGS reaction.

[0078] Reforming / RWGS conditions for one or both of these reactions include temperatures generally from about 649°C (1200°F) to about 927°C (1700°F), typically from about 725°C (1337°F) to about 900°C (1652°F), and often from about 750°C (1382°F) to about 880°C (1616°F). In preferred embodiments, the processes described herein can effectively reform (oxidize) a hydrogen source (e.g., CH4 and / or possibly other hydrocarbons such as C2H6 and / or C3H8) as described herein and / or conduct RWGS reactions at significantly lower temperatures compared to representative conventional reforming temperatures of 816°C (1500°F) due to the high activity of the catalyst. For example, reforming / RWGS conditions may include temperatures ranging from about 677° C. (1250° F.) to about 788° C. (1450° F.), or from about 704° C. (1300° F.) to about 760° C. (1400° F.). Where dry reforming occurs, if the gaseous feed mixture comprises CO2 as the oxidant for reforming, with relatively little or no H2O and / or O2, higher temperatures may be used, such as from about 843° C. (1550° F.) to about 1010° C. (1850° F.), or from about 885° C. (1625° F.) to about 941° C. (1725° F.). The presence of significant concentrations (e.g., 100 to 1000 mole-ppm) of H2S and / or other sulfur-containing contaminants can warrant increased temperatures, such as in the range of from about 732°C (1350°F) to about 843°C (1550°F), or from about 760°C (1400°F) to about 816°C (1500°F), to maintain desired conversion levels (e.g., greater than about 85% CH4 conversion). Advantageously, it has been found that the compensating effect of increasing temperature in response to increased sulfur concentration in the gaseous feed mixture does not adversely affect catalyst stability. That is, the overall catalyst life is substantially unchanged relative to a comparison between baseline sulfur-free operation and sulfur-containing operation conducted at the higher compensating temperatures.

[0079] Particularly in the case of large-scale operation, the reactor is operated with limited heat release to its surroundings (e.g., in the case of adiabatic operation) so that the catalyst bed temperature can vary as a given reaction proceeds (e.g., a fixed bed temperature profile can be characterized by an increasing or decreasing profile along the axial length of the reactor in the case of an exothermic or endothermic reaction, respectively). Therefore, the temperatures given herein associated with reforming / RWGS conditions or other downstream FT reaction conditions and / or cracking reaction conditions should be understood as average (or weighted average) catalyst bed temperatures. However, in view of the high activity of the catalyst compositions described herein, particularly with respect to reforming / RWGS catalysts, the temperatures given herein, and particularly those temperatures associated with reforming / RWGS conditions, may in some embodiments be maximum or peak catalyst bed temperatures.

[0080] Still other reforming / RWGS conditions may also include a pressure above ambient pressure, i.e., above a gauge pressure of 0 kPa (0 psig), corresponding to an absolute pressure of 101 kPa (14.7 psia). Because the reforming reaction produces more moles of product than moles of reactants, equilibrium may be favored at relatively low pressures in some cases. Representative reforming / RWGS conditions may include a gauge pressure generally from about 0 kPa (0 psig) to about 2.00 MPa (290 psig), typically from about 100 kPa (15 psig) to about 1.50 MPa (218 psig), and often from about 500 kPa (73 psig) to about 1.00 MPa (145 psig). According to some embodiments, it may be desirable to operate at higher pressures, for example in the range of from about 207 kPa (30 psig) to about 5.2 MPa (750 psig), such as from about 1.4 MPa (200 psig) to about 3.4 MPa (500 psig). For example, the gaseous effluent recycled from the downstream FT reaction or optional wax cracking or isomerization may have a pressure P greater than 2.1 MPa (300 psig). 再循环 , and in order to minimize the energy losses associated with lowering the pressure of this recycle stream, in this case the reforming / RWGS pressure may be increased to bring it close to P 再循环 or the same (e.g., the reforming / RWGS reactor pressure may be P 再循环 At least 50% of P 再循环 At least 75% of P 再循环 90% or P 再循环 Representative reforming / RWGS conditions may also include typically from about 0.05 hr -1 About 10 hours -1 , typically from about 0.1 hr -1 To about 8.0hr -1 , and often from about 0.5hr -1 To about 5.0hr -1WHSV. As understood in the art, WHSV is the weight flow rate of the gaseous feed mixture (or the total weight flow rate of all inputs or gaseous feed mixture components as described above to one or more reactors used in the reforming stage or RWGS stage) divided by the total weight of the catalyst in the reforming / RWGS reactor, and represents the equivalent catalyst bed weight of the gaseous feed mixture (or all inputs or components) processed per hour. WHSV is related to the inverse of the reactor residence time. The reforming / RWGS catalyst can be contained in the reactor in the form of a fixed bed, but other catalyst systems are also possible, such as moving beds and fluidized bed systems that may be beneficial in processes using continuous catalyst regeneration. Regardless of the specific bed configuration, preferably, the catalyst bed includes discrete particles of the reforming / RWGS catalyst, which is contrary to the overall form of the catalyst. For example, such discrete catalyst particles can have a spherical or cylindrical diameter of less than about 10 mm and often less than about 5 mm (e.g., about 2 mm or about 3 mm). In the case of cylindrical catalyst particles (eg, formed by extrusion), these may have a comparable length dimension (eg, from about 1 mm to about 10 mm, such as about 5 mm).

[0081] Advantageously, within any of the above temperature ranges and relative to a gaseous feed mixture including CH4, the high activity of the catalyst can achieve a conversion of at least about 60% (e.g., from about 60% to about 99%), at least about 75% (e.g., from about 80% to about 99%), at least about 85% (e.g., from about 85% to about 99%), or at least about 90% (e.g., from about 90% to about 97%) of that component. For a given gaseous feed mixture and reforming / RWGS catalyst, the desired conversion level can be obtained or controlled by adjusting the specific reactor or catalyst bed temperature and / or other reforming / RWGS conditions (e.g., WHSV and / or pressure), as will be understood by those skilled in the art based on the knowledge gained from this disclosure. Advantageously, the noble metal-containing catalysts described herein can have sufficient activity to achieve significant CH4 conversion, such as at least about 60% or at least about 75%, in a stable manner at temperatures of up to about 732°C (1350°F), or even up to about 704°C (1300°F) (e.g., as a peak or maximum catalyst bed temperature). In the case of dry reforming, such as if the oxidant used for reforming (depending on the composition of the gaseous feed mixture) is primarily, substantially all, or all CO2 as described above, such CH4 conversion levels can be achieved at higher temperatures, such as up to about 918°C (1685°F), or in some cases up to about 885°C (1625°F) (e.g., as a peak or maximum catalyst bed temperature). As understood in the art, the conversion of CH4 can be calculated based on the following:

[0082] 100*(CH4 进料 -CH4产物 ) / CH4 进料 ,

[0083] Among them CH4 进料 is the total amount (e.g., total weight or total moles) of CH4 in the gaseous feed mixture supplied to the one or more reactors used in the reforming stage or RWGS stage (or the total amount in all inputs or in all gaseous feed mixture components), and CH4 产物 is the total amount of CH4 in the synthesis gas intermediate obtained from this stage. In the case of continuous processing, these total amounts can be more conveniently expressed as flow rate or total amount per unit time (e.g., total weight / hr or total mole / hr). For other hydrocarbons that may be present in the gaseous feed mixture, such as C2H6 and / or C3H8, the same or higher conversion levels can be achieved, replacing CH4, but more preferably in combination with CH4. Under a given set of reforming / RWGS conditions, these C2 and / or C3 hydrocarbons are generally more easily converted to synthesis gas intermediates relative to CH4. The conversion of C2H6 and / or C3H8 can be determined in a manner similar to that described above for the determination of CH4 conversion. These conversion levels of CH4, C2H6 and / or C3H8 can be based on a "single pass" conversion achieved in a single pass through the reforming / RWGS stage (e.g., the reforming / RWGS reactor of this stage), or based on the overall conversion achieved by returning a recycled portion of the FT synthesis effluent or the refining effluent to the reforming / RWGS stage (e.g., the reforming / RWGS reactor of this stage), as described herein. In this regard, the recycled portion of (i) the H2 and CO2-rich fraction or (ii) the hydrogen source and CO2-rich fraction (or even a portion of such fraction (i) or (ii)) can contain unconverted CH4, C2H6 and / or C3H8, which can be converted continuously through the first reaction stage, thereby increasing the conversion of these light hydrocarbons on an overall basis. Similarly, by returning a recycled portion of the FT synthesis effluent or the refining effluent, i.e., recycling hydrocarbons obtained from all or a portion of a separated fraction, such as a separated fraction rich in naphtha boiling range hydrocarbons (which may alternatively be referred to as a naphtha boiling range hydrocarbon fraction), the overall conversion of hydrocarbons can be increased relative to the single pass conversion. To the extent that such fractions may contain a certain amount of CH4, C2H6 and / or C3H8, the use of hydrocarbon recycling can also increase the conversion of these light hydrocarbons on an overall basis.

[0084] In view of reforming reactions that produce both H2 and CO (e.g., reforming of CH4, C2H6 and / or C3H8), the concentrations of both components in the syngas intermediate (reformate) can be increased relative to the gaseous feed mixture (or the combined input or gaseous feed mixture components fed to one or more reactors used in the reforming stage or RWGS stage). In the presence of CO2 in the gaseous mixture, the RWGS reaction alone or in combination with the reforming can also result in an increase in the CO concentration. In this regard, the extent of the RWGS reaction according to which CO2 is converted to CO under equilibrium constraints can be characterized as a conversion of CO2 in the reforming stage or RWGS stage to at least about 60%, at least about 70%, or at least about 80%, the conversion being determined in a manner similar to that described above for the determination of CH4 conversion. In some embodiments, depending on the H2 concentration in the gaseous feed mixture and the extent of the RWGS reaction, the concentration of CO can be increased, while the concentration of H2 can be decreased. In representative embodiments, the syngas intermediate may include CO in an amount of at least about 5 mol% (e.g., from about 5 mol% to about 50 mol%) or at least about 8 mol% (e.g., from about 8 mol% to about 35 mol%). In other embodiments that achieve high levels of conversion of CH4, C2H6, and / or C3H8, the syngas intermediate may include higher amounts of CO, such as at least about 30 mol% (e.g., from about 30 mol% to about 65 mol%) or at least about 40 mol% (e.g., from about 40 mol% to about 55 mol%). In further representative embodiments, the syngas intermediate may include H2 in an amount of at least about 30 mol% (e.g., from about 30 mol% to about 90 mol%) or at least about 40 mol% (e.g., from about 40 mol% to about 80 mol%). With respect to the gaseous feed mixture, depending on the amount of H2 present, and the amount of oxidants CO2 and H2O present (e.g., the stoichiometric molar ratios of which react with CH4 to produce H2:CO are 1:1 and 3:1, respectively), in the case of a high ratio, the H2:CO molar ratio of the syngas intermediate may be from about 1.0 to about 7.0, such as from about 4.0 to about 6.5. Otherwise, in the case of a lower ratio, the H2:CO molar ratio of the syngas intermediate may be from about 1.0 to about 3.0, such as from about 1.8 to about 2.4 or from about 2.1 to about 2.7. According to yet another embodiment, for example, in the case of reforming CH4, C2H6 and / or C3H8 with an oxidant (which may be mainly, substantially all or all CO2), the H2:CO molar ratio of the syngas intermediate may be smaller in view of the stoichiometry of the dry reforming reaction alone. For example, the H2:CO molar ratio may be from about 0.5 to about 1.5, such as from about 0.8 to about 1.2. According to a further embodiment, the H2:CO molar ratio of the syngas intermediate can be "adjusted" using the amount of H2O (steam) input into the gaseous mixture as a "adjustment means".For example, more or less H2O may be added to obtain a desired or set point H2:CO molar ratio, wherein such set point is a discrete value within any of the above ranges. Operation of the reforming stage or RWGS stage may include, for example, adjusting the H2:CO molar ratio of the syngas intermediate to a value from about 2.1 to about 2.5, wherein higher amounts of steam input correspond to higher molar ratios. According to yet other embodiments wherein the gaseous mixture includes a fresh make-up feed further comprising H2, adjusting the amount of such H2 in such fresh make-up feed may be yet another "adjustment means" of "adjusting" the H2:CO molar ratio of the syngas intermediate, instead of or in combination with adjusting the amount of steam input to the gaseous mixture.

[0085] In any case, the molar ratios as described above may represent a syngas intermediate or a portion thereof used for FT synthesis, such as a syngas intermediate or a portion thereof obtained directly from a reactor used in a reforming stage or a RWGS stage, or a syngas intermediate or a portion thereof obtained before the FT synthesis stage (e.g., upstream of the FT synthesis stage), after adjusting the H2:CO molar ratio according to intermediate operations (e.g., by adding a source of H2 and / or a source of CO to the intermediate or a portion thereof). A representative source of H2 and / or CO is a recycled portion of (i) a fraction of the FT synthesis effluent rich in H2 and CO2 or (ii) a fraction of the FT synthesis effluent rich in a source of hydrogen and CO2 (or even a portion of such a fraction (i) or (ii)), as described herein. Another representative source of H2 is hydrogen that has been purified (e.g., by PSA or membrane separation), and another representative source of H2 and CO is unpurified hydrogen (e.g., syngas) produced by steam methane reforming. In other embodiments, water may be removed (eg, condensed) from the syngas intermediate used for FT synthesis, or a portion thereof, between (a) the reforming stage or RWGS stage and (b) the FT synthesis stage.

[0086] Fischer-Tropsch (FT) synthesis

[0087] As described above, upon production of a synthesis gas intermediate comprising H2 and CO (i.e., a H2 / CO mixture) in the first or initial reaction stage, a second stage may then be performed to convert the synthesis gas intermediate into C4 hydrocarbons contained in the liquid hydrocarbon product. + Hydrocarbons. The second stage typically involves Fischer-Tropsch (FT) synthesis to produce higher molecular weight hydrocarbons according to the following reactions:

[0088] (2n+1)H2+nCO→C n H 2n+2 +n H2O.

[0089] Specifically, the FT synthesis reaction can be used to produce alkanes with two or more carbon atoms, the distribution of which is as described above. A representative process may include converting all or part of a synthesis gas intermediate via FT synthesis, optionally after one or more intermediate operations performed on the intermediate, the intermediate operation may be used to provide a FT feed having a composition and / or characteristics different from the composition and / or characteristics of the synthesis gas intermediate. Such intermediate operations include cooling, heating, pressurization, decompression, separation of one or more components (e.g., removing condensed water), addition of one or more components (e.g., adding H2 and / or CO to adjust the H2:CO molar ratio of the FT feed relative to the synthesis gas intermediate), and / or the reaction of one or more components (e.g., using a separate water gas shift reaction or a reaction of H2 and / or CO of a reverse water gas shift reaction), which is performed on the synthesis gas intermediate to provide the FT feed to the FT reactor of the FT synthesis stage. In view of the temperature and pressure in the FT reactor typically used in the FT synthesis stage relative to the temperature and pressure in the reactor used in the reforming stage or the RWGS stage, the synthesis gas intermediate can be cooled, separated from the condensed water and pressurized. In some embodiments, these may be the only intermediate operations to which the syngas intermediate is subjected to provide the FT feed. In other embodiments, cooling and pressurization may be the only intermediate operations. In yet other embodiments, intermediate operations that may be omitted include drying the syngas intermediate to remove gas phase H2O (which is therefore different from condensing liquid phase H2O and may include, for example, using an adsorbent selective for water vapor, such as 5A molecular sieve) and / or removing CO2 according to conventional acid gas treatment steps (e.g., amine washing). In yet other embodiments, the intermediate operation may be the addition (i.e., a combination of the syngas intermediate or a portion thereof with) (i) a fraction of the FT synthesis effluent rich in H2 and CO2 or (ii) a fraction of the FT synthesis effluent rich in a hydrogen source and CO2 (or a portion of (i) or (ii), such as a recycled portion thereof). According to some embodiments, CO2 removal may be performed on the syngas intermediate upstream of the FT synthesis stage (e.g., as an intermediate operation). Preferably, water produced in the reactor of the reforming stage or RWGS stage is condensed from the synthesis gas intermediate before the FT reactor and / or the H2:CO molar ratio of the synthesis gas intermediate is also preferably not adjusted. The use of no intermediate operations, the use of limited intermediate operations, and / or the omission of certain intermediate operations between the reforming stage or RWGS stage and the FT synthesis stage results in advantages associated with an overall simplification of the process for producing liquid hydrocarbon products.

[0090] The conditions in the FT synthesis stage, and more particularly the FT reactor used in this stage, are suitable for converting H2 and CO to C4 +Hydrocarbons. In representative embodiments, FT reaction conditions suitable for at least one FT reactor or, more specifically, a catalyst bed contained in such a reactor may include FT reaction temperatures ranging from about 121°C (250°F) to about 288°C (550°F), or from about 193°C (380°F) to about 260°C (500°F). FT reaction pressures may include gauge pressures ranging from about 621 kPa (90 psig) to about 5.00 MPa (725 psig), or from about 2.50 MPa (362 psig) to about 3.50 MPa (508 psig).

[0091] In the FT reactor, the FT feed representing all or part of the synthesis gas intermediate can be contacted with a suitable FT catalyst (e.g., a FT catalyst particle bed disposed in the FT reactor) under FT reaction conditions, optionally after one or more intermediate operations described above, which FT reaction conditions may include temperature and / or pressure as described above. Representative FT catalysts include one or more transition metals selected from cobalt (Co), iron (Fe), ruthenium (Ru) and nickel (Ni) as FT active metals. Preferred FT catalysts generally include at least about 5% by weight of transition metals on a solid support, typically about 5% by weight to about 15% by weight of transition metals, and often at least about 15% by weight of transition metals. The phrase "on a solid support" is intended to cover catalysts in which the active metal is on the surface of the support and / or in the porous internal structure of the support. Representative solid supports include one or more metal oxides selected from the group consisting of: aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, magnesium oxide, strontium oxide, etc. The solid support may include all or substantially all (e.g., greater than about 95% by weight) of one or more of such metal oxides. Preferred FT catalysts include transition metal cobalt (Co) in amounts described above (eg, at least about 10 wt %) on a support including aluminum oxide (alumina).

[0092] The FT catalysts and FT reaction conditions described herein are generally suitable for achieving at least about 20% (e.g., from about 20% to about 99% or from about 20% to about 75%), at least about 30% (e.g., from about 30% to about 95% or from about 30% to about 65%), or at least about 50% (e.g., from about 50% to about 90% or from about 50% to about 85%) H2 and / or CO conversion (H2 conversion or CO conversion). Taking into account the FT synthesis reaction chemistry, these FT conversion levels can be based on H2 conversion or CO conversion, depending on which reactant is stoichiometrically limited in the FT feed or in the syngas intermediate, and these FT conversion levels can be determined in a manner similar to that described above for the determination of CH4 conversion. Preferably, these FT conversion levels are based on CO conversion. These FT conversion levels can be based on a "single pass" conversion achieved in a single pass through the FT synthesis stage (e.g., the FT reactor of that stage), or based on the overall conversion achieved by returning a recycled portion of the FT product to the FT synthesis stage (e.g., the FT reactor of that stage), as described herein.

[0093] The desired H2 conversion and / or CO conversion in the FT reactor can be achieved by adjusting the above-mentioned FT reaction conditions (e.g., FT reaction temperature and / or FT reaction pressure) and / or adjusting the weight hourly space velocity (WHSV) as defined above. The FT reaction conditions may include typically from about 0.01 hr -1 About 10 hours -1 , typically from about 0.05hr -1 About 5 hours -1 , and often from about 0.3hr -1 About 2.5 hours -1 The weight hourly space velocity (WHSV) of the reactor. The conversion level (e.g., CO conversion) can be increased, for example, by increasing the pressure and decreasing the WHSV, which have the effect of increasing the reactant concentration and the reactor residence time, respectively. The FT reaction conditions can optionally include returning a recycled portion of the FT product, exiting the FT reactor, back to the FT feed (or possibly back to a syngas intermediate) for combination with the FT feed (or possibly with a syngas intermediate), or back to the FT reactor itself. Recycle operation allows operation at a relatively low "single pass" conversion through the FT reactor while achieving a high overall conversion due to the recycle. In some embodiments, such a low single pass conversion can advantageously limit the high molecular weight hydrocarbons (e.g., normal C 20 + The amount of hydrocarbons).

[0094] Preferably, however, the FT reaction conditions include relatively little or even no FT product recycle. For example, the FT reaction conditions may include a weight ratio of recycled FT product to FT feed (i.e., a "recycle ratio"), wherein the recycled FT product and the FT feed (e.g., all or a portion of the syngas intermediate) together provide a combined feed to the FT reactor, the weight ratio of which is generally less than about 1:1, typically less than about 0.5:1, and often less than about 0.1:1. In some cases, the recycle ratio may be 0, meaning that no FT product recycle is used, so that the single-pass conversion is equal to the overall conversion. In the case of such a low recycle ratio, a relatively high single-pass H2 conversion or CO conversion is expected in view of process efficiency and economy, such as at least about 50% (e.g., from about 50% to about 95%), at least about 60% (e.g., from about 60% to about 92%), or at least about 70% (e.g., from about 70% to about 90%). As the single-pass conversion level increases, the distribution of hydrocarbons in the FT product will generally shift toward those with an increased number of carbon atoms.

[0095] Thus, embodiments of the present invention relate to processes for producing liquid hydrocarbon products from a synthesis gas comprising H2 and CO (e.g., a synthesis gas intermediate or a FT feed obtained after one or more intermediate operations performed on the intermediate), as described above. The synthesis gas intermediate or FT feed can generally be produced by reforming and / or RWGS reactions as described above. The process comprises contacting the synthesis gas with a FT catalyst as described herein, such as a catalyst comprising at least about 5 wt% Co, such as from about 5 wt% to about 15 wt% Co, or at least about 10 wt% Co, and / or optionally other transition metals on a solid support such as a refractory metal oxide (such as alumina). The process comprises converting H2 and CO in the synthesis gas into hydrocarbons, including C4 + hydrocarbon.

[0096] Advantageously, in the absence of FT product recycle, compression costs are saved and the overall design of the integrated process can be simplified. This requires increasing the single pass conversion and the associated distribution of hydrocarbons in the FT product towards those with an increased number of carbon atoms (including normal C 2+ hydrocarbons that are solid at room temperature and obtained as an undesirable wax fraction). 20 + It should be understood that various aspects of the present invention are related to the conversion of these hydrocarbons into C4-C 19 hydrocarbons, thereby increasing the yield of liquid hydrocarbon products. In this regard, according to a representative process, the synthesis gas intermediate is converted into C4 + The second stage of hydrocarbons involves combining FT synthesis with cracking to reduce the molecular weight of hydrocarbons, in particular by converting the normal C 20 +Compared to cracking alone, the combination of wax cracking and isomerization can be particularly advantageous for: (a) substantially eliminating all normal C 20 + Hydrocarbons, taking into account that some branched C 20 + hydrocarbons are more desirable relative to their straight-chain (normal) counterparts; and (b) improving the properties of liquid hydrocarbon products, for example, by producing C4-C 19 Hydrocarbons, depress the freezing point of jet fuel fractions and diesel fractions.

[0097] FT synthesis with optional downstream or in-situ cracking

[0098] According to the above description, including C4 + A liquid hydrocarbon product of hydrocarbons may be obtained after the step of converting the synthesis gas intermediate via FT synthesis. For example, the liquid hydrocarbon product may be separated from the FT product, and according to a preferred embodiment, the liquid hydrocarbon product may correspond in amount and composition to the FT synthesis effluent. The liquid hydrocarbon product may be separated using techniques known in the art (e.g., phase separation and / or fractionation), more specifically as a C4-rich + Alternatively, in a more specific embodiment according to the above description, the liquid hydrocarbon product may be obtained after a step of converting the synthesis gas intermediate via a combination of FT synthesis and cracking. The term "cracking" is used throughout this disclosure to describe the reduction of the C 2+ produced in situ in the FT synthesis and / or downstream of the FT synthesis. 20 + In terms of additional reactions to increase the molecular weight of hydrocarbons, in preferred embodiments, given that the cracking catalysts described herein have activity in cracking these hydrocarbons (optionally in conjunction with isomerization), the term should be understood to encompass "cracking and isomerization", which reactions are beneficial in reducing and / or eliminating hydrocarbons that are solid at room temperature (i.e., waxes) and increasing branching in the molecular structure of liquid hydrocarbons. Similarly, the term "refining" encompasses additional cracking reactions occurring in a separate cracking or refining reactor downstream of the FT reactor as well as additional isomerization reactions.

[0099] In case the liquid hydrocarbon product is obtained from a combination of FT synthesis and cracking, the latter reaction may be carried out in a downstream cracking reactor and / or possibly within the FT reactor itself (i.e. in situ). Thus, the liquid hydrocarbon product which is a fraction of the FT synthesis effluent may more particularly be a fraction of such a FT synthesis effluent obtained as a product of a FT reactor with in situ cracking. As described above, cracking (whether in situ in the FT reactor or in a separate reactor downstream of the FT reactor) may be carried out in combination with isomerization for the purpose of removing waxes from the liquid hydrocarbon product (and, in the case of a combination of cracking and isomerization, increasing branching in the molecular structure of the liquid hydrocarbon product) which waxes would otherwise be present in the FT synthesis effluent in the absence of such cracking (and optional isomerization). In this regard, a reactor located downstream of the FT reactor and used for the separation and / or recovery of C4 + Any separate "cracking reactor" in which the liquid hydrocarbon product is conditioned in this manner (by reducing or eliminating wax from the liquid hydrocarbon product) before the hydrocarbon fraction is fractionated may alternatively be referred to as a "finishing reactor". Whether the FT synthesis effluent is obtained after a separate FT synthesis reaction or after a FT synthesis reaction combined with in-situ cracking (e.g., a combination of in-situ cracking and in-situ isomerization), the liquid hydrocarbon product may be a fraction of the FT synthesis effluent obtained from the FT reactor and may be separated from the FT synthesis effluent. In the case of cracking in a separate cracking or finishing reactor after FT synthesis, the liquid hydrocarbon product may be a fraction of the finishing effluent. In such a case where the FT synthesis effluent is obtained after cracking in a separate cracking or finishing reactor, the product immediately downstream of the FT reactor (e.g., the product taken out of the reactor) may be the FT synthesis effluent, which may correspond in amount and composition to the cracking feed, or to the feed to the cracking or finishing reactor (e.g., in the case where no intermediate operation is performed between the FT reactor and the cracking or finishing reactor, the FT synthesis effluent and the cracking feed may be the same).

[0100] In case a FT synthesis effluent is obtained after a FT synthesis reaction in combination with in situ cracking, the "FT product" may be considered to be a putative (or transient intermediate) product comprising the hydrocarbons present in the FT synthesis effluent, but distinct from the FT synthesis effluent, also comprising hydrocarbons otherwise obtained from FT synthesis alone (in the absence of cracking), and in particular the wax fraction (e.g. comprising normal C 20 + hydrocarbons), which have been converted into normal or branched C4-C 19 Hydrocarbons, contribute to the yield of liquid hydrocarbons present in the FT synthesis effluent. Thus, in case the FT reactor is operated without in situ cracking, the FT product may correspond to the FT synthesis effluent.

[0101] As will be appreciated by those skilled in the art, utilizing the knowledge gained from the present disclosure, alternative and additional separation and / or reaction (e.g., cracking) steps may be performed to (i) increase the C4 + hydrocarbon concentration and / or (ii) increase the C4 + The yield of hydrocarbons, and thus the overall yield of liquid hydrocarbon products, can be increased. According to specific embodiments, the hydrocarbon product or fraction (e.g., after separation from the FT synthesis effluent or the refining effluent) can include at least about 60 wt % (e.g., from about 60 wt % to about 100 wt %), at least about 90 wt % (e.g., from about 90 wt % to about 100 wt %), or at least about 95 wt % (e.g., from about 95 wt % to about 99 wt %) of a combined amount of liquid hydrocarbons. In addition to such combined amounts, or alternatively, the hydrocarbon product or fraction can include at least about 25 wt % (e.g., from about 25 wt % to about 85 wt %), at least about 40 wt % (e.g., from about 40 wt % to about 80 wt %), or at least about 50 wt % (e.g., from about 50 wt % to about 75 wt %) of an amount of (i) hydrocarbons characterizing naphtha or gasoline boiling range hydrocarbons, such as C4-C9 hydrocarbons, (ii) hydrocarbons characterizing jet fuel boiling range hydrocarbons, such as C9-C 16 hydrocarbons, and / or (ii) hydrocarbons characterizing diesel boiling range hydrocarbons, such as C 16 -C 25 Hydrocarbons. According to other specific embodiments (e.g., using a H2 / CO2-rich fraction or recycling of a hydrocarbon / CO2-rich fraction, combined with cracking), at least about 40% (e.g., from about 40% to about 95%), at least about 55% (e.g., from about 55% to about 95%), or at least about 70% (e.g., from about 70% to about 95%), or at least about 80% (e.g., from about 80% to about 99%) of the feed carbon content of the gaseous feed mixture (e.g., the carbon content of CH4 and / or CO2 present in the mixture) forms liquid hydrocarbon products. These percentages are expressed in weight % or mole %.

[0102] According to another embodiment, a separated fraction of a liquid hydrocarbon product, such as any fraction rich in a particular C4 + Recycling of separated fractions of hydrocarbons, such as separated fractions enriched in (i) naphtha or gasoline boiling range hydrocarbons (i.e., a "naphtha boiling range hydrocarbon fraction"), (ii) jet fuel boiling range hydrocarbons (i.e., a "jet fuel boiling range hydrocarbon fraction"), or (iii) diesel boiling range hydrocarbons (i.e., a "diesel boiling range hydrocarbon fraction"), can be used to modify those C4 hydrocarbons recovered from the process. + The process may be performed to provide a product composition of hydrocarbons corresponding to the product yield of the process. In this regard, a particular process may be performed in which no liquid hydrocarbon product is present (e.g., substantially no C4 +hydrocarbons, such as those present in the separated fractions) are recycled to the process, for example such that naphtha boiling range hydrocarbons, jet fuel boiling range hydrocarbons and diesel boiling range hydrocarbons are recovered or removed as output of the process (e.g., as separated fractions). In this case, these recovered C4 + The hydrocarbons may include jet fuel boiling range hydrocarbons in an amount of at least about 55% by weight, with a combination of naphtha boiling range hydrocarbons and diesel boiling range hydrocarbons accounting for all or substantially all of the balance. + The hydrocarbons may include a combination of at least about 40 weight percent naphtha boiling range hydrocarbons and diesel boiling range hydrocarbons. However, other specific processes may include recycling C4 + The present invention relates to the recycling of a given separated fraction, such as in the case of recycling all or a portion of a given separated fraction, to reduce or eliminate the yield of various types of hydrocarbons recycled in favor of other types of hydrocarbons. For example, compared to the C4 + In the case where naphtha boiling range hydrocarbons in the liquid hydrocarbon product (e.g., present in the separated fraction) are recycled to the process, the recovered C4 + The hydrocarbons may include jet fuel boiling range hydrocarbons in an amount of at least about 80% by weight, with diesel boiling range hydrocarbons accounting for all or substantially all of the balance. + The hydrocarbons may include at least about 15 wt. % diesel boiling range hydrocarbons.

[0103] More generally, any hydrocarbon fraction can be recycled to reduce the yield of the hydrocarbon fraction while increasing the yield of one or more other hydrocarbon fractions. For example, if it is desired to operate a process with jet fuel boiling range hydrocarbons with high yield, it can be implemented by recycling all or substantially all of the naphtha boiling range hydrocarbons and diesel boiling range hydrocarbons (e.g., present in the separation fraction), while recovering and removing all or substantially all of the jet fuel boiling range hydrocarbons from the process. The advantage of this operational flexibility is the reforming / RWGS catalysts described herein, in terms of their surprising "robustness" for converting any unwanted hydrocarbon fractions that can be recycled to the first stage of the process. This is different from the characteristics of conventional reforming catalysts, which lack the ability to convert heavier hydrocarbon fractions such as diesel boiling range hydrocarbons in a stable manner. Therefore, the operation of recycling certain hydrocarbon fractions provides a simple and easy-to-understand strategy for controlling (increasing or reducing) the overall process selectivity of certain hydrocarbons.

[0104] Those skilled in the art, using the knowledge gained from this disclosure, will more generally understand the recycling of various types of C4 + Hydrocarbons will affect these and other types of C4 + Importantly, the use of cracking as described herein provides yet another mechanism by which the production of hydrocarbons can be improved by reducing or eliminating C20 + In some embodiments, for example, due to a combination of recycling and cracking of a hydrocarbon / CO2-rich fraction, the recovered C4 + The hydrocarbons may consist of or consist essentially of any one or more of naphtha boiling range hydrocarbons, jet fuel boiling range hydrocarbons, and / or diesel boiling range hydrocarbons (e.g., free of hydrocarbons having less than 4 carbon atoms or more than 20 carbon atoms). In other embodiments, the recovered C4 + The hydrocarbons may consist of or consist essentially of jet fuel boiling range hydrocarbons and / or diesel boiling range hydrocarbons (eg, free of hydrocarbons having fewer than 9 carbon atoms or more than 20 carbon atoms).

[0105] As described above, in the case where the FT synthesis effluent downstream of the FT reactor includes a significant amount (e.g., at least about 1 wt%, at least about 5 wt%, at least about 10 wt%, or at least about 20 wt%) of normal C 20 + In the embodiment of hydrocarbons, an optional downstream cracking or finishing reactor separate from the FT reactor may be desirable, where the hydrocarbons can be cracked to increase the C4 + Hydrocarbons (e.g., C4-C 19The overall yield of hydrocarbons (hydrocarbons). In the case where some waxes are still retained in the FT synthesis effluent even after in-situ cracking, this cracking or refining reactor can be combined with the in-situ wax cracking in the FT reactor as described above. The cracking or refining feed to the downstream cracking or refining reactor can include some or all of the FT synthesis effluent, optionally after one or more intermediate operations such as cooling, heating, pressurization, decompression, separation of one or more components, addition of one or more components and / or reaction of one or more components. In view of the temperatures and pressures commonly used in the cracking or refining reactor of the FT synthesis stage, the FT synthesis effluent can be heated to a temperature suitable for the cracking or refining reactor before cracking or refining, relative to those used in the FT reactor of this stage, as described herein. In some embodiments, the heating can be the only intermediate operation that the FT synthesis effluent is subjected to, to provide cracking or refining feed. Alternatively, for even greater operational simplicity and efficiency, even this heating may be omitted, given that the FT reaction conditions may include temperatures that are the same or substantially the same (e.g., within about 10°C (18°F)) as those used in the downstream cracking or refining reactor, such as within the temperature range described below for the cracking or refining reaction conditions. In other embodiments, intermediate operations that may be omitted include pressurization and decompression, as it has been found that the cracking or refining reaction conditions may advantageously include pressures that are the same or substantially the same as those described above for the FT reaction conditions. For example, the pressure in the cracking or refining reactor may be the same as the pressure in the upstream FT reactor, reduced by the nominal pressure drop associated with the piping and possible other process equipment between these reactors. Thus, the cost of pressurization (compression) or decompression (expansion) of the FT synthesis effluent upstream of the cracking or refining reactor may be advantageously avoided. As with the intermediate operations between the reforming stage or RWGS stage and the FT synthesis stage, the use of no intermediate operations, the use of limited intermediate operations, and / or the omission of certain intermediate operations between the FT reactor and the cracking or refining reactor of the FT synthesis stage produces advantages associated with an overall simplification of the integrated process. For example, particular advantages arise if all or substantially all of the syngas intermediates are used in the FT feed and / or all or substantially all of the FT synthesis effluent is used in the cracking or refining feed. In other embodiments, all or substantially all of the syngas intermediates (e.g., except for the condensed aqueous portion) are used in the FT feed and / or all or substantially all of the FT synthesis effluent is used in the cracking or refining feed.

[0106] Therefore, the conditions in the cracking or refining reactor are suitable for converting the normal C 20 + The hydrocarbons are converted into additional hydrocarbons, and in particular C4-C 19Hydrocarbons. In the case of a wax fraction which is typically cracked to convert the hydrocarbons obtained from the FT synthesis, the terms (i) "wax cracking", (ii) "wax cracking reactor", (iii) "wax cracking conditions", etc. may replace the corresponding terms (i) "cracking", "refining", (ii) "cracking reactor", "refining reactor", (iii) "cracking conditions", "refining conditions", etc. as used herein, or may be used interchangeably as replacements for the corresponding terms used herein. The cracking or refining reactor may be incorporated into the FT reactor, for example by using a cracking or refining catalyst bed directly after or at least downstream of the FT catalyst bed in a single vessel, or by interspersing the two catalyst types in a single vessel. Alternatively or in combination, it is preferred to use at least one separate cracking or refining reactor (e.g., as a separate cracking reactor vessel) so that the cracking reaction conditions can be maintained independently of the FT reaction conditions as described above. A separate cracking or finishing reactor may be advantageous, for example, for (i) maintaining some or all of the cracking or finishing catalyst used in the FT synthesis stage in a different reactor type than the FT reactor, such as maintaining the cracking or finishing catalyst in a fixed bed reactor, which is generally simpler in design than a FT reactor because fixed bed reactors generally do not involve the same design constraints in terms of the ability to remove the heat of reaction, (ii) removing and / or replacing the cracking or finishing catalyst at a time that is not necessarily simultaneous with the removal and / or replacement of the FT catalyst (e.g., at different intervals relative to the removal and / or replacement of the FT catalyst), and / or (iii) operating the cracking or finishing reactor at a different temperature (e.g., at a higher temperature) or under other different conditions than the FT reactor. The term "cracking catalyst" may, but need not specifically refer to a catalyst having cracking and optionally isomerizing activity contained in situ in the FT reactor, while the term "finishing catalyst" may, but need not specifically refer to a catalyst having cracking and / or isomerizing activity contained in a separate "finishing reactor" downstream of the FT reactor. Where a "cracking catalyst" is used in situ in the FT reactor and one or more "finishing catalysts" are used in a separate finishing reactor, such finishing catalyst may have the same composition and / or be in the same form (e.g., in the form of spheres or cylinders) as the cracking catalyst. More generally, any FT catalyst or cracking catalyst may independently have the form and / or size as described above for the reforming / RWGS catalyst. The finishing reactor may contain at least two catalysts, one having wax cracking activity (and optionally isomerizing activity) and one having isomerizing activity (and optionally wax cracking activity), or the finishing reactor contains a catalyst that is active only for wax cracking, only for isomerization, or for both wax cracking and isomerization.Where the FT reactor, finishing reactor are of different designs and therefore present different reaction conditions to the catalysts contained, the cracking catalyst may be of a different composition and / or form than any of the one or more finishing catalysts having wax cracking activity.

[0107] With respect to the use of a separate cracking or refining reactor, given the large carbon number distribution of hydrocarbons produced by FT synthesis, it may be important to maintain the FT synthesis effluent (or at least any portion of the effluent used in the cracking or refining reactor) from the outlet (effluent) of the FT reactor to the inlet of the cracking or refining reactor at an elevated temperature to avoid condensation of liquid hydrocarbons and / or deposition of solid hydrocarbons. Such condensation and / or deposition may be prevented if all or substantially all of the FT synthesis effluent from the outlet of the FT reactor to the inlet of the cracking or refining reactor is maintained in the vapor phase. For example, the FT synthesis effluent may be maintained at a temperature of at least about 66°C (150°F), at least about 121°C (250°F), at least about 216°C (420°F), or even at least about 327°C (620°F), from the effluent of the FT reactor to the inlet of the cracking or refining reactor, such as in the case where the FT synthesis effluent is heated from that temperature to a temperature representative of cracking or refining reaction conditions as described herein. Such temperatures (applicable to at least one cracking or refining reactor) may range from about 200°C (392°F) to about 400°C (752°F), or from about 225°C (437°F) to about 300°C (572°F). Other cracking reaction conditions may include gauge pressures from about 621 kPa (90 psig) to about 5.00 MPa (725 psig), or from about 2.50 MPa (362 psig) to about 3.50 MPa (508 psig).

[0108] In the cracking or refining reactor, the cracking feed can be contacted with a suitable cracking or isomerization catalyst (e.g., a bed of cracking catalyst particles disposed in the cracking reactor) under cracking or refining reaction conditions, which can include the above-mentioned temperature and / or pressure. The cracking reaction can be more specifically a hydrocracking reaction, which, as understood in the art, refers to the reaction of hydrocarbons with hydrogen to produce hydrocarbons with a lower number of carbon atoms and therefore a lower molecular weight. Hydrocracking is beneficial for its overall impact on the carbon number distribution of the cracking or refining feed (the carbon number distribution of the cracking or refining feed can correspond to the carbon number distribution of the FT product or FT synthesis effluent), and is particularly beneficial for reducing the normal C 20 + The weight percentage of hydrocarbons (which may correspond to the hydrocarbons present in the FT product or FT synthesis effluent) and possibly eliminated in favor of C4-C 19 As described above, the refining may further include the addition of normal C20 + Hydrocarbons are isomerized into branched hydrocarbons that do not cause undesirable waxes, and liquid hydrocarbons are isomerized into branched hydrocarbons that improve the properties of liquid hydrocarbons, and these isomerization reactions can be more specifically hydroisomerization reactions. Given that the cracking or refining reactor is used to perform hydrocracking and hydroisomerization, the cracking or refining reactor can be considered, more generally, a hydrotreating reactor, and the cracking or refining catalyst contained in the reactor can be considered, more generally, a hydrotreating catalyst.

[0109] Since hydrogen is required for hydrocracking and optional hydroisomerization reactions, in some embodiments, the hydrogen is present in the cracking or refining feed and / or FT synthesis effluent (or part thereof) input to the cracking or refining reactor. For example, hydrogen in the unconverted synthesis gas intermediate in the downstream FT reactor can allow the operation of the cracking or refining reactor without adding a supplementary hydrogen source to the downstream of the cracking or refining reactor or the FT reactor. According to some embodiments, hydrogen is present in the cracking or refining feed at a concentration of at least about 5 mol% (e.g., from about 5 mol% to about 55 mol%), at least about 10 mol% (e.g., from about 10 mol% to about 45 mol%), or at least about 15 mol% (e.g., from about 15 mol% to about 35 mol%), or at least about 20 mol% (e.g., from about 20 mol% to about 40 mol%), without introducing a supplementary hydrogen source other than the hydrogen produced in the reforming stage or RWGS stage and / or the hydrogen present in the synthesis gas intermediate. These concentrations of hydrogen can correspond to those present in FT synthesis effluent. According to other embodiments, the supplemented hydrogen source added to cracking or refining reactor or added to such reactor upstream (for example, FT reactor downstream) can be used to realize such hydrogen concentration. The representative supplemented hydrogen source is hydrogen or impure hydrogen (for example, synthesis gas) purified (for example, by PSA or membrane separation). The representative supplemented hydrogen source can be one or more gaseous feed mixture components, such as a part of one of these components, and the one or more gaseous feed mixture components can be fed to reforming stage or RWGS stage in addition, but it is directly fed to refining or cracking reactor instead, and therefore does not actually contribute to gaseous mixture. For example, one or more gaseous feed mixture components can include one or more fresh gaseous feed mixture components and / or one or more recycled gaseous feed mixture components as described herein, and a part of one or more fresh gaseous feed mixture components can be fed directly to refining reactor. In more specific embodiments, one or more of the fresh gaseous feed mixture components (a portion of which is fed directly to at least one finishing reactor) is a fresh supplemental H2-containing feed that includes hydrogen (such as in an amount of at least about 50 mol%, at least about 80 mol%, at least about 95 mol% hydrogen). More specifically, some or all of the hydrogen can be electrolysis hydrogen, fossil hydrogen with CCS, biomass gasification hydrogen, or methane pyrolysis hydrogen.

[0110] Suitable cracking / hydrocracking and / or isomerization / hydroisomerization reactions may also be carried out in the presence of steam (HO), which may be present in the cracking or refining feed and / or FT synthesis effluent in the same or alternative manner, for example as a product of a RWGS reaction occurring in an upstream reforming stage or RWGS stage. For example, a supplementary steam source may be added to a cracking or refining reactor, or added upstream of such a reactor (e.g., downstream of a FT reactor). According to some embodiments, steam may be present in the cracking or refining feed and / or FT synthesis effluent at a concentration of at least about 5 mol % (e.g., from about 5 mol % to about 45 mol %), at least about 10 mol % (e.g., from about 10 mol % to about 40 mol %), or at least about 15 mol % (e.g., from about 15 mol % to about 35 mol %), whether or not a supplementary steam source other than steam produced in the reforming stage or RWGS stage and / or steam present in the synthesis gas intermediate is introduced.

[0111] Representative cracking or refining catalysts include at least one cracking active metal on a solid support. The phrase "on a solid support" is intended to cover catalysts in which the active metal is on the surface of the support and / or in the porous internal structure of the support. Representative cracking or refining active metals can be selected from the 12th to 14th groups of the periodic table, such as from the 13th or 14th groups of the periodic table. Specific cracking or refining active metals are gallium. By the weight of the cracking or refining catalyst, at least one cracking active metal can be present, for example, in an amount from about 0.1 wt % to about 10 wt %, from about 0.5 wt % to about 8 wt %, or from about 1 wt % to about 5 wt %. If a combination of cracking active metals is used, such as a combination of metals selected from the 12th to 14th groups of the periodic table, such metals can be present in a combined amount within these ranges. Typically, the cracking or refining catalyst may not include an amount or combined amount of metals other than the above-described cracking or refining active metals on the support greater than about 1% by weight or greater than about 0.5% by weight, based on the weight of the cracking or refining catalyst (e.g., in the amount or combined amount, no metals other than metals from Groups 12 to 14 of the Periodic Table, no metals other than metals from Groups 13 or 14 of the Periodic Table, or no metals other than gallium are included). Preferably, the cracking or refining catalyst does not include metals other than the above-described cracking or refining active metals on the support (e.g., no metals other than metals from Groups 12 to 14 of the Periodic Table, no metals other than metals from Groups 13 or 14 of the Periodic Table, or no metals other than gallium).

[0112] In order to promote cracking activity, the solid support of cracking or refining catalyst can be more particularly a solid acid support. The acidity of support can be, for example, by a certain amount of programmed temperature desorption (TPD) of ammonia, i.e., using NH as described above -TPD, determined, wherein the ammonia saturated sample of support is specifically analyzed at a temperature from 275 ° C (527 ° F) to 500 ° C (932 ° F) (temperature at which it exceeds the temperature at which ammonia is physically adsorbed). Therefore, the amount of the acid site in units of millimoles (mmol / g) of the acid site of each gram of support corresponds to the millimoles of ammonia desorbed by each gram of support within the temperature range. Representative solid support includes zeolite or non-zeolite molecular sieve and has at least about 15mmol / g (for example, from about 15mmol / g to about 75mmol / g) acid site, or at least about 25mmol / g (for example, from about 25mmol / g to about 65mmol / g) acid site, measured by NH -TPD. In the case of zeolite molecular sieves, the acidity is a function of the silica to alumina (SiO2 / Al2O3) framework molar ratio, and in embodiments where the solid support comprises a zeolite molecular sieve (zeolite), its silica to alumina framework molar ratio may be less than about 60 (e.g., from about 1 to about 60), or less than about 40 (e.g., from about 5 to about 40). Specific solid supports may include one or more zeolite molecular sieves (zeolites) having a structural type selected from the group consisting of: FAU, fer, mel, mtw, MWW, mor, BEA, ltl, MFI, lta, emt, eri, maz, mei, and ton, and preferably selected from one or more of FAU, fer, MWW, MOR, BEA, ltl, and MFI. Zeolite structures with these and other structure types are described in Meier, WM et al., Atlas of Zeolite Structure Types, 4th edition, Elsevier: Boston (1996), and further references are provided. Specific examples include zeolite Y (FAU structure), zeolite X (FAU structure), MCM-22 (MWW structure) and ZSM-5 (MFI structure), wherein ZSM-5 is exemplary.

[0113] Solid supports other than zeolites and non-zeolitic molecular sieves include metal oxides, such as any one or more of silica, alumina, titania, zirconium oxide, magnesium oxide, calcium oxide, strontium oxide, etc. In representative embodiments, the solid support may include (i) a single type of zeolite molecular sieve, (ii) a single type of non-zeolitic molecular sieve, or (iii) a single type of metal oxide, wherein (i), (ii) or (iii) is present in an amount greater than about 75% by weight (e.g., from about 75% by weight to about 99.9% by weight) or greater than about 90% by weight (e.g., from about 90% by weight to about 99% by weight) based on the weight of the cracking or refining catalyst. Other components of the support, such as binders and other additives, may be present in small amounts, such as less than about 10% by weight (e.g., from about 1% by weight to about 10% by weight) or in a combined amount based on the weight of the cracking or refining catalyst.

[0114] An exemplary cracking catalyst includes gallium as a cracking active metal in an amount as described above (e.g., from about 0.5 wt % to about 8 wt %, such as from about 1 wt % to about 5 wt %, based on the weight of the cracking catalyst) on a support that includes or may consist essentially of ZSM-5. A representative silica to alumina framework molar ratio for ZSM-5 is as described above.

[0115] The cracking or refining catalysts described herein and their associated reaction conditions can generally be suitable for achieving at least about 50% (e.g., from about 50% to about 100%), at least about 70% (e.g., from about 70% to about 98% or from about 70% to about 100%), or at least about 90% (e.g., from about 90% to about 95% or from about 90% to about 100%) normal C 20 + Hydrocarbon to C1-C 19 In the case of using both a cracking catalyst contained in a FT reactor for in situ cracking and a finishing catalyst contained in a separate finishing reactor downstream of the FT reactor, these conversion levels may represent the conversion obtained from the combined cracking catalyst and finishing catalyst (e.g., as based on the C 20 + Compared with the operation of the FT synthesis stage without in-situ cracking or a separate finishing reactor, C 20 + The conversion of hydrocarbons is important for increasing the 19 It is important to increase the yield of hydrocarbons, and thus the overall yield of liquid hydrocarbon products. Preferably, in the case of a separate cracking or finishing reactor (whether or not used in combination with in-situ cracking in a FT reactor), the C 20 +At least about 40% (e.g., from about 40% to about 100%), at least about 55% (e.g., from about 55% to about 98% or from about 55% to about 100%), or at least about 65% (e.g., from about 65% to about 97% or from about 65% to about 100%) of the hydrocarbons are converted to C4-C 19 That is, in a separate cracking or refining reactor from normal C 20 + The yields of these hydrocarbons from hydrocarbon conversion are within these ranges. Preferably, the finishing effluent (the product of the finishing reactor) includes less than about 10 wt %, or even less than about 5 wt % of hydrocarbons that are solid at room temperature (e.g., normal C 20 + Advantageously, the FT synthesis stage utilizing in situ cracking and / or separate finishing reactors can be effective to provide an FT synthesis effluent and / or finishing effluent that is free or substantially free of residual wax, or a sufficiently low content of hydrocarbons that are solid at room temperature such that these hydrocarbons remain dissolved in any recovered C4 hydrocarbons obtained as an output of the process. + hydrocarbons (e.g., a recovered diesel boiling range hydrocarbon fraction).

[0116] Thus, embodiments of the present invention relate to using a cracking or finishing reactor after a FT reactor to increase the overall selectivity and yield of desired products and / or decrease the overall selectivity and yield of undesired products relative to a FT synthesis stage in the absence of cracking or finishing, i.e., relative to a baseline FT synthesis stage without an in-situ cracking or separate finishing reactor. For example, in a representative embodiment, in a FT synthesis stage utilizing an in-situ cracking and / or separate finishing reactor, C4-C 19 The selectivity and / or yield of hydrocarbons can be increased by at least about 15% (e.g., from about 15% to about 70%), at least about 30% (e.g., from about 30% to about 65%), or at least about 45% (e.g., from about 45% to about 60%). 19 The selectivity for hydrocarbons is based on the percentage of carbon in the CO converted by FT that results in these hydrocarbons. 19 The yield of hydrocarbons is based on the percentage of carbon in the CO introduced into the FT synthesis stage (e.g., CO introduced with the FT feed, whether converted or unconverted) that results in these hydrocarbons. 19These increases in selectivity and / or yield of hydrocarbons can be achieved without significant differences between the CO conversion obtained in a baseline FT synthesis stage and the CO conversion obtained in a FT synthesis stage utilizing in situ cracking and / or a separate finishing reactor. For example, the CO conversion values ​​obtained in both cases can be within the ranges described above with respect to the performance criteria for the FT synthesis stage. That is, the utilization of in situ cracking and / or a separate finishing reactor generally does not significantly affect the CO conversion obtained in the FT synthesis stage, such that the CO conversion achieved in the baseline FT synthesis stage and the FT synthesis stage utilizing in situ cracking and / or a separate finishing reactor can be the same or substantially the same. In a representative embodiment, in a FT synthesis stage utilizing in situ cracking and / or a separate finishing reactor, the CO conversion of C4-C 19 The single-pass selectivity and / or yield of hydrocarbons can be at least about 45% (e.g., from about 45% to about 85%), at least about 50% (e.g., from about 50% to about 80%), or at least about 55% (e.g., from about 55% to about 75%).

[0117] As noted above, the conversion level in the cracking or finishing reactor can be based on a "single pass" conversion achieved in a single pass through the reactor, or based on an overall conversion achieved by returning a recycle portion of the finishing effluent to the cracking or finishing reactor, as described above with respect to FT synthesis. 20 + The desired conversion of hydrocarbons can be achieved by adjusting the above cracking or refining reaction conditions (e.g., cracking reaction temperature and / or pressure), and / or adjusting the weight hourly space velocity (WHSV) as defined above. The cracking or refining reaction conditions can include generally from about 0.05 hr -1 About 35 hours -1 , typically from about 0.1 hr -1 About 20 hours -1 , and often from about 0.5hr -1 About 10 hours -1The weight hourly space velocity (WHSV) of the cracking or refining reaction conditions can optionally include returning the recycled portion of the refining effluent, leaving the cracking or refining reactor, returning to the FT synthesis effluent, for combination with the refining feed, or returning to the refining reactor itself. The recycle operation allows operation under a relatively low "single pass" conversion through the cracking or refining reactor, while achieving a high overall conversion due to the recycle. However, preferably, the cracking or refining reaction conditions include little or even no recycle of the refining effluent. For example, the cracking or refining reaction conditions may include a weight ratio (i.e., "recycle ratio") of the recirculated refining effluent to the cracking feed, wherein the recirculated refining effluent and the FT synthesis effluent together provide a combined feed for the cracking or refining reactor, and the weight ratio corresponds to those recycle ratios for the above FT synthesis. Preferably, the recycle ratio can be 0, meaning that the refining effluent is not used for recycling, so that the single pass conversion is equal to the overall conversion. Advantageously, in the absence of polishing effluent recycle, utility costs are saved and the overall design of the integrated process is simplified.

[0118] Therefore, embodiments of the present invention relate to a method for converting a C4-C 19 The normal C in a hydrocarbon feed (such as an FT synthesis effluent or a refinery feed as described above) 20 + The process for converting hydrocarbons into FT products may include all or part of the FT products described above. 20 + The hydrocarbon feed can include, for example, C4-C6 hydrocarbons in an amount of at least about 40 wt % (e.g., from about 40 wt % to about 90 wt %) or at least about 50 wt % (e.g., from about 50 wt % to about 80 wt %). 19 The feed may also include H2 and / or H2O (e.g., in amounts as described above for FT synthesis effluent), CO and / or CO2. The process comprises contacting the feed with a cracking catalyst as described above, for example, the cracking catalyst comprises an active metal selected from Groups 12 to 14 of the Periodic Table (e.g., gallium) on a zeolite molecular sieve support (e.g., ZSM-5) to achieve normal C 20 + The conversion of hydrocarbons at the conversion level and having C4-C 19 Hydrocarbon yields and selectivities.

[0119] As described above, in the case where the step includes FT synthesis combined with cracking, the step of converting the synthesis gas intermediate into a liquid hydrocarbon product can involve the use of a FT reactor in which in-situ or integrated cracking is performed. Examples of such reactors include a single container containing a fixed bed of cracking catalyst downstream of a fixed bed of FT catalyst (e.g., directly after a fixed bed of FT catalyst), or a single container containing a single fixed bed of two catalysts dispersed or mixed in a suitable weight ratio. Alternatively, a fluidized bed of two catalyst types as described herein can be used, wherein the advantages of the fluidized bed reactor operation are increased heat and mass transfer and thus the overall uniformity of FT and cracking reaction conditions. In an alternative embodiment, two catalysts can be used in a slurry bed (e.g., slurry bubbling) configuration, or these catalysts can be otherwise incorporated into a tube of a multi-tube configuration. An ebullating bed reactor can also be used. Any of these reactor configurations (such as a slurry reactor, a multi-tube reactor, or an ebullating bed reactor) can generally be a feature of a FT reactor, whether or not the reactor contains a catalyst or a catalyst functional component, for in-situ or integrated cracking. Thus, the forms of the FT catalysts and cracking catalysts described herein can be suitable for use in these various reactor configurations, and include spherical forms having a relatively small average diameter, such as from about 100 μm to about 1 mm, or from about 250 μm to about 750 μm, as well as other forms (e.g., cylindrical) as described above. Typically, FT synthesis in combination with in-situ or integrated cracking refers to performing two of these reactions at least to some extent using at least one FT reactor of the FT synthesis stage. Representative conditions in such reactors may include any of the above-described FT reaction conditions or cracking reaction conditions, such as any of the ranges of temperature, pressure, and WHSV given for these conditions.

[0120] Another embodiment for performing FT synthesis combined with in-situ or integrated cracking involves the use of a single catalyst composition, i.e., a bifunctional catalyst comprising an FT functional component and a cracking functional component, which components correspond individually to the FT catalyst and the cracking catalyst as described above. For example, in the case of the cracking functional component, it may include one or more cracking active metals selected from Groups 12 to 14 of the periodic table; the one or more cracking active metals may be deposited on a solid acidic support; and the solid acidic support may include a zeolite molecular sieve having a silica to alumina framework molar ratio of less than about 50. Likewise, in the case of the FT functional component, in a specific embodiment, the component corresponds to the FT catalyst as described above.

[0121] When combined in a single catalyst composition, the functional components of the bifunctional catalyst can be present in equal or substantially equal weight ratios. For example, (i) FT functional components and (ii) cracking functional components can be present in a bifunctional catalyst in a weight ratio of (i): (ii) of about 1: 1. However, generally the weight ratio can vary, for example, the weight ratio of (i): (ii) can be from about 10: 1 to about 1: 10, such as from about 5: 1 to about 1: 5, or from about 3: 1 to about 1: 3. Therefore, a representative bifunctional catalyst can include (i) a FT functional component, the FT functional component including one or both of (a) one or more FT active metals and (b) a solid support of a FT catalyst (e.g., including one or more metal oxides) as described above, and (ii) a cracking functional component, the cracking functional component including one or both of (a) one or more cracking active metals and (b) a solid support of a cracking catalyst (e.g., a solid acidic support) as described above. It will be appreciated from the above description (including the weight ratios in which (i) and (ii) may be combined) that (a) and (b) of (i) and (a) and (b) of (ii) may be present in the bifunctional catalyst as a whole in amounts less than those in which they are present in their respective FT catalysts and cracking catalysts, as described above. For example, in the case of the FT functional component of the bifunctional catalyst, such bifunctional catalyst as a whole may include a lower amount of transition metal (i.e., one or more FT active metals, such as Co as described above), such as an amount of at least about 3 wt % (e.g., from about 3 wt % to about 30 wt %), and typically at least about 5 wt % (e.g., from about 5 wt % to about 25 wt %), based on the weight of the bifunctional catalyst. Likewise, in the case of a cracking functional component of a bifunctional catalyst, such bifunctional catalyst as a whole may include a lower amount of a metal from Group 12 to Group 14 of the Periodic Table (i.e., one or more cracking active metals as described above), such as an amount from about 0.03 wt % to about 2 wt %, or from about 0.1 wt % to about 1 wt %, based on the weight of the bifunctional catalyst.

[0122] Thus, the step of converting a synthesis gas intermediate comprising a H2 / CO mixture into a liquid hydrocarbon product via FT synthesis combined with cracking can be carried out in a FT reactor, wherein the cracking is carried out in situ, or is integrated. More specifically, the step can include contacting the synthesis gas intermediate (or H2 / CO mixture) with a bifunctional catalyst having a FT functional component and a cracking functional component.

[0123] Through and Recirculation Operation / Exemplary Embodiments

[0124] The process for producing a liquid hydrocarbon product as described herein may be carried out in (configured for) straight-through operation, whereby a gaseous feed mixture is input and a liquid hydrocarbon product is withdrawn (optionally after separation from the FT synthesis effluent or from the refining effluent as described above), without recycling any portion of the material obtained in the first or second reaction stages. In the case of straight-through operation, the "gaseous feed mixture" and the "fresh make-up feed" (which may represent a combination of more than one fresh gaseous feed components) are generally equivalent, and the conversion levels and product yields obtained by the process represent those of a single pass through the reforming and / or RWGS and FT synthesis stages. As described above, certain aspects of the invention are associated with a liquid hydrocarbon production process that allows for efficient management / conversion of CO2 present in the gaseous feed mixture or the fresh make-up feed, which may be improved by recycle operation. In particular, recycling of CO2 (e.g., present in a fraction rich in (i) H2 and CO2 or (ii) a hydrogen source and CO2 that can be separated from the FT synthesis effluent or from the refining effluent) back to the first stage (e.g., a reforming stage, such as a reforming / RWGS stage) and / or recycling back to the second FT synthesis stage for further reaction can promote its complete or substantially complete overall conversion. For example, in representative embodiments in which recycle operation is used as described herein, the overall conversion of CO2 present in the fresh make-up feed (e.g., having a composition as described above with respect to the "gaseous feed mixture", and which can represent a combination of two or more fresh gaseous feed components) can be at least about 90%, at least about 95%, or even at least about 99%, with the deviation from complete or 100% conversion being caused substantially or at least in part by CO2 losses in the purge leaving the gaseous recycle loop, which is used to control the accumulation of unwanted impurities in the loop. That is, according to some embodiments, the CO2 introduced into the process in the fresh make-up feed can be substantially recycled to extinction. With respect to the fractions that can be separated and / or recovered from the FT synthesis effluent as described above, the fractions rich in (i) H2 and CO2 or (ii) a hydrogen source and CO2 can, for example, be recycled to the first stage (e.g., a reforming stage, such as a reforming / RWGS stage) and / or recycled to the second FT synthesis stage to obtain the important advantages as described herein. In some cases, only the recycled portion of the fraction (i) or (ii) can be recycled to the first stage, or other portions of the recycled portion of the fraction (i) or (ii) can be recycled to the first stage and the second stage. As further described herein, conversion and product yields can be further improved by recycling at least a portion of the C4 +The process is regulated by the use of a plurality of hydrocarbons, for example by recycling all or part of a separated fraction rich in naphtha boiling range hydrocarbons or another type of hydrocarbon. In this case, the fraction is usually recycled to the first stage, where the recycled hydrocarbons can be reformed to increase the yield of the synthesis gas intermediate including the H2 / CO mixture.

[0125] Figure 1 An exemplary embodiment of a process 1 for producing a liquid hydrocarbon product and utilizing recycle is described. As illustrated, a gaseous feed mixture 6 is provided to a reforming stage or RWGS stage 100, which may include one or more reforming / RWGS reactors for contacting the gaseous feed mixture 6 with a reforming / RWGS catalyst under reforming / RWGS conditions as described herein. The reactions occurring in the reforming stage or RWGS stage 100 produce a synthesis gas intermediate 8, which may be subjected to any one or more intermediate operations as described herein. For example, water (such as in the form of condensed liquid water 9) may be separated from the synthesis gas intermediate 8 to provide a FT feed 10. Alternatively or in combination with such removal of the condensed liquid water 9, a portion of a fraction 14 of the FT synthesis effluent 12 (which may be a fraction rich in (i) H2 and CO2 or (ii) a hydrogen source and CO2 as described herein) may be added to the synthesis gas intermediate 8 to provide the FT feed 10.

[0126] The fraction 14 of the FT synthesis effluent 12 can be more specifically a fraction rich in (i) H2 and CO2 relative to the liquid hydrocarbon product 16 and relative to the FT synthesis effluent 12. The fraction rich in (i) can be alternatively referred to as a fraction rich in H2 / CO2 and is typically a gaseous fraction (e.g., substantially entirely or entirely a gaseous phase fraction) that can be used to form a gaseous recycle loop of the process. The fraction can include at least about 20 mol% (e.g., from about 20 mol% to about 95 mol%), at least about 40 mol% (e.g., from about 40 mol% to about 90 mol%), or at least about 60 mol% (e.g., from about 60 mol% to about 85 mol%) of a combined amount of H2 and CO2. The remainder of the fraction can include CO, CH4, C2H6, C3H8 and / or H2O. For example, the remainder can include all or substantially all of one of these components, or two or more of these components. The fraction 14 of the FT synthesis effluent 12 can be more specifically a fraction rich in (ii) hydrogen source and CO2 relative to the liquid hydrocarbon product 16 and relative to the FT synthesis effluent 12. The fraction rich in (ii) can be alternatively referred to as a fraction rich in hydrocarbons / CO2 (or a fraction rich in methane / CO2) and is typically a gaseous fraction (e.g., substantially entirely or entirely a gaseous phase fraction) that can be used to form a gaseous recycle loop of the process. The fraction can include at least about 20 mol% (e.g., from about 20 mol% to about 95 mol%), at least about 40 mol% (e.g., from about 40 mol% to about 90 mol%), or at least about 60 mol% (e.g., from about 60 mol% to about 85 mol%) of a combined amount of hydrocarbons (e.g., one or more of CH4, C2H6, C3H8). The remainder of the fraction can include H2, CO and / or H2O. For example, the remainder can include all or substantially all of one of these components, or two or more of these components. Therefore, fraction 14 can be considered as FT synthesis effluent 12 ( Figure 1 ) or refined effluent 13( Figure 2 ) which comprises hydrocarbons (e.g. CH4, C2H6 and / or C3H8) which are in the gas phase at room temperature and which are generated as light hydrocarbon by-products of the FT synthesis and / or introduced as a source of hydrogen into the fresh make-up feed.

[0127] Further based on Figure 1In the embodiment depicted in , a second part 4b of the fraction 14 of the FT synthesis effluent 12 (which may be a fraction enriched in (i) or (ii)) may be added (or recycled) to the synthesis gas intermediate 8, having the effect of changing the composition of the FT feed 10 relative to the composition of the synthesis gas intermediate 8, and more particularly relative to the H2:CO molar ratio of the FT feed 10. Whether or not any intermediate operations are performed, the FT feed 10 (which in the absence of any intermediate operations would be the same as the synthesis gas intermediate 8) or part thereof is provided to a FT synthesis stage 200, which may include one or more FT reactors for contacting the FT feed 10 (or synthesis gas intermediate 8) with a FT synthesis catalyst system and subjecting it to FT reaction conditions as described herein. The reactions taking place in the FT synthesis stage 200 produce a FT synthesis effluent 12 which may be obtained directly from the FT synthesis stage 200. All or part of the FT synthesis effluent 12 may be provided to a separation stage 300 to separate the various fractions as described above, optionally after further intermediate operations such as cooling via a cooler 250. According to Figure 1 In the illustrated embodiment, the separated fraction may include (e.g., in one or more other fractions) or may be composed of (A) a fraction 14 enriched in (i) or (ii) and (B) a fraction comprising C4 + The liquid hydrocarbon product 16 may be composed of a liquid hydrocarbon product 16 having a plurality of hydrocarbons and may have any more specific characteristics regarding its composition, as described above. Depending on the specific operations that occur in the separation stage 300, the liquid hydrocarbon product may be obtained in the form of its separated fractions 16b, 16c, such as a fraction 16b rich in jet fuel boiling range hydrocarbons and a fraction 16c rich in diesel boiling range hydrocarbons. Alternatively, the liquid hydrocarbon product 16 may be separated downstream of the separation stage, such as in a separate liquid product separation stage 400, which may utilize a fractionator (e.g., a distillation tower) to separate a fraction 16b rich in jet fuel boiling range hydrocarbons and a fraction 16c rich in diesel boiling range hydrocarbons. In addition to being rich in these respective types of hydrocarbons, the separated fractions may more particularly consist of or consist essentially of these respective types of hydrocarbons. For example, the separated fraction 16b may consist of or consist essentially of jet fuel boiling range hydrocarbons, and the separated fraction 16c may consist of or consist essentially of diesel boiling range hydrocarbons. Another example of a separated fraction is Figure 2 The separated fraction 16a shown in FIG. 1 may be enriched in naphtha boiling range hydrocarbons, or more particularly may consist of or consist essentially of naphtha boiling range hydrocarbons. Figure 2 In the embodiment illustrated in FIG. 1 , at least a portion of the separated fraction 16a is recycled to the reforming stage or RWGS stage 100, although in other embodiments this separated fraction may be fully recovered as an output of the process and thereby contribute to the yield of naphtha boiling range hydrocarbons.

[0128] In order to improve overall CO2 conversion and management, at least a portion of the fraction 14 enriched in (i) or (ii) may be recycled back to upstream operations or stages of the process, including the reforming stage or RWGS stage 100, and / or the FT synthesis stage 200. Typically, for example, the recycled portion 4 of the fraction 14 (e.g., a fraction enriched in (i) as described above, which fraction may alternatively be referred to as a H2 / CO2-rich fraction, or a fraction enriched in (ii) as described above, which fraction may alternatively be referred to as a hydrocarbon / CO2-rich fraction) may be obtained after removal of a purge 20, which serves to limit the accumulation of undesirable impurities in the gaseous recycle loop, and in particular non-condensable impurities such as N2 and other impurities that may be present in the fresh make-up feed 2. Separation of the purge 20 provides a recycled portion 4 of the fraction 14 enriched in H2 / CO2, which can then be advantageously used to improve the performance of the overall process in various aspects. For example, the recycle portion 4 may be recycled to either or both of the stages 100, 200 to increase the overall CO2 conversion of the process (e.g., over a "single pass" or straight-through CO2 conversion that may be obtained based on the stages being operated separately or based on the two stages being operated together). Alternatively or in combination, when introduced into one or both of the stages 100, 200, and in particular the FT synthesis stage 200, the CO2 present in the fraction 14 or its recycle portion 4 may advantageously suppress or reduce net CO2 production in that stage (e.g., due to the water gas shift reaction). Figure 1 In the specific example shown, in the case where the stage 100 requires a feed gas at a higher pressure than provided by the recycle portion 4, a first portion 4a of the recycle portion 4 may be recycled to the reforming stage or RWGS stage 100 (e.g. by combining with the fresh make-up feed 2) after optional compression by the compressor 360, and / or a second portion 4b may be recycled to the FT synthesis stage 200 (e.g. by combining with the syngas intermediate 8 or the FT feed 10) after compression by the compressor 350. Typically, the portions 4a, 4b as well as the purge 20 and the recycle portion 4 will have the same composition as the fraction 14, although in some embodiments this may not be the case (e.g. if the purge 20 is provided as a result of a separation such that the stream is enriched in certain undesirable impurities).

[0129] With respect to recycling the fraction 14, or any portion thereof, to certain stages of the process, the selection of a given recycle configuration may depend, at least in part, on the above considerations regarding increasing the overall CO2 conversion of the process and / or suppressing CO2 production in a given stage. With knowledge of the present disclosure, one skilled in the art will understand the applicability of these and other considerations to a given process within the scope of the present invention. As is apparent from the above description, the recycle portion 4, as well as any portion 4a, 4b thereof that may be directed to different locations, constitutes a "portion of the fraction" 14, or alternatively a "portion of the fraction" 14, wherein the fraction is enriched in (i) or (ii) as described throughout the present disclosure. Thus, for example, the gaseous feed mixture 6 may be provided to the reforming stage or RWGS stage 100 as a combination of fresh make-up feed 2 and a portion of the fraction 14 (e.g., the entire recycle portion 4 or a portion 4a of the portion).

[0130] According to a specific embodiment, the fresh supplemental feed 2 may include biogas or consist essentially of biogas. In such embodiments, the gaseous feed mixture 6 may include feed mixture components 2a, 2b ( Figure 2 ) is present in the biogas. According to other specific embodiments, the fresh supplemental feed 2 may include CO2 that has been removed from the atmosphere (e.g., via direct air capture) or captured from the exhaust stream of biomass combustion, and may also include electrolytic H2 (e.g., generated via the use of renewable electricity), fossil hydrogen with CCS, biomass gasification hydrogen, or methane pyrolysis hydrogen. According to still other specific embodiments, the fresh supplemental feed 2 may include effluent from biomass gasification, including, for example, CO2, H2, and CO, and optionally CH4, and may also include supplemental H2, which is electrolytic H2 (e.g., generated via the use of renewable electricity), fossil hydrogen with CCS, biomass gasification hydrogen, or methane pyrolysis hydrogen. According to still other specific embodiments, the fresh supplemental feed 2 may include a retentate gas containing, for example, CO2, H2, CH4, and CO.

[0131] Figure 2 Another exemplary embodiment of a process 1 for producing a liquid hydrocarbon product is depicted. Figure 1 and Figure 2 , various aspects associated with the processes described herein are apparent, including the ability to input a recycle stream directly into the reactors, as opposed to combining the recycle stream with other process streams prior to feeding the combined streams into the reactors. Thus, for example, a gaseous feed mixture 6 may be produced by combining the first portion 4a of fraction 14 with the fresh make-up feed 2, such as Figure 1 as shown, or can be generated in situ in the reactor of the reforming stage or RWGS stage 100 from a combination of the first part 4a of the fraction 14 and a fresh make-up feed, according to Figure 2 , the gaseous feed mixture 6 is provided as a combination of fresh gaseous feed mixture components, namely a fresh supplementary CO2 and / or CH4-containing feed 2a and a fresh supplementary H2-containing feed 2b, wherein feeds 2a and 2b may in certain embodiments consist of a single combined feed. Figure 1 As shown in FIG. 1 , the FT feed 10 may be in the form of Figure 2 It is generated in situ in the FT reactor 200a depicted in FIG. 2 from a combination of the second part 4b of the fraction 14 and the synthesis gas intermediate 8 . Figure 2 Further depicted are options for compression, such as by using a syngas intermediate / FT feed compressor 125 in addition to recycle gas compressors 350 and 360, where compressor 125 is used to achieve a suitable pressure in FT reactor 200a consistent with the FT reaction conditions described herein. Figure 2 Also further depicted are options for removing water, such as using a liquid product separation stage 400 for the purpose of removing condensed liquid water 9, optionally with Figure 1 The combination of removing condensed liquid water 9 from the synthesis gas intermediate 8 is shown in FIG.

[0132] like Figure 2 As further illustrated in FIG. 1 , according to certain embodiments, the FT synthesis stage 200 may include both a FT reactor 200a and a downstream finishing reactor 200b. Figure 1 In some embodiments consistent with the present invention, the FT synthesis stage may include at least one FT reactor 200a containing a mixture of FT catalyst and cracking catalyst (such as those catalysts having compositions as described herein). The FT synthesis stage may also include at least one finishing reactor 200b downstream of at least one FT reactor 200a, such as in the case where the FT reactor 200a provides a FT synthesis effluent 12, and the process also includes feeding the FT synthesis effluent 12 to the finishing reactor 200b. The finishing reactor may contain one or more finishing catalysts, wherein the FT catalyst is completely or substantially absent from the finishing reactor 200b. Such FT catalyst that may be completely or substantially absent from the finishing reactor may refer to a specific FT catalyst contained in the FT reactor 200a, or may refer to any other FT catalyst as described herein. The finishing catalyst may have the same composition and / or the same form as the cracking catalyst contained in the FT reactor, or these compositions and / or forms may be different depending on how the FT reactor and the finishing reactor are operated. Typically, in conjunction with Figure 2In other consistent embodiments, the FT synthesis stage may include at least one FT reactor comprising a bifunctional catalyst having a FT functional component and a cracking functional component (such as those functional components having a composition as described herein). The FT synthesis stage may also include at least one refining reactor 200b downstream of at least one FT reactor 200a, such as in the case where the FT reactor 200a provides a FT synthesis effluent 12, and the process also includes feeding the FT synthesis effluent 12 to the refining reactor 200b. The refining reactor may include a refining catalyst in which the FT functional component is substantially absent from the refining catalyst. Such a FT functional component that may be completely or substantially absent from the refining catalyst may refer to a specific FT functional component of the catalyst contained in the FT reactor 200a, or may refer to any other FT functional component as described herein. The refining catalyst may have the same composition as the cracking functional component, corresponding to the same composition as the bifunctional catalyst contained in the FT reactor, but excluding the FT functional component. Alternatively, depending on how the FT reactor and the refining reactor operate, the composition of the refining catalyst and the cracking functional component may be different.

[0133] Usually, in Figure 2 In some embodiments, in the FT synthesis stage, the step of converting the synthesis gas intermediate 8 comprising a H2 / CO mixture may include contacting the intermediate or the mixture with a mixture of a FT catalyst and a cracking catalyst (e.g., contained in the FT reactor 200a) to provide a FT synthesis effluent 12. Converting the synthesis gas intermediate 8 comprising a H2 / CO mixture may also include, for example, contacting the FT synthesis effluent 12 with a finishing catalyst (e.g., contained in the finishing reactor 200b) in the substantial absence of a FT catalyst to provide a finishing effluent 13. Typically, in the presence of Figure 2 In other consistent embodiments, in the FT synthesis stage, the step of converting the synthesis gas intermediate 8 comprising a H2 / CO mixture may include contacting the intermediate or the mixture with a bifunctional catalyst having a FT functional component and a cracking functional component (e.g., contained in the FT reactor 200a) to provide a FT synthesis effluent 12. Converting the synthesis gas intermediate 8 comprising a H2 / CO mixture may also include contacting the FT synthesis effluent 12 with, for example, a finishing catalyst (e.g., contained in the finishing reactor 200b) in which the FT functional component is substantially absent to provide a finishing effluent 13. In any such embodiments, the cracking catalyst or the cracking functional component, as the case may be, may have any composition as described herein, for example, such a catalyst or functional component may include one or more cracking active metals selected from Groups 12 to 14 of the periodic table.

[0134] from Figure 2The illustrated embodiments will appreciate that the gaseous feed mixture may include as components fresh gaseous feed mixture components, as input to the process, and recycled gaseous feed mixture components. Figure 1 The fresh supplemental feed 2 shown may be used as Figure 2 A combination of fresh gaseous feed mixture components is provided, i.e., a fresh supplemental CO2 and / or CH4-containing feed 2a and a fresh supplemental H2-containing feed 2b as described herein. All or a portion of the fresh supplemental H2-containing feed 2b (such as the first portion 25a) may be added directly to the reforming stage or RWGS stage 100 (e.g., the reforming / RWGS reactor used in that stage), and thus may be a component of the gaseous feed mixture. All or a portion of the fresh supplemental H2-containing feed 2b (such as the second portion 25b) may be added directly to the finishing reactor 200b as a finishing reactor co-feed. Thus, in conjunction with Figure 2 In a consistent embodiment, in the FT synthesis stage, the refining catalyst (e.g., contained in the refining reactor 200b) can be in contact with the FT synthesis effluent 12, in addition to contacting with the fresh supplemental H2-containing feed 2b or a portion 25b thereof having a composition as described herein. The feed can include, for example, H2 derived from water electrolysis, fossil hydrogen with CCS, biomass gasification hydrogen, or methane pyrolysis hydrogen. Regardless of the source, H2 can be present in the fresh supplemental H2-containing feed 2b in an amount of at least about 50 mol% of H2, and is therefore present in the portions 25a, 25b having the same composition.

[0135] Thus, the gaseous feed mixture may include a first portion 25a of the fresh supplemental H2-containing feed 2b, i.e., that portion that is fed directly to the reforming stage or RWGS stage 100 (e.g., the reforming / RWGS reactor used in that stage), which first portion 25a provides input to the process. A representative process may also include feeding a second portion 25b of the fresh supplemental H2-containing feed 2b directly to the FT synthesis stage 200, or in a preferred embodiment, directly to the finishing reactor 200b used in that stage. In this regard, various aspects of the present invention are associated with the discovery that feeding hydrogen (a convenient source of which is present in the fresh supplemental H2-containing feed 2b as described herein) directly to the finishing reactor 200b can be beneficial in promoting hydroprocessing (e.g., hydrocracking and hydroisomerization) reactions in the reactor. Importantly, the introduction of portion 25b of the feed (which would otherwise be fed to the reforming stage or RWGS stage 100 together with portion 25a) directly into the finishing reactor 200b reduces the CO partial pressure in the reactor, thereby improving the efficiency of the finishing catalyst contained in the reactor for converting C 20 +The properties of the hydrocarbons, and / or otherwise improve the stability of the catalyst (i.e., reduce its deactivation rate). As described above, the portion 25b that is fed directly to the finishing reactor 200b can be more specifically the second portion, wherein the first portion 25a is fed directly to the reforming stage or RWGS stage 100 (e.g., the reforming / RWGS reactor used in this stage).

[0136] Other specific aspects of the invention are associated with the following implementations: the flow rates of fresh streams and recycle streams in the processes described herein can be advantageously adjusted as a basis for controlling relevant process parameters, including CO concentration (CO mole %) or CO partial pressure, and H2:CO mole ratio at different points (measurement points or control points) in the FT synthesis stage (e.g., controlling the CO mole % or CO partial pressure in the finishing reactor 200b and / or controlling the H2:CO mole ratio in the FT reactor 200a). In certain exemplary embodiments involving CO concentration (CO mole %) control, the feed rate of the fresh make-up H2-containing feed to the finishing reactor 200b (e.g., the feed rate of the second portion 25b) is adjusted to maintain the CO mole % or CO partial pressure in the FT synthesis stage (such as in the finishing reactor 200b of the stage). For example, the feed rate can be adjusted to maintain a set point or maximum CO mole % or CO partial pressure, which in the case of a finishing reactor 200b can be a measured CO mole % or CO partial pressure at the reactor inlet or upstream of the reactor (e.g., in the FT synthesis effluent or finishing feed), or a calculated CO mole % or CO partial pressure (e.g., based on other parameters indicative of CO mole % or CO partial pressure). The feed rate can, for example, increase in response to a measured or calculated CO mole % or CO partial pressure above the set point or maximum value, and conversely decrease in response to a measured or calculated CO mole % or CO partial pressure below the set point or maximum value. Adjustment can also include suspending the flow of fresh make-up H2-containing feed (i.e., adjusting the feed rate to zero) and then resuming the flow. The set point or maximum CO mol% in the total gaseous feed (including the combination of 12 and 25b) entering stage 200b can be, for example, any discrete value from about 5 mol% to about 25 mol%, from about 3 mol% to about 15 mol%, or from about 1 mol% to about 10 mol%. The set point or maximum CO partial pressure can be, for example, any discrete value from about 34 kPa (5 psi) to about 1.38 MPa (200 psi), from about 34 kPa (5 psi) to about 689 kPa (100 psi), or from about 69 kPa (10 psi) to about 344 kPa (50 psi). As described herein, according to a preferred embodiment, a fresh supplemental H2-containing feed (such as second portion 25b) can be fed directly to a finishing reactor 200b located downstream of the FT reactor 200a.

[0137] As an alternative to or in combination with CO mole % control or CO partial pressure control, another process parameter that can be controlled in the FT synthesis stage is the H2:CO mole ratio, which may be particularly significant from the perspective of the operation of the FT reactor of this stage. As described herein, a representative process may include: (a) feeding at least a portion of a fraction rich in (i) H2 and CO2 or (ii) a hydrogen source and CO2 to the FT synthesis stage, wherein the fraction has been separated from the effluent of the FT synthesis stage; and (b) feeding at least a portion of a fraction rich in (i) H2 and CO2 or (ii) a hydrogen source and CO2 to a reforming and / or RWGS stage, wherein the fraction has been separated from the effluent of the FT synthesis stage. For example, the second portion 4b of fraction 14 can be fed to the FT reactor 200a, and the first portion 4a of fraction 14 can be fed to the reforming and / or RWGS reaction 100. The fraction 4b fed to the FT reactor is thus provided as at least part of the feed to the reactor (e.g. as FT feed 10 upstream of the FT reactor, e.g. Figure 1 As shown, or in situ in the FT reactor 200a, such as Figure 2 The effluent of the FT synthesis stage from which the fraction enriched in (i) or (ii) is separated may more specifically be Figure 1 The FT synthesis effluent 12 shown or Figure 2 The feed rate of the fraction 4b enriched in (i) or (ii) may be adjusted to help maintain the FT synthesis stage, or more specifically, in the Figure 1 In the FT feed 10 shown or in Figure 2 The H2:CO molar ratio in the FT reactor 200a is shown to be within a certain range. Similarly, the fraction 4a fed to the reforming / RWGS reactor provides at least a portion of the feed to that reactor (e.g., as Figure 1 A portion of feed 6 or with Figure 2The feed rate of the fraction 4a enriched in (i) or (ii) can be adjusted to change the stoichiometry of the feed entering the reforming and / or RWGS stage, which in turn can change the H2:CO ratio of the reforming and / or RWGS stage effluent, which in turn is fed to the FT synthesis stage and thereby can help maintain a set point or minimum H2:CO molar ratio in the FT synthesis stage. Such a set point or minimum H2:CO molar ratio can be a measured value or a calculated value (e.g., calculated based on a measured composition of the FT feed), which can be any discrete value within the ranges described herein relative to the syngas intermediate or FT feed. For example, the set point or minimum H2:CO molar ratio can be any discrete value within the range from about 2.1 to about 2.5. Depending on the composition (e.g., hydrogen content) of the fraction enriched in (i) or (ii), the feed rates of the other fractions 4b and 4a can be adjusted, for example, in response to a measured or calculated H2:CO molar ratio outside the target range. The adjustment can also include suspending the flow of the fraction or a portion of the fraction (i.e., adjusting the feed rate to zero), and then resuming the flow. The adjustment can be based on increasing or decreasing the flow rate, or increasing or decreasing the percentage, which is represented by the partial fraction fed to the FT synthesis stage (e.g., the FT reactor 200a of this stage) relative to the entire fraction. As described herein, the partial fraction 14 enriched in (i) or (ii) and fed to the FT synthesis stage can be the second part 4b. For example, the gaseous feed mixture can include the first part 4a as a recycled gaseous feed mixture component, which is fed to the reforming stage or RWGS stage 100 (e.g., the reforming / RWGS reactor of this stage).

[0138] With regard to separation and / or recovery of the liquid hydrocarbon product obtained from the FT synthesis stage, according to a particular embodiment, the effluent of this stage comprising this product may be such as Figure 1 The FT synthesis effluent 12 shown or Figure 2 In the case where the refining effluent 13 may be downstream of the FT synthesis effluent 12, separating the liquid hydrocarbon product from the refining effluent may also include separating it from the FT synthesis effluent. Thus, according to a representative process, the liquid hydrocarbon product may be included in the FT synthesis effluent (e.g., the effluent of the FT reactor 200a) or the refining effluent, and such a process may include separating the C4 + The liquid hydrocarbon product of the hydrocarbon is separated from the corresponding FT synthesis effluent or the refining effluent. In addition, as described herein, a fraction rich in (i) H2 and CO2 or (ii) a hydrogen source and CO2 can also be separated from the corresponding FT synthesis effluent or the refining effluent. For example, Figure 1The use of a separation stage 300 to perform these separations (e.g., gas / liquid separation) on the FT synthesis effluent 12 is shown, and Figure 2 These separations are shown in a similar manner using separation stage 300 for refining effluent 13. In either case, separation stage 300 may result in providing a C4 + The liquid hydrocarbon product 16 is composed of hydrocarbons and can then be further separated (e.g., fractionated) in a liquid product separation stage 400. In the same manner as described herein with respect to recycling a fraction enriched in (i) or (ii) and separated from the FT synthesis effluent 12, such as Figure 1 As shown in FIG. 1 , these fractions may also be recycled when separated from the refined effluent 13, such as Figure 2 . For example, a representative process may also include recycling the fraction to the reforming stage or RWGS stage 100 (e.g., recycled to the reforming / RWGS reactor of this stage) and / or recycling it to the FT synthesis stage (e.g., recycled to the FT reactor of this stage), and preferably recycling it to both stages. In some embodiments, the fraction rich in (ii) hydrogen source and CO2 may be primarily CH4, which originates from the hydrogen source input to the process (e.g., in a fresh gaseous feed mixture component, such as freshly supplemented feed 2a containing CO2 and / or CH4) and / or is generated as a light hydrocarbon byproduct of FT synthesis, which becomes a component of the "light tail" fraction (ii) of the FT synthesis effluent. The fraction may include other light hydrocarbons, such as C2H6 and / or C3H8.

[0139] like Figure 1 and Figure 2 As shown, these processes may include fractionating the liquid hydrocarbon product 16 obtained, for example, from the separation stage 300 into one or more separate fractions enriched in various types of hydrocarbons. Figure 1 and Figure 2 A separated fraction 16b rich in jet fuel boiling range hydrocarbons (which may be referred to as a jet fuel boiling range fraction) and a separated fraction 16c rich in diesel fuel boiling range hydrocarbons (which may be referred to as a diesel boiling range fraction) are depicted, but Figure 2 Additionally depicted is a separated fraction 16a rich in naphtha boiling range hydrocarbons (which may be referred to as a naphtha boiling range fraction). To the extent these separated fractions are recovered from the process as output, they may contribute to the C4 + The hydrocarbon yield and represents all or substantially all of the C4 + hydrocarbons, possibly in addition to residual amounts of such hydrocarbons that may be present in the condensed liquid water 9. As further described herein, a representative process may include recycling all or a portion of the separated fractions, thereby adjusting the product composition according to the proportions of the various types of hydrocarbons recovered. Figure 2 As shown, at least a portion of the naphtha boiling range fraction 16a, such as hydrocarbon recycle 30b, may be recycled to the reforming stage or RWGS stage 100. In the event that only a portion is recycled, the recovered portion 30a may represent the C4 hydrocarbons recovered from the process. + Hydrocarbon yield of hydrocarbons.

[0140] The following examples are set forth as representative of the present invention. These examples should not be construed as limiting the scope of the present invention, as other equivalent embodiments will be apparent in view of this disclosure and the appended claims.

[0141] Example 1

[0142] Reforming of gaseous feed mixtures

[0143] A pilot scale experiment was conducted in which a gaseous mixture was continuously fed to a reactor containing catalyst particles having a composition of 1 wt% Pt and 1 wt% Rh on a ceria support. -1 The performance of the system for reforming / RWGS was tested under conditions of a WHSV of 1.30 W, 864°C (1587°F), and a gauge pressure of 346 kPa (50 psig). The gaseous mixture tested was a composition containing methane, ethane, propane, and CO2 in addition to H2O ("IH 2 The gaseous feed mixture and the synthesis gas product obtained from the feed ("IH 2 Type of product) are summarized in Table 1 below.

[0144] Table 1

[0145]

[0146] From these results, it can be seen that the CO2-steam reforming catalyst and process can provide a synthesis gas product that exhibits high hydrocarbon conversion and has an H2:CO molar ratio suitable for subsequent direct processing via a Fischer-Tropsch reaction (e.g., without the need for prior (upstream) adjustment of the ratio).

[0147] Example 2

[0148] Fischer-Tropsch (FT) testing

[0149] The FT test was conducted in a 0.5 inch (6 mm) water jacket upflow reactor with a mixture of 35% hydrocracking / isomerization catalyst (1% Ga-ZSM-5) and 65% Fischer-Tropsch catalyst (20% Co, 1% Pt, 1% Rh), followed by a fixed bed finishing reactor with 100% Ga-ZSM-5 catalyst. All catalysts were 35 to 60 mesh sizes. The liquid product obtained was condensed and removed. The gas separated from the product continued to enter the repeated FT+ finishing reactor system, and the additional liquid product was condensed and removed. In this way, each of the two reactor stages can reach a conversion of 50% to 60%, with the final overall conversion through the two reactor stages far exceeding 65% after the system reaches a steady state for a sufficient time. The gas separated from the second stage gas was then measured and analyzed. Even after more than 500 hours of testing, the Fischer-Tropsch catalyst had minimal deactivation when shut down intermittently and restarted with hydrogen treatment. Gallons of Fischer-Tropsch liquid were collected during the test.

[0150] The FT system utilizes an upflow liquid-filled reactor through which the gas is bubbled. The reactor has good heat transfer due to the liquid and good temperature uniformity due to the water jacket and the diluted mixed catalyst, which dissipates the heat of reaction. The FT test results for three test cycles are provided in Table 2.

[0151] Table 2

[0152]

[0153] The FT product is a high quality water-white hydrocarbon liquid product having an oxygen content of less than 0.6 wt % and is easily separated from water. A representative distillation curve for this product is shown in Figure 3 In the , the relative amounts of gasoline, jet fuel and diesel boiling range hydrocarbons are indicated. A representative FT gas product composition is provided in Table 3. This can be burned in the reformer to provide heat energy or otherwise recycled to extinction.

[0154] Table 3

[0155]

[0156]

[0157] Example 3

[0158] Reverse Water Gas Shift (RWGS)

[0159] The catalyst used to perform the reforming reaction in Example 1 is additionally effective for performing the RWGS reaction. At low temperatures, the balance is more favorable to methanation and low CO production. In order to achieve high conversion of CO2 to CO, the RWGS reaction must be performed at sufficiently high temperatures. At 913°C (1675°F) and 103 kPa (15 psig) gauge pressure, a Pt / Rh catalyst on ceria obtained 75% conversion of CO2 to CO with a H2:CO molar ratio of 2.9 in the product syngas. The experimental results are summarized in Table 4.

[0160] Table 4

[0161] <![CDATA[CO2+H2]]> <![CDATA[CO2+H2]]> Feed 1 Product 1 Feed 2 Product 2 Methane, mol% .2 .2 Ethane, mol% Propane, mol% <![CDATA[CO2 mole %]]> 24 7.2 31 7.8 Water, mol% 20.4 10.0 <![CDATA[H2, mol%]]> 76 53.8 69 61.2 CO, mol% 18.4 20.8 <![CDATA[% CO2 conversion]]> 75 73 <![CDATA[H2:CO molar ratio]]> 2.92 2.92 Gas flow ratecc / min 615 440 920 750 Recovery weight % 89 85

[0162] While for a typical FT feed the H2:CO molar ratio in the product gas is high at 2.9, according to simulation studies this ratio is reduced to 2.1 when combined with the recycled FT gas product.

[0163] Example 4

[0164] Electric reformer research

[0165] An electrically heated reformer was used with a catalyst as described in Example 1 and an "IH" having a composition of approximately 24 mol % H, 17.5 mol % methane, 17.5 mol % propane, and 41 mol % CO. 2 The reactor electrical heaters were placed in jackets that protected them from exposure to the process gas and also facilitated replacement in case of heater burnout. Typical experimental parameters and results for the preparation of synthesis gas from the gaseous feed mixture are summarized in Table 5.

[0166] Table 5

[0167]

[0168] In conclusion, the electric reformer operated in a reliable manner for more than 500 hours and there was no significant difference in the WHSV between 0.7 and 1.5 hours. -1 During operation, the reformer hydrocarbon conversion is typically 90% to 95%, such as Figure 4 As shown, and as Figure 5 As shown, the H2:CO molar ratio of the synthesis gas produced during this period is also consistent. Although this molar ratio has been measured to be as low as 2.4, the average value is higher and in practice the ratio can be adjusted as needed. The reforming product composition is also stable over time, as shown in FIG. Figure 6The material balance during operation is centered around 100%, providing an indication of the reliability of the measured parameters. In summary, the results demonstrate that the electric reformer performs well in extended operation to produce synthesis gas from a mixture including methane and CO2, which is expected to provide favorable results for a variety of feeds such as biogas.

[0169] In summary, various aspects of the present invention relate to processes for converting low value gaseous feed mixtures into liquid hydrocarbon products utilizing reforming and / or RWGS reactions, such as C4 hydrocarbons having carbon derived from renewable sources. + Those of hydrocarbons, such as CH4 and CO2 (which are the main components of biogas), and / or electrolytic H2, fossil hydrogen with CCS, biomass gasification hydrogen or methane pyrolysis hydrogen, and CO2 derived from direct air capture, biomass gasification or biomass combustion. Additional processing steps may optionally include FT synthesis alone or in combination with cracking to achieve the desired hydrocarbon molecular weight distribution. Those skilled in the art, using the knowledge gained from this disclosure, will recognize that various changes can be made to these processes to obtain these and other advantages without departing from the scope of this disclosure. Therefore, it should be understood that the features of the present disclosure are susceptible to modification and / or replacement without departing from the scope of this disclosure. The specific embodiments illustrated and described herein are for illustrative purposes only and are not limitations of the invention set forth in the appended claims.

Claims

1. A method for producing C4 + A process for producing a liquid hydrocarbon product from hydrocarbons, the process comprising: (a) in a reforming stage or RWGS stage, contacting a gaseous feed mixture comprising mainly (i) H2 and CO2 or (ii) a hydrogen source and CO2 with a reforming / RWGS catalyst to produce a synthesis gas intermediate comprising a H2 / CO mixture; as well as (b) in a Fischer-Tropsch (FT) synthesis stage, converting the synthesis gas intermediate at least partly via FT synthesis into the liquid hydrocarbon product.

2. The process of claim 1, wherein the gaseous feed mixture comprises (i) at least about 75 mole percent of a combined amount of H2 and CO2 or (ii) at least about 75 mole percent of a combined amount of the hydrogen source and CO2.

3. A process according to claim 1 or claim 2, wherein the gaseous feed mixture comprises one or more of CO, H2O and O2 in an amount independently less than about 10 mol% or in a combined amount less than about 10 mol%.

4. The process according to any one of claims 1 to 3, wherein the gaseous feed mixture comprises biogas.

5. The process according to any one of claims 1 to 4, wherein the C4 + The hydrocarbons include at least about 80 weight percent of a combined amount of naphtha boiling range hydrocarbons, jet fuel boiling range hydrocarbons, and / or diesel boiling range hydrocarbons.

6. The process according to any one of claims 1 to 5, wherein the recovered C4 + The hydrocarbons include jet fuel boiling range hydrocarbons in an amount of at least about 55 weight percent, wherein a combination of naphtha boiling range hydrocarbons and diesel boiling range hydrocarbons account for about 10% of the recovered C4 + At least about 40 weight percent of the hydrocarbons, and further wherein none of the liquid hydrocarbon products are recycled to the process.

7. The process according to any one of claims 1 to 5, wherein the recovered C4 + The hydrocarbons include jet fuel boiling range hydrocarbons in an amount of at least about 80 weight percent, wherein diesel boiling range hydrocarbons account for the recovered C4 + At least about 15 weight percent of the hydrocarbons, and further wherein naphtha boiling range hydrocarbons in the liquid hydrocarbon product are recycled to the process.

8. A process according to any one of claims 1 to 7, wherein the reforming / RWGS catalyst comprises a noble metal on a solid support comprising ceria.

9. The process of claim 8, wherein the noble metal is selected from the group consisting of Pt, Rh, Ru, Pd, Ag, Os, Ir and Au.

10. The process of claim 9, wherein the noble metal is Pt.

11. The process of any one of claims 8 to 10, wherein the cerium oxide is present in an amount of at least about 60% by weight of the solid support.

12. The process of any one of claims 8 to 11, wherein the solid support further comprises alumina.

13. The process of claim 12, wherein the cerium oxide and the aluminum oxide are present in a combined amount of at least about 95% by weight of the solid support.

14. A process according to any one of claims 1 to 13, wherein step (b) comprises a combination of said FT synthesis and wax cracking.

15. A process according to claim 14, wherein the FT synthesis stage comprises at least one FT reactor comprising a mixture of FT catalyst and cracking catalyst.

16. The process of claim 15, wherein the FT synthesis stage further comprises at least one finishing reactor downstream of the at least one FT reactor, the finishing reactor comprising a finishing catalyst, wherein the FT catalyst is substantially absent from the finishing reactor.

17. A process according to claim 16, wherein the finishing catalyst has the same composition and / or the same form as the cracking catalyst.

18. The process of claim 14, wherein the FT synthesis stage comprises at least one FT reactor comprising a bifunctional catalyst having a FT functional component and a cracking functional component.

19. The process of claim 18, wherein the FT synthesis stage further comprises at least one finishing reactor downstream of the at least one FT reactor, the finishing reactor comprising a finishing catalyst, wherein the FT functional component is substantially absent from the finishing catalyst.

20. The process of claim 19, wherein the finishing catalyst has the same composition as the cracking functional component.

21. The process of any one of claims 16, 17, 19 and 20, wherein the gaseous feed mixture comprises one or more gaseous feed mixture components, wherein a portion of the one or more gaseous mixture components is fed directly to the at least one finishing reactor.

22. The process of claim 21, wherein the one or more gaseous feed mixture components comprise one or more fresh gaseous feed mixture components and / or one or more recycled gaseous feed mixture components, wherein the one or more gaseous feed mixture components are one of the one or more fresh gaseous feed mixture components, and the portion of the one or more gaseous feed mixture components is directly fed to the at least one finishing reactor.

23. A process according to claim 22, wherein the one or more gaseous mixture components are fresh supplemental H2-containing feed comprising electrolytic hydrogen, and a portion of the one or more gaseous mixture components are directly fed to the at least one finishing reactor.

24. The process of any one of claims 1 to 23, wherein at least about 70% of the CO2 carbon in the gaseous feed mixture forms the C4 + hydrocarbon.

25. A liquid hydrocarbon product comprising naphtha boiling range hydrocarbons, jet fuel boiling range hydrocarbons, and / or diesel boiling range hydrocarbons having a renewable carbon content of at least about 70%.

26. The liquid hydrocarbon product of claim 25, wherein at least about 20% of the total carbon content of the liquid hydrocarbon product is derived from CO2.

27. A liquid hydrocarbon product according to claim 26, wherein the CO2 is contained in biogas.

28. A C4 recovery process comprising substantially all naphtha boiling range hydrocarbons, jet fuel boiling range hydrocarbons and / or diesel boiling range hydrocarbons. + hydrocarbon fraction, wherein (i) the recovered C4 + At least about 20% of the total carbon content of the hydrocarbon fraction is derived from atmospheric CO2 and / or (ii) the recovered C4 + At least about 20% of the total hydrogen content of the hydrocarbon fraction is derived from electrolytic hydrogen.

29. A process for producing a liquid hydrocarbon product comprising naphtha boiling range hydrocarbons, jet fuel boiling range hydrocarbons and / or diesel boiling range hydrocarbons, the process comprising: (a) in a reforming stage or RWGS stage, contacting a gaseous feed mixture comprising mainly (i) H2 and CO2 or (ii) a hydrogen source and CO2 with a reforming / RWGS catalyst to produce a synthesis gas intermediate comprising a H2 / CO mixture; as well as (b) in a Fischer-Tropsch (FT) synthesis stage, converting the synthesis gas intermediate into the liquid hydrocarbon product via a combination of Fischer-Tropsch (FT) synthesis and wax cracking.

30. A process according to claim 29, wherein step (b) comprises contacting the H2 / CO mixture with a mixture of a FT catalyst and a cracking catalyst to provide a FT synthesis effluent.

31. A process according to claim 30, wherein the cracking catalyst comprises one or more cracking active metals selected from Groups 12 to 14 of the Periodic Table.

32. A process according to claim 30 or claim 31 wherein step (b) further comprises contacting the FT synthesis effluent with a finishing catalyst in the substantial absence of the FT catalyst to provide a finishing effluent.

33. A process according to claim 32, wherein step (b) comprises contacting the H2 / CO mixture with a bifunctional catalyst having a FT functional component and a cracking functional component to provide a FT synthesis effluent.

34. The process of claim 33, wherein the cracking functional component comprises one or more cracking active metals selected from Groups 12 to 14 of the Periodic Table.

35. A process according to claim 33 or claim 34 wherein step (b) further comprises contacting the FT synthesis effluent with a finishing catalyst in which the FT functional component is substantially absent to provide a finishing effluent.

36. A process according to claim 32 or claim 35, wherein in step (b), the refining catalyst is contacted with a fresh make-up H2-containing feed in addition to the FT synthesis effluent, wherein the fresh make-up H2-containing feed comprises at least about 50 mol% H2 and is provided directly to the refining catalyst.

37. A process according to claim 31 or claim 34 wherein the one or more cracking active metals are deposited on a solid acidic support.

38. The process of claim 37, wherein the solid acidic support comprises a zeolite molecular sieve having a silica to alumina framework molar ratio of less than about 50.

39. The process of any one of claims 1 to 15, 18, 29 to 31, 33, 34, 37 and 38, wherein the liquid hydrocarbon product is contained in a FT synthesis effluent, wherein the process further comprises: Will include the C4 + separating said liquid hydrocarbon product of hydrocarbons from said FT synthesis effluent, and A fraction enriched in (i) H2 and CO2 or (ii) the hydrogen source and CO2 is separated from the FT synthesis effluent.

40. The process of any one of claims 16, 17, 19 to 23, 32, 35 and 36, wherein the liquid hydrocarbon product is contained in a refining effluent, wherein the process further comprises: Will include the C4 + said liquid hydrocarbon product of hydrocarbons is separated from said refining effluent, and A fraction enriched in (i) H2 and CO2 or (ii) said hydrogen source and CO2 is separated from said refined effluent.

41. A process according to claim 39 or claim 40, wherein the fraction enriched in (i) H2 and CO2 or (ii) the hydrogen source and CO2 comprises CH4.

42. The process of any one of claims 39 to 41, further comprising: recycling the fraction enriched in (i) H2 and CO2 or (ii) the hydrogen source and CO2 to the reforming stage or the RWGS stage, and / or The fraction enriched in (i) H2 and CO2 or (ii) the hydrogen source and CO2 is recycled to the FT synthesis stage.

43. The process of any one of claims 1 to 24 and 29 to 42, further comprising fractionating the liquid hydrocarbon product into one or more separate fractions enriched in naphtha boiling range hydrocarbons, jet fuel boiling range hydrocarbons, or diesel boiling range hydrocarbons.

44. The process of claim 43, wherein the one or more separated fractions include a naphtha boiling range hydrocarbon fraction, the process further comprising recycling at least a portion of the naphtha boiling range hydrocarbon fraction to the reforming stage or the RWGS stage.

45. The process of any one of claims 1 to 24 and 29 to 44, wherein the gaseous feed mixture comprises biogas present in the gaseous feed mixture as a fresh gaseous feed mixture component.

46. ​​A process according to any one of claims 1 to 24 and 29 to 45, wherein the gaseous feed mixture comprises a fresh make-up H2-containing feed comprising electrolytic hydrogen.

47. A process according to claim 46, further comprising feeding a portion of the fresh make-up H2-containing feed directly to the FT synthesis stage.

48. A process according to any one of claims 1 to 24 and 29 to 47 wherein the reforming / RWGS catalyst is disposed in a catalyst bed volume within an electrically heated reforming reactor.

49. A process according to claim 48, wherein the electrically heated reforming reactor is internally and / or externally heated by resistive and / or inductive heating elements.

50. The process of any one of claims 1 to 24 and 29 to 49, wherein the hydrogen source comprises one or more of CH4, C2H6, C3H8 and H2O.

51. A process according to claim 50, wherein the hydrogen source comprises one or more of CH4, C2H6, C3H8 present in a fraction rich in (i) H2 and CO2 or (ii) said hydrogen source and CO2, said fraction having been removed from a fraction comprising said C4 + The effluent of the FT synthesis stage of hydrocarbon products is separated and has been further recycled to the reforming stage or to the RWGS stage.

52. A process according to claim 51 , wherein the effluent of the FT synthesis stage is a FT synthesis effluent or a polishing effluent.

53. A process according to any one of claims 1 to 24 and 29 to 52, wherein the gaseous feed mixture comprises a first portion of fresh make-up H2-containing feed, the first portion providing input to the process.

54. The process of claim 53 further comprising feeding a second portion of the fresh make-up H2-containing feed directly to the FT synthesis stage.

55. A process according to claim 54, wherein the feed rate of the second portion of the fresh make-up H2-containing feed is adjusted to maintain the CO partial pressure in the FT synthesis stage.

56. The process of claim 55 comprising feeding the second portion of the fresh supplemental H2-containing feed directly to a finishing reactor of the FT synthesis stage, the finishing reactor being downstream of the FT reactor, wherein the feed rate of the second portion of the fresh supplemental H2-containing feed is adjusted to maintain the CO partial pressure in the finishing reactor.

57. A process according to any one of claims 1 to 24 and 29 to 56, comprising feeding to the FT synthesis stage a portion of a fraction enriched in (i) H2 and CO2 or (ii) the hydrogen source and CO2, said fraction having been separated from the effluent of the FT synthesis stage.

58. A process according to claim 57, wherein the portion of the fraction enriched in (i) or (ii) is fed to a FT reactor to provide at least a portion of the FT feed, and wherein the effluent of the FT synthesis stage from which the fraction enriched in (i) or (ii) is separated is a FT synthesis effluent or a refining effluent.

59. A process according to claim 57 or claim 58, wherein the feed rate of the portion of the fraction enriched in (i) or (ii) is adjusted to maintain the H2:CO molar ratio in the FT synthesis stage.

60. The process of claim 59, wherein the portion of the fraction enriched in (i) or (ii) is the second portion, and wherein the gaseous feed mixture comprises the first portion of the fraction enriched in (i) or (ii).

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