Fischer-Tropsch catalyst activation

Abstract

A process for converting a mixture of hydrogen and carbon monoxide to a hydrocarbon composition comprising one or more optionally oxygen-containing hydrocarbons, the process comprising the steps of: (a) providing a first catalyst material comprising cobalt (e.g., in oxide form) supported on a support; (b) contacting the first catalyst material with carbon monoxide at a first pressure (P1) and a first temperature (T1) to provide a passivated catalyst material wherein P1 is at least 1 bara and at most 50 bara, and T1 is at most 300 DEG C; (c) contacting the passivated catalyst material with a reducing agent at a second temperature (T2) and a second pressure (P2) to form an activated catalyst material wherein P2 is at least 10 bara, and wherein P2 is greater than or equal to P1, and wherein T2 is at most 300 DEG C; and (d) contacting the activated catalyst material with a mixture of hydrogen and carbon monoxide.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority from European patent application No. 22211257.5, filed on December 2, 2022, which is hereby incorporated by reference in its entirety.

[0003] BACKGROUND OF THE DISCLOSURE

[0004] field

[0005] The present disclosure relates to methods for activating Fischer-Tropsch catalysts, Fischer-Tropsch processes using such activated catalysts, and methods of improving at least one aspect of the performance of Fischer-Tropsch catalysts. Technical Background

[0006] The conversion of synthesis gas to hydrocarbons by the Fischer-Tropsch process has been known for many years.The growing importance of alternative energy sources has led to renewed interest in the Fischer-Tropsch (FT) process as it allows a direct and environmentally acceptable route to high quality fuels and feedstock chemicals.

[0007] The FT process is known for producing straight-chain hydrocarbons used in fuels and oxygenates used as valuable feedstock chemicals. Hydrocarbon fuels derived from the FT process are better able to meet increasingly stringent environmental regulations than fuels produced by conventional refining because FT-derived fuels generally have lower levels of sulfur, nitrogen, and aromatic compounds that contribute to potent pollutants such as SO2, NO x The FT process reduces the emission of fuel oil and particulate matter. Alcohols derived from the FT process generally have a higher octane rating than hydrocarbons and therefore burn more completely, thereby reducing the environmental impact of such fuels. The alcohols and other oxygenates obtained can also be used as reagents in other processes, such as in the synthesis of lubricants.

[0008] A variety of transition metals have been identified as catalytically active in the conversion of synthesis gas to hydrocarbons and their oxygenated derivatives. In particular, cobalt, nickel, ruthenium, and iron have been studied, usually in combination with support materials, the most common of which are alumina, silica, and carbon.

[0009] In a typical preparation of a supported cobalt-containing FT synthesis catalyst, a solid support material is contacted with a solution of a soluble cobalt compound (e.g., cobalt nitrate). The impregnated support is then calcined and / or oxidized to form cobalt oxide, typically one or more of CoO, Co2O3, or Co3O4. However, such oxides generally have poor FT catalytic activity and must be reduced to form the preferred catalytically active species of cobalt metal. During calcination, cobalt oxide crystallites form on the support material. The properties of these crystallites, which serve as precursors to the active catalyst, are known to have an impact on both the activity and selectivity of the final FT catalyst.

[0010] Prior to starting the Fischer-Tropsch synthesis reaction, the FT catalyst is required to be in a reduced catalyst form of a FT catalyst (e.g., cobalt metal). Reduction of the FT catalyst typically occurs in the FT synthesis reactor, although it can occur remotely from the reactor where the catalyst is reversibly passivated or maintained under inert conditions to prevent reoxidation of the catalyst, for example by encapsulating the catalyst in wax.

[0011] The method of activating the FT catalyst is known to have an impact on the performance of the Fischer-Tropsch synthesis reaction and is therefore typically carried out under conditions that differ from those of the Fischer-Tropsch synthesis reaction.

[0012] Therefore, there is a need to develop new methods for activating FT catalysts.

[0013] Overview

[0014] The present inventors have discovered a method for producing a highly active catalyst composition for FT synthesis. In particular, it has been found that the method and the compositions derived therefrom are capable of producing FT catalysts that benefit from at least one property improvement compared to FT catalysts that have not been activated according to the method of the present invention. In addition, the method also allows for the production of intermediate catalyst materials that are resistant to environmental oxidation; notably, this can allow for the ex ternary preparation of passivated catalyst intermediates that can subsequently be stored, transported and introduced into a Fischer-Tropsch reactor, where activation is accomplished under mild conditions, with inert by-products formed only upon final reduction. An additional advantage of preparing the passivated catalyst intermediate ex ternary with subsequent activation accomplished in a Fischer-Tropsch reactor is that the final activation conditions are mild, and therefore the Fischer-Tropsch reactor and gas supply equipment do not need to be capable of reaching abnormally high pressures and temperatures, reducing equipment costs at the time of use.

[0015] Thus, in one aspect, the present disclosure provides a process for converting a mixture of hydrogen and carbon monoxide into a hydrocarbon composition comprising one or more optionally oxygenated hydrocarbons, the process comprising the steps of:

[0016] (a) providing a first catalyst material comprising cobalt (e.g., in the form of an oxide) supported on a support;

[0017] (b) contacting the first catalyst material with carbon monoxide at a first pressure (P1) and a first temperature (T1) to provide a passivated catalyst material, wherein P1 is at least 1 bara and at most 50 bara, and T1 is at most 300° C.;

[0018] (c) contacting the passivated catalyst material with a reducing agent at a second temperature (T2) and a second pressure (P2) to form an activated catalyst material, wherein P2 is at least 10 bara, and wherein P2 is greater than P1, and wherein T2 is at most 300°C; and

[0019] (d) contacting the activated catalyst material with a mixture of hydrogen and carbon monoxide.

[0020] In certain embodiments as otherwise described herein, the passivated catalyst material as otherwise described herein comprises at least 5 weight percent (e.g., at least 25%, at least 50%, or even at least 75%) of the cobalt of the passivated catalyst material in the form of cobalt carbide.

[0021] In certain embodiments as otherwise described herein, the activated catalyst material as otherwise described herein comprises hcp cobalt metal in a ratio to fcc cobalt metal of at least 50:50 as measured by x-ray diffraction. In certain desirable embodiments as otherwise described herein, the hcp metal is present in a ratio to fcc cobalt metal of at least 75:25 (e.g., at least 80:20 or at least 85:15) as measured by x-ray diffraction.

[0022] In some embodiments, all steps (a) to (d) of the process are performed in a Fischer-Tropsch reactor.

[0023] In some embodiments, steps (a) and (b) of the process are performed outside of a Fischer-Tropsch reactor, and steps (c) and (d) of the process are performed within a Fischer-Tropsch reactor.

[0024] In certain embodiments, step (b) is performed as a two-step process as follows:

[0025] (bi) contacting the first catalyst material with carbon monoxide at an initial passivation pressure (P1initial) of at least 1 bara and at most 50 bara and an initial passivation temperature (T1initial) of at most 300° C. to provide a passivated catalyst material; and

[0026] (b-ii) contacting the passivated catalyst material with carbon monoxide at a first pressure (P1) of at least 1 bara and at most 50 bara and a first temperature (T1) of at most 300°C.

[0027] In certain embodiments, steps (a) and (bi) of the process are performed outside of a Fischer-Tropsch reactor, and steps (b-ii) to (d) of the process are performed within a Fischer-Tropsch reactor.

[0028] Another aspect of the present disclosure is the use of the catalyst activation method as described herein to increase the selectivity of the conversion of carbon monoxide and hydrogen to hydrocarbons having five or more carbon atoms (C5+) compared to a catalyst that has been activated using reduction alone.

[0029] Another aspect of the present disclosure is the use of the catalyst activation method as described herein to increase the conversion of carbon monoxide and hydrogen to hydrocarbons (compared to a catalyst that has been activated using reduction alone).

[0030] Another aspect of the present disclosure is the use of the catalyst activation method as described herein to increase the catalyst life of a catalyst.

[0031] Other aspects of the present disclosure will be apparent to those skilled in the art in view of the following description.

[0032] Detailed description

[0033] The present disclosure relates to Fischer-Tropsch synthesis processes and methods of improving the performance of Fischer-Tropsch synthesis processes using cobalt-based catalysts.

[0034] The present inventors have discovered that treating a catalyst material with carbon monoxide can form a metal carbide, such as cobalt carbide, which produces a passivated catalyst material. The passivated catalyst material can then be converted to an activated catalyst material by treatment with a reducing agent, and this activated catalyst material can then be used to convert hydrogen and carbon monoxide into a hydrocarbon composition. The inventors have surprisingly discovered that the pressure at which the carbon monoxide treatment is carried out can have a significant impact on the performance of the catalyst in a Fischer-Tropsch synthesis reaction.

[0035] Advantageously, the formation of metal carbides (e.g., cobalt carbide) produces a catalyst passivation material that resists atmospheric oxidation or other degradation, and therefore can be stored and / or transported because the metal carbides cannot be further oxidized by molecular oxygen or other common oxidants. In addition, metal carbides are known for their remarkable hardness, which results in a mechanically more robust passivated catalyst material that can better withstand the mechanical stress that may occur during transportation and handling (e.g., during loading into a reactor) between sites. In addition, the inventors have found that the passivated catalyst material containing cobalt carbide can be easily converted into an activated catalyst material under relatively mild conditions, producing methane as the main by-product. This generation of methane is superior to traditional activation methods, such as using hydrogen to reduce from oxides, which produces undesirable by-products (e.g., water). Under these conditions, water can be a potent oxidant, inhibiting reduction, promoting cobalt sintering and being harmful to catalyst and reactor function. Furthermore, since the conditions for activation according to the present disclosure are mild, high-pressure hydrogen equipment may not be necessary for activation, simplifying equipment capital requirements. In fact, in many cases, the carbide material can itself be converted into an activated catalyst under Fischer-Tropsch reaction conditions.

[0036] Such a method can allow for the physical separation of catalyst preparation and Fischer-Tropsch synthesis, wherein a stable, passivated catalyst is prepared at a first location and transported to a Fischer-Tropsch reactor (in some cases over many miles), where the catalyst is depassivated by activation under relatively mild conditions and then used for Fischer-Tropsch synthesis. This is particularly advantageous because the reactor requirements for the two methods are generally quite different. In addition, the method allows for the use of a dispersed Fischer-Tropsch reactor that does not require conventional high-temperature, high-pressure catalyst activation. Thus, for many Fischer-Tropsch reactors, far fewer high-temperature, high-pressure reactors can be used to activate the catalyst, and the Fischer-Tropsch reactor can have lower temperature and / or lower pressure capabilities.

[0037] The cobalt metal typically formed in the activated form of a Fischer-Tropsch catalyst material (e.g., by reduction of cobalt oxide) typically consists of a mixture of two metallic phases: hexagonal close-packed (hcp) cobalt and face-centered cubic (fcc) cobalt. Due to the small energy difference between these two phases, both phases are typically present in significant amounts. The inventors have noted that hcp cobalt is more active for the FT process than typical mixed-phase cobalt. See, for example, Journal of Catalysis 277, 14-26 (2011). Advantageously, while the reduction of cobalt oxide provides a mixture of hcp cobalt and fcc cobalt, the reduction of a passivated catalyst based on cobalt carbide surprisingly produces a catalyst comprising almost exclusively cobalt metal in the hcp phase.

[0038] Thus, one aspect of the present disclosure provides a process for converting a mixture of hydrogen and carbon monoxide into a hydrocarbon composition comprising one or more optionally oxygenated hydrocarbons, the process comprising the steps of:

[0039] (a) providing a first catalyst material comprising cobalt (e.g., in the form of an oxide) supported on a support;

[0040] (b) contacting the first catalyst material with carbon monoxide at a first pressure (P1) and a first temperature (T1) to provide a passivated catalyst material, wherein P1 is at least 1 bara and at most 50 bara and T1 is at most 300° C.;

[0041] (c) contacting the passivated catalyst material with a reducing agent at a second temperature (T2) and a second pressure (P2) to form an activated catalyst material, wherein P2 is at least 10 bara, and wherein P2 is greater than P1, and wherein T3 is at most 300°C; and

[0042] (d) contacting the activated catalyst material with a mixture of hydrogen and carbon monoxide.

[0043] The catalyst materials described herein include various forms of cobalt, a support, and optionally other metals or reaction modifiers.Supported cobalt-based materials are well known in the art and can generally be adapted for use in the methods and materials described herein.

[0044] In certain embodiments as further described herein, the catalyst materials as described herein comprise cobalt in the range of 5% to 35% by weight on an elemental basis. For example, in certain embodiments as further described herein, cobalt may be present in the range of 7-35% by weight, or 10-35% by weight, or 5-25% by weight, or 7-25% by weight, or 10-25% by weight, or 5-20% by weight, or 7-20% by weight, or 10-20% by weight.

[0045] The catalyst materials as described herein may include other metal species, for example as promoters. For example, in certain embodiments as otherwise described herein, the catalyst material includes manganese, for example, in an amount ranging from up to 15 wt%, such as up to 12 wt%, or up to 10 wt%, or up to 7 wt%, or up to 5 wt%, or up to 3 wt%, or up to 2 wt%, calculated on an elemental basis; typically, when manganese is present, it will be present in an amount of at least 0.1 wt%, or at least 0.2 wt%, or at least 0.3 wt%, or at least 0.5 wt%, or at least 0.5 wt%, calculated on an elemental basis. In certain such embodiments, the catalyst material comprises 0.1-15 wt%, for example 0.2-15 wt%, or 0.3-15 wt%, or 0.4-15 wt%, or 0.5-15 wt%, or 0.1-12 wt%, or 0.2-12 wt%, or 0.3-12 wt%, or 0.4-12 wt%, or 0.5-12 wt%, or 0.1-10 wt%, or 0.2-10 wt%, or 0.3-10 wt%, or 0.4-10 wt%, or 0.5-10 wt%, or 0.1-7 wt%, or 0. %. Manganese is preferably in an amount in the range of 0.2-7 wt%, or 0.3-7 wt%, or 0.4-7 wt%, or 0.5-7 wt%, or 0.1-5 wt%, or 0.2-5 wt%, or 0.3-5 wt%, or 0.4-5 wt%, or 0.5-5 wt%, or 0.1-3 wt%, or 0.2-3 wt%, or 0.3-3 wt%, or 0.4-3 wt%, or 0.5-3 wt%, or 0.1-2 wt%, or 0.2-2 wt%, or 0.3-2 wt%, or 0.4-2 wt%, or 0.5-2 wt%. In some embodiments, manganese is present in relatively larger amounts, such as 2-15 wt %, such as 3-15 wt %, or 4-15 wt %, or 2-12 wt %, or 3-12 wt %, or 4-12 wt %, or 2-10 wt %, or 3-10 wt %, or 4-10 wt %, or 2-7 wt %, or 3-7 wt %, or 4-7 wt %. Of course, in other embodiments, manganese is substantially absent (e.g., less than 0.1 wt % or less than 0.5 wt % manganese is present). Other metals may be present, for example, as additives.

[0046] Various support materials are known in the art and can be selected based on the precise requirements of the FT reactor or other chemical, mechanical, or economic requirements. In certain embodiments, as further described herein, the support comprises at least one of titanium oxide, zirconium oxide, ceria, aluminum oxide, silicon oxide, and zinc oxide. In specific embodiments, as further described herein, the support comprises exactly one of titanium oxide, zirconium oxide, ceria, aluminum oxide, silicon oxide, and zinc oxide. In another specific embodiment, as further described herein, the support comprises titanium oxide. In another specific embodiment, as further described herein, the support is titanium oxide.

[0047] The first catalyst material can be prepared using traditional methods in the art. In certain embodiments, cobalt is introduced onto a carrier by introducing a solution containing a soluble cobalt salt (e.g., cobalt nitrate) onto the carrier and calcining and / or oxidizing the composition to form insoluble cobalt particles (e.g., as cobalt oxide) on the carrier. In certain embodiments, the first catalyst material comprises a composition of a calcined metal (e.g., including calcined cobalt) adhered to the carrier. In specific embodiments, the cobalt of the first catalyst material (i.e., as at least a portion of cobalt, at most all cobalt, such as at least 50%, at least 75% or at least 90%) is in the form of at least one of cobalt oxide and cobalt hydroxide. For example, the cobalt can be cobalt oxide (e.g., CoO, Co3O4 or Co2O3 or a combination thereof) or cobalt hydroxide (e.g., Co(OH)2 or Co(OH)3 or a combination thereof) or a combination of cobalt oxide and cobalt hydroxide.

[0048] The present inventors have determined that the pressure and temperature at which the catalyst material is contacted with carbon monoxide when it is converted to carbide form when used in a Fischer-Tropsch process can have an impact on the performance of the catalyst.

[0049] The catalyst material is formed by contacting the catalyst material with carbon monoxide at a first pressure (P1) of at least 1 bara and at most 50 bara and a first temperature (T1) of at most 300°C. Advantageously, the passivated catalyst material includes cobalt carbide. The relative proportions of the metal species can be determined by any suitable technique known to the skilled person, such as fitting an x-ray diffraction pattern. In certain embodiments as described herein, at least 25 mol % or at least 50 mol % of the cobalt of the passivated catalyst material measured by x-ray diffraction are in the form of cobalt carbide. For example, in some embodiments, at least 75 mol % or even at least 90 mol % of the cobalt of the passivated catalyst material are in the form of cobalt carbide. Of course, in other embodiments, passivation can be effective even when the conversion to carbide is lower (for example, when the surface carbide of the catalyst particles is sufficient to protect the cobalt metal inside the particles).

[0050] The reaction of converting the catalyst material to the passivated catalyst material is carried out at a first pressure (P1) and a first temperature (T1), wherein P1 is at least 1 bara and at most 50 bara and T1 is at most 300° C. In certain embodiments as otherwise described herein, P1 is in the range of 1 bara to at most 10 bara, and in other embodiments as otherwise described herein, P1 is at least 5 bara, preferably in the range of 5 bara to 50 bara. Examples of suitable ranges for P1 include 1-10 bara, or 2-10 bara, or 2-10 bara, or 3-10 bara, or 4-10 bara, or 5-10 bara, or 5-30 bara, or 5-25 bara, or 7-50 bara, or 7-30 bara, or 7-25 bara, or 10-50 bara, or 7-30 bara, or 7-25 bara, or 10-50 bara, or 10-30 bara, or 10-25 bara. Carbon monoxide can be provided in the process gas with various concentrations, for example, at least 5 volume %, for example, at least 25 volume %, at least 50 volume %, or at least 75 volume %; the process gas may further include, for example, an inert gas, such as nitrogen. In certain embodiments, the first temperature (T1) is in the range of 25°C to 250°C, for example, 50°C to 225°C. For example, in specific embodiments, T1 is in the range of 25°C to 200°C, or 75°C to 200°C, or 100°C to 200°C, or 125°C to 200°C. In specific embodiments, T1 is about 200°C. In other embodiments, T1 does not exceed 150°C, or does not exceed 100°C. For example, in certain embodiments, T1 is in the range of 25°C to 150°C, such as 50°C to 125°C, or 50°C to 100°C. One of ordinary skill in the art will perform passivation with carbon monoxide under conditions (e.g., temperature, pressure, time) that provide the desired degree of carbide conversion.

[0051] Advantageously, the process according to the present disclosure results in the formation of a passivated catalyst material as an intermediate product, and this passivated catalyst material has improved atmospheric oxidation resistance. This is effected by chemically protecting at least a portion of the cobalt metal as a carbide. As described elsewhere, this carbide can then be converted into an activated catalyst material. One benefit of this process is that the passivated catalyst material can be formed in one reactor, which may be particularly suitable or optimized for a catalyst passivation process, and then transported to another reactor for use in the FT process, minimizing the risk of formation of undesirable metal oxides. Given the industry trend towards decentralization of FT reactors, in some cases it may be beneficial to be able to geographically separate catalyst production and catalyst use in the FT process.

[0052] Therefore, in certain embodiments, the method as described in addition herein also includes packaging the passivated catalyst material. The passivated catalyst material can be packaged in a closed container, such as a drum, a bag, a box, a tank or a modular catalyst container. Similarly, in certain embodiments as described in addition herein, the method further includes transporting the passivated catalyst material to a position away from the reactor where it is passivated. In a specific embodiment, transportation is to different reactors, or to different buildings, different locations, different facilities or different factories. In some such embodiments, the position away from the reactor where the passivated catalyst material is passivated is at least one mile from the reactor, for example, at least ten miles from the reactor, at least twenty miles from the reactor, at least fifty miles from the reactor or at least one hundred miles from the reactor.

[0053] For example, the passivated catalyst material can be produced in a first reactor, optionally packaged, and then transported to a second reactor. In specific embodiments, the first and second reactors are not equivalent (e.g., the first reactor can be optimized for producing the passivated catalyst material, and the second reactor can be optimized for the FT process). Notably, the second reactor need not be constructed to the same specifications as the first reactor; since the FT process is typically conducted under less stringent conditions than those used for the initial reduction, lower grade materials can be used in the FT reactor where the passivated catalyst is activated and used than in the reactors where the initial reduction is performed.

[0054] Advantageously, the passivation techniques and passivated catalysts described herein can allow reactor specialization, wherein a first reactor can be efficiently constructed, scaled, and operated to produce the passivated catalyst material, while a second reactor can be efficiently constructed, scaled, and operated for relatively mild activation of the passivated material and subsequent Fischer-Tropsch synthesis. For example, the emerging field of biomass conversion is amenable to the use of relatively smaller Fischer-Tropsch reactors that can be placed close to the site of biomass generation (e.g., municipal waste or agricultural or agricultural waste).

[0055] The packaging and transportation of the passivated catalyst also allows for lower risk in the catalyst production process, since standardized passivated catalysts can be produced and quality checked before being transported to the Fischer-Tropsch reactor site. This can allow for optimization and standardization of passivation protocols in ways that would be unavailable to a Fischer-Tropsch reactor. In addition, offsite catalyst production allows for identification of catalyst batches that do not meet specific specifications, and eliminates the reliance on the Fischer-Tropsch reactor and its operator to continuously produce highly active catalyst materials. Since synthesis reactor downtime can be costly, any method step that reduces the risk of reactor downtime (e.g., due to inappropriate catalyst preparation) or accelerates catalyst preparation (e.g., those in the present disclosure) is very valuable.

[0056] Thus, another aspect of the present disclosure is a passivated catalyst material for synthesizing a Fischer-Tropsch hydrocarbon composition from a gas feed comprising carbon monoxide and hydrogen, the passivated catalyst material comprising cobalt supported on a carrier, wherein at least 25 mol % (e.g., at least 50 mol %) of the cobalt of the passivated catalyst material as measured by x-ray diffraction is in the form of cobalt carbide. In certain desirable embodiments, at least 75 mol % (e.g., at least 90 mol %) of the cobalt of the passivated catalyst material as measured by x-ray diffraction is in the form of cobalt carbide. The amount of cobalt and the amount and identity of any other metals, the carrier, and other specific features of the passivated catalyst material may be as described above. The passivated catalyst material may be prepared as described herein and may be packaged as described above.

[0057] As described above, the passivated catalyst material is then contacted with a reducing agent at a second temperature and a second pressure to convert at least a portion of the cobalt carbide to cobalt metal and thereby form an activated catalyst material suitable for use in the FT process.

[0058] Where the passivated catalyst is formed in a reactor separate from the reactor used to carry out the Fischer-Tropsch reaction, the catalyst must be loaded into the reactor zone prior to treatment with the reducing agent. Thus, when the passivated catalyst material is transported from elsewhere, the method may include unpacking the passivated catalyst material (e.g., from a closed container in which it is packaged, such as a drum, bag, box, canister, or modular catalyst container).

[0059] It is noteworthy that reducing agent can be selected to effectively convert the desired part or all of cobalt carbide into cobalt metal.In certain embodiments, the amount of cobalt carbide in the activated catalyst material (i.e., by the fraction of the total amount of cobalt) is no more than 50 mol% of the amount of cobalt carbide in the passivated catalyst material (i.e., by the fraction of the total amount of cobalt).For example, in certain embodiments as described in addition herein, the amount of cobalt carbide in the activated catalyst material (i.e., by the fraction of the total amount of cobalt) is no more than 25 mol%, such as no more than 10 mol%, or no more than 5 mol%, or no more than 1 mol%.In certain embodiments as described in addition herein, in the activated catalyst material, at least 50 mol% of cobalt is in the form of cobalt metal, such as at least 75 mol% or at least 90 mol%, or at least 95 mol%, or at least 99 mol% of cobalt is in the form of cobalt metal.

[0060] A surprising effect of the methods and materials described herein is that the cobalt metal formed as part of the activated catalyst material has unexpectedly been found to have a greater proportion of hcp cobalt metal and less of the other common cobalt metal phase, fcc cobalt metal, than cobalt metal formed by conventional reduction of metal oxides (e.g., formed during the production of reduced catalyst materials as described elsewhere herein and in conventional reduction of cobalt oxide / cobalt hydroxide-based catalyst materials for the FT process). This is advantageous because hcp cobalt metal has been found to exhibit higher FT process activity than fcc cobalt metal. The higher activity of hcp cobalt metal means that less catalyst can be used to achieve the same production volume as conventional catalysts, and / or the reactor can be operated at a lower temperature. Both of these effects can result in significant cost savings. Thus, in certain embodiments as described elsewhere herein, the activated catalyst material comprises cobalt metal, wherein the cobalt metal comprises hcp cobalt metal in a ratio of at least 50:50 (e.g., at least 60:40 or at least 70:30) to fcc cobalt metal as measured by x-ray diffraction. For example, in certain embodiments as further described herein, the cobalt metal comprises hcp cobalt metal in a ratio of at least 75:25 (e.g., at least 80:20 or at least 85:15) to fcc cobalt metal. This contrasts with the lower ratios (typically 50:50 or less) found in conventional materials. The amounts of hcp and fcc cobalt can be determined using x-ray diffraction.

[0061] In a specific embodiment, the reducing agent is hydrogen, H . Hydrogen can be mixed with other gases (e.g., inert carrier gases). Examples of such inert carrier gases include nitrogen, carbon dioxide, argon, or helium. Hydrogen can also be mixed with carbon monoxide, with or without one or more other carrier gases. In certain embodiments, reduction is achieved by contacting the passivated catalyst material with a reducing agent, wherein the reducing agent comprises at least 50% by volume of H (e.g., at least 60% by volume, or at least 70% by volume, or at least 80% by volume, or at least 90% by volume, or at least 95% by volume, or substantially 100% by volume of H ).

[0062] In certain embodiments, reduction is achieved by contacting the passivated catalyst material with a reducing agent, wherein the reducing agent comprises hydrogen and carbon monoxide. In certain embodiments, the reducing agent is a mixture of hydrogen and carbon monoxide, i.e., synthesis gas. When the reducing agent is synthesis gas, the volume ratio (H2:CO) of hydrogen and carbon monoxide in the reducing agent is generally at least 1:1, preferably at least 1.1:1, more preferably at least 1.2:1, more preferably at least 1.3:1, more preferably at least 1.4:1, more preferably at least 1.5:1, or even at least 1.6:1. When the reducing agent is synthesis gas, the volume ratio (H2:CO) of hydrogen and carbon monoxide in the reducing agent is at most 5:1, preferably at most 3:1, most preferably at most 2.2:1. Examples of suitable volume ratios of hydrogen to carbon monoxide (H2:CO) in the reducing agent include the following ranges: from 1:1 to 5:1; from 1.1:1 to 3:1; from 1.2:1 to 3:1; from 1.3:1 to 2.2:1; from 1.4:1 to 5:1; from 1.4:1 to 3:1; from 1.4:1 to 2.2:1; from 1.5:1 to 3:1; from 1.5:1 to 2.2:1; and from 1.6:1 to 2.2:1.

[0063] The reduction of the passivated catalyst material to the activated catalyst material is carried out at a second temperature (T2) and a second pressure (P2), wherein P2 is at least 10 bara, and wherein P2 is greater than or equal to P1, and wherein T2 is at most 300° C. In certain embodiments as further described herein, T2 is in the range of 150° C. to 300° C. Notably, the reduction of the carbide can be carried out at lower temperatures than the reduction of the cobalt oxide / cobalt hydroxide based materials, which is typically carried out in the range of 260° C. to 400° C. or even up to 500° C. For example, in certain embodiments, T2 is in the range of 150-290° C., or 150-280° C., or 150-270° C., or 180-300° C., or 180-290° C., or 180-280° C., or 180-270° C., or 200-300° C., or 200-290° C., or 200-280° C., or 200-270° C. In some or all embodiments, T2 is at most 100° C. greater than T1, for example, T2 is at most 90° C. greater than T1, or T2 is at most 70° C. greater than T1. In certain embodiments as further described herein, P2 is in the range of at least 1 bara and at most 50 bara, and T2 is at most 300° C. In certain embodiments as described herein, P2 is at least 5 bara, preferably in the range of 10 bara to 50 bara, such as 10-30 bara, or 10-25 bara, or 12-50 bara, or 12-30 bara, or 12-25 bara, or 15-50 bara, or 15-30 bara, or 15-25 bara, or 15-50 bara, or 15-30 bara, or 15-25 bara. Reduction can be carried out under the time and conditions sufficient to provide the desired degree of reduction as described above. For example, the passivated catalyst material can be reduced to the activated catalyst material for a period of time ranging from 2 hours to 48 hours, or from 2 hours to 36 hours, or from 2 hours to 24 hours, or from 2 hours to 12 hours, or from 2 hours to 8 hours. For example, the reduction can be carried out for a time in the range of 3 hours to 48 hours, or 4 hours to 48 hours, or 5 hours to 48 hours, or 5 hours to 36 hours, or 5 hours to 24 hours.

[0064] In certain embodiments, the conditions of the Fischer-Tropsch process are suitable for activating the passivated catalyst material, and therefore separate conditions are not required.

[0065] Once produced, the activated catalyst material is suitable for use in a FT process.Thus, the activated catalyst material is contacted with a gas mixture comprising carbon monoxide and hydrogen to form a hydrocarbon composition.

[0066] In some embodiments, all steps (a) to (d) of the process are performed in a Fischer-Tropsch reactor.

[0067] In some embodiments, steps (a) and (b) of the process are performed outside of the Fischer-Tropsch reactor, and steps (c) and (d) of the process are performed within the Fischer-Tropsch reactor.

[0068] In certain embodiments, step (b) is performed as a two-step process as follows:

[0069] (bi) contacting the catalyst material with carbon monoxide at an initial passivation pressure (P1initial) of at least 1 bara and at most 50 bara and an initial passivation temperature (T1initial) of at most 300° C. to provide a passivated catalyst material; and

[0070] (b-ii) contacting the passivated catalyst material with carbon monoxide at a first pressure (P1) of at least 1 bara and at most 50 bara and a first temperature (T1) of at most 300°C.

[0071] In certain embodiments, steps (a) to (bi) of the process are performed outside of a Fischer-Tropsch reactor and steps (b-ii) to (d) of the process are performed within a Fischer-Tropsch reactor.

[0072] The initial passivation pressure (PI initial ) will be in the same range as described for the first pressure (PI) and can be the same or different from the pressure used for the first pressure (PI). The initial passivation temperature (T1 initial ) will be in the same range as described for the first temperature (T1) and can be the same or different from the temperature used for the first temperature (T1).

[0073] A person skilled in the art can adapt a conventional FT process to use the catalyst materials described herein. In certain embodiments of the Fischer-Tropsch process of the present disclosure, the volume ratio of hydrogen to carbon monoxide (H2:CO) in the gaseous reactant mixture is typically at least 1:1, preferably at least 1.1:1, more preferably at least 1.2:1, more preferably at least 1.3:1, more preferably at least 1.4:1, more preferably at least 1.5:1 or even at least 1.6:1. In some or all embodiments of the present invention, the volume ratio of hydrogen to carbon monoxide (H2:CO) in the gaseous reactant mixture is at most 5:1, preferably at most 3:1, and most preferably at most 2.2:1. Examples of suitable volume ratios of hydrogen to carbon monoxide (H2:CO) in the gaseous reactant mixture include the following ranges: from 1:1 to 5:1; from 1.1:1 to 3:1; from 1.2:1 to 3:1; from 1.3:1 to 2.2:1; from 1.4:1 to 5:1; from 1.4:1 to 3:1; from 1.4:1 to 2.2:1; from 1.5:1 to 3:1; from 1.5:1 to 2.2:1; and from 1.6:1 to 2.2: 1. The gaseous reactant stream may also contain other gaseous components, such as nitrogen, carbon dioxide, water, methane, and other saturated and / or unsaturated light hydrocarbons, each preferably present at a concentration of less than 30% by volume.

[0074] According to the present disclosure, conventional Fischer-Tropsch temperatures may be used to produce optionally oxygenated hydrocarbons. For example, the temperature of the reaction may suitably be in the range of 100 to 400° C., such as 150 to 350° C., or 150 to 250° C. The pressure of the reaction may suitably be in the range of 10 to 100 bar (1 to 10 MPa), such as 15 to 75 bar (1.5 to 7.5 MPa) or 20 to 50 bar (2.0 to 5.0 MPa).

[0075] In a preferred embodiment, the temperature of the Fischer-Tropsch reaction is in the range of 150 to 350° C., more preferably 180 to 300° C., and most preferably 200 to 260° C. In a preferred embodiment, the pressure of the Fischer-Tropsch reaction is in the range of 10 to 100 bar (1 to 10 MPa), more preferably 10 to 60 bar (1 to 6 MPa), and most preferably 20 to 45 bar (2 to 4.5 MPa).

[0076] The Fischer-Tropsch synthesis reaction can be carried out in the reactor of any suitable type, and for example, the reaction can be carried out in a fixed-bed reactor, a slurry bed reactor or a CANS reactor. Specifically with respect to the CANS reactor, the catalyst material through passivation as described herein can be packaged in a modular catalyst container (for example, in a different place and then transported to a reactor site) in the reactor tube applicable to the CANS reactor. CANS can be loaded with catalyst and put into a device (plant) for redistribution. The CANS design means that loading and unloading, transporting and storing catalyst (in CANS) are easier, and this becomes very useful for the method. Catalyst can be loaded in the CAN and reduced and passivated before being stored, transported and subsequently loaded into the Fischer-Tropsch device, and in the Fischer-Tropsch device, catalyst can be reactivated. The CANS reactor and associated containers applicable to the methods described herein are described in WO 2011 / 048361, which is hereby incorporated herein by reference in its entirety for its disclosure of this tank and its purposes.

[0077] It may be desirable to introduce the passivated catalyst material into the reactor zone before the activated catalyst material is formed, that is, so that activation of the catalyst occurs in situ in the reactor zone. The method allows the passivated catalyst material to be loaded from the first reactor or from another site (e.g., by unpacking it from a container, or by connecting a tank to the reactor zone). Subsequently, before forming the activated catalyst material, the second reactor can be purged of undesirable components, such as atmospheric oxygen or moisture, allowing a highly active catalyst to be provided under carefully controlled conditions. Therefore, in certain embodiments as further described herein, the method further comprises introducing the passivated catalyst material into the reactor zone.

[0078] In some cases, the passivated catalyst material can replace a previous catalyst material. For example, the previous catalyst material can be a spent catalyst material that has lost activity or selectivity due to accidental degradation. As another example, the spent catalyst material can be a material optimized for a specific process or product distribution, and different catalysts with different optimizations are desired. Therefore, in certain embodiments as further described herein, the method further includes removing the spent catalyst material from the reactor zone before introducing the passivated catalyst material into the reactor zone.

[0079] The hydrocarbon composition can vary based on changes in process conditions known in the art. In certain embodiments, the hydrocarbon composition comprises hydrocarbons (e.g., straight-chain hydrocarbons, branched-chain hydrocarbons, saturated or unsaturated hydrocarbons) and oxygen-containing derivatives thereof. Examples of oxygen-containing derivatives thereof include hydrocarbons having one or more functional groups of alcohols, aldehydes, ketones, carboxylic acids, esters, and combinations thereof. In certain embodiments as further described herein, the hydrocarbon composition comprises at least one of alkanes, olefins, and alcohols.

[0080] Another aspect of the present disclosure is the use of the catalyst activation method as described herein to increase the selectivity of the conversion of carbon monoxide and hydrogen to hydrocarbons having five or more carbon atoms (C5+) compared to a catalyst that has been activated using reduction alone.

[0081] Another aspect of the present disclosure is the use of the catalyst activation method as described herein to increase the conversion of carbon monoxide and hydrogen to hydrocarbons (compared to a catalyst that has been activated using reduction alone).

[0082] Another aspect of the present disclosure is that the catalyst material comprising cobalt (e.g., in the form of an oxide) supported on a support is at least partially oxidized. At least 10% of the cobalt is in an oxidized form, for example, at least 20% of the cobalt is in an oxidized form, or at least 30% is in an oxidized form, or at least 50% is in an oxidized form. This can be in the form of fully oxidized cobalt or a passivated material having an oxide layer and a metal core.

[0083] Because the use of the catalyst activation method as described herein increases the productivity of the catalyst in the Fischer-Tropsch reaction, this enables one of ordinary skill in the art to lower the reaction temperature to achieve the same conversion of carbon monoxide and hydrogen to hydrocarbons as compared to a catalyst that has been activated using reduction alone, and therefore another aspect of the present disclosure is to use the catalyst activation method as described herein to increase the catalyst life of the catalyst.

[0084] Because the use of the catalyst activation method as described herein increases the productivity of the catalyst in the Fischer-Tropsch reaction, this enables one of ordinary skill in the art to lower the reaction temperature to achieve the same conversion of carbon monoxide and hydrogen to hydrocarbons as compared to a catalyst that has been activated using reduction alone. Because lower reaction temperatures can provide an increase in selectivity for hydrocarbons having five or more carbon atoms (C5+), another aspect of the present disclosure is the use of the catalyst activation method as described herein to increase the selectivity of carbon monoxide and hydrogen to hydrocarbons having five or more carbon atoms (C5+) (compared to a catalyst that has been activated using reduction alone). Example

[0085] The following examples illustrate specific embodiments of the methods of the present disclosure and various uses thereof. They are set forth for illustrative purposes only and should not be considered to limit the scope of the present disclosure.

[0086] The Fischer-Tropsch catalysts were prepared by impregnating a titanium dioxide support with cobalt nitrate hexahydrate and manganese acetate tetrahydrate, followed by drying and calcination at 300° C. The catalysts were activated according to the appropriate listed H2 and CO conditions as detailed below. The catalysts were activated by reacting the corresponding catalysts with a 1.8% H2:CO mixture containing 51% N2 gas at 30 barg and 8800 hr. -1The Fischer-Tropsch reaction was carried out by contacting the reactor at a gas hourly space velocity of 1.5 sq. m. The applied temperature for the FT reaction is given in brackets next to the CO conversion.

[0087] In Comparative Examples A to C, H2 reduction was performed using 100% H2 at atmospheric pressure (1 bara) at 5000 hr-1 GHSV for 15 hours, and the temperature of H2 reduction was 300° C. In Examples 1-3, the temperature, pressure, and duration of the treatment are shown in Tables 1 to 3 below.

[0088] Table 1 - 10% Co 5% Mn TiO2

[0089]

[0090] Table 2 - 10% Co 1% Mn TiO2

[0091]

[0092] Table 3 - 10% Co 1% Mn TiO2

[0093]

[0094] As can be seen from the results presented in Tables 1 to 3, the examples that included treatment with CO and then reduction with hydrogen produced significantly improved performance in conversion of CO at a given applied temperature compared to examples that used only standard hydrogen reduction.

[0095] The details shown herein are presented as examples and only for the purpose of illustrative discussion of certain embodiments of the present disclosure, and are presented in order to provide the most useful and easily understood description of the principles and concepts of the various embodiments of the present disclosure. In this regard, no attempt is made to show the details associated with the method of the present disclosure in more detail than is necessary for a basic understanding of the methods described herein, and the descriptions taken by these embodiments make it clear to those skilled in the art how several forms of the method of the present disclosure can be embodied in practice. Therefore, before describing the disclosed methods and apparatus, it should be understood that the aspects described herein are not limited to specific embodiments, equipment or configurations, and therefore can certainly vary. It should also be understood that the terms used herein are only used for the purpose of describing specific aspects, and unless specifically defined herein, are not intended to be restrictive.

[0096] The terms "a," "an," "the," and similar referents used in the context of describing the methods of the present disclosure (especially in the context of the following embodiments and claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context.

[0097] All methods described herein can be performed in any suitable order of steps, unless otherwise indicated herein or otherwise clearly contradictory to the context. The use of any and all examples or exemplary language (e.g., "such as") provided herein is intended only to better illustrate the methods of the present disclosure and does not limit the scope of the present disclosure. The language in the specification should not be interpreted as indicating any unclaimed elements that are essential to the practice of the methods of the present disclosure.

[0098] Unless the context clearly requires otherwise, throughout the specification and claims, the words "comprise," "comprising," and the like are to be construed in an inclusive sense, rather than an exclusive or exhaustive sense; that is, in the sense of "including but not limited to." Words using the singular or plural number also include the plural and singular, respectively. Furthermore, when used in this application, the words "herein," "above," and "below," and words of similar import shall refer to this application as a whole and not to any particular portions of this application.

[0099] As will be understood by one of ordinary skill in the art, each embodiment disclosed herein may comprise, consist essentially of, or consist of the elements, steps, ingredients, or components specifically stated thereof. As used herein, the transition terms "comprise" or "comprises" are meant to include, but are not limited to, and permit the inclusion of unspecified elements, steps, ingredients, or components, even in major amounts. The transition phrase "consisting of does not include any unspecified elements, steps, ingredients, or components. The transition phrase "consisting essentially of limits the scope of the embodiment to the specified elements, steps, ingredients, or components and those elements, steps, ingredients, or components that do not materially affect the embodiment.

[0100] All percentages, ratios and proportions herein are by weight unless otherwise specified.

[0101] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the disclosure are approximations, the numerical values ​​set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0102] The grouping of alternative elements or embodiments of the present disclosure should not be construed as limiting. Each group member can quote and claim protection individually or in any combination with other members of the group or other elements found herein. For convenience and / or patentability reasons, it is contemplated that one or more members of a group can be included in the group or deleted from the group. When any such inclusion or deletion occurs, the specification is considered to comprise the group after amendment, thereby realizing the written description of all Markush groups used in the appended claims.

[0103] Some embodiments of various aspects of the present disclosure are described herein, including the best mode known to the inventors for performing the methods described herein. Of course, upon reading the foregoing description, variations of these described embodiments will become apparent to those of ordinary skill in the art. The skilled person will appropriately adopt such variations, and therefore may implement the methods of the present disclosure in a manner different from that specifically described herein. Therefore, the scope of the present disclosure includes all modifications and equivalents of the subject matter recited in the appended claims as permitted by applicable law. In addition, the present disclosure encompasses any combination of the above-mentioned elements in all their possible variations, unless otherwise indicated herein or otherwise clearly contradicted by the context.

[0104] As used herein, the phrase "at least a portion" is used to mean at least a portion of a desired amount, up to a whole possible amount.

[0105] Finally, it should be understood that the various embodiments herein are illustrative of the method of the present disclosure. Other modifications that may be employed are within the scope of the present disclosure. Thus, by way of example and not limitation, alternative configurations of the method may be used according to the teachings herein. Therefore, the method of the present disclosure is not limited to what is precisely shown and described.

Claims

1. A process for converting a mixture of hydrogen and carbon monoxide into a hydrocarbon composition comprising one or more optionally oxygenated hydrocarbons, said process comprising the steps of: (a) providing a first catalyst material comprising cobalt (e.g., in the form of an oxide) supported on a support; (b) contacting the first catalyst material with carbon monoxide at a first pressure (P1) and a first temperature (T1) to provide a passivated catalyst material, wherein P1 is at least 1 bara and at most 50 bara, and T1 is at most 300° C.; (c) contacting the passivated catalyst material with a reducing agent at a second temperature (T2) and a second pressure (P2) to form an activated catalyst material, wherein P2 is at least 10 bara, and wherein P2 is greater than or equal to P1, and wherein T2 is at most 300°C; and (d) contacting the activated catalyst material with a mixture of hydrogen and carbon monoxide.

2. The process of claim 1 wherein each catalyst material comprises cobalt in the range of 5 wt% to 35 wt% on an elemental basis.

3. A process according to claim 1 or claim 2, wherein each catalyst material further comprises manganese, ruthenium or rhenium, for example in the range of up to 15 wt% on an elemental basis.

4. A process according to any one of claims 1 to 3, wherein at least 50 mole % of the cobalt of the passivated catalyst material is in the form of cobalt carbide as determined by x-ray diffraction.

5. The method according to any one of claims 1 to 4, wherein the catalyst material is contacted with carbon monoxide at a first pressure (P1) in the range of 1 bara to 10 bara.

6. The method according to any one of claims 1 to 5, wherein the catalyst material is contacted with carbon monoxide at a first temperature (T1) in the range of 25°C to 260°C.

7. The method according to any one of claims 1 to 6, wherein the contact with the reducing agent is contact with hydrogen, and the second temperature (T2) is in the range of 180°C to 290°C.

8. The process according to any one of claims 1 to 7, wherein all steps (a) to (d) of the process are carried out in a Fischer-Tropsch reactor.

9. The process according to any one of claims 1 to 7, wherein steps (a) and (b) are performed outside the Fischer-Tropsch reactor, and steps (c) and (d) are performed in the Fischer-Tropsch reactor.

10. The method of claim 9, further comprising transporting the passivated catalyst material produced in step (b) to a location remote from the reactor in which it was passivated (e.g., to a different reactor, building, site, or facility).

11. The method of claim 10, wherein the location remote from the reactor in which the passivated catalyst material is passivated is at least 10 miles from the reactor.

12. The method according to any one of claims 1 to 7, wherein step (b) is performed as a two-step process: (bi) contacting the catalyst material with carbon monoxide at an initial passivation pressure (P1initial) of at least 1 bara and at most 10 bara and an initial passivation temperature (T1initial) of at most 300° C. to provide a passivated catalyst material; and (b-ii) contacting the passivated catalyst material with carbon monoxide at a first pressure (P1) of at least 1 bara and at most 10 bara and a first temperature (T1) of at most 300°C.

13. The process according to claim 12, wherein steps (a) and (bi) are performed outside the Fischer-Tropsch reactor, and steps (b-ii) to (d) are performed in the Fischer-Tropsch reactor.

14. The method of claim 12 or 13, further comprising transporting the passivated catalyst material produced in step (bi) to a location remote from the reactor in which it was passivated (e.g., to a different reactor, building, site, or facility).

15. The method of claim 14, wherein the location remote from the reactor in which the passivated catalyst material is passivated is at least 10 miles from the reactor.

16. Use of the catalyst activation method according to any one of claims 1 to 15 for increasing the selectivity of the conversion of carbon monoxide and hydrogen to hydrocarbons having five or more carbon atoms (C5+) compared to a catalyst which has been activated using reduction alone.

17. Use of a catalyst activation method according to any one of claims 1 to 15 for increasing the conversion of carbon monoxide and hydrogen to hydrocarbons compared to a catalyst which has been activated using reduction alone.

18. Use of the catalyst activation method according to any one of claims 1 to 15 for increasing the catalyst life of a catalyst compared to a catalyst which has been activated using reduction alone.

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