Electrothermal steam methane reforming synthetic fuel

Abstract

The invention relates to a process for the production of synthesis gas for the production of hydrocarbon products, in particular synthetic fuels, said process comprising the steps of: providing a hydrocarbon feed gas; optionally, purifying the hydrocarbon feed gas in a gas purification unit; optionally, pre-reforming the hydrocarbon feed gas with the steam feedstock in a pre-reforming unit; performing steam methane reforming in a reforming reactor heated by a power source; the synthesis gas is provided to a synthetic fuel synthesis unit, preferably a Fischer-Tropsch synthesis unit, for converting the synthesis gas to a hydrocarbon product and producing a tail gas. The invention also relates to a system for producing synthesis gas for producing hydrocarbon products, in particular synthetic fuels.

Description

[0001] This application is a divisional application of the application with the application date of December 2, 2020, application number 2020800841142, and invention name “Electrothermal Steam Methane Reforming Synthetic Fuel”. Technical Field

[0002] Embodiments of the present invention generally relate to methods and systems for producing synthesis gas from a hydrocarbon feed gas, such as a methane-rich gas, particularly natural gas, preferably having 80% by volume or more methane, wherein the synthesis gas is produced by electrothermal steam methane reforming, and the synthesis gas is used to produce hydrocarbon products, particularly synthetic fuels, such as diesel, by subsequent Fischer-Tropsch synthesis. The present invention also relates to methods and systems for producing synthesis gas for producing hydrocarbon products, wherein the synthesis gas is produced by using electrothermal steam methane reforming and autothermal reforming. Tail gas from Fischer-Tropsch synthesis can be recycled to the electrothermal steam methane reforming and / or the autothermal reforming. Background Art

[0003] The classic method for producing synthesis gas (syngas) involves steam reforming of a hydrocarbon feed gas (typically natural gas) and the associated major CO2 emissions. Because the highly endothermic steam reforming reaction is favored in conventional steam methane reformers (SMRs), i.e., flame reformers using large furnaces operating at temperatures around 1000°C, economies of scale are favored to achieve high process efficiency and comprehensive waste heat management. Consequently, such facilities are difficult to scale down economically due to their complex design and high upfront capital investment.

[0004] The conversion of hydrocarbon feed gas into synthesis gas by such conventional SMR results in a synthesis gas having an H2 / CO modulus of about 3 or higher (e.g., 3-5). However, in order to use the synthesis gas for downstream Fischer-Tropsch synthesis of hydrocarbon products such as diesel, the steam-to-carbon molar ratio (S / C ratio) in the synthesis gas must be reduced in order to lower its H2 / CO molar ratio. However, it is generally not possible to achieve a sufficiently low H2 / CO molar ratio in the synthesis gas by steam methane reforming unless other methods are employed, such as adding CO2 to the feed or removing hydrogen from the synthesis gas.

[0005] In the Fischer-Tropsch (FT) process, CO and hydrogen in the synthesis gas combine in a number of reactions to produce various hydrocarbon compounds, usually with the molecular formula C n H (2n+2) The simplified reaction given below is commonly used in FT synthesis:

[0006] (2n+1)H2+nCO→C n H (2n+2) +n H2O

[0007] Here n is usually 10-30, and the formation of methane is undesirable (n=1).

[0008] It should be noted that FT-synthesis is very complex and the above equation is a considerable simplification. In practice, the syngas feed has a H2 / CO ratio of about 2, such as 1.8-2.2 or preferably 1.9-2.1, required for FT synthesis.

[0009] Therefore, the desired H2 / CO modulus in the syngas is about 2.0, such as 1.8-2.2, such as 1.9-2.1.

[0010] It is known to achieve this by operating the steam reforming at a low S / C ratio. For example, synthetic fuels such as diesel can be produced from natural gas by FT synthesis, wherein the synthesis gas is produced by using a conventional SMR and autothermal reforming in an autothermal reformer (ATR), optionally with pre-reforming upstream of the conventional SMR. Thus, processes / apparatuses are known in which, for example, a portion of the natural gas feed bypasses the steam methane reformer and enters the autothermal reformer together with the recycled tail gas from the downstream FT synthesis, and wherein the CO2 in the synthesis gas from the autothermal reformer is removed and output, i.e., the CO2 is removed without being recycled. Applicant's patent US9,353,022 discloses a method for removing CO2 from the produced synthesis gas and recycling the FT tail gas. Applicant's patent US9,828,246 discloses a method and apparatus for producing liquid hydrocarbons by Fischer-Tropsch synthesis, wherein the reforming portion of the apparatus comprises a process line comprising autothermal reforming and a separate process line comprising steam methane reforming.

[0011] For large-scale plants for the production of diesel from synthesis gas produced from natural gas as hydrocarbon feed gas, it is well known that the preferred solution is to use an ATR without an upstream conventional SMR, i.e. a stand-alone ATR, optionally together with an upstream pre-reformer, since, among other things, the use of conventional SMRs in the downstream FT synthesis instead of autothermal reforming leads to a lower overall plant efficiency.

[0012] Typically, a hydrocarbon feed gas, i.e. natural gas, is mixed with steam, preheated in a fired heater, passed through a pre-reformer and then preheated again in a fired heater to about 500-700°C before passing through an autothermal reformer. A portion of the tail gas from the downstream Fischer-Tropsch tail gas (FT tail gas) is added to this preheated stream together with an oxygen-rich stream produced in an air separation unit (ASU) or directly to the autothermal reformer. The ASU required to produce the oxygen is usually a considerable capital expenditure. The FT tail gas typically contains CO2 and N2, methane, unconverted H2 and CO and, in some cases, light hydrocarbons including olefins formed in the FT synthesis. The recycle of hydrocarbon compounds increases the efficiency of the entire plant. The portion of the tail gas that is not recycled is used as fuel for the process heaters and for other purposes in the plant / process. In some cases, part of the tail gas can be exported directly or indirectly, for example by using the excess gas to produce steam or generate electricity.

[0013] This conventional approach to producing syngas and downstream synthetic fuels comes with associated CO2 emissions. SUMMARY OF THE INVENTION

[0014] An object of the present invention is to provide a method and system for converting a hydrocarbon feed gas (e.g., methane-rich gas) into a synthesis gas suitable for producing hydrocarbon products (particularly diesel), which synthesis gas has a low oxygen consumption in an ATR and is thus more energy efficient than prior art methods (processes) and systems (apparatus).

[0015] Another object of the present invention is to provide a sustainable method and system for converting a hydrocarbon feed gas (eg, a methane-rich gas) into a synthesis gas suitable for producing hydrocarbon products, particularly diesel.

[0016] Another object of the present invention is to enable the construction of compact plants for the production of hydrocarbon products.

[0017] Another object of the present invention is to enable the construction of plants with high carbon utilization efficiency.

[0018] The present invention addresses these and other objects.

[0019] Thus, the present invention is directed to a more sustainable production of hydrocarbon products from hydrocarbon feed gases by applying electrothermal steam methane reformer (eSMR) technology that allows for reduced carbon dioxide emissions.

[0020] Embodiments of the present invention generally relate to methods and systems for converting a hydrocarbon feed gas into synthesis gas for use in producing liquid hydrocarbon products, particularly synthetic fuels such as diesel.The hydrocarbon feed gas is preferably natural gas.

[0021] A first aspect of the present invention relates to a method for producing synthesis gas for use in producing hydrocarbon products (particularly synthetic fuels), comprising the following steps:

[0022] - providing a hydrocarbon feed gas,

[0023] - performing steam methane reforming in a reforming reactor comprising a pressure-resistant shell containing a structured catalyst, the structured catalyst being arranged to catalyze steam reforming of the hydrocarbon feed gas, the structured catalyst comprising macrostructures of an electrically conductive material, the macrostructures supporting a ceramic coating, wherein the ceramic coating supports a catalytically active material; the steam methane reforming comprising the steps of:

[0024] -i) supplying the hydrocarbon feed gas to a reforming reactor,

[0025] -ii) allowing the hydrocarbon feed gas to undergo a steam methane reforming reaction over the structured catalyst and withdrawing synthesis gas from the reforming reactor, and

[0026] -iii) providing electrical power via an electrical conductor connecting a power source positioned outside the pressure vessel to the structured catalyst, allowing current to flow through the macrostructural material, thereby heating at least a portion of the structured catalyst to a temperature of at least 500° C., such as 600, 700, 800, or 900° C.,

[0027] - providing at least a portion of the synthesis gas from step ii) to a synthetic fuel synthesis unit for converting said synthesis gas into said hydrocarbon products and generating a tail gas.

[0028] The term "synfuel synthesis unit" refers to a Fischer-Tropsch (FT) synthesis stage that includes one or more FT reactors. The FT synthesis stage may also include a product workup unit (PWU), which comprises one or more refining units, such as a hydrorefining unit, such as a hydrocracker, for upgrading the crude hydrocarbon product into hydrocarbon products. The PWU can be co-located with the FT reactors and other associated units, or in a separate location.

[0029] The hydrocarbon product is preferably a synthetic fuel, such as diesel and / or kerosene. The hydrocarbon product may also be in the form of naphtha and / or LPG (liquefied petroleum gas). For more information on the FT synthesis stage, see Steynberg A. and Dry M. "Fischer-Tropsch Technology", Studies in Surface Sciences and Catalysts, vol. 152.

[0030] In conventional SMRs, outlet temperatures are typically 850-900°C due to mechanical limitations. In the electric reforming reactor according to the present invention, the outlet gas temperature can be above 900°C, for example, above 950°C, above 1000°C, or even above 1050°C. This increases methane conversion, while the higher temperature itself also reduces the H2 / CO ratio. Any of these factors contributes to the economics of a gas-to-liquids (GTL) plant, which in this context refers to a plant that converts a hydrocarbon feed gas, preferably natural gas, into synthesis gas, which is then converted into hydrocarbon products, particularly synthetic fuels such as diesel.

[0031] The electric reforming reactor also avoids the need to burn carbon-rich gas to provide heat for the endothermic steam reforming reaction in a conventional SMR. This reduces the CO2 emissions of the facility, as well as other emissions associated with combustion, such as NO x Furthermore, when the electricity required for the electric reforming reactor comes from renewable energy, the overall CO2 emissions are significantly reduced compared to conventional SMRs.

[0032] Electric reforming reactors are also more compact than conventional steam reformers. This has the potential to reduce the overall cost of the plant, thereby improving economic efficiency.

[0033] When the plant capacity is low, for example less than 2000, for example less than 1000 barrels of hydrocarbon product per day, for example 300 or 500 barrels per day, it may not be economical to construct an air separation unit for the GTL plant.

[0034] The use of conventional SMRs in conjunction with the production of synthesis gas for the production of hydrocarbon products is uneconomical in small-scale plants due to high capital costs. With the present invention, it is now also possible to more economically design plants that produce, for example, approximately 300 barrels per day, 500 barrels per day, or 1000 barrels per day of hydrocarbon products.

[0035] The use of autothermal reforming brings some advantages, in particular when the tail gas produced is recycled to the front end, i.e. to the reforming section comprising a reforming reactor, in this case also an autothermal reforming unit. Therefore, in an embodiment according to the first aspect of the present invention, the method further comprises performing autothermal reforming in an autothermal reforming unit (ATR) after performing said steam methane reforming to produce said synthesis gas.

[0036] In one embodiment of the first aspect of the invention, the method comprises recycling at least part of the tail gas upstream of the reforming reactor, i.e., upstream of the electrothermal SMR (eSMR) and / or the ATR. This allows for greater flexibility in the modules for conditioning the syngas to maintain it at the desired value, which is typically in the range of 1.8-2.2, preferably 1.9-2.1.

[0037] "Tail gas" or "FT tail gas" refers to the waste gas from the Fischer-Tropsch synthesis unit, which includes: 5-35 vol% CO, 5-35 vol% H2, 5-35 vol% CO2, and greater than 2 vol% CH4. The tail gas may also contain higher hydrocarbons such as ethane and propane, including olefins, as well as argon and nitrogen.

[0038] The term "at least a portion of the tail gas" means that all or part of the tail gas is recycled upstream of the reforming reactor or upstream of the ATR, or part of the tail gas can be recycled to the reforming reactor and another part to the ATR.

[0039] It will also be understood that the term "upstream", eg "upstream of the ATR" also includes adding the flow directly to the ATR.

[0040] As mentioned above, autothermal reforming (ATR) is a technology commonly used in the production of synthesis gas (syngas), in which the conversion of a hydrocarbon feedstock (such as natural gas) is carried out in a single reactor by a combination of partial combustion and steam reforming. The ATR reactor consists of a burner, a combustion chamber and a fixed bed catalyst section, which is located in a refractory lined pressure shell. The key components in the ATR reactor are the burner and the catalyst bed. ATR technology is well known in the art, and in this regard, please refer to the patent US 9,828,246 of the above-mentioned applicant.

[0041] According to current practice, in ATR-based configurations (methods or systems, or interchangeable processes or equipment), the ATR feed gas is typically heated to the required inlet temperature of approximately 500-700°C via a fired heater. This fired heater is fueled by combustible gases (e.g., feed gas and / or tail gas). Consequently, the fired heater emits CO2 into the atmosphere. Furthermore, fired heaters are typically large, capital-intensive pieces of equipment.

[0042] In a conventional arrangement, the tail gas is recycled to the ATR to provide a syngas H2 / CO ratio of 1.8-2.2, preferably 1.9-2.1, depending on the nature of the FT synthesis. Typically, the remaining tail gas is used as fuel or for other energy purposes, such as for steam generation or power generation, and in some cases, part of the tail gas is even exported.

[0043] By the present invention, the fired heater is partially or completely replaced by an electric steam reformer, i.e., an eSMR. The eSMR does not require fuel and therefore does not emit CO2 or other environmentally unfavorable components such as CO, methane, particulate matter, and NO. x If the electrical power for the electric reformer comes partly or mainly / entirely from renewable energy sources such as wind and / or solar, this will also reduce overall CO2 emissions.

[0044] This means that the present invention allows a large part of the tail gas produced to be recycled to the reforming section. Since the fuel demand is smaller, less tail gas is needed to meet the fuel demand. Recycling a larger amount of tail gas to the reforming section will in principle lead to an undesirable reduction in the H2 / CO ratio in the synthesis gas. However, this can be solved by adjusting the power supplied to the electrothermal reformer. This generally means that the load on the electrothermal reformer reactor will be higher than the fired heater in the reference case of the ATR alone. The increase in load also means that the oxygen consumption in the ATR is reduced compared to the reference case, thereby also reducing the capital expenditure associated with the air separation unit (ASU).

[0045] In one embodiment, the reforming reactor, i.e., the eSMR, produces an outlet gas having a temperature of 500° C. or higher, such as greater than 550° C., greater than 600° C., or about 650° C. or greater than 650° C. The outlet gas from the eSMR is then directed to the ATR to produce the syngas. Compared to conventional designs using fired heaters for preheating, the novel method according to the present invention can save oxygen.

[0046] A conventional approach in the art to reduce oxygen consumption in an ATR unit is to include a heat exchange reformer in series or parallel with the ATR. However, the use of heat exchange reformers carries the risk of metal dust and high alloys, and can require expensive materials. The risk of metal dust is avoided when using an electric reformer.

[0047] Furthermore, a reduction in the oxygen consumption in the ATR is achieved without compromising the quality of the synthesis gas, ie maintaining the H2 / CO molar ratio in the synthesis gas in the range of 1.8-2.2, preferably 1.9-2.1.

[0048] In an embodiment according to the first aspect of the invention, the electricity supplied is generated at least in part by renewable energy. Suitable renewable resources are, for example, wind, i.e. wind energy from windmills and / or solar energy from, for example, solar panels and water, such as hydropower. The reforming reactor according to the invention, i.e. an electrothermal steam methane reformer (eSMR), is a very compact steam reforming reactor that requires a lower capital investment than conventional (conventional) steam reforming plants. The hydrocarbons in the hydrocarbon feed gas are preferably mainly methane; however, the hydrocarbon feed gas may also contain small amounts of higher hydrocarbons. The hydrocarbon feed gas is preferably from a methane-rich source, such as natural gas, but since electricity facilitates the heating, this would be an improvement over existing or conventional flame reformers (i.e. conventional SMRs) by saving CO2 emissions from the plant.

[0049] In one embodiment according to the first aspect of the invention, the production of hydrocarbon products is regulated according to the availability of renewable energy sources.

[0050] In a typical process for producing hydrocarbon products using autothermal reforming and, optionally, conventional steam methane reforming prior to the autothermal reforming, natural gas, typically a mixture of primarily methane with some higher hydrocarbons, nitrogen, and CO₂, is used as the sole carbonaceous material in the feed to the steam methane reformer. Due to the H₂ / CO ratio, the resulting synthesis gas is not optimal for use in the FT synthesis reaction. Therefore, conventional practice associated with the use of autothermal reforming is to remove the CO₂ produced simultaneously during the reforming process and recycle the desired amount back to the reforming stage. Adding this CO₂ to the feed alters the H₂ / CO ratio. Careful control of the amount of recycled CO₂ can achieve the desired H₂ / CO ratio.

[0051] By means of the present invention, the desired modulus (H2 / CO ratio, i.e., H2 / CO molar ratio) of the synthesis gas can also be obtained by adding CO2 available in the process or fed into the plant to a hydrocarbon feed gas (preferably natural gas) and then reforming the resulting mixture in an eSMR. In addition, excess hydrogen can be separated from the synthesis gas.

[0052] Therefore, in an embodiment according to the first aspect of the present invention, the method further comprises:

[0053] - providing a hydrogen separation unit, such as a hydrogen membrane unit, downstream of the reforming reactor and separating excess hydrogen from the synthesis gas stream,

[0054] and / or

[0055] - adding CO2 to the hydrocarbon feed gas, preferably by providing a CO2 removal unit downstream of the reforming reactor, separating CO2 from the synthesis gas and recycling at least part of said CO2 to the hydrocarbon feed gas.

[0056] Likewise, this allows for a simple adjustment of the module of the synthesis gas, i.e. the H2 / CO molar ratio, in the range of 1.8-2.2, preferably 1.9-2.1. This embodiment also enables the use of excess hydrogen in purification units downstream of the PWU (e.g. hydrorefining such as hydrocracking) and upstream of the reforming reactor (e.g. hydrodesulfurization unit or hydrogenator unit upstream of the sulfur absorber).

[0057] While the addition of CO2 to a hydrocarbon feed gas is known in connection with the use of autothermal reforming, it has now also been found that CO2 can be added to a hydrocarbon feed gas without such autothermal reforming.

[0058] In one embodiment of the first aspect of the present invention, the method further comprises providing a reforming unit, preferably an ATR, for separately reforming the tail gas and optionally recycling at least a portion of the reformed tail gas to the synthetic fuel synthesis unit, i.e., the FT synthesis stage. Recycling to the FT synthesis stage can, in particular, increase the conversion of the synthesis gas in the FT synthesis stage. Furthermore, the method is preferably performed without autothermal reforming of the synthesis gas.

[0059] In one embodiment according to the first aspect of the present invention, a combination of steam superheating and steam generation is integrated into the waste heat recovery of the hot syngas product from the reforming reactor and / or ATR, and superheated steam is used as the steam feed in the steam methane reforming step. If an ATR is included downstream of the eSMR, the waste heat recovery will be from the ATR. The combination of steam superheating and steam generation can also be used to generate electricity. Some or all of this power can be used in the eSMR.

[0060] In one embodiment according to the first aspect of the invention, the gas pressure within the reforming reactor (eSMR) is between 20 and 100 bar, preferably between 25 and 50 bar, and the temperature of the outlet gas from the reforming reactor is 850 to 1150° C., preferably 900 to 1150° C. These outlet gas temperatures are preferably used in embodiments where autothermal reforming is not used. In the case of using an ATR, as described above, the outlet gas has a temperature of 500° C. or higher, for example, higher than 550° C., higher than 600° C., or about or higher than 650° C., preferably up to 700° C. The outlet gas from the eSMR is then directed to the ATR to produce the synthesis gas.

[0061] In one embodiment according to the first aspect of the invention, the space velocity, estimated as the gas flow rate relative to the geometric surface area of ​​the structured catalyst, is between 0.6 and 60 Nm 3 / m 2 / h, and / or relative to the occupied volume of the structured catalyst, the gas flow rate is 700Nm 3 / m 2 / h and 70000Nm 3 / m 2 Preferably, the gas flow rate is between 7000 Nm / h relative to the occupied volume of the structured catalyst. 3 / m 2 / h and 10000Nm 3 / m 2 / h.

[0062] In an embodiment according to the first aspect of the present invention, the site area of ​​the reforming reactor is 0.4 m 2 and 4m 2 Preferably, the site area is between 0.5 and 1m 2 The term "site area" here is meant to be equivalent to "ground area", i.e. the area of ​​land that the reforming reactor will occupy when installed.

[0063] In one embodiment according to the first aspect of the present invention, the method further comprises providing a plurality of reforming reactors arranged in parallel with each other.

[0064] With the reduced site area, it is now possible to significantly reduce the capital expenditure (CAPEX) of the equipment, while also reducing CO2 emissions and oxygen consumption when using ATRs. In addition, multiple eSMRs can be arranged in a combined site area, i.e., multiple eSMRs, while still occupying a much smaller area than a single conventional SMR.

[0065] In one embodiment according to the first aspect of the present invention, the method further comprises:

[0066] - pre-reforming of the hydrocarbon gas together with a steam feed in a pre-reforming unit (pre-reformer) prior to said steam reforming,

[0067] and / or

[0068] - Purification of the hydrocarbon feed gas in a gas purification unit before said steam reforming and / or before said pre-reforming.

[0069] Therefore, an optional pre-reforming step may be provided before the electrothermal steam methane reforming. In the pre-reforming unit, all higher hydrocarbons may be converted to carbon oxides and methane, but the pre-reforming unit also favors light hydrocarbons. Providing a pre-reforming unit and therefore a pre-reforming step may have several advantages, including providing an effective sulfur guard, resulting in a feed gas that is virtually sulfur-free entering the downstream unit. The pre-reforming step may be carried out at a temperature of 300-650°C, preferably 390-500°C, for example 390-480°C. Preferably, the pre-reforming is carried out in one or more adiabatic pre-reforming stages with interstage preheating, i.e. heating is performed between the pre-reforming stages. The steam feed added to the pre-reforming may also be derived from superheated steam used as steam feed in the step of carrying out the steam methane reforming. Optionally, where a pre-reforming step is used, steam is only added to the pre-reforming, i.e. steam is not added to the reforming reactor, since the necessary steam has already been introduced during the pre-reforming.

[0070] Furthermore, an optional step of purifying the hydrocarbon feed gas in a gas purification unit can be provided prior to the steam reforming and / or prior to the pre-reforming. In the gas purification unit, impurities such as sulfur, chlorine, and heavy metals are removed from the hydrocarbon feed gas, preferably natural gas, using several catalytic reactors, as is well known to those skilled in the art. A small amount of hydrogen can be added to the natural gas before entering the gas purification unit; the natural gas can also be compressed and preheated to the temperature required by the purification unit.

[0071] The hydrocarbon feed gas to the reforming reactor is provided as purified hydrocarbon feed gas, pre-reformed hydrocarbon feed gas, or steam-added hydrocarbon feed gas. All components of the hydrocarbon feed gas are pressurized upstream of the reforming reactor, either individually or together. Preferably, steam is pressurized separately; the other components of the hydrocarbon feed gas can be pressurized together. The pressures of the components of the hydrocarbon feed gas are selected so that the pressure within the reforming reactor is between 20 and 100 bar, preferably between 25 and 50 bar.

[0072] The present invention also improves carbon utilization, such that between 50% and 100%, preferably greater than 60%, i.e., greater than 70% and 100%, for example, between 70% and 90%, of the carbon in the hydrocarbon feed gas is converted into synthetic fuel. This means that between 50% and 100% of the carbon atoms in the hydrocarbon feed gas (e.g., natural gas) can be converted into carbon in hydrocarbon product (e.g., diesel) molecules.

[0073] In another embodiment of the first aspect of the present invention, the amount of hydrocarbon feed gas is 20000 Nm 3 / h to 200000Nm 3 / h. In a second aspect, the present invention relates to a system for producing synthesis gas, the synthesizer being used to produce hydrocarbon products, in particular synthetic fuels, the system comprising:

[0074] a reforming reactor comprising a pressure-resistant shell containing a structured catalyst, the structured catalyst being arranged to catalyze the steam reforming of a feed gas comprising hydrocarbons, the structured catalyst comprising macrostructures of an electrically conductive material, the macrostructures supporting a ceramic coating, wherein the ceramic coating supports a catalytically active material; wherein the reforming reactor further comprises an electrical power source positioned external to the pressure-resistant shell and an electrical conductor connecting the electrical power source to the structured catalyst, allowing an electrical current to flow through the macrostructure material, thereby heating at least a portion of the structured catalyst to a temperature of at least 500° C., such as 600, 700, 800, or 900° C.,

[0075] - a synfuel synthesis unit arranged to receive at least part of the synthesis gas from said reforming reactor for converting said synthesis gas into said hydrocarbon products and producing a tail gas.

[0076] In one embodiment according to the second aspect of the invention, the system comprises an autothermal reforming unit (ATR) downstream of the reforming reactor, and / or a pre-reforming unit, i.e. a pre-reformer, upstream of the reforming reactor, and / or a gas purification unit for purifying hydrocarbon gases upstream of the pre-reforming unit and / or upstream of the reforming reactor.

[0077] In another embodiment according to the second aspect of the present invention, the system comprises means, such as a recycle compressor, for recycling at least part of the tail gas upstream of the reforming reactor or upstream of the ATR.

[0078] In an embodiment according to the second aspect of the present invention, the system does not have an ATR downstream of the reforming reactor. The system may further include a pre-reforming unit upstream of the reforming reactor, and / or a gas purification unit for purifying hydrocarbon gas upstream of the pre-reforming unit and / or upstream of the reforming reactor.

[0079] In an embodiment according to the second aspect of the invention, the system comprises a reforming unit for separately reforming the tail gas, preferably an ATR, and optionally further comprises a circuit for recycling at least a portion of the reformed tail gas to the synthetic fuel synthesis unit, ie the FT synthesis section.

[0080] In one embodiment according to the second aspect of the present invention, the system does not have an autothermal reforming unit (ATR) downstream of the reforming reactor.

[0081] The structured catalyst of the reforming reactor of the system is configured for steam reforming. This reaction occurs according to the following reaction:

[0082]

[0083]

[0084] The structured catalyst consists of a metal structure, a ceramic phase, and an active phase. The metal structure can be FeCr alloy, AlNiCo, or similar alloys. The ceramic phase can include Al2O3, MgAl2O3, CaAl2O3, ZrO2, or a combination thereof. The catalytically active material can include Ni, Ru, Rh, Ir, or a combination thereof.

[0085] In one embodiment according to the second aspect of the present invention, the catalyst pellets are loaded above, around, inside or below the structured catalyst of the reforming reactor. The catalyst material of this reaction may include Ni / Al2O3, Ni / MgAl2O3, Ni / CaAl2O3, Ru / MgAl2O3 or Rh / MgAl2O3. The catalytically active material may include Ni, Ru, Rh, Ir or a combination thereof. This can improve the overall gas conversion rate in the reforming reactor.

[0086] In one embodiment, the macrostructure has / has multiple parallel channels, multiple non-parallel channels and / or multiple labyrinthine channels. The channel has a wall that defines the channel. Several macrostructures of different forms and shapes can be used, as long as the surface area of ​​the structured catalyst exposed to the gas is as large as possible. In a preferred embodiment, the macrostructure has parallel channels because such parallel channels give the structured catalyst a very small pressure drop. In a preferred embodiment, the parallel longitudinal channels are inclined in the longitudinal direction of the macrostructure. In this way, the gas molecules flowing through the macrostructure will mostly tend to hit the wall in the channel, rather than flowing directly through the channel without having to contact the wall. In order to provide a macrostructure with sufficient resistivity, the size of the channel should be appropriate. For example, the channel can be quadratic (as shown in a cross section perpendicular to the channel) and the side length of the square is between 1 and 3 mm; however, it is conceivable to have a channel with a maximum range of about 4 cm in the cross section. In addition, the thickness of the wall should be small enough to provide a relatively large resistance and large enough to provide sufficient mechanical strength. The wall can, for example, have a thickness between 0.2 and 2 mm, such as about 0.5 mm, and the ceramic coating supported by the wall has a thickness between 10 μm and 500 μm, such as between 50 μm and 200 μm, such as 100 μm. In another embodiment, the macrostructure of the structured catalyst is cross-corrugated. Typically, when the macrostructure has parallel channels, the pressure drop from the inlet to the outlet of the reforming reactor system can be significantly reduced compared to a reactor in which the catalyst material is in pellet form (e.g., a standard SMR).

[0087] In one embodiment, the macrostructure is an extruded and sintered structure. Alternatively, the macrostructure is a 3D printed structure. 3D printed structures can be provided with or without subsequent sintering. Extruding or 3D printing a macrostructure, and optionally subsequently sintering it, forms a uniformly and coherently shaped macrostructure, which can then be coated with a ceramic coating.

[0088] Preferably, the macrostructure has been manufactured by 3D printing or by extruding a mixture of powdered metal particles and a binder onto an extruded structure and subsequently sintering the extruded structure, thereby providing a material with a high geometric surface area per unit volume.

[0089] Preferably, the macrostructure is manufactured by 3D printing or extruding a mixture of powdered metal particles and a binder into an extruded structure and subsequently sintering the extruded structure to provide a material with a high geometric surface area / volume. Preferably, the 3D printed extruded structure is sintered in a reducing atmosphere to provide the macrostructure. Alternatively, the macrostructure is a 3D printed metal additive manufacturing melting process, that is, a 3D printing process without subsequent sintering, such as powder bed fusion or direct energy deposition process. Examples of such powder bed fusion or direct energy deposition processes are laser beam, electron beam or plasma 3D printing processes. As another option, the macrostructure can be manufactured as a 3D metal structure by a binder-based metal additive manufacturing process and then sintered at a first temperature T1 in a non-oxidizing atmosphere, where T1>1000°C, to provide the macrostructure.

[0090] Before the second sintering in an oxidizing atmosphere, a ceramic coating that may contain a catalytically active material is provided on the macrostructure to form a chemical bond between the ceramic coating and the macrostructure. Alternatively, the catalytically active material can be impregnated onto the ceramic coating after the second sintering. When a chemical bond is formed between the ceramic coating and the macrostructure, there may be a particularly high thermal conductivity between the electrothermal macrostructure and the catalytically active material supported by the ceramic coating, thereby providing close and almost direct contact between the heat source and the catalytically active material of the structured catalyst. Due to the close proximity between the heat source and the catalytically active material, heat transfer is effective, thereby being able to heat the structured catalyst very efficiently. Therefore, a compact reforming reactor system is possible in terms of gas processing per reforming reactor system volume, and therefore a reforming reactor system that accommodates a structured catalyst can be compact. The reforming reactor system of the present invention does not require a furnace, which greatly reduces the overall size of the reactor. In addition, compared to known tubular steam reformers, the amount of synthesis gas produced in a single pressure shell is significantly increased, which is an advantage. In a standard tubular steam reformer, the amount of synthesis gas produced in a single tube of the tubular steam reformer is as high as 500 Nm 3 / h. In contrast, the reforming reactor of the present invention is arranged to produce up to or more than 2000Nm 3 / h, for example, even reaching or exceeding 10000Nm in a single pressure shell 3 / h. This can be achieved by not having O in the feed gas. 2 This is achieved with a methane content of less than 10% in the syngas produced. 3 / h of synthesis gas, it is no longer necessary to provide a plurality of pressure shells or means for distributing the feed gas to a plurality of such individual pressure shells.

[0091] As used herein, the terms "3D printing" and "3D printing" are intended to refer to metal additive manufacturing processes. Such metal additive manufacturing processes encompass 3D printing processes in which material is attached to a structure under computer control to create a three-dimensional object, wherein the structure is solidified, for example by sintering, to provide a macrostructure. Furthermore, such metal additive manufacturing processes encompass 3D printing processes that do not require subsequent sintering, such as powder bed fusion or direct energy deposition processes. Examples of such powder bed fusion or direct energy deposition processes are laser beam, electron beam, or plasma 3D printing processes.

[0092] Preferably, the catalytically active material is a particle having a size of 5 nm to 250 nm. The ceramic coating may, for example, be an oxide comprising Al, Zr, Mg, Ce and / or Ca. Exemplary coatings are calcium aluminate or magnesium aluminate spinel. Such a ceramic coating may comprise further elements, such as La, Y, Ti, K or combinations thereof. Preferably, the conductor is made of a different material than the macrostructure. The conductor may be, for example, iron, nickel, aluminum, copper, silver or alloys thereof. The ceramic coating is an electrically insulating material, typically having a thickness of about 100 μm, for example about 10-500 microns.

[0093] The macrostructure is advantageously a coherent or consistent internal connecting material so that electrical conductivity is achieved throughout the macrostructure, thereby achieving thermal conductivity throughout the structured catalyst, and in particular providing heating of the catalytically active material supported by the macrostructure. By using a coherent or consistent internal connecting material, a uniform distribution of current within the macrostructure can be ensured, thereby ensuring a uniform distribution of heat within the structured catalyst. Throughout this text, the term "coherent" is a synonym for cohesive, and therefore refers to a material that is always internally connected or always coupled. The effect of the structured catalyst as a coherent or consistent internal connecting material is to control the connectivity within the structured catalyst material, thereby obtaining electrical conductivity of the macrostructure. It should be noted that even if the macrostructure is further modified, such as by providing slits within portions of the macrostructure or implementing insulating materials within the macrostructure, the macrostructure is still represented as a coherent or consistent internal connecting material.

[0094] In one embodiment, the structured catalyst includes an electrically insulating portion arranged to increase the current path between the conductors to a length greater than the maximum dimension of the structured catalyst. Providing a current path between the conductors that is greater than the maximum dimension of the structured catalyst can be achieved by providing an electrically insulating component between the conductors and preventing current from flowing through certain portions of the structured catalyst. Such an electrically insulating component is arranged to increase the current path and, therefore, the resistance through the structured catalyst. In one embodiment, the length of at least one electrically insulating component is arranged to ensure that the minimum current path between the conductors is greater than the maximum dimension of the macrostructure.

[0095] Non-limiting examples of such insulating components are cutouts, slits or holes in the structure. Optionally, solid insulating materials, such as ceramics in the cutouts or slits in the structure, can be used. In the case where the solid insulating material is a porous ceramic material, the catalytically active material can be advantageously incorporated into the holes, for example by impregnation. The solid insulating material in the cutout or slit helps to maintain the distance between the structured catalyst portions on both sides of the cutout or slit. As used herein, the term "maximum dimension of a structured catalyst" refers to the maximum internal dimension of the geometric form occupied by the structured catalyst. If the structured catalyst is box-shaped, the maximum dimension will be the diagonal from one corner to the farthest corner, also referred to as the space diagonal.

[0096] It should be noted that although the current passing through the structured catalyst may be distorted or entangled through the structured catalyst due to the provision of electrically insulating components to increase the current path, the gas passing through the reformer reactor system enters at one end of the reformer reactor system and passes through the structured catalyst once before exiting the reformer reactor system. Inert material is advantageously present in associated gaps between the structured catalyst and the remainder of the reformer reactor system to ensure that the gas within the reformer reactor system passes through the structured catalyst and the catalytically active material supported thereby.

[0097] In an embodiment according to the second aspect of the present invention, the length of gas passing through the structured catalyst is less than the length of current passing from one conductor through the structured catalyst to the next conductor. The ratio of gas channel length to current channel length can be less than 0.6, or 0.3, 0.1, or even as low as 0.002.

[0098] In one embodiment, the structured catalyst has an electrical insulating member that is arranged to provide a zigzag path for the current path through the structured catalyst. Here, the terms "zigzag path" and "zigzag path" mean a path with a corner that tracks the path from one conductor to another conductor at a variable angle. A zigzag path is, for example, a path that goes up, turns, and then goes down. A zigzag path may have many turns, going up and then down multiple times through the structured catalyst, even if one turn is enough to make the path a zigzag path.

[0099] In one embodiment according to the second aspect of the present invention, the reforming reactor includes at least two conductors electrically connected to the structured catalyst and to a power source positioned outside the pressure vessel, wherein the power source is sized to heat at least a portion of the structured catalyst to a temperature of at least 500° C. by passing an electric current through the macrostructure, wherein the at least two conductors are connected to the structured catalyst at locations on the structured catalyst closer to the first end of the structured catalyst than to the second end of the structured catalyst, and wherein the structured catalyst is configured to direct the electric current from one conductor substantially toward the second end of the structured catalyst and back to a second of the at least two conductors. This allows for better protection of the connection between the conductors and the catalyst and better control of the temperature of the syngas.

[0100] Any embodiment of the first aspect of the invention may be used in combination with the second aspect of the invention, and vice versa.

[0101] The following is a detailed description of the embodiments of the present invention depicted in the accompanying drawings. The embodiments are examples and are detailed enough to clearly convey the present invention. However, the level of detail provided is not intended to limit the intended variations of the embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention as defined by the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0102] FIG. 1 is a schematic diagram of a method and system according to an embodiment of the present invention, including an eSMR but without an ATR ( Figure 1a ), and another embodiment comprising an eSMR and an ATR ( Figure 1b ). Figure 2 A schematic diagram of a specific embodiment of a structured catalyst for an electrothermal reforming reactor (eSMR) is shown in perspective view. Figure 3a Shown in cross section is a cross section through one embodiment of an eSMR having a structured catalyst comprising an array of macrostructures. Figure 3b Shows Figure 3a An eSMR with part of the pressure vessel and thermal insulation removed. DETAILED DESCRIPTION

[0103] Figure 1aSchematic diagram of a system 10 for a method (process) and system (apparatus) for producing synthesis gas for use in producing hydrocarbon products, particularly synthetic fuels (e.g., diesel). The system 10 for converting a hydrocarbon feed gas 1 (preferably natural gas) into synthesis gas 17 and then into hydrocarbon products 19 includes a reforming section and a FT synthesis section 30. The reforming section includes a purification unit 50, such as a desulfurization unit (sulfur absorber), a pre-reformer 60, and an electric steam methane reforming reactor eSMR 70. The reforming section may also include a hydrogen removal unit 90. The FT synthesis section 30 includes one or more FT reactors and a product post-processing unit (PWU). Hydrocarbon products 19, such as diesel and / or kerosene, and a FT tail gas (tail gas) 21 are produced from the FT synthesis section.

[0104] Hydrocarbon feed gas 1 is directed to a purification unit 50, from which purified, preheated hydrocarbon feed gas 5 is produced. A stream comprising steam 7 is added to the resulting purified feed gas 8, which is passed through a heater 40a to form preheated feed gas 9. Preheated feed gas 9 is sent to a pre-reformer 60. Pre-reformed hydrocarbon feed gas 11 exits pre-reformer 60 and is heated in an optional second heater 40b to produce preheated hydrocarbon feed gas 13. This gas 13 is sent to an eSMR 70, where it undergoes steam methane reforming to produce reformed gas 17, which is then directed to a hydrogen removal unit 90, such as a pressure swing adsorption (PSA) unit or a hydrogen membrane unit. A hydrogen stream 25 is withdrawn from this unit, along with synthesis gas 18, and is directed to the FT synthesis section 30. In the hydrogen removal unit 90, only a portion of the hydrogen is removed to achieve the desired H2 / CO ratio, i.e., to remove excess hydrogen from the synthesis gas; alternatively, only a portion of stream 17 is sent.

[0105] Figure 1b An embodiment according to the present invention is shown wherein the ATR 200 is located downstream of the eSMR 70 as part of the reforming section. Figure 1a As shown, reformed gas 17 is produced in the eSMR 70. A portion of the FT tail gas 21 from the Fischer-Tropsch synthesis section 30 can be used as fuel 21'. Another portion 21" is used as recycle in the reforming section by mixing with the reformed gas 17 (exit gas from the eSMR). The resulting reformed gas 17' is then fed to the ATR 200, from which synthesis gas 18 with the desired H2 / CO ratio is produced, which is then directed to the FT synthesis section 30.

[0106] Figure 2A specific embodiment of a structured catalyst for an eSMR 70 is shown in perspective view. The eSMR 70 includes a structured catalyst 72. The structured catalyst 72 includes a macrostructure 74 coated with a ceramic coating impregnated with a catalytically active material. Within the structured catalyst 72 are channels 74 extending along the longitudinal direction z of the macrostructure. The channels are defined by walls 76. When viewed in the direction of flow indicated by arrows 78, 80, these walls define a plurality of parallel, preferably square, channels 74. When viewed from above, the structured catalyst 72 has a substantially square perimeter defined by edge lengths e1 and e2. However, the perimeter may also be circular or have other shapes.

[0107] The walls 76 of the structured catalyst 72 are made of an extruded material coated with a ceramic coating (e.g., an oxide) applied to the macrostructure. The ceramic coating is not shown in the figure. The ceramic coating is impregnated with a catalytically active material. The ceramic coating, and therefore the catalytically active material, is present on each wall within the structured catalyst 72, over which gas flows during operation and interacts with the heated surface and catalytically active material of the structured catalyst.

[0108] Thus, during use in a reactor system for steam reforming, hydrocarbon feed gas flows through the channels 74 and interacts with the heated surface of the structured catalyst and the catalytically active material supported by the ceramic coating.

[0109] In the structured catalyst 72, slits 82 have been cut into the structured catalyst 72. These slits 82 force the current to take a zigzag path within the macrostructure, in this case downward and then upward, thereby increasing the current path and thus increasing the resistance and thus the amount of heat dissipated within the macrostructure. The slits 82 within the macrostructure may be embedded with an insulating material to ensure that no current flows transversely to the slits 82.

[0110] Channels 74 in the structured catalyst are open at both ends. When the structured catalyst is used in a reactor system, hydrocarbon feed gas flows through the unit and is heated by contact with the walls 76 of the channels 74 and by thermal radiation. This heat initiates the desired steam reforming process. The walls 76 of the channels 74 may be, for example, 0.5 mm thick, and the ceramic coating applied to the walls 75 may be, for example, 0.1 mm thick. While arrows 78 and 80 indicate downward flow of the hydrocarbon feed gas, the opposite flow direction, i.e., upward flow, is also contemplated.

[0111] Connectors 84 are attached to the structured catalyst 72. Each connector 84 connects a portion of the structured catalyst 72 to a conductor 86. The conductors 86 are all connected to a power source (not shown). Each connector 84 is connected to the upper portion of the structured catalyst. When the conductors 86 are connected to the power source, current is directed through the conductors to the corresponding connector 84 and flows through the structured catalyst 72. The slits 82 block current flow in the lateral direction ( Figure 2 Therefore, if Figure 2 As shown, the current flows downward along the slit 82 in the portion of the structured catalyst 72, then flows transversely to the longitudinal direction below the slit 82, and finally, the current flows upward along the longitudinal direction of the structured catalyst to another connector 84. Connector 84 is mechanically fixed to the structured catalyst by a mechanical fastening device (such as screws and bolts 88). However, additional or alternative fastening devices are conceivable. In one embodiment, the power supply generates a voltage of 3V and a current of 400A. Connector 84 is, for example, made of materials such as iron, aluminum, nickel, copper or its alloys.

[0112] As described above, the structured catalyst 72 is coated with a ceramic coating, such as an oxide, that supports the catalytically active material. However, the portion of the structured catalyst 72 that connects to the connector 84 should not be coated with the oxide. Instead, the macrostructures of the structured catalyst should be exposed or directly connected to the connector 84 to achieve a good electrical connection between the macrostructures and the connector.

[0113] When the connector 84 and the conductor 86 are connected to the same end of the structured catalyst, i.e. Figure 2 At the upper end shown, the gas entering the reactor system containing the structured catalyst 72 will be able to cool the connector 84 and the conductor 86. For example, the hydrocarbon gas entering such a reactor system will have a temperature of 400°C or 500°C and will therefore prevent the connector 84 and the conductor 86 from reaching temperatures much above that.

[0114] Therefore, in Figure 2 In this embodiment of the eSMR, conductor 86 is located on one side of the reactor. Current flows from one conductor to the second side of the reactor structure, and then to a second conductor. The feed gas inlet is located on the first side, and the gas outlet is located on the second side. This allows for a secure connection between conductor 86 and the catalyst and precise control of the temperature of the generated syngas.

[0115] Compared to a flame reformer (conventional SMR), an eSMR can reach higher temperatures, thus providing better methane conversion in this layout. It should be noted that the CO2 content in the process gas may vary, so adding CO2 and / or CO to the syngas (e.g. from FT tail gas) may be advantageous.

[0116] Electrothermal reforming can, for example, use a monolithic-type catalyst that is directly heated by Joule heating to provide heat for the reaction. Essentially, the eSMR 70 is conceived as a pressure-resistant shell with a centrally placed catalytic monolith connected to an externally placed power source via conductors passing through dielectric fittings in the shell. The shell of the eSMR is lined with refractory material to confine the high-temperature zone to the center of the eSMR.

[0117] From the perspective of the reforming reactor, the eSMR has several advantages over conventional flame reformers. The most obvious of these is that when electric heating technology is used, the reactor design can be made more compact, since the reforming reactor is no longer limited to systems with high external heat transfer areas. A size reduction of two orders of magnitude can be envisaged. This means that the capital investment for the technology is significantly reduced. It is estimated that the capital investment for the combined preheating and reforming sections of the eSMR (including power supply) configuration is significantly reduced. Since the syngas preparation section of the FT synthesis plant accounts for more than 60% of the capital investment of a GTL plant based on a conventional flame reformer, the substantial savings in reformer equipment will translate into a significant reduction in the cost of equipment based on eSMR.

[0118] Now go to Figure 3a and 3b . Figure 3a A cross-section through an embodiment of an eSMR 700 according to the present invention is shown. The eSMR 700 includes a structured catalyst 710 arranged as an array of macrostructures 705. Each macrostructure 705 in the array is coated with a ceramic coating impregnated with a catalytically active material. The eSMR 700 also includes conductors 740, 740', which are connected to a power source (not shown) and the structured catalyst 710, i.e., the array of macrostructures. The conductors 740, 740' pass through the wall of the pressure vessel 720 that houses the structured catalyst and pass through the insulating material 730 on the inside of the pressure vessel through fittings 750. The conductors 740' are connected to the array of macrostructures 705 by conductor contact rails 741.

[0119] In one embodiment, the power supply supplies a voltage of 26 V and a current of 1200 A. In another embodiment, the power supply supplies a voltage of 5 V and a current of 240 A. The current flows through the electrical conductors 740, 740' to the conductor contact rails 741, and the current flows from the conductor contact rails 741 through the structured catalyst 710, for example Figure 3a The conductor contact rail seen on the left, to another conductor contact rail 741, e.g. Figure 3a The conductor rail is seen on the right side of the diagram. The current can be alternating current, i.e., running alternately in two directions, or direct current, running in either direction.

[0120] Macrostructure 705 is made of a conductive material. Kanthal, an alloy of aluminum, iron, and chromium, is particularly preferred. A ceramic coating, such as an oxide, applied to the structured catalyst is impregnated with a catalytically active material. Conductors 740 and 740' are made of materials such as iron, aluminum, nickel, copper, or alloys thereof.

[0121] During operation, a feedstock of pre-reformed feed gas comprising hydrocarbons and steam enters the eSMR 700 from above as indicated by arrow 711. As indicated by arrow 712, outlet gas exits the eSMR from its bottom.

[0122] The present invention is further described in detail as follows:

[0123] 1. A method for producing synthesis gas for use in producing hydrocarbon products (particularly synthetic fuels), comprising the following steps:

[0124] - providing a hydrocarbon feed gas,

[0125] - performing steam methane reforming in a reforming reactor comprising a pressure-resistant shell containing a structured catalyst, the structured catalyst being arranged to catalyze steam reforming of the hydrocarbon feed gas, the structured catalyst comprising macrostructures of an electrically conductive material, the macrostructures supporting a ceramic coating, wherein the ceramic coating supports a catalytically active material; the steam methane reforming comprising the steps of:

[0126] -i) supplying the hydrocarbon feed gas to a reforming reactor,

[0127] -ii) allowing the hydrocarbon feed gas to undergo a steam methane reforming reaction over the structured catalyst and withdrawing synthesis gas from the reforming reactor, and

[0128] -iii) providing electrical power via an electrical conductor connecting a power source positioned outside the pressure vessel to the structured catalyst, allowing current to flow through the macrostructural material, thereby heating at least a portion of the structured catalyst to a temperature of at least 500° C.,

[0129] - providing at least a portion of the synthesis gas from step ii) to a synthetic fuel synthesis unit for converting said synthesis gas into said hydrocarbon products and generating a tail gas.

[0130] 2. The method according to item 1 further includes performing autothermal reforming in an autothermal reforming unit (ATR) after performing the steam methane reforming to produce the synthesis gas.

[0131] 3. The method according to item 1 or 2, comprising recycling at least part of the tail gas upstream of the reforming reactor and / or upstream of the ATR.

[0132] 4. A method according to any one of items 1 to 3, wherein the supplied electricity is at least partially generated by renewable energy sources.

[0133] 5. The method according to any one of items 1 or 4, further comprising:

[0134] - providing a hydrogen separation unit, such as a hydrogen membrane unit, downstream of the reforming reactor and separating excess hydrogen from the synthesis gas stream,

[0135] and / or

[0136] - adding CO2 to the hydrocarbon feed gas, preferably by providing a CO2 removal unit downstream of the reforming reactor, separating CO2 from the synthesis gas and recycling at least part of said CO2 to the hydrocarbon feed gas.

[0137] 6. The method according to any one of items 1 to 5, further comprising: providing a reforming unit, preferably an ATR, for separately reforming the tail gas and optionally recycling at least a portion of the reformed tail gas to the synthetic fuel synthesis unit.

[0138] 7. A method according to any one of items 1 to 6, wherein a combination of steam superheating and steam generation is integrated into the waste heat recovery of the synthesis gas from the reforming reactor and / or the ATR, and wherein the superheated steam is used as steam feed in the step of carrying out the steam methane reforming.

[0139] 8. The method according to any one of items 1 to 7, wherein the gas pressure in the reforming reactor is 20 to 100 bar, preferably 25 to 50 bar, and the temperature of the outlet gas of the reforming reactor is 850 to 1150°C, preferably 900 to 1150°C.

[0140] 9. The method according to any one of items 1 to 8, further comprising:

[0141] - pre-reforming the hydrocarbon gas together with a steam feed in a pre-reforming unit prior to said steam reforming,

[0142] and / or

[0143] - Purification of the hydrocarbon feed gas in a gas purification unit before said steam reforming and / or before said pre-reforming.

[0144] 10. A system for producing synthesis gas for use in producing hydrocarbon products, in particular synthetic fuels, comprising:

[0145] - a reforming reactor comprising a pressure-resistant shell containing a structured catalyst, the structured catalyst being arranged to catalyze steam reforming of a feed gas comprising hydrocarbons, the structured catalyst comprising macrostructures of an electrically conductive material, the macrostructures supporting a ceramic coating, wherein the ceramic coating supports a catalytically active material; wherein the reforming reactor further comprises an electrical power source positioned external to the pressure-resistant shell and an electrical conductor connecting the electrical power source to the structured catalyst, allowing electrical current to flow through the macrostructure material, thereby heating at least a portion of the structured catalyst to a temperature of at least 500° C.,

[0146] - a synfuel synthesis unit arranged to receive at least part of the synthesis gas from said reforming reactor for converting said synthesis gas into said hydrocarbon products and producing a tail gas.

[0147] 11. The system according to item 10 comprises an autothermal reforming unit (ATR) downstream of the reforming reactor, and / or a pre-reforming unit upstream of the reforming reactor, and / or a gas purification unit for purifying hydrocarbon gas upstream of the pre-reforming unit and / or upstream of the reforming reactor.

[0148] 12. The system according to item 10, wherein the system does not have an autothermal reformer unit (ATR) downstream of the reforming reactor.

[0149] 13. The system according to any one of items 10 to 12, comprising a reforming unit for separately reforming the tail gas, preferably an ATR, and optionally further comprising means for recycling at least a portion of the reformed tail gas to the synthetic fuel synthesis unit.

[0150] 14. The system according to any one of items 10 to 13, wherein catalyst pellets are loaded above, around, inside or below the structured catalyst of the reforming reactor.

[0151] 15. The system of any one of items 10 to 14, wherein the reforming reactor comprises at least two conductors electrically connected to the structured catalyst and a power source positioned outside the pressure vessel, wherein the power source is sized to heat at least a portion of the structured catalyst to a temperature of at least 500° C. by passing an electric current through the macrostructure, wherein the at least two conductors are connected to the structured catalyst at a location on the structured catalyst closer to a first end of the structured catalyst than to a second end of the structured catalyst, and wherein the structured catalyst is configured to direct an electric current from one conductor substantially toward the second end of the structured catalyst and back to a second of the at least two conductors.

[0152] 16. The system of any one of items 10 to 15, wherein the path length of gas through the structured catalyst is less than the path length of electric current from one conductor through the structured catalyst to the next conductor.

[0153] 17. The process according to any one of items 1 to 9, wherein the space velocity, estimated as the gas flow rate relative to the geometric surface area of ​​the structured catalyst, is between 0.6 and 60 Nm 2 / m 2 / h, and / or relative to the occupied volume of the structured catalyst, the gas flow rate is 700Nm 3 / m 3 / h and 70000Nm 3 / m 3 / h.

[0154] 18. The method according to any one of items 1 to 9 and 17, wherein the reforming reactor has a floor area of ​​0.4 m 2 and 4m 2 between.

[0155] 19. The process according to any one of items 1 to 9 and 17-18, wherein the amount of hydrocarbon feed gas is 20000 Nm 3 / h to 200000Nm 3 / h.

[0156] Although the present invention has been illustrated by description of various embodiments, and although these embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such details. Other advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicant's general inventive concept.

Claims

1. A method for producing synthesis gas for use in producing hydrocarbon products, in particular synthetic fuels, comprising the following steps: - providing a hydrocarbon feed gas, - performing steam methane reforming in a reforming reactor comprising a pressure-resistant shell containing a structured catalyst, said structured catalyst being arranged to catalyze steam reforming of said hydrocarbon feed gas, said structured catalyst comprising macrostructures of an electrically conductive material, said macrostructures supporting a ceramic coating, wherein said ceramic coating supports a catalytically active material; The steam methane reforming comprises the following steps: -i) supplying the hydrocarbon feed gas to a reforming reactor, -ii) allowing the hydrocarbon feed gas to undergo a steam methane reforming reaction over the structured catalyst and withdrawing synthesis gas from the reforming reactor, and -iii) providing electrical power via an electrical conductor connecting a power source positioned outside the pressure vessel to the structured catalyst, allowing current to flow through the macrostructural material, thereby heating at least a portion of the structured catalyst to a temperature of at least 500° C., - providing at least a portion of the synthesis gas from step ii) to a synthetic fuel synthesis unit for converting said synthesis gas into said hydrocarbon products and generating a tail gas.

2. The method of claim 1, further comprising performing autothermal reforming in an autothermal reforming unit (ATR) after performing the steam methane reforming to produce the synthesis gas.

3. The method according to claim 1 or 2, comprising recycling at least part of the tail gas upstream of the reforming reactor and / or upstream of the ATR.

4. The method according to any one of claims 1 to 3, wherein The supplied electricity is at least partially generated by renewable energy sources.

5. The method according to any one of claims 1 or 4, further comprising: - providing a hydrogen separation unit, such as a hydrogen membrane unit, downstream of the reforming reactor and separating excess hydrogen from the synthesis gas stream, and / or - adding CO2 to the hydrocarbon feed gas, preferably by providing a CO2 removal unit downstream of the reforming reactor, separating CO2 from the synthesis gas and recycling at least part of said CO2 to the hydrocarbon feed gas.

6. The method according to any one of claims 1 to 5, further comprising: A reforming unit, preferably an ATR, is provided for separately reforming the tail gas and optionally recycling at least a portion of the reformed tail gas to the synthetic fuel synthesis unit.

7. The process according to any one of claims 1 to 6, wherein a combination of steam superheating and steam generation is integrated into the waste heat recovery of the synthesis gas from the reforming reactor and / or the ATR, and wherein in the step of performing the steam methane reforming, the superheated steam is used as steam feed.

8. The method according to any one of claims 1 to 7, wherein the gas pressure in the reforming reactor is 20 to 100 bar, preferably 25 to 50 bar, and the temperature of the outlet gas of the reforming reactor is 850 to 1150°C, preferably 900 to 1150°C.

9. The method according to any one of claims 1 to 8, further comprising: - pre-reforming the hydrocarbon gas together with a steam feed in a pre-reforming unit prior to said steam reforming, and / or - Purification of the hydrocarbon feed gas in a gas purification unit before said steam reforming and / or before said pre-reforming.

10. A system for producing synthesis gas for use in producing hydrocarbon products, in particular synthetic fuels, comprising: - a reforming reactor comprising a pressure-resistant shell containing a structured catalyst, the structured catalyst being arranged to catalyze the steam reforming of a feed gas comprising hydrocarbons, the structured catalyst comprising macrostructures of an electrically conductive material, the macrostructures supporting a ceramic coating, wherein the ceramic coating supports a catalytically active material; The reforming reactor further comprises a power source disposed outside the pressure vessel and an electrical conductor connecting the power source to the structured catalyst, allowing current to flow through the macrostructure material, thereby heating at least a portion of the structured catalyst to a temperature of at least 500° C. - a synfuel synthesis unit arranged to receive at least part of the synthesis gas from said reforming reactor for converting said synthesis gas into said hydrocarbon products and producing a tail gas.

11. The system according to claim 10, comprising an autothermal reforming unit (ATR) downstream of the reforming reactor, and / or a pre-reforming unit upstream of the reforming reactor, and / or a gas purification unit for purifying hydrocarbon gas upstream of the pre-reforming unit and / or upstream of the reforming reactor.

12. The system of claim 10, wherein the system lacks an autothermal reformer unit (ATR) downstream of the reforming reactor.

13. System according to any one of claims 10 to 12, comprising a reforming unit, preferably an ATR, for separately reforming the tail gas, and optionally further comprising means for recycling at least a portion of the reformed tail gas to the synthetic fuel synthesis unit.

14. The system of any one of claims 10 to 13, wherein catalyst pellets are loaded above, around, within, or below the structured catalyst of the reforming reactor.

15. The system according to any one of claims 10 to 14, wherein: The reforming reactor includes at least two conductors electrically connected to the structured catalyst and to a power source positioned outside the pressure vessel, wherein the power source is sized to heat at least a portion of the structured catalyst to a temperature of at least 500° C. by passing an electric current through the macrostructure, wherein the at least two conductors are connected to the structured catalyst at locations on the structured catalyst closer to a first end of the structured catalyst than to a second end of the structured catalyst, and wherein the structured catalyst is configured to direct the electric current from one conductor substantially toward the second end of the structured catalyst and back to a second of the at least two conductors.

16. The system according to any one of claims 10 to 15, wherein: The path length of the gas through the structured catalyst is less than the path length of the electric current from one conductor through the structured catalyst to the next conductor.

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