Electrically heated reforming reactor for the reforming of methane and other hydrocarbons

Abstract

Disclosed is an electrically heated reforming reactor and associated reforming process that benefits from numerous advantages for obtaining and controlling heat input to catalytic conversion processes, such as the reforming of hydrocarbons (e.g., methane) using HO and / or CO as oxidants. The disclosed reactor provides the ability to focus heat input to specific regions within the catalyst bed volume. This allows for control of temperature distribution in one or more dimensions (e.g., axial and / or radial) and otherwise customization of heat input to process specific reformer feedstocks, obtain specific reformer products, efficiently utilize catalysts, and / or compensate for numerous operating parameters (e.g., flow distribution). Dynamic control of heat input can be used in response to changes in feedstock or product composition and / or catalyst activity.

Description

Cross-reference of related applications

[0001] This application requests U.S. Provisional Application No. 63 / 107,537, filed on 30 October 2020, the entire text of which is incorporated herein by reference. [Technical Field]

[0002] Aspects of the present invention relate to a reforming reactor that offers operational flexibility in establishing and controlling heat input to the catalyst layer within such a reactor, and is compact and portable for processing reformer raw materials at various locations without preferably generating CO2 associated with combustion in conventional reforming reactors. [Background technology]

[0003] The ongoing search for crude oil alternatives to produce hydrocarbon fuels is increasingly driven by several factors. These include dwindling oil reserves, projected increases in energy demand, and growing concerns about greenhouse gas (GHG) emissions from non-renewable carbon sources. Given the abundance of natural gas reserves and biogas from biosources, methane has become the focus of many possible routes for supplying liquid hydrocarbons. The main commercial process for converting methane into fuel involves a first conversion step to produce synthesis gas, followed by a second downflow Fischer-Tropsch (FT) synthesis step. In the second step, the synthesis gas, which contains a mixture of hydrogen (H2) and carbon monoxide (CO), is subjected to the addition of hydrogen gas to successively cleave the CO bonds and form CC bonds. This mechanism produces hydrocarbons, particularly straight-chain alkanes, whose molecular weight distribution can be controlled to some extent by changing the FT reaction conditions and catalytic properties. Alternatively, FT synthesis can also be used to purify oxygen-containing compounds, particularly lower alcohols such as methanol, using known operating parameters.

[0004] In addition to its use as a precursor for liquid hydrocarbons and / or oxygen-containing compounds, synthesis gas needs to be used as a source of hydrogen, particularly in the refining industry. For example, the demand for hydrogen gas is increasing as it becomes increasingly important to meet the requirements for clean fuels through hydrogen consumption processes such as hydrodesulfurization.

[0005] Regarding the first conversion step described above, known methods for producing synthesis gas from methane include partial oxidation reforming and autothermal reforming (ATR) based on the exothermic oxidation of methane with oxygen. Conversely, steam methane reforming (SMR) uses steam as an oxidizer, requiring energy investment for the generation of the steam itself, and its thermodynamics are significantly different because the reaction between methane and water absorbs heat. Recently, it has also been proposed to use carbon dioxide (CO2) as an oxidizer for methane, thereby forming the desired synthesis gas through the reaction of the most oxidized form of carbon with the most reduced form of carbon. CH4 + CO2 → 2CO + 2H2

[0006] This reaction is called "dry reforming" of methane, and because it is highly endothermic, dry reforming of methane is not thermodynamically more advantageous than ATR or SMR. However, the stoichiometric consumption of 1 mole of carbon dioxide per mole of methane may reduce the overall carbon footprint of liquid fuel production and result in a "greener" consumption of methane. When reforming higher hydrocarbons, the rate of CO2 consumption per mole of raw material increases (e.g., C2-C6 paraffins). In either case, thermodynamic barriers remain a major challenge, related to the fact that CO2 is completely oxidized and very stable, requiring a large amount of energy to activate as an oxidizer.

[0007] Therefore, known processes for producing synthesis gas by reforming methane and other hydrocarbons using H2O and / or CO2 as oxidizers may require temperatures up to 1000°C (1832°F). This temperature is typically achieved in a combustion furnace surrounding a series of vertically arranged tubes filled with reforming catalysts. A portion of the hydrocarbons supplied additionally to the parallel tubes, including the oxidizer, is supplied as gaseous reformer feedstock and used as the desired combustion heat source, in which case it is burned with oxygen in the furnace. However, this gas combustion heating requires the installation and support of a large and complex system infrastructure. These limitations may not apply particularly to smaller reforming operations where simpler and more compact reactor designs yield greater value and practicality. According to U.S. 3,147,080, U.S. 2016 / 0288074, and U.S. 2017 / 0101312, the use of electricity to heat the catalyst-filled tubes of a reforming reactor has been proposed in this field, for example, to supply some of the heat required for the catalyst in combination with radiant combustion heat. According to WO 2019 / 228796 and WO 2019 / 228797, conductive materials are coated with ceramic coatings supporting catalytically active materials. However, the use of such equipment in high-temperature conversion processes such as reforming and other processes that provide effective establishment and control of heat input to the catalyst layer remains necessary. [Overview of the project]

[0008] Aspects of the present invention relate to the discovery of an electrically heated reactor and associated reforming process that benefit from a number of advantages in obtaining and controlling heat input to a catalytic conversion process, such as the reforming of hydrocarbons (e.g., methane) using H2O and / or CO2 as an oxidizing agent. Electricity can be used to rapidly and efficiently raise the temperature of the catalyst layer by electrical resistance or induction heating, for example, from the ambient temperature after catalyst loading to reaction temperatures exceeding 500°C (932°F), 700°C (1292°F), or 850°C (1562°F). Another advantage is that the heat input can be concentrated in a specific region within the catalyst layer volume to achieve a number of processing purposes. These include controlling the temperature distribution in one or more dimensions (e.g., axial and / or radial), customizing the heat input in other ways to process specific reformer raw materials, obtaining specific reformer products, efficiently utilizing the catalyst, and / or compensating for many operating parameters (e.g., flow rate distribution). Dynamic control of the heat input can be used in response to changes in the composition of the raw materials or products and / or catalytic activity.

[0009] Other advantages include the elimination of conventional reactors and associated equipment (e.g., burners), and the elimination of CO2 emissions from fuel combustion. If renewable electricity (e.g., from solar or wind energy) can be used for heat generation, the carbon footprint associated with reformed / synthesis gas production can be further reduced or eliminated. Further advantages can be achieved by the increased simplicity of the disclosed electric reforming reactor compared to those requiring gas combustion furnaces, resulting in a compact and even transportable (e.g., skid-mounted) reactor of the present invention. Thus, according to some embodiments, the reactor and possibly other associated equipment (e.g., a downflow Fischer-Tropsch synthesis reactor) are transported to a location where they can be effectively utilized, including a hydrocarbon source such as natural gas (e.g., wellhead gas). Such sources are typically "stuck," meaning they lack access to suitable equipment for conversion into value-added products and are therefore usually flared (burned). The processes described herein can effectively monetize such otherwise unavailable methane and other hydrocarbon sources.

[0010] A particular embodiment of the present invention relates to an electrically heated reforming reactor including an outer shell defining an internal space including a catalyst layer volume for housing a catalyst. The reforming reactor may further include a plurality of heating elements configured to extend partially or completely through the catalyst layer volume and to heat individual regions within the catalyst layer volume. In other embodiments, the reforming reactor may further include at least one heating element configured to extend in one direction through the catalyst layer volume and to heat the catalyst layer volume. Another particular embodiment relates to a reforming process using the electrically heated reforming reactor described herein, for example, a process for producing synthesis gas products. A typical process may include bringing reformer feedstock, including (i) hydrocarbons and (ii) both H2O and / or CO2, into contact with a catalyst placed in the catalyst layer volume of the electrically heated reforming reactor, wherein the plurality of heating elements partially or completely pass through the catalyst layer volume and, therefore, partially or completely, through the catalyst layer itself. The process may further include supplying different heating rates to the catalyst by different heating elements, such as heating elements positioned at different radial positions and / or heating elements positioned at different axial positions. After the reformer feedstock comes into contact with the catalyst, synthesis gas products are generated, and these synthesis gas products are removed from the catalyst layer and the reactor.

[0011] According to other specific embodiments, the heating element may be in the form of a solid wire or rod that does not contain or surrounds empty spaces within the catalyst particles or catalyst layer volume. In some embodiments, the heating element may be structurally separate from the catalyst, meaning that the catalyst is not coated on or otherwise attached to the heating element. In some embodiments, the heating element may be electrically insulated, but not thermally insulated from the catalyst, so that the catalyst itself is not directly heated by resistance heating (e.g., by applying a voltage through the catalyst itself). That is, the catalyst itself is not directly heated by resistance heating (e.g., by inducing eddy currents in the catalyst itself). In preferred embodiments, the catalyst is in the form of a catalyst particle fixed layer through which one or more heating elements partially or completely pass.

[0012] These and other embodiments, aspects, and advantages related to the present invention will be apparent from the following detailed description.

[0013] A more complete understanding of exemplary embodiments of the present invention and their advantages can be obtained by referring to the following description, considering the accompanying drawings in which the same reference numerals are used to identify the same or similar features.

Brief Description of the Drawings

[0014] [Figure 1A] A representative reforming reactor is shown that includes a heating element that extends in a vertical direction or may extend in the same direction as the overall or bulk flow direction of the gaseous reaction mixture through the reactor. In FIG. 1A, the vertical direction may be parallel to the plane of the paper that divides the reactor into a front and a rear portion, or may be perpendicular to the central plane A'-A that divides the reactor into an upper and a lower portion. [Figure 1B] A representative reforming reactor is shown that includes a heating element that extends in a vertical direction or may extend in the same direction as the overall or bulk flow direction of the gaseous reaction mixture through the reactor. [Figure 1C] A representative reforming reactor is shown that includes a heating element that extends in a vertical direction or may extend in the same direction as the overall or bulk flow direction of the gaseous reaction mixture through the reactor. [Figure 1D] A representative reforming reactor is shown that includes a heating element that extends in a vertical direction or may extend in the same direction as the overall or bulk flow direction of the gaseous reaction mixture through the reactor. [Figure 1E] A representative reforming reactor is shown that includes a heating element that extends in a vertical direction or may extend in the same direction as the overall or bulk flow direction of the gaseous reaction mixture through the reactor. [Figure 1F] A representative reforming reactor is shown that includes a heating element that extends in a vertical direction or may extend in the same direction as the overall or bulk flow direction of the gaseous reaction mixture through the reactor. [Figure 2A]A typical reforming reactor is shown, which includes heating elements that may extend horizontally or perpendicular to the overall or bulk flow direction of the gaseous reaction mixture passing through the reactor. In Figure 2A, the horizontal direction may be parallel to the plane of paper dividing the reactor into front and rear sections, or parallel to the central plane A'-A dividing the reactor into upper and lower sections. [Figure 2B] A typical reforming reactor is shown, which includes heating elements that may extend horizontally or perpendicular to the overall or bulk flow direction of the gaseous reaction mixture passing through the reactor. [Figure 2C] A typical reforming reactor is shown, which includes heating elements that may extend horizontally or perpendicular to the overall or bulk flow direction of the gaseous reaction mixture passing through the reactor. [Figure 2D] A typical reforming reactor is shown, which includes heating elements that may extend horizontally or perpendicular to the overall or bulk flow direction of the gaseous reaction mixture passing through the reactor. [Figure 2E] A typical reforming reactor is shown, which includes heating elements that may extend horizontally or perpendicular to the overall or bulk flow direction of the gaseous reaction mixture passing through the reactor. [Modes for carrying out the invention]

[0015] The figures should be understood as simplified diagrams of an electroheated reforming reactor and the flow of reactants and products undergoing the reaction, for the sake of clarity and ease of explanation and understanding. These figures and elements are not necessarily depicted in proportion. Valves, instruments, and other equipment and systems that are not essential to understanding the various aspects of the present invention are not shown. As will be apparent to those skilled in the art, electroheated reforming reactors and processes utilizing these reactors have structures and elements that are partially determined by their particular application. Furthermore, although the drawings show specific embodiments having combinations of multiple elements, this is not intended to limit the scope of the invention as defined by the claims, which require fewer elements and / or different combinations of elements, and this is obvious to those skilled in the art.

[0016] The formulas "weight %" and "mol %" used here represent weight percentage and mole percentage, respectively. The expressions "wt-ppm" and "mol-ppm" represent mole percentage. For an ideal gas, "mol %" and "mol-ppm" are equal to volume percentage and volume percentage, respectively.

[0017] The term “reformer feedstock” means a composition comprising at least (i) one or more hydrocarbons such as methane, and (ii) H2O, CO2, or a combination thereof as an oxidizing agent. The reformer feedstock is subjected to steam reforming with H2O as the oxidizing agent, dry reforming with CO2 as the oxidizing agent, or CO2-steam reforming when two oxidizing agents are present in the reformer feedstock. The term “reformer product” means the reaction product composition obtained after contacting the reformer feedstock with the catalyst. With respect to the reformer feedstock, the conversion of hydrocarbons and oxidizing agents initially present in the reformer feedstock usually results in a decrease in the concentration of these components in the reformer product, and with respect to the reformer feedstock, it results in a concentration of the conversion products CO and H2 in the reformer product. Therefore, the term “synthesis product” is used to refer to a specific reformer product. The term “gaseous mixture” means the composition within the catalyst of a reformer reactor when undergoing conversion from the reformer feedstock to the reformer product (e.g., the synthesis product). Gaseous mixtures typically have intermediate concentrations of reformer feedstock and reformer product components relative to the components of the reformer feedstock and reformer product. Under the conditions used for reforming (e.g., temperature and pressure), the gaseous mixture becomes completely or at least largely gaseous. However, the term “gaseous mixture” does not exclude the presence of compounds that are liquid under ambient temperature and pressure conditions, such as water. When these compounds are reformed, they are hydrocarbons found in liquid fuels, including naphtha and jet fuel, e.g., C6-C6. 16 It may further contain hydrocarbons. Electrically heated reforming reactor and heating element

[0018] Embodiments of the present invention relate to an electrically heated reforming reactor having the above-described features and related advantages. As shown in Figure 1A, a typical reactor 100 may include an outer shell 2 defining an internal space 4 including a catalyst layer volume 50 for housing a catalyst, such as reforming catalyst particles as described herein. The reactor 100 further includes a plurality of heating elements 5' which may extend partially or completely through the catalyst layer volume 50 and be configured to heat separate regions within the reactor. Generally, an electrically heated reforming reactor may include such an outer shell defining an internal space including a catalyst layer volume, the catalyst layer volume may be located, for example, at least radially centered around the internal space. Generally, the reactor may include at least one heating element extending in one direction through the catalyst layer volume. For example, one heating element may extend centrally in one direction at least radially around the internal space and around the catalyst layer volume (for example, along the central axis of the internal space and catalyst layer volume, although both are generally cylindrical, other shapes are also possible). Optionally, additional heating elements can extend through other regions of the catalyst layer volume to provide a desired degree of heat input and temperature control in the desired region, which are typically in the same direction as one heating element and identical to one another.

[0019] Regardless of the presence of one or more heating elements, these heating elements include a conductive material such as a suitable metal or alloy. The metal or alloy forming the conductive material may include one or more of, for example, Cu, Ag, Al, Cr, Fe, and Ni, and can withstand the modification temperatures specified herein. Specific examples include nichrome alloy (an alloy of nickel and chromium) or Kanthal (an alloy of iron, chromium, and aluminum).

[0020] Typical heating elements may be elongated in one dimension (e.g., one dimension is at least an order of magnitude larger than the other dimensions, e.g., at least two orders of magnitude larger), and can take the form of a resistance wire or resistance rod (having a length dimension much larger than the radial dimension). Other heating elements may be elongated in two dimensions (e.g., the second dimension is at least an order of magnitude larger than the other dimensions, e.g., at least two orders of magnitude larger), and may be, for example, a planar heating element with a flat surface or a heating element in the form of a curved surface (e.g., having a length and width dimension or a length dimension and circumference dimension much larger than the thickness dimension). Examples include rectangular or circular planar heating elements (with long width and length dimensions, or long angular and radius dimensions), and tubular heating elements (with long circumference and length dimensions). These heating elements can also be manufactured from suitable metals or alloys as described above, for example, such metals or alloys may be coated or printed on two-dimensionally elongated (e.g., metal, glass, ceramic, polymer) substrates (e.g., as a metal / alloy-supported paste). The combination of conductive material and substrate can be characterized as a thick-film heating element, as is commonly used in the art.

[0021] Regardless of these specific forms, a typical heating element may have an insulating layer surrounding a conductive material, thereby transferring heat to the catalyst without the material directly contacting it. The insulating layer may include ceramic materials such as alumina, silicon oxide, or high-melting-point metal oxides such as magnesium oxide. Alternatively or additionally, the heating element may include a coating layer, tube, or sheath surrounding the conductive material, and any insulating layer. Alloys of copper, nickel, or stainless steel, such as Incoloy®, Inconel®, Hastelloy®, or Monel®, can be used as such coating layers, tubes, or sheaths. For example, certain wire or rod-shaped heating elements have a central or core conductive material surrounded by an intermediate insulating layer, the intermediate insulating layer further surrounded by an outer coating layer.

[0022] Generally, heating elements are configured such that the conductive material does not directly contact the catalyst, but rather an insulating layer or coating layer contacts the catalyst. Typical heating elements also often have either no catalyst attached to their surface, or a catalyst support material, such as a substrate to which catalyst particles have been washed, attached to their surface. That is, in a preferred embodiment, for example, catalyst particles are packed into the reforming reactor to surround the first heating element present in the reforming reactor (e.g., extending partially or completely through the catalyst layer volume), but the heating element and the catalyst are structurally separate, whether physically attached to or not attached to the heating element. The particles of the reforming catalyst may have a form (shape) and size suitable for use in a stationary layer. In the case of spherical catalyst particles, the diameter of these particles may be, for example, generally in the range of about 1 mm to about 10 mm, typically about 1 mm to about 5 mm, and often about 1 mm to about 3 mm. Catalyst particles having other geometric shapes that are also suitable for stationary layers include cylindrical catalyst particles (e.g., when manufactured by extrusion). In the case of cylindrical catalysts, the diameter of the catalyst particles can be any diameter within the above range. For example, extrudes with diameters of 1.59 mm (1 / 16 inch), 3.18 mm (1 / 8 inch), and 6.35 mm (1 / 4 inch) can be formed. Cylindrical catalyst particles generally have a length of about 1 mm to 10 mm, typically 1 mm to 5 mm, and often about 1 mm to 3 mm.

[0023] The heating elements, in particular one or more heating elements used in any of the embodiments described herein, may be resistive heating elements or induction heating elements. In the case of resistive heating elements, a voltage source is used to supply alternating current or direct current through a conductive material having sufficient resistance to generate a desired amount of heat by Joule heating. Typical voltages that can be applied to the heating elements are in the range of about 50 to about 5000V, for example, about 100 to about 2500V or about 200 to about 1000V. When one or more voltage sources are used to supply alternating current, typical frequencies are in the range of about 10 to about 1000Hz, for example, about 25 to about 100Hz or about 50 to about 60Hz. In the case of induction heating elements, an energy source such as an electron oscillator is used to supply alternating current through an electromagnet, which establishes an alternating magnetic field within a conductive material and induces eddy currents. These eddy currents, combined with the resistance of the conductive material, generate a desired amount of heat by Joule heating. According to the particular embodiments described above, the electromagnet or inductor coupled to the energy source may, for example, be in the form of a coil wound on a conductive material wound on the intermediate insulating layer and / or outer coating layer of the heating element. In view of this and the general disclosure of various embodiments herein, one or more (e.g., multiple) heating elements may be in the form of resistive or inductive wires or rods, for example, solid wires or rods that do not contain or surround any catalyst particles or catalyst layer volume. In other embodiments, one or more heating elements may be in the form of plates, such as rectangular or circular plates, which can be formed by printing conductive material or generally by thick-film element manufacturing techniques. In further embodiments, one or more heating elements may be in the form of tubular members of various dimensions, such as tubes having various diameters and optionally substantially constant length. Such tubes may contain or surround catalyst particles.

[0024] Optionally, in the case of resistive heating, a voltage source can be used to generate a desired amount of heat only in selected portions of the conductive material of one or more heating elements, for example, a linear segment of a one-dimensionally elongated heating element, or an area segment of a two-dimensionally elongated heating element. Alternatively, instead of generating heat in some segments and not in others, different amounts of heat can be generated in different one-dimensional or two-dimensional portions of the conductive material (e.g., these linear or area segments). Such objectives can be achieved, for example, by using a multi-zone heating element. Alternatively, multiple voltage sources can be used to independently control the heat input in individual linear or area segments in a given plane extending along a given line or through the catalyst layer volume. In the case of induction heating, if an electromagnet or inductor induces eddy currents in such selected portions or varying eddy currents in such different portions, it is also possible to generate a desired amount of heat only in selected portions of the conductive material of one or more heating elements, or varying amounts of heat in different portions. In this way, heating of a specific or target region within the catalyst layer volume by resistive heating and / or induction heating can be enhanced.

[0025] From the embodiment shown in Figure 1A, it is understood that the reactor 100 includes a reformer feedstock inlet 10 and a reformer product outlet 20, which are configured to flow the gaseous mixture (reaction gaseous mixture) in an overall or overall flow direction corresponding to the direction of the arrows associated with the reformer feedstock inlet 10 and the reformer product outlet 20. On the other hand, Figure 1A shows a reactor configured to flow the gaseous mixture downward (e.g., a downward flow reactor), but other flow configurations are possible in other embodiments, for example, for an upward flow reactor or a reactor configured for horizontal flow. The reformer feedstock inlet 10 and / or reformer product outlet 20 can cooperate with other structures in the reactor, such as distributing, guiding (e.g., through channels) and / or collecting the gaseous mixture before, during, and after it passes through the catalyst layer volume 50. These structures may include, for example, a feedstock inlet distributor 12 and a product outlet collector 22. Furthermore, as shown in Figure 1A, the catalyst layer volume 50 may be centrally located around the internal space 4, for example, with respect to at least the width (e.g., radial) dimension. For example, the catalyst layer volume 50 may be located radially inward with respect to the surrounding insulation layer 75, which includes ceramic, glass fiber, other inert or refractory materials, and / or thermal insulating materials such as a gas barrier, and may be optionally centrally located. The surrounding insulation layer 75 reduces heat loss to the surrounding environment and, according to some embodiments, allows the reactor to operate substantially adiabatically when used for synthesis gas production according to the processes described herein. Furthermore, the surrounding insulation layer 75 allows the outer shell 2 of the reactor 100 to operate such a process at a much lower temperature than the temperature inside the catalyst, thereby relaxing the maximum temperature specifications of the materials used in the reactor structure and improving the ease of handling during or before / after the operation of the reactor.

[0026] Similarly, according to the front section view shown in Figure 1A, along the page plane providing a view of the inside of the reactor after the front portion has been removed, one or more heating elements 5' extend in one direction (e.g., along a straight line without bending or curving to change direction) along the entire flow direction, which in a particular embodiment of Figure 1A is vertical. Generally, the multiple heating elements 5' can extend over, for example, at least a portion of the length of the catalyst layer volume 50 (e.g., at least about 30%, at least about 50%, at least about 70%, or at least about 90%), and this length of the catalyst layer volume 50 may be from its inlet end 6a (e.g., the vertical position corresponding to this inlet end) to its outlet end 6b (e.g., the vertical position corresponding to this outlet end), and such a length is, for example, vertical. As shown in the embodiment of Figure 1A, these heating elements 5' can extend over substantially the entire length of their total length, or over the entire length. The amount of extension across the length of the catalyst layer volume can affect the amount of heat input and the degree of temperature control to regions located above and below the axis of the catalyst layer volume.

[0027] In other embodiments, the heating elements 5' may extend in one direction, partially or completely through the catalyst layer volume, but in a direction different from the overall flow direction. For example, in the embodiment of Figure 1A, this overall flow direction may more specifically be axial with respect to the cylindrical portion of the internal space defined by the outer shell containing the catalyst layer volume 50 (and the catalyst layer itself during operation). As an example of heating elements 5' extending in a direction different from the overall flow direction, according to the embodiment shown in Figure 2A, one or more heating elements 5' may each extend in one direction over at least a portion of the width of the catalyst layer volume 50 (e.g., at least about 30%, at least about 50%, at least about 70%, or at least about 90%). This may be the width from a first periphery 6c to an opposing second periphery 6d located at a certain distance from the first periphery 6c at a coaxial position (e.g., vertical height). Such a width may be, for example, horizontal, and more specifically, it may correspond to a distance across the horizontal cross-section of the catalyst layer volume 50 where the overall flow direction is vertical. In certain embodiments, the width or portion of the heating element 5' that extends thereon may correspond to the diameter or chord length of the circular horizontal cross-section of the catalyst layer volume 50. As shown in the embodiment of Figure 2A, the heating element 5' may extend substantially or entirely over the width. The amount of extension across the catalyst layer volume width can affect the amount of heat input and the degree of temperature control in the region from the radial center of the catalyst layer volume to the region located around the radial center.

[0028] As shown in the embodiments of Figures 1A and 2A, the opposing ends of each heating element 5' may be electrically coupled to each electrical lead 7', 8' (for example, using mechanical, welded, or brazed connections). The positive lead 7' is further coupled to the positive terminal of the voltage source 25, and the negative lead 8' is further coupled to the negative terminal of the voltage source 25. As described above, the electrical leads 7', 8' generally include materials having lower resistance than the conductive material of the heating element 5', particularly metals. On the other hand, in the embodiments of Figures 1A and 2A, the positive lead 7' and negative lead 8' are typically coupled to the voltage source 25, and multiple voltage sources may be coupled to or controlled by multiple heating elements 5', respectively, or a single voltage source may be coupled to or controlled by multiple heating elements 5'. That is, according to a particular embodiment, including the particular embodiment described below, the plurality of heating elements 5' may include one or more individually controllable heating elements, for example, one or more heating elements being controlled by their individual (single) voltage sources, which are configured to supply an independent (e.g., constant or time-varying) voltage to the heating element. According to another particular embodiment, including the particular embodiment described below, the plurality of heating elements 5' may include one or more groups of individually controllable heating elements, for example, one or more groups being controlled by their individual (single) voltage sources, which are configured to supply an independent (e.g., constant or time-varying) voltage to the heating element. A typical group includes heating elements 5' extending within a common plane (e.g., a common vertical plane or a common horizontal plane that are parallel or perpendicular to the overall flow direction, respectively) or a common cylindrical plane within the reactor.

[0029] In this specification, a single heating element or group of heating elements is described to the extent that, for example, a resistive heating element can be controlled separately in relation to a voltage source. However, according to other embodiments, the same single heating element or group of heating elements can similarly be controlled separately in relation to an energy source, such as in the case of an induction heating element (e.g., an electron oscillator).

[0030] Figure 1B shows a specific embodiment according to the embodiment of Figure 1A, and in particular provides an exemplary upper cross-sectional view through the central plane A'-A that divides the reactor into upper and lower sections. The set of central heating elements 5', also shown in the front cross-sectional view of Figure 1A, is enclosed in a dashed frame for reference. Further as shown, additional heating elements 5' extending in the same direction (e.g., through the central plane A'-A) are arranged along the common chord C' of the circular cross-section of the catalyst layer volume 50. The heating elements 5' along the common chord C' shown in Figure 1B for reference are connected by thin dots, and such a common chord C' may include the diameter of the circular cross-section. With reference to the circular cross-section of the catalyst layer volume 50, one or more groups of heating elements 5' can be arranged along at least about 50%, at least about 70%, or at least about 90% of the length of their respective common chords, and this parameter affects the extent to which heat can be input and the temperature can be controlled across the horizontal cross-sectional area of ​​the entire catalyst layer volume. Accordingly, Figure 1B shows a group of heating elements (or a subset of all heating elements) along the common chord C' that can be independently controlled by each voltage source 25A, 25B, 25C, 25D, 25E, providing a specific embodiment that offers independent control of the heat input to the catalyst layer volume through these sets. These groups along the common chord C' may be characterized by extending on a corresponding common vertical plane parallel to the entire flow direction.

[0031] Figure 1C shows another specific example according to the embodiment of Figure 1A, providing an exemplary upper cross-sectional view through the central plane A'-A that divides the reactor into upper and lower sections, as shown in Figure 1B. According to this embodiment, the heating element 5' is planar (for example, in the form of a flat rectangle). It also extends not only in the axial or longitudinal dimensions (for the heating element 5' shown in Figures 1A and 1B) but also in the widthwise dimension corresponding to the dimension over which the common chord C' extends in the embodiment of Figure 1B. In the embodiment of Figure 1C, each planar heating element 5' may be controlled separately by their respective voltage sources 25A, 25B, 25C, 25D, 25E ​​to provide heat and temperature control in the same manner as described above with respect to the embodiment of Figure 1B.

[0032] Figure 1D shows another specific example according to the embodiment of Figure 1A, and, as with Figures 1B and 1C, provides an exemplary upper cross-sectional view through the central plane A'-A that divides the reactor into upper and lower sections. As shown in Figure 1B, the set of central heating elements 5', also shown in the front cross-sectional view of Figure 1A, is enclosed by a dashed frame for reference. As further shown in the embodiment of Figure 1C, additional heating elements 5' extending in the same direction (e.g., through the central plane A'-A) are positioned at a common radius R' of circles concentric with these circular cross-sections in the plane of the circular cross-sections of the catalyst layer volume 50 and the internal space 4. The heating elements 5' along the common radius R' are connected by thin dots for reference in Figure 1D, but such heating elements 5' may also include a single central heating element corresponding to radius R=0. Referring to the circular cross-section of the catalyst layer volume 50, one or more groups of heating elements 5' can be arranged with a varying radius extending outward to at least about 50%, at least about 70%, or at least about 90% of the radius of the catalyst layer volume 50, and this parameter affects the extent to which heat input and temperature control are possible at radial positions across the entire horizontal cross-sectional region of the catalyst layer volume. Accordingly, Figure 1D provides a particular embodiment showing a group of heating elements (or a subset of all heating elements) along a common radius R' that can be separately controlled by the respective voltage sources 25A, 25B, and 25C, providing independent control of the heat input to the catalyst layer volume through these groups. These groups along the common radius R' may be characterized by extending on a corresponding common cylindrical surface parallel to the entire flow direction. Thus, the heating elements can extend axially (e.g., perpendicular to the entire flow direction) along the cylindrical portion of the internal space or along the cylindrical portion of the catalyst layer volume, and such heating elements can be spaced around the circumference of the circular cross-section of the cylindrical portion. In a more specific embodiment, a separate group of heating elements extending axially along a separate cylindrical portion may be spaced radially at regular intervals (e.g., radial intervals divided by a certain distance). Alternatively, such separate groups may be spaced radially at irregular intervals, preferably providing heat input and / or temperature control toward the center or periphery of the catalyst layer volume.

[0033] Figure 1E shows another specific example according to the embodiment of Figure 1A, and, as with Figures 1B-1D, provides an exemplary upper cross-sectional view through the central plane A'-A that divides the reactor into upper and lower sections. According to this embodiment, the heating element 5' may include a single central heating element. Alternatively, or in combination, the heating element 5' may include, for example, a curved heating element (e.g., in the form of a tube), such a curved heating element is stretched not only in axial or longitudinal dimensions (as in the case of the heating element 5' shown in Figures 1A-1D) but also in circumferential dimensions corresponding to the dimensions over which the common radius R' extends in the embodiment of Figure 1D. In the embodiment of Figure 1E, the single central heating element and / or each tubular heating element 5' can be controlled separately by their respective voltage sources 25A, 25B, 25C to provide heat and temperature control in the same manner as described above with respect to the embodiment of Figure 1D.

[0034] Figure 1F shows the embodiment described above with respect to Figure 1A, where the heating element 5' is in the form of a linear segment extending in the direction shown in the embodiment of Figure 1A. In the case of a segment, the desired amount of heat can be generated only at a selected axial position of a given length across the catalyst layer volume. In the embodiment of Figure 1F, separate voltage sources (not shown) can be used to control the individual segments. Alternatively, the heating element may be configured to generate heat only in a selected axial portion, or to generate a varied amount of heat in different portions of the selected axial portion, for example, when a multi-zone heating element is used. Such embodiments allow for further temperature control in these directions using heating elements that extend longitudinally or axially. Similarly, Figure 2E shows the embodiment described above with respect to Figure 2A, where the heating element 5' is in the form of a linear segment extending in the direction shown in the embodiment of Figure 2A. Such embodiments allow for further temperature control in these directions using heating elements that extend widthwise or radially. As those skilled in the art will understand, a further advantage is that heat is generated only in selected portions of the specific heating element configuration shown in Figures 1B-1E and 2B-2D, or that different amounts of heat are generated in different portions, which can correspond to linear segments of a one-dimensionally elongated heating element or area segments of a two-dimensionally elongated heating element.

[0035] Figure 2B shows a characteristic cross-sectional view through a central plane A'-A that divides the reactor into upper and lower sections, according to a specific example of the embodiment in Figure 2A. This figure shows a set of central heating elements 5' extending along chords of a circular cross-section of the catalyst layer volume 50, where these chords include the diameter of the circular cross-section. Thus, Figure 2B provides a specific embodiment showing multiple heating elements extending within a common horizontal plane (or common cross-section of the catalyst layer volume 50), i.e., within the central plane A'-A of Figure 2A. Each element extends substantially across its entire width (e.g., chord or diameter) and is independently controllable by its respective voltage sources 25A, 25B, 25C, 25D, 25E, providing independent control of the heat input to the catalyst layer volume through these heating elements 5'. These heating elements 5' may be characterized to extend within a common horizontal plane perpendicular to the entire flow direction. Multiple similar heating elements 5' may extend horizontally and extend over at least a portion, e.g., all or substantially all, of the width of the catalyst layer volume, but may also extend in vertical or axial positions other than the central plane A'-A, e.g., above and / or below the vertical or axial position. For example, the heating elements shown in Figure 2(A) extend horizontally both above and below the axial position of the central plane A'-A.

[0036] Therefore, the heating elements may extend radially (e.g., horizontally along the chord of the circular cross-section, perpendicular to the overall flow direction) relative to the cylindrical portion of the internal space or the cylindrical portion of the catalyst layer volume, and may be spaced axially at regular intervals (e.g., axial intervals divided by a certain distance). Alternatively, such individual groups may be spaced irregularly in the axial direction, for example, to preferentially provide heat input and / or temperature control to one end of the catalyst layer volume relative to the opposite end. For example, the spacing at which heating elements are positioned closer to one end of the catalyst volume (or reactor or its internal space) may be smaller than the spacing at which heating elements are positioned closer to the opposite end. According to a particular embodiment, the spacing near the inlet end that communicates with the reformer raw material inlet 10 can be smaller than the spacing near the outlet end that communicates with the reformer product outlet 20 (regardless of whether the reactor is used in an upward flow or downward flow configuration), for example, if the spacing from the inlet end to the outlet end gradually increases. The spacing of these radially extending heating elements allows for the concentration of heat input and / or temperature control at locations where heat demand and / or reaction heat consumption or generation are generally greatest.

[0037] Figures 2C and 2D show other examples of the embodiment of Figure 2A, with other characteristic upper cross-sectional views passing through the central plane A'-A that divides the reactor into upper and lower sections. These figures show the central planar heating element 5', more specifically the central rectangular heating element in the embodiment of Figure 2C and the central circular heating element in the embodiment of Figure 2D, respectively, where each heating element extends across a portion of the circular cross-section of the catalyst layer volume 50 in the central plane A'-A. Thus, in the embodiments shown in Figures 2C and 2D, these heating elements 5' are elongated in two dimensions, i.e., in the dimensions of width and length (or depth), or in the dimensions of angle and radial direction. These planar heating elements differ from those shown in the embodiment of Figure 2B, where the heating element 5' is elongated in one dimension rather than two. These planar heating elements, unlike the heating elements shown in the embodiments of Figures 1C and 1E, are two-dimensionally elongated but have surfaces aligned substantially parallel to the entire flow direction (e.g., parallel to this direction or having elongated dimensions parallel to this direction). In view of a planar heating element 5' having a surface substantially perpendicular to the entire flow direction, such a planar heating element 5' may further include an opening 30 for accommodating a gaseous mixture flow through the catalyst layer volume, the size of which can be designed to improve the flow distribution of the gaseous mixture. In addition, similar planar heating elements may extend across a portion of the circular cross-section of the catalyst layer volume, but may extend at vertical or axial positions other than the central plane A'-A, for example, above and / or below this vertical or axial position. In this case, depending on the particular operation, the opening of the heating element 5' positioned above and / or below a given heating element 5' may be axially aligned with the opening 30 of the given heating element 5', or it may be axially offset. For example, an axially offset opening can provide a beneficial mixing effect, while an axially aligned opening can reduce pressure loss.

[0038] In yet another embodiment, the heating element may be three-dimensional, for example, in the form of a block-shaped heater that can be filled into the catalyst layer volume. For example, the elongated heating element 5' according to the embodiment of Figure 1A can be manufactured to have a considerable diameter, and the planar heating element 5' according to the embodiments of Figures 2C and 2D can be manufactured to have a considerable thickness (height in the axial dimension). In the latter case, the holes 30 are closer to catalyst tubes in a conventional reformer in which a solid block supplies heat around such a conventional reformer.

[0039] Advantageously, the electrically heated reformer reactor may be portable (e.g., by air, sea, or land), taking into consideration the possibility of compactness by using electricity as the heat source rather than hydrocarbon fuels, along with, optionally, one or more upward-flow gas treatment vessels and / or downward-flow Fischer-Tropsch (FT) synthesis reactors and other treatment equipment (e.g., upward-flow and / or downward-flow). Thus, a typical embodiment may involve transporting such reactors and optionally associated equipment to remote locations of available quantities of reformer feedstock sources that are not economically transportable and treatable at locations operating on an existing refinery scale. For example, these remote locations may include wellheads and biomass digesters that are sources of methane or other light hydrocarbons. Alternatively or additionally, in addition to upward-flow and downward-flow treatment equipment, such associated equipment may include sufficient process and treatment equipment to control, monitor, and evaluate performance. In some embodiments, a portable electric reformer and associated equipment can be fully operational when commissioned (connected) to a local source of reformer feedstock (e.g., purified or impure methane and steam), as well as electricity and possibly other utilities.

[0040] In a typical embodiment, the electric heating reforming reactor and any related equipment, particularly the processing and analysis equipment, are usually located at a distance of approximately 10 m². 3 Less than (for example, about 2m) 3 ~about 10m 3 ), typically 8m 3 Less than (for example, about 2m) 3 ~approximately 8m 3)、 often 6m 3 or less (e.g., about 2m 3 ~ about 6m 3 )、 about 10m 3 It can be contained or at least has the possibility of being contained in a container having a volume such as less than. Overall, due to the improvement in the simplicity and compactness of the electric heating reforming reactor described in this specification, it becomes advantageously possible to operate on a small scale, whereby, in some embodiments, they can be transported by, for example, trucks, ships, trains, or airplanes to suitable reformer raw materials (e.g., the mouth or source of stranded natural gas). In some embodiments, these reactors and any associated equipment can be attached to skids to facilitate their transportation.

[0041] A further advantage resulting from using multiple heating elements is the ability to compensate for possible gas flow distribution inconsistencies that can occur when the catalyst layer is perpendicular to the gas flow and has a large surface area parallel to the gas flow (e.g., a relatively large layer diameter to length ratio, or a relatively small length to diameter ratio, L / D) with respect to the axial length. For example, the use of temperature distribution control in the radial dimension can be used to detect and / or offset the effects of flow channeling. This can give the reactor design, particularly the catalyst layer volume, internal space, and the dimensions of the reactor itself, great flexibility. In some embodiments, the electric reforming reactor can be made relatively wide and short as needed by combining its respective wide and short internal space and catalyst layer volume. For example, in the case of a cylindrical reactor having at least a cylindrical central portion, the L / D and / or the internal space or catalyst layer volume of such a cylindrical portion can be less than about 10 (e.g., about 0.5 to about 10), less than about 7 (e.g., about 1 to about 7), or less than about 3 (e.g., about 1 to about 3). Modification process

[0042] Other embodiments of the present invention relate to a reforming process or a process for producing a synthesis gas product, comprising contacting reformer feedstock, comprising (i) hydrocarbons and (ii) both H2O and / or CO2, with a catalyst disposed within the catalyst layer volume of an electrically heated reforming reactor as described herein. For example, the catalyst layer volume (containing the reforming catalyst during operation) may have a plurality of heating elements extending partially or completely through it to provide a desired degree of heat input and temperature control in a desired region of the catalyst. Unlike conventional gas combustion furnaces, the heating elements can provide uniform or non-uniform heating, which is particularly tuned to a given process, feedstock, desired product and / or performance, or changing reaction parameters. Thus, a typical process includes utilizing a predetermined configuration of heating elements (e.g., the configuration described herein), supplying different heating rates to the catalyst by heating elements positioned at different radial locations, and / or supplying different heating rates to the catalyst by heating elements positioned at different axial locations. The heat input is the amount of heat that the catalyst can transfer per unit time (e.g., joules / second or watts), or the amount of heat that can be transferred per unit volume per unit time (e.g., watts / cm³). 3 Based on ), a typical process may further include contacting the raw materials with a catalyst to achieve transformation by reforming, followed by the extraction of the synthesis gas product.

[0043] Generally, heating elements positioned at different radial locations can be used to control the radial temperature distribution within the catalyst layer volume, and heating elements positioned at different axial locations can be used to control the axial temperature distribution. However, as described above, for example, when using segmented or multi-zone heating elements, it is also possible to control the axial temperature distribution using heating elements positioned at different radial locations, and / or using heating elements positioned at different axial locations. In some cases, heating elements positioned at different radial locations can be used in combination with heating elements positioned at different axial locations. For example, reforming may be performed using heating elements positioned at different radial locations or heating elements positioned at different axial locations to supply a faster heating rate (e.g., communicating with the reformer feedstock inlet) at the inlet end of the catalyst layer volume to the opposite side of the outlet end. In certain embodiments, the heat input can be increased within the range of the first 10%, the first 20%, or the first 50% of the axial length of the catalyst layer volume, relative to the heat input for the remaining axial length of the axial length of the catalyst layer volume. In particular, in endothermic reforming reactions, by controlling the axial temperature distribution, it is possible to achieve a distribution with a minimum temperature (e.g., along the centerline of the catalyst layer) that is higher than the minimum temperature obtained in a comparative baseline method where the same total heat input is uniformly supplied to the catalyst. Similar to such comparative baseline methods, the reforming process can be made substantially adiabatic by using at least partially a peripheral insulating layer surrounding the catalyst layer. Controlling the axial temperature distribution can eliminate the minimum layer temperature located downstream of the inlet end of the catalyst layer volume, for example, when the heating element provides an axial temperature distribution that steadily increases from the inlet end to the outlet end (e.g., along the centerline of the catalyst layer). In general, according to typical reforming reactions, providing a greater heat input closer to the reactor inlet than to the reactor outlet can reduce the temperature gradient, or the temperature difference between the highest and lowest temperatures in the catalyst layer (e.g., compared to the comparative baseline method described above). This can result in a higher hydrocarbon conversion rate under a given set of other equivalent process conditions.

[0044] A further important advantage of the electroheated reforming reactors described herein and related processes using these reactors is the ability to control different heat inputs over time (e.g., in a time-dependent manner) during a given process. For example, in response to various operating parameters that may change over time, including the composition of the reformer feedstock, the composition of the synthesis gas products, and / or the years or conditions of use of the catalyst, the heat input to different regions within the catalyst layer volume can be controlled to compensate for or otherwise utilize the effects of such changes. For example, the heat input can be increased at an axial position moving over time from the inlet end to the outlet end of the catalyst layer (e.g., providing the maximum heat input) to compensate for catalyst deactivation that may occur in that direction, thereby improving the overall utilization rate of the catalyst. Controlling the heat input in this manner may be based on the predicted rate of catalyst deactivation over time. Alternatively, this control may be based on temperature measurements within the catalyst layer indicating the starting position of the reforming reaction (e.g., low temperature measurements due to the start of an endothermic reaction). Or, this control may be based on measurements of other indicators of catalyst deactivation, such as pressure drop or conversion losses in the reactor or catalyst layer.

[0045] In response to changes in the reformer feedstock composition, such as H2S, or an increase in the measured concentration of other components that may be detrimental to catalytic activity, the heat input in a given region (e.g., the inlet end or near the outlet end, or possibly the central region of the catalyst layer) can be increased. In response to changes in the synthesis gas composition, such as a decrease in the measured concentration of H2, an increase in the measured concentration of hydrocarbons, or the measurement of other indicators of conversion loss, the heat input in a given region (e.g., the inlet end or near the outlet end, or possibly the central region of the catalyst layer) can be increased. In response to changes in process performance, particularly any parameter that may affect conversion (e.g., operating pressure or space velocity), the heat input in a given region (e.g., the inlet end or near the outlet end, or possibly the central region of the catalyst layer) can be increased.

[0046] According to a specific example of a reforming process or a process for producing synthesis gas products, the reformer feedstock is (i) methane and / or other hydrocarbons (e.g., CH4, C2H6, C2H4, C3H8, C3H6, C4H 10 C4H8, C5H 12 , C5H 10 (ii) any one or a mixture thereof of high molecular weight hydrocarbons, and (ii) CO2 may be included. In this regard, by dry reforming of these hydrocarbons, CO2 alone can function as an oxidizing agent to oxidize methane and / or other hydrocarbons to CO and H2, for example in the case of alkanes, which can be produced as follows: C n H 2n+2 +nCO2→2nCO+(n+1)H2

[0047] In a preferred embodiment, i.e., an embodiment in which the reformer feedstock further includes H2O, the combination of CO2 and H2O can function as an oxidizing agent. The reaction in this case is a "CO2-steam reforming reaction" further comprising steam reforming as a pathway for producing synthesis gas from methane and / or other hydrocarbons, which, for example in the case of alkanes, can be produced as follows: C n H 2n+2 +nH2O→nCO+(2n+1)H2

[0048] On the other hand, while the theoretical molar H2:CO ratio of the synthesis gas product produced from the dry reforming of methane is 1, adding steam reforming to the CO2-steam reforming of methane advantageously offers the possibility of increasing the molar ratio to a value favorable to the downflow Fischer-Tropsch synthesis for producing liquid hydrocarbons, as follows: (2n+1)H2+nCO→C n H 2n+2 +nH2O

[0049] Therefore, C4 is preferred as a liquid fuel or a component of liquid fuel. + Hydrocarbons, for example, C4~C 12It has been observed that it is preferable for hydrocarbons to be formed with a molar H2:CO ratio of approximately 2. By adjusting the relative amounts of CO2 and / or H2O as oxidants, the amounts of CO and / or H2 in the reformer feedstock, and optionally other operating parameters, and in some cases using downflow conversion (e.g., water-gas shift reaction), synthesis gas products with H2:CO ratios of approximately 0.75:1 to 5:1, for example, approximately 0.75:1 to 2.5:1, approximately 1:1 to 2.5:1, or approximately 1.7:1 to 2.3:1 can be obtained.

[0050] Accordingly, typical reforming catalysts that may be included in the catalyst layer volume of the electroheated reforming reactor described herein are suitable for catalyzing the reaction of methane and / or other hydrocarbons with CO2 and / or H2O. Certain catalysts may contain noble metals on a solid support, or two or more noble metals. The expression "on a solid support" is intended to include catalysts in which the active metal is present on the surface of the support and / or within the porous internal structure of the support. The solid support preferably contains a metal oxide, particularly cerium oxide. Based on the weight of the solid support, cerium oxide may be present in an amount of at least about 60% by weight, preferably at least about 75% by weight (e.g., relative to the total amount of metal oxides in the solid support). The solid support may contain all or substantially all combined amounts (e.g., more than about 95% by weight) of cerium oxide and one or more other metal oxides such as aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, magnesium oxide, and strontium oxide. Such other metal oxides are preferably alumina. In addition to cerium oxide and one or more other metal oxides, other components may also be present in the solid support, preferably in combined amounts representing a small portion of the solid support, such as less than about 10% by weight, less than about 5% by weight, or less than about 1% by weight. In other embodiments, the solid support may contain such other metal oxides alone or in combination with small amounts (e.g., less than about 50% by weight or less than about 30% by weight) of cerium oxide.

[0051] Precious metals are understood to be a type of metallic element that is resistant to oxidation. In typical embodiments, the catalyst may contain at least two precious metals selected from the group consisting of, for example, platinum (Pt), rhodium (Rh), ruthenium (Ru), palladium (Pd), silver (Ag), osmium (Os), iridium (Ir), and gold (Au), where, according to a particular embodiment, the term "consisting of" is used only to indicate that the precious metals are selected group members, but does not preclude the addition of other precious metals and / or other common metals. Thus, catalysts containing precious metals include catalysts containing at least two types of precious metals, catalysts containing at least three types of precious metals, and catalysts containing two types of precious metals and a third non-precious metal such as an accelerator metal (e.g., a transition metal). According to a preferred embodiment, the precious metal is present in an amount of about 0.05% to about 5% by weight, about 0.3% to about 3% by weight, or about 0.5% to about 2% by weight, based on the weight of the catalyst, or optionally, at least two precious metals are present independently in an amount of about 0.05% to about 5% by weight. For example, a typical catalyst may contain two precious metals, Pt and Rh, and Pt and Rh may be present independently in any amount within these ranges (e.g., about 0.05% to about 5% by weight). That is, Pt may be in this amount, Rh may be in this amount, or both Pt and Rh may be in this amount.

[0052] In typical embodiments, at least two noble metals (e.g., Pt and Rh) are substantially the only noble metals present in the catalyst, and the abundance or combination of any other noble metals can be less than about 0.1% by weight or less than about 0.05% by weight based on the weight of the catalyst. In even more typical embodiments, at least two noble metals (e.g., Pt and Rh) are substantially the only metals present in the catalyst, excluding metals present in the solid support (e.g., cerium present as cerium oxide in the solid support). For example, the abundance or combination of any other metals, in addition to the at least two noble metals and the metals in the solid support, can be less than about 0.1% by weight or less than about 0.05% by weight based on the weight of the catalyst. Any metals present in a catalyst containing noble metals can generally have particle sizes in the range of about 0.3 nm to about 20 nm, generally about 0.5 nm to about 10 nm, and generally about 1 nm to about 5 nm.

[0053] Precious metals can be incorporated into a solid support according to known catalyst preparation techniques, including sublimation, impregnation, or dry mixing. Impregnation is a preferred technique, and an impregnation solution of one or more soluble compounds of precious metals in a polar (aqueous) or nonpolar solvent (e.g., organic) can be brought into contact with the solid support, preferably under an inert atmosphere. Such contact can be carried out, for example, in an ambient atmosphere of nitrogen, argon, and / or helium gas, or in a non-inert atmosphere such as air, preferably under stirring. The solvent can then be evaporated from the solid support, for example, using heating, a fluidized gas, and / or vacuum conditions, leaving the precious metal-impregnated support dry. When impregnating, for example, two types of precious metals simultaneously, they can be dissolved in the same impregnation solution or impregnated separately using different impregnation solutions and contact steps. In either case, the precious metal-impregnated support may undergo further preparation steps, such as washing with a solvent to remove excess precious metal and impurities, further drying, calcination, etc., in order to provide a catalyst.

[0054] The solid support itself can be manufactured according to known methods, such as extrusion to form cylindrical particles (extruded products) or spray-drying to form oil droplets. Regardless of the specific shape of the solid support and the resulting catalyst particles (e.g., any shape such as cylindrical or spherical), as described above, the amount of noble metal present in the catalyst means the average weight of such noble metal in a given catalyst particle, regardless of the specific distribution of the noble metal in the particles. In this regard, it is understood that different preparation methods can provide different distributions, such as the noble metal being mainly supported on or near the surface of the solid support, or being uniformly distributed throughout the solid support. Generally, based on the weight of the solid support, or otherwise based on the weight of the catalyst, the weight percent described herein may mean the weight percent in a single catalyst particle, but more typically it means the average weight percent of a number of catalyst particles, such as the number in a reactor forming the catalyst layer used in the methods described herein.

[0055] For reformer feedstocks containing methane, an important source of this methane is natural gas, particularly stuck natural gas that cannot be readily converted to synthesis gas products in an economical manner using known processes. Natural gas containing relatively high concentrations of CO2, e.g., at least about 10 mol% or at least about 25 mol%, can represent a suitable methane source, as some of the catalysts described herein function well without removing CO2 upstream (e.g., by scrubbing with an amine solution). Other sources of methane for reformer feedstocks can be obtained from coal or biomass (e.g., lignocellulose or char) gasification, from biomass digesters, or as effluents from renewable hydrocarbon fuel (biofuel) production processes (e.g., pyrolysis processes such as hydrolysis processes, or fatty acid / triglyceride hydrogenation processes). Other sources of methane can be obtained from wellheads or wastewater from industrial processes, including petroleum refining processes (as refinery off-gas), power production processes, steelmaking processes or non-ferrous metal production processes, chemical (e.g., methanol) production processes or coke production processes. Process gases, which are generally known to contain hydrocarbons (e.g., C1-C3 hydrocarbons) and optionally other gaseous components such as CO2, can provide all or part of the reformer feedstock, or at least all or part of the methane component of this feedstock.

[0056] If the reformer feedstock includes methane obtained from renewable resources (e.g., biomass), such as methane obtained from a process flow obtained by hydrothermal cracking, as described in U.S. Patent No. 8,915,981, transferred to the Gas Technology Society, the processes described herein can be used to produce renewable synthesis gas products (e.g., including renewable CO) that can be further processed to provide renewable hydrocarbon-containing fuels, fuel mixture components, and / or chemicals. Thus, the reformer feedstock may include methane from non-renewable sources (e.g., natural gas) and / or methane from renewable sources (e.g., biomass), the latter of which reduces the overall carbon footprint associated with the synthesis gas products and downstream products. Natural gas and / or other methane sources for reformer feedstock can be pre-treated before reforming (e.g., dry reforming, steam reforming, or CO2-steam reforming) to remove H2S and other sulfur-containing contaminants, but this is not required.

[0057] In typical embodiments, the modification period is generally about 0.05 hours. -1 ~Approximately 10 hours -1 Typically, this takes about 0.1 hours. -1~ Approximately 4.0 hours -1 In most cases, it takes about 0.3 hours. -1~ Approximately 2.5 hours -1 This may include the weight space velocity (WHSV). As those skilled in the art will understand, WHSV is the weight flow rate of the reformer feedstock divided by the weight of the catalyst in the reactor, and represents the equivalent catalyst layer weight of the feedstock flow processed per hour. WHSV is related to the reciprocal of the residence time in the reactor.

[0058] Other reforming conditions include an average catalyst layer temperature generally between approximately 649°C (1200°F) and 816°C (1500°F), where the specific temperature of the entire catalyst layer is preferably controlled primarily by resistance or induction heating elements as described herein. The average catalyst layer temperature as described herein refers to a weighted average layer temperature that takes into account the amount or weight fraction of catalyst at a given temperature. In more specific embodiments, reforming conditions may include average catalyst layer temperatures in the range of approximately 677°C (1250°F) to 788°C (1450°F) or approximately 704°C (1300°F) to 760°C (1400°F). As mentioned above, the presence of large amounts (e.g., 100-1000 mol-ppm) of H2S and / or other sulfur-containing contaminants can, for example, ensure an increase in the average catalyst bed temperature in the range of approximately 732°C (1350°F) to approximately 843°C (1550°F) and approximately 760°C (1400°F) to approximately 816°C (1500°F) in order to maintain the desired hydrocarbon conversion rate level (e.g., above approximately 85%). Further reforming conditions may include pressures exceeding the ambient pressure, i.e., pressures higher than 0 kPa (0 psig) gauge pressure, which corresponds to an absolute pressure of 101 kPa (14.7 psia). Since the number of moles of the product produced by the reforming reaction is greater than the number of moles of the reactants, it is advantageous to balance at relatively low pressures. Therefore, the reforming conditions can generally include gauge pressures ranging from approximately 0 kPa (0 psig) to approximately 517 kPa (75 psig), typically from approximately 0 kPa (0 psig) to approximately 345 kPa (50 psig), and in many cases from approximately 103 kPa (15 psig) to approximately 207 kPa (30 psig).

[0059] The average catalyst layer temperature range given above is generally suitable for achieving conversion rates of at least about 80% (e.g., about 80% to about 99%), at least about 85% (e.g., about 85% to about 97%), or at least about 90% (e.g., about 90% to about 99%) of methane and / or other hydrocarbons (e.g., conversion of methane, conversion of C1-C3 hydrocarbon combinations, conversion of C1-C4 hydrocarbon combinations, conversion of naphtha boiling point range hydrocarbons, conversion of jet fuel boiling point range hydrocarbons, etc.) by adjusting, for example, a specific reactor or catalyst layer temperature (e.g., by using heating elements described herein to introduce more or less heat into various regions within the catalyst layer volume) and / or other reforming conditions (e.g., WHSV and / or pressure), as can be understood by knowledge acquired by those skilled in the art from this disclosure. Advantageously, the noble metal-containing catalysts described herein have sufficient activity to achieve, for example, a remarkable hydrocarbon (e.g., methane) conversion rate of at least about 85% in a stable manner at an average catalyst layer temperature of about 732°C (1350°F) or less, or about 704°C (1300°F) or less. For oxidizing reactants, at the hydrocarbon conversion rate levels described herein, the typical conversion rate for CO2 is at least about 50% (e.g., about 50% to about 75%), while the typical conversion rate for H2O is at least about 70% (e.g., about 70% to 90%). As is understood in the art, the conversion rate of a particular compound (e.g., methane) or combination of compounds (e.g., C1-C4 hydrocarbons or C1-C3 hydrocarbons) can be calculated based on the following method. 100*(X 原料 -X 生成物 ) / X 原料

[0060] Here, X 原料 is the total amount (e.g., total weight or total moles) of compound X in the reformer feed supplied to the reactor, and X 生成物is the total amount of compound X in the synthesis gas withdrawn from the reactor. In the case of a continuous process, these total amounts are more conveniently expressed as flow rate or total amount per unit time (e.g., total weight / hour or total moles / hour). Other performance criteria that can be achieved using an electric reforming reactor in combination with catalysts and reforming conditions as described herein include a high hydrogen yield, or a portion of the total hydrogen in methane and / or other hydrogen-containing compounds in the reformer feedstock supplied to the reactor (e.g., total hydrogen in hydrocarbons such as C2-C4 hydrocarbons or C2-C3 hydrocarbons) that is converted to H2 in the synthesis gas withdrawn from the reactor. In typical embodiments, the hydrogen yield is at least about 70% (e.g., about 70% to about 85%). As described above with respect to conversion, the amount supplied to and removed from the reactor can be expressed as flow rate.

[0061] In addition to the H2:CO molar ratio within the above range, typical synthesis gas products generally have a combined concentration of H2 and CO of at least about 35 mol% (or volume%) (e.g., about 35 mol% to about 85 mol%), typically at least about 50 mol% (e.g., about 50 mol% to about 80 mol%), and often at least about 60 mol% (e.g., about 60 mol% to about 75 mol%). As mentioned above, the balance of synthesis gas products may be substantially or entirely CO2 and water, depending on the conditions of such a process (e.g., reactor conditions such as average catalyst bed temperature, pressure, gravimetric space velocity, catalyst composition, etc.) and the specific dry reforming process involving the reactants or gas mixture.

[0062] In typical embodiments, CO2 is generally present in the synthesis gas product at a concentration of less than approximately 45 mol% (e.g., approximately 5 mol% to approximately 45 mol%), and typically less than approximately 35 mol% (e.g., approximately 10 mol% to approximately 35 mol%). Water can generally be present at a concentration of less than approximately 20 mol% (e.g., approximately 1 mol% to approximately 25 mol%), and typically less than approximately 15 mol% (e.g., approximately 5 mol% to approximately 15 mol%). Small amounts of unconverted hydrocarbons can also be present in the synthesis gas. For example, combinations of C1-C4 hydrocarbons (e.g., combinations of methane, ethane, propane, and butane) that can contain only C1-C3 hydrocarbons can be present at a concentration of less than approximately 5 mol%, and typically less than approximately 2 mol%.

[0063] Overall, aspects of the present invention relating to electrically heated reforming reactors and their use in processes for producing synthesis gas products offer several advantages in controlling the heat input to specific regions within the catalyst layer, thereby customizing the temperature distribution along one, two, or three dimensions, in order to achieve operational objectives and manage changes in process parameters. Other advantages of these reactors relate to their compactness, portability, and ease of operation (e.g., rapid heating and commissioning of hydrocarbon reforming), in addition to their flexibility in terms of economically manageable reformer feedstock sources (e.g., remote methane sources). Those skilled in the art who have knowledge derived from this disclosure will recognize that various modifications can be made to the disclosed reactors and methods to obtain these and other advantages without departing from the scope of the disclosure. Accordingly, it should be understood that the features of the disclosure are susceptible to modification and / or substitution without departing from the scope of aspects of the present invention. The specific embodiments shown and described herein are for illustrative purposes only and do not limit the present invention as described in the appended claims.

Claims

1. An electrically heated reforming reactor comprising an outer shell defining an internal space including a catalyst layer volume for housing a catalyst, wherein the electrically heated reforming reactor further comprises a plurality of induction heating elements extending partially or completely through the catalyst layer volume and configured for induction heating by an alternating magnetic field from an energy source, The plurality of induction heating elements include independently controllable heating elements for generating different amounts of heat at different axial positions within the catalyst layer volume. An electrically heated reforming reactor, wherein the plurality of induction heating elements are in the form of inductive wires or rods that extend axially with respect to the cylindrical portion of the internal space and are spaced apart at regular or irregular intervals in the radial direction.

2. The electrically heated reforming reactor according to claim 1, further comprising a reformer raw material inlet and a reformer product outlet configured to allow the gaseous reaction mixture to flow along the entire flow direction from the inlet end to the outlet end of the catalyst layer volume.

3. An electrically heated reforming reactor comprising an outer shell defining an internal space including a catalyst layer volume for housing a reforming catalyst, further comprising a plurality of heating elements configured to extend partially or completely through the catalyst layer volume and to heat the catalyst layer volume, An electrically heated reforming reactor, each of the aforementioned heating elements comprising a core of a conductive material surrounded by a sheath which is a copper or nickel alloy.

4. (i) hydrocarbons and (ii) H ２ O and / or CO ２ A method for producing a synthesis gas product, comprising the step of bringing a reformer raw material containing both of the above into contact with a catalyst disposed in the catalyst layer volume of an electrically heated reformer according to claim 1 or claim 2, The independently controllable heating element generates different amounts of heat on the catalyst at different axial positions, A method comprising the step of removing the synthesis gas product after contact.

5. The method according to claim 4, wherein the independently controllable heating element provides a faster heating rate at the inlet end of the catalyst layer volume to the opposite outlet end.

6. The method according to claim 4, wherein the independently controllable heating element controls the axial temperature distribution within the catalyst layer volume.

7. A method for producing a synthesis gas product, comprising the step of bringing reformer feedstock, comprising (i) a hydrocarbon and (ii) both H₂O and / or CO₂, into contact with a catalyst disposed within the catalyst layer volume having a plurality of heating elements extending partially or completely through it, The plurality of heating elements supply the catalyst with different heating rates that are controlled in a time-dependent manner. The manufacturing method further comprises the step of removing the synthesis gas product after contact.

8. The method according to claim 7, wherein the different heating rates, which are controlled in a time-dependent manner, are controlled according to the composition of the reformer raw materials, the composition of the synthesis gas product, or the number of years or conditions of use of the catalyst.

9. A method for producing synthesis gas products, The process includes the step of bringing a reformer feedstock comprising (i) a hydrocarbon and (ii) both H₂O and / or CO₂ into contact with a catalyst placed in the catalyst layer volume of the electric heating reformer described in claim 3, The method further comprises the step of removing the synthesis gas product after the contact.

10. The method according to any one of claims 7 to 9, wherein the plurality of heating elements are resistance heating elements or induction heating elements.

11. The method according to any one of claims 7 to 9, wherein the plurality of heating elements include independently controllable heating elements for generating different amounts of heat at different axial positions within the catalyst layer volume.

12. The electric heating reformer further includes a reformer raw material inlet and a reformer product outlet, wherein the reformer raw material inlet and the reformer product outlet are configured to allow the reformer raw material to flow throughout the entire flow direction from the inlet end to the outlet end of the catalyst layer volume, The plurality of heating elements extend in one direction along the entire flow direction over at least a portion of the length from the inlet end to the outlet end, or The plurality of heating elements extend in one direction different from the overall flow direction. The method according to any one of claims 7 to 9.

13. The method according to any one of claims 7 to 9, wherein the catalyst layer volume is located within an internal space defined by the outer shell of the electric heating reformer, and the plurality of heating elements extend axially with respect to the cylindrical portion of the internal space and are spaced apart radially at regular or irregular intervals.

14. The method according to any one of claims 7 to 9, wherein the catalyst layer volume is located within an internal space defined by the outer shell of the electric heating reformer, and the plurality of heating elements extend radially with respect to the cylindrical portion of the internal space and are spaced apart at regular or irregular intervals in the axial direction.

15. The method according to any one of claims 7 to 9, wherein the plurality of heating elements are in the form of resistant or inductive wires or rods.

16. The method according to any one of claims 7 to 9, wherein one of the plurality of heating elements extends through the center of the catalyst layer volume.

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