Catalyst on a balumonite-type support for catalysis of

Abstract

The present disclosure provides a catalytic material having a catalyst supported by a support of the hibonite type. The catalytic materials include a first catalytic material comprising an oxidative coupling methane catalyst for oxidative coupling of methane and a second selective oxidation catalytic material comprising a selective oxidation catalyst that preferentially oxidizes hydrogen and carbon monoxide relative to methane. Also provided are systems comprising the first and second catalytic materials for performing OCM reactions using a low temperature feed gas mixture, and methods of making C2 + compounds using the same.

Description

BACKGROUND TECHNICAL FIELD

[0002] The present disclosure relates generally to supported catalysts, and more particularly to catalysts on hibonite-type supports that can be used in a variety of catalytic reactions, such as the oxidative coupling of methane to produce C2 hydrocarbons. 2+

[0003] Description of the Prior Art Catalysis is the process by which the rate of a chemical reaction is increased or decreased by a catalyst. Positive catalysts lower the rate-limiting free energy change to the transition state, and thus increase the speed of a chemical reaction at a given temperature. Negative catalysts have the opposite effect. Substances that increase the activity of a catalyst are called promoters or activators, while substances that deactivate a catalyst are called catalytic poisons or deactivators. Unlike other reagents, catalysts are not consumed by the chemical reaction, but rather participate in multiple chemical transformations. In the case of positive catalysts, the catalyzed reaction typically has a lower rate-limiting free energy change to the transition state than the corresponding uncatalyzed reaction, resulting in an increased reaction rate at the same temperature. Thus, at a given temperature, positive catalysts tend to increase the yield of desired products while decreasing the yield of undesirable side products. While catalysts are not consumed by the reaction itself, they can be inhibited, deactivated, or destroyed by secondary processes, leading to a loss of catalytic activity.

[0004] Catalysts are often characterized as being either heterogeneous or homogeneous. Heterogeneous catalysts exist in a different phase than the reactants (e.g., solid metal catalyst and gaseous reactants), and the catalytic reaction typically occurs on the surface of the heterogeneous catalyst. Thus, in order for the catalytic reaction to occur, the reactants must diffuse to and / or adsorb onto the catalyst surface. This transport and adsorption of the reactants is often the rate-limiting step in heterogeneous catalytic reactions. Heterogeneous catalysts are also typically easy to separate from the reaction mixture by conventional techniques such as filtration or distillation. For example

[0005] One heterogeneous catalytic reaction with commercial potential is the oxidative coupling of methane (OCM) to ethylene: 2CH4+ O2 à C2H4 + 2H2O. See, for example, Zhang, Q., Journal of Natural Gas Chemistry ​​., 12:81, 2003; Olah, G. "Hydrocarbon Chemistry", 2nd Edition, John Wiley & Sons (2003). The reaction is exothermic (AH = -67 kcal / mole) and generally shows up at very high temperatures (>700°C). OCM processes include both a heterogeneous catalytic step involving the activation of oxygen and methane on the surface of a catalyst to generate methyl radicals (CH3·) and a homogeneous gas phase step involving the coupling of methyl radicals with ethane (C2H6) followed by dehydrogenation to ethylene (C2H4). The activation of O2 on the surface of the catalyst to the desired species is the key step that controls the activation of methane to methyl radicals and the subsequent oxidative dehydrogenation of ethane.

[0006] The use of heterogeneous catalysts, such as in OCM reactions, presents a number of challenges, particularly on a commercial scale. Commercial catalytic processes must be able to achieve high conversion of the reactant (hydrocarbon) feedstock at high gas hourly space velocities. However, when using a fixed bed of heterogeneous catalyst, the pressure drop across the catalyst bed prevents operation at the high gas space velocities required for industrial operation. Additionally, many commercially important catalytic reactions, such as OCM, are exothermic, and controlling the exotherm (hot spots) within the catalyst bed can be difficult. Finally, many commercially important heterogeneous catalysts contain expensive and / or rare metals, so methods to reduce the amount of catalyst used for a given process are often desirable. For example That is To address these challenges, many heterogeneous catalysts are used in conjunction with a support. The use of a support provides certain advantages. For example, the support provides a surface on which the catalyst can spread, increasing the effective surface area of the catalyst and reducing the required catalyst loading. The support can also interact synergistically with the catalyst to enhance the catalytic performance of the catalyst.

[0007] Due to the high bond strength (bond dissociation energy) of the tetrahedral C-H bond in methane, the OCM process occurs under conditions of high temperature (typically between 650°C and 950°C), high pressure, and / or high water vapor pressure. Long exposure to high temperatures, combined with large amounts of oxygen and sometimes steam, can cause the catalyst to deactivate by sintering through the support. Thus, there is a continuing need for high activity and robust supported OCM catalysts that can control the exotherm and improve the yield and selectivity in methane oxidative coupling.

[0008] Due to the high bond strength (bond dissociation energy) of the tetrahedral C-H bond in methane, the OCM process occurs under conditions of high temperature (typically between 650°C and 950°C), high pressure, and / or high water vapor pressure. Long exposure to high temperatures, combined with large amounts of oxygen and sometimes steam, can cause the catalyst to deactivate by sintering through the support. Thus, there is a continuing need for high activity and robust supported OCM catalysts that can control the exotherm and improve the yield and selectivity in methane oxidative coupling. SUMMARY

[0009] ​Briefly, disclosed are catalytic materials comprising a catalyst supported on a brownmillerite-type support for methane oxidative coupling (OCM), catalytic materials comprising a catalyst supported on a brownmillerite-type support for selective oxidation of hydrogen and / or carbon monoxide relative to methane, OCM reactors, and methods of using such catalytic materials.

[0010] In one aspect, provided herein is a catalytic material for methane oxidative coupling (OCM) comprising: a support comprising an alkaline earth metal hexaaluminate and an OCM catalyst in contact with the support. The OCM catalyst comprises a rare earth oxide and at least one dopant.

[0011] Also provided is a method of using such catalytic material in an OCM reaction.

[0012] In one aspect, provided herein is a catalytic material for selective oxidation of at least hydrogen relative to methane comprising: a support comprising an alkaline earth metal hexaaluminate and a selective oxidation catalyst (SOC) in contact with the support. The SOC comprises a noble metal.

[0013] Also provided is a method of using such catalytic material in a catalytic selective oxidation reaction.

[0014] In one aspect, provided herein is a method for methane oxidative coupling (OCM). The method comprises introducing a gaseous mixture comprising methane, oxygen, and hydrogen into a reactor, wherein the reactor comprises a selective oxidation catalytic material and an OCM catalytic material; contacting the gaseous mixture with the selective oxidation catalytic material to combust hydrogen in the gaseous mixture and generate a heated gaseous mixture having a temperature capable of initiating an OCM reaction, the selective oxidation catalytic material comprising a selective oxidation catalyst (SOC) in contact with a first support; and contacting the heated gaseous mixture with the OCM catalytic material to initiate an OCM reaction and produce an OCM effluent comprising C 2+ compounds, the OCM catalytic material comprising an OCM catalyst in contact with a second support. At least one of the first support and the second support comprises an alkaline earth metal hexaaluminate. 2+

[0015] These and other aspects of the invention will become evident upon reference to the following detailed description. To that end, various references are set forth herein which describe in more detail certain background information, procedures, compounds, and / or compositions, and each such reference is incorporated by reference in its entirety. BRIEF DESCRIPTION OF DRAWINGS

[0016] ​In the drawings, the size and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the dimensions of some of the elements can be exaggerated relative to other elements to improve understanding of the illustrations. Furthermore, certain specific shapes, structures, and features are shown in the drawings as examples and are not meant to be limiting. The same reference numerals in different drawings represent the same element, and hatched regions indicate elements that interact with each other.

[0017] Figures 1A-1D A top view of an exemplary carrier shape is illustrated in accordance with embodiments of the present disclosure.

[0018] Figure 2A A side view depiction of a carrier in accordance with embodiments of the present disclosure.

[0019] Figure 2B An end view showing the top of a carrier in accordance with embodiments of the present disclosure.

[0020] Figure 3 Methane oxidative coupling reactions at the surface of a metal oxide catalyst are schematically depicted.

[0021] Figure 4 An exemplary system for methane oxidative coupling is illustrated in accordance with embodiments of the present disclosure.

[0022] Figure 5 An exemplary system for methane oxidative coupling is illustrated in accordance with embodiments of the present disclosure.

[0023] Figure 6 An exemplary system for methane oxidative coupling is illustrated in accordance with embodiments of the present disclosure.

[0024] Figure 7 Comparative hydrothermal stability results for a brownmillerite supported catalyst and an alpha-alumina supported catalyst in methane oxidative coupling are shown.

[0025] Figure 8 Combustion selectivity of a brownmillerite supported platinum catalyst in a selective oxidation reaction in accordance with embodiments of the present disclosure is shown.

[0026] Figure 9 Comparative combustion selectivity of a gamma-alumina supported platinum catalyst in a selective oxidation reaction in accordance with embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0027] In the following description, certain specific details are set forth in order to provide a thorough understanding of various embodiments. However, one skilled in the art will understand that the application can be practiced without these details. In other instances, well-known structures have not been described in detail in order to avoid unnecessarily obscuring the description of the embodiments. Unless the context requires otherwise, throughout the specification and claims which follow, the word "comprise" and variations thereof, such as "comprises" and "comprising," are to be construed in an open, inclusive sense, that is, as "including, but not limited to." Further, the headings provided herein are merely for convenience and do not interpret the scope or meaning of the claimed application.

[0028] References in the specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase "in one embodiment" or "in an embodiment" in various places in the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In addition, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. It should also be noted that the term "or" is generally employed in its sense including "and / or" unless the content clearly dictates otherwise.

[0029] Definitions As used herein, and unless the context dictates otherwise, the following terms have the meanings indicated below.

[0030] "Catalyst" means a substance that alters the rate of a chemical reaction. A catalyst can increase the rate of a chemical reaction ( That is "positive catalyst") or decrease the rate of a reaction ( That is "negative catalyst"). A catalyst participates in a reaction in a cyclical manner, such that the catalyst is regenerated in a cycle. "Catalyze" means to have the properties of a catalyst.

[0031] "Catalytic material" means a plurality of catalyst particles in combination with a carrier.

[0032] "Extrudate" means a material in a semi-solid state that is prepared by forcing such material through a die or opening of appropriate shape. Extrudates can be prepared into various shapes and structures by conventional methods known in the art.

[0033] "Granules" or "pressed granules" mean a material in a semi-solid state that is prepared by applying pressure to the material ( That is, compressed) into a desired shape. Pellets having a variety of sizes and shapes can be prepared according to conventional techniques in the art.

[0034] A "monolith" or "monolithic support" is generally a structure formed from a single structural unit, preferably having channels disposed therethrough in an irregular or regular pattern, with porous or non-porous walls separating adjacent channels. Examples of such monolithic supports include, For example , ceramic or metallic foam-like or porous structures. The single structural unit can be used in place of or in addition to conventional particulate or pelletized form For example , pellets or extrudates). Monoliths generally have a porosity fraction in the range of about 60% to 90% and a flow resistance that is significantly less than the flow resistance of a packed bed of similar volume For example , about 10% to 30% of the flow resistance of a packed bed of similar volume.

[0035] "Active" or "catalytically active" refers to a catalyst that has significant activity in a reaction of interest. For example, in some embodiments, a catalyst has OCM activity That is , a selectivity for C2 of 5% or more and / or a methane conversion of 5% or more in an OCM reaction.

[0036] "Light-off temperature" is the temperature at which a catalyst or catalytic material has sufficient catalytic activity to initiate a desired reaction. In certain embodiments, For example , for an exothermic reaction like OCM, the light-off temperature is at a sufficient level to not only allow initiation of the catalytic reaction, but to proceed at a rate that is self-sustaining in heat, For example , generating sufficient thermal energy to maintain the reaction temperature at or above the initiation temperature.

[0037] "Dopant" is a compound added to or incorporated into a catalyst base material to optimize catalytic performance For example , increase or decrease catalytic activity. A doped catalyst can increase or decrease the selectivity, conversion, and / or yield of a reaction catalyzed by the catalyst compared to the undoped catalyst. A dopant that increases catalytic activity is referred to as a "promoter", while a dopant that decreases catalytic activity is referred to as a "poison". Dopants can be present in the catalyst in any form and can be derived from any suitable elemental source For example , chloride, bromide, iodide, nitrate, oxynitrate, oxyhalide, acetate, formate, hydroxide, carbonate, phosphate, sulfate, alkoxide, etc.).

[0038] When used in the context of catalyst dopants, "atomic percentage" (at% or at / at) or "atomic ratio" refers to the ratio of the total number of dopant atoms to the total number of non-oxygen atoms in the base material. For example, the atomic percentage of the dopant in a strontium-doped La₂O₃ catalyst is calculated by dividing the total number of strontium atoms by the sum of the total number of lanthanum atoms and multiplying by 100. That is The percentage of dopants is determined by (Sr atoms / La atoms) x 100.

[0039] "Metal salts" include metal acids and salts of metal acids.

[0040] "Conversion rate" refers to the mole fraction of reactants that are converted into one or more products. That is ,percentage).

[0041] "Selectivity" refers to the percentage of reactants that are converted into a specific product. For example C2 selectivity is the percentage of methane converted to form ethane and ethylene; C3 selectivity is the percentage of methane converted to form propane and propylene; CO selectivity is the percentage of methane converted to form CO. 2+ Selectivity is the sum of C2 selectivity and C3 selectivity.

[0042] "Yield" is a measure of the product obtained relative to the theoretically maximum yield that can be obtained. For example (Percentage). Yield is calculated by dividing the amount of product obtained in moles by the theoretical yield in moles. The yield percentage is calculated by multiplying that value by 100. C2 yield is defined as the sum of the molar flow rates of ethane and ethylene at the reactor outlet multiplied by 2 and divided by the molar flow rate of methane at the inlet. C3 yield is defined as the sum of the molar flow rates of propane and propylene at the reactor outlet multiplied by 3 and divided by the molar flow rate of methane at the inlet. 2+ The yield is the sum of the C2 and C3 yields. The yield can also be calculated by multiplying the methane conversion by the relevant selectivity; for example, the C2 yield equals the methane conversion multiplied by the C2 selectivity.

[0043] The “C2” yield is the combined yield of ethane and ethylene.

[0044] The “C2” selectivity is the combined selectivity of ethane and ethylene.

[0045] "Oxide" refers to a metallic compound containing oxygen. Examples of oxides include, but are not limited to, metal oxides (M... x O y ), metal halide oxides (M) x O y X z Metal oxynitrates (M) x O y (NO3)x ), metal phosphates (M) x (PO4) y ), where x, y, and z are numbers from 1 to 100.

[0046] "Mixed oxides" or "mixed metal oxides" refer to compounds containing two or more metal oxides and oxygen. That is M1 x M2 y O z In this model, M1 and M2 are the same or different metallic elements, O represents oxygen, and x, y, and z are numbers from 1 to 100. Mixed oxides can contain metallic elements in various oxidation states and can contain more than one type of metallic element. Mixed oxides containing 2, 3, 4, 5, 6, or more metallic elements can be represented in a similar manner. Mixed oxides also include hydroxyl oxides (…). For example M x O y OH z Where M is a metallic element, O is oxygen, x, y, and z are numbers from 1 to 100, and OH is a hydroxyl group. Mixed oxides can be represented in this paper as M1-M2, where M1 and M2 are each independently metallic elements.

[0047] "Rare earth oxides" refer to oxides of Group 3 elements, lanthanides, or actinides. Rare earth oxides include mixed oxides containing rare earth elements. Examples of rare earth oxides include, but are not limited to, La₂O₃, Nd₂O₃, Yb₂O₃, Eu₂O₃, Sm₂O₃, Y₂O₃, Ce₂O₃, CeO₂, Pr₂O₃, and Ln₁₂O₃. 4-x Ln2 x O6、La 4-x Ln1 x O6、La 4-x Nd x O6 (where Ln1 and Ln2 are each an independent lanthanide element, and Ln1 and Ln2 are distinct with x being a number greater than 0 and less than 4), La3NdO6, LaNd3O6, La 1.5 Nd 2.5 O6、La 2.5 Nd 1.5 O6、La 3.2 Nd 0.8 O6、La 3.5 Nd 0.5 O6、La 3.8 Nd 0.2 O6, Y-La, Zr-La, Pr-La and Ce-La.

[0048] "Catalyst precursor" refers to a catalyst support impregnated with a solution of an active metal salt but prior to the formation of metal oxides or metal elements (through catalyst calcination). Catalyst precursors are stable intermediates in the production of supported catalysts.

[0049] OCM catalytic material In one aspect, this disclosure provides a catalytic material (also referred to as "OCM catalytic material") for the oxidative coupling of methane. In some embodiments, the OCM catalytic material comprises one or more OCM catalysts combined with a support.

[0050] OCM catalysts can be any catalyst composition capable of promoting OCM reactions, such as those described in U.S. Patent Nos. 8,921,256, 8,962,517, 9,738,571, 9,751,079, and 9,956,544, the entire disclosure of which is incorporated herein by reference.

[0051] In some embodiments, the OCM catalysts disclosed herein comprise rare earth oxides ( That is (lanthanides, actinides and group 3 elements) and dopants.

[0052] Rare earth oxides may contain any rare earth element, and in some embodiments, the rare earth element is a lanthanide element, including lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), ytterbium (Yb), or yttrium (Y).

[0053] In some embodiments, rare earth oxides may include lanthanide oxides, including lanthanum oxide (La2O3), cerium(IV) oxide (CeO2), cerium(III) oxide (Ce2O3), praseodymium oxide (Pr2O3), neodymium oxide (Nd2O3), samarium oxide (Sm2O3), europium oxide (Eu2O3), gadolinium oxide (Gd2O3), ytterbium oxide (Yb2O3), yttrium oxide (Y2O3), or combinations thereof.

[0054] In some embodiments, rare earth oxides are such as La3NdO6, LaNd3O6, La 1.5 Nd 2.5 O6、La 2.5 Nd 1.5 O6、La 3.2 Nd 0.8 O6、La 3.5 Nd 0.5 O6、La 3.8 Nd 0.2Rare earth mixed oxides such as O6 or combinations thereof. Certain lanthanide mixed oxides such as lanthanum yttrium oxide (LaYO3), lanthanum zirconium oxide (La2Zr2O7), or lanthanum-cerium (La2Ce2O7) can also be used as OCM catalysts in OCM reactions.

[0055] In some embodiments, the dopant is selected from alkaline earth metals. For example, in some embodiments, the dopant is selected from beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and combinations thereof. In some more specific embodiments, the dopant is Be. In some more specific embodiments, the dopant is Ca. In some more specific embodiments, the dopant is Sr. In some more specific embodiments, the dopant is Ba. In some embodiments, the OCM catalyst may comprise Nd₂O₃ as a base material and Sr as a dopant. In some other embodiments, the OCM catalyst may comprise Nd₂O₃ as a base material and Mg as a dopant.

[0056] In some embodiments, the alkaline earth metal may be in the form of an oxide. For example, the dopant may be magnesium oxide (MgO), calcium oxide (CaO), strontium oxide (SrO), barium oxide (BaO), or a combination thereof. In some embodiments, the OCM catalyst may comprise Nd₂O₃ as the base material and SrO as the dopant. In some other embodiments, the OCM catalyst may comprise Nd₂O₃ as the base material and MgO as the dopant.

[0057] Rare earth oxides can be doped with varying amounts of alkaline earth metals to produce alkaline earth metal-doped rare earth oxides. In some embodiments, the dopant may be present in the OCM catalyst at a weight of up to 75%. For example, the rare earth oxide may be doped with about 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 35%, 40%, 45%, 50%, 55%, or 60% alkaline earth metals by weight of the OCM catalyst.

[0058] In other embodiments, the concentration of the dopant is measured in atomic percentages (at / at). In some of these embodiments, the dopant may be present in the OCM catalyst at up to 75% at / at. For example, in one embodiment, the concentration of the alkaline earth metal element ranges from 0.01% to 1% at / at, 1% to 5% at / at, 5% to 10% at / at, 10% to 20% at / at, 20% to 30% at / at, 30% to 40% at / at, or 40% to 50% at / at, such as about 1% at / at, about 2% at / at, about 3% at / at, about 4% at / at, about 5% at / at, about 6% at / at, about 7% at / at, about 8% at / at, about 9% at / at, about 10% at / at, about 11% at / at, about 12% at / at, and about 13% at / at. Approximately 14% at / at, approximately 15% at / at, approximately 16% at / at, approximately 17% at / at, approximately 18% at / at, approximately 19% at / at, or approximately 20% at / at.

[0059] The elemental composition of the OCM catalyst disclosed herein can be determined by inductively coupled plasma mass spectrometry (ICP-MS). ICP-MS is a highly sensitive mass spectrometry method capable of determining concentrations below 10-1. 12 One-third of the components consist of a series of metals and several non-metals. ICP is based on coupling inductively coupled plasma, which is the method for generating ions (ionization), with a mass spectrometer, which is the method for separating and detecting ions. The ICP-MS method is well known in the art.

[0060] The amount of OCM catalyst in the OCM catalytic material can vary, for example, from 1 to 5 wt%, from 5 to 15 wt%, from 15 to 25 wt%, from 25 to 35 wt%, from 35 to 45 wt%, or from 45 to 55 wt%. In some embodiments, the OCM catalyst is present in amounts of about 5 wt%, about 10 wt%, about 12.5 wt%, about 15 wt%, about 17.5 wt%, or about 20 wt%.

[0061] The OCM catalyst is disposed on and / or impregnated in a support. In some embodiments, the OCM catalyst is impregnated in a support. In some embodiments, the support is a calcareous aluminate support. In some embodiments, the calcareous aluminate support comprises an alkaline earth metal hexaaluminate, such as calcium hexaaluminate (CaAl). 12 O 19 Barium hexaaluminate (BaAl) 12 O 19 ) or SrAl 12 O19 ).

[0062] In some embodiments, the carrier comprises black aluminum calcium stone (CaAl) 12 O 19 The catalyst comprises SrO-doped Nd₂O₃ supported on alumina. In some other embodiments, the support comprises alumina, and the catalyst comprises MgO-doped Nd₂O₃ supported on alumina.

[0063] The carriers according to this disclosure can be provided in any quantity or form. In some embodiments, the carriers can be provided in the form of aggregated particles. ， For example, granules or extrudates. In some other embodiments, the carrier may be provided in a monolithic form. For example The carrier can be in the form of blocks, honeycomb, foil, mesh, etc. In some embodiments, the carrier is provided in the form of extruded or granulated cylinders, spheres, rods, trefoil, tetralobes, rings, annular shapes, stars, wheels, or strips.

[0064] In some embodiments, the carrier has a non-mosaic shape. A non-mosaic shape is advantageous in the embodiments of this disclosure because the resulting catalytic material cannot be tightly packed together, and void spaces remain between the individual formed parts. For example, the non-mosaic shape can be circular, elliptical, or polygonal (regular or irregular) in a top view.

[0065] In some embodiments, the non-tessellated shape is circular ( For example , Figure 1A In some embodiments, the circle has a diameter ranging from about 5 mm to 30 mm, for example, about 5 mm to about 10 mm, about 10 mm to about 20 mm, or about 20 mm to about 30 mm. In some more specific embodiments, the diameter of the circle is 5 mm, 8 mm, 10 mm, 12 mm, 14 mm, 16 mm, 18 mm, 20 mm, 22 mm, 22 mm, or 26 mm.

[0066] In other embodiments, the non-tessellated shape is elliptical ( For example , Figure 1B In some embodiments, the ellipse has a large diameter ranging from about 10 mm to about 30 mm and a small diameter ranging from about 5 mm to about 20 mm. In other embodiments, the ellipse has a large diameter ranging from about 20 mm to about 30 mm and a small diameter ranging from about 6 mm to about 18 mm. For example, in some more specific embodiments, the large diameter ranges from about 22 mm to about 26 mm, and the small diameter ranges from about 10 mm to about 14 mm.

[0067] In some embodiments, the non-tessellated shape is a polygon ( For example , Figure 1C The polygon can be an irregular polygon or a regular polygon. In some embodiments, the polygon has an effective diameter ranging from about 5 mm to about 50 mm, for example, from about 5 mm to about 10 mm, from about 10 mm to about 20 mm, from about 20 mm to about 30 mm, from about 30 mm to about 40 mm, or from about 40 mm to about 50 mm. In some more specific embodiments, the effective diameter ranges from about 22 to 26 mm. In some embodiments, the polygon is a pentagon or a hexagon.

[0068] In some embodiments, the carrier includes rounded or chamfered edges. In some embodiments, the carrier includes grooves and / or channels on the edges. For example , Figure 1D The groove is typically a raised shape (circular) that cuts into the outer edge of the carrier. In some embodiments, the carrier includes one or more grooved edges. In some other embodiments, the one or more grooves have a diameter ranging from about 2 mm to about 10 mm, for example, about 6 mm.

[0069] Furthermore, since the pressure drop across the catalyst bed is an important factor to consider, in some embodiments, the support includes a convex surface instead of a conventional flat surface. The convex surface allows for the filling of more void volume within the catalyst bed. That is The resulting catalytic material will not be densely packed.

[0070] The carrier may include one or more pores extending through it. In some embodiments, the carrier has 1 to 12, 2 to 10, 2 to 6, 3 to 10, 3 to 6, 4 or 10, or 4 to 6 pores extending through it. In some embodiments, the pores may be positioned equally spaced and symmetrically around the cross-section of the carrier to maximize the strength of the resulting catalytic material. Thus, one pore may be centrally located, three pores may be arranged in a triangular pattern, four pores may be arranged in a square pattern, five pores may be arranged in a square pattern with a central pore, six pores may be arranged in a hexagonal pattern or a pentagonal pattern with a central pore, and so on.

[0071] Figure 2A and 2B The illustration shows a carrier 200 that can be used in this disclosure. (Reference) Figure 2A and 2B The carrier 200 is in the form of a cylinder 202 having a height C and a diameter D. One or both ends 204, 206 of the cylinder 202 are dome-shaped. In some embodiments and as shown Figure 2BAs shown, for the carrier 200, both ends 204 and 206 of the cylinder 202 are domes with convex surfaces 208. The dome ends 204 and 206 have heights A and B, which may be the same or different. In some embodiments, heights A and B are the same.

[0072] The aspect ratio of carrier 200, defined as the total height divided by the diameter, i.e. (A+B+C) / D, can be set in the range of 0.5 to 2.0 or 0.75 to 1.50 to reduce the tendency of carrier particles to stack, while providing a reduced tendency to break.

[0073] In some embodiments, the ratio of the rounded tips 204, 206 to the cylindrical portion of the carrier 200 ( That is (A+B) / C) can be set to a range of 0.4 to 3.0 or 0.5 to 2.5. The rounded ends 204 and 206 can form a segment with a circular or elliptical cross-section, and ideally have a radius R ≥ D / 2.

[0074] In some embodiments, the cylinder 202 has a height C ranging from 1 mm to 25 mm and a diameter D ranging from 4 mm to 40 mm.

[0075] In some embodiments, the carrier 200 has five symmetrically positioned holes 210 extending through it. The holes 210 have a circular cross-section.

[0076] The carrier ranges from 0.1 to 100 m 2 / g, 1 to 100 m 2 / g, 1 to 50 m 2 / g, 1 to 20 m 2 / g, 1 to 10 m 2 / g, 1 to 5m 2 / g, 1 to 4 m 2 / g, 1 to 3 m 2 / g or 1 to 2 mg 2 The BET (Brunauer, Emmett, Teller) surface area per g, as measured by nitrogen absorption. In some embodiments, the support has a surface area of ​​20 to 80 m². 2 / g BET surface area. In some embodiments, at least 50%, 60%, 70%, 80%, 90%, 95%, or 100% of the surface area of ​​the carrier can be in direct contact ( For example (Coated and / or impregnated with) OCM catalyst.

[0077] The carrier comprises a pore volume greater than about 0.1 cc / g, greater than about 0.2 cc / g, greater than about 0.3 cc / g, greater than about 0.4 cc / g, greater than about 0.5 cc / g, greater than about 0.6 cc / g, greater than about 0.7 cc / g, greater than about 0.8 cc / g, greater than about 0.9 cc / g, or greater than about 1.0 cc / g, as determined by mercury porosimetry. In some embodiments, the carrier comprises 0.2 to 0.65 cm³ / g. 3 / g pore volume.

[0078] In some more specific embodiments, the carrier has a porosity between 40% and 60%, a pore volume between 0.2 cc / g and 0.65 cc / g, and a pore size between 20 and 80 m³. 2 BET surface area between / g.

[0079] The aforementioned catalytic materials disclosed in the various embodiments herein, when used as heterogeneous catalysts in methane oxidative coupling, can achieve a C content of at least 100°C, at least 200°C, at least 300°C, at least 400°C, at least 450°C, at least 480°C, at least 490°C, at least 500°C, at least 510°C, at least 520°C, at least 550°C, at least 600°C, at least 650°C, at least 700°C, at least 750°C, at least 800°C, at least 850°C, at least 900°C, or at least 950°C, with a C content of at least 10%, at least 20%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, or at least 70%. 2+ Selective conversion of methane to C 2+ Hydrocarbons. In some embodiments, the OCM catalyst uses 35% to 85% C2O4. 2+ Selective conversion of methane to C 2+ Hydrocarbons, including 40% to 85%, 50% to 85%, and 60% to 85% C 2+ Selectivity, and also includes 70% to 85% C 2+ Selectivity.

[0080] The aforementioned catalytic materials disclosed in the various embodiments herein, when used as heterogeneous catalysts in methane oxidative coupling, are capable of converting methane to C at methane conversion rates of at least 5%, at least 8%, at least 10%, at least 12%, at least 14%, at least 15%, at least 18%, at least 20%, at least 22%, or at least 25% when used as heterogeneous catalysts in methane oxidative coupling. 2+ hydrocarbon.

[0081] The aforementioned catalytic materials disclosed in the various embodiments herein, when used as heterogeneous catalysts in methane oxidative coupling, are capable of converting methane to C2C2 in yields of at least 10%, at least 20%, at least 30%, at least 400%, at least 450%, at least 480%, at least 490%, at least 500%, at least 510%, at least 520%, at least 550%, at least 600%, at least 650%, at least 700%, at least 750%, at least 800%, at least 850%, or at least 900% at inlet temperatures of at least 100°C, at least 200°C, at least 300°C, at least 400°C, at least 450°C, at least 700°C, at least 800°C, or at least 900°C. 2+ hydrocarbon.

[0082] The aforementioned catalytic materials disclosed in the various embodiments herein, when used as heterogeneous catalysts in methane oxidative coupling, are capable of achieving at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, or at least 90% C₂ when used as heterogeneous catalysts. 2+ Selectivity.

[0083] In some more specific embodiments, when the catalyst is used as a heterogeneous catalyst in methane oxidative coupling at a temperature of at least 400°C and a pressure of at least about 2 barg, the OCM catalytic material contains at least 20% C. 2+ Selectivity.

[0084] In other, more specific embodiments, when the catalyst is used as a heterogeneous catalyst in an OCM at a temperature of at least 600°C and a pressure of at least about 8 barg, the OCM catalytic material comprises at least 20% C. 2+ Selective catalysts.

[0085] The OCM catalysts disclosed in the various embodiments herein are stable at the OCM reaction temperature after a given operating time. In some embodiments, the OCM catalysts, when used as heterogeneous catalysts in methane oxidative coupling, retain at least 90% of the C2O content after at least about 1,000 hours, at least about 2,000 hours, at least about 5,000 hours, at least about 10,000 hours, or at least about 20,000 hours. 2+ Selectivity. In some other embodiments, after using the catalyst as a heterogeneous catalyst in methane oxidative coupling at a gas space-time velocity (GHSV) for at least about 1,000 hours, at least about 2,000 hours, at least about 5,000 hours, at least about 10,000 hours, or at least about 20,000 hours, the OCM catalyst can retain at least 90% C2+ selectivity.

[0086] Preparation of OCM catalytic material In one aspect, this disclosure provides a method for preparing the above-described OCM catalytic material.

[0087] In some embodiments, OCM catalysts are prepared by mixing a base catalyst precursor and a dopant precursor in a solvent to provide a catalyst precursor solution. Examples of solvents include, but are not limited to, water, methanol, ethanol, propanol, isopropanol, butanol, tetrahydrofuran, diethyl ether, dimethoxyethane, acetonitrile, toluene, or mixtures thereof. In some embodiments, the base catalyst precursor comprises a rare earth metal salt selected from rare earth metal nitrates, rare earth metal acetates, rare earth metal citrates, rare earth metal lactates, rare earth metal carbonates, or combinations thereof. In some embodiments, the rare earth metal salt is lanthanum nitride or neodymium nitrate. In some embodiments, the dopant precursor comprises an alkaline earth metal salt selected from alkaline earth metal nitrates, alkaline earth metal acetates, alkaline earth metal citrates, alkaline earth metal lactates, alkaline earth metal carbonates, or combinations thereof. In some embodiments, the alkaline earth metal salt is strontium nitrate. In some embodiments, the catalyst precursor solution is prepared by dissolving neodymium(III) hexahydrate and strontium nitrate in DI water.

[0088] A catalyst precursor solution is applied to support particles to provide support particles comprising a base catalyst precursor and a dopant precursor. In some embodiments, the application of the catalyst precursor solution is performed by immersing the support particles in the catalyst precursor solution or by a so-called "initial wetting" impregnation, wherein the volume of the solution used is approximately equal to the pore volume of the support particles. Impregnation can be performed at ambient temperature or elevated temperature and at atmospheric pressure or elevated pressure. In some embodiments, impregnation is performed at ambient temperature ( That is It was conducted for about one hour at 20°C to 25°C and atmospheric pressure (about 1 bar absolute pressure).

[0089] After impregnation, the support particles are removed from the catalyst precursor solution and then dried and calcined to provide the OCM catalytic material of this disclosure. The drying temperature can be from 80°C to 120°C, and the drying time can be from 1 minute to 6 hours. In some embodiments, the support particles are dried in a convection oven at 110°C for approximately four hours. The oven temperature is increased from ambient temperature to 110°C at a rate of 5°C / minute. In some embodiments, the support particles are dried in stagnant air without airflow. After drying, the oven temperature is increased from the drying temperature (…) at a rate of 5°C / minute. For example The temperature is increased from 110°C to the calcination temperature. The calcination temperature can be from 400°C to 900°C, and the calcination time ranges from 5 minutes to 5 hours. In some embodiments, the catalyst carrier-impregnated carrier particles are calcined at 800°C for about 5 hours to decompose the metal salt into metal oxides. In some embodiments, calcination decomposes rare earth metal salts into rare earth oxides and alkaline earth metal salts into alkaline earth metal oxides.

[0090] After the calcination step, the support particles containing the OCM catalyst are cooled from 800°C to ambient temperature to provide a supported OCM catalyst.

[0091] During the heating, cooling, and temperature holding steps, the carrier particles may be exposed to an oxygen-containing atmosphere. The atmosphere may contain 15 mol% to 25 mol% oxygen and 75 mol% to 85 mol% nitrogen. In some embodiments, the atmosphere may be air.

[0092] The impregnation and calcination steps can be repeated once or multiple times to increase the amount of OCM catalyst on the support particles.

[0093] Systems and methods for oxidative coupling of methane using OCM catalytic material In one aspect, this disclosure provides OCM catalytic materials for improving the yield, selectivity, and / or conversion of OCM reactions.

[0094] Selective catalytic oxidative coupling of methane to ethylene ( That is The OCM reaction is illustrated by the following reaction (1):

[0095] Figure 3 The first part of the OCM reaction occurring on the surface of a metal oxide catalyst 300 is schematically shown, followed by methyl radical coupling in the gas phase. The lattice structure of metal atoms 314 and oxygen atoms 320 is shown, with dopant 324 incorporated into the lattice structure. In this reaction, methane molecules 328 bind to the active site ( For example The surface oxygen 330 is activated when hydrogen atom 334 dissociates from methane molecule 328. As a result, methyl radical 340 is generated on or near the catalytic surface. The two methyl radicals generated therefrom can couple in the gas phase to produce ethane and / or ethylene, which are collectively referred to as "C2" coupling products.

[0096] The yields of C2H4 and C2H6 are limited by further reactions in the gas phase and to some extent on the catalyst surface. Several possible reactions that occur during the oxidation of methane are shown below as reactions (2) to (8):

[0097] The OCM catalyst disclosed herein is highly active and can optionally operate at much lower temperatures. In some embodiments, the OCM catalyst disclosed herein is capable of efficiently converting methane at temperatures below 900°C, below 800°C, below 700°C, below 600°C, below 550°C, or below 500°C. That is (High yield, conversion and / or selectivity) for ethylene. In other embodiments, staged oxygen addition, designed thermal management, rapid quenching and / or advanced separation may also be used.

[0098] Therefore, one aspect of this disclosure is a method for preparing ethane and / or ethylene, comprising converting methane to ethane and / or ethylene in the presence of an OCM catalytic material as disclosed herein. The OCM reaction is typically carried out by passing a feed gas containing hydrocarbons or a mixture of hydrocarbons and oxygen through a catalyst bed containing an OCM catalytic material.

[0099] In a preferred embodiment, the hydrocarbons are a mixture of hydrocarbons, primarily methane. For example (Natural gas). The oxygen-containing gas used in this disclosure can be air, oxygen-enriched air, or oxygen. The reactant gas mixture may further contain other gases, provided that these gases do not negatively affect the reaction. Examples of such other gases include carbon dioxide, nitrogen, helium, and hydrogen. Hydrogen can be from a variety of sources, including streams from other chemical processes such as ethane cracking, methanol synthesis, or methane conversion to aromatics. Carbon dioxide can be obtained from natural gas or formed as exhaust or recirculation streams.

[0100] The exothermic heat (free energy) of the reaction follows the order of the above reactions, and due to the proximity of the active sites, it will mechanically favor the formation of ethylene, while minimizing the complete oxidation reaction that forms CO and CO2.

[0101] The important performance parameters used to measure the performance of OCM catalysts in OCM reactions are selected from the single-pass methane conversion percentage (SCR). That is The parameters include the percentage of methane converted in a single pass on the catalytic material or catalytic bed, the reaction inlet gas temperature, the reaction operating temperature, the total reaction pressure, the methane partial pressure, the gas space-time velocity (GHSV), the O2 source, the catalyst stability, and the ethylene / ethane ratio.

[0102] Typical temperatures for operating the OCM reaction according to this disclosure are 950°C or lower, 900°C or lower, 850°C or lower, 800°C or lower, 750°C or lower, 700°C or lower, 650°C or lower, 600°C or lower, 550°C or lower, 500°C or lower, 450°C or lower, or 400°C or lower. As used herein, the operating temperatures presented generally refer to the temperature immediately adjacent to the reactor inlet. As will be understood, in the absence of an integrated temperature control system, the exothermic nature of the OCM reaction can result in a temperature gradient throughout the reactor indicating the reaction progress, where the inlet temperature can range from about 400°C to about 600°C, and the outlet temperature from about 700°C to about 900°C. Typically, such a temperature gradient can range from about 100°C to about 500°C. By using a segmented adiabatic reactor with an interstage cooling system, a more complete catalytic reaction can be carried out stepwise without generating extreme temperatures. For example Temperatures exceeded 900°C.

[0103] In some embodiments, the inlet gas temperature in the OCM reaction catalyzed by the disclosed OCM catalytic material is <700°C, <675°C, <650°C, <625°C, <600°C, <575°C, <550°C, <525°C, <500°C, <490°C, <480°C, <470°C, <460°C, <450°C, <440°C, <430°C, or <420°C. In some embodiments, the reaction operating temperature in the OCM reaction catalyzed by the disclosed OCM catalytic material is (…). That isThe outlet temperature is <950℃, <925℃, <900℃, <875℃, <850℃, <825℃, <800℃, <775℃, <750℃, <725℃, <700℃, <675℃, <650℃, <625℃, <600℃, <590℃, <580℃, <570℃, <560℃, <550℃, <540℃, <530℃, <520℃, <510℃, <500℃, <490℃, <480℃, <460℃, or <450℃.

[0104] The single-pass methane conversion rate in OCM reactions catalyzed by OCM catalysts is typically >5%, >10%, >15%, >20%, >25%, >30%, >35%, >40%, >45%, >50%, >55%, >60%, >65%, >70%, >75%, or even >80%.

[0105] In some embodiments, the inlet reaction pressure in the OCM reaction catalyzed by the OCM catalytic material is >1 atm, >1.1 atm, >1.2 atm, >1.3 atm, >1.4 atm, >1.5 atm, >1.6 atm, >1.7 atm, >1.8 atm, >1.9 atm, >2 atm, >2.1 atm, >2.1 atm, >2.2 atm, >2.3 atm, >2.4 atm, >2.5 atm, >2.6 atm, >2.7 atm, >2.8 atm, >2.9 atm, >3.0 atm, >3.5 atm, >4.0 atm, >4.5 atm, >5.0 atm, >5.5 atm, >6.0 atm, >6.5 atm, >7.0 atm, >7.5 atm, >8.0 atm, >8.5 atm. atm, >9.0 atm, >10.0 atm, >11.0 atm, >12.0 atm, >13.0 atm, >14.0 atm, >15.0 atm, >16.0 atm, >17.0 atm, >18.0 atm, >19.0 atm or >20.0 atm.

[0106] In some embodiments, the methane partial pressure in the OCM reaction catalyzed by the OCM catalytic material is >0.3 atm, >0.4 atm, >0.5 atm, >0.6 atm, >0.7 atm, >0.8 atm, >0.9 atm, >1 atm, >1.1 atm, >1.2 atm, >1.3 atm, >1.4 atm, >1.5 atm, >1.6 atm, >1.7 atm, >1.8 atm, >1.9 atm, >2.0 atm, >2.1 atm, >2.2 atm, >2.3 atm, >2.4 atm, >2.5 atm, >2.6 atm, >2.7 atm, >2.8 atm, >2.9 atm, >3.0 atm, >3.5 atm, >4.0 atm, >4.5 atm, >5.0 atm, >5.5 atm. atm, >6.0 atm, >6.5 atm, >7.0atm, >7.5atm, >8.0atm, >8.5atm, >9.0atm, >10.0atm, >11.0atm, >12.0atm, >13.0atm, >14.0atm, >15.0atm, >16.0atm, >17.0 atm, >18.0 atm, >19.0 atm or >20.0 atm.

[0107] In some embodiments, the GSHV in the OCM reaction catalyzed by the OCM catalytic material is >5,000 / hour, >10,000 / hour, >15,000 / hour, >20,000 / hour, >50,000 / hour, >75,000 / hour, >100,000 / hour, >120,000 / hour, >130,000 / hour, >150,000 / hour, >200 >250,000 / hour, >300,000 / hour, >350,000 / hour, >400,000 / hour, >450,000 / hour, >500,000 / hour, >750,000 / hour, >1,000,000 / hour, >2,000,000 / hour, >3,000,000 / hour or >4,000,000 / hour.

[0108] The OCM reaction catalyzed by the disclosed OCM catalytic material can be carried out using O2 sources other than pure O2 (while still maintaining high C2+ yield, C2+ selectivity, conversion, etc.). For example, in some embodiments, the O2 source in the OCM reaction catalyzed by the disclosed OCM catalytic material is air, oxygen-enriched air, pure oxygen, oxygen diluted with nitrogen (or another inert gas), or oxygen diluted with CO2. In some embodiments, the O2 source is O2 diluted with CO2 or an inert gas (e.g., nitrogen or helium) to obtain O2 of >99%, >98%, >97%, >96%, >95%, >94%, >93%, >92%, >91%, >90%, >85%, >80%, >75%, >70%, >65%, >60%, >55%, >50%, >45%, >40%, >35%, >30%, >25%, >20%, >15%, >10%, >9%, >8%, >7%, >6%, >5%, >4%, >3%, >2%, or >1%.

[0109] The disclosed OCM catalytic materials are highly stable under the conditions required for any number of catalytic reactions (e.g., OCM reactions). The stability of OCM catalytic materials is defined as the catalyst maintaining its catalytic performance without significant degradation. For example The time duration during which C2+ yield, C2+ selectivity, or conversion decreases by >20%, >15%, >10%, >5%, or greater than 1%. In some embodiments, the OCM catalyst has the following durations under the conditions required for the OCM reaction: >1 hour, >5 hours, >10 hours, >20 hours, >50 hours, >80 hours, >90 hours, >100 hours, >150 hours, >200 hours, >250 hours, >300 hours, >350 hours, >400 hours, >450 hours, >500 hours, >550 hours, >600 hours, >650 hours, >700 hours, >750 hours, >800 hours, >850 hours, >900 hours, >950 hours, >1000 hours, > Stability over 2,000 hours, >3,000 hours, >4,000 hours, >5,000 hours, >6,000 hours, >7,000 hours, >8,000 hours, >9,000 hours, >10,000 hours, >11,000 hours, >12,000 hours, >13,000 hours, >14,000 hours, >15,000 hours, >16,000 hours, >17,000 hours, >18,000 hours, >19,000 hours, >20,000 hours, >1 year, >2 years, >3 years, >4 years, or >5 years.

[0110] In some embodiments, the ratio of ethylene to ethane in the OCM reaction catalyzed by the OCM catalytic material is >0.3, >0.4, >0.5, >0.6, >0.7, >0.8, >0.9, >1, >1.1, >1.2, >1.3, >1.4, >1.5, >1.6, >1.7, >1.8, >1.9, >2.0, >2.1, >2.2, >2.3, >2.4, >2.5, >2.6, >2.7, >2.8, >2.9, >3.0, >3.5, >4.0, >4.5, >5.0, >5.5, >6.0, >6.5, >7.0, >7.5, >8.0, >8.5, >9.0, >9.5, >10.0.

[0111] In some embodiments, the methane conversion rate in the OCM reaction catalyzed by the OCM catalytic material is greater than 5%, greater than 10%, greater than 20%, greater than 30%, greater than 40%, greater than 50%, greater than 60%, greater than 75%, or greater than 90%.

[0112] In some embodiments, the C2+ selectivity in the OCM reaction catalyzed by the OCM catalytic material is greater than 30%, greater than 35%, greater than 40%, greater than 45%, greater than 50%, greater than 55%, greater than 60%, greater than 65%, greater than 70%, or greater than 75%.

[0113] In some embodiments, the ethylene yield in the OCM reaction catalyzed by the OCM catalytic material is greater than 10%, greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%. In some other embodiments, the C content in the OCM reaction catalyzed by the OCM catalytic material is greater than 10%, greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%. 2+ The yield of hydrocarbons is greater than 5%, greater than 10%, greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%.

[0114] In various embodiments of the aforementioned method for methane oxidative coupling, a method for oxidatively coupling methane to C under adiabatic conditions is provided. 2+ A method for processing hydrocarbons, comprising passing a feed gas containing methane through a packed catalyst bed at a linear velocity of 1 m / s or higher, the packed catalyst bed comprising any OCM catalytic material described herein.

[0115] In any of the embodiments described herein, the linear velocity in the OCM method ranges from about 0.1 m / s to about 10 m / s, for example, from about 1 m / s to about 10 m / s or from about 1 to about 5 m / s. In some embodiments, the linear velocity ranges from about 2 m / s to about 10 m / s, for example, from about 2 m / s to about 4 m / s.

[0116] In other embodiments, methane is converted to C 2+ C of hydrocarbons2+ Selectivity greater than about 50%, for example, greater than about 55% or even greater than about 60%.

[0117] In some embodiments of the OCM method described herein, the method produces ethylene, which is used as a starting material to prepare downstream products of ethylene. In other embodiments of the OCM method described herein, the final product is a polymer-grade ethylene product (greater than 99 wt% ethylene, e.g., 99.96 wt% or greater).

[0118] In some embodiments, a method for oxidative coupling of methane to C 2+ The method for producing hydrocarbons involves injecting a feed gas containing methane, oxygen, and vapor into a reactor section containing the disclosed OCM catalyst. The feed gas contacts the disclosed OCM catalyst to produce hydrocarbons containing C. 2+ The gaseous products of hydrocarbons.

[0119] In such embodiments, the disclosed OCM material is capable of achieving the aforementioned C at a vapor-to-methane molar ratio of at least about 0.25:1, at least about 0.5:1, at least about 0.75:1, at least about 1:1, at least about 1.5:1, at least about 2:1, at least about 3:1, at least about 4:1, or at least about 5:1. 2+ Selectivity.

[0120] In such embodiments, the disclosed OCM catalyst is capable of achieving the above-mentioned methane conversion rates at steam to methane molar ratios greater than at least about 0.25:1, greater than at least about 0.5:1, greater than at least about 0.75:1, greater than at least about 1:1, greater than at least about 1.5:1, greater than at least about 2:1, greater than at least about 3:1, greater than at least about 4:1, or greater than at least about 5:1.

[0121] In some embodiments, the disclosed OCM catalyst can exhibit improved performance characteristics of the OCM reaction in the presence of high-temperature steam, while maintaining the minimum physical strength characteristics required for commercial operation. In other embodiments, the disclosed OCM catalyst can maintain the performance characteristics of the OCM reaction in the presence of high-temperature steam at the same level as when steam is absent in the feed gas, while maintaining the minimum physical strength characteristics required for commercial operation. In still other embodiments, the disclosed OCM catalyst can exhibit improved performance characteristics of the OCM reaction in the presence of high-temperature steam, while reducing other performance characteristics to a level lower than that of conventional catalysts.

[0122] In some embodiments, adding steam to the feed gas can increase the methane conversion on the OCM catalyst by at least about 150%, at least about 200%, at least about 250%, at least about 300%, or at least about 400%.

[0123] refer to Figure 4 This illustrates a method according to the present disclosure for using an OCM catalytic material to perform an OCM reaction to produce C. 2+ System 400 comprising compounds including ethylene (C2H4) . In some embodiments, system 400 includes an OCM reactor 410 comprising an OCM catalyst 412 of the present disclosure. In some embodiments, the OCM catalyst 412 may be stratified within the OCM reactor 410. In some embodiments, system 400 may include one or more OCM reactors 410 connected in series and / or parallel. In some embodiments, the OCM reactor 410 is an adiabatic reactor. In some embodiments, the OCM reactor 410 operates under adiabatic conditions. In some embodiments, the OCM reactor 410 is an isothermal reactor. In some embodiments, the OCM reactor 410 operates under isothermal conditions. The OCM reactor 410 can operate at pressures from 0 kPa (gauge pressure) to 2,000 kPa (gauge pressure), including pressures from 100 kPa (gauge pressure) to 2,000 kPa (gauge pressure), 250 kPa (gauge pressure) to 2,000 kPa (gauge pressure), 500 kPa (gauge pressure) to 2,000 kPa (gauge pressure), 700 kPa (gauge pressure) to 1,500 kPa (gauge pressure), and also includes pressures from 750 kPa (gauge pressure) to 1,250 kPa (gauge pressure).

[0124] like Figure 4 As shown, a gas mixture feed 420 can enter the OCM reactor 410 via a feed inlet. The gas mixture feed 420 contains methane (CH4) and oxygen (O2). In some embodiments, methane and oxygen are fed into the OCM reactor 410 via separate inlets. The gas mixture feed 420 can be formed by mixing a hydrocarbon stream 422 and an oxidant stream 424 containing oxygen. Reactants can be supplied to the OCM reactor 410 such that the reactants are mixed in the OCM reactor 410 to form a reactant mixture before contacting the OCM catalyst material 412. In some embodiments, the oxidant stream 424 is provided by an air stream or an oxygen stream generated by an air separation unit. In some embodiments, the oxidant stream 424 further contains vapor, which can be injected via line 426 or otherwise added to the oxidant stream 424. In some embodiments, the hydrocarbon stream 422 and the oxidant stream 424 are mixed in a mixing device 430.

[0125] The feed temperature should be high enough to allow the OCM reaction to ignite. In some embodiments, the gas mixture feed 420 is preheated to a temperature of 450°C to 800°C. When the heated gas mixture comes into contact with the OCM catalyst 412, it becomes activated and initiates the OCM reaction to produce a product containing C. 2+Compounds (including C2H4 and C2H6) and non-C 2+ OCM effluent 440 contains impurities (including one or more of CO, CH4, H2, and CO2). Because the OCM reaction is exothermic, the temperature at which the OCM reaction is carried out and / or maintained is typically higher than the temperature of the heated gas mixture used to activate or ignite the OCM catalyst. In some embodiments, the OCM reaction is carried out and / or maintained at temperatures from 450°C to 950°C, for example, 500°C to 950°C, 550°C to 950°C, 600°C to 950°C, 650°C to 950°C, 700°C to 950°C, 750°C to 950°C, 800°C to 950°C, 850°C to 950°C, and also includes temperatures from 875°C to 925°C. In some embodiments, the OCM catalyst 412 and the gas mixture feed 420 may be heated to approximately the same temperature. OCM effluent 440 may exit the OCM reactor 410 via product outlet 428.

[0126] Selective oxidation catalytic material One of the major hurdles to overcome in achieving a commercially viable OCM process is the high ignition and reaction temperatures required to initiate the OCM reaction. Conventional methods for conducting OCM reactions typically utilize a high-temperature furnace to preheat the reactant feed to the temperature required for ignition or "ignition" of the OCM catalyst to initiate the reaction. Operating a high-temperature furnace can be quite expensive, and because high-temperature furnaces burn fuel (… That is (Natural gas) is used to generate the required heat, thus also creating a source of emissions.

[0127] Furthermore, the reactants are fed at the high temperatures required to ignite the OCM catalyst and carry out the OCM reaction. For example Mixing reactant feeds (containing methane and oxygen) can pose potential process safety and operational problems. For example, mixing reactant feeds at high temperatures may cause the mixed reactant gases to ignite before reaching the OCM catalyst bed. This premature ignition can damage the reactor and the OCM catalyst bed. Damage to the catalyst may impair its ability to ignite and initiate the OCM reaction. Furthermore, because methane is converted to carbon dioxide and carbon monoxide instead of the desired C2O, the process may be disrupted. 2+ Premature ignition of the product-mixed reactant gas feed may reduce the selectivity of the OCM reaction. Furthermore, various process disturbances ( For example Flow disturbances and temperature deviations can lead to premature ignition of the mixed reactant gas feed. Therefore, feeding mixed reactants at the high temperatures required to ignite the OCM catalyst and carry out the OCM reaction may cause process safety issues.

[0128] In some embodiments, the OCM catalytic material can be combined with a selective oxidation catalytic material for use in an OCM reaction using a cryogenic gas mixture feed to produce C. 2+ Compounds. In some embodiments, when a selective oxidation catalyst is used in addition to the OCM catalyst of this disclosure, the OCM reaction can be carried out using a gas mixture fed at a temperature of less than or equal to 375°C, for example less than or equal to 350°C, less than or equal to 325°C, or less than or equal to 300°C. Selective oxidation catalysts can be used by avoiding contact with the gas mixture at elevated temperatures (…). For example The selective oxidation catalyst helps improve the overall safety of the OCM process by addressing the associated problems of mixing methane and oxygen at 450°C or higher. Furthermore, selective oxidation catalysts can help avoid the need for high-temperature furnaces or preheaters typically used in conventional OCM processes, thus eliminating associated furnace / preheater air emissions from the process. Additionally, selective oxidation catalysts can help promote C2+ selectivity in the OCM reaction by preferentially burning hydrogen, carbon monoxide, or both relative to methane in the gas mixture feed.

[0129] In one aspect of this disclosure, a catalytic material (also referred to as a "selective oxidation catalytic material") is provided for the selective oxidation reaction of at least hydrogen. By employing a selective oxidation catalytic material in combination with the aforementioned OCM catalytic material, this disclosure allows for OCM reactions to be carried out using a cryogenic gas mixture feed.

[0130] In some embodiments, the selective oxidation catalytic material comprises a selective oxidation catalyst (SOC) on a support. In some embodiments, the support is a black aluminum calcium stone type support comprising the aforementioned alkaline earth metal hexaaluminate. In some other embodiments, the support is silica, alumina, titanium dioxide, zirconium oxide, cerium dioxide, hafnium dioxide, cordierite, silicon carbide, aluminum hydroxide, monocalcium aluminate, tricalcium aluminate, and zeolite ( For example ZSM-5 zeolite, Y zeolite, MCM-41 zeolite).

[0131] SOC can be any catalyst composition capable of selectively or preferentially oxidizing hydrogen and / or CO relative to methane. In some embodiments, SOC comprises at least one of a metal, a metal oxide, or a mixture of metal oxides. Exemplary metals, metal oxides, and mixed metal oxides suitable for use as the SOC of this disclosure include, but are not limited to, platinum, platinum oxide, chromium, chromium(II), chromium(III), chromium(VI) oxides, copper, copper(I), copper(II), copper(III), palladium, palladium(II), cobalt, cobalt(II), cobalt(III), iron, iron(II), iron(III), manganese, manganese(II), manganese(III), gold, gold(III), cerium, cerium(IV), tin, tin(II), tin(IV), bismuth, bismuth(III), indium, indium(III), molybdenum, molybdenum(IV), molybdenum(VI), antimony, antimony(III), lanthanum, lanthanum(III), aluminum, silver, osmium, tungsten, lead, zinc, nickel, rhodium, ruthenium, thallium, tellurium, germanium, gadolinium, and Bi₂Mo₃O₃. 12 In2Mo3O 12 Al2Mo3O 12 Fe2Mo3O 12 Cr2Mo3O 12 La2Mo3O 12 Ce2Mo3O 12 Or a combination thereof.

[0132] In some embodiments, the SOC comprises at least one noble metal selected from the group consisting of silver (Ag), palladium (Pd), platinum (Pt), rhodium (Rh), ruthenium (Ru), gold (Au), iridium or osmium (Os), and combinations thereof. In some more specific embodiments, the SOC comprises palladium or platinum.

[0133] The amount of SOC in the selective oxidation catalyst can vary, for example, from about 0.001 wt% to 5 wt%, such as from about 0.001 wt% to about 0.005 wt%, from about 0.005 wt% to about 0.01 wt%, from about 0.01 wt% to about 0.05 wt%, from about 0.05 wt% to about 0.1 wt%, from about 0.1 wt% to about 0.5 wt%, from about 0.5 wt% to about 1 wt%, from about 1 wt% to about 2 wt%, from about 2 wt% to about 3 wt%, from about 3 wt% to about 4 wt%, or from about 4 wt% to about 5 wt%. In some embodiments, the SOC catalyst is present in amounts of about 0.001 wt%, about 0.002 wt%, about 0.005 wt%, about 0.008 wt%, about 0.01 wt%, about 0.02 wt%, about 0.05 wt%, about 0.1 wt%, about 0.2 wt%, about 0.5 wt%, about 1 wt%, about 1.5 wt%, about 2 wt%, about 2.5 wt%, about 3.0 wt%, about 3.5 wt%, about 4 wt%, or about 4.5 wt%, or about 5 wt%.

[0134] Preparation of selective oxidation catalytic material In one aspect, this disclosure provides a method for preparing the above-described selective oxidation catalytic material.

[0135] In some embodiments, selective oxidation catalysts are prepared by dissolving a SOC metal salt in a solvent to provide a catalyst precursor solution. Examples of solvents include, but are not limited to, water, methanol, ethanol, propanol or isopropanol, butanol, tetrahydrofuran, diethyl ether, dimethoxyethane, acetonitrile, toluene, or mixtures thereof. In some embodiments, the SOC metal salt comprises a metal chloride, a metal nitrate, a metal acetate, a metal citrate, a metal lactate, a metal carbonate, or a combination thereof. In some embodiments, the metal salt is palladium acid. In some embodiments, the catalyst precursor solution is prepared by dissolving tetraammineplatinum nitrate (Pt(NH3)4(NO3)2) in DI water.

[0136] A catalyst precursor solution is applied to support particles to provide support particles comprising a base catalyst precursor and a dopant precursor. In some embodiments, the application of the catalyst precursor solution is performed by immersing the support particles in the catalyst precursor solution or by a so-called "initial wetting" impregnation, wherein the volume of the solution used is approximately equal to the pore volume of the support particles. Impregnation can be performed at ambient temperature or elevated temperature and at atmospheric pressure or elevated pressure. In some embodiments, impregnation is performed at ambient temperature ( That is It was conducted for about one hour at 20°C to 25°C and atmospheric pressure (about 1 bar absolute pressure).

[0137] After impregnation, the support particles are removed from the catalyst precursor solution and then dried and calcined to provide the selective oxidation catalyst material of this disclosure. The drying temperature can be from 80°C to 120°C, and the drying time can be from 1 minute to 6 hours. In some embodiments, the support particles are dried in a convection oven at 110°C for approximately four hours. The oven temperature is increased from ambient temperature to 110°C at a rate of 5°C / minute. In some embodiments, the support particles are dried in stagnant air without airflow. After drying, the oven temperature is increased from the drying temperature (…) at a rate of 5°C / minute. For example The temperature is increased from 110°C to the calcination temperature. The calcination temperature can be from 400°C to 900°C, such as 400°C, 500°C, 600°C, 700°C, 800°C, or 900°C, and the calcination time ranges from 5 minutes to 5 hours. In some embodiments, the catalyst support-impregnated support particles are calcined at 600°C for about 4 hours to decompose the metal salt into metal elements.

[0138] After the calcination step, the carrier particles containing SOC are cooled from 600°C to ambient temperature to prepare supported SOC.

[0139] During the heating, cooling, and temperature holding steps, the carrier particles may be exposed to an oxygen-containing atmosphere. The atmosphere may contain 15 mol% to 25 mol% oxygen and 75 mol% to 85 mol% nitrogen. In some embodiments, the atmosphere may be air.

[0140] The impregnation and calcination steps can be repeated once or multiple times to increase the amount of SOC on the carrier particles.

[0141] Systems and methods for oxidative coupling of methane using selective oxidation and OCM catalytic material Now for reference Figure 5 This illustrates a method according to the present disclosure for using selective oxidation and OCM catalytic materials to perform OCM reactions to produce C. 2+System 500 for compounds including ethylene (C2H4) . System 500 includes an OCM reactor 510 comprising a selective oxidation catalyst 512 and an OCM catalyst 514. In some embodiments, system 500 may include one or more OCM reactors 510 connected in series and / or parallel. In some embodiments, the OCM reactor 510 is an adiabatic reactor. In some embodiments, the OCM reactor 510 operates under adiabatic conditions. In some embodiments, the OCM reactor 510 is an isothermal reactor. In some embodiments, the OCM reactor 510 operates under isothermal conditions. The OCM reactor 510 can operate at pressures from 0 kPa (gauge pressure) to 2,000 kPa (gauge pressure), including pressures from 100 kPa (gauge pressure) to 2,000 kPa (gauge pressure), 250 kPa (gauge pressure) to 2,000 kPa (gauge pressure), 500 kPa (gauge pressure) to 2,000 kPa (gauge pressure), 700 kPa (gauge pressure) to 1,500 kPa (gauge pressure), and also includes pressures from 750 kPa (gauge pressure) to 1,250 kPa (gauge pressure).

[0142] like Figure 5 As shown, the OCM reactor 510 receives a gas mixture feed 520 at its inlet. The gas mixture feed 520 comprises methane (CH4), oxygen (O2), hydrogen (H2), and carbon monoxide (CO). The gas mixture feed 520 can be formed by mixing a hydrocarbon stream 522 containing CH4, H2, and CO with an oxidant stream 524 containing O2. In some embodiments, the oxidant stream 524 is provided by an air stream or O2 stream generated by an air separation unit. In some embodiments, the oxidant stream 524 further comprises vapor, which may be injected via line 526 or otherwise added to the oxidant stream 524. In some embodiments, the hydrocarbon stream 522 and the oxidant stream 524 are mixed in a mixing device 530. The mixing device 530 can be any known device suitable for mixing a first gas stream containing hydrocarbons and a second gas stream containing oxygen, such as, for example, the mixing device described in U.S. Patent No. 3,706,534. In some aspects, the mixing device 530 includes a process line or mixing tee.

[0143] In some embodiments, the gas mixture feed 520 is introduced into the OCM reactor 510 at a temperature less than or equal to 375°C, for example, less than or equal to 350°C, less than or equal to 325°C, or less than or equal to 300°C. In some embodiments, the gas mixture feed 520 is introduced into the OCM reactor 510 at a pressure of 200 kPa (gauge pressure) to 1,400 kPa (gauge pressure), including pressures of 500 kPa (gauge pressure) to 1,200 kPa (gauge pressure), 600 kPa (gauge pressure) to 1,100 kPa (gauge pressure), 700 kPa (gauge pressure) to 1,000 kPa (gauge pressure), and also including pressures of 750 kPa (gauge pressure) to 950 kPa (gauge pressure). In some embodiments, the gas mixture feed 520 has a temperature at the inlet of the OCM reactor 510 ranging from 15°C to 375°C, including temperatures in the ranges of 15°C to 50°C, 50°C to 75°C, 75°C to 100°C, 100°C to 125°C, 125°C to 150°C, 150°C to 175°C, 175°C to 200°C, 200°C to 225°C, 225°C to 250°C, 250°C to 275°C, 275°C to 300°C, 300°C to 325°C, 325°C to 350°C, or 350°C to 375°C at the inlet of the OCM reactor 510. In some embodiments, the temperature of the gas mixture feed 520 at the inlet of the OCM reactor 510 is 15°C to 250°C. In some embodiments, the hydrocarbon stream 522 for forming the gas mixture feed 520 has a temperature of less than or equal to 375°C, including temperatures in the ranges of 15°C to 50°C, 50°C to 75°C, 75°C to 100°C, 100°C to 125°C, 125°C to 150°C, 150°C to 175°C, 175°C to 200°C, 200°C to 225°C, 225°C to 250°C, 250°C to 275°C, 275°C to 300°C, 300°C to 325°C, 325°C to 350°C, or 350°C to 375°C. In some embodiments, the oxidant stream 524 for forming the gas mixture feed 520 has a temperature in the range of 0°C to 250°C, including temperatures in the ranges of 0°C to 10°C, 10°C to 20°C, 20°C to 30°C, 30°C to 40°C, 40°C to 50°C, 50°C to 100°C, 100°C to 150°C, 150°C to 200°C, or 200°C to 250°C.

[0144] By providing the gas mixture feed 520 to the OCM reactor 510 at a relatively low temperature, embodiments of this disclosure improve the safety of the OCM process by substantially eliminating the risk of premature ignition of the gas mixture feed 520. While advantageous, the low temperature of the gas mixture feed 520 poses an obstacle to the successful execution of the OCM reaction (i.e., the minimum temperature required to ignite or activate the OCM catalyst 514 to initiate the OCM reaction). Depending on the OCM catalyst 514, at least 450°C is required. For example Ignition and initiation of the OCM reaction are achieved at a minimum temperature of 450°C to 700°C, and more typically 500°C to 700°C.

[0145] Therefore, to overcome this obstacle, embodiments of this disclosure utilize a selective oxidation catalyst 512 from a gas mixture feed 520 within a thermally heated OCM reactor 510. Upon contact with the gas mixture feed 520, the selective oxidation catalyst 512 promotes the combustion of hydrogen in the gas mixture feed 520 to generate a heated gas mixture having a temperature of at least 450°C. In some embodiments, upon contact with the gas mixture feed 520, the selective oxidation catalyst 512 promotes the combustion of hydrogen in the gas mixture feed 520 to generate a heated gas mixture having a temperature in the range of 450°C to 950°C (including temperatures in the ranges of 450°C to 500°C, 500°C to 550°C, 550°C to 600°C, 600°C to 650°C, 650°C to 700°C, 700°C to 750°C, 750°C to 800°C, 800°C to 850°C, 850°C to 900°C, or 900°C to 950°C). In some embodiments, the heated gas mixture has a temperature in the range of 500°C to 800°C. Therefore, the selective oxidation catalyst 512 can be used to create a temperature difference between the temperature of the gas mixture feed 520 at the inlet of the OCM reactor 510 and the temperature of the heated gas mixture. In some embodiments, the temperature difference ranges from 75°C to 600°C, including temperature differences ranging from 75°C to 100°C, 100°C to 150°C, 150°C to 200°C, 200°C to 250°C, 250°C to 300°C, 300°C to 350°C, 350°C to 400°C, 400°C to 450°C, 450°C to 500°C, 500°C to 550°C, or 550°C to 600°C.

[0146] By using selective oxidation catalyst 512, when the temperature of the gas mixture feed 520 is increased by self-heating, less CH4 in the gas mixture feed 520 is consumed or burned, resulting in more CH4 available to participate in the OCM reaction. Consequently, more CH4 is used to convert CH4 to C. 2+ Selectivity of the OCM reaction of the compound ( That is C 2+(Selectivity) can be maintained or improved. In some embodiments, the OCM reaction has a C content of at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, or at least 70%. 2+ Selectivity. In some embodiments, the OCM reaction has a C content of 35% to 85%. 2+ Selectivity, including 40% to 85%, 50% to 85%, and 60% to 85% C 2+ Selectivity, and also includes 70% to 85% C 2+ Selectivity.

[0147] In addition to the selective oxidation catalyst 512, the OCM reactor 510 also includes the OCM catalyst 514 of this disclosure to promote the OCM reaction to produce a product containing C. 2+ Compounds (including C2H4 and C2H6) and non-C 2+ OCM effluent 540 contains impurities (including one or more of CO, CH4, H2, and carbon dioxide (CO2). When contacted by a heated gas mixture, the OCM catalyst 514 becomes activated. That is (to achieve ignition) and initiate the OCM reaction to produce C 2+ Compounds (including C2H4 and C2H6) and non-C 2+ OCM effluent 540 contains impurities (including one or more of CO, CH4, H2, and CO2). Because the OCM reaction is exothermic, the temperature at which the OCM reaction is carried out and / or maintained is typically higher than the temperature of the heated gas mixture used to activate or ignite the OCM catalyst 514. In some embodiments, the OCM reaction is carried out and / or maintained at temperatures in the range of 450°C to 950°C, including temperatures in the ranges of 500°C to 950°C, 550°C to 950°C, 600°C to 950°C, 650°C to 950°C, 700°C to 950°C, 750°C to 950°C, 800°C to 950°C, 850°C to 950°C, and further including temperatures in the range of 875°C to 925°C. The OCM effluent 540 leaving the OCM reactor 510 will typically have a temperature corresponding to the OCM reaction temperature ( That is (450°C to 950°C) and can be directed to downstream units and / or separation subsystems for additional processing as described herein.

[0148] The selective oxidation catalyst 512 and the OCM catalyst 514 can be arranged in various ways within the OCM reactor 510. For example, in some embodiments, the OCM reactor 510 may include a first catalyst bed containing the selective oxidation catalyst 512 and a second catalyst bed containing the OCM catalyst 514 downstream of the first catalyst bed, such as... Figure 5As shown. In some embodiments, the OCM reactor 510 may include a single catalyst bed comprising at least one layer of selective oxidation catalyst 512 and at least one layer of OCM catalyst 514. In some embodiments, the OCM reactor 510 may include a single catalyst bed comprising a mixture of selective oxidation catalyst 512 and OCM catalyst 514. The OCM reactor 510 may also include one or more layers of inert material or inert material bed (not shown), which may serve as a physical support for the catalyst materials 512, 514 in the catalyst bed. Exemplary inert materials include, but are not limited to, silica, alumina, and zirconium oxide. In some embodiments, the OCM reactor 510 may include a first catalyst bed containing selective oxidation catalyst 512 and inert material (as one or more different layers or as a mixture), and a second catalyst bed containing OCM catalyst 514.

[0149] Continue to refer to Figure 5 The OCM reactor 510 may include one or more temperature elements 550 to provide an indication of the temperature within the OCM reactor 510. The temperature element 550 may be any suitable temperature measuring device, including but not limited to thermocouples and resistance temperature detectors (RTDs). Figure 5 As shown, temperature element 550 is located in selective oxidation catalyst 512 upstream of OCM catalyst 514. For example, in the case where OCM reactor 510 includes a first catalyst bed containing selective oxidation catalyst 512 and a second catalyst bed containing OCM catalyst 514, temperature element 550 is located near the end of the first catalyst bed and upstream of the second catalyst bed. In another example, in the case where OCM reactor 510 includes a single catalyst bed containing a selective oxidation catalyst layer 512 upstream of OCM catalyst layer 514, temperature element 550 is located in selective oxidation catalyst layer 512, near the interface between selective oxidation catalyst layer 512 and OCM catalyst layer 514. Temperature element 550 can be used to provide one or more signals indicating the temperature of the heated gas mixture before the heated gas mixture contacts OCM catalyst 514. Temperature element 550 can be part of a control system operable to maintain the temperature of the heated gas mixture at a desired setpoint by, for example, controlling or otherwise regulating the temperature of hydrocarbon stream 522, oxidant stream 524, or both. For example (Minimum OCM catalyst ignition temperature).

[0150] In some embodiments, examples of this disclosure include methods for using alkane ( For example (C2H6, C3H8) to generate olefins ( Example AsThe post-bed pyrolysis (PBC) unit 560 for C2H4 is located downstream of the OCM reactor 510. Figure 5 As shown. PBC unit 560 can be a separate reactor, or PBC unit 560 can be included as part of OCM reactor 510. For example The downstream section of OCM catalyst 514 in the same container). Since the OCM reaction is exothermic and generates heat, the heat generated by the OCM reaction can be used to process alkanes ( For example C2H6) cracks into olefins ( For example (C2H4). PBC unit 560 can be pyrolyzed at temperatures ranging from 600°C to 1,000°C, including temperatures ranging from 700°C to 1,000°C, 750°C to 1,000°C, 775°C to 1,000°C, and also including temperatures ranging from 800°C to 950°C.

[0151] PBC unit 560 can be used to crack additional external alkanes 565 besides those contained in OCM effluent 540. For example (C2H6, C3H8). The heat capacity in OCM effluent 540 is sufficient to crack some additional external alkane 565. The additional external alkane 565 can be provided by the process's recycle stream or a completely independent alkane source. The external alkane 565 can be heated before being injected into PBC unit 560. The external alkane 565 can be heated, for example, by heat exchange with OCM reactor 510 and / or OCM effluent 540 or another process stream. Compared to OCM effluent 540, PBC effluent 570 exits PBC unit 560 and includes a higher concentration of olefins (C2H6, C3H8). For example , C2H4) and H2.

[0152] In some embodiments, embodiments of this disclosure include injecting an ignition assembly 580 into an OCM reactor 510. The ignition assembly 580 can be any substance having a lower auto-ignition temperature than CH4, such as, for example, dimethyl ether or methanol. The ignition assembly 580 can be provided as an additional device to the OCM reactor 510. That is (Through combustion via ignition assembly 580) to increase the temperature of the gas mixture feed 520. Although Figure 5 The diagram shows that the ignition component 580 is injected directly into the OCM reactor 510. The ignition component 580 can also be added to one or more of the gas mixture feed 520, hydrocarbon stream 522, or oxidant stream 524.

[0153] Now for reference Figure 6 This illustrates a method according to the present disclosure for using selective oxidation and OCM catalytic materials to perform OCM reactions to produce C. 2+System 600 of compounds (including ethylene (C2H4)). Figure 6 The system 600 shown is similar to Figure 5 The system 500 shown, and in Figure 6 The same reference numerals are used to identify the same components. Figure 6 The system 600 shown and Figure 5 The main difference between the systems 500 shown is that the OCM reactor 610 includes a single catalyst bed containing selective oxidation catalytic materials and OCM catalytic materials.

[0154] like Figure 6 As shown, the OCM reactor 610 includes a single catalyst bed 618 comprising a selective oxidation catalyst 512 and an OCM catalyst 514. In some embodiments, the catalyst bed 618 may comprise at least one layer of selective oxidation catalyst 512 and at least one layer of OCM catalyst 514. In some embodiments, the catalyst bed 618 may comprise a mixture of selective oxidation catalyst 512 and OCM catalyst 514.

[0155] Downstream products As described above, the catalytic materials disclosed herein can be used in reactions to prepare many valuable hydrocarbon compounds. For example, in one embodiment, the catalytic materials can be used to prepare ethylene from methane via an OCM reaction. Ethylene can be converted into many different compounds, including low-density polyethylene, high-density polyethylene, dichloroethane, ethylene oxide, ethylbenzene, straight-chain alcohols, vinyl acetate, alkanes, α-olefins, various hydrocarbon-based fuels, ethanol, etc. These compounds can then be further processed using methods well known to those skilled in the art to obtain other valuable chemicals and consumer products. Propylene can be similarly converted into various compounds and consumer products, including polypropylene, propylene oxide, propanol, etc.

[0156] Therefore, in some embodiments, this disclosure provides a method for preparing downstream products of ethylene. The method comprises converting ethylene into downstream products of ethylene through oligomerization, wherein the ethylene has been prepared by an OCM reaction using either the OCM catalyst disclosed herein alone or in combination with the SOC catalyst disclosed herein. In some embodiments, the downstream product of ethylene is low-density polyethylene, high-density polyethylene, dichloroethane, ethylene oxide, ethylbenzene, ethanol, or vinyl acetate. In other embodiments, the downstream product of ethylene is a hydrocarbon fuel, such as natural gasoline or C4-C hydrocarbons. 14 Hydrocarbons include alkanes, alkenes, and aromatics. Some specific examples include 1-butene, 1-hexene, 1-octene, hexane, octane, benzene, toluene, xylene, etc.

[0157] Ethylene oligomerization into higher hydrocarbons ( For example C4-C 14This can be achieved by using any number of catalysts known to those skilled in the art. Examples of such catalysts include catalytic zeolites, crystalline borosilicate molecular sieves, homogeneous metal halide catalysts, Cr catalysts with pyrrole ligands, or other catalysts. Exemplary methods for converting ethylene into higher hydrocarbon products are disclosed in the following references: Catalysis Science & Technology (2011), 1(1), 69-75; Coordination Chemistry Reviews (2011), 255(7-8), 861-880; Eur. Patent Application (2011), EP 2287142 A1 20110223; Organometallics (2011), 30(5), 935-941; Designed Monomers and Polymers (2011), 14(1), 1-23; Journal of Organometallic Chemistry 689 (2004) 3641–3668; Chemistry--A European Journal (2010), 16(26), 7670-7676; Acc. Chem. Res. 2005, 38, 784-793; Journal of Organometallic Chemistry, 695(10-11): 1541-1549 May 15 2010; Catalysis Today, Vol. 6, No. 3, January 1990, pp. 329-349; U.S. Patent Nos. 5,968,866; 6,800,702; 6,521,806; 7,829,749; 7,867,938; 7,910,670; 7,414,006 and Chem. Commun., 2002, 858–859, each of which is incorporated herein by reference in its entirety.

[0158] The following examples are provided for illustrative purposes and not for limitation.

[0159] Example Example 1 Preparation of SrO / Nd2O3 OCM catalyst supported on black aluminum calcium silicate To prepare this SrO-doped Nd2O3 OCM catalyst contained on a black aluminum calcium silicate support of 15.0 wt% Nd2O3-0.5 wt% SrO, the surface area of ​​the black aluminum calcium silicate particles was measured by BET (Brunauer, Emmett, Teller) measurement, and the pore volume was measured by mercury porosimetry (MIP). The average pore volume of the black aluminum calcium silicate particles was calculated, and the amount of catalyst precursor solution that could be absorbed by the black aluminum calcium silicate particles was estimated. Next, a catalyst precursor solution was prepared at room temperature by dissolving neodymium(II) nitrate hexahydrate (177.8 g) and strontium nitrate (4.19 g) in deionized (DI) water (100 ml). The catalyst precursor solution was stirred until the neodymium(II) nitrate hexahydrate and strontium nitrate were completely dissolved. 42.28 g of black aluminum calcium silicate granules were placed in a wire basket and immersed in a catalyst precursor solution for one hour, allowing approximately 11 ml of the catalyst precursor solution to be absorbed by the black aluminum calcium silicate granules. The immersed granules were then transferred from the basket to a ceramic crucible and dried in a convection oven by increasing the oven temperature from ambient temperature to 110°C at a rate of 5°C / min and maintaining this temperature at 110°C for 4 hours in stagnant air (no airflow). Subsequently, the temperature of the convection oven was increased from 110°C to 800°C at a rate of 5°C / min. The immersed black aluminum calcium silicate granules were calcined in the convection oven by maintaining this temperature at 800°C for 5 hours and then cooled to room temperature at a rate of 20°C / min. The SrO / Nd₂O₃ impregnated black aluminum calcium silicate granules were ground and sieved to a particle size range of 200 μm to 500 μm.

[0160] Example 2 Hydrothermal stability of SrO / Nd2O3 OCM catalysts supported on calcite The hydrothermal stability of the SrO / Nd₂O₃ OCM catalyst supported on calcareous alumina in Example 1 was tested in a 2 mm reactor. After loading the calcareous alumina-supported OCM catalyst into the reactor, the reactor was heated to 700 °C. A gaseous mixture consisting of approximately 63 mol% CH₄, 7.1 mol% O₂, and 25 mol% H₂O, with the remainder being He, was fed at a rate of 6167 h⁻¹. -1 The catalyst bed is filled with air velocity (GHSV) and pressure of 8 barg.

[0161] Figure 7 The comparison of the hydrothermal stability of OCM catalysts supported on calcareous alumina and α-alumina supported on time of operation (TOS) is shown. Figure 7As shown, the calcareous alumina-supported OCM catalyst of this disclosure exhibits higher hydrothermal stability than the α-alumina-supported OCM catalyst. For the α-alumina-supported OCM catalyst, the methane conversion efficiency rapidly decreases after 670 minutes of exposure to the gas mixture feed. In contrast, the methane conversion efficiency of the calcareous alumina-supported OCM catalyst remains the same after 770 minutes of exposure to the gas mixture feed.

[0162] Example 3 Preparation of 0.2 wt% Pt-black aluminum calcium stone selective oxidation catalyst To prepare this selective oxidation catalyst containing Pt at a level of 0.2 wt% on a ferruginous alumina support, the surface area of ​​the ferruginous alumina particles was measured by BET (Brunauer, Emmett, Teller) measurement, and the pore volume was measured by mercury intrusion porosimetry (MIP). The average pore volume of the ferruginous alumina particles was calculated, and the amount of catalyst precursor solution that could be absorbed by the ferruginous alumina particles was estimated. Next, the catalyst precursor solution was prepared by dissolving hexachloroplatinic acid (3.18 g) in DI water (150 ml). The catalyst precursor solution was stirred until the hexachloroplatinic acid was completely dissolved. Ferrous alumina particles (199.6 g) were placed in a wire basket, which was then immersed in the catalyst precursor solution for one hour, allowing approximately 51 ml of the catalyst solution to be absorbed by the ferruginous alumina particles. The doped ferruginous alumina particles were then transferred from the basket into a ceramic crucible. Pt-impregnated black aluminum calcium carbonate granules were dried in a convection oven by raising the temperature from ambient temperature to 110°C at a heating rate of 5°C / min and maintaining it at 110°C for 4 hours in stagnant air (no airflow). Subsequently, the temperature of the convection oven was raised from 110°C to 600°C at a heating rate of 5°C / min. The impregnated black aluminum calcium carbonate granules were calcined in the convection oven by maintaining them at 600°C for 5 hours and then cooled to room temperature at a rate of 20°C / min. The Pt-impregnated black aluminum calcium carbonate granules were ground and sieved to a particle size range of 200 μm to 500 μm.

[0163] Example 4 Preparation of 0.1 wt% Pt-black aluminum calcium stone selective oxidation catalyst To prepare this selective oxidation catalyst containing Pt at a level of 0.1 wt% on a ferruginous alumina support, the surface area of ​​the ferruginous alumina particles was measured by BET (Brunauer, Emmett, Teller) measurement, and the pore volume was measured by mercury intrusion porosimetry (MIP). The average pore volume of the ferruginous alumina particles was calculated, and the amount of catalyst precursor solution that could be absorbed by the ferruginous alumina particles was estimated. Next, the catalyst precursor solution was prepared by dissolving hexachloroplatinic acid (3.18 g) in DI water (150 ml). The catalyst precursor solution was stirred until the hexachloroplatinic acid was completely dissolved. Ferrous alumina particles (199.8 g) were placed in a wire basket, which was then immersed in the catalyst precursor solution for one hour, allowing approximately 51 ml of the catalyst solution to be absorbed by the ferruginous alumina particles. The immersed ferruginous alumina particles were then transferred from the basket into a ceramic crucible. The impregnated black aluminum calcium carbonate granules were dried in a convection oven by raising the temperature from ambient temperature to 110°C at a heating rate of 5°C / min and maintaining it at 110°C for 4 hours in stagnant air (no airflow). Subsequently, the temperature of the convection oven was raised from 110°C to 600°C at a heating rate of 5°C / min. The impregnated black aluminum calcium carbonate granules were calcined in the convection oven by maintaining them at 600°C for 5 hours and then cooled to room temperature at a rate of 20°C / min. The Pt-impregnated black aluminum calcium carbonate granules were ground and sieved to a particle size range of 200 μm to 500 μm.

[0164] Example 5 Effect of catalyst support on combustion selectivity The effect of catalyst support on combustion selectivity was evaluated using Pt SOC supported on black alumina and, in contrast, Pt SOC supported on γ-alumina. The reactor was heated to 250 °C during hydrogen combustion. A gaseous mixture consisting of approximately 73.3 mol% CH4, 12.1 mol% O2, 4.5 mol% H2, and 3.7 mol% CO, with the remainder being He, was fed at 37,400 h⁻¹. -1 The catalyst bed is filled with air velocity (GHSV) and pressure of 8 barg.

[0165] Figure 8 The combustion selectivity of Pt SOC supported on black aluminum calcium stone prepared according to Example 3 is shown. Figure 8 The combustion selectivity of Pd SOC supported on γ-alumina is shown. For example... Figure 8 As shown, Pt SOC supported on black aluminum calcium aluminate can selectively oxidize CO and H2 relative to CH4. Conversely, as Figure 9 As shown, Pt SOC supported on γ-alumina also consumes O2 during the SOC reaction, which reduces the SOC reaction efficiency.

[0166] The various embodiments described above can be combined to provide other embodiments. All U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referenced in this specification and / or listed in the application data sheet, including U.S. Provisional Patent Application No. 63 / 504,577, filed May 26, 2023, are incorporated herein by reference in their entirety. If necessary, aspects of the embodiments can be modified to employ various patent, application and disclosure concepts to provide further embodiments. These and other changes can be made to the embodiments in light of the detailed description above. Generally, the terminology used in the following claims should not be construed as limiting the claims to the specific embodiments disclosed in this specification and claims, but should be construed as including all possible embodiments and the full scope of equivalents obtained under the ownership of these claims. Therefore, the claims are not limited to this disclosure.

Claims

1. A catalytic material for oxidative coupling of methane (OCM), comprising: The carrier comprises an alkaline earth metal hexaaluminate; and An OCM catalyst is in contact with the support, wherein the OCM catalyst comprises a rare earth oxide and at least one dopant.

2. The catalytic material according to claim 1, wherein the rare earth oxide comprises La2O3, CeO2, Ce2O3, Pr2O3, Nd2O3, Sm2O3, Eu2O3, Gd2O3, Yb2O3, Y2O3 or combinations thereof.

3. The catalytic material according to claim 1, wherein the rare earth oxide is selected from La3NdO6, LaNd3O6, La 1.5 Nd 2.5 O6、La 2.5 Nd 1.5 O6、La 3.2 Nd 0.8 O6、La 3.5 Nd 0.5 O6、La 3.8 Nd 0.2 Rare earth mixed oxides of O6, LaYO3, La2Zr2O7 or La2Ce2O7.

4. The catalytic material according to any one of claims 1 to 3, wherein the dopant comprises an alkaline earth metal in the form of an element or an oxide.

5. The catalytic material according to claim 4, wherein the dopant comprises an alkaline earth metal oxide selected from MgO, CaO, SrO and BaO.

6. The catalytic material according to claim 4, wherein the dopant comprises an alkaline earth metal element selected from Mg, Ca, Sr and Ba.

7. The catalytic material according to any one of claims 1 to 6, wherein the OCM catalyst is present in the catalytic material in an amount of 1 wt% to 25 wt%.

8. The catalytic material according to any one of claims 1 to 7, wherein the OCM catalyst is disposed on the support, impregnated in the support, or a combination thereof.

9. The catalytic material according to any one of claims 1 to 8, wherein the support comprises calcium hexaaluminate (CaAl). 12 O 19 Barium hexaaluminate (BaAl) 12 O 19 ), Strontium hexaaluminate (SrAl) 12 O 19 (or a combination thereof).

10. The catalytic material according to claim 9, wherein the support comprises CaAl 12 O 19 .

11. The catalytic material according to any one of claims 1 to 10, wherein the carrier is in the form of an extruded or granulated cylinder, sphere, rod, trefoil, tetralobe, ring, annular, star-shaped, wheel-shaped or strip-shaped object.

12. The catalytic material according to any one of claims 1 to 11, wherein the support has a non-mosaic shape selected from circular, elliptical or polygonal shapes.

13. The catalytic material according to any one of claims 1 to 12, wherein the support comprises one or more pores extending therethrough.

14. A method for oxidative coupling of methane (OCM), the method comprising contacting a gas mixture comprising methane and oxygen with a catalytic material according to any one of claims 1 to 13.

15. The method of claim 14, wherein the gas mixture feed further comprises steam.

16. A catalytic material for selectively oxidizing at least hydrogen relative to methane, said catalytic material comprising: The carrier comprises an alkaline earth metal hexaaluminate; and A selective oxidation catalyst (SOC) is in contact with the support, wherein the SOC contains a noble metal.

17. The catalytic material according to claim 16, wherein the SOC comprises silver, palladium, platinum, rhodium, ruthenium, gold, iridium, or osmium.

18. The catalytic material according to claim 16 or 17, wherein the SOC is present in the catalytic material in an amount ranging from 0.001 wt% to 5 wt%.

19. The catalytic material according to any one of claims 16 to 18, wherein the SOC is disposed on the support, impregnated in the support, or a combination thereof.

20. The catalytic material according to any one of claims 16 to 19, wherein the support comprises calcium hexaaluminate (CaAl). 12 O 19 Barium hexaaluminate (BaAl) 12 O 19 ) or SrAl 12 O 19 ).

21. The catalytic material according to claim 20, wherein the support comprises CaAl 12 O 19 .

22. The catalytic material according to any one of claims 16 to 21, wherein the carrier is in the form of an extruded or granulated cylinder, sphere, rod, trefoil, tetralobe, ring, annular, star-shaped, wheel-shaped or strip-shaped object.

23. The catalytic material according to any one of claims 16 to 22, wherein the support has a non-mosaic shape selected from circular, elliptical or polygonal shapes.

24. The catalytic material according to any one of claims 16 to 23, wherein the support comprises one or more pores extending therethrough.

25. A method for catalytic combustion reaction, the method comprising contacting a gas mixture feed comprising methane, oxygen and hydrogen at a first temperature with a catalytic material according to any one of claims 16 to 24, wherein the catalytic material promotes the combustion of hydrogen in the gas mixture feed relative to methane to generate a heated gas mixture having a second temperature greater than the first temperature.

26. The method of claim 25, wherein the gas mixture feed further comprises carbon monoxide, and wherein the catalytic material promotes the combustion of hydrogen and carbon monoxide relative to methane.

27. The method of claim 25, wherein the first temperature is not greater than 375°C.

28. The method of claim 25, wherein the second temperature is at least 450°C.

29. A method for oxidative coupling of methane (OCM), comprising: A gas mixture containing methane, oxygen, and hydrogen is introduced into a reactor, wherein the reactor includes a selective oxidation catalyst and an OCM catalyst. The gas mixture feed is contacted with the selective oxidation catalyst to combust the hydrogen in the gas mixture feed and generate a heated gas mixture with a temperature capable of initiating an OCM reaction, the selective oxidation catalyst comprising a selective oxidation catalyst (SOC) in contact with a first support; and The heated gas mixture is contacted with the OCM catalyst to initiate the OCM reaction and produce a product containing C. 2+ The OCM effluent of the compound, wherein C 2+ The compound includes ethylene, and the OCM catalytic material comprises an OCM catalyst in contact with a second support. At least one of the first carrier and the second carrier comprises an alkaline earth metal hexaaluminate.

30. The method of claim 29, wherein the OCM catalyst comprises a rare earth oxide and at least one dopant.

31. The method according to claim 30, wherein the rare earth oxide comprises La2O3, CeO2, Ce2O3, Pr2O3, Nd2O3, Sm2O3, Eu2O3, Gd2O3, Yb2O3, Y2O3 or combinations thereof.

32. The method according to claim 30, wherein the rare earth oxide is selected from La3NdO6, LaNd3O6, La 1.5 Nd 2.5 O6、La 2.5 Nd 1.5 O6、La 3.2 Nd 0.8 O6、La 3.5 Nd 0.5 O6、La 3.8 Nd 0.2 Rare earth mixed oxides of O6, LaYO3, La2Zr2O7 and La2Ce2O7.

33. The method according to any one of claims 30 to 32, wherein the dopant comprises an alkaline earth metal in the form of an element or an oxide.

34. The method of claim 33, wherein the dopant comprises an alkaline earth metal oxide selected from MgO, CaO, SrO and BaO.

35. The method of claim 33, wherein the dopant comprises an alkaline earth metal element selected from Mg, Ca, Sr and Ba.

36. The method according to any one of claims 29 to 35, wherein the OCM catalyst is present in the OCM catalytic material in an amount of 1 wt% to 25 wt%.

37. The method according to any one of claims 29 to 36, wherein at least one of the first carrier and the second carrier comprises calcium hexaaluminate (CaAl). 12 O 19 Barium hexaaluminate (BaAl) 12 O 19 ), Strontium hexaaluminate (SrAl) 12 O 19 Alkaline earth metal hexaaluminates and their combinations thereof.

38. The method of claim 37, wherein at least one of the first carriers comprises CaAl. 12 O 19 .

39. The method according to any one of claims 29 to 36, wherein each of the first carrier and the second carrier comprises a material selected from calcium hexaaluminate (CaAl). 12 O 19 Barium hexaaluminate (BaAl) 12 O 19 ), Strontium hexaaluminate (SrAl) 12 O 19 Alkaline earth metal hexaaluminates and their combinations thereof.

40. The method of claim 39, wherein each of the first carriers comprises CaAl 12 O 19 .

41. The method according to any one of claims 29 to 40, wherein the first carrier and the second carrier are independently in the form of an extruded or granulated cylinder, sphere, rod, trefoil, tetralobe, ring, annular, star, wheel or strip.

42. The method according to any one of claims 29 to 41, wherein the first carrier and the second carrier independently have non-tessellated shapes selected from circles, ellipses and polygons.

43. The method according to any one of claims 29 to 42, wherein the first carrier and the second carrier independently include one or more holes extending therethrough.

44. The method according to any one of claims 29 to 43, wherein the SOC comprises a noble metal.

45. The method of claim 44, wherein the SOC comprises silver, palladium, platinum, rhodium, ruthenium, gold, iridium, or osmium.

46. ​​The method according to any one of claims 29 to 43, wherein the SOC comprises a metal, a metal oxide, or a mixture of metal oxides, the metal, metal oxide, or mixture of metal oxides comprising at least one of platinum, chromium, copper, palladium, cobalt, iron, manganese, gold, cerium, bismuth, indium, molybdenum, rhodium, ruthenium, germanium, gadolinium, antimony, thallium, tellurium, lead, zinc, or tin.

47. The method according to any one of claims 29 to 46, wherein the SOC is present in the selective oxidation catalyst in an amount ranging from 0.001 wt% to 5 wt%.

48. The method according to any one of claims 29 to 47, wherein the gas mixture feed further comprises carbon monoxide.

49. The method of claim 48, wherein the selective oxidation catalyst preferentially combusts hydrogen and carbon monoxide relative to methane.

50. The method according to any one of claims 29 to 49, wherein the gas mixture feed has a temperature of less than or equal to 375°C at the inlet of the reactor.

51. The method of claim 50, wherein the gas mixture feed at the inlet of the reactor has a temperature in the range of 300°C to 375°C.

52. The method according to any one of claims 29 to 50, wherein the gas mixture feed has a temperature of less than 300°C at the inlet of the reactor.

53. The method of claim 52, wherein the gas mixture feed at the inlet of the reactor has a temperature of 15°C to 250°C.

54. The method according to any one of claims 29 to 53, wherein the heated gas mixture feed has a temperature of at least 450°C.

55. The method according to any one of claims 29 to 54, wherein the heated gas mixture has a temperature in the range of 500°C to 800°C.

56. The method according to any one of claims 29 to 55, wherein the OCM reaction is carried out at a temperature in the range of 450°C to 950°C.

57. The method according to any one of claims 29 to 56, wherein the OCM reaction is related to C 2+ The compound has at least 35% selectivity.

58. The method according to any one of claims 29 to 57, wherein the OCM reaction has a methane conversion rate of greater than 20%.

59. The method according to any one of claims 29 to 58, wherein the OCM reaction has a C content greater than 10%. 2+ Yield.

60. The method according to any one of claims 29 to 59, wherein the reactor comprises a first catalyst bed on which the selective oxidation catalytic material is placed and a second catalyst bed on which the OCM catalytic material is placed, wherein the second catalyst bed is located downstream of the first catalyst bed.

61. The method according to any one of claims 29 to 59, wherein the reactor comprises a single catalyst bed, the single catalyst bed comprising a mixture of the selective oxidation catalytic material and the OCM catalytic material.

62. The method according to any one of claims 29 to 59, wherein the reactor comprises a single catalyst bed, the single catalyst bed comprising at least one layer of the selective oxidation catalytic material and at least one layer of the OCM catalytic material.

63. A method for preparing a downstream product of ethylene, the method comprising converting ethylene into a downstream product of ethylene, wherein the ethylene has been prepared by the method according to any one of claims 14 to 15 or by the method according to any one of claims 29 to 62.

64. The method of claim 63, wherein the downstream product of ethylene is low-density polyethylene, high-density polyethylene, dichloroethane, ethylene oxide, ethylbenzene, ethanol, or vinyl acetate.

65. The method of claim 64, wherein the downstream product of ethylene is natural gasoline.

66. The method of claim 65, wherein the downstream products of ethylene comprise 1-hexene, 1-octene, hexane, octane, benzene, toluene, xylene, or combinations thereof.

67. The method of claim 66, wherein converting the ethylene into the downstream product of ethylene comprises oligomerizing the ethylene.

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