A method for the catalytic conversion of methane to olefins, aromatics and hydrogen in a joule heat coupled metal catalytic reactor without oxygen

Abstract

The present application relates to a kind of methods for catalytically converting methane to olefins, aromatics and hydrogen in joule heat coupled metal catalytic reactor.The methane feed gas heated by hot joule heat is passed into metal catalytic reactor for catalytic conversion reaction to prepare olefins, aromatics and hydrogen using joule heat as heat source.The conversion rate of methane is 35-85%;The selectivity of olefins is 65-90%;The selectivity of aromatics is 13-40%;Zero carbon deposition.The present application has the characteristics of electric heating conversion efficiency > 90%, long catalyst life, high methane conversion rate and product selectivity, zero carbon deposition, catalyst does not need to be enlarged, small industrialization difficulty, good process repeatability, safe and reliable operation, etc., and has broad industrial application prospect.

Description

Technical Field

[0001] This invention belongs to the field of catalysis, specifically relating to a method for the anaerobic catalytic conversion of methane to olefins, aromatics and hydrogen using a Joule thermally coupled metal catalytic reactor. This process achieves efficient conversion of methane to high-value chemicals and features high electrothermal conversion efficiency, excellent catalyst stability and low carbon deposition. Background Technology

[0002] The development and effective utilization of natural gas (methane) resources represent the development direction of the contemporary energy structure and are also one of the important ways to ensure sustainable development and achieve green energy. In recent years, developed Western countries have also made breakthrough progress in the development of shale gas and "combustible ice," triggering a "shale gas revolution." my country's shale gas resources are diverse in type and relatively concentrated in distribution, with a recoverable resource potential of 25 trillion cubic meters (excluding the Qinghai-Tibet Plateau), comparable to my country's conventional natural gas reserves and similar to the 24 trillion cubic meters in the United States. The country has already made arrangements in the field of shale gas development, aiming to achieve technological breakthroughs in several different types of shale oil and gas areas and initially establish economically viable production capacity.

[0003] However, the efficient utilization of gaseous hydrocarbon resources (methane) has become a crucial factor restricting the development of my country's energy industry. Converting this abundant resource into fuels and high-value-added chemicals (especially low-carbon olefins) has reignited global interest and is also an important step in improving my country's energy structure. Low-carbon olefins, such as ethylene, are very important raw materials or intermediates in chemical processes. Traditionally, low-carbon olefins (C2-C4) mainly originate from petrochemical processes such as naphtha cracking, making ethylene production a key indicator of a country's or region's petrochemical production level. With the increasing depletion of petroleum resources, exploring non-traditional routes to produce low-carbon olefins has become a focus of current research. Consequently, some typical alternative routes have emerged, such as starting from syngas and further converting it into methanol or dimethyl ether to obtain low-carbon olefins. However, this route is complex and has low atom economy. To shorten the reaction path, the Fischer-Tropsch route for direct synthesis of low-carbon olefins from syngas has also been extensively studied. However, all of the above alternative routes require the consumption of CO or H2 to remove O from CO, inevitably resulting in a C atom utilization rate of less than 50%. Despite high production costs, significant CO2 emissions, and less than 50% atom utilization, indirect processes still dominate in natural gas industrial applications.

[0004] In contrast, the direct conversion of natural gas has enormous economic potential and is more environmentally friendly. However, the direct conversion of natural gas remains a challenge in chemical and chemical engineering processes. The main component of natural gas is methane, whose C-H bond energy is as high as 434 kJ / mol. Methane molecules themselves have almost no electron affinity, and their ionization energy is high while their polarizability is low. Therefore, the activation of the C-H bond in methane is considered the "holy grail" of chemistry. Keller and Bhasin reported the activation of the C-H bond in methane with the participation of O2. Their pioneering work ignited worldwide enthusiasm for the oxidative coupling of methane to ethylene under high-temperature (>1073 K) conditions. During this period, hundreds of catalytic materials were synthesized and tested, reaching a peak in the 1990s. During oxidative coupling, the introduction of molecular oxygen (O2) inevitably leads to the over-oxidation of methane and its products, resulting in a large number of thermodynamically more stable products than methane, such as CO2 and H2O, ultimately leading to relatively low C atom utilization efficiency. The development of methane oxidative coupling processes has stagnated due to bottlenecks in the development of new materials and catalysts, and new economically feasible processes are still rarely reported. A recent study proposed using weakly oxidizing gaseous sulfur (S) to replace molecular oxygen (O2) in the methane oxidative coupling reaction. At a temperature of 1323 K (reaction gas: 5% CH4 / Ar), the optimal PdS / ZrO2 catalyst can achieve a methane conversion rate of 16%, however, the selectivity for C2H4 is only about 20%, while producing large amounts of CS2 and H2S as byproducts. These studies indicate that the activation of methane by oxygen (or an oxidant) inevitably leads to peroxidation.

[0005] Therefore, the direct anaerobic (or oxidant-free) conversion of methane is considered the most ideal route for methane activation and conversion. Under anaerobic (or oxidant-free) conditions, excessive oxidation of methane or its products can be effectively avoided, suppressing the emission of greenhouse gas CO2 and thus improving the utilization rate of C atoms. The challenges of the direct catalytic conversion of methane to ethylene are: 1) controllably activating methane to break its first C-H bond; 2) suppressing its deep dehydrogenation on the catalyst surface; and 3) avoiding the generation of greenhouse gas CO2 and carbon deposits. Points 1 and 2 concern the catalyst, while point 3 concerns the reaction process. Overoxidation of products in aerobic processes is unavoidable, leading to unavoidable CO2 production. Only anaerobic processes can avoid CO2 production, but they are prone to carbon deposition; therefore, research on how to avoid carbon deposition has become the current focus of attention in anaerobic processes. The key to solving the carbon deposition problem lies in understanding its sources. Taking the anaerobic aromatization process as an example, the carbon deposition mainly originates from: deep dehydrogenation of methane on the surface of Mo species in the catalyst ("graphitized carbon deposition"); and cyclization and coupling carbon deposition at the acidic sites of the B sites in the molecular sieve channels or pores of the support during product diffusion ("polyaromatic carbon deposition"). Therefore, the three challenges of the direct conversion of methane to ethylene all lie in the design and construction of the catalyst.

[0006] In 1993, researchers at the Dalian Institute of Chemical Physics first reported the anaerobic aromatization of CH4 in a continuous flow mode on a Mo / HZSM-5 catalyst. At 973 K and atmospheric pressure, the CH4 conversion was approximately 6%, and the selectivity for aromatics was greater than 90% (excluding reaction carbon deposition), marking a significant milestone in the study of anaerobic aromatization of CH4. Over the past decade, research by scientists from various countries has primarily focused on catalyst preparation and development, reaction and deactivation mechanisms, but rapid carbon deposition and deactivation of catalysts have limited further industrial scale-up.

[0007] Recently, Siluria Inc. (US201241246, US2013165728, US2014121433, CA2837201, US8921256B29) in the United States developed a composite catalyst prepared using a bio-template method. This catalyst achieved a methane conversion rate of 26% and an ethylene selectivity of 52% in an oxidative coupling reaction at 600-650℃. The company is currently conducting pilot-scale testing and anticipates industrial-scale demonstration in 2017-2018. For the selective oxidation of methane to methanol or formaldehyde, the oxidation rate of the target products methanol and formaldehyde is much faster than that of the feedstock methane, resulting in lower selectivity and hindering large-scale application.

[0008] Two patents have been applied for previously (application numbers: 201310174960.5 and 201511003407.0). These two patents disclose a metal-doped silicon-based catalyst, which is then placed in a reactor in a fixed bed, fluidized bed, or moving bed to catalyze the conversion of methane into olefins. The disadvantages of these two methods are that the catalyst bed pressure drop is large, the catalyst has poor thermal conductivity and the bed temperature difference is large, and the catalyst preparation conditions are harsh and difficult to scale up. Summary of the Invention

[0009] This invention further investigates the causes of the aforementioned problems in the catalytic conversion of methane to olefins, aromatics, and hydrogen (MTOAH) process. CFD simulations of the fixed-bed catalyst temperature show an inverted parabolic trend from the reactor inner wall to the axial center of the catalyst bed, indicating overall temperature non-uniformity with the lowest temperature at the axial center. Furthermore, the MTOAH reaction is a strongly endothermic process, further exacerbating the non-uniformity of the bed temperature distribution. This non-uniformity leads to insufficient heat in areas far from the wall, hindering methane conversion. To address this issue, this invention directly loads the active component onto the inner wall of a metal tube, resulting in a metal catalytic reactor that effectively overcomes the axial temperature difference and avoids carbon buildup.

[0010] CFD simulations of conventional electric heating or gas-fired heating show that the temperature distribution within the reactor is extremely uneven, severely limiting the highly endothermic methane conversion process. In conventional electric heating, the electricity is converted into heat and conducted to the gas through the reactor wall, with a heating efficiency of approximately 30-40%; even with gas-fired heating, the heating efficiency remains around 40-50%.

[0011] To address the aforementioned issues, this invention incorporates active metal or non-metal components into the inner wall of the alloy tube, integrating the catalyst and reactor into a single unit. Simultaneously, Joule heating directly acts on the methane gas, achieving highly efficient catalytic conversion of methane.

[0012] To achieve the above objectives, the technical solution of the present invention is as follows:

[0013] A method for the anaerobic catalytic conversion of methane to olefins, aromatics, and hydrogen using a Joule-coupled metal catalytic reactor involves directly connecting a DC or AC power supply to both ends of the metal catalytic reactor. Joule heating is achieved by utilizing the resistance heating of the metal reactor. Methane feedstock is introduced into the Joule-heated metal catalytic reactor for catalytic conversion to produce olefins, aromatics, and hydrogen. The Joule heating power is 100W-100KW, the current range is 5-10000A, and the voltage range is 1-1000V.

[0014] Preferably, the metal catalytic reactor includes an active component and a metal tube. The catalyst active component is coated and doped on the contact surface between the metal tube and the reactant, forming a thin layer of catalytic dopant on the contact surface between the metal tube and the reactant. The catalyst active component and the substrate metal at the contact surface of the metal tube form a catalyst. The contact surface refers to the inner wall and / or outer wall of the metal tube.

[0015] Preferably, the thickness of the catalytic dopant layer is 100 nanometers to 1 millimeter, more preferably 200 nanometers to 0.5 millimeters, more preferably 500 nanometers to 200 micrometers, and most preferably 1 micrometer to 50 micrometers.

[0016] Preferably, the doping is lattice doping; the active component of the catalyst is a metal element, or a mixture of metal and non-metal elements, and the metal element doping amount is 0.1-20 wt.%, more preferably 0.1-15 wt.%, and even more preferably 0.1-5 wt.%, based on the total weight of the dopant layer as 100%. Lattice doping refers to the formation of chemical bonds between the doped metal element and certain elements in the matrix metal material, confining the doped metal element within the lattice of the doped matrix, thereby producing specific catalytic properties.

[0017] Preferably, the metal element exists in one or more of the following states: oxide, carbide, nitride, silicide, and alloy; the metal element includes one or more of the following: magnesium, aluminum, calcium, barium, titanium, manganese, vanadium, niobium, tungsten, molybdenum, chromium, iron, cobalt, nickel, copper, zinc, tin, gallium, zirconium, lanthanum, cerium, ruthenium, gold, palladium, or platinum, and more preferably one or more of the following: aluminum, barium, titanium, manganese, vanadium, niobium, tungsten, molybdenum, chromium, iron, cobalt, nickel, copper, zinc, gallium, gold, lanthanum, cerium, ruthenium, gold, palladium, or platinum.

[0018] Preferably, in the metal catalytic reactor, the base metal tube is made of the following materials: GH1015, GH1040, GH1131, GH1140, GH2018, GH2036, GH2038, GH2130, GH2132, GH2135, GH2136, GH2302, GH2696, GH3030, GH3039, GH3044, GH3028, GH3128, GH3530, GH3536, GH605, GH600, GH4033, GH4037, GH4043, GH4049, GH4133, GH4133B, GH4169, GH4145, Hastelloy G-30, Hastelloy G-35, Hastelloy N, Hastelloy S, Inconel 600, Inconel 601, Inconel Inconel 751, Inconel 754, Inconel 758, Incoloy 783, IncoloyDS, Incoloy 800, Incoloy800H, Incoloy 802, Incoloy 803, Incoloy 804, Incoloy 825, Incoloy 903, Incoloy 907, Incoloy 909, Incoloy 925, Incoloy MA956、Incoloy One or more of A-286, Incoloy 25-6Mo, and Monel 400.

[0019] Preferably, the metal catalytic reactor is prepared using the following coating and doping techniques: electrochemical deposition and conversion deposition precipitation, or one or more of electroplating, electroless plating, electrochemical deposition, conversion deposition precipitation, chemical vapor deposition (CVD), and physical vapor deposition (PVD).

[0020] The purpose of the following preparation process is to improve the dispersion and adhesion of metal elements on the surface of the metal substrate.

[0021] Electrochemical deposition method includes the following steps:

[0022] (1) Boil the base pipe in 10-20wt.% NaOH or KOH solution for 1-2 hours to remove oil, rinse it clean, and air dry it at room temperature for later use.

[0023] (2) The substrate pipe treated in step (1) is heated in a hot N2 atmosphere at a temperature of 300-500℃ for 1-2 hours to form an anti-corrosion conductive film layer.

[0024] (3) At room temperature, prepare an aqueous or organic solution of the precursor for doping metal elements, adjust the pH of the solution to 3.3-6.5, immerse the metal tube to be doped in the precursor solution, connect the power supply and use it as the cathode, and platinum as the anode. After connecting the circuit, adjust the distance between the anode and cathode to 2-5 cm, adjust the DC regulated power supply to maintain constant current mode, and the current is 5mA-0.5A. After electrodeposition for 0.5-2 hours, wash and dry with deionized water. After the deposition is completed, a metal catalytic reactor is obtained.

[0025] The precursor of the doped metal element used in the electrochemical deposition method is one or more of the following: metal nitrate, soluble halide, soluble sulfate, soluble carbonate, soluble phosphate, soluble C methanol salt, soluble ethanol salt, soluble formate, and soluble acetate.

[0026] The conversion deposition precipitation method includes the following steps:

[0027] (1) Boil the base pipe in 10-20wt.% NaOH or KOH solution for 1-2 hours to remove oil, rinse it clean, and air dry it at room temperature for later use.

[0028] (2) The substrate pipe treated in step (1) is heated in a hot N2 atmosphere at a temperature of 300-500℃ for 1-2 hours to form an anti-corrosion conductive film layer.

[0029] (3) At room temperature, prepare an aqueous or organic solution of the precursor of the doped metal element, adjust the pH of the solution to 3.8-7.2, immerse the metal tube to be doped in the precursor solution, so that the solution is in a flowing state inside the metal tube to be deposited, and then add 10-20 wt.% H2O2 aqueous solution for conversion deposition precipitation. The deposition time is 0.5-5 hours. After the deposition is completed, a metal catalytic reactor is obtained.

[0030] The precursor of the doped metal element used in the conversion deposition precipitation method is one or more of the following: metal chloride, methanol salt, ethanol salt, formate, and acetate.

[0031] Preferably, the reaction process is a continuous flow reaction mode, and when the reaction is carried out continuously, the reaction pressure is 0.05-1MPa and the feed gas flow rate is 1-100L / min.

[0032] Preferably, the feed gas includes methane, or a mixture of methane and other gases, wherein the other gases include one or two of inert atmosphere gases and non-inert atmosphere gases; the inert atmosphere gas is one or more of nitrogen, helium, neon, argon, and krypton, and the volume content of the inert atmosphere gas in the feed gas is 0-95%; the non-inert atmosphere gas is one or more of carbon monoxide, hydrogen, and alkanes with 2-4 carbon atoms, and the volume ratio of the non-inert atmosphere gas to methane is 0-10%; the volume content of methane in the feed gas is 5-100%.

[0033] Preferably, the aromatic hydrocarbon product includes one or more of benzene, toluene, p-xylene, o-xylene, m-xylene, ethylbenzene, and naphthalene.

[0034] Based on long-term research on the anaerobic catalytic conversion of methane, this invention proposes a method for the direct catalytic production of ethylene, aromatics, and hydrogen from methane under anaerobic conditions. This method involves coating the active catalyst component onto the contact surface between a metal tube and the reactants, forming a thin layer of catalytic dopant. The active catalyst component and the substrate metal at the contact surface of the metal tube together form a catalyst. This method differs from previous anaerobic methane conversion processes, particularly from patents with authorization numbers CN 111333479B, CN 111333477 A, and CN 111333478 B, in the following ways:

[0035] Table 1

[0036]

[0037] Therefore, this method has the characteristics of high electrothermal conversion efficiency, high catalyst stability, high methane conversion rate, high product selectivity, zero carbon deposition, good process repeatability, and safe and reliable operation, and has broad prospects for industrial application.

[0038] The beneficial effects of this invention are as follows:

[0039] (1) The integrated metal alloy catalytic reactor has the advantages of simpler process, milder conditions and more uniform dispersion of metal active components compared with quartz and silicon carbide doping processes.

[0040] (2) Compared with traditional particulate catalysts, the reaction process avoids axial or radial temperature differences in the catalyst. Because when the catalyst is filled into the reactor, and the catalyst itself has poor thermal conductivity, the radial temperature difference of the bed increases (the temperature gradually decreases from the reactor wall to the center). Therefore, more heat needs to be supplied in order to make the catalyst in the center reach the reaction temperature, resulting in heat loss and more side reactions in the near-wall section (high-temperature end).

[0041] (3) Compared with particulate catalysts, since there is no catalyst bed and no bed pressure drop, the reaction process is more stable.

[0042] (4) Compared with particulate catalysts, it overcomes the problem of scale-up.

[0043] (5) In the traditional electric heating process, electricity is converted into hot gas, which radiates heat to the reactor wall and conducts heat to the gas. The heating efficiency of the whole process is about 30-40%. Even with gas heating, the heating efficiency is still about 40-50%. Using Joule heating can increase the electrothermal conversion efficiency to 90%.

[0044] (6) After the Joule thermally coupled catalytic reactor, the current (electron flow) passes directly through the catalyst layer, which can excite the catalyst to induce the dissociation of methane to generate methyl radicals and hydrogen radicals, thereby greatly promoting the conversion of methane.

[0045] In summary, this invention features high catalyst stability, high methane conversion rate, high product selectivity, zero carbon deposition, good process repeatability, and safe and reliable operation. Specifically, the methane conversion rate is 35-85%, and there is zero carbon deposition. This method offers advantages such as long catalyst lifetime, high methane conversion rate, zero carbon deposition, easy product separation, no need for catalyst scale-up, low difficulty in industrialization, good process repeatability, and safe and reliable operation, demonstrating broad prospects for industrial application. Attached Figure Description

[0046] Figure 1 The product obtained in Example 18 Particle-induced X-ray emission (PIXE) analysis of metal catalytic reactors. Detailed Implementation

[0047] However, the following embodiments are only for illustrative purposes, and the scope of protection of this invention should include all the contents of the claims, not just these embodiments. Furthermore, the concentrations of NaOH solution, metal precursor solution, and H2O2 solution mentioned in the following embodiments and comparative examples all refer to mass percentage concentrations.

[0048] I. Preparation of Catalytic Reactor

[0049] Comparative Example 1

[0050] Inconel 601 alloy tubing (inner diameter 10mm, outer diameter 14mm, id10od14) was selected and degreased by boiling in a 15% NaOH solution for 1 hour. After rinsing with distilled water and air-drying at room temperature, it was then treated at 300℃ in a continuous N2 atmosphere at 200ml / min for 2 hours; subsequently, it was treated at 500℃ in a high-purity hydrogen atmosphere for 2.5 hours to obtain the blank. Metal catalytic reactor.

[0051] Example 1

[0052] Electrochemical deposition method

[0053] GH3030 and GH3530 alloy pipes (inner diameter 10mm, outer diameter 14mm, id10od14) were selected and boiled in 15% NaOH solution for 1 hour to remove oil. They were then rinsed with distilled water, dried at room temperature, and then treated in a N2 atmosphere at 300℃ with a continuous flow of 200ml / min for 2 hours. Prepare 2 L of a 10% RuCl3 aqueous solution, add 20 mL of 0.1 mol / L citric acid, and adjust the pH to 4.5 with hydrochloric acid. Connect a 0.5 mm platinum wire as the anode, and connect GH3030 and GH3530 alloy tubes as cathodes, respectively. Connect a power supply, with the platinum wire 2 cm away from the alloy tubes. Use constant current mode, set the current to 20 mA, and after deposition for 0.5 hours, obtain Ru-deposited GH3030 and GH3530 alloy tubes, respectively. Subsequently, treat them at 500℃ in a high-purity hydrogen atmosphere for 2 hours to form a 100 nm thick Ru dopant layer on the reactor contact surface. Then, allow natural cooling to obtain the desired Ru-deposited GH3030 and GH3530 alloy tubes. and A metal catalytic reactor in which Ru is doped at a concentration of 0.5 wt.%.

[0054] Example 2

[0055] Electrochemical deposition method

[0056] GH3030 alloy tubing (4mm inner diameter, 6mm outer diameter, id4od6) was selected and boiled in 15% NaOH solution for 1 hour to remove oil. It was then rinsed with distilled water, air-dried at room temperature, and subsequently treated at 300℃ in a continuous N2 atmosphere with a flow rate of 200ml / min for 2 hours. A mixed aqueous solution of 10% RuCl3 and 15% FeCl3 was prepared (2L), and 30ml of 0.1mol / L citric acid was added. The pH was adjusted to 4.5 with hydrochloric acid. A 0.5mm platinum wire was connected as the anode, and the GH3030 alloy tubing was connected as the cathode. A power supply was connected, with the platinum wire 2cm away from the alloy tubing. A constant current mode was used, with the current set at 25mA. After deposition for 0.5 hours, Ru and Fe deposited on the GH3030 alloy tubing were obtained. This was then treated at 500℃ in a high-purity hydrogen atmosphere for 2 hours to form a 110nm thick Ru and Fe dopant layer at the reactor contact surface. After natural cooling, the desired product was obtained. A metal catalytic reactor in which Ru and Fe are doped at 0.8 wt.% and 1 wt.%, respectively.

[0057] Example 3

[0058] Electrochemical deposition method

[0059] Inconel 601 alloy tubing (inner diameter 10mm, outer diameter 14mm, id10od14) was selected and boiled in 15% NaOH solution for 1 hour to remove oil. After rinsing with distilled water and air-drying at room temperature, it was then treated at 300℃ in a continuous N2 atmosphere with a flow rate of 200ml / min for 2 hours. A mixed aqueous solution of 20% Co(NO3)2 and 15% FeCl3 was prepared (2L), and 20ml of 0.1mol / L citric acid was added. The pH was adjusted to 3.8 with hydrochloric acid. A 0.5mm platinum wire was connected as the anode, and the Inconel 601 alloy tubing was connected as the cathode. A power supply was connected, with the platinum wire 2cm away from the alloy tubing. A constant current mode was used, with the current set at 25mA. After deposition for 1 hour, Co and Fe deposited in Inconel were obtained. 601 alloy tubing; subsequently treated at 500℃ in a high-purity hydrogen atmosphere for 2.5 hours to form a 110nm thick Co and Fe dopant layer on the reactor contact surface, followed by natural cooling to obtain... A metal catalytic reactor in which Co and Fe are doped at 1.5 wt.% and 0.6 wt.%, respectively.

[0060] Example 4

[0061] Electrochemical deposition method

[0062] Inconel 601 alloy tubing (inner diameter 10mm, outer diameter 14mm, id10od14) was selected and boiled in 15% NaOH solution for 1 hour to remove oil. After rinsing with distilled water and air-drying at room temperature, it was then treated at 300℃ in a continuous N2 atmosphere with a flow rate of 200ml / min for 2 hours. A mixed aqueous solution of 20% Ni(NO3)2 and 15% Co(NO3)2 was prepared (2L), and 19ml of 0.1mol / L citric acid was added. The pH was adjusted to 3.8 with nitric acid. A 0.5mm platinum wire was connected as the anode, and the Inconel 601 alloy tubing was connected as the cathode. A power supply was connected, with the platinum wire 2cm away from the alloy tubing. A constant current mode was used, with the current set at 30mA. After 1 hour of deposition, Co and Ni deposited in Inconel were obtained. 601 alloy tubing; subsequently treated at 500℃ in a high-purity hydrogen atmosphere for 2.5 hours to form a 110nm thick Co and Ni doped layer on the reactor contact surface, followed by natural cooling to obtain... A metal catalytic reactor in which Ni and Co are doped at 1.5 wt.% and 1.1 wt.%, respectively.

[0063] Example 5

[0064] Electrochemical deposition method

[0065] Inconel 600 alloy tubing (inner diameter 16mm, outer diameter 20mm, id16od20) was selected and boiled in 15% NaOH solution for 1 hour to remove oil. It was then rinsed with distilled water, air-dried at room temperature, and subsequently treated for 2 hours at 300℃ in a continuous N2 atmosphere with a flow rate of 200ml / min. A mixed aqueous solution of 10% RuCl3 and 15% Cu(NO3)2 was prepared (2L), and 32ml of 0.1mol / L citric acid was added. The pH was adjusted to 4.1 with nitric acid. A 0.5mm platinum wire was connected as the anode, and the Inconel 600 alloy tubing was connected as the cathode. A power supply was connected, with the platinum wire 2cm away from the alloy tubing. A constant current mode was used, with the current set at 25mA. After 1 hour of deposition, Ru and Cu deposited in the Inconel 600 alloy tubing were obtained. This was then treated for 2 hours at 500℃ in a high-purity hydrogen atmosphere to form a 120nm thick Ru and Cu doped layer on the reactor contact surface. After natural cooling, the desired product was obtained. A metal catalytic reactor in which Ru and Cu are doped at 0.5 wt.% and 0.6 wt.%, respectively.

[0066] Example 6

[0067] Electrochemical deposition method

[0068] Incoloy 800 alloy tubing (inner diameter 15mm, outer diameter 20mm, id15od20) was selected and boiled in 15% NaOH solution for 1 hour to remove oil. After rinsing with distilled water and air-drying at room temperature, it was then treated at 300℃ in a continuous N2 atmosphere with a flow rate of 200ml / min for 2 hours. A mixed aqueous solution of 20% Ni(NO3)2 and 15% Co(NO3)2 was prepared (2L), and 36ml of 0.1mol / L citric acid was added. The pH was adjusted to 4.3 with nitric acid. A 0.5mm platinum wire was connected as the anode, and the Incoloy 800 alloy tubing was connected as the cathode. A power supply was connected, with the platinum wire 1cm away from the alloy tubing. A constant current mode was used, with the current set at 80mA. After deposition for 1 hour, Ni and Co deposited in Incoloy were obtained. 800 alloy tubing was then treated at 500℃ in a high-purity hydrogen atmosphere for 2 hours to form a 150nm thick Ni and Co doped layer on the reactor contact surface. After natural cooling, the desired product was obtained. A metal catalytic reactor in which Ni and Co are doped at 2 wt.% and 1.2 wt.%, respectively.

[0069] Example 7

[0070] Electrochemical deposition method

[0071] Monel 400 alloy tubing (inner diameter 15mm, outer diameter 20mm, id15od20) was selected and boiled in 15% NaOH solution for 1 hour to remove oil. After rinsing with distilled water and air-drying at room temperature, it was then treated at 300℃ in a continuous N2 atmosphere with a flow rate of 200ml / min for 2 hours. A mixed aqueous solution of 20% Ni(NO3)2 and 15% Co(NO3)2 was prepared (2L), and 41ml of 0.1mol / L citric acid was added. The pH was adjusted to 4.3 with nitric acid. A 0.5mm platinum wire was connected as the anode, and an Incoloy 800 alloy tubing was connected as the cathode. A power supply was connected, with the platinum wire 1cm away from the alloy tubing. A constant current mode was used, with the current set at 80mA. After deposition for 1 hour, Ni and Co deposited in Monel tubing were obtained. 400 alloy tubing was then treated at 500℃ in a high-purity hydrogen atmosphere for 2 hours to form a 150nm thick Ni and Co doped layer on the reactor contact surface. After natural cooling, the desired product was obtained. A metal catalytic reactor in which Ni and Co are doped at 2 wt.% and 1.2 wt.%, respectively.

[0072] Example 8

[0073] Electrochemical deposition method

[0074] Inconel X-750 alloy tubing (inner diameter 15mm, outer diameter 20mm, id15od20) was selected and boiled in 15% NaOH solution for 1 hour to remove oil. After rinsing with distilled water and air-drying at room temperature, it was then treated at 300℃ in a continuous N2 atmosphere with a flow rate of 200ml / min for 2 hours. A 2L mixed aqueous solution of 20% Ni(NO3)2 and 15% Zn(NO3)2 was prepared, and 31ml of 0.1mol / L citric acid was added. The pH was adjusted to 4.3 with nitric acid. A 0.5mm platinum wire was connected as the anode, and an Incoloy 800 alloy tubing was connected as the cathode. A power supply was connected, with the platinum wire 1cm away from the alloy tubing. A constant current mode was used, with the current set at 100mA. After deposition for 1 hour, Ni and Zn deposited in Inconel were obtained. X-750 alloy tubing; subsequently treated at 500℃ in a high-purity hydrogen atmosphere for 2 hours to form a 180nm thick Ni and Zn dopant layer on the reactor contact surface, followed by natural cooling, thus obtaining... A metal catalytic reactor in which Ni and Zn are doped at 2 wt.% and 1.2 wt.%, respectively.

[0075] Example 9

[0076] Electrochemical deposition method

[0077] Hastelloy G-30 alloy tubing (inner diameter 16mm, outer diameter 20mm, id16od20) was selected and boiled in 15% NaOH solution for 1 hour to remove oil. After rinsing with distilled water and air-drying at room temperature, it was then treated at 300℃ in a continuous N2 atmosphere with a flow rate of 200 ml / min for 2 hours. A mixed aqueous solution of 25% Ni(NO3)2 and 15% La(NO3)3 was prepared (2 L), and 26 ml of 0.1 mol / L citric acid was added. The pH was adjusted to 4.3 with nitric acid. A 0.5 mm platinum wire was connected as the anode, and the Hastelloy G-30 alloy tubing was connected as the cathode. A power supply was connected, with the platinum wire 1 cm away from the alloy tubing. A constant current mode was used, with the current set at 100 mA. After deposition for 1 hour, Ni and La deposits were obtained using Hastelloy. G-30 alloy tubing; subsequently treated at 500℃ in a high-purity hydrogen atmosphere for 2 hours to form a 180nm thick Ni and La doped layer on the reactor contact surface, followed by natural cooling, thus obtaining... A metal catalytic reactor in which Ni and La are doped at 2.5 wt.% and 1.6 wt.%, respectively.

[0078] Example 10

[0079] Electrochemical deposition method

[0080] Inconel 600 alloy tubing (10mm inner diameter, 14mm outer diameter, id10od14) was selected and boiled in 15% NaOH solution for 1 hour to remove oil. It was then rinsed with distilled water, air-dried at room temperature, and subsequently treated for 2 hours at 300℃ in a continuous N2 atmosphere with a flow rate of 200ml / min. A mixed aqueous solution of 10% chloroauric acid and 15% La(NO3)3 was prepared (2L), and 35ml of 0.1mol / L citric acid was added. The pH was adjusted to 4.1 with nitric acid. A 0.5mm platinum wire was connected as the anode, and a GH2130 alloy tubing was connected as the cathode. A power supply was connected, with the platinum wire 2cm away from the alloy tubing. A constant current mode was used, with the current set at 30mA. After deposition for 1 hour, Au and La deposited in the Inconel 600 alloy tubing were obtained. This was then treated for 2 hours at 500℃ in a high-purity hydrogen atmosphere to form a 120nm thick Au and La doped layer on the reactor contact surface. After natural cooling, the desired product was obtained. A metal catalytic reactor in which Au and La are doped at 0.5 wt.% and 0.8 wt.%, respectively.

[0081] Example 11

[0082] Electrochemical deposition method

[0083] GH4169 alloy tubing (inner diameter 12mm, outer diameter 18mm, id12od18) was selected and boiled in a 15% NaOH solution for 1 hour to remove oil. It was then rinsed with distilled water, air-dried at room temperature, and subsequently treated at 300℃ in a continuous N2 atmosphere at 200ml / min for 2 hours. A 2L mixed aqueous solution of 25% Ni(NO3)2, 16% Al(NO3)3, and 15% Fe(NO3)3 was prepared, and 30ml of 0.1mol / L lemon juice was added. The pH was adjusted to 4.0 using nitric acid. A 0.5mm platinum wire was connected as the anode, and a GH4169 alloy tube was connected as the cathode. A power supply was connected, with the platinum wire 2cm away from the alloy tube. A constant current mode was used, with the current set to 100mA. After deposition for 1 hour, a GH4169 alloy tube with Ni, Al, and Fe deposits was obtained. Subsequently, it was treated at 500℃ in a high-purity hydrogen atmosphere for 2 hours to form a 160nm thick Ni, Al, and Fe dopant layer on the reactor contact surface. Then, it was naturally cooled to obtain... A metal catalytic reactor in which Ni, Al and Fe are doped at 2.5 wt.%, 1.5 wt.%, and 1.2 wt.%, respectively.

[0084] Example 12

[0085] Electrochemical deposition method

[0086] Incoloy 903 alloy tubing (inner diameter 14mm, outer diameter 18mm, id14od18) was selected and boiled in a 15% NaOH solution for 1 hour to remove oil. It was then rinsed with distilled water, air-dried at room temperature, and subsequently treated at 300℃ in a continuous N2 atmosphere at 200ml / min for 2 hours. A mixed aqueous solution of 25% La(NO3)3, 15% Ce(NO3)3, and 15% Fe(NO3)3 was prepared (2L). 22ml of 0.1mol / L citric acid was added, and the pH was adjusted to 3.6 with nitric acid. A 0.5mm platinum wire was connected as the anode, and Incoloy... Incoloy 903 alloy tubing was used as the cathode and connected to a power source. The platinum wire was 2 cm away from the alloy tubing. A constant current mode was used, with the current set at 200 mA. After deposition for 1 hour, Incoloy 903 alloy tubing with La, Ce, and Fe deposits was obtained. Subsequently, it was treated for 2 hours in a high-purity hydrogen atmosphere at 500℃ to form a 180 nm thick Ni, Al, and Fe dopant layer on the reactor contact surface. After natural cooling, the desired product was obtained. A metal catalytic reactor in which La, Ce and Fe are doped at 3 wt.%, 2.8 wt.%, and 1.1 wt.%, respectively.

[0087] Example 13

[0088] Conversion sedimentation precipitation method

[0089] Incoloy 800 alloy tubing (inner diameter 12mm, outer diameter 18mm, id12od18) was selected and boiled in 15% NaOH solution for 1 hour to remove oil. After rinsing with distilled water and air-drying at room temperature, it was then treated at 300℃ in a continuous N2 atmosphere with a flow rate of 200ml / min for 2 hours. A 2L aqueous solution of 10% Ce(NO3)2 was prepared, with 25ml of 0.1mol / L citric acid and 12ml of 10% H2O2 added. After circulating the aqueous solution for 1 hour, Ce-deposited Incoloy 800 alloy tubing was obtained. This was then treated at 500℃ in a high-purity hydrogen atmosphere for 2 hours to form a 100nm thick Ce dopant layer on the reactor contact surface. After natural cooling, the desired product was obtained. A metal catalytic reactor in which Ce is doped at a concentration of 0.8 wt.%.

[0090] Example 14

[0091] Conversion sedimentation precipitation method

[0092] GH4169 alloy tubing (inner diameter 14mm, outer diameter 18mm, id14od18) was selected and boiled in 15% NaOH solution for 1 hour to remove oil. It was then rinsed with distilled water, air-dried at room temperature, and subsequently treated at 300℃ in a continuous N2 atmosphere with a flow rate of 200ml / min for 2 hours. A mixed aqueous solution of 10% Ce(NO3)2 and 20% Fe(NO3)3 was prepared (2L), with 20ml of 0.1mol / L citric acid and 22ml of 10% H2O2 added. After circulating the aqueous solution for 1 hour, Ce-deposited GH4169 alloy tubing was obtained. This was then treated at 500℃ in a high-purity hydrogen atmosphere for 2 hours to form a 100nm thick Ce and Fe dopant layer on the reactor contact surface. After natural cooling, the desired product was obtained. A metal catalytic reactor in which Ce and Fe are doped at 1.2 wt.% and 1.1 wt.%, respectively.

[0093] Example 15

[0094] Conversion sedimentation precipitation method

[0095] Incoloy 800 alloy tubing (inner diameter 14mm, outer diameter 18mm, id14od18) was selected and boiled in 15% NaOH solution for 1 hour to remove oil. After rinsing with distilled water and air-drying at room temperature, it was then treated for 2 hours at 300℃ in a continuous N2 atmosphere with a flow rate of 200 ml / min. A mixed aqueous solution of 20% La(NO3)3, 15% Ce(NO3)3, and 20% Fe(NO3)3 was prepared (2 L), and 26 ml of 0.1 mol / L citric acid and 22 ml of 10% H2O2 were added. After 1.5 hours of aqueous solution circulation deposition, Incoloy 800 alloy tubing with La, Ce, and Fe deposits was obtained. This was then treated for 2 hours at 500℃ in a high-purity hydrogen atmosphere to form a 100 nm thick layer of La, Ce, and Fe dopants on the reactor contact surface. After natural cooling, the desired product was obtained. A metal catalytic reactor in which La, Ce and Fe are doped at 1.6 wt.%, 1.0 wt.%, and 1.1 wt.%, respectively.

[0096] Example 16

[0097] Conversion sedimentation precipitation method

[0098] Inconel 725 alloy tubing (inner diameter 14mm, outer diameter 18mm, id14od18) was selected and boiled in 15% NaOH solution for 1 hour to remove oil. After rinsing with distilled water and air-drying at room temperature, it was then treated for 2 hours at 300℃ in a continuous N2 atmosphere with a flow rate of 200 ml / min. A mixed aqueous solution of 20% Al(NO3)3, 15% Ce(NO3)3, and 20% Fe(NO3)3 was prepared (2 L), and 26 ml of 0.1 mol / L citric acid and 22 ml of 10% H2O2 were added. After 1.5 hours of aqueous solution circulation deposition, Inconel 725 alloy tubing with La, Ce, and Fe deposits was obtained. This was then treated for 2 hours at 500℃ in a high-purity hydrogen atmosphere to form a 140 nm thick layer of Al, Ce, and Fe dopants on the reactor contact surface. After natural cooling, the desired product was obtained. A metal catalytic reactor in which Al, Ce and Fe are doped at 1.4 wt.%, 1.1 wt.%, and 1.4 wt.%, respectively.

[0099] Example 17

[0100] Conversion sedimentation precipitation method

[0101] Inconel 718 alloy tubing (inner diameter 21 mm, outer diameter 25 mm, id21od25) was selected and boiled in 15% NaOH solution for 1 hour to remove oil. After rinsing with distilled water and air-drying at room temperature, it was then treated for 2 hours at 300℃ in a continuous N2 atmosphere with a flow rate of 200 ml / min. A mixed aqueous solution of 20% Ni(NO3)2 and 15% Zn(NO3)2 was prepared (2 L), with 30 ml of 0.1 mol / L citric acid and 50 ml of 10% H2O2 added. After 1.5 hours of aqueous solution circulation deposition, Ni and Zn deposited in the Inconel 718 alloy tubing were obtained. This was then treated for 2 hours at 500℃ in a high-purity hydrogen atmosphere to form a 130 nm thick Ni and Zn dopant layer on the reactor contact surface. After natural cooling, the desired product was obtained. A metal catalytic reactor in which Ni and Zn are doped at 4.5 wt.% and 1.0 wt.%, respectively.

[0102] Example 18

[0103] Conversion sedimentation precipitation method

[0104] Inconel 600 alloy tubing (inner diameter 10mm, outer diameter 14mm, id10od14) was selected and boiled in 15% NaOH solution for 1 hour to remove oil. After rinsing with distilled water and air-drying at room temperature, it was then treated for 2 hours at 300℃ in a continuous N2 atmosphere with a flow rate of 200 ml / min. 2 L of an aqueous solution of 20% La(NO3)3, 15% Ce(NO3)3, and 20% Fe(NO3)3 was prepared, and 26 ml of 0.1 mol / L citric acid and 22 ml of 10% H2O2 were added. After 1.5 hours of aqueous solution circulation deposition, Inconel 600 alloy tubing with La, Ce, and Fe deposits was obtained. This was then treated for 2 hours at 500℃ in a high-purity hydrogen atmosphere to form a 100 nm thick layer of La, Ce, and Fe dopants on the reactor contact surface. After natural cooling, the desired product was obtained. A metal catalytic reactor in which La, Ce and Fe are doped at 1.6 wt.%, 1.0 wt.%, and 1.1 wt.%, respectively.

[0105] Example 19

[0106] Conversion sedimentation precipitation method

[0107] GH600 alloy tubing (inner diameter 10mm, outer diameter 14mm, id10od14) was selected and boiled in 15% NaOH solution for 1 hour to remove oil. After rinsing with distilled water and air-drying at room temperature, it was then heated at 300℃ in a continuous N2 atmosphere at 200ml / min for 2 hours. A 2L aqueous solution of 20% Ni(NO3)2 and 15% Ce(NO3)3 was prepared, and 100ml of 0.1mol / L citric acid and 40ml of 10% H2O2 were added. After 2 hours of aqueous solution circulation deposition, GH600 alloy tubing with Ni and Ce deposits was obtained. This was then treated at 500℃ in a high-purity hydrogen atmosphere for 2 hours to form a 100nm thick Ni and Ce dopant layer on the reactor contact surface. After natural cooling, the desired product was obtained. A metal catalytic reactor in which Ni and Ce are doped at 8.5 wt.% and 2.0 wt.%, respectively.

[0108] Example 20

[0109] Conversion sedimentation precipitation method

[0110] Hastelloy G-35 alloy tubing (inner diameter 10mm, outer diameter 14mm, id10od14) was selected and boiled in 15% NaOH solution for 1 hour to remove oil. After rinsing with distilled water and air-drying at room temperature, it was then heated at 300℃ in a continuous N2 atmosphere at 200ml / min for 2 hours. A 2L aqueous solution of 20% Ni(NO3)2 and 25% Fe(NO3)3 was prepared, with 100ml of 0.1mol / L citric acid and 35ml of 10% H2O2 added. After 3 hours of aqueous solution circulation deposition, Ni and Fe deposited Hastelloy G-35 alloy tubing was obtained. This was then treated at 500℃ in a high-purity hydrogen atmosphere for 2 hours to form a 130nm thick Ni and Fe dopant layer on the reactor contact surface. After natural cooling, the desired product was obtained. A metal catalytic reactor in which Ni and Fe are doped at 8.5 wt.% and 7.8 wt.%, respectively.

[0111] Example 21

[0112] Conversion sedimentation precipitation method

[0113] Monel 400 alloy tubing (inner diameter 12mm, outer diameter 16mm, id12od16) was selected and boiled in 15% NaOH solution for 1 hour to remove oil. After rinsing with distilled water and air-drying at room temperature, it was then heated at 300℃ in a continuous N2 atmosphere at 200ml / min for 2 hours. A 2L aqueous solution of 20% Ba(NO3)2 and 15% Fe(NO3)3 was prepared, and 33ml of 0.1mol / L citric acid and 40ml of 10% H2O2 were added. After 1.5 hours of aqueous solution circulation deposition, Monel 400 alloy tubing with Ba and Fe deposits was obtained. This was then treated at 500℃ in a high-purity hydrogen atmosphere for 2 hours to form a 120nm thick layer of Ba and Fe dopants on the reactor contact surface. After natural cooling, the desired product was obtained. A metal catalytic reactor in which Ba and Fe are doped at 2.2 wt.% and 3 wt.%, respectively.

[0114] Example 22

[0115] Conversion sedimentation precipitation method

[0116] GH1015 alloy tubing (inner diameter 10mm, outer diameter 14mm, id10od14) was selected and boiled in 15% NaOH solution for 1 hour to remove oil. It was then rinsed with distilled water, air-dried at room temperature, and subsequently heated at 300℃ in a continuous N2 atmosphere at 200ml / min for 2 hours. A 2L aqueous solution of 15% Ni(NO3)2 and 25% Mg(NO3)2 was prepared, and 45ml of 0.1mol / L citric acid and 45ml of 10% H2O2 were added. After 3 hours of aqueous solution circulation deposition, GH1015 alloy tubing with Ni and Mg deposits was obtained. This was then treated at 500℃ in a high-purity hydrogen atmosphere for 2 hours to form a 120nm thick Ni and Mg dopant layer on the reactor contact surface. After natural cooling, the desired product was obtained. A metal catalytic reactor in which Ni and Mg are doped at 5.2 wt.% and 4.6 wt.%, respectively.

[0117] Example 23

[0118] Conversion sedimentation precipitation method

[0119] Inconel 783 alloy tubing (inner diameter 12mm, outer diameter 16mm, id12od16) was selected and boiled in 15% NaOH solution for 1 hour to remove oil. After rinsing with distilled water and air-drying at room temperature, it was then heated at 300℃ in a continuous N2 atmosphere at 200ml / min for 2 hours. A 2L aqueous solution of 20% Ni(NO3)2, 10% Mn(NO3)2, 15% Fe(NO3)3, and 10% Zn(NO3)2 was prepared, and 40ml of 0.1mol / L citric acid and 50ml of 10% H2O2 were added. After 3 hours of circulating deposition, Inconel 783 alloy tubing with Ni, Mn, Fe, and Zn deposits was obtained. This was then treated at 500℃ in a high-purity hydrogen atmosphere for 2 hours to form a 160nm thick Ni, Mn, Fe, and Zn dopant layer on the reactor contact surface. After natural cooling, the desired product was obtained. A metal catalytic reactor in which Ni, Mn, Fe and Zn are doped at 5 wt.%, 2.5 wt.%, 3 wt.%, and 1.5 wt.%, respectively.

[0120] II. Direct catalytic reaction of methane to olefins, aromatics and hydrogen under continuous flow conditions

[0121] All of the catalytic reactors described above can be used directly without the need to load catalyst.

[0122] All reaction examples were conducted in a continuous flow microreactor equipped with a gas mass flow meter, gas deoxygenation and dehydration tubing, and an online product analysis chromatograph (the reactor tail gas was directly connected to the chromatograph's quantitative valve for periodic real-time sampling and analysis). Unless otherwise specified, N2 in the feed gas was used as an internal standard. Online product analysis was performed using an Agilent 7890B gas chromatograph equipped with dual FID and TCD detectors. The FID detector, equipped with an HP-1 capillary column, analyzed low-carbon olefins, low-carbon alkanes, and aromatics; the TCD detector, equipped with a Hayesep D packed column, analyzed low-carbon olefins, low-carbon alkanes, methane, hydrogen, and the internal standard nitrogen. Methane conversion, hydrocarbon product selectivity, and carbon deposition were calculated based on the carbon balance before and after the reaction, using the following formulas:

[0123] Methane conversion rate

[0124]

[0125] in, The area of ​​the methane peak at the tail gas outlet after the reaction on the TCD detector; The nitrogen peak area at the tail gas outlet after the reaction on the TCD detector; The area of ​​the methane peak at room temperature on the TCD detector; The area of ​​the methane peak at room temperature on the TCD detector.

[0126] The selectivity of products and coke deposits

[0127]

[0128]

[0129] in, The total number of carbon atoms entering the reactor; The relative correction factors for methane and nitrogen on the TCD detector; C x H y Product selectivity; C x H y x is the number of C's, and y is the number of H's. C on the FID detector x H y The relative correction factor between the product and benzene; The peak area of ​​the exhaust gas after the reaction on the TCD detector; The peak area of ​​the exhaust gas after the reaction on the FID detector;

[0130] In the following examples, all products are detectable by gas chromatography.

[0131] Application Comparative Example 1

[0132] A 1.6-meter blank without doped metal active components was prepared using Comparative Example 1. 5g of 1.5wt.% Ni-1.1wt.% Co / SiO2 powder catalyst (20-40 mesh) was added to a 601 metal reactor. After replacing the air in the reactor with Ar gas at a flow rate of 0.5L / min for approximately 30 minutes, the Ar flow rate was kept constant, and the temperature was programmed to rise from room temperature to 1050℃ at a rate of 6℃ / min, while adjusting the CH4 / N2 (volume content) to 90% and the feed gas flow rate to 2L / min. After maintaining this for 30 minutes, online analysis was initiated, followed by a 200-hour stability test. Carbon buildup caused reactor blockage, halting the reaction. The analysis results showed that after 30 minutes, the methane conversion rate was 9%, the selectivity for ethylene was 21%, the selectivity for propylene was 5%, the selectivity for benzene was 5%, the selectivity for naphthalene was 15%, and the selectivity for carbon buildup was 59%. After 200 hours, the methane conversion rate decreased to 6%, and the reactor blockage led to the cessation of the reaction.

[0133] Application Comparative Example 2

[0134] A 1.6-meter blank without doped metal active components was prepared using Comparative Example 1. In the 601 metal reactor, after replacing the air in the reactor with 0.5 L / min Ar gas for approximately 30 minutes, coupled with Joule heating, and after replacing the air in the reactor with 0.5 L / min Ar gas for approximately 30 minutes, the power supply parameters were adjusted to: current 86 A, DC voltage 5 V, power 0.43 kW, and feed gas 1.0 L / min CH4. After maintaining this for 30 minutes, online analysis was started. The methane conversion rate was 19%, the selectivity for ethylene was 36%, the selectivity for propylene was 3%, the selectivity for benzene was 10%, the selectivity for toluene was 5%, the selectivity for naphthalene was 12%, and the selectivity for coke was 34%.

[0135] Application Example 1

[0136] The 1.6-meter sample obtained using Example 1 The GH3030 metal catalytic reactor was purged with 0.5 L / min Ar gas for approximately 30 minutes. After Joule heating, the air in the reactor was purged with 0.5 L / min Ar gas for approximately 30 minutes. The power parameters were then adjusted to: current 85 A, DC voltage 5 V, power 0.425 kW, and feed gas 1.0 L / min CH4. After maintaining this for 30 minutes, online analysis was initiated. The analysis results showed that the conversion rate of methane was 35%, the selectivity of ethylene was 64%, the selectivity of propylene was 9%, the selectivity of butene was 8%, the selectivity of benzene was 15%, the selectivity of p-xylene was 3%, the selectivity of naphthalene was 1%, and there was zero carbon deposition.

[0137] Application Example 2

[0138] The 1.6-meter sample obtained using Example 1 The GH3530 metal catalytic reactor was used to purge the air in the reactor with 0.5 L / min Ar gas for approximately 30 minutes. Then, Joule heating was coupled in, and after purging the air in the reactor with 0.5 L / min Ar gas for approximately 30 minutes, the power parameters were adjusted to: current 83 A, DC voltage 6 V, power 0.498 kW, and feed gas 1.8 L / min CH4. After maintaining this for 30 minutes, online analysis was started. The analysis results showed that the conversion rate of methane was 36%, the selectivity of ethylene was 61%, the selectivity of propylene was 12%, the selectivity of butene was 2%, the selectivity of benzene was 18%, the selectivity of naphthalene was 7%, and there was zero carbon deposition.

[0139] Application Example 3

[0140] The 1.6-meter sample obtained using Example 1 In the GH3030 metal catalytic reactor, after replacing the air in the reactor with 0.5 L / min Ar gas for approximately 30 minutes, coupled with Joule heating, the power supply parameters were adjusted to: current 80 A, DC voltage 6 V, power 0.48 kW, and feed gas 1.8 L / min CH4. After maintaining this for 30 minutes, online analysis was initiated. The analysis results showed that the methane conversion rate was 37%, the ethylene selectivity was 69%, the propylene selectivity was 12%, the benzene selectivity was 13%, the naphthalene selectivity was 5%, and the coking selectivity was 1%.

[0141] Application Example 4

[0142] The 1.6-meter sample obtained using Example 2 The GH3030 metal catalytic reactor was purged with 0.5 L / min Ar gas for approximately 30 minutes. After Joule heating, the power supply parameters were adjusted to: current 85 A, AC voltage 5 V, power 0.425 kW, and feed gas 1.8 L / min CH4. After maintaining this for 30 minutes, online analysis was initiated. The analysis results showed that the methane conversion rate was 40%, the ethylene selectivity was 65%, the propylene selectivity was 18%, the benzene selectivity was 12%, the naphthalene selectivity was 5%, and there was zero carbon deposition.

[0143] Application Example 5

[0144] The 1.6-meter sample obtained using Example 3 In the 601 metal catalytic reactor, after replacing the air in the reactor with 0.5 L / min Ar gas for about 30 minutes, coupled with Joule heating, the power supply parameters were adjusted to: current 90 A, DC voltage 5 V, power 0.45 kW, and feed gas 2.0 L / min CH4. After maintaining this for 30 minutes, online analysis was started. The analysis results showed that the conversion rate of methane was 45%, the selectivity of ethylene was 63%, the selectivity of propylene was 6%, the selectivity of benzene was 22%, the selectivity of naphthalene was 9%, and there was zero carbon deposition.

[0145] Application Example 6

[0146] Prepared using Example 4 In the 601 metal catalytic reactor, after replacing the air in the reactor with 0.5 L / min Ar gas for about 30 minutes, coupled with Joule heating, the power supply parameters were adjusted to: current 105 A, DC voltage 6 V, power 0.63 kW, and feed gas 3.0 L / min CH4. After maintaining this for 30 minutes, online analysis was started. The analysis results showed that the conversion rate of methane was 59%, the selectivity of ethylene was 72%, the selectivity of propylene was 6%, the selectivity of benzene was 20%, the selectivity of naphthalene was 2%, and there was zero carbon deposition.

[0147] Application Example 7

[0148] Prepared using Example 4 In the 601 metal catalytic reactor, after replacing the air in the reactor with 0.5 L / min Ar gas for approximately 30 minutes, coupled with Joule heating, the power supply parameters were adjusted to: current 98 A, AC voltage 6 V, power 0.588 kW, and feed gas 2.5 L / min CH4. After maintaining this for 30 minutes, online analysis was initiated. The analysis results showed that the methane conversion rate was 58%, the selectivity for ethylene was 70%, the selectivity for propylene was 6%, the selectivity for benzene was 20%, the selectivity for naphthalene was 4%, and there was zero carbon deposition.

[0149] Application example (8-17)

[0150] The 1.6-meter sample obtained using Example 5 In a 600 metal catalytic reactor, after replacing the air in the reactor with 0.5 L / min Ar gas for about 30 minutes, coupled with Joule heating, the flow rate of the feed gas CH4 was as follows. After maintaining this flow rate for 30 minutes, online analysis was started, and the analysis results are shown in the table below.

[0151] Table 2

[0152]

[0153] Application Example 18

[0154] The 1.6-meter sample obtained using Example 7 In a 400-ton metal catalytic reactor, after replacing the air in the reactor with 0.5 L / min Ar gas for approximately 30 minutes, coupled with Joule heating, the power supply parameters were adjusted to: current 112 A, DC voltage 7 V, power 0.784 kW, and feed gas 3 L / min CH4. After maintaining this for 30 minutes, online analysis was initiated. The analysis results showed that the methane conversion rate was 63%, the ethylene selectivity was 71%, the propylene selectivity was 4%, the benzene selectivity was 12%, the naphthalene selectivity was 12.5%, and the coking selectivity was 0.5%.

[0155] Application Example 19

[0156] The 1.6-meter sample obtained using Example 8 In an Inconel X-750 metal catalytic reactor, after replacing the air in the reactor with 0.5 L / min Ar gas for approximately 30 minutes, coupled with Joule heating, the air in the reactor was replaced with 0.5 L / min Ar gas for approximately 30 minutes. The power parameters were then adjusted to: current 115 A, DC voltage 6 V, power 0.69 kW, and feed gas 5 L / min CH4. After maintaining this for 30 minutes, online analysis was initiated. The analysis results showed that the methane conversion rate was 43%, the selectivity for ethylene was 61%, the selectivity for propylene was 9%, the selectivity for butene was 9%, the selectivity for benzene was 12%, the selectivity for naphthalene was 9%, and there was zero carbon deposition.

[0157] Application Example 20

[0158] The 1.6-meter sample obtained using Example 9 In a Hastelloy G-30 metal catalytic reactor, after replacing the air in the reactor with 0.5 L / min Ar gas for approximately 30 minutes, coupled with Joule heating, the power supply parameters were adjusted to: current 95 A, DC voltage 6.5 V, power 0.6175 kW, and feed gas 3 L / min CH4. After maintaining this for 30 minutes, online analysis was initiated. The analysis results showed that the methane conversion rate was 47%, the selectivity for ethylene was 66%, the selectivity for propylene was 7%, the selectivity for butene was 8%, the selectivity for benzene was 17%, the selectivity for naphthalene was 2%, and there was zero carbon deposition.

[0159] Application Examples 21-28

[0160] The 1.6-meter sample obtained using Example 10 In a 600 metal catalytic reactor, after replacing the air in the reactor with 0.5 L / min Ar gas for about 30 minutes, coupled with Joule heating, and after replacing the air in the reactor with 0.5 L / min Ar gas for about 30 minutes, the AC power supply power and current parameters were adjusted as follows, and the CH4 feed gas flow rate was as follows. After maintaining this for 30 minutes, online analysis was started, and the analysis results are shown in the table below.

[0161] Table 3

[0162]

[0163] Application Examples 30-39

[0164] The 1.6-meter sample obtained using Example 15 In the metal catalytic reactor, after replacing the air in the reactor with 0.5 L / min Ar gas for about 30 minutes, coupled with Joule heating, and after replacing the air in the reactor with 0.5 L / min Ar gas for about 30 minutes, the AC power supply power and current parameters were adjusted as follows, and the feed gas CH4 flow rate was as follows. After maintaining this for 30 minutes, online analysis was started, and the analysis results are shown in the table below.

[0165] Table 4

[0166]

[0167] Application Example 41

[0168] The 1.6-meter sample obtained using Example 18 In a 600-ton metal catalytic reactor, after replacing the air in the reactor with 0.5 L / min Ar gas for approximately 30 minutes, coupled with Joule heating, the power supply parameters were adjusted as follows: current 220 A, DC voltage 10 V, power 2.2 kW, and feed gas flow rate 6 L / min. CH4 was incubated for 30 minutes before online analysis began. The results showed a methane conversion rate of 82%, ethylene selectivity of 71%, propylene selectivity of 6%, butene selectivity of 6%, benzene selectivity of 15%, and naphthalene selectivity of 2%. After a 500-hour stability test, the results showed a methane conversion rate of 80%, ethylene selectivity of 69%, propylene selectivity of 7%, butene selectivity of 5%, benzene selectivity of 15%, and naphthalene selectivity of 4%. After a 1000-hour stability test, the results showed a methane conversion rate of 78%, ethylene selectivity of 67%, propylene selectivity of 6%, butene selectivity of 6%, benzene selectivity of 15%, naphthalene selectivity of 6.7%, and carbon deposition selectivity of 0.3%.

[0169] Application Examples 42-43

[0170] The 20-meter sample obtained using Example 19 In the metal catalytic reactor, after replacing the air in the reactor with 0.5 L / min Ar gas for about 30 minutes, coupled with Joule heating, and after replacing the air in the reactor with 0.5 L / min Ar gas for about 30 minutes, the AC power supply power and current parameters were adjusted as follows, and the feed gas CH4 flow rate was as follows. After maintaining this for 30 minutes, online analysis was started, and the analysis results are shown in the table below.

[0171] Table 5

[0172]

[0173] In summary, using a catalytic reactor, the present invention achieves a methane conversion rate of 35-85%, an olefin selectivity of 65-90%, an aromatic selectivity of 13-40%, and zero carbon deposition.

[0174] Therefore, it can be concluded that the catalyst of the catalytic reactor of the present invention has the characteristics of long life (>1000h), high product selectivity, zero carbon deposition, easy product separation, good process repeatability, and safe and reliable operation, and has broad prospects for industrial application.

[0175] It should be noted that, according to the above embodiments of the present invention, those skilled in the art can fully realize the scope of the independent claims and dependent claims of the present invention, and the implementation process and method are the same as those in the above embodiments; and the parts of the present invention not described in detail belong to the well-known technology in the art.

[0176] The above description is only a part of the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the protection scope of the present invention.

Claims

1. A method for the anaerobic catalytic conversion of methane to olefins, aromatics, and hydrogen using a Joule thermally coupled metal catalytic reactor, characterized in that: By directly connecting a DC or AC power supply to both ends of a metal catalytic reactor, Joule heating is achieved using the resistance heating of the metal reactor. The feed gas methane is passed into the Joule-heated metal catalytic reactor for catalytic conversion reaction to produce olefins, aromatics, and hydrogen. The power of the Joule heating is 100W-100KW, the current range is 5-10000 A, and the voltage range is 1-1000 V. The metal catalytic reactor includes an active component and a metal tube. The active catalyst component is coated and doped on the contact surface between the metal tube and the reactant, forming a thin layer of catalytic dopant on the contact surface between the metal tube and the reactant. The active catalyst component and the substrate metal at the contact surface of the metal tube form a catalyst. The contact surface refers to the inner wall and / or outer wall of the metal tube. The thickness of the catalytic dopant thin layer is 100 nanometers to 1 millimeter. The doping is lattice doping; the active component of the catalyst is a metal element, or a mixture of metal and non-metal elements, and the metal element doping amount is 0.1-20 wt.% based on the total weight of the dopant thin layer as 100%. The metal element exists in one or more states such as oxide, carbide, nitride, silicide, and alloy; the metal element includes one or more of the following: magnesium, aluminum, calcium, barium, titanium, manganese, vanadium, niobium, tungsten, molybdenum, chromium, iron, cobalt, nickel, copper, zinc, tin, gallium, zirconium, lanthanum, cerium, ruthenium, gold, palladium, or platinum. The metal catalytic reactor was prepared by the following method: Electrochemical deposition method includes the following steps: (1) Boil the base pipe in 10-20wt.% NaOH or KOH solution for 1-2 hours to remove oil, rinse it clean, and air dry it at room temperature for later use; (2) The substrate pipe treated in step (1) is heated in a hot N2 atmosphere at a temperature of 300-500℃ for 1-2 hours to form an anti-corrosion and conductive thin film layer. (3) At room temperature, prepare an aqueous or organic solution of the precursor of the doped metal element, adjust the pH of the solution to 3.3-6.5, immerse the metal tube to be doped in the precursor solution, connect the power supply and use it as the cathode, and platinum as the anode. After connecting the circuit, adjust the distance between the anode and cathode to 2-5 cm, adjust the DC regulated power supply to maintain constant current mode, and the current is 5mA-0.5A. After electrodeposition for 0.5-2 hours, wash and dry with deionized water. After the deposition is completed, a metal catalytic reactor is obtained. The precursor of the doped metal element is one or more of the following: metal nitrate, soluble halide, soluble sulfate, soluble carbonate, soluble phosphate, soluble C methanol salt, soluble ethanol salt, soluble formate, and soluble acetate. Alternatively, a conversion deposition precipitation method may be used, including the following steps: (1) Boil the base pipe in 10-20wt.% NaOH or KOH solution for 1-2 hours to remove oil, rinse it clean, and air dry it at room temperature for later use; (2) The substrate pipe treated in step (1) is heated in a hot N2 atmosphere at a temperature of 300-500℃ for 1-2 hours to form an anti-corrosion and conductive thin film layer. (3) At room temperature, prepare an aqueous or organic solution of the precursor of the doped metal element, adjust the pH of the solution to 3.8-7.2, immerse the metal tube to be doped in the precursor solution, so that the solution is in a flowing state inside the metal tube to be deposited, and then add 10-20 wt.% H2O2 aqueous solution for conversion deposition precipitation. The deposition time is 0.5-5 hours. After the deposition is completed, a metal catalytic reactor is obtained. The precursor of the doped metal element is one or more of the following: metal chloride, methanol salt, ethanol salt, formate, and acetate.

2. The method according to claim 1, characterized in that: The reaction process is a continuous flow reaction mode. When the reaction is continuous, the reaction pressure is 0.05-1MPa and the feed gas flow rate is 1-100L / min.

3. The method according to claim 1, characterized in that: The feed gas includes methane, or a mixture of methane and other gases, wherein the other gases include one or two of inert atmosphere gases and non-inert atmosphere gases; the inert atmosphere gas is one or more of nitrogen, helium, neon, argon, and krypton, and the volume content of the inert atmosphere gas in the feed gas is 0-95%; the non-inert atmosphere gas is one or more of carbon monoxide, hydrogen, and alkanes with 2-4 carbon atoms, and the volume ratio of the non-inert atmosphere gas to methane is 0-10%; the volume content of methane in the feed gas is 5-100%.

4. The method according to claim 1, characterized in that: The aromatic hydrocarbon products include one or more of benzene, toluene, p-xylene, o-xylene, m-xylene, ethylbenzene, and naphthalene.

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