Method for producing c2 hydrocarbon compounds and aromatic compounds from methane

Abstract

The present invention relates to a method for producing C2 hydrocarbon compounds and aromatic compounds from methane and, more specifically, to a method for producing C2 hydrocarbon compounds and aromatic compounds from methane, wherein in the production of C2 hydrocarbon compounds and aromatic compounds from methane, a great reduction in the amount of methane consumed, high yields of C2 hydrocarbon compounds and aromatic compounds, and an improvement in catalyst regeneration efficiency can be attained, leading to improved economic efficiency.

Description

Method for producing C2 hydrocarbon compounds and aromatic compounds from methane

[0001] The present invention relates to a method for producing C2 hydrocarbon compounds and aromatic compounds from methane, and more particularly, to a method for efficiently producing C2 hydrocarbon compounds and aromatic compounds from methane through a dehydrogenation aromatization reaction and a non-oxidation direct conversion reaction of methane.

[0002] Recently, steady efforts have been made to convert methane (CH4), which can be obtained from natural gas, shale gas, etc., into high-value products such as transportation fuels or chemical raw materials. Representative examples of high-value products obtained from methane include olefins (ethylene, propylene, butylene, etc.) and aromatic compounds. The MTO (Methanol to Olefins) technology, which produces light olefins via methanol from synthesis gas (H2+ CO) obtained through methane reforming, and the FTO (Fischer-Tropsch to Olefins) technology, which produces light olefins directly from synthesis gas, are known to be the most feasible technologies.

[0003] However, in the case of technology to produce high value-added products via synthesis gas, hydrogen (H2) or carbon monoxide (CO) is additionally required to remove oxygen atoms from carbon monoxide (CO), which results in a decrease in the utilization efficiency of hydrogen atoms or carbon atoms in the overall process.

[0004] Therefore, a new technology is required that can directly convert methane into high-value-added products without going through synthesis gas. To directly convert methane into high-value-added products, it is necessary to activate methane by cleaving the strongly formed C-H bonds (434 kJ / mol) within methane. From this perspective, active research has been conducted on the oxidative coupling of methane (OCM) technology that activates methane using oxygen. However, the intense reactivity of O2 in the OCM reaction still poses a problem: it forms large amounts of thermodynamically stable H2O and CO2, reducing the utilization efficiency of hydrogen or carbon atoms.

[0005] To address these issues, technologies for producing ethylene, aromatic compounds, and other compounds through the direct conversion of methane under anaerobic or oxygen-free conditions have recently been developed. However, due to the low reactivity of methane, these processes are conducted at high temperatures and high pressures, necessitating the development of suitable reactors and catalysts. However, research to date has highlighted the rapid decline in catalytic activity due to carbon (coke) deposition on the catalyst under high temperature and high pressure conditions as a key issue (see Non-Patent Documents 0001 and 0002).

[0006] Accordingly, U.S. Patent No. 4,424,401 discloses a method for aromatizing acetylene into a hydrocarbon mixture by diluting it with an inert gas, water, hydrogen, methane, and alcohol in the presence of a zeolite catalyst ZSM-5, and U.S. Patent No. 8,013,196 discloses a method for thermally converting a feed containing methane into an acetylene-containing exhaust by thermally cracking it, and hydrogenating the converted acetylene-containing exhaust to produce ethylene.

[0007] However, as in these prior literature, the aromatization of methane or acetylene over zeolites or other catalysts also suffered from the following problems: The catalyst exhibited very short-term performance and rapidly deactivated due to the accumulation of coke fragments and the rapid polymerization of acetylene. Furthermore, high levels of other byproducts derived from the acetylene conversion were formed.

[0008] In particular, coking, or coke formation, has an undesirable effect on mass balance and yield, as each molecule of reactant and intermediate product converted to coke is no longer available for the desired reaction to produce aromatics. The coke selectivity achieved to date has, in most cases, exceeded 20% based on the converted aliphatic material. Furthermore, coking deactivates the catalyst within a relatively short period of time, shortening the production cycle and necessitating catalyst regeneration. Coking also irreversibly shortens the catalyst's lifespan.

[0009] Therefore, there is a need in the art for the development of improved methods that enable more efficient and stable production of aromatic compounds and C2 hydrocarbon compounds, particularly from methane.

[0010] [Prior Art Literature]

[0011] [Patent Document]

[0012] (Patent Document 1) U.S. Patent No. 4,424,401 (Registration Date: January 3, 1984)

[0013] (Patent Document 2) U.S. Patent No. 8,013,196 (Registration Date: September 6, 2011)

[0014] [Non-patent literature]

[0015] (Non-patent Document 1)

[0016] (Non-patent Document 2) Mann Sakbodin et al., Hydrogen-Permeable Tubular Membrane Reactor: Promoting Conversion and Product Selectivity for Non-Oxidative Activation of Methane over an FeVSiO2 Catalyst, Angew. Chem. 2016, 128, 16383 ~ 16386

[0017] The main purpose of the present invention is to solve the above-described problems, and to provide a method for producing C2 hydrocarbon compounds and aromatic compounds from methane, which can significantly improve methane consumption, provide a high yield of C2 hydrocarbon compounds and aromatic compounds, and improve catalyst regeneration efficiency, thereby improving economic feasibility.

[0018] In order to achieve the above object, one embodiment of the present invention provides a method for producing a C2 hydrocarbon compound and an aromatic compound from methane, characterized by comprising the steps of: (a) supplying a methane-containing feed to a reactor charged with a catalyst for dehydroaromatization reaction to produce an unsaturated hydrocarbon containing an aromatic compound and an unreacted substance; (b) reacting the produced unsaturated hydrocarbon containing an aromatic compound and the unreacted substance at 900°C to 1,200°C to produce hydrogen, a C2 hydrocarbon compound, and an aromatic compound; (c) after step (b), supplying a hydrogen-containing gas to the deactivated catalyst for dehydroaromatization reaction to regenerate the catalyst for dehydroaromatization reaction; and (d) after step (c), sequentially repeating steps (a) and (b).

[0019] In a preferred embodiment of the present invention, the catalyst for the dehydroaromatization reaction may be characterized by including a zeolite; and at least one transition metal selected from the group consisting of transition metals of period 6 of the periodic table and transition metals of groups 4 to 6 of the periodic table supported on the zeolite.

[0020] In a preferred embodiment of the present invention, the transition metal may be characterized by being at least one selected from the group consisting of molybdenum, nickel, iron, and platinum.

[0021] In a preferred embodiment of the present invention, the method for producing C2 hydrocarbon compounds and aromatic compounds from methane may be characterized in that it is performed stepwise in a single reactor.

[0022] In a preferred embodiment of the present invention, the reaction of step (a) may be characterized in that it is performed at 600°C to 800°C.

[0023] In a preferred embodiment of the present invention, the regeneration temperature of step (c) may be maintained the same as the reaction temperature of step (a).

[0024] In a preferred embodiment of the present invention, the hydrogen-containing gas of step (c) may be characterized by containing 10 mol% to 100 mol% of hydrogen.

[0025] In a preferred embodiment of the present invention, it may be characterized in that after step (d), steps (c) and (d) are repeatedly performed.

[0026] In a preferred embodiment of the present invention, the C2 hydrocarbon compound may be characterized by being at least one selected from the group consisting of ethane, ethylene, and acetylene.

[0027] In a preferred embodiment of the present invention, after step (b), the method may further include a step of separating hydrogen, C2 hydrocarbon compounds, and aromatic compounds generated in step (b).

[0028] In a preferred embodiment of the present invention, the separated hydrogen may be used as a hydrogen-containing gas in step (c).

[0029] According to the present invention, in the production of C2 hydrocarbon compounds and aromatic compounds from methane, the methane consumption can be significantly improved, a high yield of C2 hydrocarbon compounds and aromatic compounds can be provided, and a method for producing C2 hydrocarbon compounds and aromatic compounds with improved economic feasibility can be provided by improving catalyst regeneration efficiency.

[0030] FIG. 1 is a schematic diagram of a reactor for producing a C2 hydrocarbon compound and an aromatic compound according to one embodiment of the present invention.

[0031] Figure 2 is a schematic diagram of a reactor for producing C2 hydrocarbon compounds and aromatic compounds according to another embodiment of the present invention.

[0032] Figure 3 is a graph showing the results of measuring (a) methane conversion, (b) C2 hydrocarbon selectivity, (c) C3~C5 selectivity, and (d) aromatic compound selectivity according to the methane supply amount of Example 1 according to the present invention.

[0033] Figure 4 is a graph showing the results of measuring (a) methane conversion, (b) C2 hydrocarbon production, (c) C3 to C5 production, and (d) aromatic compound production according to the methane supply amount of Example 1 and Comparative Examples 1 to 4 according to the present invention.

[0034] Figure 5 is a graph showing the results of measuring (a) methane conversion, (b) C2 hydrocarbon production, (c) C3 to C5 production, and (d) aromatic compound production according to the methane supply amount of Comparative Examples 5 to 10 according to the present invention.

[0035] [Explanation of symbols]

[0036] 100: Reactor

[0037] 110: Inlet

[0038] 111: Catalyst for dehydroaromatization reaction

[0039] 121: Preheating section

[0040] 122: Reaction area

[0041] 130: Exhaust

[0042] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In general, the nomenclature used herein is well known and commonly used in the art.

[0043] Throughout this specification, when a part is said to 'include' a component, this does not mean that it excludes other components, but rather that it may include other components, unless specifically stated otherwise, and 'reaction zone' means the space within the reactor where reactants undergo a reaction.

[0044] The terms “comprising,” “including,” or “having” used in this specification indicate the presence of features, values, steps, operations, components, parts, or combinations thereof described in the specification, and do not exclude the possibility that other features, values, steps, operations, components, parts, or combinations thereof that are not mentioned may be present or added.

[0045] The reactions and mixing described below can be carried out at room temperature and pressure unless otherwise specified, and can be carried out under typical reaction and mixing conditions without additional additions. However, this should not be interpreted in a way that deviates from matters clearly understood by those skilled in the art.

[0046] The present invention provides a method for producing a C2 hydrocarbon compound and an aromatic compound from methane, comprising the steps of: (a) supplying a methane-containing feed to a reactor charged with a catalyst for dehydroaromatization reaction to produce an unsaturated hydrocarbon containing an aromatic compound and an unreacted substance; (b) reacting the produced unsaturated hydrocarbon containing an aromatic compound and the unreacted substance at 900°C to 1,200°C to produce hydrogen, a C2 hydrocarbon compound, and an aromatic compound; (c) after step (b), supplying a hydrogen-containing gas to a deactivated catalyst for dehydroaromatization reaction to regenerate the catalyst for dehydroaromatization reaction; and (d) after step (c), sequentially repeating steps (a) and (b).

[0047] More specifically, the non-oxidative direct conversion reaction of methane has the problem of rapid catalytic activity reduction due to carbon (coke) deposition on the catalyst because the reaction proceeds at high temperatures due to the low reactivity of methane, resulting in low conversion rates of methane and yields of C2 hydrocarbon compounds and aromatic compounds.

[0048] Accordingly, in the present invention, prior to the non-oxidative direct conversion reaction of methane, a dehydroaromatization reaction of methane is performed at a lower temperature than the non-oxidative direct conversion reaction to generate an unsaturated hydrocarbon containing an aromatic compound, and the unsaturated hydrocarbon containing an aromatic compound, which is a hydrogen radical donor generated in the dehydroaromatization reaction, is used as a catalyst for the activation of the CH bond of methane in the non-oxidative direct conversion reaction, thereby significantly improving the methane consumption and thus improving the performance of the non-oxidative direct conversion reactor of methane. Since the linkage of these non-oxidative methane conversion reactions is more spontaneous and also reduces the required energy, the efficiency of the non-oxidative direct conversion reaction of methane can be improved.

[0049] In addition, in the dehydrogenation aromatization reaction of methane, the catalyst is regenerated using a hydrogen-containing gas at a temperature range at least the same as the temperature range of the dehydrogenation aromatization reaction of methane, so that additional energy supply is unnecessary during catalyst regeneration, thereby showing improved efficiency in terms of energy and process, and the conversion rate of methane and the yield of C2 hydrocarbon compounds and aromatic compounds can be improved after catalyst regeneration.

[0050] Hereinafter, the present invention will be described in detail.

[0051] The method for producing C2 hydrocarbon compounds and aromatic compounds from methane according to the present invention first supplies a methane-containing feed to a reactor charged with a catalyst for dehydroaromatization reaction to produce unsaturated hydrocarbons and unreacted products containing aromatic compounds [step (a)].

[0052] The above methane-containing feedstock may be used without limitation as long as it is a mixture containing methane, and may include, for example, shale gas, natural gas, etc., and preferably, in addition to methane, may contain an inert gas and / or a non-inert gas.

[0053] The methane contained in the methane-containing feed may be 2% (v / v) or more, more preferably 40% (v / v) to 100% (v / v) based on the total volume of the methane-containing feed supplied into the reactor, and the inert gas and / or non-inert gas may be 98% (v / v) or less, more preferably 60% (v / v) or less based on the total volume of the methane-containing feed.

[0054] The above inert gas and / or non-inert gas plays a role in stably generating and maintaining a reaction state, and the inert gas may be nitrogen, helium, neon, argon, or krypton, and the non-inert gas may be carbon monoxide, hydrogen, carbon dioxide, water, ethane, ethylene, propane, propylene, butane, butylene, monohydric alcohol (having 1 to 5 carbon atoms), dihydric alcohol (having 2 to 5 carbon atoms), or alkanes (having 2 to 8 carbon atoms), and preferably, the inert gas and non-inert gas may be argon, nitrogen, hydrogen, oxygen, or water.

[0055] The above methane-containing feed is supplied to a reactor charged with a catalyst for dehydroaromatization reaction, and the dehydroaromatization reaction produces a reaction product containing an aromatic compound-containing unsaturated hydrocarbon, unreacted substances, and hydrogen.

[0056] The dehydrogenation aromatization reaction of the above methane-containing feed can produce aromatic compounds and hydrogen as shown in the following reaction scheme 1. The following reaction scheme 1 is intended to facilitate the explanation of the dehydrogenation aromatization reaction of methane, and aromatic compounds produced in the dehydrogenation aromatization reaction include, in addition to benzene, toluene, ethylbenzene, styrene, xylene, naphthalene, etc., and unreacted methane, ethane, ethylene, propane, propylene, butane, butylene, etc. can also be produced.

[0057] [Reaction Formula 1]

[0058] 6CH4→ C6H6+ 9H2

[0059] At this time, the dehydrogenation aromatization reaction can be performed at 600 ℃ to 800 ℃, preferably 650 ℃ to 750 ℃, and at 0.1 bar to 10 bar, preferably 0.1 bar to 5 bar.

[0060] The above reaction conditions range takes into account the conversion rate of methane and the yield of aromatic compounds, and has the advantage of maximizing the selectivity of methane to aromatic compounds. That is, under the above conditions, the formation of paraffins, olefins, and coke is minimized, thereby supplying the hydrogen radical donor concentration necessary for additional methane activation in the non-oxidative direct conversion reaction described below, while minimizing the pressure build-up and carbon efficiency due to coke formation during the reaction.

[0061] In the above dehydrogenation aromatization reaction, if the reaction temperature is less than 600°C, the reaction catalyst activity may be too low, resulting in a too low yield of aromatic compounds. If the temperature exceeds 800°C, the deactivation rate of the catalyst for the dehydrogenation aromatization reaction due to coke formation is fast, so the residence time of methane in the reactor must be minimized to suppress coke formation, and a problem may arise in that a lot of energy is required to heat the reactor.

[0062] In addition, in the above dehydro-aromatization reaction, when the reaction pressure is less than 1 bar, coke production can be suppressed, but energy efficiency is low due to low methane activation, and when it exceeds 10 bar, coke production is promoted, which may cause problems in that the reactor residence time and product cooling must be designed efficiently.

[0063] In the above dehydrogenation aromatization reaction, the space velocity is 2,000 mlh -1 g cat -1 ~ 12,000 mlh -1 g cat -1 as, When the space velocity in the above dehydrogenation aromatization reaction is satisfied, the chain reactivity of the production of ethane and ethylene from methane and the production of aromatic compounds from ethane and ethylene during the reaction can be controlled to maximize the production of aromatic compounds, and coke production from aromatic compounds due to excessive reaction can be minimized.

[0064] At this time, the above space velocity (Weight Hourly Space Velocity: WHSV) means the reaction gas flow rate / reactor volume in the dehydrogenation aromatization reaction region, and can be obtained as the gas volume flow rate (ml / hr) / catalyst weight (g) in the dehydrogenation aromatization reaction region.

[0065] Meanwhile, the present invention may include a catalyst for dehydroaromatization reaction capable of promoting the dehydroaromatization reaction of methane. The catalyst for dehydroaromatization reaction may be a catalyst support in which a catalytically active component is supported, providing acid sites capable of inducing the dehydroaromatization reaction.

[0066] The catalyst support providing the above acid site may be a metal silicate, preferably a zeolite, more preferably a zeolite having an MFI structure such as Silicalite-1, ZSM-5, or TS-1. In this case, the zeolite may include not only Al but also an additional element of a third main group such as Ga, B, or In. In addition, non-limiting examples of the dopant may be noble metals such as Rh, Pd, Ag, Ir, Pt, and / or Au, or transition metals such as Fe, Ni, Co, and / or Cu.

[0067] In addition, the SiO2 / Al2O3 molar ratio of the zeolite is 1 to 300, preferably 10 to 100, more preferably 10 to 70. When a zeolite within the above range is used, the concentration of Bronsted acid sites can be relatively increased compared to the concentration of Lewis acid sites, thereby providing acid sites that can selectively convert ethane and ethylene compounds into aromatic compounds, and at the same time increasing the degree of dispersion of the catalytically active component on the zeolite surface.

[0068] Meanwhile, non-limiting examples of the catalytically active component may include at least one transition metal selected from the group consisting of transition metals of group 6 of the periodic table, such as molybdenum, nickel, iron, and platinum, and transition metals of groups 4 to 6 of the periodic table, and preferably molybdenum (Mo). The molybdenum can be supported with a high degree of dispersion while neutralizing the strong Bronsted acid sites of the catalyst support during catalyst production, and can be activated into molybdenum carbide during the reaction to convert methane into ethane and ethylene through the initial activation. Therefore, the reactivity can be exhibited only when there are sufficient molybdenum active sites that can interact with the acid sites of the catalyst support.

[0069] The loading ratio of the above catalytically active component, i.e., the transition metal, may be 1 wt% to 8 wt%, preferably 4 wt% to 7 wt%, based on the total weight of the catalyst. The catalyst for dehydroaromatization reaction within the above range can maximize the surface active sites for the initial activation of methane while suppressing the formation of coke containing polyaromatic compounds at acid sites, thereby increasing the selectivity of aromatic compounds.

[0070] As described above, the methane-containing feedstock undergoes a dehydroaromatization reaction to generate an aromatic compound, an unsaturated hydrocarbon containing the aromatic compound as a hydrogen radical donor, and an unreacted product. The generated aromatic compound, the unsaturated hydrocarbon containing the aromatic compound as a hydrogen radical donor, and the unreacted product undergo a non-oxidative direct conversion reaction to activate methane as shown in the following reaction scheme 2, thereby synthesizing hydrogen, C2 hydrocarbon compounds (ethylene, acetylene, and ethane), and an aromatic compound [step (b)]. At this time, the aromatized compound reversibly provides and simultaneously receives hydrogen radicals, thereby promoting the initial activation of methane.

[0071] [Chemical Formula 2]

[0072] CH4+ C6H6→ CH3·+ C6H5·+ H2

[0073] 2CH3·→ C2H6

[0074] C2H6→ C2H4+ H2

[0075] C2H4→ C2H2+ 2H2

[0076] 3C2H2→ C6H6

[0077] 2C6H5·+ H2→ 2C2H6

[0078] The above non-oxidative direct conversion reaction can be performed at 900 ℃ to 1,200 ℃, preferably 950 ℃ to 1,150 ℃, and 0.1 bar to 10 bar, preferably 0.1 bar to 5 bar, and the space velocity of the reaction zone is 200 h -1 ~ 12,000 h -1It could be.

[0079] The above reaction conditions take into account the selectivity and yield of hydrocarbons, and have the advantage of maximizing the selectivity of methane to hydrocarbons. That is, under the above conditions, coke formation is minimized, thereby minimizing pressure drop and carbon deposition due to coke formation during the reaction.

[0080] In the above non-oxidative direct conversion reaction, if the reaction temperature is less than 900°C, the reactivity is low, which may cause a problem in that the reactor size corresponding to the reaction area of ​​the non-oxidative direct conversion reaction must be large, and if it exceeds 1,200°C, side reactions (dehydrogenation and coupling) may be promoted, which may cause a problem in that coke production is promoted as a result.

[0081] In addition, in the non-oxidative direct conversion reaction, if the reaction pressure is less than 0.1 bar, the reactivity is low, which may cause a problem in that the reactor size corresponding to the reaction area of ​​the non-oxidative direct conversion reaction must be large, and if it exceeds 10 bar, side reactions (dehydrogenation and coupling) may be dominant, which may cause a problem in that coke production is promoted as a result.

[0082] Such non-oxidative direct conversion reaction is characterized by a ratio of the space velocity (GHSV) of the non-oxidative direct conversion reaction to the space velocity (WHSV) of the catalyst for the aforementioned dehydroaromatization reaction of 0.01 gml. -1 ~ 6 gml -1 It can be. The ratio of the space velocity (GHSV) of the non-oxidative direct conversion reaction to the space velocity (WHSV) of the catalyst for the above dehydroaromatization reaction is 0.01 gml -1 If it is less than 6 gml, the linkage effect of the non-oxidative direct conversion reaction and the dehydroaromatic reaction is reduced, which may cause a problem of lowering the efficiency of the non-oxidative direct conversion reactor. -1If it exceeds , the reaction temperature of the non-oxidative direct conversion reaction must be increased compared to the dehydrogenation aromatization reaction, which may cause a problem of reduced thermal efficiency.

[0083] The dehydrogenation aromatization reaction and the non-oxidation direct conversion reaction according to the present invention can be carried out stepwise in a single reactor or two or more reactors, and in terms of optimization of heat exchange according to the heat of reaction and temperature gradient, it can be preferably carried out in a single reactor, more preferably in a single reactor having a double-tube structure or a radial direction.

[0084] In one embodiment, when the dehydroaromatization reaction and the non-oxidative direct conversion reaction are performed in a single reactor, as shown in FIG. 1, the reactor (100) can be divided into a preheating section (121) and a reaction zone section (122), and the divided preheating section (121) is filled with a catalyst (111) for dehydroaromatization reaction, and the supplied methane-containing feed is reacted in the presence of the filled dehydroaromatization reaction catalyst to generate an aromatic compound-containing unsaturated hydrocarbon and an unreacted substance. The generated aromatic compound-containing unsaturated hydrocarbon and the unreacted substance are introduced into the reaction zone section (122), and in the reaction zone section (122), hydrogen, a C2 hydrocarbon compound, and an aromatic compound are generated through a non-oxidative direct conversion reaction of the aromatic compound-containing unsaturated hydrocarbon and the unreacted substance.

[0085] At this time, the reactor may use any reactor known in the technical field to which the present invention pertains, and the dimensions and shapes may vary depending on the production capacity, supply amount, and catalyst, and may be controlled by various methods known to those skilled in the art, but structurally, it is a tube-shaped reactor with an inlet (110) formed on one side to introduce a methane-containing feed, and the introduced methane-containing feed reacts in the reaction zone, and an outlet (130) formed on the other side of the inlet to discharge the reaction product upon completion of the reaction to the outside or the rear end.

[0086] In addition, the inlet position of the above reactor can be arranged in multiple places in the reactor without limitation, such as upper, lower, right, or left, and in order to maximize reactivity while lowering the concentration of radical donors and coke production generated in the dehydrogenation aromatization reaction, preferably, as shown in FIG. 2, an inlet (110) capable of supplying a methane-containing feed may be further arranged between the reaction zone (preheating zone, 121) of the dehydrogenation aromatization reaction and the reaction zone (reaction zone, 122) of the non-oxidative direct conversion reaction.

[0087] The hydrogen, C2 hydrocarbon compounds, and aromatic compounds generated in this manner can be discharged to the outside or discharged to the rear end. At this time, the C2 hydrocarbon compounds may include ethane, ethylene, and acetylene, and the aromatic compounds may include benzene, toluene, xylene, ethylbenzene, and naphthalene aromatic compounds.

[0088] The hydrogen, C2 hydrocarbon compounds, and aromatic compounds discharged from the rear end may additionally undergo a separation step. The hydrogen, C2 hydrocarbon compounds, and aromatic compounds may be separated using devices or methods known in the technical field to which the present invention pertains, and the devices and separation methods may include distillation, membrane separation, solvent extraction, and the like. The hydrogen separated from the C2 hydrocarbon compounds and aromatic compounds may be used as a hydrogen-containing gas in the catalyst regeneration described below.

[0089] After the above dehydrogenation aromatization reaction and non-oxidation direct conversion reaction, the deactivated dehydrogenation aromatization reaction catalyst is regenerated using a hydrogen-containing gas [step (c)].

[0090] At this time, the hydrogen-containing gas can be used without limitation as long as it is a non-oxidizing gas containing hydrogen, and preferably, in addition to hydrogen, it can contain an inert gas such as argon or nitrogen, and more preferably, it can be characterized by a hydrogen content of 10 mol% to 100 mol%.

[0091] If, in the hydrogen-containing gas, the hydrogen content is less than 10 mol%, it may take a long time to remove coke deposited on the catalyst surface, which may cause a problem of low energy efficiency. If the hydrogen content exceeds 100 mol%, the catalyst regeneration time may be shortened, but the design of reaction conditions capable of controlling the heat generated during regeneration may be required. At this time, the reaction conditions requiring the design may include reaction flow rate, reaction time, etc.

[0092] In this way, by using a hydrogen-containing gas as a regeneration gas during catalyst regeneration, the chemical stability of the transition metal (e.g., molybdenum) carbide, which is the metal active site of the catalyst in the dehydroaromatization reaction, can be increased during regeneration, and the regeneration heat can be minimized, thereby minimizing structural deformation of the catalyst support such as zeolite. For example, when attempting regeneration using air or oxygen, irreversible damage to the aforementioned transition metal and catalyst support may occur, but when using a hydrogen-containing gas, selective control of this is possible.

[0093] Additionally, purging with an inert gas may be performed before and / or after the regeneration step of regenerating the catalyst, but this is not essential from a process perspective when hydrogen is used as the regeneration gas. An inert gas, steam, air, etc. may be used as the purge gas.

[0094] The catalyst regeneration temperature in the above-described regeneration step can be performed within the same temperature range as the dehydrogenation aromatization reaction temperature described above. Accordingly, in the production of C2 hydrocarbon compounds and aromatic compounds of the present invention, additional energy supply is unnecessary during catalyst regeneration, thereby demonstrating improved efficiency in terms of energy and process.

[0095] If the catalyst regeneration temperature is lower than the dehydroaromatization reaction temperature range, not only will the time for regenerating the catalyst become longer, but only amorphous coke can be selectively removed, making it impossible to prevent catalyst deactivation due to an increase in the amount of crystalline coke deposited. In addition, if the temperature exceeds the dehydroaromatization reaction temperature range, hot spots and catalyst sintering may occur due to changes in the structure of the catalyst support, such as zeolite, in addition to a local temperature increase due to coke oxidation. This may ultimately further deactivate the catalyst, resulting in a loss in activity.

[0096] Meanwhile, the catalyst regeneration time can be adjusted according to the catalyst amount, regeneration conditions, etc., and in terms of energy efficiency, it can be preferably performed at 0.5 to 3 times, more preferably 3 times, the reaction time.

[0097] After the step of regenerating the catalyst for the above dehydroaromatization reaction, step (d) sequentially repeats the dehydroaromatization reaction of step (a) and the non-oxidative direct conversion reaction of step (b) by re-supplying the methane-containing feed to the regenerated catalyst.

[0098] In addition, the method for producing a C2 hydrocarbon compound and an aromatic compound according to the present invention can regenerate the deactivated catalyst [step (c)] after step (d) and then repeatedly perform the dehydrogenation aromatization reaction and the non-oxidation direct conversion reaction [step (d)].

[0099] At this time, when producing a C2 hydrocarbon compound and an aromatic compound according to the production method of the present invention, since the set temperature for producing the C2 hydrocarbon compound and the aromatic compound and the temperature for regenerating the catalyst are the same, the process energy efficiency is excellent by injecting a hydrogen-containing gas for regeneration without supplying an additional heat source, and the temperature raising and cooling processes during the reaction and regeneration can be omitted, thereby improving the ease of process operation, and since the reactor purge process during the temperature raising and cooling processes is also omitted, the use of purge gas can be reduced.

[0100] Hereinafter, the present invention will be described in more detail through specific examples. The following examples are merely illustrative examples to aid understanding of the present invention and are not intended to limit the scope of the present invention.

[0101] <Manufacturing Example 1: Preparation of a catalyst for dehydroaromatization reaction>

[0102] The 6 wt% Mo / H-ZSM-5 (SiO2 / Al2O3 = 30) catalyst was prepared by a wet impregnation method. Ammonium heptamolybdate [(NH4)6Mo7O 24 ·4H2O] 1.15 g was dissolved in 20 g of deionized water (DI water), and 10 g of H-ZSM-5 (SiO2 / Al2O3 = 30) was added thereto and maintained at 40°C for 30 minutes. Afterwards, water was removed at 50°C using a rotary vacuum evaporator (RV 10 control, IKA) to obtain a solid. The obtained solid was dried at 110°C for 10 hours and calcined at 500°C in an air atmosphere to prepare a catalyst for dehydrogenation aromatization reaction.

[0103] <Example 1>

[0104] C2 hydrocarbon compounds and aromatic compounds were produced from methane using a reactor as shown in Fig. 1. The reactor was a fixed-bed reactor, and a tubular reactor made of quartz with an inner diameter of 4 mm was installed in a furnace having individual heating zones of 10 cm and 10 cm in height, respectively. The upper part was divided into a preheating section (reaction zone for dehydroaromatic reaction) and the lower part was divided into a reaction zone (reaction zone for non-oxidative direct conversion reaction). The catalyst produced in Manufacturing Example 1 was pulverized to a particle size of 425 ㎛ to 850 ㎛ and 0.20 g was filled inside the preheating section (reaction zone for dehydroaromatic reaction). The methane-containing feed [90% (v / v) CH4, 10% (v / v) Ar] flowing into the reactor was supplied at 20 ml / min using mass flow controllers, and the reaction was carried out at 700°C in the preheating section and 1,020°C in the reaction zone for 15 minutes (Table 1). At this time, argon (Ar) gas was used as an internal standard. Thereafter, the catalyst was regenerated by changing the reaction gas to 100% H2 as shown in Table 2 and supplying it at 20 ml / min for 45 minutes. This example was continuously performed periodically for 50 hours.

[0105] <Comparative Example 1>

[0106] C2 hydrocarbon compounds and aromatic compounds were prepared in the same manner as in Example 1, but 0.5% O2 was used as the gas for catalyst regeneration as shown in Table 2. The methane-containing feed [90% (v / v) CH4, 10% (v / v) Ar] was reacted at 20 ml / min for 15 minutes, and then the reaction gas was changed to 0.5% O2 and supplied at 20 ml / min for 45 minutes to regenerate the catalyst. This comparative example was continuously performed periodically for 50 hours.

[0107] <Comparative Example 2>

[0108] C2 hydrocarbon compounds and aromatic compounds were produced from methane using a reactor as shown in Fig. 1. The reactor was a fixed-bed reactor, and a tubular reactor made of quartz with an inner diameter of 4 mm was installed in a furnace having individual heating zones of 10 cm and 10 cm in height, respectively. The upper part was divided into a preheating section (reaction zone for dehydrogenation aromatization reaction) and the lower part was divided into a reaction zone section (reaction zone for dehydrogenation aromatization reaction). The catalyst produced in Manufacturing Example 1 was pulverized to a particle size of 425 ㎛ to 850 ㎛ and 0.20 g was filled inside the preheating section. The methane-containing feed [90% (v / v) CH4, 10% (v / v) Ar] introduced into the reactor was supplied at 20 ml / min using mass flow controllers, and the preheating section was heated to 700°C, and the reaction zone was heated to 700°C for 15 minutes (Table 1). At this time, argon (Ar) gas was used as an internal standard. Afterwards, the catalyst was regenerated by supplying 20 ml / min for 45 minutes by changing the reaction gas to 100% H2, as shown in Table 2. This experiment was performed periodically for 50 hours.

[0109] <Comparative Example 3>

[0110] C2 hydrocarbon compounds and aromatic compounds were produced from methane using a reactor as shown in Fig. 1. The reactor was a fixed-bed reactor, and a tubular reactor made of quartz with an inner diameter of 4 mm was installed in a furnace having individual heating zones of 10 cm and 10 cm in height, respectively. The upper part was divided into a preheating section (reaction zone for dehydrogenation aromatization reaction) and the lower part was divided into a reaction zone (reaction zone for non-oxidative direct conversion reaction). The catalyst produced in Manufacturing Example 1 was pulverized to a particle size of 425 ㎛ to 850 ㎛ and 0.20 g was filled inside the preheating section. The methane-containing feed [90% (v / v) CH4, 10% (v / v) Ar] introduced into the reactor was supplied at 20 ml / min using mass flow controllers, and the preheating section was heated to 700°C, and the reaction zone was heated to 700°C for 15 minutes (Table 1). At this time, argon (Ar) gas was used as an internal standard. Afterwards, the catalyst was regenerated by supplying 20 ml / min for 45 minutes by converting the reaction gas to 0.5% O2, as shown in Table 2. This experiment was performed periodically for 50 hours.

[0111] Comparative Example 4

[0112] C2 hydrocarbon compounds and aromatic compounds were produced from methane using a reactor as shown in Fig. 1. The reactor was a fixed-bed reactor, and a tubular reactor made of quartz with an inner diameter of 4 mm was installed in a furnace having individual heating zones of 10 cm and 10 cm in height, respectively. The upper part was divided into a preheating section (reaction zone for dehydrogenation aromatization reaction) and the lower part was divided into a reaction zone (reaction zone for non-oxidative direct conversion reaction). The catalyst produced in Manufacturing Example 1 was pulverized to a particle size of 425 ㎛ to 850 ㎛ and 0.80 g was filled inside the preheating section. The methane-containing feed [90% (v / v) CH4, 10% (v / v) Ar] introduced into the reactor was supplied at 20 ml / min using mass flow controllers, and the preheating section was heated to 700°C, and the reaction zone was heated to 700°C for 15 minutes (Table 1). At this time, argon (Ar) gas was used as an internal standard. Afterwards, the catalyst was regenerated by converting the reaction gas to 100% H2 and supplying it at 20 ml / min for 45 minutes, as shown in Table 2. This comparative example was continuously performed periodically for 10 hours.

[0113] Comparative Example 5

[0114] C2 hydrocarbon compounds and aromatic compounds were produced from methane using a reactor as shown in Fig. 1. The reactor was a fixed-bed reactor, and a tubular reactor made of quartz with an inner diameter of 4 mm was installed in a furnace having individual heating zones of 10 cm and 10 cm in height, respectively. The upper part was divided into a preheating section (reaction zone for dehydrogenation aromatization reaction) and the lower part was divided into a reaction zone (reaction zone for non-oxidative direct conversion reaction). The catalyst produced in Manufacturing Example 1 was pulverized to a particle size of 425 ㎛ to 850 ㎛ and 0.20 g was filled inside the preheating section. The methane-containing feed [90% (v / v) CH4, 10% (v / v) Ar] introduced into the reactor was supplied at 20 ml / min using mass flow controllers, and the reaction was carried out at 700°C in the preheating section and 700°C in the reaction zone for 4 hours (Table 1). At this time, argon (Ar) gas was used as an internal standard. Afterwards, the catalyst was regenerated by changing the reaction gas to 10% O2 as shown in Table 2 and supplying it at 20 ml / min for 30 minutes. This experiment was continuously performed periodically for 36 hours.

[0115] <Comparative Example 6>

[0116] C2 hydrocarbon compounds and aromatic compounds were produced from methane using a reactor as shown in Fig. 1. The reactor was a fixed-bed reactor, and a tubular reactor made of quartz with an inner diameter of 4 mm was installed in a furnace having individual heating zones of 10 cm and 10 cm in height, respectively. The upper part was divided into a preheating section (reaction zone for dehydrogenation aromatization reaction) and the lower part was divided into a reaction zone (reaction zone for non-oxidative direct conversion reaction). The catalyst produced in Manufacturing Example 1 was pulverized to a particle size of 425 ㎛ to 850 ㎛ and 0.20 g was filled inside the preheating section. The methane-containing feed [90% (v / v) CH4, 10% (v / v) Ar] introduced into the reactor was supplied at 20 ml / min using mass flow controllers, and the reaction was carried out at 700°C in the preheating section and 700°C in the reaction zone for 4 hours (Table 1). At this time, argon (Ar) gas was used as an internal standard. Afterwards, the catalyst was regenerated by changing the reaction gas to 10% O2 as shown in Table 2 and supplying it at 20 ml / min for 10 minutes. This experiment was continuously performed periodically for 36 hours.

[0117] Comparative Example 7

[0118] C2 hydrocarbon compounds and aromatic compounds were produced from methane using a reactor as shown in Fig. 1. The reactor was a fixed-bed reactor, and a tubular reactor made of quartz with an inner diameter of 4 mm was installed in a furnace having individual heating zones of 10 cm and 10 cm in height, respectively. The upper part was divided into a preheating section (reaction zone for dehydrogenation aromatization reaction) and the lower part was divided into a reaction zone (reaction zone for non-oxidative direct conversion reaction). The catalyst produced in Manufacturing Example 1 was pulverized to a particle size of 425 ㎛ to 850 ㎛ and 0.20 g was filled inside the preheating section. The methane-containing feed [90% (v / v) CH4, 10% (v / v) Ar] introduced into the reactor was supplied at 20 ml / min using mass flow controllers, and the reaction was carried out at 700°C in the preheating section and 700°C in the reaction zone for 4 hours (Table 1). At this time, argon (Ar) gas was used as an internal standard. Afterwards, the catalyst was regenerated by changing the reaction gas to 0.5% O2 as shown in Table 2 and supplying it at 20 ml / min for 10 minutes. This experiment was continuously performed periodically for 36 hours.

[0119] Comparative Example 8

[0120] C2 hydrocarbon compounds and aromatic compounds were produced from methane using a reactor as shown in Fig. 1. The reactor was a fixed-bed reactor, and a tubular reactor made of quartz with an inner diameter of 4 mm was installed in a furnace having individual heating zones of 10 cm and 10 cm in height, respectively. The upper part was divided into a preheating section (reaction zone for dehydrogenation aromatization reaction) and the lower part was divided into a reaction zone (reaction zone for non-oxidative direct conversion reaction). The catalyst produced in Manufacturing Example 1 was pulverized to a particle size of 425 ㎛ to 850 ㎛ and 0.20 g was filled inside the preheating section. The methane-containing feed [90% (v / v) CH4, 10% (v / v) Ar] introduced into the reactor was supplied at 20 ml / min using mass flow controllers, and the reaction was carried out at 700 ℃ in the preheating section and 700 ℃ in the reaction zone for 4 hours (Table 1). At this time, argon (Ar) gas was used as an internal standard. Afterwards, the catalyst was regenerated by changing the reaction gas to 0.03% O2 ​​as shown in Table 2 and supplying it at 20 ml / min for 10 minutes. This experiment was continuously performed periodically for 36 hours.

[0121] <Comparative Example 9>

[0122] C2 hydrocarbon compounds and aromatic compounds were produced from methane using a reactor as shown in Fig. 1. The reactor was a fixed-bed reactor, and a tubular reactor made of quartz with an inner diameter of 4 mm was installed in a furnace having individual heating zones of 10 cm and 10 cm in height, respectively. The upper part was divided into a preheating section (reaction zone for dehydrogenation aromatization reaction) and the lower part was divided into a reaction zone (reaction zone for non-oxidative direct conversion reaction). The catalyst produced in Manufacturing Example 1 was pulverized to a particle size of 425 ㎛ to 850 ㎛ and 0.20 g was filled inside the preheating section. The methane-containing feed [90% (v / v) CH4, 10% (v / v) Ar] introduced into the reactor was supplied at 20 ml / min using mass flow controllers, and the preheating section was operated at 700 ℃ and the reaction section was operated at 700 ℃ for 4 hours (Table 1). At this time, argon (Ar) gas was used as an internal standard. Afterwards, the catalyst was regenerated by supplying 20 ml / min for 30 minutes by changing the reaction gas to 0.5% O2 at 500 ℃ in the preheating section and 500 ℃ in the reaction section, as shown in Table 2. This experiment was performed periodically for 36 hours.

[0123] Comparative Example 10

[0124] C2 hydrocarbon compounds and aromatic compounds were produced from methane using a reactor as shown in Fig. 1. The reactor was a fixed-bed reactor, and a tubular reactor made of quartz with an inner diameter of 4 mm was installed in a furnace having individual heating zones of 10 cm and 10 cm in height, respectively. The upper part was divided into a preheating section (reaction zone for dehydrogenation aromatization reaction) and the lower part was divided into a reaction zone (reaction zone for non-oxidative direct conversion reaction). The catalyst produced in Manufacturing Example 1 was pulverized to a particle size of 425 ㎛ to 850 ㎛ and 0.20 g was filled inside the preheating section. The methane-containing feed [90% (v / v) CH4, 10% (v / v) Ar] introduced into the reactor was supplied at 20 ml / min using mass flow controllers, and the preheating section was operated at 700 ℃ and the reaction section was operated at 700 ℃ for 4 hours (Table 1). At this time, argon (Ar) gas was used as an internal standard. Afterwards, the catalyst was regenerated by supplying the reaction gas at 20 ml / min for 30 minutes by converting it to 0.03% O2 ​​at 500 ℃ in the preheating section and 500 ℃ in the reaction section, as shown in Table 2. This experiment was performed periodically for 36 hours.

[0125] [Table 1]

[0126]

[0127] [Table 2]

[0128]

[0129] <Experimental Example 1: Measurement of methane conversion and selectivity between aromatic compounds and C2 hydrocarbons> The products obtained in the examples and comparative examples were analyzed every hour starting 30 minutes after the supply of the reactants using an Agilent 8890 GC connected online, and the gaseous products were analyzed using a thermal conductivity detector (TCD) connected to a ShinCarbon ST 80 / 100 column and two flame ionization detectors (FID) detectors each connected to an Rt-alumina BOND and RTx-VMS column. Hydrogen, methane, argon, and C2 hydrocarbon compounds (ethane, ethylene, and acetylene) were separated on a Shincarbon ST 80 / 100 column and detected by a TCD, and the conversion was calculated as the methane width compared to the internal standard argon width. Light hydrocarbons and benzene in the C1 to C5 range were separated using a RT-alumina BOND column and detected by FID, and aromatic compounds including benzene were separated using a RTx-VMS column and detected by FID. All gases were quantified using standard samples. The amount of methane converted (C-mmol) and produced (C-mmol) was converted to values ​​by integrating the amount detected at each time according to the reaction time, and is shown in Figures 3 to 5.

[0130] As shown in FIGS. 3 to 5, in Example 1, it was found that C2 compounds including ethane, ethylene, and acetylene and aromatic compounds including benzene, toluene, and naphthalene could be stably produced while minimizing the deactivation of methane conversion through optimization of reaction and regeneration, and through this, it was found that when a catalyst was used in the dehydroaromatization reaction and the non-oxidative direct conversion reaction was utilized as an area promoting methane conversion, periodic reaction and regeneration optimization were suitable for the stable production of hydrocarbons from methane.

[0131] In particular, compared to Comparative Examples 1 to 4, Example 1 showed higher reaction performance when promoting thermal decomposition by performing a non-oxidative direct conversion reaction than when only the dehydrogenation aromatization reaction was performed, and when hydrogen rather than oxygen was used as the regeneration gas in the periodic catalyst regeneration, effective stability improvement could be secured. In addition, through a comparison between Example 1 and Comparative Example 4, it was confirmed that when the concentration of aromatic compounds was abundant in the reaction zone (preheating zone) of the dehydrogenation aromatization reaction, the improvement in C2 production in the reaction zone (reaction zone) of the non-oxidative direct conversion reaction was further promoted.

[0132] In addition, through a comparison of Example 1 and Comparative Examples 5 to 10, it was confirmed that even when periodic catalyst regeneration was optimized by using oxygen as the regeneration gas, the methane conversion amount and hydrocarbon production amount according to the methane supply amount were lower than when hydrogen was used as the regeneration gas.

[0133] While the present invention has been described with reference to the above-described embodiments and the accompanying drawings, various embodiments may be constructed within the spirit and scope of the present invention. Accordingly, the scope of the present invention is defined by the appended claims and their equivalents, and is not limited to the specific embodiments described herein.

Claims

1. (a) A step of supplying a methane-containing feed to a reactor filled with a catalyst for dehydrogenation aromatization reaction to produce unsaturated hydrocarbons containing aromatic compounds and unreacted products; (b) a step of reacting the unsaturated hydrocarbon containing the aromatic compound and the unreacted substance generated above at 900°C to 1,200°C to generate hydrogen, a C2 hydrocarbon compound and an aromatic compound; (c) after step (b), a step of regenerating the dehydrogenation aromatization catalyst by supplying a hydrogen-containing gas to the deactivated dehydrogenation aromatization catalyst; and (d) A method for producing C2 hydrocarbon compounds and aromatic compounds from methane, characterized in that it comprises a step of sequentially repeating steps (a) and (b) after step (c).

2. In paragraph 1, A method for producing a C2 hydrocarbon compound and an aromatic compound from methane, characterized in that the catalyst for the dehydrogenation aromatization reaction comprises a zeolite; and at least one transition metal selected from the group consisting of a transition metal of the 6th period of the periodic table and a transition metal of groups 4 to 6 of the periodic table supported on the zeolite.

3. In paragraph 2, A method for producing a C2 hydrocarbon compound and an aromatic compound from methane, characterized in that the above transition metal is at least one selected from the group consisting of molybdenum, nickel, iron, and platinum.

4. In paragraph 1, A method for producing C2 hydrocarbon compounds and aromatic compounds from methane, characterized in that the method for producing C2 hydrocarbon compounds and aromatic compounds from methane is performed stepwise in a single reactor.

5. In paragraph 1, A method for producing a C2 hydrocarbon compound and an aromatic compound from methane, characterized in that the reaction of step (a) is performed at 600°C to 800°C.

6. In paragraph 1, A method for producing C2 hydrocarbon compounds and aromatic compounds from methane, characterized in that the regeneration temperature of step (c) is maintained the same as the reaction temperature of step (a).

7. In paragraph 1, A method for producing C2 hydrocarbon compounds and aromatic compounds from methane, characterized in that the hydrogen-containing gas of the above step (c) contains 10 mol% to 100 mol% of hydrogen.

8. In paragraph 1, A method for producing a C2 hydrocarbon compound and an aromatic compound from methane, characterized in that after the above step (d), steps (c) and (d) are repeatedly performed.

9. In paragraph 1, A method for producing a C2 hydrocarbon compound and an aromatic compound, characterized in that the C2 hydrocarbon compound is at least one selected from the group consisting of ethane, ethylene, and acetylene.

10. In paragraph 1, A method for producing a C2 hydrocarbon compound and an aromatic compound, characterized in that, after the step (b), it further comprises a step of separating the hydrogen, C2 hydrocarbon compound and aromatic compound produced in the step (b).

11. In paragraph 10, A method for producing a C2 hydrocarbon compound and an aromatic compound, characterized in that the separated hydrogen is used as a hydrogen-containing gas in step (c).

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