Natural gas pyrolysis reactor with integrated combustion and reaction sections

Abstract

The present invention relates to a natural gas pyrolysis reactor in which a combustion section and a reaction section are included as a single unit. More specifically, a natural gas pyrolysis reactor for producing blue-green hydrogen comprises: a reaction gas injection unit disposed at the bottom of the natural gas pyrolysis reactor for injecting a reaction gas; a fuel gas injection unit disposed at the bottom of the natural gas pyrolysis reactor and arranged to surround the reaction gas injection unit; and a catalytic reaction unit filled with a molten catalyst and pyrolyzing the reaction gas to produce a reaction product.

Description

Technology Field

[0001] The present invention relates to a natural gas pyrolysis reactor in which a combustion section and a reaction section are included as a single unit.

[0002] More specifically, the invention relates to a natural gas pyrolysis reactor in which a combustion section and a reaction section are integrated to minimize heat loss. Background Technology

[0003] Methane steam reforming is a representative technology for generating hydrogen from commercial natural gas; however, this technology has the problem that it emits large amounts of carbon dioxide, making it difficult to consider the resulting hydrogen as clean hydrogen unless carbon dioxide is captured and treated separately.

[0004] To overcome this, there is growing interest in the production of blue-green hydrogen through natural gas pyrolysis, which utilizes existing natural gas infrastructure to produce carbon and low-CO2 hydrogen; consequently, various studies involving plasma, molten catalysts, and solid catalysts are underway to facilitate this reaction.

[0005] The dual molten catalyst-based natural gas pyrolysis technology is characterized by melting tin, nickel-bismuth, etc., and utilizing them as catalysts to pass methane bubbles through a catalytic reactor to carry out the natural gas pyrolysis reaction.

[0006] This technology overcomes the difficulty of separating carbon catalysts in solid catalysts by utilizing the density difference between the produced carbon-molten catalysts, while also being differentiated from the plasma method in that the heat supply source is not limited to electricity but can utilize combustion heat, etc.

[0007] However, in a reactor of a conventional structure, utilizing external combustion heat requires a combustion reaction outside the reaction tube, which can result in waste heat loss. The problem to be solved

[0008] The purpose is to provide a natural gas pyrolysis reactor to solve the aforementioned problems.

[0009] More specifically, the purpose is to provide a natural gas pyrolysis reactor in which a combustion section and a reaction section are integrated to improve the energy efficiency of the reactor by minimizing heat loss.

[0010] The technical problems of the present invention are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by a person skilled in the art from the description below. means of solving the problem

[0011] According to one aspect of the present invention for achieving the above objective, a natural gas pyrolysis reactor for producing blue-green hydrogen comprises: a reaction gas injection part disposed at the bottom of the natural gas pyrolysis reactor for injecting a reaction gas; a fuel gas injection part disposed at the bottom of the natural gas pyrolysis reactor and arranged to surround the reaction gas injection part; and a catalytic reaction part filled with a molten catalyst and pyrolyzing the reaction gas to produce a reaction product.

[0012] Preferably, the reaction gas injection unit may include a reaction gas dispersion plate to disperse and inject the reaction gas.

[0013] Preferably, the reaction gas is supplied as natural gas having methane as the main component, and the natural gas may be injected by heat exchange with the reaction product.

[0014] Preferably, the fuel gas injection unit may include a fuel gas dispersion plate to disperse and inject the fuel gas.

[0015] Preferably, the fuel gas injection unit injects a mixed gas comprising fuel gas and oxygen, and the mixed gas may cause a combustion reaction in the catalytic reaction unit to generate combustion heat.

[0016] Preferably, the catalytic reaction unit may be such that bubbles are formed inside the molten catalyst by the reaction gas, and thermal decomposition occurs at the interface of the bubbles to produce hydrogen and carbon byproducts.

[0017] Preferably, the natural gas pyrolysis reactor further comprises a product discharge section for recovering reaction products, including hydrogen and carbon byproducts generated by the reaction, to the outside, wherein the product discharge section is formed at the top of the natural gas pyrolysis reactor and the product discharge section may comprise a first heat exchanger for heat exchange between the reaction products and the reaction gas.

[0018] Preferably, the natural gas pyrolysis reactor further includes a product recovery pipe for recovering reaction products, including hydrogen and carbon byproducts generated by the reaction, to the outside, and the product recovery pipe may be positioned in the center of the natural gas pyrolysis reactor.

[0019] Preferably, the height of the product recovery pipe is formed to be higher than the height of the catalyst reaction section, and the upper part of the product recovery pipe may be configured to have a product inlet section, and the lower part of the product recovery pipe may be configured to have a product recovery section.

[0020] Preferably, the upper part of the natural gas pyrolysis reactor is formed in a dome-shaped structure, and the product inlet may be positioned in the dome-shaped structure.

[0021] Preferably, the reaction product is floated and accumulated on the upper side of the molten catalyst to form an internal inclined surface, and the floated reaction product may flow into the product inlet along the internal inclined surface by its own weight.

[0022] Preferably, the product recovery unit may include a first product recovery unit in which carbon byproducts are recovered and a second product recovery unit formed by branching from the first product recovery unit in which hydrogen is recovered.

[0023] Preferably, the product recovery unit further includes a second heat exchanger, wherein the heat exchanger may exchange heat between the reaction product and the reaction gas. Effects of the invention

[0024] The present invention has the effect of providing a natural gas pyrolysis reactor in which a combustion section and a reaction section are integrated.

[0025] More specifically, integrating the reaction section and the combustion section has the effect of minimizing heat loss.

[0026] In addition, since the reaction gas and combustion gas are injected in a dispersed manner, complete mixing is not achieved, which has the effect of relatively reducing the occurrence of side reactions.

[0027] In addition, as the combustion gas is combusted within the molten catalyst, the combustion heat is evenly distributed by the convection of the molten metal.

[0028] In addition, it has the effect of improving the energy efficiency of the reactor by minimizing heat loss.

[0029] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by a person skilled in the art from the description below. Brief explanation of the drawing

[0030] FIGS. 1 and FIGS. 2 are schematic diagrams showing a natural gas pyrolysis reactor according to one embodiment. Specific details for implementing the invention

[0031] Detailed information regarding the purpose, technical configuration, and the resulting operation and effects of the present invention will be more clearly understood through the detailed description based on the drawings attached to the specification of the present invention.

[0032] The terms used herein are used merely to describe specific embodiments and are not intended to limit the invention. For example, the term "comprising" a component in this specification means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0033] Hereinafter, the present invention will be described in detail by explaining preferred embodiments of the present invention with reference to the attached drawings. The embodiments described below are provided to enable those skilled in the art to easily understand the technical concept of the present invention, and should not be interpreted as limiting the present invention, and it is obvious to those skilled in the art that the embodiments of the present invention can have various applications.

[0034] Hereinafter, the natural gas pyrolysis reactor and the method for recovering the product thereof according to the present invention will be described in detail.

[0035] FIG. 1 is a schematic diagram showing a natural gas pyrolysis reactor according to one embodiment.

[0036] Referring to FIG. 1, a natural gas pyrolysis reactor (100) for producing blue-green hydrogen can be configured to include a reaction gas injection section (111), a fuel gas injection section (121), and a catalytic reaction section (A).

[0037] The reaction gas injection unit (111) is positioned at the bottom of the natural gas pyrolysis reactor, and can inject reaction gas into the catalyst reaction unit (A) through the reaction gas injection unit (111).

[0038] In detail, the reaction gas injection part (111) preferably includes a reaction gas dispersion plate (110) to disperse and inject the reaction gas.

[0039] At this time, the reaction gas is supplied as natural gas with methane as the main component, and it is preferable to inject the natural gas by heat exchange with the reaction product. As the reaction gas is heat-exchanged with the product, it is injected into the catalytic reaction unit (A) at a temperature of about 300°C to 600°C, and as the reaction gas with a temperature increased through heat exchange is supplied, it has the effect of improving the energy efficiency.

[0040] The fuel gas injection unit (121) is positioned at the bottom of the natural gas pyrolysis reactor (100), and can inject reaction gas into the catalyst reaction unit (A) through the fuel gas injection unit.

[0041] In detail, the fuel gas injection part (121) includes a fuel gas dispersion plate (120) for dispersing and injecting the fuel gas, and it is preferable that the fuel gas dispersion plate (120) be formed to surround the reaction gas dispersion plate (110). That is, it is preferable that the fuel gas injection part be formed to surround the reaction gas injection part.

[0042] The above fuel gas injection unit can inject a mixed gas comprising the fuel gas and oxygen. In the case of the natural gas pyrolysis process, off-gas containing methane is generated during the process of purifying the produced hydrogen and methane.

[0043] Accordingly, it is preferable to inject a mixed gas according to the present invention, in which oxygen is mixed in an appropriate ratio with fuel gas (methane or hydrogen) and off-gas containing methane and hydrogen.

[0044] The above catalyst reaction section (A) is filled with a molten catalyst, and the fuel gas injected through the above fuel gas injection section generates combustion heat through a combustion reaction.

[0045] More specifically, the combustion gas is supplied in the form of bubbles, and a combustion reaction occurs when it reaches a temperature above the ignition point through heat exchange with a high-temperature molten catalyst filled inside the reactor.

[0046] In addition, the catalyst reaction unit (A) can perform a pyrolysis reaction with the reaction gas injected through the reaction gas injection unit (111). At this time, the combustion heat generated by the combustion reaction of the fuel gas is provided as a heat source for the pyrolysis reaction, thereby minimizing external energy loss and maximizing energy supply efficiency.

[0047] More specifically, the molten catalyst filled in the catalyst reaction section (A) forms bubbles inside due to the reaction gas, and thermal decomposition occurs at the interface of the bubbles, thereby producing a reaction product containing hydrogen and carbon byproducts through the thermal decomposition reaction.

[0048] At this time, the molten catalyst filled in the catalyst reaction section (A) may further include an activity promoter to promote thermal decomposition. For example, the molten catalyst may include tin, bismuth, etc., and may include an activity promoter such as nickel, molybdenum to promote the activity of tin and bismuth, which have low melting points.

[0049] Meanwhile, the hydrogen and carbon byproducts generated by the pyrolysis reaction in the catalyst reaction section (A) float on the upper surface (B) of the molten catalyst due to the difference in density with the molten catalyst.

[0050] Accordingly, in order to recover the reaction product, a product discharge section (130) as disclosed in FIG. 1 is further included, and it is preferable that the product discharge section (130) be formed at the top of the natural gas pyrolysis reactor (100).

[0051] Additionally, the product discharge section (130) may further include a first heat exchanger (not shown) for heat-exchanging the reaction product and the reaction gas.

[0052] In detail, when a first heat exchanger (not shown) is disposed in the product discharge section (130), the reaction gas supplied through the reaction gas injection section (111) performs heat exchange with the reaction product discharged through the product discharge section (130), and the heat-exchanged reaction gas is preferably supplied to the natural gas pyrolysis reactor (100) through the lower reaction gas dispersion plate (110).

[0053] At this time, when the product discharge section (130) is positioned at the top of the natural gas pyrolysis reactor (100), there is no limitation on the shape of the natural gas pyrolysis reactor (100). For example, the natural gas pyrolysis reactor (100) may have a cylindrical structure or the top of the reactor may have a dome-shaped structure.

[0054] In addition, if the above natural gas pyrolysis reactor (100) is operated continuously, it may cause carbon accumulation, which may lead to an increase in pressure within the reactor and cause aggregation due to carbon accumulation, which may result in a blockage of the reactor.

[0055] Accordingly, the present invention intends to describe in detail a configuration for recovery without using separate devices such as cyclones or filters to prevent carbon accumulation and ensure continuous recovery.

[0056] In detail, as disclosed in FIG. 2, the natural gas pyrolysis reactor (100) according to the present invention may further include a product recovery pipe (150) to recover the reaction product.

[0057] The above product recovery pipe (150) is positioned at the center inside the natural gas pyrolysis reactor (100) and can recover the reaction product, including hydrogen and carbon byproducts (solid carbon) generated by the reaction, to the outside.

[0058] In detail, the height of the product recovery pipe (150) is formed to be higher than the height of the catalyst reaction section, and it is preferable that the upper part of the product recovery pipe (150) has a product inlet section and the lower part of the product recovery pipe has a product recovery section (160, 170).

[0059] At this time, when the product recovery pipe (150) is included inside the natural gas pyrolysis reactor (100), it is preferable to form the upper part of the natural gas pyrolysis reactor (100) in a dome-shaped structure.

[0060] In detail, the upper part of the natural gas pyrolysis reactor (100) is formed into a dome-shaped structure, so that the reaction product is floated and accumulated on the upper part of the molten catalyst, and an internal inclined surface is naturally formed by the upper dome-shaped structure, and the floated reaction product is introduced into the product inlet by its own weight along the internal inclined surface and falls from the upper part to the lower part.

[0061] The above product recovery unit (160, 170) is characterized by including a first product recovery unit (160) in which carbon byproducts are recovered and a second product recovery unit (170) formed by branching from the first product recovery unit (160) in which hydrogen is recovered.

[0062] At this time, the carbon byproduct and hydrogen can be separated by weight difference and recovered to the first product recovery unit (160) and the second product recovery unit (170), respectively.

[0063] Additionally, the product recovery unit further includes a second heat exchanger (140), and it is preferable that the heat exchanger (140) heats the reaction product and the reaction gas.

[0064] As seen above, the present invention has the effect of providing a natural gas pyrolysis reactor.

[0065] More specifically, integrating the reactor and the combustion chamber has the effect of minimizing heat loss.

[0066] In addition, since the reaction gas and combustion gas are injected in a dispersed manner, complete mixing is not achieved, which has the effect of relatively reducing the occurrence of side reactions.

[0067] In addition, as the combustion gas is combusted within the molten catalyst, the combustion heat is evenly distributed by convection.

[0068] In addition, it has the effect of improving the energy efficiency of the reactor by minimizing heat loss.

[0069] In this specification, only a few examples among the various embodiments performed by the inventors are described; however, the technical concept of the present invention is not limited or restricted thereto, and it is understood that it can be modified and implemented in various ways by those skilled in the art. Explanation of the symbols

[0070] 100: Natural gas heat exchanger reactor 110: Reaction gas dispersion plate 111: Reaction gas injection section 120: Fuel gas dispersion plate 121: Fuel gas injection port 130: Product discharge section 140: Heat exchanger 150: Product recovery pipe 160: 1st Product Recovery Unit 170: 2nd Product Recovery Unit A: Catalytic reaction unit B: Reaction product floating portion

Claims

Claim 1 A natural gas pyrolysis reactor for producing blue-green hydrogen, comprising: a reaction gas injection unit disposed at the bottom of the natural gas pyrolysis reactor and injecting a reaction gas; a fuel gas injection unit disposed at the bottom of the natural gas pyrolysis reactor and arranged to surround the reaction gas injection unit; a catalytic reaction unit filled with a molten catalyst and pyrolyzing the reaction gas to produce a reaction product; and a product discharge unit for recovering the reaction product, including hydrogen and carbon byproducts produced by the reaction, to the outside. Claim 2 A natural gas pyrolysis reactor according to claim 1, wherein the reaction gas injection unit comprises a reaction gas dispersion plate for dispersing and injecting the reaction gas. Claim 3 A natural gas pyrolysis reactor according to paragraph 2, wherein the reaction gas is supplied as natural gas having methane as the main component, and the natural gas is injected by heat exchange with the reaction product. Claim 4 A natural gas pyrolysis reactor according to claim 1, wherein the fuel gas injection section comprises a fuel gas dispersion plate for dispersing and injecting the fuel gas. Claim 5 A natural gas pyrolysis reactor according to claim 4, wherein the fuel gas injection unit injects a mixed gas comprising fuel gas and oxygen, and the mixed gas causes a combustion reaction in the catalytic reaction unit to generate combustion heat. Claim 6 A natural gas pyrolysis reactor according to claim 1, wherein the catalytic reaction unit forms bubbles inside the molten catalyst by the reaction gas, and pyrolysis takes place at the interface of the bubbles to produce hydrogen and carbon byproducts. Claim 7 A natural gas pyrolysis reactor according to claim 1, wherein the product discharge section is formed at the top of the natural gas pyrolysis reactor, and the product discharge section includes a first heat exchanger that heat exchanges the reaction product and the reaction gas. Claim 8 A natural gas pyrolysis reactor according to claim 1, wherein the natural gas pyrolysis reactor further comprises a product recovery pipe for recovering reaction products, including hydrogen and carbon byproducts generated by the reaction, to the outside, wherein the product recovery pipe is positioned at the center inside the natural gas pyrolysis reactor. Claim 9 A natural gas pyrolysis reactor according to claim 8, wherein the height of the product recovery pipe is formed to be higher than the height of the catalytic reaction section, the upper part of the product recovery pipe is configured to have a product inlet section, and the lower part of the product recovery pipe is configured to have a product recovery section. Claim 10 A natural gas pyrolysis reactor according to claim 9, wherein the upper part of the natural gas pyrolysis reactor is formed in a dome-shaped structure, and the product inlet is disposed in the dome-shaped structure. Claim 11 A natural gas pyrolysis reactor according to claim 9, wherein the reaction product is floated and accumulated on the upper surface of the molten catalyst to form an internal inclined surface, and the floated reaction product flows into the product inlet along the internal inclined surface by its own weight. Claim 12 A natural gas pyrolysis reactor according to claim 9, wherein the product recovery section comprises: a first product recovery section in which carbon byproducts are recovered; and a second product recovery section formed by branching from the first product recovery section in which hydrogen is recovered. Claim 13 In claim 9, the product recovery unit further comprises a second heat exchanger; wherein the second heat exchanger exchanges heat between the reaction product and the reaction gas, a natural gas pyrolysis reactor.

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