A top inlet structure for a liquid metal pyrolysis natural gas to hydrogen production unit

Abstract

This utility model discloses a top air inlet structure for a liquid metal pyrolysis natural gas to hydrogen production device. Installed at the top of the reactor, it supplies the natural gas to be pyrolyzed into the liquid metal from the top of the reactor. It includes: an inner air inlet pipe, with its top connected to a natural gas source and its bottom extending into the liquid metal of the reactor; a gas distribution structure connected to the bottom of the inner air inlet pipe, with exhaust ports around its perimeter; an outer protective pipe, sleeved outside the inner air inlet pipe and made of TZM alloy material; and a middle heat-insulating material filling the space between the outer protective pipe and the inner air inlet pipe. This utility model's air inlet structure, located at the top of the reactor, effectively prevents the risks of liquid metal leakage and natural gas leakage associated with bottom-inlet methods. The middle heat-insulating material between the inner and outer air inlet pipes forms a composite structure, improving heat insulation performance and structural stability, and preventing premature pyrolysis of natural gas in the gas flow channel, thus avoiding carbon buildup and blockage.

Description

Technical Field

[0001] This utility model relates to the field of hydrogen production technology, and in particular to a top air inlet structure for a liquid metal pyrolysis natural gas hydrogen production device. Background Technology

[0002] Liquid metal catalytic cracking of natural gas for hydrogen production is an emerging technology that utilizes liquid metal to catalytically crack methane in a high-temperature liquid metal environment. This process directly generates hydrogen and solid carbon without producing carbon dioxide. Considered a green alternative to traditional methane steam reforming for hydrogen production, this technology has garnered significant attention in the context of carbon neutrality. It effectively addresses the high energy consumption, low conversion rate, and catalyst deactivation issues associated with traditional methane thermal or catalytic cracking, avoiding the high carbon emissions associated with methane steam reforming for hydrogen production. Furthermore, it produces value-added carbon products simultaneously with hydrogen production, thus attracting widespread interest.

[0003] This technology introduces natural gas into molten liquid metal, where it comes into contact with a catalyst at high temperatures, achieving a highly efficient pyrolysis reaction. The molten liquid metal possesses excellent thermal stability and conductivity, providing a uniform reaction environment and extending the catalyst's lifespan.

[0004] However, traditional reactors typically employ a bottom-inlet design (e.g., Chinese Patent Publication No. CN112723307A), which poses risks of liquid metal and natural gas leakage in practical applications, creating safety hazards. Furthermore, over long-term operation, the gas passages are prone to frequent blockage by carbon deposits or solidified metal, requiring periodic emptying of the liquid metal for maintenance, thus increasing operating costs. To address this, the applicant innovatively proposes a top-inlet structure to avoid the risks of liquid metal and natural gas leakage, mitigate the risk of gas passage blockage, and extend equipment maintenance cycles. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a top air inlet structure for a liquid metal pyrolysis natural gas hydrogen production device, so as to solve the problems of easy leakage of liquid metal, easy leakage of natural gas, and easy blockage of gas passage by carbon deposits in the existing bottom air inlet method of reactor.

[0006] The technical solution adopted by this utility model to solve its technical problem is: providing a top air inlet structure for a liquid metal pyrolysis natural gas to hydrogen production device, installed on the top of the reactor, for supplying the natural gas to be pyrolyzed into the liquid metal from the top of the reactor, comprising:

[0007] The inner air inlet pipe is connected to a natural gas source at the top and extends into the liquid metal of the reactor at the bottom.

[0008] A gas distribution structure is connected to the bottom of the inner air inlet pipe and has exhaust ports around it for discharging natural gas from the sides of the gas distribution structure.

[0009] The outer protective tube is fitted over the inner air intake tube and is made of TZM alloy material;

[0010] A heat-insulating material is filled between the outer protective tube and the inner air inlet tube to prevent heat conduction.

[0011] Furthermore, the top air intake structure also includes a flange;

[0012] The top of the outer protective pipe is fixedly connected to the flange, and the top air inlet structure is installed on the top of the reactor via the flange.

[0013] Furthermore, the inner air intake pipe is also made of TZM alloy material.

[0014] Furthermore, the intermediate heat insulation material is a high-temperature resistant heat insulation material.

[0015] Furthermore, the air distribution structure is provided with an air inlet in the middle and a plurality of exhaust channels are provided around the air inlet; wherein, the air inlet is connected to the air outlet end of the inner air inlet pipe, one end of the exhaust channel is connected to the air inlet, and the other end extends to the side wall of the air distribution structure.

[0016] Furthermore, the gas distribution structure is a columnar structure, and the gas discharged from each of the exhaust channels creates a swirling effect on the liquid in the reactor.

[0017] Furthermore, each of the exhaust channels is arranged in two layers, with the upper layer being the upper exhaust channel and the lower layer being the lower exhaust channel; wherein, the gas discharged from each upper exhaust channel and each lower exhaust channel respectively creates a swirling effect on the liquid in the reactor with different rotation directions.

[0018] Furthermore, the end of each upper exhaust channel connected to the air inlet is the starting end, and the end extending to the side wall of the air distribution structure is the ending end; wherein, each upper exhaust channel is inclined in a first clockwise direction as it extends from the starting end to the ending end.

[0019] The end of each lower exhaust channel connected to the air inlet is the starting end, and the end extending to the side wall of the air distribution structure is the ending end; wherein, each upper exhaust channel is inclined in a second clockwise direction as it extends from the starting end to the ending end;

[0020] Wherein, the first clockwise direction and the second clockwise direction are respectively clockwise from the top view angle of the air distribution structure and counterclockwise from the top view angle of the air distribution structure.

[0021] Furthermore, the centerline of the air intake is defined as L1;

[0022] The centerline of the upper exhaust channel is defined as L2, the intersection of L2 and the inner wall of the air inlet is defined as A1, the horizontal line connecting A1 and L1 is defined as L3, and the angle between L2 and L3 is defined as α1; wherein, the inclination angle of the upper exhaust channel must satisfy that α1 is between 55° and 60°.

[0023] The centerline of the lower exhaust channel is defined as L4, the intersection of L4 and the inner wall of the air inlet is defined as A2, the horizontal line connecting A2 and line L1 is defined as line L5, and the angle between L4 and L5 is defined as α2; wherein, the inclination angle of the lower exhaust channel must satisfy that α2 is between 55° and 60°.

[0024] Furthermore, the surface of the outer protective tube is coated with a SiC coating.

[0025] The beneficial effects of this utility model are as follows:

[0026] (1) The present invention sets the air intake structure as a whole at the top of the reactor. This innovative layout effectively prevents the risk of liquid metal leakage and natural gas leakage that exist in the lower air intake method;

[0027] (2) The upper and lower exhaust channels can form a swirling effect with opposite rotation directions. In liquid metal, a unique gas swirling counter-diffusion effect will be formed. This effect has the advantage of small and uniform bubbles, which can increase the gas-liquid contact area and improve the methane conversion rate, fundamentally solving the technical problem of bubble aggregation in traditional air intake structures.

[0028] (3) The top air intake structure includes two layers of TZM alloy tubes, inner and outer, and a middle heat insulation material in the interlayer, forming a three-layer composite structure that can achieve excellent heat insulation performance and structural stability in high-temperature environments above 1000℃.

[0029] (4) The outer protective tube is coated with SiC coating, which improves the corrosion resistance of TZM alloy material to copper-tin catalyst. Attached Figure Description

[0030] Figure 1 This is a cross-sectional view of the top air intake structure provided by this utility model;

[0031] Figure 2This is a structural diagram of the air distribution structure component in this utility model;

[0032] Figure 3 This is a front view of the air distribution structure component in this utility model;

[0033] Figure 4 yes Figure 3 Sectional view along axis AA;

[0034] Figure 5 yes Figure 3 BB-direction sectional view. Detailed Implementation

[0035] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0036] See Figures 1 to 5 This utility model provides a top air inlet structure for a liquid metal pyrolysis natural gas hydrogen production device, which is installed on the top of the reactor and is used to supply the natural gas to be pyrolyzed into the liquid metal from the top of the reactor. It includes: an inner air inlet pipe 100, a gas distribution structure 200, an outer protective pipe 300, and a middle heat insulation material 400.

[0037] The top of the inner air inlet pipe 100 is used to connect to a natural gas source, and the bottom extends into the liquid metal of the reactor.

[0038] The gas distribution structure 200 is connected to the bottom of the inner air inlet pipe 100 and has exhaust ports around it for discharging natural gas from the periphery of the gas distribution structure 200.

[0039] The outer protective pipe 300 is sleeved outside the inner air inlet pipe 100 and is made of TZM alloy material. TZM alloy material can maintain extremely high strength and hardness in the high-temperature molten liquid metal of this application, and can effectively resist the dissolution and corrosion erosion of liquid metal, ensuring pipe wall thickness and extending service life.

[0040] The intermediate heat insulation material 400 is filled between the outer protective pipe 300 and the inner air inlet pipe 100 to isolate heat conduction and prevent high temperature from being conducted to the inner air inlet pipe 100, which could cause premature cracking of natural gas and carbon buildup that could clog the inner air inlet pipe 100.

[0041] In a preferred embodiment, see Figure 1 The top air inlet structure of this utility model also includes a flange 500. The top of the outer protective pipe 300 is fixedly connected to the flange 500. The top air inlet structure is installed on the top of the reactor via the flange 500, so that the top air inlet structure can be suspended in the reactor and supply natural gas to the liquid metal in the reactor from top to bottom.

[0042] The inner air intake pipe 100 and the air distribution structure 200 are also made of TZM alloy material.

[0043] In addition, the intermediate heat insulation material 400 is a high-temperature resistant insulation material. For example, the high-temperature resistant insulation coating of Riguli Coatings Co., Ltd. can be selected (see Chinese patent with authorization announcement number CN106336797B). The high-temperature resistant insulation coating is applied to a certain thickness to fill the gap between the inner air inlet pipe 100 and the intermediate heat insulation material 400.

[0044] Thus, the top air intake structure forms a composite structure consisting of two layers of TZM alloy pipes, an inner and an outer layer, and a middle layer of heat insulation material 400. Through the combination of the three layers, excellent heat insulation performance and structural stability can be achieved in high-temperature environments above 1000℃, which greatly avoids the problem of natural gas prematurely cracking in the inner air intake pipe 100, causing carbon buildup and blocking the airflow channel.

[0045] In a preferred embodiment, see Figure 2 The air distribution structure 200 has an air inlet 210 in the middle, and a plurality of exhaust channels 220 are arranged around the air inlet 210. The air inlet 210 is connected to the air outlet of the inner air inlet pipe 100, and one end of the exhaust channel 220 is connected to the air inlet 210, while the other end extends to the side wall of the air distribution structure 200.

[0046] Furthermore, the gas distribution structure 200 is a columnar structure, and the gas discharged from each exhaust channel 220 will create a swirling effect on the liquid in the reactor.

[0047] The exhaust channels 220 are arranged in two layers: the upper layer is the upper exhaust channel 221, and the lower layer is the lower exhaust channel 222. The gas discharged from each upper exhaust channel 221 and each lower exhaust channel 222 creates a swirling effect on the liquid in the reactor with different rotation directions.

[0048] Specifically, the end of each upper exhaust channel 221 connected to the air inlet 210 is the starting end, and the end extending to the side wall of the air distribution structure 200 is the ending end. During its extension from the starting end to the ending end, each upper exhaust channel 221 is inclined in a first clockwise direction. Similarly, the end of each lower exhaust channel 222 connected to the air inlet 210 is the starting end, and the end extending to the side wall of the air distribution structure 200 is the ending end. During its extension from the starting end to the ending end, each upper exhaust channel 221 is inclined in a second clockwise direction. The first and second clockwise directions refer to two directions: one is clockwise from the top view of the air distribution structure 200, and the other is counterclockwise from the top view of the air distribution structure 200. For example, the first clockwise direction is clockwise, and the second clockwise direction is counterclockwise.

[0049] The inclination angles of the upper exhaust channel 221 and the lower exhaust channel 222 are as follows:

[0050] The centerline of the air intake 210 is defined as L1;

[0051] See Figure 4 The centerline of the upper exhaust channel 221 is defined as L2, the intersection of L2 and the inner wall of the air inlet 210 is defined as A1, the horizontal line connecting A1 and L1 is defined as L3, and the angle between L2 and L3 is defined as α1; wherein, the inclination angle of the upper exhaust channel 221 must satisfy that α1 is between 55° and 60° (inclusive).

[0052] See Figure 5 The centerline of the lower exhaust channel 222 is defined as L4, the intersection of L4 and the inner wall of the air inlet 210 is defined as A2, the horizontal line connecting A2 and line L1 is defined as line L5, and the angle between L4 and L5 is defined as α2; wherein, the inclination angle of the lower exhaust channel 222 must satisfy that α2 is between 55° and 60° (inclusive).

[0053] Therefore, the upper exhaust channel 221 is arranged in a clockwise direction when viewed from above (see...). Figure 4 The lower exhaust channel 222 is arranged counterclockwise when viewed from above (see...). Figure 5The two can form a swirling effect with opposite rotation directions, creating a unique gas swirling counter-diffusion effect in liquid metal. This effect has the advantage of small and uniform bubbles (combined with the setting of the exhaust channel aperture, the bubble diameter can be controlled within the range of 1-3mm), which can increase the gas-liquid contact area, improve the methane conversion rate, and solve the bubble aggregation phenomenon existing in traditional air intake structures. At the same time, combined with the heat insulation performance of the three-layer composite material of the top air intake structure, it can effectively prevent premature methane decomposition and carbon deposition in the airflow channel, extending the maintenance cycle from the traditional 1-2 months to more than 6 months, and significantly reducing operation and maintenance costs.

[0054] In a preferred embodiment, the surface of the outer protective tube 300 is coated with a SiC coating (wherein Al2O3 may be incorporated into the SiC coating) to improve the corrosion resistance of the TZM alloy material to copper-tin catalysts.

[0055] In this invention, the outer diameter of the air distribution structure 200 is approximately equal to the outer diameter of the outer protective tube 300. During manufacturing, the outer protective tube 300 can be divided into upper and lower sections. After the air distribution structure 200 is connected to the bottom of the inner air inlet pipe 100, its upper surface connects to the upper section of the outer protective tube 300, while the lower section of the outer protective tube 300 connects to the lower surface of the air distribution structure 200. The intermediate heat-insulating material 400 fills both the upper and lower cavities of the air distribution structure 200. Thus, both the upper and lower sides of the air distribution structure 200 are covered and protected by the intermediate heat-insulating material 400 and the outer protective tube 300. The connection can be achieved using screws.

[0056] When the top-intake structure of this invention is in operation, natural gas enters from the top of the reactor through the inner intake pipe 100, effectively preventing the risks of liquid metal leakage and natural gas leakage associated with bottom-intake methods. When natural gas is discharged through the double-layer exhaust channels of the gas distribution structure 200, a unique gas swirling and counter-diffusion effect is formed, giving methane the advantages of fine and uniform bubbles, a large gas-liquid contact area, and a high conversion rate. This solves the technical problem of bubble coalescence present in traditional intake structures. Simultaneously, combined with the thermal insulation performance of the three-layer composite material of the top-intake structure, it effectively prevents premature methane cracking and carbon deposition in the airflow channels, thereby significantly extending the maintenance cycle and reducing operating and maintenance costs.

[0057] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A top inlet structure for a liquid metal pyrolysis natural gas to hydrogen production unit, installed at the top of the reactor, for supplying the natural gas to be pyrolyzed into the liquid metal from the top of the reactor, characterized in that, include: The inner air inlet pipe (100) is connected to a natural gas source at the top and extends into the liquid metal of the reactor at the bottom; A gas distribution structure (200) is connected to the bottom of the inner air inlet pipe (100) and has exhaust ports around it for discharging natural gas from around the gas distribution structure (200). The outer protective tube (300) is fitted outside the inner air intake tube (100) and is made of TZM alloy material; A heat-insulating material (400) is filled between the outer protective tube (300) and the inner air inlet tube (100) to insulate against heat conduction.

2. The top inlet structure for a liquid metal pyrolysis natural gas hydrogen production unit according to claim 1, characterized in that, Also includes the flange (500); The top of the outer protective tube (300) is fixedly connected to the flange (500), and the top air inlet structure is installed on the top of the reactor via the flange (500).

3. The top inlet structure for a liquid metal pyrolysis natural gas hydrogen production unit according to claim 1, characterized in that, The inner air intake pipe (100) is also made of TZM alloy material.

4. The top inlet structure for a liquid metal pyrolysis natural gas hydrogen production unit according to claim 1, characterized in that, The intermediate heat insulation material (400) is a high-temperature resistant heat insulation material.

5. A top inlet structure for a liquid metal pyrolysis natural gas hydrogen production unit according to any one of claims 1 to 4, characterized in that, The air distribution structure (200) is provided with an air inlet (210) in the middle, and a plurality of exhaust channels (220) are provided around the air inlet (210); wherein, the air inlet (210) is connected to the air outlet end of the inner air inlet pipe (100), one end of the exhaust channel (220) is connected to the air inlet (210), and the other end extends to the side wall of the air distribution structure (200).

6. The top inlet structure for a liquid metal pyrolysis natural gas hydrogen production unit according to claim 5, characterized in that, The gas distribution structure (200) is a columnar structure, and the gas discharged from each of the exhaust channels (220) creates a swirling effect on the liquid in the reactor.

7. A top inlet structure for a liquid metal pyrolysis natural gas hydrogen production unit according to claim 6, characterized in that, Each of the exhaust channels (220) is arranged in two layers, with the upper layer being the upper exhaust channel (221) and the lower layer being the lower exhaust channel (222). The gas discharged from each upper exhaust channel (221) and each lower exhaust channel (222) creates a swirling effect on the liquid in the reactor with different rotation directions.

8. A top inlet structure for a liquid metal pyrolysis natural gas hydrogen production unit according to claim 7, characterized in that, The end of each upper exhaust channel (221) connected to the air inlet (210) is the starting end, and the end extending to the side wall of the air distribution structure (200) is the ending end; wherein, each upper exhaust channel (221) is inclined in a first clockwise direction as it extends from the starting end to the ending end; The end of each lower exhaust channel (222) connected to the air inlet (210) is the starting end, and the end extending to the side wall of the air distribution structure (200) is the ending end; wherein, each upper exhaust channel (221) is inclined in a second clockwise direction as it extends from the starting end to the ending end; Wherein, the first clockwise direction and the second clockwise direction are respectively the clockwise direction of the air distribution structure (200) from the top view angle and the counterclockwise direction of the air distribution structure (200) from the top view angle.

9. A top inlet structure for a liquid metal pyrolysis natural gas hydrogen production unit according to claim 8, characterized in that, The centerline of the air intake (210) is defined as L1; The centerline of the upper exhaust channel (221) is defined as L2, the intersection of L2 and the inner wall of the air inlet (210) is defined as A1, the horizontal line connecting A1 and L1 is defined as L3, and the angle between L2 and L3 is defined as α1; wherein, the inclination angle of the upper exhaust channel (221) must satisfy that α1 is between 55° and 60°; The centerline of the lower exhaust channel (222) is defined as L4, the intersection of L4 and the inner wall of the air inlet (210) is defined as A2, the horizontal line connecting A2 and line L1 is defined as line L5, and the angle between L4 and L5 is defined as α2; wherein, the inclination angle of the lower exhaust channel (222) must satisfy that α2 is between 55° and 60°.

10. A top inlet structure for a liquid metal pyrolysis natural gas hydrogen production unit according to claim 5, characterized in that, The outer protective tube (300) is coated with a SiC coating.

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