Liquid metal catalytic cracking reaction system for gaseous hydrocarbons

Abstract

Provided in the present invention is a liquid metal catalytic cracking reaction system for gaseous hydrocarbons. The system comprises a housing, a furnace body, an air inlet unit, an exhaust port, and heating coils. Heating zones of the furnace body are located on two sides of a cracking reaction zone, and the heating coils are arranged around the heating zones. According to the liquid metal catalytic cracking reaction system for gaseous hydrocarbons provided by the present invention, by means of arranging the cracking reaction zone and the heating zones as separate zones, reaction gas can rise vertically in the cracking reaction zone without forming gas cavities on the inner wall of the furnace lining in the heating zones, thereby improving the thermal efficiency; moreover, a liquid metal catalyst in the heating zones can exert transverse shear on the reaction gas flow, effectively reducing bubble coalescence and improving the cracking reaction efficiency; the furnace lining thicknesses of the cracking reaction zone and the heating zones can be set separately, taking into account the service life against gas scouring and heating efficiency; in addition, the system can be modularly combined to achieve large-scale energy-saving production.

Description

A liquid metal catalytic cracking reaction system for gaseous hydrocarbons Technical Field

[0001] This invention relates to the field of green and clean energy and material preparation technology, and in particular to a liquid metal catalytic cracking reaction system for gaseous hydrocarbons. Background Technology

[0002] High-temperature catalytic cracking of gaseous hydrocarbons using liquid metal has advantages such as zero emissions, high purity, high efficiency, low cost, and significant economies of scale. The hydrogen and solid carbon products generated by the cracking can be widely used in cutting-edge technology fields such as new energy, electronics, and aerospace, and have significant environmental and economic value. It is the mainstream trend in the development of green energy and materials preparation technologies.

[0003] However, existing liquid metal catalytic cracking reactors all employ an integrated design where heating and catalytic cracking reactions share the same reaction chamber or region. While this conventional design is relatively simple in structure, it presents several problems. First, when gaseous hydrocarbons (such as methane) enter the reaction chamber from the bottom of the cracking reactor, they diffuse to the inner wall of the furnace lining and rise along it, forming gas cavities around the inner wall. This reduces the contact area between the reactant gas and the high-temperature liquid metal catalyst, resulting in lower thermal efficiency. Second, because the gas flow direction and the liquid metal catalyst movement direction are axial, the reactant gas forms bubbles and accumulates during its ascent, further reducing the gas cracking rate. Furthermore, to improve the heating efficiency of the cracking reaction zone, the furnace lining is generally made thinner; however, a thinner lining is not resistant to the erosion of the reactant gas and has a shorter service life. Moreover, the integrated design of the heating and cracking zones makes it difficult to achieve modular combinations of multiple reactors, which is detrimental to large-scale energy-saving production.

[0004] Therefore, it is necessary to improve the existing high-temperature catalytic cracking reactors for gaseous hydrocarbons using liquid metal. Summary of the Invention

[0005] To address the technical problems existing in the current liquid metal high-temperature catalytic cracking reactor for gaseous hydrocarbons, this invention discloses a liquid metal catalytic cracking system for gaseous hydrocarbons, the system comprising an outer shell, a furnace body, an air inlet unit, an exhaust port, and a heating coil.

[0006] in,

[0007] The furnace body has a furnace lining, including a pyrolysis reaction zone and a heating zone. The heating zone is located on both sides of the pyrolysis reaction zone and is internally interconnected with the pyrolysis reaction zone. It is filled with a liquid metal catalyst, which can flow between the pyrolysis reaction zone and the heating zone. Preferably, the catalytic pyrolysis zone has an upright cylindrical or upright cubic structure, and the heating zone has a horizontal cylindrical or horizontal cubic structure. Preferably, the furnace linings of the catalytic pyrolysis zone and the heating zone are integrally formed to prevent leakage of the liquid metal catalyst. Preferably, the thickness of the furnace lining in the catalytic pyrolysis zone is greater than or equal to the thickness of the furnace lining in the heating zone.

[0008] The air intake unit is located at the lower end of the pyrolysis reaction zone of the furnace body. Gaseous hydrocarbon reaction gases can enter the pyrolysis reaction zone through the air intake unit, and fully contact and catalytically pyrolyze the liquid metal catalyst therein into hydrogen and solid carbon. The solid carbon includes carbon products such as graphite, graphene, and carbon black.

[0009] The exhaust port is located at the top of the pyrolysis reaction zone of the furnace body, allowing the hydrogen and solid carbon powder generated by pyrolysis to be discharged from the furnace body and further collected and separated.

[0010] The heating coil surrounds the outside of the furnace heating zone and is connected to a medium-frequency power supply. When the heating coil is energized, it generates an induced electromagnetic field, causing eddy currents in the liquid metal catalyst within the heating zone and heating it to the temperature required for the catalytic cracking reaction. Simultaneously, under the influence of the electromagnetic field, the liquid metal catalyst flows horizontally between the catalytic cracking zone and the heating zone.

[0011] Furthermore, the system can be modularly combined to form a reaction system array, enabling large-scale production. Preferably, the contact surfaces of the combined reaction system are filled with thermal insulation material, thereby reducing the heat dissipation surface and effectively saving energy.

[0012] The liquid metal catalytic cracking reaction system for gaseous hydrocarbons provided by this invention can achieve the following significant technical effects:

[0013] 1. Since the heating zone of the furnace body is set on both sides of the pyrolysis reaction zone, the reaction gas enters the furnace body through the gas inlet unit and rises vertically in the pyrolysis reaction zone. It will not enter the heating zone and is not easy to form gas cavities on the inner wall of the furnace lining in the heating zone. This can effectively prevent the contact area between the reaction gas and the liquid metal catalyst from being reduced, thereby improving the thermal efficiency.

[0014] 2. Under the influence of the induced electromagnetic field generated by the heating coil, the liquid metal catalyst in the heating zone will flow horizontally between the heating zone and the pyrolysis reaction zone. Since the direction of movement of the liquid metal catalyst is orthogonal to the direction of the reaction gas flow in the pyrolysis reaction zone, it can form a transverse shear on the reaction gas flow, which can effectively reduce the formation of gas bubbles and improve the pyrolysis reaction efficiency.

[0015] 3. By setting the pyrolysis reaction zone and the heating zone separately, the furnace lining thickness of the pyrolysis reaction zone can be increased and / or the furnace lining thickness of the heating zone can be decreased according to actual needs. This can improve the service life of the furnace lining in the pyrolysis zone against gas erosion and ensure the heating efficiency of the heating zone, thus balancing production safety and efficiency.

[0016] 4. The system of the present invention can be modularly combined according to the needs of hydrogen production scale, while reducing the heat dissipation surface, effectively reducing energy consumption, and realizing large-scale energy-saving production. Attached Figure Description

[0017] Figure 1a is a front view schematic diagram of a liquid metal catalytic cracking reaction system for gaseous hydrocarbons according to an embodiment of the present invention;

[0018] Figure 1b is a top view schematic diagram of a liquid metal catalytic cracking reaction system for gaseous hydrocarbons according to an embodiment of the present invention;

[0019] Figure 1c is a side view schematic diagram of a liquid metal catalytic cracking reaction system for gaseous hydrocarbons according to an embodiment of the present invention;

[0020] Figure 2 is a schematic diagram of a heating coil provided in an embodiment of the present invention;

[0021] Figure 3 is a schematic diagram of the working principle of a liquid metal catalytic cracking reaction system for gaseous hydrocarbons according to an embodiment of the present invention;

[0022] Figure 4 is a schematic diagram of a liquid metal catalytic cracking reaction system array for gaseous hydrocarbons according to an embodiment of the present invention. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solution of this invention, the technical solution of this invention will be clearly and completely described below in conjunction with the accompanying drawings.

[0024] Referring to Figures 1-2, an embodiment of the present invention provides a liquid metal catalytic cracking reaction system 100 for gaseous hydrocarbons. The system 100 includes: a shell 10, a furnace body 20, an air inlet unit 30, an exhaust port 40, and a heating coil 50.

[0025] The furnace body 20 has a furnace lining 23, including a pyrolysis reaction zone 21 and a heating zone 22. The heating zones 22 are located on both sides of the pyrolysis reaction zone 21 and are interconnected with it. After the furnace body 20 is filled with liquid metal catalyst 60, the liquid metal catalyst 60 can flow between the pyrolysis reaction zone 21 and the heating zone 22. In some embodiments, the catalytic pyrolysis zone 21 is a vertical cuboid structure, and the heating zones 22 on both sides are horizontal cylindrical structures. In other embodiments, to prevent leakage of the liquid metal catalyst, the furnace lining 23 of the furnace body 20 is integrally formed. Preferably, to balance the gas erosion resistance life and heating efficiency of the furnace lining 23 and achieve safe and efficient production, the furnace lining thickness of the pyrolysis reaction zone 21 is greater than or equal to the furnace lining thickness of the heating zone 22. Preferably, the furnace lining 23 is a high-purity corundum casting material.

[0026] The air intake unit 30 is located at the lower end of the cracking reaction zone 21. Reaction gases 70, such as methane and other gaseous hydrocarbons, can be introduced into the cracking reaction zone 21 of the furnace body 20 through the air intake unit 30, where they fully contact and catalytically crack into hydrogen and solid carbon by the high-temperature liquid metal catalyst 60 filled therein. Preferably, the number of air intake units can be set to n, where n≥1, depending on the system and the scale of hydrogen production required.

[0027] The exhaust port 40 is located at the top of the cracking reaction zone 21 and is used to discharge the hydrogen gas and solid carbon powder generated by the cracking of gaseous hydrocarbons from the furnace body 20 for further collection and separation.

[0028] The heating coil 50 is arranged around the heating zones 22 on both sides of the pyrolysis reaction zone 21 and is connected to a medium-frequency power supply. When the heating coil 50 is energized, it generates an induced electromagnetic field, which in turn generates eddy currents in the liquid metal catalyst 60 filled in the heating zone 22, thereby heating the liquid metal catalyst 60 to the temperature required for the catalytic pyrolysis reaction through induction heating. Furthermore, under the influence of the induced electromagnetic field, the liquid metal catalyst 60 in the heating zone can flow horizontally between the heating zone 22 and the pyrolysis reaction zone 21.

[0029] The following will describe in detail the specific working method of the liquid metal catalytic cracking reaction system for gaseous hydrocarbons provided by the present invention.

[0030] Referring to Figure 3, in some embodiments of the present invention, before hydrogen preparation begins, an inert gas is first introduced into the furnace body 20 through the air inlet unit 30 to prevent the liquid metal catalyst 60 from flowing back into the air inlet unit 30 and clogging the air inlet during filling. In some embodiments, the inert gas is nitrogen. The prepared liquid metal catalyst 60 is filled into the furnace body 20 in one go. The liquid metal catalyst 60 is one or a combination of two or more of copper, tin, nickel, lanthanum, gallium, indium, bismuth, lead, silver, and zinc. The heating coil 50 is connected to a medium-frequency power supply. After being energized, the heating coil 50 generates an induced electromagnetic field, forming eddy currents in the liquid metal catalyst 60 inside the heating zone 22, heating the liquid metal catalyst 60 to 800-1200°C.

[0031] Inert gas is continuously introduced into the furnace body 20 through the air inlet unit 30 to replace the air inside the furnace body 20. When the oxygen content inside the furnace body 20 is less than or equal to 0.3%, the inert gas is stopped. Then, the reaction gas 70, which has been treated by desulfurization, mercury removal, and dehydration, such as gaseous hydrocarbons like methane, is introduced into the cracking reaction zone 21 through the air inlet unit 30 to carry out the catalytic cracking reaction. Since the cracking reaction zone 21 and the heating zone 22 are set up independently, the reaction gas 70 can rise vertically inside the cracking reaction zone 21 to form bubbles 71 without entering the heating zone 22, achieving full contact with the high-temperature liquid metal catalyst 60. Utilizing the high catalytic activity and temperature of the liquid metal catalyst 60, the carbon-hydrogen bonds in the reaction gas 70 are broken to generate hydrogen and solid carbon. The reaction formula is: CH4(g) → 2H2(g) + C(solid).

[0032] The solid carbon generated by pyrolysis floats on the surface of the liquid metal catalyst 60 because its density is less than that of the liquid metal catalyst 60. The unreacted reaction gas 70 and the hydrogen generated by pyrolysis form a high-temperature hot gas flow 72, which carries the solid carbon powder and is discharged from the exhaust port 40 for further collection and separation. During the catalytic pyrolysis reaction, the liquid metal catalyst 60 located in the heating zone 22 flows horizontally 80 between the heating zone 22 and the pyrolysis reaction zone 21 under the action of an induced electromagnetic field. This laterally shears the vertically rising reaction gas flow in the pyrolysis reaction zone 21, thereby promoting the dispersion of bubbles 71, reducing aggregation, and effectively improving the pyrolysis rate of the reaction gas.

[0033] In some embodiments, the furnace lining 23 of the pyrolysis reaction zone 21 is continuously subjected to the scouring of the reaction gas 70, and the thickness of the furnace lining 23 needs to be increased to extend its gas scouring resistance life. Meanwhile, the furnace lining 23 located in the heating zone 22 needs to be reduced in thickness to improve heating efficiency. Therefore, optionally, the furnace lining thickness of the pyrolysis reaction zone 21 can be greater than or equal to the furnace lining thickness of the heating zone 22 to achieve a balance between safety and efficiency.

[0034] In other embodiments, the liquid metal catalytic cracking reaction system 100 provided by the present invention can be modularly combined to form a reaction system array 200, enabling large-scale production. Specifically, referring to Figure 4, the cracking reaction zone 21 of the furnace body 20 of the system 100 has a cubic structure. Since the cracking reaction zone 21 and the heating zone 22 are independently set, the cracking reaction zones 21 of multiple furnace bodies 20 of the liquid metal catalytic cracking reaction system 100 can be interconnected and combined through insulation material 90 to form a reaction system array 200. The reaction system array 200 not only reduces the heat dissipation surface 91 of each cracking reaction zone 21, but also ensures that they do not directly affect each other. In some embodiments, the insulation material 90 is an aerated gel insulation material.

[0035] Those skilled in the art will understand that some or all of the technical solutions provided by this invention can be implemented by computer program instructions and / or corresponding hardware facilities, and the aforementioned computer program instructions can be stored on any type of computer-readable storage medium.

[0036] The above description is merely an illustration of the technical solution or preferred embodiments of the present invention, and is not intended to limit the present invention. For those skilled in the art, based on a full understanding of the inventive concept and technical solution of the present invention, any modifications of any kind can be made without departing from the essence of the present invention, or equivalent substitutions can be made to some or all of the technical features. Any modifications, equivalent substitutions, improvements, etc., made thereby should be included within the protection scope of the present invention.

Claims

1. A liquid metal catalytic cracking of gaseous hydrocarbons reaction system, comprising: a reactor vessel having a reaction zone; a liquid metal catalyst in the reaction zone; a gaseous hydrocarbon feedstock; and a catalyst activator. The system includes: a furnace body, an air inlet unit, an exhaust port, and a heating coil, wherein, The furnace body includes a furnace lining and interconnected pyrolysis reaction zone and heating zone, with the heating zone located on both sides of the pyrolysis reaction zone; The air intake unit is located at the lower end of the pyrolysis reaction zone of the furnace body; The exhaust port is located at the top of the pyrolysis reaction zone of the furnace body; The heating coil surrounds the heating zone of the furnace body and is connected to a medium-frequency power supply.

2. The liquid metal catalytic cracking of gaseous hydrocarbons reaction system of claim 1, wherein, The pyrolysis reaction zone of the furnace body is a vertical cubic or vertical cylindrical structure.

3. The liquid metal catalytic gas hydrocarbon cracking reaction system of claim 1, wherein, The heating zone of the furnace body has a horizontal cylindrical structure.

4. The liquid metal catalytic gas hydrocarbon cracking reaction system of claim 1, wherein, The furnace lining is constructed as a single piece.

5. The liquid metal catalytic gas hydrocarbon cracking reaction system of claim 4, wherein, The furnace lining is made of high-purity corundum casting material.

6. The liquid metal catalytic gas hydrocarbon cracking reaction system of claim 4, wherein, The furnace lining thickness of the pyrolysis reaction zone is not less than the furnace lining thickness of the heating zone.

7. The liquid metal catalytic gas hydrocarbon cracking reaction system of claim 1, wherein, The number of intake units is one or more.

8. A liquid metal catalytic cracking of gaseous hydrocarbons reaction system, characterized in that, The system includes: a furnace body, an air inlet unit, an exhaust port, and a heating coil, wherein, The furnace body includes a furnace lining and interconnected pyrolysis reaction zone and heating zone. The heating zone is located on both sides of the pyrolysis reaction zone. The interior of the furnace body is filled with a liquid metal catalyst, which is one or a combination of two or more of copper, tin, nickel, lanthanum, gallium, indium, bismuth, lead, silver, and zinc. The air intake unit is located at the lower end of the pyrolysis reaction zone of the furnace body, and is used to introduce the reaction gas into the pyrolysis reaction zone to contact the liquid metal catalyst and pyrolyze it to generate hydrogen and solid carbon. The reaction gas is a gaseous hydrocarbon. The exhaust port is located at the top of the pyrolysis reaction zone of the furnace body and is used to discharge the hydrogen and solid carbon generated by the pyrolysis into the furnace body. The heating coil surrounds the heating zone of the furnace body and is connected to a medium-frequency power supply. When the heating coil is energized, it generates an induced electromagnetic field. Under the action of the induced electromagnetic field, the liquid metal catalyst in the heating zone generates eddies and is heated to the temperature required for the cracking reaction, and flows between the heating zone and the cracking reaction zone.

9. The liquid metal catalytic gas hydrocarbon cracking reaction system of claim 8, wherein, The furnace lining is a high-purity corundum casting material integrally formed and constructed.

10. The liquid metal catalytic gas hydrocarbon cracking reaction system of claim 8, wherein, The furnace lining thickness of the pyrolysis reaction zone is not less than the furnace lining thickness of the heating zone.

11. The liquid metal catalytic gas hydrocarbon cracking reaction system of claim 8, wherein, The required temperature for the pyrolysis reaction is 900-1200℃.

12. The liquid metal catalytic gas hydrocarbon cracking reaction system of claim 8, wherein, The system includes one or more of the aforementioned intake units.

13. An array of liquid metal catalytic cracking gaseous hydrocarbon reaction systems, characterized in that, The system array consists of two or more liquid metal catalytic cracking reaction systems for gaseous hydrocarbons as described in any one of claims 1 or 8, wherein the cracking reaction zones of the furnace bodies of two adjacent systems are connected to each other by thermal insulation material.

14. The liquid metal catalytic gas hydrocarbon cracking reaction system array of claim 13, wherein, The insulation material is an aerated gel insulation material.

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