A method for hydrogen production from natural gas

Abstract

The application discloses a natural gas hydrogen production method and belongs to the technical field of natural gas hydrogen production. The application solves the problems of catalyst carbon deposition and low conversion rate in hydrogen production by catalytic cracking of natural gas. The natural gas is cracked by an electric field and high temperature, and the gas rotates at the gas outlet, so that the incomplete cracking gas carried in the hydrogen gas rotates into the cracking chamber for continuous cracking. Meanwhile, the rotating gas forms a gas wall at the gas outlet, so that the subsequent gas entering and generated gas rotates into the cracking chamber for continuous cracking under the action of the gas wall, and then the gas is cooled and gas-solid separated to obtain carbon powder and hydrogen gas. The natural gas is cracked by the dual action of the electric field and high temperature, the residence time of the gas in the cracking chamber is effectively increased, the cracking rate of the natural gas can reach more than 90%, and the catalyst is not needed for cracking, so the problems of catalyst carbon deposition and low conversion rate are effectively solved.

Description

Technical Field

[0001] This invention belongs to the field of natural gas hydrogen production technology, and specifically relates to a method for producing hydrogen from natural gas. Background Technology

[0002] Natural gas to hydrogen production refers to the process of converting methane, the main component of natural gas, into hydrogen through a chemical reaction using natural gas as a raw material. The main methods of natural gas to hydrogen production include:

[0003] Natural gas steam reforming for hydrogen production: Natural gas is compressed and desulfurized, and then reacted with steam at a certain pressure in a reformer to produce hydrogen through a catalytic reaction. This is the most commonly used hydrogen production technology, but the reaction process requires the absorption of a large amount of heat, resulting in high energy consumption.

[0004] Partial oxidation of natural gas to produce hydrogen: The incomplete combustion of methane and oxygen produces carbon monoxide and hydrogen without the need for external heating, but problems such as catalyst carbon buildup need to be solved.

[0005] Natural gas autothermal reforming for hydrogen production: Combining partial oxidation and steam reforming reactions, it achieves self-heating and improves the conversion efficiency of methane.

[0006] Catalytic cracking of natural gas to produce hydrogen: This method involves the high-temperature catalytic decomposition of natural gas into hydrogen and carbon materials, characterized by high purity and low energy consumption; however, problems such as catalyst carbon buildup and low hydrogen conversion rate need to be addressed. Summary of the Invention

[0007] To address the problems of catalyst carbon buildup and low conversion rates in existing technologies for hydrogen production via natural gas catalytic cracking, this invention provides a method for producing hydrogen from natural gas.

[0008] The technical solution adopted in this invention is as follows:

[0009] A method for producing hydrogen from natural gas, comprising:

[0010] Natural gas cracking: Natural gas is cracked by an electric field and high temperature. The hydrogen produced by cracking carries the remaining gas to the gas outlet of the cracking chamber and creates a vortex at the gas outlet. This causes the incompletely cracked gas carried in the hydrogen to vortex back into the cracking chamber for further cracking. At the same time, because the vortexing gas forms a gas wall at the gas outlet, the gas that is subsequently introduced and generated also vortexes back into the cracking chamber for further cracking under the action of the gas wall when it reaches the gas outlet of the cracking chamber.

[0011] Gas cooling: Cooling the mixed gas obtained after pyrolysis;

[0012] Gas-solid separation: The cooled mixed gas is subjected to gas-solid separation to obtain carbon powder and hydrogen.

[0013] By adopting this technical solution, the present invention first utilizes the dual effects of electric field and high temperature to crack natural gas, effectively improving the conversion rate of natural gas. Simultaneously, it leverages the lightweight and high-velocity characteristics of hydrogen, allowing it to carry other gases to the gas outlet first, where a swirling motion occurs. This causes incompletely cracked gases carried in the hydrogen to swirl back into the cracking chamber for further cracking. Furthermore, because the swirling gas forms a gas wall at the gas outlet, subsequent introduced and generated gases also swirl back into the cracking chamber under the influence of this gas wall, further increasing the residence time of the gas within the cracking chamber. This further improves the cracking rate of natural gas. Ultimately, the cracking rate of natural gas using this invention can reach over 90%, and no catalyst is required for cracking, effectively solving the problems of catalyst carbon buildup and low conversion rate.

[0014] Preferably, the pyrolysis chamber includes a primary pyrolysis chamber and a secondary pyrolysis chamber that are interconnected. When the gas pressure in the primary pyrolysis chamber where the primary pyrolysis occurs is greater than a set value, the gas after the primary pyrolysis enters the secondary pyrolysis chamber from the primary pyrolysis chamber under the action of the pressure difference to continue pyrolysis.

[0015] By adopting this technical solution, in addition to increasing the residence time of natural gas in the primary cracking process, a further step is set in the secondary cracking process. Natural gas that has not been fully cracked in the primary cracking process enters the secondary cracking process for secondary cracking. Furthermore, the natural gas that has not yet been cracked in the secondary cracking process is made to swirl at the gas outlet of the secondary cracking chamber, thereby increasing the residence time of the gas in the secondary cracking process and further improving the cracking rate.

[0016] Preferably, when the gas flows to the gas outlet of the secondary cracking chamber, the gas also swirls, causing the incompletely cracked gas carried in the hydrogen to swirl back into the secondary cracking chamber for further cracking. At the same time, since the swirling gas forms a gas wall at the gas outlet, the subsequently introduced and generated gas also swirls back into the secondary cracking chamber under the action of the gas wall for further cracking until the pressure in the secondary cracking chamber is greater than the set value. Then, under the action of the pressure difference, the gas enters the cooling process.

[0017] Preferably, the temperature of the primary pyrolysis chamber is transferred to the secondary pyrolysis chamber through heat conduction and gas flow, so that the secondary pyrolysis chamber reaches the pyrolysis temperature.

[0018] By adopting this technical solution, the heat from the initial pyrolysis is transferred to the secondary pyrolysis, making full use of the heat from the initial pyrolysis and reducing the increased cost of introducing secondary pyrolysis.

[0019] Preferably, the cross-sectional dimension of the secondary pyrolysis chamber is greater than or equal to the cross-sectional dimension of the primary pyrolysis chamber, and the length of the secondary pyrolysis chamber is greater than the length of the primary pyrolysis chamber.

[0020] This technical solution makes the heat distribution more uniform, makes it easier for the expanding gas entering the pyrolysis chamber where it is re-pyrolyzed to disperse, and makes the heat absorbed by the gas more uniform.

[0021] Preferably, the gas is made to swirl by setting a barrier at the gas outlet of the pyrolysis chamber to reduce the size of the gas outlet.

[0022] By adopting this technical solution, the natural gas is blocked and collided at the gas outlet, thereby causing the natural gas to swirl back into the cracking chamber and increasing the residence time of the natural gas.

[0023] Preferably, during methane cracking, an electric field is used to ionize methane into carbon ions and hydrogen ions. The carbon ions and hydrogen ions collide and generate a high-temperature electric arc, thereby causing the methane to undergo a cracking reaction through the electric field and the high-temperature electric arc.

[0024] By adopting this technical solution, the heat generated by the collision of ions produced by the ionization of methane itself is used as the heat source for high-temperature cracking. This avoids the introduction of other impurities, reduces the difficulty of hydrogen impurity removal, and improves the efficiency of hydrogen production.

[0025] Preferably, the high-temperature electric arc fully covers the primary pyrolysis cavity.

[0026] By adopting this technical solution, the high-temperature electric arc generated can fully cover the primary cracking chamber by controlling the size of the primary cracking chamber, the amount of methane gas entering the chamber, and the electric field strength. This not only facilitates the transfer of heat to the secondary cracking chamber, but also allows the uncracked natural gas to fully contact the high-temperature electric arc, thereby improving the cracking rate.

[0027] Preferably, the hydrogen is further purified by using a catalyst after gas-solid separation.

[0028] By adopting this technical solution, hydrogen can be further purified through catalytic reaction.

[0029] Preferably, a water-cooled heat exchanger is used to cool the mixed gas during the gas cooling process, and the water vapor generated by the water-cooled heat exchanger is introduced into the catalytic process so that the water vapor provides the water and heat required for the catalytic reaction.

[0030] By adopting this technical solution, the water vapor generated in the cooling process can be utilized, thus saving production costs.

[0031] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0032] This invention first utilizes the combined effects of an electric field and high temperature to crack natural gas, effectively improving its conversion rate. Simultaneously, it leverages the lightweight and high-velocity properties of hydrogen, causing it to carry other gases to the gas outlet first. At the outlet, the hydrogen creates a swirling effect, drawing incompletely cracked gases back into the cracking chamber for further cracking. Furthermore, the swirling gas forms a gas wall at the outlet, causing subsequent incoming and generated gases to also swirl back into the cracking chamber for further cracking under the influence of this gas wall. This effectively increases the residence time of the gas within the cracking chamber, further enhancing the natural gas cracking rate. Ultimately, this invention achieves a natural gas cracking rate exceeding 90% without the need for a catalyst, effectively solving the problems of catalyst carbon buildup and low conversion rates. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the apparatus used in the method described in the first embodiment of this application;

[0034] Figure 2 yes Figure 1 A schematic diagram of the structure of a natural gas reactor;

[0035] Figure 3 yes Figure 1 Schematic diagram of the heat exchanger in the middle;

[0036] Figure 4 yes Figure 1 A schematic diagram of the first embodiment of the toner extraction device;

[0037] Figure 5 yes Figure 1 A schematic diagram of the second embodiment of the toner extraction device;

[0038] 1-Natural gas reaction unit, 11-Plasma generator, 12-Primary cracking chamber, 13-Secondary cracking chamber, 14-Baffle, 15-Ventilation hole, 16-First insulation layer, 17-Second insulation layer;

[0039] 2-Heat exchanger, 21-First inlet, 22-Second inlet, 23-Second outlet, 24-Second outlet;

[0040] 3-Toner collection device, 31-Collection chamber, 32-Third outlet, 33-Rotating shaft, 331'-Lead screw, 332'-Lead screw nut, 34-First motor, 34'-Second motor, 35-Fourth outlet, 36-Separation membrane, 37-Mounting bracket, 38-Third inlet;

[0041] 4-Catalytic device, 41-Heating component, 42-Net bag;

[0042] 100 - First pipeline, 110 - Second pipeline, 120 - Third pipeline, 130 - Fourth pipeline;

[0043] 200 - First refrigerant line, 210 - Second refrigerant line. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0045] In the description of the embodiments of this application, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. Example 1

[0046] A method for producing hydrogen from natural gas, comprising:

[0047] Natural gas cracking: Natural gas is cracked by an electric field and high temperature. The hydrogen produced by cracking carries the remaining gas to the gas outlet of the cracking chamber and creates a vortex at the gas outlet. This causes the incompletely cracked gas carried in the hydrogen to vortex back into the cracking chamber for further cracking. At the same time, because the vortexing gas forms a gas wall at the gas outlet, the gas that is subsequently introduced and generated also vortexes back into the cracking chamber for further cracking under the action of the gas wall when it reaches the gas outlet of the cracking chamber.

[0048] Gas cooling: Cooling the mixed gas obtained after pyrolysis;

[0049] Gas-solid separation: The cooled mixed gas is subjected to gas-solid separation to obtain carbon powder and hydrogen.

[0050] To implement this hydrogen production method, this embodiment provides one type of natural gas hydrogen production apparatus capable of implementing the hydrogen production method, comprising:

[0051] Natural gas reaction device 1, which performs a cracking reaction on natural gas, includes a primary cracking unit and a secondary cracking unit that are interconnected. The primary cracking unit is used to perform initial cracking on the natural gas, and the secondary cracking unit is used to further crack the uncracked natural gas in the primary cracking unit. Specifically, the primary cracking unit is connected to a natural gas source through a first pipeline 100. The natural gas source can be residential piped natural gas with a methane content of 98% or more.

[0052] Heat exchange device 2 is connected to the natural gas reactor 1 and cools the products of the natural gas reactor 1. Specifically, the heat exchange device 2 can be a shell-and-tube heat exchanger, and the second inlet 22 of the shell-and-tube heat exchanger is connected to the natural gas reactor 1 through the second pipeline 110.

[0053] A carbon powder collection device 3 is connected to the heat exchange device 2 and performs gas-solid separation on the products of the heat exchange device 2 to obtain carbon powder and hydrogen. Specifically, the second outlet 23 of the shell-and-tube heat exchanger is connected to the carbon powder collection device 3 through a third pipeline 120.

[0054] To facilitate control of the fluid flow in each pipeline, solenoid valves are installed in the first pipeline 100, the second pipeline 110, and the third pipeline 120 respectively.

[0055] The working principle of this system is:

[0056] First, natural gas supplied by a natural gas source (e.g., a total of 3 cubic meters of natural gas is introduced into the first pipeline 100 and the eighth pipeline 170) is fed into the natural gas reactor 1 through the first pipeline 100. The natural gas reactor 1 generates an electric field to electrolyze the methane component in the introduced natural gas, ionizing the methane into active ions such as carbon ions and hydrogen ions. Then, under the influence of the electric field, the carbon ions and hydrogen ions collide, generating a high-temperature electric arc. This high-temperature electric arc causes the methane to crack under high-temperature conditions, producing hydrogen gas (e.g., 6 cubic meters of hydrogen gas) and nano-sized carbon powder (e.g., ...). 1500 grams of toner are used, and the reaction products (hydrogen and nano-sized toner) are sent to heat exchange device 2 through second pipeline 110. Heat exchange device 2 cools the products (hydrogen and nano-sized toner) from 800°C to 40-60°C (for example, from 800°C to room temperature). Heat exchange device 2 sends the cooled products to toner collection device 3 through third pipeline 120. Toner collection device 3 separates the hydrogen and nano-sized toner by performing gas-solid separation treatment on the products (for example, 6 cubic meters of hydrogen and 1500 grams of toner are obtained after gas-solid separation treatment).

[0057] The combustion system provided in this embodiment mainly consists of a natural gas reactor 1, a heat exchanger 2, and a carbon powder extraction device 3. First, the methane is cracked multiple times through the primary and secondary cracking mechanisms of the natural gas reactor 1 to increase the residence time of the natural gas in the cracking chamber. The natural gas is cracked at high temperature using the principle of methane cracking reaction in the primary and secondary cracking mechanisms, and the products are hydrogen and nano-sized carbon powder. Since the products after the cracking reaction have a very high temperature, in order to avoid the high-temperature products from damaging the subsequent process equipment and thus making the entire process impossible to continue, a heat exchanger 2 connected to the natural gas reactor 1 is required. The heat exchanger 2 cools down the products after cracking in the natural gas reactor 1. Then, the carbon powder extraction device 3 performs gas-solid separation on the cooled products to obtain the gaseous product (hydrogen).

[0058] To improve the conversion rate of methane in natural gas, in this preferred embodiment, the primary cracking mechanism includes a primary cracking chamber 12 and a plasma generator 11. The inlet of the plasma generator 11 is connected to the natural gas source, and the high-temperature electric arc generated by the plasma generator 11 enters the primary cracking chamber 12. The secondary cracking mechanism includes at least one secondary cracking chamber 13. In this embodiment, one secondary cracking chamber 13 is selected; in other embodiments, multiple secondary cracking chambers 13 can be selected to form a secondary cracking mechanism.

[0059] In this embodiment, a plasma generator 11 is first set up. Specifically, the plasma generator 11 can be a high-current plasma generator as disclosed in the prior art CN216057599U, as shown in the attached figure. Figure 1The specific structure includes an electric arc main electrode, an electric arc body with a cathode connection end, and an anode installed in a mounting hole. First, by energizing both the electric arc main electrode and the anode, an electric field is generated between them. This electric field ionizes methane into carbon ions and hydrogen ions. High-energy electrons collide with methane molecules through inelastic collisions, further ionizing methane into active ions such as carbon and hydrogen ions. The electric field then causes these carbon and hydrogen ions to collide, generating a high-temperature electric arc. This high-temperature arc causes the methane gas to undergo a cracking reaction under high-temperature conditions. Simultaneously, the fluidity of natural gas under high temperature and pressure is affected by temperature and pressure. Studies have shown that the fluidity of natural gas increases with increasing temperature. This is because under high-temperature conditions, the movement speed of natural gas molecules increases, making them easier to flow and diffuse. To effectively ensure the residence time of natural gas in the high-temperature environment, a primary cracking chamber 12 and a secondary cracking chamber 13 are set up, which are interconnected. During the first cracking of methane in the natural gas in the primary cracking chamber 12, the plasma generator 11 generates products (hydrogen and nano-sized carbon powder) with a very high temperature. After the high-temperature gas continues to flow into the secondary cracking chamber 13, it will bring the secondary cracking chamber 13 to a certain temperature (the temperature at which methane in the natural gas that has not been completely cracked in the primary cracking chamber 12 continues to undergo a second cracking). Therefore, by designing two cracking chambers, the high-temperature environment coverage area is larger, thereby increasing the residence time of natural gas in the high-temperature environment. At the same time, since the density of hydrogen is lower than that of natural gas, the same volume of hydrogen is lighter than that of natural gas. Therefore, in the same temperature environment, the flow rate of hydrogen is faster than that of natural gas. Based on the above principle, by separately... The inlet and outlet of the secondary cracking chamber 13 are equipped with baffles 14, and the baffles 14 have vents 15. Because the hydrogen in the primary cracking chamber 12 flows at a faster speed, it can carry some of the natural gas to the vents 15 on the baffles 14 at the inlet of the secondary cracking chamber 13. This creates a gas wall at the vents 15, causing the unreacted natural gas in the primary cracking chamber 12 to collide with this gas wall and then flow back into the primary cracking chamber 12 for cracking. Similarly, the secondary cracking chamber 13... Because of its faster flow velocity, the hydrogen gas in chamber 3 can carry some of the natural gas to the vent holes 15 on the baffle 14 at the outlet of the secondary cracking chamber 13. This creates a gas wall at the vent holes 15, causing unreacted natural gas in the secondary cracking chamber 13 to collide with this gas wall and flow back into the secondary cracking chamber 13 for cracking. Therefore, by installing baffles 14 at both the inlet and outlet of the secondary cracking chamber 13, the residence time of natural gas in the high-temperature environment is further increased. In summary, the structure consisting of the primary cracking chamber 12, the secondary cracking chamber 13, and the baffle 14 with vent holes 15 effectively increases the residence time of natural gas in the high-temperature environment, thereby increasing the efficiency of methane cracking in natural gas.In this embodiment, the plasma generator 11 has a power of 15 kilowatts and a natural gas intake ratio of 3m³. 3 In other embodiments, the power-to-natural gas intake ratio of the corresponding plasma flame emitting device is 5 kW: 1 m³ / s. 3 .

[0060] The specific parameters of the natural gas reaction device in this embodiment are as follows: The plasma generator 11 in this preferred embodiment generates a high-temperature arc with a center temperature of 2000℃, the temperature of which gradually decreases from the inside out, reaching 800℃ at the outermost edge; the length of the high-temperature arc is 25-45cm; the primary pyrolysis chamber 12 has a length of 25-45cm and a diameter of 5-8cm; the secondary pyrolysis chamber 13 has a length greater than or equal to the length of the primary pyrolysis chamber 12 and a diameter of 6-12cm; the baffle 14 has a diameter of 3-8cm. The plasma generator 11 has 18-36 ventilation holes 15, each with a diameter of 0.4-1 mm. More preferably, the high-temperature arc generated by the plasma generator 11 is 30 cm long and completely covers the primary pyrolysis chamber 12. The primary pyrolysis chamber 12 is 30 cm long and 6 cm in diameter. The secondary pyrolysis chamber 13 is 30 cm long and 8 cm in diameter. The baffle 14 has a diameter of 6 cm and has 24 ventilation holes 15, each with a diameter of 0.8 mm.

[0061] In summary, the structure consisting of the primary cracking chamber 12, the secondary cracking chamber 13, and the baffle 14 with vent holes 15 can effectively increase the residence time of natural gas in a high-temperature environment, thereby increasing the efficiency of methane cracking in natural gas.

[0062] To effectively achieve gas-solid separation of hydrogen and nano-carbon powder, in this preferred embodiment, the carbon powder collecting device 3 includes a collecting chamber 31. Specifically, to facilitate the collection of nano-carbon powder, the collecting chamber 31 has a third outlet 32, a third inlet 38, and a fourth outlet 35. The collecting chamber 31 is connected to a third pipeline 120 through the third inlet 38, and to a fourth pipeline 130 through the fourth outlet 35. The outer wall of the lower half of the collecting chamber 31 is inclined towards the fourth outlet 35, meaning that the diameter of the upper part of the lower half of the collecting chamber 31 is larger than the diameter of the third outlet 32 ​​located below the lower half of the collecting chamber. The fourth outlet 35 facilitates the separation of hydrogen. The gas enters the next process through the fourth outlet 35. Next, the inclined outer wall and the third outlet 32 ​​facilitate the guidance of the split nano-sized carbon powder to the third outlet 32. A mounting frame 37 is disposed within the collection chamber 31. The surface of the mounting frame 37 has a filter screen. Specifically, to facilitate the adsorption of nano-sized carbon powder, since the carbon powder carries ions under high temperature and its particle size is less than 100 nm, the filter screen can be a separation membrane with a pore size greater than or equal to 100 nm. In this embodiment, its pore size is 100 nm. A transmission unit is connected to the collection chamber 31 via the transmission unit. A drive unit is connected to the transmission unit.

[0063] In this example, a metal ion membrane is first used as the separation membrane for the filter screen. Since the pore size of the metal ion membrane is larger than the particle size of the toner, and the toner carries charged ions in a high-temperature environment, the charged toner can be adsorbed onto the metal ion membrane made of metal material through electrostatic action. That is, when a charged object approaches a metal object, electrostatic induction will occur inside the metal object, causing free electrons in the object to move to the surface, making the surface charged. Therefore, the electrostatic potential generated by electrostatic induction and the static electricity of the charged object attract each other under the action of Coulomb force, thus causing adsorption. So the charged carbon powder can be adsorbed first through the metal ion membrane, while hydrogen gas passes through the pores on the metal ion membrane and is discharged, thus completing the gas-solid separation of hydrogen gas and nano-sized carbon powder. Next, by installing the filter screen on the mounting frame 37, which is movably connected to the collection chamber 31 through the transmission part and the drive part, the drive part can drive the transmission part to move the mounting frame 37, such as rotating or reciprocating. Thus, the movement of the mounting frame 37 shakes off the nano-sized carbon powder adsorbed on the separation membrane on the mounting frame 37, thereby completing the collection of nano-sized carbon powder.

[0064] In order to achieve regular rotation of the filter screen, in this preferred embodiment, the transmission part includes a rotating shaft 33, the two ends of which are movably connected to the collection chamber 31, and the mounting bracket 37 is disposed on the rotating shaft 33; the drive part includes a first motor 34, the output end of which is connected to the end of the rotating shaft 33.

[0065] In this example, the mounting bracket 37 is placed on the rotating shaft 33, and the output end of the first motor 34 is connected to the end of the rotating shaft 33. Specifically, the first motor 34 can be a servo motor. Since the speed and position accuracy of the servo motor are very accurate, the driving force can be transmitted to the rotating shaft 33 by controlling the forward or reverse rotation of the servo motor, thereby driving the rotating shaft 33 to rotate forward or reverse in a regular manner. Since the mounting bracket 37 is placed on the rotating shaft 33, the rotating shaft 33 can drive the mounting bracket 37 to move in a regular manner (i.e., forward or reverse rotation), thereby making it easier to shake off the nano-sized carbon powder adsorbed on the separation membrane.

[0066] In order to achieve regular reciprocating movement of the filter screen, in this preferred embodiment, the transmission part includes a lead screw 331' and a lead screw nut 332' that are mutually driven and cooperate with each other. The two ends of the lead screw 331' are respectively movably connected to the collection chamber 31, and the mounting bracket 37 is disposed on the lead screw nut 332'. The drive part includes a second motor 34', and the output end of the second motor 34' is connected to the end of the lead screw 331'.

[0067] In this example, the mounting bracket 37 is placed on the lead screw nut 332', and the output end of the second motor 34' is connected to the end of the lead screw 331'. Specifically, the second motor 34' can be a servo motor. Since the speed and position accuracy of the servo motor are very accurate, the driving force can be transmitted to the lead screw 331' by controlling the forward or reverse rotation of the servo motor, thereby driving the lead screw 331' to rotate forward or reverse in a regular manner. Since the lead screw nut 332' and the lead screw 331' are connected by a threaded engagement, the lead screw nut 332' can be driven to reciprocate along the direction of the lead screw 331'. Since the mounting bracket 37 is placed on the lead screw nut 332', it can be driven to move regularly (i.e., reciprocate), thereby making it easier to shake off the nano-sized carbon powder adsorbed on the separation membrane.

[0068] In this embodiment, by setting the parameters of the natural gas reactor, the conversion rate of methane in natural gas is further improved, resulting in higher hydrogen production and nano-sized carbon powder production, as shown in Table 1 (in Table 1, S1-9 correspond to Examples 1-9, and D1-6 correspond to Comparative Examples 1-6; to highlight the differences, the similarities between Examples 2-9 and Comparative Examples 1-6 and Example 1 are not listed):

[0069] Table 1

[0070]

[0071] As can be seen from Table 1, by reasonably controlling parameters such as the baffle, the primary cracking chamber, and the secondary cracking chamber, the natural gas conversion rate can reach up to 95%. When the natural gas conversion rate reaches 95%, about 93% of the carbon powder obtained has a particle size of 10-300 nm, and the purity of the obtained natural gas is over 90%. Example 10

[0072] To further improve the purity of the gaseous products (i.e., the purity of hydrogen) in the toner device, this embodiment further includes a catalytic device 4 in the plasma hydrogen production and oxygen and natural gas mixing and combustion system. The catalytic device 4 is connected to the toner collection device 3 and the first gas mixing device 6, respectively. The catalytic device 4 includes: a catalytic chamber 43; a mesh bag 42 disposed inside the catalytic chamber 43; and a heating component 41 disposed outside the catalytic chamber 43.

[0073] In this example, a mesh bag 42 is placed inside the catalytic chamber 43. Before the catalytic reaction, the catalyst is placed on the mesh bag 42 to remove impurities from the hydrogen. To further provide the temperature for the catalytic reaction, the preferred heating assembly 41 in this embodiment includes a heating tube wrapped around the outside of the catalytic chamber 43. The inlet end of the heating tube is connected to the first inlet 21 of the heat exchange device 2 via a first refrigerant pipe 200, and the outlet end of the heating tube is connected to the first outlet 24 of the heat exchange device 2 via a second refrigerant pipe 210. The purity of the hydrogen obtained in this embodiment is above 90%.

[0074] The embodiments described above merely illustrate specific implementation methods of this application, and while the descriptions are detailed and specific, they should not be construed as limiting the scope of protection of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the technical solution of this application, and these modifications and improvements all fall within the scope of protection of this application.

Claims

1. A method for producing hydrogen from natural gas, characterized in that: include: Natural gas cracking: During methane cracking, an electric field ionizes methane into carbon ions and hydrogen ions. The carbon ions and hydrogen ions collide and generate a high-temperature electric arc. The electric field and the high-temperature electric arc cause the methane to crack. The high-temperature electric arc completely covers the primary cracking chamber. The hydrogen produced by cracking carries the remaining gas to the gas outlet of the cracking chamber and creates a vortex at the gas outlet. This causes the incompletely cracked gas carried in the hydrogen to vortex back into the cracking chamber for further cracking. At the same time, because the vortexing gas forms a gas wall at the gas outlet, the gas that is subsequently introduced and generated also vortexes back into the cracking chamber for further cracking under the action of the gas wall. The pyrolysis chamber includes a primary pyrolysis chamber (12) and a secondary pyrolysis chamber (13) that are interconnected. When the gas pressure in the primary pyrolysis chamber (12) where the primary pyrolysis is located is greater than the set value, the gas after the primary pyrolysis enters the secondary pyrolysis chamber (13) from the primary pyrolysis chamber (12) under the action of the pressure difference to continue pyrolysis. The length of the primary lysis chamber (12) is 25-45cm and the diameter is 5-8cm; the length of the secondary lysis chamber (13) is greater than or equal to the length of the primary lysis chamber (12) and the diameter is 6-12cm. By setting baffles (14) at the inlet and outlet of the re-cracking chamber (13) respectively, the swirling gas forms an air wall at the gas outlet. The diameter of the baffles (14) is 3-8cm, and 18-36 ventilation holes (15) are provided on the baffles (14). The diameter of the ventilation holes (15) is 0.4-1mm. Gas cooling: Cooling the mixed gas obtained after pyrolysis; Gas-solid separation: The cooled mixed gas is subjected to gas-solid separation to obtain carbon powder and hydrogen.

2. The method for producing hydrogen from natural gas according to claim 1, characterized in that: When the gas flows to the gas outlet of the secondary cracking chamber (13), the gas also swirls, causing the incompletely cracked gas in the hydrogen to swirl back into the secondary cracking chamber (13) to continue cracking. At the same time, since the swirling gas forms a gas wall at the gas outlet, when the subsequently introduced and generated gas reaches the gas outlet of the secondary cracking chamber (13), it also swirls back into the secondary cracking chamber (13) under the action of the gas wall to continue cracking until the pressure in the secondary cracking chamber is greater than the set value. Then, under the action of the pressure difference, the gas enters the cooling process.

3. The method for producing hydrogen from natural gas according to claim 1, characterized in that: The temperature of the primary pyrolysis chamber is transferred to the secondary pyrolysis chamber (13) through heat conduction and gas flow, so that the secondary pyrolysis chamber (13) reaches the pyrolysis temperature.

4. A method for producing hydrogen from natural gas according to any one of claims 1-3, characterized in that: During methane cracking, an electric field is used to ionize methane into carbon ions and hydrogen ions. The carbon ions and hydrogen ions collide and generate a high-temperature electric arc, which in turn causes the methane to crack through the electric field and the high-temperature electric arc.

5. A method for producing hydrogen from natural gas according to any one of claims 1-3, characterized in that: It also includes removing impurities from hydrogen gas using a catalyst after gas-solid separation.

6. A method for producing hydrogen from natural gas according to claim 5, characterized in that: During the gas cooling process, a water-cooled heat exchanger is used to cool the mixed gas. At the same time, the water vapor generated by the water-cooled heat exchanger is introduced into the catalytic process, so that the water vapor provides the water and heat required for the catalytic reaction.

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