Method for producing hydrogen from natural gas

Abstract

The invention discloses a natural gas hydrogen production method, and belongs to the technical field of natural gas hydrogen production. The problems of catalyst carbon deposition and low conversion rate during hydrogen production through catalytic cracking of natural gas are solved. Natural gas is cracked through an electric field and high temperature, the gas rotates at the gas outlet, gas which is not completely cracked in hydrogen rotates into the cracking chamber to be continuously cracked, and meanwhile, the gas wall is formed at the gas outlet by the rotating gas, so that the cracking effect is improved. And when the subsequently introduced and generated gas reaches a gas outlet of the cracking chamber, the gas also rotates back into the cracking chamber under the action of the gas wall to be continuously cracked, and then the gas is cooled and subjected to gas-solid separation to obtain carbon powder and hydrogen. Natural gas is cracked under the dual effects of an electric field and high temperature, the retention time of gas in the cracking chamber is effectively prolonged, the cracking rate of the natural gas can reach 90% or above, a catalyst does not need to be used for cracking, and the problems of catalyst carbon deposition and low conversion rate are effectively solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of producing hydrogen from natural gas, and in particular relates to a method for producing hydrogen from natural gas. Background Art

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

[0003] Natural gas steam reforming 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 and has high energy consumption.

[0004] Partial oxidation of natural gas to produce hydrogen: The incomplete combustion of methane and oxygen produces carbon monoxide and hydrogen. No external heating is required, but problems such as catalyst carbon deposition need to be solved.

[0005] Natural gas autothermal reforming to produce hydrogen: Combining partial oxidation reaction and steam reforming reaction to achieve self-heating and improve the conversion efficiency of methane.

[0006] Hydrogen production by catalytic cracking of natural gas: natural gas is catalytically decomposed at high temperature to produce hydrogen and carbon materials, which have the characteristics of high purity and low energy consumption; however, there are problems such as catalyst carbon deposition and low hydrogen conversion rate that need to be solved. Summary of the invention

[0007] In view of the problems of catalyst carbon deposition and low conversion rate in the prior art when producing hydrogen through catalytic cracking of natural gas, the present invention provides a method for producing hydrogen from natural gas.

[0008] The technical solution adopted by the present invention is as follows:

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

[0010] Natural gas cracking: The natural gas is cracked by electric field and high temperature. The hydrogen produced by cracking drives the remaining gas to flow quickly to the gas outlet of the cracking chamber and swirls at the gas outlet, so that the incompletely cracked gas carried by the hydrogen swirls back to the cracking chamber for further cracking. At the same time, the swirling gas forms a gas wall at the gas outlet. When the subsequent gas introduced and generated reaches the gas outlet of the cracking chamber, it also swirls back to the cracking chamber for further cracking under the action of the gas wall;

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

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

[0013] After adopting the technical scheme, the present invention firstly utilizes the dual effects of electric field and high temperature to crack natural gas, thereby effectively improving the conversion rate of natural gas. Meanwhile, the light weight and fast flow rate of hydrogen are utilized, so that hydrogen drives the remaining gases to reach the gas outlet first and generates vortex at the gas outlet, thereby causing the incompletely cracked gas carried by the hydrogen to vortex to the cracking chamber for further cracking. Meanwhile, since the vortexing gas forms a gas wall at the gas outlet, the subsequent gas introduced and generated to reach the gas outlet of the cracking chamber also vortexes to the cracking chamber for further cracking under the action of the gas wall, thereby effectively increasing the residence time of the gas in the cracking chamber, thereby further improving the cracking rate of natural gas. Finally, the cracking rate of natural gas of the present invention can reach more than 90%, and there is no need to use a catalyst for cracking, thereby effectively solving the problems of catalyst carbon deposition and low conversion rate.

[0014] Preferably, the cracking chamber includes a primary cracking chamber and a secondary cracking chamber which are interconnected. When the air pressure in the primary cracking chamber where the initial cracking occurs is greater than a set value, the gas after the initial cracking enters the secondary cracking chamber from the primary cracking chamber under the action of the air pressure difference and continues to crack.

[0015] After adopting this technical solution, on the basis of increasing the residence time of natural gas in the primary cracking process, a re-cracking process is further arranged, and the natural gas that is not completely cracked after the primary cracking enters the re-cracking process for re-cracking, and on the basis of the re-cracking, the re-cracked natural gas that has not been cracked yet is made to swirl at the gas outlet of the re-cracking chamber, thereby increasing the residence time of the gas in the re-cracking process and further improving the cracking rate.

[0016] Preferably, when the gas flows to the gas outlet of the re-cracking chamber, the gas also swirls, so that the incompletely cracked gas contained in the hydrogen swirls back to the re-cracking chamber for further cracking. At the same time, since the swirling gas forms a gas wall at the gas outlet, the subsequent introduction and generation of gas also swirls back to the re-cracking chamber for further cracking under the action of the gas wall when it reaches the gas outlet of the re-cracking chamber, until the pressure in the re-cracking chamber is greater than the set value, and the gas enters the cooling process under the action of the pressure difference.

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

[0018] After adopting this technical solution, the heat of the initial cracking is transferred to the secondary cracking, so the heat of the initial cracking is fully utilized and the additional cost of introducing the secondary cracking is reduced.

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

[0020] After adopting this technical solution, the heat distribution is made more uniform, the expanded gas entering the cracking chamber where it is cracked again is made easier to disperse, and the heat absorbed by the gas can be made more uniform.

[0021] Preferably, a barrier is provided at the gas outlet of the cracking chamber to reduce the size of the gas outlet, thereby causing the gas to swirl.

[0022] After adopting this technical solution, the natural gas is blocked to cause collision at the gas outlet, so that the natural gas swirls back into the cracking chamber, thereby increasing the residence time of the natural gas.

[0023] Preferably, when cracking methane, the methane is ionized into carbon ions and hydrogen ions by an electric field, and the carbon ions and hydrogen ions move and collide to generate a high-temperature arc, thereby causing a cracking reaction of methane by the electric field and the high-temperature arc.

[0024] After adopting this technical solution, the heat generated by the ion collision produced by the ionization of methane itself is used as the heat source for high-temperature cracking, and other impurities will not be introduced, which reduces the difficulty of hydrogen impurity removal and improves the efficiency of hydrogen preparation.

[0025] Preferably, the high temperature arc fully covers the primary cracking chamber.

[0026] After adopting this technical solution, by controlling the size of the primary cracking chamber, the methane intake volume and the electric field strength, the high-temperature arc generated can fully cover the primary cracking chamber, which is not only beneficial for transferring heat to the secondary cracking chamber, but also allows the uncracked natural gas to fully contact with the high-temperature arc, thereby improving the cracking rate.

[0027] Preferably, the method further comprises removing impurities from the hydrogen through a catalyst after gas-solid separation.

[0028] After 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] After adopting this technical solution, the water vapor generated in the cooling process is utilized, saving production costs.

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

[0032] The present invention firstly utilizes the dual effects of electric field and high temperature to crack natural gas, thereby effectively improving the conversion rate of natural gas. Meanwhile, the light weight and fast flow rate of hydrogen are utilized, so that hydrogen drives the remaining gases to reach the gas outlet first and generates vortex at the gas outlet, thereby causing the incompletely cracked gas carried by the hydrogen to vortex to the cracking chamber for further cracking. Meanwhile, since the vortexing gas forms a gas wall at the gas outlet, the subsequent gas introduced and generated to reach the gas outlet of the cracking chamber also vortexes to the cracking chamber for further cracking under the action of the gas wall, thereby effectively increasing the residence time of the gas in the cracking chamber, thereby further improving the cracking rate of natural gas. Finally, the cracking rate of natural gas of the present invention can reach more than 90%, and there is no need to use a catalyst for cracking, thereby effectively solving the problems of catalyst carbon deposition and low conversion rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic diagram of the structure of the device used in the method described in the first embodiment of the present application;

[0034] Figure 2 yes Figure 1 Schematic diagram of the structure of the natural gas reaction device;

[0035] Figure 3 yes Figure 1 A schematic diagram of the structure of the heat exchange device;

[0036] Figure 4 yes Figure 1 A schematic structural diagram of a first embodiment of a device for extracting carbon powder;

[0037] Figure 5 yes Figure 1 A schematic structural diagram of a second embodiment of a device for extracting carbon powder;

[0038] 1-natural gas reaction device, 11-plasma generator, 12-primary cracking chamber, 13-secondary cracking chamber, 14-blocking net, 15-vent, 16-first insulation layer, 17-second insulation layer;

[0039] 2-heat exchange device, 21-first inlet, 22-second inlet, 23-second outlet, 24-second outlet;

[0040] 3-carbon powder taking device, 31-collecting chamber, 32-third outlet, 33-rotating shaft, 331′-screw, 332′-screw slider, 34-first motor, 34′-second motor, 35-fourth outlet, 36-separation membrane, 37-mounting frame, 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 pipeline, 210 - second refrigerant pipeline. DETAILED DESCRIPTION

[0044] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0045] In the description of the embodiments of the present application, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or are the positions or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0046] Example 1

[0047] A method for producing hydrogen from natural gas, comprising:

[0048] Natural gas cracking: The natural gas is cracked by electric field and high temperature. The hydrogen produced by cracking drives the remaining gas to flow quickly to the gas outlet of the cracking chamber and swirls at the gas outlet, so that the incompletely cracked gas carried by the hydrogen swirls back to the cracking chamber for further cracking. At the same time, the swirling gas forms a gas wall at the gas outlet. When the subsequent gas introduced and generated reaches the gas outlet of the cracking chamber, it also swirls back to the cracking chamber for further cracking under the action of the gas wall;

[0049] Gas cooling: Cooling the mixed gas obtained after cracking;

[0050] Gas-solid separation: The cooled mixed gas is subjected to gas-solid separation to obtain carbon powder and hydrogen.

[0051] In order to implement the hydrogen production method, this embodiment provides a natural gas hydrogen production device that can implement the hydrogen production method, which includes:

[0052] A natural gas reaction device 1, wherein the natural gas reaction device 1 performs cracking reaction on natural gas, and the natural gas reaction device 1 comprises a primary cracking mechanism and a secondary cracking mechanism which are interconnected, wherein the primary cracking mechanism is used to perform initial cracking on natural gas, and the secondary cracking mechanism is used to perform secondary cracking on natural gas that has not been cracked in the primary cracking mechanism; specifically, the primary cracking mechanism is connected to a natural gas source through a first pipeline 100, and the natural gas source can be residential pipeline natural gas, wherein the methane content is above 98%;

[0053] The heat exchange device 2 is connected to the natural gas reaction device 1 and cools down the product of the natural gas reaction device 1; the specific 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 reaction device 1 through the second pipeline 110.

[0054] The carbon powder extracting device 3 is connected to the heat exchange device 2 and performs gas-solid separation on the product 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 extracting device 3 through the third pipeline 120 .

[0055] In order to facilitate the control of the flow rate of the fluid in each pipeline, pipeline solenoid valves are respectively provided in the first pipeline 100 , the second pipeline 110 , and the third pipeline 120 .

[0056] The working principle of this system is:

[0057] First, the natural gas provided by the natural gas source (for example, 3 cubic meters of natural gas is introduced into the first pipeline 100 and the eighth pipeline 170 in total) is sent to the natural gas reaction device 1 through the first pipeline 100. The natural gas reaction device 1 generates an electric field to electrolyze the methane component in the natural gas introduced therein, and ionizes the methane into active ions such as carbon ions and hydrogen ions. Secondly, under the action of the electric field, the carbon ions and hydrogen ions move and collide to generate a high-temperature arc, and the high-temperature arc is used to crack the methane under high-temperature conditions to generate products such as hydrogen (for example, 6 cubic meters of hydrogen) and nano-scale carbon powder (for example, 1500 grams of carbon powder), and the products generated by the reaction (hydrogen and nano-scale carbon powder) are sent to the heat exchange device 2 through the second pipeline 110. The heat exchange device 2 cools the above products (hydrogen and nano-scale carbon powder), usually from 800°C to 40-60°C (for example, specifically from 800°C to room temperature). The heat exchange device 2 sends the cooled products to the carbon powder taking device 3 through the third pipeline 120. The carbon powder taking device 3 performs gas-solid separation treatment on the above products and separates the hydrogen and nano-scale carbon powder (for example, 6 cubic meters of hydrogen and 1500 grams of carbon powder are obtained after the gas-solid separation treatment).

[0058] The combustion system provided in this embodiment is mainly composed of a natural gas reaction device 1, a heat exchange device 2, and a carbon powder taking device 3. First, methane is cracked multiple times by the primary cracking mechanism and the secondary cracking mechanism of the natural gas reaction device 1 to increase the residence time of the natural gas in the cracking chamber. The principle of methane cracking reaction is adopted in the primary cracking mechanism and the secondary cracking mechanism to crack the natural gas at high temperature, and the generated products are hydrogen and nano-scale carbon powder. Since the product after the cracking reaction has a very high temperature, in order to avoid the high-temperature product from damaging the subsequent process equipment, thereby making the entire process unable to continue, it is necessary to set a heat exchange device 2 connected to the natural gas reaction device 1, so as to cool the product after the cracking of the natural gas reaction device 1 by the heat exchange device 2. Secondly, the carbon powder taking device 3 performs gas-solid separation on the cooled product to obtain a gas product (hydrogen).

[0059] In order to improve the conversion rate of methane in natural gas, in this example, the primary cracking mechanism preferably includes a primary cracking chamber 12 and a plasma generator 11, the gas inlet end of the plasma generator 11 is connected to the natural gas source, and the high-temperature arc generated by the plasma generator 11 enters the primary cracking chamber 12, and the secondary cracking mechanism includes at least one secondary cracking chamber 13. In this embodiment, one secondary cracking chamber 13 is selected, and in other embodiments, multiple secondary cracking chambers 13 can be selected to form a secondary cracking mechanism.

[0060] In this embodiment, a plasma generator 11 is first provided. Specifically, the plasma generator 11 may be a high current plasma generator as disclosed in the prior art CN216057599U. Figure 1The specific structure includes an arc main pole, an arc main body with a cathode connection end, and an anode installed in the installation hole. First, the arc main pole and the anode are energized respectively to generate an electric field between the cathode and the anode. The electric field ionizes methane into carbon ions and hydrogen ions, that is, high-energy electrons ionize methane into active ions such as carbon ions and hydrogen ions through inelastic collisions with methane molecules. The carbon ions and hydrogen ions are then moved and collided by the electric field to generate a high-temperature arc. The high-temperature arc causes the methane gas to undergo a cracking reaction under high temperature conditions. At the same time, the fluidity of natural gas under high temperature and high 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 is accelerated, making them easier to flow and diffuse. In order to effectively ensure the residence time of natural gas in a high temperature environment, a first cracking chamber 12 and a second cracking chamber 13 are arranged to be interconnected. During the first cracking of methane in the natural gas by the plasma generator 11 in the first cracking chamber 12, the generated products (hydrogen and nano-scale carbon powder) will have a very high temperature. After the high-temperature gas continues to flow to the second cracking chamber 13, the second cracking chamber 13 will have a certain temperature (even if the methane in the natural gas that has not been cracked in the first cracking chamber 12 continues to undergo a second cracking). Therefore, by designing two cracking chambers, the high-temperature environment covers a larger area, thereby increasing the residence time of natural gas in a high-temperature environment. At the same time, since the density of hydrogen is smaller than that of natural gas, the weight of hydrogen of the same volume 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 respectively placing the first cracking chamber 12 in the second cracking chamber 13, the second cracking chamber 13 will have a certain temperature (even if the methane in the natural gas that has not been cracked in the first cracking chamber 12 continues to undergo a second cracking). The air inlet and air outlet of the second cracking chamber 13 are provided with a baffle 14, and the baffle 14 is provided with an air vent 15. Since the hydrogen in the first cracking chamber 12 flows faster, it can drive part of the natural gas to flow to the air vent 15 provided on the baffle 14 at the air inlet of the second cracking chamber 13, so that a gas wall can be formed at the air vent 15, so that the unreacted natural gas in the first cracking chamber 12 hits the gas wall driven by the hydrogen and then flows back to the first cracking chamber 12 for cracking reaction. Similarly, the second cracking chamber 1 3, due to its faster flow speed, it can drive part of the natural gas to flow to the vent 15 set on the baffle 14 at the outlet end of the second cracking chamber 13, so that a gas wall can be formed at the vent 15, so that the unreacted natural gas in the second cracking chamber 13 hits the gas wall driven by hydrogen and then flows back to the second cracking chamber 13 for cracking reaction. The baffle 14 is respectively provided at the inlet end and the outlet end of the second cracking chamber 13, so that the residence time of the natural gas in the high temperature environment is further increased. In summary, the structure composed of the first cracking chamber 12, the second cracking chamber 13 and the baffle 14 with the vent 15 can effectively increase the residence time of the natural gas in the high temperature environment, thereby increasing the efficiency of methane cracking in the natural gas. .In this embodiment, the power of the plasma generator 11 is 15 kilowatts, and the proportion of the natural gas intake is 3m. 3 In other embodiments, the ratio of the power of the corresponding plasma flame emission device to the natural gas intake volume is 5kw:1m 3 .

[0061] The specific parameters of the natural gas reaction device in this embodiment are as follows: the center temperature of the high-temperature arc generated by the plasma generator 11 of this embodiment is 2000°C, the temperature of the high-temperature arc gradually decreases from the inside to the outside, the temperature at the edge is 800°C, and the length of the high-temperature arc is 25-45cm; the length of the primary cracking chamber 12 is 25-45cm, and the diameter is 5-8cm; the length of the secondary cracking chamber 13 is greater than or equal to the length of the primary cracking chamber 12, and the diameter is 6-12cm; the diameter of the baffle 14 is 3-8cm, and the baffle 14 is provided with 18-36 ventilation holes 15, and the aperture of the ventilation holes 15 is 0.4-1mm. More preferably, the length of the high-temperature arc generated by the plasma generator 11 is 30cm, and the high-temperature arc fully covers the primary cracking chamber 12; the length of the primary cracking chamber 12 is 30cm and the diameter is 6cm; the length of the secondary cracking chamber 13 is 30cm and the diameter is 8cm; the diameter of the retaining net 14 is 6cm, and the retaining net 14 is provided with 24 ventilation holes 15, and the aperture of the ventilation holes 15 is 0.8mm.

[0062] In summary, the structure formed by the cooperation of the primary cracking chamber 12, the secondary cracking chamber 13 and the baffle 14 with the vents 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.

[0063] In order to effectively achieve gas-solid separation of hydrogen and nano-carbon powder, the present embodiment preferably comprises a carbon powder taking device 3 including: a collecting chamber 31. Specifically, in order 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 the third pipeline 120 through the third inlet 38, and the collecting chamber 31 is connected to the fourth pipeline 130 through the fourth outlet 35. The outer wall of the lower half of the collecting chamber 31 is inclined toward the fourth outlet 35, that is, 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 ​​arranged below the lower half of the collecting chamber. First, by setting the fourth outlet 35, it is convenient to separate the hydrogen The gas enters the next process through the fourth outlet 35, and then by setting an inclined outer wall and a third outlet 32, the inclined outer wall is convenient for guiding the split nano-scale carbon powder to the third outlet 32; a mounting frame 37, the mounting frame 37 is arranged in the collection chamber 31, and the surface of the mounting frame 37 has a filter net. Specifically, in order to facilitate the adsorption of nano-scale carbon powder, since the carbon powder carries ions in a high temperature environment and the particle size of the carbon powder is less than 100nm, the filter net can use a separation membrane with a pore size greater than or equal to 100nm. In this embodiment, its pore size is 100nm; a transmission part, the mounting frame 37 is movably matched with the collection chamber 31 through the transmission part; a driving part, the driving part is connected to the transmission part.

[0064] In this example, the filter screen first uses a metal ion membrane as a separation membrane. Since the pore size of the metal ion membrane is larger than the particle size of the carbon powder, and the carbon powder carries ions under high temperature conditions, the charged carbon powder can be adsorbed on 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 the free electrons in the object to move to the surface, making the surface charged. Therefore, the potential generated by electrostatic induction and the static electricity of the charged object attract each other under the action of Coulomb force, so that adsorption occurs. Therefore, the charged carbon powder can be adsorbed first through the metal ion membrane, and the hydrogen is discharged through the holes in the metal ion membrane, thereby completing the gas-solid separation of hydrogen and nano-scale carbon powder. Secondly, the filter screen is installed on the mounting frame 37, and the mounting frame 37 is movably matched with the collection chamber 31 through the transmission part, and the transmission part is connected to the driving part, that is, the driving part can drive the transmission part to drive the mounting frame 37 to move, such as rotate or reciprocate, so that the nano-scale carbon powder adsorbed on the separation membrane on the mounting frame 37 is shaken off through the movement of the mounting frame 37, thereby completing the collection of nano-scale carbon powder.

[0065] In order to realize regular rotation of the filter screen, in this embodiment, preferably, the transmission part includes a rotating shaft 33, both ends of the rotating shaft 33 are respectively movably connected to the collecting chamber 31, and the mounting frame 37 is arranged on the rotating shaft 33; the driving part includes a first motor 34, and the output end of the first motor 34 is connected to the end of the rotating shaft 33.

[0066] In this example, the mounting bracket 37 is disposed 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 regularly. Since the mounting bracket 37 is disposed on the rotating shaft 33, the rotating shaft 33 can drive the mounting bracket 37 to move regularly (i.e., forward or reverse), thereby making it easier to shake off the nano-scale carbon powder adsorbed on the separation membrane.

[0067] In order to realize regular reciprocating movement of the filter screen, in this embodiment, preferably, the transmission part includes a screw rod 331' and a screw nut 332' that cooperate with each other, the two ends of the screw rod 331' are respectively movably connected to the collecting chamber 31, and the mounting bracket 37 is arranged on the screw nut 332'; the driving part includes a second motor 34', and the output end of the second motor 34' is connected to the end of the screw rod 331'.

[0068] In this example, the mounting bracket 37 is arranged on the screw nut 332′, and the output end of the second motor 34′ is connected to the end of the screw 331′. The specific 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 screw 331′ by controlling the forward or reverse rotation of the servo motor, thereby driving the screw 331′ to rotate forward or reverse regularly. Since the screw nut 332′ and the screw 331′ are transmission-matched, i.e., threaded-matched, the screw nut 332′ can be driven to reciprocate on the screw 331′ along the direction of the screw 331′ through the screw 331′. Since the mounting bracket 37 is arranged on the screw nut 332′, the mounting bracket 37 can be driven to move regularly (i.e., reciprocate), thereby making it easier to shake off the nano-scale carbon powder adsorbed on the separation membrane.

[0069] In this embodiment, the conversion rate of methane in natural gas is further improved by setting the parameters of the natural gas reaction device, that is, a higher hydrogen production and a higher production of nano-scale carbon powder, as shown in Table 1 (S1-9 in Table 1 correspond to Examples 1-9, respectively, and D1-6 correspond to Comparative Examples 1-6, respectively. In order to reflect the differences, the similarities between Examples 2-9 and Comparative Examples 1-6 and Example 1 are not filled in):

[0070] Table 1

[0071]

[0072]

[0073] It can be seen from Table 1 that by reasonably controlling the parameters such as the baffle, the primary cracking chamber and the secondary cracking chamber, the maximum conversion rate of natural gas can reach 95%. When the natural gas conversion rate reaches 95%, about 93% of the obtained carbon powder has a particle size of 10-300nm, and the purity of the obtained natural gas is above 90%.

[0074] Example 10

[0075] In order to further improve the purity of the gas product in the carbon powder device (i.e., the purity of hydrogen), the present embodiment further comprises a plasma hydrogen production and oxygen and natural gas mixed combustion system further comprising a catalytic device 4, which is respectively connected to the carbon powder taking device 3 and the first gas mixing device 6, and the catalytic device 4 comprises: a catalytic chamber 43; a net bag 42, which is arranged in the catalytic chamber 43; and a heating component 41, which is arranged outside the catalytic chamber 43.

[0076] In this example, a net bag 42 is arranged in the catalytic chamber 43. Before the catalytic reaction, the catalyst is placed on the net bag 42, and the impurities in the hydrogen are removed by the catalyst. In order to further provide the temperature for the catalytic reaction, the preferred heating component 41 of this embodiment includes a heating pipe wrapped outside the catalytic chamber 43, the inlet end of the heating pipe is connected to the first inlet 21 of the heat exchange device 2 through the first refrigerant pipeline 200, and the outlet end of the heating pipe is connected to the first outlet 24 of the heat exchange device 2 through the second refrigerant pipeline 210. The purity of the hydrogen obtained in this embodiment is more than 90%.

[0077] The above-mentioned embodiments only express the specific implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the protection scope of the present application. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the technical solution concept of the present application, and these all belong to the protection scope of the present application.

Claims

1. A method for producing hydrogen from natural gas, characterized in that: include: Natural gas cracking: The natural gas is cracked by electric field and high temperature. The hydrogen produced by cracking drives the remaining gas to flow quickly to the gas outlet of the cracking chamber and swirls at the gas outlet, so that the incompletely cracked gas carried by the hydrogen swirls back to the cracking chamber for further cracking. At the same time, the swirling gas forms a gas wall at the gas outlet. When the subsequent gas introduced and generated reaches the gas outlet of the cracking chamber, it also swirls back to the cracking chamber for further cracking under the action of the gas wall; Gas cooling: Cooling the mixed gas obtained after cracking; Gas-solid separation: The cooled mixed gas is subjected to gas-solid separation to obtain carbon powder and hydrogen.

2. A method for producing hydrogen from natural gas according to claim 1, characterized in that: The cracking chamber comprises a primary cracking chamber (12) and a secondary cracking chamber (13) which are interconnected. When the gas pressure in the primary cracking chamber (12) where the primary cracking takes place is greater than a set value, the gas after the primary cracking enters the secondary cracking chamber (13) from the primary cracking chamber (12) under the action of the gas pressure difference to continue cracking.

3. A method for producing hydrogen from natural gas according to claim 2, characterized in that: When the gas flows to the gas outlet of the re-cracking chamber (13), the gas also swirls, so that the incompletely cracked gas contained in the hydrogen swirls back to the re-cracking chamber (13) for further cracking. At the same time, since the swirling gas forms a gas wall at the gas outlet, the subsequent gas introduced and generated when it reaches the gas outlet of the re-cracking chamber (13) also swirls back to the re-cracking chamber (13) for further cracking under the action of the gas wall, until the pressure in the re-cracking chamber is greater than the set value, the gas enters the cooling process under the action of the pressure difference.

4. A method for producing hydrogen from natural gas according to claim 2, characterized in that: The temperature of the primary cracking chamber is transferred to the secondary cracking chamber (13) through heat conduction and gas flow, so that the secondary cracking chamber (13) reaches the cracking temperature.

5. A method for producing hydrogen from natural gas according to claim 2, characterized in that: The cross-sectional dimension of the secondary lysis chamber (13) is greater than or equal to the cross-sectional dimension of the primary lysis chamber (12), and the length of the secondary lysis chamber (13) is greater than the length of the primary lysis chamber (12).

6. A method for producing hydrogen from natural gas according to any one of claims 2 to 5, characterized in that: When methane is cracked, the electric field is used to ionize methane into carbon ions and hydrogen ions. The carbon ions and hydrogen ions move and collide to generate a high-temperature arc, thereby causing the methane to undergo a cracking reaction through the electric field and the high-temperature arc.

7. A method for producing hydrogen from natural gas according to claim 5, characterized in that: The high-temperature electric arc completely covers the interior of the primary cracking chamber (12).

8. A method for producing hydrogen from natural gas according to any one of claims 1 to 5, characterized in that: A barrier is provided at the gas outlet of the cracking chamber to reduce the size of the gas outlet, thereby causing the gas to swirl.

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

10. A method for producing hydrogen from natural gas according to claim 9, 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 heat exchange of 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.

Images