A device for preparing hydrogen and graphite using liquid metal and natural gas

Abstract

A device for producing hydrogen and graphite using liquid metal and natural gas includes desulfurization and dehydration equipment, a heat exchanger, a cooler, gas-solid separation equipment, a pressure swing adsorber, a hydrogen storage tank, a main control system, a cavity, a top cover, an air inlet pipe, a reactor, a vacuum pump, an exhaust pipe, a graphite tube, and an air blow pipe. The present invention utilizes liquid metal to act on natural gas to crack and produce hydrogen and graphite. Methane in the natural gas undergoes a direct cracking reaction to generate hydrogen and graphite. The production process does not emit carbon dioxide. During operation, the hydrogen produced by cracking in the reactor carries graphite dust and is discharged from the reactor, achieving continuous discharge of graphite from the reactor. The hydrogen in the product can be purified and used in industries such as fuel cells, and the carbon powder can also be used in the industrial field. The overall economic efficiency of the process is guaranteed to a certain extent. It has the potential for large-scale application in the future direction of carbon-free hydrogen production and can achieve automated continuous production. The present invention has good prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen preparation, in particular to a device for preparing hydrogen and graphite by utilizing liquid metal and natural gas. Background Art

[0002] With the continuous advancement of industrial development, humanity's demand for energy has increased dramatically. The combustion of conventional fossil fuels (such as oil and coal) produces excessive carbon dioxide, leading to rising global temperatures, melting glaciers, and rising sea levels. This has led to severe environmental problems such as drastic global climate change, crop yield declines, and air pollution. Furthermore, these energy sources are non-renewable and face the risk of depletion. To address the unprecedented pressure of carbon dioxide emissions, the world is gradually moving towards "carbon neutrality" and vigorously developing clean and renewable energy. Hydrogen, with its convenient production, high efficiency, and environmental friendliness, is an ideal secondary energy source that can effectively contribute to carbon reduction and optimize the energy structure. It is a major strategic direction in the global transition to new energy, and is bound to usher in rapid development in its development and utilization.

[0003] Currently, the main established methods for hydrogen production include fossil fuel (coal and natural gas) hydrogen production and water electrolysis. The primary form of hydrogen production from fossil fuels is natural gas steam reforming, which involves catalytically converting methane and other hydrocarbon components in natural gas into the target hydrogen through a chemical reaction. The reaction formula is: CH4 + 0.5 H2O → 0.5 CO + 1.5 H2, with ΔH = 103 kJ / mol. This method is subject to technical limitations. The main issue is that while hydrogen is produced, it also produces a large amount of the greenhouse gas CO2. Although subsequent pressure swing adsorption CO2 capture can reduce the CO2 concentration in the product to a certain extent, the current high cost and low efficiency of CO2 capture make it difficult to achieve low-carbon development. Water electrolysis primarily uses electricity to dissociate water molecules in the electrolyte to produce hydrogen and oxygen, which can achieve truly carbon-free emissions. However, current water electrolysis technology is limited by the high cost and short lifespan of electrode materials and electrolyte membranes, as well as high back-end power consumption, making it difficult to effectively scale up. Summary of the Invention

[0004] In order to overcome the drawbacks of the existing technology of producing hydrogen through fossil energy and water electrolysis due to the limitations of the equipment and technology used, as described in the background, the present invention provides a device for producing hydrogen and graphite using liquid metal and natural gas, which can directly crack methane in natural gas under high temperature conditions to produce hydrogen and solid carbon, directly producing solid carbon powder without carbon dioxide emissions. The hydrogen in the product can be purified and used in industries such as fuel cells. It has good overall economic efficiency and has the potential for large-scale application in the future direction of carbon-free hydrogen production.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] A device for preparing hydrogen and graphite using liquid metal and natural gas, comprising desulfurization and dehydration equipment, a heat exchanger, a cooler, a gas-solid separation equipment, a pressure swing adsorber, a hydrogen storage tank, a main control system, a cavity, a top cover, an air inlet pipe, a reactor, a vacuum pump, an exhaust pipe, a graphite tube, and an air blow pipe; the device is characterized in that a vacuum tube is installed outside one end of the cavity, and the air outlet end of the vacuum tube is connected to the air inlet end of the vacuum pump; the outer side of the cavity is a double-layer structure, and a water inlet A and a water outlet A are installed at one end of the outer side of the cavity; the cavity The inner bottom is respectively installed with refractory bricks and heat insulation boards, the reactor is installed on the heat insulation board, the outside of the reactor is sequentially installed with fillers, asbestos cloth, heaters, and brackets from the inside to the outside, the side end of the bracket is installed with a thermocouple, and the thermocouple measuring end is in contact with the outer wall of the reactor, and the thermocouple signal output end is electrically connected to the signal input end of the main control system; the upper part of the reactor is installed with heat insulation board B and heat insulation board A and serves as a buffer zone; the top cover is connected to the upper part of the cavity, the outer side of the top cover is a double-layer structure, and the outer side of the top cover is installed with an inlet Water inlet C, water outlet C, safety valve and pressure sensor, the air inlet pipe is installed on the top cover of the device, the lower part of the air inlet pipe is connected to the graphite tube with a flexible bellows, and the lower end of the graphite tube has a number of air holes; the buffer zone is equipped with a guide plate, one end of the guide plate is connected to the exhaust pipe on the upper part of one side of the cavity, and the other end of the guide plate is equipped with a distribution pipe, one end of the distribution pipe is connected to the air inlet on the guide plate, and the other end is connected to one end of an air guide pipe, and the other end of the air guide pipe is connected to the blowing pipe at the side end of the cavity, the blowing pipe, air inlet The side end of the tube is connected in parallel to one side of the hydrogen pipeline of the hydrogen storage tank; the gas input end of the desulfurization and dehydration equipment is connected to the natural gas pipe, the gas output end of the desulfurization and dehydration equipment is connected to the inlet of the heat exchanger, the heat exchanger outlet is connected to the upper end of the air inlet pipe, the side end of the exhaust pipe is connected to the inlet of the cooler, the cooler outlet is connected to the inlet of the gas-solid separation equipment, the cooler outlet is connected to the inlet of the pressure swing adsorber, the pressure swing adsorber outlet is connected to the inlet of the hydrogen storage tank, and the pipe connecting the exhaust pipe and the cooler is located inside the heat exchanger.

[0007] Furthermore, the bottom of the cavity is a double-layer structure and a water inlet B, a water outlet B and a cooling water channel B are respectively installed on the outer side of the lower end.

[0008] Furthermore, a plurality of supports are installed at the lower end of the bottom of the cavity.

[0009] Furthermore, the filler is fused magnesia and the heater is an electric heater.

[0010] Furthermore, the insulation board A and the insulation board B are made of ceramic fiberboard.

[0011] Furthermore, the guide plate is a conical structure;

[0012] Furthermore, the reactor contains copper-bismuth alloy.

[0013] The present invention has the following beneficial effects: it utilizes liquid metal to crack natural gas to produce hydrogen and graphite. Methane in the natural gas undergoes a direct cracking reaction to generate hydrogen and solid carbon (graphite). This process emits no carbon dioxide. During operation, the hydrogen generated by cracking in the reactor carries graphite dust with it and is discharged from the reactor, achieving continuous discharge of graphite from the reactor. The hydrogen in the product can be purified and used in industries such as fuel cells, while the carbon powder can also be used in industrial applications. The overall economic viability of the process is guaranteed, and it has the potential for large-scale application in carbon-free hydrogen production in the future, enabling automated continuous production. Based on the foregoing, the present invention has promising application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0015] Figure 2 It is a schematic diagram of the guide plate structure.

[0016] Figure 3 It is a schematic diagram of the intake pipe structure.

[0017] Figure 4 This is the process intention of the present invention. DETAILED DESCRIPTION

[0018] Figure 1 、 2, 3, and 4, a device for preparing hydrogen and graphite by using liquid metal and natural gas, including a desulfurization and dehydration device (not shown in the figure), a heat exchanger (not shown in the figure), a cooler (not shown in the figure), a gas-solid separation device (not shown in the figure), a pressure swing adsorber (PSA) (not shown in the figure), a hydrogen storage tank (not shown in the figure), a main control system (not shown in the figure), a cavity 1, a top cover 2, an air inlet pipe 4, a reactor 17, a vacuum pump (not shown in the figure), an air inlet 401, a graphite tube 404, and an air blowing pipe 11; a vacuum pump is installed in the middle of the right end of the cavity 1 in sequence. Flange 113, vacuum tube 15, the vacuum flange 113 and the vacuum tube 15 are sealed with a sealing ring B23, and the air outlet end of the vacuum tube 15 is connected to the air inlet end of the vacuum pump; the outer side of the cavity 1 is a double-layer structure, and the space between the inner and outer layers is used as a cooling water channel A103. The upper and lower parts of the left end of the cavity 1 are respectively equipped with a water inlet A101 and a water outlet A102 that are interconnected with the cooling water channel A103. The water inlet A101 is connected to the tap water pipe, and the water outlet A102 is connected to the workshop waste water tank through a pipe; the center axis position of the bottom of the cavity 1 is respectively equipped with a waterproof Fire bricks 21, insulation board 20, the lower end of the reactor 17 is installed on the insulation board 20, the outside of the reactor 17 is sequentially installed with filler 18, asbestos cloth 19, heater 3, and bracket 13 from the inside to the outside, the electrodes at both ends of the heater 3 are fixed on the insulation board 28 through the feed flange 108 and connected to the external heating power supply, the feed flange 108 and the insulation board 28 are sealed with a sealing ring B23, the upper and lower parts of the right end of the bracket 13 each have a through hole in the horizontal direction, and a thermocouple 16 is installed in each through hole, and the measuring end of the thermocouple 16 is tightly fitted with the outer wall of the reactor 17, the thermocouple 1 6 The lead end is led out from the electrode flange 14 through the temperature measuring flange 112. The temperature measuring flange 112 and the electrode flange 14 are sealed with a sealing ring F27. The thermocouple signal output end and the signal input end of the main control system are connected via a wire. A heat insulation board B10 is installed on the top of the reactor 17. An exhaust hole is provided at the central axis of the heat insulation board B10. The outer diameter of the heat insulation board B10 is consistent with the inner diameter of the reactor 17. A heat insulation board A9 is installed above the heat insulation board B10 and a buffer zone 29 is used between the two. A mounting hole for the air inlet pipe 4 is provided at the central axis of the heat insulation board A9 and the diameter is consistent with the outer diameter of the air inlet pipe 4.The top cover 2 is connected to the cavity through a connecting flange 111 and sealed by a sealing ring D25. The outer side of the top cover 2 adopts a double-layer water-cooling structure as a cooling water channel C203. The left and right ends of the outer side of the top cover 2 are respectively equipped with a water inlet C201 and a water outlet C202 that are interconnected with the cooling water channel C203, and are equipped with flanges A204, flanges B205, and air inlet flanges 206 that are interconnected with the outer layer of the top cover. The upper ends of flanges A204 and flanges B205 are respectively connected to connecting pipes A5 and connecting pipes B6 and a sealing ring A is used between the two. 22 seal, the other ends of the connecting pipe A5 and the connecting pipe B6 are respectively installed with a safety valve and a pressure sensor, the upper end of the intake pipe 4 is connected to the intake flange 206 through a flange 402, and the two are sealed with a sealing ring B23, the water inlet C201 is connected to the tap water pipe, and the water outlet C202 is connected to the workshop waste water tank through a pipeline; the lower part of the intake pipe 4 and the graphite tube 404 are connected by a flexible metal bellows 403, the lower end of the graphite tube 404 is annularly distributed with a number of air holes 405, and the lower end of the graphite tube 404 is located in the reactor 17 The lower part; the buffer zone 29 is provided with a guide plate 7 in the middle, the right end of the guide plate 7 is connected to the exhaust flange 114 at the upper right end of the cavity, the left end of the guide plate 7 is provided with a distribution pipe 701, one end of the distribution pipe 701 is connected to the air inlet on the guide plate 7, and the other end is connected to the air guide pipe 8, the air inlet end of the air guide pipe 8 is connected to the blowing flange 110 on the left end of the cavity, the blowing flange 110 is sealed with a sealing ring C24 between the blowing pipe 11, the blowing pipe 11, the left end of the air inlet pipe 4 is connected in parallel with one side of the hydrogen pipeline of the hydrogen storage tank (the hydrogen pipeline and the blowing pipe A solenoid valve controlled by a timed switch is connected in series between the gas pipe 11 and the side end of the intake pipe. The gas input end of the desulfurization and dehydration equipment is connected to the natural gas pipeline, the gas output end of the desulfurization and dehydration equipment is connected to the heat exchanger inlet, the heat exchanger outlet is connected to the upper end of the intake pipe 4, the right end of the exhaust flange 12 is connected to the cooler inlet, the cooler outlet is connected to the gas-solid separation equipment inlet, the cooler outlet is connected to the PSA inlet, and the PSA outlet is connected to the hydrogen storage tank inlet. The pipes connecting the exhaust flange 12 and the cooler are arranged in a circular pattern within the heat exchanger.

[0019] Figure 1 、 2 As shown in Figures 3 and 4, a cooling water channel B106 is installed at the bottom of chamber 1. A water inlet B104, a water outlet B105, and a cooling water channel B106 are installed at the lower ends of both sides of cooling water channel B106. Water inlet B104 is connected to the tap water pipe, and water outlet B105 is connected to the production area wastewater tank via a pipe. Four supports 107 are installed at the lower end of the bottom of chamber 1. Filler 18 is made of fused magnesia, and heater 3 is an electric heater. Insulation panels A9 and B10 are made of ceramic fiberboard. The upper end of air inlet pipe 4 is connected to natural gas; guide plate 7 is a conical structure; reactor 17 contains a copper-bismuth alloy, and its volume is approximately four-fifths of the reactor's internal height.

[0020] Figure 1 、 2 As shown in Figures 3 and 4, sealing ring B23 seals between vacuum flange 113 and vacuum tube 15. A vacuum pump evacuates chamber 1, evacuating as much air as possible from chamber 1 to prevent oxidation during operation and shortening the reactor's service life. Chamber 1's double-layer water-cooling structure, via cooling channels A103 and B106 (cooling water flows from the tap and, after absorbing heat, is discharged into the wastewater tank), prevents excessive external temperatures during operation, which could cause burns and other safety hazards. It also cools the seals, ensuring sealing effectiveness and extending service life. Asbestos cloth 19 is U-shaped. Filler 18 is used between reactor 17 and heater 3 and is enclosed by asbestos cloth 19 to prevent leakage from the gaps in heater 3 and the bottom of reactor 17. The material used for filler 18 is fused magnesia, which provides excellent thermal insulation and high-temperature electrical insulation. Bracket 13 secures heater 3, which melts the metal in reactor 17 and keeps it molten. The thermocouple signal at the lower end of reactor 17 is fed back to the heating power output of the main control system to control the temperature of reactor 17, while the thermocouple at the upper end is used to monitor the temperature of reactor 17. The water inlet C201, water outlet C202, and cooling water channel C203 installed on the top cover 2 can prevent safety accidents such as burns caused by excessive temperatures on the upper side of the top cover, and are also used to cool the seals installed thereon. The safety valve is used to automatically release pressure when the air pressure inside cavity 1 exceeds the pressure limit, ensuring safe operation of the equipment. The pressure sensor is used to monitor the air pressure inside cavity 1. When the air pressure inside cavity 1 is higher or lower than the set value, an alarm sound and light prompt is issued to ensure safe operation of the equipment.

[0021] The flexible bellows 403 connects the air inlet 401 of the air inlet pipe 4 to the graphite tube 404, preventing damage to the graphite tube 404 caused by the contraction force of the liquid metal solidification and the expansion force of the metal during secondary heating during abnormal shutdown. The multiple air holes 405 provided at the lower end of the graphite tube 404 ensure that small bubbles are formed when natural gas enters the liquid metal 30 through the air holes 405, which helps to improve the conversion rate. The air blowing pipe 11 is connected to the external hydrogen pipeline. In this way, natural gas enters the liquid metal 30 in the reactor 17 through the air inlet pipe 4, where it is cracked into hydrogen, graphite, and some graphene. The hydrogen carries graphite dust and other particles into the buffer zone and, under the action of the purge gas, enters the exhaust flange together, achieving continuous and efficient liquid metal natural gas hydrogen and graphite production.

[0022] Figure 1 、 2As shown in Figures 3 and 4, the heater 3 installed outside the reactor is used to melt the metal in the reactor 17 and keep it in a molten state; the air inlet pipe 4 is used to introduce natural gas into the reactor. The natural gas reacts in the liquid metal and is cracked into hydrogen and graphite, etc. The hydrogen carries the graphite dust and the like into the buffer zone, and under the action of the purge gas, they enter the exhaust pipe through the exhaust flange 114 together. The hydrogen and graphite powder and the like enter the back-end processing system along the exhaust pipe for separation and treatment to obtain pure hydrogen and graphite powder, which can realize continuous and efficient liquid metal natural gas hydrogen and graphite production.

[0023] Figure 1 、 2 As shown in Figures 3 and 4, when the present invention is working, natural gas passes through the desulfurization and dehydration equipment for desulfurization and dehydration, absorbs heat from the hydrogen discharged from the exhaust flange through the heat exchanger, and then enters the reactor 17 through the air inlet pipe 4. Then, under the action of the liquid metal in the reactor, it is cracked into hydrogen and graphite powder, etc. The hydrogen carries the graphite dust, etc. into the heat exchanger through the exhaust flange 12, exchanges heat with the natural gas, realizes preheating of the natural gas, effectively utilizes the preheating, and reduces energy consumption. After passing through the heat exchanger, hydrogen, graphite dust, etc. enter the cooler for cooling to prevent high-temperature gas and dust from entering the gas-solid separator and causing damage to the equipment. Hydrogen, un-cracking natural gas and graphite dust are separated in the gas-solid separation equipment, and the gas-solid separation equipment collects the separated graphite dust, etc. Hydrogen, un-cracking natural gas, etc. enter the PSA for separation. The separated high-purity hydrogen is mainly depressurized in the hydrogen buffer tank supporting the hydrogen storage tank and then stored in the hydrogen storage tank. Part of the hydrogen regularly enters the natural gas intake pipeline and the blowpipe 11 through the solenoid valve with the valve core opened. The hydrogen in the blowpipe 11 regularly purges the guide plate 7 to prevent graphite dust, etc. from caking in the buffer zone 29 and causing blockage, which is not conducive to the discharge of hydrogen and graphite dust, etc. The hydrogen entering the natural gas intake pipe 4 enters the intake pipe 4 together with the natural gas. The hydrogen can react with the carbon produced by premature cracking in the intake pipe 4 to produce methane, thereby avoiding clogging the air holes on the intake pipe 4 and affecting continuous production. As described above, the present invention utilizes liquid metal to crack natural gas to produce hydrogen and graphite. Methane in natural gas undergoes a direct cracking reaction to generate hydrogen and solid carbon (graphite). This production process emits no carbon dioxide. During operation, the hydrogen generated by cracking in the reactor carries graphite dust and is discharged from the reactor, achieving continuous discharge of graphite from the reactor. The hydrogen in the product can be purified and used in industries such as fuel cells, while the carbon powder can also be used in industrial applications. This process offers a certain degree of economic viability, has the potential for large-scale application in the future of carbon-free hydrogen production, and can achieve automated continuous production. In this invention, the principle of hydrogen production from natural gas is as follows: High-temperature cracking of methane in natural gas to produce hydrogen is a highly endothermic reaction. The energy gained by methane molecules causes the C-H bonds in the methane molecules to break, resulting in their conversion into hydrogen molecules and solid carbon.

[0024] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be regarded as illustrative and non-restrictive in all respects. The scope of the present invention is defined by the appended claims rather than the foregoing description, and all changes that come within the meaning and range of equivalents of the claims are intended to be included therein.

[0025] In addition, it should be understood that although this specification is described in terms of implementation methods, the implementation methods do not only include an independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A device for preparing hydrogen and graphite using liquid metal and natural gas, comprising a desulfurization and dehydration device, a heat exchanger, a cooler, a gas-solid separation device, a pressure swing adsorber, a hydrogen storage tank, a main control system, a cavity, a top cover, an air inlet pipe, a reactor, a vacuum pump, an exhaust pipe, a graphite tube, and an air blow pipe; characterized in that A vacuum tube is installed on the outside of one side of the cavity, and the air outlet end of the vacuum tube is connected to the air inlet end of the vacuum pump; the outside of the cavity is a double-layer structure, and a water inlet A and a water outlet A are installed on one end of the outside of the cavity; refractory bricks and heat insulation boards are installed on the bottom of the cavity, and the reactor is installed on the heat insulation board. Fillers, asbestos cloth, heaters, and brackets are installed on the outside of the reactor from the inside to the outside. A thermocouple is installed on the side end of the bracket, and the thermocouple measuring end is in contact with the outer wall of the reactor. The thermocouple signal output end is electrically connected to the signal input end of the main control system; heat insulation board B and heat insulation board A are installed on the upper part of the reactor and serve as a buffer zone; the top cover is connected to the upper part of the cavity, and the outside of the top cover is a double-layer structure. A water inlet C, a water outlet C, a safety valve and a pressure sensor are installed on the outside of the top cover. The air intake pipe is installed on the top cover, and the lower part of the air intake pipe is connected to the graphite tube with a flexible bellows. The air intake pipe is connected to the intake pipe of the gas station, and the other end of the air intake pipe is connected to the intake port of the gas station.

2. The device for preparing hydrogen and graphite by utilizing liquid metal and natural gas according to claim 1, characterized in that: The bottom of the cavity is a double-layer structure and the outer side of the lower end is respectively equipped with a water inlet B, a water outlet B and a cooling water channel B.

3. The device for preparing hydrogen and graphite by utilizing liquid metal and natural gas according to claim 1, characterized in that: A plurality of supports are installed at the lower end of the bottom of the cavity.

4. The device for preparing hydrogen and graphite by utilizing liquid metal and natural gas according to claim 1, characterized in that: The filler is fused magnesia and the heater is an electric heater.

5. The device for preparing hydrogen and graphite by utilizing liquid metal and natural gas according to claim 1, characterized in that: The insulation board A and the insulation board B are made of ceramic fiberboard.

6. The device for preparing hydrogen and graphite by utilizing liquid metal and natural gas according to claim 1, characterized in that: The guide plate has a conical structure.

7. The device for preparing hydrogen and graphite by utilizing liquid metal and natural gas according to claim 1, characterized in that: The reactor contains a copper-bismuth alloy.

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