CO2 hydrate generation system and method utilizing liquid hydrogen cold energy

Abstract

The invention relates to a CO2 hydrate generation system and method utilizing liquid hydrogen cold energy. The CO2 hydrate generation system comprises a liquid hydrogen storage tank, an immersed pump, a liquid hydrogen booster pump, a liquid hydrogen vaporizer, a CO2 gas supply device, a mixer, a hydrate separator, a temperature sensor, a pressure sensor, a flow sensor, a liquid hydrogen booster pipeline, a CO2 gas supply pipeline, a circulation pipeline, a CO2 hydrate storage pipeline and related valves. According to the system, CO2 hydrate is generated by utilizing cold energy generated in the liquid hydrogen pressurization vaporization process, the device structure is simplified, a reaction kettle is omitted, the carbon dioxide hydrate is directly generated in the heat exchanger, meanwhile, a circulating system of unreacted substances is arranged, unreacted CO2 and water can be recycled, and the energy consumption is reduced. Organic integration of two kinds of energy and key technologies in the environment field is achieved, the problem of liquid hydrogen cold energy waste is solved, and a new effective way is provided for carbon dioxide sequestration.

Description

Technical Field

[0001] The present invention relates to the field of cold energy utilization and carbon dioxide capture and storage, and in particular to a CO2 hydrate generation system and method utilizing liquid hydrogen cold energy. Background Art

[0002] Carbon dioxide capture and storage (CCS) technology is considered one of the key means to mitigate the greenhouse effect. As a new form of carbon dioxide storage, CO2 hydrate has the advantages of high CO2 storage density, relatively low formation conditions and good stability, and has attracted widespread attention.

[0003] At the same time, liquid hydrogen releases a large amount of cold energy during the vaporization process. If this cold energy is directly discarded, it will cause a huge waste of energy. Therefore, using liquid hydrogen cold energy to generate CO2 hydrate can not only achieve the capture and storage of CO2, but also improve energy utilization efficiency, which has important environmental protection and energy significance. Based on the above utilization, the present invention designs a CO2 hydrate generation system and method using liquid hydrogen cold energy. Summary of the invention

[0004] The present invention proposes a CO2 hydrate generation system and method using liquid hydrogen cooling energy. The specific design scheme is as follows:

[0005] The present invention provides a CO2 hydrate generation system using liquid hydrogen cold energy, comprising a liquid hydrogen storage tank, a submersible pump, a liquid hydrogen booster pump, a buffer tank, a liquid hydrogen vaporizer, a gas storage cylinder group, a CO2 gas supply device, a mixer, a water storage tank, a hydrate separator, a circulation pump, a pressure sensor, a temperature sensor, a flow sensor, a liquid hydrogen booster pipeline, a CO2 gas supply pipeline, a circulation pipeline, and a CO2 hydrate storage pipeline.

[0006] The liquid hydrogen boosting pipeline is connected to the liquid hydrogen storage tank, the first stop valve, the liquid hydrogen boosting pump, the buffer tank, the liquid hydrogen vaporizer, and the gas storage bottle group in sequence. The submersible pump in the liquid hydrogen storage tank transports the liquid hydrogen to the liquid hydrogen boosting pump for pressurization. After the liquid hydrogen is pressurized, it enters the liquid hydrogen vaporizer to vaporize into high-pressure hydrogen gas, and then enters the hydrogen storage bottle group for storage.

[0007] The CO2 gas supply pipeline is connected to the CO2 gas supply device, the pressure reducing valve, the mixer and the liquid hydrogen vaporizer in sequence, and the CO2 is transported to the liquid hydrogen vaporizer to generate CO2 hydrate.

[0008] The circulation pipeline is connected to the hydrate separator, the circulation pump and the mixer in sequence to circulate the unreacted carbon dioxide and water to regenerate hydrates.

[0009] Furthermore, the liquid hydrogen vaporizer adopts a shell and tube heat exchanger, the outlet of the buffer tank is connected to the tube side inlet of the liquid hydrogen vaporizer, the tube side outlet of the liquid hydrogen vaporizer is connected to the hydrogen storage bottle group, the outlet of the mixer is connected to the shell side inlet of the liquid hydrogen vaporizer, and the shell side outlet of the liquid hydrogen vaporizer is connected to the inlet of the hydrate separator.

[0010] Furthermore, the inner wall of the shell and the outer wall of the tube bundle of the liquid hydrogen vaporizer are coated with an anti-clogging coating, the coating is a polytetrafluoroethylene coating or a ceramic coating, and the tube bundle is made of a material with a high thermal conductivity coefficient.

[0011] Furthermore, the liquid hydrogen vaporizer is provided with a temperature sensor for monitoring temperature changes; the liquid hydrogen vaporizer and each storage tank and pipeline are provided with a pressure sensor for monitoring pressure changes; the liquid hydrogen booster pipeline and CO2 gas supply pipeline are provided with a flow sensor for monitoring fluid flow.

[0012] Furthermore, the temperature sensor, pressure sensor, flow sensor and various valves are all connected to a control system for receiving monitoring data and controlling the opening and other operating parameters of the valves.

[0013] Furthermore, the CO2 gas source in the CO2 gas supply device mainly comes from the flue gas and combustion gas generated by the combustion of fossil fuels and industrial process emissions, and is pretreated, purified and cleansed.

[0014] Furthermore, the mixing ratio of the carbon dioxide and water can be controlled by a pressure reducing valve and a third stop valve.

[0015] Furthermore, the hydrate separator is a cyclone separator, which is connected to the shell side outlet of the liquid hydrogen vaporizer to separate CO2 hydrate from unreacted substances. The circulating pump connects the hydrate separator and the mixer to recycle unreacted CO2 and water.

[0016] At the same time, the present invention provides a method for generating CO2 hydrate using liquid hydrogen cold energy using the above-mentioned device, the method comprising the following steps:

[0017] S1: Open the first stop valve and the second stop valve, start the submersible pump, start the booster pump, and transport the liquid hydrogen in the liquid hydrogen storage tank to the booster pump for pressurization. After the liquid hydrogen is pressurized, it enters the buffer tank for buffering, and then enters the liquid hydrogen vaporizer from the pipe inlet to release cold energy, vaporize into high-pressure hydrogen, and then be transported to the hydrogen storage bottle group for storage.

[0018] S2: Open the third stop valve and the pressure reducing valve. The CO2 in the CO2 gas supply device and the water from the water storage tank are fully mixed in the mixer to form a carbon dioxide-water mixed solution. The mixing ratio is adjusted according to actual needs by controlling the valve opening of the pressure reducing valve and the third stop valve through the control system. Then the mixed solution enters the liquid hydrogen vaporizer from the shell side inlet to absorb cold energy.

[0019] S3: Liquid hydrogen enters the liquid hydrogen vaporizer from the tube side inlet, and exchanges heat with the carbon dioxide-water mixed solution in the shell side at the tube bundle, so that the liquid hydrogen is vaporized and releases cold energy, and at the same time, the carbon dioxide-water mixed solution reacts in the shell side of the shell and tube heat exchanger to form carbon dioxide hydrate.

[0020] The inner wall of the shell and the outer wall of the tube bundle of the shell and tube heat exchanger are coated with an anti-clogging coating. The temperature, pressure and flow changes of the shell and tube heat exchanger and the entire system are monitored in real time through temperature sensors, pressure sensors and flow sensors, and the monitoring data is transmitted to the control system. The control system automatically controls the opening of various valves based on the monitoring data, adjusts the flow of liquid hydrogen, the mixing ratio of carbon dioxide and water, and other operating parameters to maintain suitable reaction conditions.

[0021] S4: After the reaction is completed, the generated CO2 hydrate and the unreacted substances enter the hydrate separator together. In the separator, the CO2 hydrate is separated and sealed through the CO2 hydrate storage pipeline. The unreacted CO2 and water are transported back to the mixer through the circulation pump for recycling. This process is repeated to achieve a continuous CO2 hydrate production process.

[0022] The advantages of the present invention are:

[0023] (1) The present invention applies a large amount of cold energy released during the vaporization of liquid hydrogen to the formation reaction of CO2 hydrates, organically combining the utilization of liquid hydrogen cold energy with CO2 capture and storage. While reducing the cost of CO2 capture and storage, it improves the overall economic and environmental benefits of the liquid hydrogen industry chain, and provides an innovative solution to greenhouse gas emissions and comprehensive energy utilization.

[0024] (2) The present invention simplifies the device structure, eliminates the reaction kettle, and directly generates carbon dioxide hydrate in the heat exchanger. At the same time, a circulation system for unreacted substances is provided, which can recycle unreacted CO2 and water, further improving the utilization rate of raw materials, reducing resource waste, and reducing production costs and environmental impacts.

[0025] (3) The present invention can use a control system to achieve precise control and automated operation of the CO2 hydrate formation process, ensure the stability and reliability of the reaction, and improve product quality and production safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of a CO2 hydrate generation system utilizing liquid hydrogen cooling energy provided by the present invention.

[0027] Figure 2 This is a cross-sectional view of a liquid hydrogen vaporizer.

[0028] In the figure: 1 liquid hydrogen storage tank, 2 submersible pump, 3 first stop valve, 4 liquid hydrogen booster pump, 5 buffer tank, 6 liquid hydrogen vaporizer, 7 second stop valve, 8 gas cylinder group, 9 CO2 gas supply device, 10 pressure reducing valve, 11 mixer, 12 third stop valve, 13 water storage tank, 14 hydrate separator, 15 circulation pump, 16 pressure sensor, 17 temperature sensor, 18 liquid hydrogen booster pipeline, 19 CO2 gas supply pipeline, 20 circulation pipeline, 21 CO2 hydrate storage pipeline, 61 tube side inlet, 62 tube side outlet, 63 shell side inlet, 64 shell side outlet, 65 partition, 66 tube bundle, 67 baffle, 68 shell, 69 tube box. DETAILED DESCRIPTION

[0029] Reference Figures 1-2 As shown, the present invention provides a CO2 hydrate generation system using liquid hydrogen cold energy, including a liquid hydrogen storage tank 1, a submersible pump 2, a liquid hydrogen booster pump 4, a buffer tank 5, a liquid hydrogen vaporizer 6, a gas storage bottle group 8, a CO2 gas supply device 9, a mixer 11, a water storage tank 12, a hydrate separator 14, a circulation pump 15, a liquid hydrogen booster pipeline 18, a CO2 gas supply pipeline 19, a circulation pipeline 20, and a CO2 hydrate storage pipeline 21.

[0030] In the liquid hydrogen boosting pipeline 18, the liquid hydrogen storage tank 1 is connected in sequence with the first stop valve 3, the liquid hydrogen boosting pump 4, the buffer tank 5, the liquid hydrogen vaporizer 6, and the gas storage bottle group 8. The submersible pump 2 in the liquid hydrogen storage tank 1 transports the liquid hydrogen to the liquid hydrogen boosting pump 4 for pressurization. After the liquid hydrogen is pressurized, it enters the liquid hydrogen vaporizer 6 to be vaporized into high-pressure hydrogen gas, and then enters the hydrogen storage bottle group 8 for storage.

[0031] In the CO2 gas supply pipeline 19, the CO2 gas supply device 9 is connected to the pressure reducing valve 10, the mixer 12 and the liquid hydrogen vaporizer 6 in sequence, and the CO2 is transported to the liquid hydrogen vaporizer 6 to generate CO2 hydrate.

[0032] In the circulation pipeline 20, the hydrate separator 14 is connected to the circulation pump 15 and the mixer 12 in sequence, so that the unreacted carbon dioxide and water are recycled to regenerate hydrates.

[0033] The liquid hydrogen vaporizer 6 adopts a shell and tube heat exchanger, the tube side inlet of the liquid hydrogen vaporizer 6 is connected to the outlet of the buffer tank 5, the tube side outlet of the liquid hydrogen vaporizer 6 is connected to the hydrogen storage bottle group 8, the shell side inlet of the liquid hydrogen vaporizer 6 is connected to the outlet of the mixer 11, and the shell side outlet of the liquid hydrogen vaporizer 6 is connected to the inlet of the hydrate separator 14. Liquid hydrogen goes through the tube side, and transfers cold energy to the carbon dioxide-water mixed solution in the shell side through the tube wall. Carbon dioxide and water go through the shell side, and after heat exchange with the liquid hydrogen in the tube side, the temperature drops rapidly, creating suitable low temperature conditions for the formation of carbon dioxide hydrates. The shell side is a reaction place with a large space, and the mixed solution reacts under suitable temperature and pressure conditions to generate carbon dioxide hydrates. A baffle 67 is arranged in the shell side, which can improve the flow state of the fluid, increase the turbulence of the fluid, and improve the heat transfer efficiency. At the same time, it promotes the mixing of carbon dioxide and water again, which is conducive to the formation of hydrates.

[0034] The inner wall of the shell and the outer wall of the tube bundle of the liquid hydrogen vaporizer 6 are coated with an anti-clogging coating, which is a polytetrafluoroethylene coating or a ceramic coating, and the tube bundle is made of a material with a high thermal conductivity coefficient.

[0035] The liquid hydrogen vaporizer 6 is provided with a temperature sensor for monitoring temperature changes; the liquid hydrogen vaporizer 6 and each storage tank and pipeline are provided with a pressure sensor for monitoring pressure changes; the liquid hydrogen booster pipeline 18 and the CO2 gas supply pipeline 19 are provided with a flow sensor for monitoring fluid flow. The temperature sensor, pressure sensor, flow sensor and various valves are connected to the control system to receive monitoring data and control the valve opening and other operating parameters.

[0036] The CO2 gas source in the CO2 gas supply device 9 mainly comes from the flue gas and combustion gas generated by the combustion of fossil fuels and industrial process emissions, which are stored in the CO2 gas supply device 9 after pretreatment, purification and purification. After that, the CO2 is reduced in pressure by the pressure reducing valve 10 and fully mixed with the water from the water storage tank 13 in the mixer 11 to form a carbon dioxide-water mixed solution, and the mixing ratio is controlled by the pressure reducing valve 10 and the third stop valve 12.

[0037] The hydrate separator 14 adopts a cyclone separator, which is connected to the shell outlet of the liquid hydrogen vaporizer 6 to separate the CO2 hydrate from the unreacted substances. The circulating pump 15 connects the hydrate separator 14 with the mixer 11 to recycle the unreacted CO2 and water.

[0038] The present invention also provides a method for generating CO2 hydrate using liquid hydrogen cold energy, comprising the following steps:

[0039] S1: Open the first stop valve 3 and the second stop valve 7, start the submersible pump 2, start the booster pump 4, and transport the liquid hydrogen in the liquid hydrogen storage tank 1 to the booster pump 4 for pressurization. After the liquid hydrogen is pressurized, it enters the buffer tank 5 for buffering, and then enters the liquid hydrogen vaporizer 6 from the pipe inlet 61 to release cold energy, vaporize into high-pressure hydrogen, and then be transported to the hydrogen storage bottle group 8 for storage.

[0040] S2: Open the third stop valve 12 and the pressure reducing valve 10, and the CO2 in the CO2 supply device 9 and the water from the water storage tank 11 are fully mixed in the mixer 11 to form a carbon dioxide-water mixed solution. The mixing ratio is adjusted according to actual needs by controlling the valve opening of the pressure reducing valve 10 and the third stop valve 12 through the control system. Then the mixed solution enters the liquid hydrogen vaporizer 6 from the shell side inlet 63 to absorb cold energy.

[0041] S3: Liquid hydrogen enters the liquid hydrogen vaporizer 6 from the tube side inlet 61, and exchanges heat with the carbon dioxide-water mixed solution in the shell side at the tube bundle 66, so that the liquid hydrogen is vaporized and releases cold energy, and at the same time, the carbon dioxide-water mixed solution reacts in the shell side of the shell and tube heat exchanger to generate carbon dioxide hydrate.

[0042] The inner wall of the shell and the outer wall of the tube bundle of the shell and tube heat exchanger are coated with an anti-clogging coating. The temperature, pressure and flow changes of the shell and tube heat exchanger and the entire system are monitored in real time through temperature sensors, pressure sensors and flow sensors, and the monitoring data is transmitted to the control system. The control system automatically controls the opening of various valves based on the monitoring data, adjusts the flow of liquid hydrogen, the mixing ratio of carbon dioxide and water, and other operating parameters to maintain suitable reaction conditions.

[0043] S4: After the reaction is completed, the generated CO2 hydrate and the unreacted substances enter the hydrate separator 14 together. In the separator, the CO2 hydrate is separated and sealed through the CO2 hydrate sealing pipeline 22. The unreacted CO2 and water are transported back to the mixer 11 through the circulation pump 15 for recycling. This process is repeated to realize a continuous CO2 hydrate production process.

[0044] It is known from common technical knowledge that the present invention can be implemented by other embodiments that do not deviate from its spirit or essential features. Therefore, the above disclosed embodiments are only illustrative in all respects and are not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are included in the present invention.

Claims

1. A CO2 hydrate generation system using liquid hydrogen cold energy, characterized in that: It comprises a liquid hydrogen storage tank (1), a submersible pump (2), a liquid hydrogen booster pump (4), a buffer tank (5), a liquid hydrogen vaporizer (6), a gas cylinder group (8), a CO2 gas supply device (9), a mixer (11), a water storage tank (12), a hydrate separator (14), a circulation pump (15), a liquid hydrogen booster pipeline (18), a CO2 gas supply pipeline (19), a circulation pipeline (20), and a CO2 hydrate storage pipeline (21); The liquid hydrogen boosting pipeline (18) is connected to the liquid hydrogen storage tank (1), the first stop valve (3), the liquid hydrogen boosting pump (4), the buffer tank (5), the liquid hydrogen vaporizer (6), and the gas storage bottle group (8) in sequence; the submersible pump (2) in the liquid hydrogen storage tank (1) transports the liquid hydrogen to the liquid hydrogen boosting pump (4) for pressurization; after the liquid hydrogen is pressurized, it enters the liquid hydrogen vaporizer (6) to be vaporized into high-pressure hydrogen gas, and then enters the hydrogen storage bottle group (8) for storage; The CO2 gas supply pipeline (19) is connected to the CO2 gas supply device (9), the pressure reducing valve (10), the mixer (12) and the liquid hydrogen vaporizer (6) in sequence, and transports the CO2 to the liquid hydrogen vaporizer (6) to generate CO2 hydrate; The circulation pipeline (20) is connected to the hydrate separator (14), the circulation pump (15) and the mixer (12) in sequence, and unreacted carbon dioxide and water are recycled to regenerate hydrates.

2. A CO2 hydrate generation system using liquid hydrogen cold energy according to claim 1, characterized in that: The liquid hydrogen vaporizer (6) adopts a shell and tube heat exchanger, the outlet of the buffer tank (5) is connected to the tube side inlet of the liquid hydrogen vaporizer (6), the tube side outlet of the liquid hydrogen vaporizer (6) is connected to the hydrogen storage bottle group (8), the outlet of the mixer (11) is connected to the shell side inlet of the liquid hydrogen vaporizer (6), and the shell side outlet of the liquid hydrogen vaporizer (6) is connected to the inlet of the hydrate separator (14).

3. A CO2 hydrate generation system using liquid hydrogen cold energy according to claim 2, characterized in that: The inner wall of the shell of the liquid hydrogen vaporizer (6) and the outer wall of the tube bundle are coated with an anti-clogging coating, the coating is a polytetrafluoroethylene coating or a ceramic coating, and the tube bundle is made of a material with a high thermal conductivity coefficient.

4. A CO2 hydrate generation system using liquid hydrogen cold energy according to claim 1, characterized in that: The liquid hydrogen vaporizer (6) is provided with a temperature sensor for monitoring temperature changes; the liquid hydrogen vaporizer (6) and each storage tank and pipeline are provided with a pressure sensor for monitoring pressure changes; the liquid hydrogen booster pipeline (18) and the CO2 gas supply pipeline (19) are provided with a flow sensor for monitoring fluid flow.

5. A CO2 hydrate generation system using liquid hydrogen cold energy according to claim 1, characterized in that: The temperature sensor, pressure sensor, flow sensor and various valves are all connected to the control system for receiving monitoring data and controlling the opening of the valves and other operating parameters.

6. A CO2 hydrate generation system using liquid hydrogen cold energy according to claim 1, characterized in that: The CO2 gas source in the CO2 gas supply device (9) mainly comes from the flue gas and combustion gas generated by the combustion of fossil fuels and industrial process emissions, and is pre-treated, purified and cleansed.

7. A CO2 hydrate generation system using liquid hydrogen cold energy according to claim 1, characterized in that: The mixing ratio of the carbon dioxide and water is controlled by a pressure reducing valve (10) and a third stop valve (12).

8. A CO2 hydrate generation system using liquid hydrogen cold energy according to claim 1, characterized in that: The hydrate separator (14) is a cyclone separator, which is connected to the shell outlet of the liquid hydrogen vaporizer (6) to separate CO2 hydrate from unreacted substances. The circulating pump (15) connects the hydrate separator (14) and the mixer (11) to recycle unreacted CO2 and water.

9. The method of the CO2 hydrate generation system using liquid hydrogen cooling energy according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: Open the first stop valve (3) and the second stop valve (7), start the submersible pump (2), start the booster pump (4), and transport the liquid hydrogen in the liquid hydrogen storage tank (1) to the booster pump (4) for pressurization. After the liquid hydrogen is pressurized, it enters the buffer tank (5) for buffering, and then enters the liquid hydrogen vaporizer (6) from the pipe inlet (61) to release cold energy, vaporize into high-pressure hydrogen, and then transport it to the hydrogen storage bottle group (8) for storage. S2: Open the third stop valve (12) and the pressure reducing valve (10), and the CO2 in the CO2 supply device (9) and the water from the water storage tank (11) are fully mixed in the mixer (11) to form a carbon dioxide-water mixed solution. The mixing ratio is adjusted according to actual needs by controlling the valve opening of the pressure reducing valve (10) and the third stop valve (12) through the control system, and then the mixed solution enters the liquid hydrogen vaporizer (6) from the shell side inlet (63) to absorb cold energy; S3: Liquid hydrogen enters the liquid hydrogen vaporizer (6) from the tube side inlet (61), and exchanges heat with the carbon dioxide-water mixed solution in the shell side at the tube bundle (66), so that the liquid hydrogen is vaporized and releases cold energy, and at the same time, the carbon dioxide-water mixed solution reacts in the shell side of the shell and tube heat exchanger to form carbon dioxide hydrate; The inner wall of the shell side and the outer wall of the tube bundle of the shell and tube heat exchanger are coated with an anti-clogging coating. The temperature, pressure and flow changes of the shell and tube heat exchanger and the entire system are monitored in real time through temperature sensors, pressure sensors and flow sensors, and the monitoring data are transmitted to the control system. The control system automatically controls the opening of various valves according to the monitoring data, adjusts the flow of liquid hydrogen, the mixing ratio of carbon dioxide and water and other operating parameters to maintain suitable reaction conditions; S4: After the reaction is completed, the generated CO2 hydrate and the unreacted substances enter the hydrate separator (14) together. In the separator, the CO2 hydrate is separated and sealed through the CO2 hydrate sealing pipeline (22). The unreacted CO2 and water are transported back to the mixer (11) through the circulation pump (15) for recycling. This process is repeated to achieve a continuous CO2 hydrate production process.

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