Liquefied natural gas multi-energy coupling reforming hydrogen production and carbon capture utilization system and method

Abstract

The invention relates to the technical field of LNG receiving stations, in particular to a liquefied natural gas multi-energy coupling reforming hydrogen production and carbon capture utilization system and method. Comprising a first control valve, a first heat exchanger, an expansion machine, a first compressor, a second heat exchanger, a third heat exchanger, a second control valve, a pressure swing adsorption separator, a hydrogen fuel cell, an LNG heat exchanger, a dry ice machine, a second compressor, a separator, a third control valve, a water storage tank, a fourth heat exchanger, a steam superheater, a methane reforming reactor and a combustion chamber, according to the system, methane is directly converted into COlt with the purity larger than or equal to 99% in an LNG receiving station through a methane steam reforming and pressure swing adsorption separation technology; 0.2 ppm of vehicle fuel cell grade hydrogen thoroughly gets rid of dependence on outsourcing hydrogen or electrolytic hydrogen; meanwhile, the chemical energy, the cold energy and the pressure energy of LNG are integrated, and the processes of reforming hydrogen production, expansion power generation, combustion power generation, CO2 trapping through the cold energy and the like are coupled, so that material and energy self-sufficiency of the system is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of LNG receiving stations, in particular to a liquefied natural gas multi-energy coupling reforming hydrogen production and carbon capture and utilization system and method. BACKGROUND

[0002] Traditional liquefied natural gas (LNG) receiving stations mainly use cold energy for single purpose (such as power generation, refrigeration, etc.), and the cold energy utilization rate is low; in winter, seawater or the like is used as a gasification heat source, and due to the low water temperature, the gasification heat transfer efficiency is reduced, ice blockage is easily caused, and the stable supply of LNG is affected; some receiving stations use natural gas combustion to heat the heat source to alleviate the above problems, but the CO2 generated by combustion is directly discharged, which not only wastes carbon resources but also increases the environmental burden.

[0003] Hydrogen energy is an important energy storage medium, and the fuel cell in the current market needs to use high-purity hydrogen, and the main component of LNG, methane, cannot directly enter the fuel cell; the existing hydrogen source relies on the purchase of high-pressure hydrogen (long transportation distance and high cost) or on-site electrolysis (high power consumption and high impurity risk), which is difficult to meet the demand for low-cost and stable hydrogen supply; although steam methane reforming (SMR) can be considered: it is one of the main ways of large-scale hydrogen production, but it needs to supply high-purity water, purchase electricity, and install a CO2 capture device, which has high overall energy consumption and water consumption, and does not meet the development direction of zero-carbon hydrogen energy.

[0004] At the same time, the LNG receiving station, the CO2 capture device, the power generation device and the hydrogen production equipment are independently constructed, which has the problems of equipment duplication, large occupation area, low overall energy efficiency and material flow fragmentation; in the future, hydrogen fuel cell vehicles, unmanned aerial vehicles and other scenarios have an urgent need for distributed, low-cost and low-carbon hydrogen sources, and the existing technical route is difficult to quickly replicate to LNG terminals, floating devices and ocean-going ships. SUMMARY

[0005] The present application relates to the technical field of LNG receiving stations, in particular to a liquefied natural gas multi-energy coupling reforming hydrogen production and carbon capture and utilization system and method.

[0006] To achieve the above-mentioned purpose, in a first aspect, the present application provides a liquefied natural gas multi-energy coupling reforming hydrogen production and carbon capture and utilization system, comprising a first control valve, a first heat exchanger, an expander, a first compressor, a second heat exchanger, a third heat exchanger, a second control valve, a pressure swing adsorption separator, a hydrogen fuel cell, an LNG heat exchanger, a dry ice machine, a second compressor, a separator, a third control valve, a water storage tank, a fourth heat exchanger, a steam superheater, a methane reforming reactor and a combustion chamber. The first compressor, the third heat exchanger, the pressure swing adsorption separator and the hydrogen fuel cell are connected, the second heat exchanger is connected with the third heat exchanger, the expander and the LNG heat exchanger respectively, the first control valve is connected with the expander, the combustion chamber and the methane reforming reactor respectively, the combustion chamber is connected with the pressure swing adsorption separator and the steam superheater respectively, the methane reforming reactor is connected with the first heat exchanger and the steam superheater respectively, the third control valve, the water storage tank and the steam superheater are connected, the separator, the second compressor, the LNG heat exchanger and the dry ice machine are connected, and the second control valve is connected with the third heat exchanger.

[0007] In the second aspect, the application further provides a liquefied natural gas multi-energy coupling reform hydrogen production and carbon capture and utilization method, which is applied to the liquefied natural gas multi-energy coupling reform hydrogen production and carbon capture and utilization system in the first aspect. Hydrogen is produced by reforming reaction of natural gas and high-temperature steam, and hydrogen is purified under pressure swing adsorption separation; Dry ice is prepared by using LNG cold energy, and power is generated by expansion of LNG gasification pressurization or LNG combustion; Carbon capture is completed by separating and recovering CO2 after LNG gasification combustion, and dry ice is prepared by using LNG cold energy; Condensed water after LNG gasification combustion is separated and recovered, and the sensible heat of high-temperature flue gas is used to heat the condensed water; The waste heat of the external water source absorption system is used to form a water resource cycle.

[0008] The method comprises the following steps: Part of the gasified natural gas enters the methane reforming reactor through the first control valve, and high-temperature H2 and CO are generated by reforming reaction with high-temperature steam, and then the high-temperature H2 and CO are cooled by heat exchange with an external water source in the first heat exchanger, a first compressor is used to compress the high-temperature and high-pressure mixed gas, and then the high-temperature and high-pressure mixed gas is cooled by circulating water in the third heat exchanger to become high-pressure gas entering the pressure swing adsorption separator, so that the mixed gas is separated efficiently, pure hydrogen is obtained, the pure hydrogen is input into the hydrogen fuel cell, and the separated CO is returned to the combustion chamber to participate in combustion power generation.

[0009] The method comprises the following steps: LNG is heat-exchanged with high-pressure CO2 in the LNG heat exchanger, and then is heated and gasified into natural gas by circulating water in the second heat exchanger, gas brought by LNG gasification is expanded in the expander to generate power, and part of the natural gas is allowed to enter the combustion chamber to generate power by the first control valve.

[0010] The carbon capture includes: Part of the natural gas is combusted in the combustion chamber to generate electricity, and the high-temperature flue gas can heat the water source in the steam superheater, and then enter the fourth heat exchanger to be cooled by the external water source, and then enter the separator to separate the liquid water and CO2, the separated CO2 is first combined with the low-temperature reflux CO2 to reach the pre-cooling state, and then compressed into high-pressure gas by the second compressor, and then enters the LNG heat exchanger to exchange heat with the LNG to reach the liquefied state, and the liquid CO2 is vaporized to produce dry ice in the dry ice machine, part of which is vaporized into low-temperature gaseous CO2 and returned to the front of the second compressor for pre-cooling and recirculation, and the remaining liquid CO2 is output as dry ice products.

[0011] The condensate water after the LNG gasification combustion is separated and recovered, and the sensible heat of the high-temperature flue gas is used to heat the condensate water, including: The flue gas enters the separator to separate the liquid water and CO2, and the separated liquid water is collected in the water storage tank and enters the steam superheater to be heated by the flue gas into high-temperature water vapor, and then enters the methane reforming reactor to participate in the reforming reaction to produce hydrogen.

[0012] The external water source absorbs the waste heat of the system to form a water resource cycle, including: The external water source enters the first heat exchanger through the first control valve, first exchanges heat with the high-temperature mixed gas, and then enters the fourth heat exchanger to continue to absorb the waste heat in the flue gas, and the temperature of the external water source is raised again, and then the LNG is gasified into natural gas in the second heat exchanger, and then enters the third heat exchanger to exchange heat with the high-temperature and high-pressure mixed gas, and the heat is brought back to the second heat exchanger before, realizing the cold and hot circulation of the system.

[0013] The liquefied natural gas multi-capacity coupling hydrogen production and carbon capture and utilization system, part of the gasified natural gas enters the methane reforming reactor through the first control valve, and is subjected to a reforming reaction with high-temperature water vapor to generate high-temperature H2 and CO, and is subjected to heat exchange with an external water source in the first heat exchanger to be cooled, and then is compressed into 3-4 MPa high-temperature and high-pressure mixed gas in the first compressor, and then enters the third heat exchanger to be cooled by circulating water into high-pressure gas into the pressure swing adsorption separator, realizing efficient separation of the mixed gas, and the obtained pure hydrogen is introduced into the hydrogen fuel cell, and the separated CO is returned to the combustion chamber to participate in combustion and power generation; the LNG is first subjected to heat exchange with high-pressure CO2 in the LNG heat exchanger, and then is further heated and gasified into natural gas (NG) in the second heat exchanger, so as to meet the temperature requirement of external delivery; secondly, the gas brought by the LNG gasification is subjected to expansion power generation in the expander, and then part of the natural gas enters the combustion chamber through the first control valve to be combusted and generate power, realizing utilization of the pressure energy and chemical energy of the LNG gasification pressurization, and the remaining natural gas is delivered to downstream users through the NG pipe network; after part of the natural gas is combusted and generates power in the combustion chamber, the high-temperature flue gas can be introduced into the steam superheater to heat the water source, and the main components of the flue gas are CO2 and water vapor, and then the flue gas is cooled by external water source in the fourth heat exchanger, and then is introduced into the separator 13 to separate liquid water and CO2; the separated CO2 is combined with the low-temperature backflow CO2 to reach a pre-cooling state, is compressed into high-pressure gas by the second compressor, and then is introduced into the LNG heat exchanger to exchange heat with the LNG to reach a liquefaction state; the liquid CO2 is vaporized to produce dry ice in the dry ice machine, part of the vaporized CO2 is backflowed to the front of the second compressor to be pre-cooled and recycled, and the remaining liquid CO2 is output as a dry ice product; after the liquid water and CO2 are separated in the separator, the liquid water is collected into the water storage tank, and then is introduced into the steam superheater to heat the water source by using the sensible heat of the flue gas to become high-temperature water vapor, and enters the methane reforming reactor to participate in the hydrogen production reaction, when the water required by the reforming reaction is insufficient, the water source can be supplemented through the third control valve; the external water source (such as seawater) enters the first heat exchanger to exchange heat with the high-temperature mixed gas discharged from the methane reforming reactor, and absorbs the sensible heat of the high-temperature flue gas in the fourth heat exchanger to be further heated, which can prevent the ice blockage problem caused by too low temperature of the water source in winter, and then the LNG is further heated and gasified in the second heat exchanger; the cooled water source is subjected to heat exchange with the high-temperature and high-pressure H2 and CO mixed gas in the third heat exchanger to be warmed, and finally returns to the second heat exchanger as a heat source to participate in the gasification of the LNG again, realizing circulation of the water resource system; in addition, when the water source in the system is excessive, the excess water can be discharged through the second control valve.The system integrates the chemical energy, cold energy and pressure energy of LNG, couples the processes of reforming hydrogen production, expansion power generation, combustion power generation, cold energy CO2 capture, etc., improves the comprehensive utilization rate of LNG energy, breaks the limitation of single utilization of cold energy, directly converts methane into fuel cell grade hydrogen with purity of 99% and CO of 0.2ppm in a LNG receiving station through the process of methane steam reforming+pressure swing adsorption separation, completely gets rid of the dependence on external purchase of hydrogen or electrolytic hydrogen, reduces the cost and impurity risk of hydrogen source, provides power for the equipment such as compressor in the system through the expansion power generation of LNG gasification and the partial LNG combustion power generation (internal combustion engine and other heat engine systems), realizes energy self-sufficiency and reduces external power consumption. CO2 in the flue gas of LNG combustion is recovered, and the cold energy of LNG is used to convert it into dry ice, avoiding direct emission of CO2, and at the same time, high value-added carbon products are produced, realizing carbon capture and resource utilization, the water vapor in the flue gas is recovered for methane wet reforming, the high-temperature flue gas sensible heat is used to improve the LNG gasification heat source temperature (to solve the ice blocking problem), and the circulating water is used to cool the reforming product, the flue gas is cooled, and the LNG final stage gasification process is connected, reducing the repeated construction of equipment, improving the system integration and resource recycling efficiency, and adapting to the low-cost and low-carbon emission demand of distributed scenarios (such as LNG terminal and floating device), thereby solving the problems of insufficient energy utilization in traditional LNG receiving station, high cost of hydrogen source acquisition for hydrogen fuel cell hydrogenation station and dependence on external supply. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort.

[0015] Fig. 1 is the connection diagram of the liquefied natural gas multi-energy coupling reforming hydrogen production and carbon capture and utilization system provided by the present application.

[0016] Fig. 2 is the flow chart of the liquefied natural gas multi-energy coupling reforming hydrogen production and carbon capture and utilization method provided by the present application.

[0017] In the figure: 1-first control valve, 2-first heat exchanger, 3-expander, 4-first compressor, 5-second heat exchanger, 6-third heat exchanger, 7-second control valve, 8-pressure swing adsorption separator, 9-hydrogen fuel cell, 10-LNG heat exchanger, 11-dry ice machine, 12-second compressor, 13-separator, 14-third control valve, 15-water storage tank, 16-fourth heat exchanger, 17-steam superheater, 18-methane reforming reactor, 19-combustion chamber. DETAILED DESCRIPTION

[0018] Embodiments of the present application are described in detail below with reference to the attached drawing figures, wherein like reference numerals identify like elements or elements with similar functions throughout the described views. The embodiments described below are exemplary in nature and are intended to be illustrative of the present application rather than to be limiting of the present application.

[0019] Referring to Figs. 1-2 In a first aspect, the present application provides a liquefied natural gas multi-capacity coupling reforming hydrogen production and carbon capture and utilization system, comprising a first control valve 1, a first heat exchanger 2, an expander 3, a first compressor 4, a second heat exchanger 5, a third heat exchanger 6, a second control valve 7, a pressure swing adsorption separator 8, a hydrogen fuel cell 9, a LNG heat exchanger 10, a dry ice machine 11, a second compressor 12, a separator 13, a third control valve 14, a water storage tank 15, a fourth heat exchanger 16, a steam superheater 17, a methane reforming reactor 18 and a combustion chamber 19. The first compressor 4, the third heat exchanger 6, the pressure swing adsorption separator 8 and the hydrogen fuel cell 9 are connected, the second heat exchanger 5 is connected with the third heat exchanger 6, the expander 3 and the LNG heat exchanger 10 respectively, the first control valve 1 is connected with the expander 3, the combustion chamber 19 and the methane reforming reactor 18 respectively, the combustion chamber 19 is connected with the pressure swing adsorption separator 8 and the steam superheater 17 respectively, the methane reforming reactor 18 is connected with the first heat exchanger 2 and the steam superheater 17 respectively, the third control valve 14, the water storage tank 15 and the steam superheater 17 are connected, the separator 13, the second compressor 12, the LNG heat exchanger 10 and the dry ice machine 11 are connected, and the second control valve 7 is connected with the third heat exchanger 6.

[0020] In the embodiment of the present application, part of the natural gas after gasification enters the methane reforming reactor 18 through the first control valve 1, and is subjected to a reforming reaction with high-temperature water vapor to generate high-temperature H2 and CO, and is cooled in the first heat exchanger 2 by exchanging heat with an external water source, and then is compressed into high-temperature and high-pressure mixed gas with a pressure of 3-4 MPa in the first compressor 4, and then enters the third heat exchanger 6 to be cooled into high-pressure gas by circulating water, and then enters the pressure swing adsorption separator 8 to realize efficient separation of the mixed gas, and the obtained pure hydrogen enters the hydrogen fuel cell 9, and the separated CO returns to the combustion chamber 19 to participate in combustion and power generation; the LNG is first subjected to heat exchange with high-pressure CO2 in the LNG heat exchanger 10, and then is further heated and gasified into natural gas (NG) in the second heat exchanger 5 by circulating water, so as to meet the temperature requirement of external delivery; secondly, the gas brought by the LNG gasification is subjected to expansion power generation in the expander 3, and then part of the natural gas enters the combustion chamber 19 through the first control valve 1 to be combusted and generate power, so as to realize utilization of the pressure energy and chemical energy after the LNG gasification and pressurization, and the remaining natural gas is delivered to downstream users through the NG pipe network; after part of the natural gas is combusted and generates power in the combustion chamber 19, the high-temperature flue gas can enter the steam superheater 17 to heat a water source, and the main components of the flue gas are CO2 and water vapor, and then the flue gas enters the fourth heat exchanger 16 to be cooled by an external water source, and then enters the separator 13 to separate liquid water and CO2; the separated CO2 is first combined with low-temperature backflow CO2 to reach a pre-cooling state, is compressed into high-pressure gas by the second compressor 12, and then enters the LNG heat exchanger 10 to exchange heat with the LNG to make the LNG reach a liquefaction state; the liquid CO2 is vaporized into dry ice in the dry ice machine 11, part of the vaporized CO2 is backflowed to the front of the second compressor 12 to be pre-cooled and recycled, and the remaining liquid CO2 is output as a dry ice product; after the liquid water and CO2 are separated in the separator 13, the liquid water is collected in the water storage tank 15, and then enters the steam superheater 17 to be heated by the sensible heat of the flue gas to become high-temperature water vapor, and enters the methane reforming reactor 18 to participate in hydrogen production reaction, and when the water required by the reforming reaction is insufficient, the water source can be supplemented through the third control valve 14; the external water source (such as seawater) enters the first heat exchanger 2 to exchange heat with the high-temperature mixed gas discharged from the methane reforming reactor 18, and is further heated in the fourth heat exchanger 16 by absorbing the sensible heat of the high-temperature flue gas, so as to prevent the ice blockage problem caused by too low temperature of the water source in winter, and then the LNG is further heated and gasified in the second heat exchanger 5; the cooled water source is heated and warmed in the third heat exchanger 6 by exchanging heat with the mixed gas of high-temperature and high-pressure H2 and CO, and finally returns to the second heat exchanger 5 again to participate in the final gasification of the LNG before the second heat exchanger 5 as a heat source, so as to realize circulation of the water resource system; in addition, when the water source in the system is excessive, the excessive water can be discharged through the second control valve 7.The system integrates the chemical energy, cold energy and pressure energy of LNG, couples the processes of reforming hydrogen production, expansion power generation, combustion power generation, cold energy CO2 capture, etc., improves the comprehensive utilization rate of LNG energy, breaks the limitation of single utilization of cold energy, directly converts methane into fuel cell grade hydrogen with purity ≥ 99% and CO ≤ 0.2 ppm in a LNG receiving station through the process of methane steam reforming + pressure swing adsorption separation, completely gets rid of the dependence on external purchase of hydrogen or electrolytic hydrogen, reduces the cost and impurity risk of hydrogen source, provides power for the compressors and other equipment in the system through the expansion power generation of LNG gasification and the partial LNG combustion power generation (internal combustion engine and other heat engine systems), realizes energy self-sufficiency, and reduces external power consumption. CO2 in the flue gas of LNG combustion is recovered, and the LNG cold energy is used to convert it into dry ice, avoiding direct emission of CO2, while producing high value-added carbon products, realizing carbon capture and resource utilization, the water vapor in the flue gas is recovered for methane wet reforming, the high-temperature flue gas sensible heat is used to improve the LNG gasification heat source temperature (to solve the ice blocking problem), and the circulating water is used to cool the reforming product, the flue gas is cooled, and the LNG final gasification process is connected in series, reducing the repeated construction of equipment, improving the system integration and resource recycling efficiency, and adapting to the low-cost and low-carbon emission demand of distributed scenarios (such as LNG wharf and floating device), thereby solving the problems of insufficient energy utilization of traditional LNG receiving station, great carbon emission reduction pressure, high hydrogen source acquisition cost of hydrogen fuel cell 9 hydrogen refueling station, and dependence on external supply.

[0021] Referring to the drawings, in a second aspect, the application further provides a liquefied natural gas multi-energy coupling reforming hydrogen production and carbon capture and utilization method, which is applied to the liquefied natural gas multi-energy coupling reforming hydrogen production and carbon capture and utilization system as described in the first aspect above, and comprises the following steps: S1, using natural gas and high-temperature steam for reforming reaction to produce hydrogen, and purifying hydrogen through pressure swing adsorption separation; In the embodiment of the application, part of the gasified natural gas enters the methane reforming reactor 18 through the first control valve 1, reacts with high-temperature steam to generate high-temperature H2 and CO, is cooled in the first heat exchanger 2 with an external water source, is compressed to 3-4 MPa high-temperature high-pressure mixed gas in the first compressor 4, is then cooled by circulating water in the third heat exchanger 6 to high-pressure gas, and enters the pressure swing adsorber 8, realizing efficient separation of the mixed gas, and obtaining pure hydrogen which is fed into the hydrogen fuel cell 9, and the separated CO is returned to the combustion chamber 19 to participate in combustion power generation.

[0022] S2, using LNG cold energy to prepare dry ice, through expansion power generation after LNG gasification pressurization or LNG combustion power generation; In the embodiment of the present application, LNG is first exchanged with high-pressure CO2 in the LNG heat exchanger 10, and then enters the second heat exchanger 5 to be further heated by circulating water to be gasified into natural gas (NG) to meet the requirement of delivery temperature; secondly, the gas brought by LNG gasification is expanded in the expander 3 to generate power, and then part of the natural gas enters the combustion chamber 19 to generate power by the first control valve 1, realizing the utilization of pressure energy and chemical energy after LNG gasification pressurization, and the remaining natural gas is delivered to downstream users through the NG pipe network.

[0023] S3 completes carbon capture by separating and recovering CO2 after LNG gasification and combustion, and using LNG cold energy to make dry ice.

[0024] In the embodiment of the present application, after part of the natural gas is combusted in the combustion chamber 19 to generate power, the high-temperature flue gas can be introduced into the steam superheater 17 to heat the water source, and the main components of the flue gas are CO2 and water vapor, then the flue gas enters the fourth heat exchanger 16 to be cooled by external water source, and then is introduced into the separator 13 to separate liquid water and CO2; the separated CO2 is first combined with the low-temperature reflux CO2 to reach the pre-cooling state, is compressed into high-pressure gas by the second compressor 12, and then is introduced into the LNG heat exchanger 10 to exchange heat with LNG to reach the liquefaction state; the liquid CO2 is vaporized to make dry ice in the dry ice machine 11, part of which is vaporized into low-temperature gaseous CO2 to be pre-cooled before the second compressor 12 and then recycled, and the remaining liquid CO2 is output as a dry ice product.

[0025] S4 recovers the condensed water after LNG gasification and combustion by separation, and uses the high-temperature flue gas to condense the water.

[0026] In the embodiment of the present application, after the liquid water and CO2 are separated in the separator 13, the liquid water is collected in the water storage tank 15, and then is introduced into the steam superheater 17 to heat the water source by using the sensible heat of the flue gas to become high-temperature water vapor, and enters the methane reforming reactor 18 to participate in the hydrogen production reaction, and when the water required by the reforming reaction is insufficient, the third control valve 14 can be used to supplement the water source, thereby providing a high-temperature steam source for the reforming reaction.

[0027] S5 uses external water source to absorb the waste heat of the system to form a water resource cycle.

[0028] In the embodiment of the present application, the external water source (such as seawater) enters the first heat exchanger 2 to exchange heat with the high-temperature mixed gas discharged by the methane reformer 18, and absorbs the high-temperature flue gas sensible heat in the fourth heat exchanger 16 to further increase the temperature, which can prevent the ice blockage problem caused by the too low temperature of the water source in winter, and then the LNG is further heated and gasified in the second heat exchanger 5; the cooled water source is heated and warmed up by the high-temperature and high-pressure mixed gas of H2 and CO in the third heat exchanger 6, and finally returns to the second heat exchanger 5 as a heat source to participate in the gasification of the last stage of LNG again, realizing the circulation of the water resource system; in addition, when the water source in the system is too much, the excess water can be discharged through the second control valve 7, which can not only assist in completing the efficient gasification of LNG, but also realize the cold and heat circulation of the system.

[0029] The above disclosed is only the preferred embodiment of the liquefied natural gas multi-capacity coupling reforming hydrogen production and carbon capture and utilization system and method of the present application, of course, cannot limit the scope of the present application, those skilled in the art can understand that all or part of the above-mentioned embodiments are implemented, and equivalent changes made according to the claims of the present application still belong to the scope covered by the present application.

Claims

1. A system for multi-capacity coupling of liquefied natural gas (LNG) reforming for hydrogen production and carbon capture and utilization, characterized in that ； The first control valve, the first heat exchanger, the expander, the first compressor, the second heat exchanger, the third heat exchanger, the second control valve, the pressure swing adsorption separator, the hydrogen fuel cell, the LNG heat exchanger, the dry ice machine, the second compressor, the separator, the third control valve, the water storage tank, the fourth heat exchanger, the steam superheater, the methane reforming reactor and the combustion chamber; The first compressor, the third heat exchanger, the pressure swing adsorption separator and the hydrogen fuel cell are connected, the second heat exchanger is connected with the third heat exchanger, the expander and the LNG heat exchanger respectively, the first control valve is connected with the expander, the combustion chamber and the methane reforming reactor respectively, the combustion chamber is connected with the pressure swing adsorption separator and the steam superheater respectively, the methane reforming reactor is connected with the first heat exchanger and the steam superheater respectively, the third control valve is connected with the water storage tank and the steam superheater, the separator is connected with the second compressor, the LNG heat exchanger and the dry ice machine, and the second control valve is connected with the third heat exchanger.

2. The method for multi-energy coupling reforming hydrogen production and carbon capture and utilization of liquefied natural gas, applied to the multi-energy coupling reforming hydrogen production and carbon capture and utilization system of liquefied natural gas according to claim 1, characterized in that, The method comprises the following steps: Hydrogen is prepared by reforming reaction of natural gas and high-temperature water vapor, and hydrogen is purified under pressure swing adsorption separation; Dry ice is prepared by LNG cold energy, and power is generated by expansion of LNG gasification after pressure increase or LNG combustion; Carbon capture is completed by separating and recovering CO2 after LNG gasification combustion, and dry ice is prepared by LNG cold energy; Condensed water after LNG gasification combustion is separated and recovered, and condensed water is heated by high-temperature flue gas; External water source waste heat is absorbed to form water resource circulation.

3. The liquefied natural gas multi-energy coupling reforming hydrogen production and carbon capture utilization method according to claim 2, characterized in that: The hydrogen production by reforming reaction of natural gas and high-temperature water vapor and the hydrogen purification under pressure swing adsorption separation comprise: Part of the gasified natural gas enters the methane reforming reactor through the first control valve, and high-temperature H2 and CO are generated by reforming reaction with high-temperature water vapor, and the high-temperature H2 and CO are cooled in the first heat exchanger by heat exchange with external water source, the first compressor compresses the high-temperature and high-pressure mixed gas, and then the high-temperature and high-pressure mixed gas is cooled to high-pressure gas in the third heat exchanger by circulating water, the high-pressure gas enters the pressure swing adsorption separator to realize efficient separation of the mixed gas, pure hydrogen is obtained, the pure hydrogen is introduced into the hydrogen fuel cell, and the separated CO is returned to the combustion chamber to participate in combustion power generation.

4. The liquefied natural gas multi-energy coupling reforming hydrogen production and carbon capture utilization method according to claim 2, characterized in that: The dry ice preparation by LNG cold energy, the power generation by expansion of LNG gasification after pressure increase or the power generation by LNG combustion comprise: The LNG is heat-exchanged with high-pressure CO2 in the LNG heat exchanger, and then the LNG is heated and gasified to natural gas in the second heat exchanger by circulating water, the gas brought by the LNG gasification is expanded in the expander to generate power, and part of the natural gas enters the combustion chamber to generate power through the first control valve.

5. The method of claim 2, wherein the LNG multi-functional coupling reforming hydrogen production and carbon capture utilization method, The carbon capture by separating and recovering CO2 after LNG gasification combustion and preparing dry ice by LNG cold energy comprises: ​ Part of the natural gas is combusted in the combustion chamber to generate electricity, and its high-temperature flue gas can be introduced into a steam superheater to heat a water source, then into a fourth heat exchanger to be cooled by an external water source, and then introduced into a separator to separate liquid water and CO2. The separated CO2 is first combined with low-temperature backflow CO2 to achieve a pre-cooling state, compressed into high-pressure gas by a second compressor, introduced into an LNG heat exchanger to be heated by LNG to achieve a liquefied state, and then vaporized in a dry ice machine to produce dry ice. Part of the vaporized CO2 is backflowed to the front of the second compressor for pre-cooling and recirculation, and the remaining liquid CO2 is output as a dry ice product.

6. The method of claim 2, wherein the LNG multi-functional coupling reforming hydrogen production and carbon capture utilization method, It is characterized in that; The separation and recovery of the condensed water after the LNG gasification combustion, and the heating of the condensed water by the high-temperature flue gas include: The flue gas is introduced into a separator to separate liquid water and CO2, the separated liquid water is collected into a water storage tank, and the water is introduced into a steam superheater to be heated by the flue gas into high-temperature water vapor, and then introduced into a methane reforming reactor to participate in the reforming reaction to produce hydrogen.

7. The liquefied natural gas multi-energy coupling reforming hydrogen production and carbon capture utilization method of claim 2, characterized in that; The use of external water sources to absorb system waste heat to form a water resource cycle includes: The external water source enters the first heat exchanger through the first control valve, first exchanges heat with the high-temperature mixed gas, then enters the fourth heat exchanger to continue to absorb the waste heat in the flue gas, the temperature of the external water source is raised again, then the LNG is gasified into natural gas in the second heat exchanger, and then introduced into the third heat exchanger to exchange heat with the high-temperature high-pressure mixed gas, and the heat is brought back to the second heat exchanger before, realizing the cold and hot circulation of the system.

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