A hydrogen production and liquefaction device system and method based on LNG receiving station

Abstract

The present invention provides a hydrogen production and liquefaction device system and method based on an LNG receiving station, wherein the hydrogen production and liquefaction device system includes a hydrogen liquefaction and cold energy utilization section, a natural gas cold energy power generation and water electrolysis hydrogen production section, a natural gas hydrogen production section, a liquid hydrogen storage unit, and an LNG supply unit. The hydrogen production and liquefaction method includes independent hydrogen production and hydrogen liquefaction; the hydrogen production includes the following steps: LNG is reformed to produce hydrogen after cold energy utilization; the energy generated by cold energy utilization is used for water electrolysis to produce hydrogen; the hydrogen liquefaction includes sequentially performing H2-NG precooling, LNG precooling, liquid nitrogen precooling, and ultra-low temperature precooling. The present invention fully relies on a large amount of LNG cold energy in the LNG receiving station to realize the liquefaction and production of hydrogen, realizes the optimal matching of the LNG and hydrogen energy industry chain, reduces the cost of hydrogen production and liquefaction, and at the same time does not produce carbon dioxide, which is beneficial to environmental protection.

Description

Technical Field

[0001] The present invention belongs to the field of LNG cold energy utilization and hydrogen energy green technology, and specifically relates to LNG cold energy utilization, hydrogen production technology and hydrogen liquefaction technology, and especially relates to a hydrogen production and liquefaction system based on an LNG receiving station and a process method thereof. Background Art

[0002] In the future world energy development arena, hydrogen energy will play a vital role. As an energy carrier and energy interconnection medium, it has significant advantages of zero carbon and high efficiency. If hydrogen energy is widely used, it will promote global energy transformation and upgrading.

[0003] At present, the most important and influential part of the hydrogen energy industry chain is the production and transportation of hydrogen. There are five main technical routes for hydrogen production: hydrogen production from industrial tail gas, hydrogen production from chemical raw materials, hydrogen production from petrochemical raw materials, hydrogen production from water electrolysis, and new hydrogen production methods. The cost of hydrogen production from natural gas and coal is relatively low, becoming the core of short-term development of hydrogen energy. Hydrogen production from water electrolysis by renewable energy power generation is green hydrogen due to no carbon dioxide emissions, and is considered to be the ultimate solution for the future source of hydrogen production. Although the technology of hydrogen production from water electrolysis is relatively mature, and the hydrogen production efficiency can reach 70%, the cost of hydrogen production from water electrolysis is too high, and the main factor is the electricity price, which accounts for 78% of the total cost. Therefore, the decline in electricity prices will inevitably lead to a substantial reduction in hydrogen costs. However, the development of hydrogen energy in the near future still depends on fossil energy hydrogen production. Natural gas hydrogen production has high output, low processing costs, and low greenhouse gas emissions. Therefore, natural gas has become the main raw material for hydrogen production in many countries.

[0004] CN 112408323A discloses a natural gas hydrogen production device and method, the natural gas hydrogen production device includes a central transmission unit and a catalytic reaction unit arranged around it, the catalytic reaction unit is arranged with a reforming catalytic zone, a cooling zone and a conversion catalytic zone from bottom to top; the bottom of the natural gas hydrogen production device is provided with a combustion-supporting gas inlet; the top of the central transmission unit is provided with a raw gas inlet; the natural gas hydrogen production device is provided with a baffle; the center line of the baffle coincides with the center line of the natural gas hydrogen production device; the natural gas hydrogen production method includes: preheating the raw gas and passing it through the combustion zone of the combustion-supporting gas, and then successively obtaining hydrogen-rich gas through reforming reaction, cooling and conversion catalysis. Although the above method can produce hydrogen, the hydrogen is gaseous hydrogen, and there are great safety hazards in the transportation process of hydrogen, which is not used in the market.

[0005] CN 112301363A discloses a mobile hydrogen production device, which comprises a truck and a mobile hydrogen production box installed on the truck; a power distribution module, a water treatment and cooling water module, a water electrolysis hydrogen production module, and a hydrogen liquefaction module are installed in the mobile hydrogen production box; the power distribution module is connected to an external power supply line; the water treatment and cooling water module is respectively connected to an external water supply system and a water electrolysis hydrogen production module, and the clean electrolyzed water is sent to the water electrolysis hydrogen production module after impurity removal from the external water supply, and cooling water is provided for the water electrolysis hydrogen production module at the same time; the water electrolysis hydrogen production module is also connected to a hydrogen liquefaction module, and is used for transmitting the hydrogen produced by the water electrolysis hydrogen production module to the hydrogen liquefaction module for liquefaction; the device can effectively realize water electrolysis hydrogen production and hydrogen liquefaction, but an external circuit is required in the process of water electrolysis hydrogen production, which increases the hydrogen production cost in the process of water electrolysis hydrogen production, and the external circuit may have safety hazards.

[0006] CN 112391641A discloses a water electrolysis hydrogen production device and method, the device comprises a power generation system, a hot water circulation system and a water electrolysis hydrogen production system; the power generation system is used to heat water to produce water vapor, and use the water vapor to generate electricity; the water electrolysis hydrogen production system is used to use the electric energy provided by the power generation system to electrolyze water to produce hydrogen; the hot water circulation system is used to circulate the hot water after the power generation by the power generation system and recover the waste heat, and use the recovered waste heat to heat the circulated water, and then send the heated water to the heat exchanger for heating. The method described in the patent includes the following steps: (1) using a power generation system to heat water to produce water vapor, and using the water vapor to generate electricity; (2) using a water electrolysis hydrogen production system, and using the electricity provided by the power generation system to electrolyze water to produce hydrogen; (3) using a hot water recycling system to circulate and recover the hot water after the power generation of the power generation system and to heat the recycled water using the recovered waste heat, and then sending the heated water to the water electrolysis hydrogen production system as an electrolyte and to electrolyze water to produce hydrogen. The device can effectively realize the production of hydrogen by electrolysis of water, but the hydrogen is gaseous hydrogen, which is not easy to store; in addition, there are great safety hazards in the transportation of hydrogen, and the transportation cost is high.

[0007] Therefore, how to provide a low-cost, low-energy consumption method for producing and liquefying hydrogen has become a technical problem that urgently needs to be solved in this field. Summary of the invention

[0008] The purpose of the present invention is to provide a hydrogen production and liquefaction device system and method based on an LNG receiving station. The hydrogen production and liquefaction device system based on an LNG receiving station provided by the present invention fully relies on a large amount of LNG cold energy in the LNG receiving station to realize the liquefaction and production of hydrogen, realizes the optimal matching of the LNG and hydrogen energy industry chain, reduces the cost of hydrogen production and liquefaction, and at the same time does not produce carbon dioxide, which is beneficial to environmental protection.

[0009] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides a hydrogen production and liquefaction device system based on an LNG receiving station, the hydrogen production and liquefaction device system includes a hydrogen liquefaction and cold energy utilization section, a natural gas cold energy power generation and water electrolysis hydrogen production section, a natural gas hydrogen production section, a liquid hydrogen storage unit and an LNG supply unit;

[0011] The hydrogen liquefaction and cold energy utilization section includes H 2 -NG precooling unit, LNG precooling unit, liquid nitrogen precooling unit and ultra-low temperature precooling unit;

[0012] The natural gas cold energy power generation and water electrolysis hydrogen production section includes an LNG cold energy utilization power generation unit and a water electrolysis hydrogen production unit; the LNG cold energy utilization power generation unit is used to supply power to the water electrolysis hydrogen production unit;

[0013] The hydrogen outlet generated by the water electrolysis hydrogen production unit is connected to the H 2 -NG precooling unit connection;

[0014] The natural gas hydrogen production section comprises a natural gas reforming hydrogen production unit and a hydrogen purification precooling unit connected in sequence; the hydrogen outlet of the hydrogen purification precooling unit is connected to the H 2 -NG precooling unit connection;

[0015] The ultra-low temperature pre-cooling unit is connected to the liquid hydrogen storage unit via a throttle valve;

[0016] A para-ortho-hydrogen conversion reactor is arranged between the ultra-low temperature precooling unit and the throttle valve;

[0017] The LNG supply unit is independently connected to the LNG cold energy utilization power generation unit and the LNG precooling unit; the LNG flows into the water electrolysis hydrogen production unit after passing through the LNG cold energy utilization power generation unit; the LNG flows into the natural gas reforming hydrogen production unit after passing through the LNG precooling unit.

[0018] The H of the present invention 2 The NG precooling unit, the LNG precooling unit, the liquid nitrogen precooling unit and the ultra-low temperature precooling unit each independently include a para-ortho-hydrogen conversion reactor.

[0019] The working principle of the LNG cold energy utilization power generation unit of the present invention is: LNG realizes cold energy power generation by using a refrigerant; the refrigerant includes ethane, propane or butane. The present invention realizes cold energy power generation in the LNG cold energy utilization power generation unit by relying on the cold energy provided by the LNG supply unit, which can be directly supplied to the water electrolysis hydrogen production unit in the device system to realize the production of hydrogen.

[0020] Preferably, excess hydrogen generated by endothermic vaporization of liquid hydrogen in the liquid hydrogen storage unit is returned to the para-ortho-hydrogen conversion reactor, and after being reprocessed, flows into the liquid hydrogen storage unit via a throttle valve.

[0021] Preferably, the hydrogen production and liquefaction device system further includes a heat exchange unit.

[0022] Preferably, the LNG flows sequentially through the LNG pre-cooling unit, H 2 -NG pre-cooling unit and heat exchange unit before flowing into the natural gas reforming hydrogen production unit.

[0023] Preferably, the hydrogen produced by the natural gas reforming hydrogen production unit flows through the heat exchange unit as a heat source and then flows into the hydrogen purification precooling unit.

[0024] The present invention passes through the LNG precooling unit and H 2 -The LNG from the NG precooling unit flows into the heat exchange unit as a cold source, and after being processed by the heat exchange unit, part of it flows into the natural gas reforming hydrogen production unit, and part of it directly returns to the NG external transmission system. The present invention does not specifically limit the flow rate of the LNG flowing into the natural gas reforming hydrogen production unit. The flow rate of the LNG flowing into the natural gas reforming hydrogen production unit is mainly determined according to the scale of hydrogen production and the scale of cold energy power generation, while ensuring the heat exchange balance of the heat exchange unit.

[0025] Preferably, the hydrogen production and liquefaction device system also includes an LNG cold energy air separation unit.

[0026] Preferably, the byproduct oxygen pipeline of the water electrolysis hydrogen production unit is connected to the LNG cold energy air separation unit.

[0027] Preferably, the refrigerant source of the LNG cold energy air separation unit is an LNG supply unit.

[0028] In a second aspect, the present invention provides a method for producing and liquefying hydrogen based on an LNG receiving station, wherein the method for producing and liquefying hydrogen includes independently performing hydrogen production and hydrogen liquefaction.

[0029] Preferably, the hydrogen production comprises the following steps: LNG is reformed to produce hydrogen after being utilized for cold energy; and the energy generated by the utilization of cold energy is used for electrolysis of water to produce hydrogen.

[0030] The LNG of the present invention is reformed to produce hydrogen after cold energy utilization, and the energy generated by cold energy utilization is used to electrolyze water to produce hydrogen. The purity of the produced hydrogen is ≥ 99.7%, and it does not contain CO, H 2 S.

[0031] Preferably, the hydrogen liquefaction comprises sequentially carrying out 2 -NG pre-cooling, LNG pre-cooling, liquid nitrogen pre-cooling and ultra-low temperature pre-cooling.

[0032] Preferably, the hydrogen after ultra-low temperature pre-cooling enters the para-ortho-hydrogen conversion reactor, and the hydrogen passing through the para-ortho-hydrogen conversion reactor is stored in a liquid hydrogen storage unit.

[0033] Preferably, the hydrogen is passed through H 2 -NG is pre-cooled and cooled to -50°C to -30°C, for example, -50°C, -45°C, -40°C, -35°C or -30°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0034] Preferably, the hydrogen is cooled to -155°C to -135°C after LNG pre-cooling, for example, it can be -155°C, -150°C, -145°C, -140°C or -135°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0035] Preferably, the hydrogen is pre-cooled with liquid nitrogen and cooled to -190°C to -185°C, for example, -190°C, -189°C, -188°C, -187°C, -186°C or -185°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0036] Preferably, the hydrogen is cooled to -250°C to -243°C after ultra-low temperature pre-cooling, for example, it can be -250°C, -249°C, -248°C, -247°C, -246°C, -245°C, -244°C or -243°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0037] Preferably, the cold source used by the liquid nitrogen precooling unit comes from an LNG cold energy air separation unit.

[0038] Preferably, the pressure in the liquid nitrogen pre-cooling unit is 0.6MPag-1.0MPag, for example, it can be 0.6MPag, 0.7MPag, 0.8MPag, 0.9MPag or 1.0MPag, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0039] Preferably, the cold energy source for the ultra-low temperature pre-cooling includes liquid hydrogen gasification, liquid hydrogen, an external hydrogen expansion cycle or a helium expansion refrigeration cycle.

[0040] Preferably, the supply pressure of LNG is 2 MPag-6 MPag, for example, it can be 2 MPag, 3 MPag, 4 MPag, 5 MPag or 6 MPag, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0041] Preferably, the supply temperature of LNG is -160°C to -145°C, for example, it can be -160°C, -158°C, -156°C, -154°C, -152°C, -150°C, -148°C or -145°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0042] Preferably, the temperature of the liquid nitrogen pre-cooling unit is -196°C to -190°C, for example, it can be -196°C, -195°C, -194°C, -193°C, -192°C, -191°C or -190°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0043] As a preferred technical solution of the present invention, the hydrogen production and liquefaction method comprises independently performing hydrogen production and hydrogen liquefaction;

[0044] The hydrogen production comprises the following steps: LNG is reformed to produce hydrogen after being subjected to cold energy utilization; the energy generated by the cold energy utilization is used to electrolyze water to produce hydrogen;

[0045] The hydrogen liquefaction comprises the following steps: 2 -NG precooling, LNG precooling, liquid nitrogen precooling and ultra-low temperature precooling; the hydrogen after ultra-low temperature precooling enters the para-ortho-hydrogen conversion reactor, and the hydrogen after the para-ortho-hydrogen conversion reactor is stored in the liquid hydrogen storage unit; the hydrogen is precooled by H 2 -NG is pre-cooled to -50℃ to -30℃; hydrogen is pre-cooled to -155℃ to -135℃ after LNG; hydrogen is pre-cooled to -190℃ to -185℃ after liquid nitrogen; hydrogen is pre-cooled to -250℃ to -243℃ after ultra-low temperature pre-cooling; the cold source used for liquid nitrogen pre-cooling comes from the LNG cold energy air separation unit.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] The hydrogen production and liquefaction device system based on the LNG receiving station provided by the present invention fully relies on the large amount of LNG cold energy in the LNG receiving station to realize the liquefaction and production of hydrogen, realizes the optimal matching of the LNG and hydrogen energy industry chains, reduces the hydrogen production cost and liquefaction cost, and at the same time does not produce carbon dioxide, which is beneficial to environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a device diagram of a hydrogen production and liquefaction system based on an LNG receiving station of the present invention;

[0049] Among them, 1 is the hydrogen liquefaction and cold energy utilization section; 2 is the natural gas cold energy power generation and water electrolysis hydrogen production section; 3 is the natural gas hydrogen production section; 1-1 is H 2 -NG precooling unit; 1-2 is LNG precooling unit; 1-3 is liquid nitrogen precooling unit; 1-4 is ultra-low temperature precooling unit; 2-1 is LNG cold energy utilization power generation unit; 2-2 is water electrolysis hydrogen production unit; 3-1 is natural gas reforming hydrogen production unit; 3-2 is hydrogen purification precooling unit; 4 is LNG supply unit; 5 is LNG cold energy air separation unit; 6 is heat exchange unit; 7 is para-ortho hydrogen conversion reactor; 8 is throttle valve; 9 is liquid hydrogen storage unit. DETAILED DESCRIPTION

[0050] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0051] The LNG used in the specific implementation of the present invention is the same LNG, and its supply pressure is 6MPag and the supply temperature is -150°C. The composition of the LNG is shown in the following table:

[0052] Components <![CDATA[CH 4 ]]> <![CDATA[C 2 H 6 ]]> <![CDATA[C 3 H 8 ]]> <![CDATA[C 4 H 10 ]]> <![CDATA[C 5 H 12 ]]> <![CDATA[N 2 ]]> S content(%) 97.032 2.014 0.346 0.200 0.25 0.10 0.058

[0053] Example 1

[0054] This embodiment provides a hydrogen production and liquefaction device system based on an LNG receiving station, such as Figure 1 As shown, it includes a hydrogen liquefaction and cold energy utilization section 1, a natural gas cold energy power generation and water electrolysis hydrogen production section 2, a natural gas hydrogen production section 3, a liquid hydrogen storage unit 9 and an LNG supply unit 4;

[0055] The hydrogen liquefaction and cold energy utilization section 1 includes H 2 -NG precooling unit 1-1, LNG precooling unit 1-2, liquid nitrogen precooling unit 1-3 and ultra-low temperature precooling unit 1-4;

[0056] The natural gas cold energy power generation and water electrolysis hydrogen production section 2 includes an LNG cold energy utilization power generation unit 2-1 and a water electrolysis hydrogen production unit 2-2; the LNG cold energy utilization power generation unit 2-1 is used to supply power to the water electrolysis hydrogen production unit 2-2;

[0057] The hydrogen outlet generated by the water electrolysis hydrogen production unit 2-2 is connected to the H 2 -NG precooling unit 1-1 connection;

[0058] The natural gas hydrogen production section 3 comprises a natural gas reforming hydrogen production unit 3-1 and a hydrogen purification precooling unit 3-2 connected in sequence; the hydrogen outlet of the hydrogen purification precooling unit 3-2 is connected to the hydrogen outlet of the hydrogen purification precooling unit 3-2. 2 -NG precooling unit 1-1 connection;

[0059] The ultra-low temperature pre-cooling unit 1-4 is connected to the liquid hydrogen storage unit 9 via a throttle valve 8;

[0060] A para-ortho-hydrogen conversion reactor 7 is provided between the ultra-low temperature pre-cooling unit 1-4 and the throttle valve 8;

[0061] The LNG supply unit 4 is independently connected to the LNG cold energy utilization power generation unit 2-1 and the LNG precooling unit 1-2; LNG flows through the LNG cold energy utilization power generation unit 2-1 and then flows into the water electrolysis hydrogen production unit 2-2; LNG flows through the LNG precooling unit 1-2 and then flows into the natural gas reforming hydrogen production unit 3-1.

[0062] The hydrogen production and liquefaction device system also includes a heat exchange unit 6;

[0063] LNG flows through LNG precooling unit 1-2, H 2 -NG precooling unit 1-1 and heat exchange unit 6 flow into natural gas reforming hydrogen production unit 3-1;

[0064] The hydrogen produced by the natural gas reforming hydrogen production unit 3 - 1 flows through the heat exchange unit 6 as a heat source and then flows into the hydrogen purification precooling unit 3 - 2 .

[0065] The hydrogen production and liquefaction device system also includes an LNG cold energy air separation unit 5;

[0066] The byproduct oxygen pipeline of the water electrolysis hydrogen production unit 3-2 is connected to the LNG cold energy air separation unit 5;

[0067] The refrigerant source of the LNG cold energy air separation unit 5 is the LNG supply unit 4 .

[0068] Using the hydrogen production and liquefaction device system based on the LNG receiving station provided in this embodiment, the hydrogen production and liquefaction method includes independently performing hydrogen production and hydrogen liquefaction.

[0069] The hydrogen production comprises the following steps: LNG is reformed to produce hydrogen after being utilized for cold energy; and the energy generated by the utilization of cold energy is used for electrolyzing water to produce hydrogen.

[0070] The hydrogen liquefaction comprises the following steps: 2 -NG pre-cooling, LNG pre-cooling, liquid nitrogen pre-cooling and ultra-low temperature pre-cooling; hydrogen is pre-cooled by H 2-NG is cooled to -50°C after pre-cooling; hydrogen is cooled to -155°C after pre-cooling by LNG; hydrogen is cooled to -190°C after pre-cooling by liquid nitrogen; hydrogen is cooled to -250°C after ultra-low temperature pre-cooling; the cold source used for liquid nitrogen pre-cooling comes from the LNG cold energy air separation unit.

[0071] The hydrogen gas pre-cooled at ultra-low temperature is introduced into the para-ortho-hydrogen conversion reactor 7 and then stored in the liquid hydrogen storage unit 9 through the throttle valve 8.

[0072] The cold source used by the liquid nitrogen pre-cooling units 1-3 comes from the LNG cold energy air separation unit 5.

[0073] The liquid nitrogen pressure in the liquid nitrogen precooling unit 1-3 is 1.0 MPag.

[0074] The temperature of the liquid nitrogen pre-cooling unit 1-3 is -196°C.

[0075] The cold source of the ultra-low temperature pre-cooling unit 1-4 comes from the gasification of liquid hydrogen.

[0076] In this embodiment, the purity of hydrogen obtained by reforming LNG to produce hydrogen after cold energy utilization is 99.78%, and the purity of hydrogen obtained by electrolyzing water to produce hydrogen after the energy generated by cold energy utilization is 99.82%. This embodiment fully relies on LNG cold energy to achieve hydrogen production and hydrogen liquefaction, reducing the cost of hydrogen production, and no toxic and harmful gases are emitted during the hydrogen production and liquefaction process, which is beneficial to environmental protection.

[0077] Example 2

[0078] The hydrogen production and liquefaction device system based on the LNG receiving station provided in Application Example 1, the hydrogen production and liquefaction method includes independent hydrogen production and hydrogen liquefaction.

[0079] The hydrogen production comprises the following steps: LNG is reformed to produce hydrogen after being utilized for cold energy; and the energy generated by the utilization of cold energy is used for electrolyzing water to produce hydrogen.

[0080] The hydrogen liquefaction comprises the following steps: 2 -NG pre-cooling, LNG pre-cooling, liquid nitrogen pre-cooling and ultra-low temperature pre-cooling; hydrogen is pre-cooled by H 2 -NG is pre-cooled to -30℃; hydrogen is pre-cooled to -135℃ after LNG; hydrogen is pre-cooled to -185℃ after liquid nitrogen; hydrogen is pre-cooled to -243℃ after ultra-low temperature pre-cooling.

[0081] The hydrogen gas pre-cooled at ultra-low temperature is introduced into the para-ortho-hydrogen conversion reactor 7, and then flows to the liquid hydrogen storage unit 9 through the throttle valve 8.

[0082] The cold source used by the liquid nitrogen pre-cooling units 1-3 comes from the LNG cold energy air separation unit 5.

[0083] The liquid nitrogen pressure in the liquid nitrogen precooling unit 1-3 is 0.8 MPag.

[0084] The temperature of the liquid nitrogen pre-cooling unit 1-3 is -190°C.

[0085] The cooling source of the ultra-low temperature pre-cooling unit 1-4 comes from the liquid hydrogen gasification

[0086] This embodiment fully relies on LNG cold energy to realize hydrogen production and hydrogen liquefaction, which reduces the cost of hydrogen production, and no toxic and harmful gases are emitted during the hydrogen production and liquefaction process, which is beneficial to environmental protection.

[0087] Example 3

[0088] The hydrogen production and liquefaction device system based on the LNG receiving station provided in Application Example 1, the hydrogen production and liquefaction method includes independent hydrogen production and hydrogen liquefaction.

[0089] The hydrogen production comprises the following steps: LNG is reformed to produce hydrogen after being utilized for cold energy; and the energy generated by the utilization of cold energy is used for electrolyzing water to produce hydrogen.

[0090] The hydrogen liquefaction comprises the following steps: 2 -NG pre-cooling, LNG pre-cooling, liquid nitrogen pre-cooling and ultra-low temperature pre-cooling; hydrogen is pre-cooled by H 2 -NG is pre-cooled to -40℃; hydrogen is pre-cooled to -145℃ after LNG; hydrogen is pre-cooled to -190℃ after liquid nitrogen; hydrogen is pre-cooled to -248℃ after ultra-low temperature pre-cooling.

[0091] The hydrogen gas pre-cooled at ultra-low temperature is introduced into the para-ortho-hydrogen conversion reactor 7, and then flows to the liquid hydrogen storage unit 9 through the throttle valve 8.

[0092] The cold source used by the liquid nitrogen pre-cooling units 1-3 comes from the LNG cold energy air separation unit 5.

[0093] The liquid nitrogen pressure in the liquid nitrogen precooling unit 1-3 is 0.6 MPag.

[0094] The temperature of the liquid nitrogen pre-cooling unit 1-3 is -196°C.

[0095] The cold source of the ultra-low temperature pre-cooling unit 1-4 comes from the external hydrogen expansion cycle.

[0096] This embodiment fully relies on LNG cold energy to realize hydrogen production and hydrogen liquefaction, which reduces the cost of hydrogen production, and no toxic and harmful gases are emitted during the hydrogen production and liquefaction process, which is beneficial to environmental protection.

[0097] Example 4

[0098] The hydrogen production and liquefaction device system based on the LNG receiving station provided in Application Example 1, the hydrogen production and liquefaction method includes independent hydrogen production and hydrogen liquefaction.

[0099] The hydrogen production comprises the following steps: LNG is reformed to produce hydrogen after being utilized for cold energy; and the energy generated by the utilization of cold energy is used for electrolyzing water to produce hydrogen.

[0100] The hydrogen liquefaction comprises the following steps: 2 -NG pre-cooling, LNG pre-cooling, liquid nitrogen pre-cooling and ultra-low temperature pre-cooling; hydrogen is pre-cooled by H 2 -NG is pre-cooled to -45℃; hydrogen is pre-cooled to -148℃ after LNG; hydrogen is pre-cooled to -188℃ after liquid nitrogen; hydrogen is pre-cooled to -245℃ after ultra-low temperature pre-cooling.

[0101] The hydrogen gas pre-cooled at ultra-low temperature is introduced into the para-ortho-hydrogen conversion reactor 7, and then flows to the liquid hydrogen storage unit 9 through the throttle valve 8.

[0102] The cold source used by the liquid nitrogen pre-cooling units 1-3 comes from the LNG cold energy air separation unit 5.

[0103] The liquid nitrogen pressure in the liquid nitrogen precooling unit 1-3 is 0.9 MPag.

[0104] The temperature of the liquid nitrogen precooling unit 1-3 is -194°C.

[0105] The cold source of the ultra-low temperature pre-cooling unit 1-4 comes from the helium expansion refrigeration cycle.

[0106] This embodiment fully relies on LNG cold energy to realize hydrogen production and hydrogen liquefaction, which reduces the cost of hydrogen production, and no toxic and harmful gases are emitted during the hydrogen production and liquefaction process, which is beneficial to environmental protection.

[0107] Example 5

[0108] The only difference between this embodiment and embodiment 1 is that the step of producing hydrogen only includes reforming LNG to produce hydrogen after utilizing cold energy.

[0109] This embodiment fully relies on LNG cold energy to realize hydrogen production and hydrogen liquefaction, which reduces the cost of hydrogen production, and no toxic and harmful gases are emitted during the hydrogen production and liquefaction process, which is beneficial to environmental protection.

[0110] Example 6

[0111] The only difference between this embodiment and embodiment 1 is that the step of producing hydrogen only includes using the energy generated by cold energy to electrolyze water to produce hydrogen.

[0112] This embodiment fully relies on LNG cold energy to realize hydrogen production and hydrogen liquefaction, which reduces the cost of hydrogen production, and no toxic and harmful gases are emitted during the hydrogen production and liquefaction process, which is beneficial to environmental protection.

[0113] In summary, the hydrogen production and liquefaction device system based on the LNG receiving station provided by the present invention fully relies on the large amount of LNG cold energy in the LNG receiving station to realize the liquefaction and production of hydrogen, realizes the optimal matching of the LNG and hydrogen energy industry chain, reduces the cost of hydrogen production and liquefaction, and at the same time does not produce carbon dioxide, which is beneficial to environmental protection. The purity of hydrogen produced by the hydrogen production and liquefaction device system based on the LNG receiving station provided by the present invention is above 99.7%.

[0114] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A hydrogen production and liquefaction device system based on an LNG receiving station, characterized in that: The hydrogen production and liquefaction device system includes a hydrogen liquefaction and cold energy utilization section, a natural gas cold energy power generation and water electrolysis hydrogen production section, a natural gas hydrogen production section, a liquid hydrogen storage unit and an LNG supply unit; The hydrogen liquefaction and cold energy utilization section includes an H2-NG precooling unit, an LNG precooling unit, a liquid nitrogen precooling unit and an ultra-low temperature precooling unit connected in sequence; The natural gas cold energy power generation and water electrolysis hydrogen production section includes an LNG cold energy utilization power generation unit and a water electrolysis hydrogen production unit; the LNG cold energy utilization power generation unit is used to supply power to the water electrolysis hydrogen production unit; The hydrogen outlet generated by the water electrolysis hydrogen production unit is connected to the H2-NG precooling unit; The natural gas hydrogen production section comprises a natural gas reforming hydrogen production unit and a hydrogen purification precooling unit connected in sequence; the hydrogen outlet of the hydrogen purification precooling unit is connected to the H2-NG precooling unit; The ultra-low temperature pre-cooling unit is connected to the liquid hydrogen storage unit via a throttle valve; A para-ortho-hydrogen conversion reactor is arranged between the ultra-low temperature precooling unit and the throttle valve; The LNG supply unit is independently connected to the LNG cold energy utilization power generation unit and the LNG precooling unit; the LNG flows through the LNG cold energy utilization power generation unit and then flows into the water electrolysis hydrogen production unit; the LNG flows through the LNG precooling unit and then flows into the natural gas reforming hydrogen production unit; The hydrogen production and liquefaction device system also includes a heat exchange unit; LNG flows through the LNG precooling unit, H2-NG precooling unit and heat exchange unit in sequence and then flows into the natural gas reforming hydrogen production unit; The hydrogen produced by the natural gas reforming hydrogen production unit flows through the heat exchange unit as a heat source and then flows into the hydrogen purification precooling unit.

2. The hydrogen production and liquefaction device system according to claim 1, characterized in that: The hydrogen production and liquefaction device system also includes an LNG cold energy air separation unit; The byproduct oxygen pipeline of the water electrolysis hydrogen production unit is connected to the LNG cold energy air separation unit.

3. A method for producing and liquefying hydrogen based on an LNG receiving station, characterized in that: The hydrogen production and liquefaction method is carried out in the hydrogen production and liquefaction device system according to claim 1 or 2.

4. The method for producing and liquefying hydrogen according to claim 3, characterized in that: The hydrogen production and liquefaction method includes independently performing hydrogen production and hydrogen liquefaction.

5. The method for producing and liquefying hydrogen according to claim 4, characterized in that: The hydrogen production comprises the following steps: LNG is reformed to produce hydrogen after being utilized for cold energy; and the energy generated by the utilization of cold energy is used for electrolyzing water to produce hydrogen.

6. The method for producing and liquefying hydrogen according to claim 4, characterized in that: The hydrogen liquefaction includes sequentially performing H2-NG precooling, LNG precooling, liquid nitrogen precooling and ultra-low temperature precooling; The hydrogen after ultra-low temperature pre-cooling enters the para-ortho-hydrogen conversion reactor, and the hydrogen passing through the para-ortho-hydrogen conversion reactor is stored in the liquid hydrogen storage unit.

7. The method for producing and liquefying hydrogen according to claim 6, characterized in that: The hydrogen is pre-cooled by H2-NG and cooled to -50℃ to -30℃.

8. The method for producing and liquefying hydrogen according to claim 6, characterized in that: The hydrogen is pre-cooled by LNG and cooled to -155℃ to -135℃.

9. The method for producing and liquefying hydrogen according to claim 6, characterized in that: The hydrogen is pre-cooled with liquid nitrogen and cooled to -190°C to -185°C.

10. The method for producing and liquefying hydrogen according to claim 6, characterized in that: The hydrogen is pre-cooled at ultra-low temperature and then cooled to -250℃ to -243℃.

11. The method for producing and liquefying hydrogen according to claim 6, characterized in that: The cold source used by the liquid nitrogen precooling unit comes from the LNG cold energy air separation unit.

12. The method for producing and liquefying hydrogen according to claim 6, characterized in that: The liquid nitrogen pressure in the liquid nitrogen precooling unit is 0.6MPag-1.0MPag.

13. The method for producing and liquefying hydrogen according to claim 6, characterized in that: The temperature of the liquid nitrogen precooling unit is -196°C to -190°C.

14. The method for producing and liquefying hydrogen according to claim 5, characterized in that: The supply pressure of LNG is 2MPag-6MPag.

15. The method for producing and liquefying hydrogen according to claim 5, characterized in that: The supply temperature of the LNG is -160°C to -145°C.

16. The method for producing and liquefying hydrogen according to claim 5, characterized in that: The hydrogen production and liquefaction method comprises independently performing hydrogen production and hydrogen liquefaction; The hydrogen production comprises the following steps: LNG is reformed to produce hydrogen after being subjected to cold energy utilization; the energy generated by the cold energy utilization is used to electrolyze water to produce hydrogen; The hydrogen liquefaction includes H2-NG precooling, LNG precooling, liquid nitrogen precooling and ultra-low temperature precooling in sequence; the hydrogen after ultra-low temperature precooling enters the para-ortho-hydrogen conversion reactor, and the hydrogen after the para-ortho-hydrogen conversion reactor is stored in the liquid hydrogen storage unit; the hydrogen is cooled to -50°C to -30°C after H2-NG precooling; the hydrogen is cooled to -155°C to -135°C after LNG precooling; the hydrogen is cooled to -190°C to -185°C after liquid nitrogen precooling; the hydrogen is cooled to -250°C to -243°C after ultra-low temperature precooling; the cold source used for the liquid nitrogen precooling comes from the LNG cold energy air separation unit.

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