An apparatus system and method for coupling hydrogen production and ammonia synthesis

Abstract

The present invention provides a device system and method for coupling hydrogen production and ammonia synthesis. The device system includes a hydrogen purification unit, an ammonia synthesis unit, and an energy transfer unit. The energy transfer unit is used to recover the energy generated in the ammonia synthesis unit and transfer the recovered energy to the hydrogen purification unit for reuse. The method includes using hydrogen as a medium to transfer the energy generated in the ammonia synthesis process to the hydrogen purification process. The device system provided by the present invention deeply couples the hydrogen production process and the ammonia synthesis process, reduces the device energy consumption of the system, reduces the energy loss of the system, and is conducive to large-scale promotion and application.

Description

Technical Field

[0001] The present invention belongs to the technical field of green chemical engineering, and relates to a device system for coupling hydrogen production and ammonia synthesis, and particularly to a device system and method for coupling hydrogen production and ammonia synthesis. Background Art

[0002] Hydrogen energy has gradually become a current research hotspot due to its many advantages such as high calorific value, zero emissions, pollution-free, and wide application. However, due to the small density and high danger of hydrogen, it has problems of difficult storage and transportation. Ammonia, as one of the most basic raw materials in modern chemical and agricultural production, is relatively easy to store and transport, and its production process generally involves a synthesis reaction of hydrogen and nitrogen. Therefore, synthesizing ammonia from hydrogen is one of the effective methods to solve the problem of hydrogen energy storage and transportation.

[0003] In this regard, some technical personnel combine the electrolytic water hydrogen production technology with the ammonia synthesis technology, and couple clean energy power generation. While achieving zero-carbon hydrogen production, hydrogen energy is stored and transported in the form of liquid ammonia, thus effectively solving the problem of difficult hydrogen energy storage and transportation.

[0004] However, although the above technology realizes the combination of hydrogen production and ammonia synthesis processes to convert hydrogen into ammonia, it only uses the hydrogen produced by the hydrogen production system as the raw material gas for ammonia synthesis, and does not further couple and optimize the two processes and two systems, resulting in high device energy consumption and energy loss in the device.

[0005] Therefore, how to provide a device system and method for coupling hydrogen production and ammonia synthesis to achieve deep coupling of the hydrogen production process and the ammonia synthesis process, thereby reducing the device energy consumption of the system and reducing the energy loss of the system has become an urgent problem to be solved by those skilled in the art at present. Summary of the Invention

[0006] The purpose of the present invention is to provide a device system and method for coupling hydrogen production and ammonia synthesis. The device system deeply couples the hydrogen production process and the ammonia synthesis process, reduces the device energy consumption of the system, reduces the energy loss of the system, and is conducive to large-scale popularization and application.

[0007] To achieve the purpose of this invention, the present invention adopts the following technical solutions:

[0008] In the first aspect, the present invention provides a device system for coupling hydrogen production and ammonia synthesis. The device system includes a hydrogen purification unit, an ammonia synthesis unit, and an energy transfer unit.

[0009] The energy transfer unit is used to recover the energy generated in the ammonia synthesis unit and transfer the recovered energy to the hydrogen purification unit for reuse.

[0010] The device system provided by the present invention realizes the deep coupling between the hydrogen purification process and the ammonia synthesis process in the hydrogen production process by setting an energy transfer unit to transfer the energy generated by the ammonia synthesis unit to the hydrogen purification unit for reuse, thereby reducing the device energy consumption of the system, reducing the energy loss of the system, and being conducive to large-scale popularization and application.

[0011] Preferably, the hydrogen purification unit includes a hydrogen gas-liquid separator and a drying tower.

[0012] Preferably, the ammonia synthesis unit includes an ammonia synthesizer and an ammonia gas-liquid separator.

[0013] Preferably, the ammonia synthesizer is used to carry out the ammonia synthesis reaction to generate reaction gas.

[0014] Preferably, the ammonia gas-liquid separator is used to carry out gas-liquid separation on the reaction gas to generate recycle gas.

[0015] Preferably, the energy transfer unit includes a heat transfer sub-unit and / or a cold energy transfer sub-unit.

[0016] Preferably, the heat transfer sub-unit is used to transfer the heat of the reaction gas to the drying tower for heating and regeneration of the drying tower.

[0017] Preferably, the cold energy transfer sub-unit is used to transfer the cold energy of the recycle gas to the drying tower for cold tower treatment of the drying tower.

[0018] Preferably, the heat transfer sub-unit includes a reaction gas-purified regeneration gas heat exchanger.

[0019] Preferably, the cold energy transfer sub-unit includes a purified regeneration gas-recycle gas heat exchanger.

[0020] Optionally, the outlet of the reaction gas-purified regeneration gas heat exchanger and the cold flow inlet are respectively connected to the drying tower, and the hot flow inlet is connected to the ammonia synthesizer, so as to transfer the heat generated in the ammonia synthesis process to the hydrogen purification process by using the purified hydrogen as a medium.

[0021] Optionally, the outlet and the hot flow inlet of the purified regeneration gas-recycle gas heat exchanger are respectively connected to the drying tower, and the cold flow inlet is connected to the ammonia gas-liquid separator, so as to transfer the cold energy generated in the ammonia synthesis process to the hydrogen purification process by using the purified hydrogen as a medium.

[0022] Optionally, the outlet of the reaction gas-purified regeneration gas heat exchanger is connected to the drying tower, the cold flow inlet is connected to the hydrogen gas-liquid separator, and the hot flow inlet is connected to the ammonia synthesizer, so as to transfer the heat generated in the ammonia synthesis process to the hydrogen purification process by using the hydrogen before purification as a medium.

[0023] Optionally, the outlet of the purified regeneration gas - recycle gas heat exchanger is connected to the drying tower, the cold - stream inlet is connected to the ammonia gas - liquid separator, and the hot - stream inlet is connected to the hydrogen gas - liquid separator, so as to transfer the cold energy generated in the ammonia synthesis process to the hydrogen purification process by using the hydrogen before purification as the medium.

[0024] In the present invention, the heat transfer sub - unit further includes a reaction gas - mixed gas heat exchanger, which is used to transfer the heat of the reaction gas to the raw material mixed gas for subsequent ammonia synthesis reaction.

[0025] In the present invention, the cold energy transfer sub - unit further includes a reaction gas - recycle gas heat exchanger, which is used to transfer the cold energy of the recycle gas to the reaction gas for subsequent gas - liquid separation.

[0026] Preferably, the device system further includes a hydrogen production unit.

[0027] Preferably, the hydrogen production unit includes a renewable energy power supply sub - unit and an electrolyzer.

[0028] Preferably, the renewable energy power supply sub - unit is used to provide the required electric energy for the device system.

[0029] Preferably, the electrolyzer is used to provide hydrogen for the hydrogen purification unit.

[0030] In the present invention, the electric energy source of the renewable energy power supply sub - unit includes any one or a combination of at least two of wind power generation, photovoltaic power generation or hydro - power generation.

[0031] In a second aspect, the present invention provides a method for coupling hydrogen production and ammonia synthesis using the device system as described in the first aspect. The method includes: using hydrogen as the medium to transfer the energy generated in the ammonia synthesis process to the hydrogen purification process.

[0032] Preferably, the hydrogen includes hydrogen before purification and / or hydrogen after purification.

[0033] Preferably, the transfer mode of the energy includes heat transfer and / or cold energy transfer.

[0034] Preferably, the heat transfer includes: using hydrogen as the medium to transfer the heat of the reaction gas in the ammonia synthesis process to the hydrogen purification process for heating and regeneration of the drying tower.

[0035] Preferably, the cold energy transfer includes: using hydrogen as the medium to transfer the cold energy of the recycle gas in the ammonia synthesis process to the hydrogen purification process for cold - tower treatment of the drying tower.

[0036] Preferably, the hydrogen is used as the raw material gas for the ammonia synthesis process for ammonia synthesis reaction after the energy transfer.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The device system provided by the present invention realizes deep coupling between the hydrogen production process and the ammonia synthesis process by setting an energy transfer unit to transfer the energy generated by the ammonia synthesis unit to the hydrogen purification unit for reuse, thereby reducing the device energy consumption of the system, reducing the energy loss of the system, and being conducive to large-scale popularization and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a schematic diagram of the device system provided by the present invention;

[0040] Figure 2 is a flowchart of the method provided by the present invention;

[0041] Figure 3 is a schematic flow diagram of the hydrogen production unit in the device system provided in Embodiment 1;

[0042] Figure 4 is a schematic flow diagram of the hydrogen purification unit, ammonia synthesis unit, and energy transfer unit in the device system provided in Embodiment 1.

[0043] Wherein: 10 - hydrogen production unit; 11 - power supply; 12 - electrolytic cell; 13 - oxygen gas-liquid separator; 14 - hydrogen gas-liquid separator; 15 - oxygen gas-water separator; 16 - first hydrogen gas-water separator; 17 - pure water tank; 20 - hydrogen purification unit; 21 - hydrogen buffer tank; 22 - deoxidation tower; 23 - second hydrogen gas-water separator; 24 - drying tower; 25 - regeneration gas separator; 30 - ammonia synthesis unit; 31 - mixed gas compressor; 32 - mixed gas separator; 33 - ammonia synthesizer; 34 - ammonia gas-liquid separator; 35 - cooler; 40 - energy transfer unit; 41 - reaction gas - purified regeneration gas heat exchanger; 42 - purified regeneration gas - recycle gas heat exchanger; 43 - reaction gas - mixed gas heat exchanger; 44 - reaction gas - recycle gas heat exchanger. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0044] The technical solution of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0045] The present invention provides a device system for coupling hydrogen production and ammonia synthesis, as Figure 1 shown, the device system includes a hydrogen purification unit 20, an ammonia synthesis unit 30, and an energy transfer unit 40; the energy transfer unit 40 is used to recover the energy generated in the ammonia synthesis unit 30 and transfer the recovered energy to the hydrogen purification unit 20 for reuse.

[0046] Specifically, the hydrogen purification unit 20 includes a hydrogen gas-liquid separator and a drying tower; the ammonia synthesis unit 30 includes an ammonia synthesizer and an ammonia gas-liquid separator; wherein, the ammonia synthesizer is used to carry out an ammonia synthesis reaction to generate a reaction gas, and the ammonia gas-liquid separator is used to carry out gas-liquid separation on the reaction gas to generate a recycle gas. The energy transfer unit 40 includes a heat transfer sub-unit and / or a cold transfer sub-unit; the heat transfer sub-unit is used to transfer the heat of the reaction gas to the drying tower for heating and regeneration of the drying tower; the cold transfer sub-unit is used to transfer the cold of the recycle gas to the drying tower for cold tower treatment of the drying tower. The heat transfer sub-unit includes a reaction gas-purified regeneration gas heat exchanger, and the cold transfer sub-unit includes a purified regeneration gas-recycle gas heat exchanger.

[0047] Wherein, the outlet and the cold stream inlet of the reaction gas-purified regeneration gas heat exchanger are respectively connected to the drying tower, and the hot stream inlet is connected to the ammonia synthesizer; the outlet and the hot stream inlet of the purified regeneration gas-recycle gas heat exchanger are respectively connected to the drying tower, and the cold stream inlet is connected to the ammonia gas-liquid separator.

[0048] Alternatively, the outlet of the reaction gas-purified regeneration gas heat exchanger is connected to the drying tower, the cold stream inlet is connected to the hydrogen gas-liquid separator, and the hot stream inlet is connected to the ammonia synthesizer; the outlet of the purified regeneration gas-recycle gas heat exchanger is connected to the drying tower, the cold stream inlet is connected to the ammonia gas-liquid separator, and the hot stream inlet is connected to the hydrogen gas-liquid separator.

[0049] In addition, the device system further includes a hydrogen production unit, and the hydrogen production unit includes a renewable energy power supply sub-unit and an electrolytic cell; the renewable energy power supply sub-unit is used to supply the required electric energy to the device system, and the electrolytic cell is used to supply hydrogen to the hydrogen purification unit.

[0050] It can be seen that the device system provided by the present invention realizes deep coupling between the hydrogen production process and the ammonia synthesis process by setting an energy transfer unit to transfer the energy generated by the ammonia synthesis unit to the hydrogen purification unit for reuse, thereby reducing the device energy consumption of the system, reducing the energy loss of the system, improving the energy utilization rate of the system, and being conducive to large-scale popularization and application.

[0051] The present invention also provides a method for coupling hydrogen production and ammonia synthesis using the above device system, as Figure 2 shown, the method includes: using hydrogen as a medium to transfer the energy generated in the ammonia synthesis link to the hydrogen purification link.

[0052] Specifically, the hydrogen gas includes the hydrogen gas before purification and / or the hydrogen gas after purification. The energy transfer methods include heat transfer and / or cold transfer; the heat transfer includes: using hydrogen gas as a medium to transfer the heat of the reaction gas in the ammonia synthesis section to the hydrogen gas purification section for heating and regeneration of the drying tower; the cold transfer includes: using hydrogen gas as a medium to transfer the cold of the recycle gas in the ammonia synthesis section to the hydrogen gas purification section for cold tower treatment of the drying tower. The hydrogen gas is used as the feed gas for the ammonia synthesis reaction after energy transfer.

[0053] The above method transfers the energy generated by the ammonia synthesis unit to the hydrogen gas purification unit for reuse in a device system with a specific structure, realizing the deep coupling between the hydrogen gas purification process and the ammonia synthesis process in the hydrogen production process. Moreover, the whole process flow is simple and efficient, with lower operating costs and higher economic benefits.

[0054] Example 1

[0055] This example provides a device system for coupling hydrogen production and ammonia synthesis, as Figure 3 and Figure 4 shown ( Figure 3 The A in Figure 4 is connected to the A' in

[0056] As Figure 3 shown, the electrical energy source of the power supply 11 in the hydrogen production unit 10 is a combination of wind power generation and photovoltaic power generation. In addition, the electrical energy source of the power supply 11 can also be only wind power generation, photovoltaic power generation or other forms of renewable energy or their combinations. The present invention does not limit the form of the electrical energy source of the power supply 11; the hydrogen production unit 10 includes an electrolytic cell 12, and an oxygen gas-liquid separator 13 and a hydrogen gas-liquid separator 14 that are respectively and independently connected to the electrolytic cell 12; the gas phase outlet of the oxygen gas-liquid separator 13 is also connected to an oxygen gas-water separator 15, and the gas phase outlet of the hydrogen gas-liquid separator 14 is also connected to a first hydrogen gas-water separator 16; the electrolytic cell 12 and the pure water tank 17 are connected to each other by a water pump.

[0057] As Figure 4As shown, the hydrogen purification unit 20 includes a hydrogen buffer tank 21, a deoxidation tower 22, a second hydrogen gas-water separator 23, and a drying tower 24 connected in sequence. A regeneration gas separator 25 is also connected in parallel between the second hydrogen gas-water separator 23 and the drying tower 24. The inlet of the hydrogen buffer tank 21 is connected to the gas phase outlet of the first hydrogen gas-water separator 16.

[0058] In this embodiment, the ammonia synthesis unit 30 includes a mixed gas compressor 31, a mixed gas separator 32, an ammonia synthesizer 33, and an ammonia gas-liquid separator 34 connected in sequence. The mixed gas compressor 31 is used to mix and compress hydrogen and nitrogen. The hydrogen is sourced from the drying tower 24, and the nitrogen is sourced from an external air separation unit (not shown in the figure). The gas phase outlet of the ammonia gas-liquid separator 34 is connected back to the mixed gas compressor 31, and the liquid phase outlet is connected to an external liquid ammonia production device (not shown in the figure). Such a connection is to send the recycled gas after gas-liquid separation by the ammonia gas-liquid separator 34 back to the mixed gas compressor 31, so that the recycled gas is also used as part of the raw material gas required for the ammonia synthesis reaction.

[0059] In this embodiment, the energy transfer unit 40 includes a reaction gas-purification regeneration gas heat exchanger 41 and a purification regeneration gas-recycled gas heat exchanger 42. The energy transfer unit 40 may also include a reaction gas-mixed gas heat exchanger 43 and a reaction gas-recycled gas heat exchanger 44.

[0060] As Figure 4 shown, the outlet and the cold stream inlet of the reaction gas-purification regeneration gas heat exchanger 41 are respectively connected to the drying tower 25, and the hot stream inlet is connected to the ammonia synthesizer 33, so as to use the purified hydrogen as a medium to transfer the heat generated in the ammonia synthesis process to the hydrogen purification process for heating and regeneration of the drying tower 25. The outlet and the hot stream inlet of the purification regeneration gas-recycled gas heat exchanger 42 are respectively connected to the drying tower 25, and the cold stream inlet is connected to the ammonia gas-liquid separator 34, so as to use the purified hydrogen as a medium to transfer the cold generated in the ammonia synthesis process to the hydrogen purification process for cold tower treatment of the drying tower 25.

[0061] In addition, the reaction gas-purification regeneration gas heat exchanger 41 may also have its outlet connected to the drying tower 25, the cold stream inlet connected to the hydrogen gas-liquid separator 14, and the hot stream inlet connected to the ammonia synthesizer 33, so as to use the hydrogen before purification as a medium to transfer the heat generated in the ammonia synthesis process to the hydrogen purification process for heating and regeneration of the drying tower 25. The purification regeneration gas-recycled gas heat exchanger 42 may also have its outlet connected to the drying tower 25, the cold stream inlet connected to the ammonia gas-liquid separator 34, and the hot stream inlet connected to the hydrogen gas-liquid separator 14, so as to use the hydrogen before purification as a medium to transfer the cold generated in the ammonia synthesis process to the hydrogen purification process for cold tower treatment of the drying tower 25.

[0062] The heat flow inlet of the reaction gas - mixed gas heat exchanger 43 is connected to the reaction gas - purified and recycled gas heat exchanger 41, and the cold flow inlet is connected to the mixed gas separator 32, which is used to transfer the heat of the reaction gas to the mixed gas and heat the mixed gas to facilitate the subsequent ammonia synthesis reaction; the heat flow inlet of the reaction gas - recycle gas heat exchanger 44 is connected to the reaction gas - mixed gas heat exchanger 43, and the cold flow inlet is connected to the ammonia gas - liquid separator 34, which is used to transfer the cold of the recycle gas to the reaction gas and cool the reaction gas to facilitate the subsequent gas - liquid separation; a cooler 35 is also connected between the reaction gas - recycle gas heat exchanger 44 and the ammonia gas - liquid separator 34, which is used to further cool the reaction gas.

[0063] The above - mentioned device system is used for coupling hydrogen production and ammonia synthesis. Specifically: hydrogen is used as a medium to transfer the energy generated in the ammonia synthesis section to the hydrogen purification section, and the transfer methods of the energy include heat transfer and / or cold transfer; the heat transfer includes: using hydrogen as a medium to transfer the heat of the reaction gas in the ammonia synthesis section to the hydrogen purification section for heating and regeneration of the drying tower 24; the cold transfer includes: using hydrogen as a medium to transfer the cold of the recycle gas in the ammonia synthesis section to the hydrogen purification section for cold tower treatment of the drying tower 24. After the energy transfer, the hydrogen is used as the raw material gas for the ammonia synthesis section to carry out the ammonia synthesis reaction.

[0064] Comparative Example 1

[0065] This comparative example provides a device system for coupling hydrogen production and ammonia synthesis. Except for removing the energy transfer unit 40 and making an adaptive adjustment to the connection mode between the hydrogen purification unit 20 and the ammonia synthesis unit 30, the rest of the structure is the same as that of Example 1, so it will not be described in detail here.

[0066] The energy consumption of the device systems provided by Example 1 and Comparative Example 1 was compared after 1 hour of normal start - up of the ammonia synthesis reaction under the same operating conditions. The total energy consumption in the hydrogen purification and ammonia synthesis stages of the former was 9735 KW, while that of the latter was 11790 KW. Compared with Comparative Example 1, the device system provided by Example 1 could save 17.43% of the energy consumption. At the same time, two devices, namely the electric heater and the regenerator cooler, required for the original hydrogen purification part were reduced.

[0067] It can be seen that the device system provided by the present invention realizes the deep coupling between the hydrogen production process and the ammonia synthesis process by setting an energy transfer unit to transfer the energy generated by the ammonia synthesis unit to the hydrogen purification unit for reuse, thereby reducing the device energy consumption of the system, reducing the energy loss of the system, improving the energy utilization rate of the system, and being conducive to large - scale popularization and application.

[0068] The applicant declares that the above description is only a specific embodiment 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 conceived by any person skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and the disclosure scope of the present invention.

Claims

1. An apparatus system for coupling hydrogen production and ammonia synthesis, characterized in that, The described device system includes a hydrogen purification unit, an ammonia synthesis unit, and an energy transfer unit; The energy transfer unit is used to recover the energy generated in the ammonia synthesis unit and transfer the recovered energy to the hydrogen purification unit for reuse; The hydrogen purification unit includes a hydrogen gas-liquid separator and a drying tower; The ammonia synthesis unit includes an ammonia synthesizer and an ammonia gas-liquid separator; The ammonia synthesizer is used to carry out an ammonia synthesis reaction to generate reaction gas; The ammonia gas-liquid separator is used to carry out gas-liquid separation on the reaction gas to generate recycle gas; The energy transfer unit includes a heat transfer sub-unit and / or a cold quantity transfer sub-unit; The heat transfer sub-unit is used to transfer the heat of the reaction gas to the drying tower for heating and regeneration of the drying tower; The cold quantity transfer sub-unit is used to transfer the cold quantity of the recycle gas to the drying tower for cold tower treatment of the drying tower.

2. The device system according to claim 1, wherein The heat transfer sub-unit includes a reaction gas-purified regenerated gas heat exchanger, and the cold quantity transfer sub-unit includes a purified regenerated gas-recycle gas heat exchanger; The outlet of the reaction gas-purified regenerated gas heat exchanger and the cold fluid inlet are respectively connected to the drying tower, and the hot fluid inlet is connected to the ammonia synthesizer; The outlet of the purified regenerated gas-recycle gas heat exchanger and the hot fluid inlet are respectively connected to the drying tower, and the cold fluid inlet is connected to the ammonia gas-liquid separator.

3. The device system according to claim 1, wherein The heat transfer sub-unit includes a reaction gas-purified regenerated gas heat exchanger, and the cold quantity transfer sub-unit includes a purified regenerated gas-recycle gas heat exchanger; The outlet of the reaction gas-purified regenerated gas heat exchanger is connected to the drying tower, the cold fluid inlet is connected to the hydrogen gas-liquid separator, and the hot fluid inlet is connected to the ammonia synthesizer; The outlet of the purified regenerated gas-recycle gas heat exchanger is connected to the drying tower, the cold fluid inlet is connected to the ammonia gas-liquid separator, and the hot fluid inlet is connected to the hydrogen gas-liquid separator.

4. The device system according to claim 1, characterized in that, The device system further includes a hydrogen production unit; The hydrogen production unit includes a renewable energy power supply sub-unit and an electrolyzer; The renewable energy power supply sub-unit is used to supply the required electric energy to the device system; The electrolyzer is used to supply hydrogen to the hydrogen purification unit.

5. A method for coupling hydrogen production and ammonia synthesis using the device system described in any one of claims 1-4, characterized in that, The method includes: using hydrogen as a medium to transfer the energy generated in the ammonia synthesis link to the hydrogen purification link.

6. The method according to claim 5, characterized in that The hydrogen includes hydrogen before purification and / or hydrogen after purification.

7. The method according to claim 5, characterized in that, The transfer mode of the energy includes heat transfer and / or cold quantity transfer; The heat transfer includes: using hydrogen as a medium to transfer the heat of the reaction gas in the ammonia synthesis link to the hydrogen purification link for heating and regeneration of the drying tower; The cold quantity transfer includes: using hydrogen as a medium to transfer the cold quantity of the recycle gas in the ammonia synthesis link to the hydrogen purification link for cold tower treatment of the drying tower.

8. The method according to claim 5, wherein The hydrogen is used as the raw material gas for the ammonia synthesis reaction in the ammonia synthesis link after the energy transfer.

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