Continuous separation system and method for hydrogen-doped natural gas

Abstract

The invention discloses a hydrogen-doped natural gas continuous separation system and method.The system comprises a first-stage solid hydrogen storage tank which is arranged on a hydrogen-doped natural gas pipeline and comprises a plurality of first hydrogen storage tank bodies connected in parallel, and the first hydrogen storage tank bodies are filled with magnesium-based solid hydrogen storage materials and used for continuously conducting first-stage hydrogen absorption and hydrogen desorption reactions; the second-stage solid hydrogen storage tank is arranged at the downstream of the first-stage solid hydrogen storage tank in series and comprises a plurality of second hydrogen storage tank bodies which are connected in parallel, and the second hydrogen storage tank bodies are filled with titanium, vanadium or rare earth hydrogen storage alloy materials and thermosensitive expansion materials and are used for continuously carrying out second-stage hydrogen absorption and hydrogen desorption reactions. The secondary solid hydrogen storage tank is additionally arranged, and the secondary solid hydrogen storage tank and the primary solid hydrogen storage tank are made of hydrogen storage materials different from those of the primary solid hydrogen storage tank, so that the hydrogen absorption and hydrogen desorption processes are more sufficient, hydrogen absorption is safer, and the hydrogen desorption efficiency is higher; through material selection and structural design of the solid hydrogen storage alloy in the second-stage solid hydrogen storage tank, self pressure maintaining of the second-stage solid hydrogen storage tank can be achieved, and therefore the hydrogen absorption reaction can be better promoted.

Description

Technical Field

[0001] The present invention relates to the field of hydrogen energy storage, transportation and utilization, and particularly relates to a continuous separation system and method for hydrogen-doped natural gas. Background Art

[0002] The transportation of hydrogen has always been a difficult problem restricting the development of the hydrogen energy industry chain. In comparison, both pure hydrogen pipeline transportation and hydrogen-doped natural gas pipeline transportation can achieve long-distance, large-scale, and low-energy consumption transportation of hydrogen energy. However, the planning and construction of pure hydrogen pipelines require a long cycle, and it is difficult to achieve large-scale hydrogen transportation capacity in the short term.

[0003] Mixing hydrogen with natural gas and using existing natural gas pipelines and their distribution networks for transportation is currently the best potential way to safely, efficiently, large-scale, and long-distance transport hydrogen to end-users. Carrying out hydrogen energy storage, transportation and utilization in the form of hydrogen-doped natural gas is the main way to quickly break through the bottleneck of large-scale development of the hydrogen energy industry. The transportation of hydrogen-doped natural gas can be carried out through existing natural gas pipelines, and then high-purity hydrogen can be obtained through hydrogen-natural gas separation technology. This method can effectively reduce the transportation cost of hydrogen. However, how to separate hydrogen-doped natural gas at low cost and high efficiency and meet the needs of hydrogen-consuming terminals is still a problem to be solved at present.

[0004] Chinese Patent Application CN113566113A discloses a device and method for extracting hydrogen from hydrogen-doped natural gas during transportation. The device includes at least one magnesium-based solid-state hydrogen storage and transportation device. The magnesium-based solid-state hydrogen storage and transportation device includes a hydrogen storage chamber, and the hydrogen storage chamber includes a storage cavity containing magnesium-based solid-state hydrogen storage material and a heat exchange cavity for circulating a heat exchange medium. The storage cavity is connected to the natural gas pipeline through an inlet pipe and an outlet pipe. The inlet pipe is provided with a first hydrogen concentration detector, a first flow meter and a first valve, and the outlet pipe is also provided with a second hydrogen concentration detector, a second flow meter and a second valve. The heat exchange cavity is provided with an inlet and an outlet communicating with the outside. After the hydrogen-doped natural gas is transported over a long distance through the natural gas pipeline, this solution uses a magnesium-based solid-state hydrogen storage and transportation device near hydrogen-consuming units such as hydrogen refueling stations to absorb and store the hydrogen in the natural gas pipeline and transport it to the hydrogen-consuming unit, solving the problem of transporting hydrogen over a distance of hundreds of kilometers between the natural gas pipeline and the hydrogen-consuming unit. However, such solutions still need to be improved in terms of the continuity of hydrogen and natural gas separation and the separation efficiency of hydrogen.

[0005] Therefore, there is an urgent need for a system and method for continuously and efficiently separating hydrogen-doped natural gas, which can effectively ensure the stable operation of natural gas pipeline transportation and the separation effect while ensuring the required hydrogen quality.

[0006] The information disclosed in this background art section is only intended to increase the understanding of the overall background of the present invention, and should not be regarded as an admission or any form of implication that this information constitutes prior art already known to those of ordinary skill in the art. Summary of the Invention

[0007] The object of the present invention is to provide a continuous separation system and method for hydrogen-doped natural gas. By adding a secondary solid hydrogen storage tank and using different hydrogen storage materials from the primary solid hydrogen storage tank, the hydrogen absorption and release processes are made more complete, the hydrogen absorption is safer, and the hydrogen release efficiency is higher.

[0008] Another object of the present invention is to provide a continuous separation system and method for hydrogen-doped natural gas. Through the material selection and structural design of the solid hydrogen storage alloy in the secondary solid hydrogen storage tank, the self-pressure maintenance of the secondary solid hydrogen storage tank is achieved, which is more conducive to promoting the hydrogen absorption reaction.

[0009] To achieve the above object, according to the first aspect of the present invention, a continuous separation system for hydrogen-doped natural gas is provided, including: a primary solid hydrogen storage tank, which is arranged on the hydrogen-doped natural gas pipeline and includes a plurality of first hydrogen storage tank bodies connected in parallel. The first hydrogen storage tank body is filled with a magnesium-based solid hydrogen storage material and is used for continuously performing primary hydrogen absorption and release reactions; a secondary solid hydrogen storage tank, which is serially arranged downstream of the primary solid hydrogen storage tank and includes a plurality of second hydrogen storage tank bodies connected in parallel. The second hydrogen storage tank body is filled with a hydrogen storage alloy material of titanium-based, vanadium-based or rare-earth-based and a thermally sensitive expansion material and is used for continuously performing secondary hydrogen absorption and release reactions.

[0010] Further, in the above technical solution, the hydrogen absorption temperature of the first hydrogen storage tank body can be controlled at 200°C to 400°C; the hydrogen absorption temperature of the second hydrogen storage tank body can be controlled at 30°C to 100°C.

[0011] Further, in the above technical solution, the materials in the second hydrogen storage tank body can be filled through a metal hydride filling tube extending axially in the tank body. The filling tube can be provided with: a microchannel plate, the number of which is multiple and arranged in layers, and gas microchannels are uniformly arranged on each layer of the microchannel plate; a thermally sensitive expansion plate, which is arranged between adjacent microchannel plates and is press-formed with the microchannel plate.

[0012] Further, in the above technical solution, the microchannel plate can be prepared from a titanium-based, vanadium-based or rare-earth-based material and a thermally conductive fibrous material, and the proportion of the thermally conductive fibrous material can be 2wt% to 10wt%.

[0013] Further, in the above technical solution, the thickness of the microchannel plate can be 3 to 10 mm, and the diameter of the gas microchannel can be 1 to 5 mm.

[0014] Further, in the above technical solution, the thickness of the thermally sensitive expansion plate can be 1 to 2 mm, which is pressed from a thermally sensitive deformation alloy, and the deformation temperature can be 10°C to 100°C.

[0015] Further, in the above technical solution, during the hydrogen absorption stage, a cooling medium can be introduced into the shell side of the second hydrogen storage tank body.

[0016] Further, in the above technical solution, a gas cooling and boosting pump can be provided between the primary solid-state hydrogen storage tank and the secondary solid-state hydrogen storage tank. It is used during the hydrogen absorption stage, can boost the gas from the primary solid-state hydrogen storage tank while performing split cooling, and together with the cooling medium, cool the gas entering the secondary solid-state hydrogen storage tank to the required hydrogen absorption temperature.

[0017] Further, in the above technical solution, the system can further include: a hydrogen buffer tank, which is arranged on the hydrogen circulation pipeline downstream of the secondary solid-state hydrogen storage tank, and is used to purge and cool the corresponding first hydrogen storage tank body and the second hydrogen storage tank body after a hydrogen absorption and hydrogen release process is completed for the primary solid-state hydrogen storage tank and the secondary solid-state hydrogen storage tank group.

[0018] Further, in the above technical solution, a heat flow tube can be provided inside the first hydrogen storage tank body, and the heat medium is high-temperature heat-conducting oil, and the temperature range can be 75°C to 500°C; a circulating cooling coil can be provided outside the first hydrogen storage tank body, and the coolant is water, ethylene glycol, propylene glycol or dichloromethane.

[0019] According to the second aspect of the present invention, the present invention provides a method for continuous separation of hydrogen-doped natural gas, using the system of any one of the foregoing, including the following steps: A. Assemble the first hydrogen storage tank body of the primary solid-state hydrogen storage tank and the second hydrogen storage tank body of the secondary solid-state hydrogen storage tank; sequentially perform hydrogen absorption and hydrogen release processes in each group of hydrogen storage tank bodies; B. During the hydrogen absorption process, after primary hydrogen absorption, the gas is boosted and cooled and then undergoes secondary hydrogen absorption, and natural gas is exported after secondary hydrogen absorption; during the hydrogen release process, after primary hydrogen release, the heat of hydrogen is used to heat the material filled in the corresponding second hydrogen storage tank body, perform secondary hydrogen release, and hydrogen is exported after secondary hydrogen release; C. After the hydrogen release process of each hydrogen storage tank body ends, purge and cool through circulating hydrogen; the second hydrogen storage tank body is additionally cooled using a cooling medium to prepare for the next hydrogen absorption process.

[0020] Further, in the above technical solution, the boosting and cooling in step B can specifically include: after primary hydrogen absorption, boost the gas while performing split cooling; during the secondary hydrogen absorption process, perform heat exchange through the cooling medium in the shell side of the second hydrogen storage tank body.

[0021] Further, in the above technical solution, the cooling medium in the shell side can perform heat exchange with the tube side. Under the action of the heat-conducting fibrous material and the thermally sensitive expansion plate of the microchannel plate in the tube side, the temperature in the tube side is controlled within the secondary hydrogen absorption temperature range, and the thermally sensitive expansion plate expands at the secondary hydrogen absorption temperature, thereby compressing the hydrogen gas volume inside the gas microchannel, increasing the secondary hydrogen absorption pressure and thus improving the hydrogen absorption efficiency.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1) By adding a secondary solid-state hydrogen storage tank, the present invention can effectively improve the separation efficiency of hydrogen-doped natural gas, and the hydrogen absorption in the hydrogen absorption stage is more complete;

[0024] 2) By filling the secondary solid-state hydrogen storage tank with hydrogen storage alloy materials and thermally sensitive expansion materials of titanium-based, vanadium-based or rare-earth-based systems, and taking advantage of the fact that the hydrogen absorption temperature of such materials is close to room temperature, the hydrogen absorption temperature is easier to control; while the hydrogen release temperature is slightly lower than that of the primary solid-state hydrogen storage tank, and the heat carried away by the hydrogen gas flow in the primary solid-state hydrogen storage tank can be fully utilized to heat the secondary solid-state hydrogen storage material, thereby improving the hydrogen release efficiency;

[0025] 3) Through the structural design inside the secondary solid-state hydrogen storage tank, during the hydrogen absorption process of the secondary solid-state hydrogen storage tank, the filling pipe is in contact with the cooling medium, and its temperature is reduced to the hydrogen absorption temperature of the secondary solid-state hydrogen storage tank (i.e., 30°C to 100°C). And since the inside of the filling pipe is filled with a heat-conducting material, the temperature inside the tube can be quickly controlled within the hydrogen absorption temperature range; while the thermally sensitive expansion plate can undergo expansion deformation at this hydrogen absorption temperature (i.e., it can deform and expand at 10°C to 100°C), so it can promote the contraction of the gas microchannels of the metal hydride microchannel plate, thereby compressing the internal hydrogen gas volume, increasing the hydrogen absorption pressure inside the microchannels, and further improving the hydrogen absorption efficiency; during the hydrogen release process, the secondary solid-state hydrogen storage tank can be heated by the heat of the hydrogen gas in the primary solid-state hydrogen storage tank, and the hydrogen gas is directly released and discharged. Since the secondary hydrogen release temperature is slightly lower than the primary hydrogen release temperature, no additional heating facilities are required;

[0026] 4) A gas cooling and boosting pump can be provided between the primary solid-state hydrogen storage tank and the secondary solid-state hydrogen storage tank, and selective control is carried out through the inlet pump valve and the hydrogen release valve. The gas cooling and boosting pump can be enabled in the hydrogen absorption stage. While boosting the gas from the primary solid-state hydrogen storage tank, it is shunted and cooled. By adding the gas cooling and boosting pump, not only can a certain gas pressure be ensured when entering the secondary solid-state hydrogen storage tank in the hydrogen absorption stage (the hydrogen partial pressure in the primary solid-state hydrogen storage tank has been greatly reduced due to hydrogen absorption), but also the cooling and compression effects can be significantly improved through the shunt cooling of the pump; in addition, by enabling the gas cooling and boosting pump provided at the front end of the secondary solid-state hydrogen storage tank in the hydrogen absorption stage, it can cooperate with the cooling medium in the shell side of the secondary solid-state hydrogen storage tank to cool the gas entering the secondary solid-state hydrogen storage tank to the required hydrogen absorption temperature, which not only has a synergistic cooling effect, but also can be controlled to the required hydrogen absorption temperature in a shorter time.

[0027] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and be implemented according to the content of the specification, and at the same time to make the above and other objects, technical features and advantages of the present invention more understandable, one or more preferred embodiments are listed below and described in detail with reference to the accompanying drawings as follows. Description of the Drawings

[0028] Figure 1 is a connection schematic diagram of the hydrogen-doped natural gas continuous separation system of the present invention.

[0029] Figure 2 is a schematic structural diagram of the secondary solid hydrogen storage tank of the present invention.

[0030] Figure 3 is the present invention Figure 2 Cross-sectional structural schematic diagram of the metal hydride filling tube in.

[0031] Figure 4 is the present invention Figure 3 partial enlarged view of.

[0032] Main reference numeral description:

[0033] 1 - Primary solid hydrogen storage tank, 1a, 1b - First solid hydrogen storage tank body, 11 - Primary intake valve, 12 - Primary inlet flowmeter, 13 - Heat flow pipe, 14 - Circulating cooling coil, 15 - Primary outlet valve, 16 - Primary outlet flowmeter, 2 - Secondary solid hydrogen storage tank, 2a, 2b, 2c - Second solid hydrogen storage tank body, 20 - Metal hydride filling tube, 201 - Metal hydride microchannel plate, 2011 - Gas microchannel, 202 - Thermosensitive expansion plate, 21 - Secondary intake valve, 22 - Outlet branch valve, 23 - Hydrogen circulation branch valve, 24 - Filter plate, 25 - Cooling medium inlet, 26 - Cooling medium outlet, 27 - Intake port, 28 - Outlet port, 3 - Hydrogen buffer tank, 31 - Hydrogen compressor, 32 - Circulating hydrogen valve, 4 - Temperature controller, 5 - Circulating refrigerator, 51 - Cooling pipeline valve, 6 - Gas cooling and boosting pump, 61 - Inlet pump valve, 62 - Bleed valve, 7 - Hydrogen output valve, 8 - Natural gas output valve. Detailed Description of the Preferred Embodiments

[0034] The following will describe in detail the specific embodiments of the present invention with reference to the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0035] Unless otherwise clearly stated, in the whole specification and claims, the term "comprising" or its variations such as "comprises" or "including" etc. will be understood to include the stated elements or components, without excluding other elements or other components.

[0036] In this document, for the convenience of description, spatial relative terms such as "below", "beneath", "under", "above", "over", "on", etc. may be used to describe the relationship between one element or feature and another element or feature in the drawings. It should be understood that spatial relative terms are intended to encompass different orientations of an object during use or operation in addition to the orientation depicted in the figures. For example, if an object in the figure is flipped, an element described as "below" or "under" another element or feature will be oriented "above" that element or feature. Thus, the exemplary term "below" can encompass both the below and above directions. The object may also have other orientations (rotated 90 degrees or other orientations) and the spatial relative terms used herein should be interpreted accordingly.

[0037] In this document, the terms "first", "second", etc. are used to distinguish two different elements or parts, and are not used to define a specific position or relative relationship. In other words, in some embodiments, the terms "first", "second", etc. may also be interchanged with each other.

[0038] Example 1

[0039] As Figure 1 shown, this embodiment provides a continuous separation system for hydrogen-doped natural gas. Compared with the hydrogen-doped natural gas separation system in the prior art, a first-stage solid hydrogen storage tank is added, which can not only realize the continuous separation of hydrogen-doped natural gas, but also make the separation of hydrogen and natural gas more sufficient and more efficient. The system of this embodiment includes a first-stage solid hydrogen storage tank 1 and a second-stage solid hydrogen storage tank 2. Among them, the first-stage solid hydrogen storage tank 1 is arranged on the hydrogen-doped natural gas pipeline and includes a plurality of first hydrogen storage tank bodies connected in parallel ( Figure 1 two tank bodies are shown in the figure, namely 1a and 1b), each first hydrogen storage tank body is filled with a magnesium-based solid hydrogen storage material, the hydrogen absorption temperature of the first hydrogen storage tank body can be controlled at 200°C to 400°C, the hydrogen absorption pressure is controlled at about 5 MPa, and the hydrogen release temperature is slightly higher, which can be controlled at 250°C to 450°C. Two or more first hydrogen storage tank bodies are provided for continuous first-stage hydrogen absorption and hydrogen release reactions. The second-stage solid hydrogen storage tank 2 is arranged in series downstream of the first-stage solid hydrogen storage tank 1 and includes a plurality of second hydrogen storage tank bodies connected in parallel ( Figure 1 three tank bodies are shown in the figure, namely 2a, 2b and 2c), each second hydrogen storage tank body is filled with a hydrogen storage alloy material of titanium-based, vanadium-based or rare earth-based and a thermally sensitive expansion material, the hydrogen absorption temperature of the second hydrogen storage tank body can be controlled at 30°C to 100°C, the hydrogen absorption pressure is controlled at about 3 MPa, and the hydrogen release temperature is lower than that of the first-stage solid hydrogen storage tank 1, which can be controlled at 200°C to 300°C. Two or more second hydrogen storage tank bodies are provided for continuous second-stage hydrogen absorption and hydrogen release reactions.

[0040] The above technical solution of this embodiment can effectively improve the separation efficiency of hydrogen-blended natural gas by adding a secondary solid-state hydrogen storage tank, and the hydrogen absorption in the hydrogen absorption stage is more complete; by filling the secondary solid-state hydrogen storage tank with titanium, vanadium or rare earth hydrogen storage alloy materials and thermally sensitive expansion materials, and utilizing the fact that the hydrogen absorption temperature of such materials is close to room temperature (easier to control) and the hydrogen release temperature is slightly lower than the hydrogen release temperature of the primary solid-state hydrogen storage tank, the heat carried away by the hydrogen flow in the primary solid-state hydrogen storage tank can be fully utilized to heat the secondary solid-state hydrogen storage material and improve the hydrogen release efficiency.

[0041] Combine the following Figure 1 The hydrogen-blended natural gas continuous separation system of this embodiment is described in detail:

[0042] The hydrogen-blended natural gas pipeline is connected to the primary solid hydrogen storage tank 1 and the secondary solid hydrogen storage tank 2 in sequence, wherein the primary solid hydrogen storage tank 1 ( Figure 1 The left dotted line frame portion) includes a first solid-state hydrogen storage tank body 1a and a first solid-state hydrogen storage tank body 1b connected in parallel, and a secondary solid-state hydrogen storage tank 2 ( Figure 1 The dotted line frame part on the right side of the middle) includes a second solid-state hydrogen storage tank body 2a, a second solid-state hydrogen storage tank body 2b and a second solid-state hydrogen storage tank body 2c connected in parallel. When absorbing and releasing hydrogen, a first solid-state hydrogen storage tank body and a second solid-state hydrogen storage tank body can independently perform two-stage hydrogen absorption and release as a group, thereby realizing the continuous separation of two-stage hydrogen-blended natural gas.

[0043] A first-level air inlet valve 11 and a first-level inlet flowmeter 12 are sequentially arranged on the pipeline (i.e., each branch) between the hydrogen-blended natural gas pipeline and the first-level solid hydrogen storage tank 1. A heat flow pipe 13 is arranged inside the tank body of each first solid hydrogen storage tank. The heat medium can be high-temperature heat transfer oil with a temperature range of 75°C to 500°C, which is used to heat the hydrogen storage material in the tank body and is controlled by a temperature controller 4 so that the temperature inside the tank reaches a preset temperature. If the temperature inside the tank exceeds the preset temperature during hydrogen absorption or desorption, it can be cooled by a circulating cooling coil 14. The circulating cooling coil 14 is connected to a circulating refrigerator 5 outside the tank and is controlled by a cooling pipeline valve 51. The coolant can be water, ethylene glycol, propylene glycol or dichloromethane. A first-level outlet valve 15 and a first-level outlet flowmeter 16 are arranged on the downstream pipeline of each first solid hydrogen storage tank body.

[0044] Each second solid-state hydrogen storage tank body is provided with an independent secondary intake valve 21. The outlet pipelines of each second solid-state hydrogen storage tank body are respectively connected to the hydrogen circulation branch line and the gas outlet branch line. A hydrogen circulation branch line 23 is correspondingly provided on the hydrogen circulation branch line, and a part of the hydrogen separated during the hydrogen release stage can be introduced into the hydrogen buffer tank 3 through the hydrogen compressor 31. The hydrogen buffer tank 3 can be connected to each first solid-state hydrogen storage tank body through the circulating hydrogen valve 32, so as to provide hydrogen purging for the two-stage tank bodies. Specifically, the hydrogen buffer tank 3 is arranged on the hydrogen circulation pipeline downstream of the second-stage solid-state hydrogen storage tank, and is used to purge and cool the corresponding first hydrogen storage tank body and the second hydrogen storage tank body after the first-stage solid-state hydrogen storage tank and the second-stage solid-state hydrogen storage tank complete a hydrogen absorption and hydrogen release process. An outlet branch line valve 22 is provided on the gas outlet branch line, which is used to provide the separated hydrogen or natural gas for the hydrogen use terminal and the natural gas use terminal. After the hydrogen absorption is completed, the outlet branch line valve 22 of the corresponding branch and the downstream natural gas output valve 8 can be opened to output natural gas. When releasing hydrogen, the outlet branch line valve 22 of the corresponding branch and the downstream hydrogen output valve 7 are opened to output hydrogen.

[0045] Furthermore, as Figures 2 - 4 shown, preferably but not limited to, the hydrogen storage material in the second hydrogen storage tank body is filled through the metal hydride filling pipe 20 extending axially in the tank body. A microchannel plate 201 and a thermally sensitive expansion plate 202 are provided in the filling pipe 20. Among them, the number of the microchannel plates 201 is multiple and they are arranged in layers. The microchannel plate 201 is preferably prepared from titanium-based, vanadium-based or rare earth-based materials and thermally conductive fibrous materials. The proportion of the thermally conductive fibrous materials is preferably 2wt% - 10wt%. Gas microchannels 2011 are uniformly arranged on each layer of the microchannel plate 201. The thickness of the microchannel plate 201 can be 3 - 10 mm, and the diameter of the gas microchannels 2011 can be 1 - 5 mm. The thermally sensitive expansion plate 202 is arranged between adjacent microchannel plates and is pressed and formed with the microchannel plate 201 (the pressure used for pressing between each layer of plates is not more than 20 MPa). The thickness of the thermally sensitive expansion plate 202 can be 1 - 2 mm, and it is pressed from a thermally sensitive deformation alloy. The deformation temperature is 10°C - 100°C, and the thermal expansion rate is 0.8×10 -6 ~2.1×10 -6 / K (10 - 100°C). Since the hydrogen absorption temperature of the second hydrogen storage tank body is relatively low (a temperature slightly higher than room temperature), during the hydrogen absorption stage, a cooling medium is introduced into the shell side of the second hydrogen storage tank body. The cooling medium enters the shell side from the inlet 25 and flows out from the outlet 26, and exchanges heat with the filling pipe 20 during this process.

[0046] In this embodiment, by adopting the above-mentioned structural design inside the secondary solid-state hydrogen storage tank 2, during the hydrogen absorption process of the secondary solid-state hydrogen storage tank (all the gas in the primary solid-state hydrogen storage tank 1 enters the secondary solid-state hydrogen storage tank 2), the tube side contacts with the cooling medium, so that its temperature is reduced to the hydrogen absorption temperature of the secondary solid-state hydrogen storage tank (i.e., 30°C to 100°C). And due to the heat-conducting material filled inside the filling tube 20, the temperature inside the tube side can be quickly controlled within the hydrogen absorption temperature range. The thermosensitive expansion plate 202 expands and deforms at this hydrogen absorption temperature (it can deform and expand at 10°C to 100°C). Therefore, it can promote the contraction of the gas microchannels 2011 of the metal hydride microchannel plate 201, thereby compressing the internal hydrogen gas volume, increasing the hydrogen absorption pressure in the microchannels, and further improving the hydrogen absorption efficiency. During the hydrogen release process, the secondary solid-state hydrogen storage tank can be heated by the hydrogen heat of the primary solid-state hydrogen storage tank 1, and the hydrogen is directly released and discharged. Since the secondary hydrogen release temperature is slightly lower than the primary hydrogen release temperature, no additional heating facilities are required.

[0047] Furthermore, as Figure 1 shown, preferably but not restrictively, in this embodiment, a gas cooling and boosting pump 6 can be provided between the primary solid-state hydrogen storage tank and the secondary solid-state hydrogen storage tank, and an inlet pump valve 61 and a hydrogen release valve 62 are provided at the same time. The gas cooling and boosting pump 6 can be enabled during the hydrogen absorption stage to boost the gas from the primary solid-state hydrogen storage tank 1 and perform split cooling at the same time. By adding the gas cooling and boosting pump 6, not only can it ensure that there is a certain gas pressure when entering the secondary solid-state hydrogen storage tank 2 during the hydrogen absorption stage (the hydrogen partial pressure in the primary solid-state hydrogen storage tank has been greatly reduced due to hydrogen absorption), but also the cooling and compression effects can be significantly improved through the split cooling of the pump. By enabling the gas cooling and boosting pump 6 provided at the front end of the secondary solid-state hydrogen storage tank during the hydrogen absorption stage, the gas entering the secondary solid-state hydrogen storage tank can be cooled to the required hydrogen absorption temperature through the combined action with the cooling medium in the shell side of the secondary solid-state hydrogen storage tank, so it has a synergistic cooling effect.

[0048] Example 2

[0049] This embodiment provides a method for continuous separation of hydrogen-doped natural gas, which is characterized in that the system of Embodiment 1 is adopted, and it includes the following steps:

[0050] Step S101, assemble the first hydrogen storage tank body of the primary solid-state hydrogen storage tank 1 and the second hydrogen storage tank body of the secondary solid-state hydrogen storage tank 2, so that the hydrogen absorption and hydrogen release processes are carried out in sequence in each group of hydrogen storage tank bodies.

[0051] In step S102, during the hydrogen absorption process, after primary hydrogen absorption, the gas is pressurized and cooled and then undergoes secondary hydrogen absorption, and natural gas is exported after secondary hydrogen absorption; during the hydrogen release process, after primary hydrogen release, the heat of the hydrogen is used to heat the hydrogen storage material filled in the corresponding second hydrogen storage tank body 2 to perform secondary hydrogen release, and hydrogen is exported after secondary hydrogen release.

[0052] The "pressurization and cooling of the gas after primary hydrogen absorption" in step S102 is preferably: after primary hydrogen absorption, while pressurizing the gas, it is shunted and cooled; during the secondary hydrogen absorption process, heat exchange is carried out through the cooling medium in the shell side of the second hydrogen storage tank body. That is, while pressurizing through the gas cooling and pressurizing pump 6, the gas cooling and pressurizing pump 6 and the cooling medium in the shell side of the second hydrogen storage tank body are used for collaborative cooling, and the hydrogen absorption temperature required for the secondary solid hydrogen storage tank can be obtained in a relatively short time. Further, the cooling medium in the shell side exchanges heat with the tube side, and under the action of the heat-conducting fibrous material and the thermally sensitive expansion plate 202 of the microchannel plate 201 in the tube side, the temperature in the tube side can be controlled within the range of the secondary hydrogen absorption temperature, and the thermally sensitive expansion plate 202 expands at the secondary hydrogen absorption temperature and then compresses the hydrogen volume inside the gas microchannel 2011, which can effectively increase the secondary hydrogen absorption pressure and thus improve the hydrogen absorption efficiency.

[0053] Specifically, during hydrogen absorption, first use the temperature controller 4 to heat the primary solid hydrogen storage tank 1a to reach the predetermined temperature T 1 After that (that is, the primary hydrogen absorption temperature is 200°C to 400°C), open the intake valve 11 in front of the primary solid hydrogen storage tank 1a, and control the intake gas flow rate to be v 进 (0.02 to 5 m 3 / min) through the primary inlet flowmeter 12; open the primary outlet valve 16 and control the outlet gas flow rate of the primary solid hydrogen storage tank 1a to be v 出 (0.05 to 3 m 3 / min); open the inlet valve to the pump 61, close the hydrogen release valve 62, and open one (or two) secondary intake valves 21 in front of the secondary solid hydrogen storage tank 2a for secondary hydrogen absorption; open the corresponding outlet branch valve 22 and the valve 8 on the natural gas output pipeline to allow natural gas to enter the natural gas end user. During hydrogen release, when the intake valve 11 of the primary solid hydrogen storage tank 1a is closed, start the temperature controller 4 to control the heating temperature, and heat the primary solid hydrogen storage tank 1a to the hydrogen release temperature T 2 (that is, 250°C to 450°C); at the same time, close the inlet valve to the pump 61, open the primary outlet valve 15, the hydrogen release valve 62, the valve 22 on the corresponding outlet branch, and the valve 7 on the hydrogen output pipeline of the primary solid hydrogen storage tank 1a, and directly transport the hydrogen to the hydrogen-using terminal.

[0054] When the temperature of the first-stage solid hydrogen storage tank 1a exceeds the required temperature during hydrogen absorption or release, the circulating refrigerator 5 and the cooling pipeline valve 51 are opened to cool and control the temperature of the first-stage solid hydrogen storage tank 1a, so as to maintain the required hydrogen absorption or release temperature of the first-stage solid hydrogen storage tank; set the pressure P of the first-stage solid hydrogen storage tank a , when the pressure reaches the set pressure boundary P a , after that, the intake valve 11 in front of the first-stage solid hydrogen storage tank 1a is closed, and the intake valve 11 of the first-stage solid hydrogen storage tank 1b is opened, so that the hydrogen-doped natural gas can enter the second group of solid hydrogen storage tanks, and the above operations are repeated for the first-stage solid hydrogen storage tank 1b to perform the two-stage hydrogen absorption and release processes of the second group.

[0055] Step S103, after the hydrogen release process of each hydrogen storage tank body is completed, purge and cool down by circulating hydrogen; the second hydrogen storage tank body is additionally cooled by a cooling medium to prepare for the next hydrogen absorption process.

[0056] Specifically, during the hydrogen absorption and release processes, the pressure in the hydrogen buffer tank 3 can be monitored in real time. When the pressure drops to the lower limit P 1 (0.1 - 0.8 MPa), when performing the hydrogen release step, the hydrogen circulation branch valve 23 and the hydrogen compressor 31 can be opened to supplement hydrogen to the hydrogen buffer tank 3 to make the pressure in the hydrogen buffer tank 3 reach the tank internal pressure P 2 (5 - 12 MPa). After each hydrogen release is completed, the hydrogen in the hydrogen buffer tank can be used to purge the first-stage solid hydrogen storage tank and the second-stage solid hydrogen storage tank for 1 - 5 minutes, and the purge flow rate is v 吹 (0.01 - 2 m 3 / min), and gas evacuation is carried out through the evacuation valve and pipeline (not shown in the figure).

[0057] In this embodiment, after completing the hydrogen absorption process, hydrogen release process, and purge and cooling process in the above steps, the first group of two-stage solid hydrogen storage tanks enters the standby state, preparing for the second hydrogen absorption and release processes. Since each group can be independently controlled, it does not affect the hydrogen absorption and release processes of other groups.

[0058] The foregoing description of the specific exemplary embodiments of the present invention is for the purposes of illustration and exemplification. These descriptions are not intended to limit the present invention to the precise forms disclosed, and obviously, many changes and variations are possible in light of the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical applications, so that those skilled in the art can implement and utilize various different exemplary embodiments of the present invention, as well as various different selections and changes. Any simple modifications, equivalent changes, and modifications made to the above exemplary embodiments shall fall within the protection scope of the present invention.

Claims

1. A continuous separation system for hydrogen-doped natural gas, characterized in that, it includes: A primary solid-state hydrogen storage tank, which is arranged on the hydrogen-doped natural gas pipeline and includes a plurality of first hydrogen storage tank bodies connected in parallel. The first hydrogen storage tank body is filled with a magnesium-based solid-state hydrogen storage material for continuously performing primary hydrogen absorption and hydrogen release reactions; A secondary solid-state hydrogen storage tank, which is arranged in series downstream of the primary solid-state hydrogen storage tank and includes a plurality of second hydrogen storage tank bodies connected in parallel. The second hydrogen storage tank body is filled with a hydrogen storage alloy material of titanium-based, vanadium-based or rare earth-based and a thermally sensitive expansion material for continuously performing secondary hydrogen absorption and hydrogen release reactions.

2. The continuous separation system for hydrogen-doped natural gas according to claim 1, characterized in that, the hydrogen absorption temperature of the first hydrogen storage tank body is controlled at 200°C to 400°C; the hydrogen absorption temperature of the second hydrogen storage tank body is controlled at 30°C to 100°C.

3. The continuous separation system for hydrogen-doped natural gas according to claim 1, characterized in that, the materials in the second hydrogen storage tank body are filled through a metal hydride filling pipe extending axially in the tank body, and the filling pipe is provided with: Microchannel plates, the number of which is multiple and are arranged in layers, and gas microchannels are uniformly arranged on each layer of microchannel plates; Thermally sensitive expansion plates, which are arranged between adjacent microchannel plates and are press-molded with the microchannel plates.

4. The continuous separation system for hydrogen-doped natural gas according to claim 3, characterized in that, the microchannel plates are prepared from a titanium-based, vanadium-based or rare earth-based material and a heat-conducting fibrous material, and the proportion of the heat-conducting fibrous material is 2wt% to 10wt%.

5. The continuous separation system for hydrogen-doped natural gas according to claim 3, characterized in that, the thickness of the microchannel plates is 3 to 10 mm, and the diameter of the gas microchannels is 1 to 5 mm.

6. The continuous separation system for hydrogen-doped natural gas according to claim 3, characterized in that, the thickness of the thermally sensitive expansion plates is 1 to 2 mm, and they are pressed from a thermally sensitive deformation alloy, and the deformation temperature is 10°C to 100°C.

7. The continuous separation system for hydrogen-doped natural gas according to claim 3, characterized in that, during the hydrogen absorption stage, a cooling medium is introduced into the shell side of the second hydrogen storage tank body.

8. The continuous separation system for hydrogen-doped natural gas according to claim 7, characterized in that, a gas cooling and boosting pump is provided between the primary solid-state hydrogen storage tank and the secondary solid-state hydrogen storage tank, which is enabled during the hydrogen absorption stage to boost the gas from the primary solid-state hydrogen storage tank while performing shunt cooling, and jointly act with the cooling medium to cool the gas entering the secondary solid-state hydrogen storage tank to the required hydrogen absorption temperature.

9. The continuous separation system for hydrogen-doped natural gas according to claim 1, characterized in that, the system further includes: A hydrogen gas buffer tank, which is arranged on the hydrogen gas circulation pipeline downstream of the secondary solid-state hydrogen storage tank, and is used to purge and cool the corresponding first hydrogen storage tank body and second hydrogen storage tank body after the primary solid-state hydrogen storage tank and the secondary solid-state hydrogen storage tank complete a hydrogen absorption and hydrogen release process.

10. The continuous separation system for hydrogen-doped natural gas according to claim 1, characterized in that, A heat flow tube is provided inside the first hydrogen storage tank body, and the heat medium is high-temperature heat-conducting oil with a temperature range of 75°C to 500°C; a circulating cooling coil is provided outside the first hydrogen storage tank body, and the coolant is water, ethylene glycol, propylene glycol or dichloromethane.

11. A method for continuous separation of hydrogen-doped natural gas, characterized in that using the system according to any one of claims 1 to 10, comprising the following steps: A. Assemble the first hydrogen storage tank body of the primary solid hydrogen storage tank and the second hydrogen storage tank body of the secondary solid hydrogen storage tank; successively perform the hydrogen absorption and hydrogen release processes in each group of hydrogen storage tank bodies; B. During the hydrogen absorption process, after the first-stage hydrogen absorption, the gas is pressurized and cooled and then undergoes second-stage hydrogen absorption, and the natural gas is exported after the second-stage hydrogen absorption; During the hydrogen release process, after the first-stage hydrogen release, the heat of the hydrogen is used to heat the material filled in the corresponding second hydrogen storage tank body, and second-stage hydrogen release is performed, and the hydrogen is exported after the second-stage hydrogen release; C. After the hydrogen release process of each hydrogen storage tank body is completed, purge and cool down through circulating hydrogen; the second hydrogen storage tank body is additionally cooled using a cooling medium to prepare for the next hydrogen absorption process.

12. The method for continuous separation of hydrogen-doped natural gas according to claim 11, characterized in that the pressurization and cooling in step B specifically include: After the first-stage hydrogen absorption, while pressurizing the gas, perform split cooling; during the second-stage hydrogen absorption process, heat exchange is performed through the cooling medium in the shell side of the second hydrogen storage tank body.

13. The method for continuous separation of hydrogen-doped natural gas according to claim 12, characterized in that The cooling medium in the shell side exchanges heat with the tube side. Under the action of the heat-conducting fibrous material of the microchannel plate and the thermally sensitive expansion plate in the tube side, the temperature in the tube side is controlled within the second-stage hydrogen absorption temperature range, and the thermally sensitive expansion plate expands at the second-stage hydrogen absorption temperature, thereby compressing the hydrogen gas volume inside the gas microchannel, increasing the second-stage hydrogen absorption pressure, and thus improving the hydrogen absorption efficiency.

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