Hydrogen purification method based on magnesium-based solid hydrogen storage material

Abstract

The invention relates to the technical field of purification, and discloses a hydrogen purification method based on a magnesium-based solid hydrogen storage material, which comprises the following steps: S11, packaging the magnesium-based solid hydrogen storage material into a plurality of purification units, connecting the two purification units in parallel, and arranging a thermal interaction unit between the two parallel purification units to form a primary purification module; and S2, purification: introducing the low-purity hydrogen into the purification module, so that the low-purity hydrogen is respectively subjected to a hydrogen absorption reaction and a hydrogen desorption reaction for multiple times in the purification units connected in parallel, the low-purity hydrogen is purified, heat is supplied to the purification units which are subjected to the hydrogen desorption reaction through the heat interaction unit, and heat energy released by the hydrogen absorption reaction is stored. Based on the selective adsorption capacity of the solid hydrogen storage material to hydrogen, the solid hydrogen storage material is used for adsorbing hydrogen and discharging impurity gas, so that the purity of hydrogen is improved, and the heat interaction unit is used for storing heat energy released by a hydrogen absorption reaction and applying the heat energy to a hydrogen desorption reaction, so that the energy consumption in the purification process is reduced.

Description

Technical Field

[0001] The present invention relates to the field of purification technology, and in particular to a method for purifying hydrogen based on magnesium-based solid-state hydrogen storage materials. Background Art

[0002] With the development of industry, the demand for hydrogen is increasing. Conventional hydrogen contains various impurities and cannot directly meet hydrogen usage standards. To improve hydrogen quality, meet the needs of different applications, ensure safety, and promote the sustainable development of the hydrogen energy industry, hydrogen purification is essential.

[0003] The currently used hydrogen purification methods, such as low-temperature separation, low-temperature adsorption, pressure swing adsorption, membrane separation, etc., can meet certain purity requirements, but each method has different problems such as high energy consumption, high investment cost, complex equipment, and low efficiency. Summary of the Invention

[0004] The present invention aims to provide a hydrogen purification method based on magnesium-based solid-state hydrogen storage materials, so as to purify low-purity hydrogen through the selective adsorption ability of magnesium-based solid-state hydrogen storage materials for hydrogen and reduce energy consumption during the purification process.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a hydrogen purification method based on magnesium-based solid-state hydrogen storage materials, comprising the following steps: S1: building a hydrogen purification system and S2: purification, wherein low-purity hydrogen is purified by running the hydrogen purification system built by S1, wherein S1 includes S11: encapsulating the magnesium-based solid-state hydrogen storage material into a plurality of purification units, and connecting two purification units in parallel, and providing a thermal interaction unit between the two parallel purification units to form a primary purification module; S2 purification includes S21, which allows low-purity hydrogen to be introduced into the purification module, so that the low-purity hydrogen undergoes hydrogen absorption reaction and hydrogen desorption reaction in the parallel purification units respectively, so as to purify the low-purity hydrogen, and heat is supplied to the purification unit undergoing hydrogen desorption reaction through the heat interaction unit and the heat energy released by the hydrogen absorption reaction is stored.

[0006] The beneficial effects of this solution are: magnesium-based solid-state hydrogen storage materials can reversibly absorb and desorb hydrogen at specific temperatures and pressures (primary reaction: Mg + H₂ ↔ MgH₂). Their crystal lattice exhibits selective adsorption for hydrogen molecules, while exhibiting weak adsorption for some impurities (such as CO and CH₄), offering potential for purification. This solution leverages the selective adsorption capacity of magnesium-based solid-state hydrogen storage materials to adsorb hydrogen and expel impurities, thereby increasing hydrogen purity to as high as 99.9999%. Furthermore, a thermal interaction unit is used to store the heat released by the hydrogen absorption reaction and reuse it for the desorption reaction, reducing energy consumption during the purification process.

[0007] Furthermore, S1 also includes S12: connecting a plurality of primary purification modules in series to form two parallel purification channels; during purification in S2, adjacent purification units in each purification channel alternately perform hydrogen absorption reactions.

[0008] Furthermore, S1 also includes S13: the purification unit includes an air outlet pipe, and cooling units are respectively fixed on the outer walls of the air outlet pipes of the two parallel purification units, and the cooling units are connected to the heat interaction unit to form a final purification module, which is arranged at the air outlet end of the purification channel and connected in series with the purification channel.

[0009] Furthermore, S1 also includes S14: providing a drying and filtering unit, which is provided at the air inlet ends of the two purification channels and is connected to the purification channels through a reversing valve.

[0010] Furthermore, S2 also includes S20 drying and impurity removal: low-purity hydrogen containing impurities is passed through a drying and filtering unit, filtered and dried by the drying and filtering unit to obtain low-purity hydrogen, and the low-purity hydrogen is passed into a purification channel composed of several primary purification modules, and after several hydrogen absorption reactions and hydrogen release reactions, it reaches the final purification module and is absorbed and released by the purification unit of the final purification module to obtain high-purity hydrogen.

[0011] Furthermore, S2 also includes S22 cooling: high-purity hydrogen is discharged from the outlet pipe of the final purification module and cooled by a cooling unit.

[0012] Furthermore, the S21 process includes an adsorption stage for hydrogen absorption reaction and a desorption stage for hydrogen release reaction. The temperature of the adsorption stage is 100-450°C and the pressure is 0.5-5 MPa; the temperature of the desorption stage is 100-450°C and the pressure is 0.1-1 MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a flow chart of an embodiment of the present invention; Figure 2 This is a schematic diagram of the connection of the purification system according to an embodiment of the present invention; Figure 3 Schematic diagram of the oil circuit of the heat interaction unit of the primary purification module according to an embodiment of the present invention; Figure 4 Schematic diagram of the oil circuit of the heat interaction unit of the primary purification module according to an embodiment of the present invention; Figure 5 Schematic diagram of the internal structure of the first storage chamber according to an embodiment of the present invention.

[0014] The figure marks in the drawings of the specification include: primary purification module 100, final purification module 200, drying and filtration unit 300, first purification unit 110, second purification unit 120, thermal interaction unit 130, first storage chamber 131, second storage chamber 132, first hydrogen cooling unit 141, second hydrogen cooling unit 142, first inlet and outlet 151, second inlet and outlet 152, third inlet and outlet 153, heating wire 154. DETAILED DESCRIPTION

[0015] Example 1 Example 1 is basically as shown in the attached Figure 1-4 As shown, Figure 1-4 The method for purifying hydrogen based on magnesium-based solid-state hydrogen storage materials shown in FIG. 1 includes the following steps: S1 constructing a hydrogen purification system and S2 purifying. In this embodiment, the connection relationship of the hydrogen purification system is as follows: Figure 2 As shown, S1 builds a hydrogen purification system including the following steps: S11: Encapsulate the magnesium-based solid-state hydrogen storage material into several purification units, and connect two purification units in parallel, and set a thermal interaction unit 130 between the two parallel purification units to form a primary purification module 100; specifically, the primary purification module 100 includes a first purification unit 110 and a second purification unit 120. The structures of the first purification unit 110 and the second purification unit 120 are basically the same, including a shell and a valve assembly, a heat transfer cavity is nested outside the shell, and the shell is filled with solid-state hydrogen storage material. An air inlet pipe, an air outlet pipe and an exhaust pipe are provided on the shell, and the air inlet pipe, the air outlet pipe and the exhaust pipe all extend to the outside of the heat transfer cavity. The valve assembly includes a first control valve and an exhaust valve. In this embodiment, the first control valve and the exhaust valve are both one-way solenoid valves. The first control valve is set on the outlet pipe, and the exhaust valve is set on the exhaust pipe.

[0016] like Figure 3 As shown, the heat exchange unit 130 includes a first storage chamber 131, a second storage chamber 132, heat transfer oil and an oil pump. The first storage chamber 131 and the second storage chamber 132 are respectively connected to the heat transfer chambers of the first purification unit 110 and the second purification unit 120 to form a heat conduction loop. Specifically, as shown in FIG. Figure 5As shown, the first storage chamber 131 includes a tank body, a temperature sensor and a heating wire 154. The tank body is provided with a first inlet and outlet 151, a second inlet and outlet 152, a third inlet and outlet 153 and an isolation plate. The first inlet and outlet 151 is provided on the lower side wall of the tank body and is connected to the heat conduction cavity of the first purification unit 110. The second inlet and outlet 152 is provided on the opposite side of the first inlet and outlet 151 and is connected to the heat conduction cavity of the second purification unit 120. The third inlet and outlet 153 is provided on the top of the tank body. The isolation plate is provided on the first inlet and outlet 151 and the second inlet and outlet 153. 2 to prevent the incoming heat-conducting oil with a lower temperature from flowing out directly. The temperature sensor and the heating wire 154 are both arranged at the bottom of the tank. When the temperature sensor detects that the temperature of the heat-conducting oil in the tank is lower than the preset value, the heating wire 154 starts and heats the heat-conducting oil in the tank, thereby heating the heat-conducting oil to the required temperature through the heating wire 154. The heat-conducting oil is located in the heat-conducting loop. The oil pump is arranged on the heat-conducting loop and can control the flow direction of the heat-conducting oil. In this embodiment, the oil pump is a servo motor, and the flow direction of the heat-conducting oil in the heat-conducting loop is controlled by the forward and reverse rotation of the servo motor.

[0017] S12: Connecting several primary purification modules 100 in series to form two parallel first purification channels and second purification channels, wherein the first purification channel is composed of first purification units 110 that alternately perform hydrogen absorption reactions in series, and the second purification channel is composed of second purification units 120 that alternately perform hydrogen absorption reactions in series; S13: Fix cooling units on the outer wall of the outlet pipes of the two parallel purification units respectively, and connect the cooling units with the heat exchange unit 130 to form a final purification module 200. The final purification module 200 is set at the outlet end of the purification channel and connected in series with the purification channel; S14: Set a drying and filtering unit 300. The drying and filtering unit 300 is set at the inlet end of the two purification channels and connected to the purification channels through a reversing valve. Specifically, Figure 4 As shown, the first hydrogen cooling unit 141 and the second hydrogen cooling unit 142 are respectively arranged on the outer wall of the gas outlet pipe of the first purification unit 110 and the second purification unit 120 of the final purification module 200, and are connected to the first storage chamber and the second storage chamber of the heat exchange unit 130. Figure 3 As shown, the first hydrogen cooling unit 141 and the second hydrogen cooling unit 142 both include a liquid inlet pipe and a liquid outlet pipe. The liquid inlet pipe is connected to the second storage chamber 132, and the liquid outlet pipe is connected to the third inlet and outlet 153. A cooling pump is provided on the liquid inlet pipe and can drive the flow of thermal oil, so that the thermal oil is used to cool the purified hydrogen and the heated thermal oil is transferred to the hot oil storage tank, thereby reducing the energy consumed by the hot oil storage tank.

[0018] S2 purification includes the following steps: S20 Drying and impurity removal: The low-purity hydrogen containing impurities passes through the drying and filtering unit 300, is filtered and dried by the drying and filtering unit 300, and low-purity hydrogen is obtained. The low-purity hydrogen is introduced into a purification channel composed of a plurality of primary purification modules 100, and the adjacent purification units in each purification channel are controlled to alternately perform hydrogen absorption reactions, so that the low-purity hydrogen undergoes several hydrogen absorption reactions and hydrogen release reactions, reaches the final purification module 200, and is absorbed and released by the purification units of the final purification module 200, thereby obtaining high-purity hydrogen.

[0019] S21, low-purity hydrogen is introduced into the purification module, so that the low-purity hydrogen undergoes hydrogen absorption reaction and hydrogen desorption reaction in the parallel purification units respectively, so as to purify the low-purity hydrogen. Specifically, the purification process includes an adsorption stage and a desorption stage. The temperature for the hydrogen absorption reaction in the adsorption stage is 100-450°C and the pressure is 0.5-5 MPa; the temperature for the hydrogen desorption reaction in the desorption stage is 100-450°C and the pressure is 0.1-1 MPa, and the heat interaction unit 130 is used to supply heat to the purification unit performing the hydrogen desorption reaction and store the heat energy released by the hydrogen absorption reaction.

[0020] S22 Cooling: The high-purity hydrogen is discharged from the outlet pipe of the final purification module 200 and cooled by a cooling unit.

[0021] The above is only an embodiment of the present invention, and common knowledge such as the specific technical solutions and / or characteristics in the solution are not described in detail here. It should be pointed out that the technical means for solving the problems in the above-mentioned embodiments of the present invention can be used in combination to solve multiple technical problems at the same time. For those skilled in the art, without departing from the technical solution of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention. These will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A method for purifying hydrogen based on a magnesium-based solid-state hydrogen storage material, characterized in that: The method comprises the following steps: S1 constructing a hydrogen purification system and S2 purification, purifying low-purity hydrogen by running the hydrogen purification system constructed by S1, wherein S1 includes S11: encapsulating a magnesium-based solid-state hydrogen storage material into a plurality of purification units, connecting two purification units in parallel, and providing a heat exchange unit between the two parallel purification units to form a primary purification module; S2 purification includes S21, which allows low-purity hydrogen to be introduced into the purification module, so that the low-purity hydrogen undergoes hydrogen absorption reaction and hydrogen desorption reaction in the parallel purification units respectively, so as to purify the low-purity hydrogen, and heat is supplied to the purification unit undergoing hydrogen desorption reaction through the heat interaction unit and the heat energy released by the hydrogen absorption reaction is stored.

2. The method for purifying hydrogen based on magnesium-based solid hydrogen storage materials according to claim 1, characterized in that: S1 also includes S12: connecting several primary purification modules in series to form two parallel purification channels; during S2 purification, adjacent purification units in each purification channel alternately perform hydrogen absorption reactions.

3. The method for purifying hydrogen based on magnesium-based solid hydrogen storage materials according to claim 2, characterized in that: S1 also includes S13: fixing cooling units on the outer walls of the outlet pipes of the two parallel purification units respectively, and connecting the cooling units with the heat exchange unit to form a final purification module, which is arranged at the outlet end of the purification channel and connected in series with the purification channel.

4. The method for purifying hydrogen based on magnesium-based solid hydrogen storage materials according to claim 3, characterized in that: S1 further includes S14: providing a drying and filtering unit, which is provided at the air inlet ends of the two purification channels and communicates with the purification channels through a reversing valve.

5. The method for purifying hydrogen based on magnesium-based solid hydrogen storage materials according to claim 4, characterized in that: S2 also includes S20 drying and impurity removal: low-purity hydrogen containing impurities passes through a drying and filtering unit, is filtered and dried by the drying and filtering unit to obtain low-purity hydrogen, and the low-purity hydrogen is passed into a purification channel composed of several primary purification modules, and reaches the final purification module after several hydrogen absorption and desorption reactions and is absorbed and released by the purification unit of the final purification module to obtain high-purity hydrogen.

6. The method for purifying hydrogen based on magnesium-based solid hydrogen storage materials according to claim 5, characterized in that: S2 also includes S22 cooling: high-purity hydrogen is discharged from the outlet pipe of the final purification module and cooled by a cooling unit.

7. The method for purifying hydrogen based on a magnesium-based solid hydrogen storage material according to claim 1, wherein: The S21 process includes an adsorption stage for hydrogen absorption reaction and a desorption stage for hydrogen release reaction. The temperature of the adsorption stage is 100-450°C and the pressure is 0.5-5 MPa; the temperature of the desorption stage is 100-450°C and the pressure is 0.1-1 MPa.

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