Plate-hole DBD plasma assisted proton exchange membrane ammonia hydrogen production device

Abstract

The present invention discloses a device for producing hydrogen from ammonia using plate-hole DBD plasma in coordination with a proton exchange membrane. An air inlet and an ammonia decomposition reaction unit are arranged at the upper part of a device main body, and an air outlet and a hydrogen separation unit are arranged at the lower part of the device main body. The ammonia decomposition reaction unit is a parallel plate-hole DBD structure, and the hydrogen separation unit is composed of a parallel plate-hole DBD and a proton exchange membrane. The ammonia decomposition reaction unit and the hydrogen separation unit are connected by a high-voltage electrode with small holes covered with a blocking medium, and the inside of the device main body is filled with a catalyst; a spiral coil is arranged on the outer surface of the device; the present invention can improve the efficiency of producing hydrogen from ammonia and effectively separate hydrogen by combining ammonia decomposition, membrane separation and plasma treatment.

Description

Technical Field

[0001] The invention belongs to the field of plasma technology, and in particular relates to a device for producing hydrogen by using plate-hole DBD plasma in coordination with proton exchange membrane ammonia. Background Art

[0002] Hydrogen is an ideal renewable clean energy source. It is not only easy to obtain in various ways, but also its combustion product is only water as a carbon-free energy source. At the same time, hydrogen is widely used in aerospace, electronics, chemical industry, energy and other fields, and has broad application prospects. At present, the commonly used hydrogen production methods mainly include hydrocarbon hydrogen production, alcohol hydrogen production, biological hydrogen production, water electrolysis hydrogen production, ammonia hydrogen production, etc. However, hydrocarbon, alcohol and other hydrogen production methods will produce CO X Carbon oxides such as carbon dioxide will lead to increased environmental pollution; biological hydrogen production will also produce greenhouse gases such as carbon dioxide; and hydrogen production by water electrolysis is expensive, inefficient, and has complex equipment, which cannot meet the development needs of hydrogen energy. In contrast, NH3, as a carbon-free clean energy, ammonia hydrogen production not only does not burden the environment, but also has the advantages of higher volume density, relatively low cost, and easier liquefaction. It can be used as a chemical storage medium for hydrogen storage and transportation, which can well solve the problems of hydrogen storage and transportation.

[0003] The traditional methods of ammonia decomposition mainly include thermal decomposition and catalytic decomposition. At 425°C, the thermodynamic equilibrium conversion rate of ammonia can reach 98%, but in practical applications, its thermal decomposition reaction is difficult to achieve kinetically, and high temperature may cause problems such as reactor damage and flash explosion. On the other hand, ammonia decomposition to produce hydrogen usually cooperates with metal catalysts such as Ru, but although precious metal catalysts can effectively improve the efficiency of ammonia decomposition, it will undoubtedly increase the cost of ammonia hydrogen production, and the improvement effect of cheap metals is not ideal. In order to explore more efficient hydrogen production methods, scholars continue to introduce new hydrogen production technologies.

[0004] In recent years, scientific research and engineering application fields have begun to pay more and more attention to the application of plasma in the field of ammonia decomposition and hydrogen production. The coupling of plasma technology and catalytic technology can not only integrate the rapidity and efficiency of plasma, but also integrate the high selectivity of catalysts, greatly improving the decomposition efficiency of ammonia. Dielectric barrier discharge (DBD) can produce a large area of ​​low-temperature plasma, i.e., non-equilibrium plasma, at normal pressure. It has the characteristics of high electron energy and low gas temperature. At present, non-equilibrium plasma has been applied to organic pollutant treatment and material surface treatment. The DBD mode has the advantages of good uniformity and stability, moderate energy density, and simple structure, and is more promising in various industrial applications. The plate-hole DBD structure can focus the arc energy on the edge of the small hole, thereby improving the discharge stability and discharge intensity.

[0005] Since different industries have purity requirements for hydrogen energy, hydrogen must be separated from mixed gases. The main methods for separating hydrogen include adsorption, cryogenic separation, and membrane permeation. Compared with traditional separation methods, membrane separation technology has the characteristics of low energy consumption, low investment, and easy use. Among them, palladium alloy membrane permeation separation technology has the advantages of high hydrogen selectivity, strong hydrogen permeability, and good chemical and thermal stability, and has attracted much attention in the field of ammonia hydrogen production.

[0006] Most of the current devices that use DBD plasma to produce hydrogen from ammonia cannot avoid the randomness and dispersion of the discharge in space, and cannot achieve effective utilization of energy. There are problems such as serious reverse reaction in the ammonia decomposition process, the generation of mixed gases as products, and the inability to simultaneously and continuously decompose and purify the gas. Summary of the invention

[0007] In view of this, the present invention provides a device for producing hydrogen from ammonia using plate-hole DBD plasma in collaboration with proton exchange membrane, which can match appropriate discharge plasma according to the requirements of ammonia decomposition, achieve effective treatment of ammonia, improve the phenomenon of "ammonia-hydrogen mixing" of the product, separate hydrogen in time, and reduce reverse reaction.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A device for producing hydrogen from ammonia using plate-hole DBD plasma in coordination with proton exchange membrane, wherein an air inlet and an ammonia decomposition reaction unit are arranged at the upper part of the device body, and an air outlet and a hydrogen separation unit are arranged at the lower part of the device body, the ammonia decomposition reaction unit and the hydrogen separation unit are connected by a high-voltage electrode, the center of the high-voltage electrode is provided with a small hole, and a spiral coil is arranged on the outer surface of the device body, the ammonia decomposition reaction unit is a parallel plate DBD structure, including a high-voltage electrode covering a blocking medium and an upper grounding electrode covering the blocking medium; the hydrogen separation unit is composed of a parallel plate DBD structure in coordination with a proton exchange membrane structure, including a high-voltage electrode with holes covering a blocking medium and a lower grounding electrode covering the blocking medium, and the proton exchange membrane encloses and surrounds the blocking medium connected to the lower grounding electrode.

[0010] Furthermore, the device body is a closed cylindrical structure, the upper end is a circular upper grounding electrode, the lower end is a circular lower grounding electrode, and the outer surface of the device body is an annular quartz tube with a thickness of 1 mm.

[0011] Furthermore, the air inlet is located at the top of the device body and away from the small hole on the high-voltage electrode. The diameter of the air inlet is 2.0mm-5.0mm. A mass flow meter can be provided at the air inlet. The ammonia input pipe forms a sealed connection with the ammonia decomposition reaction unit through the air inlet; an air outlet is provided at the bottom of the device body. The diameter of the air outlet is 2.0mm-5.0mm. The hydrogen separation reaction unit forms a sealed connection with the hydrogen gas transmission pipeline through the air outlet.

[0012] Furthermore, the distance between the spiral coil surrounding the outside of the device body and the surface of the device body is 1 mm, and the number of turns of the spiral coil is 100.

[0013] Furthermore, the high-voltage electrode with small holes is also a gas flow channel, the height of the gas flow channel is 5mm, the outer diameter of the high-voltage electrode is 5cm-50cm, the inner diameter is 4mm-7mm, and the diameter of the small holes is 2.0mm-5.0mm.

[0014] Furthermore, the ammonia decomposition reaction unit is filled with a catalyst Ni / MgO, and the hydrogen separation unit is filled with a zeolite molecular sieve.

[0015] Furthermore, the spacing between the high-voltage electrode and the upper grounding electrode is 5mm-10mm, the diameter of the upper grounding electrode is 5cm-50cm, the spacing between the high-voltage electrode and the lower grounding electrode is 5mm-10mm, the diameter of the lower grounding electrode is 5cm-50cm, the diameter of the blocking medium is 6cm-50cm, and the thickness of the blocking medium is 1mm.

[0016] Furthermore, the proton exchange membrane is a palladium-copper alloy membrane.

[0017] Preferably, the material of the blocking medium is quartz glass, ceramic, epoxy, polytetrafluoroethylene, or tempered glass.

[0018] Furthermore, the high voltage electrode, the upper grounding electrode and the lower grounding electrode are made of copper, aluminum alloy stainless steel, or gold / copper.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention combines plasma treatment with hydrogen separation treatment, realizes hydrogen production by decomposing ammonia and separates hydrogen in time by reasonably matching discharge plasma, thereby greatly improving the conversion rate of ammonia, improving the stability and timeliness of ammonia decomposition, and improving the phenomena of "ammonia decomposition reverse reaction" and "ammonia-hydrogen mixing", which is of great significance and practical value for realizing more efficient and economical industrial application of hydrogen production by decomposing ammonia. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0022] Figure 1 This is an internal structural diagram of the device for producing hydrogen from ammonia using plate-hole DBD plasma in cooperation with proton exchange membrane;

[0023] Figure 2 This is an external structural diagram of the device for producing hydrogen from ammonia using plate-hole DBD plasma in cooperation with proton exchange membrane;

[0024] Figure 3 Schematic diagram of the high voltage electrode structure with a small hole flat plate barrier medium of the present invention;

[0025] Figure 4 It is a schematic diagram of the internal cross section of the device for producing hydrogen from ammonia using plate-hole DBD plasma in cooperation with proton exchange membrane according to the present invention;

[0026] Figure 5 It is a schematic diagram of the structure of the ammonia decomposition reaction unit in the device for producing hydrogen from ammonia using plate-hole DBD plasma in cooperation with proton exchange membrane according to the present invention;

[0027] Figure 6 It is a schematic diagram of the structure of the hydrogen separation unit in the device for producing hydrogen from ammonia using plate-hole DBD plasma in cooperation with proton exchange membrane of the present invention.

[0028] In the figure, 1-air inlet, 2-upper ground electrode, 3-high voltage electrode, 4-proton exchange membrane, 5-lower ground electrode, 6-air outlet, 7-spiral coil, 8-small hole, 9-barrier medium, 10-catalyst Ni / MgO, 11-zeolite molecular sieve. DETAILED DESCRIPTION

[0029] The following will describe the implementation methods of the present invention in detail with reference to the embodiments, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0030] like Figure 1-6As shown, an embodiment of the present invention discloses a device for producing hydrogen from ammonia using plate-hole DBD plasma in cooperation with proton exchange membrane, comprising a device body, an air inlet 1 and an ammonia decomposition reaction unit are arranged at the upper part of the device body, a gas outlet 6 and a hydrogen separation unit are arranged at the lower part of the device body, the ammonia decomposition reaction unit and the hydrogen separation unit are connected by a high-voltage electrode 3, a small hole 8 is arranged at the center of the high-voltage electrode 3, a spiral coil 7 is arranged on the outer surface of the device body, the ammonia decomposition reaction unit is a parallel plate DBD structure, including a high-voltage electrode 3 covering a blocking medium 9 and an upper grounding electrode 2 covering the blocking medium 9; the hydrogen separation unit is a parallel plate DBD structure in cooperation with a proton exchange membrane 4, including a high-voltage electrode 3 covering a blocking medium 9 and a lower grounding electrode 5 covering the blocking medium 9, and the proton exchange membrane 4 encloses and surrounds the blocking medium 9 connected to the lower grounding electrode 5.

[0031] The main body of the device is a cylindrical structure with closed sides, with a circular upper grounding electrode 2 at the upper end and a circular lower grounding electrode 5 at the lower end. The outer surface of the main body of the device is a ring-shaped quartz tube with a thickness of 1 mm. The air inlet 1 is located at the top of the main body of the device and away from the small hole 8 on the high-voltage electrode 3. The air inlet flow rate of the air inlet 1 is adjustable, and the diameter of the air inlet 1 is adjustable from 2.0 mm to 5.0 mm. The air inlet 1 can be provided with a mass flow meter. The ammonia input pipe is sealed and connected with the ammonia decomposition reaction unit through the air inlet 1; the bottom of the main body of the device is provided with an air outlet 6, and the diameter of the air outlet 6 is adjustable from 2.0 mm to 5.0 mm. The hydrogen separation reaction unit is sealed and connected with the hydrogen gas transmission pipeline through the air outlet 6. The pretreated gas completes the reaction in the ammonia decomposition reaction unit and then enters the hydrogen separation unit from the small hole 8, and the gas is discharged through the air outlet 6.

[0032] like Figure 2 As shown, a spiral coil 7 is wrapped around the outside of the device body, which can generate a parallel magnetic field in the reaction area of ​​the device body. The distance between the spiral coil and the surface of the device body is 1 mm, and the number of turns of the spiral coil is 100.

[0033] like Figure 3 As shown, the high-voltage electrode 3 with the small hole 8 is also a gas flow channel. The height of the gas flow channel is 5 mm. The outer diameter of the high-voltage electrode 3 is adjustable from 5 cm to 50 cm, the inner diameter is adjustable from 4 mm to 7 mm, and the diameter of the small hole 8 is adjustable from 2.0 mm to 5.0 mm.

[0034] like Figure 4As shown, it is a cross-sectional view of the device body, the spacing between the high-voltage electrode 3 and the upper grounding electrode 2 is adjustable from 5mm to 10mm, the diameter of the upper grounding electrode 2 is adjustable from 5cm to 50cm, the spacing between the high-voltage electrode 3 and the lower grounding electrode 5 is adjustable from 5mm to 10mm, the diameter of the lower grounding electrode 5 is adjustable from 5cm to 50cm, the diameter of the blocking medium 9 is adjustable from 6cm to 50cm, and the thickness of the blocking medium 9 is 1mm. The proton exchange membrane 4 is a palladium-copper alloy membrane, etc.; the material of the blocking medium 9 is but not limited to quartz glass, ceramic, epoxy, polytetrafluoroethylene, tempered glass, etc.; the high-voltage electrode, the upper grounding electrode and the lower grounding electrode can be but not limited to copper, aluminum alloy, stainless steel, gold-plated / copper, etc.

[0035] The workflow of the present invention is as follows Figure 5 , 6 As shown, the details are as follows:

[0036] like Figure 5 As shown, the ammonia decomposition reaction unit is a plate-hole dielectric barrier structure, the ammonia decomposition reaction unit is filled with catalyst Ni / MgO10, and the reaction gas flows out through the small hole 8.

[0037] like Figure 6 As shown, the hydrogen separation unit is a plate-pore dielectric barrier structure, the hydrogen separation unit is filled with a catalyst zeolite molecular sieve 11, and hydrogen permeates from the proton exchange membrane 4 to the gas outlet 6.

[0038] The present invention realizes hydrogen production from ammonia by direct purification in coordination with DBD plasma. The Ar / NH3 mixed gas is firstly processed by an ammonia decomposition reaction unit. The energetic charged ions, highly active groups and light and electrical effects in the plasma cooperate with the catalyst Ni / MgO. The ammonia molecules collide with high-energy metastable argon atoms to produce Penning excitation and ionization reactions, so that the NH bond is broken, which can effectively generate electron collision reactions to excite and produce NH * NH2 * and H free radicals to generate hydrogen which flows into the hydrogen separation unit through the small holes; in the hydrogen separation unit, the zeolite molecular sieve can absorb excess ammonia, and its microporous structure will also promote the generation of micro-discharges. Hydrogen is decomposed into H free radicals under the action of plasma, and high-concentration H free radicals penetrate from the proton exchange membrane to the gas outlet, ultimately achieving hydrogen purification.

[0039] In the device of the present invention, the ammonia decomposition reaction unit and the hydrogen separation unit are placed in a complete and closed system. The two are continuous in action mechanism and process, and at the same time belong to two independent working links without direct interaction. The spiral coil outside the main body of the device plays an auxiliary role in the work of the system. The charged particles are subjected to the Lorentz force to make circular motion under the action of the magnetic field, which not only increases the residence time of the gas particles, but also increases the probability of collision. That is, the gas first enters the ammonia decomposition reaction unit and is in the moving process. After the plasma treatment, it directly enters the hydrogen separation unit to start the second stage of the purification process.

[0040] The above description shows and describes several preferred embodiments of the invention, but as mentioned above, it should be understood that the invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the invention concept described herein through the above teachings or the technology or knowledge of the relevant field. Changes and modifications made by those skilled in the art should be within the scope of protection of the claims attached to the invention without departing from the spirit and scope of the invention.

Claims

1. A device for producing hydrogen from ammonia using plate-hole DBD plasma in cooperation with proton exchange membrane, characterized in that: The upper part of the device body is provided with an air inlet and an ammonia decomposition reaction unit, and the lower part of the device body is provided with an air outlet and a hydrogen separation unit. The ammonia decomposition reaction unit and the hydrogen separation unit are connected by a high-voltage electrode, and a small hole is provided in the center of the high-voltage electrode. A spiral coil is provided on the outer surface of the device body. The ammonia decomposition reaction unit is a parallel plate DBD structure, including a high-voltage electrode covering a blocking medium and an upper grounding electrode covering the blocking medium; the hydrogen separation unit is composed of a parallel plate DBD structure and a proton exchange membrane structure, including a high-voltage electrode covering a blocking medium and a lower grounding electrode covering the blocking medium, and the proton exchange membrane encloses and surrounds the blocking medium connected to the lower grounding electrode.

2. The plate-hole DBD plasma assisted proton exchange membrane ammonia hydrogen production device according to claim 1, characterized in that: The device body is a closed cylindrical structure, the upper end is a circular upper grounding electrode, and the lower end is a circular lower grounding electrode. The outer surface of the device body is a ring-shaped quartz tube with a thickness of 1 mm.

3. The plate-hole DBD plasma assisted proton exchange membrane ammonia hydrogen production device according to claim 1, characterized in that: The air inlet is located at the top of the device body and away from the small hole on the high-voltage electrode. The diameter of the air inlet is 2.0mm-5.0mm. The air inlet is provided with a mass flow meter. The ammonia input pipe forms a sealed connection with the ammonia decomposition reaction unit through the air inlet; the bottom of the device body is provided with an air outlet. The diameter of the air outlet is 2.0mm-5.0mm. The hydrogen separation reaction unit forms a sealed connection with the hydrogen gas transmission pipeline through the air outlet.

4. The plate-hole DBD plasma assisted proton exchange membrane ammonia hydrogen production device according to claim 1, characterized in that: The distance between the spiral coil surrounding the outside of the device body and the surface of the device body is 1 mm, and the number of turns of the spiral coil is 100.

5. The plate-hole DBD plasma assisted proton exchange membrane ammonia hydrogen production device according to claim 1, characterized in that: The high-voltage electrode with small holes is also a gas flow channel. The height of the gas flow channel is 5 mm. The outer diameter of the high-voltage electrode is 5 cm-50 cm, the inner diameter is 4 mm-7 mm, and the diameter of the small holes is 2.0 mm-5.0 mm.

6. The device for producing hydrogen from ammonia using plate-hole DBD plasma in cooperation with proton exchange membrane according to claim 1, characterized in that: The ammonia decomposition reaction unit is filled with Ni / MgO catalyst, and the hydrogen separation unit is filled with zeolite molecular sieve.

7. The device for producing hydrogen from ammonia using plate-hole DBD plasma in cooperation with proton exchange membrane according to claim 1, characterized in that: The spacing between the high-voltage electrode and the upper grounding electrode is 5mm-10mm, the diameter of the upper grounding electrode is 5cm-50cm, the spacing between the high-voltage electrode and the lower grounding electrode is 5mm-10mm, the diameter of the lower grounding electrode is 5cm-50cm, the diameter of the blocking medium is 6cm-50cm, and the thickness of the blocking medium is 1mm.

8. The device for producing hydrogen from ammonia using plate-hole DBD plasma in cooperation with proton exchange membrane according to any one of claims 1 to 7, characterized in that: The proton exchange membrane is a palladium-copper alloy membrane.

9. The device for producing hydrogen from ammonia using plate-hole DBD plasma in cooperation with proton exchange membrane according to any one of claims 1 to 7, characterized in that: The material of the blocking medium is quartz glass, ceramic, epoxy, polytetrafluoroethylene, and tempered glass.

10. The device for producing hydrogen from ammonia using plate-hole DBD plasma in cooperation with proton exchange membrane according to any one of claims 1 to 7, characterized in that: The high voltage electrode, the upper grounding electrode and the lower grounding electrode are made of copper, aluminum alloy stainless steel, or gold-plated copper.

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