Plasma nitrogen fixation device of spatial non-uniform plasma electric field

Abstract

The invention discloses a plasma nitrogen fixation device of a spatial non-uniform plasma electric field, which belongs to the field of energy power equipment and comprises a solution storage device, a plasma reactor, a non-uniform thickness barrier medium, a high-voltage electrode, a central high-voltage electrode bar, a three-way connector, an air inlet, a grounding electrode and an absorption aqueous solution. The high-voltage electrode and the grounding electrode are respectively positioned in the nitrogen fixation device and the absorption aqueous solution, the non-uniform thickness barrier medium is made of polytetrafluoroethylene and clings to the surface of the high-voltage electrode, and the bottom of the plasma reactor is provided with a small hole for reaction tail gas to enter the absorption aqueous solution; one side of the three-way joint is connected with the high-voltage electrode and the plasma reactor, and the other side is connected with the air inlet. According to the invention, polytetrafluoroethylene with non-uniform thickness is used as a discharge barrier medium, a plasma electric field with non-uniform space is generated, the high-electric-field-intensity power generation characteristic and the low-electric-field-intensity discharge characteristic are coupled, the air nitrogen fixation efficiency is improved, and the problem that the air nitrogen fixation yield of an existing uniform-intensity electric field is limited is solved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of energy power equipment, and particularly relates to a nitrogen fixation device based on a spatial non-uniform plasma electric field, which is especially suitable for converting nitrogen and oxygen in air into nitrate and nitrite through plasma discharge. BACKGROUND

[0002] Traditional plasma nitrogen fixation devices mostly use a single-intensity electric field formed by a uniform-thickness blocking medium, and have problems such as low efficiency of generating nitrogen oxides, and insufficient absorption of reaction products. In the uniform electric field, high-energy electrons are concentratedly distributed, which limits the dissociation efficiency of nitrogen molecules, and reaction products are prone to escape at the gas-liquid interface. In addition, the discharge gap and the structure of the reactor in the existing device lack optimization, the gas residence time is short, and the energy utilization rate is low. Therefore, there is an urgent need for a device capable of regulating the plasma reaction path through the gradient distribution of electric field intensity, so as to improve the nitrogen fixation efficiency and the product absorption rate. SUMMARY

[0003] The application provides a plasma nitrogen fixation device of a spatial non-uniform plasma electric field, which is characterized by comprising a solution reservoir, a plasma reactor, a non-uniform-thickness blocking medium, a high-voltage electrode, a central high-voltage electrode rod, a tee joint, an air inlet, a grounding electrode, and an absorption aqueous solution.

[0004] The solution reservoir is a container with a closed bottom, and the upper part thereof is sealingly connected with the plasma reactor, and is used for storing the absorption aqueous solution; the plasma reactor is a cylindrical quartz glass cavity, and a small exhaust hole with a diameter of 0.2 mm is formed in the bottom of the plasma reactor, and a discharge gap with a width of 2-3 mm is formed between the inner wall of the plasma reactor and the non-uniform-thickness blocking medium.

[0005] Further, the non-uniform-thickness blocking medium is made of polytetrafluoroethylene, and the thickness thereof changes periodically along the surface of the high-voltage electrode, and the thickness alternately distributes between 1 mm and 2 mm, and the distance between the wave crest and the wave trough is 10-20 mm.

[0006] The high-voltage electrode is connected with the central high-voltage electrode rod, the central high-voltage electrode rod penetrates through the top of the plasma reactor and extends axially to the central position in the reactor, and forms a spatial non-uniform discharge gap with the inner wall of the reactor;

[0007] Further, the central high-voltage electrode rod is connected with a high-voltage power supply at the end thereof, and the exposed part at the front end is arranged in a spaced manner with the non-uniform-thickness blocking medium, and the discharge voltage ranges from 10 kV to 30 kV.

[0008] Further, the tee joint is made of polytetrafluoroethylene, a first port of the tee joint is connected with an output end of the high-voltage power supply, a second port of the tee joint is sealingly connected with the top of the plasma reactor, and a third port of the tee joint is in communication with the air inlet through a gas guide pipe.

[0009] Further, the air inlet is arranged at the lateral port of the tee joint, the air is the inlet type, and the controllable flow range is 1-5 L / min.

[0010] Further, the grounding electrode is immersed in the absorption aqueous solution, and the arrangement position is kept at a liquid surface spacing of 0.5-2 cm from the bottom of the solution reservoir.

[0011] Further, the absorption aqueous solution is stored in the lower cavity of the solution reservoir, and initially uses ultrapure water or distilled water, the liquid level covers the grounding electrode and is slightly lower than the exhaust hole at the bottom of the plasma reactor.

[0012] The present application has the beneficial effects that: a spatial non-uniform electric field is formed by the periodic thickness change of the polytetrafluoroethylene barrier medium, nitrogen activation is excited in the low-pressure area, and nitrogen oxidation is promoted in the high-pressure area, and meanwhile, the bottom micropore design enhances gas-liquid mass transfer and strengthens nitrogen oxide absorption. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 It is a longitudinal section schematic diagram of the overall structure of the present application.

[0014] Figure 1 The reference signs are as follows: 1, solution reservoir, 2, plasma reactor, 3, non-uniform thickness barrier medium, 4, high-voltage electrode, 5, center high-voltage electrode rod, 6, tee joint, 7, air inlet, 8, grounding electrode, 9, absorption aqueous solution. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application is described in detail below in combination with the drawings and specific embodiments.

[0016] Referring to Figure 1 , the present application embodiment provides a spatial non-uniform plasma electric field plasma nitrogen fixation device, which comprises a solution reservoir 1, a plasma reactor 2, a non-uniform thickness barrier medium 3, a high-voltage electrode 4, a center high-voltage electrode rod 5, a tee joint 6, an air inlet 7, a grounding electrode 8, and an absorption aqueous solution 9.

[0017] Referring to Figure 1 , the high-voltage electrode 4 is connected with the center high-voltage electrode rod 5, the center high-voltage electrode rod 5 passes through the inside of the tee joint 6 and is positioned and fixed at one side of the plasma reactor 2 by the tee joint 6, and the end of the center high-voltage electrode rod 5 is a high-voltage positive electrode connected into the plasma reactor 2.

[0018] Referring to Figure 1The uneven thickness barrier medium 3 is made of polytetrafluoroethylene and has a periodic thickness variation of 1-2 mm on the surface of the high-voltage electrode.

[0019] Referring to Figure 1 The ground electrode 8 is a metal rod body and is placed in the absorbing aqueous solution 9, which is arranged at a distance of 0.5-2 cm from the bottom of the solution reservoir 1. The absorbing aqueous solution 9 is stored in the lower cavity of the solution reservoir 1 and serves as the ground electrode and the absorbing liquid. The liquid level covers the ground electrode 8 and is slightly lower than the uneven thickness barrier medium 3 in the plasma reactor 2. The absorbing solution is initially ultrapure water or distilled water.

[0020] The working process of the application is as follows: when working, the high-voltage positive electrode access end 4 is connected to a single power supply high-voltage electricity, and the voltage is generally 10 kV, under the condition that the ground end 9 has been grounded.

[0021] After the single power supply high-voltage electricity is turned on, barrier medium discharge occurs between the uneven thickness barrier medium 3 and the plasma reactor 2, and the nitrogen oxides after the space nitrogen fixation are absorbed by the absorbing aqueous solution 9 as nitrate and nitrite ions.

[0022] The device of the application can be used to carry out plasma nitrogen fixation of the space non-uniform plasma electric field under different flow rates, different power supply types, different power supply parameters, and different electrode parameters.

[0023] The above description is only a preferred embodiment of the application, and the protection scope of the application is not limited thereto. Any person skilled in the art can make equivalent replacements or changes to the technical solutions and the inventive concept of the application within the disclosed technical scope, such as the types of the uneven thickness barrier medium material and the discharge gap size in the application, which should be covered within the protection scope of the application.

Claims

1. A plasma nitrogen fixation device with a spatially non-uniform plasma electric field, characterized in that... By utilizing an insulating material of non-uniform thickness as a barrier medium to form a spatially non-uniform plasma barrier medium discharge, the efficiency of nitrogen fixation in air to generate nitrogen oxides is improved, and the absorption rate of nitrate and nitrite ions generated by water absorption is further enhanced. The system consists of a solution storage tank (1), a plasma reactor (2), a barrier medium of non-uniform thickness (3), a high-voltage electrode (4), a central high-voltage electrode rod (5), a three-way connector (6), an air inlet (7), a grounding electrode (8), and an absorption aqueous solution (9).

2. The plasma nitrogen fixation device according to claim 1, characterized in that: The non-uniform thickness blocking medium (3) is made of polytetrafluoroethylene, and its thickness varies periodically along the surface of the high voltage electrode, with the thickness varying periodically between 1 and 2 mm.

3. The plasma nitrogen fixation device according to claim 1, characterized in that: The high-voltage electrode (4) is connected to the central high-voltage electrode rod (5), which is axially arranged through the plasma reactor (2), forming a spatial non-uniform discharge gap between the inner wall of the plasma reactor (2) and the central high-voltage electrode rod (5).

4. The plasma nitrogen fixation device according to claim 1, characterized in that: The grounding electrode (8) is immersed in the absorbent aqueous solution (9) and is positioned at a distance of 0.5-2 cm from the bottom of the solution reservoir (1).

5. The plasma nitrogen fixation device according to claim 1, characterized in that: The plasma reactor (2) is a cylindrical quartz glass cavity with a 0.2 mm diameter exhaust hole at the bottom. A discharge space with a 2-3 mm discharge gap is formed between the inner wall of the reactor and the non-uniform thickness barrier medium (3).

6. The plasma nitrogen fixation device according to claim 1, characterized in that: The three-way connector (6) is made of insulating polytetrafluoroethylene. The first port is connected to the high-voltage power output terminal, the second port is connected to the top of the plasma reactor (2), and the third port is connected to the air inlet (7) through a gas guide pipe.

7. The plasma nitrogen fixation device according to claim 1, characterized in that: The air inlet (7) is located on the side port of the three-way connector (6), and the air type is air.

8. The plasma nitrogen fixation device according to claim 1, characterized in that: The absorbent aqueous solution (9) is stored in the lower cavity of the solution storage tank (1) and serves as both the ground electrode and the absorbent. The liquid level covers the ground electrode (8) and is slightly lower than the non-uniform thickness barrier medium (3) in the plasma reactor (2). The absorbent solution is initially made of ultrapure water or distilled water.

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