阅读说明：本技术 高通量低温等离子体放电装置和分解硫化氢的方法 (High-flux low-temperature plasma discharge device and method for decomposing hydrogen sulfide ) 是由 张婧 徐伟 张铁 任君朋 王世强 张树才 王林 关银霞 孙峰 刘全桢 石宁 周 于 2019-01-16 设计创作，主要内容包括：本发明涉及等离子体化学领域,公开了一种高通量低温等离子体放电装置和分解硫化氢的方法,包括：第一空腔(1),嵌套在第一空腔(1)的内部的第二空腔(2)；设置在第一空腔(1)中的高压电极(3)和接地电极(4),阻挡介质,阻挡介质设置在所述高压电极(3)和/或所述接地电极(4)的外表面。本发明提供的低温等离子体放电装置具有硫化氢转化率高、能耗低以及能够实现大流量硫化氢处理的优点。(The invention relates to the field of plasma chemistry, and discloses a high-flux low-temperature plasma discharge device and a method for decomposing hydrogen sulfide, which comprise the following steps: a first cavity (1), a second cavity (2) nested inside the first cavity (1); the high-voltage electrode (3) and the grounding electrode (4) are arranged in the first cavity (1), and the blocking medium is arranged on the outer surface of the high-voltage electrode (3) and/or the grounding electrode (4). The low-temperature plasma discharge device provided by the invention has the advantages of high hydrogen sulfide conversion rate, low energy consumption and capability of realizing large-flow hydrogen sulfide treatment.)

1. A high flux, low temperature plasma discharge device, the device comprising:

the device comprises a first cavity (1), wherein a first inlet (11) and a first outlet (12) are respectively arranged on the first cavity (1);

the second cavity (2) is nested inside the first cavity (1), and a second inlet (21) and a second outlet (22) are respectively arranged on the second cavity (2);

the high-voltage electrodes (3) and the grounding electrodes (4) are arranged in the first cavity (1), the high-voltage electrodes (3) and the grounding electrodes (4) are respectively multiple, the number of the high-voltage electrodes (3) and the number of the grounding electrodes (4) are respectively equal to or larger than 1, and high-voltage electrode layers formed by the high-voltage electrodes (3) and grounding electrode layers formed by the grounding electrodes (4) are alternately arranged;

a barrier medium arranged on the outer surface of the high voltage electrode (3) and/or the ground electrode (4);

the distance between the high-voltage electrode (3) and the grounding electrode (4) is L₁The thickness of the barrier medium is D₁，L₂＝L₁-D₁And L₂And D₁The ratio of (0.1-150): 1, preferably (0.2 to 100): 1; more preferably (0.5 to 80): 1; more preferably (0.5 to 50): 1.

2. the device of claim 1, wherein in two adjacent layer structures, the centers of the electrodes in the upper layer structure are aligned with or offset from the centers of the electrodes in the lower layer structure.

3. The device according to claim 1 or 2, wherein the gap between two adjacent layer structures is greater than 0 and less than or equal to 100 mm.

4. The device according to claim 1 or 2, wherein in each of the layer structures, a gap between two adjacent electrodes is greater than 0 and 100mm or less.

5. The device of any one of claims 1-4, wherein L is used₂And length L of discharge tube₃Each independently is 1: (2 to 1500), preferably 1: (20-500), more preferably 1: (20-300).

6. The device according to any of claims 1-5, wherein the individual high voltage electrodes (3) are connected in parallel with each other; preferably, the first and second electrodes are formed of a metal,

the respective ground electrodes (4) are connected in parallel with each other.

7. The device of any one of claims 1-6, wherein the blocking medium is made of an electrically insulating material; preferably, the material of the barrier medium is at least one selected from glass, quartz, ceramic, enamel, polytetrafluoroethylene and mica;

the grounding electrode (4) and the high-voltage electrode (3) are made of conductive materials, and preferably, the grounding electrode (4) and the high-voltage electrode (3) are made of at least one material independently selected from graphite tubes, graphite powder, metal tubes, metal rods, metal powder, alloy tubes, alloy rods, alloy powder and graphite rods.

8. The device according to any one of claims 1-7, further comprising a ground wire (5) having one end electrically connected to the ground electrode (4).

9. The device according to any of claims 1-8, wherein the first inlet (11) is arranged at an upper portion of the first cavity (1) and the first outlet (12) is arranged at a bottom portion of the first cavity (1).

10. The device according to any one of claims 1 to 9, wherein at least one of said plurality of high voltage electrodes (3) and said plurality of ground electrodes (4) is a hollow structure, and said hollow structures are in communication with each other to form said second cavity;

preferably, each of the high voltage electrode (3) and each of the ground electrodes (4) are hollow structures, and the hollow structures are communicated with each other to form the second cavity.

11. The device according to any one of claims 1-9, wherein each of said hv electrodes (3) is a hollow structure, and the hollow structures are in communication with each other to form said second cavity.

12. The device according to any one of claims 1 to 9, wherein each of said ground electrodes (4) is a hollow structure, and the hollow structures are in communication with each other to form said second cavity.

13. The device according to any one of claims 1-12, wherein each of said high voltage electrodes (3) is of the same size and each of said ground electrodes (4) is of the same size, and each of said high voltage electrodes (3) and each of said ground electrodes (4) is cylindrical; preferably, the first and second electrodes are formed of a metal,

the diameters of the high-voltage electrode (3) and the grounding electrode (4) are respectively 0.1-100 mm, preferably 0.5-50 mm.

14. The device according to claim 13, wherein the aspect ratio of the high voltage electrode (3) and the ground electrode (4) is (5-600): 1, preferably (10-400): 1.

15. the device according to any of claims 1-14, wherein the second inlet (21) and the second outlet (22) are arranged in a lower part and an upper part, respectively, of the second cavity (2).

16. A method of decomposing hydrogen sulfide, the method being implemented in a high flux low temperature plasma discharge apparatus as claimed in any one of claims 1 to 15, the method comprising: grounding a grounding electrode (4) of the high-flux low-temperature plasma discharge device, connecting a high-voltage electrode (3) with a power supply, performing dielectric barrier discharge, introducing a raw material gas containing hydrogen sulfide into a first cavity (1) of the high-flux low-temperature plasma discharge device from a reactor inlet to perform decomposition reaction of the hydrogen sulfide, leading out a material flow obtained after decomposition from a first outlet, and maintaining the temperature required by the high-flux low-temperature plasma discharge device by continuously introducing a heat-conducting medium into a second cavity of the high-flux low-temperature plasma discharge device from a second inlet and leading out the heat-conducting medium from a second outlet.

17. The method of claim 16, wherein the condition of the dielectric barrier discharge comprises: the discharge voltage is 2kV to 80kV, preferably 5kV to 30kV, more preferably 5kV to 20kV, and even more preferably 5kV to 15 kV; the discharge frequency is 200-30000 Hz, preferably 500-15000 Hz, and more preferably 500-13000 Hz;

the conditions of the decomposition reaction include: the reaction temperature is 0-800 ℃, preferably 40-500 ℃, more preferably 119-444.6 ℃, the reaction pressure is 0-0.6MPa, preferably 0-0.3MPa,

the residence time of the raw gas containing hydrogen sulfide in the discharge area of the high-flux low-temperature plasma discharge device is 1 × 10^-5120s, preferably 2 × 10^-5～60s。

18. The method according to claim 16 or 17, wherein the hydrogen sulfide decomposition reaction is carried out in the presence of a carrier gas selected from at least one of nitrogen, hydrogen, helium, argon, water vapor, carbon monoxide, carbon dioxide, methane, ethane, and propane; preferably, the carrier gas is selected from at least one of hydrogen, argon, helium, and nitrogen.

Technical Field

The invention relates to the field of plasma chemistry, in particular to a high-flux low-temperature plasma discharge device and a method for decomposing hydrogen sulfide.

Background

Hydrogen sulfide (H)₂S) is a highly toxic and malodorous acid gas, which not only can cause the corrosion of materials such as metal, but also can harm the health of human bodies and pollute the environment. At present, the traditional Claus method (Claus) is adopted by large and medium-sized oil refineries in China to treat H-containing oil₂And (4) tail gas of S, and recovering sulfur. The process recovers only the sulfur in the hydrogen sulfide, but converts valuable hydrogen to water. From a comprehensive view of resourcesIn view of utilization, in the conventional hydrogen sulfide recovery process, hydrogen resources are not effectively utilized.

Therefore, the decomposition of hydrogen sulfide into sulfur and hydrogen gradually becomes a technical field of great attention of domestic and foreign researchers.

At present, the hydrogen sulfide decomposition method mainly comprises the following steps: high temperature decomposition, electrochemical, photocatalytic, and low temperature plasma methods. Among the aforementioned methods, the pyrolysis method is relatively mature in industrial technology, but the thermal decomposition of hydrogen sulfide strongly depends on the reaction temperature and is limited by the thermodynamic equilibrium, and the conversion rate of hydrogen sulfide is only 20% even if the reaction temperature is 1000 ℃ or higher. In addition, the high temperature conditions place high demands on reactor materials, which also increases operating costs. In addition, since the thermal decomposition conversion of hydrogen sulfide is low, a large amount of hydrogen sulfide gas needs to be separated from the tail gas and circulated in the system, thereby reducing the efficiency of the apparatus and increasing the energy consumption, which all bring difficulties to large-scale industrial application thereof. Although the adoption of the membrane technology can effectively separate products, thereby breaking balance limitation and improving the conversion rate of hydrogen sulfide, the thermal decomposition temperature often exceeds the limit heat-resistant temperature of the membrane, so that the structure of the membrane material is damaged. The electrochemical method has the defects of multiple operation steps, serious equipment corrosion, poor reaction stability, low efficiency and the like. The photocatalytic method for decomposing hydrogen sulfide mainly refers to the research of photocatalytic water decomposition, and the research focuses on the aspects of developing high-efficiency semiconductor photocatalysts and the like. The method for decomposing the hydrogen sulfide by utilizing the solar energy has the advantages of low energy consumption, mild reaction conditions, simple operation and the like, and is a relatively economic method. However, this method has problems such as a small treatment amount, low catalytic efficiency, and easy deactivation of the catalyst.

Compared with other decomposition methods, the low-temperature plasma method has the advantages of simple operation, small device volume, high energy efficiency and the like, and the involved reaction has high controllability and can be flexibly applied under the conditions of small treatment capacity and difficult centralized treatment. In addition, the hydrogen sulfide decomposition device has the characteristics of high energy density and shortened reaction time, can realize effective decomposition of hydrogen sulfide at a lower temperature, and is suitable for occasions with different scales, dispersed layouts and variable production conditions. Besides, the low-temperature plasma method recovers hydrogen resources while recovering sulfur, and can realize resource utilization of hydrogen sulfide.

At present, researchers at home and abroad carry out extensive research on the technology of decomposing hydrogen sulfide by low-temperature plasma, and the used discharge forms mainly comprise glow discharge, corona discharge, sliding arc discharge, microwave plasma, radio frequency plasma, dielectric barrier discharge and the like.

CN102408095A uses medium to block discharge and light catalyst to decompose hydrogen sulfide, and its method is to pack solid catalyst with light catalytic activity in plasma zone, however, this method has the disadvantage that sulfur produced by hydrogen sulfide decomposition will deposit under catalyst bed.

CN103204466A discloses a temperature-controlled hydrogen sulfide decomposition device and method, the device is characterized in that a central electrode is made of metal, a grounding electrode is made of temperature-controlled circulating liquid, and the hydrogen sulfide decomposition process can be continuously and stably carried out through temperature control of a liquid grounding electrode. In addition, CN103204467A discloses a device and a method for preparing hydrogen by continuously and stably decomposing hydrogen sulfide, which is characterized in that a central electrode is made of metal, a ground electrode is used as temperature-controllable circulating liquid, temperature control is performed through a liquid ground electrode, raw material is fed in a circumferential direction and reversely passes through a discharge area in a spiral mode along an axial direction, so that generated sulfur is timely and centrifugally separated. However, in order to ensure that the hydrogen sulfide is decomposed as sufficiently as possible in the methods disclosed in CN103204466A and CN103204467A, it is necessary to control the flow rate of the hydrogen sulfide so that the residence time of the hydrogen sulfide in the inner cylinder of the reactor is longer and to control the size of the inner cylinder so that more electric energy is obtained per unit volume of gas in the inner cylinder, and since the current prior art cannot provide a more powerful power source, the methods disclosed in CN103204466A and CN103204467A can only achieve the highest conversion rate of the hydrogen sulfide of about 20% even if the residence time of the hydrogen sulfide is longer and the size of the inner cylinder is controlled so that more electric energy is obtained per unit volume of gas in the inner cylinder, and when the highest conversion rate of the hydrogen sulfide reaches about 20%, the energy consumption of the decomposition reaction of the hydrogen sulfide is considerably high and is not suitable for large-scale industrial applications. Further, the methods disclosed in CN103204466A and CN103204467A have the drawback that the kinds of the liquid-applicable ground electrodes are very few, and the disclosed salt solutions and the like can generally only maintain the temperature of the reactor at 100 ℃ or lower, whereas elemental sulfur is generally solid at 100 ℃ or lower, which is likely to cause the reactor to be clogged.

Disclosure of Invention

The invention aims to overcome the defects of low hydrogen sulfide conversion rate, high energy consumption and incapability of realizing large-flow hydrogen sulfide treatment in the process of decomposing hydrogen sulfide into hydrogen and elemental sulfur in the prior art, and provides a novel high-flux low-temperature plasma discharge device and a method for decomposing hydrogen sulfide by using the device.

In order to achieve the above object, a first aspect of the present invention provides a high-flux low-temperature plasma discharge device, comprising:

the first cavity is provided with a first inlet and a first outlet respectively;

the second cavity is nested in the first cavity, and a second inlet and a second outlet are respectively arranged on the second cavity;

the high-voltage electrodes and the grounding electrodes are arranged in the first cavity, the high-voltage electrodes and the grounding electrodes are respectively multiple and respectively form a layer structure with the number being more than or equal to 1, and high-voltage electrode layers formed by the high-voltage electrodes and grounding electrode layers formed by the grounding electrodes are alternately arranged;

the blocking medium is arranged on the outer surface of the high-voltage electrode and/or the grounding electrode;

the distance between the high voltage electrode and the ground electrode is L₁The thickness of the barrier medium is D₁，L₂＝L₁-D₁And L₂And D₁The ratio of (0.1-150): 1, preferably (0.2 to 100): 1; more preferably (0.5 to 80): 1;more preferably (0.5 to 50): 1.

in the present invention, D₁Representing the total thickness of the barrier medium between two nearest neighboring high voltage and ground electrodes L₁Represents the distance between the high voltage electrode and the ground electrode which is closest.

The plasma discharge device provided by the invention is a jacket type dielectric barrier discharge device, the basic structure of the plasma discharge device mainly comprises a high-voltage electrode, a grounding electrode, a barrier medium and the like, and the jacket type structure can enable a heat-conducting medium to circularly heat or cool the discharge device, so that the flexible temperature control of a discharge area is realized.

In particular, the plasma discharge device having the specific structure of the present invention can significantly improve the conversion rate of hydrogen sulfide relative to the prior art.

Preferably, in two adjacent layer structures, the center of the electrode in the upper layer structure is aligned with or offset from the center of the electrode in the lower layer structure.

Preferably, the gap between two adjacent layer structures is greater than 0 and equal to or less than 100 mm.

In the present invention, in each layer structure, it is preferable that each electrode in the same layer structure is parallel to each other.

Preferably, in each of the layer structures, a gap between two adjacent electrodes is greater than 0 and 100mm or less.

In the present invention, unless otherwise specified, "gaps" each represent the shortest distance.

The high-voltage electrode layer formed by a plurality of the high-voltage electrodes and the grounding electrode layer formed by a plurality of the grounding electrodes are alternately arranged, and the following steps are represented: according to the material flow direction, when the first layer is a high-voltage electrode layer, the second layer is preferably a grounding electrode layer, and the subsequent layers which may exist are alternately arranged according to the arrangement mode of the first layer and the second layer; likewise, in terms of the direction of flow, when the first layer is a ground electrode layer, the second layer is preferably a high-voltage electrode layer, and the subsequent layers that may be present are arranged alternately in the manner of arrangement of the first layer and the second layer, and it is also understood that one high-voltage electrode layer and an adjacent one of the ground electrode layers are arranged as a group, and the groups are arranged in sequence to form, for example, a high-voltage electrode layer-ground electrode layer-high-voltage electrode layer-ground electrode layer, or to form, for example, an arrangement of high-voltage electrode layer-ground electrode layer-high-voltage electrode layer. In the above-described alternate stacking arrangement, the high-voltage electrode in the high-voltage electrode layer and the ground electrode in the adjacent ground electrode layer may be disposed in parallel or perpendicular to each other, or the high-voltage electrode in the high-voltage electrode layer and the ground electrode in the adjacent ground electrode layer may be disposed at an angle, as long as a uniform electric field can be generated in the first cavity. Particularly preferably, the high voltage electrode in the high voltage electrode layer and the ground electrode in the adjacent ground electrode layer of the present invention may be disposed parallel to each other or perpendicular to each other.

The present invention is not particularly limited to the specific form of the aforementioned second cavity, but several preferred embodiments of the second cavity are provided hereinafter in the present invention in order to achieve a more excellent decomposition efficiency of hydrogen sulfide.

The heat conducting medium contained in the second cavity of the invention can maintain the temperature required by the first cavity. Specifically, the structure of the invention can enable the heat-conducting medium to circularly flow in the shell layer, ensure the discharge intensity and simultaneously maintain the whole discharge device within a certain temperature range, so that the generated sulfur flows out of the discharge device in a liquid state, the sulfur generated by the decomposition of hydrogen sulfide can be effectively prevented from being solidified, and the decomposition process can be continuously and stably operated for a long period while achieving higher conversion rate.

Particularly preferably L₂And length L of discharge tube₃The ratio of the discharge tubes to the discharge tube is 1 (2-1500), preferably 1 (20-500), more preferably 1 (20-300), and the length of the discharge tube is L₃For the effective length of the single high voltage electrode and the single ground electrode participating in the discharge control L₂And length L of discharge tube₃The proportional relationship between each is independently 1: (2-1500), preferably 1: (20-500) more preferably 1: (20 to 300), can showObviously reduces the energy consumption for decomposing the hydrogen sulfide gas.

Preferably, the respective high voltage electrodes are connected in parallel with each other.

Preferably, the respective ground electrodes are connected in parallel with each other.

According to a preferred embodiment (embodiment 1), the blocking medium is arranged on the outer surface of the hv electrode.

According to another preferred embodiment (embodiment 2), the barrier medium is disposed on an outer surface of the ground electrode.

According to another preferred embodiment (embodiment 3), the blocking medium is provided on the outer surface of the high voltage electrode and the ground electrode.

In the foregoing embodiment 1 and embodiment 2, the device of the present invention is capable of realizing single dielectric barrier discharge. In the case of single-dielectric barrier discharge, the thickness D1 of the barrier medium is the thickness of the barrier medium on the corresponding high-voltage electrode or the corresponding ground electrode, and it should be further noted that, because an electric field exists between the ground electrode and the high-voltage electrode, the thickness herein refers to the thickness of the barrier medium on the corresponding one of the high-voltage electrode or the ground electrode.

In the foregoing embodiment 3 of the present invention, a dual dielectric barrier discharge can be realized in the device of the present invention. In the case of the double-dielectric barrier discharge, the thickness D1 of the barrier medium is the sum of the thicknesses of the barrier medium on the corresponding high-voltage electrode and the corresponding ground electrode, because an electric field exists between the ground electrode and the high-voltage electrode, and thus the sum of the thicknesses herein represents the sum of the thicknesses of the barrier medium on the corresponding one of the high-voltage electrode and the one of the ground electrode.

The invention is not particularly limited in the form of fixing the blocking medium to the high voltage electrode and/or the ground electrode, and the blocking medium may be fixed to the outer surface of the high voltage electrode and/or the ground electrode in any form that can be fixed, or the blocking medium may be coated on the outer surface of the high voltage electrode or the ground electrode in the form of a coating.

Preferably, the material forming the barrier medium is an electrically insulating material, more preferably the material forming the barrier medium is selected from at least one of glass, ceramic, enamel, polytetrafluoroethylene, and mica. The glass can be quartz glass or hard glass; the material forming the barrier medium can also be other metal and non-metal composite materials with high-voltage electric insulation design, and the like. The ceramic may be an alumina ceramic.

Preferably, the device of the present invention further comprises a ground wire, one end of which is electrically connected to the ground electrode.

Preferably, the first inlet is disposed at an upper portion of the first cavity, and the first outlet is disposed at a bottom portion of the first cavity.

Preferably, the second inlet is disposed at a lower portion of the second cavity, and the second outlet is disposed at an upper portion of the second cavity.

According to a preferred embodiment, at least one of the plurality of high voltage electrodes and the plurality of ground electrodes is a hollow structure, and the hollow structures are communicated with each other to form the second cavity.

According to another preferred embodiment, each of the high voltage electrodes and each of the ground electrodes are hollow structures, and the hollow structures are communicated with each other to form the second cavity.

According to another preferred embodiment, each of the high voltage electrodes is a hollow structure, and the hollow structures are communicated with each other to form the second cavity.

According to another preferred embodiment, each of the ground electrodes has a hollow structure, and the hollow structures are communicated with each other to form the second cavity.

The dimensions of each of the high voltage electrodes of the present invention may be the same or different, and preferably, the dimensions of each of the high voltage electrodes are the same.

The size of each of the ground electrodes of the present invention may be the same or different, and preferably, the size of each of the ground electrodes is the same.

The same dimensions as described above in the present invention mean that the dimensions and shapes are all the same.

Preferably, each of the high voltage electrodes and each of the ground electrodes have a cylindrical shape. It should be noted that the present invention is not limited to the high voltage electrode and the ground electrode being cylindrical, and may also be serpentine, fin-shaped, S-shaped, wave-shaped, screw-shaped, or spike-shaped (i.e. having a protrusion structure on the side wall).

Preferably, when each of the high voltage electrode and the ground electrode is cylindrical, the diameters of the high voltage electrode and the ground electrode are each independently 0.1 to 100mm, and more preferably 0.5 to 50 mm.

Preferably, the height-diameter ratio of the high-voltage electrode and the ground electrode is (5-600): 1, preferably (10-400): 1.

the inner diameters of the present invention each represent a diameter.

Preferably, the material forming the ground electrode is selected from the group consisting of a graphite tube, graphite powder, a metal tube, a metal rod, metal powder, or a graphite rod. The grounding electrode of the invention generates larger micro discharge current under the condition of certain injection power, and is more beneficial to the broken bond decomposition reaction of hydrogen sulfide. The metal tube and the metal rod in the material forming the ground electrode may include an elemental metal tube, an elemental metal rod, an alloy metal tube, and an alloy metal rod. The inventors of the present invention have found that the use of a solid conductive material as the ground electrode of the device of the present invention enables the conversion rate of hydrogen sulfide to be more significantly improved when the device of the present invention is used to perform a hydrogen sulfide decomposition reaction.

The material for forming the high-voltage electrode is a conductive material, and preferably, the material for forming the high-voltage electrode is at least one selected from one or more mechanical mixtures of graphite tube, graphite powder, metal rod, metal tube, metal powder, graphite rod and conductive powder. The metal rod and the metal pipe can comprise an elemental metal rod, an alloy metal rod, an elemental metal pipe and an alloy metal pipe, and the metal powder can comprise elemental metal powder, alloy metal powder and a mechanical mixture of elemental metal powder and/or alloy metal powder. The material forming the high voltage electrode of the present invention may be other rod-shaped or tubular materials having conductive properties.

The metal powder of the present invention means that when the outer surface of the ground electrode and/or the high voltage electrode is coated with the barrier medium, the barrier medium may be disposed in a hollow tubular form, and the metal powder is filled in the barrier medium to form the barrier medium coated ground electrode and/or high voltage electrode; the metal powder can be elementary metal powder, alloy metal powder, or a mechanical mixture of elementary and/or alloy metal powder.

The graphite powder of the present invention means that, when the outer surface of the ground electrode and/or the high voltage electrode is coated with the barrier medium, the barrier medium may be provided in a hollow tubular form, and the graphite powder is filled in the middle of the barrier medium to form the barrier medium coated ground electrode and/or high voltage electrode.

The invention can lead the temperature of the discharge device with the sleeve structure to be maintained between 119 ℃ and 444.6 ℃ for example by introducing the heat-conducting medium into the area between the second cavities, so as to ensure that sulfur generated by the decomposition of hydrogen sulfide flows out of the discharge area in a liquid state.

The device of the present invention may also be filled with a catalyst capable of catalyzing the decomposition of hydrogen sulfide into elemental sulfur and hydrogen gas, preferably in the first cavity of the discharge device. The present invention has no particular requirement on the loading volume and the loading type of the catalyst, and the type of the catalyst may be, for example, any one or more of the catalysts disclosed in CN102408095A, CN101590410A, and CN 103495427A.

The material forming the first cavity of the present invention may be, for example: an electrically conductive metallic material or an electrically insulating material, which is capable of serving as a structural support and is resistant to high temperatures, is preferred.

In the present invention, the material forming the second cavity is not particularly limited as long as the material forming the second cavity can withstand the set temperature of the heat transfer medium. The material forming the second cavity of the present invention may be, for example: an electrically conductive metallic material or an electrically insulating material, which is capable of serving as a structural support and is resistant to high temperatures, is preferred.

The following provides a preferred embodiment of the decomposition of hydrogen sulfide using the aforementioned apparatus of the present invention:

nitrogen gas is introduced into the first cavity of the device from the first inlet to purge the discharge region of air, and the gas is withdrawn from the first outlet. Meanwhile, the heat-conducting medium is introduced into the second cavity from the second inlet, and the introduced heat-conducting medium is led out from the second outlet. The temperature of the heat transfer medium is maintained at the temperature required for the system reaction. Then raw material gas containing hydrogen sulfide is introduced into the first cavity of the device from the first inlet, a high-voltage power supply (HV) is connected after the raw material gas flow is stable, and a plasma discharge field is formed between the central electrode and the grounding electrode by adjusting voltage and frequency. The hydrogen sulfide gas is ionized in the discharge area and decomposed into hydrogen and elemental sulfur, and the elemental sulfur generated by discharge slowly flows down along the wall of the first cavity and flows out from the first outlet.

A second aspect of the present invention provides a method of decomposing hydrogen sulfide, the method being implemented in the high flux low temperature plasma discharge apparatus according to the first aspect of the present invention, the method comprising: grounding a grounding electrode of the high-flux low-temperature plasma discharge device, connecting a high-voltage electrode with a power supply, performing dielectric barrier discharge, introducing a raw material gas containing hydrogen sulfide from an inlet of a reactor into a first cavity of the high-flux low-temperature plasma discharge device to perform decomposition reaction of the hydrogen sulfide, leading out a material flow obtained after decomposition from a first outlet, and continuously introducing a heat-conducting medium into a second cavity of the high-flux low-temperature plasma discharge device from a second inlet and leading out the heat-conducting medium from a second outlet to maintain the temperature required by the high-flux low-temperature plasma discharge device.

Preferably, the dielectric barrier discharge conditions include: the discharge voltage is 2kV to 80kV, preferably 5kV to 30kV, more preferably 5kV to 20kV, and even more preferably 5kV to 15 kV; the discharge frequency is 200 to 30000Hz, preferably 500 to 15000Hz, and more preferably 500 to 13000 Hz.

Preferably, the conditions of the hydrogen sulfide decomposition reaction comprise that the reaction temperature is 0-800 ℃, preferably 40-500 ℃, more preferably 119-444.6 ℃, the reaction pressure is 0-0.6MPa, preferably 0-0.3MPa, and the retention time of the raw material gas containing hydrogen sulfide in the discharge area of the low-temperature plasma discharge device is 1 × 10^-5120s, preferably 2 × 10^-5～60s。

Preferably, the hydrogen sulfide decomposition reaction is carried out in the presence of a carrier gas selected from at least one of nitrogen, hydrogen, helium, argon, water vapor, carbon monoxide, carbon dioxide, methane, ethane and propane; more preferably, the carrier gas is selected from at least one of hydrogen, argon, helium, and nitrogen.

Particularly preferably, the carrier gas is selected from at least one of hydrogen, argon, helium, and nitrogen.

Preferably, the content of the hydrogen sulfide gas in the feed gas is such that the content of the hydrogen sulfide gas at the first inlet of the low-temperature plasma discharge device is 1 × 10-8-100 vol%; more preferably 10 to 100 vol%.

In the present invention, the raw material gas does not include the aforementioned carrier gas of the present invention, the raw material gas is pure hydrogen sulfide gas or industrial waste gas containing hydrogen sulfide and other gases obtained in industrial production, and the carrier gas defined in the present invention is a gas that is actively added to be mixed with the raw material gas, although the raw material gas may contain the same kind of gas as the carrier gas defined in the present invention, and the method of the present invention can control the amount of the carrier gas added as needed.

The device provided by the invention also has the advantages of high hydrogen sulfide conversion rate, low energy consumption and capability of realizing large-flow hydrogen sulfide treatment.

In addition, the device provided by the invention can generate uniform and efficient dielectric barrier discharge, so that hydrogen sulfide is directly decomposed to generate hydrogen and sulfur with high efficiency.

In addition, the device provided by the invention can realize continuous and stable operation of the hydrogen sulfide decomposition process under the condition of obviously higher hydrogen sulfide conversion rate, and can realize long-period operation. In addition, the device provided by the invention can also be used for the hydrogen sulfide treatment process with large flow and various concentrations.

Drawings

Fig. 1 is a schematic cross-sectional structure diagram of a preferred embodiment of the high-flux low-temperature plasma discharge device provided by the present invention.

Fig. 2 is a schematic cross-sectional structure diagram of another preferred embodiment of the high-flux low-temperature plasma discharge device provided by the invention.

Fig. 3 is a schematic perspective view of the interior of the first cavity of a preferred embodiment of the high flux low temperature plasma discharge device shown in fig. 1.

Description of the reference numerals

1. A first cavity 2 and a second cavity

11. First inlet 21, second inlet

12. First outlet 22, second outlet

3. High voltage electrode

4. Grounding electrode

5. Grounding wire

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

The structure of a preferred embodiment of the high flux low temperature plasma discharge device of the present invention is provided below in conjunction with fig. 1 and 2, specifically:

the device includes:

the device comprises a first cavity 1, a second cavity and a third cavity, wherein a first inlet 11 and a first outlet 12 are respectively arranged on the first cavity 1;

a second cavity 2, wherein the second cavity 2 is nested inside the first cavity 1, and a second inlet 21 and a second outlet 22 are respectively arranged on the second cavity 2, and the heat-conducting medium introduced from the second inlet 21 can be led out from the second outlet 22;

the high-voltage electrodes 3 and the grounding electrodes 4 are arranged in the first cavity 1, the high-voltage electrodes 3 and the grounding electrodes 4 are respectively multiple and respectively form a layer structure with the number being more than or equal to 1, and high-voltage electrode layers formed by the multiple high-voltage electrodes 3 and grounding electrode layers formed by the multiple grounding electrodes 4 are alternately arranged;

the blocking medium is arranged on the outer surface of the high-voltage electrode 3 and/or the grounding electrode 4;

the distance between the high voltage electrode 3 and the ground electrode 4 is L₁The thickness of the barrier medium is D₁，L₂＝L₁-D₁And L₂And D₁The ratio of (0.1-150): 1, preferably (0.2 to 100): 1; more preferably (0.5 to 80): 1; more preferably (0.5 to 50): 1.

specifically, the difference between fig. 1 and fig. 2 of the present invention is mainly that the relative positions of the high voltage electrode in each layer structure and the ground electrode in the adjacent layer structure are different, and the high voltage electrode in the upper layer structure and the ground electrode in the adjacent lower layer structure in fig. 1 are aligned and arranged, so that the reactant enters the first cavity 1, and the main flowing direction is a straight direction from top to bottom; in fig. 2, the high voltage electrode in each upper layer structure and the ground electrode in the adjacent lower layer structure are arranged in a hollow manner, so that the reactant enters the first cavity 1 and the main flowing direction is the alternating flowing direction from top to bottom and the horizontal direction. As can be seen from fig. 1 and 2, the average residence time of the reactants in the apparatus provided in fig. 2 is longer with a constant reactant flow rate.

In fig. 1 and 2, the present invention exemplarily provides the electrode tubes to be hollow and to communicate with each other in series and/or in parallel to constitute a second cavity.

Preferably, the gap between two adjacent layer structures is greater than 0 and equal to or less than 100 mm.

Preferably, in each of the layer structures, a gap between two adjacent electrodes is greater than 0 and 100mm or less.

Preferably L₂And length L of discharge tube₃Each independently is 1: (2-1500), more preferably 1: (20-500), more preferably 1: (20-300).

The device of the invention also has the following preferred features:

preferably, the respective high voltage electrodes 3 are connected in parallel with each other.

Preferably, the respective ground electrodes 4 are connected in parallel with each other.

Preferably, the device further comprises a grounding wire 5, and one end of the grounding wire 5 is electrically connected with the grounding electrode 4.

Preferably, the first inlet 11 is disposed at an upper portion of the first cavity 1, and the first outlet 12 is disposed at a bottom portion of the first cavity 1.

According to a preferred embodiment, at least one of the plurality of high voltage electrodes 3 and the plurality of ground electrodes 4 is a hollow structure, and the hollow structures are communicated with each other to constitute the second cavity.

According to another preferred embodiment, each of the high voltage electrodes 3 and each of the ground electrodes 4 are hollow structures, and the hollow structures are communicated with each other to form the second cavity.

According to another preferred embodiment, each of the high voltage electrodes 3 is a hollow structure, and the hollow structures are communicated with each other to form the second cavity.

According to another preferred embodiment, each of the ground electrodes 4 is a hollow structure, and the hollow structures are communicated with each other to form the second cavity.

Preferably, the high voltage electrodes 3 are the same size, the ground electrodes 4 are the same size, and the high voltage electrodes 3 and the ground electrodes 4 are cylindrical.

According to a preferred embodiment, the dimensions of each high voltage electrode 3 are identical to the dimensions of each ground electrode 4.

Preferably, the diameters of the high voltage electrode 3 and the ground electrode 4 are each independently 0.1 to 100mm, more preferably 0.5 to 50 mm.

Preferably, the ratio of the diameter of the high voltage electrode 3 and the ground electrode 4 to the length of the respective high voltage electrode 3 and ground electrode 4 is each independently 1: (5-600), preferably 1: (10-400).

Preferably, the second inlet 21 and the second outlet 22 are provided at a lower portion and an upper portion of the second cavity 2, respectively.

In order to more intuitively describe the arrangement of the ground electrodes and the high voltage electrodes in the device of the present invention, the present invention provides a schematic perspective structure of the inside of the first cavity shown in fig. 3, a plurality of high voltage electrodes 3 are arranged in parallel in a layered structure in fig. 3, and a layered structure in which a plurality of ground electrodes 4 are arranged in parallel is provided in adjacent upper and/or lower layers of the layered structure.

The high-flux low-temperature plasma discharge device provided by the invention also has the following specific advantages:

(1) the device preferably uses a conductive solid material as a grounding electrode, and when the grounding electrode is matched with the structure of the device, micro discharge current generated by discharge is larger, so that the device is more favorable for the discharge decomposition reaction of hydrogen sulfide molecules.

(2) The device sets up jacket structure, and the accessible is controlled heat-conducting medium temperature in the jacket and is carried out temperature control to discharge device, can make the sulphur that hydrogen sulfide discharge decomposition produced flow out the discharge zone smoothly, avoids sulphur solidification to block up discharge device, makes the continuous stable going on of discharging.

(3) The device is preferably controlled L₂And D₁The ratio of (0.1-150): 1, preferably (0.2 to 100): 1; more preferably (0.5 to 80): 1; more preferably (0.5 to 50): 1, the conversion rate of the hydrogen sulfide can be obviously improved and the energy consumption for decomposition can be reduced by matching with other structures of the device.

The present invention will be described in detail below by way of examples. In the following examples, various raw materials used were commercially available unless otherwise specified.

The thickness of the barrier dielectric is the same in the following examples.

The hydrogen sulfide conversion in the following examples was calculated according to the following formula:

percent conversion of hydrogen sulfide-moles of hydrogen sulfide converted/moles of initial hydrogen sulfide × 100%

The energy consumption for decomposing hydrogen sulfide in the following examples was measured by an oscilloscope and calculated using lissajous figures.