1. A device for decomposing hydrogen sulfide to prepare hydrogen and sulfur by using an atmospheric pressure microwave plasma torch is characterized by comprising an atmospheric pressure microwave plasma generator (1), a chemical reaction buffer chamber (2) and a decomposition product collecting device (3);

the atmospheric pressure microwave plasma generator (1) comprises a waveguide tube flange interface (11), a discharge tube (212), a microwave plasma coupling waveguide tube (12) and a working gas injection unit (13); the microwave plasma coupling waveguide tube (12) is arranged at the bottom of the quartz glass tube (21) through a waveguide tube flange interface (11), the discharge tube (212) extends into the chemical reaction buffer chamber (2) from the bottom of the quartz glass tube (21), and a working gas injection unit (13) is arranged below the microwave plasma coupling waveguide tube (12); the atmospheric pressure microwave plasma generator (1) is communicated with a gas mixing container (43), and the gas mixing container (43) is respectively communicated with a first working gas (411) and a second working gas (422) through a first gas flow controller (41) and a second gas flow controller (42);

the chemical reaction buffer chamber (2) is composed of a quartz glass tube (21) coaxial with the discharge tube (212) and a metal mesh or a metal cylinder (22) sleeved on the outer wall of the quartz tube, wherein the inner tube is the discharge tube (212), and the quartz glass tube is the outer tube (21); one end of the quartz glass tube (21) is connected with a flange interface (11) of the microwave plasma coupling waveguide tube (12), so that the discharge tube (212) extends deep into the chemical reaction buffer chamber (2), and the carrier gas of plasma discharge flows through the plasma discharge tube (212) in a vortex airflow mode; a cylindrical cooling rod (23) is inserted from the other end of the quartz glass tube (21) along the axial inner portion of the chemical reaction buffer chamber (2), and the end face is communicated with the decomposition product collecting device (3) through a gas discharge pipe (25);

the decomposition product collecting device (3) comprises a filter bag (31), an alkaline solution pool (32), a pipeline (33) filled with a drying agent and a gas separating device (34) which are connected in sequence; the gas decomposed and discharged by the chemical reaction buffer chamber (2) is connected to a filter bag (31) of a decomposed product collecting device (3) through a gas discharge pipe (25), solid powder sulfur in the gas is recovered through the filter bag (31), unreacted hydrogen sulfide is absorbed through a next-stage alkaline solution pool (32), the gas passes through a pipeline (33) filled with a drying agent, and finally, hydrogen components in the gas are separated out through a gas separating device (34) and stored for later use;

a first working gas (411) and a second working gas (422) introduced into an atmospheric pressure microwave plasma generator (1) are respectively connected to an inlet of a gas mixing container (43) through a first gas flow controller (41) and a second gas flow controller (42), an outlet of the gas mixing container (43) is connected with a gas inlet of a working gas injection unit (13) of the atmospheric pressure microwave plasma generator (1), a gas outlet end of the working gas injection unit (13) is connected with a gas inlet end of a discharge tube (212), and finally the mixed gas of the first working gas (411) and the second working gas (422) enters the discharge tube (212) through the gas injection unit (13) in a vortex gas flow manner, plasma discharge is excited in the discharge tube (212) under the excitation of microwaves, and a plasma discharge state is maintained; an outwardly projecting plasma torch is formed at the outlet end of the discharge tube (212) by the mixed flow of the first working gas (411) and the second working gas (422), introducing a swirling gas flow into the chemical reaction buffer chamber (2).

2. An apparatus for producing hydrogen and sulfur by decomposing hydrogen sulfide with an atmospheric pressure microwave plasma torch as set forth in claim 1, wherein the first working gas (411) is H₂S gas or H₂The mixed gas of S and other gases and the second working gas (422) are carrier gases.

3. The device for producing hydrogen and sulfur by decomposing hydrogen sulfide with the atmospheric pressure microwave plasma torch as claimed in claim 1, wherein the microwave frequency of the atmospheric pressure microwave plasma generator (1) is 2.45GHz, and the waveguide is a rectangular waveguide; the inner diameter of the plasma discharge tube (212) ranges from 1.6 cm to 2.6cm when the adopted waveguide tube is WR340, and the inner diameter of the plasma discharge tube (212) ranges from 2.6cm to 4.6cm when the adopted waveguide tube is WR 430.

4. The device for producing hydrogen and sulfur by decomposing hydrogen sulfide with the atmospheric pressure microwave plasma torch as claimed in claim 1, wherein the microwave frequency of the atmospheric pressure microwave plasma generator (1) is 915MHz, and the adopted waveguide is a rectangular waveguide; the model of the waveguide tube is that the inner diameter of the WR975 plasma discharge tube (212) is in the interval of 7.6-8.6 cm.

5. The apparatus for producing hydrogen and sulfur by decomposing hydrogen sulfide with an atmospheric pressure microwave plasma torch as set forth in claim 1, wherein the outer tube (21) has a diameter 2 to 4 times as large as the diameter of the discharge tube (212) and a length of 3 self tube diameters or more.

6. The apparatus for producing hydrogen and sulfur by decomposing hydrogen sulfide with an atmospheric pressure microwave plasma torch as claimed in claim 1, wherein the cooling rod (23) is a hollow metal tube made of metal, and cooling water flows through the inside of the metal tube through a water inlet pipe and a water outlet pipe communicated with the metal tube to cool the cooling rod (23).

7. The apparatus for producing hydrogen and sulfur by decomposing hydrogen sulfide with an atmospheric pressure microwave plasma torch as set forth in claim 1, wherein the diameter of the cooling rod (23) is 0.6 to 2 times the diameter of the plasma discharge tube (212).

8. The apparatus for producing hydrogen and sulfur by decomposing hydrogen sulfide with an atmospheric pressure microwave plasma torch as set forth in claim 1, wherein the end face of the cooling rod (23) is spaced from the end port of the discharge tube (212) by a length of 1 to 3 times the outer diameter of the discharge tube (212).

9. The apparatus for producing hydrogen and sulfur by decomposing hydrogen sulfide with an atmospheric pressure microwave plasma torch as set forth in claim 1, wherein the end surface of the cooling rod (23) opposite to the discharge tube (212) is shaped as a plane, a semicircle, a semi-ellipse, or a cone.

Background

With the development of technology, hydrogen is gradually becoming a fuel for new technologies, and the demand of hydrogen is increasing. However, from a global perspective, hydrogen production also relies primarily on steam reforming of natural gas, and new methods for producing hydrogen are urgently needed to meet market demand. Therefore, the hydrogen sulfide is directly decomposed to prepare the hydrogen and the sulfur, the development requirement of the current hydrogen energy is met, the pollution problem caused by the hydrogen sulfide discharged by industry can be solved, and the direct decomposition of the hydrogen sulfide by various methods is a hot spot concerned at present. The currently adopted methods mainly comprise the following steps according to related reports: thermal decomposition (direct thermal decomposition, catalytic thermal decomposition, super adiabatic decomposition), electrochemical decomposition, photocatalytic decomposition, plasma method, and the like. Since the thermal decomposition of hydrogen sulfide is limited by thermodynamic equilibrium, the conversion rate is low even at high temperatures; electrochemical methods and photocatalytic methods suffer from problems of low efficiency, complex structure, and the like. Compared with the above mentioned method, the plasma method has rapid response, high energy efficiency and large adjustable range of gas flow and composition components, and meets the requirement of hydrogen sulfide decomposition under various production conditions. At present, various discharge methods, such as corona discharge, glow discharge, dielectric barrier discharge, sliding arc discharge, radio frequency plasma, microwave plasma and the like, have been put into practical use in the application of hydrogen sulfide decomposition to produce hydrogen gas and sulfur, and among them, with the development of microwave technology in recent years, the technology of microwave plasma treatment under atmospheric pressure has attracted industrial attention. The atmospheric pressure microwave plasma has high energy conversion efficiency and high electron and active particle density, and is a discharge form capable of keeping a stable discharge state under the atmospheric pressure condition; in addition, the flow of the working gas of the atmospheric pressure microwave plasma torch is large, so that the experimental device can be amplified to the actual working condition of industrial application; also, the atmospheric pressure microwave plasma torch is less expensive to operate and maintain. For example, the method for producing hydrogen by decomposing H2S directly by microwave plasma, which is proposed by Dongyong-Yong et al in "decomposing H2S by microwave plasma method" published in the solar bulletin (Vol.18, No. 2, 4 months 1997).

The invention adopts the atmospheric pressure microwave plasma torch to decompose the hydrogen sulfide to prepare the hydrogen and the sulfur, and effectively inhibits the reverse composite reaction of decomposition reactants by directly cooling the plasma jet, thereby greatly improving the conversion rate. The hydrogen production and sulfur conversion effects obtained by different cooling modes are greatly different, and different from the reported traditional cooling mode of decomposing hydrogen sulfide gas by atmospheric pressure microwave plasma jet in the research (university of Wuhan engineering, Master academic thesis, author Xuyao, 4 months in 2013), the invention provides a method for afterglow direct cooling in a reaction buffer chamber, so that the conversion rate of hydrogen production by hydrogen sulfide decomposition is remarkably improved under the conditions of atmospheric circulation (dozens of liters per minute) and more approximate working conditions (adopting nitrogen as diluent gas).

Disclosure of Invention

The invention provides a method for decomposing H by utilizing an atmospheric pressure microwave plasma torch and combining a method for directly cooling an afterglow area in a reaction buffer chamber₂And the S gas is used for preparing hydrogen and sulfur.

In order to achieve the purpose, the invention adopts the technical scheme that:

a device for decomposing hydrogen sulfide to prepare hydrogen and sulfur by utilizing an atmospheric pressure microwave plasma torch mainly comprises an atmospheric pressure microwave plasma generator 1, a chemical reaction buffer chamber 2 and a decomposition product collecting device 3. A discharge tube 212 in which hydrogen sulfide gas is mixed into a plasma carrier gas and flows through the atmospheric pressure microwave plasma generator 1 in a vortex flow; the discharge tube 212 of the atmospheric pressure microwave plasma generator 1 extends into the chemical reaction buffer chamber 2 connected with the atmospheric pressure microwave plasma generator, and the generated plasma is sprayed into the chemical reaction buffer chamber 2 with the cooling function; the gas discharged from the other end of the chemical reaction buffer chamber 2 passes through the decomposition product collecting means 3. The method comprises the following specific steps:

the atmospheric pressure microwave plasma generator 1 adopts a double-cavity excitation atmospheric pressure microwave plasma torch which is proposed in patent CN207070436U, and the specific structure and the working principle refer to the patent. The atmospheric pressure microwave plasma generator 1 comprises a waveguide pipe flange interface 11, a discharge pipe 212, a microwave plasma coupling waveguide pipe 12 and a working gas injection unit 13, wherein the microwave plasma coupling waveguide pipe 12 is arranged at the bottom of a quartz glass pipe 21 through the waveguide pipe flange interface 11, the discharge pipe 212 extends into a chemical reaction buffer chamber 2 from the bottom of the quartz glass pipe 21, and the working gas injection unit 13 is arranged below the microwave plasma coupling waveguide pipe 12. The atmospheric pressure microwave plasma generator 1 is communicated with a gas mixing container 43, and the gas mixing container 43 is communicated with a first working gas 411 and a second working gas 422 through a first gas flow controller 41 and a second gas flow controller 42 respectively.

The chemical reaction buffer chamber 2 is composed of a quartz glass tube 21 coaxial with the discharge tube 212 and a metal mesh or metal cylinder 22 sleeved on the outer wall of the quartz tube, wherein the inner tube is the discharge tube 212, and the quartz glass tube is the outer tube 21. One end of the quartz glass tube 21 is vertically fixed on the flange interface 11 of the microwave plasma coupling waveguide tube 12 of the atmospheric pressure microwave plasma generator 1 through a clamping groove, so that the discharge tube 212 of the atmospheric pressure microwave plasma generator 1 extends into the chemical reaction buffer chamber 2 to a certain depth, and the carrier gas of plasma discharge flows through the plasma discharge tube 212 in a vortex airflow manner; a cylindrical cooling rod 23 is extended from the other end of the quartz glass tube 21 along the axial inside of the chemical reaction buffer chamber 2 until the end face of the cooling rod 23 is spaced from the end of the discharge tube 212 by a length 1 to 3 times the outer diameter of the discharge tube 212, and this end face of the quartz glass tube 21 is connected to a gas discharge pipe 25 via a connecting flange 24, and the discharge pipe 25 is connected to the decomposition product collecting means 3. The cooling rod 23 is a hollow metal tube made of metal, and cooling water flows through a water inlet pipe and a water outlet pipe communicated with the metal tube (the water inlet pipe is a thin metal tube extending into the hollow metal tube of the cooling rod 23, and the water outlet pipe is an outlet for leading out the water injected into the cooling rod 23 after flowing inside the cooling rod 23), so that the cooling water can effectively cool the whole cooling rod 23 when flowing inside the cooling rod 23. The water outlet and inlet pipes of the cooling rod 23 are led out of the chemical reaction buffer chamber 2 through the sealing ports on the connecting flange 24.

The decomposition product collecting device 3 comprises a filter bag 31, an alkaline solution pool 32, a pipeline 33 filled with a drying agent and a gas separating device 34 which are connected in sequence. The gas decomposed and discharged from the chemical reaction buffer chamber 2 is connected to a filter bag 31 of the decomposition product collecting device 3 through a gas discharge pipe 25, solid powder sulfur in the gas is recovered through the filter bag 31, then the gas passes through a next stage alkaline solution pool 32 to absorb unreacted hydrogen sulfide, then the gas passes through a pipeline 33 filled with a drying agent to absorb water vapor in the gas, and finally the hydrogen component in the gas is separated out through a gas separating device 34 to be stored for later use.

The first working gas 411 and the second working gas 422 introduced into the atmospheric pressure microwave plasma generator 1 are respectively connected to the inlet of the gas mixing container 43 through the first gas flow controller 41 and the second gas flow controller 42, the outlet of the gas mixing container 43 is connected to the gas inlet of the working gas injection unit 13 of the atmospheric pressure microwave plasma generator 1, the gas outlet of the working gas injection unit 13 is connected to the gas inlet of the discharge tube 212, and finally the mixed gas of the first working gas 411 and the second working gas 422 enters the discharge tube 212 through the gas injection unit 13 in a vortex gas flow manner, plasma discharge is excited in the discharge tube 212 under the excitation of microwaves, and the plasma discharge state is maintained at a certain input power. An outwardly projecting plasma torch is formed at the outlet end of the discharge tube 212 by the mixed flow gas of the first working gas 411 and the second working gas 422, thereby introducing a swirling gas flow into the chemical reaction buffer chamber 2.

Further, the first working gas 411 is H₂S gas or H₂A mixed gas of S and other gases; the second working gas 422 is a plasma carrier gas (the plasma carrier gas may be nitrogen or argon or a mixture of the two, and hydrogen sulfide gas is mixed into the carrier gas and flows through the discharge tube 212 of the atmospheric pressure microwave plasma generator 1 in a vortex gas flow manner); the first gas flow controller 41 and the second gas flow controller 42 are used to adjust the flow rates of the first working gas 411 and the second working gas 422, and the mixture ratio of the two, respectively.

Furthermore, the diameter of the outer tube 21 is 2-4 times of the diameter of the discharge tube 212, and the length is more than 3 self tube diameters.

Further, the end surface of the cooling rod 23 facing the discharge tube 212 may have a flat, semicircular, semi-elliptical, or tapered shape.

Further, the diameter of the cooling rod 23 is 0.6 to 2 times of the diameter of the plasma discharge tube 212.

Further, the microwave frequency adopted by the discharge of the microwave plasma generator 1 is 2.45GHz or 915MHz industrial frequency. The microwave frequency of the atmospheric pressure microwave plasma generator 1 is 2.45GHz, the adopted waveguide is a rectangular waveguide, the value interval of the inner diameter of the plasma discharge tube 212 is 1.6-2.6cm when the adopted waveguide type is WR340, and the value interval of the inner diameter of the plasma discharge tube 212 is 2.6-4.6cm when the adopted waveguide type is WR 430. The microwave frequency of the atmospheric pressure microwave plasma generator 1 can also be 915MHz, the correspondingly adopted waveguide is a rectangular waveguide, and the model of the waveguide is that the inner diameter of the WR975 plasma discharge tube 212 is 7.6-8.6 cm.

The invention has the beneficial effects that: the invention adopts the atmospheric pressure microwave plasma torch to decompose the hydrogen sulfide to prepare the hydrogen and the sulfur, effectively inhibits the reverse composite reaction of decomposition reactants by directly carrying out extraction cooling on plasma jet, and can obviously improve H₂The conversion rate of S and the hydrogen production efficiency are further improved compared with the traditional method.

Drawings

FIG. 1 is a block diagram of the system structure of an apparatus for producing hydrogen and sulfur by decomposing hydrogen sulfide using an atmospheric pressure microwave plasma torch.

FIG. 2 is a schematic diagram showing the structure of a chemical reaction buffer chamber in an apparatus for producing hydrogen and sulfur by decomposing hydrogen sulfide using an atmospheric pressure microwave plasma torch.

In the figure: 1 atmospheric pressure microwave plasma generator; 2 a chemical reaction buffer chamber; 3 a decomposition product collecting device;

11 waveguide flange interface; 212 a discharge tube; 12 microwave plasma coupled waveguide; 13 a working gas injection unit; 21 a quartz glass tube; 22 a metal mesh or cylinder; 23 cooling the rod; 24 a connecting flange; 25 gas discharge pipe; 31 a filter bag; a 32 alkaline solution pool; 33 a line containing a desiccant; 34 a gas separation device; 41 a first gas flow controller; 42 a second gas flow controller; 43 a gas mixing vessel; 411 a first working gas; 422 a second working gas.

Detailed Description

The invention is further described with reference to specific embodiments.

A device for decomposing hydrogen sulfide to prepare hydrogen and sulfur by utilizing an atmospheric pressure microwave plasma torch mainly comprises an atmospheric pressure microwave plasma generator 1, a chemical reaction buffer chamber 2 and a decomposition product collecting device 3. The plasma carrier gas can be nitrogen or argon or a mixed gas of the nitrogen and the argon, and hydrogen sulfide gas is mixed into the carrier gas and flows through the discharge tube 212 of the atmospheric pressure microwave plasma generator 1 in a vortex gas flow mode; the discharge tube 212 of the atmospheric pressure microwave plasma generator 1 extends into the chemical reaction buffer chamber 2 connected with the atmospheric pressure microwave plasma generator, and the generated plasma is sprayed into the chemical reaction buffer chamber 2 with the cooling function; the gas discharged from the other end of the chemical reaction buffer chamber 2 passes through the decomposition product collecting means 3.

The atmospheric pressure microwave plasma generator 1 is mainly responsible for generating plasma discharge in the discharge tube 212 by the first and second working gases 411 and 412 under atmospheric pressure, maintaining a stable plasma discharge state under coupling of microwave power, and forming a plasma torch downstream of the discharge tube 212 of the microwave plasma coupling waveguide 12 under driving of the flowing gas.

The atmospheric pressure microwave plasma generator 1 (the specific structure and operation principle refer to a double-cavity excited atmospheric pressure microwave plasma torch proposed in patent CN 207070436U) mainly comprises a microwave power supply, a magnetron, a circulator, a directional coupler, a microwave plasma coupling waveguide 12, a discharge tube 212 and a working gas injection unit 13. The microwave power supply regulates the microwave power output by the magnetron by setting working parameters, and the microwave generated by the magnetron is transmitted in a single direction through the circulatorTo the directional coupler, which finally injects energy into the discharge tube 212 of the microwave plasma-coupled waveguide 12, the first working gas 411 may be a gas, such as hydrogen₂S gas, the second working gas 422, nitrogen gas as a carrier gas, were mixed by the first and second gas flow controllers 41 and 42 in such a ratio that hydrogen sulfide was 10% in the gas, and the total flow rate of the gas was set to 15 l/min, and the gas was injected into the discharge tube 212 from the upstream inlet of the discharge tube 212 by the working gas injection unit 13 in a swirling flow.

When the microwave plasma generator is used, the second working gas 422 is firstly injected into the discharge tube 212 of the microwave plasma generator 1 through the working gas injection unit 13, then the microwave power supply is turned on for ignition, and the output power is adjusted through the control panel of the microwave power supply. The microwave generated by the magnetron is transmitted to the directional coupler through the circulator, and finally energy is injected into the microwave plasma coupling waveguide 12 through the cross-section graded waveguide, so that the second working gas 422 carrier gas excites plasma discharge in the discharge tube 212, a plasma discharge state is maintained under the coupling input of microwave power, a plasma torch is formed at the downstream of the discharge tube 212 under the drive of flowing gas flow, and the first gas flow controller 41 is opened to introduce the first working gas 411 after the discharge is stable. Adjusting the first gas flow controller to vary the H mixed into the carrier gas₂S ratio, H is carried out under the working condition that the atmospheric pressure microwave plasma discharge is stable₂Decomposition of S and preparation of hydrogen and sulfur. The tail gas discharged from the chemical reaction buffer chamber 2 is connected to the decomposition product collecting device 3 through a discharge pipe 25, solid powder sulfur in the tail gas is recovered through a filter bag 31 therein, and then is introduced into an alkaline solution tank 32 to absorb unreacted hydrogen sulfide, then the gas is passed through a drying agent 33 to absorb water vapor in the gas, and finally the hydrogen component in the tail gas is separated out by a gas separating device 34 and stored for later use.

The above-mentioned embodiments only express the embodiments of the present invention, but not should be understood as the limitation of the scope of the invention patent, it should be noted that, for those skilled in the art, many variations and modifications can be made without departing from the concept of the present invention, and these all fall into the protection scope of the present invention.