Low-temperature plasma reaction device and reaction method thereof

Abstract

The invention discloses a low-temperature plasma reaction device and a reaction method thereof, and relates to the technical field of fluidized bed reactors, the low-temperature plasma reaction device comprises an outer shell, the bottom of the outer shell is provided with a gas inlet, the top of the outer shell is provided with a gas outlet, the side wall of the outer shell is provided with a feed port and a control device, and the outer shell is internally provided with a gas distributor; the gas distributor is provided with a plurality of gas distribution holes, the discharge end of the feed port is located above the gas distributor, catalysts can be stacked on the upper surface of the gas distributor, the gas distributor is provided with a rotating motor, the output end of the rotating motor is connected with a cleaning brush, and the rotating motor is used for driving the cleaning brush to rotate. The cleaning brush can clean the upper surface of the gas distributor, a plasma generating device is further installed in the outer shell, and the rotating motor and the plasma generating device are both electrically connected with the control device. The cleaning brush is arranged, and the rotating motor drives the cleaning brush to rotate, so that agglomerated particles can be fully stirred, and the agglomeration problem is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of fluidized bed reactors, and in particular to a low-temperature plasma reaction device and a reaction method thereof. Background Art

[0002] In the field of industrial waste gas treatment, the synergistic application of low-temperature denitrification and ozone synthesis technology is becoming an innovative solution for the efficient purification of nitrogen oxides. Low-temperature denitrification technology, leveraging the characteristics of low-temperature catalysts such as manganese and cerium-based catalysts, can reduce nitrogen oxides in flue gas to nitrogen and water using reducing agents such as ammonia or urea in a relatively low-temperature environment of 100-300°C. This technology is particularly suitable for scenarios with limited waste heat, such as waste incineration and chemical exhaust, reducing energy consumption while also reducing equipment anti-corrosion costs. Ozone synthesis technology, on the other hand, generates highly oxidizing ozone (O3) to oxidize the insoluble nitric oxide (NO) in the flue gas into easily absorbed high-valent nitrogen oxides (such as NO2, N2O5, etc.), creating favorable conditions for subsequent alkaline solution absorption or catalytic reduction.

[0003] When the two are combined, ozone synthesis can be used as a pretreatment link for low-temperature denitrification. The reaction activity of nitrogen oxides is first enhanced through ozone oxidation, and then the removal is completed by utilizing the efficient conversion capacity of low-temperature catalysts. This not only breaks through the bottleneck of slow reaction rate and easy poisoning of catalysts at low temperatures of a single technology, but also forms an "oxidation-reduction" synergistic purification chain, significantly improving the comprehensive removal efficiency of nitrogen oxides in complex flue gases, and providing a new technical path for achieving green and low-carbon emissions in the industrial field. Of course, in addition to being able to efficiently purify nitrogen oxides in flue gas, the combination of the two can also have many other uses, including but not limited to the reaction of malodorous gases (such as ammonia, hydrogen sulfide, sulfides and mercaptans, etc.) with ozone, which can be used for deodorization, etc.

[0004] Existing low-temperature denitrification processes typically utilize a fluidized bed reactor, a device in which gases undergo chemical reactions within an ebullient bed of solid material or catalyst. This is also known as an "ebullient bed reactor." Within a certain flow rate range, the gas vigorously agitates the catalyst or solid particles of material, which form a certain thickness (bed), causing them to behave like a boiling liquid and possess some of the characteristics of liquids, such as fluid pressure on the vessel walls, overflow, and viscosity. This operating condition is called a "fluidized bed." The upper portion of the reactor has an expanded section housing a cyclone separator to recover catalyst carried away by the gas; the bottom is equipped with a raw material inlet pipe and a gas distribution plate; and the middle portion is the reaction section, equipped with cooling water pipes and guide baffles to control the reaction temperature and improve gas-solid contact conditions.

[0005] In traditional fluidized bed reactors, biomass particles and catalyst particles are prone to uneven distribution during flow, leading to particle agglomeration. Of course, catalyst agglomeration can also occur in the absence of biomass particles. This particle agglomeration reduces the gas-solid contact area, significantly affecting the conversion rate and selectivity of the reaction. Furthermore, solid catalyst particle agglomeration can easily lead to severe gas backmixing, increasing the frequency of collisions between particles during the catalytic cracking process. Increased collisions between catalyst particles can also easily lead to catalyst particle pulverization, which is then carried along with the gas flow, resulting in significant catalyst loss.

[0006] Therefore, the art urgently needs a new low-temperature plasma reaction device and reaction method thereof to solve the above problems. Summary of the Invention

[0007] The purpose of the present invention is to provide a low-temperature plasma reaction device and a reaction method thereof to solve the problems existing in the above-mentioned prior art, reduce the generation of agglomerated particles, improve reaction efficiency, and reduce catalyst loss.

[0008] To achieve the above object, the present invention provides the following solutions:

[0009] The present invention discloses a low-temperature plasma reaction device, comprising an external shell, wherein the bottom of the external shell is provided with an air inlet, the top of the external shell is provided with an air outlet, the side wall of the external shell is provided with a feed port and a control device, a gas distributor is installed inside the external shell, the gas distributor is provided with a plurality of air distribution holes, the discharge end of the feed port is located above the gas distributor, a catalyst can be stacked on the upper surface of the gas distributor, a rotating motor is installed on the gas distributor, the output end of the rotating motor is connected to a cleaning brush, the rotating motor is used to drive the cleaning brush to rotate, and the cleaning brush can clean the upper surface of the gas distributor, a plasma generating device is also installed in the external shell, and the rotating motor and the plasma generating device are both electrically connected to the control device.

[0010] Preferably, the rotary motor is fixed to the lower surface of the gas distributor, the output shaft of the rotary motor passes through the center of the gas distributor upward, and the center of the cleaning brush is fixedly connected to the output shaft of the rotary motor.

[0011] Preferably, the plasma generating device is a plasma generator.

[0012] Preferably, the cleaning brush is mounted with conductive metal.

[0013] Preferably, the conductive metal is made of copper, aluminum or nickel.

[0014] Preferably, a plurality of temperature sensors are installed in the external shell, and the temperature sensors are spaced apart in the vertical direction, and the temperature sensors are electrically connected to the control device.

[0015] Preferably, a pressure sensor is installed in the external housing, and the pressure sensor is electrically connected to the control device.

[0016] Preferably, a gas concentration sensor is installed in the external shell, and the gas concentration sensor is electrically connected to the control device.

[0017] Preferably, a cyclone separator is installed at the air outlet.

[0018] The present invention also discloses a reaction method of a low-temperature plasma reaction device, comprising the following steps:

[0019] S1, placing a catalyst into the outer shell through the feed port;

[0020] S2, charging the reaction gas into the outer shell through the air inlet, and at the same time, starting the rotating motor and the plasma generating device;

[0021] S3. The gas generated by the reaction is discharged from the gas outlet.

[0022] Compared with the prior art, the present invention has achieved the following technical effects:

[0023] The present invention uses a rotating motor to drive a cleaning brush for stirring. The rotation of the cleaning brush fully stirs the catalyst, increasing its contact area with the reaction gas and improving reaction efficiency. The continuously rotating cleaning brush also prevents catalyst agglomeration, preventing catalyst pulverization and loss, and can also break up some agglomerated particles. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 This is an external schematic diagram of a low-temperature plasma reaction device according to Example 1;

[0026] Figure 2 This is a diagram showing the internal parts distribution of the low-temperature plasma reaction device of Example 1;

[0027] Figure 3This is a schematic diagram of the structure of a cleaning brush in a low-temperature plasma reaction device in Example 1;

[0028] In the figure: 1-external shell; 2-air inlet; 3-air outlet; 4-feed port; 5-control device; 6-gas distributor; 7-rotating motor; 8-plasma generator; 9-temperature sensor; 10-pressure sensor; 11-gas concentration sensor; 12-cleaning brush; 13-conductive metal. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] The purpose of the present invention is to provide a low-temperature plasma reaction device and a reaction method thereof to solve the problems existing in the above-mentioned prior art, reduce the generation of agglomerated particles, improve reaction efficiency, and reduce catalyst loss.

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Example 1

[0033] like Figure 1-Figure 3As shown, this embodiment provides a low-temperature plasma reaction device, including an outer shell 1, which is a cylindrical shell structure. An air inlet 2 is provided at the bottom of the outer shell 1. The air inlet 2 can be connected to the gas source of the reaction gas through a pipeline, so as to fill the interior of the outer shell 1 with the reaction gas required during the reaction process. An air outlet 3 is provided at the top of the outer shell 1, and a tapered portion is provided between the air outlet 3 and the outer shell 1. The diameter of the tapered portion gradually decreases from bottom to top, so as to collect the generated gas so that it all flows out from the air outlet 3. If necessary, the air outlet 3 can also be connected to a generated gas collection container through a pipeline for collecting the generated gas. A feed port 4 and a control device 5 are provided on the side wall of the outer shell 1. The feed port 4 is used to introduce a catalyst. If the reaction requires, other reaction materials can also be introduced through the feed port 4. The control device 5 can use an existing control panel, which can control the operation of related electrical appliances while also viewing related operating parameters. A gas distributor 6 is installed inside the outer shell 1. The gas distributor 6 is a disc structure. The side wall of the gas distributor 6 is welded to the inner wall of the outer shell 1. The gas distributor 6 is provided with a number of vertically through-holes for distributing gas to facilitate the reaction gas to pass from bottom to top. The discharge end of the feed port 4 is located above the gas distributor 6. The catalyst (and other reaction materials) added from the feed port 4 can fall onto the gas distributor 6, so that the upper surface of the gas distributor 6 can be piled with catalyst. The gas distributor 6 is installed with a rotating motor 7. The output end of the rotating motor 7 is connected to a cleaning brush 12. The rotating motor 7 is used to drive the cleaning brush 12 to rotate, and the cleaning brush 12 can clean the upper surface of the gas distributor 6. A plasma generator 8 is also installed in the outer shell 1. The rotating motor 7 and the plasma generator 8 are both electrically connected to the control device 5 and are uniformly controlled by the control device 5.

[0034] During actual use, the staff puts the catalyst into the outer shell 1 through the feed port 4, then starts the rotating motor 7 and the plasma generator 8, and introduces the malodorous gas (i.e., reaction gas) into the outer shell 1 through the air inlet 2. The reaction gas reacts under the working conditions of the catalyst and the discharge of the plasma generator 8, and the final product generated by the reaction will flow upward and out of the air outlet 3.

[0035] In this embodiment, the housing of the rotating motor 7 is fixed to the lower surface of the gas distributor 6 by bolts, the output shaft of the rotating motor 7 passes upward through the center of the gas distributor 6, the center of the cleaning brush 12 is fixedly connected to the output shaft of the rotating motor 7 by key connection or welding, and the bristles of the cleaning brush 12 are in contact with the upper end of the air hole of the cloth.

[0036] In actual use, it is only necessary to start the rotating motor 7, and the output shaft of the rotating motor 7 can drive the cleaning brush 12 to rotate. During the rotation of the cleaning brush 12, the catalyst can be fully stirred to avoid catalyst agglomeration, and the contact area between the catalyst and the reaction gas can be increased; the air holes can also be cleaned to prevent the catalyst from blocking the air holes and affecting the passage of the reaction gas.

[0037] In this embodiment, the plasma generating device 8 is an existing plasma generator, and its principle is: a low voltage is increased to positive high voltage and negative high voltage through a boost circuit, and the positive high voltage and negative high voltage are used to ionize the air (mainly oxygen) to produce a large number of positive ions and negative ions, and the number of negative ions is greater than the number of positive ions (the number of negative ions is approximately 1.5 times the number of positive ions).

[0038] Furthermore, the specific model of the plasma generator may be an existing dielectric barrier discharge (DBD) type.

[0039] In this embodiment, a conductive metal 13 is installed on the cleaning brush 12. The conductive metal 13 can enhance the conductivity of the cleaning brush 12, thereby increasing the contact probability between the reaction gas and electricity, that is, indirectly increasing the discharge effect of the plasma generator 8, thereby improving the reaction efficiency.

[0040] In this embodiment, the conductive metal 13 is a rectangular block structure, and its size matches the size of the cleaning brush 12. The material of the conductive metal 13 includes but is not limited to copper, aluminum, nickel or other materials with good conductive properties.

[0041] In this embodiment, a plurality of temperature sensors 9 are installed in the outer shell 1. The temperature sensors 9 are spaced apart in the vertical direction to measure the temperature at different heights in the outer shell 1. Specifically, three temperature sensors 9 can be provided. The specific distance between two adjacent temperature sensors 9 can be adjusted according to actual needs, so it is not limited here. Figure 2 As shown, the temperature sensor 9 and the plasma generator 8 are distributed on both sides of the interior of the external shell 1, and the temperature sensor 9 is electrically connected to the control device 5. The temperature data detected by the temperature sensor 9 can be transmitted to the control panel (i.e., the control device 5) in a timely manner and displayed on the display screen on the control panel for the staff to understand.

[0042] In this embodiment, a pressure sensor 10 is installed in the outer shell 1 for measuring the air pressure inside the outer shell 1 in real time. The pressure sensor 10 is arranged on the same side as the temperature sensor 9 and the plasma generator 8 ( Figure 2At the center position of the rear), the pressure sensor 10 is electrically connected to the control device 5 to transmit the measured pressure value to the control panel, which is displayed on the display screen on the control panel for the staff to understand.

[0043] In this embodiment, a gas concentration sensor 11 is installed within the outer housing 1 and is located below the pressure sensor 10. Gas concentration sensor 11 is used to measure the generated gas concentration. Gas concentration sensor 11 is electrically connected to the control device 5 to transmit the measured gas concentration value to the control panel, which displays it on the display screen for staff to understand.

[0044] In this embodiment, a cyclone separator is installed at the gas outlet 3. The reason for the cyclone separator is that, under the influence of the gas flow within the outer shell 1, a small amount of catalyst may be carried by the generated gas and flow upward together. Therefore, a cyclone separator is required. The generated gas will enter the inlet of the cyclone separator, and the catalyst mixed in the generated gas will flow out of the solid outlet under the separation effect of the cyclone separator and fall back into the interior of the outer shell 1. The separated gas will flow out of the gas outlet of the cyclone separator and ultimately flow to the outside of the outer shell 1 through the gas outlet 3.

[0045] In this embodiment, a discharge port may be further provided on the side wall of the outer shell 1 , and after the experiment is completed, the catalyst in the outer shell 1 may be poured out from the discharge port.

[0046] In addition, a water inlet and a water outlet can be set on the side wall of the external shell 1. In some experiments, liquid water needs to be added to the external shell 1. At this time, the water inlet can be used to introduce an external water source into it. After the experiment is over, the water in the external shell 1 can be poured out through the water outlet.

[0047] In addition, an electric control valve can be added to the above-mentioned feed port 4, air inlet 2, air outlet 3, discharge port, water inlet and water outlet according to actual needs to control their opening and closing, and the electric control valve is also electrically connected to the control device 5 and is uniformly controlled by the control device 5.

[0048] Example 2

[0049] This embodiment provides a reaction method of a low-temperature plasma reaction device, based on the low-temperature plasma reaction device disclosed in Example 1, comprising the following steps:

[0050] S1. A catalyst is placed into the outer shell 1 through the feed port 4. The catalyst can be an existing Cu-Mn / SAPO-34 catalyst. The Cu-Mn / SAPO-34 catalyst is a bimetallic modified material based on chabazite molecular sieve (SAPO-34) and is widely used in the field of selective catalytic reduction (SCR) denitrification.

[0051] S2. Reactive gas is charged into the outer shell 1 through the gas inlet 2. The reactive gas may be ammonia (different gases may be used in different experiments). At the same time, the rotating motor 7 and the plasma generator 8 are started.

[0052] S3. The gas generated by the reaction is discharged from the gas outlet 3. In this experiment, the gas generated is nitrogen.

[0053] Based on the above experimental process, further exploratory experiments can be conducted, such as exploring the effect of plasma generator 8 on experimental efficiency by changing its operating efficiency. Alternatively, ozone can be added to the ammonia gas during the process, and the effect of ozone on the ammonia reaction efficiency can be studied by continuously adjusting the input ozone content. Finally, in each of the above experiments, the interior of the outer shell 1 is always in a low-temperature reaction environment (100-300°C) due to the heat release of the plasma generator 8 and the exothermic reaction of ammonia. Studies have shown that under such temperature regulation, the ammonia reaction efficiency is higher.

[0054] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third" and the like are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0055] In the description of the present invention, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; they may refer to mechanical or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application.

[0056] If the present invention discloses or involves components or structural parts that are fixedly connected to each other, then, unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (for example, connection using bolts or screws), and can also be understood as: a non-detachable fixed connection (for example, riveting, welding). Of course, the mutual fixed connection can also be replaced by an integrated structure (for example, manufactured by integrated molding using a casting process) (except where it is obviously impossible to use an integrated molding process).

[0057] In addition, unless otherwise stated, the terms used in any technical solution disclosed in the present invention to express positional relationships or shapes include states or shapes that are approximate, similar, or close thereto.

[0058] Any component provided by the present invention may be assembled from multiple separate components, or may be a separate component manufactured by an integral molding process.

[0059] It should be noted that the structures, proportions, sizes, etc. depicted in the drawings of this specification are only used to match the contents disclosed in the specification so that people familiar with this technology can understand and read them. They are not used to limit the conditions under which the present invention can be implemented. Therefore, they have no substantive technical significance. Any modification of the structure, change in the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed in the present invention without affecting the efficacy and purpose that can be achieved by the present invention.

[0060] It should also be noted that in the embodiments of the present application, the same figure mark represents the same component or the same part.

[0061] Adaptive changes based on actual needs are all within the scope of protection of the present invention.

[0062] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A low-temperature plasma reaction device, characterized in that: The invention comprises an external shell (1), wherein the bottom of the external shell (1) is provided with an air inlet (2), the top of the external shell (1) is provided with an air outlet (3), the side wall of the external shell (1) is provided with a feed port (4) and a control device (5), a gas distributor (6) is installed inside the external shell (1), the gas distributor (6) is provided with a plurality of air distribution holes, the discharge end of the feed port (4) is located above the gas distributor (6), the upper surface of the gas distributor (6) can be stacked with a catalyst, the gas distributor (6) is installed with a rotating motor (7), the output end of the rotating motor (7) is connected to a cleaning brush (12), the rotating motor (7) is used to drive the cleaning brush (12) to rotate, and the cleaning brush (12) can clean the upper surface of the gas distributor (6), and a plasma generator (8) is also installed in the external shell (1), and the rotating motor (7) and the plasma generator (8) are both electrically connected to the control device (5).

2. The low-temperature plasma reaction device according to claim 1, characterized in that: The rotating motor (7) is fixed to the lower surface of the gas distributor (6), the output shaft of the rotating motor (7) passes through the center of the gas distributor (6) upward, and the center of the cleaning brush (12) is fixedly connected to the output shaft of the rotating motor (7).

3. The low-temperature plasma reaction device according to claim 1, characterized in that: The plasma generating device (8) is a plasma generator.

4. The low-temperature plasma reaction device according to claim 1, characterized in that: Conductive metal (13) is installed on the cleaning brush (12).

5. The low-temperature plasma reaction device according to claim 4, characterized in that: The conductive metal (13) is made of copper, aluminum or nickel.

6. The low-temperature plasma reaction device according to claim 1, characterized in that: A plurality of temperature sensors (9) are installed in the outer shell (1), and the temperature sensors (9) are spaced apart and distributed in a vertical direction. The temperature sensors (9) are electrically connected to the control device (5).

7. The low-temperature plasma reaction device according to claim 1, characterized in that: A pressure sensor (10) is installed in the outer housing (1), and the pressure sensor (10) is electrically connected to the control device (5).

8. The low-temperature plasma reaction device according to claim 1, characterized in that: A gas concentration sensor (11) is installed in the outer shell (1), and the gas concentration sensor (11) is electrically connected to the control device (5).

9. The low-temperature plasma reaction device according to claim 1, characterized in that: A cyclone separator is installed at the air outlet (3).

10. A reaction method of a low-temperature plasma reaction device, characterized in that: The low-temperature plasma reaction device according to any one of claims 1 to 9 comprises the following steps: S1, placing a catalyst into the outer shell (1) through the feed port (4); S2, charging the reaction gas into the outer shell (1) through the gas inlet (2), and at the same time, starting the rotating motor (7) and the plasma generating device (8); S3. The gas generated by the reaction is discharged from the gas outlet (3).

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