Low-temperature plasma ammonia production system and method

Abstract

The invention discloses a low-temperature plasma ammonia production system and method. The system comprises a solid ammonia source storage tank, a solid ammonia source metering and conveying device, a pneumatic conveying fan and a low-temperature plasma discharge system, an outlet of the solid ammonia source storage tank is communicated with an inlet of the solid ammonia source metering and conveying device, an outlet of the solid ammonia source metering and conveying device and an outlet of the pneumatic conveying fan are combined through a pipeline and then are communicated with an inlet of the low-temperature plasma discharge system, and the system and the method are high in ammonia production rate, short in response time and low in cost.

Description

Technical Field

[0001] The invention belongs to the technical field of coal-fired air pollutant control and relates to a low-temperature plasma ammonia production system and method. Background Art

[0002] As liquid ammonia is listed as a major hazard source and strictly controlled, it is imperative to carry out technical transformation of the ammonia area of ​​thermal power plants to replace liquid ammonia. Urea and its precursors, as stable and non-toxic solid ammonia sources, have significant advantages in the application field of replacing liquid ammonia as denitrification reducing agents.

[0003] Patent with publication number CN221847104U: A vertical solid catalyst urea hydrolysis reactor, comprising a hydrolysis reactor tank body; a baffle and a plurality of heating coils are arranged in the hydrolysis reactor tank body, wherein the baffle is directly opposite to each heating coil, and a plurality of solid catalyst filler layers are arranged on the side of the baffle directly opposite to the heating coil, and each heating coil is distributed in sequence from top to bottom, and a urea solution inlet is arranged on the top of the hydrolysis reactor tank body, and the urea solution inlet is connected to a feed distributor, and the feed distributor is located above the heating coil. A baffle and a plurality of heating coils are arranged in the tank body of the hydrolysis reactor, wherein the baffle is directly opposite to each heating coil, and a plurality of solid catalyst filling layers are arranged on the side of the baffle directly opposite to the heating coil. The urea heated by the heating coil directly enters the area where the solid catalyst filling layer is located and contacts with the solid catalyst, so that the catalyst and urea are in full contact. Meanwhile, the heating coils are sequentially distributed from top to bottom, and the volume of the urea solution required to react under different loads of the unit can be accurately controlled to produce the required amount of product, with high flexibility. In addition, in the utility model, the feed distributor is located above the heating coil, so that the entering urea solution can be evenly heat-exchanged and heated with the heating coil, and the heat exchange effect is better.

[0004] The above-mentioned urea pyrolysis and urea hydrolysis are currently commonly used alternative technologies for ammonia zone transformation. The principle is to decompose urea powder / urea aqueous solution into NH3 under a certain temperature or pressure range. However, whether it is pyrolysis or hydrolysis, urea decomposition is driven by inputting heat, which causes huge energy consumption in the ammonia production process. In addition, the process flow of pyrolysis and hydrolysis technology is complicated, and both have problems such as slow ammonia production rate and long response time, which cause large investment and operating costs in actual application. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art and provide a low-temperature plasma ammonia production system and method, which has a high ammonia production rate, a short response time and a low cost.

[0006] To achieve the above object, the present invention discloses a low-temperature plasma ammonia production system, comprising a solid ammonia source storage tank, a solid ammonia source metering and conveying device, a pneumatic conveying fan and a low-temperature plasma discharge system;

[0007] The outlet of the solid ammonia source storage tank is connected to the inlet of the solid ammonia source metering and conveying device, and the outlet of the solid ammonia source metering and conveying device and the outlet of the pneumatic conveying fan are connected to the inlet of the low-temperature plasma discharge system through pipelines.

[0008] The further improvement of the low temperature plasma ammonia production system of the present invention is:

[0009] It also includes an intelligent control system, which is connected to the control end of the solid ammonia source metering and conveying device, the control end of the pneumatic conveying fan and the control end of the low-temperature plasma discharge system.

[0010] It also includes an ammonia-air mixing device, a fan and a steam supply system; the outlet of the low-temperature plasma discharge system is connected to the inlet of the ammonia-air mixing device, the outlet of the steam supply system is connected to the inlet of the ammonia-air mixing device, and the outlet of the fan is connected to the inlet of the ammonia-air mixing device.

[0011] The outlet of the low-temperature plasma discharge system is connected with a gas-solid separation device.

[0012] It also includes a partition injection system, and the outlet of the ammonia-air mixing device is connected to the partition injection pipeline in the partition injection system.

[0013] The steam of the steam supply system comes from the auxiliary steam header or the steam generator.

[0014] The low-temperature plasma ammonia production method of the present invention comprises the following steps:

[0015] The solid ammonia output from the solid ammonia source storage tank enters the low-temperature plasma discharge system through the solid ammonia source metering and conveying device and the pneumatic conveying fan. The plasma emitted by the low-temperature plasma discharge system is decomposed into ammonia and isocyanic acid.

[0016] The further improvement of the low temperature plasma ammonia production method of the present invention is:

[0017] It also includes an ammonia-air mixing device, a fan and a steam supply system; the outlet of the low-temperature plasma discharge system is connected to the inlet of the ammonia-air mixing device, the outlet of the steam supply system is connected to the inlet of the ammonia-air mixing device, and the outlet of the fan is connected to the inlet of the ammonia-air mixing device.

[0018] It also includes a partition injection system, and the outlet of the ammonia-air mixing device is connected to the partition injection pipeline in the partition injection system.

[0019] Also includes:

[0020] The low-temperature plasma discharge system outputs ammonia and isocyanic acid which enter the ammonia-air mixing device. At the same time, the steam output by the steam supply system enters the ammonia-air mixing device, and the air output by the fan enters the ammonia-air mixing device. In the ammonia-air mixing device, air, steam, ammonia and isocyanic acid are mixed, wherein isocyanic acid reacts with steam to further decompose isocyanic acid and other gas sources into ammonia. The denitrified mixed gas output by the ammonia-air mixing device is sent to the partitioned injection pipeline.

[0021] The present invention has the following beneficial effects:

[0022] During the specific operation of the low-temperature plasma ammonia production system and method described in the present invention, the solid ammonia output from the solid ammonia source storage tank enters the low-temperature plasma discharge system through the solid ammonia source metering and conveying device and the pneumatic conveying fan, and the plasma emitted by the low-temperature plasma discharge system is decomposed into ammonia and isocyanic acid. It should be noted that the present invention adopts low-temperature plasma ammonia production technology, which can quickly and efficiently generate NH3 with lower energy consumption, thereby overcoming the problems of slow ammonia production rate and long response time of traditional technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0024] Figure 1 It is a system schematic diagram of the present invention;

[0025] Among them, 1 is a solid ammonia source storage tank, 2 is a solid ammonia source metering and conveying device, 3 is a pneumatic conveying fan, 4 is a low-temperature plasma discharge system, 5 is a gas-solid separation device, 6 is a steam supply system, 7 is an ammonia-air mixing device, 8 is a fan, 9 is a zoned injection system, 91 is a zoned NOx measuring device, 92 is a zoned injection pipeline, 93 is a zoned ammonia escape detection device, and 10 is an intelligent control system. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0027] In the description of the present invention, it should be understood that the terms “include” and “comprises” indicate the presence of described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0028] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0029] It should be further understood that the term "and / or" used in the present specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in the present invention generally indicates that the associated objects are in an "or" relationship.

[0030] It should be understood that, although the terms first, second, third, etc. may be used to describe preset ranges, etc. in the embodiments of the present invention, these preset ranges should not be limited to these terms. These terms are only used to distinguish preset ranges from each other. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0031] The word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings here can usually be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0033] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0034] As is known to all, the low-temperature plasma discharge system is the core part of the application of low-temperature plasma technology. The following is a detailed introduction to the system:

[0035] Low-temperature plasma is a state of matter, the fourth state after solid, liquid and gas. When the applied voltage reaches the discharge voltage of the gas, the gas is broken down, producing a mixture including electrons, various ions, atoms and free radicals. These high-energy electrons, free radicals and other active particles interact with pollutants in the exhaust gas, causing the pollutant molecules to decompose in a very short time, and various subsequent reactions occur to achieve the purpose of degrading pollutants. Since the electron temperature is very high during the discharge process, but the heavy particle temperature is very low, the entire system is in a low-temperature state, so it is called low-temperature plasma.

[0036] The low-temperature plasma discharge system is mainly composed of the following parts: Power supply system: provides stable voltage and current to ensure the continuous discharge process. Discharge chamber: It is the main place to generate low-temperature plasma. It usually adopts dielectric barrier discharge (DBD) technology. The double dielectric layer design makes the discharge more stable while avoiding direct contact and wear of the electrodes. Gas supply system: Provides working gas to the discharge chamber, usually air or oxygen. These gases are ionized during the discharge process to form low-temperature plasma. Cooling system: Used to cool the discharge chamber and other heat-generating components to ensure the stable operation of the system.

[0037] The low-temperature plasma discharge system has the following significant features: Low energy consumption: By optimizing the discharge parameters and structural design, energy consumption can be greatly reduced and energy utilization efficiency can be improved. High efficiency: Active particles such as high-energy electrons and free radicals in the low-temperature plasma can react quickly with pollutant molecules, with high degradation efficiency. No secondary pollution: No harmful substances are generated during the discharge process, and the treated waste gas can meet the emission standards and will not cause secondary pollution to the environment.

[0038] Embodiment 1

[0039] refer to Figure 1 The low-temperature plasma ammonia production system of the present invention comprises a solid ammonia source storage tank 1, a solid ammonia source metering and conveying device 2, a pneumatic conveying fan 3 and a low-temperature plasma discharge system 4; the outlet of the solid ammonia source storage tank 1 is connected to the inlet of the solid ammonia source metering and conveying device 2, and the outlet of the solid ammonia source metering and conveying device 2 and the outlet of the pneumatic conveying fan 3 are connected to the inlet of the low-temperature plasma discharge system 4 through a pipeline. The intelligent control system 10 is connected to the control end of the solid ammonia source metering and conveying device 2, the control end of the pneumatic conveying fan 3, and the control end of the low-temperature plasma discharge system 4, and the solid ammonia source metering and conveying device 2, the pneumatic conveying fan 3 and the low-temperature plasma discharge system 4 are controlled by the intelligent control system 10.

[0040] Accordingly, the present invention discloses a method for producing ammonia by low-temperature plasma, which is implemented based on the low-temperature plasma ammonia production system. The low-temperature plasma ammonia production system includes a solid ammonia source storage tank 1, a solid ammonia source metering and conveying device 2, a pneumatic conveying fan 3 and a low-temperature plasma discharge system 4; specifically, the low-temperature plasma ammonia production method includes the following steps:

[0041] The solid ammonia outputted from the solid ammonia source storage tank 1 enters the low-temperature plasma discharge system 4 through the solid ammonia source metering and conveying device 2 and the pneumatic conveying fan 3, and the plasma emitted by the low-temperature plasma discharge system 4 is decomposed into ammonia and isocyanic acid.

[0042] Embodiment 2

[0043] refer to Figure 1The low-temperature plasma ammonia production system of the present invention comprises a solid ammonia source storage tank 1, a solid ammonia source metering and conveying device 2, a pneumatic conveying fan 3, a low-temperature plasma discharge system 4, an ammonia-air mixing device 7, a fan 8 and a steam supply system 6; the outlet of the solid ammonia source storage tank 1 is connected to the inlet of the solid ammonia source metering and conveying device 2, the outlet of the solid ammonia source metering and conveying device 2 and the outlet of the pneumatic conveying fan 3 are connected to the inlet of the low-temperature plasma discharge system 4 through a pipeline; the outlet of the low-temperature plasma discharge system 4 is connected to the inlet of the ammonia-air mixing device 7, the outlet of the steam supply system 6 is connected to the inlet of the ammonia-air mixing device 7, and the outlet of the fan 8 is connected to the inlet of the ammonia-air mixing device 7.

[0044] Embodiment 3

[0045] refer to Figure 1 The low-temperature plasma ammonia production system of the present invention includes a solid ammonia source storage tank 1, a solid ammonia source metering and conveying device 2, a pneumatic conveying fan 3, a low-temperature plasma discharge system 4, a gas-solid separation device 5, a steam supply system 6, an ammonia-air mixing device 7, a fan 8, a partitioned injection system 9 and an intelligent control system 10; the partitioned injection system 9 includes a partitioned NOx measuring device 91, a partitioned injection pipeline 92 and a partitioned ammonia escape detection device 93.

[0046] The outlet of the solid ammonia source storage tank 1 is connected to the inlet of the solid ammonia source metering and conveying device 2. The outlet of the solid ammonia source metering and conveying device 2 and the outlet of the pneumatic conveying fan 3 are connected to the inlet of the low-temperature plasma discharge system 4 through pipelines. The outlet of the low-temperature plasma discharge system 4 is divided into two routes, one of which is connected to the inlet of the gas-solid separation device 5, and the other is connected to the inlet of the ammonia-air mixing device 7. The outlet of the steam supply system 6 is connected to the inlet of the ammonia-air mixing device 7, the outlet of the ammonia-air mixing device 7 is connected to the partition injection pipeline 92 in the partition injection system 9, and the outlet of the fan 8 is connected to the inlet of the ammonia-air mixing device 7.

[0047] The intelligent control system 10 is connected to the control end of the solid ammonia source metering and conveying device 2, the control end of the pneumatic conveying fan 3, the control end of the low-temperature plasma discharge system 4, the control end of the steam supply system 6 and the control end of the fan 8. The solid ammonia source metering and conveying device 2, the pneumatic conveying fan 3, the low-temperature plasma discharge system 4, the steam supply system 6 and the fan 8 are controlled by the intelligent control system 10.

[0048] The low-temperature plasma discharge system 4 includes a low-temperature plasma power supply, an inner electrode, an outer electrode and a blocking medium. The inner electrode, the outer electrode and the blocking medium constitute a discharge area. The low-temperature plasma power supply provides high-voltage and high-frequency power to the low-temperature plasma discharge system 4 under the control of the intelligent control system 10. Under the action of high-energy electrons, solid denitrification agents such as urea / ammonium carbamate are decomposed into gaseous ammonia sources such as ammonia and isocyanic acid.

[0049] The steam of the steam supply system 6 comes from an auxiliary steam header or a steam generator.

[0050] The partitioned injection system 9 includes a partitioned NOx measuring device 91, a partitioned injection pipe 92 and a partitioned ammonia escape detection device 93. The partitioned injection system 9 can divide the flue into rectangular, circular or irregular partitions according to the flue layout. Each partition is equipped with a set of partitioned NOx measuring devices 91, partitioned injection pipes 92 and partitioned ammonia escape detection devices 93. The intelligent control system 10 calculates the real-time distribution of nitrogen oxides in the denitrification zone according to the real-time data of the flue layout, the partitioned NOx measuring device 91 and the partitioned ammonia escape detection device 93, and accurately adjusts the injection amount of each partition according to the distribution of nitrogen oxides.

[0051] The present embodiment discloses a method for producing ammonia by low-temperature plasma, which is implemented based on the low-temperature plasma ammonia production system. The low-temperature plasma ammonia production system includes a solid ammonia source storage tank 1, a solid ammonia source metering and conveying device 2, a pneumatic conveying fan 3, a low-temperature plasma discharge system 4, a gas-solid separation device 5, a steam supply system 6, an ammonia-air mixing device 7, a fan 8, a partition injection system 9 and an intelligent control system 10; the partition injection system 9 includes a partition NOx measuring device 91, a partition injection pipeline 92 and a partition ammonia escape detection device 93; specifically, the low-temperature plasma ammonia production method includes the following steps:

[0052] The solid ammonia outputted from the solid ammonia source storage tank 1 enters the low-temperature plasma discharge system 4 through the solid ammonia source metering and conveying device 2 and the pneumatic conveying fan 3. The plasma emitted by the low-temperature plasma discharge system 4 is decomposed into ammonia and isocyanic acid, and then enters the ammonia-air mixing device 7. At the same time, the steam outputted from the steam supply system 6 enters the ammonia-air mixing device 7, and the air outputted from the fan 8 enters the ammonia-air mixing device 7. In the ammonia-air mixing device 7, air, steam, ammonia and isocyanic acid are mixed, wherein isocyanic acid reacts with steam to further decompose gas sources such as isocyanic acid into ammonia. The denitrified mixed gas outputted from the ammonia-air mixing device 7 is sent to the partitioned injection pipeline 92.

[0053] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and disclosure of the invention. This application is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The specification and examples are to be considered exemplary only, and the true scope and spirit of the present invention are indicated by the following claims.

[0054] It should be understood that the present invention is not limited to the exact construction that has been described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

[0055] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A low-temperature plasma ammonia production system, characterized in that: It comprises a solid ammonia source storage tank (1), a solid ammonia source metering and conveying device (2), a pneumatic conveying fan (3) and a low-temperature plasma discharge system (4); The outlet of the solid ammonia source storage tank (1) is connected to the inlet of the solid ammonia source metering and conveying device (2), and the outlet of the solid ammonia source metering and conveying device (2) and the outlet of the pneumatic conveying fan (3) are connected to the inlet of the low-temperature plasma discharge system (4) through a pipeline.

2. The low-temperature plasma ammonia production system according to claim 1, characterized in that: It also includes an intelligent control system (10), which is connected to a control end of the solid ammonia source metering and conveying device (2), a control end of the pneumatic conveying fan (3), and a control end of the low-temperature plasma discharge system (4).

3. The low-temperature plasma ammonia production system according to claim 1, characterized in that: It also includes an ammonia-air mixing device (7), a fan (8) and a steam supply system (6); the outlet of the low-temperature plasma discharge system (4) is connected to the inlet of the ammonia-air mixing device (7), the outlet of the steam supply system (6) is connected to the inlet of the ammonia-air mixing device (7), and the outlet of the fan (8) is connected to the inlet of the ammonia-air mixing device (7).

4. The low-temperature plasma ammonia production system according to claim 3, characterized in that: The outlet of the low-temperature plasma discharge system (4) is connected to a gas-solid separation device (5).

5. The low-temperature plasma ammonia production system according to claim 3, characterized in that: It also includes a partition injection system (9), and the outlet of the ammonia-air mixing device (7) is connected to the partition injection pipeline (92) in the partition injection system (9).

6. The low-temperature plasma ammonia production system according to claim 3, characterized in that: The steam of the steam supply system (6) comes from an auxiliary steam header or a steam generator.

7. A method for producing ammonia using low-temperature plasma, characterized in that: The low-temperature plasma ammonia production system according to claim 1 comprises the following steps: The solid ammonia outputted from the solid ammonia source storage tank (1) enters the low-temperature plasma discharge system (4) through the solid ammonia source metering and conveying device (2) and the pneumatic conveying fan (3), and the plasma emitted by the low-temperature plasma discharge system (4) is decomposed into ammonia and isocyanic acid.

8. The low-temperature plasma ammonia production method according to claim 7, characterized in that: It also includes an ammonia-air mixing device (7), a fan (8) and a steam supply system (6); the outlet of the low-temperature plasma discharge system (4) is connected to the inlet of the ammonia-air mixing device (7), the outlet of the steam supply system (6) is connected to the inlet of the ammonia-air mixing device (7), and the outlet of the fan (8) is connected to the inlet of the ammonia-air mixing device (7).

9. The method for producing ammonia using low-temperature plasma according to claim 7, characterized in that: It also includes a partition injection system (9), and the outlet of the ammonia-air mixing device (7) is connected to the partition injection pipeline (92) in the partition injection system (9).

10. The method for producing ammonia using low-temperature plasma according to claim 7, characterized in that: Also includes: The low-temperature plasma discharge system (4) outputs ammonia and isocyanic acid which enter the ammonia-air mixing device (7). At the same time, the steam output by the steam supply system (6) enters the ammonia-air mixing device (7). The air output by the fan (8) enters the ammonia-air mixing device (7). In the ammonia-air mixing device (7), air, steam, ammonia and isocyanic acid are mixed. The isocyanic acid reacts with the steam to further decompose the gas sources such as isocyanic acid into ammonia. The denitrified mixed gas output by the ammonia-air mixing device (7) is sent to the partition injection pipeline (92).

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