Reactor suitable for online reaction regeneration of SCR (Selective Catalytic Reduction) denitration catalyst in power plant

Abstract

The utility model discloses a reactor suitable for online reaction regeneration of an SCR denitration catalyst in a power plant, which comprises a plurality of fixed bed reactors which are communicated with one another in series; a gas outlet is formed in the bottom end of the side wall of the fixed bed reactor at the lowermost end; each fixed bed reactor is connected with a gas inlet pipe; the regeneration gas distribution switchers are correspondingly arranged on one side of the upper end of each fixed bed reactor and are connected with the corresponding gas inlet pipes; the plurality of blowing refilling devices are correspondingly arranged on the other side of the upper end of each fixed bed reactor; and the gas content detector is arranged at the gas outlet. According to the scheme, the plurality of fixed bed reactors, the regeneration gas distribution switcher and the blowing refilling device work cooperatively, so that the online continuous reaction regeneration operation of the denitration catalytic reaction can be realized, and the efficiency of the reactors can be improved.

Description

Technical Field

[0001] This application relates to the field of catalytic reaction technology, and in particular to a reactor suitable for online reaction regeneration of SCR denitrification catalysts in power plants. Background Technology

[0002] SCR (Selective Catalytic Reduction) denitrification catalyst regeneration technology mainly involves the comprehensive management of waste flue gas denitrification catalysts as hazardous waste. It requires the unified treatment of harmful substances to avoid adverse effects on the natural environment and human health, gradually reduce the degree of environmental pollution, improve resource utilization, maintain the harmonious development of modern society, and create a good living environment for people.

[0003] Existing SCR denitrification reactors are prone to catalyst deactivation, mainly due to catalyst poisoning, catalyst micropore blockage, high-temperature sintering, and loss of active components. Catalyst micropore blockage refers to the installation location of the SCR reactor, typically between the coal bath and the air preheater. During actual operation, this area carries a large amount of fly ash, causing small particles of fly ash and salts to clog the catalyst micropores, adversely affecting the activity of the SCR denitrification catalyst. Catalyst poisoning occurs when elements such as arsenic and alkali metals are produced in the flue gas. Prolonged contact with the catalyst causes a chemical reaction, gradually losing the active substances on the catalyst surface. High-temperature sintering and loss of active components occur because the catalyst is exposed to high temperatures for extended periods, gradually reducing its surface area and pore volume, hindering the effective function of the SCR denitrification catalyst.

[0004] The catalyst failures mentioned above result in short catalyst life, leading to short operating cycles, severe ash blockage, and inability to regenerate online in the SCR denitrification reactor. Utility Model Content

[0005] The embodiments of this application provide a reactor suitable for online reaction regeneration of SCR denitrification catalysts in power plants.

[0006] Embodiments of this application provide a reactor suitable for online reaction regeneration of SCR denitrification catalysts in power plants, comprising:

[0007] Several fixed-bed reactors are connected in series; the bottom side wall of the lowest fixed-bed reactor has an air outlet; each fixed-bed reactor is equipped with an air inlet pipe.

[0008] Several regenerated gas distribution switches are respectively installed on one side of the upper end of each fixed bed reactor and connected to the corresponding gas inlet pipe;

[0009] Several injection feeders are correspondingly installed on the opposite side of the upper end of each fixed-bed reactor;

[0010] A gas content detector is installed at the gas outlet.

[0011] In one embodiment, the regenerated gas distribution switcher employs a gas distribution tray with a nano-metal mesh or metal film.

[0012] In one embodiment, a first solenoid valve is provided between the gas distribution tray and the inlet pipe.

[0013] In one embodiment, each jet injector is connected to a first liquid line and a second liquid line;

[0014] The first liquid tube delivers the active metal salt solution;

[0015] The second liquid pipe delivers the catalyst cleaning agent solution.

[0016] In one embodiment, a second solenoid valve is provided on the first liquid pipe.

[0017] In one embodiment, a third solenoid valve is provided on the second liquid line.

[0018] In one embodiment, each air inlet pipe is connected to a first air pipe and a second air pipe;

[0019] The first gas tube delivers regenerated gas;

[0020] The second gas pipe delivers the raw material gas.

[0021] In one embodiment, each fixed-bed reactor has an outlet at the bottom of its sidewall.

[0022] In one embodiment, a fourth solenoid valve is provided at the air outlet.

[0023] This application has the following advantages over the prior art:

[0024] This scheme, through the coordinated operation of several fixed-bed reactors, a regeneration gas distribution switch, and a jet injector, can achieve online continuous regeneration of the denitrification catalytic reaction, thereby improving reactor efficiency. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the reactor structure for online reaction regeneration of SCR denitrification catalyst in power plants, as described in this application embodiment. Detailed Implementation

[0027] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0029] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation", "connection" and "joining" should be interpreted broadly, for example, they can refer to fixed connection, detachable connection, or integral connection; for those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0030] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0031] In the development of modern society, thermal power plants are a major development area, requiring relevant departments in my country to strengthen their supervision. Considering the development patterns of thermal power plants, it is necessary to formulate comprehensive management plans and measures to ensure that all operations of thermal power plants are strictly implemented in accordance with relevant standards and regulations, reducing nitrogen oxide emissions, and ensuring unified treatment of pollutants to effectively reduce environmental pollution. Currently, most thermal power plants adopt the SCR (Selective Catalytic Reduction) flue gas denitrification process, which can promptly replace inactive catalysts under high-temperature and fly ash conditions, maintaining the internal working environment of the thermal power plant and ensuring the safety of construction personnel.

[0032] Currently, most thermal power plants employ denitrification systems, opting for highly efficient catalytic reduction (CCR) to enable SCR (Self-Catalyst Catalysis) to chemically react nitrogen oxides in flue gas under the influence of a reducing agent and high temperatures. Different factors result in different reaction effects. If sulfur trioxide is chosen as an antioxidant and detoxifying auxiliary component, no byproducts or environmental pollution are generated during the denitrification process, making operation convenient, simple, and easy to maintain. In response, relevant departments in my country have increased their research and development efforts on SCR denitrification catalyst regeneration technology. They are combining the application needs of various fields, considering specific influencing factors and application conditions, and innovating diverse implementation schemes. Furthermore, they are able to record detailed information on air quality, hazardous substances, and the implementation process, providing favorable conditions for the research and development of SCR denitrification catalyst regeneration technology. Currently, the SCR denitrification catalyst regeneration technologies developed in my country, analyzed by their types, mainly include honeycomb, plate, and corrugated types. The most commonly used type is the honeycomb catalyst, mainly due to its own advantages and characteristics, such as large surface area, high activity, and small size, which expands its application range and allows it to play a major role in the development of various fields.

[0033] In addition, during the research and development and application of SCR denitrification catalyst regeneration technology, it is necessary to consider its own catalyst failure modes, which mainly include catalyst poisoning, catalyst micropore blockage, sintering caused by high temperature, and loss of active components.

[0034] Existing fixed-bed SCR denitrification reactors suffer from problems such as short catalyst life (<500 hours) due to catalyst failure, requiring frequent reaction regeneration, short operating cycles, severe ash blockage, low equipment efficiency, and inability to regenerate online.

[0035] Reference Figure 1 The embodiments of this application provide a reactor suitable for online reaction regeneration of SCR denitrification catalysts in power plants, comprising:

[0036] Several fixed-bed reactors 1 are connected in series with each other; the bottom side wall of the lowest fixed-bed reactor 1 is provided with an air outlet 11; each fixed-bed reactor 1 is provided with an air inlet pipe 12.

[0037] Several regeneration gas distribution switchers 2 are respectively installed on one side of the upper end of each fixed bed reactor 1 and connected to the corresponding gas inlet pipe 12.

[0038] Several injection feeders 3 are respectively installed on the other side of the upper end of each fixed bed reactor 1;

[0039] Gas content detector 4 is installed at gas outlet 11.

[0040] Specifically, solid bed reactors can be tubular in structure. Solid bed reactors can be used in series or independently.

[0041] The regenerated gas distribution switch 2 is used to evenly disperse the gas input into the solid bed reactor, so that the catalyst in the solid bed reactor can more evenly degrade the input gas.

[0042] In one embodiment, the regeneration gas distribution switch 2 employs a gas distribution tray with a nano-metal mesh or metal film.

[0043] In one embodiment, a first solenoid valve is provided between the gas distribution tray and the inlet pipe 12.

[0044] The first solenoid valve, installed between the gas distribution tray and the inlet pipe 12, can control whether gas is input, control the flow rate of the input gas, and, in special cases, control the output of gas from the solid bed reactor from the inlet pipe 12.

[0045] In one embodiment, each air inlet pipe 12 is connected to a first air pipe 121 and a second air pipe 122;

[0046] The first gas pipe 121 delivers regenerated gas;

[0047] The second gas pipe 122 delivers the raw material gas.

[0048] Specifically, the regenerated gas can be air, and the feed gas can be olefins.

[0049] All first gas pipes 121 can be connected to the same container holding regeneration gas, or each first gas pipe 121 can correspond to a container holding regeneration gas, or other corresponding methods as required by actual needs. Similarly, all second gas pipes 122 can be connected to the same container holding raw material gas, or each second gas pipe 122 can correspond to a container holding raw material gas, or other corresponding methods as required by actual needs.

[0050] Understandably, the first trachea 121 and the second trachea 122 can be combined into a single trachea, which delivers regenerated gas or raw material gas according to actual needs.

[0051] The injection replenisher 3 is used to inject an active metal salt solution or a catalyst cleaning agent solution into the solid bed reactor to regenerate the catalyst or clean the existing catalyst. The active metal salt solution can be a solution containing active metal salts such as vanadium, molybdenum, nickel, titanium, or tungsten, and the concentration of the catalyst cleaning agent solution can be set according to actual needs.

[0052] In one embodiment, each jet filler 3 is connected to a first liquid pipe 31 and a second liquid pipe 32;

[0053] The first liquid tube 31 delivers the active metal salt solution;

[0054] The second liquid pipe 32 delivers the catalyst cleaning agent solution.

[0055] Specifically, all first liquid pipes 31 can be connected to the same container holding the active metal salt solution, or each first liquid pipe 31 can correspond to a container holding the active metal salt solution, or other corresponding methods depending on actual needs. Similarly, all second liquid pipes 32 can be connected to the same container holding the catalyst cleaning agent solution, or each second liquid pipe 32 can correspond to a container holding the catalyst cleaning agent solution, or other corresponding methods depending on actual needs.

[0056] Understandably, the first liquid pipe 31 and the second liquid pipe 32 can be combined into a single liquid pipe, which can deliver active metal salt solution or catalyst cleaning agent solution according to actual needs.

[0057] The injection replenisher 3 can be a pressurized injection device that uses micro-foam distributed nozzles to inject a certain volume of active metal salt solution containing vanadium, molybdenum, nickel, titanium, tungsten and other active metal salts or a catalyst cleaning agent solution of a first concentration according to electrical signal instructions.

[0058] In one embodiment, a second solenoid valve is provided on the first liquid pipe 31.

[0059] In one embodiment, a third solenoid valve is provided on the second liquid pipe 32.

[0060] Specifically, the second solenoid valve can control whether the active metal salt solution is delivered to the first liquid pipe 31, and the flow rate of the active metal salt solution delivered to the first liquid pipe 31. Similarly, the third solenoid valve can control whether the catalyst cleaning agent solution is delivered to the second liquid pipe 32, and the flow rate of the catalyst cleaning agent solution delivered to the second liquid pipe 32.

[0061] Gas content detector 4 is installed at the outlet 11 of the fixed-bed reactor 1 to detect the content of ammonia gas generated after the reaction in the fixed-bed reactor 1. Understandably, gas content detector 4 can be an ammonia content detector. If the detected ammonia content is unqualified, the emitted gas will be reacted again; if the detected ammonia content is qualified, the reacted gas will be discharged.

[0062] Since all the fixed-bed reactors 1 are connected in series, an outlet 11 can be opened only in the bottom fixed-bed reactor 1, and all the gas generated in the fixed-bed reactor 1 is output from this outlet 11.

[0063] In one embodiment, each fixed-bed reactor 1 has an outlet 11 at the bottom of its sidewall.

[0064] Specifically, the gas generated in each fixed-bed reactor 1 can be partially output from its respective outlet 11, while the remainder enters the lower fixed-bed reactor 1.

[0065] In one embodiment, a fourth solenoid valve is provided at the air outlet 11.

[0066] Specifically, by setting a fourth solenoid valve at the outlet 11, it is possible to control whether the gas generated by each fixed bed reactor 1 is discharged from its own outlet 11.

[0067] For example, continue to refer to Figure 1 The figure shows an example of three fixed-bed reactors 1 connected in series. From top to bottom, the fixed-bed reactors 1 are the first fixed-bed reactor 1, the second fixed-bed reactor 1, and the third fixed-bed reactor 1. Each fixed-bed reactor 1 has a diameter of 1.2 meters and a height of 3 meters. The regeneration gas distribution switch 2 has a diameter of 1 meter and its metal mesh has an aperture of 50 nanometers.

[0068] At an airspeed of 1.0 × 10 4 h -1 Using simulated flue gas conditions with a total flue gas flow rate of 650 mL / min, NO and NH3 of 500 ppm, and O2 of 5%, the reactor of this embodiment was used to carry out the SCR denitrification catalytic reaction. It already had high catalytic activity at low temperature (150°C), and the NO conversion rate reached 57%. As the reaction temperature continued to rise, the catalytic activity gradually increased. When the temperature exceeded 250°C, the conversion rate exceeded 90%, and when the catalyst reached 350°C, the conversion rate was as high as 96%.

[0069] After 500 hours of reaction, the catalyst activity decreases and ash accumulation becomes severe. At this point, the first solenoid valve connected to the regeneration gas distribution switch 2 controls the first fixed-bed reactor 1 to purge the catalyst with air, while the second and third fixed-bed reactors 1 continue to be purged with raw material gas for reaction. After the first fixed-bed reactor 1 is purged for 2 hours, the first and third fixed-bed reactors 1 are purged with raw material gas for reaction. The second fixed-bed reactor 1 is purged with regeneration gas for activation and regeneration, and so on, to achieve a continuous reaction and regeneration process of the three reactors without stopping the reactor.

[0070] After 1000 hours of reaction, the catalyst activity decreases and blockage becomes severe. At this point, the third solenoid valve of the injector 3 controls the first fixed-bed reactor 1 to introduce catalyst cleaning agent to activate and clean the catalyst. The second and third fixed-bed reactors 1 continue to be purged with feed gas for reaction. After the first fixed-bed reactor 1 is cleaned for 2 hours, it is purged with feed gas for reaction. The second fixed-bed reactor 1 is purged with catalyst cleaning agent to activate and clean the catalyst. The first and third fixed-bed reactors 1 then react, and so on. This continuous reaction and regeneration process of the three reactors is achieved without shutting down the reactor.

[0071] After 10,000 hours of reaction, the catalyst activity decreases and the active metal is severely lost. At this point, the catalyst is regenerated by injecting a certain volume of active metal salt solution containing vanadium, molybdenum, nickel, titanium, tungsten, etc. into the first fixed-bed reactor 1 through the second solenoid valve controlled by the injection replenisher 3. The second and third fixed-bed reactors 1 are still fed with feed gas for reaction. After the catalyst is regenerated in the first fixed-bed reactor 1 for 2 hours, the first fixed-bed reactor 1 is fed with feed gas for reaction. The second fixed-bed reactor 1 is then fed with another active metal salt solution to regenerate the catalyst. The first and third fixed-bed reactors 1 then react, and so on, to achieve a continuous reaction and regeneration process of the three reactors without stopping the reactor.

[0072] Under this model, the SCR denitrification catalytic unit in the power plant can operate continuously and stably for more than 30,000 hours, which is far higher than the existing unit's level of 500 to 1,000 hours. This greatly improves the unit's efficiency, reduces the risk of catalyst replacement, and saves costs.

[0073] By setting up several fixed-bed reactors, a regeneration gas distribution switch, and a jet injector to work together, the denitrification catalytic reaction can be continuously regenerated online, which can improve the efficiency of the reactor. When the catalyst becomes clogged with ash, it can be cleaned without stopping the machine. This solves the problems of short operating cycles, severe ash blockage, low single-unit efficiency, and inability to regenerate online that exist in the fixed-bed reactors currently used in power plant denitrification units.

[0074] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A reactor suitable for online reaction regeneration of SCR denitrification catalyst in power plants, characterized in that, include: A plurality of fixed-bed reactors (1) are connected in series with each other; the bottom of the side wall of the lowest fixed-bed reactor (1) is provided with an air outlet (11); each fixed-bed reactor (1) is provided with an air inlet pipe (12); Several regeneration gas distribution switchers (2) are respectively installed on one side of the upper end of each fixed bed reactor (1) and connected to the corresponding gas inlet pipe (12); Several injection feeders (3) are respectively arranged on the other side of the upper end of each of the fixed bed reactors (1); A gas content detector (4) is installed at the gas outlet (11).

2. The reactor for online reaction regeneration of SCR denitrification catalyst in power plants according to claim 1, characterized in that, The regenerated gas distribution switch (2) uses a gas distribution tray with nano-metal mesh or metal film.

3. The reactor for online reaction regeneration of SCR denitrification catalyst in power plants according to claim 2, characterized in that, A first solenoid valve is provided between the gas distribution tray and the gas inlet pipe (12).

4. The reactor for online reaction regeneration of SCR denitrification catalyst in power plants according to claim 1, characterized in that, Each of the aforementioned jet fillers (3) is connected to a first liquid pipe (31) and a second liquid pipe (32); The first liquid tube (31) delivers an active metal salt solution; The second liquid pipe (32) delivers the catalyst cleaning agent solution.

5. The reactor for online reaction regeneration of SCR denitrification catalyst in power plants according to claim 4, characterized in that, A second solenoid valve is provided on the first liquid pipe (31).

6. The reactor for online reaction regeneration of SCR denitrification catalyst in power plants according to claim 4, characterized in that, A third solenoid valve is provided on the second liquid pipe (32).

7. The reactor for online reaction regeneration of SCR denitrification catalyst in power plants according to claim 1, characterized in that, Each of the aforementioned air inlets (12) is connected to a first air pipe (121) and a second air pipe (122); The first gas pipe (121) delivers regenerated gas; The second gas pipe (122) delivers the raw material gas.

8. The reactor for online reaction regeneration of SCR denitrification catalyst in power plants according to claim 1, characterized in that, Each of the fixed-bed reactors (1) has an outlet (11) at the bottom of its sidewall.

9. The reactor for online reaction regeneration of SCR denitrification catalyst in power plants according to claim 8, characterized in that, A fourth solenoid valve is installed at the air outlet (11).

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