Device for evaluating arsenic poisoning resistance of denitration catalyst

Abstract

The utility model relates to the field of denitration catalyst performance evaluation, in particular to a denitration catalyst arsenic poisoning resistance evaluation device which comprises a mixing preheater, an As2O3 steam reactor, a catalyst reactor, a flue gas analyzer and a collector, and the mixing preheater and the As2O3 steam reactor are both communicated with the front end of the catalyst reactor; the flue gas analyzer and the collector are both communicated with the tail end of the catalyst reactor. The device has high controllability, can accurately adjust and stably maintain key parameters such as arsenide concentration, temperature, humidity and the like, and can simulate complex gas components and dynamic change conditions in actual flue gas. Therefore, a more real and reliable experimental environment is provided for arsenic poisoning resistance evaluation of the catalyst, the research and development process of the efficient arsenic poisoning resistance catalyst is accelerated, and continuous progress, application and popularization of the SCR technology are promoted.

Description

Technical Field

[0001] This utility model relates to the field of performance evaluation of denitrification catalysts, specifically a device for evaluating the anti-arsenic poisoning performance of denitrification catalysts. Background Technology

[0002] With increasing environmental awareness and increasingly stringent emission regulations, selective catalytic reduction (SCR) technology is becoming increasingly important as a key means of controlling nitrogen oxide (NOx) pollution from industrial emission sources such as coal-fired power plants. SCR technology utilizes a specialized catalyst, under suitable temperature conditions, to efficiently convert NOx into harmless nitrogen (N2) and water (H2O) using ammonia (NH3) as a reducing agent, thereby significantly reducing the NOx content in flue gas. However, in actual operation, the performance stability and durability of SCR catalysts face many challenges, among which arsenic (As) poisoning is particularly prominent.

[0003] Coal-fired flue gas contains various harmful components, among which arsenic compounds (such as arsenic trioxide, As₂O₃) pose a serious threat to SCR catalysts. The adsorption and accumulation of arsenic compounds on the catalyst surface not only occupies active sites but also leads to a decrease in the catalyst's specific surface area and porosity. These changes in physical and chemical properties directly weaken the catalyst's catalytic activity and reduce denitrification efficiency. In the long run, arsenic poisoning will severely affect the overall performance and long-term stable operation of the SCR system, increase maintenance costs, and may even force the system to shut down for catalyst replacement, adversely affecting both environmental and economic benefits.

[0004] Given the severity of arsenic poisoning, the scientific and industrial communities are actively working to develop SCR denitrification catalysts with excellent resistance to arsenic poisoning. However, a key challenge in catalyst development is how to accurately and systematically evaluate their resistance to arsenic poisoning under actual operating conditions.

[0005] Most existing evaluation devices employ simple fixed-bed reactors or simulated flue gas systems, which have significant limitations in simulating real flue gas environments. For example, they often cannot precisely control key parameters such as arsenic concentration, temperature, and humidity, which fluctuate considerably in actual flue gas and significantly impact catalyst performance. Furthermore, existing devices cannot effectively simulate the complex gaseous composition (such as oxygen, carbon dioxide, and sulfur oxides) and dynamically changing conditions (such as load fluctuations and start-up / shutdown processes) in real flue gas, factors that are also crucial for evaluating the catalyst's resistance to arsenic poisoning.

[0006] In view of this, the present invention is proposed. Utility Model Content

[0007] The purpose of this invention is to provide a device for evaluating the anti-arsenic poisoning performance of denitrification catalysts. This device is highly controllable and can accurately adjust and stably maintain key parameters such as arsenic concentration, temperature, and humidity. At the same time, it can simulate the complex gas composition and dynamic changes in actual flue gas.

[0008] This invention provides a device for evaluating the arsenic poisoning resistance of denitrification catalysts, comprising a mixing preheater, an As2O3 steam reactor, a catalyst reactor, a flue gas analyzer, a collector, and an AsH3 generator.

[0009] Both the mixing preheater and the As2O3 steam reactor are connected to the front end of the catalyst reactor;

[0010] Both the flue gas analyzer and the collector are connected to the end of the catalyst reactor;

[0011] The AsH3 generator is connected to the As2O3 steam reactor.

[0012] As a preferred embodiment of this technical solution, it further includes a cooler, one end of which is connected to the As2O3 steam reactor and the other end of which is connected to the catalyst reactor.

[0013] As a preferred embodiment of this technical solution, it further includes an ammonia storage tank, which is connected to the catalyst reactor, and the connecting pipeline is equipped with valves and flow meters.

[0014] As a preferred embodiment of this technical solution, it further includes a nitrogen storage tank, a nitric oxide storage tank, an oxygen storage tank, and a sulfur dioxide storage tank. The nitrogen storage tank, the nitric oxide storage tank, the oxygen storage tank, and the sulfur dioxide storage tank are all connected to the mixing preheater, and valves and flow meters are installed on the connecting pipelines.

[0015] As a preferred embodiment of this technical solution, it further includes an air storage tank, which is connected to the As2O3 steam reactor, and the connecting pipeline is equipped with a valve and a flow meter.

[0016] In a preferred embodiment of this technical solution, the collector includes a gas washing bottle and an activated carbon adsorber, and the catalyst reactor, the gas washing bottle, and the activated carbon adsorber are connected in sequence.

[0017] As a preferred embodiment of this technical solution, a valve is provided between the mixing preheater and the catalyst reactor.

[0018] As a preferred embodiment of this technical solution, a valve is provided between the As2O3 steam reactor and the cooler.

[0019] In a preferred embodiment of this technical solution, valves are provided between the catalyst reactor, the gas washing bottle, and the flue gas analyzer.

[0020] In a preferred embodiment of this technical solution, the pipelines connecting the mixing preheater, the As2O3 steam reactor, the cooler, and the catalyst reactor are all equipped with heat tracing cables.

[0021] The device for evaluating the arsenic poisoning resistance of denitration catalysts of this invention has at least the following beneficial effects:

[0022] The device for evaluating the arsenic poisoning resistance of denitrification catalysts of this invention has high controllability. It can accurately adjust and stably maintain key parameters such as arsenic concentration, temperature, and humidity. At the same time, it can simulate the complex gas composition (such as oxygen, carbon dioxide, sulfur oxides, etc.) and dynamically changing conditions (such as load fluctuations, start-up and shutdown processes) in actual flue gas, and control the amount of arsenic deposited on the catalyst. It can provide a more realistic and reliable experimental environment for evaluating the arsenic poisoning resistance of catalysts, accelerate the research and development process of high-efficiency arsenic poisoning resistance catalysts, and promote the continuous progress and application of SCR technology. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the device for evaluating the anti-arsenic poisoning performance of the denitrification catalyst of this utility model.

[0025] Explanation of reference numerals in the attached figures:

[0026] 1: Mixing preheater; 2: As2O3 steam reactor; 3: Catalyst reactor; 4: Flue gas analyzer; 5: AsH3 generator; 6: Cooler; 7: Ammonia storage tank; 8: Nitrogen storage tank; 9: Nitric oxide storage tank; 10: Oxygen storage tank; 11: Sulfur dioxide storage tank; 12: Air storage tank; 13: Gas washing bottle; 14: Activated carbon adsorber. Detailed Implementation

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

[0028] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0029] Furthermore, 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0030] Example

[0031] like Figure 1 As shown, this embodiment provides a device for evaluating the anti-arsenic poisoning performance of a denitrification catalyst, including a mixing preheater 1, an As2O3 steam reactor 2, a catalyst reactor 3, a flue gas analyzer 4, a collector, and an AsH3 generator 5. The mixing preheater 1 and the As2O3 steam reactor 2 are both connected to the front end of the catalyst reactor 3; the flue gas analyzer 4 and the collector are both connected to the end of the catalyst reactor 3; and the AsH3 generator 5 is connected to the As2O3 steam reactor 2.

[0032] In this embodiment, the device for evaluating the arsenic poisoning resistance of the denitrification catalyst involves As2O3 generated by the As2O3 steam reactor 2 and the reaction gas preheated by the mixing preheater 1 sequentially entering the catalyst reactor 3 to evaluate the denitrification performance of the catalyst in the catalyst reactor 3. This device can effectively simulate the complex gaseous composition (such as oxygen, carbon dioxide, sulfur oxides, etc.) and dynamically changing conditions (such as load fluctuations, start-up and shutdown processes) in actual flue gas, control the amount of arsenic deposited on the catalyst, and evaluate its denitrification performance. It features simple operation, strong applicability, good repeatability, and low environmental pollution.

[0033] When evaluating the anti-arsenic poisoning performance of the denitrification catalyst, the catalyst in the catalyst reactor 3 is first loaded with As2O3. After injecting As2O3 vapor into the catalyst reactor 3 through the As2O3 vapor reactor 2 for a period of time, the AsH3 generator 5 is turned off and the pipeline is purged with air for 30 minutes. Then, the air is turned off and the reaction gas control is turned on, and the denitrification performance of the catalyst can be evaluated.

[0034] The arsenic generator mainly consists of an AsH3 generator and an As2O3 vapor reactor. AsH3 is injected into the As2O3 vapor reactor via air purging. Firstly, the air purging process helps stabilize the gas conditions within the system, ensuring that reactant gases (such as NOx and NH3) can fully contact the catalyst during subsequent denitrification performance evaluation, without interference from residual As2O3 or AsH3. This improves the accuracy and repeatability of experimental results. Secondly, after shutting down the AsH3 generator, continuing to purge the pipeline with air for 30 minutes effectively removes residual AsH3 gas from the system. AsH3 is a highly toxic gas; residual AsH3 not only affects the accuracy of subsequent experiments but may also harm experimental personnel and the environment. Air purging ensures that there is no residual AsH3 in the system, improving experimental safety. Therefore, this design not only ensures the uniformity of arsenic loading on the catalyst surface and the safety of the experiment but also improves the accuracy and repeatability of the experiment while reducing environmental pollution.

[0035] Based on the above technical solution, in order to simultaneously test the arsenic poisoning resistance of multiple catalysts, multiple catalyst reactors 3 can be added to the existing catalyst reactor 3. The multiple catalyst reactors 3 are set in parallel. When different denitrification catalysts are filled in the catalyst reactor 3, the arsenic poisoning resistance of multiple catalysts can be tested simultaneously.

[0036] Specifically, a cooler 6 is installed after the As2O3 steam reactor 2. One end of the cooler 6 is connected to the As2O3 steam reactor 2, and the other end is connected to the catalyst reactor 3. The temperature of the As2O3 steam reactor 2 is usually 700-900 degrees Celsius. The As2O3 produced is cooled to 400-550 degrees Celsius by the cooler 6 before being sent to the catalyst reactor 3.

[0037] In this embodiment, the device for evaluating the arsenic poisoning resistance of the denitrification catalyst is further equipped with an ammonia storage tank 7. The ammonia storage tank 7 is connected to the catalyst reactor 3, and valves and flow meters are installed on the connecting pipeline. The ammonia in the ammonia storage tank 7 enters the catalyst reactor 3 as one of the reaction gases to participate in the reaction.

[0038] Similarly, in this embodiment, the device for evaluating the arsenic poisoning resistance of the denitrification catalyst is also equipped with a nitrogen storage tank 8, a nitric oxide storage tank 9, an oxygen storage tank 10, and a sulfur dioxide storage tank 11. All four tanks are connected to the mixing preheater 1, and valves and flow meters are installed on the connecting pipelines. The reaction gases N2, NO, O2, and SO2 are controlled by their respective valves and flow meters and enter the mixing preheater 1. After being preheated to 100-120°C by the mixing preheater 1, they enter the catalyst reactor 3.

[0039] The AsH3 generated by AsH3 generator 5 is carried into As2O3 steam reactor 2 by air. Therefore, an air storage tank 12 is also provided in the denitrification catalyst anti-arsenic poisoning performance evaluation device. The air storage tank 12 is connected to As2O3 steam reactor 2, and valves and flow meters are installed on the connected pipeline.

[0040] Based on the above technical solution, and further preferably, the collector includes a gas washing bottle 13 and an activated carbon adsorber 14, wherein the catalyst reactor 3, the gas washing bottle 13, and the activated carbon adsorber are connected in sequence. Part of the gas exiting the catalyst reactor 3 enters the flue gas analyzer 4 to analyze the denitrification activity of the catalyst, and part enters the collector for collection. The gas collected by the collector is first washed with NaOH solution or H2O2 solution in the gas washing bottle 13 before entering the activated carbon adsorber 14 for adsorption treatment.

[0041] To further control the flow rate of the outlet gas from the catalyst reactor 3 into the flue gas analyzer 4 and the collector, valves are installed between the catalyst reactor 3 and the gas washing bottle 13 and the flue gas analyzer 4.

[0042] Based on the above technical solution, in order to monitor the gas composition in the catalyst reactor 3 and the absorption effect of the collector in real time, an online gas composition monitoring instrument can be installed between the catalyst reactor 3 and the collector.

[0043] In addition, valves are also installed between the mixing preheater 1 and the catalyst reactor 3, and between the As2O3 steam reactor 2 and the cooler 6.

[0044] Based on the above technical solution, more preferably, the pipelines between the mixing preheater 1, the As2O3 steam reactor 2, the cooler 6, and the catalyst reactor 3 are all equipped with heat tracing cables for insulation.

[0045] When using the arsenic poisoning resistance evaluation device of this utility model to evaluate the denitrification performance of the catalyst, the main steps include:

[0046] (1) The denitrification catalyst is loaded into catalyst reactor 3;

[0047] (2) Turn on AsH3 generator 5;

[0048] (3) Open As2O3 steam reactor 2 and control the temperature to 700-900℃;

[0049] (4) Turn on the cooler 6;

[0050] (5) After injecting As2O3 vapor into the catalyst reactor 3 for a period of time (controlling the As2O3 deposition on the catalyst to 1-5wt%), turn off the AsH3 generator 5.

[0051] (6) Continue to purge the pipeline with air for 30 minutes, then turn off the air.

[0052] (7) Turn on the reaction gas control and evaluate the denitrification performance of the catalyst.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A device for evaluating the arsenic poisoning resistance of a denitrification catalyst, characterized in that, The system comprises a mixing preheater (1), an As2O3 vapor reactor (2), a catalyst reactor (3), a flue gas analyzer (4), a collector and an AsH3 generator (5), The mixing preheater (1) and the As2O3 vapor reactor (2) are both in communication with the front end of the catalyst reactor (3); The flue gas analyzer (4) and the collector are both in communication with the end of the catalyst reactor (3); The AsH3 generator (5) is in communication with the As2O3 vapor reactor (2).

2. The device for evaluating the arsenic poisoning resistance of a denitration catalyst according to claim 1, characterized by, A cooler (6) is further included, one end of which is in communication with the As2O3 vapor reactor (2) and the other end of which is in communication with the catalyst reactor (3).

3. The device for evaluating the arsenic poisoning resistance of a denitration catalyst according to claim 1, characterized by, An ammonia gas storage tank (7) is further included, which is in communication with the catalyst reactor (3) and a valve and a flow meter are arranged on the pipeline in communication.

4. The device for evaluating the arsenic poisoning resistance of a denitration catalyst according to claim 1, characterized by, A nitrogen gas storage tank (8), a nitric oxide storage tank (9), an oxygen gas storage tank (10) and a sulfur dioxide storage tank (11) are further included, which are all in communication with the mixing preheater (1) and a valve and a flow meter are arranged on the pipeline in communication.

5. The device for evaluating the arsenic poisoning resistance of a denitration catalyst according to claim 1, characterized by, An air storage tank (12) is further included, which is in communication with the As2O3 vapor reactor (2) and a valve and a flow meter are arranged on the pipeline in communication.

6. The device for evaluating the arsenic poisoning resistance of a denitration catalyst according to claim 1, characterized by The collector comprises a gas washing bottle (13) and an activated carbon adsorber (14), and the catalyst reactor (3), the gas washing bottle (13) and the activated carbon adsorber (14) are in sequence.

7. The device for evaluating the arsenic poisoning resistance of a denitration catalyst according to claim 1, characterized by A valve is arranged between the mixing preheater (1) and the catalyst reactor (3).

8. The device for evaluating the arsenic poisoning resistance of a denitration catalyst according to claim 2, characterized by, A valve is arranged between the As2O3 vapor reactor (2) and the cooler (6).

9. The device for evaluating the arsenic poisoning resistance of a denitration catalyst according to claim 6, characterized by, Valves are arranged between the catalyst reactor (3) and the gas washing bottle (13) and the flue gas analyzer (4).

10. The device for evaluating the arsenic poisoning resistance of a denitration catalyst according to claim 2, characterized by Heat tracing bands are arranged on the pipelines among the mixing preheater (1), the As2O3 vapor reactor (2), the cooler (6) and the catalyst reactor (3).

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