Device and method for evaluating performance of carbon-based ozone decomposition catalyst

Abstract

The invention relates to the field of catalyst performance evaluation, in particular to a performance evaluation device and method for a carbon-based ozone decomposition catalyst. The device comprises an air generator, a first mass flow meter, an ozone generator, a first switch control valve, a measuring pipe, a second switch control valve and an ozone analyzer which are sequentially connected together through a pipeline, a second mass flow meter is connected in parallel to the pipeline between the air generator and the first mass flow meter and the pipeline between the ozone generator and the first switch control valve through a pipeline; a third switch control valve is connected in parallel on a pipeline between the second mass flow meter and the first switch control valve and a pipeline between the second switch control valve and the ozone analyzer through a pipeline; the device is used for evaluating the performance of the catalyst, the conversion rate and the failure rate are used as key indexes for evaluating the performance of the ozonolysis catalyst, the inlet and outlet concentrations of ozone can be detected in real time, the sample testing error is small, and the rapid evaluation of the performance of the ozonolysis catalyst can be realized.

Description

Technical Field

[0001] This invention relates to the field of catalyst performance evaluation, and specifically to a performance evaluation device and method for carbon-based ozone decomposition catalysts. Background Technology

[0002] Indoor ozone primarily originates from laser printers, copiers, electronic sterilizers, negative ion purifiers, plasma sterilizers, corona machines, and air purifiers with UV radiation. These appliances generate high voltage and ultraviolet light during operation, decomposing some oxygen in the air into oxygen atoms. These oxygen atoms then recombine with oxygen molecules to form ozone. Ozone concentrations around 0.15 ppm are odorible and can easily irritate mucous membranes, causing health problems such as coughing and dry mouth. Even ozone concentrations below 80 ppb can affect the cardiovascular and respiratory systems. The National Health Commission of China stipulates that the safe standard for ozone is 0.15 ppm, and maintaining indoor ozone levels at 0.05 ppm is considered the ideal environment in daily life.

[0003] To eliminate or reduce the harm of ozone in ambient air to human health, catalytic decomposition using activated carbon-supported active components is the mainstream technology for ozone elimination. The performance of existing carbon-based ozone decomposition catalysts is mainly judged by the concentration of ozone in the exhaust gas. However, the determination of ozone exhaust gas concentration still relies on traditional detection methods, such as sodium indigo disulfonate spectrophotometry, potassium iodide spectrophotometry, and ultraviolet absorption spectrophotometry, which severely restricts the research and optimization of catalysts. The potassium iodide spectrophotometric method requires collecting gases before and after the reaction using an absorption bottle, and then calculating the ozone concentration using titration, a cumbersome process with a long testing time per test. Summary of the Invention

[0004] This invention addresses the problems of low testing efficiency and long testing time in existing carbon-based ozone decomposition catalyst performance evaluation technologies by providing a performance evaluation device for carbon-based ozone decomposition catalysts. This device enables rapid evaluation of the performance of carbon-based ozone decomposition catalysts.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: a performance evaluation device for a carbon-based ozone decomposition catalyst, comprising an air generator, a first mass flow meter, an ozone generator, a first switch control valve, a measuring tube, a second switch control valve, and an ozone analyzer connected sequentially by pipelines; a second mass flow meter is also connected in parallel through a pipeline between the air generator and the first mass flow meter, and between the ozone generator and the first switch control valve; a third switch control valve is also connected in parallel through a pipeline between the second mass flow meter and the first switch control valve, and between the second switch control valve and the ozone analyzer; the first mass flow meter and the second mass flow meter are respectively connected to a first mass flow meter controller and a second mass flow meter controller.

[0006] In addition, this invention also provides a performance evaluation method for carbon-based ozone decomposition catalysts, using the aforementioned apparatus, and employing conversion rate and failure rate as key indicators for evaluating the performance of ozone decomposition catalysts. The method includes the following steps: S1. Open the third switch control valve (10), close the first switch control valve (7) and the second switch control valve (9), turn on the air generator (1), adjust the first mass flow meter controller (3) and the second mass flow meter controller (6), control the air flow of the first mass flow meter (2) and the second mass flow meter (5) to be 1-3 L / min, turn on the ozone generator (4), adjust the lamp cover of the ozone generator (4), the total flow of ozone gas carried by the air flow is 2-5 L / min, the ozone outlet concentration is 5-8 ppm, and the initial concentration without passing through the sample is collected by the ozone analyzer. ; S2. Place the test tube of the sample to be tested into the position of the test tube (8), open the first switch control valve (7) and the second switch control valve (9), close the third switch control valve (10), and use the ozone analyzer to collect the initial concentration of the sample. Manually record the ozone concentration every 10 minutes, and stop the test after 60 minutes; S3. Based on the detected ozone exhaust gas concentration, the ozone conversion rate η of the ozone decomposition catalyst and the failure rate k of the ozone decomposition catalyst at different times are obtained: In the formula: t — Test duration, in minutes; n—Discrete acquisition sequence number recorded every 10 minutes during the test; —The conversion rate of ozone by the ozone decomposition catalyst at t min, % —Ozone outlet concentration at test time t min, ppm; —Initial ozone concentration before testing, ppm; k—the failure rate of the ozone decomposition catalyst, % / min.

[0007] As a further limitation of the technical solution of the present invention, in step S2, the inner diameter of the measuring tube is 8-10 mm, the particle size of the ozone decomposition catalyst sample is 20-30 mesh, the filling height is 0.5-1 cm, the filling height of the mixed quartz sand is 0.5-1 cm, the bulk density of the ozone decomposition catalyst is tested, and the filling amount of the ozone decomposition catalyst is calculated, wherein the filling amount = bulk density × volume.

[0008] Compared with the prior art, the present invention has the following beneficial effects: This invention proposes a performance evaluation device and method for carbon-based ozone decomposition catalysts, using conversion rate and failure rate as key indicators for evaluating the performance of ozone decomposition catalysts. The performance evaluation device provided by this invention is simple to set up, can monitor the inlet and outlet concentrations of ozone in real time, has small sample testing errors, and a standardized testing process, providing reliable data for the research and development of ozone decomposition catalysts and enabling rapid evaluation of their performance. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the connection structure of the performance evaluation device for the carbon-based ozone decomposition catalyst of the present invention.

[0010] Figure 2 This is a graph showing the removal rate and failure rate of the catalyst to be tested in Example 2 of the present invention.

[0011] The markings in the image are as follows: 1-Air generator, 2-First mass flow meter, 3-First mass flow meter controller, 4-, 5-Second mass flow meter, 6-First mass flow meter controller, 7-First switch control valve, 8-Measuring tube, 9-Second switch control valve, 10-Third switch control valve. Detailed Implementation

[0012] The present invention will be further described below with reference to specific embodiments. Example 1

[0013] like Figure 1 As shown, a performance evaluation device for a carbon-based ozone decomposition catalyst includes an air generator 1, a first mass flow meter 2, an ozone generator 4, a first switch control valve 7, a measuring tube 8, a second switch control valve 9, and an ozone analyzer 11, all connected sequentially by pipelines. A second mass flow meter 5 is also connected via a pipeline between the air generator 1 and the first mass flow meter 2, and between the ozone generator 4 and the first switch control valve 7. A third switch control valve 10 is also connected via a pipeline between the second mass flow meter 5 and the first switch control valve 7, and between the second switch control valve 9 and the ozone analyzer 11. The first mass flow meter 2 and the second mass flow meter 5 are respectively connected to a first mass flow meter controller 3 and a second mass flow meter controller 6. Example 2

[0014] A method for evaluating the performance of a carbon-based ozone decomposition catalyst, using the aforementioned apparatus, employs conversion rate and failure rate as key performance indicators. The method includes the following steps: S1. Open the third switch control valve 10, close the first switch control valve 7 and the second switch control valve 9, turn on the air generator 1, adjust the first mass flow meter controller 3 and the second mass flow meter controller 6, control the air flow of the first mass flow meter 2 and the second mass flow meter 5 to be 1-3L / min, turn on the ozone generator 4, adjust the lamp cover of the ozone generator 4, the total flow rate of ozone gas carried by the air flow is 2-5L / min, the ozone outlet concentration is 5-8ppm, and the initial concentration C0 of the ozone generator without the sample is collected using an ozone analyzer.

[0015] S2. Place the sample test tube into position 8, open the first switch control valve 7 and the second switch control valve 9, close the third switch control valve 10, and use an ozone analyzer to collect the initial concentration C of the sample. t Ozone concentration was manually recorded every 10 minutes, and the test was stopped after 60 minutes. The inner diameter of the measuring tube was 8-10 mm, the particle size of the ozone decomposition catalyst sample was 20-30 mesh, the filling height was 0.5-1 cm, and the filling height of the mixed quartz sand was 0.5-1 cm. The bulk density of the ozone decomposition catalyst was tested, and the filling amount of the ozone decomposition catalyst was calculated, where the filling amount = bulk density × volume.

[0016] S3. Based on the detected ozone exhaust gas concentration, the ozone conversion rate η of the ozone decomposition catalyst and the failure rate k of the ozone decomposition catalyst at different times are obtained: In the formula: t — Test duration, in minutes; n—Discrete acquisition sequence number recorded every 10 minutes during the test; —The conversion rate of ozone by the ozone decomposition catalyst at t min, % —Ozone outlet concentration at test time t min, ppm; —Initial ozone concentration before testing, ppm; k—the failure rate of the ozone decomposition catalyst, % / min.

[0017] Sample M was selected, which was manganese sulfate supported on activated carbon. L As an ozone decomposition catalyst, its performance was evaluated under the following test conditions: (1) the inner diameter of the measuring tube 8 was 8 mm, M L Particle size is (20-30) mesh, M LThe bulk density is 0.442 g / mL, the filling height is 6 mm, the filling mass is 0.13 g, the quartz sand filling height is 4 mm, and the quartz sand filling mass is 0.32 g; (2) The ambient temperature and humidity are consistent with the room temperature, the air flow rate carrying ozone is 3 L / min, the third switch control valve 10 is opened, the first switch control valve 7 and the second switch control valve 9 are closed, after the airflow stabilizes for 30 min, the initial ozone concentration is about 6.56 ppm, the measuring tube is connected, the third switch control valve 10 is closed, the first switch control valve 7 and the second switch control valve 9 are opened, the timing starts at 10:15, a data is recorded every 10 min, the test ends at 11:15, the above formula is used to calculate, the test results are shown in Table 1 and Figure 1 As shown.

[0018] Table 1 Catalyst performance evaluation results

[0019] like Figure 1 The catalyst sample ML showed a removal rate of 86.13% at 60 min and an inactivation rate of -0.2043% / min.

[0020] The performance evaluation device for ozone decomposition catalysts provided by this invention is simple to set up, can monitor the inlet and outlet concentrations of ozone in real time, has small sample testing errors, and has a standardized testing process, providing reliable data for the research and development of ozone decomposition catalysts and enabling rapid evaluation of the performance of ozone decomposition catalysts.

Claims

1. A performance evaluation device for a carbon-based ozone decomposition catalyst, characterized in that, The system includes an air generator (1), a first mass flow meter (2), an ozone generator (4), a first switch control valve (7), a measuring tube (8), a second switch control valve (9), and an ozone analyzer (11) connected sequentially by pipelines. A second mass flow meter (5) is also connected by a pipeline between the air generator (1) and the first mass flow meter (2), and between the ozone generator (4) and the first switch control valve (7). A third switch control valve (10) is also connected by a pipeline between the second mass flow meter (5) and the first switch control valve (7), and between the second switch control valve (9) and the ozone analyzer (11). The first mass flow meter (2) and the second mass flow meter (5) are respectively connected to a first mass flow meter controller (3) and a second mass flow meter controller (6).

2. A method for evaluating the performance of a carbon-based ozone decomposition catalyst, using the evaluation apparatus as described in claim 1, characterized in that... Includes the following steps: S1. Open the third switch control valve (10), close the first switch control valve (7) and the second switch control valve (9), turn on the air generator (1), adjust the first mass flow meter controller (3) and the second mass flow meter controller (6), control the air flow of the first mass flow meter (2) and the second mass flow meter (5) to be 1-3 L / min, turn on the ozone generator (4), adjust the lamp cover of the ozone generator (4), the total flow of ozone gas carried by the air flow is 2-5 L / min, the ozone outlet concentration is 5-8 ppm, and the initial concentration without passing through the sample is collected by the ozone analyzer. ; S2. Place the test tube of the sample to be tested into the position of the test tube (8), open the first switch control valve (7) and the second switch control valve (9), close the third switch control valve (10), and use the ozone analyzer to collect the initial concentration of the sample. Manually record the ozone concentration every 10 minutes, and stop the test after 60 minutes; S3. Based on the detected ozone exhaust gas concentration, the ozone conversion rate η of the ozone decomposition catalyst and the failure rate k of the ozone decomposition catalyst at different times are obtained: In the formula: t — Test duration, in minutes; n—Discrete acquisition sequence number recorded every 10 minutes during the test; —The conversion rate of ozone by the ozone decomposition catalyst at t min, % —Ozone outlet concentration at test time t min, ppm; —Initial ozone concentration before testing, ppm; k—the failure rate of the ozone decomposition catalyst, % / min.

3. The performance evaluation method for a carbon-based ozone decomposition catalyst according to claim 1, characterized in that, In step S2, the inner diameter of the measuring tube (8) is 8-10 mm, the particle size of the ozone decomposition catalyst sample is 20-30 mesh, the filling height is 0.5-1 cm, the filling height of the mixed quartz sand is 0.5-1 cm, the bulk density of the ozone decomposition catalyst is tested, and the filling amount of the ozone decomposition catalyst is calculated, where the filling amount = bulk density × volume.

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