A method for evaluating ozone abatement coating removal benefits
By using a fixed-bed continuous flow reactor and SEM energy dispersive spectroscopy analysis, combined with flow field simulation and measured data correction, the shortcomings of existing technologies in evaluating the benefits of ozone reduction coatings have been addressed. This enables a comprehensive evaluation of the benefits of catalytic coatings, including accurate assessments of ozone reduction effects, economic benefits, and health benefits.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BEIJING INSTITUTE OF PETROCHEMICAL TECHNOLOGY
- Filing Date
- 2022-08-24
- Publication Date
- 2026-04-17
AI Technical Summary
Existing technologies lack effective methods to assess the benefits of ozone-reducing coatings in outdoor applications, particularly their impact on atmospheric flow and building morphology, as well as their economic and health benefits.
The catalyst performance was evaluated using a fixed-bed continuous flow reactor. The exposure ratio and ozone uptake rate of the catalyst on the coating surface were analyzed by SEM energy dispersive spectroscopy. The ozone concentration distribution gradient on the building surface was simulated. The ozone reduction effect and economic benefits of the catalytic coating were evaluated by flow field simulation and correction based on measured data.
It enables a comprehensive benefit assessment of catalytic coatings in outdoor applications, including accurate evaluation of ozone reduction effects, economic benefits, and health benefits, providing insights into the practical application prospects of catalytic coatings and the economic benefits of pollutant emission reduction.
Smart Images
Figure CN115394374B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of pollutant reduction coating technology, and in particular to a method for evaluating the removal efficiency of ozone reduction coatings. Background Technology
[0002] Currently, some atmospheric pollutant reduction coatings have been successfully developed in the laboratory, such as new air-purifying coatings and negative ion exterior wall coatings. The decomposition of NOx and VOCs using titanium dioxide is being studied, and the evaluation methods for the decomposition effect are still under development. Currently, NOx decomposition coatings are mainly applied to roads and building exteriors to degrade NOx generated from urban traffic sources. The evaluation method targets the performance requirements of asphalt roads, conducting various performance tests on photocatalytic coatings, including adhesion, water resistance, skid resistance, abrasion resistance, and freeze-thaw cycles. This verifies that the photocatalytic coating can effectively cure and penetrate onto asphalt pavements. Finally, an indoor degradation simulation study of the prepared photocatalytic coating is conducted using the naphthylethylenediamine hydrochloride spectrophotometric method. This simulates various conditions under natural atmospheric conditions, analyzing the degradation effect of the photocatalytic coating on nitrogen oxides under natural light and ultraviolet light, the degradation effect on nitrogen oxides at different concentrations, and the degradation effect on nitrogen oxides with different catalyst dosages. The formulation of the photocatalytic coating system is optimized, thus indirectly verifying the effectiveness of nano-TiO2 photocatalytic coatings in degrading pollutants in vehicle exhaust under actual asphalt road conditions.
[0003] However, since NOx decomposition coatings are mainly used around urban roads, and the evaluation methods are not applicable to ozone decomposition coatings, there is an urgent need for an evaluation method for near-ground ozone reduction coatings to assess their benefits. Summary of the Invention
[0004] The purpose of this invention is to provide a method for evaluating the ozone reduction benefits of ozone-reducing coatings. This method is applicable to outdoor applications of ozone-reducing coatings and can assess the effects of atmospheric flow and building morphology on ozone reduction. It can also evaluate the economic and health benefits of ozone reduction.
[0005] The objective of this invention is achieved through the following technical solution:
[0006] A method for evaluating the ozone reduction efficiency of coatings, the method comprising:
[0007] Step 1: First, a fixed-bed continuous flow reactor was used to conduct a laboratory performance evaluation of the ozone catalytic decomposition catalyst.
[0008] Step 2: Elemental energy dispersive spectroscopy (SEM) was used to analyze the exposure ratio (S) of the catalyst on the coating surface for coatings containing different amounts of catalyst. bAnd the ozone uptake rate M, and the ozone reduction effect N of the catalytic coating per unit area;
[0009] Step 3: Apply catalytic coating to the surface of the building to be tested and obtain information on the building's external dimensions, building scale, and total area.
[0010] Step 4: Establish the ozone concentration distribution gradient on the surface of the building under test with catalytic coating under different meteorological conditions, and determine the ozone reduction boundary distance of the building under test and the ozone reduction effect N of the catalytic coating per unit area.
[0011] Step 5: To determine the accuracy of the ozone reduction boundary distance of the building under test, a reference building with a similar area is used, and the concentration gradient distribution of the flow field simulation in the external flow domain is compared and verified to correct the data obtained in step 4.
[0012] As can be seen from the technical solution provided by the present invention, the above method is applicable to outdoor use of catalytic coatings, can evaluate the effect of atmospheric flow field and building morphology on ozone reduction, and can also evaluate the economic and health benefits brought about by ozone reduction. Attached Figure Description
[0013] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0014] Figure 1 This is a schematic diagram of the evaluation method for the ozone reduction coating removal efficiency provided in an embodiment of the present invention. Detailed Implementation
[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments, and do not constitute a limitation of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.
[0016] like Figure 1 The diagram shown is a schematic flowchart of a method for evaluating the removal efficiency of ozone-reducing coatings according to an embodiment of the present invention. The method includes:
[0017] Step 1: First, a fixed-bed continuous flow reactor was used to conduct a laboratory performance evaluation of the ozone catalytic decomposition catalyst.
[0018] In this step, the laboratory performance evaluation of the ozone catalytic decomposition catalyst is performed as follows:
[0019] The catalyst needs to withstand 100 ppm ozone at room temperature and a space velocity greater than 1000 h⁻¹. -1 Under certain conditions, the efficiency of decomposition into oxygen is >90%.
[0020] Step 2: Elemental energy dispersive spectroscopy (SEM) was used to perform elemental energy scanning on coatings containing different amounts of catalyst (hereinafter referred to as "catalytic coatings") to analyze the exposure ratio of the catalyst on the coating surface, S. b And the ozone uptake rate M;
[0021] In this step, the different amounts of catalyst refer to the content of the catalyst in a unit mass of coating, which is 10-30% in this example.
[0022] Among them, the exposure ratio S b The calculation formula is:
[0023]
[0024] In the formula: S represents the area of the catalyst exposed on the coating surface; S0 represents the area of the coating with added catalyst used for measurement;
[0025] The ozone uptake rate M was obtained as follows:
[0026] A catalytic coating is applied to the inner surface of the box model. O3 with a concentration of A ppm is introduced at the inlet, and the concentration of O3 at the outlet is measured to be B ppm. From this, C = AB is calculated, and the reduction in O3 concentration is C ppm.
[0027] In this process, the ozone reduction is entirely derived from the conversion of ozone absorbed by the catalyst. Therefore, the ozone uptake rate M of the catalytic coating is:
[0028]
[0029] In the formula: M represents the uptake rate of O3 by the catalytic coating.
[0030] Step 3: Apply catalytic coating to the surface of the building to be tested and obtain information on the building's external dimensions, building scale, and total area.
[0031] Step 4: Establish the ozone concentration distribution gradient of the catalytic coating applied to the surface of the building under different meteorological conditions (mainly wind direction and wind speed), and determine the ozone reduction boundary distance of the building under test and the ozone reduction effect N of the catalytic coating applied per unit area.
[0032] In this step, local wind speed, wind direction, and ozone diffusion rate conditions are first statistically analyzed. A model is then created using typical Class 3-5 buildings as representatives to calculate the application area d (in meters) of the catalytic coating. 2 The ozone reduction effect of the catalytic coating was analyzed using Fluent software with the above factors added. Specifically, multiple sets of inlet boundary conditions were set at the inlet, with different speeds, directions, and ozone concentrations (a in ppb). The zero-order reaction of ozone decomposition was used as the reaction mechanism. Different pre-exponential factors and activation energies were used as the reaction rates of the catalytic coating to simulate the ozone concentration gradient distribution on the surface of the building under test and the ozone concentration (b in ppb) at the outlet.
[0033] Determine the distance at which the ozone concentration no longer changes, i.e. the ozone reduction boundary, and then establish the ozone concentration distribution gradient of the catalytic coating on the surface of the building under test under different meteorological conditions (mainly wind direction and wind speed). That is, draw a longitudinal ozone concentration distribution gradient map on the surface of the catalytic coating of the building under test with the surface of the catalytic coating of the building under test as the origin under different wind speeds and wind directions.
[0034] Finally, under different meteorological factors and ozone diffusion rates, the furthest distance where the ozone concentration is stable in the ozone concentration distribution gradient map is taken as the ozone reduction distance of the catalytic coating. Then, the ozone reduction effect N of the catalytic coating per unit area is calculated.
[0035]
[0036] In the formula: N represents the ozone reduction effect of the catalytic coating per unit area, in ppb·m³. -2 .
[0037] Step 5: To determine the accuracy of the ozone reduction boundary distance of the building under test, a reference building with a similar area is used, and the concentration gradient distribution of the flow field simulation in the external flow domain is compared and verified to correct the data obtained in step 4.
[0038] In this step, catalytic coating is sprayed onto the wall of a reference building with a similar area, and ozone concentration monitoring points with different heights and spacings are set up.
[0039] The average value of the ozone concentration monitoring values at different heights under the same spacing is taken as the measured ozone concentration value at that spacing.
[0040] Finally, using the measured ozone concentration value P and the distance I, the relationship is obtained as: P = kI 2 +m, where k and m are constants; and based on this relationship, a longitudinally measured ozone concentration distribution gradient map of the building's catalytic coating surface is plotted, thereby determining the farthest reduction boundary of the catalytic coating;
[0041] By comparing the differences between the measured and simulated data, the number of grids in the simulation was changed and the algorithm model was adjusted to make the simulated data match the measured data.
[0042] In practice, we can also select actual data from a certain region in my country within the past year as the research object, combined with the total building area S of that region. 总 The ozone reduction N' after applying catalytic coating to buildings in the area was calculated, i.e., N' = N·S 总 ;
[0043] By using air quality data and meteorological data to simulate air quality, the distribution of ozone concentration in the following year can be predicted.
[0044] By distributing the ozone reduction in the region evenly across data from various time periods that predict the ozone concentration distribution for the following year, the distribution of the new ozone concentration in the following year after applying the catalytic coating can be obtained.
[0045] Next, calculate the cost per unit area of catalytic coating and construction cost (X1), the environmental benefits of ozone pollution reduction (X2), and the health benefits of reduced morbidity due to lower ozone concentration (X3). Compare these with the precursor emission reduction pressure corresponding to the ozone reduction concentration, i.e., the economic volume X of VOCs / NOx reduction equivalent to the ozone reduction concentration. Finally, assess the comprehensive benefit Y of the ozone reduction coating. The specific formula is as follows:
[0046]
[0047] Among them, K1, K2, and K3 represent the weighting factors of each indicator. It is feasible when the comprehensive benefit Y < 0.8.
[0048] In its specific implementation, the method further includes:
[0049] Establish the relationship between the cost of catalytic coating application area and the benefits of ozone reduction, as well as the relationship between the incidence of disease, and select a reasonable scheme that maximizes economic benefits, health benefits, and environmental benefits by combining statistical graphs, so as to provide a guarantee for local ozone reduction work.
[0050] It is worth noting that the contents not described in detail in the embodiments of the present invention belong to the prior art known to those skilled in the art.
[0051] In summary, the method described in the embodiments of the present invention can comprehensively evaluate the benefits of ozone reduction coatings (i.e., catalytic coatings), accurately determine the actual application prospects of the coatings and the health effects of ozone reduction coating applications, as well as the economic benefits of pollutant emission reduction, thereby effectively assessing the degree of regional ozone reduction.
[0052] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims. The information disclosed in the background section is intended only to enhance the understanding of the overall background technology of the present invention and should not be construed as an admission or implication in any way that such information constitutes prior art known to those skilled in the art.
Claims
1. A method for evaluating the ozone reduction efficiency of coatings, characterized in that, The method includes: Step 1: First, a fixed-bed continuous flow reactor was used to conduct a laboratory performance evaluation of the ozone catalytic decomposition catalyst. Step 2: Elemental energy dispersive spectroscopy (SEM) was used to analyze the exposure ratio (S) of the catalyst on the coating surface for coatings containing different amounts of catalyst. b And the ozone uptake rate M; Step 3: Apply catalytic coating to the surface of the building to be tested and obtain information on the building's external dimensions, building scale, and total area. Step 4: Establish the ozone concentration distribution gradient on the surface of the building under test with catalytic coating under different meteorological conditions, and determine the ozone reduction boundary distance of the building under test and the ozone reduction effect N of the catalytic coating per unit area. The specific process of step 4 is as follows: First, local wind speed, wind direction, and ozone diffusion rate conditions are statistically analyzed. A model is then created using typical Class 3-5 buildings as representatives to calculate the application area d of the catalytic coating (in meters). 2 The ozone reduction effect of the catalytic coating was analyzed using Fluent software with the above factors added. Specifically, multiple sets of inlet boundary conditions were set at the inlet, with different ozone concentrations (a, in ppb) based on velocity, direction, and concentration. The zero-order reaction of ozone decomposition was used as the reaction mechanism. Different pre-exponential factors and activation energies were used as the reaction rates of the catalytic coating to simulate the ozone concentration gradient distribution on the surface of the building under test and the ozone concentration (b, in ppb) at the outlet. Determine the distance at which the ozone concentration no longer changes, i.e. the ozone reduction boundary, and then establish the ozone concentration distribution gradient on the surface of the building to be tested with the catalytic coating under different meteorological conditions. That is, draw a longitudinal ozone concentration distribution gradient map on the surface of the catalytic coating of the building to be tested with the catalytic coating surface as the origin under different wind speeds and wind directions. Finally, under different meteorological factors and ozone diffusion rates, the furthest distance where the ozone concentration is stable in the ozone concentration distribution gradient map is taken as the ozone reduction distance of the catalytic coating. Then, the ozone reduction effect N of the catalytic coating per unit area is calculated. In the formula: N represents the ozone reduction effect of the catalytic coating per unit area, in ppb·m³. -2 ; Step 5: To determine the accuracy of the ozone reduction boundary distance of the building under test, a reference building with a similar area is used, and the concentration gradient distribution of the flow field simulation in the external flow domain is compared and verified to correct the data obtained in step 4. In step 5, catalytic coating is sprayed onto the wall of a reference building with a similar area, and ozone concentration monitoring points with different heights and spacings are set up. The average value of the ozone concentration monitoring values at different heights under the same spacing is taken as the measured ozone concentration value at that spacing. Finally, using the measured ozone concentration value P and the distance I, the relationship is obtained as: P = kI 2 +m, where k and m are constants; and based on this relationship, a longitudinally measured ozone concentration distribution gradient map of the building's catalytic coating surface is plotted, thereby determining the farthest reduction boundary of the catalytic coating; By comparing the differences between the measured and simulated data, the number of grids in the simulation was changed and the algorithm model was adjusted to make the simulated data match the measured data.
2. The method for evaluating the ozone reduction efficiency of coatings according to claim 1, characterized in that, In step 1, the process of conducting laboratory performance evaluation of the ozone catalytic decomposition catalyst is as follows: The catalyst needs to withstand 100 ppm ozone at room temperature and a space velocity greater than 1000 h⁻¹. -1 Under certain conditions, the efficiency of decomposition into oxygen is >90%.
3. The method for evaluating the removal efficiency of ozone-reducing coatings according to claim 1, characterized in that, In step 2, the exposure ratio S b The calculation formula is: In the formula: S represents the area of the catalyst exposed on the coating surface; S0 represents the area of the coating with added catalyst used for measurement; The ozone uptake rate M was obtained as follows: Using a box model, O3 with a concentration of A ppm is introduced at the inlet, and the concentration of O3 at the outlet is measured to be B ppm. From this, the reduction in O3 concentration is calculated to be C ppm. In this process, the ozone reduction is entirely derived from the conversion of ozone absorbed by the catalyst. Therefore, the ozone uptake rate M of the catalytic coating is: In the formula: M represents the uptake rate of O3 by the catalytic coating.
4. The method for evaluating the ozone reduction efficiency of coatings according to claim 1, characterized in that, The method further includes: Establish the relationship between the cost of catalytic coating application area and the benefits of ozone reduction, as well as the relationship between the incidence of disease. Combine statistical graphs to select a reasonable scheme that maximizes economic, health, and environmental benefits, and provide a guarantee for local ozone reduction efforts.