A low-temperature degradation catalyst for asphalt fume and a preparation method thereof
By loading MnOx and CeOx or CoOx active components onto a nano-TiO2 support, a low-temperature degradation catalyst was prepared, which solved the problems of high energy consumption and incomplete degradation in the existing technology for asphalt fume treatment, and achieved low-temperature and efficient catalytic degradation, thus protecting the environment and health.
Patent Information
- Application Number
- CN202310980406.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-08-03
- Publication Date
- 2025-11-28
- Estimated Expiration
- 2043-08-03
AI Technical Summary
Existing technologies for treating asphalt fumes include high-temperature combustion, which is energy-intensive and economically impractical; low-temperature plasma, which is incompletely decomposed; and photocatalytic oxidation, which is ineffective at degrading large organic molecules, leading to environmental pollution and health risks.
A low-temperature degradation catalyst was prepared by loading MnOx and CeOx or CoOx as active components onto a nano-TiO2 support, which catalyzes the degradation of asphalt smoke at 250–400 °C.
Achieving efficient catalytic degradation of asphalt fumes under low-temperature conditions reduces energy consumption, minimizes environmental pollution, protects health, and achieves energy conservation and emission reduction.
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Figure CN116889891B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of asphalt fume treatment in air pollution, and particularly relates to a low-temperature degradation catalyst for asphalt fume and a preparation method thereof. BACKGROUND
[0002] The statements herein are provided only to enhance understanding of the present application and are not necessarily intended to constitute the prior art.
[0003] Asphalt is a high-viscosity organic liquid, which is a complex mixture composed of hydrocarbon compounds and derivatives with different molecular weights and usually exists in a semi-solid state at room temperature. Asphalt is widely used in road construction due to its good ductility and viscosity. Since asphalt is semi-solid at room temperature, it must be heated during use, and asphalt fume is generated during the heating process. Asphalt fume is a smog-like substance formed by the diffusion of components in asphalt into the air during the heating and use process. The components of asphalt fume are very complex, and the substances such as polycyclic aromatic hydrocarbons contained therein are highly toxic and difficult to degrade, causing great harm to the environment and human beings.
[0004] Methods for treating asphalt fume include high-temperature combustion, catalytic combustion, low-temperature plasma, and photocatalytic oxidation, etc. The high-temperature combustion method has the disadvantages of high energy consumption, high operating cost, and poor economic practicability. The catalytic combustion method requires a catalyst with good performance, and the low-temperature plasma method has the disadvantage of incomplete decomposition of organic matter, causing secondary pollution. The photocatalytic oxidation method can only degrade and treat part of the substances in asphalt fume, and it is difficult to degrade macromolecular organic matter therein, so the treatment effect is not obvious. SUMMARY
[0005] In view of the deficiencies in the prior art, the present application aims to provide a low-temperature degradation catalyst for asphalt fume and a preparation method thereof. The catalyst has good low-temperature catalytic properties and can achieve efficient low-temperature degradation of asphalt fume.
[0006] To achieve the above-mentioned purpose, the present application is implemented by the following technical solutions:
[0007] In a first aspect, the present application provides a low-temperature degradation catalyst for asphalt fume, which comprises a carrier and an active component loaded thereon. The active component comprises two kinds, one of which is MnO x , and the other is CeO x or CoO x , and the molar ratio of manganese to cerium / cobalt is 1:0.25-1; the carrier is nano-TiO2.
[0008] In some embodiments, the average specific surface area of the catalyst is 29.7-36.3 m 2 / g, and the average pore size is 7.8-8.9 nm.
[0009] In a second aspect, the present application provides a preparation method of the catalyst for catalytic degradation of asphalt fume, comprising the following steps:
[0010] The cerium soluble salt or cobalt soluble salt and manganese soluble salt are dissolved in an ethanol aqueous solution in a proportion to obtain an active solution; then the active solution is impregnated into nano-TiO2 powder, and the catalyst is prepared after drying, calcining and grinding, wherein the calcining temperature is 500-600℃ and the calcining time is 4-6h.
[0011] Since the adopted nano-TiO2 powder is lipophilic, it is not wetted by water, and therefore ethanol is used as a surfactant to ensure that the active component can be loaded on the TiO2 carrier.
[0012] In some embodiments, the average particle size of the nano-TiO2 powder is 100nm.
[0013] In some embodiments, the manganese soluble salt is manganese nitrate, and the cerium soluble salt is cerium nitrate.
[0014] In some embodiments, the volume fraction of the ethanol aqueous solution is 40%-60%.
[0015] In some embodiments, the particle size of the ground catalyst is 20-40 mesh.
[0016] In some embodiments, the drying temperature is 100-110℃, and the drying time is 10-15h.
[0017] In some embodiments, the temperature for catalytic degradation of asphalt fume by using the catalyst is 250-400℃.
[0018] Preferably, the temperature for catalytic degradation of asphalt fume by using the catalyst is 250-300℃.
[0019] The beneficial effects achieved by one or more embodiments of the present application are as follows:
[0020] The asphalt fume can be catalytically degraded at a low temperature (250-300℃), and the asphalt fume shows high catalytic activity at a low temperature, so that the environment of various asphalt fume production and use sites can be improved, the health of workers can be protected, and the purpose of energy saving and emission reduction can be achieved on the basis of lower energy consumption. BRIEF DESCRIPTION OF DRAWINGS
[0021] The drawings constituting a part of the specification of the present application are used to provide further understanding of the present application, and the illustrative embodiments of the present application and the description thereof are used to explain the present application, and do not constitute an improper limitation on the present application.
[0022] Figure 1 is a bitumen smoke degradation efficiency curve of the catalyst prepared in Example 1-2;
[0023] Figure 2 is an XRD pattern of the catalyst prepared in Example 1-2.
[0024] Figure 3 is a bitumen smoke catalytic degradation curve of Examples 2-4.
[0025] Figure 4 is a bitumen smoke catalytic degradation curve of Examples 2 and Comparative Examples 1-2.
[0026] Figure 5 is a bitumen smoke catalytic degradation curve of the catalyst prepared in Examples 5 and 6;
[0027] Figure 6 is an XRD pattern of the catalyst prepared in Examples 5 and 6. DETAILED DESCRIPTION
[0028] It should be noted that the following detailed description is illustrative only and is intended to provide further description of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.
[0029] In the following specific examples, the molar ratio of the catalysts is Mn / TiO2 0.1, Ce / TiO2 0.025 and 0.05, respectively, the molar content of the active component Mn is 8.70-8.89%, the molar content of the active component Ce is 2.22-4.34%, and the molar content of the carrier TiO2 is 86.96-88.89%.
[0030] Example 1
[0031] Mn 0.1 Ce 0.025 Preparation of the Mn / TiO2 catalyst:
[0032] 1) 7.158 g of a 50% mass fraction manganese nitrate solution and 2.171 g of Ce(NO3)3·6H2O were weighed, 80 mL of a 50% volume fraction ethanol aqueous solution was added, and magnetic stirring was performed for 30 min to completely dissolve the solution, thereby obtaining a precursor solution.
[0033] 2) 15.973 g of a 100 nm particle diameter anatase lipophilic nano-titanium dioxide powder was weighed, and the carrier powder was slowly added to the prepared precursor solution under continuous stirring of an electric mixer, and stirring was continued for 30 min to fully mix the carrier and the precursor solution, thereby obtaining a viscous catalyst slurry.
[0034] 3) After the obtained catalyst slurry is immersed at room temperature for 12 h, it is put into a drying oven and dried at a temperature of 105°C for 12 h to obtain a dry product; the obtained dry product is put into a muffle furnace and calcined at 500°C for 5 h under an air atmosphere to obtain a blocky catalyst.
[0035] 4) After the obtained blocky catalyst is ground, it is passed through a 20-40 mesh sieve to obtain a Mn 01 Ce 0025 / TiO2catalyst.
[0036] Example 2
[0037] Mn 0.1 Ce 0.05 Preparation of a Mn
[0038] 1) 7.158 g of a 50% mass fraction manganese nitrate solution and 4.342 g of Ce(NO3)2·6H2O are weighed, 80 mL of a 50% volume fraction ethanol aqueous solution is added, and the mixture is magnetically stirred for 30 min until it is completely dissolved to obtain a precursor solution.
[0039] 2) 15.973 g of a 100 nm particle diameter anatase oil-wet nanometer titanium dioxide powder is weighed, and the carrier powder is slowly added to the prepared precursor solution under continuous stirring of an electric mixer, and stirring is continued for 30 min to fully mix the carrier and the precursor solution to obtain a viscous catalyst slurry.
[0040] 3) After the obtained catalyst slurry is immersed at room temperature for 12 h, it is put into a drying oven and dried at a temperature of 105°C for 12 h to obtain a dry product; the obtained dry product is put into a muffle furnace and calcined at 500°C for 5 h under an air atmosphere to obtain a blocky catalyst.
[0041] 4) After the obtained blocky catalyst is ground, it is passed through a 20-40 mesh sieve to obtain a Mn 0.1 Ce 0.05 / TiO2catalyst.
[0042] Figure 1 The catalytic degradation curves of the catalysts prepared in Example 1 and Example 2 on asphalt smoke are set to have a reaction space velocity of 8000 h -1 , and Figure 1 It can be seen that when the reaction space velocity is 8000 h -1 , the catalytic degradation efficiency of the catalysts in Example 1 and Example 2 on asphalt smoke can reach about 90% at 300°C.
[0043] Figure 2The XRD pattern of the catalyst prepared by using the catalysts of embodiments 1 and 2 of the present application is shown in the figure. It can be seen from the figure that the catalysts of embodiment 1 and embodiment 2 both have strong anatase diffraction peaks at 2θ = 25.42°, 37.84°, 48.14°, 54° and 55.15°, and no other crystal form of TiO2 appears, which indicates that the anatase TiO2 crystal form is well maintained and does not change at the calcination temperature, which is beneficial to the activity of the catalyst. Moreover, the catalysts of embodiment 1 and embodiment 2 do not have diffraction peaks of CeO x , which indicates that the dispersibility of the active component Ce of the catalyst is good and no sintering and agglomeration phenomenon occurs.
[0044] Embodiment 3
[0045] The difference from embodiment 2 is that the prepared catalyst is Mn 0.1 Ce 0.075 / TiO2 catalyst.
[0046] Embodiment 4
[0047] The difference from embodiment 2 is that the prepared catalyst is Mn 0.1 Ce 0.1 / TiO2 catalyst.
[0048] Comparative example 1
[0049] The difference from embodiment 2 is that the temperature for calcining the dried product is 600℃, and a blocky catalyst is obtained, and the other conditions are the same as those of embodiment 2.
[0050] Comparative example 2
[0051] The difference from embodiment 2 is that the temperature for calcining the dried product is 400℃, and a blocky catalyst is obtained, and the other conditions are the same as those of embodiment 2.
[0052] Figure 3 The catalytic degradation curve of asphalt smoke of embodiments 2-4. Figure 4 The catalytic degradation curve of asphalt smoke of embodiments 2 and comparative examples 1-2.
[0053] Embodiment 5
[0054] Mn 0.1 Co 0.05 / TiO2 catalyst:
[0055] 1) 7.158 g of manganese nitrate solution with a mass fraction of 50% and 2.910 g of Co(NO3)2·6H2O were weighed, 80 mL of ethanol aqueous solution with a volume fraction of 50% was added, and magnetic stirring was performed for 30 min to completely dissolve them, to obtain a precursor solution.
[0056] 2) Take 15.973 g of anatase lipophilic nano-titanium dioxide powder with a particle diameter of 100 nm, slowly add the carrier powder into the prepared precursor solution under continuous stirring of the electric mixer, continue stirring for 30 min, mix the carrier and the precursor solution thoroughly, and obtain a viscous catalyst slurry.
[0057] 3) After the obtained catalyst slurry is immersed at room temperature for 12 h, it is placed into a drying box, dried at a temperature of 105°C for 12 h to obtain a dry product; the obtained dry product is placed into a muffle furnace, calcined at 500°C for 5 h under an air atmosphere, and a blocky catalyst is obtained.
[0058] 4) After the obtained blocky catalyst is ground, it is passed through a 20-40 mesh sieve, and a Mn 0.1 Co 0.05 / TiO2 catalyst with a particle size of 20-40 μm is obtained.
[0059] Example 2
[0060] Mn 0.1 Co 0.1 / TiO2 catalyst:
[0061] 1) Take 7.158 g of a 50% mass fraction manganese nitrate solution and 5.820 g of Co(NO3)2·6H2O, add 80 mL of a 50% volume fraction ethanol aqueous solution, magnetically stir for 30 min to completely dissolve, and obtain a precursor solution.
[0062] 2) Take 15.973 g of anatase lipophilic nano-titanium dioxide powder with a particle diameter of 100 nm, slowly add the carrier powder into the prepared precursor solution under continuous stirring of the electric mixer, continue stirring for 30 min, mix the carrier and the precursor solution thoroughly, and obtain a viscous catalyst slurry.
[0063] 3) After the obtained catalyst slurry is immersed at room temperature for 12 h, it is placed into a drying box, dried at a temperature of 105°C for 12 h to obtain a dry product; the obtained dry product is placed into a muffle furnace, calcined at 500°C for 5 h under an air atmosphere, and a blocky catalyst is obtained.
[0064] 4) After the obtained blocky catalyst is ground, it is passed through a 20-40 mesh sieve, and a Mn 01 Co 01 / TiO2 catalyst.
[0065] Figure 5 The catalytic degradation curve of asphalt smoke by the catalyst prepared in Examples 1 and 2 is shown in FIG. 1. Figure 1It can be seen that the catalytic degradation efficiency of the asphalt fume of the catalysts of Example 1 and Example 2 can reach about 90% at 250℃.
[0066] Figure 6 The XRD patterns of the catalysts prepared by using the embodiments of the present application are shown in the figure. It can be seen from the figure that the catalysts of Example 1 and Example 2 both have strong anatase diffraction peaks at 2θ = 25.42°, 37.84°, 48.14°, 54° and 55.15°, and the catalysts of Example 1 and Example 2 both do not have diffraction peaks of MnO x and CoO x , which indicates that the dispersibility of the active components of the catalysts is good.
[0067] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. The application of a low-temperature degradation catalyst for asphalt fumes in the low-temperature degradation of asphalt fumes, characterized in that: The catalyst comprises a carrier and active components loaded on the catalyst, the active components include two kinds, one is MnO x , and the other is CeO x or CoO x , the molar ratio of manganese to cerium / cobalt is 1:0.25~1; the carrier is nano TiO2; The catalyst has an average specific surface area of 29.7~36.3 m². 2 / g, with an average pore size of 7.8~8.9 nm; The preparation method of the low-temperature degradation catalyst for asphalt fumes includes the following steps: A cerium-soluble salt, cobalt-soluble salt, or manganese-soluble salt is dissolved in an aqueous ethanol solution in a certain proportion to obtain an active solution; then, nano-TiO2 powder is impregnated with the active solution, dried, calcined, and ground to obtain a catalyst.
2. The application according to claim 1, characterized in that: The roasting temperature is 500~600℃ and the roasting time is 4~6h.
3. The application according to claim 1, characterized in that: The average particle size of the nano-TiO2 powder is 100 nm.
4. The application according to claim 1, characterized in that: The manganese soluble salt is manganese nitrate; the cerium soluble salt is cerium nitrate; and the cobalt soluble salt is cobalt nitrate.
5. The application according to claim 1, characterized in that: The volume fraction of the ethanol aqueous solution is 40% to 60%.
6. The application according to claim 1, characterized in that: The particle size of the ground catalyst is 20-40 mesh.
7. The application according to claim 1, characterized in that: The drying temperature is 100~110℃, and the drying time is 10~15h.
8. The application according to claim 1, characterized in that: During the degradation of asphalt fumes using the catalyst, the catalytic degradation temperature is 200~400℃.
9. The application according to claim 8, characterized in that: The catalyst is used to catalytically degrade asphalt fumes at a temperature of 250~300℃.