Composite catalyst for recovering monophenol from waste fan blades as well as preparation method and application of composite catalyst

Abstract

The invention discloses a composite catalyst for recovering monophenol from waste fan blades as well as a preparation method and application of the composite catalyst. The catalyst is prepared by taking a beta molecular sieve as a carrier and CeO2-Fe2O3 bimetallic oxide as an active component through a coprecipitation-calcination method. By changing the proportion of Ce < 2 + > / Fe < 3 + >, precise regulation and control of intermetallic interaction can be realized, and the content of active oxygen species and acid sites on the surface of the catalyst is remarkably increased. Meanwhile, due to the ordered macroporous structure of the beta molecular sieve, the shape selectivity of reactants is enhanced, the monophenol yield is remarkably increased, and the problem of carbon deposition in the catalysis process is effectively inhibited. The catalyst has high specific surface area, excellent catalytic activity and cycling stability, and can realize efficient catalytic conversion of waste fan blades within 450-650 DEG C. The process is simple and convenient to operate, low in energy consumption and high in monophenol yield, has both environmental and economic benefits, and provides a new strategy for resource utilization of fan blades.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of resource recycling, and particularly relates to a composite catalyst for recovering monophenol products from waste wind turbine blades and a preparation method and application thereof. BACKGROUND

[0002] The installed capacity of wind power in China is currently the largest in the world, and the problem of waste wind turbine blade disposal is increasingly prominent. From the material composition, waste wind turbine blades are mainly made of fiber-reinforced thermoset composites, in which the reinforcing fiber accounts for 60-70wt.%, and the polymer epoxy resin matrix material accounts for 30-40wt.%. This composite material, which has high strength and lightweight characteristics, has significant resource utilization potential.

[0003] The difficulty of recycling waste wind turbine blades lies in the highly cross-linked and dense structure formed by the cross-linking reaction of epoxy resin and curing agent. Currently, there are three typical recycling methods: mechanical recycling, chemical solvent decomposition and pyrolysis. Mechanical recycling (such as CN120156036A, CN119752162A, etc.) decomposes polymers into small particles through physical treatment (such as grinding, crushing or shredding), but this method does not change the chemical structure of epoxy resin, resulting in low added value of the recycled products. Chemical solvent decomposition (such as CN120156034A, CN119976801A, etc.) uses supercritical water, acetic acid or dimethylformamide solvent to selectively break cross-linking bonds, although it has the advantage of recycling high-value monomers, but the dense cross-linked structure of epoxy resin will hinder the mass transfer of the solvent, resulting in the need to improve the processing efficiency. In contrast, pyrolysis, as a thermal treatment process carried out at a mild temperature (400℃-700℃) without oxygen, can efficiently destroy the cross-linked structure of polymers, and has the advantages of continuous operation, simple implementation and strong adaptability to industrialization, etc., and has become a promising recycling scheme for waste wind turbine blades.

[0004] For the pyrolysis of waste fan blades, Chinese patent CN119954169A discloses a device and method for treating waste fan blades using microwave pyrolysis, and uses strong oxidizing agents or organic acids to remove residual carbon in the recovered fibers, dissolve and extract Si and Al elements, and then prepare SAPO molecular sieves through hydrothermal reaction. Patent CN119974304A proposes a method for recycling glass fibers from retired fan blades by limiting the temperature and time of pyrolysis reaction and the temperature and time of oxidation reaction, which can reduce the damage to the performance of glass fibers, thereby improving the mechanical properties. It can be found that the existing patents mainly focus on the resource recovery of glass fiber components in the blades, while the recycling of high molecular epoxy resin components is less. CN119569540A proposes a method for improving the yield of phenolic chemicals by catalytic pyrolysis of retired fan blades, which uses spectroscopy to pre-separate the raw materials into light wood fragments, polyethylene terephthalate (PET) foam fragments, glass fiber reinforced plastic fragments, and polyvinyl chloride (PVC) fragments. Subsequently, light wood is activated and carbonized to prepare a catalyst, and combined with catalytic pyrolysis to obtain phenolic chemicals. However, the target product of pyrolysis is mainly all phenolic products, and the product types are still mixed, the chemical properties of each phenolic product are different, and it is difficult to be directly applied. In addition, the use of carbon material catalysts involves the use of a large amount of activators, and the catalyst products have weak controllability, weak anti-coking ability, and poor reusability, which limits their industrialization and application.

[0005] Therefore, in order to improve the yield of single phenolic products and improve the industrial feasibility of catalytic pyrolysis of waste fan blades, and realize the resource recovery and high-value recycling of waste fan blades, the present application is proposed. SUMMARY

[0006] The present application aims to overcome the defects of the prior art and provide a composite catalyst for recovering single phenolic products from retired fan blades, as well as a preparation method and application thereof.

[0007] In order to achieve the above-mentioned purpose, the following technical solutions are adopted:

[0008] In a first aspect, the present application provides a composite catalyst suitable for recovering single phenolic products from retired fan blades, which comprises a carrier and an active component. The carrier is a beta molecular sieve, and the active component is a CeO2-Fe2O3 bimetallic oxide.

[0009] Preferably, the weight percentage of each component in the composite catalyst is: 5-20wt.% CeO2, 5-30wt.% Fe2O3 and 50-90wt.% beta molecular sieve.

[0010] In a second aspect, the present application provides a preparation method of the composite catalyst, comprising the following steps:

[0011] (1) A certain mass ratio of CeO2 to Fe2O3 is taken to weigh Ce salt and Fe salt, an organic chelating agent is added, and then mixed and dissolved in deionized water to obtain a solution;

[0012] (2) The beta molecular sieve is added to the solution obtained in step (1) and stirred and mixed uniformly;

[0013] (3) A precipitating agent is added dropwise, the pH is adjusted to 8-10, and a co-precipitation reaction is performed;

[0014] (4) The precipitate is filtered, washed, and dried to obtain a precursor;

[0015] (5) Calcination is performed under an air atmosphere to obtain a composite catalyst.

[0016] The steps are described in detail below.

[0017] Step (1)

[0018] Preferably, the mass ratio of CeO2 is 5-20 wt.%, and the mass ratio of Fe2O3 is 5-30 wt.%;

[0019] Preferably, the Ce salt is at least one of cerium nitrate, cerium chloride, or cerium sulfate;

[0020] Preferably, the Fe salt is at least one of iron nitrate, iron chloride, or iron sulfate;

[0021] Preferably, the organic chelating agent is at least one of citric acid, ethylenediaminetetraacetic acid, tartaric acid, or gluconic acid;

[0022] Preferably, the added molar amount of the organic chelating agent is 0.5-2 times the total molar amount of metal ions.

[0023] Step (2)

[0024] Preferably, the average pore size of the beta molecular sieve is 5-10 nm, and the specific surface area is 300-600 m 2 / g.

[0025] Step (3)

[0026] Preferably, the precipitating agent is at least one of ammonia, sodium hydroxide, or sodium carbonate.

[0027] Preferably, the time of the co-precipitation reaction is 4-5 h.

[0028] Step (4)

[0029] Preferably, the drying temperature is 80-100 DEG C, and the drying time is 1-2h.

[0030] Step (5)

[0031] Preferably, the calcination temperature is 400-600 DEG C, and the drying time is 2-6h.

[0032] In a third aspect, the application further provides application of the composite catalyst in preparation of monophenol products by catalytic pyrolysis of waste fan blades.

[0033] The waste fan blades are pyrolyzed in the presence of the composite catalyst under inert atmosphere to obtain monophenol products.

[0034] Preferably, the pyrolysis temperature is 450-650 DEG C, and the pyrolysis time is 30-60min.

[0035] Preferably, the mass ratio of the catalyst to the waste fan blades in the catalytic pyrolysis process is 1:1-1:20.

[0036] Preferably, the monophenol products are phenol, o-cresol, 4-ethylphenol, 4-isopropylphenol, 4-isopropenylphenol and 2,4-diisopropylphenol.

[0037] Compared with the prior art, the application has the following beneficial effects:

[0038] 1. The CeO2-Fe2O3 / beta molecular sieve composite catalyst is adopted in the application, the mass ratio of CeO2 to Fe2O3 and the shape-selective pore structure of the beta molecular sieve are regulated, the selectivity of the catalytic reaction is significantly improved, the yield of monophenol products (phenol, o-cresol, 4-ethylphenol, 4-isopropylphenol, 4-isopropenylphenol and 2,4-diisopropylphenol) is doubled or more, and the generation of by-products such as polycyclic aromatic hydrocarbons is reduced.

[0039] 2. The crosslinking network of thermosetting polymers such as epoxy resins and unsaturated polyesters is broken by the synergistic effect of the CeO2-Fe2O3 transition metal oxide and the beta molecular sieve, the pyrolysis temperature is reduced, the yield of monophenol products is improved, and the catalytic efficiency is significantly improved compared with the traditional non-catalytic efficiency.

[0040] 3. The regular pore structure of the beta molecular sieve inhibits the deposition of macromolecular coke precursors, the CeO2-Fe2O3 transition metal oxide can promote coke gasification, reduce catalyst deactivation, prolong the stability of the catalytic system, and reduce the regeneration frequency and cost.

[0041] 4. The catalyst has strong controllability. By adjusting the metal loading, molecular sieve type and reaction conditions (temperature, atmosphere, etc.), it can be applied to different resin substrates of fan blade waste, optimize the distribution of monophenol products, and realize precise resource utilization of waste fan blades. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 A fixed bed test platform for monophenol product yield of the embodiments of the present application;

[0043] Figure 2 The yield of monophenol products recovered from waste fan blades under different embodiments of the present application. DETAILED DESCRIPTION

[0044] The technical solutions of the present application will be described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0045] The present application will be further described below by examples. Unless otherwise specified, the materials in the examples are prepared according to the existing methods or directly purchased from the market.

[0046] The epoxy resin-based fan blades come from the retired fan blades from actual wind farms and are preliminarily cut.

[0047] The yield of monophenol products is used as the evaluation index of recovery effect, and the yield of monophenol is quantitatively determined by gas chromatography-mass spectrometry (GC-MS) analysis method, and its calculation formula is:

[0048] Y monophenols =m monophenols / m0×100% (1)

[0049] In formula (1), Y monophenols represents the total yield of monophenol compounds (wt.%); m monophenols is the total mass (g) of monophenol compounds in pyrolysis oil, including phenol, o-cresol, 4-ethylphenol, 4-isopropylphenol, 4-isopropenylphenol and 2,4-diisopropylphenol, etc.; m0 is the mass of resin components in the retired fan blades.

[0050] The pyrolysis and gasification reactions of the comparative examples and the embodiments can be carried out in a fixed bed reactor, and the test platform is as follows: Figure 1As shown. Before the experiment, the reactor was heated to the set pyrolysis temperature, and the air was purged with a nitrogen flow of 200 mL / min. Then, the catalyst-epoxy resin mixture was rapidly fed into the reaction zone to begin the pyrolysis process. A condenser was used to collect the pyrolysis oil. The yield of monophenolic products is shown in the figure. Figure 2 As shown.

[0051] Example 1

[0052] Cerium nitrate and ferric nitrate were dissolved in deionized water at a mass ratio of 10 wt.% CeO2 and 10 wt.% Fe2O3, respectively. Citric acid, with a mass ratio equal to the total molar amount of metal ions, was added and stirred until completely dissolved. Additionally, 80 wt.% of a solution with an average pore size of 7 nm and a specific surface area of ​​450 m² was added. 2 / g of beta molecular sieve was stirred for 2 hours to form a homogeneous slurry. Ammonia was added dropwise to adjust the pH to 9, and the co-precipitation reaction was carried out at room temperature for 4 hours. After filtration and washing, the slurry was dried at 90℃ for 1.5 hours and then calcined at 500℃ for 4 hours in air to obtain the catalyst 10Ce-10Fe / beta.

[0053] Epoxy resin-based wind turbine blades were mixed with a 10Ce-10Fe / beta catalyst at a mass ratio of 1:2. The mixture was then pyrolyzed at 600℃ for 30 min under a nitrogen atmosphere. The resulting pyrolysis oil was then distilled under reduced pressure to obtain monophenolic products such as phenol, o-cresol, 4-ethylphenol, 4-isopropylphenol, 4-isopropenylphenol, and 2,4-diisopropylphenol, with a total yield of 18.51 wt.%.

[0054] Example 2

[0055] Cerium nitrate and ferric chloride were dissolved in deionized water at a mass ratio of 15 wt.% CeO2 and 7.5 wt.% Fe2O3. EDTA was then added at a mass ratio of 1.5 times the total molar amount of metal ions, and the mixture was stirred until completely dissolved. 77.5 wt.% of EDTA with an average pore size of 7 nm and a specific surface area of ​​450 m² was then added. 2 / g of beta molecular sieve was stirred for 1 hour to form a homogeneous slurry. Ammonia was added dropwise to adjust the pH to 10, and the co-precipitation reaction was carried out at room temperature for 5 hours. After filtration and washing, the slurry was dried at 100℃ for 1.5 hours and then calcined at 600℃ for 4 hours in air to obtain the catalyst 15Ce-7.5Fe / beta.

[0056] Epoxy resin-based wind turbine blades were mixed with a 15Ce-7.5Fe / beta catalyst at a mass ratio of 1:2. The mixture was then pyrolyzed at 480℃ for 50 min under a nitrogen atmosphere. The resulting pyrolysis oil was then distilled under reduced pressure to obtain monophenolic products such as phenol, o-cresol, 4-ethylphenol, 4-isopropylphenol, 4-isopropenylphenol, and 2,4-diisopropylphenol, with a total yield of 21.54 wt.%.

[0057] Example 3

[0058] Ce sulfate and Fe sulfate were dissolved in deionized water according to the mass ratio of CeO2 5wt.%, Fe2O3 15wt.%, and the total moles of metal ions were added 0.5 times of ethylenediaminetetraacetic acid, and stirred until completely dissolved. 80wt.% of beta zeolite with an average pore size of 7nm and a specific surface area of 450m 2 / g was added, and stirred for 1h to form a uniform slurry. Ammonia water was added to adjust the pH to 9, and the co-precipitation reaction was carried out at room temperature for 5h. After filtration and washing, it was dried at 80℃ for 1h, and then calcined at 600℃ for 2h in air atmosphere to obtain catalyst 5Ce-15Fe / beta.

[0059] The epoxy resin-based fan blade was mixed with 5Ce-15Fe / beta catalyst, and the mass ratio of catalyst to blade was 1:3. Pyrolysis was carried out at 580℃ for 45min under nitrogen atmosphere, and the obtained pyrolysis oil was subjected to vacuum rectification to obtain monophenolic products such as phenol, o-cresol, 4-ethylphenol, 4-isopropylphenol, 4-isopropenylphenol, and 2,4-diisopropylphenol, with a total yield of 16.59wt.%.

[0060] Example 4

[0061] Ce sulfate and Fe sulfate were dissolved in deionized water according to the mass ratio of CeO2 10wt.%, Fe2O3 15wt.%, and the total moles of metal ions were added 0.5 times of ethylenediaminetetraacetic acid, and stirred until completely dissolved. 80wt.% of beta zeolite with an average pore size of 7nm and a specific surface area of 450m 2 / g was added, and stirred for 1h to form a uniform slurry. Ammonia water was added to adjust the pH to 10, and the co-precipitation reaction was carried out at room temperature for 5h. After filtration and washing, it was dried at 80℃ for 1h, and then calcined at 500℃ for 2h in air atmosphere to obtain catalyst 10Ce-15Fe / beta.

[0062] The epoxy resin-based fan blade was mixed with 10Ce-15Fe / beta catalyst, and the mass ratio of catalyst to blade was 1:4. Pyrolysis was carried out at 520℃ for 55min under nitrogen atmosphere, and the obtained pyrolysis oil was subjected to vacuum rectification to obtain monophenolic products such as phenol, o-cresol, 4-ethylphenol, 4-isopropylphenol, 4-isopropenylphenol, and 2,4-diisopropylphenol, with a total yield of 21.53wt.%.

[0063] Example 5

[0064] CeCI3and Fe2(S04)3were dissolved in deionized water with CeO2mass ratio of 15wt.%and Fe2O3mass ratio of 7.5wt.%, and 1 times of the total moles of metal ions of glucose acid was added, and stirred until completely dissolved. 77.5wt.%of beta zeolite with average pore size of 7nm and specific surface area of 450m 2 / g was added, and stirred for 1h to form a uniform slurry. Ammonia water was added to adjust the pH to 9, and the co-precipitation reaction was carried out at room temperature for 5h. After filtration and washing, it was dried at 80℃ for 1h, and then calcined at 600℃ for 2h in air atmosphere to obtain catalyst 15Ce-7.5Fe / beta.

[0065] The epoxy resin-based fan blade was mixed with 15Ce-7.5Fe / beta catalyst, and the mass ratio of catalyst to blade was 1:2. Pyrolysis was carried out at 530℃ for 35min under nitrogen atmosphere, and the obtained pyrolysis oil was subjected to vacuum rectification to obtain monophenolic products such as phenol, o-cresol, 4-ethylphenol, 4-isopropylphenol, 4-isopropenylphenol and 2,4-diisopropylphenol, with a total yield of 27.84wt.%.

[0066] Comparative Example 1

[0067] The epoxy resin-based fan blade was pyrolyzed at 550℃ for 40min under nitrogen atmosphere, and the obtained pyrolysis oil was subjected to vacuum rectification to obtain monophenolic products such as phenol, o-cresol, 4-ethylphenol, 4-isopropylphenol, 4-isopropenylphenol and 2,4-diisopropylphenol, with a total yield of 9.41%; at the same time, the solid residue was subjected to air oxidation at 500℃ for 8min to recover the complete glass fiber.

[0068] Comparative Example 2

[0069] The difference from Example 1 is that the beta zeolite is replaced by MCM-41 zeolite, and the obtained pyrolysis oil is subjected to vacuum rectification to obtain monophenolic products such as phenol, o-cresol, 4-ethylphenol, 4-isopropylphenol, 4-isopropenylphenol and 2,4-diisopropylphenol, with a total yield of 12.47wt.%.

[0070] Comparative Example 3

[0071] The difference from Example 1 is that the beta zeolite is replaced by ZSM-5 zeolite, and the obtained pyrolysis oil is subjected to vacuum rectification to obtain monophenolic products such as phenol, o-cresol, 4-ethylphenol, 4-isopropylphenol, 4-isopropenylphenol and 2,4-diisopropylphenol, with a total yield of 10.14wt.%.

[0072] Comparative Example 4

[0073] The difference from Example 1 is that no Fe component is loaded, and the specific preparation steps are as follows:

[0074] Ce(NO3)3 was dissolved in deionized water with a mass fraction of 10wt.% CeO2, and 1 times the total moles of metal ions of citric acid was added, and stirred until completely dissolved. 90wt.% of beta zeolite with an average pore size of 7nm and a specific surface area of 450m 2 / g was added, and stirred for 2h to form a uniform slurry. Ammonia water was added to adjust the pH to 9, and the co-precipitation reaction was carried out at room temperature for 4h. After filtration and washing, it was dried at 90℃ for 1.5h, and then calcined at 500℃ in air atmosphere for 4h to obtain catalyst 10Ce / beta.

[0075] The epoxy resin-based fan blade was mixed with the 10Ce / beta catalyst, and the mass ratio of catalyst to blade was 1:2, and pyrolysis was carried out at 600℃ for 30min under nitrogen atmosphere. The obtained pyrolysis oil was subjected to vacuum rectification to obtain monophenolic products such as phenol, o-cresol, 4-ethylphenol, 4-isopropylphenol, 4-isopropenylphenol, and 2,4-diisopropylphenol, with a total yield of 11.91wt.%.

[0076] Comparative Example 5

[0077] The difference from Example 1 is that no Ce component is loaded, and the specific preparation steps are as follows:

[0078] Fe(NO3)3 was dissolved in deionized water with a mass fraction of 10wt.% Fe2O3, and 1 times the total moles of metal ions of citric acid was added, and stirred until completely dissolved. 90wt.% of beta zeolite with an average pore size of 7nm and a specific surface area of 450m 2 / g was added, and stirred for 2h to form a uniform slurry. Ammonia water was added to adjust the pH to 9, and the co-precipitation reaction was carried out at room temperature for 4h. After filtration and washing, it was dried at 90℃ for 1.5h, and then calcined at 500℃ in air atmosphere for 4h to obtain catalyst 10Fe / beta.

[0079] The epoxy resin-based fan blade was mixed with the 10Fe / beta catalyst, and the mass ratio of catalyst to blade was 1:2, and pyrolysis was carried out at 600℃ for 30min under nitrogen atmosphere. The obtained pyrolysis oil was subjected to vacuum rectification to obtain monophenolic products such as phenol, o-cresol, 4-ethylphenol, 4-isopropylphenol, 4-isopropenylphenol, and 2,4-diisopropylphenol, with a total yield of 12.77wt.%.

[0080] Comparative Example 6

[0081] The catalyst 10Ce / beta obtained in Comparative Example 4 was mechanically mixed with the catalyst 10Fe / beta obtained in Comparative Example 5:

[0082] The 10Ce / beta catalyst and 10Fe / beta catalyst are mixed in a mass ratio of 1:1, and mixed with the epoxy resin-based fan blade in a mass ratio of 1:2, pyrolyzed at 600°C for 30 min under a nitrogen atmosphere, and the obtained pyrolysis oil is subjected to vacuum rectification to obtain monophenol products such as phenol, o-cresol, 4-ethylphenol, 4-isopropylphenol, 4-isopropenylphenol, and 2,4-diisopropylphenol, with a total yield of 15.33 wt.%.

[0083] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A composite catalyst for recovering monophenolic products from waste and old fan blades, characterized by, The composite catalyst takes beta molecular sieve as a carrier and CeO2-Fe2O3 bimetallic oxide as an active component.

2. The composite catalyst of claim 1, wherein In the composite catalyst, the weight percentage of each component is 5-20wt.% of CeO2, 5-30wt.% of Fe2O3 and 50-90wt.% of beta molecular sieve.

3. A process for the preparation of the composite catalyst according to claim 1 or 2, characterized in that, The method comprises the following steps: (1) A certain mass ratio of CeO2 to Fe2O3 is taken as the mass percentage of Ce salt and Fe salt, an organic chelating agent is added, and then they are mixed and dissolved in deionized water to obtain a solution; (2) The beta molecular sieve is added to the solution obtained in step (1) and stirred and mixed uniformly; (3) A precipitating agent is added dropwise, the pH is adjusted to 8-10, and a coprecipitation reaction is performed; (4) The precipitate is filtered, washed and dried to obtain a precursor; (5) The precursor is calcined in an air atmosphere to obtain a composite catalyst.

4. The production method according to claim 3, characterized by, In step (1), the mass percentage of CeO2 is 5-20wt.%, the mass percentage of Fe2O3 is 5-30wt.%, the Ce salt is at least one of cerium nitrate, cerium chloride or cerium sulfate, and the Fe salt is at least one of iron nitrate, iron chloride or iron sulfate.

5. The preparation method according to claim 3, characterized in that, In step (1), the organic chelating agent is at least one of citric acid, ethylenediaminetetraacetic acid, tartaric acid or gluconic acid, and the addition amount is 0.5-2 times the total molar number of metal ions.

6. The preparation method according to claim 3, characterized in that, The average pore diameter of the beta molecular sieve in step (2) is 5-10 nm, and the specific surface area is 300-600 m 2 / g.

7. The preparation method according to claim 3, characterized in that, In step (3), the precipitating agent is at least one of ammonia, sodium hydroxide or sodium carbonate, and the time of the coprecipitation reaction is 4-5h.

8. The preparation method according to claim 3, characterized in that, In step (5), the calcination temperature is 400-600℃, and the drying time is 2-6h.

9. The application of the composite catalyst of claim 1 or 2 or the composite catalyst prepared by the preparation method of any one of claims 3-8 in the preparation of monophenolic products by catalytic pyrolysis of waste fan blades.

10. Use according to claim 9, characterized in that, The temperature of the pyrolysis reaction is 450-650℃, and the time of the pyrolysis reaction is 30-60min; In the catalytic pyrolysis process, the mass ratio of the catalyst to the waste fan blades is 1:1-1:20; The monophenolic products include phenol, o-cresol, 4-ethylphenol, 4-isopropylphenol, 4-isopropenylphenol and 2,4-diisopropylphenol.

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