Catalyst for producing diesel oil by degrading polyolefin and application of catalyst
By using molybdenum carbide and solid acid catalysts in combination, the problem of low catalytic selectivity was solved, efficient catalytic effect of catalytic degradation of polyolefins to produce diesel was achieved, and the production ratio of aromatic compounds was increased.
Patent Information
- Application Number
- CN202510699715.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-28
- Publication Date
- 2025-09-19
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The catalytic selectivity of preparing diesel by catalytic degradation of polyolefins in the prior art is low.
A combined catalytic system of molybdenum carbide and a solid acid catalyst is used. By treating a mixture of ammonium molybdate and melamine at high temperature under an inert atmosphere, molybdenum carbide is prepared as a catalyst and used in combination with a solid acid catalyst to catalyze the degradation of polyolefins to produce diesel.
The catalytic selectivity was significantly improved, the production ratio of aromatic compounds was increased, and the efficiency of catalytic degradation of polyolefins to produce diesel was improved.
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Abstract
Description
Technical Field
[0001] The present invention relates to the field of degradation catalysis, and in particular to a catalyst for degrading polyolefins to produce diesel and application thereof. Background Art
[0002] Polyolefins are thermoplastics, with polyethylene, polypropylene, and polyvinyl chloride being the most widely used. Due to their excellent chemical and thermal stability, they are widely used in a wide range of fields, such as food packaging, clothing, and construction. Currently, polyolefins account for over a quarter of all plastics used. However, due to their resistance to biodegradation, large amounts of discarded polyolefin plastics accumulate in the environment, resulting in a significant waste of resources and placing significant pressure on the economy, society, and the ecological environment.
[0003] Current polyolefin recycling methods primarily include physical, chemical, and biological treatment. Physical methods, in addition to incineration and landfill, primarily involve collection, sorting, cleaning, crushing, and melt regeneration for recycling, which can affect the plastic's final properties. Chemical methods involve cracking or degrading polyolefins into relatively small molecular compounds through heat, light, or other chemical treatments and reactions. Catalytic degradation is a highly efficient treatment method.
[0004] With the development of energy conservation and environmental protection, the degradation of polyolefins to produce fuel oil has become a cutting-edge research area. Catalytic degradation of polyolefins to produce diesel fuel has gained popularity due to its industrialization. However, the catalytic selectivity of current catalytic degradation of polyolefins to produce diesel fuel is relatively low. Summary of the Invention
[0005] In order to solve the problem of low catalytic selectivity in the prior art of catalytic degradation of polyolefins to produce diesel, the present invention provides a catalyst for degrading polyolefins to produce diesel and its application.
[0006] A catalyst for producing diesel by degrading polyolefins, comprising molybdenum carbide.
[0007] A catalyst for producing diesel by degrading polyolefins comprises the following components in parts by weight: 1 part by weight of molybdenum carbide and 2-3 parts by weight of a solid acid catalyst.
[0008] The molybdenum carbide is prepared by reacting ammonium molybdate and melamine at high temperature.
[0009] The preparation method of molybdenum carbide comprises the following steps: uniformly mixing ammonium molybdate and melamine, then keeping the mixture at 750° C.-850° C. for 2-5 hours under an inert atmosphere, and cooling the mixture to obtain the molybdenum carbide.
[0010] The inert atmosphere is an argon atmosphere.
[0011] The heating rate when keeping at a temperature of 750℃-850℃ is 2-5℃ / min.
[0012] The mass ratio of the ammonium molybdate to melamine is 1:1-2. Preferably, the mass ratio of the ammonium molybdate to melamine is 1:2.
[0013] The solid acid is HND-270 solid acid catalyst produced by Jiangyin Nanda Synthetic Chemical Co., Ltd. It is an inorganic composite solid acid catalyst with the dual properties of Lewis-Bronsted acid.
[0014] An application of the catalyst as claimed in claim 1 in producing diesel from polyolefins.
[0015] The polyolefin is polyethylene.
[0016] Beneficial effects: The catalytic degradation of polyolefins to prepare diesel in the present invention has a greatly improved catalytic selectivity after adjusting and optimizing process parameters. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 This is the gas chromatography-mass spectrometry chromatogram of the liquid product of polyethylene catalyzed by molybdenum carbide at 180°C;
[0018] Figure 2 This is the mass spectrum of peak 2+TIC scan in Table 1;
[0019] Figure 3 This is the mass spectrum of peak 3+TIC scan in Table 1;
[0020] Figure 4 This is the mass spectrum of peak 9+TIC scan in Table 1;
[0021] Figure 5 This is the mass spectrum of peak 15+TIC scan in Table 1;
[0022] Figure 6 This is the mass spectrum of peak 29+TIC scan in Table 1;
[0023] Figure 7 This is the mass spectrum of peak 31+TIC scan in Table 1;
[0024] Figure 8 This is the mass spectrum of peak 43+TIC scan in Table 1;
[0025] Figure 9 This is the mass spectrum of peak 44+TIC scan in Table 1;
[0026] Figure 10 This is the mass spectrum of peak 59+TIC scan in Table 1;
[0027] Figure 11 This is the mass spectrum of peak 60+TIC scan in Table 1;
[0028] Figure 12 Table 1 Peak 79+ TIC scan mass spectrum;
[0029] Figure 13 This is the mass spectrum of peak 84+TIC scan in Table 1;
[0030] Figure 14 This is the gas chromatography-mass spectrometry chromatogram of the liquid product of polyethylene degradation by molybdenum carbide / solid acid combined catalysis at 260°C;
[0031] Figure 15 This is the mass spectrum of peak 2+TIC scan in Table 2;
[0032] Figure 16 This is the mass spectrum of peak 5+TIC scan in Table 2;
[0033] Figure 17 This is the mass spectrum of peak 6+TIC scan in Table 2;
[0034] Figure 18 This is the mass spectrum of peak 8+TIC scan in Table 2;
[0035] Figure 19 This is the mass spectrum of peak 9+TIC scan in Table 2;
[0036] Figure 20 This is the mass spectrum of peak 13+TIC scan in Table 2;
[0037] Figure 21 This is the mass spectrum of peak 41+TIC scan in Table 2. DETAILED DESCRIPTION
[0038] Molybdenum carbide (MoC) is a gray hexagonal crystal. It possesses a high melting point and hardness, excellent thermal and mechanical stability, and excellent corrosion resistance. Its catalytic properties are not only reflected in its efficient catalysis for oil hydrorefining, desulfurization, and denitrogenation, but also demonstrate unique advantages in methane reforming for hydrogen production.
[0039] Example 1
[0040] The preparation method of the catalyst for degrading polyolefins to produce diesel in this embodiment comprises the following steps:
[0041] Mix 200 mg of ammonium molybdate and melamine directly into a ceramic crucible (mass ratio of 1:2). Place the mixture in a quartz tube and heat the tube to 800°C at a rate of 3°C per minute in an argon atmosphere. Maintain this temperature for 3 hours, then allow it to cool naturally to room temperature. After cooling, remove the product from the crucible.
[0042] Example 2
[0043] The preparation method of the catalyst for degrading polyolefins to produce diesel in this embodiment comprises the following steps:
[0044] 1) 200 mg of ammonium molybdate and melamine were directly mixed in a ceramic crucible (mass ratio of 1:2). The mixture was placed in a quartz tube and heated to 800°C in an argon atmosphere at a rate of 3°C per minute. This temperature was maintained for 3 hours and then allowed to cool naturally to room temperature. After cooling, the product was removed from the crucible to obtain molybdenum carbide (MoC).
[0045] 2) uniformly mixing molybdenum carbide and solid acid to obtain a catalyst; wherein the mass ratio of molybdenum carbide to solid acid is 1:2, and the solid acid is HND-270 solid acid catalyst purchased from Jiangyin Nanda Synthetic Chemical Co., Ltd.
[0046] Example 3
[0047] The preparation method of the catalyst for degrading polyolefins to produce diesel in this embodiment comprises the following steps:
[0048] 1) Mix 200 mg of ammonium molybdate and melamine directly into a ceramic crucible (mass ratio of 1:
[0049] 1.5), place the mixture crucible in a quartz tube and heat the tube to 780°C in an argon atmosphere at a rate of 3°C per minute. Maintain this temperature for 5 hours and then allow it to cool naturally to room temperature. After cooling, remove the product from the crucible to obtain molybdenum carbide (MoC).
[0050] 2) uniformly mixing molybdenum carbide and solid acid to obtain a catalyst; wherein the mass ratio of molybdenum carbide to solid acid is 1:2, and the solid acid is HND-270 solid acid catalyst purchased from Jiangyin Nanda Synthetic Chemical Co., Ltd.
[0051] Example 4
[0052] The preparation method of the catalyst for degrading polyolefins to produce diesel in this embodiment comprises the following steps:
[0053] 1) 200 mg of ammonium molybdate and melamine were directly mixed in a ceramic crucible (mass ratio of 1:1). The mixture was placed in a quartz tube and heated to 850°C in an argon atmosphere at a rate of 3°C per minute. This temperature was maintained for 2 hours, followed by natural cooling to room temperature. After cooling, the product was removed from the crucible to obtain molybdenum carbide (MoC).
[0054] 2) uniformly mixing molybdenum carbide and solid acid to obtain a catalyst; wherein the mass ratio of molybdenum carbide to solid acid is 1:3, and the solid acid is HND-270 solid acid catalyst purchased from Jiangyin Nanda Synthetic Chemical Co., Ltd.
[0055] Experimental example
[0056] (1) The molybdenum carbide prepared in Example 1 was used to catalyze the degradation of polyethylene. The effect of the catalyst molybdenum carbide on the degradation of polyethylene was tested at a temperature ranging from 180°C to 280°C. When the reaction temperature was 180°C, the reaction mixture was cooled to room temperature, the exhaust sampling valve was opened, and small organic molecules escaped. The reactor was then opened, and a brown liquid was found in the degradation product. The filtrate was filtered and collected, and the yield was calculated by weighing to be 65%. No obvious coking was observed on the catalyst surface. This shows that the catalyst molybdenum carbide can effectively catalyze the degradation of polyethylene.
[0057] The degradation experiment of polyethylene by molybdenum carbide was carried out at 260℃. According to the above steps, the product was found to be a brown liquid. When the sampling valve was opened, small molecular organic matter escaped. The liquid sample was analyzed by gas chromatography-mass spectrometry. Figure 1 This is the gas chromatography-mass spectrometry analysis of the liquid degradation product at 260°C. The component analysis is shown in Table 1. It can be seen that the composition of the degradation liquid is very complex, with 136 components, mainly branched aromatic compounds, as well as some long-chain aliphatic hydrocarbons and cyclic aliphatic hydrocarbons. In Table 1, the peaks with a component proportion higher than 2% are mainly peak 2 with a total area of 2.88%, peak 3 with a total area of 3.1%, peak 9 with a total area of 2.24%, peak 15 with a total area of 2.29%, peak 29 with a total area of 2.16%, peak 31 with a total area of 2.26%, peak 43 with a total area of 2.62%, peak 44 with a total area of 2.35%, peak 59 with a total area of 2.47%, peak 60 with a total area of 2.06%, peak 79 with a total area of 2.39%, and peak 84 with a total area of 2.06%. Taking these 12 peaks as an example, their mass spectra are analyzed, and peak 2 is a seven-membered ring conjugated olefin compound, and peaks 4, 44, 79, and 84 are aliphatic hydrocarbon compounds. This shows that in the depolymerization process of polyethylene, the chain is first broken to form olefins, and the olefins then undergo dehydrogenation and cyclization to form aromatic hydrocarbons, and part of the olefins are hydrogenated to form aliphatic hydrocarbons.
[0058] Table 1 Gas chromatography analysis of the composition of the liquid product of polyethylene catalytic degradation by molybdenum carbide at 260℃
[0059]
[0060]
[0061]
[0062]
[0063]
[0064]
[0065]
[0066]
[0067]
[0068]
[0069] (2) Polyethylene degradation experiments were conducted at 260°C using the molybdenum carbide and solid acid of Example 2 to depolymerize polyethylene and prepare aromatic compounds. Following the above steps, the product was found to be a brown liquid. Small organic molecules escaped upon opening the sampling valve. The liquid samples were analyzed by gas chromatography-mass spectrometry. Figure 14 This is the gas chromatography-mass spectrometry analysis of the liquid degradation product at 260°C. The component analysis is shown in Table 2. It can be seen that the composition of the degradation liquid is very complex, with 100 components. Compared with the polyethylene degradation product catalyzed by molybdenum carbide, the proportion of aromatic compounds is increased, indicating that the molybdenum carbide / solid acid combined catalytic degradation of polyethylene to produce aromatic compounds has good catalytic selectivity. In Table 2, the peaks with a component proportion higher than 3% mainly include peak 2 with a total area of 9.11%, peak 5 with a total area of 3.4%, peak 6 with a total area of 7.47%, peak 8 with a total area of 3.69%, peak 9 with a total area of 3.49%, peak 13 with a total area of 4.44%, and peak 41 with a total area of 3.06%. Taking these 7 peaks as an example, their mass spectra are analyzed, and only peak 9 is a higher aliphatic hydrocarbon compound. Peaks 2, 5, 6, 8, 13, and 41 are all aromatic compounds and contain only one benzene ring. This shows that in the depolymerization process of polyethylene catalyzed by molybdenum carbide and solid acid as a combined catalyst, molybdenum carbide and solid acid as a combined catalyst catalyze the depolymerization of polyethylene to form chain aromatic compounds with good catalytic selectivity.
[0070] Table 2 Gas chromatography analysis of the composition of the liquid product of polyethylene degradation by molybdenum carbide / solid acid combined catalysis at 260℃
[0071]
[0072]
[0073]
[0074]
[0075]
[0076]
Claims
1. A catalyst for degrading polyolefins to produce diesel, characterized in that: The catalyst includes molybdenum carbide.
2. A catalyst for degrading polyolefins to produce diesel, characterized in that: The invention comprises the following components in parts by weight: 1 part by weight of molybdenum carbide and 2-3 parts by weight of a solid acid catalyst.
3. The catalyst for producing diesel from polyolefin degradation according to claim 1 or 2, characterized in that The molybdenum carbide is prepared by reacting ammonium molybdate and melamine at high temperature.
4. The catalyst for producing diesel from polyolefin degradation according to claim 3, characterized in that The preparation method of molybdenum carbide comprises the following steps: uniformly mixing ammonium molybdate and melamine, then keeping the mixture at 750° C.-850° C. for 2-5 hours under an inert atmosphere, and cooling the mixture to obtain the molybdenum carbide.
5. The catalyst for producing diesel from polyolefin degradation according to claim 4, characterized in that The inert atmosphere is an argon atmosphere.
6. The catalyst for producing diesel from degrading polyolefins according to claim 4, characterized in that The heating rate when keeping at a temperature of 750℃-850℃ is 2-5℃ / min.
7. The catalyst for producing diesel from polyolefin degradation according to claim 4, characterized in that The mass ratio of the ammonium molybdate to melamine is 1:1-2.
8. The catalyst for producing diesel from polyolefin degradation according to claim 4, characterized in that The solid acid catalyst is HND-270 solid acid catalyst produced by Jiangyin Nanda Synthetic Chemical Co., Ltd.
9. Use of the catalyst as claimed in claim 1 in the production of diesel by degrading polyolefins.
10. The use according to claim 9, characterized in that The polyolefin is polyethylene.