Preparation method and application of multi-component molten salt catalyst for polyolefin pyrolysis recovery
By preparing a multi-component molten salt catalyst, the problems of poor heat transfer characteristics and high energy consumption in the pyrolysis of polyolefins were solved, achieving efficient conversion and high selectivity of high-value chemicals at low temperatures, and reducing overall costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-24
- Publication Date
- 2026-04-03
AI Technical Summary
In existing technologies, the pyrolysis process of polyolefin plastics suffers from poor heat transfer characteristics, high energy consumption, complex product composition, and poor economic efficiency. In particular, traditional catalysts are prone to coking and deactivation, resulting in low reaction efficiency.
A multi-component molten salt catalyst, including AlCl3 and NaCl, as well as other metal chlorides such as NiCl2, TiCl4, and FeCl3, was prepared without an external hydrogen source or additional additives to achieve efficient conversion of polyolefins under oxygen-free and high-temperature conditions.
It achieves low-temperature, high-efficiency, and selective conversion of polyolefins to generate high-value chemicals, reduces energy consumption and overall costs, inhibits the formation of waxy byproducts, and improves reaction efficiency and product selectivity.
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Figure CN121775877A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of catalytic polyolefin pyrolysis recovery technology, specifically a method for preparing a multi-component molten salt catalyst for polyolefin pyrolysis recovery and its application. Background Technology
[0002] Polyolefin plastics, mainly including polyethylene (PE), polypropylene (PP), and polystyrene (PS), are the world's most important thermoplastics. They are lightweight, durable, strong, and inexpensive, and possess high electrical insulation and corrosion resistance, making them widely used in food packaging, daily containers, pipes, and building materials. However, with the continuous increase in plastic production and consumption, the disposal of waste plastics has become a very difficult problem. Global plastic production exceeded 400 million tons in 2023 and is projected to exceed 1.1 billion tons by 2050, with polypropylene and polyethylene accounting for the vast majority. Currently, nearly 60% of global plastic products are landfilled or discarded into the environment without treatment, causing a serious "white pollution" problem.
[0003] Polyolefins are saturated hydrocarbons lacking reactive functional groups. Their stable C-C and CH bonds make them difficult to degrade under natural conditions, leading to their accumulation and posing a long-term threat to the ecological environment. Traditional mechanical recycling is inefficient for low-value, mixed, or polluting plastics, while pyrolysis technology can convert plastics into small-molecule hydrocarbon fuels or chemicals under high-temperature, anaerobic conditions, enabling the resource utilization of waste plastics. In recent years, pyrolysis-based resource recycling has become the mainstream disposal method for polyolefin plastics. Traditional pyrolysis processes are typically carried out at temperatures above 500°C, achieving random chain breakage through free radical reactions to produce a mixture of gaseous, liquid, and solid hydrocarbons. However, traditional pyrolysis technology has several significant drawbacks: the poor heat transfer characteristics of plastics lead to uneven temperature distribution in the reaction system and unstable product quality; the high reaction energy barrier requires a large energy input; the complex product composition, with a high proportion of waxy byproducts, reduces the overall economic efficiency of the process; although catalytic cracking can improve this, solid catalysts are prone to coking and deactivation, and the limited diffusion of polymer melts shortens their lifespan. To address these issues, multi-component molten salt catalysts have emerged, breaking through traditional limitations through liquid reaction media and becoming a research hotspot in recent years.
[0004] The core advantage of multi-component molten salt catalysts lies in their unique catalytic mechanism. The highly active components in the molten salt system interact with polyolefin molecules through electrophilic interactions, forming carbocation intermediates, which then lead to the controlled breaking of the carbon chain through a series of reactions such as hydrogen transfer, isomerization, and cyclization. Studies have shown that AlCl3-NaCl molten salt catalysts can significantly reduce the cracking temperature and related energy consumption of polyolefins. In terms of product regulation, multi-component molten salt catalysts exhibit superior performance. Unlike the complex product distribution produced by traditional pyrolysis, molten salt catalysis can directionally guide the reaction pathway, generating high-value-added chemicals, thus providing a possibility for the treatment of mixed plastic waste. Summary of the Invention
[0005] The technical problem to be solved by this invention is how to prepare a multi-component molten salt catalyst that can successfully achieve the efficient conversion of various polyolefin polymers into liquid alkanes under the conditions of no external hydrogen source, no additional additives and no precious metal catalyst.
[0006] The objective of this invention can be achieved through the following technical solutions: A method for preparing a multi-component molten salt catalyst includes the following steps: Weigh AlCl3 and NaCl in a glove box, and then grind them thoroughly in a mortar with 10-12% by mass of NiCl2, TiCl4, FeCl3, PdCl2, RuCl3, ZnCl2, SnCl2, LiCl, PtCl2, GaCl3 and CrCl3 to make them uniformly mixed. Add the ground molten salt to a Schlenk flask and stir to ensure that the molten salt is mixed evenly, thus obtaining a multi-component molten salt catalyst.
[0007] Furthermore, the molar ratio of AlCl3 to NaCl is 2:1.
[0008] Furthermore, NiCl2, TiCl4, FeCl3, PdCl2, RuCl3, ZnCl2, SnCl2, LiCl, PtCl2, GaCl3, and CrCl3... Furthermore, the mass fractions of the metal inorganic salts AlCl3, NiCl2, TiCl4, FeCl3, PdCl2, RuCl3, ZnCl2, SnCl2, LiCl, PtCl2, GaCl3, and CrCl3 are all 10-12%.
[0009] Furthermore, the stirring conditions are anhydrous, oxygen-free, and at 150-160°C.
[0010] Furthermore, the stirring time is 1-2 hours.
[0011] The present invention also proposes the application of a multi-component molten salt catalyst prepared by the above method in the upgrading and recycling of polyolefins.
[0012] The beneficial effects of this invention are: 1. Improve reaction efficiency: Molten salt medium can provide uniform and efficient heating, reduce the activation energy of the reaction, and make it easier for polyolefin macromolecules to break down into the target product.
[0013] 2. Optimize product distribution: Suppress side reactions of excessive cracking to generate gas and coke, improve the yield of high-quality liquid oil, and promote the formation of high-value chemicals such as α-olefins and styrene.
[0014] 3. Economic efficiency and sustainability: Some molten salts are inexpensive and readily available, and some components can be recycled, reducing the overall process cost.
[0015] 4. Synergistic effect mechanism: Multi-component molten salt catalysts are not simply a superposition of single functions. The alkali metal salt matrix is responsible for efficient heat transfer and lowering the reaction energy barrier, while the introduced active metal components or acidic sites precisely catalyze the breaking and recombination of C-C bonds. This synergy of physical and chemical effects is the key to achieving low-temperature, high-efficiency, and highly selective conversion.
[0016] 5. Comparison with single catalysts: Compared with traditional precious metal catalysts, multi-component molten salt catalysts, especially non-toxic and inexpensive systems represented by table salt, have a huge cost advantage, avoiding high catalyst investment. At the same time, their catalytic environment can often effectively inhibit the formation of waxy byproducts, which is a common and thorny problem in traditional pyrolysis processes.
[0017] 6. The multi-component molten salt catalyst prepared by this invention can provide a large number of strong Lewis acid aluminum active sites, providing sufficient catalytic centers for C-C bond breaking and chain reconstruction. On the other hand, the high polarity environment of the molten salt can stabilize the carbocation intermediate in the high-charge reaction system, effectively suppressing side reactions such as coking and excessive cracking, and significantly improving the selectivity and yield of the target product. Attached Figure Description
[0018] Figure 1 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of POE dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1).
[0019] Figure 2 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of POE dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% FeCl3).
[0020] Figure 3 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of POE dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% TiCl3).
[0021] Figure 4 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of POE dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10%RuCl3).
[0022] Figure 5 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of POE dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% PdCl3).
[0023] Figure 6 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of POE dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% NiCl3).
[0024] Figure 7 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of POE dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% ZnCl3).
[0025] Figure 8 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of POE dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% SnCl3).
[0026] Figure 9 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of POE dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% LiCl3).
[0027] Figure 10 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of POE dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% PtCl3).
[0028] Figure 11 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of POE dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% GaCl3).
[0029] Figure 12 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of POE dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10%CrCl3).
[0030] Figure 13 Analysis of the unsaturation ratio of hydrocarbon products in the PBE catalytic upgrading and conversion process dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1).
[0031] Figure 14 Analysis of the unsaturation ratio of hydrocarbon products in PBE catalytic upgrading and conversion in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% FeCl3).
[0032] Figure 15 Analysis of the unsaturation ratio of hydrocarbon products in PBE catalytic upgrading and conversion in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% TiCl3).
[0033] Figure 16 Analysis of the unsaturation ratio of hydrocarbon products in PBE catalytic upgrading and conversion in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% RuCl3).
[0034] Figure 17 Analysis of the unsaturation ratio of hydrocarbon products in PBE catalytic upgrading and conversion in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% PdCl3).
[0035] Figure 18 Analysis of the unsaturation ratio of hydrocarbon products in PBE catalytic upgrading and conversion in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% NiCl3).
[0036] Figure 19 Analysis of the unsaturation ratio of hydrocarbon products in PBE catalytic upgrading and conversion in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% ZnCl3).
[0037] Figure 20 Analysis of the unsaturation ratio of hydrocarbon products in PBE catalytic upgrading and conversion in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% SnCl3).
[0038] Figure 21 Analysis of the unsaturation ratio of hydrocarbon products in PBE catalytic upgrading and conversion in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% LiCl3).
[0039] Figure 22 Analysis of the unsaturation ratio of hydrocarbon products in PBE catalytic upgrading and conversion in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% PtCl3).
[0040] Figure 23 Analysis of the unsaturation ratio of hydrocarbon products in PBE catalytic upgrading and conversion in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% GaCl3).
[0041] Figure 24 Analysis of the unsaturation ratio of hydrocarbon products in PBE catalytic upgrading and conversion in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10%CrCl3).
[0042] Figure 25 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of PP dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1).
[0043] Figure 26 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of PP dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% FeCl3).
[0044] Figure 27 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of PP dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% TiCl3).
[0045] Figure 28 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of PP dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10%RuCl3).
[0046] Figure 29 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of PP dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% PdCl3).
[0047] Figure 30 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of PP dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% NiCl3).
[0048] Figure 31 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of PP dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% ZnCl3).
[0049] Figure 32 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of PP dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% SnCl3).
[0050] Figure 33 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of PP dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% LiCl3).
[0051] Figure 34 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of PP dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% PtCl3).
[0052] Figure 35 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of PP dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10% GaCl3).
[0053] Figure 36 Analysis of the unsaturation ratio of hydrocarbon products in the catalytic upgrading and conversion of PP dissolved in liquid paraffin oil (AlCl3 / NaCl molar ratio 2:1 and 10%CrCl3). Detailed Implementation
[0054] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0055] Example 1: Weigh AlCl3 and NaCl in a 2:1 molar ratio in a glove box and grind them thoroughly in a mortar until they are uniformly mixed. Add the ground molten salt to a Schlenk flask and stir for 1 hour under anhydrous and oxygen-free conditions at 150°C to ensure the molten salt is uniformly mixed. After cooling to room temperature, remove it from the glove box for later use.
[0056] Example 2: Weigh out AlCl3 and NaCl (molar ratio 2:1) and 10% NiCl2 (mass fraction) in a mortar and grind them thoroughly until homogeneous. Add the ground molten salt to a Schlenk flask and stir for 1 hour under anhydrous and oxygen-free conditions at 130°C to ensure uniform mixing. After cooling to room temperature, remove from the glove box for later use.
[0057] Example 3: Weigh out AlCl3 and NaCl (molar ratio 2:1) and 10% TiCl4 (mass fraction) in a mortar and grind them thoroughly until homogeneous. Add the ground molten salt to a Schlenk flask and stir for 1 hour under anhydrous and oxygen-free conditions at 130°C to ensure uniform mixing. After cooling to room temperature, remove from the glove box for later use.
[0058] Example 4: Weigh out AlCl3 and NaCl (molar ratio 2:1) and 10% FeCl3 (mass fraction) in a mortar and grind them thoroughly until homogeneous. Add the ground molten salt to a Schlenk flask and stir for 1 hour under anhydrous and oxygen-free conditions at 130°C to ensure uniform mixing. After cooling to room temperature, remove from the glove box for later use.
[0059] Example 5: Weigh AlCl3 and NaCl (molar ratio 2:1) and 10% PdCl2 (mass fraction) in a mortar and grind them thoroughly until homogeneous. Add the ground molten salt to a Schlenk flask and stir for 1 hour under anhydrous and oxygen-free conditions at 130°C to ensure uniform mixing. After cooling to room temperature, remove from the glove box for later use.
[0060] Example 6: Weigh AlCl3 and NaCl (molar ratio 2:1) and 10% RuCl3 (mass fraction) in a mortar and grind them thoroughly until homogeneous. Add the ground molten salt to a Schlenk flask and stir for 1 hour under anhydrous and oxygen-free conditions at 130°C to ensure uniform mixing. After cooling to room temperature, remove from the glove box for later use.
[0061] Example 7: Weigh out AlCl3 and NaCl (molar ratio 2:1) and 10% ZnCl2 (mass fraction) in a mortar and grind them thoroughly until homogeneous. Add the ground molten salt to a Schlenk flask and stir for 1 hour under anhydrous and oxygen-free conditions at 130°C to ensure uniform mixing. After cooling to room temperature, remove from the glove box for later use.
[0062] Example 8: Weigh out AlCl3 and NaCl (molar ratio 2:1) and SnCl2 (mass fraction 10%) in a mortar and grind them thoroughly until homogeneous. Add the ground molten salt to a Schlenk flask and stir for 1 hour under anhydrous and oxygen-free conditions at 130°C to ensure uniform mixing. After cooling to room temperature, remove from the glove box for later use.
[0063] Example 9: Weigh AlCl3 and NaCl (molar ratio 2:1) and 10% LiCl (mass fraction) in a mortar and grind them thoroughly until homogeneous. Add the ground molten salt to a Schlenk flask and stir for 1 hour under anhydrous and oxygen-free conditions at 130°C to ensure uniform mixing. After cooling to room temperature, remove from the glove box for later use.
[0064] Example 10: Weigh AlCl3 and NaCl (molar ratio 2:1) and 10% PtCl2 (mass fraction) in a mortar and grind them thoroughly until homogeneous. Add the ground molten salt to a Schlenk flask and stir for 1 hour under anhydrous and oxygen-free conditions at 130°C to ensure uniform mixing. After cooling to room temperature, remove from the glove box for later use.
[0065] Example 11: Weigh AlCl3 and NaCl (molar ratio 2:1) and 10% GaCl3 (mass fraction) in a mortar and grind them thoroughly until homogeneous. Add the ground molten salt to a Schlenk flask and stir for 1 hour under anhydrous and oxygen-free conditions at 130°C to ensure uniform mixing. After cooling to room temperature, remove from the glove box for later use.
[0066] Example 12: Weigh out AlCl3 and NaCl (molar ratio 2:1) and 10% CrCl3 (mass fraction) in a mortar and grind them thoroughly until homogeneous. Add the ground molten salt to a Schlenk flask and stir for 1 hour under anhydrous and oxygen-free conditions at 130°C to ensure uniform mixing. After cooling to room temperature, remove from the glove box for later use.
[0067] Example 13: Polyolefin elastomer (POE) and liquid paraffin oil were weighed into a 20ml glass bottle at a mass ratio of 1:4 and stirred at 130℃ for 1 hour to ensure that the polymer was fully dissolved in the liquid paraffin oil.
[0068] Example 14: Propylene-based elastomer (PBE) and liquid paraffin oil were weighed into a 20ml glass bottle at a mass ratio of 1:4 and stirred at 130℃ for 1 hour to ensure that the polymer was fully dissolved in the liquid paraffin oil.
[0069] Example 15: Polypropylene (PP) and liquid paraffin oil were weighed into a 20ml glass bottle at a mass ratio of 1:4 and stirred at 130℃ for 1 hour to ensure that the polymer was fully dissolved in the liquid paraffin oil.
[0070] Application Example 1: Pyrolysis of polyolefin elastomers using a multi-component molten salt catalyst: Under a nitrogen atmosphere, a homogeneously mixed polyolefin elastomer and liquid paraffin oil (mass ratio 1:4), along with the molten salt prepared in Example 1 (molar ratio 2:1), were added to a high-pressure reactor. The reactor was heated to 170°C with mechanical stirring and the reaction was continued for 5 hours, with pressure changes recorded every half hour. After the reaction, the reactor was allowed to cool to room temperature, forming a two-phase system: the upper layer consisted of hydrocarbon products and swollen polymer, while the lower layer was an inorganic salt ionic liquid. The upper hydrocarbon product was extracted and collected using dichloromethane.
[0071] Application Example 2-12: Pyrolysis of Polyolefin Elastomers (POE) using a Multicomponent Molten Salt Catalyst: The difference between Application Example 2-12 and Application Example 1 is that the "multi-component molten salt catalyst prepared in Example 2-12" is used instead of the "multi-component molten salt catalyst prepared in Example 1", while the other steps are the same as in Application Example 1.
[0072] Application Example 13: Pyrolysis of Propylene-Based Elastomers (PBE) using a multi-component molten salt catalyst: Under a nitrogen atmosphere, a homogeneously mixed propylene-based elastomer (PBE) and liquid paraffin oil (mass ratio 1:4), along with the molten salt prepared in Example 1 (molar ratio 2:1), were added to a high-pressure reactor. The reactor was heated to 170°C with mechanical stirring and reacted for 5 hours, with pressure changes recorded every half hour. After the reaction, the reactor was allowed to cool to room temperature, forming a two-phase system: the upper layer consisted of hydrocarbon products and swollen polymers, while the lower layer was an inorganic salt ionic liquid. The upper hydrocarbon product was collected using dichloromethane extraction.
[0073] Application Examples 14-24: Pyrolysis of Propylene-Based Elastomers (PBE) using Multicomponent Molten Salt Catalysts: The difference between Application Examples 14-24 and Application Example 13 is that the "multi-component molten salt catalyst prepared in Example 2-12" is used instead of the "multi-component molten salt catalyst prepared in Example 1", while the other steps are the same as in Application Example 13.
[0074] Application Example 25: Pyrolysis of Polypropylene (PP) using a multi-component molten salt catalyst: Under a nitrogen atmosphere, a homogeneously mixed mixture of polypropylene (PP) and liquid paraffin oil (mass ratio 1:4), along with the molten salt prepared in Example 1 (molar ratio 2:1), was added to a high-pressure reactor. The reactor was heated to 170°C with mechanical stirring and reacted for 5 hours, with pressure changes recorded every half hour. After the reaction, the reactor was allowed to cool to room temperature, forming a two-phase system: an upper layer of hydrocarbon products and swollen polymer, and a lower layer of inorganic salt ionic liquid. The upper hydrocarbon product was collected using dichloromethane extraction.
[0075] Application Examples 26-36: Pyrolysis of Polypropylene (PP) using a multi-component molten salt catalyst: The difference between Application Examples 26-36 and Application Example 25 is that the "multi-component molten salt catalyst prepared in Example 1" is replaced with the "multi-component molten salt catalyst prepared in Example 2-12" respectively, while the other steps are the same as in Application Example 25.
[0076] Figure 1 This is a graph showing the unsaturation percentage of hydrocarbon products in polymer upgrading and conversion in Application Example 1 of the present invention. Figure 2-12 Analysis of the unsaturation percentage of hydrocarbon products in polymer upgrading and conversion in Application Examples 2-12 of this invention; Figure 13 This is a graph showing the unsaturation percentage of hydrocarbon products in polymer upgrading and conversion in Application Example 13 of the present invention. Figure 14-24 Analysis of the unsaturation percentage of hydrocarbon products in polymer upgrading and conversion in Examples 14-24 of this invention; Figure 25 This is a graph showing the unsaturation percentage of hydrocarbon products in polymer upgrading and conversion in Application Example 25 of the present invention. Figure 26-36 Analysis of the unsaturation percentage of hydrocarbon products in polymer upgrading and conversion in Examples 26-36 of this invention.
[0077] from Figure 2-12 As can be seen from 14-24 and 26-36, compared with the metal molten salt prepared in Example 1 for polymer upgrading and recycling, the product has a higher unsaturation ratio, indicating that the metal catalyst is more inclined to promote the dehydrogenation reaction in the polymer degradation process or inhibit the hydrogenation / saturation reaction, and the catalytic cleavage mode is more likely to form unsaturated bonds (such as olefins and aromatics).
[0078] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention.
Claims
1. A method for preparing a multi-component molten salt catalyst, characterized in that, Includes the following steps: Weigh AlCl3 and NaCl in a glove box, and then grind them thoroughly in a mortar with NiCl2, TiCl4, FeCl3, PdCl2, RuCl3, ZnCl2, SnCl2, LiCl, PtCl2, GaCl3 and CrCl3 to make them uniformly mixed. Add the ground molten salt to a Schlenk flask and stir to ensure that the molten salt is mixed evenly, thus obtaining a multi-component molten salt catalyst.
2. The method for preparing a multi-component molten salt catalyst according to claim 1, characterized in that, The molar ratio of AlCl3 to NaCl is 2:
1.
3. The method for preparing a multi-component molten salt catalyst according to claim 1, characterized in that, The mass fractions of NiCl2, TiCl4, FeCl3, PdCl2, RuCl3, ZnCl2, SnCl2, LiCl, PtCl2, GaCl3, and CrCl3 are all 10-12%.
4. The method for preparing a multi-component molten salt catalyst according to claim 1, characterized in that, The inorganic metal salts are all AlCl3, NiCl2, TiCl4, FeCl3, PdCl2, RuCl3, ZnCl2, SnCl2, LiCl, PtCl2, GaCl3, and CrCl3.
5. The method for preparing a multi-component molten salt catalyst according to claim 1, characterized in that, The stirring conditions are anhydrous, oxygen-free, and at 150-160°C.
6. The method for preparing a multi-component molten salt catalyst according to claim 1, characterized in that, The stirring time is 1-2 hours.
7. A multi-component molten salt catalyst, characterized in that, It is prepared by the preparation method described in any one of claims 1-6.
8. The present invention also provides an application of a multi-component molten salt catalyst in the upgrading and recycling of polyolefins.