A method for producing aviation kerosene from waste polyolefin plastics

Abstract

The present application provides a kind of method for producing aviation kerosene from waste polyolefin plastics, comprising the following steps: waste polyolefin cracking-alkylation coupling reaction to generate gasoline, secondary alkylation reaction to extend carbon chain to obtain high-quality aviation kerosene, to obtain aviation kerosene;The method of the present application realizes the transformation of waste polyolefin plastics into aviation kerosene, innovatively uses amide-AlCl3 eutectic solvent as bifunctional catalyst, through cracking-alkylation coupling reaction and secondary alkylation reaction, a variety of waste polyolefin plastics can be converted into aviation kerosene-rich hydrocarbon products (aviation kerosene accounts for more than 65% in hydrocarbon product), not only realizes the high-value utilization of waste polyolefin plastics, solves the pollution problem of waste polyolefin plastics, at the same time provides a new aviation kerosene production mode, and has many advantages such as simple process, economic benefit etc.

Description

Technical Field

[0001] This invention belongs to the field of waste plastic resource utilization technology, specifically relating to a method for producing aviation kerosene from waste polyolefin plastics. Background Technology

[0002] Polyolefin plastics (such as polyethylene PE, polypropylene PP, polystyrene PS, and polyvinyl chloride PVC) are the world's largest-produced and most widely used polymer materials. Their non-degradable nature leads to over 300 million tons of waste plastic entering the environment annually, creating persistent pollution covering soil, water, and oceans. Traditional treatment methods include landfilling, which consumes land resources and disrupts the ecological balance; incineration, which releases toxic substances like dioxins and wastes chemical energy; and mechanical recycling, which struggles to achieve high-value utilization due to plastic degradation. More seriously, polyolefin production is highly dependent on petroleum resources, with 8-10% of the world's crude oil consumed annually in plastic manufacturing. Aviation kerosene, a core energy source for air transport, also relies on petroleum cracking-hydroisomerization technology in its traditional production, facing multiple challenges such as non-renewable raw materials, lengthy processes, and high CO2 emission intensity (up to 85 kgCO2 / GJ). While bio-jet fuel technology offers some alternatives, its limited raw material supply and production costs make it difficult to meet the rapidly growing demand for aviation energy. Therefore, developing a non-petroleum-based, low-cost aviation kerosene production technology using waste polyolefins as raw materials has become a key breakthrough in solving the dual problems of plastic pollution and energy crisis.

[0003] Among existing thermochemical conversion technologies for waste polyolefin plastics, pyrolysis requires high temperatures of 400-600℃, and the products have a wide distribution (C1-C2). 35+ Aviation kerosene range (C7-C) 18 The proportion of chlorine in plastics is less than 40%, and complex fractionation and purification are required. Although catalytic pyrolysis can improve the yield of liquid products, chlorine and sulfur impurities in plastics can easily poison and deactivate traditional catalysts such as zeolites, shortening their lifespan to less than 200 hours and resulting in high operating costs. Hydrocracking technology consumes a large amount of hydrogen (200-300 kg of hydrogen per ton of plastic), and the reaction selectivity is significantly affected by the distribution of acidic sites on the catalyst, making it difficult to accurately control the carbon chain length.

[0004] In recent years, deep eutectic solvents (DES) have emerged as promising candidates in the field of catalysis due to their unique physicochemical properties, such as low volatility, high solubility, designability, and strong hydrogen bonding. DES are formed by non-covalent bonding between hydrogen bond donors (such as carboxylic acids, alcohols, and amides) and hydrogen bond acceptors (such as quaternary ammonium salts, metal salts, and sugars). Their melting points are 50–100 °C lower than those of single components, and their acidity, Lewis acid site density, and polarity can be precisely designed by controlling the proportions and types of components. However, existing DES catalytic systems primarily focus on biomass conversion (such as cellulose hydrolysis and lignin depolymerization) or single pyrolysis reactions. There are no reports of their application in the coupled pyrolysis-alkylation reaction of waste polyolefins for the targeted synthesis of aviation kerosene, indicating that their potential has not yet been fully explored. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention aims to provide a method for producing aviation kerosene from polyolefin plastics.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for producing aviation kerosene from waste polyolefin plastics includes the following steps:

[0008] Step S1. Waste polyolefin plastic particles, C4-C6 alkanes, amide-AlCl3 eutectic solvent, initiator, and polychlorinated methane are placed in a reactor, and a cracking-alkylation coupled reaction is carried out in an anhydrous, closed environment; wherein, the C4-C6 alkanes are added before the waste polyolefin plastic particles and amide-AlCl3 eutectic solvent are coexisted in the reactor; after the reaction is completed, the reactor is cooled to room temperature;

[0009] Step S2. Add C4-C6 olefins to a reactor cooled to room temperature to carry out a secondary alkylation reaction and obtain hydrocarbon products.

[0010] Furthermore, in step S1, the amide-AlCl3 eutectic solvent includes an amide compound and AlCl3, wherein the amide compound is selected from one or more of formamide, acetamide, and N-methylformamide; and the molar ratio of the amide compound to AlCl3 is 1:1.5.

[0011] Further, in step S1, the polychlorinated methane is selected from one or more of dichloromethane, chloroform, and carbon tetrachloride; the volume ratio of amide-AlCl3 eutectic solvent to polychlorinated methane is 1:2 to 1:3; the C4-C6 alkane is selected from one or more of isopentane, n-butane, n-pentane, isohexane, and n-hexane; the initiator is selected from one or more of tert-butyl chloride, tert-butyl bromide, tert-butyl iodine, isobutyl chloride, and isopentane chloride; the mass ratio of C4-C6 alkane, waste polyolefin plastic particles, initiator, and amide-AlCl3 eutectic solvent is C4-C6 alkane: waste polyolefin plastic particles: initiator: amide-AlCl3 eutectic solvent = (20~60): (20~40): (1~20): (20~200).

[0012] Furthermore, the waste polyolefin plastic particles are obtained by pretreatment of waste polyolefin plastics, and their particle size is 40~400 mesh.

[0013] Furthermore, the waste polyolefin plastic is one of low-density polyethylene, high-density polyethylene, polypropylene, and polyvinyl chloride; or it is a mixture of two or more of low-density polyethylene, high-density polyethylene, polypropylene, polyvinyl chloride, and polystyrene, and the polystyrene content in the mixture is 0~25wt%.

[0014] Furthermore, in step S1, the reaction conditions for the cracking-alkylation coupling reaction include: a reaction temperature of 60~100℃, a stirring rate of 250~1000rpm, and a reaction time of 2~3h.

[0015] Furthermore, in step S2, the mass ratio of the C4-C6 olefins added to the reactor to the C4-C6 alkanes and waste polyolefin plastic particles added in step S1 is C4-C6 olefins: C4-C6 alkanes: waste polyolefin plastic particles = (3~6): (1~2): (1~2).

[0016] Furthermore, in step S2, the C4-C6 olefin is selected from one or more of isobutene, 1-pentene, 2-pentene, 2-methyl-1-butene, 3-methyl-1-butene, isoprene, 1-hexene, 2-hexene, 3-hexene, 2-methyl-1-pentene, and 4-methyl-1-pentene.

[0017] Furthermore, in step S2, the reaction conditions for the secondary alkylation reaction include: a reaction temperature of 60~100℃, a stirring rate of 250~1000rpm, and a reaction time of 0.5~2h.

[0018] Furthermore, the method for producing aviation kerosene from polyolefin plastics further includes:

[0019] Step S3. After the secondary alkylation reaction is completed, the reactor is allowed to stand and cool to room temperature to obtain a two-phase system. The upper layer of the two-phase system consists of hydrocarbon products rich in aviation kerosene and unreacted swollen polymers; the lower layer consists of amide-AlCl3 eutectic solvent and polychlorinated methane.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] This invention enables the conversion of polyolefin plastics into aviation kerosene. It innovatively uses amide-AlCl3 eutectic solvent as a bifunctional catalyst. Through cracking-alkylation coupling reaction and secondary alkylation reaction, it can convert various polyolefin plastics into hydrocarbon products rich in aviation kerosene (aviation kerosene accounts for more than 65% of the hydrocarbon products). This not only realizes the high-value utilization of waste polyolefin plastics and solves the pollution problem of waste polyolefin plastics, but also provides a new method for aviation kerosene production, with many advantages such as simple process and high economic benefits. Detailed Implementation

[0022] The present invention will be further described below through specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0023] This invention first provides a method for producing aviation kerosene from waste polyolefin plastics, comprising the following steps:

[0024] Step S1. Waste polyolefin plastic particles, C4-C6 alkanes, amide-AlCl3 eutectic solvent, initiator, and polychlorinated methane are placed in a reactor, and a cracking-alkylation coupled reaction is carried out in an anhydrous, closed environment; wherein, the C4-C6 alkanes are added before the waste polyolefin plastic particles and amide-AlCl3 eutectic solvent are coexisted in the reactor; after the reaction is completed, the reactor is cooled to room temperature;

[0025] Step S2. Add C4-C6 olefins to a reactor cooled to room temperature to carry out a secondary alkylation reaction to obtain hydrocarbon products;

[0026] Step S3. After the secondary alkylation reaction is completed, the reactor is allowed to stand and cool to room temperature to obtain a two-phase system; the upper layer of the two-phase system consists of hydrocarbon products rich in aviation kerosene and unreacted swollen polymer; the lower layer consists of amide-AlCl3 eutectic solvent and polychlorinated methane.

[0027] This invention innovatively employs an amide-AlCl3 eutectic solvent as a bifunctional catalyst to catalyze a first cracking-alkylation coupled reaction of polyolefin plastics. Subsequently, C4-C6 olefins are added to the reaction system for a secondary alkylation reaction. The entire reaction process is energy-efficient and yields high-yield, high-purity aviation kerosene. Simultaneously, it effectively realizes the high-value utilization of waste polyolefin plastic resources, greatly improving the pollution problem of waste polyolefin plastics and contributing to carbon recycling. In step S1, waste polyolefin plastic particles and C4-C6 alkanes are reactants. The amide-AlCl3 eutectic solvent acts as a bifunctional catalyst to couple the cracking and alkylation reactions. The abundant aluminum active species (anionic, cationic, and molecularly active species) in this catalytic system dissociate Lewis acid sites. Under the influence of these Lewis acid sites, the initiator undergoes halide ion extraction to generate initial carbocations, driving the cracking-alkylation of the polyolefin. The process involves two parallel cycles: ① Crack cycle: Long-chain polyolefins undergo isomerization followed by C-C bond cleavage to form chloromethyl carbocations, which participate in the cracking-alkylation cycle of polyolefins. ② Alkylation cycle: The olefin intermediate undergoes alkylation with acceptor alkanes to form high-quality gasoline. Driven by carbocations, these cycles achieve closed-loop amplification and selective control, inhibiting polymerization and coking, and efficiently converting heavy fractions into high-octane components without external hydrogenation. The addition of polychloromethane also reduces system viscosity, increases mass transfer, and improves the stability of the amide-AlCl3 eutectic solvent system. The coexistence of polyolefin plastic particles and the amide-AlCl3 eutectic solvent before the reactor, with C4-C6 alkanes already present in the reactor, ensures simultaneous cracking and alkylation of polyolefins, preventing direct catalytic degradation of polyolefin plastics by the amide-AlCl3 eutectic solvent and the generation of large amounts of low-value-added products (C4-C6 alkanes). 20+ (Heavy oil or heavy wax); Anhydrous and closed environment can avoid catalyst deactivation, produce fewer by-products, and avoid secondary pollution; In step S2, C4-C6 olefins are added to the reactor, and amide-AlCl3 eutectic solvent is used as alkylation catalyst. The carbon chain is extended through secondary alkylation, which significantly improves the quality of the oil. The whole process realizes the conversion of polyolefin plastics into aviation kerosene.

[0028] Specifically, in step S1, the amide-AlCl3 eutectic solvent includes amide compounds and AlCl3, wherein the amide compounds are selected from one or more of formamide, acetamide, and N-methylformamide; and the molar ratio of the amide compounds to AlCl3 is 1:1.5.

[0029] Specifically, in step S1, the polychlorinated methane is selected from one or more of dichloromethane, chloroform, and carbon tetrachloride, and the volume ratio of amide-AlCl3 eutectic solvent to polychlorinated methane is 1:2 to 1:3; the C4-C6 alkane is selected from one or more of isopentane, n-butane, n-pentane, isohexane, and n-hexane; the initiator is selected from one or more of tert-butyl chloride, tert-butyl bromide, tert-butyl iodine, isobutyl chloride, and isopentane chloride; the mass ratio of C4-C6 alkane, waste polyolefin plastic particles, initiator, and amide-AlCl3 eutectic solvent is C4-C6 alkane: waste polyolefin plastic particles: initiator: amide-AlCl3 eutectic solvent = (20~60): (20~40): (1~20): (20~200).

[0030] Specifically, in step S1, the waste polyolefin plastic particles are obtained by pretreatment of waste polyolefin plastics, and their particle size is 40~400 mesh.

[0031] Furthermore, the waste polyolefin plastic is one of low-density polyethylene, high-density polyethylene, polypropylene, and polyvinyl chloride; or a mixture of two or more of low-density polyethylene, high-density polyethylene, polypropylene, polyvinyl chloride, and polystyrene, and the polystyrene content in the mixture is 0~25wt%; when the polystyrene content in the mixture is higher than 25wt%, more benzene compounds will be generated during the reaction, causing the benzene compounds in the product to exceed the upper limit (≤25.0vol%) specified in the aviation kerosene standard (GB 6537—2018 "No. 3 Jet Fuel").

[0032] Furthermore, in step S1, the reaction conditions for the cracking-alkylation coupling reaction include: a reaction temperature of 60~100℃, a stirring rate of 250~1000rpm, and a reaction time of 2~3h.

[0033] Furthermore, in step S2, the mass ratio of the C4-C6 olefins added to the reactor to the C4-C6 alkanes and waste polyolefin plastic particles added in step S1 is C4-C6 olefins: C4-C6 alkanes: waste polyolefin plastic particles = (3~6): (1~2): (1~2).

[0034] Specifically, in step S2, the C4-C6 olefins include, but are not limited to, one or more of isobutene, 1-pentene, 2-pentene, 2-methyl-1-butene, 3-methyl-1-butene, isoprene, 1-hexene, 2-hexene, 3-hexene, 2-methyl-1-pentene, and 4-methyl-1-pentene.

[0035] Furthermore, in step S2, the reaction conditions for the secondary alkylation reaction include: a reaction temperature of 60~100℃, a stirring rate of 250~1000rpm, and a reaction time of 0.5~2h.

[0036] The following examples and comparative examples will be used to illustrate the implementation of this application in more detail.

[0037] The method for determining the polyolefin conversion rate in the following examples is as follows:

[0038] Unreacted polyolefin suspension solids were separated from the upper phase by simple filtration. During the separation process, multiple washes with isopentane were performed to quantitatively determine the conversion rate.

[0039]

[0040] In the following examples, all chemicals were purchased from Tokyo Chemical Industry Co., Ltd.

[0041] The parameter information of the low-density polyethylene used in the following examples is as follows:

[0042] Density: 0.920 g / cm³ 3

[0043] Melt flow index: 40g / 10min

[0044] Molecular weight (MW): 80,000-120,000 g / mol

[0045] Molecular weight distribution (MW / MN): 2.5-3.5

[0046] Branching frequency: 0.5-1 branch / 10,000 carbon atoms.

[0047] Example 1

[0048] The method for producing aviation kerosene from waste polyolefin plastics in this embodiment includes the following steps:

[0049] Place a dry Schlenk flask in a glove box and add acetamide. Under inert gas (N2) protection, slowly add anhydrous aluminum trichloride to the Schlenk flask containing acetamide. The molar ratio of acetamide to anhydrous aluminum trichloride is 1:1.5. After the addition is complete, stir the reaction at room temperature for 80 minutes. After the reaction is complete, the system becomes a homogeneous pale yellow transparent liquid, which is the acetamide-1.5AlCl3 eutectic solvent. Since the reaction is exothermic, the reaction system should be cooled simultaneously and continuously stirred to maintain a low temperature.

[0050] Waste low-density polyethylene (LDPE) plastic is crushed, screened, and dehydrated to obtain low-density polyethylene plastic particles with a particle size of 40-400 mesh.

[0051] 0.20 g of low-density polyethylene plastic granules, 0.20 g of isopentane, and 5 mg of tert-butyl chloride were placed in a 35 ml borosilicate glass tube reactor. Then, 1 g of acetamide-1.5AlCl3 eutectic solvent (approximately 0.6 ml) and 1.2 ml of dichloromethane were added to the borosilicate glass tube reactor (the reactor was equipped with a top-opening screw cap lined with polytetrafluoroethylene (PTFE)). The cracking-alkylation coupling reaction was carried out in an anhydrous, sealed environment: at atmospheric pressure, 70 °C, and 500 rpm for 3 h with stirring. The borosilicate glass tube reactor was cooled to room temperature, and then 0.60 g of isopentene was added to the reactor. A secondary alkylation reaction was carried out in an anhydrous, sealed environment: at atmospheric pressure, 70 °C, and 500 rpm for 1 h with stirring, to obtain a hydrocarbon product.

[0052] The reactor was allowed to stand and cool to room temperature to obtain a two-phase system. The upper layer consisted of hydrocarbon products and unreacted swollen polymer (low-density polyethylene); the lower layer consisted of acetamide-1.5AlCl3 eutectic solvent and dichloromethane.

[0053] The conversion rate of low-density polyethylene was determined to be 99.5%. Gas chromatography analysis was performed on the hydrocarbon products, including aviation kerosene (C7-C). 18 Isoalkanes accounted for approximately 81.0%, with a yield of 80.6%.

[0054] Catalyst recycling experiment: 0.20 g of low-density polyethylene plastic particles, 0.20 g of isopentane, and 5 mg of tert-butyl chloride were placed in a high-pressure reactor. Then, 1 g of acetamide-1.5AlCl3 eutectic solvent (approximately 0.6 ml) and 1.8 ml of dichloromethane were added to the reactor. A cracking-alkylation coupling reaction was carried out in an anhydrous, sealed environment: 70℃ / 2 MPa (N2), stirred at 500 rpm for 3 h. The reactor was then cooled to room temperature, and 0.60 g of isopentene was added. A secondary alkylation reaction was carried out in an anhydrous, sealed environment: 70℃ / 2 MPa (N2), stirred at 500 rpm for 1 h, yielding hydrocarbon products. The reactor was then allowed to stand for cooling. The mixture was cooled to room temperature to obtain a two-phase system. The upper layer of the two-phase system consisted of hydrocarbon products and unreacted swollen polymer (low-density polyethylene); the lower layer consisted of acetamide-1.5AlCl3 eutectic solvent and dichloromethane. The high-pressure reactor was transferred to a glove box, and the upper liquid was collected using a dropper. The product was analyzed, and the conversion rate of low-density polyethylene and the yield of aviation kerosene were determined. The lower liquid (acetamide-1.5AlCl3 eutectic solvent and dichloromethane) was circulated five times. The conversion rate of low-density polyethylene in all five cycles was above 95%, and the yield of aviation kerosene was 80.8%-77.5%-78.7%-79.3%-79.1%, indicating that the amide-AlCl3 eutectic solvent catalyst of the present invention has good stability.

[0055] Example 2

[0056] The method for producing aviation kerosene from waste polyolefin plastics in this embodiment includes the following steps:

[0057] Place a dry Schlenk flask in a glove box and add formamide. Under inert gas (N2) protection, slowly add anhydrous aluminum trichloride to the Schlenk flask containing formamide. The molar ratio of formamide to anhydrous aluminum trichloride is 1:1.5. After the addition is complete, stir the reaction at room temperature for 80 minutes. After the reaction is complete, the system becomes a homogeneous pale yellow transparent liquid, which is the formamide-1.5AlCl3 eutectic solvent. Since the reaction is exothermic, the reaction system should be cooled simultaneously and continuously stirred to maintain a low temperature.

[0058] Waste low-density polyethylene (LDPE) plastic is crushed, screened, and dehydrated to obtain low-density polyethylene plastic particles with a particle size of 40-400 mesh.

[0059] 0.20 g of low-density polyethylene plastic granules, 0.20 g of isopentane, and 5 mg of tert-butyl chloride were placed in a 35 ml borosilicate glass tube reactor. Then, 1 g of formamide-1.5AlCl3 eutectic solvent (approximately 0.6 ml) and 1.2 ml of dichloromethane were added to the borosilicate glass tube reactor (the reactor was equipped with a top-opening screw cap lined with polytetrafluoroethylene (PTFE)). The cracking-alkylation coupling reaction was carried out in an anhydrous, sealed environment: at atmospheric pressure, 70 °C, and 500 rpm for 3 h with stirring. The borosilicate glass tube reactor was cooled to room temperature, and then 0.60 g of isopentene was added to the reactor. A secondary alkylation reaction was carried out in an anhydrous, sealed environment: at atmospheric pressure, 70 °C, and 500 rpm for 1 h with stirring, to obtain a hydrocarbon product.

[0060] The reactor was allowed to stand and cool to room temperature to obtain a two-phase system. The upper layer consisted of hydrocarbon products and unreacted swollen polymer (low-density polyethylene); the lower layer consisted of formamide-1.5AlCl3 eutectic solvent and dichloromethane.

[0061] The conversion rate of low-density polyethylene was determined to be 99.0%. Gas chromatography analysis was performed on the hydrocarbon products, including aviation kerosene (C7-C). 18 Isoalkanes accounted for approximately 80.2%, with a yield of 79.4%.

[0062] Example 3

[0063] The method for producing aviation kerosene from waste polyolefin plastics in this embodiment includes the following steps:

[0064] Place a dry Schlenk flask in a glove box and add N-methylformamide. Under inert gas (N2) protection, slowly add anhydrous aluminum trichloride to the Schlenk flask containing N-methylformamide. The molar ratio of N-methylformamide to anhydrous aluminum trichloride is 1:1.5. After the addition is complete, stir the reaction at room temperature for 60 minutes. After the reaction is complete, the system becomes a homogeneous pale yellow transparent liquid, which is the N-methylformamide-1.5AlCl3 eutectic solvent. Since the reaction is exothermic, the reaction system should be cooled simultaneously and stirred continuously to maintain a low temperature.

[0065] Waste low-density polyethylene (LDPE) plastic is crushed, screened, and dehydrated to obtain low-density polyethylene plastic particles with a particle size of 40-400 mesh.

[0066] 0.20 g of low-density polyethylene plastic granules, 0.20 g of isopentane, and 5 mg of tert-butyl chloride were placed in a 35 ml borosilicate glass tube reactor. Then, 1 g of N-methylformamide-1.5AlCl3 eutectic solvent (approximately 0.6 ml) and 1.2 ml of dichloromethane were added to the borosilicate glass tube reactor (the reactor was equipped with a top-opening screw cap lined with polytetrafluoroethylene (PTFE)). The cracking-alkylation coupled reaction was carried out in an anhydrous, sealed environment: at atmospheric pressure, 70 °C, and 500 rpm for 3 h with stirring. The borosilicate glass tube reactor was cooled to room temperature, and then 0.60 g of isopentene was added to the reactor. A secondary alkylation reaction was carried out in an anhydrous, sealed environment: at atmospheric pressure, 70 °C, and 500 rpm for 1 h with stirring, to obtain a hydrocarbon product.

[0067] The reactor was allowed to stand and cool to room temperature to obtain a two-phase system. The upper layer consisted of hydrocarbon products and unreacted swollen polymer (low-density polyethylene); the lower layer consisted of N-methylformamide-1.5AlCl3 eutectic solvent and dichloromethane.

[0068] The conversion rate of low-density polyethylene was determined to be 99.0%. Gas chromatography analysis was performed on the hydrocarbon products, including aviation kerosene (C7-C). 18 Isoalkanes accounted for approximately 78.5%, with a yield of 77.7%.

[0069] Example 4

[0070] The method for producing aviation kerosene from waste polyolefin plastics in this embodiment includes the following steps:

[0071] Place a dry Schlenk flask in a glove box and add acetamide. Under inert gas (N2) protection, slowly add anhydrous aluminum trichloride to the Schlenk flask containing acetamide. The molar ratio of acetamide to anhydrous aluminum trichloride is 1:1.5. After the addition is complete, stir the reaction at room temperature for 80 minutes. After the reaction is complete, the system becomes a homogeneous pale yellow transparent liquid, which is the acetamide-1.5AlCl3 eutectic solvent. Since the reaction is exothermic, the reaction system should be cooled simultaneously and continuously stirred to maintain a low temperature.

[0072] Waste high-density polyethylene (HDPE) plastic is crushed, screened, and dehydrated to obtain high-density polyethylene plastic granules with a particle size of 40 mesh to 400 mesh.

[0073] 0.20 g of high-density polyethylene plastic granules, 0.20 g of isopentane, and 5 mg of tert-butyl chloride were placed in a 35 ml borosilicate glass tube reactor. Then, 1 g of acetamide-1.5AlCl3 eutectic solvent (approximately 0.6 ml) and 1.2 ml of dichloromethane were added to the borosilicate glass tube reactor (the reactor was equipped with a top-opening screw cap lined with polytetrafluoroethylene (PTFE)). The cracking-alkylation coupled reaction was carried out in an anhydrous, sealed environment: at atmospheric pressure, 70 °C, and 500 rpm for 3 h with stirring. The borosilicate glass tube reactor was cooled to room temperature, and then 0.60 g of isopentene was added to the reactor. A secondary alkylation reaction was carried out in an anhydrous, sealed environment: at atmospheric pressure, 70 °C, and 500 rpm for 1 h with stirring, to obtain a hydrocarbon product.

[0074] The reactor was allowed to stand and cool to room temperature to obtain a two-phase system. The upper layer consisted of hydrocarbon products and unreacted swollen polymer (high-density polyethylene); the lower layer consisted of acetamide-1.5AlCl3 eutectic solvent and dichloromethane.

[0075] The conversion rate of high-density polyethylene was determined to be 96.0%. Gas chromatography analysis of hydrocarbon products was performed, and aviation kerosene (C7-C...) was also analyzed. 18 Isoalkanes accounted for approximately 81.5%, with a yield of 78.2%.

[0076] Example 5

[0077] The method for producing aviation kerosene from waste polyolefin plastics in this embodiment includes the following steps:

[0078] Place a dry Schlenk flask in a glove box and add acetamide. Under inert gas (N2) protection, slowly add anhydrous aluminum trichloride to the Schlenk flask containing acetamide. The molar ratio of acetamide to anhydrous aluminum trichloride is 1:1.5. After the addition is complete, stir the reaction at room temperature for 80 minutes. After the reaction is complete, the system becomes a homogeneous pale yellow transparent liquid, which is the acetamide-1.5AlCl3 eutectic solvent. Since the reaction is exothermic, the reaction system should be cooled simultaneously and continuously stirred to maintain a low temperature.

[0079] Waste polypropylene (PP) plastic is crushed, screened, and dehydrated to obtain polypropylene plastic granules with a particle size of 40-400 mesh.

[0080] 0.20 g of polypropylene plastic granules, 0.20 g of isopentane, and 5 mg of tert-butyl chloride were placed in a 35 ml borosilicate glass tube reactor. Then, 1 g of acetamide-1.5AlCl3 eutectic solvent (approximately 0.6 ml) and 1.2 ml of dichloromethane were added to the borosilicate glass tube reactor (the reactor was equipped with a top-opening screw cap lined with polytetrafluoroethylene (PTFE)). The cracking-alkylation coupled reaction was carried out in an anhydrous, sealed environment: at atmospheric pressure, 70 °C, and 500 rpm for 3 h with stirring. The borosilicate glass tube reactor was cooled to room temperature, and then 0.60 g of isopentene was added to the reactor. A secondary alkylation reaction was carried out in an anhydrous, sealed environment: at atmospheric pressure, 70 °C, and 500 rpm for 1 h with stirring, to obtain a hydrocarbon product.

[0081] The reactor was allowed to stand and cool to room temperature to obtain a two-phase system. The upper layer consisted of hydrocarbon products and unreacted swollen polymer (polypropylene); the lower layer consisted of acetamide-1.5AlCl3 eutectic solvent and dichloromethane.

[0082] The conversion rate of polypropylene was determined to be 99.0%. Gas chromatography analysis was performed on the hydrocarbon products, including aviation kerosene (C7-C). 18 Isoalkanes accounted for approximately 77.5%, with a yield of 76.7%.

[0083] Example 6

[0084] The method for producing aviation kerosene from waste polyolefin plastics in this embodiment includes the following steps:

[0085] Place a dry Schlenk flask in a glove box and add acetamide. Under inert gas (N2) protection, slowly add anhydrous aluminum trichloride to the Schlenk flask containing acetamide. The molar ratio of acetamide to anhydrous aluminum trichloride is 1:1.5. After the addition is complete, stir the reaction at room temperature for 80 minutes. After the reaction is complete, the system becomes a homogeneous pale yellow transparent liquid, which is the acetamide-1.5AlCl3 eutectic solvent. Since the reaction is exothermic, the reaction system should be cooled simultaneously and continuously stirred to maintain a low temperature.

[0086] Waste polyvinyl chloride (PVC) plastic is crushed, screened, and dehydrated to obtain PVC plastic particles with a particle size of 40-400 mesh.

[0087] 0.20 g of polyvinyl chloride (PVC) plastic granules, 0.20 g of isopentane, and 5 mg of tert-butyl chloride were placed in a 35 ml borosilicate glass tube reactor. Then, 1 g of acetamide–1.5AlCl3 eutectic solvent (approximately 0.6 ml) and 1.2 ml of dichloromethane were added to the reactor (the borosilicate glass tube reactor was equipped with a top-opening screw cap lined with polytetrafluoroethylene (PTFE). A cracking-alkylation coupled reaction was carried out in an anhydrous, sealed environment: at atmospheric pressure, 70 °C, and with stirring at 500 rpm for 3 h. The borosilicate glass tube reactor was cooled to room temperature, and then 0.60 g of isopentene was added to the reactor. A secondary alkylation reaction was carried out in an anhydrous, sealed environment: at atmospheric pressure, 70 °C, and with stirring at 500 rpm for 1 h, yielding a hydrocarbon product.

[0088] The reactor was allowed to stand and cool to room temperature to obtain a two-phase system. The upper layer consisted of hydrocarbon products and unreacted swollen polymer (polyvinyl chloride); the lower layer consisted of acetamide-1.5AlCl3 eutectic solvent and dichloromethane.

[0089] The conversion rate of polyvinyl chloride was determined to be 99.0%. Gas chromatography analysis of the hydrocarbon products revealed that aviation kerosene (C7-C50) was present. 18 Isoalkanes accounted for approximately 68.0%, with a yield of 67.3%.

[0090] Example 7

[0091] The method for producing aviation kerosene from waste polyolefin plastics in this embodiment includes the following steps:

[0092] Place a dry Schlenk flask in a glove box and add acetamide. Under inert gas (N2) protection, slowly add anhydrous aluminum trichloride to the Schlenk flask containing acetamide. The molar ratio of acetamide to anhydrous aluminum trichloride is 1:1.5. After the addition is complete, stir the reaction at room temperature for 80 minutes. After the reaction is complete, the system becomes a homogeneous pale yellow transparent liquid, which is the acetamide-1.5AlCl3 eutectic solvent. Since the reaction is exothermic, the reaction system should be cooled simultaneously and continuously stirred to maintain a low temperature.

[0093] Waste polyvinyl chloride (PVC) plastic and polystyrene (PS) plastic are crushed, screened and dehydrated to obtain PVC plastic particles and polystyrene plastic particles with a particle size of 40-400 mesh.

[0094] 0.15 g of polyvinyl chloride (PVC) plastic granules, 0.05 g of polystyrene (PS) plastic granules, 0.20 g of isopentane, and 5 mg of tert-butyl chloride were placed in a 35 ml borosilicate glass tube reactor. Then, 1 g of acetamide–1.5AlCl3 eutectic solvent (approximately 0.6 ml) and 1.2 ml of dichloromethane were added to the reactor (the borosilicate glass tube reactor was equipped with a top-opening screw cap lined with polytetrafluoroethylene (PTFE). A cracking-alkylation coupled reaction was carried out in an anhydrous, sealed environment: at atmospheric pressure, 70 °C, and 500 rpm for 3 h with stirring. The borosilicate glass tube reactor was cooled to room temperature, and then 0.60 g of isopentene was added to the reactor. A secondary alkylation reaction was carried out in an anhydrous, sealed environment: at atmospheric pressure, 70 °C, and 500 rpm for 1 h with stirring, yielding a hydrocarbon product.

[0095] The reactor was allowed to stand and cool to room temperature to obtain a two-phase system. The upper layer consisted of hydrocarbon products and unreacted swollen polymers (polyvinyl chloride and polystyrene); the lower layer consisted of acetamide-1.5AlCl3 eutectic solvent and dichloromethane.

[0096] The conversion rate of polyvinyl chloride was determined to be 99.0%, and the conversion rate of polystyrene was 68.5%. Gas chromatography analysis was performed on the hydrocarbon products, including aviation kerosene (C7-C). 18 Isoalkanes and benzene compounds accounted for approximately 72.5%, with a yield of 55.2%.

[0097] Comparative Example 1

[0098] Preparation of Rh / Nb2O5 catalyst: 2.63 mL of RhCl3·3H2O (3 g / 100 mL) solution was added to a 100 mL round-bottom flask, followed by the addition of 1 g of support (Nb2O5) and 60 mL of deionized water. The mixture was stirred at room temperature for 12 h. After impregnation, the water was removed by rotary evaporation and dried at 80 °C for 12 h to ensure complete removal. Subsequently, the prepared catalyst was calcined at 400 °C for 3 h in a mixed atmosphere of oxygen and argon (1:1). The theoretical metal loading of the obtained catalyst was 3 wt%.

[0099] Waste low-density polyethylene (LDPE) plastic is crushed, screened, and dehydrated to obtain low-density polyethylene plastic particles with a particle size of 40-400 mesh.

[0100] The catalyst was pre-reduced in a tube furnace at 300°C for 2 hours under a hydrogen atmosphere. 0.20 g of Rh / Nb2O5 catalyst and 0.20 g of low-density polyethylene plastic particles were weighed and reacted continuously at 300°C and a hydrogen pressure of 3 MPa for 24 hours. After cooling to room temperature, the product was analyzed.

[0101] The conversion rate of low-density polyethylene was determined to be 99.0%. Gas chromatography analysis was performed on the hydrocarbon products, including aviation kerosene (C7-C). 18 Isoalkanes accounted for approximately 57.0%, with a yield of 56.4%.

[0102] Example 8

[0103] The steps in this embodiment are basically the same as those in Example 1, except that the amount of isopentane added is 0.60g;

[0104] The conversion rate of low-density polyethylene was determined to be 99.5%. Gas chromatography analysis was performed on the hydrocarbon products, including aviation kerosene (C7-C). 18 Isoalkanes accounted for approximately 73.0%, with a yield of 72.6%.

[0105] Example 9

[0106] The steps in this embodiment are basically the same as those in Embodiment 1, except that 0.20g of isopentane is replaced with 0.20g of n-butane;

[0107] The conversion rate of low-density polyethylene was determined to be 99.5%. Gas chromatography analysis was performed on the hydrocarbon products, including aviation kerosene (C7-C). 18 Isoalkanes accounted for approximately 65.0%, with a yield of 64.7%.

[0108] Example 10

[0109] The steps in this embodiment are basically the same as those in Embodiment 1, except that 0.20g of isopentane is replaced with 0.20g of n-pentane;

[0110] The conversion rate of low-density polyethylene was determined to be 97.0%. Gas chromatography analysis of hydrocarbon products was performed, and aviation kerosene (C7-C...) was also analyzed. 18 Isoalkanes accounted for approximately 81.0%, with a yield of 78.6%.

[0111] Example 11

[0112] The steps in this embodiment are basically the same as those in Embodiment 1, except that 0.20g of isopentane is replaced with 0.20g of isohexane;

[0113] The conversion rate of low-density polyethylene was determined to be 96.0%. Gas chromatography analysis of hydrocarbon products was performed, and aviation kerosene (C7-C) was also analyzed. 18 Isoalkanes accounted for approximately 82.3%, with a yield of 79.0%.

[0114] Example 12

[0115] The steps in this embodiment are basically the same as those in Embodiment 1, except that 0.20g of isopentane is replaced with 0.20g of n-hexane;

[0116] The conversion rate of low-density polyethylene was determined to be 92.5%. Gas chromatography analysis was performed on the hydrocarbon products, including aviation kerosene (C7-C). 18 Isoalkanes accounted for approximately 82.5%, with a yield of 76.3%.

[0117] Example 13

[0118] The steps in this embodiment are basically the same as those in Embodiment 1, except that 5 mg of tert-butyl chloride is replaced with 5 mg of isobutyl chloride;

[0119] The conversion rate of low-density polyethylene was determined to be 99.5%. Gas chromatography analysis was performed on the hydrocarbon products, including aviation kerosene (C7-C). 18 Isoalkanes accounted for approximately 81.2%, with a yield of 80.8%.

[0120] Example 14

[0121] The steps in this embodiment are basically the same as those in Embodiment 1, except that 5 mg of tert-butyl chloride is replaced with 5 mg of isopentyl chloride;

[0122] The conversion rate of low-density polyethylene was determined to be 99.5%. Gas chromatography analysis was performed on the hydrocarbon products, including aviation kerosene (C7-C). 18 Isoalkanes accounted for approximately 81.4%, with a yield of 81.0%.

[0123] Example 15

[0124] The steps in this embodiment are basically the same as those in Example 1, except that the amount of isopentene added is 0.30g.

[0125] The conversion rate of low-density polyethylene was determined to be 99.5%. Gas chromatography analysis was performed on the hydrocarbon products, including aviation kerosene (C7-C). 18 Isoalkanes accounted for approximately 70.3%, with a yield of 70.0%.

[0126] Example 16

[0127] The steps in this embodiment are basically the same as those in Example 1, except that the amount of isopentene added is 1.20g;

[0128] The conversion rate of low-density polyethylene was determined to be 99.5%. Gas chromatography analysis was performed on the hydrocarbon products, including aviation kerosene (C7-C). 18 Isoalkanes accounted for approximately 83.5%, with a yield of 83.1%.

[0129] Example 17

[0130] The steps in this embodiment are basically the same as those in Embodiment 1, except that 0.60g of isopentene is replaced with 0.60g of 2-methyl-1-pentene.

[0131] The conversion rate of low-density polyethylene was determined to be 99.5%. Gas chromatography analysis was performed on the hydrocarbon products, including aviation kerosene (C7-C). 18 Isoalkanes accounted for approximately 82.2%, with a yield of 81.8%.

[0132] Example 18

[0133] The steps in this embodiment are basically the same as those in Example 1, except that the reaction temperature of the cracking-alkylation coupling reaction and the reaction temperature of the secondary alkylation reaction are both 60°C.

[0134] The conversion rate of low-density polyethylene was determined to be 92.0%. Gas chromatography analysis of hydrocarbon products was performed, and aviation kerosene (C7-C...) was also analyzed. 18 Isoalkanes accounted for approximately 80.7%, with a yield of 74.2%.

[0135] Example 19

[0136] The steps in this embodiment are basically the same as those in Example 1, except that the reaction temperature of the cracking-alkylation coupling reaction is 100°C and the reaction time is 1 hour, and the reaction temperature of the secondary alkylation reaction is 60°C.

[0137] The conversion rate of low-density polyethylene was determined to be 99.5%. Gas chromatography analysis was performed on the hydrocarbon products, including aviation kerosene (C7-C). 18 Isoalkanes accounted for approximately 80.7%, with a yield of 80.3%.

[0138] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent transformations or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for producing aviation kerosene from waste polyolefin plastics, characterized in that, Includes the following steps: Step S1. Waste polyolefin plastic particles, C4-C6 alkanes, amide-AlCl3 eutectic solvent, initiator, and polychlorinated methane are placed in a reactor, and a cracking-alkylation coupled reaction is carried out in an anhydrous, closed environment; wherein, the C4-C6 alkanes are added before the waste polyolefin plastic particles and amide-AlCl3 eutectic solvent are coexisted in the reactor; after the reaction is completed, the reactor is cooled to room temperature; Step S2. Add C4-C6 olefins to a reactor cooled to room temperature to carry out a secondary alkylation reaction and obtain hydrocarbon products.

2. The method for producing aviation kerosene from waste polyolefin plastics according to claim 1, characterized in that, In step S1, the amide-AlCl3 eutectic solvent includes amide compounds and AlCl3, wherein the amide compounds are selected from one or more of formamide, acetamide, and N-methylformamide; and the molar ratio of the amide compounds to AlCl3 is 1:1.

5.

3. The method for producing aviation kerosene from waste polyolefin plastics according to claim 1, characterized in that, In step S1, the polychlorinated methane is selected from one or more of dichloromethane, chloroform, and carbon tetrachloride, and the volume ratio of amide-AlCl3 eutectic solvent to polychlorinated methane is 1:2 to 1:3; the C4-C6 alkane is selected from one or more of isopentane, n-butane, n-pentane, isohexane, and n-hexane; the initiator is selected from one or more of tert-butyl chloride, tert-butyl bromide, tert-butyl iodine, isobutyl chloride, and isopentane chloride; the mass ratio of C4-C6 alkane, waste polyolefin plastic particles, initiator, and amide-AlCl3 eutectic solvent is C4-C6 alkane: waste polyolefin plastic particles: initiator: amide-AlCl3 eutectic solvent = (20~60): (20~40): (1~20): (20~200).

4. The method for producing aviation kerosene from waste polyolefin plastics according to claim 1, characterized in that, The waste polyolefin plastic particles are obtained by pretreatment of waste polyolefin plastics, and their particle size is 40~400 mesh.

5. The method for producing aviation kerosene from waste polyolefin plastics according to claim 4, characterized in that, The waste polyolefin plastic is one of low-density polyethylene, high-density polyethylene, polypropylene, and polyvinyl chloride; or it is a mixture of two or more of low-density polyethylene, high-density polyethylene, polypropylene, polyvinyl chloride, and polystyrene, and the polystyrene content in the mixture is 0~25wt%.

6. The method for producing aviation kerosene from waste polyolefin plastics according to claim 1, characterized in that, In step S1, the reaction conditions for the cracking-alkylation coupling reaction include: a reaction temperature of 60~100℃, a stirring rate of 250~1000rpm, and a reaction time of 2~3h.

7. The method for producing aviation kerosene from waste polyolefin plastics according to claim 1, characterized in that, In step S2, the mass ratio of the C4-C6 olefins added to the reactor to the C4-C6 alkanes and waste polyolefin plastic particles added in step S1 is C4-C6 olefins: C4-C6 alkanes: waste polyolefin plastic particles = (3~6): (1~2): (1~2).

8. The method for producing aviation kerosene from waste polyolefin plastics according to claim 1, characterized in that, In step S2, the C4-C6 olefin is selected from one or more of isobutene, 1-pentene, 2-pentene, 2-methyl-1-butene, 3-methyl-1-butene, isoprene, 1-hexene, 2-hexene, 3-hexene, 2-methyl-1-pentene, and 4-methyl-1-pentene.

9. The method for producing aviation kerosene from waste polyolefin plastics according to claim 1, characterized in that, In step S2, the reaction conditions for the secondary alkylation reaction include: a reaction temperature of 60~100℃, a stirring rate of 250~1000rpm, and a reaction time of 0.5~2h.

10. The method for producing aviation kerosene from waste polyolefin plastics according to claim 1, characterized in that, The method for producing aviation kerosene from waste polyolefin plastics further includes: Step S3. After the secondary alkylation reaction is completed, the reactor is allowed to stand and cool to room temperature to obtain a two-phase system. The upper layer of the two-phase system consists of hydrocarbon products rich in aviation kerosene and unreacted swollen polymers; the lower layer consists of amide-AlCl3 eutectic solvent and polychlorinated methane.

Images