A mixed plastic recycling apparatus

Abstract

The application relates to the technical field of plastic recycling devices, in particular to a mixed plastic recycling device which comprises a barrel body, a feeding area, a reaction area and a separation area are sequentially arranged in the barrel body from top to bottom and are sequentially communicated, the feeding area is used for inputting plastics and chloroaluminate ionic liquid, the reaction area is used for reacting the plastics and the chloroaluminate ionic liquid, a conveying pump is arranged between the reaction area and the separation area, the conveying pump is used for conveying the solution in the separation area into the reaction area, when the device is used, the processing process condition is mild, the recycling treatment of polyvinyl chloride and polyolefin can be completed at normal temperature and normal pressure, high-purity organic raw materials can be obtained, solid-liquid-gas multiphase complete separation is realized, the repeated utilization of a catalyst and the recycling of products can be automatically completed, the waste and old plastics can be continuously treated, the operation is simple, the treatment is complete, and the device is greatly different from traditional methods which need to be dechlorinated first and then cracked and other multi-step separation operations, so that the technological process is greatly simplified, the recycling efficiency is improved, and the energy consumption is low.

Description

Technical Field

[0001] This invention relates to the field of plastic recycling equipment technology, and in particular to a mixed plastic recycling equipment. Background Technology

[0002] Plastic products are widely used in packaging, building materials, electronics, cables, and daily necessities due to their light weight, low cost, and good processing performance. However, the large-scale use of plastics has also brought about waste disposal and environmental pollution problems. Currently, common methods for waste plastic disposal include landfill, incineration, and mechanical recycling. Landfill occupies land resources and may cause secondary pollution; incineration can reduce volume, but it produces acidic gases and toxic byproducts when processing chlorinated plastics; mechanical recycling is limited by the complexity of plastic types, performance degradation, and limited reuse value.

[0003] Among various plastics, polyvinyl chloride (PVC) is particularly difficult to recycle. PVC decomposes easily when heated, releasing hydrogen chloride gas and organic chlorides, which not only harm the environment but also corrode equipment. Furthermore, PVC products typically contain a variety of additives such as plasticizers, stabilizers, and fillers, resulting in a complex composition that is difficult to separate effectively during recycling. When PVC is mixed with other thermoplastics, it significantly affects the mechanical and processing properties of the recycled materials, further limiting their recycling. Therefore, developing efficient, safe, and resource-efficient recycling devices for difficult-to-recycle plastics like PVC has become a pressing technical challenge in this field.

[0004] Other commonly used plastics, such as polyethylene, also face numerous challenges in recycling. Waste polyethylene originates widely and is diverse, often mixed with other plastics or impurities such as polypropylene (PP), polyvinyl chloride (PVC), and polyester (PET), leading to difficulties in sorting and high recycling costs. Regarding common recycling methods, in physical recycling, polyethylene molecular chains are prone to thermal oxidative degradation during repeated hot-melt extrusion processes, resulting in a decrease in molecular weight and weakened mechanical properties. This makes the quality of recycled materials significantly lower than that of virgin materials, making it difficult to meet the requirements of high-end applications. In chemical recycling, due to the stable chemical structure of polyethylene, chain breaking and pyrolysis usually require high temperatures or strong catalytic conditions, resulting in high energy consumption, limited conversion efficiency, and the easy generation of complex byproducts. Therefore, the economic efficiency and environmental friendliness of the process remain insufficient.

[0005] In summary, the recycling of common plastics such as polyvinyl chloride (PVC) and polyethylene not only involves pre-treatment challenges such as sorting and washing, but also faces technical bottlenecks such as the degradation of recycled material performance and the complexity of chemical recycling processes. Therefore, there is an urgent need to develop new recycling methods or devices to improve the efficiency and quality of common plastic recycling and promote resource recycling and green sustainable development. Summary of the Invention

[0006] The technical problem this invention aims to solve is as follows: In terms of physical recycling of polyethylene and other commonly used plastics, the polyethylene molecular chain is prone to thermal oxidative degradation during multiple hot-melt extrusion processes, resulting in a decrease in molecular weight and weakened mechanical properties. This makes the quality of recycled materials significantly lower than that of virgin materials, making it difficult to meet the requirements of high-end applications. In terms of chemical recycling, due to the stable chemical structure of polyethylene, chain breaking and pyrolysis usually require high temperature or strong catalytic conditions, resulting in high energy consumption, limited conversion efficiency, and easy generation of complex by-products. The economic efficiency and environmental friendliness of the process are still insufficient. Therefore, a mixed plastic recycling device is provided.

[0007] The technical solution adopted by the present invention to solve its technical problem is: a mixed plastic recycling device, including a barrel, wherein a feeding zone, a reaction zone and a separation zone are arranged sequentially from top to bottom in the barrel, the feeding zone is used to input plastic and chloroaluminate ionic liquid, the reaction zone is used to react plastic and chloroaluminate ionic liquid, a transfer pump is arranged between the separation zone and the reaction zone, the transfer pump is used to transport the solution in the separation zone to the reaction zone, and an exhaust pipe connected to the reaction zone is arranged on the barrel; The separation zone includes an alkane recovery zone, an overflow zone, and a liquid collection zone, arranged sequentially from top to bottom and interconnected. The alkane recovery zone is used to collect alkanes after the reaction. A diversion cone is installed in the overflow zone to divert liquid flowing down from the reaction zone into the overflow zone. The input end of the delivery pump is connected to the liquid collection zone. A recovery pipe is installed on the tank body and is connected to the separation zone. Compared with existing technologies, this solution offers milder processing conditions, completing the recovery of polyvinyl chloride and polyolefins at room temperature and pressure. It can obtain high-purity organic raw materials, achieve complete separation of solid, liquid, and gas phases, automatically complete the reuse of catalysts and the recovery of products, and can continuously process waste plastics. The operation is simple and the treatment is thorough.

[0008] In order to realize the alkane recovery zone, in some preferred embodiments, an inner shell is provided on the inner peripheral wall of the barrel at the separation zone, and an alkane recovery zone is formed between the inner shell and the inner peripheral wall of the barrel. An overflow pipe is provided in the inner shell, and one end of the overflow pipe is connected to the overflow zone.

[0009] To achieve automatic recovery, in some preferred embodiments, a valve is provided on the recovery pipe, and a float is provided inside the inner shell. The float is connected to the valve signal and is used to open the valve when the float rises to a set liquid level.

[0010] To achieve the overflow zone and liquid collection zone, in some preferred embodiments, a partition plate is provided within the separation zone. The partition plate is located below the inner shell, dividing the cavity and forming an upper overflow zone and a lower liquid collection zone. The partition plate is provided with a concave overflow trough and a recovery trough, which are arranged side by side. A through hole is provided in the recovery trough, connecting the recovery trough and the liquid collection zone. A diverting cone is located above the overflow trough and is used to guide impurities in the downstream material into the overflow trough, while the liquid overflows into the recovery trough.

[0011] In some preferred embodiments, the inner shell is annular, and a channel is formed in the middle of the inner shell, the channel connecting the overflow area and the reaction area, and the diversion cone is located directly below the channel.

[0012] In some preferred embodiments, the end of the inner shell near the reaction zone is a first flared opening facing upwards from the reaction zone toward the overflow zone, and one end of the channel is connected to the small end of the first flared opening.

[0013] In some preferred embodiments, the end of the inner shell near the overflow area is a second flared opening facing downwards from the reaction area toward the overflow area, the other end of the channel is connected to the small end of the second flared opening, and one end of the overflow pipe is disposed at the second flared opening.

[0014] In some preferred embodiments, a pushing mechanism is provided between the reaction zone and the alkane recovery zone. The pushing mechanism is used to continuously push the falling plastic into the reaction zone, allowing the reacted liquid to pass through the pushing mechanism.

[0015] In some preferred embodiments, the pushing mechanism is a screw conveyor.

[0016] In some preferred embodiments, the feeding zone includes a feed inlet and a catalyst filling inlet located above the barrel. Both the feed inlet and the catalyst filling inlet are connected to the reaction zone. The feed inlet is used for plastic input, and the catalyst filling inlet is used for injecting chloroaluminate ionic liquid. A crusher is installed inside the feed inlet.

[0017] The beneficial effects of this invention are as follows: The mixed plastic recycling device of this invention operates under mild conditions, completing the recycling of polyvinyl chloride (PVC) and polyolefins at ambient temperature and pressure. It yields high-purity organic raw materials, achieving complete separation of solid, liquid, and gas phases. It automatically reuses the catalyst and recovers the products, enabling continuous processing of waste plastics. The operation is simple and thorough, a stark contrast to traditional methods that require multiple separation steps such as dechlorination and pyrolysis. This significantly simplifies the process, improves recycling efficiency, and reduces energy consumption. Furthermore, it avoids the problems encountered in physical recycling of polyethylene and other commonly used plastics. For example, in physical recycling, polyethylene molecular chains are prone to thermal oxidative degradation during repeated hot-melt extrusion, resulting in a decrease in molecular weight and weakened mechanical properties, making the quality of recycled materials significantly lower than virgin materials and difficult to meet the requirements of high-end applications. In chemical recycling, due to the stable chemical structure of polyethylene, chain breaking and pyrolysis usually require high temperatures or strong catalytic conditions, leading to high energy consumption, limited conversion efficiency, and the easy generation of complex byproducts. Therefore, the economic and environmental friendliness of the process remains insufficient. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a top view of the present invention.

[0020] In the diagram: 1. Barrel body, 2. Feeding zone, 3. Reaction zone, 4. Separation zone, 5. Transfer pump, 6. Exhaust pipe, 7. Alkane recovery zone, 8. Overflow zone, 9. Liquid collection zone, 10. Diverter cone, 11. Recovery pipe, 12. Inner shell, 13. Overflow pipe, 14. Float, 15. Valve, 16. Divider plate, 17. Overflow trough, 18. Recovery trough, 19. Through hole, 20. Channel, 21. First flare, 22. Second flare, 23. Pushing mechanism, 24. Feed inlet, 25. Catalyst injection port. Detailed Implementation

[0021] like Figure 1-2 As shown, a mixed plastic recycling device includes a barrel 1. Inside the barrel 1, a feeding zone 2, a reaction zone 3, and a separation zone 4 are arranged in sequence. The reaction zone 3 is located below the feeding zone 2, and the separation zone 4 is located below the reaction zone 3. Thus, the feeding zone 2, reaction zone 3, and separation zone 4 are arranged in sequence from top to bottom. The feeding zone 2 is used to input the plastic and chloroaluminate ionic liquid to be reacted. The reaction zone 3 is used to react the plastic and chloroaluminate ionic liquid. A transfer pump 5 is provided between the separation zone 4 and the reaction zone 3. The transfer pump 5 is used to transfer the solution in the separation zone 4 to the reaction zone 3. An exhaust pipe 6 is provided on the barrel 1 and is connected to the reaction zone 3. The exhaust pipe 6 can be connected to an external gas collection device. The separation zone 4 includes an alkane recovery zone 7, an overflow zone 8, and a liquid collection zone 9 arranged sequentially from top to bottom and interconnected. The alkane recovery zone 7 is used to collect alkanes after the reaction. A diversion cone 10 is provided in the overflow zone 8 to divert the liquid flowing down from the reaction zone 3 into the overflow zone 8. The input end of the transfer pump 5 is connected to the liquid collection zone 9. A recovery pipe 11 is provided on the tank body 1 and is connected to the separation zone 4.

[0022] An inner shell 12 is provided on the inner peripheral wall of the barrel 1 at the separation zone 4. An alkane recovery zone 7 is formed between the inner shell 12 and the inner peripheral wall of the barrel 1. An overflow pipe 13 is provided inside the inner shell 12. One end of the overflow pipe 13 is connected to the overflow zone 8. A valve 15 is provided on the recovery pipe 11. A float 14 is provided inside the inner shell 12. The float 14 is signal-connected to the valve 15 and is used to open the valve 15 when the float 14 rises to the set liquid level.

[0023] A partition plate 16 is provided in the separation zone 4. The partition plate 16 is located below the inner shell 12. The partition plate 16 divides the cavity and forms an upper overflow zone 8 and a lower liquid collection zone 9. The partition plate 16 is provided with a concave overflow groove 17 and a recovery groove 18. The overflow groove 17 and the recovery groove 18 are arranged side by side. The recovery groove 18 is provided with a through hole 19, which connects the recovery groove 18 and the liquid collection zone 9. The flow divider cone 10 is located above the overflow groove 17 and is used to guide impurities in the downstream material of the reaction into the overflow groove 17, while the liquid overflows into the recovery groove 18.

[0024] The inner shell 12 is annular, and a channel 20 is formed in the middle of the inner shell 12. The channel 20 connects the overflow zone 8 and the reaction zone 3. The diverter cone 10 is located directly below the channel 20. The end of the inner shell 12 near the reaction zone 3 is a first horn-shaped opening 21 with the opening facing upward from the reaction zone 3 to the overflow zone 8. One end of the channel 20 is connected to the small end of the first horn-shaped opening 21. The end of the inner shell 12 near the overflow zone 8 is a second horn-shaped opening 22 with the opening facing downward from the reaction zone 3 to the overflow zone 8. The other end of the channel 20 is connected to the small end of the second horn-shaped opening 22. One end of the overflow pipe 13 is located at the second horn-shaped opening 22.

[0025] A pushing mechanism 23 is provided between the reaction zone 3 and the alkane recovery zone 7. The pushing mechanism 23 is used to push the falling plastic into the reaction zone 3. The liquid after the reaction can flow directly downward through the pushing mechanism 23. The pushing mechanism 23 is a screw conveyor.

[0026] The feeding zone 2 includes a feed inlet 24 and a catalyst filling inlet 25 located above the barrel 1. There are two feed inlets 24. Both the feed inlet 24 and the catalyst filling inlet 25 are connected to the reaction zone 3. The feed inlet 24 is used for plastic input, and the catalyst filling inlet 25 is used for injecting chloroaluminate ionic liquid. A crusher is installed inside the feed inlet 24.

[0027] The principle is as follows: During operation, an appropriate amount of aluminochloride ionic liquid is injected into the catalyst injection port 25, with the amount of aluminochloride ionic liquid reaching the top of the umbrella-shaped diversion cone 10 in the separation zone 4. Then, the polyvinyl chloride and other polyolefin plastics to be recovered are added separately through the feed inlet 24 at the top of the tank 1. The transfer pump 5 is started to circulate the solution in the aluminochloride ionic liquid collection zone 9 at the bottom of the separation zone 4 to the reaction zone 3. Under the catalytic action of the aluminochloride ionic liquid and at room temperature and pressure, the pulverized plastics can be completely converted into C4–C within about 30 minutes. 12 Isoalkanes and high-purity HCl are discharged from the exhaust pipe 6 at reaction zone 3. A screw conveyor below reaction zone 3 continuously pushes the plastic granules upwards, while the aluminochloride ion liquid continuously flows downwards. During this process, the plastic granules react, transforming into a transparent liquid. The liquid flows through the first funnel 21, through channel 20, and then through the diversion cone 10. Impurities in the liquid fall into the overflow tank 17 under the guidance of the diversion cone 10, while the liquid overflows from the overflow tank 17 into the recovery tank 18. Due to stratification, the lighter alkanes float to the top and flow from the overflow pipe 13 into the alkane recovery zone 7. As more and more alkanes accumulate, the float 14 in the alkane recovery zone 7 floats to a set point. When the position is reached, valve 15 of recovery pipe 11 is opened, and the alkanes generated by the reaction are discharged from recovery pipe 11. The transfer pump 5 continues to work, and plastic is continuously added. The hydrocarbons generated by the reaction are intermittently discharged from recovery pipe 11, thus completing the plastic recycling work. This scheme uses chloroaluminate ionic liquid as catalyst, such as C4PyCl-2AlCl3, to couple the endothermic dechlorination / bond breaking reaction of PVC with the exothermic alkylation reaction of isobutane / isopentane (iC4 / iC5) at 30°C, directly converting PVC and polyolefins into gasoline-range (C6-C12) chlorine-free liquid alkanes and recyclable HCl. The carbon recovery rate reaches 97%, and it is applicable to actual mixed plastic waste.

[0028] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A mixed plastic recycling device, characterized in that: The container includes a barrel (1), which is provided with a feeding zone (2), a reaction zone (3) and a separation zone (4) connected sequentially from top to bottom. The feeding zone (2) is used to input plastic and chloroaluminate ionic liquid. The reaction zone (3) is used to react plastic and chloroaluminate ionic liquid. A transfer pump (5) is provided between the separation zone (4) and the reaction zone (3). The transfer pump (5) is used to transfer the solution in the separation zone (4) to the reaction zone (3). An exhaust pipe (6) connected to the reaction zone (3) is provided on the barrel (1). The separation zone (4) includes an alkane recovery zone (7), an overflow zone (8), and a liquid collection zone (9) arranged sequentially from top to bottom and interconnected. The alkane recovery zone (7) is used to collect alkanes after the reaction. A diversion cone (10) is provided in the overflow zone (8). The diversion cone (10) is used to divert the liquid flowing down from the reaction zone (3) to the overflow zone (8). The input end of the transfer pump (5) is connected to the liquid collection zone (9). A recovery pipe (11) is provided on the barrel (1). The recovery pipe (11) is connected to the separation zone (4).

2. The mixed plastic recycling device according to claim 1, characterized in that: An inner shell (12) is provided on the inner peripheral wall of the barrel (1) at the separation zone (4). An alkane recovery zone (7) is formed between the inner shell (12) and the inner peripheral wall of the barrel (1). An overflow pipe (13) is provided inside the inner shell (12). One end of the overflow pipe (13) is connected to the overflow zone (8).

3. The mixed plastic recycling device according to claim 2, characterized in that: A valve (15) is provided on the recovery pipe (11), and a float (14) is provided inside the inner shell (12). The float (14) is connected to the valve (15) and is used to open the valve (15) when the float (14) floats to the set liquid level.

4. A mixed plastic recycling device according to claim 2, characterized in that: A partition plate (16) is provided in the separation zone (4). The partition plate (16) is located below the inner shell (12). The partition plate (16) divides the cavity and forms an upper overflow zone (8) and a lower liquid collection zone (9). A concave overflow groove (17) and a recovery groove (18) are provided on the partition plate (16). The overflow groove (17) and the recovery groove (18) are arranged side by side. A through hole (19) is provided in the recovery groove (18). The through hole (19) connects the recovery groove (18) and the liquid collection zone (9). The diversion cone (10) is located above the overflow groove (17) and is used to guide impurities in the downstream material of the reaction into the overflow groove (17). The liquid overflows into the recovery groove (18).

5. A mixed plastic recycling device according to claim 2, characterized in that: The inner shell (12) is annular, and a channel (20) is formed in the middle of the inner shell (12). The channel (20) connects the overflow area (8) and the reaction area (3). The diversion cone (10) is located directly below the channel (20).

6. A mixed plastic recycling device according to claim 5, characterized in that: The inner shell (12) has a first horn-shaped opening (21) with its opening facing upwards from the reaction zone (3) toward the overflow zone (8) at one end. One end of the channel (20) is connected to the small end of the first horn-shaped opening (21).

7. A mixed plastic recycling device according to claim 5 or 6, characterized in that: The inner shell (12) has a second horn-shaped opening (22) with its opening facing downwards from the reaction zone (3) toward the overflow zone (8) at one end. The other end of the channel (20) is connected to the small end of the second horn-shaped opening (22). One end of the overflow pipe (13) is located at the second horn-shaped opening (22).

8. A mixed plastic recycling device according to claim 1, characterized in that: A pushing mechanism (23) is provided between the reaction zone (3) and the alkane recovery zone (7). The pushing mechanism (23) is used to push the falling plastic into the reaction zone (3) so that the liquid after the reaction can pass through the pushing mechanism (23).

9. A mixed plastic recycling device according to claim 8, characterized in that: The pushing mechanism (23) is a screw conveyor.

10. A mixed plastic recycling device according to claim 1, characterized in that: The feeding zone (2) includes a feed inlet (24) and a catalyst injection port (25) located above the barrel (1). Both the feed inlet (24) and the catalyst injection port (25) are connected to the reaction zone (3). The feed inlet (24) is used for plastic input, and the catalyst injection port (25) is used for injecting chloroaluminate ionic liquid. A crusher is installed inside the feed inlet (24).

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