Reaction system for regenerating waste pbt into pbt-s based on electrolysis method
By converting waste PBT into PBST through electrolysis, the problem of chemical recycling is solved, and efficient and environmentally friendly PBT regeneration is achieved, generating biodegradable plastics. Hydrogen production is then driven by water electrolysis to drive value-added conversion.
Patent Information
- Application Number
- CN202521489778.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-16
- Publication Date
- 2026-08-25
- Estimated Expiration
- 2035-07-16
AI Technical Summary
Existing technologies cannot efficiently chemically recycle waste PBT, leading to environmental pollution and a decline in mechanical performance. Traditional recycling methods pose health risks.
Waste PBT is converted into PBST through an electrolytic process involving crushing, degradation, electrolysis, product separation, and polymerization. The process includes a crushing device, a degradation device, an electrolysis system, and a PBST polymerization reactor. High-value-added small molecules are prepared by combining alkali and alcohol degradation and electrolysis of water to produce hydrogen. Finally, esterification and polycondensation are used to generate PBST.
This achieves efficient chemical recycling of PBT, generating biodegradable PBST, reducing environmental pollution, and driving value-added transformation using renewable energy.
Smart Images
Figure CN224677997U_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of biodegradable plastics, specifically relating to a reaction system for regenerating waste PBT into PBST based on electrolysis. Background Technology
[0002] Polybutylene terephthalate (PBT) is a common engineering plastic with high mechanical strength, good dimensional stability, and easy secondary processing, and is widely used in automobiles, electronics, machinery and equipment. PBT decomposes very slowly in the natural environment, and long-term accumulation causes soil and water pollution, affecting the ecosystem. Therefore, developing efficient technologies for treating waste PBT has become a key challenge in addressing the accumulation of recalcitrant polyester waste. Traditional recycling methods such as incineration and landfill produce toxic gases and microplastic pollution, which seriously harm human health and the natural environment. Physical recycling achieves recycling without changing the chemical composition of the plastic through mechanical recycling and modification (Guangdong Chemical Industry, 2021, 48(16): 170-172). However, its mechanical properties will decrease with the increase of recycling times, and it can only be used as a secondary product. In contrast, chemical recycling depolymerizes PBT to generate high-value-added small molecule monomers, which has the advantages of being environmentally friendly and highly efficient in degradation. However, existing equipment cannot achieve the chemical recycling of PBT. Utility Model Content
[0003] This invention is proposed to overcome the shortcomings of the existing technology, and its purpose is to provide a reaction system for regenerating waste PBT into PBST based on electrolysis.
[0004] This utility model is achieved through the following technical solution: A reaction system for regenerating waste PBT into PBST based on electrolysis includes a waste PBT treatment system, an electrolysis and electrolysis product treatment system, and a PBST polymerization system; the waste PBT treatment system includes a crushing device, a degradation device, and a degradation product separation device connected in sequence; the degradation product separation device is connected to a degradation solid product recovery device and a degradation liquid product recovery device respectively. The electrolysis and electrolysis product processing system includes an electrolysis system, the feed inlet of which is connected to a raw material storage tank, the cathode outlet of which is connected to a gas recovery system, the anode outlet of which is connected to an electrolysis product separation device, and the outlet of the electrolysis product separation device is connected to an alkali recovery tank and an electrolysis product tank, respectively; the outlet of the electrolysis product tank is connected to a PBST polymerization reactor. The PBST polymerization system includes a PBST polymerization reactor and a polymerization product separation device connected to its outlet.
[0005] In the above technical solution, the degradation device is provided with a solid feed inlet, a liquid feed inlet and a discharge outlet. The solid feed inlet is connected to the discharge outlet of the crushing device. Water, potassium hydroxide and BDO are added to the degradation device from the liquid feed inlet. The discharge outlet is connected to the feed inlet of the degradation product separation device.
[0006] In the above technical solution, the degradation product separation device is provided with an acidification liquid inlet, a degradation product inlet, a liquid outlet, and a solid outlet; the acidification liquid formic acid enters the degradation product separation device from the acidification liquid inlet; the degradation product inlet is connected to the discharge port of the degradation device; the solid outlet is connected to the degradation solid product recovery device; and the liquid outlet is connected to the degradation liquid product recovery device.
[0007] In the above technical solution, the outlet of the alkali recovery tank is connected to the raw material storage tank.
[0008] In the above technical solution, the PBST polymerization reactor is provided with three inlets and one outlet. The three inlets are respectively connected to the outlet of the degradation solid product recovery device, the outlet of the degradation liquid product recovery device, and the outlet of the electrolysis product tank. The liquid outlet of the polymerization product separation device is connected to the liquid recovery device, and the solid outlet of the polymerization product separation device is connected to the PBST collection and storage device.
[0009] In the above technical solution, the polymerization product separation device is provided with a chloroform inlet, a methanol inlet, a polymerization product inlet, a liquid outlet, and a solid outlet; the polymerization product inlet is connected to the outlet of the PBST polymerization reactor; chloroform enters the polymerization product separation device from the chloroform inlet; methanol enters the polymerization product separation device from the methanol inlet.
[0010] The beneficial effects of this invention are as follows: This invention provides a reaction system for regenerating waste PBT into PBST based on electrolysis. First, the waste PBT treatment system uses an alkaline-alcohol combined degradation method to degrade PBT into 1,4-butanediol (BDO) and terephthalic acid (PTA). Then, an electrolysis and product separation and purification system uses water electrolysis to produce hydrogen coupled with BDO oxidation to prepare succinic acid (SA). Finally, the three products obtained and purified above are subjected to esterification and polycondensation through a PBST polymerization system to obtain polybutylene terephthalate (PBST). This invention effectively utilizes PBT degradation products, simultaneously generating hydrogen through electrocatalytic preparation of SA, providing a new approach for using renewable energy to drive the value-added conversion of waste plastics into biodegradable plastics. Attached Figure Description
[0011] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the chemical reaction principle upon which this utility model is based; Figure 3 This is the infrared spectrum of the biodegradable plastic PBST in Application Example 1 of this utility model.
[0012] in: 1. Waste PBT treatment system; 11. Crushing device; 12. Degradation device; 13. Degradation product separation device; 14. Degradation solid product recovery device; 15. Degradation liquid product recovery device; 2. Electrolysis and electrolysis product processing system; 21. Electrolysis system; 22. Gas recovery system; 23. Raw material storage tank; 24. Alkali recovery tank; 25. Electrolysis product separation device; 26. Electrolysis product tank; 3. PBST polymerization system; 31. PBST polymerization reactor; 32. Polymerization product separation device; 33. Liquid recovery device; 34. PBST collection and storage device.
[0013] For those skilled in the art, other related figures can be obtained from the above figures without any creative effort. Detailed Implementation
[0014] To enable those skilled in the art to better understand the technical solution of this utility model, the technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.
[0015] like Figure 1 As shown, a reaction system for regenerating waste PBT into PBST based on electrolysis includes a waste PBT treatment system 1, an electrolysis and electrolysis product treatment system 2, and a PBST polymerization system 3. The waste PBT treatment system 1 includes a crushing device 11, a degradation device 12 and a degradation product separation device 13 connected in sequence; the degradation product separation device 13 is connected to a degradation solid product recovery device 14 and a degradation liquid product recovery device 15 respectively. In this embodiment, the crushing device 11 is a plastic crusher; In this embodiment, the degradation device 12 is a reaction vessel, which is provided with a solid feed inlet, a liquid feed inlet, and a discharge outlet. The solid feed inlet is connected to the discharge outlet of the pulverizing device 11. Water, potassium hydroxide (KOH), and BDO are added to the degradation device 12 through the liquid feed inlet. The discharge outlet is connected to the feed inlet of the degradation product separation device 13. The volume ratio of water to BDO in the degradation device 12 is 1:1.1 to 1:9, the mass ratio of BDO to PBT is 1:0.05 to 1:0.5, the mass of KOH is 1.1 to 1.8 times the ester equivalent, and the degradation temperature of the degradation device 12 is 120 °C to 210 °C. In this embodiment, the degradation product separation device 13 is a filter, and it is provided with an acidification liquid inlet, a degradation product inlet, a liquid outlet, and a solid outlet. Formic acid (HCOOH) enters the degradation product separation device 13 through the acidification liquid inlet to acidify the degradation products. The degradation product inlet is connected to the outlet of the degradation device 12. The solid outlet is connected to the degradation solid product recovery device 14. The liquid outlet is connected to the degradation liquid product recovery device 15. The degradation liquid product recovery device 15 includes a rotary evaporator. BDO is obtained through the degradation liquid product recovery device 15, and PTA is obtained through the degradation solid product recovery device 14. The electrolysis and electrolysis product processing system 2 includes an electrolysis system 21. The inlet of the electrolysis system 21 is connected to a raw material storage tank 23. The cathode outlet of the electrolysis system 21 is connected to a gas recovery system 22. The anode outlet of the electrolysis system 21 is connected to an electrolysis product separation device 25. The outlet of the electrolysis product separation device 25 is connected to an alkali recovery tank 24 and an electrolysis product tank 26, respectively. The outlet of the alkali recovery tank 24 is connected to the raw material storage tank 23. The outlet of the electrolysis product tank 26 is connected to a PBST polymerization reactor 31. In this embodiment, the electrolysis system 21 is a commercially available electrolysis system; The PBST polymerization system 3 includes a PBST polymerization reactor 31 and a polymerization product separation device 32 connected to its outlet. The PBST polymerization reactor 31 is provided with three inlets and one outlet. The three inlets are respectively connected to the outlet of the degradation solid product recovery device 14, the outlet of the degradation liquid product recovery device 15, and the outlet of the electrolysis product tank 26. The liquid outlet of the polymerization product separation device 32 is connected to the liquid recovery device 33, and the solid outlet of the polymerization product separation device 32 is connected to the PBST collection and storage device 34. The polymerization product separation device 32 is a filter, which includes a chloroform inlet, a methanol inlet, a polymerization product inlet, a liquid outlet, and a solid outlet; the polymerization product inlet is connected to the outlet of the PBST polymerization reactor 31; chloroform enters the polymerization product separation device 32 from the chloroform inlet to further dissolve the polymerization product; methanol enters the polymerization product separation device 32 from the methanol inlet to precipitate the polymerization product, thereby obtaining PBST.
[0016] The chemical principle upon which this utility model device is based is as follows: Figure 2 As shown.
[0017] The infrared spectrum of PBST synthesized using this invention is as follows: Figure 3 As shown.
[0018] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments of the present invention can be combined with each other.
[0019] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.
[0020] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0021] The applicant declares that the above description is only a specific embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model fall within the protection and disclosure scope of the present utility model.
Claims
1. A reaction system for regenerating waste PBT into PBST based on electrolysis, characterized in that: It includes a waste PBT treatment system (1), an electrolysis and electrolysis product treatment system (2), and a PBST polymerization system (3); the waste PBT treatment system (1) includes a crushing device (11), a degradation device (12), and a degradation product separation device (13) connected in sequence; the degradation product separation device (13) is connected to a degradation solid product recovery device (14) and a degradation liquid product recovery device (15), respectively. The electrolysis and electrolysis product processing system (2) includes an electrolysis system (21), the inlet of which is connected to a raw material storage tank (23), the cathode outlet of which is connected to a gas recovery system (22), the anode outlet of which is connected to an electrolysis product separation device (25), and the outlet of the electrolysis product separation device (25) is connected to an alkali recovery tank (24) and an electrolysis product tank (26), respectively; the outlet of the electrolysis product tank (26) is connected to a PBST polymerization reactor (31). The PBST polymerization system (3) includes a PBST polymerization reactor (31) and a polymerization product separation device (32) connected to its outlet.
2. The reaction system for regenerating waste PBT into PBST based on electrolysis according to claim 1, characterized in that: The degradation device (12) is provided with a solid feed inlet, a liquid feed inlet and a discharge outlet. The solid feed inlet is connected to the discharge outlet of the crushing device (11). Water, potassium hydroxide and BDO are added to the degradation device (12) from the liquid feed inlet. The discharge port is connected to the inlet of the degradation product separation device (13).
3. The reaction system for regenerating waste PBT into PBST based on electrolysis according to claim 1, characterized in that: The degradation product separation device (13) is provided with an acidification liquid inlet, a degradation product inlet, a liquid outlet and a solid outlet; the acidification liquid formic acid enters the degradation product separation device (13) from the acidification liquid inlet; the degradation product inlet is connected to the discharge port of the degradation device (12); the solid outlet is connected to the degradation solid product recovery device (14); and the liquid outlet is connected to the degradation liquid product recovery device (15).
4. The reaction system for regenerating waste PBT into PBST based on electrolysis according to claim 1, characterized in that: The outlet of the alkali recovery tank (24) is connected to the raw material storage tank (23).
5. The reaction system for regenerating waste PBT into PBST based on electrolysis according to claim 1, characterized in that: The PBST polymerization reactor (31) is provided with three feed inlets and one discharge outlet. The three feed inlets are respectively connected to the discharge outlet of the degradation solid product recovery device (14), the discharge outlet of the degradation liquid product recovery device (15), and the discharge outlet of the electrolysis product tank (26). The liquid outlet of the polymerization product separation device (32) is connected to the liquid recovery device (33), and the solid outlet of the polymerization product separation device (32) is connected to the PBST collection and storage device (34).
6. The reaction system for regenerating waste PBT into PBST based on electrolysis according to claim 1, characterized in that: The polymerization product separation device (32) is provided with a chloroform inlet, a methanol inlet, a polymerization product inlet, a liquid outlet, and a solid outlet; the polymerization product inlet is connected to the outlet of the PBST polymerization reactor (31); chloroform enters the polymerization product separation device (32) from the chloroform inlet; methanol enters the polymerization product separation device (32) from the methanol inlet.