Chlorine-containing waste plastic all-component recycling device

Abstract

The invention discloses a chlorine-containing waste plastic all-component recycling device which comprises a feeding unit, a pretreatment and reaction unit, a liquid-liquid separation and fractionation unit, an HCl treatment unit, an ionic liquid recycling unit and a process control and safety protection unit. Under the mild condition, efficient upgrading of the chlorine-containing mixed waste plastic is achieved, energy consumption and equipment corrosion are remarkably reduced, harm of chlorine is thoroughly eliminated through multifunctional cooperation of the ionic liquid, the chlorine is subjected to in-situ trapping and conversion, the transfer and storage risks of intermediate products are avoided, the economical efficiency of chlorine atoms is improved, and the method is suitable for industrial production. Environmental protection cost is changed into economic benefit; according to the present invention, the comprehensive utilization rate of the carbon / hydrogen / chlorine element is high, the high octane number alkylate oil and the high value chemicals can be simultaneously produced, the product value and the resource utilization rate are maximized, the self-adaptive optimization of the production process is achieved through the process control and the safety protection, and the stability and the economy of the system operation are improved.

Description

Technical Field

[0001] This invention relates to the field of waste plastic recycling, and in particular to a device for the complete recycling of chlorine-containing waste plastics. Background Technology

[0002] Plastics are a class of ubiquitous synthetic polymer materials used in almost all commercial and industrial sectors. Among them, chlorinated plastics such as polyvinyl chloride (PVC), chlorinated polyethylene (CPE), and polyvinylidene chloride (PVDC) occupy an important position in the global plastics market due to their excellent mechanical properties, flame retardancy, and chemical resistance.

[0003] However, the widespread use of these plastics in key sectors such as construction, packaging, and medicine is often accompanied by problems of "difficult degradation and recycling," and their accumulated environmental footprint has evolved into a global issue. This is mainly due to the high chlorine content of chlorinated plastics; for example, chlorine content in PVC accounts for approximately 57% of its total mass. The stable carbon-chlorine bonds in their molecular structure make them difficult to degrade under natural conditions. More seriously, improper handling may release harmful substances such as hydrogen chloride, and even generate persistent organic pollutants, posing long-term ecological risks.

[0004] Currently, chemical recycling methods utilize processes such as pyrolysis, hydrothermal treatment, or solvent decomposition to break down and recombine chlorine-containing waste plastics at the molecular level, altering their chemical structure to transform low-value waste plastics into high-value chemical raw materials, such as functional carbon materials or specialty chemicals. This avoids the high-difficulty, fine sorting required for mechanical recycling, demonstrating significant economic and environmental sustainability advantages and gradually becoming a key pathway for the resource utilization of chlorine-containing plastics. However, the large amount of chlorine in chlorine-containing plastic molecules easily generates toxic byproducts such as HCl, dioxins, and polychlorinated biphenyls (PCBs) during chemical conversion, leading not only to equipment corrosion and environmental emissions but also reducing the quality of the target product. Existing technologies often employ pre-alkali washing for dechlorination or add expensive corrosion-resistant equipment, resulting in complex processes and treating chlorine as waste, failing to achieve resource utilization.

[0005] Recent research has achieved breakthroughs in specific areas. For example, Chinese patent CN116554913 discloses a process system and method for the degradation and high-value utilization of polyolefins. This method utilizes chloroaluminate-type ionic liquids to achieve the co-conversion of polyolefins such as PVC and PP at room temperature, efficiently converting mixed plastics into chlorine-free liquid hydrocarbon products. Simultaneously, it quantitatively removes chlorine from PVC and generates HCl as a byproduct, achieving efficient utilization of the carbon skeleton. However, the HCl generated in the above process is usually treated by alkaline absorption or water absorption, forming chlorinated salt solutions or dilute hydrochloric acid, which are used only as low-value-added chemicals or even directly discharged, resulting in waste of chlorine resources and increased secondary salt load.

[0006] Therefore, in order to solve the above-mentioned technical problems, providing a closed-loop recycling device for carbon-chlorine full-component chlorine-containing plastics is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] In view of this, the present invention provides a device for the complete recycling of chlorine-containing waste plastics.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0009] A device for recycling all components of chlorine-containing waste plastics, the device comprising a feeding unit (A), a pretreatment and reaction unit (B), a liquid-liquid separation and fractionation unit (C), an HCl treatment unit (D), an ionic liquid recovery unit (E), and a process control and safety protection unit (F).

[0010] The feeding unit (A) is located at the leftmost end. The pretreatment and reaction unit (B) is located to the right of the feeding unit (A). The HCl treatment unit (D) is located upwards from the pretreatment and reaction unit (B). The liquid-liquid separation and fractionation unit (C) and the ionic liquid recovery unit (E) are located to the right of the pretreatment and reaction unit (B).

[0011] Preferably, the feeding unit (A) includes a waste plastic storage bin (1) and a conveyor belt (2), the waste plastic storage bin (1) and the conveyor belt (2) are arranged sequentially from top to bottom, the feeding unit (A) is connected to the pretreatment and reaction unit (B), and the waste plastic (0) is fed in from the left end of the feeding unit (A).

[0012] Preferably, the pretreatment and reaction unit (B) includes a crusher (3), a conveyor belt (4) and an ionic liquid reactor (5), wherein the crusher (3) and the ionic liquid reactor (4) are arranged sequentially from left to right; the crusher (3) and the ionic liquid reactor (5) are connected by the conveyor belt (4) and are arranged in a straight line to facilitate the flow of materials from left to right.

[0013] Preferably, the liquid-liquid separation and fractionation unit (C) includes a filter (6) and a liquid hydrocarbon fractionation tower (7). The filter (6) is located at the upper end of the liquid-liquid separation and fractionation unit (C). The liquid phase inlet of the filter (6) is connected to the pretreatment and reaction unit (B). The liquid phase outlet of the filter (6) is connected to the liquid hydrocarbon fractionation tower (7) to the lower left. The liquid phase outlet of the filter (6) is connected to the ionic liquid recovery unit (E) to the lower right. The right side of the liquid hydrocarbon fractionation tower (7) is connected to the chemical product outlet (8).

[0014] Preferably, the HCl treatment unit (D) includes an HCl absorption tower (11) and a tail gas outlet (12). The HCl absorption tower (11) is arranged vertically to the ionic liquid reactor (5) and is located directly above the ionic liquid reactor (5). It is connected to the gas phase outlet at the top of the ionic liquid reactor (5) through an HCl gas pipeline and to the ionic liquid distillation tower (10) through a liquid pipeline. The tail gas main pipe is centrally led to the tail gas outlet (13) at the top of the device. The HCl absorption tower (8) is connected to the chemical product outlet (8).

[0015] Preferably, the ionic liquid recovery unit (E) includes an ionic liquid distillation column (9) and an ionic liquid distillation column (10), the ionic liquid distillation column (9) being connected to the ionic liquid reactor (5), and the ionic liquid distillation column (10) being connected to the HCl absorption column (11).

[0016] Preferably, the central control unit (13) of the process control and safety protection unit (F) is located at one end of the front of the device, which facilitates centralized monitoring by the operator and is electrically connected to the detection instruments and actuators on each unit.

[0017] Preferably, the device is mounted on an integrated skid-mounted base.

[0018] Preferably, the device is equipped with a safety spray system around its perimeter.

[0019] Preferably, the various devices are connected by short straight pipelines and valves, and the overall footprint is arranged in the form of "feeding-pretreatment-reaction-separation-fractionation".

[0020] The present invention achieves the following technical effects compared to the prior art:

[0021] (1) Through process design, this invention achieves efficient upgrading of chlorine-containing mixed waste plastics under mild conditions, significantly reducing energy consumption and equipment corrosion;

[0022] (2) This invention utilizes the multifunctional synergy of ionic liquids to not only completely eliminate the harm of chlorine, but also to capture and transform it in situ, avoiding the transfer and storage risks of intermediate products, improving the economy of chlorine atoms, and turning environmental protection costs into economic benefits.

[0023] (3) The present invention has a high comprehensive utilization rate of carbon / hydrogen / chlorine elements, and can simultaneously produce high octane alkylated oil and high-value chemicals, thereby maximizing product value and resource utilization.

[0024] (4) This invention achieves adaptive optimization of the production process through process control and safety protection, thereby improving the stability and economy of system operation. Attached Figure Description

[0025] Figure 1 This is a diagram of the device of the present invention;

[0026] Among them, A-feeding unit; B-pretreatment and reaction unit; C-liquid-liquid separation and fractionation unit; D-HCl treatment unit; E-ionic liquid recovery unit; F-process control and safety protection unit;

[0027] 0-Waste plastic; 1-Waste plastic storage silo; 2-Conveyor belt; 3-Crusher; 4-Conveyor belt; 5-Ionic liquid reactor; 6-Filter; 7-Liquid hydrocarbon fractionation tower; 8-Chemical product outlet; 9-Ionic liquid regeneration tower; 10-Ionic liquid regeneration tower; 11-HCl absorption tower; 12-Tail gas outlet; 11-Central control panel. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] This invention discloses a device for the full-component recycling of chlorine-containing waste plastics. The device includes a feeding unit A, a pretreatment and reaction unit B, a liquid-liquid separation and fractionation unit C, an HCl treatment unit D, an ionic liquid recovery unit E, and a process control and safety protection unit F.

[0030] Among them, the feeding unit A is located at the leftmost end, and the pretreatment and reaction unit B is located to the right of the feeding unit A. The liquid-liquid separation and fractionation unit C is located to the right of the pretreatment and reaction unit B. The HCl treatment unit D is located above the pretreatment and reaction unit B. The ionic liquid recovery unit E is located to the right of the pretreatment and reaction unit B and the liquid-liquid separation and fractionation unit C.

[0031] Feeding unit A includes a waste plastic storage bin 1 and a conveyor belt 2, which are arranged sequentially from left to right. Feeding unit A is connected to pretreatment and reaction unit B, and waste plastic 0 is fed in from the left end of feeding unit A.

[0032] The pretreatment and reaction unit B includes a crusher 3, a conveyor belt 4, and an ionic liquid reactor 5, which are arranged sequentially from left to right. The crusher 3 and the ionic liquid reactor 5 are connected by the conveyor belt 4 and are arranged in a straight line to facilitate the flow of materials from left to right.

[0033] The liquid-liquid separation and fractionation unit C includes a filter 6 and a liquid hydrocarbon fractionation tower 7. The filter 6 is located at the upper end of the liquid-liquid separation and fractionation unit C. The liquid phase inlet of the filter 6 is connected to the pretreatment and reaction unit B. The liquid phase outlet of the filter 6 is connected to the liquid hydrocarbon fractionation tower 6 on the lower left side. The liquid phase outlet of the filter 6 is connected to the ionic liquid recovery unit E on the lower right side. The right side of the liquid hydrocarbon fractionation tower 6 is connected to the chemical product outlet 8.

[0034] The HCl treatment unit D includes an HCl absorption tower 11 and a tail gas outlet 12. The HCl absorption tower 11 is arranged vertically above the ionic liquid reactor 5. It is connected to the gas phase outlet at the top of the ionic liquid reactor 5 through an HCl gas pipeline and to the ionic liquid distillation tower 10 through a liquid pipeline. The tail gas main pipe is centrally led to the tail gas outlet 12 at the top of the device. The HCl absorption tower 11 is connected to the chemical product outlet 8.

[0035] The ionic liquid recovery unit E includes an ionic liquid distillation column 9 and an ionic liquid distillation column 10. The ionic liquid distillation column 9 is connected to the ionic liquid reactor 5; the ionic liquid distillation column 10 is connected to the HCl absorption column 11.

[0036] The central control console 11 of the process control and safety protection unit F is located at one end of the front of the device, which is convenient for the operator to monitor centrally and is electrically connected to the detection instruments and actuators on each unit.

[0037] The device is mounted on an integrated skid-mounted base.

[0038] Safety sprinklers are installed around the device.

[0039] The various pieces of equipment are connected by short, straight pipes and valves, and the overall layout is arranged in the form of "feeding-pretreatment-reaction-separation-fractionation".

[0040] The working principle of this invention is as follows:

[0041] Chlorine-containing waste plastics are fed into the pretreatment and reaction unit via the waste plastic storage bin and conveyor belt of the feeding unit. The chlorine-containing waste plastics are crushed in the pretreatment and reaction unit and dechlorinated and pyrolyzed in the presence of chloroaluminate ionic liquid at room temperature or low temperature to convert the chlorine-containing waste plastics into chlorine-free liquid hydrocarbons and HCl-containing reaction gas to obtain a reaction mixture.

[0042] The liquid reaction mixture is fed from the bottom of the pretreatment and reaction unit into the liquid-liquid separation unit to separate the reaction mixture into liquid hydrocarbon products and ionic liquids. The liquid hydrocarbon products are statically fractionated in the liquid hydrocarbon fractionation unit and output as liquid products. The ionic liquids are sent to the ionic liquid recovery unit for impurity removal by vacuum distillation and are then recycled to the pretreatment and reaction unit and the HCl treatment unit through ionic liquid pipelines.

[0043] The HCl gas discharged from the top of the pretreatment and reaction unit is introduced into the HCl treatment unit through a gas pipeline, so that the reaction gas comes into contact with the ammonium salt ionic liquid for absorption. The HCl in the reaction gas is absorbed and fixed in the ionic liquid to obtain an HCl-rich ionic liquid, thus achieving safe storage of HCl.

[0044] The chlorination reaction of HCl-rich ionic liquid produces chlorinated organic compounds and chlorination reagents, and the used ionic liquid obtained after the reaction is returned to the ionic liquid recovery unit, realizing the closed-loop recycling of resources.

[0045] During the above steps, the process control and safety protection unit performs real-time monitoring and interlocking control of temperature, pressure, flow rate, HCl concentration, and ionic liquid loading in the feeding unit, pretreatment and reaction unit, liquid-liquid separation and fractionation unit, HCl treatment unit, and ionic liquid recovery unit. HCl / Cl2 Leakage and exhaust emissions are protected and controlled to meet standards, thereby achieving efficient recycling of all carbon, hydrogen, and chlorine components in chlorine-containing waste plastics.

[0046] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A device for the complete recycling of chlorine-containing waste plastics, characterized in that, The device includes a feeding unit (A), a pretreatment and reaction unit (B), a liquid-liquid separation and fractionation unit (C), an HCl treatment unit (D), an ionic liquid recovery unit (E), and a process control and safety protection unit (F). The feeding unit (A) is located at the leftmost end. The pretreatment and reaction unit (B) is located to the right of the feeding unit (A). The HCl treatment unit (D) is located upwards from the pretreatment and reaction unit (B). The liquid-liquid separation and fractionation unit (C) and the ionic liquid recovery unit (E) are located to the right of the pretreatment and reaction unit (B).

2. The device for the complete recycling of chlorine-containing waste plastics according to claim 1, characterized in that, The feeding unit (A) includes a waste plastic storage bin (1) and a conveyor belt (2), which are arranged sequentially from top to bottom. The feeding unit (A) is connected to the pretreatment and reaction unit (B), and the waste plastic (0) is fed in from the left end of the feeding unit (A).

3. The device for the complete recycling of chlorine-containing waste plastics according to claim 1, characterized in that, The pretreatment and reaction unit (B) includes a crusher (3), a conveyor belt (4) and an ionic liquid reactor (5). The crusher (3) and the ionic liquid reactor (4) are arranged sequentially from left to right. The crusher (3) and the ionic liquid reactor (5) are connected by the conveyor belt (4) and are arranged in a straight line to facilitate the flow of materials from left to right.

4. The device for the complete recycling of chlorine-containing waste plastics according to claim 1, characterized in that, The liquid-liquid separation and fractionation unit (C) includes a filter (6) and a liquid hydrocarbon fractionation tower (7). The filter (6) is located at the upper end of the liquid-liquid separation and fractionation unit (C). The liquid phase inlet of the filter (6) is connected to the pretreatment and reaction unit (B). The liquid phase outlet of the filter (6) is connected to the liquid hydrocarbon fractionation tower (7) to the lower left. The liquid phase outlet of the filter (6) is connected to the ionic liquid recovery unit (E) to the lower right. The right side of the liquid hydrocarbon fractionation tower (7) is connected to the chemical product outlet (8).

5. The device for the complete recycling of chlorine-containing waste plastics according to claim 1, characterized in that, The HCl treatment unit (D) includes an HCl absorption tower (11) and a tail gas outlet (12). The HCl absorption tower (11) is arranged vertically to the ionic liquid reactor (5) and is located directly above the ionic liquid reactor (5). It is connected to the gas phase outlet at the top of the ionic liquid reactor (5) through an HCl gas pipeline and to the ionic liquid distillation tower (10) through a liquid pipeline. The tail gas main pipe is centrally led to the tail gas outlet (13) above the device. The HCl absorption tower (8) is connected to the chemical product outlet (8).

6. The device for the complete recycling of chlorine-containing waste plastics according to claim 1, characterized in that, The ionic liquid recovery unit (E) includes an ionic liquid distillation column (9) and an ionic liquid distillation column (10). The ionic liquid distillation column (9) is connected to the ionic liquid reactor (5), and the ionic liquid distillation column (10) is connected to the HCl absorption column (11).

7. The device for the complete recycling of chlorine-containing waste plastics according to claim 1, characterized in that, The central control console (13) of the process control and safety protection unit (F) is located at one end of the front of the device, which is convenient for the operator to monitor centrally and is electrically connected to the detection instruments and actuators on each unit.

8. The device for the complete recycling of chlorine-containing waste plastics according to claim 1, characterized in that, The device is mounted on an integrated skid-mounted base.

9. The device for the complete recycling of chlorine-containing waste plastics according to claim 1, characterized in that, The device is equipped with a safety spray system around its perimeter.

10. The device for the complete recycling of chlorine-containing waste plastics according to claim 1, characterized in that, The various pieces of equipment are connected by short, straight pipes and valves, and the overall layout is arranged in the form of "feeding-pretreatment-reaction-separation-fractionation".

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