System and method for producing oil from waste plastic by pyrolysis

Abstract

The application discloses a waste plastic pyrolysis oil system and method, which comprises a cracking reaction unit, a gas input unit and a condensation circulation unit, wherein the cracking reaction unit comprises a tubular pyrolysis reactor 2, a spiral feeder 3 is arranged in the tubular pyrolysis reactor, a waste plastic feeding pipe, a heavy oil feeding pipe 1 and a catalyst feeding pipe 4 are all communicated with the feeding end of the spiral feeder 3 and used for uniformly mixing powdery waste plastic, heavy oil and catalyst; the gas input unit is communicated with the sampling end of the tubular pyrolysis reactor 2 and used for inputting inert gas into the tubular pyrolysis reactor 2; and the condensation circulation unit is connected with the discharging port of the tubular pyrolysis reactor 2 and used for condensing and recycling waste plastic pyrolysis products.

Description

Technical Field

[0001] This invention belongs to the field of waste plastic resource utilization technology, specifically relating to a waste plastic pyrolysis oil production system and method. Background Technology

[0002] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art.

[0003] The amount of waste plastics discarded is enormous. If they are not effectively recycled, they will not only occupy land resources, but also cause environmental pollution and other problems.

[0004] Currently, pyrolysis is considered a relatively ideal method for recycling waste plastics. Furthermore, with petroleum resources becoming increasingly scarce, the recovery of chemical materials and petroleum gas through the pyrolysis of plastics is becoming increasingly important.

[0005] Existing methods for producing oil from plastic pyrolysis often involve directly adding a catalyst to the plastic for pyrolysis. This method has the following drawbacks: the plastic and catalyst are difficult to mix uniformly, requiring high pyrolysis temperatures, which not only makes it difficult to achieve low energy consumption but also easily leads to low pyrolysis oil yield. Furthermore, high-temperature pyrolysis promotes coking, making it difficult to avoid a high coke content. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a waste plastic pyrolysis oil production system and method for recycling the initial products of waste plastic pyrolysis.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0008] In a first aspect, the present invention provides a waste plastic pyrolysis oil production system, comprising a pyrolysis reaction unit, a gas input unit, a condensation circulation unit, and a catalytic regeneration unit, wherein...

[0009] The pyrolysis reaction unit includes a heavy oil feed pipe, a tubular pyrolysis reactor, and a catalyst feed pipe. The tubular pyrolysis reactor is equipped with a screw feeder, and the material inlet of the screw feeder is connected to the crusher through a telescopic feeder.

[0010] Both the heavy oil feed pipe and the catalyst feed pipe are connected to the feed end of the screw feeder, and are used to mix the waste plastic powder, heavy oil and catalyst evenly.

[0011] The gas input unit is connected to the inlet end of the tubular pyrolysis reactor and is used to introduce inert gas into it;

[0012] The condensation circulation unit is connected to the outlet of the tubular pyrolysis reactor and is used to condense and recover the pyrolysis products of waste plastics.

[0013] The catalytic regeneration unit is connected to the discharge port of the solid-liquid separation device and is used to recycle the pyrolysis catalyst of waste plastics.

[0014] The pyrolysis reaction unit provides a heating and melting environment for the pyrolysis of plastics; the gas input unit ensures that the pyrolysis reaction is conducted in an inert atmosphere or carries the pyrolysis gas into the condensation unit; the condensation circulation unit can effectively collect and separate heavy oil and light oil; and the catalytic regeneration unit is used for the regeneration of deactivated catalysts.

[0015] In some embodiments, the heavy oil includes low-grade coal tar, wood tar, or diesel oil. It has advantages such as low price, high conversion efficiency, and recyclability.

[0016] In some embodiments, the crusher discharge port is connected to a telescopic feeder, which is controlled by a mechanical screw and located in the low-temperature zone at the top of the reactor. A storage bin is provided in the middle of the feeder for adding the required materials to the reactor. A temperature control switch is provided at the end, and the temperature sensor of the temperature control switch extends into the constant temperature zone of the pyrolysis furnace to detect the constant temperature inside the tube. Once the required temperature is reached, the material is fed into the screw feeder, thereby reducing the impact of secondary reactions of the reactants on the results.

[0017] In some embodiments, the starting end of the circulation pipe of the condensation circulation unit is connected to the discharge end of the tubular pyrolysis reactor, and the ending end of the circulation pipe is connected to the interior of the tubular pyrolysis reactor.

[0018] Preferably, the circulation pipeline is provided with an air distribution box, a heavy oil separator, a heavy oil purifier, and a heavy oil condenser in sequence from the starting end to the end.

[0019] More preferably, the heavy oil separator is a multi-stage condenser. After high-temperature steam enters the separator, the gas rises and evaporates; the higher the position, the lower the temperature, and hydrocarbons with different boiling points condense into liquid fractions at different heights. At the bottom of the separator, viscous residues such as heavy oil are collected.

[0020] A further preferred embodiment includes a light oil condenser bottle, the inlet of which is connected to the light oil outlet of the heavy oil separator, and the bottle body is immersed in a water bath.

[0021] Preferably, the solid-liquid separator and the catalyst regeneration device are connected by a feeding auger, which is used to draw the deactivated catalyst into the reactor.

[0022] Preferably, it also includes an oil storage tank, which is connected to the liquid outlet of the solid-liquid separator.

[0023] As a further preferred embodiment, the catalyst regeneration device is provided from top to bottom with a feeding auger, a built-in centrifugal separator, an opening regulator, a partitioned pipeline, and an activation zone, with the feeding auger connected to the solid outlet of the solid-liquid separator;

[0024] The upper end of the opening regulator is located at the discharge port of the built-in centrifugal separator, and the lower end is connected to the partition pipe. The partition pipe is connected to the activation zone and is used to receive the deactivated catalyst obtained by centrifugal separation and transport the deactivated catalyst to the activation zone for activation. The activation zone is connected to the oxygen-enriched gas transmission pipe.

[0025] Preferably, the activation zone is connected to the tubular pyrolysis reactor via a feeding auger.

[0026] The activation unit is divided into an upper feeding zone and a lower activation zone, which are connected by a partitioned pipe. An oxygen-enriched gas supply pipe and an air distribution box are installed at the bottom of the activation zone to uniformly introduce oxygen into the zone. The opening regulator is located in the middle of the feeding zone and the activation zone, and includes two inwardly inclined baffles, with the bottom of the baffles connected to the inlet of the partitioned pipe. The built-in centrifugal separator is located at the bottom of the feeding zone, with its outlet above the opening regulator, used to separate the deactivated catalyst and send it into the activation zone through the partitioned pipe. The activation zone is used to heat and decarbonize the deactivated catalyst to achieve activation. The feeding auger is connected to the activation zone, with its other end connected to the catalyst inlet, used to re-feed the activated catalyst back into the pyrolysis reactor.

[0027] More preferably, the catalyst regeneration device is connected to the catalyst feed pipe.

[0028] More preferably, the telescopic feeder is controlled by a temperature control switch. The temperature control switch controls the telescopic feeder to add material after the pyrolysis furnace reaches the required temperature, in order to ensure a constant reaction temperature and prevent excessive secondary reactions.

[0029] In some embodiments, the angle between the opening adjuster baffle and the vertical direction is 30-60°.

[0030] Secondly, the present invention provides a method for producing oil from waste plastic pyrolysis, comprising the following steps:

[0031] Waste plastics are ground, washed, and dried to obtain waste plastic powder;

[0032] After the waste plastic powder, tar and catalyst are mixed evenly, they are pyrolyzed in an inert atmosphere. The mass ratio of waste plastic powder to tar is 1-2:10; the pyrolysis temperature is 150-300℃ and the pyrolysis time is 20-40min.

[0033] The pyrolysis products are separated to obtain heavy oil and light oil.

[0034] In some embodiments, the waste plastic is selected from one or more of PE, HDPE, PVC, PET, PP, and PS.

[0035] Preferably, the waste plastic powder is passed through a 300-mesh sieve.

[0036] The beneficial effects achieved by one or more embodiments of the present invention described above are as follows:

[0037] 1. This invention prepares light oil or fuel oil by mixing and pyrolyzing heavy oil with waste plastics, ensuring thorough mixing of the heavy oil and plastics, thus protecting the plastic components. Uniform heavy oil coating ensures even heating of the plastic particles, while the similar polarity of the solvent and the plastic powder promote melting.

[0038] Pyrolysis of plastics using heavy oil can produce pyrolysis oil at low temperatures. The heavy oil promotes the cracking of plastics and inhibits coking.

[0039] 2. This invention improves the pyrolysis process. First, it determines suitable pyrolysis conditions and materials to ensure a sufficiently inert environment so that the plastic powder can be fully melted and reacted. At the same time, the tubular pyrolysis reactor can ensure that the reaction occurs after reaching the rated temperature, avoiding the influence of other reactions during the heating process.

[0040] 3. The present invention rationally designs the amount of each component added and determines an appropriate ratio to achieve the highest oil production rate and a greater amount of gas components. Specifically, it is manifested in a fixed mass fraction ratio of plastic to tar, reducing tar loss caused by excessive tar, and achieving the effect of complete plastic melting at the lowest ratio.

[0041] 4. This invention improves the structure of the catalytic regeneration unit by dividing the activation unit into a feeding zone and an activation zone, and incorporating a built-in centrifugal separator and an opening regulator, enabling the reactivation of deactivated catalysts. Catalyst recycling is achieved through feeding and discharging augers. Attached Figure Description

[0042] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0043] Figure 1 This is a schematic diagram of the waste plastic pyrolysis system provided in an embodiment of the present invention.

[0044] Figure 2 This is a schematic diagram of the structure of the pyrolysis reactor provided in an embodiment of the present invention;

[0045] Figure 3 This is a schematic diagram of the structure of the catalytic regeneration unit provided in an embodiment of the present invention;

[0046] Figure 4 This is a schematic diagram of the oil yield from waste plastic pyrolysis provided in an embodiment of the present invention.

[0047] Among them, 1-heavy oil feed pipe, 2-tubular pyrolysis reactor, 2.1-telescopic feeder, 2.2-temperature control switch, 3-screw feeder, 4-catalyst feed pipe, 5-air distribution box, 6-heavy oil condenser, 7-heavy oil purifier, 8-crusher, 9-air distribution box, 10-nitrogen pressure reducing valve, 11-feeding auger, 12-catalytic regeneration device, 12.1-discharging auger, 12.2-built-in centrifugal separator, 12.3-first opening regulator, 12.4-zoned pipeline, 12.5-activation zone, 13-oxygen-enriched gas transmission pipe, 14-solid-liquid separator, 15-oil storage tank, 16-heavy oil separator, 17-light oil condenser bottle, 18-waste gas absorption device. Detailed Implementation

[0048] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0049] The present invention will be further described below with reference to the embodiments.

[0050] All raw materials used in this invention can be purchased through commercial channels.

[0051] This invention provides a method for preparing oil products by pyrolysis of waste plastics, such as... Figure 1 As shown, this invention proposes a system for producing oil from plastics through tar melting and pyrolysis, comprising: a pyrolysis reaction unit, a gas input unit, a condensation circulation unit, and a catalytic regeneration unit, wherein:

[0052] The pyrolysis reaction unit includes a heavy oil feed pipe 1, a tubular pyrolysis reactor 2, a spiral feed pipe 2.1, a telescopic feeder 2.2, a temperature control switch 3, a catalyst feed pipe 4, and a material crusher 8. The heavy oil feed pipe 1 and the spiral feed pipe 3 are connected to the inlet of the tubular pyrolysis reactor 2 to supply reactants and heavy oil solvent. The telescopic feeder 2.1 is connected to the temperature control switch 2.2, with one end extending into the constant temperature zone of the pyrolysis reactor to control the addition of materials by the telescopic feeder at a suitable temperature. The catalyst feed pipe 4 is used to add the catalyst required for the reaction, and the material crusher 8 is used to crush the reactants to a suitable size.

[0053] The gas input unit includes an electronic gas flow meter 9 and a gas pressure reducing valve 10. The electronic gas flow meter 9 and the gas pressure reducing valve 10 are connected to the tubular pyrolyzer. The electronic flow meter 9 is used to control the rate at which the pyrolysis reaction gas is introduced to ensure a stable experimental environment.

[0054] The condensation circulation unit includes an air distribution box 5, a heavy oil separator 16, a light oil condenser 17, a heavy oil purifier 7, and a heavy oil storage tank 6. The air distribution box 5 is connected to the outlet of the pyrolysis reactor to ensure a constant gas emission rate, allowing the oil-gas mixture to condense fully. The heavy oil separator 16 is connected to the tail end of the air distribution box 5 and is used to condense and recover the heavy oil generated and remaining in the reaction. The heavy oil purifier 7 and the heavy oil storage tank 6 are connected to the heavy oil separator 16 and are used to purify the collected heavy oil and temporarily store it before circulating it back into the pyrolysis reactor.

[0055] The catalytic regeneration unit includes a catalytic regeneration device 12 and an oxygen-enriched gas supply pipe 13. The catalytic regeneration device 12 includes a feeding auger 12.1, a built-in centrifugal separator 12.2, an opening regulator 12.3, a partitioned pipe 12.4, and an activation zone 12.5. The reaction device is divided into an upper feeding auger 12.1 and a lower activation zone 12.5, which are connected by the partitioned pipe 12.4. The built-in centrifugal separator is located directly above the opening regulator 12.3. During the reaction, the deactivated catalyst mixture is driven by the feeding auger 12.1 into the built-in centrifugal separator 12.2 for centrifugal separation. Under the control of the opening regulator 12.3, it enters the activation zone 12.5 through the partitioned pipe 12.4. The bottom of the activation zone 12.5 is connected to an oxygen-enriched gas supply pipe 13 to provide oxygen-enriched gas for oxidative regeneration of the deactivated catalyst at high temperature. Specifically, oxygen-enriched gas is provided at a rate of 800 mL / min within the range of 700℃-800℃, and the reaction is carried out in the activation zone for 15 min. Since the coke on the catalyst surface has been removed by centrifugation, the coke content in the pores is low, and reactivation can be achieved by oxidative regeneration in a short time.

[0056] One end of the feeding auger 11 extends into the activation zone 12.5, and the other end is connected to the catalyst feed pipe 4. It is used to feed the reactivated catalyst back into the pyrolysis reactor 2. The density of the reactivated catalyst is greater than that of the deactivated catalyst. After heating, the two catalysts will separate into layers. The denser reactivated catalyst will be deposited in the lower layer of the activation zone 12.5. Therefore, the feeding auger 11 extends into the bottom of the activation zone 12.5 to drive the reactivated catalyst back into the pyrolysis reactor 2.

[0057] A method for producing oil by melting plastics with tar, comprising:

[0058] Step 1: Grind and wash the waste plastic, and dry it to obtain powdered plastic with a mesh size of less than 200.

[0059] Waste plastic is washed and ground to obtain plastic powder. The purpose of step one is to obtain uniform plastic powder with small particle size so that the subsequent mixing and pyrolysis reaction can proceed smoothly.

[0060] Specifically, the waste plastic is one or more of PE, HDPE, PVC, PET, PP, and PS, with a plastic particle size of 200-300 mesh. This invention preferably uses 300-mesh plastic powder, but other powders with smaller particle sizes can also be used.

[0061] Step 2: Place the plastic powder obtained in Step 1 into a spiral feed tube, introduce tar through the liquid feed tube, and stir thoroughly. The mass ratio of plastic to tar is 10% to 20%.

[0062] The obtained plastic powder is thoroughly mixed with the pre-prepared tar to obtain a homogeneous mixture. Specifically, the mixture is thoroughly stirred using a screw feeder. The purpose of step two is to obtain a plastic powder mixture coated with tar, which serves as a pre-preparation material for subsequent pyrolysis.

[0063] The tar used has the same polarity as the plastic and is mixed through a screw feeder. The preferred mass ratio of plastic to tar is 10%, and the preferred tar is low-grade coal tar or wood tar. The purpose is to reduce industrial costs and achieve higher economic benefits.

[0064] Step 3: Place the mixture obtained in Step 2 at the top of the reactor and introduce gas to create an inert environment inside the reactor. The gas introduction rate is 700 ml / min-1000 ml / min, and the time is 20 min-40 min. Before the reaction, add a catalyst with a catalyst-to-mixture mass ratio of 5%-20%.

[0065] The thoroughly stirred mixture is placed in the upper part of the pyrolysis tube, and an inert gas is introduced into the tube. The purpose of step three is to create an inert environment within the pyrolysis tube, ensuring complete pyrolysis of the mixture and preventing oxidation and combustion reactions. Furthermore, the addition of a catalyst lowers the activation energy of the reaction, reducing the pyrolysis temperature and further promoting complete pyrolysis.

[0066] Specifically, the inert gas introduced is at least one of argon, helium, and nitrogen, at an inlet rate of 800 ml / min for 30 min. The catalyst used is preferably ZSM-5 or CaO, based on experimental results.

[0067] Step 4: Pyrolyze the mixture under an inert atmosphere to allow the plastic to fully dissolve in the tar. The pyrolysis temperature is 150℃~300℃, the heating rate is 10℃ / min-20℃ / min, and the pyrolysis time is 20-40min.

[0068] The purpose of step four is to fully combine the two materials through high-temperature melting to obtain a liquid product, which is then subjected to pyrolysis to obtain a light oil product with a low molecular weight, thereby achieving better economic benefits.

[0069] Specifically, the inert atmosphere during the pyrolysis reaction is at least one of argon, helium, and nitrogen, and the gas introduction rate is 200 ml / min. Alternatively, the introduced gas can be air, and the reaction temperature is required to be 100℃-150℃.

[0070] Step 5: Classify the reaction mixture, pass the solid-liquid mixture into a solid-liquid separator, and pass the gas through a distribution box;

[0071] The reacted solid-liquid mixture is fed into a solid-liquid separator via a conduit, with the liquid product flowing directly into a storage tank. The reacted gas is stored in an air distribution box. Specifically, the flow rate in the air distribution box should be lower than the ventilation rate.

[0072] The purpose of step five is to classify and recover the products obtained from the reaction. The liquid oil generated and remaining from the reaction is collected in a storage tank for subsequent recycling, while the remaining solid mixture is classified and recovered by subsequent equipment.

[0073] Step 6: Collect the oil in the storage tank and pass the solid mixture into the catalytic regeneration unit through the feeding auger. Collect the deactivated catalyst and add it to the catalyst regeneration device for recycling.

[0074] The oil in the storage tank is collected using an oil suction pipe, and the remaining liquid on the pipe wall can be collected by rinsing with solvent. The separated solid waste mainly consists of deactivated catalyst and coke produced by pyrolysis. Since the catalyst itself hardly participates in the reaction, and the carbonaceous solids are mainly generated in the pores on the catalyst surface during pyrolysis, a large amount of carbon deposits are present on the catalyst surface. These are classified by a built-in centrifugal separator. The deactivated catalyst with carbon deposits on the surface enters the rotating drum of the separator. During high-speed rotation, under the influence of centrifugal force, the denser catalyst particles move outward along the axis and enter the collection chamber on the outside of the separator for regeneration. The coke on the outside of the catalyst with lower density is discharged outward through the inner channel of the axis. The deactivated catalyst is then fed into a catalyst regeneration device for reuse, reducing costs. The remaining solid carbon is discharged through a pipe.

[0075] Specifically, the solvent used for oil recovery is acetone solution. Heavy oil in the storage tank is circulated into the reaction tube through a circulation pipe to form a circulation loop, while light oil is collected through a condenser bottle. The components remaining on the bottle wall are preferably collected by rinsing with acetone solvent.

[0076] Step 7: Adjust the air distribution box, calibrate the appropriate flow rate, and introduce the gas into the serpentine condenser. After condensation, the gas is connected to the heavy oil separator. The separated heavy oil is then introduced into the purifier and collected in the heavy oil storage tank for recycling. The remaining light oil components are collected in the condenser flask, and the gas is absorbed by the colorless silica gel in the second condenser flask before being introduced into the gas collection device.

[0077] Step 8: Recover the remaining gas and liquid in the tube after the experiment.

[0078] After the experiment, continue to purge the gas into the pipeline. After a period of time, flush the pipeline with a reagent and collect the liquid in the pipeline. Specifically, nitrogen is preferred as the gas to be purged, and acetone or ethanol is preferred as the flushing reagent. The gas purging rate is 800 ml / min, and the time is 30-40 min.

[0079] The following are specific embodiments of the present invention:

[0080] (1) Screen, wash and crush the purchased plastic to below 200 mesh, dry it in an air drying oven at 80℃ for 24 hours, and take the dried plastic granules for later use.

[0081] (2) Take 2g of plastic granules, mix them with an appropriate amount of tar at a mass fraction ratio of 1:10, stir for 10 minutes, and place them into the upper part of the reactor after they are evenly mixed.

[0082] (3) The mixture was pyrolyzed using a fixed-bed reactor with a diameter of 4 cm and a length of 60 cm. Before pyrolysis, nitrogen gas was introduced into the reactor at a rate of 800 ml / min for 30 min. After an inert atmosphere was formed in the reactor, a catalyst with a mass fraction of 10% was added. The reactor was heated uniformly to 200 °C at a rate of 20 °C / min. The mixture was placed in the middle of the reactor and the reaction time was 30 min to allow the mixture to be fully pyrolyzed.

[0083] (4) The gas after the reaction is passed into the air distribution box for cooling, and after the appropriate flow rate is calibrated, it is passed into the serpentine condenser to collect the purified heavy oil product; at the same time, the solid-liquid mixture in the reactor is passed into the separator to collect the filtered liquid product, and the solid product is passed into the separator to precipitate the catalyst.

[0084] (5) Pass the obtained catalyst into the catalyst regeneration device, restore it and recycle it, and put the purified heavy oil into the heavy oil storage tank for later use.

[0085] After the experiment, the experimental instruments were rinsed with acetone and then washed twice with ethanol.

[0086] The results showed that pyrolysis following tar melting of plastics resulted in a high oil production rate and gas yield, but a relatively low solids yield. In contrast, plastics not coated with solvents exhibited higher solids yields due to uneven heating and the inability to undergo pyrolysis after melting.

[0087] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A waste plastic pyrolysis oil production system, characterized in that: It includes a pyrolysis reaction unit, a gas input unit, a condensation cycle unit, and a catalytic regeneration unit, among which, The pyrolysis reaction unit includes a heavy oil feed pipe, a tubular pyrolysis reactor, and a catalyst feed pipe. The tubular pyrolysis reactor is equipped with a screw feeder, and the material inlet of the screw feeder is connected to the crusher through a telescopic feeder. The heavy oil feed pipe and the catalyst feed pipe are both connected to the feed end of the screw feeder, and are used to mix the waste plastic powder, heavy oil and catalyst evenly. The gas input unit is connected to the inlet end of the tubular pyrolysis reactor and is used to introduce inert gas into it; The condensation circulation unit is connected to the outlet of the tubular pyrolysis reactor and is used to condense and recover the pyrolysis products of waste plastics. The catalytic regeneration unit includes a catalyst regeneration device and an oxygen-enriched gas supply pipe. The catalyst regeneration device is arranged from top to bottom as follows: a feeding auger, a built-in centrifugal separator, an opening regulator, a partitioned pipeline, and an activation zone. The feeding auger is connected to the solid outlet of the solid-liquid separator. The upper end of the opening regulator is located at the outlet of the built-in centrifugal separator, and the lower end is connected to the partitioned pipeline, which is connected to the activation zone. It is used to receive the deactivated catalyst obtained from centrifugal separation and transport the deactivated catalyst to the activation zone for activation. The activation zone is connected to the oxygen-enriched gas supply pipe. One end of the feeding auger extends into the bottom of the activation zone, and the other end is connected to the catalyst feed pipe, which is used to feed the reactivated catalyst back into the tubular pyrolysis reactor.

2. The waste plastic pyrolysis oil production system according to claim 1, characterized in that: The crusher discharge port is connected to a telescopic feeder. A temperature control switch is installed at the end of the telescopic feeder. The temperature sensor of the temperature control switch extends into the constant temperature zone of the pyrolysis furnace to detect the constant temperature inside the tube. Once the required temperature is reached, the material is fed into the screw feeder.

3. The waste plastic pyrolysis oil production system according to claim 1, characterized in that: The starting end of the circulation pipe of the condensation circulation unit is connected to the discharge end of the tubular pyrolysis reactor, and the end of the circulation pipe is connected to the inside of the tubular pyrolysis reactor.

4. The waste plastic pyrolysis oil production system according to claim 3, characterized in that: The circulation pipeline is equipped with an air distribution box, a condenser, a heavy oil separator, a heavy oil purifier, and a heavy oil condenser in sequence from the beginning to the end.

5. The waste plastic pyrolysis oil production system according to claim 4, characterized in that: The heavy oil separator is a multi-stage condensation device.

6. The waste plastic pyrolysis oil production system according to claim 4, characterized in that: It also includes a light oil condenser bottle, whose inlet is connected to the light oil outlet of the heavy oil separator, and the bottle body is immersed in a water bath.

7. The waste plastic pyrolysis oil production system according to claim 1, characterized in that: It also includes an oil storage tank, which is connected to the liquid outlet of the solid-liquid separator.

8. A method for producing oil from waste plastics using the waste plastic pyrolysis oil production system according to any one of claims 1-7, characterized in that: Includes the following steps: Step 1: Grind and wash the waste plastic, and dry it to obtain waste plastic powder with a mesh size of less than 200. Step 2: Mix waste plastic powder, heavy oil and catalyst evenly using a screw feeder. The mass ratio of waste plastic powder to heavy oil is 1-2:

10. Step 3: Introduce gas to create an inert environment inside the reactor; Step 4: Pyrolyze the mixture under an inert atmosphere; the pyrolysis temperature is 150-300℃, and the pyrolysis time is 20-40 min. Step 5: Classify the reaction mixture. The solid-liquid mixture is passed into a solid-liquid separator, and the gas is passed through a gas distribution box. The reaction mixture is then passed into the solid-liquid separator through a conduit, and the separated liquid product flows directly into the oil storage tank. Step 6: Collect the oil from the storage tank and pass the solid mixture into the catalytic regeneration unit through the feeding auger. Collect the deactivated catalyst and add it to the catalyst regeneration device for recycling. Step 7: Adjust the air distribution box, calibrate the appropriate flow rate, and introduce the air into the condenser tube. After condensation, the air is connected to the heavy oil separator. The separated heavy oil is introduced into the heavy oil purifier and collected in the heavy oil condenser for recycling. The remaining light oil components are collected by the light oil condenser bottle. The gas is absorbed by the colorless silica gel in the second condenser bottle and then introduced into the gas collection device.

9. The method for producing oil from waste plastic pyrolysis according to claim 8, characterized in that: The waste plastics are selected from one or more of PE, HDPE, PVC, PET, PP, and PS.

10. The method for producing oil from waste plastic pyrolysis according to claim 8, characterized in that: The waste plastic powder was passed through a 300-mesh sieve.

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