A processing method and system for fluidized cracking of waste plastics

Abstract

The present disclosure relates to a processing method and system for fluidized cracking of waste plastics, the method comprising the following steps: allowing waste plastic particles to continuously enter a cracking reactor under the action of a carrier gas to contact with a fluidized contact agent, perform a cracking reaction, and obtain cracking products and a contact agent to be regenerated; allowing the cracking products to enter a separation unit for separation treatment, and obtain dry gas, liquefied gas, gasoline fraction, diesel fraction, and wax oil fraction. The present disclosure can use a carrier gas to introduce solid waste plastic particles into a cracking reactor for fluidized cracking, thereby achieving continuous cracking and resource utilization of waste plastics.

Description

Technical Field

[0001] The present disclosure relates to the field of waste plastic resource recycling and processing, and in particular, to a processing method and system for fluidized cracking of waste plastic. Background Art

[0002] With the advancement of science and technology and industrial development, plastics are widely used as packaging materials in people's daily lives. Used waste plastics cannot be decomposed by themselves in nature. Only a few types of waste plastics can be reprocessed and reused through specific recycling channels. A large amount of waste plastics enters landfills in the form of domestic garbage. Since waste plastics are not easy to decompose, they occupy a lot of space. In recent years, the amount of waste plastics has increased rapidly. It has become an urgent task to recycle waste plastics quickly and greenly.

[0003] The simplest way to deal with waste plastics is to incinerate them directly, but direct incineration will produce toxic gases that are harmful to the human body and cause secondary environmental pollution. Waste plastic pyrolysis technology is to pyrolyze waste plastics under anaerobic or anoxic conditions by heating or with a catalyst to pyrolyze polymers into low molecular weight substances, and obtain gasoline, kerosene, diesel fractions and some pyrolysis gases. On the one hand, waste plastic pyrolysis technology alleviates the pollution problem caused by waste plastics, and on the other hand, it realizes the recycling of waste plastics, which is an important direction for the resource treatment of waste plastics.

[0004] At present, waste plastic cracking and recycling technologies mainly include waste plastic pyrolysis and catalytic pyrolysis technologies. CN107746722A discloses a method and device for preparing gasoline and diesel by cracking waste plastics. The system dissolves the crushed and impurity-removed waste plastics in liquid pyrolysis oil, and melts, dehydrates, dechlorinates, and cracks to improve the quality through precise temperature control. The process requires a large amount of solvent oil. For example, CN101374930A discloses a method and device for contact decomposition of waste plastics, which belongs to catalytic pyrolysis technology. A heated and stirred rotary kiln is used as a reactor, an FCC catalyst is used as a heat medium and a catalytic center, and an appropriate amount of Ca and Fe compounds are added to decompose the waste plastics at 350 to 500 ° C. However, after the device is operated for a period of time, the contact agent in the reactor needs to be taken out and regenerated. More waste plastic cracking technologies use intermittent thermal cracking reactors. Such methods have the problem of small processing scale, and impurities in the product cannot be removed. Summary of the invention

[0005] The purpose of the present disclosure is to provide a processing method and system for fluidized cracking of waste plastics, which can use a carrier gas to introduce solid waste plastic particles into a cracking reactor for fluidized cracking, thereby achieving continuous cracking and resource utilization of waste plastics.

[0006] In order to achieve the above-mentioned object, the present disclosure provides a first aspect of a processing method for fluidized cracking of waste plastics, comprising the following steps:

[0007] S1. The waste plastic particles are continuously introduced into a cracking reactor under the action of a carrier gas to contact with a fluidized contact agent to carry out a cracking reaction, thereby obtaining a cracking product and a contact agent to be regenerated;

[0008] S2. The cracking products are sent into a separation unit for separation treatment to obtain dry gas, liquefied gas, gasoline fraction, diesel fraction and wax oil fraction.

[0009] Optionally, in step S1, the cracking reactor is a fluidized bed reactor, and the conditions of the cracking reaction include: a reaction temperature of 450 to 700°C, preferably 490 to 600°C; a weight hourly space velocity of 1 to 100 h -1 ; The mass ratio of the contact agent to the waste plastic particles is (1-30):1, preferably (5-20):1.

[0010] Optionally, the method also includes: dividing the dry gas separated by the separation unit into at least two parts, so that the first part of the dry gas is used as the carrier gas for transporting the waste plastic particles; and the second part of the dry gas and the contact agent to be regenerated enter the contact agent regeneration unit respectively to regenerate the contact agent to be regenerated; and returning the regenerated contact agent to the continuous contact cracking unit; optionally, based on the total weight of the contact agent to be regenerated, the carbon content of the contact agent to be regenerated is 0.5% by weight to 5.0% by weight.

[0011] Optionally, before step S1, the method further comprises: S0, subjecting the chlorine-containing waste plastic raw material to hot-melt dechlorination treatment to obtain hydrogen chloride-containing gas and dechlorinated waste plastic cracking raw material; subjecting the dechlorinated waste plastic cracking raw material to cooling treatment and crushing treatment to obtain the waste plastic particles.

[0012] Optionally, step S0 includes: in a waste plastic raw material processing unit, heating, melting and dehydrating the chlorine-containing waste plastic raw material under shear conditions; then drawing out the water-containing air in the waste plastic raw material processing unit to obtain dehydrated and deaired waste plastic; continuing to heat the dehydrated and deaired waste plastic in the waste plastic raw material processing unit to perform dechlorination treatment to obtain dehydrated and dechlorinated waste plastic; and sequentially performing the cooling treatment and crushing treatment on the dehydrated and dechlorinated waste plastic to obtain the waste plastic particles.

[0013] Optionally, the process conditions in the waste plastic raw material processing unit include: the dehydration treatment temperature is 100-150°C, preferably 100-120°C; the dechlorination treatment reaction temperature is 150-370°C, preferably 300-350°C, the reaction time is 0.1-0.5h, preferably 0.2-0.4h; the particle size of the obtained waste plastic particles is 100-2000μm.

[0014] Optionally, in step S1, the carrier gas is nitrogen or at least part of the dry gas obtained by the separation unit, preferably the dry gas from the separation unit; the mass ratio of the carrier gas to the waste plastic particles is 0.05 to 1:1, and the carrier gas temperature is below 80°C, preferably 40 to 80°C.

[0015] Optionally, in step S1, the contact agent is one or more selected from a silica-alumina material catalyst, quartz sand or coal char powder; preferably, the particle size of the contact agent is 20 to 3000 μm; optionally, the silica-alumina material is selected from a catalyst containing a molecular sieve and / or a catalyst not containing a molecular sieve; preferably, the catalyst containing a molecular sieve is selected from a catalyst containing one or more molecular sieves selected from X molecular sieve, Y molecular sieve, mordenite, ZSM-5, columnar clay molecular sieve, SAPO, and one or more waste FCC catalysts; preferably, the catalyst not containing a molecular sieve is selected from a catalyst containing one or more of the first raw materials. A catalyst prepared from raw materials, wherein the first raw material includes amorphous silica-alumina, kaolin, montmorillonite, rectorite, illite, chlorite, pseudo-boehmite, and silicon dioxide; or a catalyst prepared from one or more of the second raw materials treated by acid washing, calcination, and screening as raw materials, wherein the second raw material includes amorphous silica-alumina, kaolin, montmorillonite, rectorite, illite, and chlorite; or a catalyst prepared from one or more of the second raw materials treated by acid washing, calcination, and screening and pseudo-boehmite and / or silicon dioxide as raw materials; optionally, the coal tar powder is coal powder and / or petroleum coke powder.

[0016] Optionally, the regeneration treatment is carried out in a dense fluidized bed regenerator; preferably, the process conditions of the regeneration treatment include: air residence time of 0.5 to 60 seconds, preferably 1.0 to 10 seconds, the gasification temperature of the dense bed is 600 to 750°C, preferably 600 to 700°C, the gas introduced is a gas containing 10 to 50 volume % oxygen, and the linear velocity of the dense bed is 0.05 to 0.6 m / s, preferably 0.2 to 0.4 m / s.

[0017] Optionally, the method further comprises: allowing the hydrogen chloride-containing gas to enter a hydrogen chloride absorption unit and contact the hydrogen chloride absorbent to perform hydrogen chloride absorption treatment; optionally, allowing the hydrogen chloride-containing gas to enter the hydrogen chloride absorption unit under the action of a vacuum system; wherein the hydrogen chloride absorbent is water or an alkaline solution with a pH greater than 7; optionally, the alkaline solution comprises one or more of a sodium hydroxide solution, a potassium hydroxide solution, a calcium hydroxide solution, a sodium bicarbonate solution, a sodium carbonate solution and an ammonia solution.

[0018] Optionally, the waste plastic particles include one or more of PVC, LDPE, HDPE, PS, PP and PET; preferably include PVC and one or more selected from PVC, LDPE, HDPE, PS, PP and PET; based on the total weight of the dried waste plastics, the content of PVC is less than 10 weight%, and the ash content is 1 to 40 weight%, preferably 5 to 20 weight%.

[0019] A second aspect of the present disclosure provides a processing system for fluidized cracking of waste plastics, the system comprising a continuous contact catalytic cracking unit and a separation unit; the continuous contact cracking unit is provided with a cracking feed inlet, a contact agent inlet, a continuous reactor, a cracking product outlet and a catalyst outlet to be regenerated; the separation unit is provided with a cracking product separation inlet, a dry gas outlet, a liquefied gas outlet, a gasoline fraction outlet, a diesel fraction outlet and a wax oil fraction outlet; the cracking feed inlet is respectively connected to a waste plastic source and a carrier gas source so that the waste plastic source enters the continuous contact cracking unit under the action of the carrier gas; the contact agent inlet of the contact catalytic cracking unit introduces fresh contact agent through a first pipeline; the cracking product outlet is connected to the cracking product separation inlet of the separation unit.

[0020] Optionally, the system further comprises a waste plastic raw material processing unit, a contact agent regeneration unit and a hydrogen chloride absorption unit; the waste plastic raw material processing unit is provided with a waste plastic raw material inlet, a hydrogen chloride-containing gas outlet and a dechlorinated waste plastic cracking raw material outlet, and the dechlorinated waste plastic cracking raw material outlet of the waste plastic raw material processing unit is connected with the cracking raw material inlet of the contact catalytic cracking unit; optionally, the waste plastic raw material processing unit comprises a waste plastic melting dechlorination device and a cooling and crushing device; the inlet of the waste plastic melting dechlorination device is formed as the waste plastic raw material inlet, and the outlet of the waste plastic melting dechlorination device is formed as The outlet for dechlorinated material, optionally, the waste plastic melting dechlorination device also includes a waste gas outlet, which is formed as the outlet for hydrogen chloride-containing gas; the inlet for the material to be dechlorinated is connected to the outlet for the molten material; the cooling and crushing device is provided with an inlet for cooling and crushing and an outlet for waste plastic particles, the inlet for cooling and crushing is connected to the outlet for dechlorinated material, and the outlet for waste plastic particles is formed as the outlet for dechlorinated waste plastic cracking raw materials; optionally, the waste plastic melting dechlorination device is a hot screw pump; the contact agent regeneration unit is provided with an inlet for contact agent to be regenerated, an air inlet, a second dry gas inlet, The flue gas outlet and the regenerated catalyst outlet are connected; the inlet of the contact agent to be regenerated is connected to the outlet of the contact agent to be regenerated of the continuous contact cracking unit, the second dry gas inlet is connected to the lead-out pipeline of the dry gas outlet of the separation unit, and the regenerated contact agent outlet is connected to the contact agent inlet of the continuous contact cracking unit through a second pipeline; the hydrogen chloride absorption unit is provided with a hydrogen chloride-containing gas inlet and a dechlorination gas outlet, and the hydrogen chloride-containing gas inlet is connected to the hydrogen chloride-containing gas outlet of the waste plastic raw material processing unit; the waste plastic raw material processing unit also includes a shearing device and a water-containing air outlet; optionally The system also includes a particle transmission unit, which includes an input port, an output port and a carrier gas inlet, wherein the input port is connected to the dechlorinated waste plastic cracking raw material outlet of the waste plastic raw material processing unit, the output port is connected to the cracking raw material inlet of the contact catalytic cracking unit, and the carrier gas inlet is connected to a carrier gas source for introducing a carrier gas into the particle transmission unit so that the particulate material from the dechlorinated waste plastic cracking raw material outlet enters the cracking raw material inlet under the purge action of the carrier gas; optionally, the carrier gas inlet of the particle transmission unit is connected to the lead-out pipeline of the dry gas outlet of the separation unit.

[0021] Through the above technical scheme, the present disclosure provides a processing method and system for fluidized cracking of waste plastics. The method can directly send waste plastic particles into a cracking reactor under the action of a carrier gas to contact with a fluidized contact agent to carry out a cracking reaction, thereby realizing fluidized cracking of solid waste plastics and recycling of waste plastics; there is no need to melt the waste plastic particles or add solvent oil; and fluidized cracking is also easy to achieve large-scale processing and production; the waste plastic particles are sent into a cracking reactor by using a carrier gas to contact with a high-temperature heat carrier for rapid pyrolysis, thereby reducing the residence time of the products and obtaining a more ideal product distribution; the method has strong adaptability to raw materials, and the waste plastics in the landfill can be dehydrated, dechlorinated and reduced in situ, and the subsequent cracking recovery can be processed in a centralized manner, which is easy to expand the production scale and reduce the processing cost.

[0022] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0024] Figure 1 A schematic flow chart of the processing method for fluidized cracking of waste plastics provided in the present invention.

[0025] Description of Reference Numerals

[0026] 1- Waste plastic storage tank, 2- Waste plastic raw material processing unit, 3- Particle transmission unit, 4- Continuous contact catalytic cracking unit, 5- Contact agent regeneration unit, 6- Separation unit, 7- Hydrogen chloride absorption unit DETAILED DESCRIPTION

[0027] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0028] In the present disclosure, unless otherwise stated, the words "first", "second", "third", etc. are used only to distinguish different components and do not have actual meanings such as the order of connection. In the present disclosure, the directional words used, such as "upper, lower, top, bottom", generally refer to the upper and lower, top and bottom of the device in normal use. "Inside and outside" refer to the outline of the device.

[0029] The first aspect of the present disclosure provides a processing method for fluidized cracking of waste plastics, such as Figure 1 As shown, the following steps are included:

[0030] S1. The waste plastic particles are continuously introduced into a cracking reactor under the action of a carrier gas to contact with a fluidized contact agent to carry out a cracking reaction, thereby obtaining a cracking product and a contact agent to be regenerated;

[0031] S2. The cracking products are sent into a separation unit for separation treatment to obtain dry gas, liquefied gas, gasoline fraction, diesel fraction and wax oil fraction.

[0032] The method provided by the present disclosure can directly send waste plastic particles into a cracking reactor under the action of a carrier gas to contact with a fluidized contact agent to carry out a cracking reaction, thereby realizing fluidized cracking of solid waste plastics and recycling of waste plastics; there is no need to melt the waste plastic particles or add solvent oil; and fluidized cracking is also easy to achieve large-scale processing and production; the waste plastic particles are sent into a cracking reactor using a carrier gas to contact with a high-temperature heat carrier for rapid pyrolysis, thereby reducing the residence time of the products and obtaining a more ideal product distribution.

[0033] In the present disclosure, the cracking reactor used for fluidized cracking and the device used for product separation are all conventionally selected devices in the art.

[0034] In one embodiment, the waste plastic particles include one or more of PVC, LDPE, HDPE, PS, PP and PET; preferably include PVC and one or more selected from PVC, LDPE, HDPE, PS, PP and PET; based on the total weight of the dried waste plastics, the content of PVC is less than 10 weight%, and the ash content is 1 to 40 weight%, preferably 5 to 20 weight%.

[0035] In one embodiment, in step S1, the cracking reactor is a fluidized bed reactor, and the conditions of the cracking reaction include: a reaction temperature of 450 to 700°C, preferably 490 to 600°C; a weight hourly space velocity of 1 to 100 h -1 ; The mass ratio of the contact agent to the waste plastic particles is (1-30):1, preferably (5-20):1.

[0036] In one embodiment, if Figure 1 As shown, the method further includes: dividing the dry gas separated by the separation unit into at least two parts, and using the first part of the dry gas as the carrier gas for transporting the waste plastic particles; and

[0037] The second part of the dry gas and the contact agent to be regenerated are respectively introduced into the contact agent regeneration unit to regenerate the contact agent to be regenerated; the regenerated contact agent is returned to the continuous contact cracking unit; optionally, the carbon content of the contact agent to be regenerated is 0.5 wt% to 5.0 wt% based on the total weight of the contact agent to be regenerated. In the present disclosure, the dry gas obtained by separating the cracking product is used as a carrier gas for conveying waste plastic particles and for sintering and regenerating the catalyst to be regenerated in the contact agent regeneration unit, so that the cracking dry gas can be further utilized, and when the carbon content of the contact agent to be regenerated is high, the introduction of dry gas during the regeneration process can improve the sintering and regeneration efficiency of the contact agent.

[0038] In one embodiment, if Figure 1 As shown, before step S1, the method further includes:

[0039] S0, subjecting the chlorine-containing waste plastic raw material to hot melt dechlorination treatment to obtain hydrogen chloride-containing gas and dechlorinated waste plastic cracking raw material; subjecting the dechlorinated waste plastic cracking raw material to cooling treatment and crushing treatment to obtain the waste plastic particles. The present disclosure can achieve effective dechlorination of chlorine-containing waste plastic, and further achieve the removal of chlorine element in subsequent fluidized cracking products.

[0040] In a further embodiment, Figure 1 As shown, step S0 includes:

[0041] In the waste plastic raw material processing unit, the chlorine-containing waste plastic raw material is heated, melted and dehydrated under shearing conditions; then the water-containing air in the waste plastic raw material processing unit is drawn out to obtain dehydrated and de-aired waste plastic;

[0042] The dehydrated and deaerated waste plastic is heated up in the waste plastic raw material processing unit to perform dechlorination treatment to obtain dehydrated and dechlorinated waste plastic; the dehydrated and dechlorinated waste plastic is subjected to the cooling treatment and crushing treatment in sequence to obtain the waste plastic particles. The present invention has strong adaptability to raw materials. The waste plastic in the landfill can be dehydrated and dechlorinated in situ, and the subsequent cracking and recovery can be processed in a centralized manner, which is easy to expand the production scale and reduce the processing cost.

[0043] In one embodiment, the process conditions in the waste plastic raw material processing unit include: wherein the dehydration treatment temperature is 100-150°C, preferably 100-120°C; the dechlorination treatment reaction temperature is 150-370°C, preferably 300-350°C, and the reaction time is 0.1-0.5h, preferably 0.2-0.4h;

[0044] The particle size of the obtained waste plastic particles is 100 to 3000 μm.

[0045] In one embodiment, in step S1, the carrier gas is nitrogen or at least part of the dry gas obtained by the separation unit, preferably the dry gas from the separation unit; the mass ratio of the carrier gas to the waste plastic particles is 0.05 to 1:1, and the carrier gas temperature is below 80°C, preferably 40 to 80°C.

[0046] In one embodiment, in step S1, the contact agent is one or more selected from silicon-aluminum material catalyst, quartz sand or coal coke powder; preferably, the particle size of the contact agent is 20 to 3000 μm;

[0047] Optionally, the silicon-aluminum material is selected from a catalyst containing a molecular sieve and / or a catalyst not containing a molecular sieve; preferably, the catalyst containing a molecular sieve is a catalyst containing one or more molecular sieves selected from X molecular sieve, Y molecular sieve, mordenite, ZSM-5, pillared clay molecular sieve, SAPO, and one or more waste FCC catalysts;

[0048] Preferably, the catalyst not containing molecular sieve is selected from a catalyst prepared with one or more of the first raw materials as raw materials, wherein the first raw material includes amorphous silica-alumina, clay, kaolin, montmorillonite, rectorite, illite, chlorite, pseudo-boehmite, and silicon dioxide; or

[0049] A catalyst selected from one or more of the second raw materials that have been acid-washed, calcined, and sieved as raw materials, wherein the second raw materials include amorphous silica-alumina, clay, kaolin, montmorillonite, rectorite, illite, and chlorite; or a catalyst selected from one or more of the second raw materials that have been acid-washed, calcined, and sieved and pseudo-boehmite and / or silicon dioxide as raw materials;

[0050] Optionally, the coal tar powder is coal powder and / or petroleum coke powder.

[0051] In one embodiment, in step S2, the regeneration process is performed in a dense phase-fluidized bed regenerator;

[0052] Preferably, the regeneration treatment is carried out in a dense fluidized bed regenerator; preferably, the process conditions of the regeneration treatment include: air residence time of 0.5 to 60 seconds, preferably 1.0 to 10 seconds, dense bed gasification temperature of 600 to 750°C, preferably 600 to 700°C, gas introduced is a gas containing 10 to 50% by volume of oxygen, and the linear velocity of the dense bed is 0.05 to 0.6 m / s, preferably 0.2 to 0.4 m / s. The dense fluidized bed regenerator in the present disclosure adopts a device conventionally selected in the art.

[0053] In one embodiment, if Figure 1As shown, the method further comprises: allowing the hydrogen chloride-containing gas to enter a hydrogen chloride absorption unit to contact with a hydrogen chloride absorbent for hydrogen chloride absorption treatment; optionally, allowing the hydrogen chloride-containing gas to enter the hydrogen chloride absorption unit under the action of a vacuum system;

[0054] The hydrogen chloride absorbent is water or an alkali solution with a pH greater than 7; optionally, the alkali solution includes one or more of sodium hydroxide solution, potassium hydroxide solution, calcium hydroxide solution, sodium bicarbonate solution, sodium carbonate solution and ammonia water.

[0055] In the dechlorination treatment disclosed herein, chlorine in PVC is decomposed into a gas phase, and a vacuum system is used to quickly separate HCl, thereby avoiding secondary reaction of HCl, improving the dechlorination efficiency of waste plastics, and reducing the anti-corrosion pressure of subsequent equipment.

[0056] The second aspect of the present disclosure provides a processing system for fluidized cracking of waste plastics, such as Figure 1 As shown, the system includes a continuous contact catalytic cracking unit 4 and a separation unit 6;

[0057] The continuous contact cracking unit 4 is provided with a cracking feed inlet, a contact agent inlet, a continuous reactor, a cracking product outlet and a catalyst outlet to be regenerated;

[0058] The separation unit 6 is provided with a cracking product separation inlet, a dry gas outlet, a liquefied gas outlet, a gasoline fraction outlet, a diesel fraction outlet and a wax oil fraction outlet;

[0059] The cracking raw material inlet is respectively connected with the waste plastic source and the carrier gas source so that the waste plastic source enters the continuous contact cracking unit under the action of the carrier gas;

[0060] The contact agent inlet of the contact catalytic cracking unit introduces fresh contact agent through the first pipeline; the cracked product outlet is connected to the cracked product separation inlet of the separation unit 6.

[0061] In one embodiment, if Figure 1 As shown, the system also includes a waste plastic raw material processing unit 2, a contact agent regeneration unit 5 and a hydrogen chloride absorption unit 7;

[0062] The waste plastic raw material processing unit 2 includes a waste plastic melting dechlorination device and a cooling and crushing device; the inlet of the waste plastic melting dechlorination device is formed as a waste plastic raw material inlet, and the outlet of the waste plastic melting dechlorination device is formed as a dechlorinated material outlet. Optionally, the waste plastic melting dechlorination device also includes a waste gas outlet, and the waste gas outlet is formed as a hydrogen chloride-containing gas outlet; the inlet of the material to be dechlorinated is connected with the outlet of the molten material; the cooling and crushing device is provided with an inlet to be cooled and crushed and an outlet for waste plastic particles, the inlet to be cooled and crushed is connected with the outlet for dechlorinated material, and the outlet for waste plastic particles is formed as an outlet for dechlorinated waste plastic cracking raw materials; optionally, the waste plastic melting dechlorination device is a hot screw pump;

[0063] The contact agent regeneration unit 5 is provided with an inlet for the contact agent to be regenerated, an air inlet, a second dry gas inlet, a flue gas outlet and a regenerated catalyst outlet; the inlet for the contact agent to be regenerated is connected with the outlet for the contact agent to be regenerated of the continuous contact cracking unit, the second dry gas inlet is connected with the lead-out pipeline of the dry gas outlet of the separation unit, and the outlet for the regenerated contact agent is connected with the inlet for the contact agent of the continuous contact cracking unit through the second pipeline;

[0064] The hydrogen chloride absorption unit 7 is provided with a hydrogen chloride-containing gas inlet and a dechlorinated gas outlet, and the hydrogen chloride-containing gas inlet is connected to the hydrogen chloride-containing gas outlet of the waste plastic raw material processing unit 2;

[0065] The waste plastic material processing unit 2 also includes a shearing device and a water-containing air outlet;

[0066] Optionally, the system also includes a particle transmission unit 3, which includes an input port, an output port and a carrier gas inlet, wherein the input port is connected to the dechlorinated waste plastic cracking raw material outlet of the waste plastic raw material processing unit 2, the output port is connected to the cracking raw material inlet of the contact catalytic cracking unit 4, and the carrier gas inlet is connected to a carrier gas source for introducing a carrier gas into the particle transmission unit 3 so that the particulate material from the dechlorinated waste plastic cracking raw material outlet enters the cracking raw material inlet under the purge action of the carrier gas.

[0067] In one embodiment, the carrier gas inlet of the particle transport unit 3 is connected to the outlet pipeline of the dry gas outlet of the separation unit 6 .

[0068] In a specific implementation manner, Figure 1 As shown, the system includes a waste plastic storage tank 1, a waste plastic raw material processing unit 2, a particle transmission unit 3, a continuous contact catalytic cracking unit 4, a contact agent regeneration unit 5, a separation unit 6 and a hydrogen chloride absorption unit 7; wherein

[0069] The continuous contact cracking unit 4 is provided with a cracking feed inlet, a contact agent inlet, a continuous reactor, a cracking product outlet and a catalyst outlet to be regenerated;

[0070] The separation unit 6 is provided with a cracking product separation inlet, a dry gas outlet, a liquefied gas outlet, a gasoline fraction outlet, a diesel fraction outlet and a wax oil fraction outlet;

[0071] The cracking raw material inlet is respectively connected with the waste plastic source and the carrier gas source so that the waste plastic source enters the continuous contact cracking unit under the action of the carrier gas;

[0072] The contact agent inlet of the contact catalytic cracking unit introduces fresh contact agent through the first pipeline; the cracked product outlet is connected to the cracked product separation inlet of the separation unit 6;

[0073] The waste plastic raw material processing unit 2 is provided with a waste plastic raw material inlet, a hydrogen chloride-containing gas outlet and a dechlorinated waste plastic cracking raw material outlet, and the dechlorinated waste plastic cracking raw material outlet of the waste plastic raw material processing unit 2 is connected to the cracking raw material inlet of the contact catalytic cracking unit 4;

[0074] The waste plastic raw material processing unit 2 includes a waste plastic melting dechlorination device and a cooling and crushing device; the inlet of the waste plastic melting dechlorination device is formed as a waste plastic raw material inlet, and the outlet of the waste plastic melting dechlorination device is formed as a dechlorinated material outlet. Optionally, the waste plastic melting dechlorination device also includes a waste gas outlet, and the waste gas outlet is formed as a hydrogen chloride-containing gas outlet; the inlet of the material to be dechlorinated is connected with the outlet of the molten material; the cooling and crushing device is provided with an inlet to be cooled and crushed and an outlet for waste plastic particles, the inlet to be cooled and crushed is connected with the outlet for dechlorinated material, and the outlet for waste plastic particles is formed as an outlet for dechlorinated waste plastic cracking raw materials; optionally, the waste plastic melting dechlorination device is a hot screw pump;

[0075] The contact agent regeneration unit 5 is provided with an inlet for the contact agent to be regenerated, an air inlet, a second dry gas inlet, a flue gas outlet and a regenerated catalyst outlet; the inlet for the contact agent to be regenerated is connected with the outlet for the contact agent to be regenerated of the continuous contact cracking unit, the second dry gas inlet is connected with the lead-out pipeline of the dry gas outlet of the separation unit, and the outlet for the regenerated contact agent is connected with the inlet for the contact agent of the continuous contact cracking unit through the second pipeline;

[0076] The hydrogen chloride absorption unit 7 is provided with a hydrogen chloride-containing gas inlet and a dechlorinated gas outlet, and the hydrogen chloride-containing gas inlet is connected to the hydrogen chloride-containing gas outlet of the waste plastic raw material processing unit 2;

[0077] The waste plastic material processing unit 2 also includes a shearing device and a water-containing air outlet;

[0078] The particle transmission unit 3 includes an input port, an output port and a carrier gas inlet, the input port is connected to the dechlorinated waste plastic cracking raw material outlet of the waste plastic raw material processing unit 2, the output port is connected to the cracking raw material inlet of the contact catalytic cracking unit 4, and the carrier gas inlet is connected to a carrier gas source for introducing carrier gas into the particle transmission unit 3 so that the particulate material from the dechlorinated waste plastic cracking raw material outlet enters the cracking raw material inlet under the purge action of the carrier gas; the carrier gas inlet of the particle transmission unit 3 is connected to the lead-out pipeline of the dry gas outlet of the separation unit 6.

[0079] Each device used in the present disclosure is a device conventionally selected in the art.

[0080] like Figure 1 As shown, the specific process flow of waste plastic processing using the waste plastic fluidized cracking processing system provided in the above specific embodiment includes:

[0081] The chlorine-containing waste plastics (including PVC and one or more selected from PVC, LDPE, HDPE, PS, PP and PET) stored in the waste plastic storage tank 1 enter the waste plastic raw material processing unit 2, and are first heated and melted under shear conditions in the waste plastic melting dechlorination device (hot screw pump) to perform dehydration and deaeration. The separated water and air are introduced out of the device through pipeline 20. The dehydrated and deaerated waste material is continuously heated to the dechlorination temperature in the waste plastic melting dechlorination device for dechlorination treatment. The gaseous hydrogen chloride is pumped into the hydrogen chloride absorption unit 7 through the vacuum system, and a small amount of non-condensable gas in the hydrogen chloride absorption unit 7 is discharged through pipeline 21. The dehydrated and dechlorinated waste plastic is cooled and crushed in sequence by a cooling and crushing device, and the waste plastic particles are passed through a particle transmission unit 3. The dry gas from the separation unit 6 is introduced into the particle transmission unit 3 through a pipeline 12 as a carrier, so that the waste plastic particles continuously enter the continuous contact catalytic cracking unit 4 through a pipeline 8 under the action of the carrier gas; the supplemented fresh contact agent 14 and the regenerated contact agent introduced from the contact agent regeneration unit 5 through a pipeline 13 enter the contact cracking unit 4, and the waste plastic particles are contacted with the contact agent in the catalytic cracking unit 4 for cracking reaction, and the generated oil and gas enter the subsequent separation unit 6 through a pipeline 10, and are separated. The separated dry gas leaves the device through pipelines 12 and 18, enters the particle transmission unit 3 and the contact agent regeneration unit 5 as fuel respectively, and the separated liquefied gas and gasoline-diesel wax oil leave the device through pipeline 11; the carbon-bearing contact agent (contact agent to be regenerated) obtained after the catalytic cracking reaction enters the contact agent regeneration unit 5 through pipeline 9, and the coke on the carbon-bearing contact agent and the cracked dry gas from pipeline 18 react completely with the air from pipeline 15, and the generated flue gas leaves the device through pipeline 17, and can be directly discharged into the atmosphere after meeting the standards, and the regenerated contact agent is led out of the regenerator through pipeline 13, and the balance agent and ash are discharged from pipeline 17.

[0082] The present disclosure is described in detail below using examples, but the examples do not limit the scope of application of the present disclosure. The contact agent SL-1 used is prepared by the method disclosed in Example 1 of patent CN102974383A. The average particle size of SL-1 is 80 μm.

[0083] The catalytic cracking catalyst used is the trade name CRC-1 (produced by Qilu Petrochemical Company). The balance agent of the catalytic cracking catalyst is SL-2 with an average particle size of 65 μm; the quartz sand is SL-3 with a particle size of 300 μm.

[0084] In the following examples, the residual chlorine content in the waste plastic raw material and the dechlorinated waste plastic liquid material obtained by dechlorination treatment was tested by fluorescence method (XRF). The particle size of the contact agent was measured by a particle size detector.

[0085] In the following examples, the manufacturer of the high temperature fast pyrolysis chromatograph is Frontier Co., Ltd. of Japan and the model is PY-3030.

[0086] Example 1

[0087] This example is used to test the effect of different temperatures on the dechlorination of waste plastics, and specifically includes the following steps:

[0088] LDPE, HDPE, PS, PP and PVC are mixed in a mass percentage of 4:4:8:3:1, the mixed plastic packaging material is crushed to a particle size of less than 1 cm and then dried, and the mixed plastic is used as a chlorine-containing waste plastic raw material, wherein the chlorine content is 2.9% by weight. A twin-screw pump is used as a device for preliminary melting, liquefaction and dechlorination of waste plastics (i.e., a waste plastic melting dechlorination device), and the feed rate is about 100kg / h.

[0089] The chlorine-containing waste plastic raw material is introduced into a twin-screw pump, heated and melted under the shearing conditions of the twin-screw pump, and first dehydrated at a temperature of 130°C (the temperature of the dehydration treatment is based on the screw inlet temperature); the temperature is continued to rise for dechlorination treatment to obtain dehydrated and dechlorinated waste plastic; the dechlorination treatment reaction temperature is listed in Table 1, and the reaction time is 0.5h (wherein, the outlet temperature of the twin-screw pump is used as the dechlorination reaction temperature, and the time from entering the dechlorination reaction tank to exiting the dechlorination reaction tank is used as the dechlorination time). The outlet temperature of the twin-screw pump is listed in Table 1 below, and the dehydrated and dechlorinated waste plastic particles DCl-1 to DCl-5 series are obtained. The properties of the obtained dehydrated and dechlorinated waste plastic are shown in Table 1.

[0090] DCl-2 was cooled and crushed (particle size was less than 0.2 cm) to obtain waste plastic particles. High-temperature rapid pyrolysis chromatography was used as a reaction analysis device. The reaction temperature was 550°C, the reaction time was 2s, SL-1 was used as a contact agent, and the mass ratio of the contact agent to the waste plastic particles was 7:1. The distribution of pyrolysis reaction products is shown in Table 3.

[0091] Example 2

[0092] The DCl-2 was crushed (particle size was less than 0.5 cm), and a high-temperature rapid pyrolysis chromatography was used as a reaction analysis device. The reaction temperature was 590 °C, SL-3 was used as a contact agent, and the mass ratio of the contact agent to the waste plastic was 20:1. The distribution of the pyrolysis reaction products is shown in Table 3.

[0093] Example 3

[0094] The method of Example 1 was adopted, real waste plastic was used as raw material, a twin-screw pump was used as the equipment for preliminary melting, liquefaction and dechlorination of the waste plastic, the feed rate was about 100 kg / h, the outlet temperature was 220°C, the dechlorination time was 15 min, and liquefied dechlorinated waste plastic DCl-6 was obtained. The properties of the obtained liquefied dechlorinated waste plastic are shown in Table 2.

[0095] The DCl-6 was crushed (particle size was less than 0.3 cm), and a high temperature rapid pyrolysis chromatography was used as a reaction analysis device. The reaction temperature was 510 °C, the reaction time was 30 s, SL-2 was used as a contact agent, and the mass ratio of the contact agent to the waste plastic was 15:1. The distribution of the pyrolysis reaction products is shown in Table 3.

[0096] Example 4

[0097] The method of Example 1 was adopted, real waste plastic was used as raw material, a twin-screw pump was used as the equipment for preliminary melting, liquefaction and dechlorination of the waste plastic, the feed rate was about 100 kg / h, the outlet temperature was 320°C, the dechlorination time was 20 min, and liquefied dechlorinated waste plastic DCl-7 was obtained. The properties of the obtained liquefied dechlorinated waste plastic are shown in Table 2.

[0098] The DCl-7 was crushed (particle size was less than 0.4 cm), and a high temperature rapid pyrolysis chromatography was used as a reaction analysis device. The reaction temperature was 680 °C, the reaction time was 30 s, SL-3 was used as a contact agent, and the mass ratio of the contact agent to the waste plastic was 25:1. The distribution of the pyrolysis reaction products is shown in Table 3.

[0099] Example 5

[0100] use Figure 1 The processing method shown specifically comprises the following steps:

[0101] The invention relates to a method for preparing a plastic packaging material comprising LDPE, HDPE, PS, PP and PVC in a mass percentage of 4:4:8:3:1, crushing and drying the mixed plastic packaging material, wherein the chlorine content of the mixed plastic is 2.9% by weight; introducing the chlorine-containing waste plastic raw material into a waste plastic raw material processing unit, heating, melting and dehydrating the chlorine-containing waste plastic raw material under shearing conditions; then leading out the water-containing air in the waste plastic raw material processing unit to obtain dehydrated and de-aired waste plastic; wherein the dehydration treatment temperature is 130° C.;

[0102] The dehydrated and deaerated waste plastic is continuously heated in the waste plastic raw material processing unit for dechlorination treatment to obtain dehydrated and dechlorinated waste plastic; the dechlorination reaction temperature is 320° C., and the reaction time is 20 min; during the dechlorination process, a vacuum system is used to introduce the hydrogen chloride-containing gas obtained by the dechlorination treatment into a hydrogen chloride absorption unit, and the hydrogen chloride absorbent is a NaOH aqueous solution; liquefied dechlorinated waste plastic DCl-8 is obtained, and the properties of the obtained liquefied dechlorinated waste plastic are shown in Table 2;

[0103] The dehydrated and dechlorinated waste plastic (i.e., DC1-8) is subjected to the cooling treatment and the pulverizing treatment in sequence to obtain the waste plastic particles having an average particle size of 0.2 cm;

[0104] Then, the waste plastic particles are continuously introduced into the cracking reactor of the continuous contact catalytic cracking unit 4 through the particle transmission unit under the action of carrier gas to contact with the fluidized contact agent SL-2 to carry out fluidized cracking reaction; wherein the carrier gas is dry gas from the separation unit 6, the mass ratio of the carrier gas to the waste plastic particles is 0.1:1, and the carrier gas temperature is below 80°C; the conditions of the cracking reaction include: reaction temperature of 550°C, reaction time of 17s, weight hourly space velocity of 4h -1 ; The mass ratio of the contact agent to the waste plastic particles is 7:1; the contact agent is fresh contact agent SL-2, and the distribution of cracking reaction products is shown in Table 3.

[0105] The first part of the obtained dry gas is used as a carrier gas, and the second part is introduced into the contact agent regeneration unit 5 to regenerate the contact agent. The carbon content of the contact agent to be regenerated in the contact agent regeneration unit 5 is 0.1% by weight; the process conditions of the regeneration treatment include: the reaction conditions in the dense phase fluidized bed regenerator: the gas velocity is 0.1m / s, the gasification temperature of the dense phase bed is 660℃, the gas introduced is a gas containing 27% by volume of oxygen, and the bed density of the dense phase bed is 500-600cm 3 / g.

[0106] Example 6

[0107] The method in Example 5 is used, and the difference from Example 5 is that the conditions of the cracking reaction include: the reaction temperature is 480°C, the reaction time is 17.2s, and the weight hourly space velocity is 5h -1 ; The mass ratio of the contact agent to the waste plastic particles is 30:1; the contact agent is fresh contact agent SL-2, and the distribution of cracking reaction products is shown in Table 3.

[0108] Comparative Example 1

[0109] The processing was carried out according to the method of Example 5, which differs from Example 5 in that the cracking reactor was replaced by an intermittent autoclave reactor, DCl-8 was placed in the autoclave as the cracking reaction raw material, there was no heat carrier contact agent in the autoclave, the pyrolysis temperature was 480°C, the time was 1 hour, and the pressure was normal pressure. The product distribution, cracking gas composition and properties of each fraction are shown in Table 4.

[0110] Table 1

[0111] Sample name DCl-1 DCl-2 DCl-3 DCl-4 DCl-5 Outlet temperature / ℃ 330 320 310 300 285 w(Cl) / (μg / g) 750 1630 1720 2900 6430 Dechlorination rate / weight% 97.41 94.38 94.07 90.00 77.83

[0112] According to the data in Table 1, when the outlet temperature of the screw pump is 300-350°C, the dechlorination rate is higher and the dechlorination effect is better.

[0113] Table 2

[0114] Example Example 3 Example 4 Example 5 Sample name DCl-6 DCl-7 DCl-8 W (ash content) / weight% 23.05 0.517 0 W(C) / weight% 49.55 61 86.03 W(H) / weight% 7.22 8.3 12.66 W(N) / weight% 0.17 0.04 - W(S) / weight% 0.17 <0.2 - W(O) / weight% 19.83 5.2 0.2 W(Cl) / weight% 1.32 0.18 0.14 W(metal analysis) / (μg / g) Al 3010 1390 - Ca 28710 220 - Fe 8620 427 - Mg 961 425 - Na 1420 2460 - Si 7090 207 - Zn 304 538.2 -

[0115] According to the data in Table 2, by comparing Example 3 with Examples 4 to 5, it can be seen that the dechlorination temperature in Examples 4 and 5 is 320° C., the chlorine content in the obtained dechlorinated waste plastics is lower, and the dechlorination effect is better.

[0116] Table 3 Product distribution (dry basis)

[0117]

[0118] Table 4 Product distribution (dry basis)

[0119]

[0120] According to Table 4, by comparing Example 5 with Comparative Example 1, it can be seen that the method provided by the present disclosure can realize fluidized cracking of solid waste plastics, and the yield of light components such as liquefied gas and C5-180°C fraction in the cracking product is higher, and the yield of dry gas, heavy distillation range components (>350°C fraction) and coke is lower. In addition, in Comparative Example 1, it is necessary to stop the work and add new reaction materials and introduce reaction products at regular intervals, and continuous production cannot be achieved; while the method provided by the present application can realize continuous fluidized cracking, which is conducive to expanding production.

[0121] By comparing Example 5 with Example 6, it can be seen that in Example 5, the cracking reaction temperature is between 490 and 600°C, the mass ratio of the contact agent to the waste plastic particles is between (5 and 20): 1, and the yield of liquefied gas and C5-180°C fraction in the reaction product obtained in Example 5 is higher.

[0122] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0123] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0124] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A processing method for fluidized cracking of waste plastics, characterized in that: The following steps are involved: S1. The waste plastic particles are continuously introduced into a cracking reactor under the action of a carrier gas to contact with a fluidized contact agent to carry out a cracking reaction, thereby obtaining a cracking product and a contact agent to be regenerated; S2, allowing the cracked products to enter a separation unit for separation treatment to obtain dry gas, liquefied gas, gasoline fraction, diesel fraction and wax oil fraction; Before step S1, the method further comprises: S0, subjecting the chlorine-containing waste plastic raw material to hot-melt dechlorination treatment to obtain hydrogen chloride-containing gas and dechlorinated waste plastic cracking raw material; subjecting the dechlorinated waste plastic cracking raw material to cooling treatment and crushing treatment to obtain the waste plastic particles; Step S0 includes: in a waste plastic raw material processing unit, heating, melting and dehydrating the chlorine-containing waste plastic raw material under shearing conditions; then drawing out the water-containing air in the waste plastic raw material processing unit to obtain dehydrated and deaerated waste plastic; allowing the dehydrated and deaerated waste plastic to continue to be heated in the waste plastic raw material processing unit for dechlorination treatment to obtain dehydrated and dechlorinated waste plastic; allowing the dehydrated and dechlorinated waste plastic to be cooled and crushed in sequence to obtain the waste plastic particles; wherein the process conditions in the waste plastic raw material processing unit include: wherein the dehydration treatment temperature is 100-150°C; The particle size of the obtained waste plastic particles is 100~2000μm.

2. The method according to claim 1, characterized in that: In step S1, the cracking reactor is a fluidized bed reactor, and the conditions of the cracking reaction include: a reaction temperature of 450-700°C; a weight hourly space velocity of 1-100h -1 ; The mass ratio of contact agent to waste plastic particles is (1~30):

1.

3. The method according to claim 2, characterized in that The conditions of the cracking reaction include: a reaction temperature of 490-600° C.; a mass ratio of the contact agent to the waste plastic particles of (5-20):

1.

4. The method according to claim 1, characterized in that: The method further includes: Dividing the dry gas separated by the separation unit into at least two parts, and using the first part of the dry gas as the carrier gas for transporting the waste plastic particles; and The second part of the dry gas and the contact agent to be regenerated are respectively introduced into the contact agent regeneration unit to regenerate the contact agent to be regenerated; and the regenerated contact agent is returned to the continuous contact cracking unit.

5. The method according to claim 4, characterized in that Based on the total weight of the contact agent to be regenerated, the carbon content of the contact agent to be regenerated is 0.5% to 5.0% by weight.

6. The method according to claim 1, characterized in that The process conditions in the waste plastic raw material processing unit include: the dehydration treatment temperature is 100~120℃; the dechlorination treatment reaction temperature is 150~370℃, and the reaction time is 0.1~0.5h.

7. The method according to claim 1, characterized in that The process conditions in the waste plastic raw material processing unit include: the dechlorination treatment reaction temperature is 300~350℃, and the reaction time is 0.2~0.4h.

8. The method according to claim 1, characterized in that In step S1, the carrier gas is nitrogen or at least a portion of the dry gas obtained by the separation unit; the mass ratio of the carrier gas to the waste plastic particles is 0.05-1:1, and the carrier gas temperature is below 80°C.

9. The method according to claim 8, characterized in that In step S1, the carrier gas is dry gas from the separation unit; the carrier gas temperature is 40-80°C.

10. The method according to claim 1, characterized in that In step S1, the contact agent is one or more selected from silicon-aluminum material catalyst, quartz sand or coal char powder.

11. The method according to claim 10, characterized in that The particle size of the contact agent is 20-3000 μm.

12. The method according to claim 10, characterized in that The silicon-aluminum material is selected from a catalyst containing a molecular sieve and / or a catalyst not containing a molecular sieve.

13. The method according to claim 12, characterized in that The molecular sieve-containing catalyst is one or more selected from catalysts containing one or more molecular sieves selected from X molecular sieve, Y molecular sieve, mordenite, ZSM-5, pillared clay molecular sieve, SAPO, and waste FCC catalysts.

14. The method according to claim 12, characterized in that The catalyst not containing molecular sieve is selected from catalysts prepared with one or more of the first raw materials as raw materials, wherein the first raw materials include amorphous silica-alumina, clay, kaolin, montmorillonite, rectorite, illite, chlorite, pseudo-boehmite and silicon dioxide; or The catalyst not containing molecular sieve is selected from a catalyst prepared using one or more of the second raw materials that have been treated with acid washing, calcination and screening as raw materials, and the second raw materials include amorphous silica-alumina, clay, kaolin, montmorillonite, rectorite, illite and chlorite; or selected from a catalyst prepared using one or more of the second raw materials that have been treated with acid washing, calcination and screening and pseudo-boehmite and / or silica as raw materials.

15. The method according to claim 4, characterized in that The regeneration treatment is carried out in a dense fluidized bed regenerator; the process conditions of the regeneration treatment include: an air residence time of 0.5 to 60 seconds, a gasification temperature of the dense bed of 600 to 750° C., an oxygen-containing gas of 10 to 50% by volume, and a linear velocity of the dense bed of 0.05 to 0.6 m / s.

16. The method according to claim 15, characterized in that The process conditions of the regeneration treatment include: air residence time of 1.0~10 seconds, gasification temperature of the dense bed of 600~700°C, and linear velocity of the dense bed of 0.2~0.4m / s.

17. The method according to claim 1, characterized in that The method further comprises: allowing the hydrogen chloride-containing gas to enter a hydrogen chloride absorption unit and contact with a hydrogen chloride absorbent to perform hydrogen chloride absorption treatment; The hydrogen chloride absorbent is water or an alkaline solution with a pH greater than 7.

18. The method according to claim 17, characterized in that The method further comprises: allowing the hydrogen chloride-containing gas to enter the hydrogen chloride absorption unit under the action of a vacuum system; The alkali solution includes one or more of sodium hydroxide solution, potassium hydroxide solution, calcium hydroxide solution, sodium bicarbonate solution, sodium carbonate solution and ammonia water.

19. The method according to claim 1, characterized in that The waste plastic particles include one or more of PVC, LDPE, HDPE, PS, PP and PET.

20. The method according to claim 19, characterized in that The waste plastic particles include PVC and one or more selected from PVC, LDPE, HDPE, PS, PP and PET; based on the total weight of the dried waste plastics, the content of PVC is less than 10 weight % and greater than 0, and the ash content is 1-40 weight %.

21. The method according to claim 20, characterized in that Based on the total weight of the dried waste plastic, the ash content is 5-20% by weight.

22. A processing system for fluidized cracking of waste plastics, characterized in that: The system includes a continuous contact catalytic cracking unit and a separation unit; The continuous contact cracking unit is provided with a cracking feed inlet, a contact agent inlet, a continuous reactor, a cracking product outlet and a catalyst outlet to be regenerated; The separation unit is provided with a cracking product separation inlet, a dry gas outlet, a liquefied gas outlet, a gasoline fraction outlet, a diesel fraction outlet and a wax oil fraction outlet; The cracking raw material inlet is respectively connected to the waste plastic source and the carrier gas source so that the waste plastic source enters the continuous contact cracking unit under the action of the carrier gas; The contact agent inlet of the contact catalytic cracking unit introduces fresh contact agent through a first pipeline; the cracked product outlet is connected to the cracked product separation inlet of the separation unit; The system also includes a waste plastic raw material processing unit; the waste plastic raw material processing unit includes a waste plastic melting dechlorination device and a cooling and crushing device; the inlet of the waste plastic melting dechlorination device is formed as a waste plastic raw material inlet, the outlet of the waste plastic melting dechlorination device is formed as a dechlorinated material outlet, the waste plastic melting dechlorination device also includes a waste gas outlet, and the waste gas outlet is formed as a hydrogen chloride-containing gas outlet; the inlet of the material to be dechlorinated is connected with the outlet of the molten material; the cooling and crushing device is provided with an inlet to be cooled and crushed and an outlet for waste plastic particles, the inlet to be cooled and crushed is connected with the outlet for the dechlorinated material, and the outlet for the waste plastic particles is formed as an outlet for dechlorinated waste plastic cracking raw materials.

23. The system according to claim 22, characterized in that The system also includes a waste plastic raw material processing unit, a contact agent regeneration unit and a hydrogen chloride absorption unit; the waste plastic raw material processing unit is provided with a waste plastic raw material inlet, a hydrogen chloride-containing gas outlet and a dechlorinated waste plastic cracking raw material outlet, and the dechlorinated waste plastic cracking raw material outlet of the waste plastic raw material processing unit is connected with the cracking raw material inlet of the contact catalytic cracking unit; The contact agent regeneration unit is provided with an inlet for contact agent to be regenerated, an air inlet, a second dry gas inlet, a flue gas outlet and a regenerated catalyst outlet; the inlet for contact agent to be regenerated is connected with the outlet for contact agent to be regenerated of the continuous contact cracking unit, the second dry gas inlet is connected with the lead-out pipeline of the dry gas outlet of the separation unit, and the outlet for regenerated contact agent is connected with the inlet for contact agent of the continuous contact cracking unit through the second pipeline; The hydrogen chloride absorption unit is provided with a hydrogen chloride-containing gas inlet and a dechlorinated gas outlet, and the hydrogen chloride-containing gas inlet is connected to the hydrogen chloride-containing gas outlet of the waste plastic raw material processing unit; The waste plastic material processing unit also includes a shearing device and a water-containing air outlet.

24. The system according to claim 22, characterized in that The waste plastic melting dechlorination device is a hot screw pump.

25. The system according to claim 22, characterized in that The system also includes a particle transmission unit, which includes an input port, an output port and a carrier gas inlet. The input port is connected to the dechlorinated waste plastic cracking raw material outlet of the waste plastic raw material processing unit, the output port is connected to the cracking raw material inlet of the contact catalytic cracking unit, and the carrier gas inlet is connected to a carrier gas source for introducing carrier gas into the particle transmission unit so that the particulate material from the dechlorinated waste plastic cracking raw material outlet enters the cracking raw material inlet under the purge action of the carrier gas.

26. The system according to claim 25, characterized in that The carrier gas inlet of the particle transmission unit is communicated with an outlet pipeline of the dry gas outlet of the separation unit.

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