An integrated device for waste plastic pyrolysis oil and gas dust removal and catalytic quality improvement

Abstract

A waste plastic pyrolysis oil and gas dust removal and catalytic quality improvement integrated device, comprising a shell, a fixed catalyst bed, a filter element, and a nitrogen blowing system; the filter element is installed inside the shell, dividing the shell cavity into a pre-filter cavity and a post-filter cavity; a nitrogen backflush structure is installed on the nitrogen blowing main pipe in the shell for blowing nitrogen from the filter element port of the filter element to the inside of the filter element; the fixed catalyst bed is installed in the post-filter cavity; the fixed catalyst bed is filled with a catalyst; unpurified waste plastic high-temperature pyrolysis oil and gas enters from the bottom of the shell, the dust in the pyrolysis oil and gas is filtered and captured by the filter element, and discharged from the bottom outlet of the shell, the filtered pyrolysis oil and gas enter the fixed catalyst bed, the pyrolysis oil and gas react with the catalyst in the fixed catalyst bed to achieve catalytic quality improvement of oil and gas, and then the oil and gas are discharged from the top outlet of the shell.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental protection, and specifically relates to an integrated device for pyrolysis of waste plastics to remove oil and gas dust and catalyze and improve quality. Background Art

[0002] In today's life, plastic products have become an important part of people's daily life. All aspects of life are inseparable from them. How to deal with used plastics is an urgent problem that we need to solve together. Although traditional mechanical recycling technology can achieve the recycling of waste plastics to a certain extent, it can only process some types of plastics, affecting the quality of recycled plastics. Ideally, the recycling rate can only reach about 10%. Most of the waste plastics will be disposed of by landfill or incineration, which causes great waste of resources and environmental pollution.

[0003] With the improvement of environmental protection concepts and technical requirements, chemical recycling technology has received more and more attention and favor. Among them, waste plastic pyrolysis technology is an effective way to recycle waste plastic resources by heating plastics in an oxygen-free or oxygen-deficient environment to decompose them into small molecular compounds, thereby producing oil and gas. The high-temperature oil and gas produced by pyrolysis are complex in composition and greatly affected by the composition of raw materials. The utilization rate of pyrolysis oil and gas is not high; in addition, pyrolysis oil and gas contains a large amount of solid phase substances such as dust, which will have an adverse effect on the quality of oil and gas products and subsequent separation and purification when mixed with oil and gas.

[0004] Therefore, in order to address the problems and pain points of high dust content, low quality and serious pollution emissions in the pyrolysis oil and gas of waste plastics, it is urgent to provide an integrated dust removal and catalytic utilization device for the high-temperature pyrolysis oil and gas of waste plastics. Summary of the invention

[0005] The technical problem solved by the present invention is: in order to solve the problems in the prior art that the oil and gas from the pyrolysis of waste plastics has a large dust content, which easily leads to catalyst deactivation, poor quality, a large number of by-products, and serious emissions of toxic pollutants, a waste plastic pyrolysis oil and gas dust removal and catalytic quality improvement integrated device is provided, which can simplify the oil and gas purification process, reduce the failure rate of system equipment, and realize the dust removal, catalytic quality improvement and utilization of the oil and gas from the pyrolysis of waste plastics.

[0006] The technical solution of the present invention is: an integrated device for waste plastic pyrolysis oil and gas dust removal and catalytic quality improvement, including: a shell, a fixed catalyst bed, a filter element, and a nitrogen injection system;

[0007] The nitrogen blowing system includes a nitrogen blowing main pipe, a nitrogen backflush structure, and a nitrogen supply unit outside the housing, which is used to backflush the filter cake structure formed on the outside of the filter element and discharge it from the bottom outlet of the housing;

[0008] The filter element is installed inside the housing, dividing the inner cavity of the housing into a pre-filter cavity and a post-filter cavity; a nitrogen backflush structure is installed on a nitrogen injection main pipe inside the housing to inject nitrogen from the filter element port of the filter element into the interior of the filter element; a fixed catalyst bed is installed in the post-filter cavity; the fixed catalyst bed is filled with a catalyst;

[0009] The high-temperature pyrolysis oil and gas from unpurified waste plastics enters from the bottom of the shell, and the dust in the pyrolysis oil and gas is filtered and captured by the filter element and discharged from the bottom outlet of the shell. The filtered pyrolysis oil and gas enter the fixed catalyst bed, where the pyrolysis oil and gas react with the catalyst to achieve catalytic quality improvement of the oil and gas, and then the oil and gas are discharged from the top outlet of the shell.

[0010] Preferably, the fixed catalyst bed is composed of a catalyst bed flower plate, a catalyst bed baffle, and a catalyst bed fixing structure; the catalyst bed flower plate is provided with small holes, the size of which allows pyrolysis oil and gas to pass through while preventing the catalyst from falling; a catalyst bed baffle is provided in the bed for partitioning and fixing the catalyst; a fixed catalyst bed fixing structure is provided along the inner wall of the device on the upper and lower sides of the catalyst bed for fixing and disassembling the catalyst bed.

[0011] Preferably, the diameter of the small hole is ≤10 mm, the catalyst is a shaped porous solid particle with a certain physical strength, and the particle size is 10 to 50 mm.

[0012] Preferably, the device further comprises a charring system; the charring system burns the carbon deposits in the catalyst gaps by introducing oxygen into the shell, thereby achieving catalyst regeneration by high-temperature charring;

[0013] The charring system includes an oxygen or air flow meter and a normal temperature nitrogen flow meter, an oxygen or air regulating valve and a normal temperature nitrogen regulating valve, a cavity temperature monitoring and a filter element temperature monitoring, a cavity pressure monitoring before filtration, a cavity pressure monitoring after filtration and a cavity outlet oxygen content monitoring;

[0014] The amount of oxygen and nitrogen introduced into the shell is monitored by an oxygen or air flow meter and a normal temperature nitrogen flow meter respectively, and the oxygen and nitrogen flow rates are controlled by an oxygen or air regulating valve and a normal temperature nitrogen regulating valve respectively, thereby achieving control of the oxygen content at the shell outlet; the cavity outlet oxygen content monitoring is used to monitor the change of oxygen content in the shell during catalyst regeneration; the cavity pressure monitoring before filtration and the cavity pressure monitoring after filtration are used to monitor the pressure change during catalyst regeneration; cavity temperature monitoring and filter element temperature monitoring are provided to monitor the temperature change during catalyst regeneration. When the pressure change / temperature change exceeds the preset range, normal temperature nitrogen is introduced into the shell.

[0015] Preferably, the high pressure alarm value is 15 to 20 kPa.G, the low pressure alarm value is -10 to 5 kPa.G; the charring temperature is 400 to 600°C; and the oxygen content during the charring process does not exceed 1%.

[0016] Preferably, the filter element comprises a sintered catalyst coating, a filter element frame, and a filter element fixing bolt;

[0017] The filter element skeleton is a cylindrical barrel structure, a perforated mesh metal membrane is installed as a filter element on the outer wall of the barrel of the filter element skeleton, a sintered catalyst coating is arranged on the outer wall of the mesh metal membrane, and the open end of the cylindrical barrel structure is fixed to the inner wall of the shell through a filter element fixing plate; the thickness of the sintered catalyst coating is 0.5 to 2 mm, and the pore size on the mesh metal membrane is 5 to 20 μm.

[0018] Preferably, the starting methods of the nitrogen blowing system include: one is to start after the pressure difference between the pre-filtration cavity and the post-filtration cavity reaches a preset value, and the other is to start after setting a fixed time interval; when the starting conditions are met, the high-pressure nitrogen fills the internal space of the filter element in a short time, so that the filter element is filled with pressure and shakes, and the filter cake structure formed on the outside of the filter element is blown back and dropped.

[0019] Preferably, the preset value ranges from 500 to 3000 Pa; the time interval is generally 10 to 30 minutes; the pressure of the high-pressure nitrogen is 0.3-0.5 MPa.G; and the short time is 1 to 5 seconds.

[0020] Preferably, an insulation layer is arranged outside the shell, and a heating source is arranged inside the insulation layer; the heating source includes electric heating, high-temperature flue gas or heat transfer oil, and the high-temperature flue gas and heat transfer oil are realized by winding a coil on the outer wall of the shell, and the electric heating is realized by winding an electric heating wire on the outer wall.

[0021] Preferably, the device further comprises a filter element inspection hole arranged in the middle of the shell and a quick-release flange-type head at the upper part of the shell.

[0022] A method for treating waste plastic pyrolysis oil and gas by using the waste plastic pyrolysis oil and gas dust removal and catalytic quality improvement integrated device, characterized by comprising:

[0023] Step 1: Install the waste plastic pyrolysis oil and gas dust removal and catalytic quality improvement integrated device and make the air tightness meet the start-up requirements;

[0024] Step 2: Before starting, the device should be replaced with inert gas, and the heating source in the shell should be controlled simultaneously or sequentially to heat the device and control the cavity monitoring temperature and filter element monitoring temperature above the dew point temperature of the waste plastic pyrolysis oil and gas;

[0025] Step three, introducing the high-temperature pyrolysis oil and gas of unpurified waste plastic into the shell from the bottom of the shell, and the pyrolysis oil and gas are subjected to dust removal and catalytic treatment by the device, and at the same time, the filter cake structure formed on the outside of the filter element is backblown off according to the pre-set nitrogen injection system startup method; the charring system is started regularly for catalyst regeneration, the temperature in the shell is monitored, and the oxygen content at the shell outlet is controlled not to exceed 1% during the charring process.

[0026] The beneficial effects of the present invention compared with the prior art are:

[0027] (1) In view of the large dust content of oil and gas from high-temperature pyrolysis of waste plastics and the room for improvement in oil and gas quality, this device combines oil and gas dust removal and catalytic quality improvement into one device, which can not only achieve oil and gas purification and dust removal, but also improve the quality of oil and gas;

[0028] (2) The device utilizes the upper space of the dust collector to set up a fixed catalyst bed, in which a catalyst can be loaded to form a catalytic reactor for the pyrolysis oil and gas after dust removal, thereby further catalyzing and improving the quality of the pyrolysis oil and gas;

[0029] (3) The device can achieve precise control of dust removal and reaction temperature by arranging the heating source outside the shell; according to actual conditions, the heating source can be electric heating, high-temperature flue gas or heat transfer oil, and the heat source selection is flexible;

[0030] (4) In order to solve the problem of catalyst deactivation after a period of operation, the device is equipped with a charring system to realize online catalyst charring regeneration;

[0031] (5) After the system has been running for a period of time, a layer of filter cake structure will form on the outside of the filter element. This device is equipped with a backflush system for the filter element, which performs backflush according to the system inlet and outlet pressure difference or at regular intervals to clean the filter element;

[0032] (6) The device is provided with an inspection port, which allows the filter element to be pulled out for inspection after the device is shut down; a flange-type quick-release head is provided on the top of the device, which allows the catalyst bed to be loaded and removed. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is an integrated device for waste plastic pyrolysis oil and gas dust removal and catalytic quality improvement as described in the present invention;

[0034] Figure 2 This is a schematic diagram of the structure of the metal membrane or ceramic membrane sintered catalyst coating filter element of the present invention;

[0035] Figure 3 This is a schematic diagram of the fixed catalyst bed structure of the present invention;

[0036] Figure 4It is a schematic diagram of the temperature control system of the device according to the present invention;

[0037] In the figure: shell a, heating heat source a1, insulation layer a2; fixed catalyst bed b, catalyst bed flower plate b1, catalyst bed baffle b2, catalyst bed fixing structure b3; high-temperature nitrogen pulse valve c; high-temperature nitrogen injection main pipe d; high-temperature nitrogen backflush structure e; filter element f, sintered catalyst coating f1, filter element skeleton f2, filter element fixing bolts f3, filter element fixing flower plate f4; regulating valve g, oxygen or air regulating valve g1, normal temperature nitrogen regulating valve g2; flow meter h, oxygen or air flow meter h1, normal temperature nitrogen flow meter h2; temperature and pressure monitoring i, cavity pressure monitoring i1 before filtration, cavity temperature monitoring i2, filter element temperature monitoring i3, cavity pressure monitoring i4 after filtration, cavity outlet oxygen content monitoring i5; filter element inspection hole j; quick-release flange head k. DETAILED DESCRIPTION

[0038] The present invention will be further described below in conjunction with the embodiments.

[0039] An integrated device for pyrolysis of waste plastics for oil and gas dust removal and catalytic quality improvement, comprising a device housing a, a fixed catalyst bed b, a high-temperature nitrogen pulse valve c, a high-temperature nitrogen injection main pipe d, a high-temperature nitrogen backflush structure e, a filter element f, a regulating valve g, a flow meter h, and a temperature and pressure monitor i;

[0040] The shell a is provided with a heating source a1 and a heat preservation layer a2 from the inside to the outside respectively; a filter element f is provided at the lower part of the device, and the filter element f is fixed on the filter element fixing plate f4 by a bolt structure, and the filter element fixing plate f4 is welded to the inner wall of the shell a, and the filter element f comprises a sintered catalyst coating f1, a filter element skeleton f2, a filter element fixing bolt f3 and a filter element fixing plate f4; a high-temperature nitrogen backflush structure e is provided above the filter element, and the high-temperature nitrogen backflush structure e adopts a Venturi structure, and the upper end face of the opening of the structure is fixed on the high-temperature nitrogen injection main pipe d, and the lower end face is close to the filter element port, and the high-temperature nitrogen injection main pipe d extends to the outside of the shell and is provided with a high-temperature nitrogen pulse valve c; a fixed catalyst bed b is provided above the high-temperature nitrogen injection main pipe d, and is connected to the catalyst bed fixing structure b3 by bolts, and the catalyst bed fixed structure b4 is provided with a high-temperature nitrogen pulse valve c; a fixed catalyst bed b is provided above the high-temperature nitrogen injection main pipe d, and is connected to the catalyst bed fixed structure b3 by bolts, and the catalyst bed fixed structure b3 ... The fixed structure b3 is fixed to the inner wall of the shell a by welding, and the fixed catalyst bed b includes a catalyst bed plate b1, a catalyst bed baffle b2, and a catalyst bed fixed structure b3; the regulating valve g and the flow meter h are respectively arranged on the oxygen (air) and normal temperature nitrogen pipelines, the regulating valve g includes an oxygen or air regulating valve g1 and a normal temperature nitrogen regulating valve g2, and the flow meter h includes an oxygen or air flow meter h1 and a normal temperature nitrogen flow meter h2; the lower part of the device is provided with a pre-filtration cavity pressure monitor i1 and a cavity temperature monitor i2, the surface of the filter element is provided with a filter element temperature monitor i3 by angle iron welding, and the top of the device is provided with a post-filtration cavity pressure monitor i4 and a cavity outlet oxygen content monitor i5; the middle shell opening of the device is provided with a filter element inspection hole j, and the upper part of the shell is provided with a quick-release flange head k;

[0041] Among them, the high-temperature pyrolysis oil and gas of unpurified waste plastics generated from the upstream process enters the device from the bottom. When the pyrolysis oil and gas pass through the filter element f, the dust in the pyrolysis oil and gas will be filtered and captured, and the captured ash is discharged from the bottom outlet of the device. The filtered pyrolysis oil and gas enter the fixed catalyst bed b at the top of the device. The fixed catalyst bed b is filled with a catalyst. The pyrolysis oil and gas are catalytically upgraded in the fixed catalyst bed b, and then the oil and gas are discharged from the top outlet of the device to enter the downstream process flow;

[0042] Among them, the unpurified waste plastic high-temperature pyrolysis oil and gas enters the inner cavity of the device and passes through the filter element f, such as Figure 2 As shown, the filter element f includes a sintered catalyst coating f1, a filter element frame f2, and a filter element fixing bolt f3. The thickness of the sintered catalyst coating f1 is 0.5 to 2 mm, and the aperture of the perforated metal film outside the filter element frame is 5 to 20 μm. The dust in the high-temperature pyrolysis oil and gas is intercepted by physical filtration, and the dust removal efficiency is ≥ 99%. At the same time, the high-temperature pyrolysis oil and gas undergo a catalytic reaction in the sintered catalyst coating f1 on the inner layer of the filter element, thereby achieving catalytic quality improvement of the pyrolysis oil and gas. The filter element f is fixed to the filter element fixing plate f4 by a bolt structure, and the filter element fixing plate f4 is welded to the inner wall of the housing a.

[0043] Among them, the types of catalysts sprayed on the sintered catalyst coating f1 can be metal oxides (nano-alumina, NiO, CaO, etc.), molecular sieve catalysts (HY type molecular sieve, ZSM-5, etc.), precious metal component catalysts, etc. The catalyst type can be screened and determined according to the different components and target products of the oil and gas from the high-temperature pyrolysis of waste plastics;

[0044] In addition, during normal operation, high-temperature pyrolysis oil and gas flows from the outside of the filter element to the inside of the filter element, and during injection, high-temperature nitrogen flows from the inside of the filter element to the outside of the filter element; after a period of operation, a layer of filter cake structure will form on the outside of the filter element f. If it is not treated, it will increase the filtration pressure drop of the device, which will affect the filtration effect and the normal operation of the equipment; the device sets the post-filtration cavity pressure monitoring i4 and the pre-filtration cavity pressure monitoring i1 on the inside and outside of the filter element f respectively. When the pressure monitoring difference between the inside and outside reaches the preset value, the high-temperature nitrogen injection system is started, and the pressure difference is 500~3000Pa;

[0045] Among them, the high-temperature nitrogen injection system includes a high-temperature nitrogen injection main pipe d, a high-temperature nitrogen back-blowing structure e and a high-temperature nitrogen pulse valve c. The device sets the number of high-temperature nitrogen pulse valves c according to the number of filter elements f, and the number of filter elements corresponding to each pulse valve can be adjusted according to actual working conditions; there are two ways to start the high-temperature nitrogen injection system: one is to start after the pressure monitoring difference between the inside and the outside reaches a preset value, and the pressure difference is 500-3000Pa; the other is to start at a fixed time interval, and the time interval is generally 10-30 minutes; when the starting conditions are met, pressurized high-temperature nitrogen (0.3-0.5MPa.G) enters the high-temperature nitrogen back-blowing structure e through the high-temperature nitrogen pulse valve c, and the opening and closing time of the high-temperature nitrogen pulse valve c is 1-5 seconds. The pressurized high-temperature nitrogen fills the internal space of the filter element in a short time, so that the filter element is full of pressure and shakes, and the filter cake structure formed on the outside of the filter element is backblown and dropped, and the dropped ash is accumulated at the bottom of the dust collector device and discharged;

[0046] In addition, if Figure 3 As shown, the extra space at the top of the device is used to set up a fixed catalyst bed b, and the pyrolysis oil and gas passing through the filter element f enters the fixed catalyst bed b at the top of the device. The pyrolysis oil and gas undergo a catalytic reaction on the bed, and the pyrolysis oil and gas after the reaction are discharged from the top outlet of the device and enter the downstream process flow;

[0047] Among them, the fixed catalyst bed b is composed of a catalyst bed flower plate b1, a catalyst bed baffle b2, and a catalyst bed fixed structure b3; the catalyst bed flower plate b1 is provided with small holes with a diameter of ≤10mm, which allow the pyrolysis oil and gas to pass through while preventing the catalyst from falling. The catalyst is generally a shaped porous solid particle with a certain physical strength, and the particle size is 10-50mm; a catalyst bed baffle b2 is arranged in the bed for partitioning and fixing the catalyst, and the number of catalyst bed baffles b2 should not be too many, generally 3-8 pieces; a fixed catalyst bed fixed structure b3 is arranged along the inner wall of the device on both sides of the upper and lower sides of the catalyst bed for fixing and disassembling the catalyst bed; the connection form of the catalyst bed fixed structure b3 and the catalyst bed and the device shell is detachable, which is convenient for the installation and maintenance of the catalyst bed; the pyrolysis oil and gas passing through the filter element f enters the fixed catalyst bed b at the top of the device, and the pyrolysis oil and gas undergo a catalytic reaction on the bed. The pyrolysis oil and gas after the reaction are discharged from the top outlet of the device and enter the downstream process flow;

[0048] In order to ensure and control the temperature of the device, a heating source a1 and a heat insulation layer a2 are provided on the outer wall of the device shell a. The heating source a1 can be electric heating, high-temperature flue gas or heat transfer oil. The high-temperature flue gas and heat transfer oil are realized by winding a coil around the outer wall, and the electric heating is realized by winding an electric heating wire around the outer wall.

[0049] The device has a catalyst regeneration function. The catalyst regeneration process is that oxygen and carbon deposits in the catalyst gaps are burned under high temperature conditions, thereby realizing catalyst regeneration by high-temperature charring. The charring temperature is 400-600°C. The system monitors the oxygen and nitrogen consumption through the oxygen or air flow meter h1 and the normal temperature nitrogen flow meter h2, respectively, and controls the oxygen and nitrogen flow rates through the oxygen or air regulating valve g1 and the normal temperature nitrogen regulating valve g2, respectively, to achieve control of the oxygen content at the outlet of the device. The nitrogen purity is ≥99.99%, and the reason why the nitrogen is at normal temperature is to prevent overheating during the charring process, thereby affecting the operation and safety of the device.

[0050] The following is combined with Figure 1 , Attachment Figure 2 , Attachment Figure 3 and attached Figure 4 The working process of the present invention is further explained and illustrated.

[0051] Step 1: Confirm that the air tightness of the device and its auxiliary systems meets the start-up requirements in accordance with relevant specifications. Before starting, the device must be replaced with inert gas. The inert gas is generally high-temperature nitrogen. The replacement time is determined according to the amount of high-temperature nitrogen and the volume of the device. The replacement time is 1 to 4 hours;

[0052] Step 2, such as Figure 4As shown, in order to ensure and control the temperature of the device, a heating heat source a1 and a heat insulation layer a2 are provided on the outer wall of the device shell a. The heating heat source a1 can be electric heating, high-temperature flue gas or heat transfer oil. The high-temperature flue gas and heat transfer oil are realized by winding a coil around the outer wall, and the electric heating is realized by winding an electric heating wire around the outer wall. The device temperature control system is turned on, the device starts heating up, and the cavity monitoring temperature and the filter element monitoring temperature are controlled to be above the dew point temperature of the waste plastic pyrolysis oil and gas, and the temperature is ≥400°C. Inert gas replacement and device heating up can be carried out simultaneously.

[0053] Step three, such as Figure 1 As shown, the unpurified waste plastic high-temperature pyrolysis oil and gas generated from the upstream process enters the device from the bottom. The waste plastic high-temperature pyrolysis oil and gas contains a lot of dust, and the temperature range is 450-550°C. The back-end process of the device is equipped with an induced draft fan as the power source of the pyrolysis oil and gas. When the pyrolysis oil and gas pass through the filter element f, the dust in the pyrolysis oil and gas will be filtered and captured, and the captured ash is discharged from the bottom outlet of the device. The filtered pyrolysis oil and gas enter the fixed catalyst bed b at the top of the device. The fixed catalyst bed b is filled with a catalyst. The pyrolysis oil and gas realizes oil and gas catalytic quality improvement in the fixed catalyst bed b, and then the oil and gas are discharged from the top outlet of the device to enter the downstream process flow;

[0054] During the working process, according to the start-up mode of the high-temperature nitrogen injection system, when the start-up conditions are met, the pressurized high-temperature nitrogen enters the high-temperature nitrogen back-blowing structure e through the high-temperature nitrogen pulse valve c. The opening and closing time of the high-temperature nitrogen pulse valve c is 1 to 5 seconds. The pressurized high-temperature nitrogen fills the internal space of the filter element in a short time, so that the filter element is filled with pressure and shakes, and the filter cake structure formed on the outside of the filter element is back-blown and dropped. The dropped ash is accumulated at the bottom of the dust collector device and discharged;

[0055] During the working process, the oxygen and nitrogen consumption are monitored by the oxygen or air flow meter h1 and the normal temperature nitrogen flow meter h2 respectively, and the oxygen and nitrogen flow rates are controlled by the oxygen or air regulating valve g1 and the normal temperature nitrogen regulating valve g2 respectively, so as to control the oxygen content at the outlet of the device. The oxygen content does not exceed 1% during the charring process.

[0056] To ensure safety during the charring process, the device is provided with a pre-filtration cavity pressure monitor i1 and a post-filtration cavity pressure monitor i4 for monitoring pressure changes during catalyst regeneration; a cavity temperature monitor i2 and a filter element temperature monitor i3 are provided for monitoring temperature changes during catalyst regeneration, the filter element temperature monitor i3 is fixed and connected to the filter element surface by angle iron welding, and a cavity outlet oxygen content monitor i5 is provided for monitoring oxygen content changes in the device during catalyst regeneration; wherein, the cavity temperature monitor i2 (the temperature inside the shell, which can be the pre-filtration cavity or the post-filtration cavity) and the oxygen or air regulating valve g1 and the normal temperature nitrogen regulating valve g2 form a regulating loop, when the temperature is lower than this range, the oxygen or air regulating valve g1 is opened and the normal temperature nitrogen regulating valve g2 is reduced, when the temperature exceeds this temperature range, the oxygen or air regulating valve g1 is reduced and the normal temperature nitrogen regulating valve g2 is opened.

[0057] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. An integrated device for waste plastic pyrolysis oil and gas dust removal and catalytic quality improvement, characterized in that include: It includes a shell, a fixed catalyst bed, a filter element, and a nitrogen injection system; The nitrogen blowing system includes a nitrogen blowing main pipe, a nitrogen backflush structure, and a nitrogen supply unit outside the housing, which is used to backflush the filter cake structure formed on the outside of the filter element and discharge it from the bottom outlet of the housing; The filter element is installed inside the housing, dividing the inner cavity of the housing into a pre-filter cavity and a post-filter cavity; a nitrogen backflush structure is installed on a nitrogen injection main pipe inside the housing to inject nitrogen from the filter element port of the filter element into the interior of the filter element; a fixed catalyst bed is installed in the post-filter cavity; the fixed catalyst bed is filled with a catalyst; The high-temperature pyrolysis oil and gas from unpurified waste plastics enters from the bottom of the shell, and the dust in the pyrolysis oil and gas is filtered and captured by the filter element and discharged from the bottom outlet of the shell. The filtered pyrolysis oil and gas enter the fixed catalyst bed, where the pyrolysis oil and gas react with the catalyst to achieve catalytic quality improvement of the oil and gas, and then the oil and gas are discharged from the top outlet of the shell.

2. The device according to claim 1, characterized in that: The fixed catalyst bed is composed of a catalyst bed flower plate, a catalyst bed baffle, and a catalyst bed fixing structure; the catalyst bed flower plate is provided with small holes, the size of which allows pyrolysis oil and gas to pass through while preventing the catalyst from falling; a catalyst bed baffle is arranged in the bed for partitioning and fixing the catalyst; a fixed catalyst bed fixing structure is arranged along the inner wall of the device on the upper and lower sides of the catalyst bed for fixing and disassembling the catalyst bed.

3. The device according to claim 2, characterized in that: The diameter of the small hole is ≤10mm, the catalyst is a shaped porous solid particle with a certain physical strength, and the particle size is 10-50mm.

4. The device according to claim 1, characterized in that: The charring system also includes a charring system; the charring system burns the carbon deposits in the catalyst gaps by introducing oxygen into the shell, thereby regenerating the catalyst by high-temperature charring; The charring system includes an oxygen or air flow meter and a normal temperature nitrogen flow meter, an oxygen or air regulating valve and a normal temperature nitrogen regulating valve, a cavity temperature monitoring and a filter element temperature monitoring, a cavity pressure monitoring before filtration, a cavity pressure monitoring after filtration and a cavity outlet oxygen content monitoring; The oxygen or air flow meter and the normal temperature nitrogen flow meter are used to monitor the amount of oxygen and nitrogen introduced into the shell, respectively, and the oxygen or air regulating valve and the normal temperature nitrogen regulating valve are used to control the oxygen and nitrogen flow rates, respectively, so as to control the oxygen content at the shell outlet; The oxygen content monitoring at the cavity outlet is used to monitor the changes in oxygen content in the shell during catalyst regeneration; the cavity pressure monitoring before filtration and the cavity pressure monitoring after filtration are used to monitor the pressure changes during catalyst regeneration; cavity temperature monitoring and filter element temperature monitoring are provided to monitor the temperature changes during catalyst regeneration. When the pressure change / temperature change exceeds the preset range, room temperature nitrogen is introduced into the shell.

5. The device according to claim 1, characterized in that: The high pressure alarm value is 15 to 20 kPa.G, and the low pressure alarm value is -10 to 5 kPa.G; the charring temperature is 400 to 600°C; the oxygen content during the charring process does not exceed 1%.

6. The device according to claim 1, characterized in that: The filter element includes a sintered catalyst coating, a filter element frame, and filter element fixing bolts; The filter element skeleton is a cylindrical barrel structure, a perforated mesh metal membrane is installed as a filter element on the outer wall of the barrel of the filter element skeleton, a sintered catalyst coating is arranged on the outer wall of the mesh metal membrane, and the open end of the cylindrical barrel structure is fixed to the inner wall of the shell through a filter element fixing plate; the thickness of the sintered catalyst coating is 0.5 to 2 mm, and the pore size on the mesh metal membrane is 5 to 20 μm.

7. The device according to claim 1, characterized in that: The starting methods of the nitrogen blowing system include: one is to start after the pressure difference between the pre-filter cavity and the post-filter cavity reaches a preset value, and the other is to start after setting a fixed time interval; when the starting conditions are met, the high-pressure nitrogen fills the internal space of the filter element in a short time, so that the filter element is filled with pressure and shakes, and the filter cake structure formed on the outside of the filter element is blown back and dropped.

8. The device according to claim 6, characterized in that: The preset value ranges from 500 to 3000 Pa; the time interval is generally 10 to 30 minutes; the pressure of the high-pressure nitrogen is 0.3-0.5 MPa.G; and the short time is 1 to 5 seconds.

9. The device according to claim 1, characterized in that: An insulation layer is arranged outside the shell, and a heating source is arranged inside the insulation layer; the heating source includes electric heating, high-temperature flue gas or heat transfer oil. The high-temperature flue gas and heat transfer oil are realized by winding a coil around the outer wall of the shell, and the electric heating is realized by winding an electric heating wire around the outer wall.

10. The device according to claim 1, characterized in that: It also includes a filter element inspection hole arranged in the middle of the shell body and a quick-detachable flange-type sealing head on the upper part of the shell body.

11. A method for treating waste plastic pyrolysis oil and gas by using the waste plastic pyrolysis oil and gas dust removal and catalytic quality improvement integrated device according to claim 4, characterized in that include: Step 1: Install the waste plastic pyrolysis oil and gas dust removal and catalytic quality improvement integrated device as described in claim 4 and make the air tightness meet the start-up requirements; Step 2: Before starting, the device should be replaced with inert gas, and the heating source in the shell should be controlled simultaneously or sequentially to heat the device and control the cavity monitoring temperature and filter element monitoring temperature above the dew point temperature of the waste plastic pyrolysis oil and gas; Step three, introducing the high-temperature pyrolysis oil and gas of unpurified waste plastic into the shell from the bottom of the shell, and the pyrolysis oil and gas are subjected to dust removal and catalytic treatment by the device, and at the same time, the filter cake structure formed on the outside of the filter element is backblown off according to the pre-set nitrogen injection system startup method; the charring system is started regularly for catalyst regeneration, the temperature in the shell is monitored, and the oxygen content at the shell outlet is controlled not to exceed 1% during the charring process.

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