A device for efficiently cracking waste plastics to produce fuel oil

Abstract

The application discloses a device for efficiently cracking waste plastics to prepare fuel oil, which comprises a pretreatment module, a double-stage dechlorination reaction module, a multistage pyrolysis reaction module, a condensation separation module and a tail gas treatment module connected in sequence, wherein the tail gas treatment module is used for collecting non-condensable gas, and the non-condensable gas is ignited and used for heating of the multistage pyrolysis reaction module. The application has the beneficial effect that the non-condensable gas collected by the tail gas treatment module is ignited and used for heating of the multistage pyrolysis reaction module, so that efficient self-circulation utilization of energy is realized, and system energy consumption is reduced.

Description

Technical Field

[0001] This invention relates to the field of waste plastic pyrolysis equipment, and more particularly to an apparatus for the efficient pyrolysis of waste plastics to produce fuel oil. Background Technology

[0002] With the widespread use of waste plastic products, the amount of plastic waste worldwide is increasing year by year, and the disposal of waste plastic has become a serious environmental problem. Currently, the main methods for disposing of waste plastic include landfill, incineration, and resource utilization. While landfill is simple, it occupies a large amount of land resources, and waste plastic is difficult to degrade in the natural environment, causing long-term ecological pollution. Incineration can reduce the volume of waste, but the combustion process produces large amounts of toxic and harmful substances, such as dioxins, posing a serious threat to air quality and human health. Furthermore, incineration is accompanied by energy waste and cannot effectively recover the high-calorific-value components of waste plastic. In contrast, resource utilization is gradually becoming a promising solution. Through technological means, waste plastic can be converted into useful chemical raw materials or fuel oil to achieve resource recycling, reducing environmental pollution and generating economic benefits.

[0003] Waste plastic pyrolysis technology is a chemical process that cracks waste plastics into small-molecule hydrocarbons under high-temperature, oxygen-free or oxygen-deficient conditions. This process can effectively convert waste plastics into products such as liquid fuel oil, gaseous fuel gas, and solid carbon black. Pyrolysis not only recovers energy from waste plastics but also reduces the difficulty of waste disposal and environmental pollution. However, current waste plastic pyrolysis equipment on the market generally suffers from the following problems: First, traditional pyrolysis equipment has high energy consumption and cannot efficiently utilize the heat generated during the reaction, leading to energy waste. Second, due to the complexity of waste plastics, controlling the temperature and time of the pyrolysis reaction is difficult, often resulting in uneven composition and unstable quality of the oil and gas products, affecting subsequent separation and utilization. Third, the oil and gas produced during the cracking process need to be condensed, but traditional condensation systems are inefficient and cannot effectively separate light and heavy oils, thus reducing the purity of the fuel oil. Furthermore, the cracking process also produces non-condensable exhaust gases, which may contain harmful components. Direct emission without effective treatment will cause secondary pollution.

[0004] To address these issues, several improved waste plastic pyrolysis units have emerged in recent years. These units have improved the yield and quality of oil products from waste plastic pyrolysis by optimizing reactor structure, improving condensation system design, and adding exhaust gas purification modules. However, these units still suffer from problems such as insufficient energy efficiency in practical applications. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes an apparatus for the efficient pyrolysis of waste plastics to produce fuel oil, which mainly solves the problem of insufficient energy utilization in existing waste plastic pyrolysis devices.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0007] An apparatus for efficiently pyrolyzing waste plastics to produce fuel oil includes a pretreatment module, a two-stage dechlorination reaction module, a multi-stage pyrolysis reaction module, a condensation separation module, and a tail gas treatment module connected in sequence. The tail gas treatment module is used to collect non-condensable gases and ignite them for heating the multi-stage pyrolysis reaction module.

[0008] In some embodiments, the pretreatment module includes a grinding chamber, an impurity prevention assembly installed at the inlet of the grinding chamber, a grinding propeller installed inside the grinding chamber, and a first heating assembly installed outside the grinding chamber.

[0009] In some embodiments, the two-stage dechlorination reaction module includes a dechlorination chamber, and a second heating component is provided outside the dechlorination chamber. The dechlorination chamber is provided inside a controllable flap that divides the dechlorination chamber into a first dechlorination chamber and a second dechlorination chamber.

[0010] In some embodiments, the outlet end of the second dechlorination chamber is connected to a cooling device.

[0011] In some embodiments, the first dechlorination chamber is connected to the HCl collection chamber.

[0012] In some embodiments, the multi-stage pyrolysis reaction module includes a pyrolysis chamber and a multi-stage catalyst bed installed inside the pyrolysis chamber, each stage of the catalyst bed being equipped with a corresponding spiral heater and a temperature controller.

[0013] In some embodiments, the bottom of the pyrolysis chamber is connected to the two-stage dechlorination reaction module via a heat recovery pipe.

[0014] In some embodiments, the condensation separation module includes a filter, a collection tank, and a separator connected in sequence, wherein the separator is provided with multiple condensation gradient oil separation units, and the output end of the separator injects waxy substances into a waxy substance collection device.

[0015] In some embodiments, the exhaust gas treatment module includes a gas collection chamber and a burner. The output end of the separator injects non-condensable gas into the gas collection chamber via an adsorbent pipe. The heat generated by the non-condensable gas after passing through the burner is injected into the multi-stage pyrolysis reaction module.

[0016] In some embodiments, an intelligent control system is also included, which is used to control the pretreatment module, the two-stage dechlorination reaction module, the multi-stage pyrolysis reaction module, the condensation separation module, and the tail gas treatment module.

[0017] The beneficial effects of this invention are as follows: by collecting non-condensable gas in the exhaust gas treatment module and igniting the gas for heating in the multi-stage pyrolysis reaction module, efficient self-circulation of energy is achieved, reducing system energy consumption. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the apparatus for efficient pyrolysis of waste plastics to produce fuel oil, as disclosed in an embodiment of the present invention.

[0019] Wherein: 1-Grinding chamber, 101-Circulating water inlet, 102-Circulating water outlet, 103-Feed inlet, 2-Impurity prevention component, 3-Grinding propeller, 4-First heating component, 5-Dechlorination chamber, 501-Flip plate, 502-First dechlorination chamber, 503-Second dechlorination chamber, 6-Second heating component, 7-Cooling device, 8-HCl collection chamber, 9-Cracking chamber, 10-Catalyst bed, 11-Spiral heater, 12-Temperature controller, 13-Heat recovery pipe, 14-Filter screen, 15-Collection tank, 16-Separator, 17-Waxy collection device, 18-Gas collection chamber, 19-Adsorbent pipeline, 20-Intelligent control system. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer and more explicit, the content of this invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to this invention are shown in the accompanying drawings, not all of them.

[0021] This embodiment proposes an apparatus for the efficient pyrolysis of waste plastics to produce fuel oil, comprising a pretreatment module, a two-stage dechlorination reaction module, a multi-stage pyrolysis reaction module, a condensation separation module, and a tail gas treatment module connected in sequence. The tail gas treatment module is used to collect non-condensable gases and ignite them for heating the multi-stage pyrolysis reaction module.

[0022] In this embodiment, by collecting non-condensable gas through the exhaust gas treatment module and igniting the gas for heating the multi-stage pyrolysis reaction module, efficient self-circulation of energy is achieved, reducing system energy consumption.

[0023] In one example, such as Figure 1As shown, the pretreatment module includes a crushing chamber 1, an impurity prevention component 2 installed at the inlet of the crushing chamber 1, a crushing propeller 3 installed inside the crushing chamber 1, and a first heating component 4 installed outside the crushing chamber 1. Specifically, the crushing chamber 1 is a hollow shell with a circulating water inlet 101 and a circulating water outlet 102 on its surface to ensure circulating cooling of the crushing chamber 1. A feed inlet 103 is provided above the crushing chamber 1, through which waste plastic is fed. During the pretreatment process, the crushing chamber 1 is heated by the first heating component 4 to heat the waste plastic to a suitable pyrolysis temperature. Simultaneously, a temperature monitoring device monitors the temperature in real time and starts the crushing propeller 3 to achieve automatic crushing and cleaning of the waste plastic under certain temperature and pressure conditions.

[0024] Continue reading Figure 1 The dual-stage dechlorination reaction module includes a dechlorination chamber 5, specifically connected to the outlet of the crushing chamber 1. An adsorbent is placed inside the chamber, and a suitable temperature is provided to precisely regulate the conditions of the dechlorination process, ensuring dechlorination effect and efficiency for further removal of chlorine from waste plastics. A second heating component 6 is installed outside the dechlorination chamber 5. Inside the dechlorination chamber 5, a controllable flap 501 is installed, horizontally positioned within the chamber, dividing it into a first dechlorination chamber 502 and a second dechlorination chamber 503. Waste plastics that have undergone preliminary cleaning and crushing in the pretreatment module enter the dechlorination chamber 5. The first dechlorination chamber 502 is used for preliminary dechlorination, where the waste plastics are heated to approximately 250-300°C. At this temperature, most of the hydrogen chloride gas is released. The first dechlorination chamber 502 is connected to an HCl collection chamber 8, where the hydrogen chloride gas reacts with an alkaline solution to form harmless substances, reducing the risk of corrosion in subsequent processes. The flapper 501 rotates 180° every 5 minutes, entering the second dechlorination chamber 503 at a temperature of 300-350℃. Residual chlorine is adsorbed using suitable metal oxides, composite molecular sieves, or modified adsorbents to further reduce the generation of corrosive gases. The outlet of the second dechlorination chamber 503 is connected to the cooling device 7. Finally, the waste plastic is sent to the multi-stage pyrolysis reaction module via the cooling device 7.

[0025] In this embodiment, a multi-stage pyrolysis reaction module is used for catalytic reforming to improve the quality of the produced oil. In one example, the multi-stage pyrolysis reaction module includes a cracking chamber 9 and a multi-stage catalyst bed 10 installed inside the cracking chamber 9. Each stage of the catalyst bed 10 is equipped with a corresponding spiral heater 11 and a temperature controller 12. The dechlorinated sample enters the cracking chamber 9 after passing through a cooling device 7. The temperature is individually controlled by the multi-stage spiral heaters 11, allowing the waste plastic to be pyrolyzed in different temperature ranges from 300℃ to 600℃. The oil and gas enter the condensation separation module from the top, while the carbon black (byproduct) is discharged from the bottom of the cracking chamber 9. Furthermore, the bottom of the cracking chamber 9 is connected to the two-stage dechlorination reaction module via a heat recovery pipe 13. The carbon black and surplus heat produced in the cracking chamber 9 are sent to the two-stage dechlorination reaction module to achieve resource recycling. In addition, the spiral heaters 11 are equipped with constant temperature control and heat recovery functions. The heat generated during pyrolysis can be recovered by the heat exchange system under the action of the catalyst bed 10 and used in the two-stage dechlorination reaction module, improving the overall energy efficiency of the system.

[0026] In one example, the condensation separation module includes a filter screen 14, a collection tank 15, and a separator 16 connected in sequence. The separator 16 contains multiple condensation gradient oil separation units, and the output of the separator 16 injects waxy material into a waxy material collection device 17. After the oil and gas generated in the pyrolysis chamber 9 are discharged, they pass through the filter screen 14 welded to the gas outlet and enter the collection tank 15, preventing dried waste plastic from clogging the gas outlet of the pyrolysis chamber 9 and preventing cooled waxy material from clogging the pipes. The separator 16 contains multiple condensation gradient oil separation units; by setting different condensation temperatures, different qualities of oil are obtained, including heavy oil, medium oil, and light oil. The collection tank 15 collects and automatically cleans the waxy material, preventing the separator 16 from clogging. Optionally, the separator 16 can adopt a shell-and-tube structure to increase cooling efficiency and reduce wastewater discharge.

[0027] In one example, the exhaust gas treatment module includes a gas collection chamber 18 and a burner (not shown). The output of the separator 16 injects non-condensable gas into the gas collection chamber 18 via an adsorbent pipe 19. The heat generated by the non-condensable gas after passing through the burner is injected into the multi-stage pyrolysis reaction module. The non-condensable gas generated during the condensation process of the separator 16 meets emission standards under the action of the adsorbent pipe 19 and then enters the gas collection chamber 18. This non-condensable gas provides energy for the system's pyrolysis, reducing external energy consumption.

[0028] It also includes an intelligent control system 20, which controls the pretreatment module, the two-stage dechlorination reaction module, the multi-stage pyrolysis reaction module, the condensation separation module, and the tail gas treatment module. In this embodiment, the device is equipped with the intelligent control system 20 to monitor and adjust the device's operating parameters. Through real-time monitoring of temperature, pressure, and flow rate, the operation of the pyrolysis and condensation systems is automatically controlled to ensure the equipment operates under optimal conditions, while also providing automatic shutdown protection.

[0029] The above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made based on the essence of the content of the present invention should be covered within the scope of protection of the present invention.

Claims

1. An apparatus for the efficient pyrolysis of waste plastics to produce fuel oil, characterized in that, It includes a pretreatment module, a two-stage dechlorination reaction module, a multi-stage pyrolysis reaction module, a condensation separation module, and a tail gas treatment module connected in sequence. The tail gas treatment module is used to collect non-condensable gases and ignite them for heating the multi-stage pyrolysis reaction module.

2. The apparatus for high-efficiency pyrolysis of waste plastics to produce fuel oil as described in claim 1, characterized in that, The pretreatment module includes a grinding chamber, an impurity prevention component installed at the inlet of the grinding chamber, a grinding propeller installed inside the grinding chamber, and a first heating component installed outside the grinding chamber.

3. The apparatus for high-efficiency pyrolysis of waste plastics to produce fuel oil as described in claim 1, characterized in that, The dual-stage dechlorination reaction module includes a dechlorination chamber, and a second heating component is provided on the outside of the dechlorination chamber. Inside the dechlorination chamber, a controllable flap is provided, which divides the dechlorination chamber into a first dechlorination chamber and a second dechlorination chamber.

4. The apparatus for high-efficiency pyrolysis of waste plastics to produce fuel oil as described in claim 3, characterized in that, The outlet end of the second dechlorination chamber is connected to a cooling device.

5. The apparatus for high-efficiency pyrolysis of waste plastics to produce fuel oil as described in claim 3, characterized in that, The first dechlorination chamber is connected to the HCl collection chamber.

6. The apparatus for high-efficiency pyrolysis of waste plastics to produce fuel oil as described in claim 1, characterized in that, The multi-stage pyrolysis reaction module includes a pyrolysis chamber and a multi-stage catalyst bed installed inside the pyrolysis chamber. Each stage of the catalyst bed is equipped with a corresponding spiral heater and a temperature controller.

7. The apparatus for high-efficiency pyrolysis of waste plastics to produce fuel oil as described in claim 6, characterized in that, The bottom of the pyrolysis chamber is connected to the two-stage dechlorination reaction module via a heat recovery pipe.

8. The apparatus for high-efficiency pyrolysis of waste plastics to produce fuel oil as described in claim 1, characterized in that, The condensation separation module includes a filter screen, a collection tank and a separator connected in sequence. The separator is equipped with multiple condensation gradient oil separation units. The output end of the separator injects waxy substances into a waxy substance collection device.

9. The apparatus for high-efficiency pyrolysis of waste plastics to produce fuel oil as described in claim 8, characterized in that, The exhaust gas treatment module includes a gas collection chamber and a burner. The output end of the separator injects non-condensable gas into the gas collection chamber through an adsorbent pipe. The heat generated by the non-condensable gas after passing through the burner is injected into the multi-stage pyrolysis reaction module.

10. The apparatus for high-efficiency pyrolysis of waste plastics to produce fuel oil as described in claim 1, characterized in that, It also includes an intelligent control system, which is used to control the pretreatment module, the two-stage dechlorination reaction module, the multi-stage pyrolysis reaction module, the condensation separation module, and the tail gas treatment module.

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