Device for preparing fuel oil by means of efficiently cracking waste plastic

Abstract

Disclosed in the present invention is a device for preparing a fuel oil by means of efficiently cracking waste plastic. The device comprises a pretreatment module, a two-stage dechlorination reaction module, a multistage pyrolysis reaction module, a condensation separation module and a tail gas treatment module, which are connected in sequence, wherein the tail gas treatment module is used for collecting a non-condensable gas, and igniting the non-condensable gas for a heating task of the multi-stage pyrolysis reaction module. The present invention has the beneficial effects that the non-condensable gas is collected by means of the tail gas treatment module and is ignited for the heating task of the multi-stage pyrolysis reaction module, thereby achieving efficient self-recycling of energy and reducing the energy consumption of the system.

Description

A device for efficiently cracking waste plastics to produce fuel oil Technical field:

[0001] The invention relates to the field of waste plastic cracking equipment, and in particular to a device for preparing fuel oil by efficiently cracking waste plastic. Background technology:

[0002] With the widespread use of discarded plastic products, the amount of plastic waste worldwide has increased year by year, and the disposal of discarded plastic waste has become a serious environmental problem. At present, the main methods for disposing of waste plastics include landfill, incineration and resource utilization. Although landfill is simple, it occupies a large amount of land resources, and waste plastics are difficult to degrade in the natural environment, causing long-term ecological pollution. Although incineration can reduce the volume of waste, waste plastics will produce a large amount of toxic and harmful substances, such as dioxins, during the combustion process, posing a serious threat to air quality and human health. In addition, incineration is accompanied by energy waste and cannot effectively recover the high calorific value components in waste plastics. In contrast, resource utilization has gradually become a potential solution. Through technical means, waste plastics can be converted into useful chemical raw materials or fuel oil to achieve resource recycling, which not only reduces environmental pollution but also generates economic benefits.

[0003] Waste plastic pyrolysis technology involves a chemical process that cracks waste plastics into small hydrocarbons under high-temperature, oxygen-free, or anoxic conditions. This process effectively converts waste plastics into products such as liquid fuel oil, gaseous fuel gas, and solid carbon black. Pyrolysis not only recovers the energy contained in waste plastics but also simplifies waste disposal and reduces environmental pollution. However, existing waste plastic pyrolysis equipment on the market suffers from the following common issues: First, traditional pyrolysis equipment consumes a lot of energy and fails to efficiently utilize the heat generated during the reaction, resulting in energy waste. Second, the complex nature of waste plastics makes it difficult to control the temperature and time of the pyrolysis reaction, often leading to uneven composition and unstable quality of the oil and gas products, hindering subsequent separation and utilization. Third, the oil and gas produced during the pyrolysis process must be condensed, but traditional condensation systems are inefficient, making it difficult to effectively separate light and heavy oils, thereby reducing the purity of the fuel oil. Furthermore, the pyrolysis process produces non-condensable exhaust gases, which may contain harmful components. If not effectively treated and discharged, direct discharge will cause secondary pollution.

[0004] To address these issues, several improved waste plastic pyrolysis plants have emerged in recent years. These plants have improved the yield and quality of waste plastic pyrolysis oils by optimizing reactor structure, refining condensation system design, and adding tail gas purification modules. However, in practice, these plants still suffer from issues such as insufficient energy efficiency. Summary of the invention:

[0005] In view of the above problems, the present invention proposes a device for efficiently cracking waste plastics to produce fuel oil, which mainly solves the problem of insufficient energy utilization rate of existing waste plastic cracking devices.

[0006] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0007] A device for efficiently cracking 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 the non-condensable gases for heating tasks in the multi-stage pyrolysis reaction module.

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

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

[0010] In some embodiments, the outlet 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 cracking chamber and a multi-stage catalyst bed installed inside the cracking chamber, and each stage of the catalyst bed is installed with a corresponding spiral heater and a temperature control meter.

[0013] In some embodiments, the bottom of the cracking chamber is connected to the dual-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 a plurality of condensation gradient oil separation units are arranged inside the separator, and the output end of the separator injects the wax into the wax collection device.

[0015] In some embodiments, the tail gas treatment module includes a gas collection chamber and a burner. The output end of the separator injects the non-condensable gas into the gas collection chamber through an adsorbent pipe, and 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 further 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 the present invention are: by collecting non-condensable gas in the tail gas treatment module and igniting the gas for the heating task of the multi-stage pyrolysis reaction module, efficient self-circulation of energy can be achieved, thereby reducing system energy consumption. Description of the drawings:

[0018] FIG1 is a schematic structural diagram of an apparatus for efficiently cracking waste plastics to produce fuel oil according to an embodiment of the present invention;

[0019] Among them: 1-crushing chamber, 101-circulating water inlet, 102-circulating water outlet, 103-feeding port, 2-impurity prevention component, 3-crushing 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 control meter, 13-heat recovery pipe, 14-filter, 15-collecting tank, 16-separator, 17-wax collection device, 18-gas collection chamber, 19-adsorbent pipeline, 20-intelligent control system. Specific implementation method:

[0020] To make the objectives, technical solutions, and advantages of the present invention more clear and distinct, the present invention is 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 for the purpose of explaining the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all of the present invention.

[0021] This embodiment proposes a device for efficiently cracking waste plastics to produce fuel oil, which includes a pretreatment module, a two-stage dechlorination reaction module, a multi-stage pyrolysis reaction module, a condensation separation module, and an exhaust gas treatment module connected in sequence. The exhaust gas treatment module is used to collect non-condensable gases and ignite the non-condensable gases for heating tasks in the multi-stage pyrolysis reaction module.

[0022] In this embodiment, the tail gas treatment module collects non-condensable gas, and the gas is ignited and used for the heating task of the multi-stage pyrolysis reaction module to achieve efficient self-circulation of energy and reduce system energy consumption.

[0023] In one example, as shown in FIG1 , the pretreatment module includes a crushing chamber 1, an anti-impurity component 2 installed at the entrance 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, and a circulating water inlet 101 and a circulating water outlet 102 are provided on the surface of the shell to ensure the circulation cooling of the crushing chamber 1. A feed port 103 is provided above the crushing chamber 1, and waste plastics are fed into the feed port 103. During the pretreatment process, the crushing chamber 1 is heated by the first heating component 4, and the waste plastics are heated to a suitable cracking temperature. At the same time, a temperature monitoring device monitors the temperature in real time, and the crushing propeller 3 is started to realize automatic crushing and cleaning of the waste plastics under certain temperature and pressure.

[0024] Continuing with Figure 1, the dual-stage dechlorination reaction module includes a dechlorination chamber 5. Specifically, the dechlorination chamber 5 is connected to the outlet of the pulverization chamber 1. An adsorbent is installed inside the chamber and a suitable temperature is provided to precisely adjust the conditions of the dechlorination process, ensuring the dechlorination effect and efficiency, and further removing the chlorine element from the waste plastic. A second heating assembly 6 is provided outside the dechlorination chamber 5. A controllable flap 501 is provided inside the dechlorination chamber 5. The flap 501 is horizontally arranged in the dechlorination chamber 5 and divides the dechlorination chamber 5 into a first dechlorination chamber 502 and a second dechlorination chamber 503. The waste plastic that has been initially cleaned and pulverized from the pretreatment module enters the dechlorination chamber 5. The first dechlorination chamber 502 is used for initial dechlorination. The waste plastic is heated to approximately 250-300°C, at which temperature most of the hydrogen chloride gas is released. The first dechlorination chamber 502 is connected to the HCl collection chamber 8. The hydrogen chloride gas enters the HCl collection chamber 8 and reacts with the alkaline solution to form harmless substances, reducing the risk of corrosion in subsequent processes. Flap 501 rotates 180° every five minutes, entering the second dechlorination chamber 503, where the temperature is maintained at 300-350°C. Suitable metal oxides, composite molecular sieves, or modified adsorbents are used to adsorb residual chlorine, further reducing the generation of corrosive gases. The outlet of the second dechlorination chamber 503 is connected to a cooling device 7, which then delivers the waste plastic to the multi-stage pyrolysis reaction module.

[0025] In this embodiment, the multi-stage pyrolysis reaction module is used to perform a catalytic reforming reaction to improve the quality of the output 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 control table 12. The dechlorinated sample enters the cracking chamber 9 after passing through the cooling device 7. The temperature is controlled separately by the multi-layer spiral heater 11, so that the waste plastic is pyrolyzed in different temperature ranges of 300°C-600°C. The oil and gas enter the condensation separation module from the top, and the carbon black (by-product) is discharged from the bottom of the cracking chamber 9. Further, the bottom of the cracking chamber 9 is connected to the two-stage dechlorination reaction module through the heat recovery pipe 13. The carbon black and surplus heat produced by the cracking chamber 9 are sent to the two-stage dechlorination reaction module to achieve resource recycling. In addition, the spiral heater 11 is equipped with a constant temperature control and heat recovery function. The heat generated during the pyrolysis process 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, thereby improving the overall energy efficiency of the system.

[0026] In one example, the condensation separation module includes a filter 14, a collection tank 15 and a separator 16 connected in sequence, wherein a plurality of condensation gradient oil separation units are arranged inside the separator 16, and the output end of the separator 16 injects the wax into the wax collection device 17. After the oil and gas generated in the cracking chamber 9 are discharged, they enter the collection tank 15 through the filter 14 welded on the gas outlet, thereby preventing the dried waste plastic from clogging the gas outlet of the cracking chamber 9 and preventing the cooled wax from clogging the pipeline. There are multiple condensation gradient oil separation units in the separator 16. By setting different condensation temperatures, oil products of different qualities are obtained, such as heavy oil, medium oil and light oil. The wax is collected and automatically cleaned through the collection tank 15 to avoid clogging of the separator 16. Optionally, the separator 16 can adopt a shell and tube structure to increase cooling efficiency and reduce wastewater discharge.

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

[0028] The device also includes an intelligent control system 20, 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. This embodiment of the device is equipped with an intelligent control system 20 to monitor and adjust the device's operating parameters. By monitoring temperature, pressure, and flow in real time, it automatically controls the operation of the cracking and condensation systems, ensuring optimal operation. It also provides an automatic shutdown protection function.

[0029] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made based on the essence of the present invention are intended to be covered by the scope of protection of the present invention.

Claims

1. A device for efficiently cracking 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, wherein the tail gas treatment module is used to collect non-condensable gases and ignite the non-condensable gases for the heating task of the multi-stage pyrolysis reaction module.

2. The device for efficiently cracking waste plastics to prepare fuel oil according to claim 1, characterized in that: The pre-processing module includes a crushing chamber, an impurity prevention component installed at the entrance of the crushing chamber, a crushing propeller installed inside the crushing chamber, and a first heating component installed outside the crushing chamber.

3. The device for efficiently cracking waste plastics to prepare fuel oil according to claim 1, characterized in that: The two-stage dechlorination reaction module includes a dechlorination chamber, a second heating assembly is provided outside the dechlorination chamber, and a controllable flap is provided inside the dechlorination chamber, which divides the dechlorination chamber into a first dechlorination chamber and a second dechlorination chamber.

4. The device for efficiently cracking waste plastics to prepare fuel oil according to claim 3, characterized in that: The outlet end of the second dechlorination chamber is connected to a cooling device.

5. The device for efficiently cracking waste plastics to prepare fuel oil according to claim 3, characterized in that: The first dechlorination chamber is connected to the HCL collection chamber.

6. The device for efficiently cracking waste plastics to prepare fuel oil according to claim 1, characterized in that: The multi-stage pyrolysis reaction module includes a cracking chamber and a multi-stage catalyst bed installed inside the cracking chamber. The catalyst bed at each stage is installed with a corresponding spiral heater and a temperature control meter.

7. The device for efficiently cracking waste plastics to produce fuel oil according to claim 6, characterized in that: The bottom of the cracking chamber is connected to the double-stage dechlorination reaction module via a heat recovery pipe.

8. The device for efficiently cracking waste plastics to produce fuel oil according to claim 1, characterized in that: The condensation separation module includes a filter, a collection tank and a separator connected in sequence, wherein a plurality of condensation gradient oil separation units are arranged inside the separator, and the output end of the separator injects the wax into the wax collection device.

9. The device for efficiently cracking waste plastics to produce fuel oil according to claim 8, characterized in that: The tail gas treatment module includes a gas collection chamber and a burner. The output end of the separator injects the non-condensable gas into the gas collection chamber through the adsorbent pipeline, and the heat generated by the non-condensable gas after passing through the burner is injected into the multi-stage pyrolysis reaction module.

10. The device for efficiently cracking waste plastics to produce fuel oil according to 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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