Method for reducing content of sulfur and chlorine in waste rubber and plastic pyrolytic oil by using waste chromium slag

Abstract

The invention discloses a method for reducing the content of sulfur and chlorine in waste rubber and plastic pyrolytic oil by using waste chromium slag, and relates to the technical field of comprehensive utilization of solid waste products. A system adopted by the method comprises a dechlorination device, a chlorine adsorption device, a graded catalytic pyrolysis device and a waste residue separation device, waste chromium residue powder is conveyed into a chlorine adsorption pipeline of the chlorine adsorption device before an experiment is started, and when the experiment is started, the waste chromium residue powder is separated from the chlorine adsorption pipeline; waste chromium slag and waste rubber and plastic sequentially pass through a dechlorination device, a graded catalytic pyrolysis device and a waste residue separation device to reduce sulfur and chlorine in waste rubber and plastic pyrolysis oil. And cyclic utilization of the waste chromium slag is realized in the in-situ catalytic pyrolysis process and the ectopic catalytic pyrolysis process. The method provided by the invention not only helps to solve the problem of environmental pollution, but also reutilizes the waste chromium slag.

Description

Technical Field

[0001] The invention relates to the technical field of comprehensive utilization of solid waste products, and in particular to a method for reducing the sulfur and chlorine contents in waste rubber and plastic pyrolysis oil by utilizing waste chromium slag. Background Art

[0002] With the rapid development of urbanization and industrialization and the annual increase in the number of cars, the application of plastic products and tires as automobile consumables has also increased. The solid waste products formed after the plastic products and tires have completed their service life will cause great harm to the environment. Therefore, the high-value resource utilization of solid waste products has become an unavoidable topic in the current social development.

[0003] Pyrolysis technology plays an important role in the treatment of waste tires and waste plastics. Through pyrolysis technology, waste rubber and plastics can be converted into economic products such as pyrolysis gas and pyrolysis oil. Among the pyrolysis products, pyrolysis oil is the most widely used. Through post-processing and treatment, it can replace traditional fuel oil or become a basic material for the preparation of chemical raw materials. The composition of plastics in life is complex, and the raw materials for the production of waste tires are also dazzling. Therefore, traditional direct pyrolysis technology seriously affects the yield and quality of pyrolysis oil. Among them, the two elements that most affect the quality of pyrolysis oil are sulfur and chlorine. How to remove chlorine in waste plastic pyrolysis oil and sulfur in waste tire pyrolysis oil is one of the key issues in the high-value utilization of pyrolysis oil. Summary of the invention

[0004] The purpose of the present invention is to provide a method for reducing the sulfur and chlorine contents in waste rubber and plastic pyrolysis oil by using waste chromium slag. The waste chromium slag is applied to remove the sulfur and chlorine elements in the waste rubber and plastic pyrolysis oil, which not only helps to solve the environmental pollution problem, but also recycles the waste chromium slag. The method realizes the simultaneous feeding and dechlorination by improving the structure of the dechlorination device; the special design of the catalytic pyrolysis device realizes the graded pyrolysis of materials in a pyrolysis device.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for reducing the sulfur and chlorine content in waste rubber and plastic pyrolysis oil by using waste chromium slag, the system used in the method comprises a dechlorination device, a chlorine adsorption device, a graded catalytic pyrolysis device and a waste slag separation device, the dechlorination device comprises a base, a motor 1, a barrel, a feed port, a dechlorination extrusion screw, an electromagnetic heating mechanism, a micropore 1 and a chlorine transmission pipeline; the motor 1 and the barrel are both fixed to the upper end of the base, the motor 1 is located on the side of the barrel, the dechlorination extrusion screw is located inside the barrel and is connected to the motor 1; the feed port is located on the upper end of the barrel side; the electromagnetic heating mechanism is located in the middle of the barrel, and the micropore 1 is arranged near the tail of the barrel near the electromagnetic heating mechanism; the micropore 1 is connected to the chlorine transmission pipeline, and the chlorine generated by the waste rubber and plastic passes through the micropore 1 into the chlorine transmission pipeline; the diameter of the dechlorination extrusion screw increases from left to right - remains unchanged - decreases in sequence, and the pitch decreases from left to right - remains unchanged - increases gradually, and a dechlorination section is arranged in the middle section of the dechlorination extrusion screw, and regularly arranged dechlorination pins are installed on the dechlorination section;

[0007] The chlorine adsorption device is connected to the waste residue separation device, and the waste residue separation device is connected to the graded catalytic pyrolysis device;

[0008] The hierarchical catalytic pyrolysis device mainly comprises a shell, a heating plate fixing frame, a heating plate, an oil and gas outlet and a driving mechanism, wherein the oil and gas outlet is located above the shell, the heating plate fixing frame and the heating plate are both located in the shell, the heating plates are arranged in several groups, each group of heating plates is fixed on the corresponding heating plate fixing frame and is circular, and the several groups of heating plates are in a circular ring shape as a whole, and blanking openings are arranged between the multiple heating plates of each group of heating plates located in the same circumferential direction; the temperature of the several groups of heating plates increases successively along the axial direction outward, and the distance between the blanking openings of each group of heating plates adjacent to each other along the axial direction outward decreases successively; the driving mechanism provides power to the heating plate fixing frame, and when the hierarchical catalytic pyrolysis device performs pyrolysis, the heating plate fixing frame is always in a rotating state;

[0009] The method comprises the following steps:

[0010] Step 1: Before the experiment, select an appropriate amount of waste chromium slag, crush it into powder, and send it into a chlorine adsorption device;

[0011] Step 2: During the experiment, the waste rubber and plastic and the waste chromium slag of a certain particle size are fed into the feed port of the dechlorination device, and the materials are heated to 200-300° C. by the electromagnetic heating mechanism. Under the action of the dechlorination extrusion screw, the chlorine element is effectively removed from the materials; the removed chlorine element is adsorbed by the waste chromium slag powder in the chlorine adsorption device;

[0012] In step 3, the waste rubber and plastic that have not been pyrolyzed in step 2 enter the graded catalytic pyrolysis device, and the heating plate fixing frame is always in a rotating state. Its rotation causes shear force, extrusion force and impact force of falling materials to be generated between the waste rubber and plastic and the waste chromium slag. Under the interaction of these forces, the particle size of the pyrolytic carbon black and the waste chromium slag is reduced, and the pyrolytic carbon black and the waste chromium slag that have completed the graded catalytic pyrolysis enter the waste slag separation device;

[0013] Step 4: Separate the waste chromium slag from the pyrolytic carbon black through the waste slag separation device, and recycle it for use in the chlorine adsorption device to complete the dechlorination and desulfurization of waste rubber and plastic and the closed-loop utilization of waste chromium slag.

[0014] In the above-mentioned method for reducing the sulfur and chlorine content in the pyrolysis oil of waste rubber and plastic by using waste chromium slag, the power of the dechlorination extrusion screw is provided by a motor 1, the dechlorination extrusion screw and the motor 1 are connected by a spline, and the rotation speed of the motor 1 is 5 to 200 r / min; the chlorine-containing oil gas generated by the material under the action of the electromagnetic heating mechanism enters the chlorine gas transmission pipeline through the micropore 1, and the aperture of the micropore 1 is 0.001 to 1 mm; the feed port is welded on the upper side of the barrel, and the electromagnetic heating mechanism is fixed in the middle position of the barrel by an interference fit, and the electromagnetic heating mechanism provides external heat for the preliminary pyrolysis of the waste rubber and plastic.

[0015] The above-mentioned method of using waste chromium slag to reduce the sulfur and chlorine content in waste rubber and plastic pyrolysis oil, the chlorine adsorption device includes a displacement fixing mechanism, two micropores, a chlorine adsorption pipeline, spiral blades and two motors, the displacement fixing mechanism is located at the upper end of the chlorine transmission pipeline, used to fix the chlorine adsorption pipeline, the chlorine adsorption pipeline is provided with two micropores running through the inside and outside, the spiral blades are located on the inner side of the chlorine adsorption pipeline, and the spiral blades are used to continuously propel the waste chromium slag in the chlorine adsorption pipeline; the power required for the chlorine transmission pipeline is provided by two motors, the rotation speed of the two motors is 5-200r / min; the aperture of the two micropores is 0.001-1mm.

[0016] The above-mentioned method of using waste chromium slag to reduce the sulfur and chlorine content in waste rubber and plastic pyrolysis oil, the oil and gas outlet of the graded catalytic pyrolysis device is connected to an oil and gas condensation purification device, and the pyrolysis oil is purified and graded and collected by the oil and gas condensation purification device; the temperature of several groups of heating plates increases successively along the axial direction outward, and the spacing between the blanking openings of each group of heating plates adjacent to each other along the axial direction outward decreases successively to achieve graded pyrolysis of waste rubber and plastic; a single heating plate is in an arc shape; the driving mechanism is motor three, the rotation speed of motor three is 10 to 100 r / min, the temperature range of the heating plate is 400 to 1200°C, and the width of the blanking opening is 0.1 to 100 mm.

[0017] The above-mentioned method of using waste chromium slag to reduce the sulfur and chlorine content in waste rubber and plastic pyrolysis oil, the waste slag separation device includes a cylinder, a separator, micropore three, a pyrolytic carbon black discharge port and a chromium slag drop port, the separator is located inside the cylinder, and the separator is provided with micropore three running through the inside and outside of the separator, the pyrolytic carbon black discharge port and the chromium slag drop port are located outside the cylinder; the aperture of the micropore three is 0.1 to 100 mm, and the micropore three can allow the waste chromium slag to pass through.

[0018] The above-mentioned method of using waste chromium slag to reduce the sulfur and chlorine content in waste rubber and plastic pyrolysis oil, after the waste chromium slag falls through the chromium slag drop port, is transported to the chlorine adsorption pipeline of the chlorine adsorption device through a screw feeding mechanism, and is used to adsorb the chlorine element generated during the pyrolysis process of waste rubber and plastic.

[0019] The above-mentioned method of using waste chromium slag to reduce the sulfur and chlorine content in waste rubber and plastic pyrolysis oil, in step 2, the waste rubber and plastic include waste tires and waste plastics, the waste tires and waste plastics are washed, dried, and crushed before use, and the particle size of the crushed waste chromium slag is 5 to 10 mm.

[0020] In the above method of using waste chromium slag to reduce the sulfur and chlorine content in waste rubber and plastic pyrolysis oil, there is a density difference between the waste chromium slag and the pyrolysis carbon black, and the two are separated under the centrifugal action of the separator.

[0021] In the above-mentioned method of using waste chromium slag to reduce the sulfur and chlorine content in waste rubber and plastic pyrolysis oil, the pyrolysis carbon black is concentrated in the middle part of the separator and discharged through the pyrolysis carbon black discharge port, and the waste chromium slag is gathered at the chromium slag discharge port after passing through the micropores, and is discharged through the chromium slag discharge port, and then sent to the chlorine adsorption device through the screw feeding mechanism.

[0022] In the above-mentioned method of reducing the sulfur and chlorine contents in waste rubber and plastic pyrolysis oil by using waste chromium slag, in step 2, the mass ratio of waste rubber and plastic to waste chromium slag is 1-100:1-100:1-100.

[0023] Compared with the prior art, the present invention brings the following beneficial technical effects:

[0024] (1) The present invention utilizes the industrial byproduct waste chromium slag, which not only solves the environmental pollution problem, but also brings into play the secondary application potential of the waste chromium slag. The waste chromium slag contains a large amount of metal oxides such as calcium oxide, aluminum oxide, magnesium oxide and iron oxide. These substances give the waste chromium slag the characteristics of catalytic pyrolysis and adsorption of harmful elements, which can not only improve the quality of pyrolysis oil, such as reducing or removing the content of sulfur and chlorine in pyrolysis oil, but also increase the degradation rate of waste tires and waste plastics in the pyrolysis process and reduce the energy consumption of pyrolysis.

[0025] (2) In the dechlorination device of the present invention, the diameter of the dechlorination extrusion screw increases from left to right, remains unchanged, and then decreases, while the pitch decreases from left to right, remains unchanged, and gradually increases. A dechlorination section is provided in the middle part of the screw, and a dechlorination pin is installed in the screw at this section. With the cooperation of the electromagnetic heating device, it not only ensures the uniform mixing of the materials during the feeding process, but also promotes the rapid precipitation of the chlorine element, realizes the simultaneous feeding and dechlorination, and improves the dechlorination treatment efficiency and dechlorination effect.

[0026] (3) In the graded catalytic pyrolysis device of the present invention, the heating plates are arranged in a ring shape, and the temperature of the heating plates increases successively along the axial direction outward. There are blanking holes between the heating plates, and the distance between the blanking holes of each group of heating plates adjacent to each other along the axial direction outward decreases successively. Compared with the traditional graded pyrolysis equipment that requires the joint participation of multiple reactors or reaction devices, the design of the present invention can realize graded pyrolysis in a graded catalytic pyrolysis device. At the same time, the displacement of the material continues to change during the rotation process, and is continuously accompanied by the existence of shear force, extrusion force and impact force. The interaction of multiple forces and the setting of the blanking hole distance between two adjacent heating plates can realize the gradual reduction of the particle size of waste rubber and plastic and waste chromium slag during the pyrolysis and falling process, avoid the occurrence of agglomeration and the peeling of carbon deposits that may exist on the surface of the waste chromium slag, and maintain the optimal catalytic selectivity of the waste chromium slag.

[0027] (4) Different from the desulfurization and dechlorination in the traditional waste rubber and plastic pyrolysis process, compared with in-situ catalytic pyrolysis, it was found through preliminary experiments that ex-situ catalytic pyrolysis is more conducive to the removal of chlorine in waste plastic pyrolysis oil, while compared with ex-situ catalytic pyrolysis, in-situ catalytic pyrolysis is more conducive to the removal of sulfur in waste tire pyrolysis oil. The present invention combines these two optimal pyrolysis forms to design an in-situ-ex-situ catalytic pyrolysis integrated system, and uses waste chromium slag as a catalyst for the removal of sulfur and chlorine, so as to achieve the recycling of waste chromium slag in the in-situ catalytic pyrolysis and ex-situ catalytic pyrolysis processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described below in conjunction with the accompanying drawings:

[0029] Figure 1 This is a process flow chart of the present invention for reducing the sulfur and chlorine contents in waste rubber and plastic pyrolysis oil by using waste chromium slag;

[0030] Figure 2 It is a structural schematic diagram of the system required by the present invention;

[0031] Figure 3 It is a structural schematic diagram of the hierarchical catalytic pyrolysis device of the present invention;

[0032] Figure 4 This is a schematic diagram of the structure of the dechlorination extrusion screw of the present invention;

[0033] Figure 5It is a structural schematic diagram of the chlorine adsorption device of the present invention;

[0034] Figure 6 It is a structural schematic diagram of the waste residue separation device of the present invention;

[0035] Figure 7 Schematic diagram of the diffusion path of chlorine gas in the present invention;

[0036] Figure 8 TG curve diagram of waste tire and waste polyvinyl chloride of the present invention;

[0037] Fig. 9 It is the DTG curve diagram of waste tire and waste polyvinyl chloride of the present invention.

[0038] In the figure:

[0039] 1. Electromagnetic heating mechanism, 2. Feeding port, 3. Dechlorination extrusion screw, 4. Motor one, 5. Base, 6. Oil and gas outlet, 7. Shell, 8. Motor three, 9. Screw feeding mechanism, 10. Motor four, 11. Heating plate fixing frame, 12. Heating plate, 13. Feeding port, 14. Dechlorination pin, 15. Dechlorination section, 16. Chlorine adsorption device, 17. Chlorine adsorption pipeline, 18. Chromium slag feeding port, 19. Motor two, 20. Cylinder, 21. Separator, 22. Micropore three, 23. Pyrolytic carbon black discharge port, 24. Displacement fixing mechanism, 25. Micropore two, 26. Spiral blade, 27. Chlorine transmission pipeline, 28. Micropore one. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0041] It is understandable that the connection relationship described in this application refers to direct or indirect connection. For example, the connection between A and B can be either a direct connection between A and B or an indirect connection between A and B through one or more other electrical components. For example, A and C can be directly connected, and C and B can be directly connected, so that A and B are connected through C. It is also understandable that the "A connects B" described in this application can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components.

[0042] In the description of this application, unless otherwise specified, " / " means "or", for example, A / B can mean A or B. "And / or" in this article is only a way to describe the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0043] In the description of this application, words such as "first" and "second" are only used to distinguish different objects, and do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit differences. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0044] The technical solution of the present application is further described in detail below in conjunction with the accompanying drawings.

[0045] 1. Pre-experimental process and relevant parameter characterization:

[0046] In the early stage of the system design used in the present invention, waste tires, waste plastics and blends are first subjected to direct pyrolysis, in-situ catalytic pyrolysis and ex-situ catalytic pyrolysis respectively through a tubular furnace. Waste chromium slag is selected as the catalyst, and the distribution law of carbon black solid, liquid oil and pyrolysis gas is explored. Subsequently, the sulfur and chlorine content of the liquid oil is characterized by an X-ray fluorescence spectrometer, and the test and characterization results are shown in Table 1. Liquid oil is the most widely used and economically valuable product. It can be seen from Table 1 that both in-situ catalytic pyrolysis and ex-situ catalytic pyrolysis are beneficial to improving the liquid oil output rate of waste tires, and in-situ catalytic pyrolysis is better than ex-situ catalytic pyrolysis. However, waste plastics show different results. In-situ catalytic pyrolysis will reduce the yield of liquid oil, but ex-situ catalytic pyrolysis can increase the yield of pyrolysis oil. This phenomenon shows that the contact mode between the catalyst and the raw material affects the distribution of pyrolysis products. Similarly, the contact mode of the catalyst during the co-pyrolysis of waste tires and waste plastics did not significantly change the yield of liquid oil, but its yield was higher than that of direct pyrolysis, indicating that the role of the catalyst in the co-pyrolysis process may not be as significant as that in the pyrolysis of a single raw material, which may be related to the synergistic effect between different raw materials.

[0047] Through the characterization of the sulfur and chlorine content in liquid oil, it was found that the presence of chromium slag during pyrolysis is conducive to reducing the sulfur and chlorine content in liquid oil. This is mainly because the calcium oxide, aluminum oxide, magnesium oxide and iron oxide in the chromium slag have chemical activity and can react with chlorine and sulfur compounds to generate stable compounds, thereby achieving the purpose of dechlorination and desulfurization. Among them, calcium oxide can react with sulfur oxides such as SO2 to generate substances such as calcium sulfate, and can also react with chloride ions to generate substances such as calcium chloride, realizing the adsorption and solidification of sulfur and chlorine during the pyrolysis process. At the same time, the catalytic effect of waste chromium slag may also change the generation path of the product, precipitating sulfide and chloride in the form of inorganic matter, thereby reducing the content of sulfur and chlorine in the pyrolysis oil. Among them, in-situ catalytic pyrolysis is more conducive to reducing the content of sulfur in waste tire liquid oil, while ex-situ catalytic pyrolysis is more conducive to reducing the content of sulfur in waste plastic liquid oil. The participation of chromium slag in the co-pyrolysis process of waste tires and waste materials can further reduce the content of sulfur and chlorine. In view of the above characterization results, the theory of equipment design is: to reduce the sulfur content in the waste rubber and plastic liquid oil by in-situ catalytic pyrolysis, and to reduce the chlorine content in the waste rubber and plastic liquid oil by ex-situ catalytic pyrolysis.

[0048] Table 1 Distribution and element contents of pyrolysis products

[0049]

[0050] Most of the waste plastics in our daily life exist in a mixed form. Therefore, waste polyvinyl chloride may inevitably be mixed into the pyrolysis process of waste plastics, which will not only lead to the deterioration of the quality of the pyrolysis products, but also cause irreversible damage to the pyrolysis equipment. Therefore, the pyrolysis process and pyrolysis temperature range of waste tires and polyvinyl chloride are characterized by thermogravimetric analysis to provide theoretical and parameter support for the pyrolysis process. The pyrolysis process and pyrolysis temperature range of waste tires and waste polyvinyl chloride are shown in Table 2. Figure 8 and Fig. 9 As shown in Table 2, Figure 8 and Fig. 9It can be seen that there is only one obvious weight loss stage in the pyrolysis process of waste tires, with a weight loss range of 330-483°C and a maximum weight loss temperature of 377°C. There are two obvious weight loss stages in the pyrolysis process of waste polyvinyl chloride, of which the first weight loss stage corresponds to a temperature range of 240-310°C and a maximum weight loss temperature of 290°C. Dechlorination reaction mainly occurs in this stage, that is, chlorine is mainly precipitated in this stage. The second weight loss stage corresponds to a temperature range of 424-496°C and a maximum weight loss temperature of 475°C. The reaction in this stage is mainly random breakage, cyclization and aromatization of hydrocarbon free radicals, with almost no precipitation of chlorine. According to the survey, the initial pyrolysis temperatures of other types of plastics, such as polyethylene (PE), polypropylene (PP) and polystyrene (PS), are mostly concentrated around 400°C. Therefore, the dechlorination temperature of waste plastics maintained at 250-300°C can meet the experimental requirements.

[0051] Table 2 Pyrolysis temperature distribution range

[0052]

[0053] Second, for the method of the present invention, a system suitable for the method is specially designed, such as Figure 2 As shown, the system can realize in-situ and ex-situ catalytic pyrolysis at the same time. Specifically, the system includes a dechlorination device, a chlorine adsorption device, a graded catalytic pyrolysis device and a waste residue separation device. The desulfurization and dechlorination process of waste rubber and plastic is completed through the cooperation of these four parts.

[0054] Specifically, the dechlorination unit is combined with Figure 2 As shown, it includes a base 5, a motor 4, a barrel, a feed port 2, a dechlorination extruder, an electromagnetic heating mechanism 1, a micropore 28 and a chlorine gas transmission pipeline 27. Among them, the base 5 is located at the bottom of the dechlorination device, the base 5 and the motor 4 are connected by bolts, the barrel is fixed on the base 5 through a barrel frame, the motor 4 is on the side of the barrel, the dechlorination extrusion screw 3 is located inside the barrel, and is splined with the motor 4, and the motor 4 provides driving force for the rotation of the dechlorination extrusion screw 3.

[0055] like Figure 4As shown, the diameter of the dechlorination extrusion screw increases from left to right, remains unchanged, and decreases from left to right, and the pitch decreases gradually, remains unchanged, and increases gradually from left to right. A dechlorination section 15 is provided in the middle section, and the dechlorination section 15 is equipped with regularly arranged dechlorination pins 14 to promote and accelerate the effective removal of chlorine elements during the feeding process and ensure the uniformity of material mixing. The feed port 2 is located on the upper side of the barrel and is connected by welding. The electromagnetic heating mechanism 1 is located in the middle part of the barrel and is fixed by interference fit to provide external energy for the preliminary pyrolysis of waste rubber and plastic (dechlorination of waste plastic). A micropore 28 is provided on the barrel of the rear section of the electromagnetic heating mechanism 1, and a chlorine adsorption device 16 is provided at the upper end of the micropore 28.

[0056] like Figure 5 As shown, the chlorine adsorption device 16 includes a displacement fixing mechanism 24, a micropore 25, a chlorine adsorption pipeline 17, a spiral blade 26 and a motor 19. The displacement fixing mechanism 24 is located at the upper end of the chlorine transmission pipeline 27, and is used to fix the chlorine adsorption pipeline 17 so that it can maintain coaxiality with the device when rotating 360°, while avoiding any movement along the axial direction.

[0057] The micropore 25 is located on the chlorine adsorption pipeline and runs through the inside and outside of the chlorine adsorption pipeline. The spiral blade 26 is located on the inner side of the chlorine adsorption pipeline 17 and is used for the continuous advancement of the waste chromium slag in the pipeline. The relative displacement of the chromium slag changes continuously during the advancement process; it is ensured that the chlorine element passing through the micropore 2 is fully in contact with the waste chromium slag and the efficient utilization rate of the waste chromium slag is ensured. The driving force of the chlorine transmission pipeline 27 is provided by the motor 2 19 through the sprocket mechanism. The specific chlorine diffusion diagram is shown in FIG. Figure 7 The power required by the chlorine gas transmission pipeline 27 is provided by the second motor 19, and the speed of the second motor is 5-200r / min.

[0058] The chlorine gas generated by the waste rubber and plastic passes through the micropore 1 28, the chlorine transmission pipeline 27, the displacement fixing mechanism and the micropore 2 25 in sequence and enters the chlorine adsorption pipeline in the chlorine adsorption device, and contacts with the waste chromium slag in the chlorine adsorption pipeline to achieve the adsorption of chlorine element; after the dechlorination process is completed, the remaining waste rubber and plastic enters the graded catalytic pyrolysis device.

[0059] The structure of the graded catalytic pyrolysis device is as follows: Figure 3 As shown, it includes a shell 7, a heating plate fixing frame 11, a heating plate 12, an oil and gas outlet 6, a catalytic pyrolysis base and a driving mechanism. The catalytic pyrolysis base is located at the bottom of the device and is used to fix the graded catalytic pyrolysis device. The oil and gas outlet 6 is located above the shell 7. The oil and gas outlet 6 is connected to the oil and gas condensation purification device and is used for purification and graded collection of pyrolysis oil.

[0060] The heating plate fixing frame 11 and the heating plate 12 are both located in the shell 7. The heating plates 12 are provided in several groups. Each group of heating plates is fixed on the corresponding heating plate fixing frame 11 and is circular. The several groups of heating plates are in a circular ring shape as a whole. A blanking hole 13 is provided between the multiple heating plates of each group of heating plates located in the same circumferential direction. The temperature of the several groups of heating plates increases successively along the axial direction outward, and the spacing between the blanking holes 13 of each group of heating plates adjacent to each other along the axial direction outward decreases successively. The driving mechanism provides power to the heating plate fixing frame 11. When the graded catalytic pyrolysis device is performing pyrolysis, the heating plate fixing frame 11 is always in a rotating state. The power of the heating plate fixing frame 11 is provided by the motor 3 8. The rotation of the heating plate fixing frame 11 can cause shear force, extrusion force and impact force of falling materials to be generated between the waste rubber and plastic and the waste chromium slag. Under the interaction of multiple forces, the particle size of pyrolytic carbon black and chromium slag can be reduced, the coke on the surface of the chromium slag can be removed, the agglomeration phenomenon can be avoided, the catalytic selectivity of the waste chromium slag can be improved, and the waste rubber and plastic pyrolytic carbon black and waste chromium slag that have completed catalytic pyrolysis can enter the waste slag separation device.

[0061] The temperature of the heating plate increases gradually along the central axis outward, and its purpose is to achieve graded catalytic pyrolysis of waste rubber and plastic in a single catalytic pyrolysis device and improve the yield of light oil. The spacing of the drop openings decreases gradually along the central axis outward. This layout utilizes the shear force and extrusion force generated by the waste rubber and plastic and waste chromium slag during the rotation process, as well as the impact force during the falling process, to reduce their particle size. In addition, this method can also remove carbon deposits on the surface of the waste chromium slag, prevent the agglomeration of the waste chromium slag, and maintain the best performance of the waste chromium slag in the entire catalytic pyrolysis process.

[0062] like Figure 6 As shown, the waste residue separation device includes a cylinder 20, a separator 21, a micropore 3 22, a pyrolytic carbon black discharge port 23 and a chromium residue discharge port. The separator 21 is located inside the cylinder, and the micropore 3 22 is arranged on the separator 21, and the micropore 3 22 runs through the inside and outside of the separator 21. There is a density difference between the waste rubber and plastic pyrolytic carbon black and the waste chromium residue. The separation of the two materials can be achieved through the centrifugal action of the separator 21. Among them, the pyrolytic carbon black of the waste rubber and plastic is mainly concentrated in the middle part of the separator 21 and discharged through the pyrolytic carbon black discharge port 23. The waste chromium slag passes through the micropore three and then gathers at the chromium slag discharge port 18. The chromium slag discharge port 18 has a downward inclination trend, which can promote the downward sliding of the waste chromium slag. The waste chromium slag after falling is transported to the chlorine adsorption pipeline of the chlorine adsorption device through the screw feeding mechanism 9, which is used to adsorb the chlorine element generated during the pyrolysis of the waste plastic, thereby realizing the continuous desulfurization and dechlorination process of the waste chromium slag. The driving force of the screw feeding mechanism 9 is provided by the motor 4 10 directly connected to the screw.

[0063] Preferably, the speed of motor one is 5-200r / min, the speed of motor two is 5-200r / min, the speed of motor three 8 is 10-100r / min, the temperature range of the heating plate is 400-1200°C, the outer spacing of the blanking port decreases along the center axis, and the width of the blanking port is 1-100mm.

[0064] The present invention will be further described below in conjunction with specific embodiments:

[0065] Embodiment 1:

[0066] This embodiment adopts the above-mentioned system.

[0067] like Figure 1 As shown, a method for reducing the sulfur and chlorine content in waste rubber and plastic pyrolysis oil by using waste chromium slag comprises the following steps:

[0068] Step 1: Experimental preparation before catalytic pyrolysis

[0069] An appropriate amount of waste chromium slag powder is added to the feed port, and the waste chromium slag is transported to the graded catalytic pyrolysis device through the dechlorination extrusion screw. Then, the chromium slag powder enters the waste slag separation device through the blanking port of the catalytic pyrolysis device, and further enters the chromium slag blanking port. Subsequently, the waste chromium slag is transported to the chlorine adsorption device through the screw feeding structure. Finally, the chlorine adsorption pipeline in the chlorine adsorption device rotates under the cooperation of the motor 2 and the sprocket mechanism, and the waste chromium slag is pushed forward in the chlorine adsorption pipeline under the action of the spiral blade 26, completing the preliminary preparations for the catalytic pyrolysis experiment.

[0070] Step 2: Put the waste rubber and plastic and waste chromium slag into the feed port to realize material transportation and dechlorination. The waste rubber and plastic and waste chromium slag that have completed the dechlorination process continue to move forward under the action of the dechlorination extrusion screw, and then enter the graded catalytic pyrolysis device for catalytic pyrolysis and desulfurization of waste tires. During the catalytic pyrolysis process, the heating plate fixing frame is in a continuous rotation state, and the power is provided by the motor three. The material will have shear force, extrusion force and impact force in the rotating state, which can reduce the agglomeration of the material, improve its dispersibility, and maintain the high catalytic selectivity of the waste chromium slag. At the same time, the temperature of the heating plate increases successively along the axis outward, and the spacing between the blanking ports between the heating plates decreases successively. Only materials that meet the particle size requirements will enter the next pyrolysis interval, and the purpose is to realize the graded catalytic pyrolysis of waste rubber and plastic and reduce the particle size of the material. The high-temperature oil and gas generated during the pyrolysis process enter the oil and gas condensation purification device through the high-temperature oil and gas outlet to realize the purification and graded collection of the pyrolysis oil. After the pyrolysis is completed, the pyrolysis carbon black and waste chromium slag formed by the waste rubber and plastic fall into the waste slag separation device at the same time.

[0071] Step 3: In the waste slag separation device, the separator rotates at high speed, and the difference in density between the two materials is used to separate the two materials. The pyrolytic carbon black is discharged from the pyrolytic carbon black discharge port, and the waste chromium slag enters the chromium slag discharge port. These chromium slags are transported to the chlorine adsorption pipeline of the chlorine adsorption device through the screw feeding mechanism to adsorb the chlorine element generated in the waste plastics, so as to realize the continuous recycling of desulfurization and dechlorination of the waste chromium slag.

[0072] The diameters of the micropore 1, micropore 2 and micropore 3 mentioned in the present invention are 0.001-1 mm, 0.001-1 mm and 0.1-100 mm respectively.

[0073] In the above step 2, the preferred mass ratio of waste rubber and plastic to waste chromium slag is 1-100:1-100:1-100.

[0074] Parts not described in the present invention can be implemented by referring to the existing technology.

[0075] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present application and are not intended to be limiting of the present application. As long as they are within the spirit and scope of the present application, appropriate changes and modifications to the above embodiments are within the scope of protection claimed in the present application.

Claims

1. A method for reducing the sulfur and chlorine content in waste rubber and plastic pyrolysis oil by using waste chromium slag, wherein the system used comprises a dechlorination device, a chlorine adsorption device, a graded catalytic pyrolysis device and a waste slag separation device, characterized in that: The dechlorination device comprises a base, a motor 1, a barrel, a feed port, a dechlorination extrusion screw, an electromagnetic heating mechanism, a micropore 1 and a chlorine gas transmission pipeline; the motor 1 and the barrel are both fixed to the upper end of the base, the motor 1 is located on the side of the barrel, the dechlorination extrusion screw is located inside the barrel and connected to the motor 1, and the feed port is located on the upper side of the barrel; the electromagnetic heating mechanism is located in the middle of the barrel; the micropore 1 is arranged at the tail of the barrel near the electromagnetic heating mechanism; the micropore 1 is connected to the chlorine gas transmission pipeline, and the chlorine generated by the waste rubber and plastic passes through the micropore 1 into the chlorine gas transmission pipeline; the diameter of the dechlorination extrusion screw increases from left to right - remains unchanged - decreases in sequence, and the pitch decreases from left to right - remains unchanged - increases gradually, a dechlorination section is arranged in the middle section of the dechlorination extrusion screw, and regularly arranged dechlorination pins are installed on the dechlorination section; The chlorine gas transmission pipeline is connected to the chlorine gas adsorption device; the chlorine gas adsorption device is connected to the waste residue separation device, and the waste residue separation device is connected to the graded catalytic pyrolysis device; The hierarchical catalytic pyrolysis device mainly comprises a shell, a heating plate fixing frame, a heating plate, an oil and gas outlet and a driving mechanism, wherein the oil and gas outlet is located above the shell, the heating plate fixing frame and the heating plate are both located in the shell, the heating plates are arranged in several groups, each group of heating plates is fixed on the corresponding heating plate fixing frame and is circular, and the several groups of heating plates are in a circular ring shape as a whole, and blanking openings are arranged between the multiple heating plates of each group of heating plates located in the same circumferential direction; the temperature of the several groups of heating plates increases successively along the axial direction outward, and the distance between the blanking openings of each group of heating plates adjacent to each other along the axial direction outward decreases successively; the driving mechanism provides power to the heating plate fixing frame, and when the hierarchical catalytic pyrolysis device performs pyrolysis, the heating plate fixing frame is always in a rotating state; The method comprises the following steps: Step 1: Before the experiment, select an appropriate amount of waste chromium slag, crush it into powder, and send it into a chlorine adsorption device; Step 2: During the experiment, the waste rubber and plastic and the waste chromium slag of a certain particle size are fed into the feed port of the dechlorination device, and the materials are heated to 200-300° C. by the electromagnetic heating mechanism. Under the action of the dechlorination extrusion screw, the chlorine element is effectively removed from the materials; the removed chlorine element is adsorbed by the waste chromium slag powder in the chlorine adsorption device; In step 3, the waste rubber and plastic that have not been pyrolyzed in step 2 enter the graded catalytic pyrolysis device, and the heating plate fixing frame is always in a rotating state. Its rotation causes shear force, extrusion force and impact force of falling materials to be generated between the waste rubber and plastic and the waste chromium slag. Under the interaction of these forces, the particle size of the pyrolytic carbon black and the waste chromium slag is reduced, and the pyrolytic carbon black and the waste chromium slag that have completed the graded catalytic pyrolysis enter the waste slag separation device; Step 4: Separate the waste chromium slag from the pyrolytic carbon black through the waste slag separation device, and recycle it for use in the chlorine adsorption device to complete the dechlorination and desulfurization of waste rubber and plastic and the closed-loop utilization of waste chromium slag.

2. The method of reducing the sulfur and chlorine content in waste rubber and plastic pyrolysis oil by using waste chromium slag according to claim 1, characterized in that: The power of the dechlorination extrusion screw is provided by a motor 1, the dechlorination extrusion screw and the motor 1 are connected by a spline, and the rotation speed of the motor 1 is 5-200r / min; the chlorine-containing oil gas generated by the material under the action of the electromagnetic heating mechanism enters the chlorine gas transmission pipeline through the micropore 1, and the aperture of the micropore 1 is 0.001-1mm; the feed port is welded on the upper side of the barrel, and the electromagnetic heating mechanism is fixed at the middle position of the barrel by an interference fit, and the electromagnetic heating mechanism provides external heat for the preliminary pyrolysis of waste rubber and plastic.

3. The method of reducing the sulfur and chlorine content in waste rubber and plastic pyrolysis oil by using waste chromium slag according to claim 1, characterized in that: The chlorine adsorption device comprises a displacement fixing mechanism, two micropores, a chlorine adsorption pipeline, a spiral blade and a second motor. The displacement fixing mechanism is located at the upper end of the chlorine transmission pipeline and is used to fix the chlorine adsorption pipeline. The chlorine adsorption pipeline is provided with two micropores running through the inside and outside of the pipeline. The spiral blade is located on the inner side of the chlorine adsorption pipeline and is used to continuously propel the waste chromium slag in the chlorine adsorption pipeline. The power required for the chlorine transmission pipeline is provided by the second motor, and the rotation speed of the second motor is 5 to 200 r / min. The aperture of the second micropore is 0.001 to 1 mm.

4. The method of reducing the sulfur and chlorine content in waste rubber and plastic pyrolysis oil by using waste chromium slag according to claim 1, characterized in that: The oil and gas outlet of the graded catalytic pyrolysis device is connected to an oil and gas condensation purification device, through which the pyrolysis oil is purified and graded and collected; the temperature of several groups of heating plates increases successively along the axial direction outward, and the spacing between the blanking openings of each group of heating plates adjacent to each other along the axial direction outward decreases successively to achieve graded pyrolysis of waste rubber and plastic; a single heating plate is in an arc shape; the driving mechanism is motor three, the rotation speed of motor three is 10 to 100 r / min, the temperature range of the heating plate is 400 to 1200°C, and the width of the blanking opening is 0.1 to 100 mm.

5. The method of reducing the sulfur and chlorine content in waste rubber and plastic pyrolysis oil by using waste chromium slag according to claim 1, characterized in that: The waste slag separation device includes a cylinder, a separator, micropore three, a pyrolytic carbon black discharge port and a chromium slag discharge port. The separator is located inside the cylinder, and micropore three is provided on the separator to penetrate inside and outside the cylinder. The pyrolytic carbon black discharge port and the chromium slag discharge port are located outside the cylinder; the aperture of the micropore three is 0.1 to 100 mm, and the micropore three can allow the waste chromium slag to pass through.

6. The method of reducing the sulfur and chlorine content in waste rubber and plastic pyrolysis oil by using waste chromium slag according to claim 5, characterized in that: The waste chromium slag falling through the chromium slag discharge port is transported to the chlorine adsorption pipeline of the chlorine adsorption device through a screw feeding mechanism to adsorb the chlorine element generated during the pyrolysis of waste rubber and plastic.

7. The method of reducing the sulfur and chlorine content in waste rubber and plastic pyrolysis oil by using waste chromium slag according to claim 1, characterized in that: In step 2, the waste rubber and plastic include waste tires and waste plastics. The waste tires and waste plastics are respectively washed, dried and crushed before use. The particle size of the crushed waste chromium slag is 5 to 10 mm.

8. The method of reducing the sulfur and chlorine content in waste rubber and plastic pyrolysis oil by using waste chromium slag according to claim 5, characterized in that: There is a density difference between the waste chromium slag and the pyrolytic carbon black, and the two are separated under the centrifugal action of the separator.

9. The method of reducing the sulfur and chlorine content in waste rubber and plastic pyrolysis oil by using waste chromium slag according to claim 8, characterized in that: The pyrolytic carbon black is concentrated in the middle part of the separator and discharged through the pyrolytic carbon black discharge port. The waste chromium slag passes through the micropore three and then gathers at the chromium slag discharge port, is discharged through the chromium slag discharge port, and is then sent to the chlorine adsorption device through the screw feeding mechanism.

10. The method of reducing the sulfur and chlorine content in waste rubber and plastic pyrolysis oil by using waste chromium slag according to claim 1, characterized in that: In step 2, the mass ratio of waste rubber and plastic to waste chromium slag is 1-100:1-100:1-100.

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