Polymer waste treatment system and method

Abstract

According to one aspect of the present invention, a system (1) is provided, the system (1) being a hollow chamber (2) having a first chamber (3) and a second chamber (4), wherein the second chamber (4) is rotatable, or the first chamber (3) and the second chamber (4) are rotatable, a heating system (19) configured to heat the second chamber (4) or to heat the first chamber (3) and the second chamber (4) separately, a lance (5) having at least one supply outlet (6), the lance (5) extending through at least the first chamber (3) into the hollow chamber (2), the system (1) being configured to supply polymer waste (7) to the second chamber (4) via at least one supply outlet (6), and at least one injector (21) for injecting at least one sweep fluid (8) into the first chamber (3) or into the first chamber (3) and the second chamber (4) in order to form a flow of fluid towards at least one gas outlet (20) for collecting a product (13) comprising at least one sweep fluid and a gas (22) from at least partially pyrolyzed polymer waste.

Description

Technical Field

[0001] The present invention relates to a system for treating polymer waste.

[0002] The present invention further relates to a method for treating polymer waste.

Background Art

[0003] Polymers are used in a wide variety of products. Polymers are typically obtained from petroleum resources, which are considered non-renewable. In this context, the accumulation of polymer waste has come to be recognized as an environmental problem, giving rise to the need for a sustainable supply of raw materials. As a result, polymer waste is often collected and sorted for recycling or thermal decomposition purposes. The subsequent treatment of polymer waste and the reuse of at least some of the materials can reduce environmental problems.

[0004] For example, polymer waste can be treated by pyrolysis, i.e., thermal decomposition of the polymer waste at high temperature in an inert atmosphere, whereby a product containing gas from the at least partially pyrolyzed polymer waste is obtained. Such treatment can be carried out, for example, in a reactor such as a rotary kiln reactor to which the polymer waste is supplied. Usually, a carrier gas is further utilized when promoting the flow, increasing the flow rate, and flushing the process train of the gas from the at least partially pyrolyzed polymer waste towards another section for post-treatment. For example, nitrogen is a commonly used carrier gas. Other examples of carrier gases include carbon dioxide or methane.

[0005] In view of the above, it would be beneficial to provide a system and method for treating polymer waste.

Summary of the Invention

[0006] The present invention is defined by the characterizing portion of the independent claims. Some specific embodiments are defined by the dependent claims.

[0007] According to a first aspect of the present invention, a system is provided, the system comprising a hollow chamber having a first chamber and a second chamber, wherein the second chamber is rotatable, or the first chamber and the second chamber are rotatable; a heating system configured to heat the second chamber individually or the first chamber and the second chamber individually; a lance having at least one supply outlet, extending through at least the first chamber into the hollow chamber, the system being configured to supply polymer waste to the second chamber via the at least one supply outlet; and at least one injector for injecting at least one sweep fluid into the first chamber or the first chamber and the second chamber to form a fluid flow towards at least one gas outlet for collecting a product comprising at least one sweep fluid and gas from the at least partially pyrolyzed polymer waste.

[0008] Various embodiments of the first aspect may include at least one feature from the following list of bullet points. · The first chamber and the second chamber are individually rotatable. · The hollow chamber comprises a barrier between the first chamber and the second chamber, with an opening provided between the barrier and the lance. · The barrier is manufactured from metal, metal alloy, heat-resistant fabric, or a combination thereof. · The system comprises a compressor disposed downstream of the gas outlet. · The hollow chamber is at least partially disposed within a housing equipped with a heating system, which includes a first space configured to receive a first heating gas having a first temperature and a second space configured to receive a second heating gas having a second temperature. The first space is aligned with the first chamber, and the second space is aligned with the second chamber. · The hollow chamber is at least partially disposed within a housing equipped with a heating system, which includes only a second space configured to receive a second heating gas having a second temperature. The second space is aligned with the second chamber. · The second space includes a plurality of heating zones, each of which is configured to receive a heating gas having a specific temperature. · The system further includes at least one movable body disposed within the first chamber. · The system further includes, within the first chamber, at least one structure protruding into the chamber from the inner surface of the hollow chamber. · The system is configured to inject at least one of a condensable gas, vapor, water, non-condensable gas, nitrogen, or a hydrocarbon such as pyrolysis oil or diesel through at least one injector. · The second chamber includes at least one residue outlet. · Each of the first chamber and the second chamber includes at least one residue outlet. · The gas outlet is constituted by either the first chamber or the second chamber.

[0009] According to a second aspect of the present invention, there is provided a method comprising the steps of providing a hollow chamber having a first chamber and a second chamber, wherein the second chamber rotates or the first and second chambers rotate; heating the second chamber or heating the first and second chambers individually; providing a lance having at least one supply outlet and extending through at least the first chamber into the hollow chamber; supplying polymer waste to the second chamber via at least one supply outlet; injecting at least one sweep fluid into the first chamber or into the first and second chambers to form a fluid flow towards at least one gas outlet for collecting a product comprising at least one sweep fluid and gas from the at least partially pyrolyzed polymer waste.

[0010] Various embodiments of the second aspect may include at least one feature from the following list of bullet points. · The method further comprises the step of rotating the first and second chambers individually. · The wall temperature of the hollow chamber is in the range of 500 to 800 °C in the first and second chambers. · The method further comprises the steps of at least partially disposing the hollow chamber within a housing having a first space and a second space; receiving a first heating gas having a first temperature in the first space, wherein the first space is aligned with the first chamber; and receiving a second heating gas having a second temperature in the second space, wherein the second space is aligned with the second chamber. · The method further comprises the step of at least partially disposing the hollow chamber within a housing including a heating system, the heating system comprising only a second space configured to receive a second heating gas having a second temperature, the second space being aligned with the second chamber. · This method further includes a step of individually heating a plurality of heating zones included in the second chamber, and each heating zone is configured to receive heating gas having a specific temperature. · The sweep fluid is at least one of a condensable gas, steam, water, a non-condensable gas, nitrogen, or a hydrocarbon such as pyrolysis oil or diesel. · The pressure gradient between the hollow chamber and at least one gas outlet is in the range of 0.1 to 5 kPa, for example, 0.5 to 2 kPa. · This method further includes a step of preliminarily melting or extruding the polymer waste before supplying the polymer waste to the second chamber. · This method further includes a step of liquefying the gas collected downstream of the gas outlet.

[0011] According to some embodiments of the present invention, significant advantages are obtained. In particular, a system and method for treating polymer waste are provided. The system includes a hollow chamber having a first chamber and a second chamber, where the second chamber is rotatable or both the first chamber and the second chamber are rotatable. A sweep fluid can be injected into the first chamber and polymer waste can be supplied to the second chamber. A product including at least one sweep fluid and a gas from at least partially pyrolyzed polymer waste is collected during operation of the reactor for post-treatment. According to some embodiments, a fluid flow is formed due to a pressure gradient between the first chamber and the second chamber, such that backflow of the gas from at least partially pyrolyzed polymer waste can be avoided. Using a condensable gas, vapor, or water as the sweep fluid is beneficial for post-treatment purposes because the sweep fluid can be easily separated or removed from the product by condensation in the post-treatment process. Removal of the sweep fluid or carrier gas that does not contribute to the yield of the liquid product in the pyrolysis of polymer waste can improve the hydrocarbon recovery rate. Use of a hydrocarbon or hydrocarbon-containing sweep fluid including water is beneficial in reducing the moisture content within the system and thus in reducing the need for water separation and wastewater management at a later stage. Maximizing the recovery of the liquid product is very important for the techno-economic performance and sustainability of the polymer waste pyrolysis process. In addition, since the condensation train of the polymer waste pyrolysis system is typically designed to remove pyrolysis water, supplying water or steam to the first chamber of the reactor does not introduce any further significant complexity to the process.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0013] FIG. 1 shows a schematic diagram of a system 1 according to at least some embodiments of the present invention. The system 1 comprises, in particular, a so-called reactor or rotary kiln reactor for thermally decomposing a material at a high temperature in a state where there is no oxygen at all or the amount of oxygen is small in order to avoid combustion of hydrocarbons. This process is also called pyrolysis.

[0014] In particular, system 1 comprises a hollow chamber 2 having a first chamber 3 and a second chamber 4. Both the first chamber and the second chamber are rotatable. System 1 is configured to process polymer waste 7. As used herein, the term "polymer waste" relates to materials mainly containing polymer materials. For example, impurities may be present in the polymer material. Usually, polymer waste 7 is a material collected for the purpose of recycling or thermal decomposition. Examples of polymer waste raw materials used according to some embodiments include polyethylene containing at least one of other components such as polypropylene, polystyrene, and polyamide, polyethylene terephthalate, and polyvinyl chloride in various amounts. The polymer waste raw material may be contaminated with trace impurities generated, for example, from biomass.

[0015] The hollow chamber 2 is typically in the shape of an elongated hollow cylinder. The term "elongated" means that the length of the hollow cylinder is substantially greater than the diameter of the hollow cylinder. For example, the length of the hollow cylinder is 18 m and the diameter of the hollow cylinder is 2 m. The hollow chamber 2 is typically made of metal or metal alloy. The entire hollow chamber 2 is configured to rotate about a rotation axis A. The rotation axis A is usually oriented horizontally or substantially horizontally. The term "horizontal axis" means an axis perpendicular to the gravity vector or perpendicular to the normal of the earth's surface. Similarly, the term "substantially horizontal axis" means an axis perpendicular to the gravity vector or an axis inclined by less than a few degrees, for example less than 10 degrees, from an axis perpendicular to the normal of the earth's surface. The rotational speed of the entire hollow chamber 2 can be, for example, in the range of 0.1 to 5 revolutions per minute (rpm), for example, in the range of 1 to 2 revolutions per minute (rpm). In the embodiment of FIG. 1, both the first chamber 3 and the second chamber 4 rotate simultaneously. According to other embodiments, as described in connection with FIG. 7, only the second chamber 4 rotates, or both the first chamber 3 and the second chamber rotate individually.

[0016] This system further includes a heating system 19 configured to heat the first chamber 3 and the second chamber 4 individually. The heating system 19 is typically arranged outside the wall of the hollow chamber 2 as indicated by the arrow 19. The heating of the first chamber 3 and the second chamber 4 occurs when the temperature of the wall of the rotatable hollow chamber 2 increases due to contact between this wall and the heating gas, particularly contact between the lateral regions of the rotatable hollow chamber and the heating gas, and the temperature of the wall rises from the ambient temperature to a range of 200°C to 800°C. Usually, the wall temperature of the lateral region of the first chamber 3 is different from the wall temperature of the lateral region of the second chamber 4. As a result, different temperatures can be provided in the first chamber 3 and the second chamber 4 as needed. The temperature in the first chamber 3 is, for example, 550°C, and the temperature in the second chamber 4 is, for example, 600°C. Usually, the temperature in the second chamber 4 is higher than the temperature in the first chamber 3. In other words, the system 1 is configured to adjust the temperature in the first chamber 3 and the temperature in the second chamber 4 by the heating system 19. The temperature in the second chamber 4 is usually higher than the decomposition temperature of the polymer waste. An example of the heating system 19 of the illustrated embodiment is shown in FIG. 2. According to another embodiment of the present invention, as shown in FIG. 3, only the second chamber 4 is heated. According to a further embodiment of the present invention, the wall of the second chamber 4 can be divided into individually heatable sub-zones or heating zones as shown in FIG. 4.

[0017] System 1 further comprises a lance 5 having at least one supply outlet 6. The lance 5 is stationary, i.e., the lance 5 is not configured to rotate, and a rotatable hollow chamber 2 is configured to rotate around the lance 5. The lance 5 can be, for example, in the shape of a hollow cylinder. The central axis of the lance 5 is typically arranged or oriented coaxially with the rotation axis A. The lance 5 is usually made of metal or metal alloy. The lance 5 extends through at least a first chamber 3 and into the hollow chamber 2. The lance 5 may further extend partially into a second chamber 4, as shown in FIG. 1. System 1 is configured to supply polymer waste 7 to the second chamber 4 via at least one supply outlet 6. The lance 5 is included in or coupled to a supply system (not shown). The supply system is typically an extrusion-type supply system. The polymer waste 7 is (mainly) pre-melted so that the feed can be in a flowable form that can pass through the lance 5.

[0018] The polymer waste 7 supplied to the second chamber 4 via at least one supply outlet 6 of the lance 5 falls by gravity onto the heated inner surface 12 of the rotatable hollow chamber 2. Due to the rotation of the hollow chamber 2, the polymer waste 7 is dispersed over at least a part of the inner surface 12 of the chamber 2 in the second chamber 4. By tilting the rotatable hollow chamber 2 by a few degrees, for example 3 to 5 degrees, from the horizontal axis, the dispersion of the polymer waste 7 over at least a part of the inner surface 12 of the chamber 2 in the second chamber 4 can be improved. In such a configuration, the rotatable hollow chamber 2 is arranged substantially horizontally.

[0019] The high-temperature wall of the hollow chamber 2 causes thermal decomposition of the polymer waste 7 in the second chamber 4, and the polymer waste 7 is converted into a gas 22 and a residue from at least partially thermally decomposed polymer waste. The residue may contain, for example, inorganic substances or inorganic contaminants. The rotatable hollow chamber 2 typically has a residue outlet 23 at the rear end 25 of the chamber 2.

[0020] The hollow chamber 2 usually further comprises a barrier 14 or a seal between the first chamber 3 and the second chamber 4. The barrier 14 or the seal is configured to allow the flow of fluid, particularly gas, from the first chamber 3 to the second chamber 4. For example, an opening 15 is provided between the barrier 14 and the lance 5. The opening 15 is permeable to the sweep fluid flowing from the first chamber 3 towards the second chamber 4, but may be impermeable in the opposite direction. Alternatively, the barrier 14 or the seal may also include features allowing the flow of gas, i.e., for example, a plurality of perforations. The barrier 14 is usually made of metal, metal alloy, or heat-resistant fabric.

[0021] The system 1 also further comprises at least one injector 21 capable of injecting at least one sweep fluid 8 into the first chamber 3. In the embodiments shown in FIGS. 1 to 9, the term "injector" means a specific unit for injecting at least one sweep fluid 8 into the first chamber 3. Such an injector may comprise, for example, at least one sweep fluid injection lance extending into the first chamber 3. Such an injector may include, for example, a nozzle. Alternatively, the term "injector" may mean a simple opening in the system 1 capable of guiding at least one sweep fluid 8 into the first chamber 3. The system 1 may comprise a plurality of injectors 21, and each injector 21 may be capable of injecting a different sweep fluid 8 into the first chamber 3. One injector 21 may be arranged, for example, to inject a condensable gas into the first chamber 3, and another injector 21 may be arranged, for example, to inject a non-condensable gas into the first chamber 3, so that the injection of the sweep fluid can be carried out independently of each other using the condensable gas and the non-condensable gas respectively. In a preferred embodiment, vapor as the condensable gas is injected via the cavity 31.

[0022] The plurality of injectors 21 can be provided, for example, each in the form of a separate sweep fluid injection lance. Such a sweep fluid injection lance can be arranged, for example, around the supply lance 5. In such a case, a protective tube covering at least a part of the plurality of injection lances 21 and at least a part of the supply lance 5 can be further provided. As a result, various sweep fluids 8 can be guided through at least a part of the protective tube separately from the supply of the polymer waste. The protective tube, the supply lance 5, and the plurality of injection lances arranged within the protective tube are stationary, i.e., not configured to rotate. Instead of, or in addition to, for example, an opening can be further provided that penetrates the front end 24 of the hollow chamber 2 in order to guide at least one sweep fluid 8 into the first chamber 3. At least one injector 21 can be included in the lance 5 or can be independent of the lance 5.

[0023] A pressure gradient is generated between the first chamber 3 and the second chamber 4, and a fluid flow, particularly a gas flow, is formed in the direction from the first chamber 3 to the second chamber 4, particularly towards the gas outlet 20. In other words, the sweep fluid is used to enhance the flow from the first chamber 3 to the second chamber 4. The pressure gradient further enhances the downstream flow towards a post-treatment section (not shown). As a result of the injection of the sweep fluid 8 into the first chamber 3, a pressure increase occurs in the first chamber 3, and the pressure in the first chamber 3 becomes greater than the pressure in the second chamber 4. The pressure gradient is, for example, in the range of 0.1 - 5 kPa, for example, in the range of 0.5 - 2 kPa. The mass flow rate and / or the flow velocity of the sweep fluid passing through at least one injector can be adjustable to vary the pressure gradient. The pressure in the first chamber 3 and the pressure in the second chamber 4 can be monitored using pressure sensors, respectively.

[0024] The sweep fluid 8 can be, for example, at least one of a condensable gas, vapor, water, a non-condensable gas, nitrogen, a hydrocarbon, or diesel. As described above, combinations of the aforementioned sweep fluid 8 can also be simultaneously injected into the first chamber 3. For example, water can be sprayed into the first chamber 3 via at least one nozzle included in at least one injector 21, or water can be directly sprayed onto the heated inner surface of the wall of the hollow chamber 2 within the first chamber 3, whereby the sprayed water instantaneously evaporates and steam is generated on-site inside the reactor, eliminating the need for a separate steam generation unit. Then, the sweep fluid can flow from the first chamber 3 to the second chamber 4, for example, via the opening 15. The flow of fluid from the first chamber 3 to the second chamber 4 avoids the backflow of the gas 22 from the at least partially pyrolyzed polymer waste. Using a condensable gas, vapor, or water as the sweep fluid 8 is beneficial for post-treatment purposes when it is necessary to separate the sweep fluid 8 from the product 13 at a later stage.

[0025] In addition, the system comprises a gas outlet 20 disposed downstream of at least one supply outlet 6 for collecting the product 13 comprising at least one sweep fluid 8 and the gas 22 from the at least partially pyrolyzed polymer waste.

[0026] According to some embodiments, a compressor (not shown) may optionally be installed downstream of the gas outlet 20 to improve or assist the flow of product 13. The compressor may also be useful for maintaining the pressure in the first chamber 3 at a specific pressure, such as atmospheric pressure, and providing a pressure lower than the specific pressure in the second chamber 4. In other words, by injecting the sweep fluid 8 into the first zone 3 and utilizing the compressor, the pressures in the first chamber 3 and the second chamber 4 can be adjusted. The compressor can control the pressure in the region where the gas outlet 20 is located. The injection of the sweep fluid 8 can be used not only to ensure that air does not enter the system 1 but also to reduce the possibility of gas flow being disrupted while reliably avoiding backflow. Since the system 1 may operate, for example, in a slight vacuum state, there is a tendency for air to leak into the system 1. This can lead to the combustion of hydrocarbons and pose a risk of fire and / or explosion. The combination of this compressor and the injection of the sweep fluid 8 functions as a system that guides the pyrolysis gas towards the outlet 20. When the normal vacuum state is lost, the injection of the sweep fluid 8 can prevent the leakage of hydrocarbons from the system 1.

[0027] Typically, a vacuum is created to remove at least one sweep fluid 8 and the gas 22 from the at least partially pyrolyzed polymer waste from each of the chambers 3, 4, and a reduced pressure is provided at the location of at least one gas outlet 20.

[0028] FIG. 2 shows a schematic view of the heating system 19 of the system 1 according to at least some embodiments of the present invention. The hollow chamber 2 of FIG. 1 is disposed within the housing 9. The heating system 19 has a first space 10 configured to receive a first heating gas having a first temperature T1. The first heating gas can be introduced into the first space 10 via at least one first heating gas inlet 26 and can be withdrawn from the first space 10 via at least one first heating gas outlet 28. Further, the heating system 19 has a second space 11 configured to receive a second heating gas having a second temperature T2. The second heating gas can be introduced into the second space 11 via at least one second heating gas inlet 27 and can be withdrawn from the second space 11 via at least one second heating gas outlet 29. As can be seen from the drawing, the first space 10 is aligned with or adjacent to the first chamber 3, and the second space 11 is aligned with or adjacent to the second chamber 4. The first space 10 can be, for example, in the shape of a first heating chamber having an annular cross-section. The second space 11 can be, for example, in the shape of a second heating chamber having an annular cross-section. The first heating gas and the second heating gas may be the same or different from each other. As a result, by heating the wall 18 of the rotatable hollow chamber 2, the first chamber 3 and the second chamber 4 can be heated individually. The temperature of the wall 18 of the rotatable chamber 2 is adjustable by varying the first temperature T1 of the first heating gas and / or the second temperature T2 of the second heating gas. The wall temperature of the hollow chamber 2 can be, for example, in the range of 200°C to 800°C in the first chamber 3 and the second chamber 4. The temperatures in the first chamber 3 and the second chamber 4 may be the same or different from each other. For example, the temperature in the first chamber 3 can be 600°C and the temperature in the second chamber 4 can be 550°C.

[0029] FIG. 3 shows a schematic view of another heating system 19 according to at least some embodiments of the present invention. As can be seen from the drawing, the heating system 19 is configured to heat only the second chamber 4. In such a configuration, water cannot be sprayed as a sweep fluid into the first chamber 3. However, any gaseous sweep fluid can be injected into the first chamber 3. For example, steam generated by a steam generator can be injected into the first chamber 3 via at least one injector.

[0030] FIG. 4 shows a schematic view illustrating details of the heating system 19 according to at least some embodiments of the present invention. As can be seen from the drawing, the second space 11 includes a plurality of heating zones 30, and each heating zone 30 is configured to receive heating gas at a specific temperature Tz1, ..., Tz n The number of heating zones 30 can be any integer greater than n = 1. As a result, the heating zones 30 can be heated at different temperatures or the same temperature Tz1, ..., Tz n and, for example, the temperatures Tz1, ..., Tz n are usually adjustable. Each heating zone 30 is provided with at least one heating gas inlet and at least one heating gas outlet. Thus, it is possible to heat each heating zone individually to generate a temperature gradient within the region of the second chamber 4. In other words, different heating zones 30 form different thermozones between adjacent regions within the second chamber. For example, the temperature may be higher in the region of the second chamber 4 in the upstream direction of the flow direction of the sweep fluid 8. The concept of the heating zone 30 can be incorporated into the heating system 19, for example, as shown in FIG. 2 or FIG. 3, that is, in an embodiment comprising a heating system 19 having a first space 10 and a second space 11, or in an embodiment comprising a heating system 10 having only the second space 11.

[0031] FIG. 5 shows a schematic view depicting details of the hollow chamber 2 of the system 1 in accordance with at least some embodiments of the present invention. The system 1 includes at least one structure 17 projecting into the chamber 2 from the inner surface 18 of the rotatable hollow chamber 2 and provided within the first chamber 3. The at least one structure 17 is a stationary or fixed structure. For example, a plurality of plate-like structures 17 may be arranged within the first chamber 3. The plurality of plates are particularly beneficial for heat exchange within the first chamber 3. By transferring and distributing the heat provided by the heating system 19 into the first chamber 3 of the hollow chamber 2, the temperature within the first chamber 3 can be rapidly adjusted or changed. The plurality of at least one structure 17 is typically made of the same material as the hollow chamber 2, but this is not necessarily the case. The material of the at least one structure typically has beneficial heat conduction properties.

[0032] FIG. 6 shows a schematic view depicting further details of the rotatable hollow chamber 2 of the system 1 in accordance with at least some embodiments of the present invention. The system 1 includes at least one movable body 16 disposed within the first chamber 3 of the rotatable hollow chamber 2. For example, the at least one movable body 16 can be a steel ball rolling within the first chamber 3 during rotation of the hollow chamber 2. Alternatively, or in addition thereto, the movable body can be, for example, a chain. The at least one movable body 16 is typically made of the same material as the hollow chamber 2, but this is not necessarily the case. The material of the at least one movable body 16 typically has beneficial heat conduction properties. A further advantage of the at least one movable body 16 is that the movable body 16 scrapes the inner surface 18 of the first chamber 3 during rotation of the hollow chamber 2 for cleaning purposes.

[0033] FIG. 7 shows a more detailed schematic view of the hollow chamber 2 of the system 1 according to at least some embodiments of the present invention. In the illustrated embodiment, the first chamber 3 and the second chamber 4 rotate individually. In other words, as indicated by the arrows rpm1, rpm2, the rotational speed of the first chamber 3 may be different from the rotational speed of the second chamber 4. The rotational speed of each of the first chamber 3 and the second chamber 4 can be, for example, in the range of 0.1 to 5 revolutions per minute (rpm), for example, in the range of 1 to 2 rpm. However, as described above, both the first chamber 3 and the second chamber 4 may be heated, or only the second chamber 4 may be heated.

[0034] According to other specific embodiments, only the second chamber 4 rotates and the first chamber 3 remains stationary. In such a configuration, as described in connection with FIG. 6, there is no movable body in the first chamber 3. However, as described above, both the first chamber 3 and the second chamber 4 may be heated, or only the second chamber 4 may be heated.

[0035] FIG. 8 shows a more detailed schematic view of the hollow chamber 2 of the system 1 according to at least some embodiments of the present invention. The inner wall surface 12 in the second chamber 4 may be partially conical in order to prevent plastic waste from being dispersed in the direction of the barrier 14. The partially conical inner wall surface can be obtained, for example, by welding a hollow insertion portion 33 having a conical inner surface to the inner wall of the hollow chamber 2 in the second chamber 4, to the barrier 14.

[0036] FIG. 9 shows a schematic diagram illustrating details of the system 1 according to at least some embodiments of the present invention. The housing 9 has a cavity 31 or a space into which the gaseous sweep fluid 8 can be introduced. A plurality of perforations 32 are further provided through the front end 24 of the hollow chamber 2. Thus, the gaseous sweep fluid 8 can flow into the first chamber 3 through the perforations 32. The gaseous sweep fluid 8 can be introduced into the first chamber 3 within the system 1 having the fixed first chamber 3 or within the system 1 having either the first chamber 3 and the second chamber 4 that rotate individually or simultaneously. The cavity 31 itself does not rotate. In other words, the details shown in FIG. 9 represent an injector 21 for injecting the sweep fluid 8 into the first chamber 3. For example, one or more other sweep fluids 8 can be additionally injected into the first chamber 3 by using one or more sweep fluid lances as described above.

[0037] FIG. 10 shows a schematic diagram of the system 1 according to at least some embodiments of the present invention. The system 1 comprises a so-called reactor or rotary kiln reactor for thermally decomposing a material at a high temperature in a state where there is no oxygen or a small amount of oxygen in order to avoid combustion of hydrocarbons. This process is also called pyrolysis.

[0038] The operating principle of the illustrated embodiment is different from that of the embodiments shown in FIGS. 1 - 9. In particular, at least one sweep fluid 8 is injected into both the first chamber 3 and the second chamber 4 constituted by the hollow chamber 2.

[0039] The hollow chamber 2 is typically in the shape of an elongated hollow cylinder. The term "elongated" means that the length of the hollow cylinder is substantially greater than the diameter of the hollow cylinder. For example, the length of the hollow cylinder is 18 m and the diameter of the hollow cylinder is 2 m. The hollow chamber 2 is typically made of metal or a metal alloy. At least the second chamber 4 is configured to rotate about the axis of rotation A. The axis of rotation A is usually oriented horizontally or substantially horizontally. The term "horizontal axis" means an axis that is perpendicular to the gravity vector or perpendicular to the normal of the earth's surface. Similarly, the term "substantially horizontally oriented axis" means an axis that is perpendicular to the gravity vector or an axis that is inclined by several degrees, for example less than 10 degrees, from an axis that is perpendicular to the normal of the earth's surface. In the embodiment shown in FIG. 10, only the second chamber 4 may be configured to rotate. According to other embodiments, as disclosed in connection with FIG. 1, both the first chamber 3 and the second chamber 4 rotate simultaneously, or as described in connection with FIG. 7, both the first chamber 3 and the second chamber rotate individually. The rotational speed of the first chamber 3 and / or the second chamber 4 can be, for example, in the range of 0.1 to 5 revolutions per minute (rpm), for example in the range of 1 to 2 rpm.

[0040] This system further comprises a heating system (not shown) as described above in connection with any of FIGS. 1-4. That is, both the first chamber 3 and the second chamber 4 are heated individually, or only the second chamber 4 is heated. Further, it may be possible to heat the heating zones of the second chamber 4 individually in order to generate a temperature gradient within the region of the second chamber 4.

[0041] System 1 further comprises a lance 5 having at least one supply outlet 6. The lance 5 is fixed, i.e., the lance 5 is not configured to rotate, and at least a part of the hollow chamber 2 is configured to rotate around the lance 5. The lance 5 can be, for example, in the shape of a hollow cylinder. The central axis of the lance 5 is typically arranged or oriented coaxially with the rotation axis A. The lance 5 is usually made of metal or metal alloy. The lance 5 extends into the hollow chamber 2 through at least the first chamber 3. The lance 5 may further extend partially into the second chamber 4 as shown in FIG. 10. System 1 is configured to supply the polymer waste 7 to the second chamber 4 via at least one supply outlet 6. The lance 5 is included in or coupled to a supply system (not shown). The supply system is typically an extrusion-type supply system. The polymer waste 7 is (mainly) pre-melted so that the feed can be converted into a flowable form that can pass through the lance 5.

[0042] The polymer waste 7 supplied to the second chamber 4 via at least one supply outlet 6 of the lance 5 falls by gravity onto the heated inner surface 12 of the second chamber 4. Due to the rotation of the second chamber 4, the polymer waste 7 is dispersed over at least a part of the inner surface 12 of the second chamber 4. By tilting the rotatable hollow chamber 2 by a few degrees from the horizontal axis, for example, 3 degrees to 5 degrees, the dispersion of the polymer waste 7 over at least a part of the inner surface 12 of the second chamber 4 can be improved. In such a configuration, the rotatable hollow chamber 2 is arranged substantially horizontally.

[0043] The high-temperature wall of the hollow chamber 2 thermally decomposes the polymer waste 7 in the second chamber 4, and the polymer waste 7 is converted into a gas 22 and a residue from the at least partially thermally decomposed polymer waste. The residue may contain, for example, inorganic substances or inorganic contaminants. The illustrated hollow chamber 2 comprises a residue outlet 23 for the first chamber 3 and a further residue outlet 23 for the second chamber 4.

[0044] The hollow chamber 2 typically further comprises a barrier 14 or a seal between the first chamber 3 and the second chamber 4. The barrier 14 or the seal is configured to allow the flow of fluid, in particular gas, from the second chamber 4 to the first chamber 3. For example, an opening 15 is provided between the barrier 14 and the lance 5. The opening 15 is permeable such that the sweep fluid 8 and the gas 22 can flow from the second chamber 4 towards the first chamber 3, but may be impermeable in the opposite direction. The barrier 14 or the seal may also include features for passing the flow of gas, i.e., for example, a plurality of perforations. The barrier 14 is typically made of metal, a metal alloy, or a heat-resistant fabric.

[0045] The illustrated system 1 further comprises a plurality of injectors 21 capable of injecting at least one sweep fluid 8 into the first chamber 3 and further into the second chamber 4. In other words, the system 1 comprises a cavity 31 or space within a housing (not shown) into which the gaseous sweep fluid 8 can be induced. The cavity 31 is fixed as part of the housing. The front end 24 of the hollow chamber 2 is further provided with a plurality of perforations 32. Accordingly, the gaseous sweep fluid 8 can flow into the first chamber 3 through the perforations 32. The gaseous sweep fluid 8 can be induced into the first chamber 3 within the system 1 having the fixed first chamber 3 or within the system 1 having the first chamber 3 and the second chamber 4 rotating individually or simultaneously. In other words, the cavity 31 shown in FIG. 10 represents an injector 21 for injecting the sweep fluid 8 into the first chamber 3. One or more identical or other sweep fluids 8 can be additionally injected into the first chamber 3, for example, by using one or more sweep fluid lances as described above. Further, as shown in FIG. 10, the same or another sweep fluid 8 is injected into the second chamber 4. The injection of the sweep fluid 8 into the second chamber 4 is typically performed through the rear end 25 of the hollow chamber 2. For example, at least one additional injection lance can be provided and / or another cavity or space into which the gaseous sweep fluid 8 can be induced, i.e., a cavity or space similar to the front end of the reactor, can be provided.

[0046] In the embodiment of FIG. 10, the term "injector" means a specific unit for injecting at least one sweep fluid 8 into the first chamber 3 or the second chamber 4. Such an injector may comprise, for example, at least one sweep fluid injection lance extending into the first chamber 3 or the second chamber 4. Such an injector may comprise, for example, a nozzle. Alternatively, the term "injector" may mean a simple opening within the system 1 through which at least one sweep fluid 8 may be directed into the first chamber 3. The system 1 may comprise a plurality of injectors 21, each injector 21 being able to inject a different sweep fluid 8 into the first chamber 3 or the second chamber 4. One injector 21 may be arranged, for example, to inject a condensable gas into the first chamber 3 or the second chamber 4, and another injector 21 may be arranged, for example, to inject a non-condensable gas into the first chamber 3 or the second chamber 4. The plurality of injectors 21 may, for example, each be provided in the form of a separate sweep fluid injection lance. Such a sweep fluid injection lance may, for example, be arranged around the supply lance 5. In such a case, a protective tube covering at least a part of the plurality of injection lances 21 and at least a part of the supply lance 5 may further be provided. As a result, the various sweep fluids 8 may be directed through at least a part of the protective tube separately from the polymer waste supply. The protective tube, the supply lance 5, and the plurality of injection lances arranged within the protective tube are fixed, i.e., not configured to rotate. The perforation 32 may instead or in addition be provided, for example, through the front end 24 of the hollow chamber 2 to direct at least one sweep fluid 8 into the first chamber 3 and / or through the rear end 25 of the hollow chamber 2 to direct at least one sweep fluid 8 into the second chamber 4. At least one injector 21 may be included in the lance 5 or may be independent of the lance 5. The mass flow rate and / or the flow velocity of the sweep fluid passing through at least one injector may be adjustable.The pressure in the first chamber 3 and the pressure in the second chamber 4 can each be monitored using a pressure sensor.

[0047] The sweep fluid 8 can be, for example, at least one of a condensable gas, vapor, water, non-condensable gas, nitrogen, hydrocarbon, or diesel. As described above, a combination of the sweep fluids 8 can be injected into the first chamber 3 and the second chamber 4 simultaneously. For example, water can be sprayed into the first chamber 3 via at least one nozzle included in at least one injector 21, or directly onto the heated inner surface of the wall of the hollow chamber 2 in the first chamber 3, whereby the sprayed water evaporates instantaneously to generate vapor in situ inside the reactor, eliminating the need for a separate vapor generation unit. Thereafter, the sweep fluid will flow towards the gas outlet 20. The flow of fluid from the cavity 31 into the first chamber 3 avoids the backflow of the gas 22 from the at least partially pyrolyzed polymer waste. Thus, a state is maintained in which there are no solid material particles being carried towards the gas outlet 20 in the cavity 31. Using a condensable gas, vapor, or water as the sweep fluid 8 is beneficial for post-treatment purposes when it is necessary to separate the sweep fluid 8 from the product 13 at a later stage.

[0048] Furthermore, the system 1 comprises a gas outlet 20 included in the first chamber 3 for collecting a product 13 comprising at least one sweep fluid 8 and a gas 22 from at least partially pyrolyzed polymer waste. By providing the gas outlet 20 away from the first chamber 3, i.e., from the second chamber 4, the content of solid matter in the form of lightweight particles or dust carried by the product 13 can be reduced. The pressure gradient between the hollow chamber 2 and at least one gas outlet 20 is typically in the range of 0.1 to 5 kPa, for example 0.5 to 2 kPa. Usually, at the position of at least one gas outlet 20, a reduced pressure is provided, for example using a compressor, to generate a vacuum, and at least one sweep fluid 8 and a gas 22 from at least partially pyrolyzed polymer waste are removed from their respective chambers 3, 4.

[0049] The inner wall surface 12 in the second chamber 4 can be partially conical to prevent the plastic waste from being dispersed in the direction of the barrier 14. The partially conical inner wall surface can be obtained, for example, by welding a hollow insert 33 having a conical inner surface to the barrier 14 and the inner wall of the hollow chamber 2 in the second chamber 4.

[0050] It should be understood that the disclosed embodiments of the present invention are not limited to the specific structures, process steps, or materials disclosed herein, but extend to their equivalents recognized by those skilled in the relevant art. It should also be understood that the terms used herein are used only for the purpose of describing specific embodiments and are not intended to be limiting.

[0051] Throughout this specification, when referring to one embodiment or embodiments, it means that the specific features, structures, or characteristics described in connection with that embodiment are included in at least one embodiment of the present invention. Thus, when the phrases "in one embodiment" or "in embodiments" are used in various places in this specification, they do not necessarily all refer to the same embodiment. When referring to a numerical value using terms such as "for example", "about", or "substantially", the exact numerical value is also disclosed.

[0052] In this specification, for convenience, a plurality of items, structural elements, components, and / or materials may be presented in a common list. However, these lists should be construed as if each member of the list is individually identified as a distinct and unique member. Thus, the individual members of such a list should not be construed as being substantially equivalent to other members of the same list based solely on their presentation within the common group, absent a contrary description. Additionally, various embodiments and examples of the present invention may be referred to herein in conjunction with alternatives to various components of the present invention. It is understood that such embodiments, examples, and alternatives should not be construed as being substantially equivalent to one another, but rather as distinct and independent representations of the present invention.

[0053] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the detailed description, numerous specific details such as examples of length, width, shape, etc. are provided to enable a complete understanding of the embodiments of the present invention. However, one of ordinary skill in the art will recognize that the present invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown in detail or described so as not to obscure aspects of the present invention.

[0054] The above examples illustrate the principles of the present invention in one or more specific applications. However, it will be apparent to those skilled in the art that numerous changes can be made to the form, usage, and details of implementation without exercising creative ability and without departing from the principles and concepts of the present invention. Therefore, the present invention is not limited except as defined by the appended claims.

[0055] In this specification, the verbs "comprise" and "have" are used as open limitations that do not exclude or require the presence of functions not described. The features described in the dependent claims can be freely combined with each other unless explicitly stated otherwise. Furthermore, throughout this document, it should be understood that even when the singular form "a" or "an" is used, the plural form is not excluded.

Industrial Applicability

[0056] Industrial applications are found in the treatment of polymer waste in at least some embodiments of the present invention.

Explanation of Reference Numerals

[0057] 1 System 2 Hollow Chamber 3 First Chamber 4 Second Chamber 5 Lance 6 Supply Outlet 7 Polymer Waste 8 Sweep Fluid 9 Housing 10 First Space 11 Second Space 12 Inner Surface of the Hollow Chamber in the Second Chamber 13 Product 14 Barrier 15 Opening 16 Movable Body 17 Structure 18 Inner Surface of the Hollow Chamber 19 Heating System 20 Gas outlet 21 Injector 22 Gas 23 Residue outlet 24 Front end 25 Rear end 26 First heating gas inlet 27 Second heating gas inlet 28 First heating gas outlet 29 Second heating gas outlet 30 Heating zone 31 Cavity 32 Perforation 33 Insertion part A Rotation axis

Claims

1. A system (1), wherein the system comprises a hollow chamber (2) having a first chamber (3) and a second chamber (4), wherein the second chamber (4) is rotatable, or the first chamber (3) and the second chamber (4) are rotatable, the hollow chamber (2); a heating system (19) configured to heat the second chamber (4), or to heat the first chamber (3) and the second chamber (4) individually; a lance (5) having at least one supply outlet (6), wherein the lance (5) extends through at least the first chamber (3) into the hollow chamber (2), and the system (1) is configured to supply polymer waste (7) to the second chamber (4) via the at least one supply outlet (6), the lance (5); at least one injector (21) for injecting at least one sweep fluid (8) into the first chamber (3), or into the first chamber (3) and the second chamber (4), to form a fluid flow towards at least one gas outlet (20) for collecting a product (13) containing at least one sweep fluid and gas (22) from at least partially pyrolyzed polymer waste; A system (1) comprising.

2. The system (1) according to claim 1, wherein the hollow chamber (2) comprises a barrier (14) between the first chamber (3) and the second chamber (4), and an opening (15) is provided between the barrier (14) and the lance (5).

3. The system (1) according to claim 1 or 2, wherein the system (1) comprises a compressor disposed downstream of the gas outlet (20).

4. The hollow chamber (2) is at least partially disposed within a housing (9) having the heating system (19), The heating system (19) is A first space (10) configured to receive a first heating gas having a first temperature (T 1 ), and a second space (11) configured to receive a second heating gas having a second temperature (T 2 ), wherein the first space (10) is aligned with the first chamber (3), and the second space (11) is aligned with the second chamber (4) or The second temperature (T 2 ) and comprises only the second space (11) configured to receive the second heating gas having the second space (11) is aligned with the second chamber (4), the system (1) according to any one of claims 1 to 3.

5. The second space (11) includes a plurality of heating zones (30), and each heating zone (30) is configured to receive heating gas having a specific temperature (T Z1 , T Zn ). The system (1) according to claim 4.

6. The system (1) according to any one of claims 1 to 5, further comprising at least one movable body (16) disposed within the first chamber (3).

7. The system (1) according to any one of claims 1 to 6 further comprises at least one structure (17) protruding into the chamber (2) from the inner surface (18) of the hollow chamber (2) within the first chamber (3).

8. The system (1) is configured to inject at least one of a condensable gas, steam, water, a non-condensable gas, nitrogen, or a hydrocarbon such as pyrolysis oil or diesel via at least one injector (21), according to any one of claims 1 to 7.

9. The gas outlet (20) is included in either the first chamber (3) or the second chamber (4), according to any one of claims 1 to 7.

10. A step of providing a hollow chamber (2) having a first chamber (3) and a second chamber (4), wherein the second chamber (4) rotates, or the first chamber (3) and the second chamber (4) rotate; A step of heating the second chamber (4), or heating the first chamber (3) and the second chamber (4) individually; Providing a lance (5) having at least one supply outlet (6) and extending through at least the first chamber (3) into the hollow chamber (2), and supplying polymer waste to the second chamber (4) via the at least one supply outlet (6); Injecting at least one sweep fluid (8) into the first chamber (3), or into the first chamber (3) and the second chamber (4), to form a fluid flow towards at least one gas outlet (20) for collecting a product (13) containing at least one sweep fluid and gas (22) from at least partially pyrolyzed polymer waste.

11. The method according to claim 10, wherein the wall temperature of the hollow chamber (2) is in the range of 500 to 800 °C in the first chamber (3) and the second chamber (4).

12. A step of at least partially disposing the hollow chamber in a housing (9) having a first space (10) and a second space (11); A step of receiving a first heating gas having a first temperature (T 1 ) in the first space (10), wherein the first space (10) is aligned with the first chamber (3), the step of receiving the first heating gas; a step of receiving a second heating gas having a second temperature (T 2 ) in the second space (11), wherein the second space (11) is aligned with the second chamber (4); a step of receiving the second heating gas The method according to claim 10 or 11, further comprising this step.

13. The sweep fluid is a condensable gas, steam, water, a non-condensable gas, nitrogen, a hydrocarbon such as pyrolysis oil or diesel The method according to any one of claims 10 to 12, which is at least one of them.

14. The method according to any one of claims 10 to 13, wherein the pressure gradient between the hollow chamber (2) and the at least one gas outlet (20) is in the range of 0.1 to 5 kPa.

15. The method according to any one of claims 10 to 14, further comprising a step of pre-melting or extruding the polymer waste before supplying the polymer waste to the second chamber (4).

16. The method according to any one of claims 10 to 15, further comprising a step of liquefying the gas collected downstream of the gas outlet (20).

Images