Recycling methods, corresponding equipment, compositions, and tires

Abstract

The present invention relates to a recycling facility comprising at least one first heat treatment apparatus for rubber-based granular material, and a second heat treatment apparatus for products derived from the first apparatus. The present invention also relates to corresponding methods, compositions, and tires.

Description

Technical Field

[0001] The present invention relates to a rubber-based tire recycling method. The present invention also relates to an installation for implementing such a recycling method. The present invention also relates to a composition for manufacturing a tire containing recovered carbon black (RCB) and a tire manufactured from such a composition.

Background Art

[0002] In Europe, millions of tires reach the end of their life every year. Therefore, recycling these tires is a realistic ecological issue. Today, various types of tire recycling are known. One of them consists of producing recovered carbon black (RCB) that can later be used for various applications. To produce RCB, usually, used tires are stripped to separate the main components (a matrix made of at least one rubber material and at least two reinforcing fillers, namely carbon black and silica) and the auxiliary macroscopic components (fabric fibers, metal shells, etc.). Normally, the main components are pyrolyzed to obtain RCB. Unfortunately, the obtained RCB generally has an average quality and can therefore only be used for certain limited applications, such as a filler for non-technical articles like rubber mats, or a pigment for paints or inks.

Summary of the Invention

[0003] An object of the present invention is to propose a method for recycling rubber-based tires that enables more efficient recycling of rubber-based products. An object of the present invention is to propose an installation for implementing such a method. Another objective of the present invention is to propose a composition for manufacturing tires containing better quality recovered carbon black (RCB). Another objective of the present invention is to propose a tire manufactured from such a composition. In view of achieving this objective, a method for recycling rubber-based tires, comprising at least the following steps: - A first step comprising: heat-treating rubber-based granular material derived from the tire in at least a first apparatus by moving the granular material inside the first apparatus while heating it to decompose the granular material; collecting the solid residue derived from the heat treatment of the granular material at a first outlet of the first apparatus; and collecting the gaseous by-product derived from the heat treatment of the granular material at a second outlet of the first apparatus, wherein the temperature reached inside the housing of the first apparatus is 350-500°C. - A second step of cleaning the solid residue by heat-treating it by moving the solid residue inside at least a second apparatus while heating it at a temperature higher than the temperature of the first step, wherein the second apparatus is connected to the first apparatus such that the second step is performed immediately after the first step, and the temperature reached inside the housing of the second apparatus is at least 500°C. A method including this is proposed.

[0004] The inventors observed that by heat-treating the granular material twice, it is possible to significantly improve the quality of the product collected after the second apparatus. In particular, by performing the second step immediately after the first step, in addition to the higher temperature inside the second apparatus, cooling of the solid residue can be avoided, improving the quality of the product collected after the second apparatus. Furthermore, by collecting gaseous by-products at the level of the first apparatus, it becomes possible to remove volatile components along with these gaseous by-products. Therefore, there are little to no volatile components in the second apparatus. This also improves the quality of the product collected after the second apparatus.

[0005] Therefore, the product collected after the second apparatus is of very good quality. For example, the product collected after the second apparatus is at least cleaner than that produced by conventional methods. For example, the product collected after the second apparatus can interact better with other substances in the new composition, and these substances will, for example, reinforce the product. In particular, the inventors have observed that this makes it possible to manufacture new tires using the product thus obtained. In particular, the inventors were able to observe that the product obtained in this manner was of such good quality that it could be used to replace not only "virgin" carbon black (hereinafter simply referred to as CB) but also "virgin" silica (hereinafter simply referred to as "silica") in standard tire compositions, at least in part. Thus, the present invention makes it possible to recycle rubber-based tires very efficiently.

[0006] The present invention also relates to a composition containing less than 6 parts by mass of silica per 100 parts by mass of the composition. Preferably, the composition according to the present invention contains 20 to 50 parts of recovered carbon black per 100 parts of filler present in the composition. More preferably, the composition according to the present invention contains at least, per 100 parts by mass of the composition 60-70 parts by mass of rubber matrix, 0-13 parts by mass of carbon black, 0-6 parts by mass of silica, 10-30 parts by mass of recovered carbon black Includes. The present invention also relates to a composition for manufacturing a tire, wherein, in 100 parts by mass of the composition, at least 60-70 parts of rubber matrix, 5-13 parts by mass of virgin carbon black, 2 to 6 parts by mass of virgin silica, 10-30 parts by mass of recovered carbon black This also relates to compositions that include [the specified element]. "Virgin silica" means silica that has not been recycled from another object, for example, another tire. "Virgin silica" also means silica that has not been previously used in a previous composition, for example, in the manufacture of a previous tire.

[0007] "Virgin carbon black" means carbon black that has not been recycled from another object, for example, another tire. "Virgin carbon black" means carbon black that has not been previously used in a previous object, for example, in a previous composition to manufacture a previous tire. Therefore, "virgin carbon black" cannot be considered the same as RCB (Recycled Carbon Black). Preferably, the remaining mass of such composition is 6 parts by mass or less (relative to 100 parts by mass of the composition), preferably 5 parts by mass or less, and preferably 4 parts by mass or less. The present invention also relates to a tire composition, wherein, in 100 parts by mass of the composition, at least 60-70 parts of rubber matrix, 5-13 parts by mass of virgin carbon black, 2 to 6 parts by mass of virgin silica, 10-30 parts by mass of recovered carbon black This also relates to compositions that include [the specified element]. Preferably, the remaining mass of such composition is 6 parts by mass or less (relative to 100 parts by mass of the composition), preferably 5 parts by mass or less, and preferably 4 parts by mass or less. Preferably, the composition of the present invention contains at least, per 100 parts by mass of the composition 60-70 parts by mass of rubber matrix, 5-13 parts by mass of carbon black, 2 to 6 parts by mass of silica, 10-30 parts by mass of recovered carbon black Includes.

[0008] The recovered carbon black of the composition of the present invention contains 20 to 35 parts by mass of silica. Preferably, the recovered carbon black contains 25 to 30 parts by mass of silica. The composition of the present invention may contain 0 to 5 parts by mass of N700 and N600 as carbon black. The recovered carbon black of the composition of the present invention exhibits an outer surface area greater than 70 square meters per gram, preferably greater than 80 square meters per gram. The recovered carbon black of the composition of the present invention exhibits less than 1 part by mass of benzo-α-pyrene. The present invention also relates to a tire manufactured from the composition of the present invention, and the tire is a vehicle tire, preferably an automobile tire or a truck tire. Other features and advantages of the present invention will become apparent upon reading the following description of specific non-limiting embodiments of the present invention. The present invention will be best understood in light of the following description with reference to the accompanying drawings.

Brief Description of the Drawings

[0009] [Figure 1] It is a schematic diagram of equipment according to a specific embodiment of the present invention. [Figure 2] It is a schematic cross-sectional view of the heat treatment apparatus of the equipment shown in FIG. 1. [Figure 3] It is a flowchart having at least some of the steps of the method implemented by the equipment shown in FIG. 1.

Modes for Carrying Out the Invention

[0010] In FIGS. 1 and 2, the equipment for recycling rubber-based products is depicted as a whole with reference numeral 10 according to a specific embodiment of the present invention. With reference to FIG. 3 in conjunction therewith, the recycling method implemented by such equipment 10 is described. While the equipment 10 is intended here to recycle used tires 13, this use is naturally not limited to this purpose, and the equipment 10 may also be intended to recycle other types of rubber-based products, such as sheaths, seals, etc. Preferably, the equipment 10 is intended to recycle used tires 13, which are used automobile tires 13 or other used tires 13 having a high silica content (for example, used tires containing at least 25 parts by mass of silica, preferably at least 30 parts by mass of silica, per 100 parts by mass of used tire), but this application is not limited to this, and the equipment 10 may also be intended to recycle other types of used tires, such as truck tires or used tires having a lower silica content. Here, the equipment 10 includes a system 11 for pre-processing used tires 13 that have been collected in advance.

[0011] For this purpose, the pretreatment system 11 includes a peeling device 12. In the first step 101 performed by the peeling device 12, the collected tires 13 are peeled to separate the main components 15 (a collection of rubber matrix and at least two types of fillers, namely carbon black and silica) from the auxiliary macroscopic components 16 (textile fibers, metal shells, etc.). The auxiliary macroscopic components themselves may be recycled either within or outside the facility 10. The pretreatment system 11 also includes a granulator 14 connected to a peeling device. In this way, during the second step 102 performed by the granulator 14, the main component 15 is formed into granular material 17.

[0012] This makes recycling easier. Preferably, in the second step 102, the main component 15 is formed into granules 17 having an average diameter of less than 8 mm, preferably less than 6 mm. In fact, it is preferable that the granular material 17 has relatively small dimensions to facilitate its recycling. The equipment 10 also includes a first family 18 comprising at least one apparatus for heat-treating granular material 17 derived from the pretreatment system 11. Preferably, the first family 18 includes at least two apparatuses 18a, 18b for heat-treating granular material 17 derived from the pretreatment system 11. The first family 18 includes, for example, 2 to 10, preferably 2 to 5, for example 2 to 3 apparatuses for heat-treating granular material 17 derived from the pretreatment system 11.

[0013] The separate heat treatment devices of the first family 18 are arranged in parallel. That is, all the heat treatment devices of the first family 18 are connected to the pretreatment system 11 in this way so that the granular material 17 is heat-treated in parallel. The separate heat treatment devices within the first family 18 are preferably identical to one another. Therefore, the following description of one device 18a also applies to the other device, in this case 18b. The device 18a includes a housing 2 whose overall orientation is primarily horizontal, and the housing 2 is held off the ground by legs. The housing 2 includes at least one inlet 4 located at a substantially first longitudinal end of the housing 2, and positioned in the cover of the housing 2. According to a particular embodiment, the device includes an inlet funnel 5 that is sealedly connected to the inlet 4 of the housing. In this way, the inlet funnel 5 is connected to the pre-processing system 11. The housing 2 further includes, in this case, at least one first outlet 6 located on the downstream side of the housing 2, substantially at the second of the two longitudinal ends of the housing 2. According to a particular embodiment, the apparatus includes a first outlet funnel 7 sealed to a first outlet 6 of the housing 2 for collecting solid residue derived from a heat treatment performed within the housing. In this case, the housing 2 includes a second outlet 8 for collecting gaseous by-products resulting from the heat treatment of particulate matter.

[0014] According to a particular embodiment, the apparatus 18a includes an outlet funnel 9 sealed to a second outlet 8 of the housing 2. The housing 2 is made of a metal material, for example. Typically, the housing 2 is made of steel such as stainless steel and is, for example, non-magnetic. Box 3 is fixed to each of the longitudinal ends of enclosure 2. The device 1 includes a screw 1 mounted within the housing 2 so as to rotate around a vertical axis X, where the vertical axis X is parallel to the overall orientation of the housing 2. Therefore, in this case, the vertical axis X is horizontal. In this case, screw 1 has a helical coil shape with its two ends fixed to the tip of the shaft portion, but of course this constitutes only one example, and any other helical shape can be used. Therefore, strictly speaking, the screw 1 itself does not have a shaft. Each shaft section has its other end connected to a coaxial shaft that runs through the box. Each box 3 is equipped with means for rotating the screw 1, and means for forming a Joule effect heating means by driving the screw 1. Therefore, the screw 1 constitutes a heating transmission means.

[0015] For this purpose, the screw 1 is formed mostly of a conductive material. Thus, in the third step 103 carried out by the first family 18, the granular material 17 is heat-treated within each housing 2. In particular, for each housing 2, the screw 10 moves the granular material 17 between the first inlet 4 and the first outlet 6 while heating the granular material 17. This demonstrates that the heat treatment of the granular material 17 is highly effective because the granular material 17 is heated while being stirred. In this case, it is necessary to pass through one of the heat treatment devices of the first family 18 once during this third step 103. The heat treatment parameters performed by each of the heat treatment devices 18a and 18b are the same for all of the heat treatment devices in the first family 18. Therefore, the heat treatment of the granular material 17 is the same regardless of which heat treatment device in the first family 18 is used. Preferably, each apparatus for heating the first family 18 is in this case shaped to thermally decompose the granular material 17 it carries. It should be recalled that thermal decomposition consists of raising the temperature of compound A (e.g., an organic compound) in an atmosphere with no or very little oxygen to decompose it into several sub-compounds B1, B2, B3, etc., which are different from the original compound A.

[0016] In this case, each heat treatment apparatus of the first family 18 is molded such that the temperature reached within the housing 2 is at least 350°C, preferably at least 400°C (hereinafter, "temperature within the housing" refers to the set temperature of the screws located inside the housing and / or the temperature of the ceiling of the housing). Typically, the temperature is between 350 and 800°C, for example, 350 and 500°C, for example, 350 and 450°C, for example, 400 and 450°C. The temperature inside the housing 2 is maintained at a constant level over time. However, as the granular material 17 moves through the housing 2, it gradually heats up due to contact with the screw 1. Furthermore, each heat treatment apparatus of the first family 18 is also molded so that the granular material 17 remains inside the enclosure for 10 minutes to 1 hour, for example 20 to 40 minutes, for example 25 to 35 minutes, for example 30 minutes. Typically, each heat treatment apparatus of the first family 18 is configured such that the granular material 17 remains inside the housing 1 at a temperature of 400 to 450°C for 25 to 60 minutes. In this way, the granular material 17 is heated to a suitable temperature over a relatively long period of time, and as a result, its processing is optimized. After this third step 103, the solid residue 21 is collected at the first outlet 6 and the gaseous by-product 22 is collected at the second outlet 8.

[0017] The separate second outlets 8 of all the heat treatment equipment in the first family 18 are connected to one common outlet 19 belonging to the equipment 10. The equipment preferably includes at least one system 20 capable of post-treating and reforming the gaseous by-product 22. Preferably, the post-processing system 20 includes a condenser 23 connected to a common outlet 19. During the first stage 111, the gaseous by-products 22 are cooled and / or their pressure is reduced, thereby allowing the collection of the condensable phase of the by-products. The condenser 23 includes, for example, a cooling tower, a scrubber, etc. In this way, the pyrolysis oil 24 (condensable phase) is collected from one side, and the non-condensable phase 25 is collected from the other side. More specifically, in this case, the pyrolysis oil 24 is collected at the bottom of the condenser 23, and the non-condensable phase 25 is collected at the top of the condenser 23. In this case, the equipment 10 includes a container 26 for storing the pyrolysis oil 24, which is connected to the outlet of the condenser 23 and collects the pyrolysis oil 24 (optionally through one or more intermediate processing steps such as filtration and additional cooling). More specifically, in this case, the container 26 is connected to the bottom of the condenser 23.

[0018] Preferably, since the container 26 is also connected to a second inlet of the condenser 23 (the first inlet is connected to a common outlet 19), some of the resulting pyrolysis oil 24 is reinjected into the condenser 23 to promote the condensation of the gaseous by-products 22. For example, the condenser 23 includes a wet scrubber, which therefore moistens the gaseous by-products 22 with at least the pyrolysis oil 24 (potentially mixed with a solvent) obtained from the container 26. Therefore, the treatment of the gaseous by-product 22 has proven to be particularly effective. Furthermore, the pyrolysis oil 24 present in the container 23 can be modified (optionally by one or more additional post-treatment steps such as filtration or additional cooling). Preferably, the post-processing system 20 also includes a device 27 for managing the non-condensable phase 25. This management device 27 is connected, for example, to the upper outlet of the condenser 23. The control device 27 includes, for example, an extraction fan 28 that is operated by suction and adjusted to maintain a reduced pressure state in the condenser 23. This enables the forced extraction of the non-condensable phase 25. In this case, the extraction fan 28 is connected to the upper outlet of the condenser 23. The control device 27 also includes a combustion furnace 29 located downstream of the extraction fan 28. Thus, at the outlet of the extraction fan 28, the non-condensable phase 25 is fed into the combustion furnace 29, where, during the second stage 112, combustion of the phase is carried out by at least one burner (gas, fuel oil, biomass, etc.).

[0019] Therefore, the burning combustion smoke 30 is collected at the outlet of the combustion furnace 29. Preferably, the control device 27 includes an organic Rankine cycle module 31 connected to the outlet of the combustion furnace 28 for converting heat from the combustion smoke into electrical energy 32 during the third stage 113. This makes it possible to modify even the non-condensable phase 25. Preferably, at least a portion of the electrical energy 32 generated by the control device 27 is used to power all or part of the equipment 1. Therefore, facility 1 has proven to be particularly interesting from an energy standpoint. Furthermore, the control device 27 includes one or more cooled combustion smoke treatment modules 33 at the outlet of the organic Rankine cycle module 31, and includes, for example, at least one filtration module 34 connected to the outlet of the organic Rankine cycle module 31. The filtration module 34 is, for example, a baghouse type filtration module.

[0020] Therefore, during the fourth stage 114, the cooled combustion smoke 33 is cooled in the filtration module 34. In this way, the filtered combustion smoke 35 can be discharged from the equipment 1 through the discharge funnel 36 at the outlet of the filtration module 34. Preferably, the equipment 1 is shaped so that a portion of the filtered combustion smoke 35 is removed before it reaches the exhaust funnel 36 and reinjected into the combustion furnace 29. This makes it easier to maintain the combustion taking place in the combustion furnace 29. Thus, it has been proven that facility 1 is particularly interesting from an energy perspective. Here, we will continue describing the recycling of the solid residue derived from the first pyrolysis 103. The distinct first outlets 8 of all heat treatment devices in the first family 18 are connected to at least one heat treatment device in the second family 37 of the heat treatment devices of facility 1. In this case, the second family 37 includes only one single heat treatment device 37a. For example, a separate outlet of the heat treatment apparatus of the first family 18 is connected to a worm screw 38, which in turn is connected to a single apparatus 37a (hereinafter simply referred to as the second heat treatment apparatus 37a) for heat treatment of the second family 37.

[0021] Thus, all first outlets 8 of the first family 18 heat treatment apparatuses are connected to the same second heat treatment apparatus 37a, in particular to the same single inlet of the second apparatus 37a. For example, all first outlets 8 of the first family 18 heat treatment apparatuses open to a worm screw 38 that carries solid residue to the inlet 6 of the second heat treatment apparatus 37a. Preferably, the second heat treatment apparatus 37a is the same as at least one of the heat treatment apparatuses of the first family 18. Therefore, what is stated above for one of the heat treatment apparatuses of the first family 18 also applies to the second heat treatment apparatus 37a. In the fourth step 104, which is carried out in the second heat treatment apparatus 37a, the screw of the apparatus moves the solid residue 21 between the first inlet and the first outlet of the housing of the apparatus while heating the solid residue 21. This demonstrates that the heat treatment of the solid residue 21 is highly effective because the solid residue 21 is heated while being stirred. In this case, it is necessary to pass through the second heat treatment apparatus 37a once during this fourth step 104.

[0022] Preferably, the second heat treatment apparatus 37a is a "finishing apparatus," that is, the second heat treatment apparatus 37a finishes the heat treatment of the solid residue. In particular, the second heat treatment apparatus is designed to clean the solid residue 21, and especially to clean the surface of the silica and carbon components present in the solid residue 21. One advantage of cleaning the aforementioned surface is that it makes the future composition (the composition described below) more activatable by a coupling agent. Therefore, the parameters of the heat treatment performed by the second heat treatment apparatus 37a are different from those of the heat treatment performed by the first family 18 heat treatment apparatus. In this case, the heat treatment apparatus 37a is molded such that the temperature reached within its casing is at least 500°C, preferably at least 600°C. Typically, the temperature is between 500 and 1000°C, for example, between 500 and 800°C, for example, between 600 and 650°C, or for example, between 620 and 650°C. The temperature inside the casing of the second heat treatment apparatus 37a is maintained constant over time. However, as the solid residue 21 moves through the casing, it gradually becomes hotter due to contact with the screw of the second heat treatment apparatus 37a.

[0023] The second heat treatment apparatus 37a is necessarily molded such that the temperature reached within its enclosure is higher than the temperature reached within the enclosure 2 of the first family 18. Furthermore, the second heat treatment apparatus 37a is also shaped so that the solid residue 21 remains inside the casing for 1 to 20 minutes, for example, 5 to 10 minutes, or for example, 6 to 7 minutes. In this case, the second heat treatment apparatus 37a is configured such that the solid residue 21 remains in its casing for a shorter time than it does in the casing 2 of the first family 18. Typically, the second heat treatment apparatus 37a is molded so that the solid residue 21 remains inside its housing 1 at a temperature of 620-680°C for 6-7 minutes. In the third step 103, and in the fourth step 104, the solid residue 21 is heated to a high temperature for a relatively short period of time, which optimizes its processing. After this fourth step 104, crude RCB (hereinafter referred to as crude RCB+ to distinguish it from crude RCB granules of the prior art) is collected at the first outlet of the second heat treatment apparatus 37a, and gaseous by-products 22 are collected at the second outlet. Note that all separate outlets of the first family 18 heat treatment equipment are directly connected to the second heat treatment equipment 37a. There is no heat treatment equipment between the first family 18 and the second heat treatment equipment 37a. In particular, there is no cooling of solid residue between the first family 18 and the second heat treatment equipment 37a.

[0024] Preferably, the second outlet of the second heat treatment apparatus 37a is connected to the post-treatment system 20 (either directly or via the common outlet 19) so as to follow the same path as the gaseous by-products 22 originating from the first family 18. Equipment 1 further includes a cooling device 39 connected to the outlet of the housing of the second heat treatment apparatus 37a. The cooling device 39 includes, for example, a screw that rotates around a vertical axis, through which a coolant circulates. Therefore, the screw allows for both cooling and movement of the crude RCB+ within the cooling device 39, thereby enabling rapid cooling of the crude RCB+. For example, the crude RCB+ remains in the cooling unit 39 for 2 to 30 minutes. Thus, during the fifth step 105, which is carried out within the cooling device 39, the crude RCB+ is cooled. The cooled crude RCB+ can then be handled safely as a whole. Preferably, the equipment 1 includes a post-processing system 40 connected to the outlet of the cooling device 39.

[0025] Therefore, the post-processing system 40 includes a grinding device 41 connected to the outlet of the cooling device 39. The grinding device 41 includes, for example, a centrifugal grinder or a jet mill grinder. In the sixth step 106 carried out in the grinding device 41, the cooled crude RCB+ is converted into powder 43. For example, the cooled crude RCB+ is ground into powder 43, the particles having an average diameter of less than 15 micrometers, for example, less than 10 micrometers. This will enable better dispersion in future compositions. The post-processing system 40 preferably includes a granulator 42 connected to the outlet of the crushing device 41. Thus, in the seventh step 107 carried out in the granulator 42, the powder 43 is converted into RCB+ granules, which will hereafter be simply referred to as RCB+. Therefore, please note that there is a difference between the crude RCB+ obtained in the fourth step 104 (second thermal decomposition) and the RCB+ obtained in the seventh step 107 (post-processing granulation). The granulation process in step 7, step 107, makes it possible to handle RCB+ in particular.

[0026] In this case, it is conceivable that the heat treatment of used tires could inevitably cause a violent reaction with oxygen. As a result, at least a portion of the equipment 1 (in particular, at least the portion included between the inlet 6 of a separate housing 2 of the first family 18 of the equipment and the outlet of the cooling device 39) is configured to ensure that this portion of the equipment is sealed from the outside air. Preferably, at least the inlet 6 of a separate housing 2 of the first family 18, -Outlet of cooling device 39, - container 26, - Combustion furnace 29 The part of the equipment included between the two is configured to ensure that this part of the equipment is sealed from the outside air. For this purpose, gate valves, airlocks, etc., can be used to assist in connecting the inlet and outlet of the respective separate elements of Equipment 1. Furthermore, at least a portion of the equipment 1 (in particular, at least the portion included between the inlet 6 of a separate housing 2 of the first family 18 of the equipment and the outlet of the cooling device 39) is configured to operate in an oxygen-free atmosphere. Preferably, at least the inlet 6 of a separate housing 2 of the first family 18, -Outlet of cooling device 39, - container 26, - Combustion furnace 29 The equipment components included between them are configured to operate in an oxygen-free atmosphere.

[0027] For this purpose, the equipment 1 may be equipped with one or more circuits for circulating a neutral gas (such as nitrogen) to the respective separate elements of the equipment 1. Alternatively or complementary, at least a portion of the apparatus 1 (in particular, the portion included between the inlet of a separate housing of the first family 18 of the apparatus 1 and the outlet of the cooling device 39) is configured to operate at a pressure lower than the ambient pressure. This allows for better extraction of volatile substances present in the housing (as gaseous byproducts) that may interfere with the thermal decomposition of particulate matter 17 or solid residue 21. The equipment 1 and related methods described herein enable very efficient recycling of used tires. At the outlet of equipment 1, for example, 30 to 40 parts by mass of RCB+, 30 to 45 parts by mass of pyrolysis oil 24, and 23 to 28 parts by mass of non-condensable gas 25 can be collected for 100 parts by mass of user granular material 17, which can enable the generation of electrical energy 32 (the total parts by mass of RCB+, pyrolysis oil 24, and non-condensable gas 25 cannot, of course, exceed 100 parts). These numerical ranges are merely examples and therefore do not limit the present invention (since the collection of pyrolysis oil 24, non-condensable gas 25, and RCB+ depends on the heat treatment parameters, the initial composition of the used tire 13, and the composition of the raw materials). Furthermore, both crude RCB+ and RCB+ possess interesting characteristics. The characteristics of RCB+ are shown in Table 1 below.

[0028] [Table 1]

[0029] It should be noted that RCB+ contains low levels of volatile substances. In particular, crude RCB+ and RCB+ have extremely low aromatic hydrocarbon (PAH) content. For example, less than 1 part by mass of benzo-α-pyrene, preferably less than 0.5 parts by mass of benzo-α-pyrene, per 100 parts by mass of RCB+ or crude RCB+. This is confirmed by direct measurement by thermomass spectrometry (ASTM D8474) and the absence of organic residues that discolor toluene (ASTM D1618). In this way, RCB+ can be handled safely. Furthermore, RCB+ has an increased usable surface area. In fact, the external surface area (STSA) value differs from the total surface area (BET) value, meaning that the majority of the pores in RCB+ do not contain residue, especially organic residue.

[0030] Thus, the inventors were able to observe that the silica and CB surfaces could be cleaned very well during recycling using Equipment 1 and the method described above. Thanks to this, the surface area of ​​RCB+ is close to the surface area of ​​the virgin filler combination used to manufacture new tires (virgin CB + virgin silica) (hereinafter simply referred to as the virgin filler combination). Hereinafter, "filler" means the sum of all carbon black (derived from virgin or recycled) and all silica (derived from virgin or recycled) present in the composition. Therefore, RCB+ can be directly reused in the manufacture of new tires, and even new vehicle tires, and even new car and truck vehicle tires.

[0031] When RCB+ is used to manufacture new tires, the composition preferably contains at least 100 parts by mass of the composition. A matrix consisting of 60-70 parts by mass of one or more types of rubber, Virgin carbon dioxide less than 15 parts by mass, Less than 7 parts by mass of virgin silica, preferably less than 6 parts by mass of virgin silica. At least 10 parts by mass of RCB+, preferably at least 12 parts by mass of RCB+, Approximately 4 parts by mass of other components, and, for example, 4 parts by mass of an inorganic substance other than silica (e.g., zinc oxide). RCB+ is added to the composition so as to include [the specified component]. For example, the composition contains at least, A matrix consisting of 60-70 parts by mass of one or more types of rubber, 0-13 parts of virgin carbon dioxide, 0-6 parts by mass of virgin silica, 10-30 parts by mass of RCB+, Approximately 4 parts by mass of other components, for example, 4 parts by mass of an inorganic substance other than silica (e.g., zinc oxide) Includes.

[0032] For informational purposes, in Europe, new tires are manufactured based on compositions containing a combination of 30 to 37 parts by mass of virgin filler per 100 parts by mass of the composition. Simply put, in Europe, standard new car tires, on average, have a composition of 100 parts by mass (with an error of at most or at least about 2 parts), A matrix consisting of one or more types of rubber, approximately 63 parts Approximately 23 virgin center backs, Approximately 10 parts virgin silica, Approximately 4 parts are inorganic substances other than silica (e.g., zinc oxide). It is manufactured based on a composition containing [the specified ingredient]. Therefore, it can be seen that RCB+ advantageously allows for the use of less virgin CB and, surprisingly, even less virgin silica. In fact, RCB+ itself contains silica, which is of particular interest. The inventors were able to observe that RCB+ contains 20 to 35 parts by mass of silica, more specifically 25 to 30 parts by mass, per 100 parts by mass of RCB+. The remainder of the RCB+ is parts by mass of carbon (at most or at least 1 part by mass of other components, e.g., additive residues).

[0033] For example, if the equipment 10 is intended to recycle used tires 13, such as used automobile tires 13 or other used tires 13, which have a high silica content, then RCB+ will contain 60 to 75 parts by mass of carbon, for example, 64 to 70 parts by mass, per 100 parts by mass of RCB+. For example, if the equipment 10 is intended to recycle other types of used tires, such as truck tires or used tires, which have a lower silica content, then the RCB+ will contain 75 to 90 parts by mass of carbon, for example 75 to 85 parts by mass of carbon, or for example 75 to 80 parts by mass of carbon, per 100 parts by mass of RCB+. Furthermore, as already pointed out, the silica in RCB+ has a good surface condition. Subsequently, the silica in RCB+ can interact appropriately with one or more coupling agents commonly used in tire manufacturing (e.g., TESPT and bis(triethoxysilylpropyl) tetrasulfide, also known as Si-69), similar to "virgin" silica. In particular, after reacting with such coupling agents, the silica in RCB+ enhances filler-polymer interactions while reducing filler-to-filler interactions and energy losses. Thus, as already pointed out, RCB+ can replace not only virgin CB but also virgin silica.

[0034] This is advantageous because silica is a relatively expensive raw material, and there are no sustainable alternative materials available to industry to replace silica. Thus, for every 100 parts by mass of the combination of virgin fillers present in a standard tire composition, at least 25 parts by mass are replaced with 25 parts by mass of RCB+, preferably at least 30 parts by mass, and preferably at least 35 parts by mass (it is considered preferable that at least a portion of the virgin silica is replaced with RCB+). Thus, for every 100 parts by mass of the combination of virgin fillers present in a standard tire composition, 25 to 50 parts by mass are replaced with the same amount of RCB+, preferably 25 to 45 parts by mass, and more preferably 25 to 40 parts by mass (it is considered preferable that at least a portion of the virgin silica is replaced with RCB+). Thus, for every 100 parts by mass of virgin silica present in a standard tire composition, at least 25 parts by mass are replaced with the same amount of RCB+, preferably at least 40 parts by mass, preferably at least 50 parts by mass, and preferably at least 60 parts by mass.

[0035] Thus, the inventors were able to observe that RCB+ was indeed of good quality and that the use of RCB+ made it possible to propose a tire composition containing 0 parts of "virgin" silica. However, preferably, the tire composition contains at least 1 part of "virgin" silica in addition to the use of RCB+. Therefore, 25 to 95 parts by mass of the same amount of RCB+, preferably 40 to 95 parts by mass, preferably 50 to 95 parts by mass, and preferably 60 to 95 parts by mass, replaces 100 parts by mass of virgin silica present in a standard tire composition. Furthermore, RCB+ has proven to be an excellent substitute for grade N700 or N600 virgin CB. RCB+ can also replace, at least partially, other virgin CB such as N500 or N300. Preferably, RCB+ is added in proportion to 100 parts of the manufacturer's standard composition. At least 90%, preferably 100%, of the parts by mass of virgin CB N700 and N600 used in the composition, and / or Typically, 0 to 30% by mass of virgin CB N500 used in the composition, preferably 0 to 25% by mass, and / or Typically, 0 to 10% of the mass of virgin CB N500 used in the above composition, preferably 0 to 5% of the mass. It will replace it. The following table shows possible compositions for standard new tires and new tires including RCB:

[0036] [Table 2]

[0037] Therefore, it is clear once again that RCB+ can replace not only virgin CB but also silica, and to a significant degree. Maintaining the first stage of thermal treatment at 500°C significantly reduces, or even suppresses, the formation of carbonaceous residue (also known as char or coke) from the polymer decomposition reaction of rubber-based granules. This has three main advantages: 1. The purity of the resulting rCB+ is enhanced by maintaining the surface activity of both the carbon black and silica components. 2. The yield strength of the pyrolysis oil is increased. 3. Carbon derived from organic matter remains in the pyrolysis oil and combustion smoke rather than in rCB+.

[0038] Furthermore, the two-stage heat treatment at the indicated temperatures is particularly advantageous because it allows for the optimization of the recycling of rubber-based granules. In particular, this treatment makes it possible to optimize the generation of pyrolysis oil 24 on the one hand and the generation of RCB+ on the other. In particular, during the first heat treatment, it is important to keep the temperature below 500°C to limit the cracking of molecules that can become pyrolysis oil (in other cases, these molecules become non-condensable gases that are not easily utilized). During the second heat treatment, since molecules that cannot become RCB+ have been separated during the first heat treatment, it is possible to "cleanse" the RCB+ and improve its quality by using a higher treatment temperature. The present invention is not limited to the embodiments described herein, but rather encompasses any variations having the main features described above, using equivalent means.

[0039] In particular, the apparatus may include one or more additional modules other than those shown, for example, for the post-treatment of pyrolysis oil, non-condensable phase, or crude or non-crude RCB+. The apparatus may also include, for example, a module for cleaning particulate matter derived from used tires, located upstream of the first heat treatment apparatus. Each heat treatment apparatus family may include several heat treatment apparatuses different from those shown.

Claims

1. A composition for manufacturing tires, comprising at least: 60-70 parts of rubber matrix, 5 to 13 parts by mass of virgin carbon black, 2 to 6 parts by mass of virgin silica, 10 to 30 parts by mass of recovered carbon black A composition containing the following:

2. The composition according to claim 1, comprising 20 to 50 parts of recovered carbon black per 100 parts of filler present in the composition.

3. The composition according to claim 1 or 2, wherein the recovered carbon black contains 20 to 35 parts by mass of silica.

4. The composition according to claim 3, wherein the recovered carbon black contains 25 to 30 parts by mass of silica.

5. The composition according to any one of claims 1 to 4, comprising 0 to 5 parts by mass of N700 and N600 as carbon black.

6. The composition according to any one of claims 1 to 5, wherein the recovered carbon black contains less than 1 part by mass of benzo-α-pyrene.

7. A tire manufactured from the composition described in any one of claims 1 to 6.

8. The tire according to claim 7, which is a tire for a vehicle.

9. The tire according to claim 7 or 8, which is an automobile tire or a truck tire.

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