Recovered carbon black obtained by solvolysis of tires

Abstract

The present invention relates to a recovered carbon black (rCB) comprising carbon black, inorganic ash, and a carbon-containing residue obtained from the decomposition of tire rubber and / or elastomer residues, characterized in that the content of the carbon-containing residue is less than or equal to 1% of the area of ​​the C1 peak, determined relative to the area percentage of the C1 peak measured using X-ray photoelectron spectroscopy, and the area percentage of the C1 peak is calculated relative to the total area of ​​the C0 to C5 peaks.

Description

[Technical field]

[0001] The present invention relates to the field of carbon-based materials of the carbon black type, in particular to "recovered" carbon blacks (rCBs) obtained by thermochemical conversion of tires at the end of their life. The present invention also relates to a method for the preparation of these rCBs, involving the recycling of the hydrocarbon fraction containing aromatic compounds, via a method for the solvolysis of waste tires. [Background technology]

[0002] Tyres are mainly composed of rubber (a mixture of elastomers of crosslinked synthetic and natural rubber type, with the addition of auxiliaries of silica, resin, sulphur, zinc oxide, carbon black, etc. type) for their elastic properties, and textile and metal fibres for their reinforcing properties. Carbon black (CB) is used in particular in rubber formulations to improve the resistance of the rubber (in terms of robustness and life), to limit deformations of the tyre during use, as well as to promote heat transfer between the tyre and the ground during running. They are generally obtained by incomplete combustion of vegetable oils or hydrocarbons, and there are more than 35 grades of them, which are sold and used as fillers (essentially for the formulation of pneumatic tyres). Their quality differs according to their intrinsic properties.

[0003] The majority of carbon blacks are characterized by a high content of elemental carbon (>90% by weight, based on the total weight of the carbon black) and may contain other chemical elements, such as hydrogen, oxygen, nitrogen, and sulfur, which are chemically bound to the carbon. They are generally supplied in the form of a black powder, which is composed of elementary graphite particles (more or less highly crystalline). The elementary graphite particles are spherical in nature (10-500 nm) and form aggregates (100-1000 nm). The aggregates themselves gather in the form of agglomerates (1-100 μm), which can then be converted in their entirety into granules (0.1-1 mm). The size of the elementary particles and the structure of the bodies (aggregate / agglomerate morphology, size, density / permeability) greatly influence the ability of carbon blacks to disperse in an elastomeric matrix and therefore, ultimately, the reinforcing properties of these blacks in tires. The "specific surface area" (i.e. S BET The ) parameter, determined by nitrogen physisorption, is characteristic of the size of the basic particles and gives information about the surface of the carbon black that may interact with the elastomeric matrix. The structure of the carbon black is characterized, for its part, by its ability to develop porosity that can be filled by liquid paraffin and therefore, ultimately, by the elastomeric matrix. A structural index corresponding to the oil absorption number is determined, the relevant analytical method being the OAN (Oil Adsorption Number) method. The abbreviation NXYZ type is the sum of the X and S of the carbon black. BET where Y and Z are numbers that represent the characteristics of the carbon black, and Y and Z are numbers arbitrarily assigned depending on the structure observed, and this abbreviation is associated with each carbon black. BETThere exists a relationship called the / OAN structure index, which allows different carbon blacks to be classified according to their grade and their reinforcing or non-reinforcing properties. For example, carbon blacks N110, N120 and N234 are very good reinforcing aids, and they are characterized by a high specific surface area and a high structure index. Depending on these intrinsic properties, carbon blacks are used to compound different rubbers, which themselves are used in the various components of tires.

[0004] During their recycling, tires are generally first crushed to obtain either crushed tire material (typically 1-10 cm pieces) still containing some textile and metal fibers, or granules (generally with dimensions less than 6 mm) without any fibers. The result can then be converted into gaseous, liquid or solid fractions via a thermal decomposition conversion process. The solid fraction obtained is predominantly composed of various grades of carbon black as a mixture, to which inorganic ash (predominantly of the type of silica and Zn-based compounds) is added. Furthermore, the thermal decomposition of the "elastomeric" fraction gives rise to carbon-based compounds of various natures (various optional recondensed decomposition products) that can be deposited on the surface of the carbon black. Similarly, depending on the operating conditions of the process, the polymer chains of the undecomposed elastomers can be adsorbed at the surface. For a given conversion method applied to a particular "scrap tire" feedstock, the rCB represents all the solid fractions composed of the initial carbon black as a mixture and modified at the surface by various carbon-based deposits (decomposition products and / or elastomer residues), and also inorganic ash. The specific properties of the rCB thus depend on the elements that compose it. In particular, the chemical composition of the rCB, the degree of agglomeration and their structure of the aggregates, and consequently the redispersion properties of the rCB in the elastomer matrix, can be radically modified with respect to the above-mentioned properties of the starting carbon black, depending on the composition at the end of the life of the treated tires (choice of feedstock) and on the recycling methods envisaged.

[0005] Among the methods of conversion by pyrolysis possible for the treatment of tires at the end of their life, pyrolysis methods are encountered very frequently (Non-Patent Documents 1 and 2, Patent Document 1). They consist of exposing the tires to temperatures between 350° C. and 800° C., usually in the absence of oxygen or in the presence of very small amounts of oxygen or air designed to contribute, by very partial combustion, the energy required for the pyrolysis method. Pyrolysis methods are operated at atmospheric pressure of the gas or gases under consideration, or in some cases under vacuum, to minimize side reactions after the decomposition of the pneumatic tire, which frequently result in the formation of residual carbon-based deposits on the surface of the final rCB already mentioned. Several techniques are used, such as the use of fixed bed, moving bed or rotary kiln reactors. The yields of these rCB methods are highly variable (approximately 25% to 60%), as are the intrinsic properties of the rCB (for example, the content of residual inorganic ash can vary from 8% to 41% by weight). On the other hand, all rCBs obtained after pyrolysis (frequently also called "pCB") are characterized by the non-negligible presence of carbon-based deposits on the surface of the starting carbon black, which is characterized in particular by the X-ray photoelectron spectroscopy (XPS) surface analysis technique, also called ESCA (Electron Spectroscopy for Chemical Analysis). This surface analysis firstly makes it possible to identify the elemental chemical composition of the material, and therefore to determine the contents of C, O, N, S, Si, Al, Zn, etc. present. Then, a precise analysis of the spectrum related to elemental carbon (C1 spectrum) gives information about the chemical environment of the constituent carbon atoms of the rCB (Non-Patent Document 3).It is thereby possible in particular to distinguish the carbon associated with the starting carbon black (C0 peak corresponding to a bond energy of about 284.2 / 284.8 eV; characteristic of C-C / C-H bonds of graphitic structures) from the carbon associated with carbon-based compounds that tend to be deposited on the surface (C1 peak corresponding to a bond energy of about 284.8 / 285.6 eV; characteristic of C-C / C-H bonds of aliphatic structures or small aromatic compounds; in this case associated with carbon-based deposits formed during the pyrolysis process). The content of carbon-based deposits shown by pCB is therefore between 5% and 40%, evaluated as a percentage of the area by XPS (the calculation is based on the C0 and C1 peaks mentioned above, as well as on the bonds C-O, C=O and COOH, and on the π-π. * (The calculation is based on the total area of ​​the C1 peak, which was assigned to the C2, C3, C4 and C5 transitions, respectively). These carbon-based deposits are to a large extent responsible for the agglomeration phenomenon that links the diverse structures of rCB at different scales; the solids leaving the reactor are often in the form of blocks of several millimeters / centimeters, which then need to be finely ground in order to reuse them (especially as an auxiliary for new rubber formulations), which requires a large energy expenditure. It should be noted that these carbon-based deposits seem to be tightly bound to the surface of the starting carbon black, since even a thermal post-treatment at a temperature higher than the temperature of the pyrolysis process itself is not sufficient to remove them (change in the area of ​​the C1 peak from 40% to 20% for a thermal treatment after pyrolysis at 600° C.: Non-Patent Document 4).

[0006] To limit the formation of carbon-based deposits on the rCB, it is possible to reduce the partial pressure of the hydrocarbons by injecting steam during the cracking reaction (steam pyrolysis method). Unfortunately, even the commonly applied high temperature conditions (often above 500° C.) result in the formation of carbon-based deposits, albeit in a limited proportion (5%-6% of the area of ​​the C1 peak). Furthermore, these gas-solid methods exhibit other disadvantages, since they generally result in a high production rate of non-condensable gases (at atmospheric conditions), often 10%-25% by weight, relative to the waste tire feedstock entering the reactor, at the expense of the amount of liquid products that may be recovered and that may be easily regraded. This is because these liquid fractions can be used to produce new hydrocarbon fractions (naphtha, gasoline, kerosene, gas oil, vacuum distillate, residual oil) that are used in refineries to produce fuels or in petrochemistry to produce bases that are subsequently used to prepare plastics.

[0007] Another alternative route, advantageous for limiting the presence of these carbon-based deposits on the rCB, consists of contacting the tire feedstock with a liquid under suitable operating conditions (particularly temperature) and dissolving and converting the tires in a homogeneous liquid phase, in which the tire feedstock will be agitated and will gradually disappear. Patent documents 2 and 3 disclose methods for the conversion of waste tires. These methods include a stage of dissolving a solid feedstock based on waste tires in the presence of a solvent, which corresponds to the recycling of the heavy liquid fraction of the filtrate obtained after distillation, which contains compounds rich in aromatic compounds (preferentially monoaromatized products). Unfortunately, the conditions for the implementation of such methods, and more particularly the choice of the heavy liquid fraction as solvent, are not favorable for the non-formation of carbon-based deposits contained in the final rCB.

[0008] The Applicant Company has developed a novel process for the conversion of waste tires, which makes it possible to obtain a "recovered" carbon black (rCB) containing a very low content of carbon-based residues (decomposition products of pneumatic tire rubber and / or elastomer residues), which also limits the phenomenon of agglomeration of the various structures of the rCB commonly encountered during the processes used in the abovementioned documents. The process consists of recycling a feedstock of waste tires, at a temperature below 400°C and a pressure below 1.5 MPa, through an operation in which the feedstock is contacted with a solvent composed at least of a hydrocarbon fraction containing a rich content of aromatic compounds, a low content of C40+ compounds (vacuum residue) and a moderate content of C5-C10 hydrocarbon compounds (gasoline), said solvent being able to originate from the process itself (recycle). The process is also characterized by a weight ratio of liquid solvent to the specific feedstock, i.e. a weight ratio of more than 3 wt / wt. Defined operating conditions, composition of the hydrocarbon fraction and weight ratio of solvent / solid feedstock make it possible to maximize the production of rCB through better dissolution / decomposition of the solid feedstock while limiting the presence of carbon-based residues in the final rCB. Moreover, such a method limits the formation of gas, whose content is between 1% and 7% by weight of the feedstock to be treated. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] European Patent No. 2661475 [Patent Document 2] U.S. Pat. No. 3,978,199 [Patent Document 3] U.S. Pat. No. 3,704,108 [Non-patent literature]

[0010] [Non-Patent Document 1] J. Yu et al., Frontiers of Environmental Science & Engineering, 2020, Volume 14, Issue 2, p. 7982 [Non-Patent Document 2] SQ Li et al., Ind. Eng. Chem. Res., 2004, Vol. 43, p. 5133 [Non-Patent Document 3] Ludovic Moulin: Valorisation du noir de carbone recupere, relation procede-product [Upgrading of recovered carbon black, method-product relationship], Process engineering, Ecole des Mines d'Albi-Carmaux, 2018) [Non-Patent Document 4] H. Darmstadt et al., Carbon, 1995, Vol. 33, No. 10, p. 1449) Summary of the Invention [Means for solving the problem]

[0011] (Subject of the Invention) The present invention relates to a recovered carbon black (rCB) comprising carbon black, inorganic ash, and a carbon-based residue resulting from the decomposition of pneumatic tire rubber and / or elastomer residue, characterized in that in the recovered carbon black, the content of the carbon-based residue is determined as a percentage of the area of ​​the C1 peak measured by X-ray photoelectron spectroscopy, and is 1% or less of the area of ​​the C1 peak, and the percentage of the area of ​​the C1 peak is calculated with respect to the total area of ​​the C0 to C5 peaks.

[0012] According to one or more embodiments, the recovered carbon black comprises 50% to 98% by weight of elemental carbon, based on the total weight of the recovered carbon black.

[0013] According to one or more embodiments, the recovered carbon black contains elemental oxygen in an amount of 0.5% to 4% by weight, based on the total weight of the recovered carbon black.

[0014] According to one or more embodiments, the recovered carbon black comprises elemental hydrogen in an amount of 0.2% to 3% by weight, based on the total weight of the recovered carbon black.

[0015] According to one or more embodiments, the recovered carbon black contains elemental nitrogen in an amount of 0.05% to 1% by weight, based on the total weight of the recovered carbon black.

[0016] According to one or more embodiments, the recovered carbon black contains elemental sulfur in an amount of 0.5% to 6% by weight, based on the total weight of the recovered carbon black.

[0017] According to one or more embodiments, the recovered carbon black contains extracted volatile organic compounds in a content of 0.2% to 20% by weight, based on the total weight of the recovered carbon black.

[0018] According to one or more embodiments, the recovered carbon black contains inorganic ash in a content of 4% to 50% by weight, based on the total weight of the recovered carbon black.

[0019] According to one or more embodiments, the specific surface area of ​​the recovered carbon black is 30 to 150 m 2 / g.

[0020] According to one or more embodiments, the structure index of the recovered carbon black is determined by the OAN analysis method according to the standard ASTM D2414 and is between 55 and 110×10 -5 m 3 / kg.

[0021] According to one or more embodiments, the content of carbon-based residue is calculated as a percentage of the area of ​​the C1 peak, as measured by photoelectron spectroscopy, and is between 0.001% and 0.05% of the area of ​​the C1 peak, and the percentage of the area of ​​the C1 peak is calculated relative to the total area of ​​the C0 to C5 peaks.

[0022] Another subject relates to a method for the conversion of waste tires to obtain recovered carbon black (rCB) according to the invention, said method comprising at least the following steps: a) passing a waste tire based solid feedstock into a reaction zone to at least partially dissolve said solid feedstock in the presence of a liquid solvent comprising aromatic compounds and thermally decomposing said at least partially dissolved solid feedstock at a temperature of less than 400° C. and a pressure of less than 1.5 MPa; obtaining a gaseous effluent and a first liquid effluent comprising carbon black; a weight ratio of the liquid solvent to the solid feedstock is greater than 3 wt / wt; b) passing the first liquid effluent obtained in step a) into a filtering and washing zone in the presence of a washing solvent to obtain a cake of filtered and washed carbon black and a second liquid effluent; said step b) being carried out at a temperature of 55° C. to 95° C.; c) sending at least a portion of said gaseous effluent obtained at the conclusion of step a) and at least a portion of said second liquid effluent obtained at the conclusion of step b) into a fractionation zone; obtaining at least a hydrocarbon fraction; said hydrocarbon fraction having an aromatics content of more than 30% by weight relative to the total weight of said hydrocarbon fraction; and additionally comprising: - C5-C10 hydrocarbon compounds; the content is less than 20% by weight, based on the total weight of the hydrocarbon fraction; and - C40+ hydrocarbon compounds, the content of which is less than 5% by weight relative to the total weight of said hydrocarbon fraction; d) the hydrocarbon fraction obtained at the end of step c) is fed, at least in part, into the reaction zone as liquid solvent of step a); e) the filtered and washed carbon black cake obtained at the end of step b) is dried at a temperature between 50 and 200° C.; the carbon black is recovered.

[0023] According to one or more embodiments, step a) comprises the following substeps: a1) the solid feedstock and the liquid solvent are passed into a first stirred reactor; at least partially dissolving the solid feedstock; a2) The at least partially dissolved solid feedstock obtained at the end of step a1) is passed into a second stirred reactor; the solid feedstock is pyrolyzed at a temperature below 400° C. to obtain a liquid effluent containing carbon black particles in suspension.

[0024] According to one or more embodiments, the aromatics content of the hydrocarbon fraction is greater than 40% by weight, relative to the total weight of said fraction.

[0025] According to one or more embodiments, the content of C40+ hydrocarbon compounds in the hydrocarbon fraction is less than 3% by weight, relative to the total weight of said fraction.

[0026] Another subject of the invention relates to a recovered carbon black (rCB) obtained by a process for the conversion of waste tires comprising at least the following steps: a) passing a waste tire based solid feedstock into a reaction zone to at least partially dissolve said solid feedstock in the presence of a liquid solvent comprising aromatic compounds and thermally decomposing said at least partially dissolved solid feedstock at a temperature of less than 400°C and a pressure of less than 1.5 MPa; obtaining a gaseous effluent and a first liquid effluent comprising carbon black; a weight ratio of liquid solvent to solid feedstock greater than 3 wt / wt; b) passing the first liquid effluent obtained in step a) into a filtering and washing zone; obtaining a cake of filtered and washed carbon black in the presence of a washing solvent and a second liquid effluent; said step b) being carried out at a temperature between 55°C and 95°C; c) sending at least in part the gaseous effluent obtained at the end of step a) and at least in part the second liquid effluent obtained at the end of step b) into a fractionation zone; obtaining at least a hydrocarbon fraction having an aromatics content of more than 30% by weight relative to the total weight of said hydrocarbon fraction and additionally comprising: - C5-C10 hydrocarbon compounds, the content of which is less than 20% by weight, based on the total weight of the hydrocarbon fraction; and - C40+ hydrocarbon compounds, the content of which is less than 5% by weight relative to the total weight of said hydrocarbon fraction; d) the hydrocarbon fraction obtained at the end of step c) is fed, at least in part, into the reaction zone as liquid solvent of step a); e) The filtered and washed carbon black cake obtained at the end of step b) is dried at a temperature between 50 and 200° C. to recover the carbon black. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] (List of Drawings) FIG. 1 is a schematic representation of an embodiment for obtaining carbon black according to the invention.

[0028] FIG. 2 is a schematic representation of the process depicted in FIG. 1, showing the reaction zone and the filtration and washing zone of the process in greater detail.

[0029] Detailed Description of the Invention (1.Definition) A Cn hydrocarbon fraction is understood to mean a fraction containing hydrocarbons having n carbon atoms.

[0030] A Cn+ fraction is understood to mean a fraction which contains hydrocarbons having at least n carbon atoms.

[0031] The BET specific surface area is measured by nitrogen physical adsorption according to standard ASTM D3663-03, as described in Rouquerol F., Rouquerol J. and Singh K., “Adsorption by Powders & Porous Solids: Principles, Methodology and Applications”, Academic Press, 1999.

[0032] The CHNS-O elemental analysis is carried out in accordance with standard ASTM D5291, a method well known to those skilled in the art, which allows the rapid determination of the carbon (C), hydrogen (H), oxygen (O), nitrogen (N) and sulfur (S) content of organic and other types of materials, and is based on the complete combustion of an extracted analytical sample at 1000° C. under oxygen.

[0033] The content of carbon-based residues is evaluated by X-ray Photoelectron Spectroscopy (XPS) surface analysis techniques well known to those skilled in the art, in particular by accurate analysis of the spectrum associated with elemental carbon (C1 spectrum), which gives information about the chemical environment of the constituent C atoms of the rCB. In particular, the content of carbon-based residues is determined by the percentage of the area of ​​the C1 peak corresponding to a bond energy of about 284.8 / 285.6 eV, which is characteristic of C-C-H bonds of aliphatic structures or small aromatic compounds associated with the residue, calculated relative to the total area of ​​the C0-C5 peaks (C0 is the peak associated with the C-C-H bonds of the graphitic structure, while C2, C3, C4 and C5 are the bonds of CO, C=O, COOH and π-π, respectively). *(which is the peak assigned to the transition). The method for determining the content of carbon-based residues is described in the publication by Darmstadt H., Roy C. and Kaliaguine S.: “Characterization of pyrolytic carbon blacks from commercial tire pyrolysis plants”, Carbon, Volume 33, No. 10 (1995), pp. 1449-1455, but also in the publication by Bendida Sahouli, Silvia Blacher, Francois Brouers, Hans Darmstadt, Christian Roy and Serge Kaliaguine: “Surface morphology and chemistry of commercial carbon black and carbon black from vacuum pyrolysis of used tyres”, Fuel, Vol. 75, No. 10 (1996), pp. 1244-1250, or also in the article by Ludovic Moulin: Valorisation du noir de carbone recupere, relation procede-produit[Upgrading of recovered carbon black, process-product relationship]. engineering. Detailed in Ecole des Mines d'Albi-Carmaux, 2018.

[0034] Thermogravimetric analysis is a technique widely used and well known to those skilled in the art, just as for the determination of the water content, the content of volatiles and the ash content of rCB. The procedure used is derived from standard ISO 9924-2 and is mainly used for vulcanized and non-vulcanized mixtures. A first temperature increase from 25°C to 600°C under nitrogen makes it possible to measure the water content (weight loss in % between 25°C and 150°C) and the content of volatiles and / or pyrolyzable phases (weight loss between 150°C and 600°C). Following this first stage, the sample is then cooled to 400°C under nitrogen. A second temperature increase between 400°C and 950°C under air makes it possible to carry out the combustion of the carbon and to measure the amount of carbon (rCB and possible carbon-based residues). The final weight measured at the end of this procedure makes it possible to determine the content of inorganic matter. The method of this analysis is detailed in the publication by Norris, C., Hale, Mike and Bennett, M., "Pyrolytic carbon: Factors controlling in-rubber performance", Plastics, Rubber and Composites, Vol. 43 (2014), pp. 245-256.

[0035] (2. Recycled Carbon Black (rCB)) The recovered carbon black (rCB) according to the present invention comprises, and preferably consists of, carbon black (CB), inorganic ash, and carbon-based residue resulting from the decomposition of pneumatic tire rubber and / or elastomer residues associated with said pneumatic tire rubber, characterized in that the content of said carbon-based residue, determined as a percentage of the area of ​​the C1 peak measured by X-ray photoelectron spectroscopy, is 1% or less of said area of ​​the C1 peak, preferably 0.001% to 0.08% of the area, more preferentially 0.001% to 0.07% of the area, and even more preferentially 0.001% to 0.05% of the area, and said percentage of the area of ​​the C1 peak is calculated with respect to the total area of ​​the C0 to C5 peaks.

[0036] More specifically, the rCB comprises 50%-98% by weight, preferably 60%-90% by weight, and even more preferably 65%-85% by weight of elemental carbon based on the total weight of said rCB. Carbon content was assessed by CHNS-O elemental analysis.

[0037] More specifically, the rCB contains elemental oxygen in an amount between 0.2% and 4% by weight, preferably between 0.4% and 3% by weight, and even more preferably between 0.8% and 2.7% by weight, based on the total weight of the rCB.

[0038] More specifically, the rCB comprises elemental hydrogen in an amount of 0.2% to 3% by weight, preferably 0.4% to 2.5% by weight, and even more preferably 0.5% to 1.5% by weight, based on the total weight of the rCB.

[0039] More specifically, the rCB contains elemental nitrogen in an amount of 0.05% to 1% by weight, preferably 0.1% to 0.7% by weight, and even more preferably 0.15% to 0.4% by weight, relative to the total weight of the rCB.

[0040] More specifically, the rCB comprises elemental sulfur in an amount of 0.5% to 6% by weight, preferably 1.5% to 5% by weight, and even more preferably 2% to 3.5% by weight, based on the total weight of the rCB.

[0041] The carbon (C), hydrogen (H), oxygen (O), nitrogen (N) and sulfur (S) contents were determined by CHNS-O elemental analysis.

[0042] Under the effect of a specific heat treatment (for example by thermogravimetric analysis "TGA" up to 600 °C under nitrogen), these elements can be released from the rCB in the form of vaporized water or of volatile organic compounds (VOCs). The amount of extracted VOCs is also a characteristic of the rCB according to the invention. Advantageously, the content of extracted VOCs is between 0.2% and 20% by weight, preferably between 0.5% and 7% by weight, even more preferably between 0.5% and 4% by weight, relative to the total weight of the rCB.

[0043] The rCB according to the invention also contains inorganic ash. The inorganic ash is composed of at least the atomic element Si, predominantly present in the oxide form SiO2 (silica), and at least the element zinc, predominantly present in the oxide form ZnO (zinc oxide) and / or in the sulfide form ZnS (zinc sulfide), preferably in the sulfide form ZnS. The application of a specific heat treatment (at least 950°C under air, by TGA analysis) makes it possible to quantify the content of inorganic ash present in the rCB according to the invention. Thus, the content of inorganic ash is advantageously between 4% and 50% by weight, preferably between 8% and 40% by weight, even more preferably between 10% and 30% by weight, relative to the total weight of the rCB.

[0044] The rCB according to the invention may also contain other heteroelements with an elemental content of less than 1% by weight, preferably less than 0.5% by weight, and even more preferably less than 0.2% by weight, relative to the total weight of the rCB. Said heteroelements may be, for example, but not limited to, the elements Al, Ca, Mg, Cl, Fe, K, Br, Co, Ti and P. The measurement of the content of these elements may be carried out by X-ray fluorescence.

[0045] Advantageously, the specific surface area of ​​the rCB according to the invention, determined by nitrogen physisorption, is between 30 and 150 m 2 / g, preferably 50 to 90m 2 / g, and even more preferably 50 to 75 m 2 / g.

[0046] Advantageously, the structure index is determined by the OAN analysis method according to standard ASTM D2414 and is between 55 and 110 x 10 -5 m 3 / kg, preferably 55 to 90 × 10 -5 m 3 / kg.

[0047] The carbon black (CB) contained in the recovered carbon black (rCB) can include several grades of commercially available carbon black, utilized alone or as a mixture.

[0048] Recovered carbon black (rCB) can be obtained by a process for the conversion of waste tires, comprising at least the following steps: a) passing a waste tire based solid feedstock into a reaction zone; at least partially dissolving the solid feedstock in the presence of a liquid solvent comprising aromatic compounds and thermally decomposing the at least partially dissolved solid feedstock at a temperature of less than 400° C. and a pressure of less than 1.5 MPa; obtaining a gaseous effluent and a first liquid effluent comprising carbon black; a weight ratio of the liquid solvent to the solid feedstock is greater than 3 wt / wt; b) passing the first liquid effluent obtained in step a) into a zone for filtering and washing; obtaining a cake of filtered and washed carbon black in the presence of a washing solvent and a second liquid effluent; said step b) is carried out at a temperature between 55° C. and 95° C.; c) sending at least in part the gaseous effluent obtained at the end of step a) and at least in part the second liquid effluent obtained at the end of step b) into a fractionation zone; obtaining at least a hydrocarbon fraction having an aromatics content of more than 30% by weight relative to the total weight of said hydrocarbon fraction and additionally comprising: - C5-C10 hydrocarbon compounds; the content is less than 20% by weight, based on the total weight of the hydrocarbon fraction; and - C40+ hydrocarbon compounds, the content of which is less than 5% by weight relative to the total weight of said hydrocarbon fraction; d) the hydrocarbon fraction obtained at the end of step c) is fed, at least in part, into the reaction zone as liquid solvent of step a); e) the filtered and washed carbon black cake obtained at the end of step b) is dried at a temperature between 50 and 200° C.; the carbon black is recovered.

[0049] Unless otherwise stated, all the above variations and embodiments can be combined with each other.

[0050] 3. Method for Preparation of rCB Another subject of the invention is a process for the preparation of rCB according to the invention, starting from waste tires. Said process is a process for the conversion, and more particularly for the solvolysis of waste tires, which, with reference to FIG. 1, in combination with an embodiment according to the invention, comprises at least the following steps: a) a solid feedstock based on waste tires (100) is fed into a reaction zone (80); said solid feedstock is at least partially dissolved in the presence of a liquid solvent (760) comprising aromatic compounds and said at least partially dissolved solid feedstock is thermally decomposed at a temperature below 400°C, preferably between 365°C and 395°C, even more preferentially between 380°C and 395°C, and at a pressure below 1.5 MPa, preferably between 0.2 and 1.2 MPa, to obtain at least a gaseous effluent (310) and a first liquid effluent (320) comprising rCB according to the invention; the weight ratio of liquid solvent (760) to solid feedstock (100) is greater than 3 wt / wt; b) the liquid effluent (320) obtained in step a) is sent into a zone (40) for filtering and washing, in the presence of a washing solvent, to obtain a cake (430) of filtered and washed rCB according to the invention and a second liquid effluent (410); said step b) is carried out at a temperature between 55°C and 95°C, preferably between 60°C and 90°C, and even more preferentially between 65°C and 85°C; c) sending at least a part, preferably in its entirety, of said gaseous effluent (310) obtained at the end of step a) and at least a part, preferably in its entirety, of the second liquid effluent (410) obtained at the end of step b) into a fractionation zone (70); obtaining at least a hydrocarbon fraction (730) having an aromatics content of more than 30% by weight, preferably more than 40% by weight relative to the total weight of said hydrocarbon fraction, and comprising: - C5-C10 hydrocarbon compounds, the content of which is less than 20% by weight, preferably less than 10% by weight and more preferentially between 1% and 8% by weight, relative to the total weight of the hydrocarbon fraction (730); and - C40+ hydrocarbon compounds, the content of which is less than 5% by weight, preferably less than 3% by weight, more preferentially less than 1% by weight and even more preferentially less than 0.5% by weight, relative to the total weight of said hydrocarbon fraction (730); d) said hydrocarbon fraction (730) obtained at the end of step c) is fed, at least in part, into the reaction zone (80) as liquid solvent (760) of step a); e) the filtered and washed rCB cake (430) according to the invention obtained at the end of step b) is dried in a drying zone (50) at a temperature between 50° C. and 200° C., preferably for a period sufficient for the content of washing solvent in the dried cake to be less than 0.5% by weight relative to the total weight of said dried cake. Advantageously, the drying time is between 10 minutes and 36 hours, more preferentially between 1 hour and 15 hours; and the rCB (520) according to the invention is recovered.

[0051] According to an essential aspect of the process according to the invention, the use of such recycled hydrocarbon fraction, having a high content of aromatic compounds, a low content of C40+ compounds (vacuum residue) and a not too high content of C5-C10 hydrocarbon compounds (gasoline), as liquid solvent (760) in the reaction zone (80) (i.e. stage d) of the process according to the invention), while using a solvent / solid feed weight ratio of at least 3 wt / wt, preferably between 3 and 10 wt / wt and more preferentially between 4 and 7 wt / wt, allows a better dissolution and decomposition of the solid feed (100), thus making it possible to maximize the production of said rCB, while limiting the presence of carbon-based residues in said rCB.

[0052] The solid feedstock (100) used in the context of the present invention is advantageously based on tires resulting from the processing of waste tires which may come from any source, such as light vehicles (LV) or heavy goods vehicles (HGV). Said solid feedstock may advantageously be provided in the form of tire granules, i.e. in the form of particles having a size of less than 6 mm. Preferably, said solid feedstock (100) is substantially free of textile fibres and metal wires and / or crushed tire material, i.e. crushed tire chunks, with a characteristic size generally between 1 cm and 20 cm. Therefore, according to a preferred embodiment of the present invention, the solid feedstock (100) is sent into a pre-treatment unit (10) to remove the textile fibres and metal wires (110) from the solid feedstock (100). Such pre-treatment units are well known to those skilled in the art and may consist of various types of crushers (ie rotary shears, shredders, granulators, rechippers), magnetic separators, or alternatively vibrating screens, separation tables.

[0053] According to step a) of the conversion process, the rubber contained in the solid feedstock (100) is dissolved on contact with a liquid solvent (760) and then thermally decomposed. The source and composition of the liquid solvent (760) will be detailed below. Step a) is preferably carried out at a temperature below 400°C, preferably between 365°C and 395°C, and even more preferentially between 380°C and 395°C, and at a pressure below 1.5 MPa, preferably between 0.2 and 1.2 MPa. At the end of step a), at least a gaseous effluent (310) and a first liquid effluent (320) containing the rCB according to the invention, as well as optionally solids (210) contained in the waste tires, such as metal wires or textile fibers, are obtained, which are discharged and separated from the liquid effluent (320) obtained at the end of this step.

[0054] The first liquid effluent (320) containing the rCB according to the invention is then sent into a filtration and washing zone (40) (i.e. stage b) of the preparation method according to the invention) to recover a cake of filtered and washed rCB according to the invention (430) and a second liquid effluent (410). This stage is carried out at a temperature between 55°C and 95°C, preferably between 60°C and 90°C, and even more preferentially between 65°C and 85°C. In an embodiment according to the invention, the viscosity of the second liquid effluent (410), measured at 100°C, is less than 10 cP, preferentially less than 5 cP and even more preferentially less than 3 cP, as measured according to standard ASTM D3236.

[0055] The filtration and washing unit may comprise any device allowing the filtration of the particles of rCB according to the invention contained in the first liquid effluent (320). Such a device may for example be provided in the form of a rotary filter operating preferentially at temperatures between 55° C. and 95° C., preferably between 60° C. and 90° C., and even more preferentially between 65° C. and 85° C. During step b), the cake of rCB according to the invention is washed with a washing solvent.

[0056] In an embodiment according to the invention, the washing solvent used during step b) is a solvent (800) external to the process, as depicted in Figure 1. The solvent may be selected from toluene or xylene, preferably xylene.

[0057] In another embodiment according to the invention, the wash solvent used during step b) consists at least in part of the light fraction (720) obtained at the end of step c). More specifically, with reference to FIG. 2, a part of the light fraction (720) can be sent to the distillation column (90) via line (725). A complementary part (735) of the light fraction is sent out of the process according to the invention as an upgradeable product. At the outlet of the distillation column (90), a light fraction (910) containing aromatics is obtained, having an end point below 200° C., preferably below 150° C., which can be used at least in part as wash solvent for the filtration / washing zone (40). The heavier fraction (920) can be sent out of the process as an upgradeable product (920).

[0058] The filtered and washed rCB cake (430) according to the invention is passed into a drying unit (50) operating at a temperature between 50 and 200°C, preferably between 50 and 150°C, in order to recover the rCB (520) according to the invention (i.e. step e) of the process according to the invention). Advantageously, the vapour effluent (510) coming from the drying unit (50) containing the washing solvent is recycled into the washing / filtration unit (40).

[0059] According to the invention, the gaseous effluent (310) obtained at the end of step a) and the second liquid effluent (410) obtained at the end of step b) are sent to a fractionation unit (70) (i.e. step c) of the process according to the invention) to obtain at least a hydrocarbon fraction (730) having an aromatics content of more than 30% by weight relative to the total weight of said hydrocarbon fraction (730) and additionally comprising at least: - C5-C10 hydrocarbon compounds, the content of which is less than 20% by weight, preferably less than 10% by weight and more preferentially between 1% and 8% by weight, relative to the total weight of the hydrocarbon fraction (730); and - C40+ hydrocarbon compounds; the content is less than 5% by weight, preferably less than 3% by weight, more preferentially less than 1% by weight and even more preferentially less than 0.5% by weight, relative to the total weight of said hydrocarbon fraction (730).

[0060] Advantageously, the hydrocarbon fraction (730) also comprises C10-C20 hydrocarbon compounds in a content ranging from 20% to 65% by weight, preferably from 30% to 65% by weight and even more preferentially from 45% to 65% by weight, relative to the total weight of the hydrocarbon fraction.

[0061] Advantageously, the hydrocarbon fraction (730) also comprises C20-C40 hydrocarbon compounds in a content ranging from 30% to 80% by weight, preferably from 30% to 70% by weight and even more preferentially from 30% to 55% by weight relative to the total weight of the hydrocarbon fraction.

[0062] Advantageously, the initial boiling point of the hydrocarbon fraction (730) is between 50°C and 325°C, preferably between 50°C and 250°C, and the end point is between 350°C and 520°C, preferably between 350°C and 450°C.

[0063] Advantageously, the fractionation zone (70) also makes it possible to obtain non-condensable gases (710), a light fraction (720) having an end point preferentially between 250°C and 325°C, and a heavy fraction (740) having an initial boiling point preferentially between 350°C and 450°C.

[0064] Advantageously, the light fraction (720) can be sent, at least in part, as a washing solvent into a washing and filtration zone (40) to obtain a filtered and washed rCB cake (430) according to the invention.

[0065] Advantageously, the light fraction (720) comprises a content of C10-hydrocarbon compounds greater than 60% by weight relative to the total weight of the light fraction (720).

[0066] Advantageously, the heavy fraction (740) comprises a content of C40+ hydrocarbon compounds greater than 60% by weight relative to the total weight of the heavy fraction (740).

[0067] According to the invention, a portion of the hydrocarbon fraction (730) is sent, at least in part, as liquid solvent (760) to the reaction zone (80) of step a), while the other portion (750) is advantageously sent outside the process according to the invention as an upgradeable product. The weight ratio of the liquid solvent (760) to the stream of solid feedstock (100) injected into the reaction zone (80) is greater than or equal to 3 weight / weight (w / w), preferentially between 3 and 10 weight / weight, more preferentially between 4 and 7 weight / weight. In particular, one of the characteristics of the liquid solvent (760) is that it contains aromatic compounds in a content of more than 30% by weight relative to the total weight of said liquid solvent (760), which makes it possible to efficiently dissolve the solid feedstock (100) and to efficiently reduce the viscosity of the reaction medium in the reaction zone (80). Another advantage of the process according to the invention is that the use of such a solvent makes it possible to remain in liquid form while limiting the pressure in the reactor to a level below 1.5 MPa, taking into account the limited production of gas and light hydrocarbons in the reaction zone (80) and the low content of C10-hydrocarbon compounds in the hydrocarbon fraction (730).

[0068] In order to better understand the invention, the description given below (as an applicable example) concerns a method for the conversion of waste tires, which makes it possible to maximize the production of rCB while limiting the presence of carbon-based residues in said rCB. With reference to FIG. 2, the solid feedstock (100) is sent into a pre-treatment unit (10) to remove textile fibers and metal wires (110) from the solid feedstock (100). The solid feedstock, which is substantially free of textile fibers and metal wires, is then sent into a reaction zone (80). The reaction zone (80) allows the thermal decomposition of the waste tires and includes a first stirred reactor (20). The first stirred reactor (20) is fed with a liquid solvent (760) and has the purpose of promoting the dissolution of tire granules or ground tire material contained in the solid feedstock (100). The liquid solvent / solid feedstock weight ratio is greater than or equal to 3 wt / wt, preferably between 3 and 10 wt / wt, more preferentially between 4 and 7 wt / wt. The temperature in the reactor (20) is preferentially between 200°C and 300°C, preferentially between 250°C and 290°C. In the first stirred reactor (20), the ground material or granules are dissolved. The time required to carry out this dissolution is preferentially between 30 minutes and 2 hours. The rubber chunks and the future rCB according to the invention, which are gradually released from the rubber, remain in suspension by mechanical or hydrodynamic stirring. This stirring is induced, for example, by an upward liquid flow resulting from a forced convection recirculation or by any other means making it possible to keep the medium in a stirred state. The metal wires, which may still be present in the solid feedstock and would not have been dissolved, precipitate and leave the base of the first stirred reactor (20) through a line (210). Under such circumstances, the temperature is too low to initiate significant carbon-carbon decomposition reactions, and only the cross-links between polymers, such as the S--S bonds associated with the vulcanization of rubber, are substantially decomposable.The resulting liquid fraction (220), containing the residual solids in suspension, is directed to a second stirred reactor (30), where the thermal decomposition reaction is carried out under mild temperature conditions, i.e. at temperatures below 400°C, preferably between 365°C and 395°C, even more preferentially between 380°C and 395°C, and for a limited time (corresponding to the residence time of the liquid fraction in the reactor (30)), preferentially between 30 minutes and 2 hours, preferentially between 45 minutes and 90 minutes. The amount of heat required to carry out the thermal decomposition reaction can be provided by an exchanger located on the pumparound (not shown in the figure) around the second stirred reactor (30) or by any other means, such as an exchanger in the wall of the reactor or an oven on the feedstock upstream of the reactor. The stirring in the second stirred reactor (30) is maintained by a mechanical stirring system or by a pumparound system or by any other means known to the person skilled in the art. Preferentially, the pressure in the reactor is maintained at a level below 1.5 MPa by a control valve (not shown in the figure).

[0069] At the end of the reaction in the second stirred reactor (30), a first liquid effluent (320) containing in suspension particles of the rCB according to the invention and a gaseous effluent (310) are obtained. The first liquid effluent (320) is then sent into a filtration and washing zone (40), which comprises a rotary filter (41) and an intermediate fractionation unit (42) (see FIG. 2). The rotary filter (41) is preferentially operated at a temperature between 50° C. and 200° C., which makes it possible to obtain a cake of the rCB according to the invention and a liquid fraction (425). The cake is then washed with a washing solvent (800), for example toluene or xylene, preferably xylene, at a temperature between 55° C. and 95° C., preferably between 60° C. and 90° C., even more preferentially between 65° C. and 85° C., which makes it possible to recover the filtered and washed rCB according to the invention (430). After the filtration / washing stage, the wash stream (405) is sent into an intermediate fractionation unit (42) to obtain a fraction (610) (which can be at least partially recycled by a line upstream of the rotary filter (41) as supplementary wash solvent) and a fraction (415) which can be sent together with the liquid portion (425) into the fractionation zone (70) as a second liquid effluent (410). The filtered and washed rCB (430) according to the invention is then sent into a drying unit (50), which is operated at a temperature between 50° C. and 200° C. and for a period sufficient for the content of wash solvent in the dried cake to be less than 0.5% by weight relative to the total weight of said dried cake. The filtered, washed and dried rCB (520) according to the invention is then advantageously pelletized (granulated) with water to form pellets of a few millimeters, for example to facilitate its transportation and its upgrading. The rCB thus produced can again be used, for example, as a reinforcing agent in the elastomer industry or as a pigment for other applications in inks, plastics or paints, after subsequent processing steps and packaging steps of the material depending on the use and application.The remaining washing solvent may be recovered at the outlet of the drying unit (50) and may be at least partially recovered via line (510).

[0070] The gaseous effluent (310) leaving the reaction zone (80) via the second reactor (30) and the second liquid effluent (410) coming from the washing / filtration zone (40) are then directed to a fractionation zone (70), which may consist of a heat exchanger, a gas-liquid separator drum, a distillation column containing a top draw, a bottom draw and a side draw, or a series of several distillation columns, for example a series of distillation columns with a top draw and a bottom draw at atmospheric pressure followed by a distillation column operating under low vacuum. This fractionation zone (70) makes it possible in particular to obtain a hydrocarbon fraction (730) which comprises aromatic compounds in a content of more than 30% by weight, preferentially more than 40% by weight, relative to the total weight of said hydrocarbon fraction (730), and which additionally comprises: - C5-C10 hydrocarbon compounds, the content of which is less than 20% by weight, preferably less than 10% by weight and more preferentially between 1% and 8% by weight, relative to the total weight of the hydrocarbon fraction (730); and - C40+ hydrocarbon compounds, the content of which is less than 5% by weight, preferably less than 3% by weight, more preferentially less than 1% by weight and even more preferentially less than 0.5% by weight, relative to the total weight of said hydrocarbon fraction (730); At least a portion of it can be recycled into the reaction zone (80) as liquid solvent (760) and another portion (750) can be upgraded as a product. Preferably, the hydrocarbon fraction is sent as liquid solvent into the first reactor (20) of the reaction zone (80).

[0071] This fractionation zone (70) also makes it possible to obtain non-condensable gases (710), a light fraction (720) having an end point preferentially between 250° C. and 325° C., and a heavy fraction (740) having an initial boiling point preferentially between 350° C. and 450° C. Advantageously, the light fraction (720) is sent, at least in part, as washing solvent into the washing and filtering device (41) of the washing and filtering zone (40) to obtain the filtered and washed rCB cake (430) according to the invention.

[0072] During the start-up of the plant, it is possible to use a temporary externally imported solvent in the absence of the production of a stable middle distillate, i.e. a hydrocarbon fraction (730), which will be composed preferentially of aromatic molecules with a content of more than 40% by weight relative to the total weight of this fraction. This fraction can therefore be composed, for example, of a conversion effluent from a process for the FCC (Fluid Catalytic Cracking) catalytic cracking of middle distillates (light cycle oil (LCO)) or heavy distillates (heavy cycle oil (HCO)).

[0073] (Example) The following examples illustrate preferred embodiments of the method according to the invention and the production of rCB, but do not limit the scope of the invention. The method used to illustrate the invention corresponds to that described in FIG.

[0074] Example 1 (in accordance with the present invention) In a first example according to the invention, use is made of waste tire granules (solid feedstock), which are produced by a granulator using a grinder. They come from heavy load vehicle tires and the granules resulting from the grinding have a size of the region of 2 millimeters. The tire granules come from the pre-treatment unit (10) and are free of textiles and metal wires. The granules are then continuously sent into a dissolution reactor where they are mixed with a liquid solvent resulting from the recycling of the hydrocarbon fraction (730) from the fractionation zone (70). A portion of the hydrocarbon fraction (730) is used as liquid solvent (760). Its composition is shown in table 1 below. The amount of solid feedstock treated is 100 kg / h. The amount of solvent recycled into the reactor (20) is 500 kg / h, which corresponds to a weight ratio of solvent / granules equal to 5 w / w. In the reactor (20), the temperature is maintained equal to 290° C., which makes it possible to dissolve the granules. The liquid part and the future rCB in suspension are then directed to the reactor (30), where the temperature is maintained equal to 385° C. for 1 hour. At the outlet of the reactor (30), a first liquid effluent (320) and a gaseous effluent (310) are recovered, the gaseous effluent (310) being sent in its entirety to the fractionation zone (70). The first liquid effluent (320) is sent to a rotary filter (41) operating at 80° C. Washing of the filtered rCB is carried out with xylene at a temperature of 80° C. The second liquid effluent (410), collected at the outlet of the washing and filtration zone (40), is sent in its entirety to the fractionation zone (70). The filtered, washed rCB (430) is sent into a drying unit (50) operating at 150° C. for 24 hours, which makes it possible to recover the filtered, washed and dried rCB (520).

[0075] (Example 2 (not in accordance with the present invention)) In Example 2, which is not in accordance with the present invention, the conversion process steps and operating conditions are identical to those of Example 1, except for the content of C40+ hydrocarbon compounds (vacuum residues, or VR) in the liquid solvent (760), which is outside the scope of the present invention, and for the step of washing the recovered carbon black (rCB), which is carried out at a temperature of 50° C.

[0076] The operating conditions for Examples 1 and 2 are summarized in Table 1 below.

[0077] [Table 1]

[0078] The main characteristics of the rCB obtained according to Examples 1 and 2 are summarized in Tables 2 and 3 below.

[0079] [Table 2]

[0080] [Table 3]

[0081] [Brief description of the drawings]

[0082] [Figure 1] 1 is a schematic representation of an embodiment for obtaining carbon black according to the present invention. [Diagram 2] FIG. 2 is a schematic representation of the process depicted in FIG. 1, showing the reaction zone and the filtration and washing zone of the process in more detail.

Claims

1. Recovered carbon black (rCB) comprising carbon black, inorganic ash, and carbon-based residue resulting from the decomposition of pneumatic tire rubber and / or elastomer residue, wherein the content of the carbon-based residue is measured by X-ray photoelectron spectroscopy. １ The percentage of the peak area is calculated, C １ The area of ​​the peak is less than 1%, and C １ The aforementioned percentage of the peak area is C ０ ~C ５ A recovered carbon black characterized by being calculated based on the total area of ​​the peak.

2. The recovered carbon black according to claim 1, characterized in that it contains elemental carbon in an amount of 50% to 98% by weight relative to the total weight of the recovered carbon black.

3. The recovered carbon black according to claim 1, characterized in that it contains elemental oxygen in an amount of 0.2% to 4% by weight relative to the total weight of the recovered carbon black.

4. The recovered carbon black according to claim 1, characterized in that it contains elemental hydrogen in an amount of 0.2% to 3% by weight relative to the total weight of the recovered carbon black.

5. The recovered carbon black according to claim 1, characterized in that it contains elemental nitrogen in an amount of 0.05% to 1% by weight relative to the total weight of the recovered carbon black.

6. The recovered carbon black according to claim 1, characterized in that it contains elemental sulfur in an amount of 0.5% to 6% by weight relative to the total weight of the recovered carbon black.

7. The recovered carbon black according to claim 1, characterized in that it contains extracted volatile organic compounds at a content of 0.2% to 20% by weight relative to the total weight of the recovered carbon black.

8. The recovered carbon black according to claim 1, characterized in that the inorganic ash content is 4% to 50% by weight relative to the total weight of the recovered carbon black.

9. The specific surface area is 30 to 150 m². ２ The recovered carbon black according to claim 1, characterized in that it is / g.

10. The structural index is determined by the OAN analysis method in accordance with standard ASTM D2414, and ranges from 55 to 110 × 10⁻¹⁰. －５ I understand ３ The recovered carbon black according to claim 1, characterized in that it is / kg.

11. The content ratio of the carbon-based residue is C １ calculated as a percentage of the area of the １ peak and measured by photoelectron spectroscopy, and is 0.001% to 0.05% of the area of the １ peak, and the percentage of the area of the ０ to ５ peak is calculated with respect to the total area of the peaks. The recovered carbon black according to claim 1, characterized in that.

12. A method for converting waste tires to obtain recovered carbon black (rCB) according to any one of claims 1 to 11, the method comprising at least the following steps: a) A step of sending a solid feed material (100) based on waste tires into a reaction zone (80), dissolving the solid feed material at least partially in the presence of a liquid solvent (760) containing aromatic compounds, and thermally decomposing the at least partially dissolved solid feed material at a temperature of less than 400°C and a pressure of less than 1.5 MPa; A gaseous effluent (310) and a first liquid effluent (320) containing carbon black are obtained; the weight ratio of the liquid solvent (760) to the solid feed material (100) is greater than 3 by weight / weight; b) The first liquid effluent (320) obtained in step a) is sent into a zone for filtration and washing (40) in the presence of a washing solvent; a cake-like substance of filtered and washed carbon black (430) and a second liquid effluent (410) are obtained; the temperature during step b) is 55°C to 95°C; c) A step of sending at least a portion of the gaseous effluent (310) obtained at the end of step a) and at least a portion of the second liquid effluent (410) obtained at the end of step b) into the fractionation zone (70); obtaining at least a hydrocarbon fraction (730); the hydrocarbon fraction (730) containing aromatic compounds at a concentration of more than 30% by weight relative to the total weight of the hydrocarbon fraction; and additionally containing: - C5-C10 hydrocarbon compounds; their content is less than 20% by weight of the total weight of the hydrocarbon fraction; and - C40+ hydrocarbon compounds; their content is less than 5% by weight of the total weight of the hydrocarbon fraction; d) A step in which at least a portion of the hydrocarbon fraction (730) obtained at the end of step c) is introduced into the reaction zone (80) as the liquid solvent (760) of step a); e) A step in which the filtered and washed carbon black cake (430) obtained at the end of step b) is dried at a temperature of 50 to 200°C; carbon black is recovered.

13. Step a) is the method according to claim 12, comprising the following sub-steps: a1) The solid feed material (100) and the liquid solvent (760) are sent into the first stirred reactor (20) to dissolve the solid feed material (100) at least partially; a2) The at least partially dissolved solid feed material obtained at the end of step a1) is sent into a second stirred reactor (30), where the solid feed material is thermally decomposed at a temperature of 400°C or less, and a liquid effluent containing suspended carbon black particles is obtained.

14. The method according to claim 12, wherein the content of aromatic compounds in the hydrocarbon fraction (730) is more than 40% by weight relative to the total weight of the fraction.

15. The method according to claim 12, wherein the content of the C40+ hydrocarbon compound in the hydrocarbon fraction (730) is less than 3% by weight of the total weight of the fraction.

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