RECOVERED CARBON BLACK OBTAINED BY TIRE SOLVOLYSIS

Abstract

Recovered carbon black (rCB) comprising carbon black, inorganic ash, and carbonaceous residues from the decomposition of tire rubber and / or elastomeric residues, characterized in that said carbonaceous residue content, determined with respect to the percentage area of ​​peak C1 measured by X-ray photoelectron spectroscopy, is less than or equal to 1% of said peak area C1, said percentage area of ​​peak C1 being calculated with respect to the total area of ​​peaks C0 to C5. No figure to be published for the abstract.

Description

Title of the invention: RECOVERED CARBON BLACK OBTAINED BY SOLVOLYSIS OF TIRES Field of invention

[0001] The present invention relates to the field of carbon materials of the carbon black type, in particular to so-called "recovered" carbon blacks (or rCB for "recovered carbon black" according to the English terminology) obtained by thermochemical transformation of end-of-life tires. It also relates to a process for preparing these rCBs via a process of solvolysis of used tires with recycling of a hydrocarbon fraction comprising aromatic compounds. State of the art

[0002] Tires are mainly made of rubbers for their elastic property (mixture of elastomers of crosslinked natural and synthetic rubber type, added with additives of the silica, resin, sulfur, zinc oxide, carbon black, etc. type) and textile and metallic fibers for their reinforcing property. Carbon blacks (or CB for "Carbon Black" according to Anglo-Saxon terminology) are in particular used in the formulations of rubbers to improve the resistance of the latter (in terms of solidity and lifespan), to limit the deformation of the tires during use and to facilitate heat transfer between the tires and the ground during rolling. They are generally obtained by incomplete combustion of hydrocarbons or vegetable oils and there are more than 35 grades, marketed and used as filler (essentially for the formulation of pneumatic rubbers).Their quality differs depending on their intrinsic properties.

[0003] Most carbon blacks are characterized by high elemental carbon contents (> 90% by weight relative to the total weight of the carbon black) and may contain other chemical elements such as hydrogen, oxygen, nitrogen and sulfur which are chemically bonded to the carbon. They are generally in the form of black powders consisting of elementary graphitic particles (more or less well crystallized) and quasi-spherical (10 to 500 nm), forming aggregates (100 to 1000 nm) which can themselves come together in the form of agglomerates (100 μm), the whole then being able to be transformed into granules (0.1 to 1 mm). The size of elementary particles and the structure of objects (morphology, size, density / aeration of aggregates / agglomerates) will largely impact the capacity of carbon blacks to disperse in an elastomer matrix and therefore, ultimately, the reinforcement properties of the latter within a tire.The "specific surface" parameter (or SBetX determined by nitrogen physisorption, is characteristic of the size of the particles. supplementary and provides information on the surface of the carbon black potentially in interaction with the elastomer matrix. The structure of a carbon black is characterized by its ability to develop porosity capable of being filled by a paraffinic oil, and therefore ultimately by an elastomer matrix. A structure index, equivalent to an oil adsorption index, is then determined, the associated analytical method being the OAN method for "Oil Adsorption Number" according to Anglo-Saxon terminology. Each carbon black is then associated with an acronym of the type NXYZ, where X is a number characteristic of the SBet of the carbon black and Y and Z are numbers designated arbitrarily according to the observed structure. In summary, there is a SBet / OAN structure index relationship which makes it possible to classify the various carbon blacks according to their grade and their reinforcing or non-reinforcing character.For example, carbon blacks NI 10, N120 and N234, very good reinforcing additives, are characterized by a high specific surface area and structure index. Depending on their intrinsic properties, carbon blacks will be used to formulate different rubbers, themselves used in the different constituent elements of a tire.

[0004] When recycled, tires are generally initially crushed to obtain either tire shreds still containing a portion of the textile and metal fibers (typically pieces of 1 to 10 cm), or aggregates (generally of dimensions less than 6 mm) free of all fibers. It is then possible to convert them into gaseous, liquid and solid fractions via thermal decomposition conversion processes. The solid fraction obtained is mainly made up of various grades of carbon blacks in a mixture, with the addition of inorganic ash (mainly silica type and Zn-based compounds). Furthermore, the thermal decomposition of the “elastomer” fraction generates carbon compounds of various natures (various decomposition products possibly recondensed) likely to be deposited on the surface of the carbon blacks.Similarly, depending on the operating conditions of said processes, non-decomposed elastomer polymer chains can adsorb on the surface. For a given conversion process applied to a specific “used tire” load, the rCB then represents the entire solid fraction consisting of the initial carbon blacks in a mixture and modified on the surface by various carbonaceous deposits (decomposition products and / or elastomer residues), as well as inorganic ash. The intrinsic properties of an rCB are therefore a function of the elements that constitute it. In particular, the chemical composition of the rCBs, the agglomeration rate of the aggregates and their structure, and consequently the redispersion properties of the rCBs in an elastomer matrix, can be drastically modified compared to those of the initial carbon blacks depending on the composition of the treated end-of-life tires (choice of load) and the . recycling process envisaged.

[0005] Among the possible thermal decomposition conversion processes for the treatment of end-of-life tires, pyrolysis processes are very frequently encountered (J. Yu et al., Frontiers of Environmental Science & Engineering, 2020, 14, 2, 7982; S. Q. Li et al., Ind. Eng. Chem. Res. 2004, 43, 5133; EP2661475). They usually consist of exposing the tires to temperatures between 350°C and 800°C in the absence of oxygen, or in the presence of a very small quantity of oxygen or air designed to provide, by very partial combustion, the energy necessary for the pyrolysis process. The latter is carried out at atmospheric pressure of the gas(es) considered or sometimes under vacuum, so as to minimize the secondary post-degradation reactions of the tire rubbers which frequently lead to the formation of residual carbon deposits on the surface of the final rCB already mentioned.The technologies implemented are multiple, such as the use of fixed-bed reactors, moving-bed reactors, rotary kiln reactors, etc. The yields of these processes in rCB are very variable (between 25 and 60% approximately) and the same is true for the intrinsic properties of the latter (for example, the residual inorganic ash content can vary from 8 to 41% by weight). On the other hand, the rCB obtained post-pyrolysis (also frequently called "pCB") are all characterized by the significant presence of carbonaceous deposits on the surface of the initial carbon blacks. These are characterized in particular using the X-ray Photoelectron Spectroscopy (XPS) surface analysis technique, also called ESCA ("Electron Spectroscopy for Chemical Analysis" in English terminology). Firstly, this surface analysis makes it possible to define the elementary chemical composition of a material and thus determine the contents present in C, O, N, S, Si, Al, Zn, etc.In a second step, the precise analysis of the spectrum associated with the carbon element (Cls spectrum) provides information on the chemical environment of the carbon atoms constituting the rCB (Ludovic Moulin thesis: Valorization of recovered carbon black, process-product relationship. Process engineering. Ecole des Mines d'Albi-Carmaux, 2018). In particular, it makes it possible to distinguish the carbon associated with the initial carbon blacks (Co peak corresponding to a binding energy of approximately 284.2 / 284.8 eV, characteristic of CC / CH bonds of a graphitic structure) from that relating to the carbon compounds likely to be deposited on the surface (Ci peak corresponding to a binding energy of approximately 284.8 / 285.6 eV, characteristic of CC / CH bonds of aliphatic structures or small aromatic compounds, associated here with the carbon deposits formed during the pyrolysis processes).Thus, the pCBs present carbon deposit contents, evaluated in % of area by XPS, between 5% and 40% (calculation based on the total area of ​​the Co and Ci peaks previously described and the C2, C3, C4 and C5 peaks respectively attributed to the CO, C=O, COOH bonds and to the jt-jt* transitions). These carbon deposits. are largely responsible for the agglomeration phenomena linking the various structures of rCBs at different scales: the solid leaving the reactor is often present in the form of blocks of several millimeters / centimeters which must then be finely ground in order to reuse it (in particular as an adjuvant for the formulation of new gums), which requires significant energy expenditure. It should be noted that these carbon deposits seem to be strongly linked to the surface of the initial carbon blacks since even post-thermal treatments at higher temperatures than the pyrolysis process itself are not sufficient to eliminate them (change from 40% to 20% of the area of ​​the Ci peak for a post-pyrolysis heat treatment at 600°C: H. Darmstadt et al., Carbon, 1995, 33, 10, 1449).

[0006] To limit the formation of carbonaceous deposits on the rCB, it is possible to lower the partial pressure of hydrocarbons by injecting steam during the cracking reactions (steam thermolysis processes). Unfortunately, the high temperature conditions generally applied (often above 500°C), still lead to the formation of carbonaceous deposits, although in limited proportions (from 5 to 6% of the peak area in Ci). Furthermore, these gas-solid processes have other disadvantages. Indeed, they generally induce high production of incondensable gases (in atmospheric conditions), often between 10% and 25% by weight relative to the load of used tires entering the reactor, which is to the detriment of the quantity of liquid products that can potentially be recovered and easily used.In fact, these liquid fractions can be used to produce new hydrocarbon cuts (naphtha, gasoline, kerosene, diesel, vacuum distillate, residues), used in refineries to produce fuels or in petrochemicals to produce bases which are then used to make plastics.

[0007] Another interesting alternative route for limiting the presence of these carbonaceous deposits on an rCB consists of bringing the tire fillers into contact with a liquid under suitable operating conditions (in particular temperature) and dissolving and converting the tires in a homogeneous liquid phase in which the tire filler would be agitated and would gradually disappear. US patents 3,978,199 and US 3,704,108 disclose processes for converting used tires comprising a step of dissolving the solid filler based on used tires in the presence of a solvent corresponding to a recycle of the heavy liquid fraction of the filtrate obtained after distillation, comprising compounds rich in aromatics (preferably mono-aromatics).Unfortunately, the conditions for implementing such processes, and more particularly the choice of a heavy liquid fraction as solvent, are not favorable to the non-formation of carbon deposits contained in the final rCB.

[0008] The Applicant has developed a new process for converting used tires making it possible to obtain a so-called "recovered" carbon black (rCB) comprising a very low content of carbon residues (decomposition products of tire rubbers and / or elastomer residues), thereby also limiting the agglomeration phenomena of the various structures of the rCB usually encountered during the processes implemented in the literature. Said process consists of recycling a load of used tires at a temperature less than or equal to 400°C and at a pressure less than 1.5 MPa, by bringing said load into contact with a solvent consisting of at least one hydrocarbon cut comprising a content rich in aromatic compounds, poor in C40+ compounds (vacuum residues) and a moderate content of C5-C10 hydrocarbon compounds (gasoline), said solvent possibly being derived from the process itself (recycle).The said process is also characterized by a mass ratio between the liquid solvent and the specific charge, i.e. by a mass ratio greater than 3 weight / weight. The operating conditions, the composition of the hydrocarbon cut and the solvent / solid charge mass ratio as defined make it possible to maximize the production of rCB via better dissolution / decomposition of the solid charge while limiting the presence of carbon residues in the final rCB. In addition, such a process limits the formation of gas to contents between 1 and 7% by weight of the charge to be treated. Objects of the invention

[0009] The present invention relates to a recovered carbon black (rCB) comprising carbon black, inorganic ash, and carbon residues from the decomposition of tire rubbers and / or elastomer residues, characterized in that said content of carbon residues, determined relative to the percentage area of ​​peak Ci measured by X-ray photoelectron spectroscopy, is less than or equal to 1% of said area of ​​peak Ci, said percentage area of ​​peak Ci being calculated relative to the total area of ​​peaks Co to C5.

[0010] According to one or more embodiments, said recovered carbon black comprises between 50% and 98% by weight of carbon element relative to the total weight of said recovered carbon black.

[0011] According to one or more embodiments, said recovered carbon black comprises between 0.5 and 4% by weight of oxygen element relative to the total weight of said recovered carbon black.

[0012] According to one or more embodiments, said recovered carbon black comprises between 0.2 and 3% by weight of hydrogen element relative to the total weight of said recovered carbon black.

[0013] According to one or more embodiments, said recovered carbon black comprises between 0.05 and 1% by weight of nitrogen element relative to the total weight of said recovered carbon black.

[0014] According to one or more embodiments, said recovered carbon black comprises between 0.5 and 6% by weight of sulfur element relative to the total weight of said recovered carbon black.

[0015] According to one or more embodiments, said recovered carbon black comprises a content of extracted volatile organic compounds of between 0.2 and 20% by weight relative to the total weight of said recovered carbon black.

[0016] According to one or more embodiments, said recovered carbon black comprises an inorganic ash content of between 4 and 50% by weight relative to the total weight of said recovered carbon black.

[0017] According to one or more embodiments, said recovered carbon black comprises a specific surface area of ​​between 30 and 150 m2 / g.

[0018] According to one or more embodiments, said recovered carbon black comprises a structure index, determined by the OAN analytical method in accordance with ASTM D2414, of between 55 and 110.105 mVkg.

[0019] According to one or more embodiments, said content of carbon residues, calculated relative to the % area of ​​the peak Ci measured by photoelectron spectroscopy, is between 0.001% and 0.05% of the area of ​​the peak Ci, said percentage of area of ​​the peak Ci being calculated relative to the total area of ​​the peaks Co to C5.

[0020] Another subject relates to a process for converting used tires to obtain recovered carbon black (rCB) according to the invention, said process comprising at least the following steps:

[0021] a) a solid charge based on used tires is sent into a reaction zone in the presence of a liquid solvent comprising aromatic compounds to at least partially dissolve said solid charge and thermally decompose said at least partially dissolved solid charge at a temperature below 400°C and at a pressure below 1.5 MPa in order to obtain a gaseous effluent and a first liquid effluent comprising carbon black, the mass ratio between the liquid solvent and the solid charge being greater than 3 weight / weight;

[0022] b) the first liquid effluent obtained in step a) is sent to a filtration and washing zone in the presence of a washing solvent in order to obtain a filtered and washed carbon black cake and a second liquid effluent, said step b) being carried out at a temperature between 55°C and 95°C;

[0023] c) at least part of said gaseous effluent obtained at the end of step a) and at least part of the second liquid effluent obtained at the end of step b) are sent to a fractionation zone to obtain at least one hydrocarbon fraction comprising a content of aromatic compounds greater than 30% by weight relative to the total weight of said hydrocarbon fraction, and further comprising:

[0024] - a content of C5-C10 hydrocarbon compounds of less than 20% by weight per relative to the total weight of the hydrocarbon fraction; and

[0025] - a content of C40+ hydrocarbon compounds of less than 5% by weight relative to to the total weight of said hydrocarbon fraction;

[0026] d) at least a portion of said hydrocarbon fraction obtained at the end of step c) is sent to the reaction zone as liquid solvent for step a);

[0027] 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.

[0028] According to one or more embodiments, step a) comprises the following sub-steps:

[0029] al) said solid charge and said liquid solvent are sent into a first stirred reactor to at least partially dissolve said solid charge;

[0030] a2) said at least partly dissolved solid charge obtained at the end of step al) in a second stirred reactor to thermally decompose said solid charge at a temperature less than or equal to 400°C and obtain a liquid effluent containing suspended carbon black particles.

[0031] According to one or more embodiments, the content of aromatic compounds in the hydrocarbon fraction is greater than 40% by weight relative to the total weight of said fraction.

[0032] 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.

[0033] Another subject matter of the invention relates to a recovered carbon black (rCB) obtained by a process for converting used tires comprising at least the following steps:

[0034] a) a solid charge based on used tires is sent into a reaction zone in the presence of a liquid solvent comprising aromatic compounds to at least partially dissolve said solid charge and thermally decompose said at least partially dissolved solid charge at a temperature below 400°C and at a pressure below 1.5 MPa in order to obtain a gaseous effluent and a first liquid effluent comprising carbon black, the mass ratio between the liquid solvent and the solid charge being greater than 3 weight / weight;

[0035] b) the first liquid effluent obtained in step a) is sent to a filtration and washing zone in the presence of a washing solvent in order to obtain a filtered and washed carbon black cake and a second liquid effluent, said step b) being carried out at a temperature between 55°C and 95°C;

[0036] c) at least part of said gaseous effluent obtained at the end of step a) and at least part of the second liquid effluent obtained at the end of step b) are sent to a fractionation zone to obtain at least one hydrocarbon cut comprising an aromatic compound content greater than 30% by weight relative to the total weight of said hydrocarbon fraction, and further comprising:

[0037] - a content of C5-C10 hydrocarbon compounds of less than 20% by weight per relative to the total weight of the hydrocarbon fraction; and

[0038] - a content of C40+ hydrocarbon compounds of less than 5% by weight relative to to the total weight of said hydrocarbon fraction;

[0039] d) at least a portion of said hydrocarbon cut obtained at the end of step c) is sent to the reaction zone as liquid solvent of step a);

[0040] 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. List of figures

[0041] [Fig-1] [Fig.l] is a schematic representation of an embodiment for obtaining a carbon black according to the invention.

[0042] [Fig.2] [Fig.2] is a schematic representation of the process shown in the [Fig.l] in which the reaction zone and the filtration and washing zone of the process are shown in more detail. Detailed description of the invention 1. Definitions

[0043] By hydrocarbon fraction Cn, we mean a fraction comprising hydrocarbons with n carbon atoms.

[0044] By Cn+ cut, we mean a cut comprising hydrocarbons with at least n carbon atoms.

[0045] The BET specific surface area is measured by nitrogen physisorption. The BET specific surface area is measured by nitrogen physisorption according to ASTM D3663-03 as described in Rouquerol F.; Rouquerol J.; Singh K. “Adsorption by Powders & Porous Solids: Principle, methodology and applications”, Academie Press, 1999.

[0046] The CHNS-O elemental analyzer, produced according to the ASTM D5291 standard, is a method well known to those skilled in the art, allowing the rapid determination of the content of carbon (C), hydrogen (H), oxygen (O), nitrogen (N), and sulfur (S) in organic matter and other types of materials, based on the total combustion of the analytical sample at 1000°C under oxygen.

[0047] The carbon residue content is evaluated by the X-ray Photoelectron Spectroscopy (XPS) surface analysis technique, well known to those skilled in the art, and, in particular, by the precise analysis of the spectrum associated with the carbon element (Cl s spectrum) which provides information on the chemical environment of the C atoms constituting the rCB. Indeed, the content of said carbon residues is determined by the % area of ​​the peak Ci corresponding to a binding energy of approximately 284.8 / 285.6 eV, characteristic of CC / CH bonds of aliphatic structures or small aromatic compounds, associated with said residues and calculated relative to the total area of ​​the peaks Co to C5 (Co being the peak associated with the CC / CH bonds of a graphitic structure and C2, C3, C4 and C5 the peaks respectively attributed to the CO, C=O, COOH bonds and to the jt-jt* transitions). The method for measuring the content of carbon residues is described in detail in the publication by Darmstadt H., Roy C., Kaliaguine S., “Characterization of pyrolytic carbon blacks from commercial tire pyrolysis plants Carbon” (1995), Carbon, Volume 33, No. 10, p.1449-1455, but also in the publication by Sahouli, Bendida; Blacher, Silvia; Brouers, François; Darmstadt, Hans; Roy, Christian; Kaliaguine, Serge: “Surface morphology and chemistry of commercial carbon black and carbon black from vacuum pyrolysis of used tires” (1996), Fuel, vol. 75, n° 10, p. 1244-1250, or in the thesis by Ludovic Moulin: Valorization of recovered carbon black, process-product relationship. Process engineering. Ecole des Mines d'Albi-Carmaux, 2018.

[0048] Thermogravimetric analysis is a widely used technique well known to those skilled in the art, both for measuring the moisture content, the volatile content and the ash content of rCBs. The protocol used is derived from the ISO9924-2 standard used mainly for vulcanizates and unvulcanized mixtures. A first temperature rise, from 25°C to 600°C under nitrogen, allows the measurement of the water content (mass loss in % between 25°C and 150°C) and the volatile content and / or pyrolyzable phase (mass loss between 150°C and 600°C). Following this first step, the sample is then cooled under nitrogen to 400°C. A second temperature rise, under air, between 400°C and 950°C allows the combustion of the carbon and the measurement of the quantity of carbon (rCB and any carbon residues). The final mass measured at the end of the protocol allows the mineral content to be determined.This method of analysis is described in detail in the publication by Noms, C.; Haie, Mike; Bennett, M. (2014) “Pyrolytic carbon: Factors controlling in-rubber performance”, Plastics, Rubber and Composites, vol. 43, pp. 245-256. 2. Recovered carbon black (rCB)

[0049] The recovered carbon black (rCB) according to the invention comprises, preferably consists of, carbon black (CB), inorganic ash, and carbon residues resulting from the decomposition of tire rubbers and / or elastomer residues associated with said tire rubbers, characterized in that said content of carbon residues, determined relative to the percentage of area of ​​the peak Ci measured by X-ray photoelectron spectroscopy, is less than or equal to 1% of said area of ​​the peak Ci, preferably between 0.001% and 0.08% of area, more preferably between 0.001 and 0.07% of area, and even more preferably between 0.001 and 0.05% area, said percentage of area of ​​peak Ci being calculated relative to the total area of ​​peaks Co to C5.

[0050] More particularly, the rCB comprises between 50% and 98% by weight of carbon element relative to the total weight of said rCB, preferably between 60% and 90% by weight, and even more preferably between 65% and 85%. The carbon content was evaluated by elemental analysis CHNS-O.

[0051] More particularly, the rCB comprises between 0.2 and 4% by weight of oxygen element relative to the total weight of the rCB, preferably between 0.4 and 3% by weight, and even more preferably between 0.8 and 2.7% by weight.

[0052] More particularly, the rCB comprises between 0.2 and 3% by weight of hydrogen element relative to the total weight of the rCB, preferably between 0.4 and 2.5% by weight, and even more preferably between 0.5 and 1.5% by weight.

[0053] More particularly, the rCB comprises between 0.05 and 1% by weight of nitrogen element relative to the total weight of the rCB, preferably between 0.1 and 0.7% by weight, and even more preferably between 0.15 and 0.4% by weight.

[0054] More particularly, the rCB comprises between 0.5 and 6% by weight of sulfur element relative to the total weight of the rCB, preferably between 1.5 and 5% by weight, and even more preferably between 2 and 3.5% by weight.

[0055] The contents of carbon (C), hydrogen (H), oxygen (O), nitrogen (N), and sulfur (S) were measured by elemental analysis CHNS-O.

[0056] Under the effect of a specific heat treatment (up to 600°C under nitrogen for example, by thermogravimetric analysis known as TGA), these elements can be released from the rCB in the form of vaporized water or volatile organic compounds (VOCs). The quantity of VOCs extracted is also characteristic of the rCB according to the invention. Advantageously, the content of VOCs extracted is between 0.2 and 20% by weight relative to the total weight of the rCB, preferably between 0.5 and 7% by weight, and even more preferably between 0.5 and 4% by weight.

[0057] The rCB according to the invention also comprises inorganic ash. The inorganic ash consists of at least the atomic element Si, predominantly present in its oxidized form SiO2 (silica), and at least the element zinc, predominantly present in its oxidized form ZnO (zinc oxide) and / or its sulfide form ZnS (zinc sulfide), preferably in its sulfide form ZnS. The application of a specific heat treatment (of at least 950°C in air, by ATG 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 relative to the total weight of the rCB, preferably between 8 and 40% by weight, and even more preferably between 10 and 30% by weight.

[0058] The rCB according to the invention may also contain other hetero-elements at elemental contents of less than 1% by weight relative to the total weight of the rCB, preferably less than 0.5% by weight and even more preferably less than 0.2% by weight. Said hetero-elements may be, for example and in a non-exhaustive manner, 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.

[0059] Advantageously, the rCB according to the invention comprises a specific surface area, determined by nitrogen physisorption, of between 30 and 150 m2 / g, preferably between 50 and 90 m2 / g and even more preferably between 50 and 75 m2 / g.

[0060] Advantageously, the structure index, determined by the analytical method O AN in accordance with standard ASTM D2414, is between 55 and 110.105 mVkg, preferably between 55 and 90.105 mVkg.

[0061] The carbon black (CB) contained in the recovered carbon black (rCB) may comprise several grades of commercial carbon blacks, taken alone or in mixture.

[0062] Recovered carbon black (rCB) can be obtained by a process for converting used tires comprising at least the following steps:

[0063] a) a solid charge based on used tires is sent into a reaction zone in the presence of a liquid solvent comprising aromatic compounds to at least partially dissolve said solid charge and thermally decompose said at least partially dissolved solid charge at a temperature below 400°C and at a pressure below 1.5 MPa in order to obtain a gaseous effluent and a first liquid effluent comprising carbon black, the mass ratio between the liquid solvent and the solid charge being greater than 3 weight / weight;

[0064] b) the first liquid effluent obtained in step a) is sent to a filtration and washing zone in the presence of a washing solvent in order to obtain a filtered and washed carbon black cake and a second liquid effluent, said step b) being carried out at a temperature between 55°C and 95°C;

[0065] c) at least part of said gaseous effluent obtained at the end of step a) and at least part of the second liquid effluent obtained at the end of step b) are sent to a fractionation zone to obtain at least one hydrocarbon fraction comprising a content of aromatic compounds greater than 30% by weight relative to the total weight of said hydrocarbon fraction, and further comprising:

[0066] - a content of C5-C10 hydrocarbon compounds of less than 20% by weight per relative to the total weight of the hydrocarbon fraction; and

[0067] - a content of C40+ hydrocarbon compounds of less than 5% by weight relative to to the total weight of said hydrocarbon fraction;

[0068] d) at least a portion of said hydrocarbon cut obtained at the end of step c) is sent to the reaction zone as liquid solvent of step a);

[0069] 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.

[0070] Unless otherwise indicated, all the variants and embodiments described above can be combined with each other. 3. Process for the preparation of rCB

[0071] The present invention also relates to the process for preparing rCB according to the invention from used tires. Said preparation process is a conversion process and, more specifically, a process for solvolysis of used tires which comprises, with reference to [Fig.l] associated with an embodiment according to the invention, at least the following steps:

[0072] a) a solid charge 100 based on used tires is sent to a reaction zone 80 in the presence of a liquid solvent 760 comprising aromatic compounds to at least partially dissolve said solid charge and thermally decompose said at least partially dissolved solid charge at a temperature below 400°C, preferably between 365°C and 395°C, and even more preferably between 380°C and 395°C, and at a pressure below 1.5 MPa, preferably between 0.2 and 1.2 MPa, in order to obtain at least one gaseous effluent 310 and a first liquid effluent 320 comprising the rCB according to the invention, the mass ratio between the liquid solvent 730 and the solid charge 100 being greater than 3 weight / weight;

[0073] b) the liquid effluent 320 obtained in step a) is sent to a filtration and washing zone 40 in the presence of a washing solvent in order to obtain a filtered and washed rCB cake according to the invention 430 and a second liquid effluent 410, said step b) being carried out at a temperature between 55°C and 95°C, preferably between 60°C and 90°C, and even more preferably between 65°C and 85°C;

[0074] c) at least in part, preferably in full, said gaseous effluent 310 obtained at the end of step a) and at least in part, preferably in full, the second liquid effluent 410 obtained at the end of step b) are sent to a fractionation zone 70 to obtain at least one hydrocarbon fraction 730 comprising a content of aromatic compounds greater than 30% by weight relative to the total weight of said hydrocarbon fraction, preferably greater than 40% by weight, and comprising:

[0075] - a content of C5-C10 hydrocarbon compounds of less than 20% by weight per relative to the total weight of the hydrocarbon fraction 730, preferably less than 10% by weight, more preferably between 1 and 8% by weight; and

[0076] - a content of C40+ hydrocarbon compounds of less than 5% by weight relative to to the total weight of said hydrocarbon fraction 730, preferably less than 3% by weight, more preferably less than 1% by weight, and even more preferably less than 0.5% by weight;

[0077] d) at least part of said hydrocarbon fraction 730 obtained at the end of step c) in the reaction zone 80 as liquid solvent 760 of step a);

[0078] e) the filtered and washed rCB cake according to the invention 430 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 sufficient time so that the washing solvent content in the dried cake is 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 preferably between 1 hour and 15 hours, to recover the rCB according to the invention 520.

[0079] According to an essential aspect of the process according to the invention, the use of such a recycled hydrocarbon cut as liquid solvent 760 of the reaction zone 80 (i.e. step d) of the process according to the invention), with a content rich in aromatic compounds, poor in C40+ compounds (vacuum residues), and a content of C5-C10 hydrocarbon compounds (gasoline) not too high, and using a solvent / solid feedstock mass ratio greater than or equal to 3 weight / weight, preferably between 3 and 10 weight / weight, more preferably between 4 and 7 weight / weight, allows better dissolution and decomposition of the solid feedstock 100, thus maximizing the production of rCB while limiting the presence of carbon residues in said rCB.

[0080] The solid filler 100 used in the context of the present invention is advantageously based on tires resulting from the treatment of used tires which may come from any origin, such as light vehicles (LV) or heavy goods vehicles (HGV) for example. Said solid filler may advantageously be in the form of tire granules, i.e. in the form of particles of sizes less than 6 mm. Preferably, said solid filler 100 is substantially free of textile fibers and metal wires, and / or tire shreds, i.e. pieces of crushed tires, of a characteristic size generally between 1 cm and 20 cm. Thus, according to a preferred embodiment according to the invention, the solid filler 100 is sent to a pretreatment unit 10 in order to remove the textile fibers and metal wires 110 from the solid filler 100.Such a pretreatment unit is well known to those skilled in the art and may consist of grinders of different types (i.e. a rotary shear, a shredder, a granulator, a refiner grinder), a magnetic separator, or even a vibrating screen, a separation table.

[0081] According to step a) of the conversion process, the gum which is contained in the solid charge 100 is dissolved in contact with the liquid solvent 760 and is then thermally decomposed. The origin and composition of the liquid solvent 760 will be described in detail below. Step a) is preferably carried out at a temperature below 400°C, preferably between 365°C and 395°C, and even more preferably 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 one gaseous effluent is obtained. 310 and the first liquid effluent 320 comprising the rCB according to the invention, and possibly solid materials 210 contained in the used tires, such as metal wires or textile fibers, which are released and separated from the liquid effluent 320 obtained at the end of this step.

[0082] The first liquid effluent 320 comprising the rCB according to the invention is then sent to the filtration and washing zone 40 (i.e. step b) of the preparation method according to the invention) in order to recover the filtered and washed rCB cake according to the invention 430 and the second liquid effluent 410. This step is carried out at a temperature between 55°C and 95°C, preferably between 60°C and 90°C, and even more preferably between 65°C and 85°C. In one embodiment according to the invention, the viscosity of the second liquid effluent 410 measured at 100°C is less than 10 cP, preferably less than 5 cP, more preferably less than 3 cP, as measured according to the ASTM D3236 standard.

[0083] The filtration and washing unit may comprise any device allowing the filtration of the rCB particles according to the invention contained in the first liquid effluent 320. Such a device may for example be in the form of a rotary filter operating preferably at a temperature between 55°C and 95°C, preferably between 60°C and 90°C, and even more preferably between 65°C and 85°C. During step b), the rCB cake according to the invention is washed using a washing solvent.

[0084] In one embodiment according to the invention, the washing solvent used during step b) is a solvent external to the process 800, as shown in [Fig. 1]. The solvent may be chosen from toluene or xylene, preferably xylene.

[0085] In another embodiment according to the invention, the washing solvent used during step b) is composed at least in part of a light cut 720 obtained at the end of step c). More particularly, referring to [Fig. 2], a fraction of the light cut 720 can be sent to a distillation column 90 via line 725. The complementary fraction 735 of the light cut is sent outside the process according to the invention as a recoverable product. At the outlet of the distillation column 90, a light cut 910 is obtained comprising aromatic compounds, the final boiling point of which is less than or equal to 200°C, preferably less than 150°C, which can serve at least in part as a washing solvent for the filtration / washing zone 40. The heavier cut 920 can be sent outside the process as a recoverable product 920.

[0086] The filtered and washed rCB cake according to the invention 430 is sent to 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 according to the invention 520 (i.e. step e) of the process according to the invention). Advantageously, the steam effluent 510 from the drying unit drying 50 including the washing solvent is recycled into the washing / filtration unit 40.

[0087] 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 the fractionation unit 70 (i.e. step c) of the process according to the invention) to produce at least one hydrocarbon fraction 730 comprising a content of aromatic compounds greater than 30% by weight relative to the total weight of said hydrocarbon fraction 730, and further comprising at least:

[0088] - a content of C5-C10 hydrocarbon compounds of less than 20% by weight per relative to the total weight of the hydrocarbon fraction 730, preferably less than 10% by weight, more preferably between 1 and 8% by weight; and

[0089] - a content of C40+ hydrocarbon compounds of less than 5% by weight relative to to the total weight of said hydrocarbon fraction 730, preferably less than 3% by weight, more preferably less than 1% by weight, and even more preferably less than 0.5% by weight.

[0090] Advantageously, the hydrocarbon fraction 730 also comprises a content of C10-C20 hydrocarbon compounds of between 20 and 65% by weight relative to the total weight of the hydrocarbon fraction, preferably of between 30 and 65% by weight, and even more preferably of between 45 and 65% by weight.

[0091] Advantageously, the hydrocarbon fraction 730 also comprises a content of C20-C40 hydrocarbon compounds of between 30 and 80% by weight relative to the total weight of the hydrocarbon fraction, preferably between 30 and 70% by weight, and even more preferably between 30 and 55% by weight.

[0092] Advantageously, the hydrocarbon fraction 730 has an initial boiling point of between 50°C and 325°C, preferably of between 50°C and 250°C, and a final boiling point of between 350 and 520°C, preferably of between 350°C and 450°C.

[0093] Advantageously, the fractionation zone 70 also makes it possible to obtain incondensable gases 710, the light cut 720 whose final boiling point is preferably between 250°C and 325°C, and a heavy cut 740, whose initial boiling point is preferably between 350°C and 450°C.

[0094] Advantageously, the light cut 720 can be sent at least in part as a washing solvent to the washing and filtration zone 40 to obtain the filtered and washed rCB cake according to the invention 430.

[0095] Advantageously, the light cut 720 comprises a content of CIO- hydrocarbon compounds greater than 60% by weight relative to the total weight of the light cut 720.

[0096] Advantageously, the heavy cut 740 comprises a content of hydro compounds carbonaceous in C40+ greater than 60% by weight compared to the total weight of the heavy cut 740.

[0097] According to the invention, at least part of a fraction of the hydrocarbon cut 730 is sent to the reaction zone 80 of step a) as liquid solvent 760, the other part 750 being advantageously sent outside the process according to the invention as a recoverable product. The mass ratio between the liquid solvent 730 and the flow rate of the solid feedstock 100 injected into the reaction zone 80 is greater than or equal to 3 weight / weight (wt / wt), preferably between 3 and 10 weight / weight, more preferably between 4 and 7 weight / weight. Indeed, one of the characteristics of the liquid solvent 760 is that it contains an aromatic content greater than 30% by weight relative to the total weight of said liquid solvent 760, making it possible to effectively dissolve the solid feedstock 100 and to effectively 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 reactors 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 CIO- hydrocarbon compounds in the hydrocarbon cut 730.

[0098] In order to better understand the invention, the description given below (as an example of application) relates to a method for converting used tires making it possible to maximize the production of rCB while limiting the presence of carbon residues in said rCB. Referring to [Fig. 2], the solid feedstock 100 is sent to the pretreatment unit 10 in order to remove the textile fibers and the metal wires 110 from the solid feedstock 100. The solid feedstock substantially free of textile fibers and metal wires is then sent to the reaction zone 80 allowing the thermal degradation of the used tires comprising a first stirred reactor 20 supplied with liquid solvent 760 and aimed at promoting the dissolution of the tire aggregates or shreds contained in the solid feedstock 100. The liquid solvent feedstock / solid feedstock mass ratio is greater than or equal to 3 weight / weight, preferably between 3 and 10, more preferably between 4 and 7 weight / weight.The temperature in the reactor 20 is preferably between 200°C and 300°C, preferably between 250°C and 290°C. In the first stirred reactor 20, the ground materials or aggregates are dissolved. The time required to achieve this dissolution is preferably between 30 minutes and 2 hours. The pieces of gum, and the future rCB according to the invention which is gradually released from the gum, remain in suspension thanks to mechanical or hydrodynamic stirring, induced for example by an upward flow of liquid resulting from recirculation by forced convection, or by any other means making it possible to keep the medium stirred. The metal wires, possibly still present in the solid charge and which have not been dissolved, se- . diment and exit the first stirred reactor 20 at its base via line 210. Under these conditions, the temperature is too low for the carbon-carbon cracking reactions to start significantly and only the crosslinking bonds between polymers, such as the SS bonds linked to the vulcanization of the rubbers, can crack significantly. The liquid fraction 220 obtained containing the residual solids in suspension is directed to a second stirred reactor 30 in which the thermal degradation reactions are carried out under moderate temperature conditions, i.e. at a temperature less than or equal to 400°C, preferably between 365°C and 395°C, and even more preferably between 380°C and 395°C, and for a limited time (corresponding to the residence time of the liquid fraction in the reactor 30) preferably between 30 minutes and 2 hours, preferably between 45 minutes and 90 minutes.The amount of heat required to carry out the thermal degradation reactions may be provided by an exchanger located on a pump-around (not shown in the figures) around the second stirred reactor 30 or by any other means such as an exchanger on the wall of the reactor or an exchanger or furnace on the load upstream of the reactor, for example. Agitation in the second stirred reactor 30 is maintained by a mechanical stirring system or by the pump-around system or by any other means known to those skilled in the art. Preferably, the pressure of the reactor is maintained at a level below 1.5 MPa by means of a control valve (not shown in the figures).

[0099] At the end of the reaction in the second stirred reactor 30, the first liquid effluent 320 containing the rCB particles according to the invention in suspension and the gaseous effluent 310 are obtained. The first liquid effluent 320 is then sent to the filtration and washing zone 40, comprising a rotary filter 41 and an intermediate fractionation unit 42 (see [Fig.2]). The rotary filter 41 preferably operates at a temperature between 50°C and 200°C, and makes it possible to obtain a cake of rCB according to the invention and a liquid fraction 425. Said cake is then washed with the washing solvent 800, such as toluene or xylene, preferably xylene, at a temperature between 55°C and 95°C, preferably between 60°C and 90°C, and even more preferably between 65°C and 85°C, making it possible to recover the filtered and washed rCB according to the invention 430.After the filtration / washing step, a washing stream 405 can be sent to the intermediate fractionation unit 42 to obtain a cut 610 which can be recycled at least in part upstream of the rotary filter 41 by means of the line as an additional washing solvent, and a cut 415 which can be sent with the liquid fraction 425, to the fractionation zone 70 as a second liquid effluent 410. The filtered and washed rCB according to the invention 430 is then sent to the drying unit 50 operating at a temperature . between 50 and 200°C, advantageously for a sufficient time so that the washing solvent content in the dried cake is less than 0.5% by weight relative to the total weight of said dried cake. The filtered, washed and dried rCB according to the invention 520 can then be advantageously pelletized (granulated) with water to form pellets of a few millimeters, for example, to facilitate its transport and recovery. The rCB thus produced can again be used in the elastomer industry as a reinforcing agent, or as a pigment for other applications in inks, plastics or paints, for example, after subsequent processing and conditioning steps of the material depending on the uses and applications. The residual washing solvent can be recovered at the outlet of the drying unit 50 and be at least partly recovered via the line 510.

[0100] The gaseous effluent 310 leaving the reaction zone 80 via the second reactor 30, and the second liquid effluent 410 from the washing / filtration zone 40 are then directed to the fractionation zone 70. The fractionation zone 70 may consist of heat exchangers, gas-liquid separator drums, a distillation column containing a top withdrawal, a bottom withdrawal and a side withdrawal, or a sequence of several distillation columns, such as a sequence of a distillation column at atmospheric pressure operating with a top withdrawal and a bottom withdrawal, followed by a distillation column operating under a low vacuum.This fractionation zone 70 particularly makes it possible to produce the hydrocarbon fraction 730 comprising a content of aromatic compounds greater than 30% by weight relative to the total weight of said hydrocarbon fraction 730, preferably greater than 40% by weight, and further comprising: .

[0101] - a content of C5-C10 hydrocarbon compounds of less than 20% by weight per relative to the total weight of the hydrocarbon fraction 730, preferably less than 10% by weight, more preferably between 1 and 8% by weight; and

[0102] - a content of C40+ hydrocarbon compounds of less than 5% by weight relative to to the total weight of said hydrocarbon fraction 730, preferably less than 3% by weight, more preferably less than 1% by weight, and even more preferably less than 0.5% by weight;

[0103] at least a portion of which can be recycled as liquid solvent 760 in the reaction zone 80, the other portion 750 being able to be recovered as product. Preferably, the hydrocarbon fraction is sent to the first reactor 20 of the reaction zone 80 as liquid solvent.

[0104] This fractionation zone 70 also makes it possible to obtain the incondensable gas 710, the light cut 720 whose final boiling point is preferably between 250°C and 325°C, and the heavy cut 740, whose initial boiling point is preferably between 350°C and 450°C. Advantageously, the light cut 720 can be sent at least in part as a washing solvent to the washing and filtration device 41 of the washing and filtration zone 40 to obtain the filtered and washed rCB cake according to the invention 430.

[0105] When starting up the installation, in the absence of production of a stabilized intermediate cut, i.e. the hydrocarbon cut 730, it is possible to temporarily use an imported solvent which will preferably consist of an aromatic molecule content greater than 40% by weight relative to the total weight of the cut. This cut may therefore consist, for example, of conversion effluents from the FCC catalytic cracking process (abbreviation of the English terminology "Fluid Catalytic Cracking," which means fluidized bed catalytic cracking), middle distillate (LCO or "light cycle oil" according to English terminology) or heavy distillate (HCO or "heavy cycle oil" according to English terminology) for example. Examples

[0106] The following examples illustrate preferred embodiments of the method according to the present invention and the production of rCB without, however, limiting its scope. The method used to illustrate the invention is in accordance with that described in [Fig. 2]. Example 1 (in accordance with the invention)

[0107] In a first example, in accordance with the invention, used tire granules (solid filler) are used, produced by granulators using crushers, which come from heavy goods vehicle tires and the grains resulting from the crushing have a size close to 2 millimeters. The tire granules come from a pretreatment unit 10 and are free of textile and metal fibers. The granules are then sent continuously to a dissolution reactor where they are mixed with the liquid solvent resulting from the recycle of the hydrocarbon fraction 730 from the fractionation zone 70. A portion of the hydrocarbon fraction 730 serves as liquid solvent 760, the composition of which is shown in Table 1 below. The quantity of solid filler treated is 100 kg / h. The quantity of solvent which is recycled into the reactor 20 is 500 kg / h, corresponding to a solvent / granulate mass ratio equal to 5 wt / wt.In the reactor 20, the temperature is maintained at 290°C, which allows the aggregates to dissolve. The liquid fractions and the future suspended rCB are then directed to the reactor 30 where the temperature is maintained at 385°C for one hour. At the outlet of the reactor 30, a first liquid effluent 320 and a gaseous effluent 310 are recovered, the latter 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. The filtered rCB is washed 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 and washed rCB 430 is sent to a drying unit 50 operating at 150°C for 24 hours allowing the recovery of the filtered, washed and dried rCB 520. Example 2 (not in accordance with the invention)

[0108] In Example 2, not in accordance with the invention, the steps of the conversion process and the operating conditions are identical to those of Example 1, except with regard to the content of C40+ hydrocarbon compounds (vacuum residues or RSV) of the liquid solvent 760 which is outside the range according to the invention, and with regard to the step of washing the recovered carbon black (rCB) which is carried out at a temperature of 50°C.

[0109] The operating conditions of Examples 1 and 2 are summarized in Table 1 below.

[0110] [Tables 1] Example 1 Example 2 Reactor temperature 30 °C 385 385 Reactor pressure 30 MPa 0.9 0.9 Feed rate 100 kg / h 100 100 Liquid solvent 760 / feed 100 wt / wt 5 5 Recycle rate 760 kg / h 500 500 Hydrocarbon cut 730 Gas % wt 0.1 0.1 Gasoline (C5-205°C) % wt 6.6 5.3 Diesel (205-370°C) % wt 51 40.9 VGO (370-520°C) % wt 41.9 33.6 RSV (520°C+) % wt 0.4 20.0 Gaseous effluent 310 kg / h 85 54 Liquid effluent 320 kg / h 515 546 Solids in liquid effluent 320 % wt 7.3 6.9 Washing temperature °C 80 50 Viscosity of the second liquid effluent 410 at 50°C cP 6.2 28.8 Viscosity of the second liquid effluent 410 at 100°C cP 2.3 7.4

[0111] The main characteristics of the rCB obtained according to examples 1 and 2 are summarized in tables 2 and 3 below.

[0112] [T ableaux2] rCB Ash content (% by weight) Sbet (ni2 / g) Carbon residue content (% area Ci ) Example 1 (compliant) 12.8 67 0.05 Example 2 (non-compliant) 12 60 2

[0113] [Tableaux3] rCB % pds C % pds O % pds H % pds N % pds S % pds SiO2 % pds ZnS % pds cov O AN xlO5 mVkg Exemple 1 (Conforme ) 81,4 0,9 0,6 0,2 3,3 4,8 8 2,1 71

Claims

Claims

1. Recovered carbon black (rCB) comprising carbon black, inorganic ash, and carbon residues from the decomposition of tire rubbers and / or elastomer residues, characterized in that said carbon residue content, determined relative to the percentage area of ​​peak Ci measured by X-ray photoelectron spectroscopy, is less than or equal to 1% of said area of ​​peak Ci, said percentage area of ​​peak Ci being calculated relative to the total area of ​​peaks Co to C5.

2. Recovered carbon black according to claim 1, characterized in that it comprises between 50% and 98% by weight of carbon element relative to the total weight of said recovered carbon black.

3. Recovered carbon black according to one of claims 1 or 2, characterized in that it comprises between 0.2 and 4% by weight of oxygen element relative to the total weight of said recovered carbon black.

4. Recovered carbon black according to any one of claims 1 to 3, characterized in that it comprises between 0.2 and 3% by weight of hydrogen element relative to the total weight of said recovered carbon black.

5. Recovered carbon black according to any one of claims 1 to 4, characterized in that it comprises between 0.05 and 1% by weight of nitrogen element relative to the total weight of said recovered carbon black.

6. Recovered carbon black according to any one of claims 1 to 5, characterized in that it comprises between 0.5 and 6% by weight of element sulfur relative to the total weight of said recovered carbon black.

7. Recovered carbon black according to any one of claims 1 to 6, characterized in that it comprises a content of extracted volatile organic compounds of between 0.2 and 20% by weight relative to the total weight of said recovered carbon black.

8. Recovered carbon black according to any one of claims 1 to 7, characterized in that the inorganic ash content is between 4 and 50% by weight relative to the total weight of said recovered carbon black.

9. Recovered carbon black according to any one of claims 1 to 8, characterized in that it comprises a specific surface area of ​​between 30 and 150 m2 / g.

10. Recovered carbon black according to any one of claims 1 to 9, characterized in that the structure index, determined by the method

11.

12. analytical OAN in accordance with ASTM D2414, is between 55 and 110.105 mVkg. Recovered carbon black according to any one of claims 1 to 10, characterized in that said carbon residue content, calculated relative to the % area of ​​peak Ci measured by photoelectron spectroscopy, is between 0.001% and 0.05% of area, said percentage area of ​​peak Ci being calculated relative to the total area of ​​peaks Co to C5. Process for converting used tires to obtain recovered carbon black (rCB) according to any one of claims 1 to 11, said process comprising at least the following steps: a) sending a solid charge (100) based on used tires into a reaction zone (80) in the presence of a liquid solvent (760) comprising aromatic compounds to at least partially dissolve said solid charge and thermally decompose said at least partially dissolved solid charge at a temperature below 400°C and at a pressure below 1.5 MPa in order to obtain a gaseous effluent (310) and a first liquid effluent (320) comprising carbon black, the mass ratio between the liquid solvent (730) and the solid charge (100) being greater than 3 weight / weight; b) the first liquid effluent (320) obtained in step a) is sent to a filtration and washing zone (40) in the presence of a washing solvent in order to obtain a filtered and washed carbon black cake (430) and a second liquid effluent (410), said step b) being carried out at a temperature between 55°C and 95°C; c) at least part of said gaseous effluent (310) obtained at the end of step a) and at least part of the second liquid effluent (410) obtained at the end of step b) are sent to a fractionation zone (70) to obtain at least one hydrocarbon fraction (730) comprising a content of aromatic compounds greater than 30% by weight relative to the total weight of said hydrocarbon fraction, and further comprising: - a content of C5-C10 hydrocarbon compounds less than 20% by weight relative to the total weight of the hydrocarbon fraction; and - a content of C40+ hydrocarbon compounds of less than 5% by weight relative to the total weight of said hydrocarbon fraction; d) at least a portion of said hydrocarbon fraction (730) obtained at the end of step c) is sent to the reaction zone (80) as liquid solvent (760) of step a); e) the filtered and washed carbon black cake (430) obtained is dried at the end of step b) at a temperature between 50 and 200°C to recover the carbon black.

13. Method according to claim 12, in which step a) comprises the following sub-steps: a1) sending said solid charge (100) and said liquid solvent (760) into a first stirred reactor (20) to at least partially dissolve said solid charge (100); a2) sending said at least partially dissolved solid charge obtained at the end of step a1) into a second stirred reactor (30) to thermally decompose said solid charge at a temperature less than or equal to 400°C and obtain a liquid effluent containing suspended carbon black particles.

14. Method according to one of claims 12 or 13, in which the content of aromatic compounds in the hydrocarbon fraction (730) is greater than 40% by weight relative to the total weight of said fraction.

15. A method according to any one of claims 12 to 14, wherein the content of C40+ hydrocarbon compounds in the hydrocarbon fraction (730) is less than 3% by weight relative to the total weight of said fraction.

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