Method for producing atmospheric distillates from heavy oil fractions derived from the solvolysis of used elastomers

Abstract

The invention relates to a method for producing atmospheric distillates from oil derived from the solvolysis of used elastomers, comprising the following steps: 1) a step of solvolysis of elastomers under highly specific conditions in order to obtain a first gaseous effluent and a first liquid effluent comprising carbon black; 2) steps of liquid / solid separation and fractionation of the first liquid effluent in order to recover the carbon black and various liquid fractions including a heavy hydrocarbon cut with an initial boiling temperature of between 340°C and 440°C; 3) a step of catalytic cracking of the heavy hydrocarbon cut obtained in a fluidised bed reactor in the presence of a solid catalyst at a temperature of between 500°C and 700°C and a pressure of between 0.1 and 0.6 MPa in order to obtain an atmospheric distillate comprising at least a gasoline cut and a diesel cut.

Description

[0001] PROCESS FOR PRODUCING ATMOSPHERIC DISTILLEAS FROM HEAVY FRACTIONS OF OIL FROM THE SOLVOLYSIS OF USED ELASTOMERS.

[0002] Scope of the invention

[0003] The present invention relates to the recycling of used elastomers by a process of solvolysis of used elastomers and to the valorization of the solvolysis oil in atmospheric distillates.

[0004] State of the art

[0005] Elastomers are chemically cross-linked polymers of natural or synthetic rubber. Due to their chemical bonds, they do not melt but begin to decompose at high temperatures. Natural rubber is primarily composed of polyisoprene, a natural polymer found in the rubber tree (Hevea brasiliensis) and guayule. Synthetic rubbers are either general-purpose or specialty rubbers and are created by combining different polymers, monomers, and laminates.Common synthetic rubbers include (but are not limited to) styrene-butadiene copolymer (SBR), polybutadiene (BR), isobutylene-isoprene copolymer (HR, Cil R, BIIR), rethylene-propylene-diene monomer (EPDM), polychloroprene (CR), acrylonitrile-butadiene copolymer (NBR, HNBR), chlorosulfonated polyethylene (CSM), fluoroelastomer (FKM), polyacrylate rubber (ACM), epichlorohydrin rubber (ECO) and silicone rubber (VMQ).

[0006] These materials are used to manufacture various objects such as tires for light vehicles, heavy goods vehicles, two-wheelers or any type of special equipment, treads in conveyor systems, vehicle door seals, but also objects like shoe soles or rubber boots.

[0007] At the end of their life cycle, these elastomer-rich objects undergo a granulation process to facilitate their material recovery. This process isolates the elastomer-rich components and removes most of the other constituents (such as the metallic or synthetic fabrics and fibers often incorporated into elastomers to enhance their properties), resulting in granules generally smaller than 25 mm. Granulation typically involves a series of grinding and separation steps, yielding a final material composed of the elastomer and any reinforcing fillers incorporated with it, such as carbon black or silica.Carbon black (or CB, as it is known in English) is used in tire formulations to improve tire durability (in terms of strength and lifespan), to limit tire deformation during use, and to facilitate heat transfer between the tire and the road surface. It is generally obtained through the incomplete combustion of hydrocarbons or vegetable oils, and more than 35 grades are commercially available and used as fillers (primarily in tire compound formulations). Their quality varies according to their intrinsic properties.

[0008] Thermal decomposition processes for converting used elastomers generally aim to produce gaseous, liquid, and solid fractions suitable for recycling. In the case of used tires, the tire is typically shredded initially to obtain either tire shreds still containing some of the textile fibers or metal wires from the tire (typically pieces of 10 cm) or granules (generally smaller than 5 mm) free of textile fibers or metal wires. These prepared materials can then be reacted by exposing them to temperature to decompose the used tire and recover a gaseous fraction, a liquid fraction, and a solid fraction. To achieve tire decomposition, it is generally necessary to expose the tire to a fairly high temperature, usually between 300°C and 900°C, for reaction times ranging from 30 minutes to several hours.

[0009] Numerous technologies exist for implementing these reactions. For example, tires can be exposed to heat in rotating furnaces (Lewandowski et al., Journal of Analytical and Applied Pyrolysis, 140, 2019, 25-53) or in moving beds (EP2661475). These technologies are robust but generally require operating at fairly high temperatures, typically averaging over 500°C.In these processes, carbon black, generally present in the feedstock at a level of 25-40% by weight and initially composed of very fine sub-micrometer or micrometer particles / agglomerates, tends to agglomerate in the presence of decomposed gum, which forms a coke binding these structures at different scales. The solid often exits the reactor in the form of blocks several millimeters or centimeters in size, which must then be finely ground in order to reuse this solid as carbon black, a process requiring significant energy expenditure. In these processes, temperature conditions are high, and the reactor contains primarily gaseous and solid fractions. The liquids produced result from the condensation of the gaseous products downstream of the reactor.These high-temperature conditions also tend to favor polycondensation and coking reactions, leading to the formation of polyaromatic structures from cyclization reactions involving the existing aromatic and olefinic structures (MF Laresgoiti, BM Caballero, I. de Marco, A. Torres, MA Cabrero, MJ Chomén. J. Anal. Appl. Pyrolysis 71 (2004) 917-934) or from coke. The higher the temperature, the greater the proportions of polyaromatic structures formed and the amount of coke produced. While aromatic molecules are good solvents and have numerous applications, particularly as petrochemical bases, polyaromatic structures are detrimental to the quality of the resulting liquid and very difficult to refine or convert. Furthermore, they are precursors to ideal coke.Therefore, it is advantageous to try to limit polycondensation reactions as much as possible in order to produce a minimum of polyaromatic structures while preserving the monoaromatic structures present.

[0010] To improve the quality of the solid phase and limit coke formation on carbon black, the hydrocarbon partial pressure can be lowered by injecting steam during the cracking reactions. However, these reactions require a high temperature, exceeding 500°C, to carry out cracking under essentially gas-solid conditions (LIS2016 / 0083657). These gas-solid processes generally induce very high levels of non-condensable gas production under atmospheric conditions, ranging from 10 to 25% by weight relative to the tire charge entering the reactor. The utilization of these reaction gases is locally complex. Therefore, these gases are generally used to generate the heat required for the reactions, but this comes at the expense of the quantity of readily usable liquid products, which is thus limited.

[0011] An alternative approach involves bringing the tire particles into contact with a liquid, heating the liquid, and dissolving and converting the tire particles into a homogeneous liquid phase in which the tire particles are agitated and gradually disappear. An example of this implementation is given in US 3,978,199 and US 3,704,108. This type of process allows the recovery of carbon black in liquid form after filtration without the agglomeration of these particles or the deposition of coke on their surface, as occurs in gas-solid phase reactions. Furthermore, implementing the process at temperatures below 450°C limits the polycondensation reactions of aromatics, the formation of coke on the surface of the carbon black particles, and the formation of gas, which is generally between 1% and 7% by weight of the incoming particle.The use of a solvent containing aromatic fractions, preferably monoaromatic, is favorable and allows for better dissolution of the charge in the reactor.

[0012] In most elastomer recycling units using the previously mentioned methods, the liquid products are recovered as a high-sulfur fuel oil with low commercial value if processed as is. These products can also be sent to refining and petrochemical complexes and processed in blends with hydrocarbon fractions from petroleum. The biogenic carbon content of the liquid fractions resulting from elastomer recovery (related to the natural rubber content in the elastomers) increases the renewable nature of the resulting hydrocarbon fractions.

[0013] Fluid catalytic cracking (FCC) units are present in nearly half of all refineries. They enable the conversion of heavy hydrocarbon feedstocks, whose initial boiling point is generally above 340°C, into lighter hydrocarbon fractions, particularly middle distillates, by cracking the molecules of the heavy feedstock in the presence of an acid catalyst.

[0014] E. Rodriguez et al. (Production of Non-Conventional Fuels by Catalytic Cracking of Scrap Tires Pyrolysis Oil, Ind. Eng. Chem. Res. 2019, 58, 5158-5167) demonstrate the potential for utilizing pyrolysis oil in a catalytic cracking process. However, the article highlights the formation of polyaromatics that do not convert to gasoline or diesel and lead to the formation of more coke compared to a traditional petroleum feedstock. The formation of polyaromatics limits the gasoline or diesel yield in the catalytic cracking process.

[0015] Objects of the invention

[0016] The Applicant has developed a new process for recovering value from solvolysis oils into atmospheric distillate (gasoline and diesel). This process combines a solvolysis reaction step of used elastomers, preferably based on used tires, a fractionation step of the solvolysis oil, and a conversion step of the heavy fraction of the solvolysis oil to recover an atmospheric distillate, with an improved yield compared to prior art processes using traditional petroleum fractions, and reduced coke formation.

[0017] The process consists of recycling a batch of spent elastomers by contacting said batch with a solvent consisting of at least one hydrocarbon fraction comprising a high content of aromatic compounds, a low content of C40+ compounds (vacuum residues), and a moderate content of C5-C10 hydrocarbon compounds (gasoline), said solvent being able to be produced from the process itself (recycled). The operating conditions and the composition of the hydrocarbon fraction as defined allow for: - maximizing the production of recovered carbon black through better dissolution / decomposition of the solid batch while limiting the presence of carbon residues in the final recovered carbon black;

[0018] - minimize gas production and therefore maximize the oils of interest;

[0019] - to generate higher quality oils, whose aromatic compounds are essentially monoaromatic and diaroaromatic, by significantly limiting the proportion of polyaromatics formed during the recycling of elastomers.

[0020] Indeed, the solvolysis oil produced, and in particular the heavy fraction of the oil with a boiling point above 340°C, possesses interesting properties and characteristics (predominantly mono-aromatic structure, limited polyaromatic content). Treating this heavy fraction of solvolysis oil by catalytic cracking improves the unit's performance and increases the yield of atmospheric distillates without promoting additional coke formation. This therefore presents considerable interest and value for the refiner due to the biogenic hydrocarbon content resulting from the recycling of elastomers.

[0021] The invention relates to a process for producing atmospheric distillates from a solid feed based on spent elastomers, said process comprising at least the following steps: a) a solid feed based on spent elastomers is sent into a reaction zone in the presence of a liquid solvent comprising aromatic compounds to dissolve at least part of said solid feed and thermally decompose said at least partially dissolved solid feed at a temperature below 400°C and at a pressure below 2 MPa in order to obtain a first gaseous effluent and a first liquid effluent comprising carbon black, the mass ratio between the liquid solvent and the solid feed being greater than 3 weight / weight; b) the first liquid effluent obtained in step a) is sent into a separation zone in order to obtain a carbon black cake and a second liquid effluent;(c) at least part of the first 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 area to obtain at least one light hydrocarbon cut having a final boiling point below 260°C and at least one intermediate hydrocarbon cut comprising an aromatic compound content exceeding 30% by weight relative to the total weight of said intermediate hydrocarbon cut, and further comprising:;

[0022] - a content of C5-C10 hydrocarbon compounds of less than 20% by weight in relation to the total weight of the hydrocarbon cut; and - a content of C40+ hydrocarbon compounds of less than 5% by weight in relation to the total weight of said hydrocarbon cut;

[0023] - a C40+ hydrocarbon content of less than 5% by weight relative to the total weight of said hydrocarbon cut; and a heavy hydrocarbon cut having an initial boiling point between 340°C and 440°C; d) at least a portion of said light hydrocarbon cut and at least a portion of said intermediate hydrocarbon cut obtained at the end of step c) are sent into the reaction zone as the liquid solvent of step a), characterized in that the mass ratio between said intermediate hydrocarbon cut and the liquid solvent is between 0.2 and 0.95 weight / weight; e) at least a portion of said heavy hydrocarbon cut obtained in step d) is sent into a catalytic cracking zone in a fluidized bed reactor in the presence of a solid catalyst, at a temperature between 500°C and 700°C, a pressure between 0.1 and 0.6 MPa to obtain a catalytic cracking effluent;f) the catalytic cracking effluent obtained at the end of step e) is distilled to obtain an atmospheric distillate composed of at least one petrol cut and one diesel cut.

[0024] Advantageously, the heavy hydrocarbon cut comprises a mass percentage of polyaromatics less than 20% by weight relative to the total aromatics of said heavy hydrocarbon cut.

[0025] Preferably, the heavy hydrocarbon cut comprises a mass percentage of polyaromatics less than 15% by weight relative to the total aromatics of said heavy hydrocarbon cut.

[0026] Advantageously, the heavy hydrocarbon cut includes a Conradson Carbon of less than 3.

[0027] Preferably, the heavy hydrocarbon cut includes a Conradson Carbon of less than 2.

[0028] Advantageously, the heavy hydrocarbon fraction comprises a total aromatics content exceeding 50% by weight relative to said heavy hydrocarbon fraction. Advantageously, the heavy hydrocarbon fraction comprises a monoaromatics mass percentage exceeding 40% by weight relative to the total aromatics.

[0029] Advantageously, the heavy hydrocarbon cut comprises a mass percentage of monoaromatics greater than 50% by weight relative to the total aromatics of said heavy hydrocarbon cut.

[0030] Advantageously, the heavy hydrocarbon cut comprises a mass percentage of diaromatics greater than 10% by weight relative to the total aromatics of said heavy hydrocarbon cut.

[0031] Advantageously, the heavy hydrocarbon cut represents between 20% and 75% by weight of the total solvolysis oil.

[0032] Advantageously, said heavy hydrocarbon cut obtained in step d) is mixed with a petroleum fossil feedstock of distillate type under vacuum (360°C+) and then sent to the catalytic cracking zone.

[0033] Advantageously, the light hydrocarbon cut comprises a total aromatics content greater than 3% by weight relative to said light hydrocarbon cut, a mass percentage of monoaromatics greater than 60% by weight relative to the total aromatics of the light cut and a mass percentage of polyaromatics less than 10% by weight relative to the total aromatics of said light cut.

[0034] Advantageously, the intermediate hydrocarbon cut comprises a total aromatics content greater than 40% by weight relative to said intermediate hydrocarbon cut, a mass percentage of monoaromatics greater than 50% by weight relative to the total aromatics of said intermediate hydrocarbon cut and a mass percentage of polyaromatics less than 15% by weight relative to the total aromatics of said intermediate hydrocarbon cut.

[0035] Advantageously, the catalytic cracking catalyst implemented in step e) includes a ZSM-Y zeolite.

[0036] Advantageously, step a) comprises the following substeps: a1) said solid feed and said liquid solvent are sent into a first stirred reactor (20) to dissolve at least part of said solid feed; a2) said at least partially dissolved solid feed obtained at the end of step a1) is sent into a second stirred reactor to thermally decompose said solid feed at a temperature less than or equal to 400°C and obtain a liquid effluent containing suspended carbon black particles.

[0037] List of figures

[0038] Figure 1 is a schematic representation of an embodiment of the production of middle distillates from used elastomers according to the invention.

[0039] Detailed description of the invention

[0040] 1. Definitions

[0041] By hydrocarbon Cn cut, we mean a cut comprising hydrocarbons with n carbon atoms.

[0042] By Cn+ cut, we mean a cut comprising hydrocarbons with at least n carbon atoms.

[0043] Unless otherwise specified, pressure is defined as absolute pressure and expressed in MPa.

[0044] The term C / O refers to the mass ratio between the mass flow rate of catalyst in the catalytic cracking unit and the mass flow rate of the feed being processed.

[0045] Atmospheric distillate is defined as a distillation fraction with a range from an initial temperature between ambient temperature and a final boiling point between 340°C and 440°C. It is composed of a gasoline fraction with a distillation range between ambient temperature and a final boiling point between 220°C and 260°C, and a diesel fraction with a distillation range between an initial temperature between 220°C and 260°C and a final boiling point between 340°C and 440°C.

[0046] Ambient temperature (“Tamb”) is typically defined as 20°C ± 5°C. The residual cut is defined as a distillation interval cut above 340°C.

[0047] Liquefied Petroleum Gas, or LPG, refers to two gases in their liquid state: propane and butane. Their advantage lies in their ability to liquefy under lower pressure than other gases (particularly methane): between 1.5 and 7 bar. Conrardson Carbon (CCR): A standardized laboratory test used to evaluate, through combustion, the propensity of a hydrocarbon feedstock to produce coke, which is detrimental to refining operations (distillation, catalysis) because it forms solid deposits (fouling).

[0048] Biogenic or pMC: This refers to the carbon contained in bio-based materials. This carbon comes from the transformation of carbon dioxide (CO2) through photosynthesis during plant growth. On land, this CO2 is captured or fixed by plant life (for example, agricultural crops or forest materials). In the oceans, CO2 is captured or fixed by photosynthetic bacteria or phytoplankton. For example, a bio-based material has an isotopic ratio 14 C / 12 C greater than 0. Conversely, a material of fossil origin has an isotopic ratio 14 C / 12C of approximately 0. The terms "renewable" or "derived from renewables" can also be used. To determine whether a material / product / compound is bio-based or derived from renewables, its modern carbon (or percent modern carbon, pMC) or biogenic carbon content is measured according to ASTM D 6866-21 ("Determination of Bio-based Content of Natural Range Materials by Radiocarbon and Isotope Ratio Mass Spectrometry Analysis"). The method in this standard measures the isotope ratio. 14 C / 12 C in a sample and compares it to the isotopic ratio 14 C / 12The bio-based content (pMC) of a standard bio-based reference material is used to obtain the percentage of bio-based content in the sample. This reference material provides a radiocarbon content approximately equivalent to the atmospheric radiocarbon fraction in 1950. The pMC (or biogenic content) of the standard bio-based reference material is therefore 100%. The pMC (or biogenic content) of a fossil-based material is approximately 0%. A current bio-based material may therefore also have a pMC greater than 100%.

[0049] The total, monoaromatic, diaromatic, and polyaromatic content of the solvolysis oil and its various fractions is determined by UV spectroscopy according to the Burdett method (Burdett R. A., Taylor LW., and Jones LC., Journal of Molecular Spectroscopy, Rept. Conf., Inst. Petroleum, London 1954, 30–41, 1955). Polyaromatics are defined as aromatics containing three or more aromatic rings.

[0050] 2. Description

[0051] The present invention relates to a process for producing atmospheric distillates from a solid feed based on spent elastomers, said process comprising at least the following steps: a) a solid feed (100) based on spent elastomers is sent into a reaction zone (80) in the presence of a liquid solvent (760) comprising aromatic compounds to dissolve at least partially said solid feed and thermally decompose said at least partially dissolved solid feed at a temperature below 400°C and a pressure below 2 MPa in order to obtain a first gaseous effluent (310) and a first liquid effluent (320) comprising carbon black, the mass ratio between the liquid solvent (760) and the solid feed (100) being greater than 3 by weight; b) the first liquid effluent (320) obtained in step a) is sent into a separation zone (40) in order to obtain a carbon black cake (420) and a second liquid effluent (410);(c) at least part of said first 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 light hydrocarbon cut (720) having a final boiling point below 260°C and at least one intermediate hydrocarbon cut (730) comprising an aromatic compound content exceeding 30% by weight relative to the total weight of said intermediate hydrocarbon cut (730), and further comprising:;

[0052] - a C5-C10 hydrocarbon compound content of less than 20% by weight relative to the total weight of the hydrocarbon fraction; and

[0053] - a C40+ hydrocarbon compound content of less than 5% by weight relative to the total weight of said hydrocarbon cut;

[0054] - a C40+ hydrocarbon content of less than 5% by weight relative to the total weight of said hydrocarbon cut; and a heavy hydrocarbon cut (740) having an initial boiling point between 340°C and 440°C; d) at least a portion of said light hydrocarbon cut (720) and at least a portion of said intermediate hydrocarbon cut (730) obtained at the end of step c) are sent into the reaction zone (80) as liquid solvent (760) of step a), characterized in that the mass ratio between said intermediate hydrocarbon cut (730) and the liquid solvent (760) is between 0.2 and 0.95 weight / weight;(e) at least a portion of said heavy hydrocarbon fraction (740) obtained in step (d) is sent to a catalytic cracking zone (20) in a fluidized bed reactor in the presence of a solid catalyst, at a temperature between 500°C and 700°C, and a pressure between 0.1 and 0.6 MPa to obtain a catalytic cracking effluent (220); (f) the catalytic cracking effluent (220) obtained at the end of step (e) is distilled to obtain an atmospheric distillate composed of a gasoline fraction (920) and a diesel fraction (930).

[0055] The solid charge (100) used in the context of the present invention is advantageously based on used elastomers which can come from any source, from tires of light vehicles (LV) or heavy goods vehicles (HGV), two wheels or any type of special machinery, vehicle door seals, but also objects such as shoe soles or rubber boots.

[0056] The said solid filler can advantageously be in the form of elastomer granules, i.e. in the form of particles of sizes less than 25mm containing more than 80% elastomers and reinforcing filler (carbon black, silica, ...), from the treatment of end-of-life waste and containing large quantities of elastomers.

[0057] Thus, according to a preferred embodiment of the invention, the solid feed (100) is sent to a pretreatment unit (10) in order to remove textile fibers and metal wires (110) from the solid feed (100). Such a pretreatment unit is well known to those skilled in the art and can consist of various types of crushers (i.e., a rotary shear, a shredder, a granulator, a refiner), a magnetic separator, or even a vibrating screen or a separation table.

[0058] According to step a) of the conversion process, the gum contained in the solid feed (100) is sent to a reaction zone (80) to be dissolved by contact with the liquid solvent (760) and 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 absolute, preferably between 0.2 MPa and 1.2 MPa absolute.At the end of step a), at least one gaseous effluent (310) and a first liquid effluent (320) are obtained, comprising carbon black and possibly solid residues (210) contained in used elastomers, particularly in 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. The mass ratio between the liquid solvent (760) and the solid feedstock (100) is greater than or equal to 3 wt / w, preferably between 3 wt / w and 10 wt / w, more preferably between 4 wt / w and 7 wt / w.

[0059] Advantageously, the residence time in the reaction zone (80) is between 0.5 hours and 4 hours.

[0060] According to one or more embodiments, step a) comprises the following substeps: a1) said solid feed and said liquid solvent are sent into a first stirred reactor to dissolve at least part of said solid feed; with a residence time between 30 minutes and 2 hours, at a temperature less than or equal to 300°C; a2) the liquid effluent obtained at the end of step a1) is sent into a second stirred reactor to thermally decompose said solid feed at a temperature less than or equal to 400°C (residence time between 30 minutes and 2 hours) and obtain a liquid effluent containing suspended carbon black particles.

[0061] The first liquid effluent (320), containing carbon black, is then sent to a separation zone (40) to recover a carbon black cake (420) and a second liquid effluent (410). This separation step can be carried out by filtration or centrifugation, preferably by centrifugation. Those skilled in the art can use any type of centrifuge technology, including plate centrifuges or centrifugal decanters. Centrifugation can be performed, for example, at a centrifugal force between 1000 G and 16000 G for a duration of between 30 seconds and 30 minutes.

[0062] Step b) is advantageously followed by a step b') of conduction drying of the centrifuged carbon black cake (420) obtained at the end of step b) which can, for example, be carried out at a temperature between 150°C and 350°C, a vacuum pressure between 0.0001 MPa and 0.01 MPa absolute, under agitation between 2 rpm and 150 rpm for a period between 1 hour and 8 hours to obtain the recovered dry carbon black.

[0063] The second liquid effluent (410) preferably consists of more than 40% by weight of the first liquid effluent (320), more preferably more than 60% by weight of the first liquid effluent (320). It may advantageously incorporate the hydrocarbon effluents resulting from the drying of carbon black.

[0064] At least part of the first 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 light hydrocarbon cut (720) having a final boiling point below 260°C and at least one intermediate hydrocarbon cut (730) comprising an aromatic compound content exceeding 30% by weight relative to the total weight of said intermediate hydrocarbon cut (730), and further comprising: - a C5-C10 hydrocarbon compound content of less than 20% by weight relative to the total weight of the hydrocarbon cut; and

[0065] - a C40+ hydrocarbon compound content of less than 5% by weight relative to the total weight of said hydrocarbon cut; and a heavy cut (740), whose initial boiling temperature is preferably between 340°C and 440°C.

[0066] Advantageously, the light cut (720) comprises at least a C10- hydrocarbon compound content greater than 60% by weight relative to the total weight of the light cut (720).

[0067] Advantageously, the light cut (720) has a final boiling point below 240°C, preferably below 220°C.

[0068] Advantageously, the light cut (720) comprises a total aromatics content greater than 3% by weight, preferably greater than 5% by weight, and more preferably greater than 10% by weight relative to the total weight of the light hydrocarbon cut (720).

[0069] Advantageously, the light cut (720) comprises a mass percentage of monoaromatics greater than 60% by weight, preferably greater than 70% by weight, and more preferably greater than 80% by weight relative to the total aromatics of the light cut (720).

[0070] Advantageously, the light cut (720) comprises a mass percentage of diaromatics greater than 5% by weight, preferably greater than 10% by weight relative to the total aromatics of the light cut (720).

[0071] Advantageously, the light cut (720) comprises a mass percentage of polyaromatics of less than 10% by weight, preferably less than 5% by weight, and more preferably less than 1% relative to the total aromatics of the light cut (720).

[0072] Advantageously, the fractionation zone (70) also allows the obtaining of non-condensable gases (710).

[0073] Advantageously, the intermediate hydrocarbon cut (730) also comprises a content of C10-C20 hydrocarbon compounds of between 20% by weight and 65% by weight relative to the total weight of the hydrocarbon cut, preferably between 30% by weight and 65% by weight, and even more preferably between 45% by weight and 65% by weight.

[0074] Advantageously, the intermediate hydrocarbon cut (730) also comprises a content of C20-C40 hydrocarbon compounds of between 30% by weight and 80% by weight relative to the total weight of the hydrocarbon cut, preferably between 30% by weight and 70% by weight, and even more preferably between 30% and 55% by weight.

[0075] Advantageously, the intermediate hydrocarbon cut (730) has an initial boiling temperature between 200°C and 260°C, and a final boiling temperature between 350°C and 520°C, preferably between 340°C and 440°C.

[0076] Advantageously, the intermediate hydrocarbon cut (730) comprises a total aromatics content greater than 40% by weight compared to the intermediate hydrocarbon cut (730), preferably greater than 50% compared to the intermediate hydrocarbon cut (730).

[0077] Advantageously, the intermediate hydrocarbon cut (730) comprises a mass percentage of monoaromatics greater than 50% by weight, preferably greater than 60% by weight, and more preferably greater than 70% by weight relative to the total aromatics of the intermediate hydrocarbon cut (730).

[0078] Advantageously, the intermediate hydrocarbon cut (730) comprises a mass percentage of diaromatics greater than 5% by weight, preferably greater than 10% by weight relative to the total aromatics of the intermediate hydrocarbon cut (730).

[0079] Advantageously, the intermediate hydrocarbon cut (730) comprises a mass percentage of polyaromatics of less than 15% by weight, preferably less than 10% by weight, and more preferably less than 5% relative to the total aromatics of the intermediate hydrocarbon cut (730).

[0080] Advantageously, the heavy cut (740) comprises a C40+ hydrocarbon content exceeding 60% by weight relative to the total weight of the heavy cut (740). The heavy hydrocarbon cut (740) represents between 20% and 75% by weight, preferably between 30% and 50% by weight, of the total solvolysis oil. This total solvolysis oil is composed of the light cut (720), the intermediate hydrocarbon cut (730), and the heavy cut (740).

[0081] The heavy hydrocarbon cut (740) comprises a total aromatics content greater than 50% by weight, preferably greater than 60% by weight, and more preferably greater than 70% by weight compared to the heavy hydrocarbon cut (740).

[0082] The heavy hydrocarbon cut (740) comprises a mass percentage of monoaromatics greater than 40% by weight, preferably greater than 50% by weight, and more preferably greater than 60% by weight relative to the total aromatics of the heavy hydrocarbon cut (740).

[0083] The heavy hydrocarbon cut (740) comprises a mass percentage of diaromatics greater than 10% by weight, preferably greater than 20% by weight, relative to the total aromatics of the heavy hydrocarbon cut (740).

[0084] The heavy hydrocarbon cut (740) comprises a mass percentage of polyaromatics of less than 20% by weight, preferably less than 15% by weight, and more preferably less than 10% relative to the total aromatics of the heavy hydrocarbon cut (740).

[0085] The heavy hydrocarbon cut (740) includes a Conradson Carbon of less than 3, preferably less than 2, more preferably less than 1.

[0086] This specific percentage of monoaromatics compared to total aromatics in the heavy hydrocarbon cut (740) makes it possible to increase the yield in atmospheric distillates without promoting the additional formation of coke in the catalytic cracking unit of step e).

[0087] According to the invention, at least part of a fraction of the light hydrocarbon cut (720) and at least part of the fraction of the intermediate hydrocarbon cut (730) are sent to the reaction zone (80) of step a) as a liquid solvent (760), the other parts (750) and (770) being advantageously sent outside the process according to the invention as a valuable product. The mass ratio between the liquid solvent (760) and the flow rate of the solid feed (100) injected into the reaction zone (80) is greater than or equal to 3 wt / wt, preferably between 3 wt / wt and 10 wt / wt, more preferably between 4 wt / wt and 7 wt / wt.Indeed, one of the characteristics of the liquid solvent (760) is that it contains an aromatics content exceeding 30% by weight relative to the total weight of said liquid solvent (760), enabling it to effectively dissolve the solid feed (100) and 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 allows it to remain in liquid form while limiting the pressure in the reactors to a level below 2 MPa. The precise optimization of the composition of the liquid solvent (760), the ratio of liquid solvent (760) to solid feed (100), and the reactor pressure also makes it possible to target a carbon black concentration in the reactor outlet effluent, allowing for proper management of this flow and the conditions suitable for carbon black separation.

[0088] During plant start-up, in the absence of production of a stabilized intermediate fraction, i.e., the intermediate hydrocarbon fraction (730), it is possible to temporarily use an imported solvent, preferably one with an aromatic molecule content exceeding 40% by weight relative to the total weight of the fraction. This fraction could therefore consist, for example, of conversion effluents from the FCC (Fluid Catalytic Cracking) process, diesel fuel, or heavy diesel fuel.

[0089] Step e)

[0090] At least a portion of the heavy hydrocarbon fraction (740) obtained in step d) is sent to a catalytic cracking zone (20) comprising at least one fluidized bed reactor (FCC) in the presence of a solid catalyst, at a temperature between 500°C and 700°C, preferably below 650°C, and a pressure between 0.1 and 0.6 MPa. The gas surface velocity is advantageously between 3 and 30 m / s. The contact time is advantageously less than 2 seconds. The C / O ratio is advantageously between 3 and 50.

[0091] In a preferred embodiment of the invention, said heavy hydrocarbon cut (740) obtained in step d) is mixed with a petroleum fossil feedstock of residue type (360°C+) in the catalytic cracking zone (20).

[0092] The addition of said heavy hydrocarbon cut (740) from solvolysis which has a Carbon Conradson lower than a residue type feed (360°C+) (generally CCR between 3 and 6) makes it possible to lower the coke yield of the units compared with a catalytic cracking unit operating with 100% of a fossil petroleum residue type feed (360°C+) thus making it possible to increase the circulation of catalyst and by a synergistic effect a better yield of atmospheric distillate (gasoline and diesel).

[0093] Indeed, in the catalytic cracking process, the coke formed on the catalyst is burned in the regeneration section, leading to a temperature increase in the catalyst. The catalyst then returns to the reaction zone at a higher temperature, providing the heat necessary for feed conversion. Thus, the more coke formed, the hotter the catalyst will return. Since the reaction zone temperature is fixed to limit the formation of cracked gases (C1 / C2), it is more advantageous to have a catalyst regenerated at a lower temperature because reaching the target temperature will require a higher catalyst flow rate. As with catalytic reactions, it is understood that the higher the catalyst-to-feed ratio (C / O), the more selectively the system can convert the processed feed.

[0094] The present invention is compatible with all catalytic cracking reactor technologies, whether it be an upward solid gas flow technology (called "riser" in Anglo-Saxon terminology), or a downward flow technology (called "dropper" or "downer" in Anglo-Saxon terminology).

[0095] The catalytic cracking unit used in this process can be configured in several ways: with a single reactor or multiple reactors, each capable of operating in either upward or downward flow. Most often, both reactors will operate in the same flow mode.

[0096] The catalyst is a solid catalyst. Its size and shape are known to those skilled in the art and will not be described further. In one or more embodiments, the catalyst contains a matrix made of clay, alumina, silica, or silica-alumina, a binder, and zeolite, for example, 15% to 50% by weight of zeolite relative to the weight of the catalyst, preferably zeolite Y and / or zeolite ZSM-5. In one or more embodiments, the catalyst comprises zeolite ZSM-5. In one or more embodiments, the grain density of the catalyst is between 1000 kg / m³ 3 and 2000 kg / m 3 According to one or more embodiments, the grain density of the catalyst is between 1250 kg / m³ 3 and 1750 kg / m 3The FCC reactor catalyst consists of particles with an average diameter generally between 40 and 140 micrometers (1 micron = 10⁻⁶ meters), and preferably between 50 and 120 micrometers.

[0097] The spent catalyst stream from the FCC reactor is separated from the cracking effluents by any gas-solid separation system known to those skilled in the art and regenerated in a regeneration zone. Passing said heavy hydrocarbon fraction (740) through the catalytic cracking zone (20) under the conditions described above yields a catalytic cracking effluent (220) with boiling points lower than that of the feedstock. The conversion on said solid catalyst of heavy products (with boiling points greater than or equal to 340°C) into light products (with boiling points below 340°C) is greater than or equal to 40% by weight, preferably greater than 75%.

[0098] Step f) Distillation of the cracking effluent

[0099] The effluent from the catalytic cracking reactor (220) is sent to a fractionation zone (90) to produce several fractions, including a diesel fraction (930) with a distillation range advantageously between 220°C and 360°C. A gasoline fraction (920) with a distillation range advantageously between 70°C and 220°C, light gases (910), and advantageously a heavy fraction (940) with a boiling point above 360°C are also generally recovered.

[0100] This type of fractionation unit is well known to those skilled in the art.

[0101] Examples

[0102] Example 1: (according to the invention) Production of a solvolysis oil from used elastomers The process used to illustrate the invention conforms to that described in Figure 1.

[0103] In this example, the solvolysis oil from spent elastomers is produced according to steps a) to d) of the invention. The spent elastomer feedstock consists of 100% used tires.

[0104] Used tire granules (solid charge (100)), produced by granulators using crushers, are used. These granules come from heavy-duty tires, and the resulting granules are approximately 4 millimeters in size. The tire granules (100) originate from a pretreatment unit (10) and are free of textile and metallic fibers. The granules (100) are then continuously fed into a dissolution reactor (step a1) where they are mixed with the liquid solvent from the intermediate hydrocarbon fraction (730) recycled from the fractionation zone (70). The mixture is then sent to the conversion reactor (80) (step a2). A portion of the hydrocarbon fractions (720) and (730), whose yields are shown in Table 1 below, serves as the liquid solvent (760) described below. The mass ratio of solvent (760) to granules (100) is 5 wt / wt.In reactor (80), the temperature is maintained at 280°C for dissolution (step a1), which dissolves the aggregates (100), and at 400°C for conversion (step a2). The residence time in reactor (80) is 1 hour. The pressure in the dissolution reactor is 0.9 MPa. At the outlet of reactor (30), a first liquid effluent (320) and a gaseous effluent (310) are collected. The latter is sent entirely to the fractionation zone (70), which allows for the recovery of, among other things, the light hydrocarbon fraction (720), the intermediate hydrocarbon fraction (730), and the heavy fraction of the solvolysis oil (740), the composition of which is given in Table 3 of Example 4.

[0105] Table 1 presents the yield structure obtained by solvolysis under the conditions of example 1. For comparison, the solvolysis process leads to less gas, 2% (of little value) and much more total oil fraction of interest 63% wt than a pyrolysis process for which the liquid oil fraction is about 40% wt (cf. MF Laresgoiti, BM Caballero, I. de Marco, A. Torres, MA Cabrero, MJ Chomôn, Characterization of the liquid products obtained in tire pyrolysis, J. Anal. Appl. Pyrolysis 71, 917-934, 2004).

[0106] Table 1

[0107] Table 2 shows the aromatic composition of the heavy cut (740), the light cut (720), and the intermediate cut (730). The Conradson carbon is also given for the heavy cut (740).

[0108] Table 2

[0109] The heavy hydrocarbon cut (740) contains 74% of the total aromatics relative to the heavy hydrocarbon cut (740). The heavy hydrocarbon cut (740) contains a significant mass percentage of monoaromatics, 71.6% by weight relative to the total aromatics. The heavy hydrocarbon cut (740) contains 18.9% by weight of diaromatics relative to the total aromatics and only 9.4% by weight of polyaromatics relative to the total aromatics.

[0110] The heavy hydrocarbon cut (740) includes a Conradson Carbon of 0.84.

[0111] The low polyaromatic content is a strong marker of the quality of the oil resulting from the conversion of tires by the Solvolysis route compared to pyrolysis oil (see the article E. Rodriguez et al., Production of Non-Conventional Fuels by Catalytic Cracking of Scrap Tires Pyrolysis Oil Ind. Eng. Chem. Res. 2019, 58, 5158-5167 and the article MF Laresgoiti, BM Caballero, I. de Marco, A. Torres, MA Cabrero, MJ Chomôn, Characterization of the liquid products obtained in tyre pyrolysis, J. Anal. Appl. Pyrolysis 71, 917-934, 2004).

[0112] This is explained by the use of an internal solvent in the solvolysis process, which allows for the conversion of the material at a lower temperature (400°C) compared to 600-700°C for pyrolysis. This promotes oil selectivity and minimizes gas production. The quality of the oil produced is thus improved, with a lower total aromatic content, particularly polyaromatics, resulting in a lower CCR (here, less than 1). The valorization of FCC is therefore significantly enhanced, as this process converts the material without the addition of hydrogen, which would otherwise produce coke. The quantity of coke in FCC will therefore be considerably lower in the case of products from solvolysis, thus allowing for better selectivity towards valuable products, i.e., atmospheric distillate.

[0113] Example 2 (comparative): Supplying a distillate under vacuum

[0114] The vacuum distillate is a heavy petroleum cut (360°C+) commonly used as a catalytic cracking feedstock; it is of Arabian Light origin. The main characteristics in terms of viscosity, density, CHONS, simulated distillation curve, and aromatic distribution as determined by UV spectroscopy are given in Table 3.

[0115] Table 3

[0116] Example 3: Conditions for catalytic cracking tests in a fluidized bed

[0117] Fluidized bed cracking tests are carried out in a pilot unit using the Short Contact Time Resid Test or SCT-RT, which allows the simulation of reactions taking place during the catalytic cracking of hydrocarbons in a fluidized bed and the study of phenomena occurring during the vaporization of the feed in the reactor in contact with the catalyst.

[0118] The FCC feedstock is injected into the reactor bottom for one second at a low temperature of 100°C. After contact with the catalyst, which is heated to 600°C and fluidized with nitrogen, the feedstock vaporizes and is transformed into lighter products. The reaction products are then conducted into a condenser cooled to -12°C, where the liquid product is separated from the gaseous mixture (composed of fluidizing nitrogen and the lighter cracking products). The liquid and gaseous products are then quantified. Samples are taken for analysis. The SCT-RT reactor operates at low pressure (1.2 bar) with a C / O ratio of 6. The zeolite-based FCC catalyst Y has a Sauter diameter of 60 micrometers.

[0119] Example 4: Catalytic cracking of 100% DSV (comparative)

[0120] In Example 4, the feed processed in the SCRT fluidized bed catalytic cracking pilot unit under the conditions of Example 3 is a petroleum fossil feed composed of 100% mass of vacuum distillate (Example 2) under the conditions of Example 2.

[0121] Example 5: catalytic cracking of a charge composed of 10% mass fraction of solvolysis oil (740) (according to the invention) and 90% DSV.

[0122] In Example 5, the feed processed in the SCRT fluidized bed catalytic cracking pilot unit under the conditions of Example 3 is a feed composed of 90% by mass of vacuum distillate (see Example 2) and 10% by mass of the heavy fraction of solvolysis oil (740) (see Example 1) under the conditions of Example 2. Example 6: Yield structure in catalytic cracking

[0123] The yield results in different cuts and coke from examples 4 and 5 are shown in Table 4.

[0124] Table 4 Replacing 10% by mass of the DSV feed with the 340C°+ cut from tire solvolysis (example 1) allows a very significant gain in products of interest, namely in atmospheric distillate cut (gasoline and diesel), ultimately leading to the production of gasoline and diesel after dedicated conventional hydrotreatments.

[0125] This cut also makes it possible to significantly reduce the gases produced that have no economic value.

[0126] These gains are also accompanied by a reduction in the production of coke and undesirable heavy cut (residue).

[0127] If we start on a production basis of a catalytic cracking unit of 966 kta (kilotons per year), the 340°C+ cut from solvolysis (740) containing about 50% wt of biogenic carbon leads to the production of 24 kta of additional fuel (gasoline and diesel), compared to a DSV feed of which 12 kta of the additional production is from biogenic source.

[0128] Example 7: Heat balance of the catalytic cracking unit

[0129] As described previously, if less coke is produced, the temperature of the regenerated catalyst will be lower (less heat is released by coke combustion due to its smaller quantity). To target the same temperature in the riser, the catalyst flow rate will be increased, resulting in a higher C / O ratio. Since this is a catalytic process, the higher the catalyst-to-C / O feed ratio, the greater the conversion of the feed into the desired product.

[0130] The results of the heat balance at the regenerator level, calculated with coke with a hydrogen content of 5% wt%, expressed in terms of regeneration temperature, catalyst ratio on C / O charge, and % residue of examples 4 and 5 are visible in Table 5.

[0131] Table 5

[0132] Thus, replacing part of the residual charge with the 340°C+ cut from tire solvolysis results in a reduction of coke yield leading to a decrease in regeneration temperature of 35°C and an increase in the C / O ratio from 8 to 9.

[0133] For the same riser temperature of 530°C, this increase in C / O translates into an increase in the load conversion to 340°C' of 4 points.

[0134] Thus, introducing the 340°C+ feedstock from solvolysis into a catalytic cracking process (CCP) improves the yield of atmospheric distillate (gasoline and diesel) and, simultaneously, through a more favorable heat balance, improves the feedstock conversion to 340°C' by 4 percentage points. The catalytic cracking process is therefore a method for valorizing solvolysis oils into atmospheric distillate.

Claims

Demands 1. Process for producing atmospheric distillates from a solid feed based on spent elastomers, said process comprising at least the following steps: a) a solid feed (100) based on spent elastomers is sent into a reaction zone (80) in the presence of a liquid solvent (760) comprising an aromatics content greater than 30% by weight relative to the total weight of said liquid solvent to dissolve at least partially said solid feed and thermally decompose said at least partially dissolved solid feed at a temperature below 400°C and at a pressure below 2 MPa in order to obtain a first gaseous effluent (310) and a first liquid effluent (320) comprising carbon black, the mass ratio between the liquid solvent (760) and the solid feed (100) being greater than 3 by weight;b) the first liquid effluent (320) obtained in step a) is sent to a separation zone (40) in order to obtain a carbon black cake (420) and a second liquid effluent (410); c) at least part of said first 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 light hydrocarbon cut (720) having a final boiling point below 260°C and comprising an aromatic compound content greater than 3% by weight relative to the total weight of said intermediate hydrocarbon cut (720) and at least one intermediate hydrocarbon cut (730) comprising an aromatic compound content greater than 40% by weight relative to the total weight of said intermediate hydrocarbon cut (730), and further comprising:; - a C5-C10 hydrocarbon compound content of less than 20% by weight relative to the total weight of the hydrocarbon fraction; and - a C40+ hydrocarbon compound content of less than 5% by weight relative to the total weight of said hydrocarbon cut; - a C40+ hydrocarbon content of less than 5% by weight relative to the total weight of said hydrocarbon fraction; and a heavy hydrocarbon fraction (740) having an initial boiling point between 340°C and 440°C; (d) at least a portion of said light hydrocarbon fraction (720) and at least a portion of said intermediate hydrocarbon fraction (730) obtained at the end of step (c) are sent to the reaction zone (80) as liquid solvent (760) of step (a), characterized in that the mass ratio between said intermediate hydrocarbon fraction (730) and the liquid solvent (760) is between 0.2 and 0.95 weight / weight; (e) at least a portion of said heavy hydrocarbon fraction (740) obtained in step (d) is sent to a catalytic cracking zone (20) comprising at least one fluidized bed reactor in the presence of a solid catalyst, at a temperature between 500°C and 700°C, a pressure between 0.1 and 0.6 MPa to obtain a catalytic cracking effluent (220); f) the catalytic cracking effluent (220) obtained at the end of step e) is distilled to obtain an atmospheric distillate composed of at least one gasoline cut (920) and one diesel cut (930).

2. A process according to claim 1, wherein the heavy hydrocarbon cut (740) comprises a mass percentage of polyaromatics less than 20% by weight relative to the total aromatics of said heavy hydrocarbon cut.

3. A process according to claim 1, wherein the heavy hydrocarbon cut (740) comprises a mass percentage of polyaromatics less than 15% by weight relative to the total aromatics of said heavy hydrocarbon cut.

4. A process according to any one of the preceding claims, wherein the heavy hydrocarbon cut (740) comprises a Conradson Carbon of less than 3.

5. A process according to any one of the preceding claims, wherein the heavy hydrocarbon cut (740) comprises a Conradson Carbon of less than 2.

6. A process according to any one of the preceding claims, wherein the heavy hydrocarbon cut (740) comprises a total aromatics content exceeding 50% by weight relative to said heavy hydrocarbon cut.

7. A process according to any one of the preceding claims, wherein the heavy hydrocarbon cut (740) comprises a mass percentage of monoaromatics greater than 40% by weight relative to the total aromatics.

8. A process according to any one of the preceding claims, wherein the heavy hydrocarbon cut (740) comprises a mass percentage of monoaromatics greater than 50% by weight relative to the total aromatics of said heavy hydrocarbon cut.

9. A process according to any one of the preceding claims, wherein the heavy hydrocarbon cut (740) comprises a mass percentage of diaromatics greater than 10% by weight relative to the total aromatics of said heavy hydrocarbon cut.

10. A process according to any one of the preceding claims, wherein the heavy hydrocarbon cut (740) represents between 20% and 75% by weight of the total solvolysis oil.

11. Process according to any one of the preceding claims, said heavy hydrocarbon cut (740) is mixed with a petroleum fossil feedstock of distillate type under vacuum (360°C+) and then sent to the catalytic cracking zone (20).

12. A process according to any one of the preceding claims, wherein the light hydrocarbon cut (720) comprises a mass percentage of monoaromatics greater than 60% by weight relative to the total aromatics of said light cut and a mass percentage of polyaromatics less than 10% by weight relative to the total aromatics of said light cut.

13. A process according to any one of the preceding claims, wherein the intermediate hydrocarbon cut (730) comprises a mass percentage of monoaromatics greater than 50% by weight relative to the total aromatics of said intermediate hydrocarbon cut and a mass percentage of polyaromatics less than 15% by weight relative to the total aromatics of said intermediate hydrocarbon cut.

14. A method according to any one of the preceding claims, wherein the catalytic cracking catalyst implemented in step e) comprises a ZSM-Y zeolite.

15. A process according to any one of the preceding claims, wherein step a) comprises the following substeps: a1) said solid feed (100) and said liquid solvent (760) are sent into a first stirred reactor (20) to dissolve at least part of said solid feed (100); a2) said at least partially dissolved solid feed obtained at the end of step a1) is sent into a second stirred reactor (30) to thermally decompose said solid feed at a temperature less than or equal to 400°C and obtain a liquid effluent containing suspended carbon black particles.

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