Method for producing a label-free process oil by means of hydrogenation

Abstract

The invention relates to a method for producing a label-free aromatic process oil from a pyrolysis oil from used tires. The method has the steps of distilling the pyrolysis oil from used tires in a fractional distillation process, wherein at least one low-boiling fraction, at least one high-boiling fraction, and optionally an atmospheric residue are obtained; and selectively hydrogenating the at least one high-boiling fraction or the atmospheric residue with hydrogen, a label-free aromatic process oil being obtained. The invention further relates to a label-free aromatic process oil and to the use of the process oil in tires or rubber mixtures.

Description

[0001] 12 / 17 / 2025 Hansen & Rosenthal GmbH & H1772O9WO BER / Kks / mnk Co. KG

[0002] Method for producing a label-free process oil

[0003] through hydrogenation

[0004] The invention relates to a method for producing a label-free aromatic process oil by hydrogenation, the aromatic process oil and its use.

[0005] Worldwide, approximately 1.5 billion end-of-life tires are generated annually, a large proportion of which are landfilled. In the European Union alone, there are approximately 3.5 million tons of end-of-life tires. A significant portion of these are incinerated, resulting in corresponding carbon dioxide emissions.

[0006] One method for the material recycling of used tires is pyrolysis, which produces recovered carbon black as its primary product. Used tires consist of several components, such as rubber, steel, carbon black, and additives. For processing by pyrolysis, the steel wire is extracted from the tires and can be reused as scrap metal. The remaining rubber is shredded, finely ground, and depolymerized in a pyrolysis reactor at high temperatures, e.g., 700 °C, in the absence of oxygen. This depolymerization process separates the rubber into its various components, including carbon black. Non-condensable gases and pyrolysis oil, also known as tire pyrolysis oil (TPO), are produced as byproducts.Due to its low flash point and, in particular, its high content of polycyclic aromatics and the high level of impurities and organic compounds with heteroatoms, such as sulfur and nitrogen, this pyrolysis oil is of little value and has no established application.

[0007] From Roy et al., “The vacuum pyrolysis of used tires: End uses for oil and carbon black products” (Journal of Analytical and Applied Pyrolysis, Volume 51, Issues 1-2, July 1999, Pages 201-221), the pyrolysis of used tires and the use of the individual pyrolysis products are known. However, not all fractions obtained are reusable, and low-cost products such as bitumen or carbon black are produced in the heavy fraction, each of which can only be reused as a fraction of the heavy fraction.

[0008] EP 2557143 Ai describes a process for producing naphthenic process oils from mineral oil products by hydrogenation. In this process, a highly naphthenic process oil with a naphthenic hydrocarbon content of 65 wt.% - 75 wt.% is obtained from a fossil feedstock at temperatures between 200 °C and 400 °C and in the presence of a metal catalyst.

[0009] The object of the invention is therefore to provide a method that allows the utilization of pyrolysis oil from waste tires as a valuable material and in particular provides a label-free product that can be reused as a raw material in industry.

[0010] The object is achieved according to the invention by a method for producing a label-free aromatic process oil according to claim 1, a process oil according to claim 5 and the use of a process oil according to claim 11.

[0011] Further details are the subject of the dependent claims or are described below.

[0012] The inventive process for producing a label-free aromatic process oil comprises at least the following steps:

[0013] a. Submission of a pyrolysis oil from used tires (TPO), hereinafter referred to as tire pyrolysis oil, wherein the tire pyrolysis oil has an aromatic content according to DIN 51378: 2020 of 30 wt.% to 50 wt.%, as well as a "Bureau of minerals correlation index" (BMCI) according to API Technical Data Book of greater than 55, a bio-based carbon content according to ASTM D6866 Method B:2022 of 40% (pMC) to 55% (pMC), and a density at 15°C of 880-970 kg / m³ 3measured according to DIN 51757 Method 3 (2011), has a sulfur content of 0.8-1.1 wt% measured according to DIN EN ISO 14596: 2007, a nitrogen content of 3500-6000 mg / kg measured according to DIN 51444: 2020, a benzo[a]pyrene content between 5 mg / kg and 150 mg / kg measured according to DIN EN 16143: 2023 and a PAH content determined as a sum according to Directive 2005 / 69 / EU of greater than 40 mg / kg and up to 850 mg / kg measured according to DIN EN 16143: 2023, and

[0014] b. optional distillation of the tire pyrolysis oil in a fractional distillation at temperatures between 100 and 500 °C under atmospheric pressure or vacuum, obtaining at least one low-boiling fraction and at least one high-boiling fraction and optionally an atmospheric residue,

[0015] c. Hydrogenation of the at least one high-boiling fraction or atmospheric residue from step b. or of the tire pyrolysis oil from step a. with hydrogen using a metal catalyst, preferably a base metal catalyst selected from cobalt-molybdenum catalysts, nickel-cobalt-molybdenum catalysts, nickel-molybdenum catalysts, a mixture of a nickel-molybdenum catalyst with zeolites, nickel-tungsten catalysts, or a mixture thereof, wherein the hydrogenation is carried out as a selective hydrogenation at temperatures between 240°C and 400°C, preferably 250°C and 300°C, particularly preferably 200°C and 350°C, and pressures of 30 bar to 200 bar, preferably 40 bar and 100 bar, particularly preferably 50 bar to 160 bar, further preferably 80 bar to 140 bar, and a residence time LHSV (liquid hourly space velocity) of between 0.1 h 1 and 0.4 h 1 preferably between 0.15 h 1 and 0.4 h 1and d. transferring the hydrogenated product from step c. into a distillation reactor, preferably a distillation column, preferably a stripping vapor column, and carrying out a distillation at temperatures between 200 and 450 °C under atmospheric pressure or vacuum to separate the lighter-boiling substances formed in the hydrogenation, whereby a heavy-boiling, aromatic process oil is obtained that has a proportion of aromatic hydrocarbons CA of more than 10 to 35 wt.%, preferably more than 10 to 30 wt.%, measured according to DIN 51378: 2020, a benzo[a]pyrene content of less than 1 mg / kg measured according to DIN EN 16143: 2023 and a PAH content determined as a sum according to Directive 2005 / 69 / EU of less than 10 mg / kg measured according to DIN EN 16143: 2023.

[0016] A PAH content determined as a sum according to Directive 2005 / 69 / EU includes the sum of the following eight polycyclic aromatic hydrocarbons: Benzo(a)pyrene (CAS No. 50-32-8), Benzo(e)pyrene (CAS No. 192-97-2), Benzo(a)anthracene (CAS No. 56-55-3), Chrysene (CAS No. 218-01-9), Benzo(b)fluoranthene (CAS No. 205-99-2), Benzo(j)fluoranthene (CAS No. 205-82-3), Benzo(k)fluoranthene (CAS No. 207-08-9), Dibenz(a,h)anthracene (CAS No. 53-70-3), which according to Bundesrat document 190 / 06 of 09.03.2006, section 29 in the use in the tire are limited.

[0017] According to the invention, pyrolysis oil from used tires is understood to be a liquid, aromatic oil produced under anaerobic conditions by thermal decomposition of used tires, in particular by thermal depolymerization of the rubber contained in the tires, selected from natural rubber and synthetic rubber, such as styrene-butadiene rubber or other copolymers of styrene, butadiene, and / or isoprene monomers, isoprene rubber, butadiene rubber, ethylene propylene diene monomer rubber, halobutyl, and butyl rubber, as well as the dissolution and degradation of the various components that constitute the complex structure of a tire. The thermal decomposition and depolymerization of the used tires can be carried out by pyrolysis, solvolysis, or hydrothermal liquefaction. The pyrolysis oil is also referred to as Tire Pyrolysis Oil, or TPO for short, and has an aromatic content of 30 wt. according to DIN 51378: 2020.% to 50 wt%, as well as a "Bureau of minerals correlation index" (BMCI) according to the API Technical Data Book of greater than 55.

[0018] The untreated TPO has a low flash point of less than 50°C, measured according to DIN EN ISO 3679:2023, and in some cases even less than 21°C. The tire pyrolysis oil has a bio-based carbon content of 40% to 55% pMC according to ASTM D6866 Method B:2022, and a density at 15°C of 880–970 kg / m³. 3 measured according to DIN 51757 Method 3 (2011), a sulfur content of 0.8 wt.% - 1.1 wt.% measured according to DIN EN ISO 14596: 2007, a nitrogen content of 3500-6000 mg / kg measured according to DIN 51444: 2020, a benzo[a]pyrene content between 5 mg / kg and 150 mg / kg measured according to DIN EN 16143: 2023 and a PAH content determined as a sum according to Directive 2005 / 69 / EU of greater than 40 mg / kg and up to 850 mg / kg measured according to DIN EN 16143: 2023.

[0019] Tire pyrolysis oil is produced by processing used tires made of rubber, steel, carbon black, and other additives. In one embodiment, the steel wire is extracted from the tires before pyrolysis. The remaining rubber, without the steel wire, is shredded, finely ground, and pyrolyzed in a pyrolysis reactor under oxygen-free conditions and at high temperatures, e.g., 700 °C. The pyrolysis process yields various components, including carbon black, non-condensable gases, and tire pyrolysis oil (TPO).

[0020] One variant of tire pyrolysis involves shredding entire tires. In this variant, the steel is separated only after pyrolysis. This pyrolysis process also produces carbon black, non-condensable gases, and tire pyrolysis oil (TPO).

[0021] A label-free aromatic process oil is defined as a hydrocarbon mixture containing at least 5% by weight of aromatic hydrocarbons, i.e., a CA content of at least 5%, preferably more than 10% by weight. The aromatic process oil is considered label-free if it has a benzo(a)pyrene content of less than 1 mg / kg as measured according to DIN EN 16143:2023 and a total polycyclic aromatic hydrocarbon content of less than 10 mg / kg as determined according to Directive 2005 / 69 / EC and measured according to DIN EN 16143:2023.

[0022] The pyrolysis oil from used tires is separated into several fractions by distillation (step B). A first fraction is a low-boiling fraction, which boils at temperatures between 40 and 300°C. This low-boiling fraction is collected separately and is not further processed in the process according to the invention. Another fraction is a high-boiling fraction, which boils at temperatures between 300 and 700°C. This high-boiling fraction is collected and further processed in the process according to the invention. The high-boiling fraction has a higher flash point and is therefore better suited for the further process.

[0023] According to the invention, the term "high-boiling fraction" is therefore understood to be the fraction that boils at temperatures between 300 and 700 °C.

[0024] According to the invention, the term "low-boiling fraction" is therefore understood to be the fraction that boils at temperatures between 40 and 300 °C.

[0025] According to the invention, "atmospheric residue" refers to the fraction that remains as residue in an atmospheric distillation. This fraction has an initial boiling point > 300°C and can be equated with the heavy fraction.

[0026] The distillation in step b) is carried out at atmospheric pressure or under vacuum, preferably in several distillation steps, either at the same pressure or at different pressures in the various distillation steps. For example, the distillation can be carried out in two distillation steps: at atmospheric pressure in the first distillation step and under vacuum in the second. A three-step distillation process is also possible, e.g., at atmospheric pressure in the first distillation step and under vacuum in the second and third distillation steps.

[0027] Distillation can be carried out in one or more distillation steps. In cases of multiple distillation steps, the higher-boiling fraction from the last distillation step is used as the feedstock.

[0028] The metal catalyst for the hydrogenation is preferably a base metal catalyst selected from cobalt-molybdenum catalysts, nickel-cobalt-molybdenum catalysts, nickel-molybdenum catalysts, nickel-tungsten catalysts, a mixture of a nickel-molybdenum catalyst with zeolites, or mixtures of the catalysts. A nickel-molybdenum catalyst is particularly preferred as the base metal catalyst. The catalyst can be activated by conventional methods. For example, the catalyst can be sulfurized before use, resulting in a nickel / nickel sulfide catalyst or a molybdenum sulfide catalyst as the active component. Preferably, no precious metal catalyst is used. The hydrogenation of the tire pyrolysis oil preferably takes place at temperatures between 250°C and 300°C, more preferably between 260°C and 350°C and a pressure between 40 bar and 160 bar, more preferably between 50 bar and 160 bar, and particularly preferably between 80 bar and 140 bar.

[0029] The hydrogenation is particularly preferably carried out at temperatures between 260 and 350 °C and pressures between 80 bar and 140 bar, and further preferably with residence times (LHSV) of 0.1 h 1 and 0.4 h 1 .,

[0030] In a preferred embodiment, the process comprises the distillation according to step b. and the reactant for the hydrogenation is the atmospheric residue from the distillation according to step b.

[0031] The residence time of the reactant (in English LHSV "Liquid Hourly Space Velocity") is preferably between 0.1 h 1 and 0.4 h 1 preferably between 0.15 h 1 and 0.4 h 1 chosen.

[0032] Preferably, the hydrogenation process according to the invention involves only a single-stage process.

[0033] The hydrogenation is carried out as a selective hydrogenation. Selective hydrogenation is a process in which hydrogen reacts selectively with mono- or polyunsaturated molecules, while other potentially hydrogenatable groups or molecules in the mixture remain largely unchanged under the chosen reaction conditions. Selectivity is achieved by selecting the catalysts and reaction parameters, such as temperature, pressure, and residence time (LHSV), so that a desired molecular group is preferentially hydrogenated, while competing molecules are not hydrogenated or are hydrogenated only to a negligible extent. The selective hydrogenation in the process according to the invention leads to the saturation of polycyclic aromatic hydrocarbons (PAHs) as defined by PAH.

[0034] The invention further relates to a label-free aromatic process oil produced from pyrolysis oil from waste tires, characterized in that the process oil has a proportion of aromatic hydrocarbons CA of more than 10 to 35 wt.%, preferably more than 10 to 30 wt.%, measured according to DIN 51378:2020, a concentration of benzo(a)pyrene <1 mg / kg measured according to DIN EN 16143:2023, a PAH content as a sum according to Directive 2005 / 69 / EU of less than 10 mg / kg measured according to DIN EN 16143:2023, and that the process oil is a hydrocarbon mixture, wherein the carbons originate from fossil sources to a maximum of 99 wt.% and from bio-based sources to a minimum of 1 wt.%, which have a bio-based carbon content measured according to ASTM D6866 Method B:2022 greater than 1% (pMC), preferably greater than 10% (pMC), particularly preferably greater than 30% (pMC).The origin of the bio-based carbon content is preferably from natural rubber and other bio-based components of the tire, such as bio-based synthetic rubbers, bio-based fillers, bio-based plasticizers, bio-based resins, bio-based waxes, bio-based antioxidants or vulcanizing chemicals, as well as bio-based reinforcing agents. Particularly preferably, the carbon contained in the process oil originates from fossil sources up to a maximum of 90% and from bio-based sources at least 10% (pMC), and more preferably from fossil sources up to a maximum of 70% and from bio-based sources at least 30% (pMC).

[0035] Bio-based sources can be of plant or animal origin. A plant-based source of hydrocarbons could be natural rubber, which is found in used tires. An animal-based source could be stearic acid, which is also found in used tires.

[0036] For example, the non-labeled aromatic process oil has a density of 910 - 965 g / cm³. 3 at 15°C according to DIN 51757 Method 3: 2011, a kinematic viscosity of 7-30 mm 2 / s at 100°C measured according to DIN EN ISO 3104:2024, an aniline point of 68-85°C measured according to DIN ISO 2977:2000.

[0037] The non-labeled aromatic process oil can have a sulfur content of less than 2 wt.% measured according to DIN EN ISO 14596: 2007, preferably less than 1.5 wt.%, particularly preferably less than 1 wt.% and further preferably less than 0.5 wt.%.

[0038] The production of a label-free aromatic process oil by means of hydrogenation has a number of advantages:

[0039] 1) Bio-based origin: Preferably, the carbon contained in the process oil is derived from bio-based sources to at least 1% (pMC), particularly preferably to at least 10% (pMC), and further preferably to at least 30% (pMC) from bio-based sources as measured according to ASTM D6866 Method B:2022.

[0040] 2) Impurities

[0041] a. Chlorine content: Through hydrogenation, the chlorine content is reduced to such an extent that it is below the detection limit of < 2 ppm as measured according to DIN ISO 15597: 2006.

[0042] b. Sulfur: The sulfur content of the aromatic process oils is significantly lower than the sulfur content of commercially available process oils made from fossil raw materials; sulfur contents measured according to DIN EN ISO 14596:2007 of 0.001 wt.% to 1.5 wt.% can be obtained, preferably between 0.002 wt.% and 1 wt.%, particularly preferably between 0.004 wt.% and 0.5 wt.%.

[0043] 3) Color: The aromatic process oils according to the invention have a significantly lighter color, considerably lighter compared to the fossil reference. For example, the process oils according to the invention have a yellow hue of ASTM 0.5-2, while the fossil reference, with an ASTM color number between 4.5 and greater than 8, is significantly darker (ASTMD6O45:2O2O).

[0044] Furthermore, the invention relates to the use of a label-free aromatic process oil produced according to a method according to one of claims 1 to 5 or a process oil according to one of claims 6 to 11 as a plasticizer in tires or rubber compounds or as a stretcher oil, i.e. extender oil in polymers.

[0045] The process oil is preferably present in the rubber compound, tire, or polymer in an amount of up to 60 phr, and more preferably up to 40 phr. When used as an extender oil, the process oil is preferably used in an amount of up to 37.5 phr. Additional plasticizers can be added to the process oil. When using pre-oiled rubbers, these amounts are in the low range of, for example, 10–20 phr. When using non-oil-treated rubbers (so-called dry grades), correspondingly higher amounts of plasticizers can be used, for example, up to 50–60 phr.

[0046] For the production of tire and rubber compounds, extracted aromatic oils, treated distillated aromatic extract (TDAE), or naphthenic base oils are typically used as plasticizers, i.e., as process oils. These conventional products are 100% mineral oil-based. The present invention replaces mineral oil-based process oils with a product from the chemical recycling of used tires, obtained from tire pyrolysis oil (TPO). The concentration of polycyclic aromatics in the processed oil is reduced compared to TPO, with values ​​for benzo(a)pyrene <1 mg / kg and Directive 2005 / 69 / EC total <10 mg / kg, both measured according to DIN EN 16143: 2023. This allows the aromatic process oil to be used in tire and rubber compounds and to replace conventional process oils such as TDAE.

[0047] The process according to the invention is explained by way of example with reference to the figures. Figure 1 shows a first embodiment of the process. First, a pyrolysis oil (TPO) 10 is provided. The pyrolysis oil 10 is separated in a first distillation step 20, yielding a low-boiling fraction 21 and an atmospheric residue 23. The atmospheric residue 23 is separated in a further distillation step 25, again yielding a low-boiling fraction 21 and a high-boiling fraction (heavy fraction) 22. The distillation of the TPO can be carried out in one or more stages, with a two-stage distillation shown in Figure 1. The high-boiling fraction 22 is transferred to a reactor for hydrogenation 30 and hydrogenated there. The hydrogenated heavy fraction 31 is fed to a further distillation 35, in which the low-boiling components formed in the hydrogenation are separated.After distillation 35, a label-free aromatic process oil 40 is obtained.

[0048] Figure 2 shows another embodiment of the process. The pyrolysis oil (TPO) 10 is again fed into the process. The pyrolysis oil is again separated in a distillation step 20, yielding a low-boiling fraction 21 and an atmospheric residue 23. The atmospheric residue 23 is transferred to a reactor for hydrogenation 30 and hydrogenated there. The resulting low-boiling fractions from the hydrogenation are thermally separated again. The result of the process is a label-free aromatic process oil 40.

[0049] Examples

[0050] Aromatic process oils that do not require labeling were produced from pyrolysis oil. For this purpose, pyrolysis oils (TPOs) were reacted with the parameters specified in Table 1 as follows:

[0051] Example 1:

[0052] 1. Distillation

[0053] In a first step, 1401 liters of pyrolysis oil (TPO) were prepared according to Table 1 and fed into a rotary evaporator. Distillation in the rotary evaporator was carried out to 24°C, thus separating the lighter components. In a second step, the residue from the rotary evaporator was transferred to a vacuum column, which was operated up to an atmospheric equivalent temperature (AET) of 425°C. The residue fraction was then cut under vacuum in a Vigreux distillation column to an AET of 47°C. The resulting product is characterized as VD3 in Table i.

[0054] 2. Hydrogenation

[0055] The resulting product VD3 was then transferred to a hydrogenation reactor, which was operated at a pressure of 90 bar, a temperature measured as "weighted average bed temperature" (WABT) of 340°C, and a residence time ("Liquid hourly space velocity" (LHSV)) of 0.23 h. 1 The resulting product VD3-Hyd-1 is characterized in Table 1.

[0056] 3. Distillation / Stripping of product VD3-Hyd-1

[0057] During hydrogenation, a small percentage of low-boiling components are formed, which must be separated before the product can be used as process oil (rubber process oil (RPO)). This is done in a vacuum distillation apparatus with a final AET of 405°C. The result is the RPO-i used in a rubber compound according to Example 3.

[0058] A process oil, RPO-i, was obtained with the parameters listed in Table 1. The results from Example 1 are shown in Table 1 as VD3-Hyd-1 (intermediate product after hydrogenation) and RPO-i (final product). The process oil has a low content of polycyclic aromatic hydrocarbons, and the relevant compounds, such as benzo[a]pyrene and PAHs, are below the required limits. Despite a high sulfur content in the tire, which is due to vulcanization, significantly reduced sulfur contents can be reliably achieved in the hydrogenated product compared to a mineral oil-based process oil. While reference products contain a sulfur content of 0.35 wt% and up to 4 wt%, the sulfur content of VD3-Hyd-1 is only 9% of the lower fossil reference limit. The chlorine content in the TPO and the neutralization number (NV) were also significantly reduced in the final product.Additionally, a product with an ASTM color of 0.7, measured according to ASTM D6045: 2020, was obtained, which is also significantly lighter compared to the mineral oil-based reference (fossil reference range 4.5 to greater than 8).

[0059] The process thus transforms a waste product (tire) into a high-quality raw material that also has a reduced proportion of fossil carbon and a high proportion of bio-based carbon due to the bio-based carbon content in the TPO (starting product).

[0060] <

[0061] < < <

[0062]

[0063] Table 1: Parameters of the reactants, intermediates and final products according to Example 1

[0064] Example 2:

[0065] 1. Distillation

[0066] In a first step, 1401 liters of pyrolysis oil TPO were prepared according to Table 2 and fed into a rotary evaporator. The rotary evaporator was distilled to 24°C to separate the lighter components. In a second step, the residue from the rotary evaporator was transferred to a vacuum column, which was operated up to an atmospheric equivalent temperature (AET) of 425°C. The residue fraction was then cut under vacuum in a Vigreux distillation down to an AET of 47°C. The resulting product is characterized as VD3 in Table 1.

[0067] 2. Hydrogenation

[0068] The resulting product VD3 was then transferred to a hydrogenation reactor, which was operated at a pressure of 90 bar, a weighted average bed temperature (WABT) of 30°C, and a residence time (liquid hourly space velocity (LHSV)) of 0.23 h. 1The resulting product VD3-Hyd-2 is characterized in Table 2. 3. Distillation / Stripping of the product VD3-Hyd-2

[0069] During hydrogenation, a small percentage of low-boiling components are produced, which must be separated before use as process oil in rubber (RPO). This is done in a vacuum distillation apparatus with a final AET of 405°C. The result is the process oil RPO-2, used in a rubber compound according to Example 3.

[0070] A process oil with the parameters listed in Table 2 was obtained. The results are named in Table 2 as VD3-Hyd-2 (intermediate product) and RPO-2 (final product). The process oil has a low content of polycyclic aromatic hydrocarbons, and the relevant compounds such as benzo[a]pyrene and PAHs are below the required limits. Despite a high sulfur content in the tire, which is due to vulcanization, significantly reduced sulfur contents can be reliably achieved in the hydrogenated product compared to a mineral oil-based process oil. While reference products contain a sulfur content of 0.35 wt% and up to 4 wt%, the sulfur content of VD3-Hyd-2 is only 1% of the lower fossil reference limit. The chlorine content and the neutralization number contained in the TPO were also significantly reduced in the final product.Additionally, a product with an ASTM color of 0.8, measured according to ASTM D6045: 2020, was obtained, which is also significantly lighter compared to the mineral oil-based reference (fossil reference range 4.5 to greater than 8). The process thus yields a high-quality raw material from a waste product (tires), which also has a reduced proportion of fossil carbon and a high proportion of bio-based carbon due to the bio-based carbon content in the TPO.

[0071] < < <

[0072]

[0073] Table 2: Parameters of reactants, intermediates and final products according to Example 2 and Example 3

[0074] Production of rubber compounds

[0075] The process oils produced according to Examples 1 and 2 above were tested in a rubber compound. The compositions for this compound are shown in Table 3. The compounds were vulcanized, and the properties of the resulting vulcanizates were measured. These properties are shown in Table 4.

[0076]

[0077] Table 3: Composition of the rubber mixtures with process oils according to the invention

[0078] a Solution-polymerized styrene-butadiene copolymer, Sprintan SLR 4602, Synthos

[0079] b Nd-catalyzed butadiene polymer, Buna CB 24, Arlanxeo

[0080] c Ultrasil 7000 GR, Evonik

[0081] d TESPT, 3,3'-bis(triethoxysilylpropyl)tetrasulfide

[0082] e TMQ, 2,2,4-trimethyl-i,2-dihydroquinoline, polymerized

[0083] f 6PPD, N-(i,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine

[0084] s CBS, N-cyclohexylbenzothiazole-2-sulfenamide

[0085] h DPG, N,N'-Diphenylguanidine

[0086]

[0087] Table 4: Properties of the rubber compounds

[0088] Example 4

[0089] 1. Distillation

[0090] In a first step, 1401 liters of pyrolysis oil TPO were prepared according to Table 5 and fed into a rotary evaporator. Distillation in the rotary evaporator was carried out to 24°C, thus separating the lighter components. In a second step, the residue from the rotary evaporator was transferred to a vacuum column, which was operated up to an atmospheric equivalent temperature (AET) of 425°C. The residue fraction was then cut under vacuum in a Vigreux distillation column up to an AET of 47°C. The resulting product is characterized as VD3 in Table 5.

[0091] 2. Hydrogenation

[0092] The resulting product VD3 was then transferred to a hydrogenation reactor, which was operated at a pressure of 90 bar, a weighted average bed temperature (WABT) of 20°C (Example 4a) or 28°C (Example 4b) with a residence time (liquid hourly space velocity (LHSV)) of 0.23 h 1 The resulting final product RPO-qa (Example 4a) or RP0-4b (Example 4b) is characterized in Table 5.

[0093] A process oil with the parameters listed in Table 5 was obtained as the final product. The results are designated in Table 5 as RP0-4a (WABT = 20°C) and RP0-4b (WABT = 28°C), respectively. The resulting product has a low content of polycyclic aromatic hydrocarbons, and the relevant compound benzo[a]pyrene was reduced by 88% (Example 4a) and 96% (Example 4b) compared to the starting mixture. Furthermore, the total polycyclic aromatics were reduced to 53% (Example 4a) and 34% (Example 4b). Despite the high sulfur content in the tire, which is due to vulcanization, significantly reduced sulfur contents can be reliably achieved in the hydrogenated product. The chlorine content and the neutralization number contained in the TPO were also significantly reduced in the final product. Additionally, a product with an ASTM color measured according to ASTM D6045: 2020 of 2.2 (Example 4a) orA value of 1.6 (Example 4b) is obtained, which is also significantly lighter compared to the mineral oil-based reference (fossil reference range 4.5 to greater than 8). The process thus yields a high-quality raw material from a waste product (tires), which also has a reduced proportion of fossil carbon and a high proportion of bio-based carbon due to the bio-based carbon content in the TPO.

[0094] < < <

[0095]

[0096] Table 5: Parameters of the reactants, intermediates and final products according to examples 4a and 4b. Forms of execution

[0097] In a first embodiment of the process for producing a label-free aromatic process oil, the process comprises the steps

[0098] a. Submission of a pyrolysis oil from used tires, wherein the tire pyrolysis oil has an aromatic content according to DIN 51378: 2020 of 30 wt.% to 50 wt.%, as well as a BMCI according to API Technical Data Book of greater than 55, a bio-based carbon content according to ASTM D6866 Method B:2022 of 40% (pMC) to 55% (pMC), a density at 15°C of 880-970 kg / m³ 3 measured according to DIN 51757 Method 3 (2011), has a sulfur content of 0.8-1.1 wt% measured according to DIN EN ISO 14596: 2007, a nitrogen content of 3500-6000 mg / kg measured according to DIN 51444: 2020, a benzo[a]pyrene content between 5 mg / kg and 150 mg / kg measured according to DIN EN 16143: 2023 and a PAH content determined as a sum according to Directive 2005 / 69 / EU of greater than 40 mg / kg and up to 850 mg / kg measured according to DIN EN 16143: 2023,

[0099] b. optional distillation of the pyrolysis oil from waste tires in a fractional distillation at temperatures between 100 and 500 °C under atmospheric pressure or vacuum, yielding at least one low-boiling fraction and at least one high-boiling fraction and optionally an atmospheric residue,

[0100] c. Hydrogenation of the at least one high-boiling fraction or the atmospheric residue from step b. or of the tire pyrolysis oil according to step a. with hydrogen using a metal catalyst, wherein the hydrogenation is a selective hydrogenation at temperatures between 240°C and 400°C and pressures of 30 bar to 200 bar and a residence time LHSV between 0.1 h 1 and 0.4 h 1 has been done and

[0101] d. Transferring the hydrogenated product from step c. into a distillation reactor, preferably a distillation column, particularly preferably a stripping vapor column, and carrying out a distillation at temperatures between 200 and 450 °C under atmospheric pressure or vacuum,

[0102] wherein an aromatic process oil is obtained which has a proportion of aromatic hydrocarbons CA of more than 10 to 35 wt.%, preferably more than 10 to 30 wt.%, measured according to DIN 51378:2020, a benzo[a]pyrene content of less than 1 mg / kg measured according to DIN EN 16143:2023 and a PAH content determined as a sum according to Directive 2005 / 69 / EU of less than 10 mg / kg measured according to DIN EN 16143:2023 and wherein the process oil is a hydrocarbon mixture which has a bio-based carbon content measured according to ASTMD6866 Method B:2022 greater than 1% (pMC), preferably greater than 10% (pMC), particularly preferably greater than 30% (pMC).

[0103] In a second embodiment of the method according to embodiment 1, the metal catalyst is a base metal catalyst selected from cobalt-molybdenum catalysts, nickel-cobalt-molybdenum catalysts, nickel-molybdenum catalysts, nickel-tungsten catalyst, a mixture of a nickel-molybdenum catalyst with zeolites or mixtures of the catalysts, wherein the catalyst is optionally activated, the metal catalyst is particularly preferably a nickel-molybdenum catalyst.

[0104] In a third embodiment of the method according to embodiment 1 or 2, the hydrogenation takes place at temperatures of 250°C and 300°C, preferably at temperatures between 200°C and 350°C and a pressure between 40 bar and 100 bar, preferably between 50 bar and 160 bar, particularly preferably between 80 bar and 140 bar.

[0105] In a fourth embodiment of the method according to one of the preceding embodiments, the method comprises the distillation according to step b. and the reactant of the hydrogenation in step c. is the atmospheric residue from the distillation according to step b.

[0106] In a 5th embodiment of the method according to one of the preceding embodiments, the method comprises only a single-stage hydrogenation step and the hydrogenation is a selective hydrogenation.

[0107] A sixth embodiment of the invention is a label-free aromatic process oil produced from pyrolysis oil from waste tires, containing a proportion of aromatic hydrocarbons C Aof more than 10 to 35 wt.%, preferably 10 to 30 wt.%, measured according to DIN 51378: 2020, a concentration of benzo(a)pyrene <1 mg / kg measured according to DIN EN 16143: 2023, a PAH content determined as sum according to Directive 2005 / 69 / EU of less than 10 mg / kg measured according to DIN EN 16143:2023, and that process oil is a hydrocarbon mixture which has a bio-based carbon content greater than 1% (pMC) measured according to ASTM D6866 Method B:2022.

[0108] In a 7th embodiment of the aromatic process oil according to embodiment 6, the chlorine content of the process oil is < 2 ppm measured according to DIN ISO 15597: 2006. In an 8th embodiment of the aromatic process oil according to one of embodiments 6 or 7, the sulfur content of the aromatic process oil is < 0.5 wt.% measured according to DIN EN ISO 14596: 2007.

[0109] In a 9th embodiment of the aromatic process oil according to one of embodiments 6 to 8, the process oil is a hydrocarbon mixture, wherein the carbons have a bio-based carbon content measured according to ASTM D6866 Method B:2022 greater than 10% (pMC), preferably greater than 30% (pMC).

[0110] In a 10th embodiment of the aromatic process oil according to one of embodiments 6 to 9, the process oil has a color number according to ASTM of 0.5 to 2.5 measured according to ASTM D6045:2020.

[0111] In an 11th embodiment of the aromatic process oil according to one of embodiments 6 to 10, the process oil is produced using a method according to one of embodiments 1 to 5.

[0112] A 12th embodiment of the invention is the use of a label-free aromatic process oil produced according to a method according to one of embodiments 1 to 5 or of a process oil according to one of embodiments 6 to 11 as a plasticizer in tires or rubber compounds or as an extender oil in polymers.

[0113] A 13th embodiment of the invention is the use according to embodiment 12, wherein the process oil is contained in the rubber compound in an amount of up to 60 phr, preferably up to 35 phr. Reference numeral list

[0114] Tire pyrolysis oil (TPO) 10 Distillation 1 20 Distillation 2 25 Low-boiling fraction 21 High-boiling fraction 22 Atmospheric residue 23 Hydrogenation 30 Hydrogenated oil 31 Vacuum distillation / stripping 35 Process oil 40

Claims

Patent claims 1. Method for producing a label-free aromatic process oil comprising the steps a. Submission of a pyrolysis oil from used tires, wherein the tire pyrolysis oil has an aromatic content according to DIN 51378: 2020 of 30 wt.% to 50 wt.%, as well as a BMCI according to API Technical Data Book of greater than 55, a bio-based carbon content according to ASTM D6866 Method B:2022 of 40% (pMC) to 55% (pMC), a density at 15°C of 880-970 kg / m³ 3 measured according to DIN 51757 Method 3 (2011), has a sulfur content of 0.8-1.1 wt% measured according to DIN EN ISO 14596: 2007, a nitrogen content of 3500-6000 mg / kg measured according to DIN 51444: 2020, a benzo[a]pyrene content between 5 mg / kg and 150 mg / kg measured according to DIN EN 16143: 2023 and a PAH content determined as a sum according to Directive 2005 / 69 / EU of greater than 40 mg / kg and up to 850 mg / kg measured according to DIN EN 16143: 2023, b. optional distillation of the pyrolysis oil from waste tires in a fractional distillation at temperatures between 100 and 500 °C under atmospheric pressure or vacuum, yielding at least one low-boiling fraction and at least one high-boiling fraction and optionally an atmospheric residue, c. Hydrogenation of the at least one high-boiling fraction or the atmospheric residue from step b. or of the tire pyrolysis oil according to step a. with hydrogen using a metal catalyst, wherein the hydrogenation is a selective hydrogenation at temperatures between 240°C and 400°C and pressures of 30 bar to 200 bar and a residence time LHSV between 0.1 h 1 and 0.4 h 1 has been done and d. Transferring the hydrogenated product from step c. into a distillation reactor, preferably a distillation column, particularly preferably a stripping vapor column, and carrying out a distillation at temperatures between 200 and 450 °C under atmospheric pressure or vacuum, wherein an aromatic process oil is obtained which has a proportion of aromatic hydrocarbons CA of more than 10 to 35 wt.%, preferably more than 10 to 30 wt.%, measured according to DIN 51378:2020, a benzo[a]pyrene content of less than 1 mg / kg measured according to DIN EN 16143:2023 and a PAH content determined as a sum according to Directive 2005 / 69 / EU of less than 10 mg / kg measured according to DIN EN 16143:2023 and wherein the process oil is a hydrocarbon mixture which has a bio-based carbon content measured according to ASTMD6866 Method B:2022 greater than 1% (pMC), preferably greater than 10% (pMC), particularly preferably greater than 30% (pMC).

2. The method according to claim 1, characterized in that the metal catalyst is a base metal catalyst selected from cobalt-molybdenum catalysts, nickel-cobalt-molybdenum catalysts, nickel-molybdenum catalysts, nickel-tungsten catalyst, a mixture of a nickel-molybdenum catalyst with zeolites or mixtures of the catalysts, wherein the catalyst is optionally activated, the metal catalyst is particularly preferably a nickel-molybdenum catalyst.

3. Method according to claim 1 or 2 characterized in that the hydrogenation takes place at temperatures between 250°C and 300°C, preferably at temperatures between 200°C and 350°C and a pressure between 40 bar and 100 bar, preferably between 50 bar and 160 bar, particularly preferably between 80 bar and 140 bar.

4. A method according to one of the preceding claims, characterized in that the method comprises the distillation according to step b. and the reactant of the hydrogenation in step c. is the atmospheric residue from the distillation according to step b.

5. A method according to one of the preceding claims, characterized in that the method comprises only a single-stage hydrogenation step and the hydrogenation is a selective hydrogenation.

6. Label-free aromatic process oil produced from pyrolysis oil from waste tires, characterized in that the process oil contains a proportion of aromatic hydrocarbons C Aof more than 10 to 35 wt.%, preferably more than 10 to 30 wt.%, measured according to DIN 51378: 2020, a concentration of benzo(a)pyrene <1 mg / kg measured according to DIN EN 16143: 2023, a PAH content determined as sum according to Directive 2005 / 69 / EU of less than 10 mg / kg measured according to DIN EN 16143:2023, and that process oil is a hydrocarbon mixture which has a bio-based carbon content greater than 1% (pMC) measured according to ASTM D6866 Method B:2022.

7. Aromatic process oil according to claim 6, characterized in that the chlorine content of the process oil is < 2 ppm, measured according to DIN ISO 15597: 2006.

8. Aromatic process oil according to claim 6 or 7, characterized in that the sulfur content of the aromatic process oil is < 0.5 wt.%, measured according to DIN EN ISO 14596: 2007.

9. Aromatic process oil according to one of claims 6 to 8, characterized in that the process oil is a hydrocarbon mixture, wherein the carbons have a bio-based carbon content measured according to ASTM D6866 Method B:2022 greater than 10% (pMC), preferably greater than 30% (pMC).

10. Aromatic process oil according to any one of claims 6 to 9, characterized in that the process oil has a color number according to ASTM of 0.5 to 2.5 as measured according to ASTM D6045:2020.

11. Aromatic process oil according to one of claims 6 to 10, characterized in that the process oil is produced by a process according to one of claims 1 to 5.

12. Use of a label-free aromatic process oil produced according to a process according to one of claims 1 to 5 or of a process oil according to one of claims 6 to 11 as a plasticizer in tires or rubber compounds or as an extender oil in polymers.

13. Use according to claim 12, wherein the process oil is contained in the rubber mixture in an amount of up to 60 phr, preferably up to 35 phr.

Images