Process for reducing impurities in a hydrocarbon-containing composition

Abstract

The invention relates to a process for reducing at least one impurity in a hydrocarbon-containing composition, wherein the process comprises the following steps: in a composition-providing step, providing a hydrocarbon-containing composition; in a pyrolysis-coke-providing step, providing a pyrolysis coke, the pyrolysis coke containing at least one catalytically active component; in a contact step, bringing the pyrolysis coke into contact with the hydrocarbon-containing composition.

Description

[0001] Process for reducing impurities in a hydrocarbon-containing composition

[0002] Technical area

[0003] The present invention relates to a process for reducing impurities in a hydrocarbon-containing composition and to the use of pyrolysis coke for reducing impurities in a hydrocarbon-containing composition.

[0004] State of the art

[0005] Chemical recycling of plastics – such as those found in mixed plastic waste – by pyrolysis is gaining increasing interest due to its potential to complement conventional mechanical recycling processes to achieve the policy goals of a circular economy for plastics.

[0006] The theoretical approach of producing steam cracker-compatible feedstocks from low-grade waste has not yet been implemented in commercially viable plants, and it remains questionable whether this approach is economically and ecologically sustainable.

[0007] To avoid the steam cracker route and thus avoid high energy consumption and a larger ecological footprint, and thus be more sustainable, the state of the art proposes producing bulk aromatic chemicals directly from mixed plastic waste. Patent application EP 3 744 814 A1 describes how gaseous pyrolysis products can be catalytically converted into high-value monocyclic aromatic compounds such as BTEX and styrene. However, this process uses technical catalysts such as metal-impregnated zeolites. A disadvantage of this process, however, is that such catalysts are rarely recovered or regenerated due to the high impurities in the decomposition products of mixed plastic waste.

[0008] Another, albeit less efficient, option for chemical recycling is to convert the pyrolysis oils into bulk chemicals such as ethylene and propylene in a steam cracker. Due to the high level of contaminants such as halogens, phosphorus, and other elements, (raw) pyrolysis oils from mixed plastic waste or other sources such as biogenic raw materials are only suitable to a limited extent. Such a process has the disadvantage of requiring complex treatment steps to remove interfering contaminants such as halogens, phosphorus, and other elements (e.g., hydrogenation) and to separate aromatic from aliphatic compounds. The specifications of existing steam crackers and subsequent synthesis steps prescribe narrow concentration ranges regarding the content of halogens, phosphorus, and other elements, as well as a limited concentration of aromatic compounds.

[0009] The final, and still common, route is thermal recycling, in which the feedstock is incinerated. This process has the disadvantage that no material recycling is possible, and thus it cannot be part of a sustainable circular economy. Furthermore, it generates a significant amount of climate-damaging emissions, making the process unsustainable.

[0010] Summary of the invention

[0011] The object of the present invention is to provide a process that eliminates the disadvantages of the aforementioned prior art. In particular, the object of the present invention is to provide a process that produces high-quality aromatic compounds from carbon-containing waste, removes impurities from the product, is suitable for use in a circular economy, is sustainable, and does not require complex follow-up steps such as purification and / or catalyst recovery.

[0012] It has now surprisingly been found that the above-mentioned object is achieved by a process for reducing at least one impurity in a hydrocarbon-containing composition, the process comprising the following steps: providing, in a composition provision step, a hydrocarbon-containing composition; providing, in a pyrolysis coke provision step, a pyrolysis coke, wherein the pyrolysis coke contains at least one catalytically active component; contacting, in a contact step, the pyrolysis coke with the hydrocarbon-containing composition.

[0013] Furthermore, it has now surprisingly been found that the above-mentioned object is achieved by the use of a pyrolysis coke for reducing at least one impurity in a hydrocarbon-containing composition, wherein the pyrolysis coke contains at least one catalytically active component.

[0014] Short description of the drawings

[0015] Figure 1 shows a schematic representation of the pyrolysis plant used in the examples. Figure 2 shows the pyrolysis plant used in the examples.

[0016] Figure 3 shows the experimental setup as used in the examples.

[0017] Figure 4 shows a schematic of the experimental setup as used in the examples.

[0018] List of reference symbols

[0019] Figure 1

[0020] 1 inert gas cylinder

[0021] 2 hand valve

[0022] 3 manual valve

[0023] 4 collecting containers for pyrolysis coke

[0024] 5 Pyrolysis reactor

[0025] 6 Transition

[0026] 7 tar filters

[0027] 8 first spiral cooler

[0028] 9 second spiral cooler

[0029] 10 3-way valve

[0030] 1 1 first wash bottle with NaOH

[0031] 12 second wash bottle with n-hexane

[0032] 13 3-way valve

[0033] 14 activated carbon filters with discharge into the outside air

[0034] 15 Safety valve

[0035] 16 lance for filling

[0036] 17 Ball valve

[0037] 18 round bar

[0038] 19 Stirring rod

[0039] 20 heating surfaces

[0040] Figure 4

[0041] 1 Insulation

[0042] 2 coke bed

[0043] 3 Entrance

[0044] 4 nitrogen bottles

[0045] 5 Pyrolysis oil storage containers

[0046] 6 Dosing pump

[0047] 7 Heating coil 8 Cooler

[0048] 9 Cooling connection

[0049] 10 product collection containers

[0050] Detailed description of the invention

[0051] As described above, the present invention is directed to a method and a use. These are described in more detail below.

[0052] Proceedings

[0053] As described above, the present invention relates to a process for reducing at least one impurity in a hydrocarbon-containing composition, the process comprising the following steps:

[0054] Providing in a composition providing step a hydrocarbon-containing composition;

[0055] Providing a pyrolysis coke in a pyrolysis coke preparation step, wherein the pyrolysis coke contains at least one catalytically active component; contacting the pyrolysis coke with the hydrocarbon-containing composition in a contact step.

[0056] The advantage of this process is that, compared to the state of the art, the proportion of high-quality aromatics in the product has been increased while, at the same time, the proportion of impurities in the product has been significantly reduced. Without wishing to be bound by any theory, it is assumed that this effect is due to the pyrolysis coke containing a catalytically active component. Consequently, no complex subsequent purification steps are necessary. Because at least one catalytically active component is present in the pyrolysis coke, it is also unnecessary to recover a catalyst from the product. Furthermore, the use of pyrolysis coke makes the process sustainable and can be incorporated into a circular economy for material recovery. a) Pyrolysis coke preparation step

[0057] Typically, the pyrolysis coke preparation step involves pyrolysis. Pyrolysis is used for the thermochemical conversion of carbonaceous feedstocks into liquid pyrolysis concentrate (pyrolysis oil), solid pyrolysis coke, and pyrolysis gas as pyrolysis products. Pyrolysis takes place under the exclusion of oxygen or at least essentially without the presence of oxygen. The proportions and quality of the pyrolysis products can be influenced by the choice of feedstock (and in particular by its residual moisture content), but above all by the prevailing process conditions. These include, in particular, the pyrolysis temperature, the residence time in the pyrolysis zone, and any subsequent processing steps.

[0058] Pyrolysis coke is preferably produced from the starting material by pyrolysis. Pyrolysis typically produces pyrolysis gas, pyrolysis oil, preferably initially in a gaseous state, and pyrolysis coke.

[0059] The starting material preferably comprises a polymer and / or a mixture of polymers. The starting material particularly preferably consists of a polymer and / or a mixture of polymers.

[0060] Preferably, the polymers are selected from the group consisting of polyethylene (PE), polypropylene (PP), polystyrene (PS), polycarbonate (PC), polyvinyl chloride (PVC), polyamide (PA), and polyethylene terephthalate (PET).

[0061] In a particularly preferred embodiment of the invention, the starting material comprises 25 to 35 wt.%, preferably 28 to 34 wt.%, polyethylene, 10 to 30 wt.%, preferably 12 to 29 wt.%, polypropylene, 1 to 10 wt.%, preferably 2 to 5 wt.%, polystyrene, 1 to 10 wt.%, preferably 2 to 6 wt.%, polyvinyl chloride, 2 to 10 wt.%, preferably 4 to 9 wt.%, polyamide, and 5 to 20 wt.%, preferably 8 to 14 wt.%, polyethylene terephthalate.

[0062] The pyrolysis will typically be carried out at temperatures in the range of 350 to 700 °C and under a system pressure in the range of 1 to 2 bar, preferably under an oxygen-free atmosphere (particularly preferably under nitrogen).

[0063] The pyrolysis coke produced in this pyrolysis step has certain properties that can act similarly to a catalyst or an adsorbent or absorbent.

[0064] First and foremost, the pyrolysis coke comprises a catalytically active component. The catalytically active component preferably comprises, or preferably consists of, at least one element, wherein the at least one element is selected from the group consisting of Si, Al, Ca, Fe, Ti, Na, Mg, Zn, Mn, Ni, Ba, Cr, Cu, B, or Sn. More preferably, the at least one element is selected from the group consisting of Si, Al, Ca, Fe, Ti, Zn, Mg, Na, and Ca. Most preferably, the at least one element is Ca.

[0065] The catalytically active component preferably contains 1.0 to 35.0 wt.%, preferably 15.0 to 30.0 wt.%, Ca, 0.1 to 20.0 wt.%, preferably 5.0 to 15.0 wt.%, Si, 0.1 to 25.0 wt.%, preferably 10.0 to 20.0 wt.%, Al, 0.1 to 10.0 wt.%, preferably 1.0 to 5.0 wt.%, Zn, 0.1 to 10.0 wt.%, preferably 0.5 to 5.0 wt.%, Fe, 0.1 to 10.0 wt.%, preferably 0.5 to 5.0 wt.%, Cu, 0.1 to 5.0 wt.%, preferably 1.0 to 3.0 wt.%, Ti, and / or 0.01 to 1.5 wt.%, preferably 0.1 to 1.0 wt% Ba.

[0066] Preferably, the at least one element in the catalytically active component is present in activated form, preferably oxidized, reduced, sulfurized, chlorinated, or in a mixture thereof.

[0067] The catalytically active component is preferably present in the pyrolysis coke in a proportion of 0.1 to 50 wt.%, preferably 0.5 to 20 wt.%, based on the total mass of the pyrolysis coke.

[0068] Preferably, the pyrolysis coke has a pore volume of more than 0.001 cm 2 / g, more preferably more than 0.01 cm 3 / g, measured according to DIN ISO 9277 - 2014-01. Typically, the pore volume of the pyrolysis coke is not higher than 0.1 cm 3 / G.

[0069] Likewise, the pyrolysis coke preferably has a pore size of more than 5 nm, more preferably more than 8 nm, and particularly preferably more than 10 nm, measured according to DIN ISO 9277 - 2014-01. Typically, the pore size of the pyrolysis coke is not higher than 50 nm.

[0070] Also preferably, the pyrolysis coke has a specific surface area of ​​more than 1.0 m 2 / g, particularly preferably more than 2 m 2 / g, and most preferably more than 4.5 m 2 / g, measured according to DIN ISO 9277 - 2014-01 . Typically, the specific surface area of ​​the pyrolysis coke is not larger than 10 m 2 / g. b) Contact step

[0071] In the contact step, the hydrocarbon-containing composition is brought into contact with the pyrolysis coke as the active component.

[0072] Contact can be achieved, for example, by passing the hydrocarbon-containing composition through the pyrolysis coke. It is also conceivable that the pyrolysis coke is simply stirred into the hydrocarbon-containing composition. However, passing through is preferred, as a continuous process offers advantages in terms of efficiency and can be better integrated into existing systems.

[0073] The hydrocarbon-containing composition is preferably liquid at 20°C and 1 bar. The hydrocarbon-containing composition is particularly preferably selected from the list consisting of petrochemical intermediates, waste oil, pyrolysis oil, most preferably the hydrocarbon-containing composition comprises or consists of pyrolysis oil. Preferably, in the contact step, no further component is used besides the pyrolysis coke which comprises a catalytically active component, wherein the catalytically active component comprises, preferably consists of, at least one element, wherein the at least one element is preferably selected from the group consisting of Si, Al, Ca, Fe, Ti, Na, Mg, Zn, Mn, Ni, Ba, Cr, Cu, B or Sn.

[0074] A process for producing a pyrolysis oil comprises the following steps: A) First, a starting material to be treated is fed into a pyrolysis zone of a reactor and pyrolyzed there at a temperature of 250 to 700 °C (measured material temperature on the inner surface of the reactor wall of the pyrolysis reactor). The residence time of the material to be pyrolyzed in the pyrolysis zone is 1 second to 1 hour. The material obtained at the end of the pyrolysis zone is called "pyrolyzed material." The pyrolyzed material includes pyrolyzed solids and pyrolysis vapors.

[0075] B) Finally, the pyrolysis oil is optionally separated from other pyrolysis products in a separation unit. In particular, the pyrolysis oil can be separated from an aqueous phase that is also formed.

[0076] Preferably, the at least one impurity of the hydrocarbon-containing compound comprises at least one halogen-containing component. The halogen-containing component preferably comprises a chlorine-containing component and / or a bromine-containing component.

[0077] Preferably, the at least one impurity comprises at least one phosphorus-containing component.

[0078] Preferably, in the process according to the present invention, the impurities Cl, Br, and P are reduced. More preferably, the hydrocarbon-containing composition after the contacting step contains less than 100 ppm Cl, less than 200 ppm Br, and / or less than 10 ppm P.

[0079] Preferably, the contact step is carried out at a temperature in the range of 350 to 1000 °C, more preferably 500 to 700 °C, even more preferably 550 to 650 °C, very preferably 575 to 625 °C. Likewise preferably, the contact step is carried out at a pressure in the range of 0.1 to 150 bar, particularly preferably 0.5 to 1.5 bar.

[0080] In a preferred embodiment of the present invention, the residence time of the hydrocarbon-containing composition on the pyrolysis coke in the contact step is from 0.1 s to 60 min, preferably from 0.5 s to 60 s, more preferably from 1 s to 45 s, even more preferably from 2.5 to 30 s, and particularly preferably from 3.0 s to 20 s.

[0081] When the contacting step is carried out continuously, the weight space velocity (WHSV) is preferably in the range of 0.01 to 50 l / h, more preferably in the range of 0.1 to 15 l / h, even more preferably in the range of 0.5 to 10 l / h, and particularly preferably in the range of 0.9 to 6.0 l / h.

[0082] In a particularly preferred embodiment of the present invention, the process is carried out at a temperature in the range from 500 to 700 °C and at a residence time of from 0.5 s to 45 s, preferably at a temperature in the range from 550 to 650 °C and at a residence time of from 2.5 s to 30 s, particularly preferably at a temperature in the range from 575 to 625 °C and at a residence time of from 3 s to 20 s and very particularly preferably at a temperature in the range from 595 to 605 °C and at a residence time of from 4.0 s to 6.0 s.

[0083] In a further particularly preferred embodiment of the present invention, the process is carried out at a temperature in the range from 500 to 700 °C and at a weight-based space velocity (WHSV) of 0.1 to 15 l / h, preferably at a temperature in the range from 550 to 650 °C and at a weight-based space velocity (WHSV) of 0.5 to 10 l / h, particularly preferably at a temperature in the range from 575 to 6250 °C and at a weight-based space velocity (WHSV) of 0.9 to 6.0 l / h and very particularly preferably at a temperature in the range from 595 to 605 °C and at a weight-based space velocity (WHSV) of 3.0 to 4.0 l / h.

[0084] The process is preferably carried out continuously. Particularly preferred is the pyrolysis coke being continuously fed into the pyrolysis coke preparation step.

[0085] In another particularly preferred embodiment of the present invention, the pyrolysis coke is moved in the contacting step relative to the direction of movement of the hydrocarbon-containing composition, preferably opposite and / or transverse to the direction of movement of the hydrocarbon-containing composition.

[0086] Especially when the contact step is carried out continuously, the residence time is also influenced by the maximum filling height of the reactor.

[0087] Typically, in order to maximize the activity of the pyrolysis coke, the highest possible filling level is achieved (a filling level of at least 50% is reasonable). In continuous operation, spent pyrolysis coke is then discharged from the reforming zone, preferably after the desired filling level has been reached, in proportion to the amount of pyrolysis coke supplied to the reforming zone. To enable the most efficient contacting of the hydrocarbon-containing composition, according to a further preferred embodiment, the hydrocarbon-containing composition is supplied to the contacting step in such a way that the volume flow of the hydrocarbon-containing composition is guided essentially entirely through flow paths present in the pyrolysis coke bed.The reactor of the contact step is therefore preferably designed such that the hydrocarbon-containing composition must not only cover the pyrolysis coke bed, but must completely penetrate it. Particularly preferably, the pyrolysis coke bed is arranged in the reactor of the contact step such that a cross-sectional area of ​​the reactor of the contact step arranged perpendicular to the flow direction is essentially completely filled with the pyrolysis coke bed. Accordingly, the residence times of the hydrocarbon-containing composition in the reactor of the contact step specified above are also based on such complete filling.Preferably, the pyrolysis bed contains no further component which comprises a catalytically active component in addition to the pyrolysis coke, wherein the catalytically active component comprises, preferably consists of, at least one element, wherein the at least one element is preferably selected from the group consisting of Si, Al, Ca, Fe, Ti, Na, Mg, Zn, Mn, Ni, Ba, Cr, Cu, B or Sn.

[0088] According to a further preferred embodiment, the volume flow of the hydrocarbon-containing composition is passed through the pyrolysis coke bed in such a way that the hydrocarbon-containing composition only comes into contact with the pyrolysis coke that has been present in the reactor of the contact step for the longest time at the end of the contact step. The hydrocarbon-containing composition is therefore first contacted with the pyrolysis coke that has just been fed to the reactor of the contact step and should also have the highest activity. Gradually, the hydrocarbon-containing composition is then contacted with catalytically increasingly less active pyrolysis coke until finally contact is also made with pyrolysis coke that is about to be discharged. In a continuous process, the feed of the pyrolysis coke to the contact step is preferably also arranged continuously.

[0089] The process of the present invention may comprise further steps. For example, the contact step may be preceded by an evaporation step in which the hydrocarbon-containing composition is evaporated. Such an embodiment has the advantage that the contact is intensified and the hydrocarbon-containing composition has a higher temperature, which can lead to more efficient conversion, thus higher aromatic yields and lower impurities.

[0090] Furthermore, the process of the present invention preferably comprises a washing step in which the pyrolysis coke is washed with an acid, a base, and / or a solvent, preferably an acid and a solvent, before being fed to the contacting step. This reduces initial product formation with even greater impurities.

[0091] Furthermore, the process of the present invention may preferably comprise a separation step after the contacting step, in which the pyrolysis coke is separated from the hydrocarbon-containing composition. Such a separation step is not necessarily required if the hydrocarbon-containing compound is contacted in the gaseous state. Furthermore, such a separation step is not necessarily required if the process is carried out continuously.

[0092] The contact step can be carried out in a reactor. Preferably, the pyrolysis coke can be exchanged continuously or discontinuously to discharge loaded or spent coke and feed in unloaded or unused coke. This can be implemented as a fixed-bed, moving-bed, fluidized-bed reactor, or in another form.

[0093] In a particularly preferred embodiment of the present invention, the pyrolysis coke can be produced directly in a pyrolysis step preceding the contacting step. In this case, the starting material is the hydrocarbon-containing composition.

[0094] use

[0095] As described above, the present invention relates to the use of a pyrolysis coke for reducing impurities in a hydrocarbon-containing composition, wherein the pyrolysis coke contains at least one catalytically active component.

[0096] The pyrolysis coke comprises a catalytically active component. The catalytically active component preferably comprises, preferably consists of, at least one element, wherein the at least one element is selected from the group consisting of Si, Al, Ca, Fe, Ti, Na, Mg, Zn, Mn, Ni, Ba, Cr, Cu, B, or Sn. Particularly preferably, the at least one element is selected from the group consisting of Si, Al, Ca, Fe, Ti, Zn, Mg, Na, and Ca. Most preferably, the at least one element is Ca. The catalytically active component preferably contains 1.0 to 35.0 wt.%, preferably 15.0 to 30.0 wt.%, Ca, 0.1 to 20.0 wt.%, preferably 5.0 to 15.0 wt.%, Si, 0.1 to 25.0 wt.%, preferably 10.0 to 20.0 wt.%, Al, 0.1 to 10.0 wt.%, preferably 1.0 to 5.0 wt.%, Zn, 0.1 to 10.0 wt.%, preferably 0.5 to 5.0 wt.%, Fe, 0.1 to 10.0 wt.%, preferably 0.5 to 5.0 wt.%, Cu, 0.1 to 5.0 wt.%, preferably 1.0 to 3.0 wt.%, Ti, and / or 0.01 to 1.5 wt.-%, preferably 0.1 to 1.0 wt.% Ba.

[0097] Preferably, the at least one element in the catalytically active component is present in activated form, preferably oxidized, reduced, sulfurized, chlorinated, or in a mixture thereof.

[0098] The catalytically active component is preferably present in the pyrolysis coke in a proportion of 0.1 to 50 wt.%, preferably 0.5 to 20 wt.%, based on the total mass of the pyrolysis coke.

[0099] Preferably, the pyrolysis coke has a pore volume of more than 0.001 cm 2 / g, more preferably more than 0.01 cm 3 / g, measured according to DIN ISO 9277 - 2014-01. Typically, the pore volume of the pyrolysis coke is not higher than 0.1 cm 3 / G.

[0100] Likewise, the pyrolysis coke preferably has a pore size of more than 5 nm, more preferably more than 8 nm, and particularly preferably more than 10 nm, measured according to DIN ISO 9277 - 2014-01. Typically, the pore size of the pyrolysis coke is not higher than 50 nm.

[0101] Also preferably, the pyrolysis coke has a specific surface area of ​​more than 1.0 m 2 / g, particularly preferably more than 2 m 2 / g, and most preferably more than 4.5 m 2 / g, measured according to DIN ISO 9277 - 2014-01. Typically, the specific surface area of ​​the pyrolysis coke is not larger than 10 m 2 / G.

[0102] Preferably, the hydrocarbon-containing composition is liquid at 20°C and 1 bar. Particularly preferably, the hydrocarbon-containing composition is selected from the list consisting of petrochemical intermediates, waste oil, and pyrolysis oil. Most preferably, the hydrocarbon-containing composition comprises or consists of pyrolysis oil.

[0103] In a particularly preferred embodiment of the invention, the hydrocarbon-containing composition comprises 5 to 85 wt.%, preferably 40 to 65 wt.%, carbon, 0.5 to 5 wt.%, preferably 1 to 3.5 wt.%, hydrogen, 0.1 to 3 wt.%, preferably 0.5 to 1.5 wt.%, nitrogen and / or 0.01 to 1 wt.%, preferably 0.1 to 0.5 wt.%, sulfur. The at least one impurity of the hydrocarbon-containing compound preferably comprises at least one halogen-containing component. The halogen-containing component preferably comprises a chlorine-containing component and / or a bromine-containing component.

[0104] Preferably, the at least one impurity comprises at least one phosphorus-containing component.

[0105] Preferably, the use according to the present invention reduces the impurities Cl, Br, and P in the hydrocarbon-containing composition. More preferably, the hydrocarbon-containing composition contains less than 100 ppm Cl, less than 200 ppm Br, and / or less than 10 ppm P after use.

[0106] Experimental part

[0107] Measurement methods a) Inductively coupled plasma optical emission spectrometry (ICP-OES)

[0108] Liquid samples

[0109] ICP measurements of liquid samples were performed using a Spectro Arcos ICP-OES in dual-side on-plasma mode. The ICP system was equipped with a Nordermeer nebulizer, a cyclone spray chamber, and a fixed glass torch with a 1.8 mm injector. The measurement conditions were HF power 1350 W, plasma gas flow 14 l / min, nebulizer flow 0.72 l / min, and auxiliary gas flow 2 l / min. The sample aspiration rate was set to 2.0 ml / min. All samples and standards were diluted 1:10 with 1-butanol. The concentration of CI was determined according to DIN 51577-5. The concentration of P was determined according to DIN EN 51363-3. The concentrations of other elements were determined according to DIN EN ISO 11885.

[0110] Solids

[0111] The concentrations of selected elements were determined according to DIN EN ISO 11885 after digestion with aqua regia according to DIN EN ISO 54321 and after fusion digestion according to DIN ISO 14869 for Ba, Ca, Cu, and Fe, or by microwave digestion according to DIN 51460-3 for other selected elements. b) Gas chromatography with mass spectrometry (GC-MS) All GC-MS measurements were performed using a gas chromatograph coupled to a mass spectrometer (GC-MS), model GCMS-QP2020 from Shimadzu Kabushiki Kaisha, Kyoto (Japan).

[0112] A nonpolar DB-5 column (30 m, 0.2 mm inner diameter, and 0.25 pm film thickness) was used. Helium (purity 5.0) was used as the carrier gas for all measurements. The injection volume is 1 pl for a dilution of 1 mg of sample in 1 ml of dichloromethane (DCM). Measurements were performed at 40 ml / min of carrier gas. After a 3-min hold time at 40 °C, the GC oven temperature was set to 320 °C (3-min hold time) with a constant heating rate of 10 K / min. The injector temperature was set to 250 °C, the MS surface to 280 °C, and the MS to 200 °C. The quadrupole MS detector was operated at a scan rate of 5000 Hz and in a mass range of 35–500 m / z, and the solvent cut time was 3 minutes.

[0113] The NIST 17 database was used to identify the substances. Since the chromatogram showed peaks, the area of ​​each peak was directly related to the percentage composition. First, each value was normalized, i.e., to the sum of the areas of the peaks that occur in the 100 largest peaks. By comparing the mass spectrograms with the NIST 17 database, substances with a similarity index (SI) > 70 were identified. An SI of 100 corresponds to an exact match between the mass spectra from the measurement and those from the NIST 17 database.

[0114] The values ​​for the GC / MS measurements are given as area % (Af %) of the areas integrated under the peaks. c) Elemental analysis

[0115] The CHNS composition was determined using a vario macro cube from Elementar. The measurements were performed using triplicate determinations based on DIN 51724-3 for S and DIN 51732 for C, H, and N. d) Specific surface area, pore size, pore volume

[0116] The specific surface area, pore size, and pore volume were determined according to DIN ISO 9277 - 2014-01 - "Determination of specific surface area of ​​solids by gas adsorption - BET method." e) Mass-specific space velocity The mass-specific space velocity WHSV is calculated using formula (1): where

[0117] WHSV is the mass-related space velocity in 1 / h,

[0118] M eed is the mass flow of the pyrolysis oil used (plus the nitrogen mass flow if applicable) in kg / h, and m C at is the mass of pyroyl coke in kg.

[0119] The mass of the pyrolysis coke can be determined by weighing before it is fed into the reactor. The mass flow m ca t can also be measured or adjusted. Alternatively, the mass flow m C at about the measured density of the oil (often in the range of 0.9 kg / m 3 ) can be calculated from the oil flow rate. f) Residence time

[0120] The residence time is calculated according to formula (2): where t is the residence time in s,

[0121] Vrohr is the empty pipe volume of the coke bed in m 3 , and l / l / gas is the volume flow of the evaporated pyrolysis oil in m 3 / s is.

[0122] Examples a) Pyrolysis (IE 1-3)

[0123] Experimental setup

[0124] The pyrolysis of the feedstocks to produce pyrolysis coke was carried out in a system as shown in Figures 1 and 2. For the pressure test, a pressure sensor was connected to the ALMEMO 710 precision measuring device. The compressed air hose was connected to a valve and inserted into the collection tank. The valve was opened for a short time and then closed again. If the pressure drop in the system was less than 1 mbar per second, the pressure test was considered successful. After the pressure test, the shut-off valve was replaced with a three-phase valve.

[0125] To purge the system with nitrogen, a nitrogen hose was connected to the collection tank and a flow rate of 0.5 l / min was set. The three-phase valve was turned to allow escaping gases from the reactor to pass through the activated carbon filter. The lambda sensor reading was checked to ensure that the oxygen content in the system had decreased to 0% by volume due to the nitrogen purge.

[0126] To heat the reactor, all temperature sensors were connected to the ALMEMO 710 precision measuring device. The temperature controller could then be switched on to heat the reactor to 520 °C.

[0127] During the heating process, the freshly filled wash bottles were connected with plastic tubing between the three-way valve behind the coolers and the gas analyzer. The coolers were then filled with ice or water, depending on the feedstock. After the gas analyzer was connected to the system, it was switched on and was ready for operation after 5-7 minutes.

[0128] For pyrolysis, the starting material was weighed and filled into the lance. After filling, the ball valve was closed, and the lance was mounted on the reactor's shut-off valve using the screw cap. Additionally, the nitrogen supply was connected to the lance, and a flow rate of approximately 0.5 l / min was set.

[0129] After reaching a stable reactor temperature, recording was started for the gas analyzer and ALMEMO 710. The three-way valve was opened so that all generated gases were directed to the scrubber bottle. By opening the ball valve of the lance and the reactor, the output material entered the reactor due to the inclination. The filler rod on the lance was pushed in, conveying the material into the reactor. The reactor shut-off valve was closed. After feeding, the energy was absorbed by the feed material as a result of the thermochemical process, leading to a temperature drop. The heat input was increased via the temperature controller to maintain a stable temperature.

[0130] The filling lance was then purged with nitrogen, disassembled, and refilled with the new batch. The filling lance was then reassembled and purged with nitrogen again for approximately five minutes. After a dwell time of 15 minutes after the last material addition, the next addition process was started.

[0131] After the residence time of the last batch had elapsed, the reactor was emptied for the last time and the reactor heater was turned off. Recording of the measured values ​​continued for approximately 10 to 15 minutes to detect any subsequent changes in temperature, pressure, or gas composition. The heat supply to the transition tube and the tar filter was also maintained for this period to prevent further clogging of these components.

[0132] Experimental procedure

[0133] The following raw materials were converted into pyrolysis coke by pyrolysis:

[0134] MPO323 (IE1) Mixed polyolefin fraction from the dual system in Germany (Der Grüne Punkt - Duales System Deutschland GmbH). MPO with fraction number 323 was used, which means it mainly contains polypropylene (PP) and polyethylene (PE). PP and PE are used, for example, for cups, films, and other household items; secondary components such as labels may also be present. The MPO323 fraction is not currently recycled and is incinerated for energy recovery. The fraction numbers are part of Germany's dual system, which can be used to define mixed plastic waste. Further information on this mixed polyolefin fraction can be found in the raw material fraction specification 323-2 flexible PO articles, version dated April 5, 2023, available at https: / / www.gruener-punkt.de / fileadmin / Dateien / Downloads / PDFs / Rohstofffraktionssp ezifikationen2023 / DOC-23-50738_- _Rohstofffraktionsspezifikation_323-2_flexible_PO-Artikel_- _v0.02.0006.pdf.

[0135] MK350 (IE2) This is a fraction of mixed plastics (polyethylene, polypropylene, polystyrene, polyethylene terephthalate) from the dual system in Germany (Der Grüne Punkt - Duales System Deutschland GmbH). Further information on this mixed plastics fraction can be found in the raw material fraction specification 350 Mixed Plastics dated April 5, 2023, available at https: / / www.gruener- punkt.de / fileadmin / Dateien / Downloads / PDFs / Rohstofffraktionssp ezifikationen2023 / DOC-23-50749_- _Rohstofffraktionsspezifikation_350_Mischkunststoffe_- _v0.02.0006.pdf.

[0136] WEEE (IE3) shredded electrical and electronic equipment

[0137] PC (CE2) Untreated polycarbonate granules commercially available from SABIC.

[0138] Results

[0139] The resulting pyrolysis cokes MPO323 (IE1) and MK350 (IE2) were analyzed for their elemental content. The results are listed in Table 1.

[0140] Table 2: Comparison of pyrolysis cokes. 1 Values ​​were measured by ICP-OES (solid) as described herein and extrapolated to the oxidic form.

[0141] 2 Fuel Processing Technology 182 (2018) 26-36 Table 3: Elemental analysis N, C, H, S as described herein of the pyrolysis coke (IE1) produced from MPO323 b) Reduction of impurities in pyrolysis oil with pyrolysis coke (CE3-4; IE4-7)

[0142] Experimental setup

[0143] Figure 1 shows the experimental setup for the process for reducing impurities from pyrolysis oil. A quartz glass cylinder with an inner diameter of 16 mm served as the reactor. The coke bed was located in the center of the glass reactor and held in place by glass wool. The upper part of the reactor was sealed by a PTFE rubber septum through which the nitrogen supply and the 0.8 mm diameter cannula for supplying the pyrolysis oil were passed. The pyrolysis oil was supplied via a cooking oil pump, which generated a constant oil flow at the desired volumetric flow rate. A tubular heater was arranged around the reactor, and a thermocouple was placed in the center of the heating zone of the reactor for temperature control. Cooling Unit 1 was located directly below the reactor. The beaker was connected to Cooling Unit 1.Cooling unit 2 was connected to the beaker with glass wool to achieve a higher liquid yield. For optimal cooling performance, the water flowed in the opposite direction to the gas. The resulting product was collected in a beaker. The excess gas was allowed to drain from cooling unit 2. To achieve maximum oil yield, the beaker was cooled in an ice-water bath.

[0144] Experimental procedure

[0145] 5 g of coke was weighed and placed in the center of the glass reactor, with the 50 mm high coke bed held in place by glass wool. The weight of the reactor was determined before and after filling. A 24 ml syringe with a 0.8 mm needle was then filled with oil. An oil sample was taken from the syringe to determine the exact composition of the oil used for analysis. The syringe was then clamped into the pump, and the needle was inserted through the membrane into the reactor. Before starting the experiment, the entire system was purged of air by purging with nitrogen (200 ml / min) for at least 3 minutes. Once the inert gas had dispersed throughout the system and the air was displaced, the nitrogen flow was set to 50 ml / min. The heater was then switched on, and the reactor was heated to the desired temperature. The temperature inside the reactor was monitored using thermocouples.Once the system reached the desired temperature of 600 °C, the syringe pump was switched on, delivering a constant flow rate of 0.25 ml / min of oil. The oil was converted into a gaseous phase in the reactor and flowed through the coke bed. The gas condensed in the cooler, and the liquid product was collected in a beaker. The mass flow of the pyrolysis oil was determined by differential weighing the syringe before and after the experiment and by determining the experiment duration. A WHSV of 3.63 l / h was determined.

[0146] The following coke materials were investigated. CE3 is untreated pyrolysis oil, so no conversion was carried out on coke. In CE4, a coke similar to that produced in CE2 was used, i.e., a pyrolysis coke based on pure polycarbonate. This pyrolysis coke contains no catalytically active component and is therefore a comparative example. In the following examples IE4-6, successively more coke was produced as in IE1, i.e., coke based on MPO323, to which CE2, i.e., coke based on pure polycarbonate, was admixed. IE7 then considers a coke bed based exclusively on coke similar to that produced in IE1. These experiments allow not only the absolute influence of a pyrolysis coke on the composition of the oil to be purified to be assessed, but also the proportional influence in combination with a pyrolysis coke that contains no catalytically active component.

[0147] Results

[0148] Table 4 shows the proportions of aromatic, monocyclic aromatic, and aliphatic hydrocarbons in the pyrolysis oils obtained from experiments CE3-4 and IE4-7. The Alip and Total proportions equal 100%, while the Mono and PAH proportions correspond to the Total proportions. It can be seen that the enrichment in aromatic hydrocarbons is generally improved by the presence of a coke bed. The process according to the invention does not achieve inferior results, but is capable of slightly increasing the aromatic proportions. Table 4: Proportions of aromatic compounds in the pyrolysis oil measured by GC / MS as described herein. a benzene, toluene, ethylbenzene, xylene; b BTEX + styrene; cMonocyclic aromatics, d Polycyclic aromatic hydrocarbons, eAliphatic compounds; Aromatic compounds

[0149] Table 5 lists the impurities measured in the pyrolysis oils from experiments CE3-4 and IE4-7. It shows that halogens such as Cl and Br were significantly reduced in the case of pure MPO. However, an effect can also be achieved with a proportion of the inventive coke.

[0150] Table 5: Contaminant content in pyrolysis oil in [ppm] measured by ICP-OES (liquid sample). c) Reduction of impurities in pyrolysis oil with pyrolysis coke from various sources (CE4, IE7, IE8)

[0151] Experimental setup

[0152] The same experimental setup as in examples CE3-4 and IE4-7 was used.

[0153] Experimental procedure

[0154] The same experimental procedure was used as in Examples CE3-4 and IE4-7. However, in addition to the cokes produced in CE1 (CE4) and IE1 (IE7), a coke produced in IE3 (IE8) was also compared.

[0155] Results: Table 6 shows the proportions of aromatic, monocyclic aromatic, and aliphatic hydrocarbons in the pyrolysis oils obtained from experiments CE3, CE4, IE8, and IE7. The Alip and Total proportions equal 100%, while the Mono and PAH proportions correspond to the Total proportions. It can be seen that the enrichment of aromatic hydrocarbons is generally improved by the presence of a coke bed. It turns out that the MPO323-based coke bed (IE1 and IE7) performs better than the WEEE-based coke bed (IE3 and IE8).

[0156] Table 6: Concentrations of aromatic compounds in the pyrolysis oil for different pyrolysis cokes measured by GC / MS as described herein. a benzene, toluene, ethylbenzene, xylene; b BTEX + styrene; c Monocyclic aromatics, d Polycyclic aromatic hydrocarbons, e Aliphatic compounds; Aromatic

[0157] Connections

[0158] Table 7 lists the impurities measured in the pyrolysis oils from experiments CE3-4 and IE7-8. It shows that halogens such as CI and Br were significantly reduced in the case of pure MPO. It also turns out that the MPO323-based coke bed (IE1 and IE7) performs better than the WEEE-based coke bed (IE3 and IE8).

[0159] Table 7 Contaminant content in pyrolysis oil for different pyrolysis cokes in [ppm] measured by ICP-OES (liquid samples) as described herein. d) Results depending on temperature and flow rate (IE7, IE9-12)

[0160] Experimental setup

[0161] The same experimental setup as in examples CE3-4 and IE4-8 was used.

[0162] Experimental procedure

[0163] The same experimental procedure was used as in Examples CE3-4 and IE4-8. However, in Examples IE9-12, different temperatures and flow rates were used than in IE7 (600 °C; 0.25 ml / min) (see Tables 8 and 9). Results

[0164] Table 8: Experiments depending on temperature and flow rate (or WH SV or residence time), impurities CI in the pyrolysis oil in [ppm] measured by ICP-OES (liquid sample); proportions of aromatic compounds in the pyrolysis oil measured by GC / MS as described herein. a Polycyclic aromatic hydrocarbons, b Aromatic compounds

[0165] Table 9: Experiments depending on temperature and flow rate (or WH SV or residence time), impurities CI in the pyrolysis oil in [ppm] measured by ICP-OES (liquid sample); proportions of aromatic compounds in the pyrolysis oil measured by GC / MS as described herein. aPolycyclic aromatic hydrocarbons, b Aromatic compounds

[0166] The examples in Tables 8 and 9 show that shorter residence times lead to a reduced reduction of impurities. Without wishing to be bound by any theory, it is assumed that shorter residence times also allow for shorter absorption or adsorption on the pyrolysis coke. It can be seen that, relatively speaking, higher temperatures with the same residence times also lead to higher impurities in the product (see IE9 vs. IE12). The impurity classification shows that lower temperatures and longer residence times represent an optimum (see IE9).

[0167] However, in addition to impurities, the effect on aromatics yield and quality should not be neglected. Tables 8 and 9 show that the total amount of aromatics increases significantly with temperature. The decrease with decreasing residence time appears negligible. In this respect, a contradictory picture is found here. While IE9 is the optimum in terms of impurities, IE12 is the optimum in terms of aromatics yield. However, with increasing temperature, the yield of polycyclic aromatics also increases. Since these are less desired, it can be seen that selecting a temperature of 600 °C and a residence time of 4.46 s (without nitrogen flow) or a WHSV of 3.63 l / h represents an optimum in terms of reducing impurities, maximizing the aromatics yield, and maximizing the quality of these aromatics.

Claims

Claims 1 . A process for reducing at least one impurity in a hydrocarbon-containing composition, the process comprising the following steps: Providing in a composition providing step a hydrocarbon-containing composition; Providing, in a pyrolysis coke provision step, a pyrolysis coke, wherein the pyrolysis coke contains at least one catalytically active component; Contacting in a contact step the pyrolysis coke with the hydrocarbon-containing composition.

2. The process according to claim 1, wherein the contacting step is carried out at a temperature in the range of 350 to 1000 °C, preferably 500 to 700 °C.

3. The process according to claim 1 or 2, wherein the contacting step is carried out at a pressure in the range of 0.1 to 150 bar, preferably 0.5 to 1.5 bar.

4. Process according to one of the preceding claims, wherein the residence time of the hydrocarbon-containing composition on the pyrolysis coke in the contact step is 0.1 s to 60 min, preferably 0.5 s to 60 s.

5. A process according to any one of the preceding claims, wherein the contacting step is carried out continuously and the mass space velocity (WHSV) is in the range of 0.1 to 30 l / h, preferably in the range of 0.25 to 15 1 / h.

6. A process according to any one of the preceding claims, wherein the pyrolysis coke is moved in the contacting step relative to the direction of movement of the hydrocarbon-containing composition, preferably opposite and / or transverse to the direction of movement of the hydrocarbon-containing composition.

7. Use of a pyrolysis coke for reducing at least one impurity in a hydrocarbon-containing composition, wherein the pyrolysis coke contains at least one catalytically active component.

8. The process according to any one of the preceding claims 1 to 6 or use according to claim 7, wherein the catalytically active component comprises at least one element, preferably consists of said at least one element being selected from the group consisting of Si, Al, Ca, Fe, Ti, Na, Mg, Zn, Mn, Ni, Ba, Cr, Cu, B or Sn, preferably selected is selected from the group consisting of Si, Al, Ca, Fe, Ti, Zn, Mg, Na, and Ca, and most preferably Ca.

9. A process according to any one of the preceding claims 1 to 6 or use according to claims 7 or 8, wherein the element is in activated form.

10. The method or use according to claim 9, wherein the element is oxidized, reduced, sulfurized, chlorinated, or a mixture thereof. 1 1. Process according to any one of the preceding claims 1 to 6 or use according to any one of the preceding claims 7 to 10, wherein the pyrolysis coke can be produced by pyrolysis of a starting material.

12. The method or use according to claim 11, wherein the starting material contains a mixture of polymers.

13. The method or use according to claim 12, wherein the polymers are selected from the group consisting of polyethylene (PE), polypropylene (PP), polystyrene (PS), polycarbonate (PC), polyvinyl chloride (PVC), polyamide (PA), and polyethylene terephthalate (PET).

14. The process according to any one of the preceding claims 1 to 6 or the use according to any one of the preceding claims 7 to 13, wherein the impurity comprises, preferably consists of, at least one halogen-containing component.

15. The method according to any one of the preceding claims 1 to 6 or use according to any one of the preceding claims 7 to 14, wherein the impurity comprises, preferably consists of, at least one phosphorus-containing component.

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