WO2025119732A1

WO2025119732A1 - Method and chemical plant for separating a steam cracker feedstock from a liquid stream

Info

Publication number: WO2025119732A1
Application number: PCT/EP2024/083741
Authority: WO
Inventors: Mathias Feyen; Maximilian Vicari; Armin Lange De Oliveira; Markus Brueggemann
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2023-12-07
Filing date: 2024-11-27
Publication date: 2025-06-12
Anticipated expiration: 2026-06-07

Abstract

The present invention relates to a method and a chemical plant for separating a steam cracker feedstock from a liquid stream comprising at least one plastic pyrolysis oil which is preferably manufactured from plastic waste. The liquid stream is converted in a first hydroprocessing step, a stream depleted in organic compounds comprising C−C double bonds and/or C−C triple bonds is then separated from the hydroprocessed liquid stream and subjected to a second hydroprocessing step to produce a steam cracker feedstock stream from the hydroprocessed stream. The method and chemical plant according to the present invention are suited to avoid undesired polymerization and fouling.

Description

Method and chemical plant for separating a steam cracker feedstock from a liquid stream

Technical Area

The present invention relates to a method and a chemical plant for separating a steam cracker feedstock from a liquid stream comprising at least one plastic pyrolysis oil which is manufactured from plastic waste.

Background of the invention

A method for processing a plastic pyrolysis oil comprising the steps a) selective hydrogenation, b) hydroprocessing and c) separation of the hydroprocessed effluent is disclosed in AU 2021/222788 A1 . At least a portion of the hydroprocessed effluent obtained after the separation in step c) is recycled into the a) selective hydrogenation and/or b) the hydroprocessing. The selective hydrogenation (step a)) at temperatures of up to 250 °C can result in undesired polymerization of plastic pyrolysis oil portions inside the hydrogenation unit. Furthermore, a separation step after a selective hydrogenation a) and a hydroprocessing b) requires a larger and therefore more expensive hydroprocessing unit because the whole hydrotreated stream obtained in step a) is subjected to the hydroprocessing of step b). In addition, the consumption of H2 is very high because of the same reason. A separation by distillation is not suited to separate a steam cracker feedstock from the stream. Hence, this method is directed to produce a steam cracking feedstock. The above discussed method is shown in Figure 1 and was used as a comparative example in the examples section of the present invention.

Document WO 2021/204820 A1 discloses a process for the purification of a feedstock stream comprising a plastic pyrolysis oil. The process comprises a single hydroprocessing step at a temperature of at least 230 °C in the presence of hydrogen. Dienic and other polymerizable components present in the plastic pyrolysis oil when entering the hydroprocessing unit at such a high process temperature cause undesired polymerization of said components which then leads to undesired foiling inside the hydroprocessing unit.

Document US2023/0287282A1 discloses a process for the purification of a hydrocarbon stream, said process comprises "performing a hydroprocessing step”. Said process results in a purified hydrocarbon stream which is suited as a feedstock for steam cracking.

Document WO2023/052765A1 discloses a method of upgrading highly olefinic oils derived from waste plastic pyrolysis in which said highly olefinic oils are mixed with hydrogen and a "saturated near zero-olefinic stream” to form an "attenuated feed stream” which is then subjected to a two-stage process with at least two hydroprocessing reactors. No distillation is applied between said at least two hydroprocessing reactors.

Document WO2018/058172A1 discloses treatment of a biomass pyrolysis oil by a process sequence a) first hydrotreatment, b) distillation, c) second hydrotreatment. Pyrolysis oils derived from biomass have a different composition, particularly a lower content of compounds having C-C double bonds and/or C-C triple bonds such as dienes, which are a major reason for undesired fouling during comparable treatments of plastic pyrolysis oils. A recycle stream separated from the first hydrotreated effluent is not disclosed in this document.

It is an objective of the present invention to provide a method and a chemical plant for separating a steam cracker feedstock stream from a liquid stream comprising at least one plastic pyrolysis oil which was obtained by pyrolysis of plastic waste. Furthermore, the method and chemical plant should decrease undesired fouling during processing when separating a steam cracker feedstock stream liquid stream comprising at least one plastic pyrolysis oil which was obtained by pyrolysis of plastic waste.

Summary of the Invention

These problems are solved by a method for separating a steam cracker feedstock from a liquid stream comprising at least one plastic pyrolysis oil, the method comprising the steps

(I) providing a liquid stream S1 , the stream S1 comprising at least one plastic pyrolysis oil, the liquid stream S1 further comprising organic compounds comprising at least one heteroatom and compounds having C-C double and/or C-C triple bonds,

(II) providing a stream S2, the stream S2 comprising H2,

(ill) feeding the liquid stream S1 and the stream S2 into a hydrogenation unit HU1 in which at least a portion of the components of the liquid stream S1 reacts with stream S2 in a hydrogenation reaction whereby a liquid stream S3 is formed, wherein the liquid stream S3 is depleted in compounds having C-C double and/or C-C triple bonds in respect to liquid stream S1, and feeding at least a portion of a liquid recycle steam S3', said liquid recycle stream S3' separated from the liquid stream S3, into said hydrogenation unit HU1, wherein the mass ratio " liquid recycle steam S3' : liquid stream S3 ” preferably ranges between from about 1 :1 to about 30:1, more preferably from about 5:1 to about 20:1 and most preferably from about 10:1 to about 15:1,

(iv) subjecting the remaining portion of the liquid stream S3 to a distillation unit DU in which the remaining portion of liquid stream S3 is separated into a valued product stream S4 and a residue stream S5, wherein the valued product stream S4 comprises organic compounds comprising at least one heteroatom, and

(v) subjecting the valued product stream S4 to a hydrogenation unit HU2 in which the valued product valued product stream S4 is converted into a stream S6, wherein the stream S6 is depleted in organic compounds comprising at least one heteroatom and/or C-C double bonds in respect to valued product stream S4.

These problems are further solved by a chemical plant for separating a steam cracker feedstock from a liquid stream comprising at least one plastic pyrolysis oil, the chemical plant comprising

(I) at least one first hydroprocessing unit HU1, the at least one first hydroprocessing unit HU1 comprising at least one inlet and at least one outlet,

(II) a recycle unit downstream of and fluidically connected to the inlet and the outlet of the first hydroprocessing unit HU1, (iii) a distillation unit DU downstream of and fluidically connected to the outlet of the first hydroprocessing unit HU1, the distillation unit DU having a bottom outlet BO and a head outlet HO, and

(iv) a second hydroprocessing unit HU2 downstream of and fluidically connected to the head outlet HO of the distillation unit DU.

Figure 1 shows a method in which a recycle stream from a second hydroprocessing unit into a first hydroprocessing unit is utilized. Such a recycle stream is employed in the method disclosed in AU 2021/222788 A1 and was used therefore as comparative example in the examples section.

Figure 2 shows the method and the chemical plant for separating a steam cracker feedstock stream from a liquid stream comprising at least one plastic pyrolysis oil according to the present invention with an liquid recycle steam S3'.

Figure 3 shows the method and the chemical plant for separating a steam cracker feedstock stream from a liquid stream comprising at least one plastic pyrolysis oil according to the present invention further comprising an optional recycle-gas stream S6".

Detailed description of the invention

The present invention is further described below with reference to the embodiments, but the present invention is not limited to these embodiments, and any modifications of these embodiments, combinations of these embodiments or substitutions within the basic spirit of the present invention are still within the scope of the present invention as claimed.

Definitions:

In the context of the present description and the accompanying claims, the term “about” preferably means a deviation of the thus described value of ±10%. In the context of the present invention, the term “combinations thereof” is inclusive of one or more of the recited elements. In the context of the present invention, the term “mixture thereof” is inclusive of one or more of the recited elements.

In the context of the present invention, the term “pyrolysis” relates to a thermal decomposition or degradation of a feedstock such as plastic waste under inert conditions and results in a gas, a liquid, and a solid char fraction. During the pyrolysis, the feedstock is converted in a pyrolysis unit into a great variety of chemicals including gases such as H2, Ci- to C4-alkanes, C2- to C4-alkenes, ethyne, propyne, 1 -butyne, plastic pyrolysis oil having a boiling temperature of 25 °C to 500 °C or more and char. The direct products from such a pyrolysis are “pyrolysis gas” and solid products. The liquid product “plastic pyrolysis oil” is then separated by condensation from the “pyrolysis gas”. In addition, water is formed during the pyrolysis which may be partially dispersed in the plastic pyrolysis oil and may be partially contacted with the plastic pyrolysis oil in a separate phase. The water formed during pyrolysis comprises various organic compounds and/or salts thereof which were also formed during the pyrolysis. The term “pyrolysis” includes slow pyrolysis, fast pyrolysis, flash catalysis and catalytic pyrolysis. These pyrolysis types differ regarding process temperature, heating rate, residence time, feed particle size, etc. resulting in different product quality. The pyrolysis unit may be operated adiabatically, isothermally, nonadiabatically, non-isothermally, or combinations thereof. The pyrolysis reactions of this disclosure may be carried out in a single stage or in multiple stages. For example, the pyrolysis unit can comprise two reactor vessels fluidly connected in series.

In the context of the present invention, the term "plastic pyrolysis oil” is understood to mean any oil originating from the pyrolysis of plastic waste. The term "plastic waste” includes rubber waste such as end-of-life tires and feedstocks comprising plastic waste. The plastic pyrolysis oil is obtained and/or obtainable from pyrolysis such plastic waste.

In the context of the present invention, the term "plastic waste” refers to any plastic material discarded after use, i.e. , the plastic material has reached the end of its useful life and is considered post-consumer waste. The plastic waste can be pure polymeric plastic waste, mixed plastic waste or film waste, including soiling, adhesive materials, fillers, residues etc. The plastic waste may have an oxygen content, a nitrogen content, sulfur content, halogen content and optionally also a heavy metal content. The plastic waste can originate from any plastic material containing source.

Accordingly, the term "plastic waste” includes industrial and domestic plastic waste and including used tires and agricultural and horticultural plastic material.

Typically, plastic waste is a mixture of different plastic materials, including hydrocarbon plastics, e.g., polyolefins such as polyethylene (HDPE, LDPE) and polypropylene, polystyrene, and copolymers thereof, etc., and polymers composed of carbon, hydrogen, and other elements such as chlorine, fluorine, oxygen, nitrogen, sulfur, silicone, etc., for example chlorinated plastics, such as polyvinylchloride (PVC), polyvinylidene chloride (PVDC), etc., nitrogencontaining plastics, such as polyamides (PA), polyurethanes (PU), acrylonitrile butadiene styrene (ABS), etc., oxy- gen-containing plastics such as polyesters, e.g., polyethylene terephthalate (PET), polycarbonate (PC), etc., silicones and/or sulfur bridges crosslinked rubbers.

Typically, the plastic material comprises additives, such as processing aids, plasticizers, flame retardants, pigments, light stabilizers, lubricants, impact modifiers, antistatic agents, antioxidants, etc. These additives may comprise elements other than carbon and hydrogen. For example, bromine is mainly found in connection to flame retardants. Heavy metal compounds may be used as lightfast pigments and/or stabilizers in plastics. Cadmium, zinc, and lead may be present in heat stabilizers and slip agents used in plastics manufacturing. The plastic waste can also contain residues. Residues in the sense of the invention are contaminants adhering to the plastic waste. The additives and residues are usually present in an amount of less than 50 wt.-%, preferably less than 30 wt.-%, more preferably less than 20 wt.-%, even more preferably less than 10 wt.-%, based on the total weight of the dry weight plastic. Examples of rubber waste (which is also considered "plastic waste” in the sense of the present invention) include end-of-life tires, rubber waste produced during manufacturing processes and discarded rubber containing products such as latex examining gloves and gaskets. End-of-life tires comprise further ingredients such as textiles and organic and inorganic additives which may be separated from the rubber portion of end-of-life tires prior to pyrolysis. Plastic pyrolysis oils obtained by pyrolysis of (predominantly) end-of-life tires are also known as tire pyrolysis oils (TPO).

Examples of bio waste which can be comprised in "plastic waste” include green waste, food waste, human waste, manure, sewage, sewage sludge and slaughterhouse waste.

To obtain the plastic pyrolysis oil according to the present invention, the feedstock is inserted into a pyrolysis reactor using a dosing unit such as a screw or an extruder or a rotary valve or a pneumatic conveyor or a liquid injector. The feedstock is optionally pre-heated in e.g., a heat exchanger prior to insertion into the pyrolysis reactor and/or subjected to a pre-pyrolysis at a temperature in the range of, for example, from about 200 °C to about 360 °C. Next, the feedstock is heated in the pyrolysis reactor to a temperature in the range of from about 350 °C to about 900 °C, more preferably in the range of from 400 °C to about 550 °C, and a pressure in the range of from about 0.5 bar to about 2 bar(abs), more preferably in the range of from 0.9 bar to about 1.5 bar(abs). The pyrolysis reactor is preferably selected from the group comprising fluidized bed reactors, moving bed reactors, entrained flow reactors, screw reactors, extruders, stirred tank reactors and rotary kiln reactor. Preferably, the pyrolysis is performed in the pyrolysis reactor under an inert atmosphere exempt of oxygen or air.

Pyrolysis processes as such are known. They are described, e.g., in EP 0713906 A1 and WO 95/03375 A1. Suitable plastic pyrolysis oils are also commercially available. The plastic pyrolysis oil is typically a liquid at 15 °C or a wax at said temperature. "Liquid at 15 °C” in the terms of the present invention means that the plastic pyrolysis oil has a density of at most 1.3 g/ml, e.g., a density in the range from 0.65 to 0.98 g/ml, at 15 °C and 1013 mbar, as determined according to DIN EN ISO 12185.

The at least one plastic pyrolysis oil comprised in the liquid stream S1 preferably further has a bromine number of about 2 g Br2/100g to about 150 g Br2/100g (determined by ASTM 1159) and/or a C5 hydrocarbon content of about 0.03 wt.-% to about 12.2 wt.-% (determined by ASTM D 5134) and/or a naphthalene content of about 0.5 wt.-% to about 18.4 wt.-% (determined by ASTM D 5134) and/or a styrene content of about 0.02 wt.-% to about 29.5 wt.-% (determined by ASTM D 5134) and/or a toluene content of about 4.3 wt.-% to about 71.5 wt.-% (determined by ASTM D 5134). Such plastic pyrolysis oils are particularly suited for the method and the chemical plant according to the present invention.

Optionally, the plastic pyrolysis oil or mixture of plastic pyrolysis oils is subjected to one or more methods selected from filtration, centrifugation, adsorption, washing, extraction before used as liquid stream S1 in the method according to the present invention and/or as feedstock for the chemical plant according to the present invention. Such op- tional pre-treatment methods are for example described in WO 2021/224287 A1, WO 2023/061834 A1, EP 0713906 A1 and WO 95/03375 A1 which are incorporated herein by reference. A skilled person knows how and in which cases to use pre-treatment methods disclosed in said documents and comparable pre-treatment methods disclosed elsewhere.

The liquid stream S1 comprises at least one plastic pyrolysis oil manufactured from the above-described feedstocks and the above-described methods or mixtures of such plastic pyrolysis oils. The liquid stream S1 further comprises organic compounds comprising at least one heteroatom and compounds having C-C double bonds (olefins, dienes, styrene) and/or C-C triple bonds which are contributed by the at least one plastic pyrolysis oil and/or further liquid hydrocarbon feedstocks optionally comprised in the liquid stream S1. Examples of such further liquid hydrocarbon feedstocks are given further below.

A liquid stream S1 comprising at least one plastic pyrolysis oil, the liquid stream S1 further comprising organic compounds comprising at least one heteroatom and compounds having C-C double and/or C-C triple bonds is provided in step (i) of the method according to the present invention (Figure 2).

The liquid stream S1 optionally further comprises at least one further liquid hydrocarbon feedstock which is different from plastic pyrolysis oils obtained by pyrolysis of plastic waste. Suitable examples of such further liquid hydrocarbon feedstocks comprise bio-oils which are manufactured from biomass as source. Such feedstocks are explained in the following section:

Biomass is biological material derived from living, or recently living organisms. The biomass used for the manufacture of bio-oils may be any material of plant or animal origin that is in principle suitable to be converted at least into bio-oils. In particular, the term biomass comprises plants or parts thereof like crops, wood, or residues thereof, marine organisms like algae, and bio waste such as organic food waste, e.g., animal fat from meat industry waste, fish fat from fish processing waste, or used cooking oil. The bio-oils can also be manufactured from more than one of the above-mentioned sources. The biomass is of plant or animal origin or a mixture thereof, preferably it is of plant origin.

Preferably, said biomass of plant origin comprises or is derived from algae, oil crops, oil palms, soybeans, rapeseed, mustard, flax, cottonseed, sunflower, corn, hemp, field pennycress, pongamia, jatropha, mahua, camelina, salicornia, carinata, lignocellulose, wood, forestry residues, agricultural residues, crop residues, residues from vegetable oil production, green waste, food waste, and used vegetable cooking oil, more preferably it comprises or is derived from algae, oil crops, oil palms, soybeans, rapeseed, pongamia, jatropha, camelina, and carinata.

In case the biomass is of animal origin, it preferably comprises or is derived from animal fat, livestock-related products like tallow, fish fat, or food waste. The biomass is converted to a liquid hydrocarbon feedstock which is different from plastic pyrolysis oils obtained by pyrolysis of plastic waste and can be comprised in the liquid stream S1. Such conversion may comprise both mechanical and physical operations, like harvesting and collecting as well as crushing, cracking, cutting, shredding, grinding, chipping, milling, extrusion, irradiation, squeezing, pressing, filtering, sieving, adsorption, and thermal treatments such as drying and torrefaction, and chemical processes, like extraction, distillation, thermochemical conversions like pyrolysis or hydrothermal liquefaction, hydrolysis, saponification, neutralization, or ketonization. Also, the mechanical, physical, and/or chemical separation of the products and by-products of said operations and processes, in particular the separation of gaseous, liquid, and solid fractions, forms part of the biomass processing. In essence, said processing comprises the removal of all by-products from the biomass conversion product stream that are not suitable or are detrimental for further use in the stream S1. The right choice of suitable process steps and operating conditions is mainly dependent on the biomass to be processed; but the one skilled in the art will be familiar with such considerations.

The product stream obtained by said biomass processing comprises, preferably consists of bio-oil. Bio-oil designates a liquid compound mixture mainly comprising highly oxygenated compounds (e.g., glycerides, esters, carboxylic acids, phenols, alcohols, ketones, aldehydes, furans, and sugars) and water, while its exact composition depends on the biomass feedstocks and the processing steps applied. The term bio-oil includes in particular vegetable oils like rapeseed oil, sunflower oil, soybean oil, corn oil, and palm oil, waste cooking oil, tall oil, animal fats, and oils obtained by thermochemical conversion of biomass, e.g., biomass-derived pyrolysis or hydrothermal liquefaction oils.

Thus, according to one embodiment of the present invention, the processing of biomass in the manufacture of the feedstock provided in step (I) comprises mechanical and physical operations and chemical processes, optionally also the separation of the obtained products and any by-products.

According to another embodiment of the present invention, the processing of biomass in the manufacture of the feedstock for use in the stream S1 comprises extraction, pyrolysis, and/or hydrothermal liquefaction of the biomass.

Such further liquid hydrocarbon feedstock (in case more than one liquid hydrocarbon feedstocks the sum of all liquid hydrocarbon feedstocks) can be comprised in the liquid stream S1 for example in a quantity of 0 wt.-%, 5 wt.-%, 10 wt.-%, 15 wt.-%, 20 wt.-%, 25 wt.-%, 30 wt.-%, 35 wt.-%, 40 wt.-%, 45 wt.-%, 50 wt.-%, 55 wt.-%, 60 wt.-%, 65 wt.-%, 70 wt.-%, 75 wt.-%, 80 wt.-% or more with the proviso that at least 2 wt.-% of the liquid stream S1 are comprised of at least one plastic pyrolysis oil manufactured by pyrolysis of plastic waste.

A stream S2 comprising H2 is provided in step (II) of the method according to the present invention. The stream S2 can consist essentially of H2 or comprise H2 together with at least one other gas. Preferably the H2 content of the stream S2 is higher than about 50 Vol.-%, more preferably higher than about 80 Vol.-% and most preferably higher than about 95 Vol.-%. This minimizes the amount of purge-gas needed to keep the H2 partial pressure high and saves H2. A high H2 partial pressure promotes the catalyst activity and allows low reaction temperatures. The advantage of low reaction temperatures is that undesired polymerization of components in stream S2 is suppressed. Such polymerization results in undesired fouling during processing.

Hydrogen (H2) used in the method and system according to the present invention is preferably "green hydrogen” which is generated for example by electrolysis of water using electricity generated from renewable energy sources (e.g., solar energy, wind energy, tidal energy, and nuclear energy) and/or low-carbon energy sources and/or a methane pyrolysis, preferably a methane pyrolysis using at least partially methane from a renewable source. Methane from a renewable source comprises biomethane.

Optionally, at least a portion of the hydrogen used in the method according to the present invention is hydrogen formed during the pyrolysis reaction and separated from the volatile pyrolysis reaction products.

In method step (ill) according to the invention, compounds having C-C double bonds and/or C-C triple bonds present in liquid stream S1 are hydrogenated in a first hydroprocessing unit HU1 in the presence of stream S2. Thereby a liquid stream S3 is formed which leaves the first hydroprocessing unit HU1. At least a portion of the liquid stream S3 is separated from liquid stream S3 and fed into the first hydroprocessing unit HU1 as a liquid recycle S3' together with liquid stream S1 and stream S2.

The first hydroprocessing unit HU1 comprises at least one stage, in which C-C double bonds and/or C-C triple bonds present in liquid stream S1 are hydrogenated. The first hydroprocessing unit HU1 is preferably a three-phase reactor, more preferably a three-phase reactor with a fixed catalyst bed. Said three-phase reactor is most preferably operated in trickling mode or pulse flow mode. Said fixed catalyst bed preferably comprises at least one catalyst which is used in at least one stage of the first hydroprocessing unit HU1 . The first hydroprocessing unit HU1 can also comprise two or more of such reactors or a single reactor can comprise one or more beds, each bed comprising one or more catalysts.

Preferably, the first hydroprocessing unit HU1 comprises one single reactor having one single catalyst bed. Thereby, the geometric shape of the first hydroprocessing unit HU1 is minimized, and a cost-efficient reactor design is assured.

The at least one hydrogenation reactor of the first hydroprocessing unit HU1 is preferably designed to function in trickling mode or pulse flow mode where the gaseous phase (gaseous stream S2 comprising H2) is continuous or semi-continuous and the liquid phase (liquid stream S1) flows along the solids, mainly along the surface of the at least one catalyst and thereby wetting them efficiently. The process temperature in the at least one hydrogenation reactor of the first hydroprocessing unit HU1 depends on catalyst type used and the degree of activity of the catalyst. The process temperature preferably ranges from about 60 °C to about 250 °C, more preferably from about 60 °C to about 200 °C and most preferably from about 80 °C to about 120 °C. The deactivation of the catalyst can optionally be compensated by raising the process temperature.

The hydrogen pressure preferably ranges from about 1.0 to about 10 MPa abs. in the in the at least one hydrogenation reactor of the first hydroprocessing unit HU1 .

The weight hourly space velocity (WHSV) of the liquid stream S1 excluding the optional liquid recycle stream S3' preferably ranges from about 0.1 t/(m³Kat/h) to about 5 t/(m³ _Kat h), more preferably from about 0.5 t/(m³ _Kat/h) to about 1.0 t/(m³Kat/h).

The process disclosed in WO2018/058172A1 does not comprise a liquid recycle S3'. The technical effect of said liquid recycle S3' present in the method according to the present invention is described below:

The chosen process conditions allow to maintain the liquid stream S1 in the liquid stage during step (ill). The amount of hydrogen present in the first hydroprocessing unit HU1 is sufficient to hydrogenate undesired C-C double bonds (olefins, dienes) and C-C triple bonds present in the liquid stream.

The dilution of liquid stream S1 by the liquid recycle stream S3' further reduces undesired fouling by polymerization inside the first hydroprocessing unit HU1. Furthermore, the temperature inside the first hydroprocessing unit HU1 can be better controlled when diluting the liquid stream S1 with a liquid recycle stream S3'.

The ratio "liquid recycle stream S3' : liquid stream ST’ preferably ranges between about 2:1 and about 20: 1, more preferably between about 8:1 and about 15: 1.

The mass ratio "liquid recycle stream S3 : liquid stream S3” preferably ranges between from about 1 :1 to about 30:1 , more preferably from about 5: 1 to about 20:1 and most preferably from about 10: 1 to about 15: 1.

Preferably, the liquid stream S1 and the optional recycle liquid stream S3' are mixed before entering the at least one reactor of the first hydroprocessing unit HU1 .

Preferably, suitable catalysts for the first hydroprocessing unit HU1 comprise at least one catalytically active metal selected from the element of groups 8 to 12 of the periodic table, more preferably the at least one catalytically active metal is selected from the group comprising or consisting of nickel, palladium, platinum, rhodium and most preferably is palladium. In case palladium is the catalytically active metal, the catalyst comprises palladium in an amount, calcu- lated as elemental palladium, in the range of from about 0.01 wt.-% to about 5 wt.-%, more preferably from about 0.1 wt.-% to about 1 wt.-%, most preferably from 0.15 to 0.8 wt-%, based on the total weight of the catalyst.

Suitable catalysts further comprise a support, preferably an inorganic support such as silica, alumina, silica-aluminas, silica-alumina phosphates, magnesium oxide, clays, carbon, and mixtures thereof. The supports may also comprise support-dopands such as zirconium dioxide, cerium dioxide, titanium dioxide, and mixtures thereof. "Silica-aluminas” also comprise zeolites.

Preferably, the catalysts for the first hydroprocessing unit HU1 further comprises a promoter, the promoter more preferably being one or more of element of the groups 10 and 11 of the periodic table of elements, preferably one or more of copper, gold, silver, and platinum, more preferably one or more of silver and platinum, most preferably silver.

Preferably, the atomic ratio of the at least one catalytically active element of groups 8 to 12 of the periodic table, more preferably of the group comprising or consisting of nickel, palladium, platinum, rhodium, and most preferably of palladium, relative to the promoter is in the range of from 0.1 : 1 to 10:1 , more preferably from 2: 1 to 7:1 , more preferably from 2.5: 1 to 6: 1.

Most preferably, the catalysts for the first hydroprocessing unit HU1 comprises palladium supported on a support material, preferably a support material as defined in the foregoing, wherein the support material is more preferably alumina or carbon, most preferably alumina.

In the context of the present invention, the at least one catalyst for the first hydroprocessing unit HU1 preferably is in the form of extrudates, pellets, rings, spherical particles or spheres, more preferably spherical particles or extrudates.

The particle size means here particle size distribution, which is measured for example by sieve methods, laser diffraction methods or other methods known in the art. A catalyst having a desired particle size and optionally desired shape may be manufactured and used.

The catalysts for the first hydroprocessing unit HU 1 , most preferably comprising or consisting of palladium is preferably activated under flow of hydrogen (for example GHSV = 1000/h) at about 50 °C to about 130 °C, for example for about 6 h to about 24 h such as about 12 h, preferably at atmospheric condition. Upon catalyst reduction in larger reactor, hydrogen can be diluted by nitrogen to avoid excess temperature.

The height and diameter of the at least one catalyst bed is chosen on reaction kinetics and optimal I iquid/gas flowpattern and pressure drop. The at least one catalyst bed may consist of one or more layers of different solid absorption materials, or/and one or different hydrogenation catalysts. The catalyst layers in the at least one catalyst bed may differ from each other by particle size or shape or activity or active sites of material. Inert particles may be used above and below each bed to improve fluid distribution in case more than one catalyst bed is used.

In case the at least one hydrogenation reactor in the first hydroprocessing unit HU1 has at least two stages, the catalyst preferably has a different particle size in at least two stages and/or optionally different shape in the at least two stages.

The hydrogenation reaction is an exothermic reaction and therefore each reaction stage may optionally be cooled.

Preferably, at least a portion of the liquid stream S3 is fed into the first hydroprocessing unit HU1 at least for a second time as recycle stream S3'. In this case, the first hydroprocessing unit HU1 preferably also comprises a recycling unit in which the desired portion of the optional recycle stream S3' can be separated from liquid stream S3. The liquid stream S1 is diluted before entering the first hydroprocessing unit HU1 with the recycle stream S3' and thereby, undesired fouling caused by polymerization of compounds having C-C double bonds (olefins, dienes, styrene) and compounds having C-C triple bonds present in liquid stream S1 is reduced.

The reactor inlet temperature of the first hydroprocessing unit HU1 is optionally and preferably adjusted by mixing warm liquid recycle stream S3' and cooled down liquid recycle stream S3' from the outlet of the at least one reactor of the first hydroprocessing unit HU1 with the liquid stream S1 to adjust the desired reactor inlet temperature. This optional and preferred concept avoids the contact with heat-exchange surfaces and thereby avoids undesired fouling of the heat exchanger surfaces and whereby the undesired fouling also causes reduction of heat-transfer inside the heat exchanger which is avoided by the optional and preferred concept. If the outlet-stream of the at least one reactor of the first hydroprocessing unit HU1 is not warm enough, then the polymerizing stable stream S3 is heated up by a heat-exchanger to adjust the necessary temperature.

About 90 % or more, preferably more than 95 % and most preferably 99 % of the dienes present in the liquid stream S1 are converted in step (ill) of the method according to the present invention.

To maintain a high H2 partial pressure in the first hydroprocessing unit HU 1 , preferably the first hydroprocessing unit HU 1 is operated with an off-gas stream S2', more preferably, when the H2 concentration in stream S2 is lower than 99.9 Vol.-%, to avoid accumulation of inert gaseous components such as N2, CH4, and C2H6 in stream S2.

The ratio "H2 content in the fresh H2 feed stream S2 : chemical H2 consumption caused by the hydrogenation reactions) in the first hydroprocessing unit HU1” preferably ranges from about 1 :1 to about 5:1 , more preferably from about 1 :1 to about 3:1 and most preferably from about 1 : 1 to about 2:1. The total pressure at the outlet of the at least one reactor in the first hydroprocessing unit HU1 preferably ranges from about 5 bar (abs.) to about 60 bar (abs.), more preferably from about 10 bar (abs.) to about 40 bar (abs) and most preferably from about 20 bar (abs.) to about 40 bar(abs).

Next, in step (iv) of the method according to the present invention at least a portion of the liquid stream S3 is subjected to a distillation in a distillation unit DU at an elevated temperature for separating the portion of liquid stream S3 into a valued product stream S4 having a final boiling point suited for a steam cracker feedstock and a liquid residue stream S5 having a higher final boiling point range than the valued product stream S4. The valued product stream S4 preferably has a final boiling point of about 200 °C to about 600 °C, more preferably about 200 °C to about 450 °C and most preferably about 200 °C to about 360 °C. "Portion of liquid stream S3 ” means the remaining portion of stream S3 after stream S3' was separated therefrom.

The residue stream S5 formed in the distillation unit DU comprises the heavy-boiling portions of stream S3 and is then optionally converted by a partial oxidation and/or a gasification process unit into syngas, wherein the syngas comprises H2, CO and CO2. Such partial oxidation reactions and gasification processes are known in the art and are for example disclosed in Ullmann's Encyclopedia of Industrial Chemistry, Vol. 16, Chapter: Gas Production, 2. Processes, pages 443-455, 2012. The skilled person can select suitable reactors and reaction conditions to convert the liquid residue stream S5 into syngas by a partial oxidation reaction and/or gasification.

Final boiling points of streams S1 , S3, S4, S5 and S6 are preferably measured by the method(s) described in ASTM D86, ASTM D7169 and for very high boiling liquids also by ASTM D7182.

The distillation unit DU comprises at least one, more preferably two distillation columns, or optionally at least one one thin film evaporator or a combination of at least one distillation column and at least one thin film evaporator. The distillation unit DU is downstream of and fluidically connected to the at least one outlet of the first hydroprocessing unit HU1.

Due to the wide boiling range of the stream S3 a two-distillation-column setup is most preferred. The first distillation column operates at about 1 bar (abs.) to about 2 bar (abs.) to separate the light boiling fraction (= stream S4a) from the stream S3, and a second distillation column to separate the heavy boiling fraction (= residue stream S5) from the remaining portion of stream S3. This remaining portion of stream S3 is not suited for the successive cracking process, preferably in the steam cracking process because of the high boiling point.

The second distillation column can be for example be operated at a pressure of about 0.01 bar (abs.). The overhead fraction obtained from the second distillation unit is denoted "stream S4b”). The valued product stream S4 preferably consists of the overhead fractions of the first distillation column (= stream S4a) and the second distillation column (= stream S4b) in case the distillation unit DU comprises two distillation columns, which is preferred. The distillation is carried out at a temperature in the range of about 0 °C to about 600 °C, more preferably from about 20 °C to about 400 °C, most preferably from about 80 °C to about 250 °C (the temperature ranges refer to atmospheric pressure of 1.013 bar). The operating pressure of the first distillation column preferably ranges from about 0.001 bar (abs.) to about 4 bar (abs.), more preferably from about 0.001 bar (abs.) to about 2.0 bar (abs.), most preferably from about 0.9 bar to about 1 .8 bar (abs). The temperature is adjusted accordingly in case the pressure is + 1.013 bar.

The operating pressure of the second distillation column preferably ranges from about 0.001 bar (abs.) to about 4 bar (abs.), more preferably from about 0.001 bar (abs.) to about 1.0 bar (abs.), most preferably from about 0.005 bar (abs.) to about 0.1 bar (abs.). The temperature is adjusted accordingly in case the pressure is # 1.013 bar.

Optionally, the distillation unit DU comprises at least one thin-film evaporator. In thin-film evaporators the medium to be evaporated or the solution to be concentrated by evaporation, respectively, is applied to the evaporator area as a thin film. Thereby, a short contact time with the heating surface is feasible and thermally unstable liquids and substances, respectively, can be evaporated in such thin-film evaporators. Furthermore, thin-film evaporators can be used for separation tasks if the product accumulating as a residue has poor flow properties and/or is prone to clumping. Thin-film evaporation processes are based on the principle of simple distillation according to which the separating capacity of said type of evaporator is limited. Suitable thin-film evaporators are available in various designs, for example as falling-film evaporators or as rotary evaporators.

Next, the valued product stream S4 is converted in step (v) of the method according to the present invention in a second hydroprocessing unit HU2 into a purified stream S6 and a gaseous stream S6'. The purified stream S6 is depleted in heteroatoms such as nitrogen, oxygen, halogens (fluorine, chlorine, bromine, iodine), and sulfur in respect to the valued product stream S4 by a hydrotreatment, optionally in the presence of a gaseous stream S4' which comprises hydrogen (H2) in the second hydroprocessing unit HU2. Optionally, the off-gas stream S2'which is the remaining portion of the stream S2 which leaves the first hydroprocessing unit HU1 and can be fed to the second hydroprocessing unit HU2. In this case, the stream S4' balances the hydrogen demand of the second hydroprocessing unit HU2. The heteroatoms leave the second hydroprocessing unit HU2 in form of their respective hydrogenated species as gaseous stream S6'.

The respective hydrogenated species of heteroatoms comprise NH3, H2O, H(Hal) (HF, HCI, HBr, HI), and H2S. NH3 and H(Hal) may form salts of type NH4Hal (NH4F, NH4CI, N H4Br, NH4I) and NH3 and H2S may form the salt NH4SH. Such salts may be formed already in the gas phase in the second hydroprocessing unit HU2 and can then form undesired deposits on metal surfaces by resublimation when stream S6 is cooled down. NH4CI, NH4F, NH4Br, NH4I and NH4SH of which at least one may be formed mainly in the second hydroprocessing unit HU2 (a minor portion may also be formed in the first hydroporocessing unit HU1) are preferably removed from the second hydroprocessing unit HU2 by water. More preferably, NH4F, NH4CI, NH4Br, NH4I and/or the respective cations and anions are removed quantitatively with water and NH4SH and/or the respective cation and anion is/are partly removed from the second hydroprocessing unit HU2 with a water stream (not shown in Figure 2).

Accordingly, the reactions in the second hydroprocessing unit HU2 comprise hydrodenitrogenation, hydrodeoxygenation, hydrodehalogenation and hydrodesulfurization. Furthermore, the reactions comprise hydrodemetallization and, preferably, also hydrogenation of the remaining C-C double bonds (olefins, dienes, styrene) and C-C triple bonds.

The at least one inlet of the second hydroprocessing unit HU2 is downstream of and fluidically connected to the distillation unit DU, i.e., the at least one opening through which valued product stream S4 leaves the distillation unit DU.

The second hydroprocessing unit HU2 may be any vessel configured to contain the hydroprocessing catalyst disclosed herein. The vessel is preferably configured for liquid- and gas phase operation. The second hydroprocessing unit HU2 may include one or more beds of the hydroprocessing catalyst, preferably in fixed bed configuration. The second hydroprocessing unit HU2 can be operated adiabatically, isothermally, non-adiabatically, non-isothermally, or combinations thereof. The second hydroprocessing unit HU2 may comprises more than one vessel. Each of such vessels is considered a hydrogenation reactor.

The valued product stream S4 can be contacted with the hydroprocessing catalyst in upward flow, downward flow, radial flow, or combinations thereof, with or without a staged addition of the valued product stream S4, the gaseous stream S2' or combinations thereof.

Preferably, heteroatoms comprising halogens (such as chlorine), nitrogen, oxygen, and sulfur are removed from the valued product stream S4 in the second hydroprocessing unit HU2. Such heteroatoms are separated from the organic residues by the hydrotreatment conditions for examples as HF, HCI, HBr, NH3, H2O and H2S and the separated heteroatoms are replaced by hydrogen atoms in the organic residue. In addition, remaining olefins and/or dienes in the valued product stream S4 which were not converted into saturated hydrocarbons in the first hydrogenation unit HU1 are converted to saturated hydrocarbons in the second hydroprocessing unit HU2.

The hydroprocessing catalyst may be any catalyst used for hydrogenation of olefins, dienes and heteroatom hydrogenation (e.g., commercially available hydroprocessing catalysts). Suitable hydroprocessing catalysts for this purpose comprise molybdenum catalysts (Mo catalysts), cobalt-molybdenum catalysts (Co-Mo catalysts), nickelmolybdenum catalysts (Ni-Mo catalysts), tungsten-molybdenum catalysts (W-Mo catalysts), cobalt-molybdenum oxides, nickel-molybdenum oxides, tungsten-molybdenum oxides, cobalt-molybdenum sulfides, nickel-molybdenum sulfides, tungsten-molybdenum sulfides, molybdenum sulfides. Suitable catalysts further comprise a support, prefer- ably an inorganic support such as silica, alumina, silica-aluminas, magnesia, clays, and mixtures thereof. Further suitable hydroprocessing catalysts are for example zeolites comprising one or more metals. More than one of the aforementioned hydroprocessing catalysts can be used together in the second hydroprocessing unit HU2.

In the context of the present invention, the catalysts for the second hydroprocessing unit HU2 preferably is in the form of extrudates, pellets, rings, spherical particles or spheres, more preferably spherical particles or extrudates.

In case the at least one hydrogenation reactor (vessel) in the second hydroprocessing unit HU2 has at least two stages, the catalyst preferably has different particle size in at least two stages and/or optionally different shape in the at least two stages.

The hydrogenation reaction is an exothermic reaction and therefore each reaction stage may optionally be cooled. An external cooling medium and/or mixing of stream S4 with at least a portion of the cold recycle gas (stream S6") can be utilized for said cooling.

The second hydroprocessing unit HU2 can be operated at various process conditions. For example, the valued product stream S4 is contacted with the hydroprocessing catalyst. Preferably, the valued product stream S4 is contacted with the hydroprocessing catalyst in the presence of a gaseous stream S4' which comprises hydrogen and/or an optional internal recycle-gas stream S6".

Optionally, the stream S4' further comprises at least a portion of the stream S2'. The presence of a stream S4' is preferred to balance the amount of hydrogen which is consumed or otherwise lost in the second hydroprocessing unit HU2. The aspect of the present invention further comprising the optional internal recycle-gas stream S6" is shown in Figure 3. The optional internal recycle-gas stream S6" is preferred because the hydrogen consumption for the method according to the present invention is reduced when applying said internal recycle-gas stream S6". The second hydroprocessing unit HU2 is preferably operated at a temperature of preferably from about 200 °C to about 400 °C, more preferably from about 240 °C to about 380 °C and most preferably from about 260 °C to about 360 °C.

The pressure during hydroprocessing in the second hydroprocessing unit HU2 preferably ranges from about 1 bar to about 200 bar, more preferably from about 10 bar to about 150 bar and most preferably from 60 bar to 80 bar.

The weight hourly space velocity (WHSV) of the valued product stream S4 preferably ranges from about 0.1 t/(m³Kat 'h) to about 5 t/(m³Kat ■ h), more preferably from about 0.5 t/(m³Kat/h) to about 1 .0 t/(m³Kat/h).

In another aspect of the present invention, the second hydroprocessing unit HU2 is operated with addition of an optional recycle-gas stream S6" which means that the hydrogen inside the second hydroprocessing unit HU2 which is not consumed by hydrogenation reactions is separated from stream S6 and a stream S6' and then fed again into the second hydroprocessing unit HU2 as recycle-gas stream S6". This aspect is shown in Figure 3.

The addition of an optional recycle-gas stream S6" as described above is also beneficial to evaporate the valued product stream S4 and keep it in the gas phase. Furthermore, the optional recycle-gas stream S6" dilutes the valued product stream S4. This limits the adiabatic temperature increase by the hydrogenation reactions and effects a high H2 partial pressure which is beneficial for the hydrogenation activity of the catalyst.

The ratio " recycle-gas stream S6" : valued product stream S4 ” is preferably between about 300 Nm³/t to about 2000 Nm³/t, more preferably between 500 Nm³/t to about 800 Nm³/t.

More preferably, the stream S6, or a portion thereof is not recycled (inserted again) into the first hydroprocessing unit HU1.

There is no need to recycle a portion of the stream S6 into the first hydroprocessing unit HU 1 because valued product stream S4 is stable enough in respect to undesired polymerization and therefore, valued product stream S4 can be heated up for insertion into the second hydroprocessing unit HU2. Preferably, stream S6 or a portion thereof is mot recycled into the first hydroprocessing unit HU1. This enables to build the first hydroprocessing unit HU1 (liquid recycle stream S3' included) and the second hydroprocessing unit HU2 (recycle-gas included) for “once through capacity” which means that the liquid stream S1 (and the streams manufactured thereof by conversion in the individual process units) only flow(s) once through the first hydroprocessing unit HU1 (which it leaves as stream S3), the distillation unit DU (valued product stream S4 which then enters HU2) and then leaves the second hydroprocessing unit HU2, converted, as stream S6. The organic compounds comprising at least one heteroatom in stream S3 are depleted in the second hydroprocessing unit HU2. The sulfur components are preferably depleted by at least 90 % in respect to stream S1 and/or the halogens containing components are preferably depleted by at least 97 % in respect to stream S1 , and the nitrogen containing components are preferably depleted by at least 99 % in respect to stream S1.

Stream S6 is then suited as a feedstock for a steam cracking process ("steam cracker feedstock”). The main reaction products from the steam cracking processes comprise ethylene, propylene, butylene isomers, butadiene, and pyrolysis gasoline.

The individual units of the chemical plant for separating a steam cracker feedstock from a liquid stream comprising at least one plastic pyrolysis oil and their connectivity to each other are shown in Figure 2 and will be described below:

The chemical plant for separating a steam cracker feedstock from a liquid stream, the liquid stream comprising at least one plastic pyrolysis oils, comprises at least one first hydroprocessing unit HU 1 , the at least one first hydroprocessing unit HU1 comprising at least one inlet and at least one outlet, optionally a recycle unit downstream of and fluidically connected to the inlet and the outlet of the first hydroprocessing unit HU 1 , at least one distillation unit DU downstream of and fluidically connected to the outlet of the first hydroprocessing unit HU1, the at least one distillation unit having a bottom outlet BO and a head outlet HO, and a second hydroprocessing unit HU2 downstream of and fluidically connected to the head outlet HO of the at least one distillation unit DU.

A liquid stream S1 comprises at least one plastic pyrolysis oil. The organic compounds comprising at least one heteroatom and compounds having 0-0 double and/or 0-0 triple bonds are converted in the first hydroprocessing unit HU1 with a stream S2. The remaining portion of stream S2 leaves the first hydroprocessing unit HU1 as stream S2'. The liquid stream S1 is converted in the first hydroprocessing unit HU1 into the stream S3. A portion of the stream S3 is recycled as stream S3' which is mixed with stream S1 and inserted into the first hydroprocessing unit HU1.

The stream S3 is separated in the distillation unit DU into a valued product stream S4 and a residue stream S5.

Optionally, the gaseous stream S4' further comprises at least a portion of the off-gas stream S2'. Gaseous stream S4' is required to balance the amount of hydrogen which is consumed or otherwise lost in the second hydroprocessing unit HU2.

The valued product stream S4 is converted in the second hydroprocessing unit HU2 with the gaseous stream S4' and optionally in addition with off-gas stream S2' into a stream S6. In this case, the gaseous stream S4' balances the hydrogen demand of second hydroprocessing unit HU2. The remaining non hydrogen portion of the off-gas stream S2' and volatile compounds formed by hydrogenation reactions with the stream S6 leave the second hydroprocessing unit HU2 as stream S6'. The specifications of all units and streams are described above in the "method” section and are preferably the same in case of the method according of the present invention and the chemical plant according to the present invention.

The present invention is further illustrated by the following set of embodiments and combinations of embodiments resulting from the dependencies and back-references as indicated. In particular, it is noted that in each instance where a range of embodiments is mentioned, for example in the context of a term such as "The method of any of embodiments 1 to 3", every embodiment in this range is meant to be explicitly disclosed for the skilled person, i.e. the wording of this term is to be understood by the skilled person as being synonymous to "The method of any of embodiments 1 , 2 and 3". Further, it is explicitly noted that the following set of embodiments represents a suitably structured part of the general description directed to preferred aspects of the present invention, and thus, suitably supports the claims of the present invention.

1 . Method for separating a steam cracker feedstock from a liquid stream comprising at least one plastic pyrolysis oil, the method comprising the steps

(ii) providing a stream S2, the stream S2 comprising H2,

(ill) feeding the liquid stream S1 and the stream S2 into a hydrogenation unit HU1 in which at least a portion of the components of the liquid stream S1 reacts with stream S2 in a hydrogenation reaction whereby a liquid stream S3 is formed, wherein the liquid stream S3 is depleted in compounds having C-C double and/or C-C triple bonds in respect to liquid stream S1 , and feeding at least a portion of a liquid recycle steam S3', said liquid recycle stream S3' separated from the liquid stream S3, into said hydrogenation unit HU1 , wherein the mass ratio " liquid recycle steam S3' : liquid stream S3 ” preferably ranges between from about 1 :1 to about 30: 1 , more preferably from about 5:1 to about 20:1 and most preferably from about 10:1 to about 15: 1,

(iv) subjecting the remaining portion of the liquid stream S3 to a distillation unit DU in which the remaining portion of liquid stream S3 is separated into a valued product stream S4 and a liquid residue stream S5, wherein the valued product stream S4 comprises organic compounds comprising at least one heteroatom, and

(v) subjecting the valued product stream S4 to a hydrogenation unit HU2 in which the valued product stream S4 is converted into a stream S6, wherein the stream S6 is depleted in organic compounds comprising at least one heteroatom and/or C-C double bonds in respect to valued product stream S4.

2. Method according to embodiment 1 wherein the at least one plastic pyrolysis oil is manufactured by a pyrolysis of plastic waste. Method according to embodiments 1 or 2 wherein the organic compounds comprising at least one heteroatom are selected from organic compounds comprising at least one of the following heteroatoms: nitrogen, oxygen, sulfur, chlorine, bromine, fluorine, iodine. Method according to any one of embodiments 1 to 3 wherein the ratio " H2 in the fresh H2 feed stream S2 : chemical H2 consumption caused by the hydrogenation reaction(s) in the first hydroprocessing unit HU 1 ” preferably ranges from about 1 :1 to about 5:1, more preferably from about 1 :1 to about 3:1 and most preferably from about 1 : 1 to about 2: 1 . Method according to any one of embodiments 1 to 4 wherein the total pressure at the outlet of the at least one reactor in the first hydroprocessing unit HU 1 preferably ranges from about 5 bar (abs.) to about 60 bar (abs.), more preferably from about 10 bar (abs.) to about 40 bar (abs) and most preferably from about 20 bar (abs.) to about 40 bar (abs). Method according to any one of embodiments 1 to 5 wherein the at least one plastic pyrolysis oil in the liquid stream S1 has a bromine number of about 2 g Br2/100g to about 150 g Br2/100g (determined by ASTM 1159) and/or a C5 hydrocarbon content of about 0.03 wt.-% to about 12.2 wt.-% (determined by ASTM D 5134) and/or a naphthalene content of about 0.5 wt.-% to about 18.4 wt.-% (determined by ASTM D 5134) and/or a styrene content of about 0.02 wt.-% to about 29.5 wt.-% (determined by ASTM D 5134) and/or a toluene content of about 4.3 wt.-% to about 71 .5 wt.-% (determined by ASTM D 5134). Method according to any one of embodiments 1 to 6 wherein the H2 comprised in stream S2 was formed by water electrolysis using electrical energy, said electrical energy preferably generated from renewable sources and/or low-carbon energy sources and/or a methane pyrolysis, preferably a methane pyrolysis using methane from a renewable source. Method according to any one of embodiments 1 to 7 wherein the liquid stream S1 and the stream S2 are mixed before fed into the first hydroprocessing unit HU1. Method according to any one of embodiments 1 to 7 wherein the liquid stream S1 and the stream S2 are separately fed into the first hydroprocessing unit HU1. Method according to any one of embodiments 1 to 9 wherein the first hydroprocessing unit HU 1 comprises at least one three-phase reactor, preferably at least one three-phase reactor with at least one catalyst bed. 11. Method according to any one of embodiments 1 to 10 wherein the first hydroprocessing unit HU1 comprises at least one three-phase reactor with at least one fixed catalyst bed, the at least one fixed bed comprising at least one heterogeneous catalyst.

12. Method according to any one of embodiments 1 to 11 wherein the first hydroprocessing unit HU1 comprises at least one three-phase reactor operating in trickling mode or pulse flow mode.

13. Method according to any one of embodiments 1 to 12 wherein the first hydroprocessing unit HU1 comprises at least one heterogeneous catalyst, which at least one heterogeneous catalyst comprises at least one catalytically active metal selected from the element of groups 8 to 12 of the periodic table, more preferably the at least one catalytically active metal is selected from the group comprising or consisting of nickel, palladium, platinum, rhodium and most preferably the catalytically active metal is palladium.

14. Method according to any one of embodiments 1 to 13 wherein the first hydroprocessing unit HU1 comprises at least one heterogeneous catalyst, which at least one heterogeneous catalyst further comprises a support, preferably an inorganic support, more preferably a support selected from the group comprising or consisting of silica, alumina, silica-aluminas, magnesium oxide, clays, carbon, and mixtures thereof.

15. Method according to any one of embodiments 1 to 14 wherein the first hydroprocessing unit HU1 comprises at least one heterogeneous catalyst, the at least one heterogeneous catalyst comprising at least one catalytically active metal which is selected from the group comprising or consisting of nickel, palladium, platinum, and rhodium and further comprises a support selected from the group comprising or consisting of silica, alumina, silica-aluminas, magnesium oxide, clays, carbon, and mixtures thereof.

16. Method according to any one of embodiments 1 to 15 wherein the first hydroprocessing unit HU1 comprises at least one heterogeneous catalyst, which comprises palladium, more preferably in an amount, calculated as elemental palladium, in the range of from about 0.01 wt.-% to about 5 wt.-%, more preferably from about

0.1 wt.-% to about 1 wt.-%, most preferably from 0.15 to 0.8 weight-%, based on the total weight of the catalyst.

17. Method according to any one of embodiments 1 to 16 wherein the temperature of the hydrogenation reaction in the first hydroprocessing unit HU 1 preferably ranges from about 40 °C to about 250 °C, more preferably from about 60 °C to about 200 °C, most preferably from about 80 °C to about 120 °C.

18. Method according to any one of embodiments 1 to 17 wherein compounds having C-C double bonds, and/or C-C triple bonds and/or styrene which are comprised in liquid stream S1 are depleted in the first hydroprocessing unit HU 1 by at least 90 %. 19. Method according to any one of embodiments 1 to 18 wherein the distillation unit DU preferably comprises two distillation columns.

20. Method according to any one of embodiments 1 to 19 wherein the distillation in the distillation unit DU is carried out at a temperature in the range of about 0 °C to about 600 °C, more preferably from about 20 °C to about 400 °C, most preferably from about 80 °C to about 250 °C.

21 . Method according to any of embodiments 1 to 20 wherein the distillation unit DU comprises, in this order, a first distillation column and a second distillation column, and wherein the operating pressure of the first distillation column preferably ranges from about 0.001 bar (abs.) to about 4 bar (abs.), more preferably from about 0.001 bar (abs.) to about 2.0 bar (abs), most preferably from about 0.9 bar to about 1.8 bar (abs.) and wherein the operating pressure of the second distillation column preferably ranges from about 0.001 bar (abs.) to about 4 bar (abs.), more preferably from about 0.001 bar (abs.) to about 1.0 bar (abs.), most preferably from about 0.005 bar (abs.) to about 0.1 bar (abs.) and wherein the temperature in the first distillation column and the second distillation column is adjusted accordingly in case the pressure is # 1.013 bar.

22. Method according to any one of embodiments 1 to 21 wherein the valued product stream S4 comprises about 60 % to about 99 % of a steam cracker feedstock which were comprised in liquid stream S1.

23. Method according to any one of embodiments 1 to 22 wherein the residue stream S5 is then converted by a partial oxidation and/or a gasification process unit into syngas, wherein the syngas comprises H2, CO and CO₂.

24. Method according to any one of embodiments 1 to 23 wherein the wherein the second hydroprocessing unit HU2 comprises at least one fixed-bed reactor.

25. Method according to any one of embodiments 1 to 24 wherein the second hydroprocessing unit HU2 comprises at least one heterogeneous catalyst.

26. Method according to any one of embodiments 1 to 25 wherein the second hydroprocessing unit HU2 comprises at least one heterogeneous catalyst, the at least one heterogeneous catalyst comprising or consisting of at least one of Co-Mo catalyst, Ni-Mo catalyst , Ni-W catalyst, Co-W catalyst, and Mo catalyst, and preferably further comprises at least catalyst support material selected from the group comprising or consisting of alumina, silica, magnesia, zirconia, titania, a zeolitic material, a silica-alumina phosphate (SAPO) material, zinc oxide, sodium oxide, mixed silica-alumina, zeolite and calcium oxide, more preferably alumina. 27. Method according to any one of embodiments 1 to 26 wherein the temperature of the hydrogenation reaction in the second hydroprocessing unit HU2 preferably ranges from about 200 °C to about 400 °C, more preferably from about 240 °C to about 380 °C, most preferably from about 260 °C to about 360 °C.

28. Method according to any one of embodiments 1 to 27 wherein the pressure of the hydrogenation reaction in the second hydroprocessing unit HU2 preferably ranges from about 1 bar to about 200 bar, more preferably from about 10 bar to about 150 bar and most preferably from about 60 bar to about 80 bar.

29. Method according to any one of embodiments 1 to 28 wherein the weight hourly space velocity (WHSV) of the valued components containing valued product stream S4 preferably ranges from about 0.1 t/(m³Kafh) to about 5 t/(m³Kat ■ h), more preferably from about 0.5 t/(m³Kat ■ h) to about 1 .0 t/(m³Kat ■ h) .

30. Method according to any one of embodiments 1 to 29 wherein the ratio "recycle-gas stream S6" : valued product stream S4” is preferably between about 300 Nm³/t to about 2000 Nm³/t, more preferably between 500 Nm³/t to about 800 Nm³/t.

31 . Method according to any one of embodiments 1 to 30 wherein the organic compounds comprising at least one heteroatom in stream S6 are depleted in the second hydroprocessing unit HU2 in respect to stream S1 .

32. Method according to any of embodiments 1 to 31 wherein the organic compounds comprising sulfur in stream S6 are depleted by at least 90 % in respect to stream S1 and/or the organic compounds in stream S6 comprising halogens are depleted by at least 97 % in respect to stream S1 and/or the organic compounds in stream S6 comprising nitrogen are depleted by at least 99 % in respect to stream S1.

33. Method according to any one of embodiments 1 to 32 wherein at least one of NH4F, NH4CI, NFhBr, NH4I and NH4SH is formed in the second hydroprocessing unit HU2 and wherein at least one of NH4CI, NH4F, N F Br, NH4I are removed quantitatively from the second hydroprocessing unit HU2 with water and/or wherein NH4SH is partly removed from the second hydroprocessing unit HU2 with water.

34. Method according to any one of embodiments 1 to 33 wherein stream S6 is further subjected to a cracking process, the cracking process selected from the group consisting of catalytic cracking, thermal cracking, and steam cracking.

35. Chemical plant for separating a steam cracker feedstock from a liquid stream comprising at least one plastic pyrolysis oil, the chemical plant comprising

(I) at least one first hydroprocessing unit HU1 , the at least one first hydroprocessing unit HU1 comprising at least one inlet and at least one outlet, (ii) a recycle unit downstream of and fluidically connected to the inlet and the outlet of the first hydroprocessing unit HU1,

(iii) a distillation unit DU downstream of and fluidically connected to the outlet of the first hydroprocessing unit HU1, the at least one distillation unit having a bottom outlet BO and a head outlet HO, and

(iv) a second hydroprocessing unit HU2 downstream of and fluidically connected to the head outlet HO of the at least one distillation unit DU.

36. Chemical plant according to embodiment 35 wherein the first hydroprocessing unit HU1 comprises at least one three-phase reactor, preferably wherein the first hydroprocessing unit HU1 comprises at least one three- phase reactor with at least one fixed catalyst bed.

37. Chemical plant according to embodiment 35 or 36 wherein the first hydroprocessing unit HU1 comprises at least one three-phase reactor with at least one fixed catalyst bed, the at least one fixed bed comprising at least one heterogeneous catalyst.

38. Chemical plant according to any one of embodiments 35 to 37 wherein first hydroprocessing unit HU1 comprises at least one three-phase reactor with at least one fixed catalyst bed, the at least one fixed bed comprising at least one catalyst which is used in at least one stage of the at least one three-phase reactor.

39. Chemical plant according to any one of embodiments 35 to 38 wherein the first hydroprocessing unit HU1 comprises at least one three-phase reactor operating in trickling mode or pulse flow mode.

40. Chemical plant according to any one of embodiments 35 to 39 wherein the first hydroprocessing unit HU1 comprises at least one heterogeneous catalyst, which at least one heterogeneous catalyst comprises at least one catalytically active metal selected from the element of groups 8 to 12 of the periodic table, more preferably selected from the group comprising or consisting of nickel, palladium, platinum, rhodium and most preferably is palladium and at least one support which is preferably an inorganic support, more preferably a support selected from the group comprising or consisting of silica, alumina, silica-aluminas, silica-alumina phosphates, magnesium oxide, clays, carbon, and mixtures thereof.

41 . Chemical plant according to any one of embodiments 35 to 40 wherein the distillation unit DU comprises preferably two distillation columns.

42. Chemical plant according to any one of embodiments 35 to 41 wherein the second hydroprocessing unit HU2 comprises at least one fixed-bed reactor.

43. Chemical plant according to any one of embodiments 35 to 42 wherein the second hydroprocessing unit HU2 comprises at least one heterogeneous catalyst. 44. Chemical plant according to any one of embodiments 35 to 43 wherein the second hydroprocessing unit HU2 comprises at least one heterogeneous catalyst, the at least one heterogeneous catalyst comprising at least one of Co-Mo catalyst, Ni-Mo catalyst , Ni-W catalyst, Co-W catalyst, and Mo catalyst, and preferably further comprises at least catalyst support material selected from the group comprising alumina, silica, magnesia, zirconia, titania, a zeolitic material, a silica-alumina phosphate (SAPO) material, zinc oxide, sodium oxide, mixed silica-alumina, zeolite and calcium oxide, more preferably alumina.

45. Use of a chemical plant according to any one of embodiments 35 to 44 for the method according to any one of embodiments 1 to 34.

46. A computer program comprising instructions which, when the program is executed by the chemical plant according to any one of embodiments 35 to 44, cause the system to perform the method according to any one of embodiments 1 to 44.

It is explicitly noted that the above set of embodiments represents a suitably structured part of the general description directed to preferred aspects of the present invention, and thus, suitably supports, but does not represent the claims of the present invention.

The residue stream S5 can be further used as a feedstock for a partial oxidation and/or a gasification process and is thereby converted into a syngas stream comprising H2, CO and CO2.

The stream S6 can be further used as a steam cracker feedstock and is thereby converted into a stream comprising at least one olefin and/or at least one C6-C8 aromatic hydrocarbon, the at least one olefin preferably selected from the group consisting of ethene, propene, n-butene, 2-butene and butadiene.

The invention further relates to a method according to the method described herein, comprising the further step: converting the stream S6 obtainable by or obtained by the method described herein; the syngas, H2, CO and/or CO2 obtainable by or obtained by the method described herein; and/or a chemical material obtained by or obtainable by the method described herein, preferably a chemical material obtained by or obtainable by the method described herein by subjecting the stream S6 to the cracking process; to obtain a monomer, polymer or polymer product.

The converting step(s) to obtain the chemical material, monomer, polymer or polymer product may comprise one or more synthesis steps and can be performed by conventional synthesis and technics well known to a person skilled in the art. Independent of the person skilled in the art to assess novelty and inventive step of the independent claim(s), the person skilled in the art to perform the converting step(s) is preferably from the technical field(s) pyrolysis, gasifi- cation, remonomerization, depolymerization, synthesis, production of monomers, polymers and polymer compounds, and/or its further processing (e.g. extrusion, injection molding). Examples of the step(s) of the conversion is/are described in "Industrial Organic Chemistry”, 3. volume, Wiley-VCH, 1997, ISBN: 978-3-527-28838-0, ..Kunststoffhand- buch", 11 volumes in 17 sub-volumes, Carl Hanser Verlag; especially volume 6, ..Polyamide", 1. edition, 1966, volume 7, ..Polyurethane", 3. edition, 1993, and volume 8, "Polyester”, 1. edition 1973; "Industrial Organic Chemistry”, 3. volume, Wiley-VCH, 1997, ISBN: 978-3-527-28838-0, "Injection Molding Reference Guide, 4th edition, CreateSpace Independent Publishing Platform, 2011, ISBN: 978-1466407824, EP0989146 (A1), EP1460094 (A1), W02006034800 (A1 ), EP 1529792 (A1), W02006042674 (A1), EP0364854 (A2), US5506275 (A), EP0897402 (A1), WO2015082316 (A1), WO2021021855 (A1), WO2021126938 (A1), W02021021902 (A1), W02021092311 (A1), W02008155271 (A1), WO2013139827 (A1), each of which is incorporated herein by reference.

In a preferred embodiment, the monomer is a di- or polyol; preferably butandiol; aldehyde; preferably formaldehyde; di- or polyisocyanate; preferably methylene diphenyl diisocyanate (MDI), polymeric methylene diphenyl diisocyanate (pMDI), toluene diisocyanate (TDI), hexamethylenediisocyanate (HDI) or isophoronediisocyanate (IPDI); amide; preferably caprolactam; alkene; preferably styrene, ethene and norbornene; alkyne, (di)ester; preferably methyl methacrylate; mono or diacid; preferably adipic acid or terephthalic acid; diamine; preferably hexamethylenediamine, nonanediamine; or sulfones; preferably 4,4'-dichlorodiphenyl sulfone.

In a preferred embodiment, the polymer is and/or the polymer product comprises polyamide (PA); preferably PA 6 or PA 66; polyisocyanate polyaddition product; preferably polyurethane (PU), thermoplastic polyurethane (TPU), polyurea or polyisocyanurate (PIR); low-density polyethylene (LDPE), high-density polyethylene (HDPE), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyvinyl acetate (PVA), polystyrene (PS), poly acrylonitrile butadiene styrene (ABS), poly styrene acrylonitrile (SAN), poly acrylate styrene acrylonitrile (ASA), polytetrafluoroethylene (PTFE), poly(methyl acrylate) (PMA), poly(methyl methacrylate) (PMMA), polybutadiene (BR, PBD), poly(cis- 1,4-isoprene), poly(trans-1 ,4-isoprene), polyoxymethylene (POM), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polybutylene adipate co-terephthalate (PBAT), polyester (PES), polyether sulfone (PESU), polyhydroxyalkanoate (PHA), poly-3-hydroxybutyrate (P3HB), poly-4-hydroxybutyrate (P4HB), polyhydroxyvalerate (PHV), polyhydroxyhexanoate (PHH), polyhydroxyoctanoate (PHO), polylactic acid (PLA), polysulfone (PSU), polyphenylene sulfone (PPSU), polycarbonate (PC), polyether ether ketone (PEEK), poly(p-phenylene oxide) (PPO), poly(p-phenylene ether) (PPE); or copolymer or mixture thereof.

In a preferred embodiment, the polymer and/or the polymer product is/are then converted into or is/are then converted into: a part of a car; preferably cylinder head cover, engine cover, housing for charge air cooler, charge air cooler flap, intake pipe, intake manifold, connector, gear wheel, fan wheel, cooling water box, housing, housing part for heat exchanger, coolant cooler, charge air cooler, thermostat, water pump, radiator, fastening part, part of battery system for electromobility, dashboard, steering column switch, seat, headrest, center console, transmission component, door module, A, B, C or D pillar cover, spoiler, door handle, exterior mirror, windscreen wiper, windscreen wiper protection housing, decorative grill, cover strip, roof rail, window frame, sunroof frame, antenna panel, headlight and taillight, engine cover, cylinder head cover, intake manifold, airbag, cushion, or coating; a cloth; preferably shirt, trousers, pullover, boot, shoe, shoe sole, tight or jacket; an electrical part; preferably electrical or electronic passive or active component, circuit board, printed circuit board, housing component, foil, line, switch, plug, socket, distributor, relay, resistor, capacitor, inductor, bobbin, lamp, diode, LED, transistor, connector, regulator, integrated circuit (IC), processor, controller, memory, sensor, microswitch, microbutton, semiconductor, reflector housing for light-emitting diodes (LED), fastener for electrical or electronic component, spacer, bolt, strip, slide-in guide, screw, nut, film hinge, snap hook (snap-in), or spring tongue; a consumer, agricultural product or pharmaceutical product; preferably tennis string, climbing rope, bristle, brush, artificial grass, 3D printing filament, grass trimmer, zipper, hook and loop fastener, paper machine clothing, extrusion coating, fishing line, fishing net, offshore line and rope, vial, syringe, ampoule, bottle, sliding element, spindle nut, chain conveyor, plain bearing, roller, wheel, gear, roller, ring gear, screw and spring dampers, hose, pipeline, cable sheathing, socket, switch, cable tie, fan wheel, carpet, box or bottle for cosmetics, mattress, cushion, insulation, detergent, dishwasher tabs or powder, shampoo, body wash, shower gel, soap, fertilizer, fungicide, or pesticide; a packaging for the food industry; preferably mono- or multi-layer blown film, cast film (mono- or multi-layer), biaxially stretched film, or laminating film; or a part of a construction; preferably a rotor blade, insulating material, frame, housing, wall, coating, or separating wall.

In a preferred embodiment, the content of the liquid stream S1 in the monomer, polymer or polymer product is 1 weight-% or more, preferably 2 weight-% or more, more preferably 5 weight-% or more, more preferably 15 weight- % or more, more preferably 30 weight-% or more, more preferably 40 weight-% or more, more preferably 60 weight-% or more, more preferably 80 weight-% or more, more preferably 90 weight-% or more, more preferably 95 weight-% or more; and/or the content of the liquid stream S1 in the monomer, polymer or polymer product is 100 weight-% or less, preferably 95 weight-% or less, more preferably 90 weight-% or less, more preferably 50 weight-% or less, more preferably 25 weight-% or less, more preferably 10 weight-% or less; and preferably the content is determined based on identity preservation and/or segregation and/or mass balance and/or book and claim chain of custody models, preferably based on mass balance, preferably the International Sustainability and Carbon Certification (ISCC) standard.

The invention will be further explained by the following non-limiting examples. Examples

Methods for separating a steam cracker feedstock from a plastic pyrolysis oil (comparative example and method according to the present invention) were simulated using ASPEN Plus™ V11 simulation software in combination with a kinetic model to calculate the conversion in the first hydroprocessing unit HU1 and the second hydroprocessing unit HU2.

Comparative example

The comparative example is a method and a chemical plant for manufacturing a steam cracker feedstock from a liquid stream S1 comprising a plastic pyrolysis oil obtained by pyrolysis of plastic waste taught in AU 2021/222788 A1 and is schematically shown in Figure 1 .

The process conditions used for the first hydroprocessing unit HU1 are summarized in Table 1 :

he chosen compositions for the streams S1, S1 S3, S4, S5, and S6 are summarized in Table 2:

tream S1 ' = stream S1 + stream S2 + stream S3'.

The composition of the liquid stream S1 of the hydroprocessing unit HU1 is described in Table 2 with a dienic components concentration of 2.06 wt.-% and olefinic components concentration of 29.94 wt.-%. The composition of the liquid stream S1 is identic to the liquid stream S1 used in the example according to the invention below. The liquid stream S1 is processed in the hydroprocessing unit HU1 with conditions described in Table 1. The catalyst in the hydroprocessing unit HU1 is a Ni-Mo catalyst on an alumina support taught in AU 2021/222788 A1 . The pressure at reactor outlet of the first hydroprocessing unit HU1 is 64 bar (abs.) and the reactor temperature rises from 113 °C (reactor inlet temperature) to 160 °C (reactor outlet temperature) by adiabatic temperature increase. Under these conditions typical trickle-bed flow of the liquid phase over the (solid) catalyst occurs which is desired.

The ratio "liquid feed S1 : liquid recycle stream S3' ” from the hydroprocessing unit HU2 (Figure 1) is 1 : 1. Hence, the concentration of dienic components with 1 .03 wt.-% is a factor of 4.3 higher than the concentration of dienic components in the example according to the present invention (see below) in the reactor inlet stream ST. The high temperature and much higher temperature increase of 47 °C (from the reactor inlet to reactor outlet of the first hydroprocessing unit HU1) in comparison to 8 °C in the example according to the present invention (see below) together with the much higher dienic components concentration causes a higher polymer formation during processing causes a risk of undesired fouling by said polymers in the first hydroprocessing unit HU1 and/or in successive process units. A typical value to evaluate the efficiency of such a selective hydrogenation is the conversion of styrene to ethylbenzene. Under these conditions a sufficient conversion of > 80 % (82 %) is achieved.

The WHSV (weight hourly space velocity) of liquid stream S1 is 0.5 t/(m³ _Kat *h). The chemical hydrogen consumption in the hydroprocessing unit HU1 is 38 Nm³/t. The molar ratio "stream comprising H2 (stream S2) fed to the hydroprocessing unit HU1 : chemical hydrogen consumption” is 1.08 : 1. The small excess of hydrogen assures the sufficient activity of the catalyst to effect 81 % conversion of the dienic components and 55 % conversion of the olefinic components (stream S3). Under these operation conditions and the catalyst used (Ni-Mo catalyst on an alumina support), no hydrogenation of the aromatic components will occur. The reactor product of hydroprocessing unit HU1 (stream S3 in Fig. 1) is directly fed to the hydroprocessing unit HU2.

The process conditions in the second hydroprocessing unit HU2 are summarized in Table 3:

Table 3 shows the process conditions of the hydroprocessing unit HU2. The pressure at reactor outlet is 63 bar (abs.). The ratio "HU2 internal recycle-gas S4" : feed stream S3” is 400 Nm³/t and the reactor inlet temperature of the second hydroprocessing unit HU2 is 300 °C. Under these conditions, the feed stream S3 of the hydroprocessing unit HU2 is partly evaporated. Caused by the low content of dienic components of < 0.2 wt.-% in the feed stream S3 of the hydroprocessing unit HU2 no undesired polymerization and fouling occurs during partial evaporation. The reactor temperature rises from an inlet temperature of 300 °C to an outlet temperature of 319 °C by the exotherm hydrogenation reactions mentioned above. The temperature rise is 19 °C because 55 % of the olefins are already hydrogenated in the hydroprocessing unit HU1 and the 1 : 1 dilution by the "liquid feed S1 : liquid recycle stream S3' from the hydroprocessing unit HU2. The hydrogen partial pressure at the outlet the reactor of 47 bar (abs.) is sufficient to assure a sufficient hydrogenation activity for HDH, HDN and HDS reactions. The catalyst in the hydroprocessing unit HU2 is a standard Ni-Mo catalyst on an alumina support which shows sufficient dienic- and olefinic- hydrogenation, hydrodesulfurization (HDS), hydrodenitration (HDN) and hydrodehalogenation (HDH) activity. The WHSV of the feed stream S3 is 0.5 t/(m³ _Kat *h).The reaction product valued product stream S4 of HU2 shows a sulfur content lower of 50 wt.-ppm, a nitrogen content of lower than 10 wt.-ppm and a chlorine content lower than 1 wt.- ppm. The cooled down condensed liquid reaction product S4 leaving the second hydroprocessing unit HU2 is fed with a ratio of 1 : 1 together with the liquid feed stream S1 back to the hydroprocessing unit HU1 to dilute the liquid feed stream S1 bevor entering the first hydroprocessing unit HU1 . The necessity and effect of the dilution is described above for the hydroprocessing unit HU1.

In the distillation unit DU, the light boiling fraction the steam cracking feedstock (stream S6) goes overhead. These are 78 wt.-% of the valued product stream S4 to the distillation unit DU. The final boiling point of valued product stream S4 is 341 °C. The high boiling components are separated by the bottoms residue stream S5. The boiling range of bottom residue stream S5 is 348 °C - 434 °C.

Hence, the fractionated product stream S6 is already hydroprocessed so this stream S6 can be feed to a steam cracker.

Example (inventive)

The method according to the present invention was simulated in this example following the schematic representation in Figure 3.

Table 4: process conditions in the first hydroprocessing unit HU1 :

he chosen compositions for the streams S1, S1 S3, S4, S5, and S6 are summarized in Table 5:

tream S1 ' = stream S1 + stream S2 + stream S3'.

The composition of the liquid stream S1 of the hydroprocessing unit HU1 is described in Table 5 with a dienic components concentration of 2.06 wt.-% and olefinic components concentration of 29.94 wt.%. The composition of the liquid stream S1 is identic to the liquid stream S1 used in the example according to the invention below. The liquid stream S1 is processed in the hydroprocessing unit HU 1 with conditions described in Table 4.

The catalyst in the first hydroprocessing unit HU 1 is a catalyst comprising palladium on an alumina support which allows very mild reaction conditions (e.g., a lower temperature). The pressure at the reactor outlet is 30 bar (abs.) in the first hydroprocessing unit HU 1 and the reactor temperature rises from 81 °C reactor inlet temperature to 89 °C reactor outlet temperature by adiabatic temperature increase. Under these conditions typical trickle bed flow of the liquid phase over the catalyst occurs. The ratio "liquid feed S1 : liquid recycle stream S3' ” causes a very low dienic components concentration of 0.24 wt.-% and olefinic components content of 12.87 wt.% in the reactor inlet stream S1 '. The low temperature and mild temperature of only 8 °C increase, the high pressure together with the low dienic components concentration assures the avoidance of undesired polymer formation and fouling during processing.

A typical value to evaluate the efficiency of such a selective hydrogenation is the conversion of styrene to ethylbenzene. Under these conditions a sufficient conversion of < 80 % (92 %) is achieved.

The WHSV (weight hourly space velocity) of the liquid stream S1 is 0.5 t/(m³Kat*h). The chemical hydrogen consumption in the first hydroprocessing unit HU1 is 43 Nm³/t. The molar ratio "stream S2 comprising hydrogen fed to the first hydroprocessing unit HU1 : chemical hydrogen consumption” is 1.14 : 1. The small excess of hydrogen assures the sufficient activity of the catalyst to effect 96 % conversion of the dienic components and 62 % conversion of the olefinic components (stream S3). Under this operation conditions no hydrogenation of the aromatic components will occur. The ratio of dienic components / olefinic components hydrogenation is 1.55 / 1. In the comparative example the ratio of dienic components I olefinic components hydrogenation is 1 .47 / 1 .

Hence the selectivity to hydrogenate the dienic components is in the inventive example higher. The lower selectivity of dienic components hydrogenation in the comparative example causes the high exothermic temperature-increase in the reactor of HU1 . This high temperature increase will reduce the lifetime of the catalyst due to increased aging.

The stream S3 leaving the first hydrogenation unit HU1 is stable enough and no undesired fouling by polymerization occurs in the first hydroprocessing unit HU1 and/or the distillation unit DU.

In the distillation unit DU, the light boiling fraction- (= valued product stream S4) goes overhead. These are 78 wt.-% of the valued product stream S4 to the distillation unit DU. The final boiling point of valued product stream S4 is 341 °C. The high boiling components are separated by the bottoms residue stream S5. The boiling range of bottom residue stream S5 is 348°C - 434°C. The valued product overhead valued product stream S4 of the distillation unit DU is further processed in the second hydroprocessing unit HU2. The remaining small amounts of dienic and olefinic components are hydrogenated in the second hydroprocessing unit HU2 to the corresponding saturated hydrocarbons. The sulfur containing components are hydrogenated to the corresponding saturated hydrocarbons and H2S. The sulfur content in the hydroprocessed product stream S6 is < 50 wt.-ppm. The nitrogen containing components are hydrogenated to the corresponding saturated hydrocarbons and NH3. The nitrogen content in the hydroprocessed product stream S6 is < 10 wt.-ppm The halogen-, like chlorine-containing components are hydrogenated to the corresponding saturated hydrocarbons and hydrohalogenic acids such as HCI. The halogens/chlorine content in the hydroprocessed product stream S6 is < 1 wt.-ppm.

The process conditions for the second hydroprocessing unit HU2 are shown in Table 6:

Table 6 shows the process conditions of the second hydroprocessing unit HU2. The pressure at reactor outlet is 63 bar(abs.). The ratio "recycle-gas stream S6" : feed valued product stream S4” is 400 Nm³/t and the reactor inlet temperature is 300 °C. Under these conditions, the inlet valued product stream S4 of the second hydroprocessing unit HU2 is partially evaporated. Caused by the low content of dienic components of < 0.1 wt.-% in the feed valued product stream S4, no undesired polymerization and fouling occurs during inside the second hydroprocessing unit HU2. The reactor temperature rises from 300 °C inlet temperature to 333 °C outlet temperature by the exotherm hydrogenation reactions inside the second hydroprocessing unit HU2 mentioned above. The temperature rise is limited to favorable low 33 °C.

The temperature increase in the inventive example is higher, than in the comparative example with 19°C cause by the missing dilution of 1 : 1 "liquid feed S1 : liquid recycle stream S3'” in the comparative example. The hydrogen partial pressure at the outlet the reactor of 47 bar (abs.) is sufficient to assure a sufficient hydrogenation activity for HDH, HDN and HDS reactions. The catalyst in the hydroprocessing unit HU2 is a standard Ni-Mo catalyst on an alumina support which shows sufficient dienic- and olefinic-hydrogenation, hydrodesulfurization (HDS), hydrodenitration (HDN) and hydrodehalogenation (HDH) activity. The WHSV of the feed stream S3 is 0.5 t/(m³Kat *h).The reaction product valued product stream S4 of HU2 shows a sulfur content lower than 50 wt.-ppm, a nitrogen content of lower than 10 wt.-ppm and a chlorine content lower than 1 wt.-ppm.

Hence, the hydroprocessed product stream S6 is already fractionated, this stream S6 can be feed to a steam cracker.

Claims

1. Method for separating a steam cracker feedstock from a liquid stream comprising at least one plastic pyrolysis oil, the method comprising the steps

(ii) providing a stream S2, the stream S2 comprising H2,

2. Method according to claim 1 wherein the at least one plastic pyrolysis oil is manufactured by a pyrolysis of plastic waste.

3. Method according to claim 1 or 2 wherein the at least one plastic pyrolysis oil in the liquid stream S1 has a bromine number of about 2 g Br2/100g to about 150 g Br2/100g (determined by ASTM 1159) and/or a C5 hydrocarbon content of about 0.03 wt.-% to about 12.2 wt.-% (determined by ASTM D 5134) and/or a naphthalene content of about 0.5 wt.-% to about 18.4 wt.-% (determined by ASTM D 5134) and/or a styrene content of about 0.02 wt.-% to about 29.5 wt.-% (determined by ASTM D 5134) and/or a toluene content of about

4.3 wt.-% to about 71 .5 wt.-% (determined by ASTM D 5134).

4. Method according to any one of claims 1 to 3 wherein the first hydroprocessing unit HU1 comprises at least one three-phase reactor, preferably at least one three-phase reactor with at least one fixed catalyst bed.

5. Method according to any one of claims 1 to 4 wherein the first hydroprocessing unit HU1 comprises at least one heterogeneous catalyst, which at least one heterogeneous catalyst comprises at least one catalytically active metal selected from the element of groups 8 to 12 of the periodic table, more preferably the at least one catalytically active metal is selected from the group comprising or consisting of nickel, palladium, platinum, rhodium and most preferably the catalytically active metal is palladium.

6. Method according to any one of claims 1 to 5 wherein the ratio "H2 in the fresh H2 feed stream S2 : chemical H2 consumption caused by the hydrogenation reaction(s) in the first hydroprocessing unit HU1” preferably ranges from about 1 : 1 to about 5: 1 , more preferably from about 1 : 1 to about 3: 1 and most preferably from about 1 :1 to about 2:1.

7. Method according to any one of claims 1 to 6 wherein the total pressure at the outlet the at least one reactor in the first hydroprocessing unit HU 1 preferably ranges from about 5 bar (abs.) to about 60 bar (abs.), more preferably from about 10 bar (abs.) to about 40 bar (abs) and most preferably from about 20 bar (abs.) to about 40 bar (abs).

8. Method according to any one of claims 1 to 7 wherein the mass ratio " liquid recycle steam S3' : liquid stream S3 ” preferably ranges between from about 1 : 1 to about 30: 1 , more preferably from about 5: 1 to about 20: 1 and most preferred from about 10:1 to about 15:1.

9. Method according to any one of claims 1 to 8 wherein the wherein the second hydroprocessing unit HU2 comprises at least one fixed-bed reactor.

10. Method according to any one of claims 1 to 9 wherein the first hydroprocessing unit HU1 comprises at least one heterogeneous catalyst, the at least one heterogeneous catalyst comprising at least one catalytically active metal which is selected from the group comprising or consisting of nickel, palladium, platinum, and rhodium.

11. Method according to any one of claims 1 to 10 wherein the second hydroprocessing unit HU2 comprises at least one heterogeneous catalyst, the at least one heterogeneous catalyst selected from the group comprising or consisting of Co-Mo catalyst, Ni-Mo catalyst, Ni-W catalyst, Co-W catalyst, and Mo catalyst.

12. Method according to any one of claims 1 to 11 wherein the residue stream S5 is converted by a partial oxidation and/or a gasification process into syngas, said syngas comprising H2, CO and CO2.

13. Method according to any of claims 1 to 12 wherein stream S6 is further subjected to a cracking process selected from catalytic cracking, thermal cracking, and steam cracking.

14. Method according to any one of claims 1 to 13, comprising the further step: converting the stream S6 obtainable by or obtained by any one of claims 1 to 13; the syngas, H2, CO and/or CO2 obtainable by or obtained by claim 12; and/or a chemical material obtained by or obtainable by any one of claims 1 to 13, preferably a chemical material obtained by or obtainable by claim 13 by subjecting the stream S6 to the cracking process; to obtain a monomer, polymer or polymer product.

15. Method according to claim 14 wherein the monomer is a di- or polyol; preferably butandiol; aldehyde; preferably formaldehyde; di- or polyisocyanate; preferably methylene diphenyl diisocyanate (MDI), polymeric methylene diphenyl diisocyanate (pMDI), toluene diisocyanate (TDI), hexamethylenediisocyanate (HDI) or isophoronediisocyanate (IPDI); amide; preferably caprolactam; alkene; preferably styrene, ethene and norbornene; alkyne, (di)ester; preferably methyl methacrylate; mono or diacid; preferably adipic acid or terephthalic acid; diamine; preferably hexamethylenediamine, nonanediamine; or sulfones; preferably 4,4'-dichlorodiphenyl sulfone.

16. Method according to claim 14 or 15 wherein the polymer is and/or the polymer product comprises polyamide (PA); preferably PA 6 or PA 66; polyisocyanate polyaddition product; preferably polyurethane (PU), thermoplastic polyurethane (TPU), polyurea or polyisocyanurate (PIR); low-density polyethylene (LDPE), high- density polyethylene (HDPE), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyvinyl acetate (PVA), polystyrene (PS), poly acrylonitrile butadiene styrene (ABS), poly styrene acrylonitrile (SAN), poly acrylate styrene acrylonitrile (ASA), polytetrafluoroethylene (PTFE), poly(methyl acrylate) (PMA), poly (methyl methacrylate) (PMMA), polybutadiene (BR, PBD), poly(cis-1 ,4-isoprene), poly(trans-1,4-isoprene), polyoxymethylene (POM), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polybutylene adipate co-terephthalate (PBAT), polyester (PES), polyether sulfone (PESU), polyhydroxyalkanoate (PHA), poly-3- hydroxybutyrate (P3HB), poly-4-hydroxybutyrate (P4HB), polyhydroxyvalerate (PHV), polyhydroxyhexanoate (PHH), polyhydroxyoctanoate (PHO), polylactic acid (PLA), polysulfone (PSU), polyphenylene sulfone (PPSU), polycarbonate (PC), polyether ether ketone (PEEK), poly(p-phenylene oxide) (PPO), poly (p- phenylene ether) (PPE); or copolymer or mixture thereof.

17. Method according to any one of claims 14 to 16 wherein the polymer and/or the polymer product is/are then converted into or is/are then converted into:

- a part of a car; preferably cylinder head cover, engine cover, housing for charge air cooler, charge air cooler flap, intake pipe, intake manifold, connector, gear wheel, fan wheel, cooling water box, housing, housing part for heat exchanger, coolant cooler, charge air cooler, thermostat, water pump, radiator, fastening part, part of battery system for electromobility, dashboard, steering column switch, seat, headrest, center console, transmission component, door module, A, B, C or D pillar cover, spoiler, door handle, exterior mirror, windscreen wiper, windscreen wiper protection housing, decorative grill, cover strip, roof rail, window frame, sunroof frame, antenna panel, headlight and taillight, engine cover, cylinder head cover, intake manifold, airbag, cushion, or coating;

- a cloth; preferably shirt, trousers, pullover, boot, shoe, shoe sole, tight or jacket;

- an electrical part; preferably electrical or electronic passive or active component, circuit board, printed circuit board, housing component, foil, line, switch, plug, socket, distributor, relay, resistor, capacitor, inductor, bobbin, lamp, diode, LED, transistor, connector, regulator, integrated circuit (IC), processor, controller, memory, sensor, microswitch, microbutton, semiconductor, reflector housing for light-emitting diodes (LED), fastener for electrical or electronic component, spacer, bolt, strip, slide-in guide, screw, nut, film hinge, snap hook (snap-in), or spring tongue;

- a consumer, agricultural product or pharmaceutical product; preferably tennis string, climbing rope, bristle, brush, artificial grass, 3D printing filament, grass trimmer, zipper, hook and loop fastener, paper machine clothing, extrusion coating, fishing line, fishing net, offshore line and rope, vial, syringe, ampoule, bottle, sliding element, spindle nut, chain conveyor, plain bearing, roller, wheel, gear, roller, ring gear, screw and spring dampers, hose, pipeline, cable sheathing, socket, switch, cable tie, fan wheel, carpet, box or bottle for cosmetics, mattress, cushion, insulation, detergent, dishwasher tabs or powder, shampoo, body wash, shower gel, soap, fertilizer, fungicide, or pesticide;

- a packaging for the food industry; preferably mono- or multi-layer blown film, cast film (mono- or multilayer), biaxially stretched film, or laminating film; or

- a part of a construction; preferably a rotor blade, insulating material, frame, housing, wall, coating, or separating wall.

18. Method according to any one of claims 14 to 17 wherein the content of the liquid stream S1 in the monomer, polymer or polymer product is 1 weight-% or more, preferably 2 weight-% or more, more preferably 5 weight- % or more, more preferably 15 weight-% or more, more preferably 30 weight-% or more, more preferably 40 weight-% or more, more preferably 60 weight-% or more, more preferably 80 weight-% or more, more preferably 90 weight-% or more, more preferably 95 weight-% or more; and/or wherein the content of the liquid stream S1 in the monomer, polymer or polymer product is 100 weight-% or less, preferably 95 weight-% or less, more preferably 90 weight-% or less, more preferably 50 weight-% or less, more preferably 25 weight-% or less, more preferably 10 weight-% or less; and preferably wherein the content is determined based on identity preservation and/or segregation and/or mass balance and/or book and claim chain of custody models, preferably based on mass balance, preferably the International Sustainability and Carbon Certification (ISCC) standard.

19. Chemical plant for separating a steam cracker feedstock from a liquid stream comprising at least one plastic pyrolysis oil, the chemical plant comprising

(I) at least one first hydroprocessing unit HU1, the at least one first hydroprocessing unit HU1 comprising at least one inlet and at least one outlet, (ii) a recycle unit downstream of and fluidically connected to the inlet and the outlet of the first hydroprocessing unit HU1,

(iii) a distillation unit DU downstream of and fluidically connected to the outlet of the first hydroprocessing unit HU1, the at least one distillation unit having a bottom outlet BO and a head outlet HO, and (iv) a second hydroprocessing unit HU2 downstream of and fluidically connected to the head outlet HO of the at least one distillation unit DU.

20. Use of a chemical plant according to claim 19 for the method according to any one of claims 1 to 18.