Chemical plant and process for separating c6-c8 aromatic hydrocarbons from a feed stream comprising at least one pyrolysis oil

Abstract

The invention relates to a process and chemical plant for separating C6-C8 aromatic hydrocarbons from a feed stream comprising at least one plastic pyrolysis oil. The process comprises the steps of a) evaporating the feedstock, b) removing olefins and dienes from the evaporated feedstock by a first hydroprocessing, c) further heating the hydroprocessed product stream, d) removing heteroatoms from the hydroprocessed product stream by a second hydroprocessing, d) continuously or discontinuously feeding a wash water stream to the hydroprocessed product stream after the second hydroprocessing, e) condensing the hydroprocessed product stream, f) separating the hydroprocessed product stream from a recycle stream and optionally from the wash water stream. The process and chemical plant prevent undesired polymerization of components in the feed stream and thereby inhibit undesired fouling.

Description

Technical Field

[0001] This invention relates to a method and chemical apparatus for separating C6-C8 aromatic hydrocarbons from a feed stream containing at least one type of plastic pyrolysis oil. Background Technology

[0002] AU 2021 / 222788 A1 and FR3118629A1 disclose methods for treating plastic pyrolysis oil, comprising steps a) selective hydrogenation, b) hydrotreating, and c) separating the hydrotreating effluent. At least a portion of the hydrotreating effluent obtained after separation in step c) is recycled to a) selective hydrogenation and / or b) hydrotreating. Selective hydrogenation (step b)) at temperatures up to 250°C (i.e., primarily in the liquid phase) can lead to undesirable polymerization of the feedstock portion within the hydrogenation unit. Furthermore, since the entire hydrotreating stream obtained in step a) is subjected to hydrotreating in step b), the separation steps following selective hydrogenation a) and hydrotreating b) require larger and therefore more expensive hydrotreating units. Additionally, H2 consumption is very high for the same reason. The second hydrotreating is operated in the gas phase, including recirculated gas operation. Distillation is not suitable for separating C6-C8 aromatic hydrocarbons from a stream. This method is intended to produce steam cracking feedstock rather than a C6-C8 aromatic hydrocarbon stream. Figure 1 The method of this type is illustrated below, and is further illustrated below as a comparative example to demonstrate the disadvantages of the method relative to the method according to the invention.

[0003] Document US 10,975,313 B2 discloses a method for obtaining aromatics from pyrolysis oil. This method utilizes a first hydrocracking unit for mild hydrocracking, a reforming unit downstream of the first hydrocracking unit, and an aromatics separation unit downstream of the reforming unit. At least a portion of the non-aromatic stream obtained in the aromatics separation unit is recycled to the reforming unit. The disclosed method requires numerous separate process steps, including (mild) hydrocracking and reforming, resulting in a highly complex overall process.

[0004] US 2023 / 287282 A1 discloses a method for purifying hydrocarbon streams, wherein a single hydrogenation step is performed at a temperature of at least 250°C. The resulting purified hydrocarbon stream is suitable as a feedstock for steam cracking.

[0005] FR 3118629 A1 (AU 2021411704 A1) discloses a method including a hydrogenation step for treating plastic pyrolysis oil. The method comprises two consecutive hydrogenation treatment steps followed by a separation step, wherein the hydrogenated plastic pyrolysis oil is combined with an aqueous solution and then separated into at least one gaseous effluent and a hydrocarbon-based effluent. Optionally, the hydrocarbon-based effluent or a portion thereof may then be fractionated.

[0006] EP 2792729 A1 discloses a method for hydrogenating a liquid feedstock containing hydrocarbons into fuel components. The resulting product can be used as fuel and feedstock for naphtha crackers. This document does not disclose the separation of C6-C8 aromatic hydrocarbons from a feedstock stream containing at least one type of plastic pyrolysis oil.

[0007] The object of this invention is to provide a method for separating a C6-C8 aromatic hydrocarbon stream from a feed stream containing at least one type of feedstock, and a chemical apparatus suitable for separating a C6-C8 aromatic hydrocarbon stream from a feed stream containing at least one type of plastic waste-derived pyrolysis oil. Furthermore, when separating a C6-C8 aromatic hydrocarbon stream from a feed stream containing at least one type of plastic pyrolysis oil, the method and chemical apparatus should reduce undesirable scaling during processing. This at least one type of plastic pyrolysis oil is obtained through the pyrolysis of plastic waste. Summary of the Invention

[0008] These problems are addressed by a method for separating C6-C8 aromatic hydrocarbons from a feed stream containing at least one type of plastic pyrolysis oil, the method comprising the following steps:

[0009] (i) Providing a liquid stream S1 comprising at least one plastic pyrolysis oil, the liquid stream S1 further comprising a C6-C8 aromatic hydrocarbon, an organic compound comprising at least one heteroatom, and a compound having a C-C double bond and / or a C-C triple bond.

[0010] (ii) Provide stream S2 containing hydrogen gas.

[0011] (iii) At least a portion of the liquid stream S1 is evaporated in the evaporation unit EU in the presence of the stream S2 and the optionally recirculated gas stream S11, thereby forming a gas stream S3 comprising the stream S2, the optionally recirculated gas stream S11 and the evaporated portion of the liquid stream S1, and a liquid stream S4 comprising the portion of the unevaporated liquid stream S1 in the evaporation unit EU.

[0012] (iv) Optionally, the gas flow S3 may be superheated in the superheater SH, thereby forming a superheated flow S5.

[0013] (v) The gas stream S3 or optionally the superheated stream S5 is fed into a first hydrogenation unit HU1, in which at least a portion of the gas stream S3 or optionally at least a portion of the superheated stream S5 reacts with the hydrogen contained therein in a hydrogenation reaction, thereby forming a gas stream S6 containing C6-C8 aromatic hydrocarbons, organic compounds containing at least one heteroatom, and compounds having C-C double bonds and / or C-C triple bonds relative to the gas stream S3.

[0014] (vi) The gas stream S6 is heated in at least one heating device HD, thereby forming a heated gas stream S7.

[0015] (vii) The heated gas stream S7 is subjected to a second hydrogenation unit HU2, in which a product stream S8 is formed, the product stream S8 comprising C6-C8 aromatic hydrocarbons and being depleted relative to the gas stream S3 of organic compounds containing at least one heteroatom and further depleted of compounds having C-C double bonds and / or C-C triple bonds.

[0016] (viii) Optionally, heat is transferred from the product stream S8 to the gas stream S3 in the superheater SH, thereby forming a cooled product stream S8b.

[0017] (ix) The washing water stream S15 is fed into the product stream S8 continuously or discontinuously to form a stream S8a that optionally contains washing water, or the washing water stream S15 is fed into the cooled product stream S8b continuously or discontinuously to form a cooled product stream S8c that optionally contains washing water.

[0018] (x) Optionally, in the evaporation unit EU, heat is transferred from the cooled product stream S8c containing wash water to the liquid stream S1, the stream S2 containing H2, and the stream S11, thereby forming a further cooled product stream S8d.

[0019] (xi) The product stream S8a, optionally containing wash water, or optionally selected from the group consisting of the cooled product stream S8b, the cooled product stream S8c, and the further cooled product stream S8d optionally containing wash water, is condensed in the condensation unit CU, thereby forming a product stream S9, which comprises a liquid phase and a gas phase.

[0020] (xii) The liquid product stream S9 is separated in the separation unit SU into a liquid product stream S10, a recirculated gas stream S11, and optionally a wastewater stream S17, wherein the recirculated gas stream S11 contains hydrogen and wherein at least a portion of the recirculated gas stream S11 is fed into the evaporation unit EU.

[0021] (xiii) Optionally, the purified product stream S10 is fed into a distillation unit DU, in which the purified product stream S10 is separated into a stable product stream S12 and a gas stream S13.

[0022] These problems are further addressed by a chemical apparatus for separating C6-C8 aromatic hydrocarbons from a feed stream containing at least one type of plastic pyrolysis oil, the apparatus comprising...

[0023] (i) Evaporation unit EU,

[0024] (ii) Optionally, a superheater SH downstream of the evaporation unit EU.

[0025] (iii) A first hydrogenation treatment unit HU1, the first hydrogenation treatment unit HU1 comprising at least one inlet and at least one outlet, the first hydrogenation treatment unit HU1 being downstream of the evaporation unit EU or the optional superheater SH, and the at least one inlet of the first hydrogenation treatment unit HU1 being fluidly connected to the evaporator or the optional superheater SH.

[0026] (iv) At least one heating unit HD, which is downstream of and fluidly connected to the at least one outlet of the first hydrogenation treatment unit HU1.

[0027] (v) A second hydrogenation treatment unit HU2 having at least one inlet and at least one outlet, the second hydrogenation treatment unit HU2 being downstream of the at least one heating unit HD, and the at least one outlet of the hydrogenation treatment unit HU2 being fluidly connected to the heating unit HD.

[0028] (vi) A condensation unit CU, which is downstream of the second hydrogenation treatment unit HU2 and fluidly connected to at least one outlet of the second hydrogenation treatment unit HU2.

[0029] (vii) Separation unit SU, which is downstream of and fluidly connected to the condensation unit CU, and

[0030] (viii) Optionally, a distillation unit DU is downstream of and fluidly connected to the separation unit SU; and optionally, an aromatic hydrocarbon extraction unit AEU is downstream of the optional distillation unit and fluidly connected to stream S12. Attached Figure Description

[0031] Figure 1 A method is shown in which a liquid recirculation flow from the second hydrogenation unit to the first hydrogenation unit is utilized. This recirculation flow is used in the method disclosed in AU 2021 / 222788 A1 and is therefore used below as a comparative example.

[0032] Figure 2 The present invention illustrates a method and chemical apparatus for separating C6-C8 aromatic hydrocarbon streams from a feed stream containing at least one type of plastic pyrolysis oil.

[0033] Figure 3 The present invention illustrates a method and chemical apparatus for separating a C6-C8 aromatic hydrocarbon stream from a feed stream containing at least one plastic pyrolysis oil, comprising an optional superheater SU and an optional step (iv).

[0034] Figure 4 The present invention illustrates a method and chemical apparatus for separating a C6-C8 aromatic hydrocarbon stream from a feed stream containing at least one plastic pyrolysis oil, comprising optional steps (iv), (viii) and (x). Detailed Implementation

[0035] The present invention is further described below with reference to embodiments, but the present invention is not limited to these embodiments, and any modifications or substitutions to these embodiments or combinations thereof within the basic spirit of the present invention are still within the scope of the present invention as claimed.

[0036] definition:

[0037] In the context of this specification and the appended claims, the term "about" preferably means a deviation of ±10% from the value described therein. In the context of this invention, the term "combination thereof" includes one or more of the listed elements. In the context of this invention, the term "mixture thereof" includes one or more of the listed elements.

[0038] In the context of this invention, the term "pyrolysis" refers to the thermal decomposition or degradation of a feedstock, such as plastic waste, under inert conditions, producing gaseous, liquid, and solid char components. During pyrolysis, the feedstock is converted in the pyrolysis unit into a wide variety of chemicals, including gases such as H2, C1- to C4-alkanes, C2- to C4-olefins, acetylene, propyne, 1-butyne, plastic pyrolysis oil having a boiling temperature of 25°C to 500°C, and char. Additionally, water is formed during pyrolysis, which may be partially dispersed in the plastic pyrolysis oil and may be partially contacted with the plastic pyrolysis oil as a separate phase. The water formed during pyrolysis contains various organic compounds and / or their salts that are also formed during pyrolysis. The term "pyrolysis" includes slow pyrolysis, fast pyrolysis, flash catalytic pyrolysis, and catalytic pyrolysis. These types of pyrolysis differ in process temperature, heating rate, residence time, feed particle size, etc., resulting in different product qualities. Pyrolysis units can be operated adiabatic, isothermal, non-adiabatic, non-isothermal, or combinations thereof. The pyrolysis reaction disclosed herein can be carried out in a single stage or in multiple stages. For example, a pyrolysis unit may comprise two reactor vessels connected in series with fluid connections.

[0039] In the context of this invention, "valuable component" means "C6-C8 aromatic hydrocarbons" (benzene, toluene, 1,2-xylene, 1,3-xylene, 1,4-xylene, and ethylbenzene).

[0040] In the context of this invention, the term "plastic pyrolysis oil" should be understood to mean any oil derived from the pyrolysis of plastic waste. The term "plastic waste" includes rubber waste such as scrap tires and raw materials containing plastic waste. Plastic pyrolysis oil is obtained and / or is available from the pyrolysis of such plastic waste.

[0041] In the context of this invention, the term "plastic waste" refers to any plastic material that is discarded after use, i.e., the plastic material has reached the end of its service life and is considered post-consumer waste. Plastic waste can be pure polymer plastic waste, mixed plastic waste, or membrane waste, including sludge, adhesive materials, fillers, residues, etc. Plastic waste may have oxygen content, nitrogen content, sulfur content, halogen content, and optionally heavy metal content. Plastic waste can originate from any source containing plastic materials.

[0042] Therefore, the term "plastic waste" includes industrial and household plastic waste, as well as used tires and agricultural and horticultural plastic materials.

[0043] Typically, plastic waste is a mixture of different plastic materials, including hydrocarbon plastics such as polyolefins such as polyethylene (HDPE, LDPE) and polypropylene, polystyrene and their copolymers, and polymers composed of carbon, hydrogen and other elements such as chlorine, fluorine, oxygen, nitrogen, sulfur, silicon, etc., such as chlorinated plastics such as polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), nitrogen-containing plastics such as polyamide (PA), polyurethane (PU), acrylonitrile butadiene styrene (ABS), oxygen-containing plastics such as polyesters such as polyethylene terephthalate (PET), polycarbonate (PC), silicone and / or sulfur-bridged crosslinked rubber.

[0044] Typically, plastic materials contain additives such as processing aids, plasticizers, flame retardants, pigments, light stabilizers, lubricants, impact modifiers, antistatic agents, antioxidants, etc. These additives may contain elements other than carbon and hydrogen. For example, the presence of bromine is primarily associated with flame retardants. Heavy metal compounds can be used as light-resistant pigments and / or stabilizers in plastics. Cadmium, zinc, and lead may be present in heat stabilizers and slip agents used in plastic manufacturing. Plastic waste may also contain residues. In the context of this invention, residues are contaminants that adhere to plastic waste. Additives and residues are generally present in amounts of less than 50 wt.-%, preferably less than 30 wt.-%, more preferably less than 20 wt.-%, and even more preferably less than 10 wt.-%, based on the total dry weight of the plastic.

[0045] Examples of rubber waste (also considered "plastic waste" in the context of this invention) include end-of-life tires, rubber waste generated during the manufacturing process, and discarded rubber-containing products such as latex inspection gloves and gaskets. End-of-life tires contain additional components, such as textiles and organic and inorganic additives, which can be separated from the rubber portion of the end-of-life tire before pyrolysis. The pyrolysis oil obtained by (primarily) the pyrolysis of end-of-life tires is also known as tire pyrolysis oil (TPO) and is understood to be "plastic pyrolysis oil" for the purposes of this invention.

[0046] Examples of biological waste that can be included in “plastic waste” include green waste, food waste, human waste, manure, sewage, sewage sludge and slaughterhouse waste.

[0047] To obtain the plastic pyrolysis oil according to the invention, the feedstock is inserted into the pyrolysis reactor using a metering unit such as a screw or extruder, a rotary valve, a pneumatic conveyor, or a liquid injector. The feedstock may optionally be preheated in, for example, a heat exchanger and / or subjected to pre-pyrolysis at a temperature, for example, in the range of about 200°C to about 360°C, before being inserted into the pyrolysis reactor. The feedstock is then heated in the pyrolysis reactor to a temperature in the range of about 350°C to about 900°C, more preferably in the range of 400°C to about 550°C, and a pressure in the range of about 0.5 bar to about 2 bar (absolute value), more preferably in the range of 0.9 bar to about 1.5 bar (absolute value). The pyrolysis reactor is preferably selected from the group consisting of fluidized bed reactors, moving bed reactors, entrained flow reactors, screw reactors, extruders, stirred tank reactors, and rotary kiln reactors. Preferably, the pyrolysis is carried out in the pyrolysis reactor under an inert atmosphere free of oxygen or air.

[0048] Pyrolysis methods are known in themselves. They are described, for example, in EP 0713906 A1 and WO 95 / 03375 A1. Suitable plastic pyrolysis oils are also commercially available. Plastic pyrolysis oils are typically liquid at 15°C or waxy at said temperature. In the terminology of this invention, "liquid at 15°C" means that the plastic pyrolysis oil has a density of at most 1.3 g / ml at 15°C and 1013 mbar, as determined according to DIN EN ISO 12185, for example, a density in the range of 0.65 to 0.98 g / ml.

[0049] The amount of C6-C8 aromatics formed by the pyrolysis reaction of the above-mentioned feedstock can be increased, for example, in the presence of a suitable catalyst. Another suitable method for increasing the amount of C6-C8 aromatics is disclosed in EP 3744814 A1: the pyrolysis gas obtained from the pyrolysis reaction of the above-mentioned feedstock is then subjected to thermal catalytic treatment at about 450°C to about 600°C (at least 50°C lower than the pyrolysis reaction temperature applied in the first step) in the presence of an aromatization catalyst such as ZSM-5, ZSM-11, ZSM-35, ZSM-23, magnesium alkali zeolite, β-zeolite, zeolite Y, zeolite X, mordenite, zeolite A, IM-5, SSZ-20, SSZ-55, MCM-22, TNU-9, metal-treated, exchanged, or impregnated catalysts, and combinations of the aforementioned catalysts and post-treatments. Other suitable catalysts include sand and alumina. Furthermore, combinations of the above-mentioned catalysts can be used for this purpose.

[0050] The amount of C6-C8 aromatics in plastic pyrolysis oil can also be increased by reforming the plastic pyrolysis oil or a mixture thereof (e.g., via catalytic reforming). Such reforming reactions are disclosed, for example, in...

[0051] https: / / www.e-education.psu.edu / fsc432 / content / catalyic-reforming-processes

[0052] And if necessary, adjustments can be made by technicians.

[0053] Plastic pyrolysis oil containing increased amounts of C6-C8 aromatic hydrocarbons can also be produced by pyrolysis of plastic waste streams containing polystyrene (Maafa, IM Pyrolysis of Polystyrene Waste: A Review. Polymers 2021, 13, 225. https: / / doi.org / 10.3390 / polym13020225).

[0054] Liquid stream S1 preferably comprises at least one plastic pyrolysis oil produced by the above method. Liquid stream S1 further comprises C6-C8 aromatic hydrocarbons, organic compounds containing at least one heteroatom, and compounds having C-C double bonds (olefins, dienes) and / or C-C triple bonds. "Further comprises" here means that such components are included in the at least one plastic pyrolysis oil and / or another liquid hydrocarbon mixed with the at least one plastic pyrolysis oil to form liquid stream S1.

[0055] The liquid stream S1, more preferably the at least one plastic pyrolysis oil contained in the liquid stream S1, comprises at least 5 wt.-%, or at least 10 wt.-%, or at least 15 wt.-%, or at least 20 wt.-%, or at least 25 wt.-%, or at least 30 wt.-%, or at least 35 wt.-%, or at least 40 wt.-%, or at least 45 wt.-%, or at least 50 wt.-%, or at least 55 wt.-%, or at least 60 wt.-%, or at least 70 wt.-%, or at least 80 wt.-%. Preferably, the C6-C8 aromatic hydrocarbons are selected from the group consisting of benzene, toluene, 1,2-xylene, 1,3-xylene, 1,4-xylene, and ethylbenzene.

[0056] The at least one plastic pyrolysis oil contained in liquid stream S1 preferably has a bromine value of about 2 g Br2 / 100 g to about 150 g Br2 / 100 g (as determined by ASTM 1159) and / or a C5 hydrocarbon content of about 0.03 wt.-% to about 12.2 wt.-% (as determined by ASTM D 5134) and / or a naphthalene content of about 0.5 wt.-% to about 18.4 wt.-% (as determined by ASTM D 5134) and / or a styrene content of about 0.02 wt.-% to about 29.5 wt.-% (as determined by ASTM D 5134) and / or a toluene content of about 4.3 wt.-% to about 71.5 wt.-% (as determined by ASTM D 5134). Such plastic pyrolysis oils or mixtures of plastic pyrolysis oils in liquid stream S1 are particularly suitable for the methods and chemical equipment according to the invention.

[0057] Optionally, the at least one plastic pyrolysis oil may be subjected to one or more methods selected from filtration, centrifugation, adsorption, washing, and extraction before being used as liquid stream S1 or a portion thereof in the method according to the invention and / or as liquid stream S1 or a portion thereof in the chemical apparatus according to the invention. Such optional pretreatment methods are described, for example, in WO 2021 / 224287A1, WO 2023 / 061834 A1, EP 0713906 A1 and WO 95 / 03375 A1, which are incorporated herein by reference. Those skilled in the art will know how and in what circumstances to use the pretreatment methods disclosed in the aforementioned documents and comparable pretreatment methods disclosed elsewhere.

[0058] In step (i) of the method according to the invention, a liquid stream S1 comprising at least one plastic pyrolysis oil is provided, the liquid stream S1 further comprising C6-C8 aromatic hydrocarbons, an organic compound comprising at least one heteroatom, and a compound having C-C double bonds and / or C-C triple bonds. The liquid stream S1 may further comprise at least one additional hydrocarbon liquid containing C6-C8 aromatic hydrocarbons different from those obtained from the pyrolysis of plastic waste. Suitable examples include pyrolysis gasoline and coke oven light oil (CAS No.: 65996-78-3). Pyrolysis gasoline is obtained or is a byproduct of the steam cracking of hydrocarbon feedstocks, such as naphtha. Pyrolysis gasoline and its manufacture are known in the art. Pyrolysis gasoline comprises C6-C8 aromatic hydrocarbons. Coke oven light oil can be obtained by extraction from gases escaping from the destructive distillation of coal at high temperatures (e.g., above 700°C). It is primarily composed of benzene, toluene, and xylene and may contain other minor hydrocarbon components.

[0059] In step (ii) of the method according to the invention, a stream S2 containing H2 is provided. Stream S2 may consist substantially of H2 or contain H2 along with at least one other gas. Preferably, the H2 content of stream S2 is greater than about 50% by volume, more preferably greater than 80% by volume, and most preferably greater than about 99% by volume. This minimizes the amount of purge gas required to maintain a high H2 partial pressure and conserves H2. Furthermore, a high H2 partial pressure promotes catalyst activity and allows for a low reaction temperature.

[0060] This additional liquid hydrocarbon feedstock (the sum of all liquid hydrocarbon feedstocks in the case of more than one liquid hydrocarbon feedstock) may, for example, be included in liquid stream S1 in an amount 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 greater, provided that at least 2 wt.-% of liquid stream S1 consists of at least one plastic pyrolysis oil produced by the pyrolysis of plastic waste.

[0061] The advantage of the low reaction temperature is that undesirable polymerization of the components in stream S3 is suppressed. Furthermore, streams S2 and S11 dilute the reactive components contained in liquid stream S1, such as compounds with C / C double bonds (e.g., dienes), compounds containing C / C triple bonds, and styrene, which further minimizes undesirable polymerization of the reactive components in the apparatus and units used in the method according to the invention, particularly in the evaporation unit EU and / or in the optional superheater SH and / or in the first hydrogenation treatment unit HU1. In addition to minimizing the undesirable polymerization, dilution also reduces the partial pressure of the reactive components in stream S1, and thus lowers the dew point of the reactive components in stream S1. Therefore, a desired high evaporation rate of the components in stream S1 is achieved at a lower temperature in the evaporation unit EU compared to the undiluted reactive components in stream S1. Dilution during evaporation further suppresses undesirable polymerization of the reactive components in stream S1.

[0062] The hydrogen (H2) used in the methods and systems according to the invention is preferably “green hydrogen” generated, for example, through water electrolysis and / or methane pyrolysis using electricity generated at least partially from renewable energy sources (e.g., solar, wind, tidal, and nuclear) and / or low-carbon energy sources, and preferably at least partially from methane pyrolysis from renewable sources. Methane from renewable sources includes biomethane.

[0063] Optionally, at least a portion of the hydrogen used in the method according to the invention is hydrogen formed during the pyrolysis reaction and separated from the volatile pyrolysis reaction products.

[0064] Next, in step (iii) of the method according to the invention, liquid streams S1 and S2 are optionally fed together with recirculated gas stream S11 into evaporation unit EU, where at least a portion of liquid stream S1 evaporates and exits evaporation unit EU, mixes with stream S2, and together with the optional recirculated gas stream S11 as gas stream S3. Those portions of liquid stream S1 that have not evaporated in evaporation unit EU exit evaporation unit EU as liquid stream S4.

[0065] Preferably, the liquid stream S1 provided in step (i) and the stream S2 provided in step (ii) are mixed before entering the evaporation unit EU and / or mixed inside the evaporation unit EU.

[0066] Preferably, the evaporation of liquid stream S1 is mild evaporation, for example, not in one stage, but in more than one evaporation stage. The desired mild evaporation of liquid stream S1 can also be achieved by adding recirculated gas stream S11 to liquid stream S1 before and / or during evaporation.

[0067] The desired mild evaporation of liquid stream S1 is more preferably achieved by evaporating liquid stream S1 in more than one evaporation stage and adding recirculated gas stream S11 to liquid stream S1 before and / or during evaporation.

[0068] The advantage of this gentle evaporation of liquid stream S1 is that it reduces the polymerization of components present in liquid stream S1, such as olefins, dienes, and other polymerizable organic compounds such as styrene and organic compounds containing C-C triple bonds. Under excessively harsh evaporation conditions, undesirable scaling occurs in the units, pipes, and other equipment used in the method according to the invention. This undesirable scaling is caused by the aforementioned polymerization.

[0069] The evaporation unit EU includes at least one evaporator selected from the group consisting of pre-evaporators, staged evaporators, and combinations thereof. Such evaporators can be rotary evaporators, circulating evaporators, falling film evaporators, rising film evaporators, climbing film plate evaporators, falling film plate evaporators, multi-effect evaporators, stirred falling film evaporators, and microstructured evaporators.

[0070] In one aspect of the invention, the evaporation unit EU includes at least one staged evaporator. Preferably, the evaporation unit EU includes at least one staged evaporator and further includes at least one pre-evaporator upstream of and fluidly connected to the at least one staged evaporator.

[0071] On the other hand, the evaporation unit EU includes at least one pre-evaporator or, for example, a series of pre-evaporators, in which the liquid stream S1 is gradually heated, thereby reducing the undesirable polymerization of compounds with C-C double bonds (e.g., dienes, olefins), compounds with C-C triple bonds, and styrene contained in the liquid stream S1.

[0072] In another aspect of the invention, the evaporation unit EU includes at least one falling film evaporator, which is particularly suitable for the desired mild evaporation of the liquid flow S1.

[0073] Multistage evaporation and suitable apparatus are described, for example, in R. Billet, Ullmann's Encyclopedia of Industrial Chemistry, 2012, Volume 13, Chapter "Evaporation", pp. 588-591 and 597-599, which are incorporated herein by reference.

[0074] The temperature range for evaporating at least a portion of the liquid flow S1 is preferably from about 140°C to about 220°C, more preferably from about 160°C to about 200°C, and most preferably from about 170°C to about 190°C.

[0075] At least one evaporator included in the evaporation unit EU may optionally further include at least one second fluid passage through which another flow, in addition to flows S1, S2, S3, S4, and optionally a recirculated gas flow S11, can flow and thereby transfer heat to the liquid flows S1 and S2 flowing to the first fluid passage included in the at least one evaporator, and optionally the recirculated gas flow S11. The first fluid passage and the at least one second fluid passage are not fluidly connected to each other. Preferably, the sole reason for the optional presence of at least one second fluid passage in the at least one evaporator of the evaporation unit EU is heat transfer from the flow to the at least one second fluid passage to the flow flowing through the first fluid passage. Heat can be transferred from flow S8c to liquid flow S1 and / or partially vaporized flow S1 and / or flow S2, and optionally to recirculated gas flow S11. Flow S8c will be explained in further detail below.

[0076] Therefore, at least a portion of the thermal energy required to evaporate the liquid stream S1 in step (iii) of the method according to the invention is optionally provided by heat transfer from stream S8c to liquid stream S1 and / or partially vaporized stream S1 and / or stream S2, and optionally to recirculated gas stream S11. This embodiment... Figure 3 As shown in the image.

[0077] Liquid stream S4, comprising a portion of the unevaporated liquid stream S1 contained in evaporation unit EU, can be converted, for example, in at least one gasifier and / or via a partial oxidation reaction unit into syngas comprising a mixture of H2, CO, and CO2. Such partial oxidation reactions are known in the art and are disclosed, for example, in Ullmann's Encyclopedia of Industrial Chemistry, Volume 16, Chapter: Gas Production, 2. Processes, pp. 443-455, 2012, which is incorporated herein by reference. Those skilled in the art can select suitable reactors and reaction conditions to convert liquid stream S4 into syngas via partial oxidation and / or gasification.

[0078] The liquid stream S4 can also be used as a raw material to undergo an aromatic hydrocarbon separation method, thereby further increasing the yield of aromatic hydrocarbons achieved by the method according to the invention.

[0079] Next, in an optional step (iv) of the method according to the invention, the gas stream S3 is superheated in at least one optional superheater SH, thereby forming a superheated and / or dried stream S5. The advantage of applying optional step (iv) in the method according to the invention is that, in the case of a gas stream S3 with a temperature below the dew point, the vapor and liquid phases directly enter the first hydrogenation treatment unit HU1, which is undesirable. If necessary, a small amount of liquid can be separated at the bottom of the at least one reactor in the first hydrogenation treatment unit HU1. The first hydrogenation treatment unit HU1 is optimized for gas-phase hydrogenation, therefore, the gas stream S3 is preferably completely vaporized before entering the first hydrogenation treatment unit HU1 to avoid polymerization and thus blockage. Due to heat losses during the journey from the evaporation unit EU to the first hydrogenation treatment unit HU1, a liquid phase can form by condensation, which, for the reasons explained above, should preferably not enter the first hydrogenation treatment unit HU1.

[0080] Therefore, the gas stream S3 is optionally and preferably superheated in at least one optional superheater SH so that the temperature of the gas stream S3 is preferably increased by about 2°C to about 50°C, more preferably by about 5°C to about 40°C, and most preferably by about 10°C to about 30°C relative to the temperature at which the gas stream S3 leaves the evaporation unit EU.

[0081] The at least one optional superheater SH more preferably includes at least one first fluid passage into which gas flow S3 is fed, superheated, and exits the optional superheater SH as superheated flow S5. Superheated flow S5 has a higher temperature than gas flow S3.

[0082] The at least one optional superheater SH is preferably a radiant superheater, a convective superheater, or a separately combusting superheater. Preferably, the at least one optional superheater SH is a shell-and-tube heat exchanger having a gas flow S3 inside the tubes. In one aspect of the invention, at least a portion of the heat energy transferred to the gas flow S3 in the at least one optional superheater SH is provided by electric heating, preferably from a renewable source (such as wind, solar, and / or tidal energy).

[0083] Preferably, the optional superheater SH further includes at least one heat exchanger, such as a shell-and-tube heat exchanger, which includes at least one first fluid passage and at least one second fluid passage (preferably shell). Gas flow S3 is fed into the first fluid passage, superheated, and exits the optional superheater SH as a superheated flow S5. Another flow, besides gas flow S3, can flow through the second fluid passage, thereby transferring heat to the gas flow S3 flowing through the first fluid passage. This embodiment... Figure 3 As shown in the image.

[0084] The first fluid passage and at least one optional second fluid passage are not fluidly connected to each other. Preferably, heat is transferred from flow S8 to gas flow S3. Flow S8 will be explained in further detail below.

[0085] More preferably, at least a portion of the thermal energy required to convert the gas flow S3 into the superheated flow S5 in the at least one optional superheater SH is provided by transferring heat from the flow S8 to the gas flow S3.

[0086] Most preferably, up to 100% of the thermal energy required to convert gas flow S3 into superheated flow S5 in the at least one optional superheater SH is provided by transferring heat from flow S8 to gas flow S3.

[0087] I'm here too Figure 3 As shown in the aspect of the invention, flow S8 exits the at least one optional superheater SH as flow S8b.

[0088] In method step (v) of the method according to the invention, the gas stream S3 ( Figure 2 ) or superheated flow S5 (in the case of applying optional step (iv), Figure 3 The feed is introduced into the first hydrogenation treatment unit HU1, where compounds containing C / C double bonds (e.g., dienes) and / or C / C triple bonds present in the gas stream S3 or the superheated stream S5 are hydrogenated in the first hydrogenation treatment unit HU1. This forms C / C single bonds.

[0089] The first hydrogenation treatment unit HU1 includes at least one stage in which CC double bonds and / or CC triple bonds present in gas stream S3 or superheated gas stream S5 are hydrogenated, while the conjugated CC bonds of the C6-ring in the C6-C8 aromatic hydrocarbons present in gas stream S3 or superheated gas stream S5 are preferably not hydrogenated in the first hydrogenation treatment unit HU1.

[0090] The first hydrotreating unit HU1 can be any vessel preferably configured to contain a hydrotreating catalyst. The vessel is preferably configured for gas-phase operation. The first hydrotreating unit HU1 may include beds of one or more hydrotreating catalysts, preferably in a fixed-bed configuration. The first hydrotreating unit HU1 can operate adiabatically, isothermally, non-adiabatically, non-isothermally, or a combination thereof. The first hydrotreating unit HU1 may contain more than one vessel. Each of such vessels is considered a hydrogenation reactor (“reactor”).

[0091] The gas stream S3 or the superheated stream S5 can be brought into contact with the hydrotreated catalyst in an upward, downward, radial, or combination thereof.

[0092] Preferably, the first hydrogenation treatment unit HU1 comprises a single reactor with a single catalyst bed. This minimizes the geometry of the first hydrogenation treatment unit HU1 and ensures a cost-effective reactor design.

[0093] The process temperature depends on the type and activity of the catalyst used. The process temperature in the first hydrotreating unit HU1 is preferably in the range of about 140°C to about 250°C, more preferably about 150°C to about 200°C, and most preferably about 170°C to about 190°C. Catalyst deactivation can optionally be compensated for by increasing the process temperature.

[0094] In the process, the pressure in the first hydrogenation treatment unit HU1 is preferably in the range of about 1.0 MPa to about 10 MPa (absolute value). The partial pressure of hydrogen gas upstream of the first hydrogenation treatment unit HU1 is preferably in the range of about 5 bar to about 50 bar, more preferably about 10 bar to about 30 bar, and most preferably about 14 bar to about 20 bar.

[0095] The weight-time space velocity (WHSV) calculated from the reference flow S1 is preferably in the range of approximately 0.5 t / (m²). 3 Kat. •h) to approximately 5 t / (m 3 Kat. •h), more preferably about 1.0 t / (m 3 Kat. •h) to approximately 3.0 t / (m 3 Kat. •h) and most preferably about 1.5 t / (m 3 Kat. •h) to approximately 2.0 t / (m 3 Kat. •h).

[0096] The amount of hydrogen exhibits a significant excess contained in the first hydrogenation processing unit HU1. The process conditions of hydrogen partial pressure, temperature, and WHSV as disclosed above ensure sufficient hydrogenation of undesirable C-C double bonds (e.g., olefins, dienes) and C-C triple bonds present in gas stream S3 or superheated stream S5, but are insufficient to hydrogenate desired C6-C8 aromatic hydrocarbons also present in gas stream S3 or superheated stream S5.

[0097] The hydrotreating catalyst can be any catalyst (e.g., commercially available hydrotreating catalyst) used for the hydrogenation of C / C double bonds (e.g., olefins, dienes) and C / C triple bonds. For this purpose, suitable hydrotreating catalysts are heterogeneous catalysts selected from the group consisting of: molybdenum catalysts (“Mo catalysts”), cobalt-molybdenum catalysts (“Co-Mo catalysts”), nickel-molybdenum 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, and molybdenum sulfides. Suitable heterogeneous catalysts further comprise a support, preferably an inorganic support selected from the group consisting of: silica, alumina, silica-alumina, magnesium oxide, clay, and mixtures thereof. Other suitable hydrotreating catalysts are, for example, zeolites containing one or more metals.

[0098] Most preferably, the at least one heterogeneous catalyst is selected from the group consisting of nickel-molybdenum catalysts and nickel-tungsten catalysts, further comprising a support, preferably an inorganic support selected from the group consisting of silica, alumina, silica-alumina, magnesium oxide, clay, and mixtures thereof. These catalysts are most suitable for use in the desired hydrogenation reaction (step (v) of the method according to the invention) in the first hydrogenation treatment unit HU1.

[0099] More than one of the aforementioned hydrotreating catalysts can be used together in the first hydrotreating unit HU1.

[0100] In one aspect of the invention, at least a portion of the catalyst comprises a recycled catalyst.

[0101] In the context of this invention, the at least one catalyst used in the first hydrogenation treatment unit HU1 is preferably in the form of an extrusion, granules, rings, spherical particles or spheres, more preferably earth-shaped particles or extrusions.

[0102] The at least one reactor in the first hydrogenation treatment unit HU1 contains at least one catalyst, preferably in the form of at least one catalyst bed.

[0103] The height and diameter of the at least one catalyst bed are selected based on reaction kinetics, optimal liquid / gas flow patterns, and pressure drop. The at least one catalyst bed may consist of one or more layers of different solid absorbent materials and one or more different hydrogenation catalysts. The catalyst layers in the at least one catalyst bed may differ from each other in terms of particle size, shape, activity, or active sites. When using more than one catalyst bed, inert particles may be used above and below each bed to improve fluid distribution.

[0104] In the case where the at least one hydrogenation reactor in the first hydrogenation treatment unit HU1 has at least two stages, the catalyst preferably has different particle sizes in the at least two stages and / or optionally different shapes in the at least two stages.

[0105] Particle size here refers to particle size distribution, which is measured, for example, by sieving, laser diffraction, or other methods known in the art. Catalysts with desired particle size and optionally desired shape can be manufactured and used.

[0106] Hydrogenation is an exothermic reaction and therefore each stage of the reaction can be optionally cooled.

[0107] Preferably, the gas stream S3 or the superheated stream S5 enters the at least one reactor of the first hydrogenation treatment unit HU1 from the bottom section and exits the at least one reactor of the first hydrogenation treatment unit HU1 in the top section. This reduces unwanted fouling, such as polymerization of reactive compounds (e.g., organic compounds having C / C double and / or triple bonds), and / or draws unwanted polymerization products formed in the bottom section of the at least one reactor further downwards and away from the bottom section of the catalyst bed by gravity. Such unwanted polymerization products can then be removed from the bottom section of the reactor without clogging other sections of the at least one catalyst bed in the at least one reactor.

[0108] About 90% or more, such as 95% or 99%, of the diene present in the gas stream S3 or the superheated stream S5 is converted in step (v) of the method according to the invention.

[0109] Next, in step (vi) of the method according to the invention, the temperature of the gas stream S6 is increased in the heating device HD to form a heated gas stream S7. A temperature increment is required because the hydrogenation process in the second hydrogenation processing unit HU2 requires a higher temperature for the gas stream to be hydrogenated than the first hydrogenation process in the first hydrogenation processing unit HU1.

[0110] The gas flow S6 preferably has a temperature in the range of about 160°C to about 280°C, more preferably about 180°C to about 230°C, and most preferably about 200°C to about 220°C.

[0111] The heated gas stream S7 preferably has a temperature in the range of about 250°C to about 400°C, more preferably about 260°C to about 380°C, and most preferably about 280°C to about 340°C.

[0112] The at least one heating device HD provides heat to the gas flow S6 by direct heating, indirect heating, or a combination thereof (e.g., direct heating with a first heating device HD´ and indirect heating with a second heating device HD´´, or vice versa).

[0113] The at least one heating device HD is preferably selected from the group consisting of: direct combustion heaters, electrically driven furnaces, and heat exchangers.

[0114] In cases where at least one heating device HD includes an electrically powered furnace, the electricity is preferably supplied by a renewable source such as wind, solar, and tidal energy. Such heating devices HD are more sustainable than, for example, direct-fired furnaces and are therefore preferred.

[0115] A direct combustion furnace, as a heating device (HD), can provide heat to a gas stream, for example, by burning gaseous or liquid fuels (such as natural gas) and oxidants (such as oxygen and / or air).

[0116] A furnace suitable as a heating device (HD) may include, for example, at least one radiant section, at least one convection section, at least one radiant coil, at least one burner, and insulation material.

[0117] The heating device HD is downstream of at least one outlet of the first hydrogenation treatment unit HD1 and is fluidly connected to at least one outlet.

[0118] Next, in step (vii) of the method according to the invention, a heated gas stream S7 is inserted into a second hydrogenation treatment unit HU2 and converted into a product stream S8 within the second hydrogenation treatment unit HU2. Through hydrogenation treatment in the second hydrogenation treatment unit HU2, the product stream S8 is depleted of heteroatoms, such as nitrogen, oxygen, halogens (fluorine, chlorine, bromine, iodine), and sulfur, relative to the heated gas stream S7. Heteroatoms leave the second hydrogenation treatment unit HU2 as part of the product stream S8 in the form of their corresponding hydrides. The corresponding hydrides of the heteroatoms include NH3, H2O, H(Hal) (HF, HCl, HBr, HI), and H2S. NH3 and H(Hal) can form salts of the NH4Hal type (NH4F, NH4Cl, NH4Br, NH4I), and NH3 and H2S can form the salt NH4SH. Such salts may have already formed in the gas phase in the second hydrogenation treatment unit HU2 and can then form undesirable deposits on the metal surface by resublimation when the stream S8 cools.

[0119] NH4Cl, NH4F, NH4Br, NH4I, and NH4SH (at least one of which can be formed primarily in the second hydrogenation treatment unit HU2 (and a small portion may also be formed in the first hydrogenation treatment unit HU1)) are preferably removed from the second hydrogenation treatment unit HU2 by water. More preferably, NH4F, NH4Cl, NH4Br, NH4I, and / or the corresponding cations and anions are quantitatively removed by water, and NH4SH and / or the corresponding cations and anions are partially removed from the second hydrogenation treatment unit HU2 by water stream S15.

[0120] Water stream S15 is fed into product stream S8. This forms product stream S8a containing water. Figure 2 (as shown in the aspects of the invention) or feeding water stream S15 into product stream S8b and thereby forming product stream S8c ( Figure 3 (As shown in the aspects of the invention). The following further explains the addition of water stream S15 to product stream S8 or product stream S8b.

[0121] Therefore, the reactions in the second hydrogenation unit include hydrodenitrogenation, hydrodeoxygenation, hydrodehalogenation, and hydrodesulfurization. Furthermore, the reactions include hydrodemetallization, and preferably, hydrogenation of the remaining C-C double bonds (olefins and dienes) and C-C triple bonds, while the conjugated C-C bonds of the C6-ring in the C6-C8 aromatics present in the heated gas stream S7 are preferably not hydrogenated in the second hydrogenation unit HU2.

[0122] The second hydrogenation treatment unit HU2 is downstream of the heating device HD, and at least one inlet fluid of the second hydrogenation treatment unit HU2 is connected to the heating device HD.

[0123] The second hydrotreating unit HU2 can be any vessel configured to contain at least one hydrotreating catalyst disclosed herein. The vessel is preferably configured for gas-phase operation. The second hydrotreating unit HU2 may include beds of one or more hydrotreating catalysts, preferably in a fixed-bed configuration. The second hydrotreating unit HU2 can operate adiabatically, isothermally, non-adiabatically, non-isothermally, or a combination thereof. The second hydrotreating unit HU2 may contain more than one vessel. Each of such vessels is considered a hydrogenation reactor.

[0124] The heated gas stream S7 can be brought into contact with the at least one hydrotreating catalyst in an upward, downward, radial, or combined manner. Preferably, the heated gas stream S7 is brought into contact with the at least one hydrotreating catalyst in a downward flow.

[0125] Preferably, the heated gas stream S7 enters the at least one hydrogenation reactor in the second hydrogenation treatment unit HU2 from the top section.

[0126] The at least one hydrotreating catalyst can be any catalyst (e.g., a commercially available hydrotreating catalyst) for the hydrogenation of C-C double bonds (e.g., olefins, dienes) and heteroatom hydrogenation. For this purpose, suitable hydrotreating catalysts are selected from the group consisting of or composed of: molybdenum catalysts (“Mo catalysts”), cobalt-molybdenum catalysts (“Co-Mo catalysts”), nickel-molybdenum 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, and molybdenum sulfides. Suitable catalysts further comprise a support, preferably an inorganic support selected from the group consisting of: silica, alumina, silica-alumina, magnesium oxide, clay, and mixtures thereof. Other suitable hydrotreating catalysts are, for example, zeolites containing one or more metals.

[0127] More preferably, the at least one hydrotreating catalyst is selected from the group consisting of molybdenum catalysts, cobalt-molybdenum catalysts, and cobalt-tungsten catalysts. These catalysts are the most suitable for use in the desired hydrotreating reaction (step (vii) of the method according to the invention) in the second hydrotreating unit HU2. Most preferably, the cobalt-molybdenum catalyst is used in the at least one hydrogenation reactor in the second hydrotreating unit HU2, preferably when the heated gas stream S7 enters the at least one hydrogenation reactor in the second hydrotreating unit HU2 from the top section.

[0128] More than one of the aforementioned hydrogenation catalysts can be used together in the second hydrogenation unit HU2, for example, by mixing them together or by using them as separate catalyst stacks, each of which contains a type of catalyst, for example in the order of stack a (with catalyst A) / stack b (with catalyst B).

[0129] In one aspect of the invention, at least a portion of the catalyst comprises a recycled catalyst.

[0130] The height and diameter of the at least one catalyst bed are selected based on reaction kinetics and optimal gas flow patterns and pressure drops. The at least one catalyst bed may consist of layers of one or more different solid absorbent materials and layers of one or more identical or different hydrogenation catalysts. The catalyst layers in the at least one catalyst bed may differ from each other in terms of particle size, shape, activity, or active sites. When using more than one catalyst bed, inert particles may be used above and below each bed to improve fluid distribution.

[0131] In the context of this invention, the at least one hydrotreating catalyst used in the second hydrotreating unit HU2 is preferably in the form of an extrusion, granules, rings, spherical particles or spheres, more preferably in the form of spherical particles or extrusions.

[0132] In the case where the at least one hydrogenation reactor (vessel) in the second hydrogenation treatment unit HU2 has at least two stages, the at least one hydrogenation treatment catalyst preferably has different particle sizes in the at least two stages and / or optionally has different shapes in the at least two stages.

[0133] Particle size here refers to particle size distribution, which is measured, for example, by sieving, laser diffraction, or other methods known in the art. Catalysts with desired particle size and optionally desired shape can be manufactured and used.

[0134] Hydrogenation is an exothermic reaction and therefore each stage of the reaction can be optionally cooled.

[0135] The second hydrogenation treatment unit HU2 can operate under various process conditions. For example, a heated gas stream S7 can be contacted with the at least one hydrogenation treatment catalyst at a temperature preferably from about 200°C to about 400°C, more preferably from about 250°C to about 380°C, and most preferably from about 280°C to about 360°C.

[0136] The temperature in the second hydrogenation processing unit HU2 is obtained by using a heated gas stream S7, which is further heated by a heating unit HU upstream of and fluidly connected to the second hydrogenation processing unit HU2.

[0137] In the process, the pressure in the second hydrogenation treatment unit HU2 is preferably in the range of about 1.0 to about 10 MPa (absolute value). The partial pressure of hydrogen gas upstream of the second hydrogenation treatment unit HU2 is in the range of about 5 bar to about 50 bar, more preferably about 10 bar to about 30 bar, and most preferably about 14 bar to about 20 bar.

[0138] The weight hourly space velocity (WHSV) of the heated gas stream S7 is preferably in the range of about 0.1 t / (m²). 3 Kat. •h) to approximately 5.0 t / (m 3 Kat. •h), more preferably about 0.5 t / (m 3 Kat. •h) to approximately 1.0 t / (m 3 Kat. •h).

[0139] More preferably, the product stream S8 or a portion thereof is not recycled (re-inserted) into the first hydrogenation treatment unit HU1 and / or the second hydrogenation treatment unit HU2.

[0140] There is no need to recycle a portion of the product stream S8 or a portion thereof into the first hydrogenation unit HU1, because the gas stream S6 is sufficiently stable relative to undesirable polymerization, and therefore, the gas stream S6 can be further heated in the heating device HD for insertion into the second hydrogenation unit HU2. This makes it possible to establish the first hydrogenation unit HU1 (including the liquid recirculated stream S3') and the second hydrogenation unit HU2 (including the recirculated gas) for "one-pass capacity," meaning that stream S1 (and its stream obtained by conversion in a separate process unit) passes through the first hydrogenation unit HU1 (which exits as stream S6) and the second hydrogenation unit HU2 only once, and then exits the second hydrogenation unit HU2 as stream S6 (converted).

[0141] The method according to the invention further includes optional step (iv) shown in Figure 3 middle.

[0142] Next, in an optional step (viii) of the method according to the invention, the product stream S8 flows to a section of the at least one optional superheater (SH) adapted to transfer heat from the product stream S8 to a gas stream S3 flowing in a fluid separation section of the at least one optional superheater (SH), adapted to transfer heat from the product stream S8 to the gas stream S3.

[0143] Thus, the product stream S8 is converted into a cooled product stream S8b, and the gas stream S3 is converted into a superheated gas stream S5.

[0144] The method according to the invention further includes optional steps (iv), (viii), and (x) as shown in Figure 4 middle.

[0145] Preferably, the washing water stream S15 is fed into the product stream S8 or product stream S8b. Thus, NH4Cl, NH4F, NH4Br, NH4I, and NH4SH (at least one of which can be formed in the second hydrogenation treatment unit HU2) are transferred from the product stream S8 to stream S8a. Figure 2 and 3 ) or stream S8b ( Figure 4 In the process, stream S8a or S8b contains at least one of NH4Cl, NH4F, NH4Br, NH4I, and NH4SH and / or the corresponding cations and anions. Subsequently, a portion of stream S8a or S8b containing at least one of NH4Cl, NH4F, NH4Br, NH4I, and NH4SH and / or the corresponding cations and anions is separated from liquid product stream S9 as wastewater stream S17 in separation unit SU. Figures 2 to 4 ).

[0146] Water stream S15 can be added continuously or discontinuously to product stream S8 or product stream S8b. When water stream S15 is added discontinuously to product stream S8 or product stream S8b, for example, when the characteristics of heat transfer within the condensation unit CU and / or separation unit SU change, this change indicates the formation of undesirable deposits of at least one of NH4Cl, NH4F, NH4Br, NH4I, and NH4SH within the second hydrogenation treatment unit HU2 and / or condensation unit CU and / or separation unit SU, and / or said undesirable deposits are identified by another means, such as based on a fixed maintenance schedule derived from experience with continuous use of the chemical equipment. Furthermore, when the deposition of the aforementioned salts is avoided, undesirable corrosion on metal surfaces and / or metal surfaces is reduced.

[0147] Next, in an optional step (ix), the washing water stream S15 is fed into the cooled product stream S8b, thereby forming a product stream S8c containing the washing water. Figure 4 The washing water of the washing water stream S15 is required to remove the aforementioned salts that may be formed as byproducts in the second hydrogenation treatment unit HU2. Such salts and / or corresponding cations and anions may then be included in product streams S8 and S8a, or in product stream S8 and sequentially cooled product streams S8b, S8c, and S8d from said product streams, and may be separated from the wastewater stream S17, in which said one or more salts are contained, in the liquid product stream S9 in the at least one separation unit SU according to the method of the invention (step (xii)).

[0148] Next, in an optional step (x) of the method according to the invention, a cooled product stream S8c containing wash water flows to a section of the evaporation unit EU, which is adapted to transfer heat from the cooled product stream S8c containing wash water to a liquid stream S1 (containing at least a portion of a gas stream S2 and an optional recirculated gas stream S11) flowing to a fluid separation section of the evaporation unit EU. Thus, stream S3 is formed (= evaporated liquid stream S1 containing at least a portion of the gas stream S2 and the optional recirculated stream S11). This optional method step is in Figure 4 As shown in the image.

[0149] Thus, the cooled product stream S8c containing washing water is converted into a further cooled product stream S8d, and the liquid stream S1 containing at least a portion of the gas stream S2 and the optional recirculated gas stream S11 is converted into a gas stream S3.

[0150] Optional steps (viii) and (x) may be applied to the method according to the invention, or both may be omitted, or either step (viii) or step (x) may be applied.

[0151] Next, in step (xi) of the method according to the invention, the product stream S8, or optionally one of the streams consisting of a cooled product stream S8b, a cooled product stream S8c containing washing water, and a further cooled product stream S8d, is condensed into a liquid product stream S9 in at least one condensation unit CU. This step is required to enable the separation of the recirculated gas stream S11 containing unconverted hydrogen from the first hydrogenation treatment unit HU1 and / or the second hydrogenation treatment unit HU2.

[0152] A condensing unit CU can be, for example, an apparatus in which one of a group of streams consisting of product stream S8 or optionally a cooled product stream S8b, a cooled product stream S8c containing wash water, and a further cooled product stream S8d is cooled by directly and / or indirectly contacting another stream having a lower temperature than one of the streams before contacting the two streams. A suitable condensing unit CU includes a heat exchanger with a cooling medium (such as air, cooling water, and other media having a suitable low temperature).

[0153] Most preferably, the at least one condensing unit CU is selected from the group consisting of an air cooler and a water cooler.

[0154] The at least one condensation unit CU is downstream of the at least one outlet of the second hydrogenation treatment unit HU2 and is fluidly connected to the at least one outlet of the second hydrogenation treatment unit HU2. Figure 2 and 3 ) or fluid connected to at least one evaporation unit EU ( Figure 4 ).

[0155] Next, in step (xii) of the method according to the invention, the product stream S9 is separated into a refined product stream S10 containing the desired C6-C8 aromatic hydrocarbons, a recirculated gas stream S11 containing unconverted hydrogen in the first hydrogenation treatment unit HU1 and the second hydrogenation treatment unit HU2, and a wastewater stream S17.

[0156] Then, the recirculated gas stream S11 is inserted into the evaporation unit EU, and the hydrogen contained therein, together with the hydrogen contained in the gas stream S2, is used for hydrogen reaction in the first hydrogenation treatment unit HU1 and the second hydrogenation treatment unit HU2.

[0157] It is beneficial to feed the recirculated gas stream S11 back to the evaporation unit EU to save a significant amount of hydrogen. This use of the recirculated gas stream S11, as described above, also facilitates the evaporation of components from the feed stream S1.

[0158] The ratio of "recirculated gas stream S11 to stream S1" is preferably around 300 Nm. 3 / t to approximately 2000 Nm 3 / t, more preferably 600 Nm 3 / t to approximately 1400 Nm 3 Between / t.

[0159] To maintain high H2 partial pressures in the first hydrogenation unit HU1 and the second hydrogenation unit HU2, preferably, when the H2 concentration in stream S2 is below 99.9% by volume, a purge gas stream from the recirculated gas stream S11 can be used to prevent the accumulation of inert gas components such as N2, CH4, and C2H6 in the recirculated gas stream S11. The purge gas stream is part of the recirculated gas stream S11 and is optionally removed from the recirculated gas stream S11 to prevent undesirable accumulation (concentration increase) of the inert gas components.

[0160] Wastewater stream S17 contains at least one salt selected from the group consisting of NH4F, NH4Cl, NH4Br, NH4I and NH4SH, which can be formed as a byproduct in the second hydrogenation treatment unit HU2.

[0161] Preferably, the wastewater stream S17 is subjected to wastewater treatment, for example, by separating dissolved H2S and NH3 in an acidic water stripping unit, and then the wastewater is transferred to a wastewater treatment facility.

[0162] The separation unit SU is downstream of the at least one condensation unit CU and is fluidly connected to the at least one condensation unit CU.

[0163] The separation unit SU can be, for example, a liquid-liquid-vapor separation unit, preferably one or more of a hydrocyclone, a settling tank, and a centrifuge, more preferably one or more of a settling tank and / or a centrifuge.

[0164] Next, in step (xiii) of the method according to the invention, the purified product stream S10 is subjected to distillation in the distillation unit DU to separate the purified product stream S10 into a stable product stream S12 leaning from high-boiling components, a gas stream S13 and a stream S14 containing high-boiling components.

[0165] A stable product stream S12 is suitable for the aromatic hydrocarbon extraction unit AEU and the gas stream S13, which contains gaseous components dissolved in the product stream S10. These gaseous components need to be removed from the purified product stream before separating the individual C6-C8 aromatic hydrocarbons contained therein.

[0166] Gas stream S13 exits distillation unit DU as top product and contains at least one of the following gases: H2, CH4, C2H6, C3H8, H2S, NH3, HF, HCl, HBr, HI.

[0167] The stable product stream S12 contains the desired C6-C8 aromatics and exits the distillation unit DU as a second product stream.

[0168] The third product stream S14 contains high-boiling-point components that are not suitable for feeding into the aromatic hydrocarbon extraction unit (AEU).

[0169] The distillation unit DU can be, for example, at least one distillation column, at least one thin-film evaporator, or a combination thereof. Preferably, the distillation unit DU includes a distillation column. The distillation column can also be a partitioned column or a column with liquid or vapor side flow.

[0170] The distillation unit DU is downstream of the separation unit SU and is fluidly connected to the separation unit SU.

[0171] The distillation unit DU may also comprise two columns, such as a first stripping column and a second column. For example, a gaseous product stream S13 containing at least one of H2, CH4, C2H6, C3H8, H2S, NH3, HF, HCl, HBr, and HI is separated from the purified product stream S10 at the top of the first column. Next, a stable product stream S12 containing the desired C6-C8 aromatic hydrocarbons and a third product stream S14 are separated.

[0172] When the distillation unit DU contains one column, the stable product stream S12 preferably exits the column as a liquid side stream. When the distillation unit DU contains two columns, the stable product stream S12 preferably exits from the top of the second column.

[0173] Distillation is carried out at a temperature ranging from about 0°C to about 600°C, more preferably from about 20°C to about 400°C, and most preferably from about 80°C to about 250°C (the temperature range relates to an atmospheric pressure of 1.013 bar). The corresponding operating pressure of the at least one distillation column preferably ranges from about 0.1 bar (absolute value) to about 20 bar (absolute value), more preferably from about 0.5 bar to about 16 bar (absolute value), and most preferably from about 1 bar to about 14 bar (absolute value). When the pressure is ≠ 1.013 bar, the temperature is adjusted accordingly.

[0174] Next, in an optional additional step (xiv) of the method according to the invention, the stable product stream S12 is separated in at least one optional aromatic hydrocarbon extraction unit AEU into a benzene-rich stream S16a, a toluene-rich stream S16b, a C8 aromatic hydrocarbon-rich stream S16c (ethylbenzene, 1,2-xylene, 1,3-xylene, and 1,4-xylene), and a stream S16d leaning towards desired C6-C8 aromatic hydrocarbons and suitable, for example, as feedstock for cracking processes, preferably steam cracking. This at least one optional aromatic hydrocarbon extraction unit AEU in… Figures 2 to 4 As shown in the image.

[0175] The at least one optional aromatic hydrocarbon extraction unit AEU is downstream of and fluidly connected to the distillation unit DU, thereby enabling a stable product stream S12 to flow from the distillation unit DU into the at least one optional aromatic hydrocarbon extraction unit AEU.

[0176] The at least one optional aromatic hydrocarbon extraction unit AEU can be any unit operation suitable for separating a stable product stream S12 into a benzene-rich stream S16a, a toluene-rich stream S16b, a C8 aromatic hydrocarbon-rich stream S16c (ethylbenzene, 1,2-xylene, 1,3-xylene, and 1,4-xylene), and a stream S16d leaning towards desired C6-C8 aromatic hydrocarbons. For example, the at least one optional aromatic hydrocarbon extraction unit AEU may comprise at least one selective adsorption unit operation, at least one selective absorption unit operation, at least one extractive distillation unit operation, at least one solvent extraction followed by distillation, and combinations thereof.

[0177] Suitable optional aromatic hydrocarbon extraction units (AEUs) are commercially available, such as Uhde's Morphylane® extractive distillation process. For example, the stable product stream S12 is first split into C... 7- Classification and C 8+ Grade division. Next, C... 7- The fractions are fed to the extractive distillation stage, where the benzene-containing stream S16a and the toluene-containing stream S16b are combined with C from the stable product stream S12. 7- - Separation of non-aromatic compounds. The stable product stream S12 is separated by C... 8+ The fraction is fed directly to the 1,4-xylene circuit instead of using xylene and ethylbenzene as stream S14b extraction.

[0178] Flow S16a preferably contains at least 90 wt.% benzene, more preferably at least 99.8 wt.% benzene.

[0179] Flow S16b preferably contains at least 90 wt.% toluene, more preferably at least 99.9 wt.% toluene.

[0180] Flow S16c preferably contains at least 90 wt.% xylene and about 10 wt.% non-aromatic C. 8+ The components, more preferably at least 93 wt.% of xylene isomers and about 2.5 wt.% of non-aromatic C 8+ Components.

[0181] Stream S16d is suitable as a feedstock for cracking processes such as (fluid) catalytic cracking, thermal cracking, and steam cracking. Major reaction products from such cracking processes include ethylene, propylene, butene isomers, butadiene, C6-C8 aromatics, and pyrolysis gasoline. At least a portion of the pyrolysis gasoline can be used as a component in liquid stream S1, together with at least one type of plastic pyrolysis oil.

[0182] Optionally, stream S16d is used as a feedstock for producing syngas (containing CO and hydrogen) via partial oxidation and / or gasification processes. Such methods for producing syngas from feedstock are disclosed, for example, in Ullmann's Encyclopedia of Industrial Chemistry, Volume 16, Chapter: Gas Production, 2. Processes, pp. 443-455, 2012.

[0183] Optionally, the method according to the invention further includes the step (xv´):

[0184] Streams S16b and / or S16c are subjected to a hydroalkylation unit in at least one optional hydroalkylation unit HAU. In this optional step (xv'), toluene and / or xylene isomers and / or ethylbenzene are converted to benzene. Therefore, the benzene yield can be increased by the optional step (xv') in the method according to the invention.

[0185] Hydroalkylation of alkyl-substituted benzene derivatives to benzene and the corresponding hydroalkylation unit HAU are known in the art and described, for example, in HO Folkins' Ullmann's Encyclopedia of Industrial Chemistry, Volume 5, Chapter “Benzene”, pp. 246-251, 2012, and Industrielle organische Chemie, 3rd Edition, K. Weissermel, H.-J. Arpe, pp. 351-352, 1988, both of which are incorporated herein by reference.

[0186] The optional hydroalkylation step (xv´) can be operated as a thermal process (e.g., at about 550°C to about 800°C and at a pressure of about 30 bar to about 100 bar) or as a catalytic process (e.g., at a temperature of about 500°C to about 650°C and at a pressure of about 30 bar to about 50 bar in the presence of a catalyst such as Cr2O3 and / or Mo2O3 on a support such as alumina, or at a temperature of about 400°C to about 480°C in the presence of a Rh / Al2O3 (rhodium on an alumina support) catalyst).

[0187] The invention is further illustrated by the following set of embodiments and by combinations of embodiments derived from the dependent relationships and reverse references shown. In particular, it should be noted that in each instance in which a series of embodiments is mentioned, for example in the context of the term "method as described in any one of Embodiments 1 to 3," each embodiment in this series is intended to clearly disclose to a person skilled in the art that the wording of the term should be understood by a person skilled in the art to be synonymous with "method as described in any one of Embodiments 1, 2, and 3." Furthermore, it should be clearly noted that the following set of embodiments represents a suitable structural portion of the general description of preferred aspects of the invention and, therefore, appropriately supports the claims of the invention.

[0188] 1. A method for separating C6-C8 aromatic hydrocarbons from a feed stream containing at least one type of plastic pyrolysis oil, the method comprising the following steps:

[0189] (i) Providing a liquid stream S1 comprising at least one plastic pyrolysis oil, the liquid stream S1 further comprising a C6-C8 aromatic hydrocarbon, an organic compound comprising at least one heteroatom, and a compound having a C-C double bond and / or a C-C triple bond.

[0190] (ii) Provide stream S2 containing hydrogen gas.

[0191] (iii) At least a portion of the liquid stream S1 is evaporated in the evaporation unit EU in the presence of the stream S2 and the optionally recirculated gas stream S11, thereby forming a gas stream S3 comprising the stream S2, the optionally recirculated gas stream S11 and the evaporated portion of the liquid stream S1, and a liquid stream S4 comprising the portion of the unevaporated liquid stream S1 in the evaporation unit EU.

[0192] (iv) Optionally, the gas flow S3 may be superheated in the superheater SH, thereby forming a superheated flow S5.

[0193] (v) The gas stream S3 or optionally the superheated stream S5 is fed into a first hydrogenation unit HU1, in which at least a portion of the gas stream S3 or optionally at least a portion of the superheated stream S5 reacts with the hydrogen contained therein in a hydrogenation reaction, thereby forming a gas stream S6 containing C6-C8 aromatic hydrocarbons, organic compounds containing at least one heteroatom, and compounds having C-C double bonds and / or C-C triple bonds relative to the gas stream S3.

[0194] (vi) The gas stream S6 is heated in at least one heating device HD, thereby forming a heated gas stream S7.

[0195] (vii) The heated gas stream S7 is subjected to a second hydrogenation unit HU2, in which a product stream S8 is formed, the product stream S8 comprising C6-C8 aromatic hydrocarbons and being depleted relative to the gas stream S3 of organic compounds containing at least one heteroatom and further depleted of compounds having C-C double bonds and / or C-C triple bonds.

[0196] (viii) Optionally, heat is transferred from the product stream S8 to the gas stream S3 in the superheater SH, thereby forming a cooled product stream S8b.

[0197] (ix) The washing water stream S15 is fed into the product stream S8 continuously or discontinuously to form a stream S8a that optionally contains washing water, or the washing water stream S15 is fed into the cooled product stream S8b continuously or discontinuously to form a cooled product stream S8c that optionally contains washing water.

[0198] (x) Optionally, in the evaporation unit EU, heat is transferred from the cooled product stream S8c containing wash water to the liquid stream S1, the stream S2 containing H2, and the stream S11, thereby forming a further cooled product stream S8d.

[0199] (xi) The product stream S8a, optionally containing wash water, or optionally selected from the group consisting of the cooled product stream S8b, the cooled product stream S8c, and the further cooled product stream S8d optionally containing wash water, is condensed in the condensation unit CU, thereby forming a product stream S9, which comprises a liquid phase and a gas phase.

[0200] (xii) The liquid product stream S9 is separated in the separation unit SU into a liquid product stream S10, a recirculated gas stream S11, and optionally a wastewater stream S17, wherein the recirculated gas stream S11 contains hydrogen and wherein at least a portion of the recirculated gas stream S11 is fed into the evaporation unit EU.

[0201] (xiii) Optionally, the purified product stream S10 is fed into a distillation unit DU, in which the purified product stream S10 is separated into a stable product stream S12 and a gas stream S13.

[0202] 2. The method according to Example 1, wherein the at least one plastic pyrolysis oil is produced by pyrolysis of plastic waste.

[0203] 3. The method according to Example 1 or 2, wherein the liquid stream S1 preferably contains at least 15 wt.-% of C6-C8 aromatic hydrocarbons, more preferably at least 50 wt.-% of C6-C8 aromatic hydrocarbons, and most preferably at least 80 wt.-% of C6-C8 aromatic hydrocarbons.

[0204] 4. The method according to any one of Examples 1 to 3, wherein the at least one plastic pyrolysis oil in the liquid stream S1 preferably contains at least 15 wt.-% of C6-C8 aromatic hydrocarbons, more preferably at least 50 wt.-% of C6-C8 aromatic hydrocarbons, and most preferably at least 80 wt.-% of C6-C8 aromatic hydrocarbons.

[0205] 5. The method according to any one of Examples 1 to 5, wherein the C6-C8 aromatic hydrocarbon in the liquid stream S1 is selected from the group consisting of: benzene, toluene, 1,2-xylene, 1,3-xylene, 1,4-xylene, ethylbenzene, and styrene.

[0206] 6. The method according to any one of Examples 1 to 5, wherein the organic compound containing at least one heteroatom is selected from organic compounds containing at least one of the following heteroatoms: nitrogen, oxygen, sulfur, chlorine, bromine, fluorine, and iodine.

[0207] 7. The method according to any one of Examples 1 to 6, wherein the at least one plastic pyrolysis oil in the liquid stream S1 has a bromine value of about 2 g Br2 / 100 g to about 150 g Br2 / 100 g (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).

[0208] 8. The method according to any one of Examples 1 to 7, wherein the hydrogen contained in stream S2 is formed by water electrolysis and / or methane pyrolysis using electrical energy (preferably generated from a renewable source and / or low-carbon energy), preferably using methane pyrolysis from a renewable source.

[0209] 9. The method according to any one of Examples 1 to 8, wherein the liquid stream S1, the recirculated gas stream S11 and the stream S2 are mixed before being fed into the evaporation unit EU and / or mixed in the evaporation unit EU.

[0210] 10. The method according to any one of embodiments 1 to 9, wherein the evaporation unit EU includes at least one device selected from the group consisting of a staged evaporator, a falling film evaporator, and a pre-evaporator, preferably wherein the evaporation unit EU consists of at least one pre-evaporator and at least one staged evaporator.

[0211] 11. The method according to any one of Examples 1 to 10, wherein the liquid stream S1 is evaporated together with a recirculated gas stream S11 added to the liquid stream S1 before and / or during evaporation.

[0212] 12. The method according to any one of Examples 1 to 11, wherein the liquid stream S4 is converted into syngas in at least one vaporizer and / or through a partial oxidation reaction unit.

[0213] 13. The method according to any one of Examples 1 to 12, wherein the superheater SH is preferably a heat exchanger, more preferably a crustal tube heat exchanger or a spiral heat exchanger.

[0214] 14. The method according to any one of Examples 1 to 13, wherein the gas stream S3 is superheated in the superheater SH such that the temperature of the gas stream S3 is preferably increased by about 2°C to about 50°C, more preferably by about 5°C to about 40°C, and most preferably by about 10°C to about 30°C relative to the temperature at which the gas stream S3 leaves the evaporation unit EU.

[0215] 15. The method according to any one of Examples 1 to 14, wherein the first hydrogenation treatment unit HU1 comprises at least one heterogeneous catalyst.

[0216] 16. The method according to any one of Examples 1 to 15, wherein the at least one heterogeneous catalyst is selected from the group consisting of or composed of: nickel-molybdenum catalysts and nickel-tungsten catalysts, further comprising a support, preferably an inorganic support selected from the group consisting of: silica, alumina, silica-alumina, magnesium oxide, clay, and mixtures thereof.

[0217] 17. The method according to any one of Examples 1 to 16, wherein the process temperature in the first hydrogenation treatment unit HU1 is preferably in the range of about 140°C to about 250°C, more preferably about 140°C to about 200°C, and most preferably about 170°C to about 190°C.

[0218] 18. The method according to any one of Examples 1 to 17, wherein the heated gas stream S7 preferably has a temperature in the range of about 200°C to about 400°C, more preferably about 240°C to about 360°C, and most preferably about 260°C to about 350°C.

[0219] 19. The method according to any one of Examples 1 to 18, wherein the at least one heating device is selected from the group consisting of a direct-fired heater, an electrically driven furnace, a heat exchanger, and combinations thereof.

[0220] 20. The method according to any one of Examples 1 to 19, wherein the second hydrogenation treatment unit HU2 comprises at least one fixed-bed reactor.

[0221] 21. The method according to any one of Examples 1 to 20, wherein the second hydrogenation treatment unit HU2 comprises at least one heterogeneous catalyst, preferably wherein the at least one heterogeneous catalyst is selected from the group consisting of or composed of: molybdenum catalyst, cobalt-molybdenum catalyst and cobalt-tungsten catalyst.

[0222] 22. The method according to any one of Examples 1 to 21, wherein the temperature of the hydrogenation reaction in the second hydrogenation treatment unit HU2 is preferably in the range of about 200°C to about 400°C, more preferably about 250°C to about 380°C, and most preferably about 280°C to about 360°C.

[0223] 23. The method according to any one of Examples 1 to 22, wherein the pressure of the hydrogenation reaction in the second hydrogenation treatment unit HU2 is preferably in the range of about 1 bar to about 200 bar, more preferably about 10 bar to about 150 bar and most preferably 15 bar to 60 bar, and / or the partial pressure of hydrogen in front of the hydrogenation treatment unit HU1 is in the range of about 5 bar to about 50 bar, more preferably about 10 bar to about 30 bar and most preferably about 14 bar to about 20 bar.

[0224] 24. The method according to any one of Examples 1 to 23, wherein the weight hourly space velocity (WHSV) of the heated gas stream S7 is preferably in the range of about 0.1 t / (m²). 3 Kat. •h) to approximately 5.0 t / (m 3 Kat. •h), more preferably about 0.5 t / (m3 Kat. •h) to approximately 1.0 t / (m 3 Kat. •h).

[0225] 25. The method according to any one of Examples 1 to 24, wherein the organic compound containing at least one heteroatom in the liquid stream S1 is at least 90%, more preferably at least 95%, and most preferably at least 99% depleted in the second hydrogenation treatment unit HU2.

[0226] 26. The method according to any one of Examples 1 to 25, wherein the at least one condensing unit CU is selected from the group comprising a heat exchanger having a cooling medium such as air, cooling water, or other medium having a suitable low temperature.

[0227] 27. The method according to any one of Examples 1 to 26, wherein the at least one separation unit SU is selected from the group consisting of hydrocyclones, settling tanks, centrifuges and combinations thereof, more preferably from settling tanks and / or centrifuges.

[0228] 28. The method according to any one of Examples 1 to 27, wherein the distillation unit DU preferably comprises a distillation column.

[0229] 29. The method according to any one of Examples 1 to 28, wherein the distillation in the distillation unit DU is carried out at a temperature (temperature range relating to atmospheric pressure of 1.013 bar) in the range of about 0°C to about 600°C, more preferably about 20°C to about 400°C, and most preferably about 80°C to about 250°C, and at a pressure in the range of about 0.1 bar (absolute value) to about 20 bar (absolute value), more preferably about 0.5 bar to about 16 bar (absolute value), and most preferably about 1 bar to about 14 bar (absolute value).

[0230] 30. The method according to any one of Examples 1 to 29, wherein the stable product stream S12 preferably contains about 60 wt.-% to about 99 wt.-%, more preferably about 75 wt.-% to about 85 wt.-% of C6-C8 aromatic hydrocarbons contained in the liquid stream S1.

[0231] 31. The method according to any one of Examples 1 to 30, wherein, in a further step (xiv), C6-C8 aromatic hydrocarbons are separated from the stable product stream S12 in at least one optional aromatic hydrocarbon extraction unit AEU to obtain streams S16a, S16b, S16c and S16d.

[0232] 32. The method according to any one of Examples 1 to 31, wherein, in a further step (xiv), C6-C8 aromatic hydrocarbons are separated from the stable product stream S12 by extractive distillation in at least one optional aromatic hydrocarbon extraction unit AEU to obtain streams S16a, S16b, S16c and S16d.

[0233] 33. The method according to any one of Examples 1 to 32, wherein C6-C8 aromatics are separated from the stable product stream S12 in at least one aromatic hydrocarbon extraction unit AEU to obtain a stream S16a containing at least 90 wt.-% benzene, a stream S16b containing at least 90 wt.-% toluene, a stream S16c containing at least 90 wt.-% C8 aromatics selected from the group consisting of 1,2-xylene, 1,3-xylene, 1,4-xylene and ethylbenzene, and a stream S16d leaning from C6-C8 aromatics.

[0234] 34. The method according to any one of Examples 1 to 33, wherein the stream S14 is further subjected to a cracking process and / or a partial oxidation process or a gasification process selected from catalytic cracking, thermal cracking and steam cracking.

[0235] 35. A chemical apparatus for separating C6-C8 aromatic hydrocarbons from a feed stream containing at least one type of plastic pyrolysis oil, the apparatus comprising...

[0236] (i) Evaporation unit EU,

[0237] (ii) Optionally, a superheater SH downstream of the evaporation unit EU.

[0238] (iii) A first hydrogenation treatment unit HU1, the first hydrogenation treatment unit HU1 comprising at least one inlet and at least one outlet, the first hydrogenation treatment unit HU1 being downstream of the evaporation unit EU or the optional superheater SH, and the at least one inlet of the first hydrogenation treatment unit HU1 being fluidly connected to the evaporation unit EU or the optional superheater SH.

[0239] (iv) At least one heating unit HD, which is downstream of and fluidly connected to the at least one outlet of the first hydrogenation treatment unit HU1.

[0240] (v) A second hydrogenation treatment unit HU2 having at least one inlet and at least one outlet, the second hydrogenation treatment unit HU2 being downstream of the at least one heating unit HD, and the at least one outlet of the hydrogenation treatment unit HU2 being fluidly connected to the heating unit HD.

[0241] (vi) A condensation unit CU, which is downstream of the second hydrogenation treatment unit HU2 and fluidly connected to at least one outlet of the second hydrogenation treatment unit HU2.

[0242] (vii) Separation unit SU, which is downstream of and fluidly connected to the condensation unit CU, and

[0243] (viii) Optionally, a distillation unit DU is downstream of and fluidly connected to the separation unit SU; and optionally, an aromatic hydrocarbon extraction unit AEU is downstream of the optional distillation unit and fluidly connected to stream S12.

[0244] 36. Use of the chemical equipment according to Example 35 for the method according to any one of Examples 1 to 34.

[0245] 37. A computer program comprising instructions which, when executed by a chemical apparatus according to embodiment 35, cause the system to perform the method according to any one of embodiments 1 to 34.

[0246] It should be clearly noted that the above set of embodiments represents appropriate structural portions of a general description of preferred aspects of the invention, and therefore appropriately supports but does not represent the claims of the invention.

[0247] Stream S14 can be further used as a feedstock for a partial oxidation process and thus converted into a syngas stream containing H2, CO and CO2.

[0248] The stream S16d can be further used as feedstock for a cracking process, preferably a steam cracking process, and thus converted into a stream containing at least one olefin and / or at least one C6-C8 aromatic hydrocarbon, wherein the at least one olefin is preferably selected from the group consisting of ethylene, propylene, n-butene, 2-butene and butadiene.

[0249] The C6-C8 aromatic hydrocarbons contained in the corresponding streams S16a, S16b and S16c can be further used as feedstocks in downstream processes.

[0250] The present invention further relates to a method, according to the method described herein, comprising the following additional steps:

[0251] (xv) The stream S14, which is obtainable by step (iii) as described herein or which is preferably obtained by step (iii) as described herein, and / or the stream S16 a, b, c or d, which is obtainable by step (xiv) as described herein or which is preferably obtained by step (xiv) as described herein, and / or the chemical material that is obtainable or obtainable by the method according to any one of the preceding claims, is converted to obtain a monomer, polymer or polymer product.

[0252] The conversion steps to obtain chemical materials, monomers, polymers, or polymer products may include one or more synthetic steps and can be carried out by conventional synthesis and techniques well known to those skilled in the art. Those skilled in the art, independent of those evaluating the novelty and inventive step of the independent claim, preferably come from one or more technical fields of pyrolysis, gasification, re-monomerization, depolymerization, synthesis, production of monomers, polymers, and polymer compounds, and / or their further processing (e.g., extrusion, injection molding). Examples of the conversion steps are described in "Industrial Organic Chemistry", Volume 3, Wiley-VCH, 1997, ISBN: 978-3-527-28838-0; "Kunststoffhandbuch", Volume 11 of 17 sub-volumes, Carl Hanser Verlag; especially Volume 6, "Polyamide", 1st edition, 1966; Volume 7, "Polyurethane", 3rd edition, 1993; and Volume 8, "Polyester", 1st edition, 1973; "Industrial Organic Chemistry", Volume 3, Wiley-VCH, 1997, ISBN: 978-3-527-28838-0; "Injection Molding Reference" Injection Molding Reference Guide, 4th Edition, CreateSpace Independent Publishing Platform, 2011, ISBN: 978-1466407824; EP0989146 (A1); EP1460094 (A1); WO 2006034800 (A1); EP1529792 (A1); WO 2006042674 (A1); EP0364854 (A2); US5506275 (A); EP0897402 (A1); WO 2015082316 (A1); WO 2021021855 (A1); WO2021126938 (A1); WO 2021021902 (A1); WO 2021092311 (A1); WO 2008155271 (A1); WO2013139827 (A1), each of which is incorporated herein by reference.

[0253] In a preferred embodiment, the monomer is a diol or polyol, preferably butanediol; an aldehyde, preferably formaldehyde; a diisocyanate or polyisocyanate, preferably methylene diphenyl diisocyanate (MDI), polymeric methylene diphenyl diisocyanate (pMDI), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI) or isophorone diisocyanate (IPDI); an amide, preferably caprolactam; an olefin, preferably styrene, ethylene and norbornene; an alkyne; a (di) ester, preferably methyl methacrylate; a monoacid or diacid, preferably adipic acid or terephthalic acid; a diamine, preferably hexamethylenediamine or nonadiamine; or a sulfone, preferably 4,4'-dichlorodiphenyl sulfone.

[0254] In a preferred embodiment, the polymer and / or the polymer product comprises polyamide (PA), preferably PA 6 or PA 66; a polyisocyanate addition polymer, 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), polyacrylonitrile butadiene styrene (ABS), polystyrene acrylonitrile (SAN), polyacrylate styrene acrylonitrile polyacrylate (ASA), polytetrafluoroethylene (PTFE), poly(methyl acrylate) (PMA), poly(methyl methacrylate) (PMMA), polybutadiene (BR, PBD), poly(cis-1,4-isoprene), poly(trans-1,4-isoprene) Poly(pentadiene), polyoxymethylene (POM), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polybutylene adipate (PBAT), polyester (PES), polyethersulfone (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), polyetheretherketone (PEEK), poly(p-phenylene oxide) (PPO), poly(p-phenylene ether) (PPE); or copolymers or mixtures thereof.

[0255] In a preferred embodiment, the polymer and / or polymer product is then converted into the following or a portion thereof:

[0256] - Automotive parts, preferably cylinder head covers, engine hoods, turbocharger housings, turbocharger baffles, intake pipes, intake manifolds, connectors, gears, fan wheels, coolant tanks, housings, heat exchanger housing parts, coolant coolers, turbocharger coolers, thermostats, water pumps, radiators, fasteners, battery system parts for electric vehicles, dashboards, steering column switches, seats, headrests, center consoles, transmission components, door modules, A, B, C, or D pillar covers, spoilers, door handles, exterior mirrors, windshield wipers, windshield wiper protection housings, decorative grilles, cover strips, roof rails, window frames, sunroof frames, antenna panels, headlights and taillights, engine hoods, cylinder head covers, intake manifolds, airbags, cushioning pads or coatings;

[0257] - Fabrics, preferably shirts, trousers, sweaters, boots, shoes, shoe soles, bodysuits or jackets;

[0258] - Electrical components, preferably electrical or electronic passive or active components, circuit boards, printed circuit boards, housing components, foil, wires, switches, plugs, sockets, distributors, relays, resistors, capacitors, inductors, spools, lamps, diodes, LEDs, transistors, connectors, voltage regulators, integrated circuits (ICs), processors, controllers, memory, sensors, microswitches, micro buttons, semiconductors, reflector housings for light-emitting diodes (LEDs), fasteners, gaskets, bolts, strips, slide-in guides, screws, nuts, membrane hinges, spring hooks (clamp-in) or spring tongues;

[0259] - Consumer goods, agricultural products, or pharmaceutical products, preferably tennis strings, climbing ropes, bristles, brushes, artificial turf, 3D printed filaments, lawnmowers, zippers, hook and loop fasteners, paper machine fabrics, extrusion coatings, fishing lines, fishing nets, offshore lines and ropes, vials, syringes, ampoules, bottles, sliding elements, spindle nuts, chain conveyors, sliding bearings, rollers, wheels, gears, ring gears, screws and spring dampers, hoses, pipes, cable sheaths, sockets, switches, cable ties, fan wheels, carpets, cosmetic boxes or bottles, mattresses, cushioning pads, insulating materials, detergents, dishwasher detergent blocks or powders, shampoos, shower gels, bath gels, soaps, fertilizers, fungicides, or pest control agents;

[0260] - For packaging in the food industry, single-layer or multi-layer blown film, cast film (single-layer or multi-layer), biaxial stretch film, or laminated film are preferred; or

[0261] - Structural components, preferably rotor blades, insulating materials, frames, housings, walls, coatings, or partition walls.

[0262] In a preferred embodiment, the content of stream S1 in the monomer, polymer, or polymer product is 1 wt% or more, preferably 2 wt% or more, more preferably 5 wt% or more, more preferably 15 wt% or more, more preferably 30 wt% or more, more preferably 40 wt% or more, more preferably 60 wt% or more, more preferably 80 wt% or more, more preferably 90 wt% or more, more preferably 95 wt% or more; and / or wherein the content of stream S1 in the monomer, polymer, or polymer product is 100 wt% or less, preferably 95 wt% or less, more preferably 90 wt% or less, more preferably 50 wt% or less, more preferably 25 wt% or less, more preferably 10 wt% or less; and preferably, wherein the content is based on a chain of custody model (identity preservation and / or segregation and / or mass balance and / or book and claim chain of custody). The models are preferably determined based on quality balance and preferably according to the International Sustainability and Carbon Certification (ISCC) standard.

[0263] The present invention will be further explained through the following non-limiting examples. Example

[0264] Using ASPEN Plus TM The V11 simulation software is combined with a kinetic model to simulate a method for separating C6-C8 aromatic hydrocarbons from a feed stream containing plastic pyrolysis oil (comparative example and method according to the invention) to calculate the conversion rates in the first hydrotreating unit HU1 and the second hydrotreating unit HU2.

[0265] Comparison Examples

[0266] The comparison examples are used to obtain information from... Figure 1 The present invention illustrates a method and chemical equipment for separating C6-C8 aromatic hydrocarbons from plastic pyrolysis oil obtained from the pyrolysis of plastic waste. This method reflects the methods disclosed in AU 2021 / 222788 A1 and FR3118629A1.

[0267] The process conditions for the first hydrogenation treatment unit HU1 are summarized in Table 1:

[0268]

[0269]

[0270] The composition of liquid stream S1 in hydrotreating unit HU1 is described in Table 2, wherein the diene component concentration is 0.8 wt.-% and the olefin component concentration is 3.23 wt.%. The total content of C6-C8 aromatic compounds is 73.13 wt.-%. The composition of liquid stream S1 is the same as that used in the following examples according to the invention. Liquid stream S1 is treated in hydrotreating unit HU1 under the conditions described in Table 1.

[0271] The catalyst in the hydrogenation unit HU1 is a Ni-Mo catalyst on an alumina support.

[0272] The pressure at the reactor outlet of the first hydrogenation unit HU1 is 64 bar (absolute value), and the reactor temperature is increased from 119°C (reactor inlet temperature) to 150°C (reactor outlet temperature) through adiabatic temperature rise. Under these conditions, typical trickle bed flow of the liquid phase over the (solid) catalyst occurs, which is desirable.

[0273] From the hydrogenation treatment unit HU2 ( Figure 1 The ratio of "liquid feed S1 : liquid recirculation stream S11" is 1 : 1. The concentration of diene component with 0.44 mol.% is 2.9 times the concentration of diene component in stream S3 according to the example of the invention, which has 0.15 mol.% (see below).

[0274] The 31°C temperature increase (from reactor inlet to reactor outlet of the first hydrogenation treatment unit HU1) is comparable to the higher 30°C in the example according to the invention (see below). The much higher diene component concentration and liquid-state flow, compared to the vapor flow in the example according to the invention (see below), result in higher polymer formation during treatment and thus promote blockage, both of which are undesirable.

[0275] The WHSV (weight hourly space velocity) of liquid flow S1 is 0.5 t / (m²). 3 Kat. h). The chemical hydrogen consumption in the first hydrogenation unit HU1 is 23 Nm. 3 / t. The molar ratio of "feed to the first hydrotreating unit HU1 containing H2 stream S2 : chemical hydrogen consumption" is 1.08 : 1. A small excess of hydrogen ensures sufficient catalyst activity to achieve 98% conversion of diene components and 37% conversion of olefin components (stream S3). Under these operating conditions and with the catalyst used (Ni-Mo catalyst on alumina support), no hydrogenation of aromatic components will occur. The reactor products of the hydrotreating unit HU1 ( Figure 1 The feed (S3) is directly fed into the hydrotreating unit HU2.

[0276] The process conditions in the second hydrogenation unit HU2 are summarized in Table 3:

[0277]

[0278] Table 3 shows the process conditions for the hydrotreating unit HU2. The pressure at the reactor outlet is 63 bar (absolute). The ratio of "HU2 internal recirculated gas S6'' : feed stream S6" is 392 Nm. 3 / t, and the reactor inlet temperature of the second hydrotreating unit HU2 is 342°C. Under these conditions, the feed stream S3 of the hydrotreating unit HU2 is completely evaporated.

[0279] Due to the feed stream S6 of the hydrotreating unit HU2 < A low content of diene components (0.01 wt.%) does not result in undesirable polymerization and scaling during complete evaporation. Through the exothermic hydrogenation reaction mentioned above, the reactor temperature increases from an inlet temperature of 342°C to an outlet temperature of 355°C. The temperature increase is 13°C because 69% of the olefins in hydrotreatment unit HU1 have already been hydrogenated and diluted 1:1 by the liquid feed S1 : liquid recirculation stream S11 from hydrotreatment unit HU2.

[0280] To limit undesirable hydrogenation of aromatic rings, this low exothermic temperature increase of 13°C is beneficial. A hydrogen partial pressure of 39 bar (absolute value) in the reactor is sufficient to ensure adequate hydrogenation activity while avoiding undesirable aromatic ring hydrogenation. The catalyst in the second hydrotreating unit HU2 is a standard Co-Mo catalyst on an alumina support, which exhibits sufficient diene and olefin hydrogenation, desulfurization, denitrification, and dehalogenation activity, as well as very low aromatic ring hydrogenation activity, but requires a higher temperature than the Co-Mo catalyst on an alumina support in the examples below according to the invention. The loss of aromatic components through aromatic ring hydrogenation is <0.5%. The WHSV of the feed stream S3 is 0.7 t / (m³). 3 Kat. h).

[0281] The cooled condensate reaction product S4 leaving the second hydrogenation treatment unit HU2 is fed back to the hydrogenation treatment unit HU1 at a 1:1 ratio along with the liquid feed stream S1 to dilute the liquid feed stream S1 before it enters the first hydrogenation treatment unit HU1. The necessity and effect of dilution in the first hydrogenation treatment unit HU1 have been described above.

[0282] The next step is to distill in the distillation unit DU before feeding the product stream S12 into the aromatic hydrocarbon extraction unit (AEU) to remove unwanted high-boiling components. High-boiling components are undesirable in the AEU because they accumulate in the solvent and contaminate it. Therefore, the efficiency of aromatic hydrocarbon extraction in the AEU will be affected.

[0283] The results of distillation in distillation unit DU are shown in Table 4 (“Top Distillate Fraction” = Stream S12, “Yield of C6-C8 Aromatic Compounds” = Total mass of C6-C8 aromatic compounds in Stream S12 : Total mass of C6-C8 aromatic compounds in Stream S8) 100):

[0284]

[0285] In distillation unit DU, the light boiling fraction, containing the majority of C6-C8 aromatic components, enters the overhead distillate. This constitutes 78 wt.-% of the feed stream S4 to distillation unit DU, thus increasing the C6-C8 aromatic component content from 69.5 wt.-% to 83.0 wt.-%. The high-boiling components are separated by the bottom stream S5. The valuable product, the overhead distillate S4, is 78 wt.-% of the feed stream S3 to distillation unit DU and contains 93 wt.-% of C6-C8 aromatic components.

[0286] The feed stream S12 from the head section of the distillation unit DU is then fed into the aromatic hydrocarbon extraction unit AEU. Here, pure benzene (> 99 wt.-%), pure toluene (> 99 wt.-%), and the xylene / ethylbenzene mixture (> 93 wt.-%) are separated by an extractive distillation process. The remaining stream S8 is lean for benzene, toluene, and the xylene / ethylbenzene mixture and contains paraffinic components, cycloalkanes, and C8+ aromatic hydrocarbons.

[0287] Example (of this invention)

[0288] In this example, according to Figure 2 The schematic diagram in the figure simulates the method according to the present invention.

[0289] Table 5 Process conditions in the evaporation section EU

[0290]

[0291]

[0292] The composition of the liquid stream S1 fed into the first hydrotreating unit HU1 is described in Table 6, wherein the diene concentration is 0.8 wt.-% and the olefin concentration is 3.23 wt.-%. The total content of C6-C8 aromatics is 73.13 wt.-%. Liquid stream S1 is processed in the evaporation section EU. Stream S1 is evaporated to 1240 Nm³ in a mixture of fresh H2 stream S2 and recirculated gas stream S11. 3 / t stream S1. The resulting saturated vapor mixture stream S3 has a dew point of 190°C at 21.9 bar (absolute value). 97.8 wt.% of the feed stream S1 is evaporated.

[0293] In the next superheater SU, the saturated vapor phase flow S3 is superheated to a temperature of 10°C to 200°C to ensure that there is still no liquid entrainment in the chemical plant and that condensation does not occur due to heat loss.

[0294] Table 7 Process conditions in the first hydrogenation treatment unit HU1:

[0295]

[0296] The catalyst in the first hydrotreating unit HU1 is a Ni-Mo catalyst on an alumina support, which allows for the reaction conditions specified in the vapor phase. At 21.8 bar (absolute value) and 82.48 vol% H2, the inlet H2 partial pressure of the first hydrotreating unit HU1 is 18 bar (absolute value). This hydrogen partial pressure is sufficient to ensure high hydrogenation activity and good selectivity of the catalysts in the first and second hydrotreating units HU1 and HU2.

[0297] In the first hydrogenation treatment unit HU1, the pressure at the reactor inlet is 21.8 bar (absolute value), and the reactor temperature is increased from 200°C reactor inlet temperature to 230°C reactor outlet temperature by adiabatic temperature increase.

[0298] Diluting the inlet stream S1 with fresh H2 stream S2 and recirculated gas stream S11 affects the concentration of low-dien components by 0.15 mol-% and the content of olefin components by 0.67 mol-%. In the comparative example, the molar concentration of dien components is 2.9 times higher. The high dilution at gas phase pressure, along with the low-dien component concentration, ensures that undesirable polymer formation and fouling are avoided during treatment.

[0299] The reactor of the hydrogenation treatment unit HU1 operates in an above-flow mode. Therefore, stream S5 enters the at least one reactor of the first hydrogenation treatment unit HU1 in the bottom region of the at least one reactor and exits the at least one reactor as stream S6 in the top section of the at least one reactor.

[0300] The WHSV (weight hourly space velocity) of liquid flow S1 is 2.0 t / (m²). 3 Kat. h). The chemical hydrogen consumption in the first hydrogenation unit HU1 is 21 Nm. 3 / t. Under these conditions, 99% conversion of diene components and 13% conversion of olefin components (flow S3) will occur, and no hydrogenation of aromatic components will occur.

[0301] The stream S3 leaving the first hydrogenation unit HU1 is stable enough (so that no undesirable scaling due to polymerization will occur) to be heated to 310°C in the heating device HD, which is then the reactor inlet temperature of the second hydrogenation treatment unit HU2.

[0302] The process conditions for the second hydrogenation unit HU2 are shown in Table 8:

[0303]

[0304] Here, the remaining trace amounts of dienes and alkenes are hydrogenated in the gas phase to the corresponding saturated hydrocarbons. Sulfur-containing components are hydrogenated to the corresponding saturated hydrocarbons and H₂S. The sulfur content in the hydrotreating product stream S6 is < 0.5 wt.-ppm. Nitrogen-containing components are hydrogenated to the corresponding saturated hydrocarbons and NH₃. The nitrogen content in the hydrotreating product stream S6 is < 10 wt.-ppm. Halogen-containing components (such as chlorine-containing components) are hydrogenated to the corresponding saturated hydrocarbons and hydrohalic acids (such as HCl). The halogen / chlorine content in the hydrotreating product stream S6 is < 1 wt.-ppm.

[0305] The pressure at the reactor inlet is 21.5 bar (absolute). The reactor inlet temperature is 310°C. Under these conditions, the inlet stream S7 of the second hydrogenation treatment unit HU2 is completed in the vapor phase (as desired). Due to the feed stream S7... < A low content of diene components (0.01 wt.-%) prevents unwanted polymerization and scaling within the second hydrotreating unit HU2. The reactor temperature is increased from an inlet temperature of 310°C to an outlet temperature of 330°C via exothermic hydrogenation. This reasonable exothermic temperature increase within the second hydrotreating unit HU2 helps to limit and thus suppress unwanted hydrogenation of C6-C8 aromatics. A hydrogen partial pressure of 17.7 bar (absolute value) in the reactor of the second hydrotreating unit HU2 is suitable for ensuring sufficient hydrogenation activity while avoiding unwanted hydrogenation of C6-C8 aromatics.

[0306] The catalyst in the second hydrotreating unit HU2 is a Co-Mo catalyst on an alumina support, which exhibits sufficient activity for diene and olefin hydrogenation, desulfurization, denitrification, and dehalogenation, as well as the desired very low activity for C6-C8 aromatic hydrocarbon hydrogenation. The loss of aromatic components through aromatic ring hydrogenation is <0.5%. The WHSV of stream S1 is 0.7 t / (m³). 3 Kat. h).

[0307] After leaving the reactor, the product stream is cooled sequentially, and the stream S10 containing valuable products is separated from the recirculated gas stream S11.

[0308] The results of the distillation unit DU are shown in Table 9 (“valuable product fraction” refers to stream S12, “yield of C6-C8 aromatic compounds” refers to the total mass of C6-C8 aromatic compounds in stream S12; the total mass of C6-C8 aromatic compounds in stream S8) 100):

[0309]

[0310] In the following distillation unit DU, dissolved gases (H2, CH4, C2H6, C3H8, H2S, and NH3) are separated as stream S13 from the valuable product fraction (stream S12) containing mostly C6-C8 aromatics. The residual stream S14 contains undesirable high-boiling aromatic components for use in the aromatics extraction unit AEU. These components will accumulate in the solvent of the aromatics extraction unit AEU and contaminate the solvent. Therefore, the efficiency of aromatics extraction in the aromatics extraction unit AEU will be affected.

[0311] These constitute 77 wt.-% of the total feed stream S10 of distillation unit DU. The content of C6-C8 aromatics increases from 69.4 wt.-% to 82.6 wt.% in distillation unit DU. High-boiling components are separated as bottom stream S14. The valuable product stream S12 is 77 wt.-% of the feed stream S10 of distillation unit DU and contains 92 wt.-% of C6-C8 aromatics.

[0312] Stream S12, exiting the second distillation unit DU, is fed to the aromatic hydrocarbon extraction unit AEU, which produces pure benzene (>99 wt.-%) in stream S16a, pure toluene (>99 wt.-%) in stream S16b, and a xylene / ethylbenzene mixture (>93 wt.-%) in stream S16c. These are separated in the aromatic hydrocarbon extraction unit AEU by extractive distillation. The remaining stream S16d is lean for benzene, toluene, and the xylene / ethylbenzene mixture and contains paraffinic components, cycloalkanes, and C8+ aromatic hydrocarbons.

Claims

1. A method for separating C6-C8 aromatic hydrocarbons from a feed stream containing at least one type of plastic pyrolysis oil, the method comprising the following steps: (i) Providing a liquid stream S1 comprising at least one plastic pyrolysis oil, the liquid stream S1 further comprising a C6-C8 aromatic hydrocarbon, an organic compound comprising at least one heteroatom, and a compound having a C-C double bond and / or a C-C triple bond. (ii) Provide stream S2 containing hydrogen gas. (iii) At least a portion of the liquid stream S1 is evaporated in the evaporation unit EU in the presence of the stream S2 and the optionally recirculated gas stream S11, thereby forming a gas stream S3 comprising the stream S2, the optionally recirculated gas stream S11 and the evaporated portion of the liquid stream S1, and a liquid stream S4 comprising the portion of the unevaporated liquid stream S1 in the evaporation unit EU. (iv) Optionally, the gas flow S3 may be superheated in the superheater SH, thereby forming a superheated flow S5. (v) The gas stream S3 or optionally the superheated stream S5 is fed into a first hydrogenation unit HU1, in which at least a portion of the gas stream S3 or optionally at least a portion of the superheated stream S5 reacts with the hydrogen contained therein in a hydrogenation reaction, thereby forming a gas stream S6 containing C6-C8 aromatic hydrocarbons, organic compounds containing at least one heteroatom, and compounds having C-C double bonds and / or C-C triple bonds relative to the gas stream S3. (vi) The gas stream S6 is heated in at least one heating device HD, thereby forming a heated gas stream S7. (vii) The heated gas stream S7 is subjected to a second hydrogenation unit HU2, in which a product stream S8 is formed, the product stream S8 comprising C6-C8 aromatic hydrocarbons and being depleted relative to the gas stream S3 of organic compounds containing at least one heteroatom and further depleted of compounds having C-C double bonds and / or C-C triple bonds. (viii) Optionally, heat is transferred from the product stream S8 to the gas stream S3 in the superheater SH, thereby forming a cooled product stream S8b. (ix) The washing water stream S15 is fed into the product stream S8 continuously or discontinuously to form a stream S8a that optionally contains washing water, or the washing water stream S15 is fed into the cooled product stream S8b continuously or discontinuously to form a cooled product stream S8c that optionally contains washing water. (x) Optionally, in the evaporation unit EU, heat is transferred from the cooled product stream S8c containing wash water to the liquid stream S1, the stream S2 containing H2, and the stream S11, thereby forming a further cooled product stream S8d. (xi) The product stream S8a, optionally containing wash water, or optionally selected from the group consisting of the cooled product stream S8b, the cooled product stream S8c, and the further cooled product stream S8d optionally containing wash water, is condensed in the condensation unit CU, thereby forming a product stream S9, which comprises a liquid phase and a gas phase. (xii) The liquid product stream S9 is separated in the separation unit SU into a liquid product stream S10, a recirculated gas stream S11, and optionally a wastewater stream S17, wherein the recirculated gas stream S11 contains hydrogen and wherein at least a portion of the recirculated gas stream S11 is fed into the evaporation unit EU. (xiii) Optionally, the purified product stream S10 is fed into a distillation unit DU, in which the purified product stream S10 is separated into a stable product stream S12, a gas stream S13, and a stream S14.

2. The method according to Example 1, wherein, This at least one type of plastic pyrolysis oil is produced by the pyrolysis of plastic waste.

3. The method according to claim 1 or 2, wherein, The liquid stream S1 preferably contains at least 15 wt.% of C6-C8 aromatic hydrocarbons, more preferably at least 50 wt.% of C6-C8 aromatic hydrocarbons, and most preferably at least 80 wt.% of C6-C8 aromatic hydrocarbons.

4. The method according to any one of claims 1 to 3, wherein, The organic compound containing at least one heteroatom is selected from organic compounds containing at least one of the following heteroatoms: nitrogen, oxygen, sulfur, chlorine, bromine, fluorine, and iodine.

5. The method according to any one of claims 1 to 4, wherein, The at least one plastic pyrolysis oil in the liquid stream S1 has a bromine value of about 2 g Br2 / 100 g to about 150 g Br2 / 100 g (as determined by ASTM 1159) and / or a C5 hydrocarbon content of about 0.03 wt.-% to about 12.2 wt.-% (as determined by ASTM D 5134) and / or a naphthalene content of about 0.5 wt.-% to about 18.4 wt.-% (as determined by ASTM D 5134) and / or a styrene content of about 0.02 wt.-% to about 29.5 wt.-% (as determined by ASTM D 5134) and / or a toluene content of about 4.3 wt.-% to about 71.5 wt.-% (as determined by ASTM D 5134).

6. The method according to any one of claims 1 to 5, wherein, The hydrogen contained in stream S2 is formed by water electrolysis and / or methane pyrolysis using electricity from renewable and / or low-carbon energy sources.

7. The method according to any one of claims 1 to 6, wherein, The evaporation unit EU includes at least one device selected from the group consisting of a staged evaporator, a falling film evaporator, and a pre-evaporator, preferably wherein the evaporation unit EU consists of at least one pre-evaporator and at least one staged evaporator.

8. The method according to any one of claims 1 to 7, wherein, The liquid stream S1 is evaporated together with the recirculated gas stream S11 added to the liquid stream S1 before and / or during evaporation.

9. The method according to any one of claims 1 to 8, wherein, The first hydrogenation unit HU1 contains at least one heterogeneous catalyst.

10. The method according to any one of claims 1 to 9, wherein, The at least one heterogeneous catalyst is selected from the group consisting of nickel-molybdenum catalysts and nickel-tungsten catalysts, and further comprises a support, preferably an inorganic support selected from the group consisting of silica, alumina, silica-alumina, magnesium oxide, clay and mixtures thereof.

11. The method according to any one of claims 1 to 10, wherein, The process temperature in the first hydrogenation unit HU1 is preferably in the range of about 140°C to about 250°C, more preferably about 140°C to about 200°C, and most preferably about 170°C to about 190°C.

12. The method according to any one of claims 1 to 11, wherein, The second hydrogenation unit HU2 contains at least one heterogeneous catalyst, preferably selected from the group consisting of molybdenum catalysts, cobalt-molybdenum catalysts and cobalt-tungsten catalysts.

13. The method according to any one of claims 1 to 12, wherein, The weight hourly space velocity (WHSV) of the heated gas stream S7 is preferably in the range of about 0.1 t / (m²). 3 Kat. •h) to approximately 5.0 t / (m 3 Kat. •h), more preferably about 0.5 t / (m 3 Kat. •h) to approximately 1.0 t / (m 3 Kat. •h).

14. The method according to any one of claims 1 to 13, wherein, The organic compound containing at least one heteroatom in the liquid stream S1 is at least 90% depleted, more preferably at least 99%, in the second hydrogenation treatment unit HU2.

15. The method according to any one of claims 1 to 14, wherein, In a further step (xiv), C6-C8 aromatics are separated from the stable product stream S12 in at least one optional aromatic hydrocarbon extraction unit AEU to obtain streams S16a, S16b, S16c and S16d.

16. The method according to any one of claims 1 to 15, further comprising the following additional steps. (xv) The stream S14 that is available or obtained in step (iii) and / or the stream S16 a, b, c or d that is available or obtained in step (xiv) and / or the chemical material that is available or obtained by the method according to any one of the preceding claims is converted to obtain a monomer, polymer or polymer product.

17. The method according to claim 16, wherein, The monomer is a diol or polyol, preferably butanediol; an aldehyde, preferably formaldehyde; a diisocyanate or polyisocyanate, preferably methylene diphenyl diisocyanate (MDI), polymeric methylene diphenyl diisocyanate (pMDI), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI) or isophorone diisocyanate (IPDI); an amide, preferably caprolactam; Olefins, preferably styrene, ethylene and norbornene; alkynes; (di) esters, preferably methyl methacrylate; monoacids or diacids, preferably adipic acid or terephthalic acid; diamines, preferably hexamethylenediamine or nonanediamine; or sulfones, preferably 4,4'-dichlorodiphenyl sulfone.

18. The method according to claim 16 or 17, wherein, The polymer and / or the polymer product contains polyamide (PA), preferably PA 6 or PA 66; polyisocyanate addition polymers, 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), polyacrylonitrile butadiene styrene (ABS), polystyrene acrylonitrile (SAN), polyacrylate styrene acrylonitrile polyacrylate (ASA), polytetrafluoroethylene (PTFE), poly(methyl acrylate) (PMA), poly(methyl methacrylate) (PMMA), polybutadiene (BR, PBD), poly(cis-1,4-isoprene), poly(trans-1,4-isoprene) Poly(pentadiene), polyoxymethylene (POM), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polybutylene adipate (PBAT), polyester (PES), polyethersulfone (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), polyetheretherketone (PEEK), poly(p-phenylene oxide) (PPO), poly(p-phenylene ether) (PPE); or copolymers or mixtures thereof.

19. The method according to any one of claims 16 to 18, wherein, The polymer and / or the polymer product are then converted into the following or a portion thereof: - Automotive parts, preferably cylinder head covers, engine hoods, turbocharger housings, turbocharger baffles, intake pipes, intake manifolds, connectors, gears, fan wheels, coolant tanks, housings, heat exchanger housing parts, coolant coolers, turbocharger coolers, thermostats, water pumps, radiators, fasteners, battery system parts for electric vehicles, dashboards, steering column switches, seats, headrests, center consoles, transmission components, door modules, A, B, C, or D pillar covers, spoilers, door handles, exterior mirrors, windshield wipers, windshield wiper protection housings, decorative grilles, cover strips, roof rails, window frames, sunroof frames, antenna panels, headlights and taillights, engine hoods, cylinder head covers, intake manifolds, airbags, cushioning pads or coatings; - Fabrics, preferably shirts, trousers, sweaters, boots, shoes, shoe soles, bodysuits or jackets; - Electrical components, preferably electrical or electronic passive or active components, circuit boards, printed circuit boards, housing components, foil, wires, switches, plugs, sockets, distributors, relays, resistors, capacitors, inductors, spools, lamps, diodes, LEDs, transistors, connectors, voltage regulators, integrated circuits (ICs), processors, controllers, memory, sensors, microswitches, micro buttons, semiconductors, reflector housings for light-emitting diodes (LEDs), fasteners, gaskets, bolts, strips, slide-in guides, screws, nuts, membrane hinges, spring hooks (clamp-in) or spring tongues; - Consumer goods, agricultural products, or pharmaceutical products, preferably tennis strings, climbing ropes, bristles, brushes, artificial turf, 3D printed filaments, lawnmowers, zippers, hook and loop fasteners, paper machine fabrics, extrusion coatings, fishing lines, fishing nets, offshore lines and ropes, vials, syringes, ampoules, bottles, sliding elements, spindle nuts, chain conveyors, sliding bearings, rollers, wheels, gears, ring gears, screws and spring dampers, hoses, pipes, cable sheaths, sockets, switches, cable ties, fan wheels, carpets, cosmetic boxes or bottles, mattresses, cushioning pads, insulating materials, detergents, dishwasher detergent blocks or powders, shampoos, shower gels, bath gels, soaps, fertilizers, fungicides, or pest control agents; - For packaging in the food industry, single-layer or multi-layer blown film, cast film (single-layer or multi-layer), biaxial stretch film, or laminated film are preferred; or - Structural components, preferably rotor blades, insulating materials, frames, housings, walls, coatings, or partition walls.

20. The method according to any one of claims 16 to 19, wherein, The content of stream S1 in the product stream containing H2 and CO, monomers, polymers or polymer products is 1 wt% or more, preferably 2 wt% or more, more preferably 5 wt% or more, more preferably 15 wt% or more, more preferably 30 wt% or more, more preferably 40 wt% or more, more preferably 60 wt% or more, more preferably 80 wt% or more, more preferably 90 wt% or more, more preferably 95 wt% or more; and / or wherein the content of stream 1 in the monomer, polymer or polymer product is 100 wt% or less, preferably 95 wt% or less, more preferably 90 wt% or less, more preferably 50 wt% or less, more preferably 25 wt% or less, more preferably 10 wt% or less; and preferably wherein the content is determined based on a source retention and / or separation and / or quality balance and / or certificate declaration chain of custody model, preferably based on quality balance, preferably the International Sustainability and Carbon Certification (ISCC) standard.

21. A chemical apparatus for separating C6-C8 aromatic hydrocarbons from a feed stream containing at least one type of plastic pyrolysis oil, the apparatus comprising... (i) Evaporation unit EU, The evaporation EU may optionally include at least two independent pathways for the fluid. (ii) Optionally, a superheater SH downstream of the evaporation unit EU. (iii) A first hydrogenation treatment unit HU1, comprising at least one inlet and at least one outlet, wherein the first hydrogenation treatment unit HU1 is downstream of the evaporation unit EU or the optional superheater SH. Furthermore, at least one inlet fluid of the first hydrogenation treatment unit HU1 is connected to the evaporation unit EU or the optional superheater SH. (iv) At least one heating unit HD, which is downstream of and fluidly connected to the at least one outlet of the first hydrogenation treatment unit HU1. (v) A second hydrogenation treatment unit HU2 having at least one inlet and at least one outlet, the second hydrogenation treatment unit HU2 being downstream of the at least one heating unit HD, and the at least one outlet of the hydrogenation treatment unit HU2 being fluidly connected to the heating unit HD. (vi) A condensation unit CU, which is downstream of the second hydrogenation treatment unit HU2 and fluidly connected to at least one outlet of the second hydrogenation treatment unit HU2. (vii) Separation unit SU, which is downstream of and fluidly connected to the condensation unit CU, and (viii) Optionally, a distillation unit DU is downstream of and fluidly connected to the separation unit SU; and optionally, an aromatic hydrocarbon extraction unit AEU is downstream of the optional distillation unit and fluidly connected to stream S12.

22. Use of the chemical equipment according to claim 21 for the method according to any one of claims 1 to 20.

Images