WO2025078579A1

WO2025078579A1 - Process for decontamination of petrochemical compositions obtained from chemical recycling of polymer materials.

Info

Publication number: WO2025078579A1
Application number: PCT/EP2024/078656
Authority: WO
Inventors: Fabrice Cuoq; Kae Shin WONG; Aaron Chi Akah; Rashed Aleisa
Original assignee: SABIC Global Technologies BV; Saudi Arabian Oil Co
Current assignee: SABIC Global Technologies BV; Saudi Arabian Oil Co
Priority date: 2023-10-13
Filing date: 2024-10-11
Publication date: 2025-04-17
Anticipated expiration: 2026-04-13

Abstract

The process of the present invention involves the steps of: (a) a stripping step in a stripping vessel (1); (b) a first liquid-liquid extraction step in a first extraction vessel (2), in which an aprotic solvent is used as extraction medium; and (c) a second liquid-liquid extraction step in a second extraction vessel (3), in which a protic solvent is used as extraction medium wherein steps (a)-(c) may be applied in any order. The application of such process allows for the purification of hydrocarbon compositions to such extent that the content of chlorine-containing compounds may be reduced to below 1 ppm by weight. Such low chlorine content is desirable for processing of the hydrocarbon composition in many different chemical processing operations, such as steam cracking operations. The presence of chlorine-containing compounds in higher contents may lead to corrosion of equipment in such processes, which may result in e.g. equipment failure and/or reduced time between service intervals of the equipment. In view of the significant impact on process economics thereof, it is clearly desirable to avoid the presence of chlorine-containing compounds to any extent.

Description

Process for decontamination of petrochemical compositions obtained from chemical recycling of polymer materials.

[0001] The present invention relates to a process for decontamination of petrochemical compositions.

[0002] In the chemical and refinery industry, a wide array of chemical conversion processes is operated. These processes are highly optimised in terms of productivity, efficiency and sustainability, in order to enable economical and profitable operation and high quality of products. A particular aspect pertaining to such optimised production is the use of high-quality raw materials, also referred to as feedstocks, as input materials.

[0003] A large number of such chemical and refinery processes utilise petrochemical compositions as feedstocks.

[0004] A particular desirable type of feedstock that presently is sought after for use in chemical and refinery industry is feedstock that finds its source in waste streams. Use of such feedstock would greatly benefit circularity of materials; it is very desirable to be able to utilise a waste material as a valuable feedstock for a new process. There is in particular a lot of interest in using materials that originate from waste plastics as feedstocks. This can be quite desirable in the petrochemical and refinery industry, as waste plastics largely are materials streams that contain a large fraction of molecules in which carbon and hydrogen make up the majority fraction of atoms. Thus, such materials have an atomic composition that is quite similar to typical hydrocarbon materials that are conventionally used in the petrochemical and refinery industry. Accordingly, materials produced from waste plastics could well be suitable for use in this industry.

[0005] In recent years, an upswing in technical developments and industrial activity has occurred in the field of conversion of waste plastic materials into feedstock streams that may be suitable for use in the petrochemical and refinery industry. For example, via technologies like pyrolysis of plastic materials, waste plastic materials that are solid at room temperature can be converted into hydrocarbon-containing streams that are liquid as such temperatures, and that therefore can be processed in chemical and refinery processes equipped for conversion of liquid hydrocarbons. Such products obtained from pyrolysis of waste plastic materials may be referred to as plastic derived oils.

[0006] Typical examples of such processes include light olefin and aromatics production processes. Light olefins, such as ethylene and propylene, and aromatics, such as benzene, are well-known valuable building blocks that are ubiquitously used in the synthesis of chemical products, not in the least place in the synthesis of polymer products, of which the most abundant examples are polyethylenes and polypropylenes.

[0007] The most widely employed processes for production of light olefins and aromatics are so-called cracking operations, typically thermal or catalytic cracking operations. In such cracking operations, hydrocarbon molecules that are present in raw materials streams, which typically are of fossil, hydrocarbon nature, are subjected to such conditions that atomic bonds break, and smaller molecules are formed. Due to the chemical reaction kinetics, such processes typically lead to a product composition that comprises a desirably high quantity of light olefins and aromatics. After leaving the cracking unit, the product composition is commonly subjected to one or more separation operations, to obtain high-quality, high-purity chemical streams that can be processed into the desirable end product, for example into polymer materials.

[0008] Thus, when employing feed streams derived from waste plastics in such cracking operations, one may produce polymer materials from waste polymer materials, and by so, establishing a circular use of polymers. It will be understood that this presents an attractive route for materials synthesis.

[0009] In order for waste plastic materials to be suitable for processing in chemical operations such as thermal or catalytic cracking operations, the products must meet very stringent materials specifications. Cracking operations are commercially performed in world-scale operations, and when process disruptions occur, a great loss of process efficiency in terms of plant downtime and off-spec products takes place. In addition, cracking processes are very sensitive processes. The conditions must be kept within strict specifications. This also has its implications on the feedstock materials that may be processed in such plants.

[0010] On the other hand, the waste plastics streams that are made available for processing typically are not very consistent in their compositions; as they emerge from waste collection operations, either at the consumer or at an industrial level, the composition of such streams can be expected to vary quite widely from one batch to the next. This can be conflicting with the requirements of the chemical processing operations for which they may serve as feedstock materials, which dictate a high level of consistency.

[0011] Accordingly, there is a need to ensure that the products that are derived from waste plastics and that may find their use as feedstocks in chemical or refinery operations such as cracking processes are suitably consistent in composition and adequately pure.

[0012] A particular component that may be present in petrochemical feedstock compositions, such as streams obtained from waste plastics such as plastic derived oils, is chlorine. In petrochemical and refinery operations, it is generally desired to process feed materials containing a particularly low content of chlorines. A desire therefore exists to have access to technologies enabling the purification of petrochemical compositions, such as plastic derived oils, from chlorine.

[0013] The present invention relates to a process for removal of chlorine-containing compounds from hydrocarbon compositions, particularly from liquid hydrocarbon compositions.

[0014] Such liquid hydrocarbon compositions may for example be pyrolysis oils. In the context of the present invention, pyrolysis oils are products obtained from processes wherein waste plastics streams are subjected to pyrolytic conditions where by the plastics are decomposed to hydrocarbon oil-range products; that is, the plastics are subjected to such conditions that chemical bonds in its polymer chains are broken, resulting in lower molecular weight products.

[0015] In the process of the present invention, hydrocarbon compositions are subjected to multiple chemical unit operations to reduce the content of chlorine-containing compounds that may be contained therein.

[0016] The process of the present invention involves subjecting a hydrocarbon composition A to:

(a) a stripping step in a stripping vessel (1);

(b) a first liquid-liquid extraction step in a first extraction vessel (2), in which an aprotic solvent is used as extraction medium; and

(c) a second liquid-liquid extraction step in a second extraction vessel (3), in which a protic solvent is used as extraction medium wherein steps (a)-(c) may be applied in any order.

[0017] In a preferred embodiment, the process of the present invention involves the steps of:

(a) subjecting a hydrocarbon composition A to a stripping step in a stripping vessel (1), in which composition A is contacted with a stripping gas B, preferably a nitrogencontaining stream B, more preferably gaseous nitrogen, to obtain a composition C;

(b) subjecting the composition C to a first liquid-liquid extraction step in a first extraction vessel (2), in which an aprotic solvent is used as extraction medium, to obtain a composition E; and

(c) subjecting the composition E to a second liquid-liquid extraction step in a second extraction vessel (3), in which a protic solvent is used as extraction medium, to obtain a hydrocarbon composition F.

[0018] In a further preferred embodiment, the process of the present invention involves the steps of:

(a) subjecting a hydrocarbon composition A to a stripping step in a stripping vessel (1), in which composition A is contacted with a nitrogen-containing stream B, to obtain a composition C;

[0019] A further embodiment of the invention relates to process of the present invention involves the steps of:

(b) subjecting the composition C to a first liquid-liquid extraction step in a first extraction vessel (2), in which an protic solvent is used as extraction medium, to obtain a composition E; and (c) subjecting the composition E to a second liquid-liquid extraction step in a second extraction vessel (3), in which an aprotic solvent is used as extraction medium, to obtain a hydrocarbon composition F.

[0020] A yet further embodiment of the invention relates to process of the present invention involves the steps of:

(a) subjecting a hydrocarbon composition A to a stripping step in a stripping vessel (1), in which composition A is contacted with a nitrogen-containing stream B, more preferably gaseous nitrogen, to obtain a composition C;

(b) subjecting the composition C to a first liquid-liquid extraction step in a first extraction vessel (2), in which an protic solvent is used as extraction medium, to obtain a composition E; and

(c) subjecting the composition E to a second liquid-liquid extraction step in a second extraction vessel (3), in which an aprotic solvent is used as extraction medium, to obtain a hydrocarbon composition F.

[0021] The application of such process allows for the purification of hydrocarbon compositions to such extent that the content of chlorine-containing compounds may be reduced to below 1 ppm by weight. Such low chlorine content is desirable for processing of the hydrocarbon composition in many different chemical processing operations, such as steam cracking operations. The presence of chlorine-containing compounds in higher contents may lead to corrosion of equipment in such processes, which may result in e.g. equipment failure and/or reduced time between service intervals of the equipment. In view of the significant impact on process economics thereof, it is clearly desirable to avoid the presence of chlorine-containing compounds to any extent.

[0022] A representation of certain embodiments of the present invention is provided in the figures 1 and 2. In figures 1 and 2:

• A: hydrocarbon composition A;

• B: nitrogen-containing stream B;

• C: stripped composition C obtained from the stripping step (a);

• D: stream D containing nitrogen and the compounds stripped from the composition A, obtained from the stripping step (a)

• E: composition E obtained from the first extraction step (b); • F: hydrocarbon composition F obtained from the second extraction step (c);

• G: purified stream G obtained from the adsorption step (d);

• H: liquid hydrocarbon steam H obtained from the liquefaction step (e);

• 1 : Stripping vessel

• 2: First extraction vessel

• 3: Second extraction vessel

• 4: Adsorption vessel

• 5: Condenser

The hydrocarbon composition A

[0023] The hydrocarbon composition A may for example be a hydrocarbon-containing oil product obtained by decomposition of waste plastics.

[0024] In accordance with the present invention, the hydrocarbon composition A as used herein may for example be defined by its boiling point range. The hydrocarbon compositions are typically products of hydrocarbon nature, and typically are mixtures of compounds of varying boiling points. For processing in process operations as typically in used in the chemical and refinery industry, the compositions may not be too viscous nor too volatile in composition. A typical boiling point range for suitable compositions may include an initial boiling point of > 25°C, and a final boiling point of < 500°C, or < 400°C, or < 350°C. The boiling points may be determined according to the method set out in ASTM D86 (2012).

[0025] The initial boiling point reflects the lowest temperature at which boiling of chemical compounds in a hydrocarbon oil mixture occurs, and therefore is an indicator for the temperature at which the most volatile compounds, typically the compounds of lowest molecular weight, start to boil, at atmospheric pressure. The final boiling point reflects the highest temperature achievable in boiling of a hydrocarbon oil composition, and thereby indicates the temperature at which the compounds of highest boiling point, typically the compounds of highest molecular weight, will boil, again under atmospheric conditions.

[0026] Preferably, the hydrocarbon composition A as used in the present invention has an initial boiling point of > 30°C, more preferably > 50°C. It is also preferred that the hydrocarbon composition A has a final boiling point of < 325°C, more preferably < 300°C, even more preferably of < 250°C, even more preferably of < 225°C, or even < 200°C. In particular, suitable hydrocarbon compositions A may have an initial boiling point of > 30°C and a final boiling point of < 300°C, more preferably an initial boiling point of > 30°C and a final boiling point of < 250°C, even more preferably an initial boiling point of > 50°C and a final boiling point of < 200°C.

[0027] Compositions having such range of initial boiling point and final boiling point are considered to be suitably processable in chemical and refinery operations, including allowing appropriate transportation, heating, cooling and separation processes to be applied, without occurring of undesirable process disruptions.

[0001] Furthermore, the hydrocarbon composition A that may be considered suitable for use in the present invention may for example comprise a quantity of n-paraffins, a quantity of isoparaffins, a quantity of olefins, a quantity of naphthenes, and/or a quantity of aromatics. The composition may for example comprise a quantity of n-paraffins, a quantity of iso-paraffins, a quantity of olefins, a quantity of naphthenes, and a quantity of aromatics.

[0028] In the context of the present invention, n-paraffins that may be present in the composition A may for example include n-alkanes having 3 to 40 carbon atoms. The isoparaffins that may be present in the composition A may for example have 3 to 40 carbon atoms. The naphtenes that may be present in the composition A may for example have 3 to 40 carbon atoms. The aromatics that may be present in the hydrocarbon composition A may for example have 6 to 40 carbon atoms.

[0029] The hydrocarbon composition A may for example comprise > 25.0 and < 95.0 wt% of n- paraffins, with regard to the total weight of the hydrocarbon composition A. Preferably, the hydrocarbon composition A comprises > 25.0 and < 80.0 wt% of n-paraffins, more preferably > 25.0 and < 70.0 wt%, even more preferably preferably > 25.0 and < 50.0 wt%.

[0030] The hydrocarbon composition A may for example comprise > 5.0 and < 40.0 wt% of isoparaffins, with regard to the total weight of the hydrocarbon stream A. Preferably, the hydrocarbon composition A comprises > 5.0 and < 30.0 wt% of iso-paraffins, more preferably > 7.5 wt% and < 25.0 wt%.

[0031] The hydrocarbon composition A may for example comprise < 50.0 wt% of olefins, with regard to the total weight of the hydrocarbon composition A. Preferably, the hydrocarbon composition A comprises < 40.0 wt% of olefins, more preferably < 35.0 wt%, even more preferably < 30.0 wt%.

[0032] The hydrocarbon composition A may for example comprise > 5.0 and < 50.0 wt% of olefins, with regard to the total weight of the hydrocarbon composition A. Preferably, the hydrocarbon composition A comprises > 10.0 and < 40.0 wt% of olefins, more preferably > 15.0 and < 35.0 wt%.

[0033] The hydrocarbon composition A may for example comprise > 5.0 and < 20.0 wt% of napththenes, with regard to the total weight of the hydrocarbon composition A. Preferably, the hydrocarbon composition A comprises > 5.0 and < 15.0 wt% of naphthenes, more preferably > 7.5 wt% and < 15.0 wt%.

[0034] The hydrocarbon composition A may for example comprise > 5.0 and < 15.0 wt% of aromatics, with regard to the total weight of the hydrocarbon composition A. Preferably, the hydrocarbon composition A comprises > 5.0 and < 12.5 wt% of aromatics, more preferably > 7.5 wt% and < 12.5 wt%.

[0035] The hydrocarbon composition A may for example comprise:

• > 25.0 and < 95.0 wt%, preferably > 25.0 and < 70.0 wt%, more preferably > 25.0 and

< 50.0 wt%, of n-paraffins; and/or

• > 5.0 and < 20.0 wt%, preferably > 5.0 and < 15.0 wt%, more preferably > 7.5 and < 15.0 wt%, of iso-paraffins; and/or

• > 5.0 and < 50.0 wt%, preferably > 10.0 and < 40.0 wt%, more preferably > 15.0 and < 35.0 wt%, more preferably > 15.0 and < 25.0 wt%, of olefins; and/or

• > 5.0 and < 20.0 wt%, preferably > 5.0 and < 15.0 wt%, more preferably > 7.5 and < 15.0 wt%, of napthenes; and/or

• > 5.0 and < 15.0 wt%, preferably > 5.0 and < 12.5 wt%, more preferably > 7.5 and < 12.5 wt%, of aromatics with regard to the total weight of the hydrocarbon composition A.

[0036] In the context of the present invention, the atomic chlorine content is to be understood to be the total weight of chlorine atoms present in molecules in the hydrocarbon composition as fraction of the total weight of the hydrocarbon stream. The atomic nitrogen content is to be understood to be the total weight of nitrogen atoms present in molecules in the hydrocarbon stream as fraction of the total weight of the hydrocarbon stream.

[0037] The hydrocarbon composition A may for example comprise a certain quantity of contaminants. For example, the hydrocarbon composition A may contain a quantity of compounds comprising chlorine atoms. The quantity of compounds comprising chlorine atoms may be expressed as the atomic chlorine content of the hydrocarbon stream A. For example, the hydrocarbon composition A may have an atomic chlorine content of 2000 ppm by weight, as determined in accordance with ASTM UOP 779-08, or < 1500 ppm, or < 1000 ppm, preferably < 800 ppm, preferably < 700 ppm, more preferably < 600 ppm, even more preferably < 500 ppm, even more preferably < 400 ppm.

[0038] The hydrocarbon composition A may for example comprise > 150 ppm of atomic chlorine, preferably > 200 ppm, more preferably > 250 ppm.

[0039] For example, the hydrocarbon composition A may comprise > 200 and < 800 ppm of atomic chlorine, preferably > 200 and < 600 ppm, more preferably > 200 and < 500 ppm.

[0040] The hydrocarbon composition A may comprise a quantity of compounds comprising nitrogen atoms. The quantity of compounds comprising nitrogen atoms may be expressed as the atomic nitrogen content of the hydrocarbon composition A. For example, the hydrocarbon composition A may have an atomic nitrogen content of < 1600 ppm by weight, as determined in accordance with ASTM D5762 (2012), preferably < 1500 ppm, more preferably < 1400 ppm, even more preferably < 1300 ppm, even more preferably < 1200 ppm, or < 1100 ppm, or < 1000 ppm. For example, the hydrocarbon composition A may have an atomic nitrogen content of <100 ppm by weight as determined in accordance with ASTM D4629 (2017).

[0041] The hydrocarbon composition A may comprise a quantity of compounds containing olefinic unsaturations. An indication for the quantity of olefinic unsaturations is the bromine number of the hydrocarbon stream. The bromine number indicates the quantity of bromine in g that reacts with 100 g of the hydrocarbon specimen when tested under the conditions of ASTM D1159-07 (2012). For example, the hydrocarbon composition A as used in the process of the present invention may have a bromine number of < 100, preferably < 95, more preferably < 90, even more preferably < 85. [0042] The product C preferably comprises < 100 ppm, more preferably < 75 ppm, even more preferably < 50 ppm, yet even more preferably < 25 ppm, of atomic chlorine.

[0043] The hydrocarbon composition A may for example be a material stream that is obtained by treatment of a waste plastics feedstock. For example, hydrocarbon composition A may be obtained by processing a waste plastics stream in a pyrolysis unit.

[0044] Such pyrolysis unit may be a continuously operating unit, wherein a stream of waste plastics is continuously supplied to the unit and at least a liquid stream comprising pyrolysis products is continuously obtained from the unit. Alternatively, the pyrolysis unit may be a batch- wise operating using wherein a quantity of waste plastics is introduced into the unit, subjected to pyrolysis conditions, and subsequently at least a liquid stream comprising pyrolysis products is obtained from the unit.

[0045] The pyrolysis process that is performed in the pyrolysis unit may be a low-severity pyrolysis process or a high-severity pyrolysis process. In a low-severity pyrolysis process, the pyrolysis may be performed at a temperature of > 250°C and < 450°C, preferably > 275°C and < 425°C, more preferably > 300°C and < 400 °C. Alternatively, the pyrolysis process may be a high-severity process performed at a temperature of > 450°C and < 750°C, preferably > 500°C and < 700 °C, more preferably > 550°C and < 650°C.

[0046] The pyrolysis process may be a catalytic process. In such pyrolysis process, for example a quantity of a zeolite catalyst such as a ZSM-5 zeolite catalyst may be used. In such pyrolysis process, for example a quantity of spent FCC catalyst may be used. In particular, a composition comprising a quantity of ZSM-5 catalyst and a quantity of spent FCC catalyst may be used. For example, a composition comprising a quantity of ZSM-5 and a quantity of spent FCC catalyst may be used, wherein the weight ratio of the spent FCC catalyst to the ZSM-5 catalyst is between 0.5 and 5.0, such as between 1.0 and 3.0.

[0047] The process of the present invention may for example involve, prior to any of steps (a)- (c), a step of pyrolysis of a waste plastics composition, wherein a hydrocarbon composition A is obtained as liquid product from the pyrolysis. [0048] The waste plastics feedstock that is used for the production of the hydrocarbon composition A of the present process may for example comprise polyolefins, polyesters, thermoplastic elastomers, polyvinyl chlorides, polystyrenes, or polycarbonates.

[0049] Waste plastic feedstocks that may be used for the production of the hydrocarbon composition A can be mixtures comprising polyolefins, polyesters, thermoplastic elastomers, polyvinyl chlorides, polystyrenes, or polycarbonates. In particular, the waste plastic feedstock that may be used for the production of the hydrocarbon composition A can be mixtures comprising > 25.0 wt% of polyolefins, with regard to the total weight of the waste plastic feedstock. Preferably, the waste plastic feedstock may comprise > 40.0 wt% of polyolefins, more preferably > 50.0 wt%, even more preferably > 60.0 wt%, or > 70.0 wt%. The waste plastic feedstock may comprise a fraction of non-thermoplastics materials. Such non-thermoplastic materials may for example be hydrocarbon-based materials, such as rubber materials, but may also be materials including paper, sand and soil. It is an advantage of the present invention that waste plastics feedstocks containing at most 10 wt%, preferably at most 5.0 wt%, more preferably at most 2.0 wt%, of materials selected from paper, sand and soil, and combinations thereof, may be used in a process for preparation of polypropylene. This allows for the processing of such feedstocks without the need for cleaning processes that may require use of solvents or detergents.

[0050] For example, the waste plastics feedstock may comprise < 10.0 wt% of ingredients being the sum of the content of glass, paper, metal, cardboard, compostable waste, wood, stone, textiles, rubber materials and superabsorbent hygiene products, with regard to the total weight of the waste plastics feedstock.

[0051] The waste plastics feedstock may for example comprise > 90.0 wt% of polymeric material, with regard to the total weight of the waste plastics feedstock.

[0052] The waste plastics feedstock may for example comprise a quantity of polyesters. For example, the waste plastics feedstock may comprise < 20.0 wt% of polyesters, preferably < 15.0 wt%, more preferably < 10.0 wt%, even more preferably < 5.0 wt%, even further preferably < 2.0 wt%. The waste plastics feedstock may in certain embodiments be free from polyesters. [0053] A particular type of polyester that typically can be present in waste plastic feedstocks such as employed in the preparation of the hydrocarbon stream A as used in the present process is polyethylene terephthalate, which may also be referred to as PET. The waste plastics feedstock may for example comprise a quantity of PET. For example, the waste plastics feedstock may comprise < 20.0 wt% of PET, preferably < 15.0 wt%, more preferably < 10.0 wt%, even more preferably < 5.0 wt%, even further preferably < 2.0 wt%. The waste plastics feedstock may in certain embodiments be free from PET.

[0054] Polyesters such as PET contain oxygen atoms in their polymeric chains. The presence of compounds comprising oxygen atoms in the hydrocarbon stream A is subject to certain limitation, since an excess quantity of oxygen atoms in the compounds that are supplied to the thermal cracker furnace may lead to problems including fouling and corrosion in the downstream processing of the cracked hydrocarbon stream D exiting from the thermal cracker furnace. Accordingly, there is a desire to control or even minimise the quantity of oxygencontaining polymers in the waste plastics feedstock that is used to prepare the hydrocarbon stream A.

[0055] The waste plastics feedstock may for example comprise a quantity of polyamides. For example, the waste plastics feedstock may comprise < 20.0 wt% of polyamides, preferably < 15.0 wt%, more preferably < 10.0 wt%, even more preferably < 5.0 wt%, even further preferably < 2.0 wt%. The waste plastics feedstock may in certain embodiments be free from polyamides.

[0056] Particular types of polyamide that typically can be present in waste plastic feedstocks such as employed in the preparation of the hydrocarbon stream A as used in the present process are polyamide 6 and polyamide 6,6, which may also be referred to as PA6 and PA66, respectively. The waste plastics feedstock may for example comprise a quantity of PA6 or PA66. For example, the waste plastics feedstock may comprise < 20.0 wt% of total of PA 6 and PA66, preferably < 15.0 wt%, more preferably < 10.0 wt%, even more preferably < 5.0 wt%, even further preferably < 2.0 wt%. The waste plastics feedstock may in certain embodiments be free from PA6 and/or PA66.

[0057] The waste plastics feedstock may for example comprise a quantity of polyvinyl chlorides, which may also be referred to as PVC. For example, the waste plastics feedstock may comprise < 5.0 wt% of PVC, preferably < 2.0 wt%, more preferably < 1.0 wt%, even more preferably < 0.5 wt%, even further preferably < 0.1 wt%. The waste plastics feedstock may in certain embodiments be free from PVC.

[0058] The waste plastics feedstock may for example comprise

• < 20.0 wt%, preferably < 10.0 wt% of polyesters; and/or

• < 20.0 wt%, preferably < 10.0 wt% of polyamides; and/or

• < 2.0 wt%, preferably < 1.0 wt% of polyvinyl chloride with regard to the total weight of polymeric material in the waste plastics feedstock .

[0059] The presented percentages of polyesters, polyamides and PVC in the waste plastics feedstock are to be understood to be percentages by weight of the total weight of polymeric material present in the waste plastics feedstock.

[0060] The waste plastic feedstock may further comprise a quantity of moisture, for example the waste plastics feedstock may contain up to 20.0 wt% of moisture, preferably up to 10.0 wt%, more preferably up to 5.0 wt%.

[0061] The nitrogen-containing stream B may for example be gaseous nitrogen. The stripping step (a) preferably is performed for a period of at least 100 minutes, preferably at least 150 minutes, even more preferably at least 200 minutes. For example, the stripping step (a) may be performed for a period of between 100 and 300 minutes, preferably between 150 and 300 minutes, even more preferably between 200 and 300 minutes The stripping step (a) is preferably performed in a stripping column, more preferably in a stripping column provided with a condenser and a reboiler. The condenser temperature may for example be between 50°C and 160°C, preferably between 70°C and 140°C, more preferably between 80°C and 120°C. The reboiler temperature may for example be between 70°C and 190°C, preferably between 85°C and 160°C, more preferably between 95°C and 140°C.

[0062] The aprotic solvent may for example be selected from dimethyl sulfoxide, dimethyl formamide, sulfolane, and n-methyl-2-pyrrolidone. Preferably, the aprotic solvent is selected from dimethyl sulfoxide and dimethyl formamide.

[0063] The aprotic solvent may for example be applied in such quantities vis-a-vis the composition C that the aprotic solvent makes up > 40.0 and < 90.0 vol% of the contents of the first extraction vessel (2), preferably > 50.0 vol% and < 65.0 vol%, more preferably > 55.0 vol% and < 60.0 vol%.

[0064] The first extraction step (b) may for example be performed at a temperature of > 15°C and < 60°C, preferably > 20°C and < 40 °C.

[0065] The first extraction step (b) may for example be performed at a pressure of > 50 and < 200 kPa, preferably > 75 and < 150 kPa, such as at atmospheric pressure.

[0066] The first extraction step (b) may for example be performed for a period of > 1.0 and < 75.0 minutes, preferably > 1.0 and < 30.0 minutes, more preferably > 5.0 and < 20.0 minutes, even more preferably > 5.0 and < 15.0 minutes.

[0067] In a preferred embodiment, the first extraction step (b) is performed using > 55.0 vol% and < 60.0 vol% of the contents of the extraction vessel (2) of dimethyl sulfoxide or dimethyl formamide as solvent, at a temperature of > 20°C and < 40 °C, for a period of > 5.0 and < 15.0 minutes, at a pressure of > 75 and < 150 kPa.

[0068] The protic solvent may for example be selected from ethylene glycol, water, methanol and ethanol. Preferably, the protic solvent is ethylene glycol.

[0069] The protic solvent may for example be applied in such quantities vis-a-vis the composition E that the protic solvent makes up > 40.0 and < 70.0 vol% of the contents of the second extraction vessel (3), preferably > 50.0 vol% and < 65.0 vol%, more preferably > 55.0 vol% and < 60.0 vol%.

[0070] The second extraction step (c) may for example be performed at a temperature of > 15°C and < 60°C, preferably > 20°C and < 40 °C.

[0071] The second extraction step (c) may for example be performed at a pressure of > 50 and < 200 kPa, preferably > 75 and < 150 kPa, such as at atmospheric pressure.

[0072] The second extraction step (c) may for example be performed for a period of > 1.0 and < 75.0 minutes, preferably > 1.0 and < 30.0 minutes, more preferably > 5.0 and < 20.0 minutes, even more preferably > 5.0 and < 15.0 minutes. [0073] In a preferred embodiment, the second extraction step (c) is performed using > 55.0 vol% and < 60.0 vol% of the contents of the second extraction vessel (3) of ethylene glycol as solvent, at a temperature of > 20°C and < 40 °C, for a period of > 5.0 and < 15.0 minutes, at a pressure of > 75 and < 150 kPa.

[0074] The stripping process (a) may further result in a stream D containing nitrogen and the compounds stripped from the composition A. This stream D may be further subjected to an adsorption step (d) in an adsorption vessel (4) to obtain a purified stream G. The adsorption may be performed using a zeolite-type adsorber.

[0075] The stream G may be liquefied in a liquefaction step (e) by feeding it to a condenser (5) to obtain a liquid hydrocarbon steam H which may be recycled back and combined with the hydrocarbon stream A in the feed to the stripping vessel (1).

[0076] The process of the present invention preferably is a continuously operated process.

[0077] The invention will now be illustrated by the following non-limiting examples.

[0078] For the purpose of demonstrating the present invention, as the hydrocarbon stream A, a plastic derived oil product was used having an initial boiling point of 30°C and a final boiling point of 180°C. The plastic derived oil product has a total chlorine content of about 350 ppm, a total nitrogen content of below 1000 ppm, and a bromine number of below 85. The plastic derived oil comprised 43 wt% of n-paraffins, 17 wt% of iso-paraffins, 19 wt% of olefins, 10 wt% of naphthenes, and 11 wt% of aromatics. The plastic derived oil had a density of about 750 kg/m³.

The

[0079] A quantity of 150 ml of the plastic derived oil was placed in a 250 ml round-bottom flask. Nitrogen was supplied to the vessel by feeding in gaseous state via a feed entry near the bottom of the vessel, using a nitrogen feed of 1.5 l/min. The stripping was performed at 20°C, at atmospheric pressure. During the stripping process, samples of the plastic derived oil were taken at certain time intervals. The atomic chlorine content of each of these samples was measure, as presented in table 1 below. Table 1 : nitrogen stripping

The first extraction step

[0080] The product of sample 7, obtained from the stripping step after 290 mins of stripping, containing 120 ppm by wt atomic chlorine, was supplied to a 100 ml penicillin flask as extraction vessel. A quantity of an aprotic solvent according table 2 below was added to make up for 58 vol% of the contents of the extraction vessel.

[0081] The first extraction step was performed for a period of 60 minutes, at 20°C, at atmospheric pressure. Samples were taken from each extraction experiment. The atomic chlorine content of each samples was determined, as presented in table 2 below.

Table 2: First extraction in aprotic solvent

The second extraction step

[0082] The product obtained from the first extraction step with dimethyl sulfoxide, containing 35 ppm by wt atomic chlorine, was supplied to a 100 ml penicillin flask as extraction vessel. A quantity of ethylene glycol as protic solvent was added to make up for 58 vol% of the contents of the extraction vessel.

[0083] The second extraction step was performed for a period of 60 minutes, at 20°C, at atmospheric. [0084] A further sample 11 was obtained from this second extraction step. This resulted in a dechlorinated hydrocarbon product comprising 0.8 ppm by wt of atomic chlorine.

5

Claims

1. Process involving subjecting a hydrocarbon composition A to:

(a) a stripping step in a stripping vessel (1);

2. Process according to claim 1 , involving the steps of:

3. Process according to any one of claims 1-2, wherein the hydrocarbon composition A is a hydrocarbon-containing oil product obtained by decomposition of waste plastics.

4. Process according to any one of claims 1-3, wherein the hydrocarbon composition A comprises > 200 ppm and < 2000 ppm by weight , preferably > 200 ppm and < 600 ppm of atomic chlorine, as determined in accordance with ASTM UOP 779-08.

5. Process according to any one of claims 1-4, wherein the hydrocarbon composition A comprises:

• > 25.0 and < 95.0 wt%, preferably > 25.0 and < 70.0 wt%, more preferably > 25.0 and < 50.0 wt%, of n-paraffins; and/or

• > 5.0 and < 20.0 wt%, preferably > 5.0 and < 15.0 wt%, more preferably > 7.5 and < 15.0 wt%, of iso-paraffins; and/or • > 5.0 and < 50.0 wt%, preferably > 10.0 and < 40.0 wt%, more preferably > 15.0 and < 35.0 wt%, more preferably > 15.0 and < 25.0 wt%, of olefins; and/or

6. Process according to any one of claims 1-5, wherein the stripping step (a) is performed for a period of at least 100 minutes, preferably at least 150 minutes, even more preferably at least 200 minutes, or for a period of between 100 and 300 minutes, preferably between 150 and 300 minutes, even more preferably between 200 and 300 minutes.

7. Process according to any one of claims 1-6, wherein the stripping step (a) is performed in a stripping column, more preferably in a stripping column provided with a condenser and a reboiler, wherein the condenser temperature may for example be between 50°C and 160°C, preferably between 70°C and 140°C, more preferably between 80°C and 120°C, and the reboiler temperature may for example be between 70°C and 190°C, preferably between 85°C and 160°C, more preferably between 95°C and 140°C.

8. Process according to any one of claims 1-7, wherein the aprotic solvent is selected from dimethyl sulfoxide, dimethyl formamide, sulfolane, and n-methyl-2-pyrrolidone, preferably from dimethyl sulfoxide and dimethyl formamide.

9. Process according to any one of claims 1-8, wherein the aprotic solvent is applied in such quantities vis-a-vis the composition C that the aprotic solvent makes up > 40.0 and < 70.0 vol% of the contents of the extraction vessel (2), preferably > 50.0 vol% and < 65.0 vol%, more preferably > 55.0 vol% and < 60.0 vol%.

10. Process according to any one claims 1-9, wherein the first extraction step (b) is performed using > 55.0 vol% and < 60.0 vol% of the contents of the extraction vessel (2) of dimethyl sulfoxide or dimethyl formamide as solvent, at a temperature of > 20°C and < 40 °C, for a period of > 5.0 and < 15.0 minutes, at a pressure of > 75 and < 150 kPa.

11. Process according to any one of claims 1-10, wherein the protic solvent is selected from ethylene glycol and water.

12. Process according to any one claims 1-11, wherein the protic solvent is applied in such quantities vis-a-vis the composition E that the protic solvent makes up > 40.0 and < 70.0 vol% of the contents of the second extraction vessel (3), preferably > 50.0 vol% and < 65.0 vol%, more preferably > 55.0 vol% and < 60.0 vol%.

13. Process according to any one of claims 1-12, wherein the second extraction step (c) is performed using > 55.0 vol% and < 60.0 vol% of the contents of the second extraction vessel (3) of ethylene glycol as solvent, at a temperature of > 20°C and < 40 °C, for a period of > 5.0 and < 15.0 minutes, at a pressure of > 75 and < 150 kPa.

14. Process according to any one of claims 1-13, wherein a stream D containing nitrogen and the compounds stripped from the composition A is obtained from the stripping process (a), wherein the stream D is be further subjected to an adsorption step (d) in an adsorption vessel (4) to obtain a purified stream G, optionally wherein the stream G is subsequently liquefied in a liquefaction step (e) by feeding it to a condenser (5) to obtain a liquid hydrocarbon steam H, which optionally is recycled back and combined with the hydrocarbon stream A in the feed to the stripping vessel (1).

15. Process according to any one of claims 1-14, wherein the process involves, prior to subjecting to any of steps (a)-(c), a step of pyrolysis of a waste plastics composition, preferably wherein the waste plastics composition comprises > 40.0 wt% of polyolefins, more preferably > 50.0 wt%, even more preferably > 60.0 wt%, or > 70.0 wt%, wherein a hydrocarbon composition A is obtained as liquid product from the pyrolysis.

16. Process according to claim 15, wherein the pyrolysis is performed a low-severity pyrolysis process, performed at a temperature of > 250°C and < 450°C, preferably > 275°C and < 425°C, more preferably > 300°C and < 400 °C; or or a high-severity pyrolysis process, performed at a temperature of > 450°C and < 750°C, preferably > 500°C and < 700 °C, more preferably > 550°C and < 650°C.