DE102022003577A1 - Continuous process for the recovery of secondary resources from waste multilayer films by oiling - Google Patents

Abstract

A continuous process is proposed for the recovery of secondary resources from a starting material (A) comprising waste containing at least 70% by mass of multilayer films, with a mass fraction of at least 80%, preferably at least 90% of organic compounds, in particular polyethylene, polypropylene, polyamide 6, polyamide 6.6, polyamide 6.12, and/or polyethylene terephthalate, as well as adhesives and adhesion promoters, in particular ethylene vinyl alcohol, as starting material (A) by oiling to obtain a product oil (P) in a two-part reactor (R) with a first, lower region (I), in which a start-up oil is introduced up to a height of at least half the total height of the same, and with a second upper region (II), which is connected to the lower region (I) and which does not contain any liquid during start-up, into which via one or more external pipeline(s) (1) by means of one, two or more pumps (2) with a ratio of directed to undirected pulse power in the range of 1/6 to 1/2 of the reactor content (RI) is pumped from the lower end of the first, lower region (I) of the two-part reactor (R), with the product oil (P) being withdrawn from the upper end of the second, upper region (II) of the two-part reactor (R), wherein the start-up oil is first heated to an operating temperature in the range from 280 to 420 °C by pumping via the one, two or more pumps (2), whereupon the pre-prepared starting material (A) is continuously fed into the first, lower region (I) of the two-part reactor (R) below the liquid level, and wherein the reactor contents (RI) are pumped from the lower end of the first, lower region (I) of the two-part reactor (R) into the second, upper region (II) of the two-part reactor (R), such that the ratio of the feed residence time of the starting material (A) to the pumping residence time of the reactor contents (RI) is in the range from 250 to 1 to 5000 to 1 lies.

Description

The invention relates to a process for the recovery of secondary resources from waste multilayer films by oiling.

The state of the art in the disposal of packaging based on multilayer films is waste incineration.

Waste can in particular be waste that arises during the production and/or use of multilayer films.

Multilayer films are mainly used as packaging material, especially for food and for medical purposes. In the food sector, they are used in particular for packaging sausage, meat, cheese and dairy products. In the pharmaceutical and medical sector, they are used primarily for packaging blood products, infusion solutions, liquid medicines or auxiliary solutions and in particular as sterile packaging. Multilayer films therefore serve a wide range of purposes in preserving food, especially sausage and cheese, as well as in packaging medicines and technical devices that require special protection.

The main aim is to ensure inertness in the interior space enclosed by the packaging, which means that the packaging material must be practically airtight and, in particular, must not allow any oxygen to pass through.

However, plastics have very different properties - some are easy to shape but permeable to air, others are airtight but mechanically less stable, and still others react with the packaged goods.

In order to meet all requirements for plastic films as packaging material, it is therefore necessary to design them as multi-layer films.

Multilayer films are predominantly produced using the coextrusion process.

In the extrusion process, which is used primarily in plastics processing, hardenable masses in a solid to viscous state are continuously pressed under pressure from a shaping opening. This is referred to in particular as a nozzle (or profile nozzle, mouthpiece, die).
In the coextrusion process, two or more similar or dissimilar materials are brought together before leaving the nozzle.

This allows two or more layers of different plastics to be combined to form two- or multi-layer films.

A special variant is blown film extrusion. Here, the melt is pressed through a tool after the extruder, which is equipped with a ring nozzle in particular. The resulting melt tube is inflated with air and cooled by cooling air from the outside and, if necessary, from the inside. This is also where the width and thickness of the film are determined. The cooled film tube is laid flat and then wound up. The state of the art is films with up to 11 layers that are placed on top of each other in the blow head.

There is also another frequently used process for producing films for use as packaging material, whereby a bottom film is connected (sealed) to an upper film. The bottom films are mainly produced in thermoforming and trayskin systems.

This manufacturing process is particularly suitable for plastic packaging for food, especially because these are often required in different sizes and shapes. The packaging is sometimes placed in the lower tray by hand or primarily using a corresponding device, and in the next step the upper film is pulled from a roll directly over it and sealed. The lower film is usually also delivered in roll form, from which the lower tray is formed in a thermoforming device immediately before filling. However, it is also possible to pre-assemble the lower trays.

The bottom and top films usually have different chemical compositions. Both films can also be multi-layered, depending on requirements.

Packaging films are also known in which the top film is sealed against coated paper or coated cardboard. The goods to be packaged are placed on a flat piece of coated paper or coated cardboard and the top film is pulled over the goods in a shrinking process, often under vacuum. Packaging films of this kind are known as skin films. They adapt to any contour of the goods to be packaged, have good sealing properties and can be printed on.

Polyethylene, polypropylene and/or polyethylene terephthalate, especially amorphous polyethylene terephthalate (APET), are often used as plastics for sealing films, particularly because they have good sealability.

Due to the high variability of their composition, as explained above, multilayer films containing waste could so far only be thermally recycled (incinerated).

In contrast, it was the object of the invention to provide a process for the material recycling of waste containing multilayer films, in particular for the extraction of secondary resources therefrom, especially for the conversion into a product oil as a crude oil substitute product, which can be operated continuously and which ensures a uniform quality of the product oil with regard to the maximum permissible oxygen and nitrogen content as well as the minimum calorific value thereof, provided that the starting material used contains waste from multilayer films in a mass fraction of at least 70%, with a mass fraction of at least 80%, preferably of at least 90% of organic compounds in the waste from multilayer films.
In particular, the oxygen content of the product oil should not exceed 4% by mass and the nitrogen content should not exceed 1.2% by mass, and the minimum calorific value should be 41 MJ/kg.

This object is achieved by a continuous process for the recovery of secondary resources from a starting material comprising waste which contains a mass fraction of at least 70% multilayer films, with a mass fraction of at least 80%, preferably of at least 90% organic compounds, in particular polyethylene, polypropylene, polyamide 6, polyamide 6.6, polyamide 6.12, and/or polyethylene terephthalate as well as adhesives and adhesion promoters, in particular ethylene vinyl alcohol, by oiling to obtain a product oil in a two-part reactor with a first, lower region, in which a start-up oil is introduced up to a height of at least half the total height of the same, and with a second, upper region which is connected to the first, lower region and which does not contain any liquid during start-up, into which the reactor contents are pumped from the lower end of the first, lower region of the two-part reactor via one or more external pipelines by means of one, two or more pumps with a ratio of directed to undirected pulse power in the range of 1/6 to 1/2, under Removal of the product oil from the upper end of the second, upper section of the two-part reactor,
wherein the start-up oil is first heated to an operating temperature in the range of 280 to 420 °C by pumping it through one, two or more pumps,
whereupon the pre-prepared starting material is continuously fed into the first, lower region of the two-part reactor below the liquid level, and wherein the reactor contents are pumped from the lower end of the first, lower region of the two-part reactor into the second, upper region of the two-part reactor such that the ratio of the feed residence time of the starting material to the pumping residence time of the reactor contents is in the range from 250 to 1 to 5000 to 1.

Oil conversion processes for making waste usable as a source for secondary resource extraction, also known as catalytic pressureless oil conversion (CDC) or thermocatalytic low-temperature conversion (NTC), are well known. These are technical depolymerization processes in which artificial or natural polymers and long-chain hydrocarbons are converted into shorter-chain, predominantly aliphatic hydrocarbons, comparable to synthetic light oil, with the addition of a zeolitic catalyst at temperatures of less than 400 °C without excess pressure. (see "Oil conversion", retrieved from Wikipedia on September 22, 2022).

An overview of the processes currently offered or operated in Germany can be found, for example, in the final report of the Federal Environment Agency on the “Evaluation of new developments in alternative thermal waste treatment plants with a focus on oiling processes” by M. Pohl and P. Quicker (Texte 77/2018, project number 82615, UBA-FB 002679). According to the detailed study therein, which also In the process known as "Catalytic Tribochemical Conversion" (CTC) and operated by Dieselwest GmbH (renamed CARBOWEST GmbH in 2021), residual waste is first processed in several stages, i.e. crushed, sieved to a maximum grain size of 2 mm, ferrous and non-ferrous metals are separated, additives in the form of synthetic or natural zeolites are added as catalysts and quicklime as a neutralizer and dried to a water content of less than 2%. The oiling process itself is carried out in the liquid phase in a reactor made up of two cylindrical vessels that taper conically in the lower area and are arranged one above the other. Starting oil is introduced. Before the processed residual waste is fed in, this is first heated to reaction temperature (320 to 420 °C depending on the starting material) by several energy input devices, in particular turbines and/or pumps, with which the reactor contents are constantly mixed and pumped around. The processed residual waste is fed into the lower part of the reactor using a screw below the liquid level. This ensures that the material fed in mixes with the oil provided and a suspension is formed, which is sucked in at the lower end of the reactor via the turbines and injected back into the upper part of the reactor via pipes and connected nozzles. The intensive mixing breaks up the polymers and causes them to evaporate as soon as the chain length is sufficiently short. The vapors are drawn off at the top of the reactor and condensed using a spray cooler to obtain the product oil.
However, this does not show a consistent quality and the continuous operational capability of the system could not be demonstrated.

The invention is based on known oiling processes for processing waste containing organic compounds, in particular the so-called “Dieselwest” process, which was described in the above-mentioned final report of the Federal Environment Agency (Texte 77/2018, project number 82615, UBA-FB 002679).

Any waste can be used as starting material, provided that it contains a mass fraction of at least 70% multilayer films, with a mass fraction of at least 80%, preferably at least 90% organic compounds, in particular polyethylene, polypropylene, polyamide 6, polyamide 6.6, polyamide 6.12, and/or polyethylene terephthalate, as well as adhesives and adhesion promoters, in particular ethylene vinyl alcohol.

The multilayer films can preferably be blown films, coextruded films or skin films.

In addition to the polymers listed above, the multilayer films can also contain polyamide 6.T/6 as well as polyethylene, polypropylene, polystyrene, polylactic acid and/or polyisobutylene.

• - 0 bis 40 Gewichtsprozent, bevorzugt 15 bis 25 Gewichtsprozent Polyamid 6, Polyamid 6.6 und/oder Polyamid 6.12 und/oder
• - 0 bis 50 Gewichtsprozent, bevorzugt 3 bis 15 Gewichtsprozent Polyethylenterephthalat und/oder
• - 10 bis 95 Gewichtsprozent, bevorzugt 40 bis 70 Gewichtsprozent Polyethylen oder Polypropylen,
• - 0 bis 10 Gewichtsprozent, bevorzugt unter 3 Gewichtsprozent Inertstoffe,

jeweils bezogen auf das Gesamtgewicht des Ausgangsmaterials (A).The source material often contains

• - 0 to 40 percent by weight, preferably 15 to 25 percent by weight of polyamide 6, polyamide 6.6 and/or polyamide 6.12 and/or
• - 0 to 50 percent by weight, preferably 3 to 15 percent by weight polyethylene terephthalate and/or
• - 10 to 95 percent by weight, preferably 40 to 70 percent by weight of polyethylene or polypropylene,
• - 0 to 10 percent by weight, preferably less than 3 percent by weight of inert substances,

each based on the total weight of the starting material (A).

The starting material may in particular contain silicon dioxide, aluminum oxide, ionomers, lubricants, antiblocking agents, regranulation material and/or polylactic acid, paper, in particular white paper or brown kraft paper and/or aluminum foil.

The starting material preferably has a bulk density between 30 and 300 kilograms per cubic meter, in particular 40 to 80 kilograms per cubic meter.

The starting material is in particular formed from predominantly flat particles, wherein the average surface diameter of the particles of the starting material is preferably between 10 and 50 millimeters, particularly preferably between 15 and 30 millimeters.
The determination of the mean surface diameter is carried out in analogy to the determination of the hydraulic diameter from the ratio of four times the area to the circumference of a particle.

The waste from multilayer films contained in the starting material mainly comes from used packaging, in particular from food packaging, technical packaging and/or pharmaceutical packaging. It can be end-user waste and/or waste from company collection systems.

Additionally or alternatively, the waste from multilayer films contained in the starting material can be production waste, processing residues, in particular trimming residues and residues from punching and/or regranulates and/or reextrudates from the starting material (A).

Before being fed into the reactor, the starting material is processed in a known manner, in particular as in the “Dieselwest” process described above, in advance in several stages, i.e. crushed to a bulk density of 30 to 300 kilograms per cubic meter, preferably 60 kilograms per cubic meter, sieved to a grain size of maximum 2 mm, preconditioned to an average surface diameter of the particles of the starting material preferably between 10 and 50 millimeters, particularly preferably between 15 and 30 millimeters, iron and non-ferrous metals are separated, additives in the form of synthetic or natural zeolites are added as catalysts and quicklime as a neutralizer and the starting material is finally dried to a water content of less than 2%.

For commissioning, start-up oil is introduced into the first, lower region of the two-part reactor up to a height of at least half of the total height thereof, preferably up to a height of at least 2/3 of the total height thereof.

As start-up oil, it is advantageous to use a mixture of product oil and a mineral oil with a boiling point greater than 280 °C, preferably in a mass ratio of 10% mineral oil to 90% product oil to 90% mineral oil to 10% product oil, in particular 50% mineral oil to 50% product oil.

The start-up oil is first heated to an operating temperature in the range of 280 to 420°C by pumping it through one, two or more pumps, after which the pre-prepared starting material is continuously fed into the first, lower area of the two-part reactor below the liquid level, preferably via a screw. Alternatively, the pre-prepared starting material can also be fed via an extruder.

The oiling process is carried out in this two-part reactor, with a first, lower and a second, upper area, which is preferably directly connected to the first, lower area. Advantageously, the first, lower and/or the second, upper area each taper at the bottom to allow the fluid to drain off during cleaning work and downtimes. The opening connecting the two areas has a diameter of at least 1/5 of the upper reactor diameter, preferably 1/3.

In one embodiment, both reactor regions can be integrated into a common reactor shell.

Preferred pumps are liquid ring vacuum pumps, impeller pumps with a recessed impeller, rotary piston pumps, screw spindle pumps with a high undirected impulse of at least 50%, preferably 80% of the total impulse power, the directed impulse is determined by the delivery pressure (pressure loss) and the volume flow in relation to the pump power introduced. The undirected impulse power is also referred to by experts as dissipated power. One advantage of this energy input is the homogeneous heating of the fluid from the inside to the outside, there are no hot walls as with external heating methods via the wall. A second significant advantage of the direct dissipative energy input is the high mixing and stress on the starting material.

The required heat of melting is provided by the surrounding fluid. The high mixing performance of the pump causes the introduced solid particles to be crushed and torn apart in the pumped flow. The catalyst particles are also mixed with the introduced and melted solid particles. The high shear forces and cavitation caused by peripheral speeds of 15 to 20 m/s and the sudden evaporation and condensation cause the original long-chain organic compounds to crack from the introduced solid particles in the liquid phase. The high shear rates also mean that the active centers of the catalysts are continuously renewed. For example, low-pressure polyethylene waste with originally typically 2000 to 4000 monomer units is cracked to an average of 3 to 16 monomer units.

What is essential to the invention is that the process is carried out in such a way that the ratio of the pumping residence time of the reactor contents to the feed residence time of the starting material is in the range from 250 to 1 to 5000 to 1. This is crucial for achieving the high shear rates required for the depolymerization processes explained above.

The pumping residence time is defined by the total liquid reactor volume divided by the total pump volume flow, which is determined by mass flow meters, for example standard Coriolis meters. The pumping residence time is itself divided into the pumping residence time in the first, lower area of the reactor and the pumping residence time in the second, upper area of the reactor. The feed residence time is defined as the ratio of the total reactor volume to the feed volume flow of the feed materials.

Preferred ratios of the pumped circulation residence time of the reactor contents to the feed residence time of the starting material are in the range from 250:1 to 5000:1.

Preferably, the process is operated such that the pumping residence time of the reactor contents is in the range from 15 to 55 seconds, preferably in the range from 25 to 40 seconds.

The very high ratio of the pumping residence time of the reactor contents to the feed residence time of the starting material according to the invention leads to a high stress on the introduced starting material due to high shear and cavitation forces, and as a result to a higher solids conversion and a lower oxygen and nitrogen concentration in the product oil compared to the starting material. The reduction in the oxygen concentration is in the range of 40 to 90%, preferably 80%, and the reduction in the nitrogen concentration is in the range of 50 to 80%, preferably 70% compared to the starting material.
The calorific value of the product oil is advantageously between 41 and 46 megajoules per kilogram, preferably around 45 megajoules per kilogram.

In the product oil, the formation of polycyclic aromatic hydrocarbons, in particular naphthalene, acenaphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene and/or benzo(a)pyrene, is advantageously minimized, and the sum of the polycyclic aromatic hydrocarbons is between 100 and a maximum of 1000 ppm, preferably a maximum of 600 ppm.

Caprolactam is advantageously contained in the product oil in a concentration of 0.5 to 5 percent by weight, preferably in a concentration of at least 1.5 percent by weight.

Advantageously, the surface loading B of the pumped flow in the second, upper region of the two-part reactor is set to a value in the range from 25 m3/m2/h to 250 m3/m2/h, preferably to a value of 100 m3/m2/h, via the volume flow of the same and via the geometry of the second upper region of the two-part reactor.

The liquid pumped through the pumps is slightly overheated by the undirected energy input as it flows through the pumps and is essentially released into the upper container by a slight pressure difference. The liquid jet bursts and spreads over the existing wall surface in the second, upper area of the two-part reactor. This creates surface area. The low-boiling components can then escape more easily.
It is further preferred that the inner walls of the two-part reactor in the second, upper region thereof are partially or completely heated and/or wetted with product oil. This supports the evaporation of more volatile hydrocarbons.

The residue from the first, lower section of the two-part reactor is advantageously discharged and allowed to settle as needed or at regular intervals and the supernatant oil mixture is returned to the first, lower section of the two-part reactor.

The vapors are continuously withdrawn from the second, upper region of the two-part reactor and condensed in a known manner, in particular in a spray cooler, preferably in a multi-stage spray cooler, to obtain the product oil.

Advantageously, the reactor contents are pumped back tangentially into the upper third of the second, upper region of the two-part reactor in order to achieve a high distribution on the wall surface of the second, upper region of the two-part reactor and thus outgassing of the products produced.

In an advantageous embodiment, the second, upper region of the two-part reactor can be used as a single-stage separation column by providing a separable flange over which one or more horizontal perforated plates can be inserted. Perforated plates with an opening ratio of 20 to 40% are advantageously used.

To prevent foaming, it is advantageous to supply the pumped flow via a centrally arranged pipe.

The invention also relates to the use of the product oil obtained in a process as described above as a petroleum substitute feedstock, in particular as a substitute feedstock for naphtha and/or high vacuum gas oil in steam crackers.

The invention also relates to the use of the product oil obtained in a process as described above as a feedstock for direct distillation for the separation of diesel fuel and/or kerosene and/or naphtha.

The invention is explained in more detail below using embodiments and a drawing.

• 1 eine schematische Darstellung eines bevorzugten Reaktors R zur Durchführung des erfindungsgemäßen Verfahrens und
• die 2A und 2B Querschnittsdarstellungen durch zwei bevorzugte Ausführungsformen von Reaktoren R zur Durchführung des erfindungsgemäßen Verfahrens.

The drawing shows in detail:

• 1 a schematic representation of a preferred reactor R for carrying out the process according to the invention and
• the 2A and 2 B Cross-sectional views through two preferred embodiments of reactors R for carrying out the process according to the invention.

1 shows a two-part reactor R with a first, lower area I and a second, upper area II.

The starting material A is continuously fed via a conveyor screw into the first, lower section I of the two-part reactor R below the liquid level therein.

Via an external pipeline 1, the reactor contents are pumped by means of a pump 2 from the first, lower region I of the reactor R into the second, upper region II of the reactor R. Product vapor is withdrawn from the upper end of the second, upper region II of the reactor R and quenched with a partial flow of cold product oil, obtaining the product oil P, which is withdrawn.

In the cross-sectional views in the 2A and 2 B A version with 4 pumps and two spray coolers (in 2A) or a version with 4 pumps and a spray cooler (in 2 B) shown.

Example 1:

The starting material (A) is provided by a manufacturer of packaging materials and is 1 A total of 26.7 tons of oil with all impurities were pumped into the reactor R shown. The composition of the starting material (A) and that of the product oil obtained (P) are shown in Table 1. The pumping residence time was on average 39 s at a reactor temperature of 380 °C. Table 1: Source material Product oil Calorific value in megajoules per kilogram 38.18 45.4 Moisture in percent by weight 4 0.2 Inert substances in weight percent 3 0.1 (Bulk) density in kilograms per cubic meter 109 821 C (measured value) in weight percent 76.2 84.4 H (measured value) in weight percent 12.6 13.3 N (measured value) in weight percent 3.2 0.7 O (measured value) in weight percent 7.1 1.5 Polyethylene in weight percent 49.9 Polyamide in weight percent 26.1 Polyethylene terephthalate in weight percent 24.0

The material data show a significant reduction in the nitrogen and especially the oxygen content in the product oil as well as a significant increase in the calorific value.

Example 2:

A similar raw material is provided by a manufacturer of packaging materials and is used in the 1 A total of 12.2 tonnes of PET were pumped into the reactor shown with all the impurities. In contrast to example 1, the proportion of PET in the starting material is significantly higher at around 80%.
The composition of the starting material (A) as well as that of the obtained product oil (P) are given in Table 2. The pumping residence time was on average 36 s at a reactor temperature of 360 °C. Table 2: Source material Product oil Calorific value in megajoules per kilogram 30.2 43.29 Moisture in percent by weight 1 0.50 Inert substances in weight percent 1 0.1 (Bulk) density in kilograms per cubic meter 134 825 C (measured value) in weight percent 67.5 83.5 H (measured value) in weight percent 6.5 12.8 N (measured value) in weight percent 1.0 0.5 O (measured value) in weight percent 28.1 3.8 Polyethylene in weight percent 11.4 Polyamide in weight percent 8.1 Polyethylene terephthalate in weight percent 80.6

The material data show a significant reduction in the nitrogen and especially the oxygen content in the product oil as well as a significant increase in the calorific value.

Claims (14)

Continuous process for the recovery of secondary resources from a starting material (A) comprising waste which contains at least 70% by mass of multilayer films, with a mass proportion of at least 80%, preferably at least 90% of organic compounds, in particular polyethylene, polypropylene, polyamide 6, polyamide 6.6, polyamide 6.12, and/or polyethylene terephthalate, as well as adhesives and adhesion promoters, in particular ethylene vinyl alcohol, as starting material (A) by oiling to obtain a product oil (P) in a two-part reactor (R) with a first, lower region (I), in which a start-up oil is introduced up to a height of at least half the total height of the same, and with a second, upper region (II), which is connected to the lower region (I) and which does not contain any liquid during start-up, into which the reactor contents (RI) are fed via one or more external pipelines (1) by means of one, two or more pumps (2) with a ratio of directed to undirected pulse power in the range from 1/6 to 1/2. from the lower end of the first, lower Region (I) of the two-part reactor (R) is pumped around, with the product oil (P) being withdrawn from the upper end of the second upper region (II) of the two-part reactor (R), wherein the start-up oil is first heated to an operating temperature in the range from 280 to 420 °C by pumping over the one, two or more pumps (2), whereupon the previously prepared starting material (A) is continuously fed into the first, lower region (I) of the two-part reactor (R) below the liquid level, and wherein the reactor contents (RI) are pumped around from the lower end of the first, lower region (I) of the two-part reactor (R) into the second upper region (II) of the two-part reactor (R) in such a way that the ratio of the feed residence time of the starting material (A) to the pumping residence time of the reactor contents (RI) is in the range from 250 to 1 to 5000 to 1. Continuous process according to Claim 1 characterized in that the multilayer films are blown films, coextruded films and/or skin films. Continuous process according to one of the Claims 1 or 2 , characterized in that the starting material (A) contains - 0 to 40 percent by weight, preferably 15 to 25 percent by weight of polyamide 6, polyamide 6.6 and/or polyamide 6.12 and/or - 0 to 50 percent by weight, preferably 3 to 15 percent by weight of polyethylene terephthalate and/or - 10 to 95 percent by weight, preferably 40 to 70 percent by weight of polyethylene or polypropylene, - 0 to 10 percent by weight, preferably less than 3 percent by weight of inert substances, in each case based on the total weight of the starting material (A). Continuous process according to one of the Claims 1 until 3 , characterized in that the starting material (A) contains silicon dioxide, aluminum oxide, ionomers, lubricants, antiblocking agents, regranulation material and/or polylactic acid, paper, in particular white paper or brown kraft paper and/or aluminum foil. Continuous process according to one of the Claims 1 until 4 , characterized in that the bulk density of the starting material (A) is between 30 and 300 kilograms per cubic meter, preferably 40 to 80 kilograms per cubic meter. Continuous process according to one of the Claims 1 until 5 , characterized in that the starting material (A) is formed from predominantly flat particles, and that the average surface diameter of the particles of the starting material (A) is between 10 and 50 millimeters, preferably between 15 and 30 millimeters. Continuous process according to one of the Claims 1 until 6 , characterized in that the multilayer films originate from used packaging, in particular from food packaging, technical packaging and/or pharmaceutical packaging, in particular from end-user waste and/or waste from operational collection systems. Continuous process according to one of the Claims 1 until 7 , characterized in that the waste from multilayer films is production waste, processing residues, in particular trimming residues and residues from punching and/or regranulates and/or reextrudates from the starting material (A). Continuous process according to one of the Claims 1 until 8th , characterized in that the oxygen content in the product oil (P) is 40 to 90%, in particular 80%, lower than in the starting material (A), and that the nitrogen content in the product oil (P) is 50 to 80%, in particular 70%, lower than in the starting material (A). Continuous process according to one of the Claims 1 until 9 , characterized in that the calorific value of the product oil (P) is between 41 and 46 megajoules per kilogram, preferably 45 megajoules per kilogram. Continuous process according to one of the Claims 1 until 10 , characterized in that in the product oil (P) the formation of polycyclic aromatic hydrocarbons, in particular naphthalene, acenaphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene and/or benzo(a) pyrene, is minimized and the sum of polycyclic aromatic hydrocarbons is between 100 and a maximum of 1000 ppm, preferably a maximum of 600 ppm. Continuous process according to one of the Claim 1 until 11 characterized in that the product oil (P) contains caprolactam in a concentration of 0.5 up to 5 percent by weight, preferably in a concentration of at least 1.5 percent by weight. Use of the product oil (P) obtained in a process according to one of the Claims 1 until 12 as a petroleum substitute feedstock, in particular as a substitute feedstock for naphtha and/or high vacuum gas oil in steam crackers. Use of the product oil (P) obtained in a process according to one of the Claims 1 until 12 as a feedstock for direct distillation to separate diesel fuel and/or kerosene and/or naphtha.

Images