DESCRIPTION

This application claims benefit from European patent application EP21217838.8, filed on 27 December 2021, its content being incorporated herein by reference.

FIELD

[0001] The present disclosure is related to the field of processing plastic material through continuous thermocatalytic conversion into fuel products.

BACKGROUND

[0002] The growth of welfare levels in modern society during the past decades has brought a significant increase in the production of all kinds of commodities, which directly or indirectly generate waste. Plastics have been one of the materials with the fastest growth because of their wide range of applications due to versatility and relatively low cost. Since the duration of life of plastic products is relatively small, there is a vast plastics waste stream that reaches each year to the final recipients thereby creating severe environmental hazards. Since the disposal of post-consumer plastics is continuously being constrained by relevant governmental legislations and escalating costs, there is considerable demand for alternatives to disposal or land filling with waste plastics. Such alternatives may include source reduction, reuse, recycling, and recovery of the inherent energy value through waste-to-energy incineration and processed fuel applications. Each of these options potentially reduces waste and conserves natural resources.

[0003] The process of thermolysis (or pyrolysis) is a well-known method of chemical reaction in which a relatively large compound is broken down into molecules due to high temperatures. Such process for converting waste plastic into liquid fuels is generally acknowledged as a convenient way to handle waste plastic, since the cost is manageable, and the final product (liquid fuel) may have properties that are more or less similar to the common petroleum fuels. In addition, the products that are deriving from the thermolysis of plastic provide the advantage of not containing any sulfur, as the petroleum products do, thereby being more environmentally friendly, since sulfur is a known pollutant that also affects the health of the general public.

[0004] EP3487958A1 describes a solid fuel pyrolysis system. The disclosed pyrolysis system comprises a first pyrolysis reactor having an infeed end with a solid fuel inlet and a discharge end with a solid removal outlet, and a second pyrolysis reactor having an infeed end with a solid fuel inlet and a discharge end with a solid removal outlet. The first and second reactors are arranged with the solid fuel inlet of the second reactor being in communication with the solid removal outlet of the first reactor for transfer of processed solid fuel from the first reactor to the second reactor.

[0005] IJS2011236516 discloses a coal reforming apparatus that includes a dryer body provided to dry low-quality coal, a pyrolysis body which pyrolyzes the dried coal and a briquetter which compression-molds the pyrolyzed coal. The coal reforming apparatus has a radical scavenger supplier which supplies drying gas with a radical scavenger so that the low-quality coal can be dried in an atmosphere containing the radical scavenger. The drying gas is supplied from a drying gas supply source and is heated by a heater while the radical scavenger is formed of an organic compound having a hydroxyl group.

[0006] Conventional plants however, that try to convert waste plastic to usable fuel do show some drawbacks, mainly related to the thermal efficiency of the overall process. In detail, in conventional plants for converting plastic to liquid fuel, the process is not continuous, meaning that when a batch of raw material is process through a thermolysis reactor chamber, then the entire operation should stop so as to cool down the reactor and remove any carbon residues. In addition, the various sections of conventional plants (thermolysis reactor, feedstock system, drying apparatus) are not interconnected, thereby each one requiring its own external source of energy to operate, while at the same time a significant amount of heating energy that is produced during each sections operation is lost, thereby resulting in a relatively low thermal efficiency of the overall plant and consequently to questionable quality of the final products.

[0007] It is thus an object of the present disclosure to overcome the aforementioned drawbacks. The described plant for converting plastic raw material into usable fuel is designed and based on a continuous closed operation cycle where each section of the plant interacts with each other in a way which achieves maximum energy efficiency. In addition, due to the arrangement and interconnection of the various individual stations/equipment of the plant, a relatively compact/controllable size of the plant is achieved, thereby allowing the installation of such a plant in a quite fast and precise manner in any workplace. Such arrangement further allows for a continuous thermolysis reaction and a continuous extraction of syngas from the reactor, thus enhancing the efficiency of the overall plant and process.

SUMMARY

[0008] According to a first aspect of the present disclosure there is provided a plant configured to convert plastic materials into usable fuel, comprising, a feedstock supply system for the storage of the plastic raw material, a material preparatory system for preparing the raw material prior to the conversion, a preheating line for increasing the temperature of the plastic raw material, a thermolysis reactor for processing the plastic raw material, one or more oil condensers, one or more-distillation towers that are connected to the one or more oil condensers, an oil preheating chamber that is connected to the thermolysis reactor and an oil boiler distillatory that is configured to vaporize olefin that is produced in the oil preheating chamber and results from syngas coming from the thermolysis reactor, said oil boiler distillatory being connected to the oil preheating chamber.

[0009] In embodiments, the plant comprises one or more three-phase separators that are connected to the one or more distillation towers, for separating a fluid from the distillation tower to gas, oil, and water phases.

[0010] In embodiments, the material preparatory system comprises at least two drying apparatuses, wherein the raw material is directed towards the at least two drying apparatus at an ambient temperature and wherein the drying apparatus heats the raw material to reach a temperature between 70-90°C, said temperature being regulated by one or more gas valves.

[0011] In embodiments, the material preparatory system comprises an oxygen extraction apparatus that is connected to the at least two drying apparatuses wherein the oxygen extraction apparatus comprises an inlet and an outlet and a rotating cylindrical chamber that is in fluid communication with said inlet and outlet, wherein the cylindrical chamber includes plastic raw material that is received from the at least two drying apparatuses at a temperature of about 70-90°C and oxygen, and wherein, during operation, exhaust gas flows through the inlet to the cylindrical chamber and pushes the oxygen towards the outlet of the apparatus thereby removing the oxygen and heating the raw material to a temperature of about 120-140 °C.

[0012] In embodiments, the preheating line comprises a plurality of heat exchanging units wherein said plurality of heat exchanging units are arranged in series and comprises a first feeding heat exchanger configured to receive raw material in solid state at a first temperature and a first conveyor heat exchanger that is connected to the first feeding heat exchanger, a second feeding heat exchanger that is configured to guide the plastic material in molten state towards a second conveyor heat exchanger at a second temperature, wherein the first temperature of the solid state is in between 100-160 °C, optionally 120-140°C, and the second temperature of the molten state is between 180- 240°C, optionally 200-220 °C.

[0013] In embodiments, the the thermolysis reactor comprises a reaction chamber for receiving the material after the preheating line, at least one gas burner that is mounted on a side of the reaction chamber for producing exhaust gases, an agitating device for agitating, heating and homogenising the plastic material and a carbon rejection device that is connected to the reaction chamber. [0014] In embodiments, the thermolysis reactor is provided with an exhaust gases collector that is connected to the at least one gas burner, wherein said exhaust gases exhaust gases are distributed within the reactor through ducts that form one or more heating jackets that surround the reactor and wherein the exhaust gases pass through the agitating device.

[0015] In embodiments, the one or more oil condensers comprise at least two heat exchanging units, a plurality of control valves and a temperature control system wherein the one or more oil condensers are designed such that when the syngas in the oil condensers, they are condensed to a temperature between 150-180°C with the use of water.

[0016] In embodiments, the one or more three-phase separators are in the form of a vessel and comprise; a primary separation section comprising an inlet for receiving a fluid from the distillation tower, wherein when the fluid enters the vessel comes in direct contact with a deflector, thereby causing separation of the fluid to liquid in the form of droplets and gas phase, a gravity section wherein the droplets are separated by gravity means, a coalescing section and a liquid collection section for receiving the liquid that was removed from the gases in the primary, the gravity and the coalescing section.

[0017] In embodiments, the feedstock supply system comprises at least one feed silo for storing the raw material, a shredder for shredding the raw material into suitable shape and size and a screw conveyor system for transferring the raw material towards the material preparatory system, wherein the at least one feed silo comprises at least one load cell configure to weight the raw material.

[0018] In embodiments, the screw conveyor system comprises a linking mechanism that is designed such that it allows to connect an additional feed silo with additional raw material to be transferred towards the material preparatory system.

[0019] In a second aspect of the disclosure, a process of converting plastic raw material to usable fuel comprising the steps of: providing plastic raw material to a feedstock supply system in an ambient temperature deducting the humidity from the plastic material through heat recovery via at least two drying apparatuses and heating the plastic to a temperature of about 70-90°C removing the oxygen through an oxygen removal apparatus that is connected to the at least two drying apparatuses and heating the plastic to a temperature of about 120-140 °C, wherein the apparatus (112) comprises an inlet and an outlet and a rotating cylindrical chamber that is in fluid communication with said inlet and outlet, wherein, the cylindrical chamber includes plastic raw material that is received from the at least two drying apparatuses at a temperature of about 70-90 °C and oxygen, and wherein, during operation, exhaust gas flows through the inlet to the cylindrical chamber and pushes the oxygen towards the outlet of the apparatus, thereby removing the oxygen and heating the raw material to a temperature of about 120-140 °C . Preheating the raw material through heat recovery to a pre-defined temperature via a preheating line, thereby creating a molten plastic, heating the molten plastic into a thermolysis reactor thereby modifying its state to gaseous. [0020] In embodiments, the process comprises the steps of transferring syngas that is produced from the heating of the molten plastic in the thermolysis reactor to an oil preheating chamber thereby producing olefin, transferring the produced olefin to an oil boiler distillatory and vaporizing the olefin into the oil boiler distillatory thereby producing syngas and transferring such syngas to the oil preheating chamber.

[0021] In embodiments, the process comprises transferring the syngas that is produced from the heating of the molten plastic in the thermolysis reactorto the at least two drying apparatuses, thereby preheating the plastic material.

[0022] In embodiments, the process comprises the step of transferring the syngas from the at least two drying apparatuses to the one or more oil condensers for condensing the syngas and subsequently transferring the part of the syngas that is not condensed in the one or more oil condensers to the one or more distillation towers, thereby producing a mixture oil, water and gas, and transferring the mixture of oil, water and gas to one or more 3-phase separators.

[0023] In embodiments, the process comprises the steps of

- transferring exhaust gases from an oil boiler distillatory to an exhaust gases collector of a thermolysis reactor,

- transferring the exhaust gases from the exhaust gases collector of the thermolysis reactor to a preheating line, transferring the exhaust gases from the preheating line to an oxygen extraction apparatus.

[0024] According to aspects of the disclosure the process comprises continuously calculating the level of carbon residues and automatically rejecting carbon residues via a carbon rejecting system when the carbon residues are above a predetermined threshold level.

[0025] Dependent embodiments of the aforementioned aspects of the disclosure are given in the dependent claims and explained in the following description, to which the reader should now refer. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Aspects of an embodiment will be described in reference to the drawings, where like numerals reflect like elements:

Figure 1 shows a process flowchart of a continuous thermolysis plastic-to-fuel conversion plant according to present concept

Figures la, lb, lc are three enlarged views of three successive parts of Figure 1

Figures 2 shows the main components of the plant according to the present concept Figure 3 shows an overview of the exhaust gas flow according to the present concept Figure 4 shows an overview of the syngas flow according to the present concept

Figure 5 shows a flowchart describing the various syngas and fractions of the overall process

DETAILED DESCRIPTION

[0027] An embodiment of the plant according to aspects of the disclosure will now be described with reference to Figures 1-5. Although the plant and the process of converting plastic raw material to usable fuel described with reference to specific examples, it should be understood that modifications and changes may be made to these examples without going beyond the general scope as defined by the claims. In particular, individual characteristics of the various embodiments shown and/or mentioned herein may be combined in additional embodiments. Consequently, the description and the drawings should be considered in a sense that is illustrative rather than restrictive. The Figures, which are not necessarily to scale, depict illustrative aspects and are not intended to limit the scope of the disclosure. The illustrative aspects depicted are intended only as exemplary.

[0028] The term "exemplary" is used in the sense of "example," rather than "ideal." While aspects of the disclosure are amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit aspects of the disclosure to the particular embodiment(s) described. On the contrary, the intention of this disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.

[0029] Various materials, methods of construction and methods of fastening will be discussed in the context of the disclosed embodiment(s). Those skilled in the art will recognize known substitutes for the materials, construction methods, and fastening methods, all of which are contemplated as compatible with the disclosed embodiment(s) and are intended to be encompassed by the appended claims. [0030] As used in this disclosure and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. As used in this disclosure and the appended claims, the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise.

[0031] Throughout the description, including the claims, the terms "comprising a," "including a," and "having a" should be understood as being synonymous with "comprising one or more," "including one or more," and "having one or more" unless otherwise stated. In addition, any range set forth in the description, including the claims should be understood as including its end value(s) unless otherwise stated. Specific values for described elements should be understood to be within accepted manufacturing or industry tolerances known to one of skill in the art, and any use of the terms "substantially," "approximately," and "generally" should be understood to mean falling within such accepted tolerances.

[0032] When an element or feature is referred to herein as being "on," "engaged to," "connected to," or "coupled to" another element or feature, it may be directly on, engaged, connected, or coupled to the other element or feature, or intervening elements or features may be present. In contrast, when an element or feature is referred to as being "directly on," "directly engaged to," "directly connected to," or "directly coupled to" another element or feature, there may be no intervening elements or features present. Other words used to describe the relationship between elements or features should be interpreted in a like fashion (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.).

[0033] Spatially relative terms, such as "top," "bottom," "middle," "inner," "outer," "beneath," "below," "lower," "above," "upper," and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the drawings. Spatially relative terms may be intended to encompass different orientations of a device in use or operation in addition to the orientation depicted in the drawings. For example, if the device in the drawings is turned over, elements described as "below", or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the example term "below" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0034] Although the terms "first," "second," etc. may be used herein to describe various elements, components, regions, layers, sections, and/or parameters, these elements, components, regions, layers, sections, and/or parameters should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or section from another region, layer, or section. Thus, a first element, component, region, layer, or section discussed herein could be termed a second element, component, region, layer, or section without departing from the teachings of the present disclosure.

[0035] Figure 1 and partial views la, lb, lc of the same Figure 1 illustrate the various stations of the plant for converting plastic material to usable fuel. Usable fuels are produced in various steps of the process. In examples, usable fuel can be produced from the thermolysis reactor ( for example carbon black), from the condensation within the oil preheating chamber (307) (for example olefin), from the condensation at the drying apparatuses (101, 104) (for example olefin, fuel oil C20 to C50), from the condensation at the oil condensers (501, 502) (for example olefin , fuel oil (C20 to C50) , diesel (C14 to C20)) as well as from the three phase separators (512, 514) (olefin, diesel (C14 to C20), kerosene (CIO to C16). More details for each part of the plant will be described later in this specification.

[0036] The plant, according to a first embodiment of the disclosure, comprises a feedstock supply system that may comprise two or more feed silos (004, Oil), a material preparatory system for preparing the raw material prior to the conversion, wherein the material preparatory system may comprise at least two drying apparatuses (101, 104), a preheating line (201, 202) for increasing the temperature of the plastic raw material, a thermolysis reactor (301) for processing the raw material, one or moil oil condensers (501, 502) and one or more distillation towers (511, 513) that is connected to the one or more oil condensers (501, 502). The plant further comprises an oil boiler distillatory (401) and an oil preheating chamber (307) that may be connected to the oil boiler distillatory (401) and to the thermolysis reactor (301). Additionally, the plant may also comprise one or more three- phase separators (512, 514) that are connected to the one or more distillation towers (511, 513) and their purpose is to separate the fluid to gas and oil and water phase. Such arrangement and interconnection of the various components of the conversion plant is advantageous since it provides a continuous closed operation cycle where each section of the plant interacts with each other, thereby achieving the maximum possible energy efficiency.

[0037] In embodiments, the feedstock supply system may also comprise a shredding device and a screw conveyor. The plastic raw material in its initial shape which may be cylindrical, or sheet shaped etc., is transferred to the shredding device where the relatively large parts are shredded and thus minimized to suitable shape and size. In an example, an overband magnet may also be used to separate the any metal residues from the raw material in an effective and quick manner. Upon separation of the metal components the shredding device forms the plastic material preferably in cylindrical shaped particles ('spheres') with a maximum diameter of 10mm. Afterwards, such spheres are guided through conveyors to holding silos where they are stored before being fed to the feed silos. The plastic materials that are suitable for the conversion according to the present disclosure may be, but not limited to, PE (polyethylene), PET (polyethylene terephthalate), HDPE (high density polyethylene), LDPE (low density polyethylene), PP (polypropylene), PS (polystyrene), ABS (acrylonitrile-butadiene-styrene copolymer). In an example, the most preferred feedstock from the above list of materials for the production of liquid hydrocarbons are the PE, PP and PS thermoplastics which with the addition of thermosetting plastics, wood, and paper to the feedstock results to the formation of carbonous substances and lowers the rate and yield of liquid products. This happens because the thermolysis products are directly related to the chemical composition and chemical structure of the plastics, since the chemical composition of the feedstock affects the thermolysis process. It has to be noted, that is of significant importance if the plastic feedstock contains PVC, since the PVC thermolysis the resulting products may contain HCI that is found to be hazardous for the fuels. In that case wherein the feedstock comprises PVC the plant should also comprise a re-treatment system to remove Hcl from the resulting pyrolysis products. The thermolysis products may be grouped as petroleum gases, petrol, kerosene, diesel, and WAX (>C ₅ o). The above-mentioned fuels may contain hydrocarbon group with different carbon chain lengths as given in below Tablel. However, it must be contemplated that there are also other ways to describe the hydrocarbons such as boiling range, phase of products at room temperature etc.

Table 1. Hydrocarbon range in commercial fuels

[0038] In embodiments of the present disclosure, the feedstock supply system may comprise two or more feed silos. A different type of plastic may be stored in each silo, such as but not limited to: PE (polyethylene), PET (polyethylene terephthalate), HDPE (high density polyethylene), LDPE (low density polyethylene), PP (polypropylene), PS (polystyrene), ABS (acrylonitrile-butadiene-styrene copolymer) or a mixture of the above. In that way, the plant has the flexibility to select a percentage of each type of plastic each time and make a mixture of different types depending on the availability of raw materials and the target parameters set for the final products, the desired "recipe" is selected each time to produce high quality liquid fuel in the best and most efficient way for the operation of the plant. In an example, feedstock is loaded into a hopper (001) and is led for storage via a screw conveyor network in weighing silos (004, Oil, 016, ...). The structured way of connecting the screw conveyors (010, 020, ...), allows the addition of storage silo (Oil, 016...) without requiring changes to the overall mechanical equipment, making the feedstock supply system easily expandable from, for example 1 to 9 silos. Each silo (004, Oil, 016, ...) may be mounted on load cells (005, 012, 018, ...). At the bottom of each silo, for example at its outlet, there may be a proportional flow valve (006) which is configured to control the flow of raw material coming out of the silo. Additionally, under each silo there may be located a conveyor link (007, 042). In detail, the material coming out of the silo is inserted in the conveyor link (007). Conveyor link is designed to have appropriate ports where screw conveyors (009, 010, 020, ...) can be connected and through them material to be directed to the next station of the plant. The construction of the conveyor link (007) is such that it allows the connection of screw conveyors between the silos (009, 010, 020, ...) so that a network of screw conveyors can be created. In this way, the mixing of the raw materials is achieved depending on the percentage of raw material from each silo, for the completion of the recipe. Maintenance of the overall equipment is also facilitated since it is not required to interrupt the entire production process.

[0039] In embodiments, a material preparatory system is used for preparing the raw material prior to the thermolysis reaction. The purpose of this system is to deduct humidity and oxygen from the plastic material and calculate the quantity of the material that will be further processed. In an example, the material preparatory system comprises at least two drying apparatus (101, 104). Feedstock is guided through a screw conveyor network (010, 020,) from the feed silos (004, 011,...) to the dryers (101, 104). Said dryers may be mounted on load cells that ensure the precision of the quantity of the material to be processed. The dryers may be of cylindrical shape and each of them may comprise a screw conveyor for filling and recirculating the plastic material. In addition, the dryers (101, 104) may also comprise one or more gas heat exchangers for diffusing relatively hot air to the plastic material during the drying process. In an example, the drying apparatus (101, 104) may be designed such that they comprise two heating jackets thereby allowing the gases to pass and the necessary heat to be transferred to the plastic material. The plastic material enters the at least two drying apparatus at an ambient temperature and is heated to a temperature between 70-90°C. In an embodiment, this preheating of the material is achieved by heat recovery the recirculation of syngas that are coming from a thermolysis reactor (301) and an oil boiler distillatory as it will be described later in that specification. In that case, through paths/ducts and specially designed proportional gas valves (122, 123) syngas gases are guided to heating jackets that surround each drying apparatus thereby increasing the temperature of the material to the desired range. As already mentioned, a jacket for the syngas is coming from the thermolysis reactor (301) and another jacket for the syngas is coming from an oil boiler distillatory. In an example, the plant may also comprise an oil preheating chamber (307) that is connected to the thermolysis reactor (301) and the oil boiler distillatory (401). In that case, syngas that is coming from an oil preheating chamber (307), where energy has been recovered (from ~400°C reduced to ~ 330°C) and their temperature when they enter the dryer heating jacket is ~ 320°C (T2), while when exiting of it ~230°C (T3). The difference in inlet-outlet temperature At of the syngas, is the recovered energy transferred to the plastic raw material. The recovered energy Er depends on the flow of the plastic raw material and its temperature difference in the dryers. According to the described arrangement, the below calculation can be derived

At = tin - tout where, Er= Energy recovery

Q- Material flow / h

At = Temperature difference ti _n = Inlet temperature tout = Output temperature

The setting of the desired temperature of the plastic raw material at 70°C - 90°C and the humidity level <1%, is achieved by the automatic control of special proportional gas valves (122, 123, ...). The flow of the syngas is regulated through the valves, depending on the current operating conditions.

[0040] Additionally, the concentrates that are collected to the drying apparatuses and are resulting from the temperature reduction of the syngas coming from the Thermolysis reactor (301), are led to the olefins tank (311) for further processing.

The condensates that are collected to the drying apparatuses and are resulting from the temperature reduction of the syngas coming from the Oil Boiler distillatory (401), are transferred to a C20 - C50 condensate storage tank. In an example, the plant comprises two dryers (101, 104). In that specific embodiment, when the plastic raw material is prepared in the first dryer (101), then it feeds the next stage of the process. While the first dryer (101) feeds the next stage, the second dryer (104) prepares the plastic raw material. Once the first dryer (101) is empty, then the supply of the next stage is done by the second dryer (104) and in the first dryer (101) the preparation of the material begins. [004.1] In embodiments, the material preparatory system comprises an oxygen extraction apparatus (112) that is connected to the at least two drying apparatus (101, 104) and is configured to receive the raw material at a temperature between 70-90°C, remove the oxygen from the rotating cylindrical chamber and increase the temperature of the raw material in the region between 120 and 140 °C. When the process of preparing the material in the dryers is completed, material is at a temperature of 70 - 90°C and humidity level < 1%. Then the material is led through screw conveyors (107, 109, 111) to the next stage and enters the oxygen extraction apparatus (112). The oxygen extraction apparatus may comprise a rotating cylindrical chamber. Such apparatus (112) may contain suitably designed diffusers with which the plastic raw material is evenly diffused in the space. The diffusers are designed and mounted on the rotating cylindrical chamber such that they also rotate with the cylindrical chamber thereby causing the plastic raw material to be smoothly distributed within the space of the oxygen removal apparatus. The increasing of material temperature from 70°C to 90°C up to the region of 120°C to 140°C and the removal of oxygen from the rotating cylindrical chamber, may be achieved by heat recovery from the recirculation of exhaust gases, which are coming from the pre-heating line (201). In detail, exhaust gases are led through specific paths into the apparatus for oxygen extraction. By the exhaust gases diffusion, oxygen is removed from the rotating cylindrical chamber of the oxygen removal apparatus and with proportional exhaust gases valves (116, 117) achieved full temperature control of material. In detail, when the thermolysis reactor is not in operation and subsequently the oxygen extraction apparatus is not working, within the rotating cylindrical chamber there is placed plastic raw material (for example granule shaped) and oxygen. Since the reactor is not in operation, no exhaust gases are produced therefore the cylindrical chamber is free of any exhaust gases at that stage. However, when the reactor starts working, the exhaust gas that are produced are continuously driven and enter through an inlet of the oxygen extraction apparatus to the rotating cylindrical chamber. As the chamber fills with exhaust gas of continuous flow, the oxygen is pushed due to that flow to an outlet of the oxygen extraction apparatus, said outlet being on an opposite end of the previously mentioned inlet of the apparatus. At the same time, the cylindrical chamber is rotating thereby causing the diffusers to spread the raw material within the chamber thus causing the increase of the temperature of the plastic material to a temperature of about 120°C to 140°C. There is succeeded therefore to have in the cylindrical chamber only CO2 and not oxygen. As mentioned previously, the oxygen extraction apparatus is fed with plastic raw material through screw conveyors (107, 109, 111) as well as from the drying apparatuses (101, 104). After the increase of the temperature to 120°C to 140°C the material is driven to the preheating line (201) through a screw conveyor (114) for further processing as it will described hereunder. The oxygen extraction apparatus therefore serves the purpose of preheating the plastic material and at the same time ensuring that no oxygen will pass through the screw conveyor (114) that transfer the plastic material to the preheating line (210) and afterward to the thermolysis reactor.

[0042] In embodiments, the preheating line (201) may comprise an array of heat exchangers with corresponding screw conveyors. Said heat exchangers may be distinguished to feeding heat exchangers IN (201), conveyor heat exchanger IN (202), feeding heat exchanger OUT (203) and conveyor heat exchanger OUT (204). A heat exchanger group that includes the above modules may be called a unit. In a preferred embodiment the preheating line may comprise 3 three said units. In an example, plastic material is introduced into the feeding heat exchanger IN (201) in solid state and at a temperature of 120 - 140°C. As it passes through the conveyor heat exchanger IN (202), feeding heat exchanger OUT (203), conveyor heat exchanger OUT (204), its temperature increases. Passing through all three (3) units of the preheating line the plastic material has become molten and its temperature at the exit from the preheating line is at 200 - 220°C. In examples, the exchangers may comprise sensors for measuring the temperature at the inlet and outlet of the material and at the inlet and outlet of the exhaust gases. In addition, each conveyor heat exchanger is suitable for gas and solid material. The increase in the temperature of the material is achieved by recovering the heat from the recirculation of the exhaust gases, which come from the thermolysis reactor (301) and the oil boiler distillatory (401). In examples, at the input and the output of the conveyor heat exchangers there may be located a first linking mechanism with which the conveyor heat exchangers are connected to each other, and the material is transferred and a second linking mechanism for the exhaust gases, with which the exhaust gases are routed, and the heating jackets of the conveyor heat exchangers are connected. Such configuration is advantageous since it allows the raw material to increase its temperature in an energy efficient manner since no external power source is required because of the heat recovery from the exhaust gases. In addition, scalability and overall maintenance of the overall system is enhanced since conveyor heat exchangers may be added or maintained without the need for modifications to the other equipment.

[0043] In embodiments, the thermolysis reactor comprises a reaction chamber (301) for receiving the material after the preheating line, at least one gas burner (302) for producing exhaust gases, an agitating device (303) for heating the plastic material and a carbon rejection device (304) that is connected to the reaction chamber. When the process of preparing the material in the preheating line section is completed, material has become molten with temperature about 220°C. Then the material is led to the thermolysis reactor (301). It has to be noted that molten plastic is continuously fed to the reactor, thereby ensuring uninterrupted operation of the entire plant. The reactor chamber where the thermolysis takes place may be made of stainless steel to ensure durability. It may be arranged horizontally and may have a semicircular shape. The at least one gas burner (302), which may be preferably two, are used to create the required temperature for the heating distributors, in order to achieve the optimal diffusion of the exhaust gases. They may preferably be mounted on one side of the reactor chamber and direct the exhaust gases through specific paths to the reactor where the thermolysis reaction of the plastic takes place. Power of the burners is proportional to a wide range and a closed loop air / fuel ratio control is performed, to achieve maximum efficiency and low NOx levels. It has to be noted that these gas burners (302) can receive variable fuels. Depending on availability, natural gas, or liquefied petroleum gas (LPG) can be used as the main fuel and noncondensable gases as supplementary fuel. Non-condensable gases are stored in a tank where, depending on the stock, the filling rate of the fuel mixture is automatically calculated. In this way, the basic fuel is saved, and the non-condensable gases are utilized. In an example, the thermolysis reactor may also comprise an exhaust gases collector (305) that is connected to the at least one gas burner (302), wherein said exhaust gases exhaust gases are distributed within the reactor through ducts that form one or more heating jackets that surround the reactor (301). Through the exhaust gas collector (305), exhaust gases are collected by reactor heating jackets that surround the reactor (301). In each heating jacket, there may be a proportional flow control valve (312) at the exhaust outlet. By controlling the flow of exhaust gases through each heating jacket, a uniform distribution of temperature is achieved on the walls of the outer surface of the reactor, achieving maximum temperature absorption by the material that comes in contact with them. In an example, the thermolysis reactor comprises a reactor screw assembly. At the exhaust outlet of the screw assembly, there is a proportional valve (312) to regulate the exhaust flow. By controlling the exhaust gas flow, the maximum thermal energy efficiency in the reactor core is achieved by adapting the flow to the current operating conditions. In addition, exhaust gases that are collected from the oil boiler distillatory and through the proportional flow control valve (406) at the exhaust outlet, the necessary vacuum in the combustion chamber of the oil boiler distillatory is automatically regulated.

[0044] In embodiments, the agitation device (303) may comprise screws in the form of helical ducts of different diameters and opposite direction which are configured to agitate and heat the material in the reactor core using the exhaust gases. In addition, scrapers that are fitted around the screws, detach and transport any residues (for example coke formation and carbonized products) that may be created during the thermolysis process and accumulate on the walls of the reactor, to a carbon black reject mechanism (304) through a fully automated process. In an example, the carbon reject system may be mounted on the bottom of the reactor chamber. Through special isolation valves, the discharge of residues from the reactor chamber is without oxygen inflow into the reactor.

[0045] In embodiments, (molten) plastic enters the thermolysis reactor, preferably at a temperature of 220°C. Its temperature begins to rise using the heat of the exhaust gases which may be led to the thermolysis reactor through two different ways: Exhaust gases are led to the outside of the reactor through ducts that form three heating jackets. In each heating jacket, there may be a proportional flow control valve (312) at the exhaust outlet. By controlling the flow of exhaust gases through each heating jacket, a uniform distribution of temperature is achieved on the walls of the outer surface of the reactor, achieving maximum temperature absorption by the material that comes in contact with them. The controlling of the exhaust temperature its constant value of the three (3) heating jackets, ensures maximum absorption of temperature by the material from the total surface of reactor. In an example, the exhaust gases are led inside the thermolysis reactor through two (2) helical paths of different diameters and opposite direction, forming two (2) screws where one is placed inside the other. By rotating the screw assembly (303), the larger diameter screw located on the outer layer pushes the material to always move in the opposite direction from the inner screw. In this way two flow streams of the material are formed, where with the repeated circulation of the flow, the heat is transferred directly and evenly throughout the material, making it completely homogenized. As the exhaust gas passes through the screw assembly (303), heat is transferred to the material in the reactor core, increasing the heat transfer rate and therefore the efficiency of the reactor.

[0046] In embodiments, the temperature inside the reactor (301) reaches to a range from 370°C to 425°C (Tl). At this temperature, the plastic becomes gaseous. The reaction of the plastic at this temperature causes the plastic carbon chain lengths to randomly break into various lengths. The syngas resulting from the thermolysis reaction (in detail, from the heating of the molten plastic and thus to its conversion of its state to gaseous) pass through specially designed sections which contain electrical resistors. In this way the temperature at these points is at the desired level to achieve gasification and any small particles that have resulted from the thermolysis reaction but have not yet been gasified. Syngas exits the reactor (301) and are led through a piping network with proportional valves (308, 309) to a catalyst chamber (306). The catalyst chamber (or converter) (306) comprises metal plates with channels or grooves that may be placed crosswise so that the gases are directed through them to maximize their contact time with them. These channels typically have a height in millimeters and catalyst thickness measured in microns. The grooves may be coated with a suitable catalyst and can be arranged so that exothermic and endothermic reactions take place in alternative channels. Heat transfer is by conduction from the exothermic to the endothermic region. The advantages of this catalyst converter over conventional reactors are since the heat transfer rates (through conduction) are very high and the endo catalytic diffusion resistances are minimal. The catalyst ensures that the final fuel has a carbon chain distribution in the C8-C25 range and peaks at C16 (ketone). The gases resulting from this process are led to the Preheating Oil chamber (307). The preheating oil chamber (307) is a heat exchanger in which condensation is achieved through energy recovery. With this mode of operation and by recovering the energy present in the syngas, the fuel is separated from the syngas that come from the Thermolysis Reactor (301) and the Oil Boiler distillatory (401). The preheating oil chamber may comprise a syngas passage chamber (different chamber for syngas from the Thermolysis Reactor (301) and different chamber for syngas from the Oil Boiler distillatory (401)) and a fuel passage chamber for olefin coming from an olefin tank (311) and is used as cooling medium of the system. As already mentioned, syngas is produced from the thermolysis reactor and from oil boiler distillatory. The type of condensate that will result from the syngas depends on the rate of energy recovery that will take place. The syngas from the Thermolysis reactor (301) and the Oil Boiler distillatory (401) enter through independent piping networks, each in a different internal chamber of the preheating oil chamber (307) at a temperature of approximately 400°C. During a first condensation that occurs within the preheating oil chamber (307), olefin is produced from syngas coming from the thermolysis reactor and concentrates from syngas from the oil boiler distillatory constitute WAX (>C50). The gases that will not condensate with the oil preheating chamber may be driven to the oil condensers (501, 502) via a piping network and with the usage of valves (126-129). After heat recovery, the olefin exits the preheating oil chamber (307) at approximately ~230°C and is forwarded to the Oil Boiler distillatory (401) for further processing. The oil boiler distillatory comprises at least one gas burner (402) that is configured to produce exhaust gases that are used for heating the oil boiler distillatory (401), an exhaust gas passage chamber and an olefin passage chamber. The syngas that is produced in the oil boiler distillatory (401) is a result from the vaporization of olefin that comes from the condensation of the syngas that is produced in the thermolysis reactor. The oil boiler distillatory may comprise a burner configured to increase olefin temperature and thereby create the syngas. Such syngas is driven to the oil preheating chamber (307) (in a different internal chamberfrom the internal chamber used for the syngas of the thermolysis reactor) and there we have the first condensation of the syngas of the oil boiler distillatory that results in the production of WAX with 050 as described previously. In examples, the gases that will not condensate in the oil preheating chamber (307) may be driven to the dryers (101, 104) to preheat the raw material to a temperature of about 70-90 °C, through heat recovery and afterwards to go to the one or more oil condensers (501, 502) for further condensations. Such configuration is shown in figures 1, lb and 4. The length of the carbon chain of the condensate that will occur, depends on their outlet temperature from the preheating oil chamber (307). The inlet-outlet temperature difference At of the syngas, is the recovered energy transferred to the fuels. The recovered Er energy depends on the flow and temperature of the fuels in the preheating oil chamber (307). For optimal efficiency, automatic system operation and syngas condensate quality control, the flow and temperature of the fuel must be fully controlled. For the control of the flow and the recirculation of the fuel there may be a proportional three-way valve and for the temperature control of the fuel there is a heating-cooling temperature control system, depending on the system requirements. The following calculation may be considered: where, Er= Energy recovery

Q= Material flow / h

At = Temperature difference t _in = Inlet temperature t _out = Output temperature from the above arises that:

Q Syngas At Syngas — Q Crude Heavy oil At Crude Heavy oil

[0047] In conclusion, the operation of the above system is based on the controlled cooling of the fuels to recover energy from the syngas. With the above-described configuration and process quality control of WAX >C ₅ o concentrates is achieved while the increase of the temperature of the fuel from ~50°C to ~230°C leading to the Oil Boiler distillatory (401), thus saving the energy that the Oil Boiler distillatory will need to further gasify the condensates. The syngas with reduced temperature, through a network of piping are led to the Dryers of the Material Preparatory section for further energy recovery.

[0048] In an embodiment and as previously described, the fuel (olefin) entering the Oil Boiler distillatory (401) may have a temperature of 220-230°C. A gas burner is used to increase the temperature. The power of the burner is proportional to a wide range and a closed loop air / fuel ratio control is performed, in order to achieve maximum efficiency and low NOx levels. [0049] A key feature of the gas burner is its multi fuel function. Depending on availability, natural gas or liquefied petroleum gas (LPG) can be used as the main fuel and non-condensable gases as supplementary fuel. Non-condensable gases (520) are stored in a tank (521) where, depending on the stock, the filling rate of the fuel mixture is automatically calculated. In this way, the basic fuel is saved, and the non-condensable gases, in a temperature of about 40 degrees C (T6), are utilized.

[0050] The Oil Boiler distillatory (401) may comprise a pair of chambers designed for maximum absorption of thermal energy. The syngas resulting from this process are led to the preheating oil chamber (307), whereby the procedure described above, the WAX (>C _S o) contained in the syngas is concentrated and separated and stored in a wax tank (525). Using software, the degree of performance is calculated and when it drops below a certain level, the regeneration process begins. At the bottom of the distillatory (401) there is a valve where when it opens, residues of WAX (>Cso) are rejected. During the regeneration process, the supply of the Oil Boiler distillatory (401) is interrupted, while the burner operates at its minimum power in order to maintain the temperature of Boiler distillatory and facilitate the elimination of residues. After the end of this regeneration stage, all parts of the unit are automatically put into production process mode.

[0051] Operation of the reactor (301) is continuous. Reactor is mounted on load cells so that it is automatically checked for its continuous feeding with material from the Preheating Line section. Using software, the degree of performance is calculated and when it drops below a certain level, the regeneration process begins. When the carbon residues reach a certain level, then automatically all parts of the unit are put into proper operation so that the reactor enters regenerative mode. At this stage the carbon black reject system (304) is activated, and the residues generated by the thermolysis process are discarded from the reactor (301). At the end of this reactor regeneration phase, all parts of the unit are automatically put into production process mode. The regeneration process does not require the reduction of the reactor (301) temperature, so the accumulated energy in the reactor mass remains and thus the recovery of its energy is not required to continue the production process. In this way the regeneration time of the reactor is limited only to the disposal of carbon residues without the loss of its thermal energy

[0052] In embodiments, the oil condensers (501, 502) may comprise two (2) vessels with heat exchangers, proportional valves, and cooling temperature control system, depending on the system requirements. Syngas is led to oil condensers through a network of pipes and valves, where they are condensed using cooling water. By controlling the flow of refrigerant through analog valves, temperature (T4) is regulated (~150C° - ~180C°). As previously described, the syngas that will not condensate in the oil preheating chamber (307) is driven to the dryers (101, 104) so as to preheat the raw material through heat recovery and afterwards they are driven to the one or more oil condensers (501, 502) for further condensations. The syngas that will not condensate within the one or more oil condensers are driven to the one or more distillation towers. The distillation towers (511, 513) separate the light fractions from the concentrates. Depending on the temperature of the syngas coming from the oil condensers (501, 502) and the temperature of the refrigerant, type of light fractions that will occur varies. The gas rises level through the tower. As the gases rise, their temperature drops, and some hydrocarbons begin to condense. Each fraction condensed to a certain level contains hydrocarbon molecules with a similar number of carbon atoms. Figure 5 briefly shows where the syngas is produced as well as the fractions that can be derived from the components of the plant.

[0053] The mixture of oil, water and gas resulting from this step is led to one or more 3-phase separators (512, 514) in a temperature of about 70-90 degrees C (T5) that may be arranged in series. The 3-phase separators (512, 514) may comprise: a primary separation section comprising an inlet for receiving a fluid (mixture of oil, water and gas) from the one or more distillation towers, wherein when the fluid enters the vessel comes in direct contact with a deflector, thereby causing separation of the fluid to liquid in the form of droplets and gas phase. a gravity section wherein the droplets are separated by gravity means a coalescing section a liquid collection section for receiving the liquid that was removed from the gases in the primary, the gravity, and the coalescing section. The primary separation section is used to separate the main portion of free liquid in the inlet stream. The liquid enters the vessel through an inlet and immediately strikes a deflector. Sudden impact causes the initial separation of liquid and gas. The secondary or gravity section, is designed to use the force of gravity to enhance separation of entrained droplets. The coalescing section utilizes a coalescer or mist extractor. It may be constructed of stainless-steel wire mesh tightly wrapped in a cylindrical shape. The effectiveness of wire mesh depends largely on the appropriate gas velocity range. If the velocity is too high, the liquids knocked out will be re-entrained. If the velocity is low, the vapour just drifts through the mesh element without the droplets impinging and coalescing. The liquid collection section acts as receiver for all liquid removed from gas in the primary, secondary, and coalescing section. In an example, in a 3-phase separator, an inlet flap device is used in order to gradually reduce the inlet momentum and evenly distribute the gas phase across the vessel diameter. [0054] In a second aspect, the previously described plant can operate a process of converting plastic raw material to usable fuel that is comprising the steps of:

Providing plastic raw material to a feedstock supply system (Oil) in an ambient temperature Deducting the humidity from the plastic material via a drying apparatus (101) and heating the plastic to a temperature between 70-90°C

Preheating the raw material to a pre-defined temperature via a preheating line (210, 203), thereby creating a molten plastic

Heating the molten plastic into a thermolysis reactor (301) thereby modifying its state to gaseous. [0055] In examples, the process may also comprise transferring syngas that is derived from the thermolysis reactor (301) to an oil preheating chamber (307) and transferring syngas that is derived from an oil boiler distillatory to an oil preheating chamber (307). The process may further comprise the step of transferring the syngas that is derived both from the thermolysis reactor (301) and the oil boiler distillatory (401) from the oil preheating chamber (307) to at least two drying apparatuses (101, 104). In examples, the process may comprise the step of transferring syngas from the at least two drying apparatuses to the one or more oil condensers for condensing the syngas and subsequently transferring that part of the syngas that was not condensed in the one or more oil condensers to the one or more distillation towers for producing a mixture of oil, water and gas and transferring that mixture to one or more 3-phase separators. [0056] In examples, the process may also comprise the steps in the following order:

- Transferring exhaust gases from an oil boiler distillatory (401) to an exhaust gas collector (305) of a thermolysis reactor.

- Transferring the exhaust gases from the thermolysis reactor (301) to a preheating line (201, 202)

- Transferring the exhaust gases from the preheating line (401) to an oxygen extraction apparatus (112).

[0057] Such process is advantageous since it allows the separation and storage of plastic raw materials in different silos (004, Oil, ...) depending on the type and quality of the plastic and allows the percentage reception of raw material from each silo in order to complete the recipe. In addition, the recovery of energy from the produced syngas and from the exhaust gases of the burners, enhances the unit efficiency. It has to be noted that according to the described process and arrangement, syngas is continuously produced and subsequently removed from the reaction chamber of the thermolysis reactor. Further, due to the slight temperature difference between the liquid plastic material entering the reactor and the temperature at which the heat treatment reaction takes place and the design of the screw assembly which provides direct and uniform heat transfer to the material from the core of the reactor and at the same time its homogenization, the residence time of the raw material in the reactor is reduced to the minimum. Last, through the light fractions distillation tower and the distillates collection from different points of the unit of the present disclosure, the final product may be divided into three (3) categories: light, medium and heavy distillates, thereby resulting in a stable and controlled quality of the final products which come from a lower temperature reaction, with or without the use of catalysts.

[0058] It should be noted that the above embodiments are only for illustrating and not limiting the technical solutions of the present disclosure. Although the present disclosure has been described in detail with reference to the above embodiments, those skilled in the art should understand that any modifications or equivalent substitutions of the present disclosure are intended to be included within the scope of the appended claims.

[0059] Although the present disclosure herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present disclosure.

[0060] It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the appended claims.

[0061] Reference numerals