NL2033241B1

NL2033241B1 - Staggered heat exchangers for cracking hydrocarbons

Info

Publication number: NL2033241B1
Application number: NL2033241A
Authority: NL
Inventors: Christiaan Van Der Ree Teunis; Goldsmits Rik
Original assignee: Bluealp Innovations B V
Priority date: 2022-10-05
Filing date: 2022-10-05
Publication date: 2024-04-18
Also published as: WO2024074660A1

Abstract

A device for heating molten long-chained hydrocarbons comprises a first heating section having at least one first material flow tube extending from a first heating section inlet to a first heating section outlet, the first material flow tube providing a flow path for the molten longchained hydrocarbons from the first heating section inlet to the first heating section outlet, and a first heating structure extending along at least a portion of the first material flow tube, the first heating structure being configured to transfer heat to the first material flow tube; and a second heating section having at least one second material flow tube and at least one third material flow tube, the at least one second material flow tube extending from a second heating section inlet to a second heating section outlet, the at least one third material flow tube extending from a third heating section inlet to a third heating section outlet, the second and third material flow tubes providing flow paths for the molten long-chained hydrocarbons from the second and third heating section inlets to the second and third heating section outlets, respectively, wherein the second and third heating section inlets being configured to receive the molten long-chained hydrocarbons from the first heating section outlet, and to split the flow path for the molten long-chained hydrocarbons towards the at least one second material flow tube and the at least one third material flow tube; and wherein the second heating section inlet and the third heating section inlet are arranged on different heights.

Description

STAGGERED HEAT EXCHANGERS FOR CRACKING HYDROCARBONS

FIELD OF THE INVENTION

The invention generally concerns methods and apparatuses to process waste plastics by means of pyrolysis, as well as the products obtained thereby. More specifically the invention concerns methods and apparatuses for heating the plastics to cracking temperatures.

Furthermore, the invention refers to a system for the separation of gas, liquid, and optionally solid particles in a pyrolyzing material. The invention further concerns a method and system to crack long-chained hydrocarbons and to separate the resulting products and in particular refers to a method and system to process plastics and polyolefins by means of cracking.

BACKGROUND OF THE INVENTION

Large quantities of waste plastics are generated in the present society. While recycling of plastics is becoming ever more efficient and effective, it is still the case that much of the waste plastic cannot be effectively or efficiently recycled and is disposed of to landfill sites where it takes many years to degrade, or it may be lost to the environment where it can be damaging to ecosystems.

Plastic materials are however made of essentially useful compounds that can be used as is and/or converted for (re)use. For example, fuels such as diesel may be derived from waste plastics, or waste plastics may be converted to raw material suitable for synthesis of new materials, such as new plastics, other hydrocarbon materials, or similar. Materials recovered from waste plastics may be useful to at least partially replace hydrocarbons more traditionally obtained from natural gas or mineral oils.

The output of plastic-to-chemical plants typically includes light hydrocarbons (LHC), heavy hydrocarbons (HHC), char, and non-condensables (gases). Currently, LHC, HHC, or mixtures thereof, are the most desirable products, however, this is market dependent.

LHC and HHC fractions are required by industry to meet certain chemical and physical specifications such as vapor pressure, initial boiling point, final boiling point, Flash point, viscosity, cloud point and cold filter plugging point. Different qualities may be desired by different customers or end-uses, but it is important that plastic-to-chemical plants produce product of stable quality. The final qualities of the product fractions is controlled by a distillation column such as those well-known and commonly used in the petrochemical industry. It is desirable that the fractions are relatively pure such that light hydrocarbons fraction and heavy hydrocarbons do not contain large portions of high boiling point compounds. Such high boiling point compounds can increase cold filter plugging points, cloud point and are often unacceptable to pyrolysis oil purchasers.

In plastic-to-chemical plants, feedstock plastics, which may comprise for the most polyethylene and polypropylene for domestic sources, form the input. These plastics made up of very long chain hydrocarbons are then cracked into shorter chains, forming a wide spectrum of molecules with a variety of chain lengths. These mixtures can be distilled into various temperature-determined fractions as is known.

A known process in the art for converting waste plastic to, among other things diesel, is the thermochemical breakdown process of pyrolysis. Pyrolysis is the thermal decomposition of the waste plastics in an inert atmosphere. In effect, the long polymer chains of the plastic’s polymers are cracked through heating, resulting in shorter hydrocarbon chains, which are generally more useful as a product.

Pyrolysis is a preferred method of performing thermochemical break down of waste plastic materials. Various attempts to provide technically and cost-effective pyrolysis of waste plastic have been attempted previously.

Technically useful results have been achieved by the technologies discussed in patent publications US2018/0010050 and WO2021053139, the contents of which publications are incorporated herein by reference.

US2018/0010050A1, discusses a method for recovering hydrocarbons from plastic wastes by pyrolysis without the use of catalysts, in particular polyolefin-rich waste. The process involves melting the plastic waste in two heating devices and mixing a stream derived from a cracking reactor with the incoming molten plastic waste of a first heating device. The heated, molten plastic is passed to a cracking reactor where the plastic materials are cracked.

Subsequent thereto the cracked materials are distilled into diesel and low boilers.

WO 2021/053139 A1 which offers a number of advancements in relation to

US2018/0010050A1, discusses, among other matters, a method for breaking down long- chain hydrocarbons from plastic-containing waste, comprising providing material containing long-chain hydrocarbons; heating a specific volume of the material containing long-chain hydrocarbons to a cracking temperature, at which cracking temperature the chains of hydrocarbons in the material start cracking into shorter chains; and for the specific volume having a temperature above the cracking temperature, exposing the specific volume to heat which is less than or equal to 50 °C above the temperature of the specific volume. After the specific volume of the material has been exposed to heat, WO 2021/053139 passes the partially cracked stream of molten plastic to a gas-liquid separation structure. The separation structure, also referred to as reactor, includes a separation zone containing a gas-liquid phase boundary, and a settling zone for heavy hydrocarbons and/or solid carbon, as well as potentially other solids such as aluminium, sands, dirt, etc., to accumulate.

Although good results have been achieved based on the above technologies, there remains room for further improvement, for example it would be useful to provide systems and processes that are more versatile than previously attempted systems.

EP 2 876 146 B1 discusses tested technology in which a process for recovering hydrocarbons from polyolefin plastic recyclables by means of pyrolytic cracking comprises: introducing the plastic recyclables into a mixing vessel under inert gas and mixing with diesel oil, removing water vapor in a first heating zone, removing acidic gases in a second heating zone, liquefying those not yet melted Plastic recyclables in a third heating zone, cracking of the plastic recyclables in a cracking reactor at approx. 400 degrees centigrade, partial condensation to prevent the discharge of paraffins, fractionation of the cracked products.

In an aspect it is an object of the present invention to provide alternatives, and preferably improvements for pyrolysis processes and apparatuses. For example, it is an object of the present invention to provide improved heating for the long-chained hydrocarbons.

Attempts to achieve effective pyrolysis of waste plastics have been previously made.

An example is discussed in patent publication WO11077419 A1 referring to a process for treating waste plastics, in which plastic is melted and then pyrolyzed in an oxygen-free atmosphere in a jacket-heated pyrolysis vessel to provide pyrolysis gases. The pyrolysis gases upwardly flow via a pipe directly linking the pyrolysis chamber to a contactor vessel, into contact with plates in the contactor vessel so that some long chain gas components condense. The condensed liquid is directly returned by downward flow through the same pipe, to the pyrolysis zone. The condensed liquid is then reheated within the pyrolysis zone and further pyrolyzed. The short chain gas components exit the contactor in gaseous form and proceed to distillation.

It is explained in WO11077419 A1 that as a batch ends, increased load on a pyrolysis chamber agitator indicates that char drying is taking place, and that the process is ending.

The pyrolysis chambers are then purged by operating double-helical agitator blades in reverse to remave char, and nitrogen is passed up through the contactor and out directly to thermal oxidisers to flush any remaining hydrocarbons, during which phase the pyrolysis vessel and contactor are isolated from the rest of the system. Such a process and system can be problematic and suboptimal. For example, the inclusion of an agitator in the pyrolysis chamber, as well as jacketed direct heating of the pyrolysis chamber, is complex yet necessary. The system also makes use of a specific type of jacket-cooled contactor with cooled contactor baffle plates that are sloped and comprise apertures, to give direct return of condensed hydrocarbons from the contactor to the pyrolysis chamber via the same pipe by which pyrolysis gases entered the contactor. This can be complex; the pyrolysis process leads to batch completion with a dry char (carbon) product; and purging associated with extended downtime of pyrolysis reactors.

There are prior attempts in which a partial condenser has been arranged directly on top of a pyrolysis vessel to return heavy hydrocarbons for further cracking. Some of these attempts have been found to be less versatile, robust, and efficient than is optimal. Without being bound by theory, and by identification through technical investigation, it may be that the condensed liquid returning from the partial condenser directly into a pyrolysis reactor vessel can lead to temperature inconsistencies and heat loss in a pyrolysis zone, requiring complex heat input at the pyrolysis zone, with possible hot spots, charring, complex agitation, and/or energy loss. Provision of a process and system that suffers less from such disadvantages may be desirable.

Another example is discussed in CH708681A1, which refers to a process for recovering hydrocarbons from polyolefin plastic recyclables by means of pyrolytic cracking. Plastic recyclables are introduced into a mixing vessel under inert gas and mixing with diesel oil, removing water vapor in a first heating zone, removing acidic gases in a second heating zone, liquefying those not yet melted plastic recyclables in a third heating zone, cracking of the plastic recyclables in a cracking reactor at about 400°C, partial condensation to prevent the discharge of paraffins, and fractionation of the cracked products.

The partial condenser in CH708681A1 is separate and spaced from the pyrolysis reactor, with a communicating pipe leading pyrolyzed gases from the pyrolysis reactor to the partial condenser. The partial condenser is adjusted so that heavy hydrocarbons that are not of the desired product character condense and are led back into a third heating zone, via a separate pipe, where they can be further cracked. The additional cracking loop reduces the inclusion of overly heavy hydrocarbons in the product.

Attempts to implement related concepts to those disclosed in CH708681A1 were found to workably result in product but showed some instability in pyrolysis and inefficiencies, for example, requiring complex heating in the pyrolysis zone. In addition, the system of

CH708681A1 may be complex to implement because of differential pressures between the partial condenser and the heating zone to which the heavy hydrocarbons are returned.

Other attempts have included US10160920 BB with a sequential cracking process for the thermal cracking of a hydrocarbon feedstock in a cascade of cracking units; US2007227874

AA discussing a method for recovering fractional hydrocarbons from recycled plastic; and

US5580443 A which discusses a process for thermally cracking a low-quality feed stock containing a considerable proportion of heavy fractions such as high-boiling fraction.

All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art.

SUMMARY

While the invention is defined in the independent claims, further aspects of the invention are 5 set forth in the dependent claims, the drawings and the following description.

BRIEF DESCRIPTION OF THE FIGURES

The figures are not to scale. Like numerals refer to like parts.

Fig. 1 shows an assembly for cracking long-chained hydrocarbons;

Fig. 2 shows an embodiment of a heating structure in more detail;

Fig. 3 shows a further embodiment of the heating structure; and

Fig. 4 shows a further embodiment of the heating structure.

DESCRIPTION

Fig. 1 shows an assembly for cracking long-chained hydrocarbons according to an embodiment of the invention. Before further describing details of the depicted embodiment, general aspects of the invention are laid out below.

According to an aspect a device for heating molten long-chained hydrocarbons comprises a first heating section having at least one first material flow tube extending from a first heating section inlet to a first heating section outlet, the first material flow tube providing a flow path for the molten long-chained hydrocarbons from the first heating section inlet to the first heating section outlet, and a first heating structure extending along at least a portion of the first material flow tube, the first heating structure being configured to transfer heat to the first material flow tube; and a second heating section having at least one second material flow tube and at least one third material flow tube, the at least one second material flow tube extending from a second heating section inlet to a second heating section outlet, the at least one third material flow tube extending from a third heating section inlet to a third heating section outlet, the second and third material flow tubes providing flow paths for the molten long-chained hydrocarbons from the second and third heating section inlets to the second and third heating section outlets, respectively, wherein the second and third heating section inlets being configured to receive the molten long-chained hydrocarbons from the first heating section outlet, and to split the flow path for the molten long-chained hydrocarbons towards the at least one second material flow tube and the at least one third material flow tube; and wherein the second heating section inlet and the third heating section inlet are arranged at different heights.

When receiving molten long-chained hydrocarbons and heating them above temperatures at which some of the hydrocarbons start cracking, water, HCI and other contaminants contained in material containing the long-chained hydrocarbons and also some of the hydrocarbons can change into a gas phase. For convectional heating, a volume in the gas phase impedes heat transmission to the long-chained hydrocarbons, as the gas phase is less heat conductive and thus will impede heating of the long-chained hydrocarbons in the liquid phase. If the long-chained hydrocarbons are heated in a continuous process wherein molten hydrocarbons enter a tube-shaped heating zone at an inlet and hydrocarbons at further increased temperatures exit the heating zone at an outlet, the hydrocarbons in the gas phase will increase in volume. This might impede heating the further hydrocarbons passing through the heating zone due to the low heat conduction of the gas phase. The increased volume of the hydrocarbons in the gas phase further pushes the liquid phase through the heating zone, such that the liquid phase passes through the heating zone faster and experiences potentially less heating.

The inventors have realized that mass densities of the hydrocarbons in the gas phase and in the liquid phase can be used to disengage liquid and gas phases in a manner overcoming at least some of the challenges presented above, without necessarily requiring removal of the gas phase from the continuous process. While such removal would remove complexity of the hydrocarbons in the continuous process, such removal would add complexity to the flow paths required for the continuous process.

In an embodiment the invention thus provides plural heat exchangers configured for continuous operation, which plural heat exchangers are arranged in a series connection such that molten long-chained hydrocarbons pass the plural heat exchangers consecutively.

At least a second heat exchanger comprises at least two material flow tubes in a parallel connection in over-and-under configuration such that long-chained hydrocarbons in a gas phase rather pass the upper at least one material flow tube, while long-chained hydrocarbons in a liquid phase rather pass the lower at least one material flow tube.

In the following directions and orientations such as up, down, top, bottom, higher, upper, lower, horizontal and vertical are provided by reference to the local direction of gravity.

In various embodiments the flow paths for the molten long-chained hydrocarbons in the second and third material flow tubes merge adjacent to the second and third heating section outlets. That is, portions of the flow path can bypass other portions of a parallel flow path.

In various embodiments the first heating section has at least two material flow tubes splitting the flow path for the molten long-chained hydrocarbons adjacent to the first heating section inlet and merging the flow path for the molten long-chained hydrocarbons adjacent to the first heating section outlet. As the molten long-chained hydrocarbons may contain gas bubbles even when entering a first heating section, the first heating section is arranged such that portions of the flow path particularly containing bubbles can bypass other portions of a parallel flow path. Further, having more than one material flow tubes increases a surface are at which the molten long-chained hydrocarbons are heated.

In various embodiments the second heating section has at least two second material flow tubes and/or at least two third material flow tubes. Having more than one second and third material flow tubes increases a surface are at which the molten long-chained hydrocarbons are heated.

In various embodiments a top portion of the first heating section is on a level with a bottom portion of the second heating section. This allows gas to pass in a downstream direction while liquids can be drained in the opposite direction, if so required.

In various embodiments the first and/or second heating sections are configured to allow the molten long-chained hydrocarbons to crack and to disengage into hydrocarbons in the gas phase and long-chained hydrocarbons in the liquid phase. The heating sections thus are provided with structure to adjust pressures, temperatures and/or mass flow to allow cracking of the hydrocarbons.

In various embodiments the device further comprises a connecting portion between the first heating section and the second heating section, wherein the connecting portion forms a flow path for the molten long-chained hydrocarbons from the first heating section to the second heating section, and the device is configured to maintain the separation of the hydrocarbons in the gas phase from the long-chained hydrocarbons in the liquid phase while passing through the connecting portion. The connecting portion is preferably a connecting tube having a circular inner cross section. To maintain separation, the connecting tube has a minimum inner diameter which is a function of the assumed mass flow, temperatures, pressures and/or gas content. In various embodiments the inner cross section of the connecting tube is adapted to allow solid material to pass and avoid clogging. In some embodiments such solid materials are metals, sand and/or glass present in received material containing long-chained hydrocarbons. The solid materials have a melting point above the long-chained hydrocarbons and thus remain in the solid phase during processing. By accommodating for such solid materials, the range of materials acceptable for processing becomes broader and/or easier to prepare for processing.

In various embodiments the connecting portion is configured such that the flow path extends substantially horizontally or extends at an angle of 0° to 45° to a horizontal plane, preferably 0° to 35° to a horizontal plane, preferably 0° to 25° to a horizontal plane, preferably 0° to 15° to a horizontal plane, preferably at an angle of 0° to 10° to a horizontal plane, with the downstream end of the flow path being higher than the upstream end. This further supports gas to pass in a downstream direction while liquids can be drained in the opposite direction, if so required.

In various embodiments the connecting portion and/or a mass flow are adjusted to maintain the separation of the hydrocarbons in the gas phase from the long-chained hydrocarbons in the liquid phase, and the flow pattern of the hydrocarbons in the gas phase and the long- chained hydrocarbons in the liquid phase inside the connecting portion preferably is in one of bubble, plug, stratified, wavy or slug patterns. At these flow patterns the separated hydrocarbons in the gas phase better bypass the long-chained hydrocarbons in the liquid phase when splitting in upper and lower material flow tubes.

In various embodiments the connecting portion provides a single fluid channel with a circular cross-section.

In various embodiments the device is configured to provide, at the connecting portion, a temperature between 250°C and 450°C, preferably between 250°C and 350°C and/or between 350°C and 450°C, a mass flow from 500 kg/h to 30000 kg/h preferably from 1000 kg/h to 20000 kg/h, preferably from 5000 kg/h to 15000 kg/h, preferably from 8000 kg/h to 12000 kg/h, a gas content of the hydrocarbons in the gas phase from 1% to 50% by mass, preferably from 5% to 40% by mass, preferably from 10% to 30% by mass, preferably from 15% to 20% by mass, a pressure between 50 kPa and 10000 kPa, preferably between 100 kPa and 8100 kPa with respect to ambient air pressure, preferably between 300 kPa and 6000 kPa, preferably between 500 kPa and 4000 kPa, preferably between 700 kPa and 2000 kPa and the connecting portion having a circular cross-section with an inner diameter of at least 20 mm, preferably of at least 35 mm, preferably of at least 50 mm, preferably of at least 100 mm.

Within the context of this disclosure, pressures are gauge pressure, and thus zero- referenced against ambient air pressure.

In more specific embodiments, the device is configured to provide, at the connecting portion, a temperature between 250°C and 450°C, a mass flow from 1000 kg/h to 20000 kg/h, a gas content of the hydrocarbons in the gas phase from 1% to 50% by mass, a pressure preferably between 100 kPa and 8100 kPa, and the connecting portion having a circular cross-section with an inner diameter of at least 50 mm. At these ranges, the flow pattern of the hydrocarbons in the gas phase and the long-chained hydrocarbons in the liquid phase inside the connecting portion is expected to be in one of bubble, plug, stratified, wavy or slug patterns.

In various embodiments, for solid material suspended in the molten long-chained hydrocarbons, the connecting portion and/or at least one of the first, second or third material flow tube provides an inner cross section adapted to allow the solid material at a predetermined maximum dimension to pass. The respective inner cross section thus determines that solid materials may be present in the long-chained hydrocarbons, if their longest dimension does not exceed a predetermined size, e.g. between 1 and 20 mm,

preferably between 1 and 10 mm. In various embodiments at least one of the first, second or third material flow tube provides a circular inner cross section having a diameter of a range between 1 and 50 mm, preferably between 20 and 30 mm.

In various embodiments the connecting portion is arranged with an upper connecting tube and a lower connecting tube; the upper connecting tube is arranged to pass the hydrocarbons in the gas phase, and the lower connecting tube is arranged to pass the long- chained hydrocarbons in the liquid phase, wherein the lower connecting tube preferably provides an inner cross section adapted to allow solid material at a predetermined maximum dimension to pass. With upper and lower connecting tubes, the separation in gas and liquid phases can be maintained in broader ranges than the ranges provided further above.

In various embodiments, the lower connecting tube is further arranged to pass solid materials, such as metals, glass and/or sand, up to predetermined maximum dimension. As more of the long-chained hydrocarbons in the liquid phase will change into the gas phase, the share of solid materials in a lower connecting tube increases with each heating section passed by the long-chained hydrocarbons.

In various embodiments the device comprises at least one third heating section, each of the at least one third heating section having at least two forth material flow tubes each extending from a respective forth heating section inlet to a respective forth heating section outlet, wherein the flow path is split among the at least two forth material flow tubes adjacent to the forth heating section inlets and merges adjacent to the forth heating section outlets, and the first and second heating sections and each of the at least one third heating section are configured such that the material containing long-chained hydrocarbons flows consecutively through each of them. Each heating section further increases the temperature of the hydrocarbons and allows for separate temperature adjustment.

According to a further aspect a method of operating a device as explained in the above embodiments is provided.

Coming back to the description of Fig. 1, the assembly comprises a heating structure 11 and a separation structure 12. The heating structure 11 is in communication with the separation structure 12 to feed fluids into the separation structure 12. Particularly, the heating structure 11 feeds fluids containing cracked and uncracked hydrocarbons into the separation structure 12.

In some embodiments a feeding device 7 is arranged to fill material containing long-chained hydrocarbons such as waste plastic or crude oil into the heating structure 11. In further embodiments, CaO and/or Zeolites are provided as additive into the feeding device. In some embodiments the feeding device 7 comprises an effector 8 for heating and/or forwarding the material containing long-chained hydrocarbons. In some embodiments the effector is a screw auger 8 arranged to heat and/or forward the material containing long-chained hydrocarbons. In some embodiments the screw auger moves 8 the material and internal friction in the material causes the material to heat up and to melt. In further embodiments the feeding device 7 comprises a heating device such as an electrical heater and/or a heating device perfused by a heating medium such as thermal oil. The feeding device 7 forwards the material containing long-chained hydrocarbons to the heating structure 11.

The heating structure 11 receives the material containing long-chained hydrocarbons. In various embodiments the heating structure comprises at least one heating zone 1, 2, 3, 4.

The heating zone 1, 2, 3, 4 is arranged to heat the material containing long-chained hydrocarbons to a cracking temperature. The heating zone 1, 2, 3, 4 is arranged to expose the material containing long-chained hydrocarbons having reached the cracking temperature to a limited temperature increase. Said differently, the material containing long-chained hydrocarbons above the cracking temperature is exposed to a temperature that is less than a predetermined temperature above the temperature of the material. It has been found that by limiting a temperature increase, a yield of usable material containing hydrocarbons having desired chain lengths resulting from the operation of the assembly is increased, and the amount of resulting solid carbons is limited. In various embodiments, the heating zone 1, 2, 3, 4 is arranged to expose the material containing long-chained hydrocarbons to a predetermined temperature of around 50 °C or less, preferably around 40 °C or less, preferably around 25 °C or less, above the temperature of the respective material containing long-chained hydrocarbons.

In the following, the temperature to which the material containing long-chained hydrocarbons is exposed will be referred to as exposure temperature. The exposure temperature will however have different values depending on the location in the assembly and the corresponding temperature of the material containing long-chained hydrocarbons.

In different embodiments the heating zone 1, 2, 3, 4 provides a flow path for the material containing long-chained hydrocarbons. The heating zone 1, 2, 3, 4 continuously or gradually increases the exposure temperature along the flow path. In some embodiments, the heating zone 1, 2, 3, 4 provides at least one material flow tube for the material containing long- chained hydrocarbons. The material generally flows through the material flow tube in a first direction. The heating zone 1, 2, 3, 4 further provides a heating tube contacting the material flow tube along a substantial length of the heating zone 1, 2, 3, 4 such that heat can transfer from the inside of the heating tube into the material flow tube. The second tube provides a flow path for a heating medium.

In some of these embodiments, the heating medium flows in a direction opposite to the first direction such that the material containing long-chained hydrocarbons heats up along the flow in the first direction, while the heating medium cools down along the flow path in the second direction. In some of these embodiments the heating medium is controlled to have a temperature not more than 50 °C above a predetermined final temperature when entering the heating tube along the heating zone 1, 2, 3, 4, and to have a temperature not more than 50 °C above a temperature of the material containing long-chained hydrocarbons when entering the heating zone 1, 2, 3, 4. In some embodiments the heating medium is controlled to have a temperature not more than 40 °C above a predetermined final temperature when entering the heating tube along the heating zone 1, 2, 3, 4, and to have a temperature not more than 40 °C above a temperature of the material containing long-chained hydrocarbons when entering the heating zone 1, 2, 3, 4. In some embodiments the heating medium is controlled to have a temperature not more than 25 °C above a predetermined final temperature when entering the heating tube along the heating zone 1, 2, 3, 4, and to have a temperature not more than 25 °C above a temperature of the material containing long- chained hydrocarbons when entering the heating zone 1, 2, 3, 4. In some embodiments temperature, velocity and/or pressure of the heating medium in the heating tube and/or the material containing long-chained hydrocarbons in the material flow tube are controlled. In some embodiments the heating tube is dimensioned such that the heating medium flowing at a predetermined velocity therethrough and having a predetermined starting velocity will have the predetermined temperature characteristics. In some embodiments the material flow tube extends coaxially inside the heating tube.

In some embodiments the heating zone 1, 2, 3, 4 comprises several heating sections, each heating section exposing the material containing long-chained hydrocarbons to a predetermined temperature. The heating sections are configured such that the material containing long-chained hydrocarbons flows consecutively through each of them. Each heating section exposes the material to a higher exposure temperature than a previous heating section. The heating sections are configured such that the exposure temperatures do not exceed 50 °C above the temperature of the material containing long-chained hydrocarbons when entering the respective heating section. In the embodiment of Fig. 1 the heating zone 1, 2, 3, 4 comprises four heating sections, while the invention in various embodiments comprises more or less heating sections.

Whether cracking takes place inside the first heating section 1 depends, apart from the temperature, on the long-chained hydrocarbons contained in the material as well as other substances contained deliberately or incidentally in the material, and the pressure of the material. In some cases, cracking substantially does not take place at low temperatures such as between 200 °C and 250 °C as the further parameters do not promote cracking. In such cases the exposure temperature may be higher than 50 °C above the temperature of the material. In some embodiments the exposure temperature at the first heating section 1 may be as high as 50 °C above the minimum temperature at which cracking substantially takes place. In some embodiments, the cracking only starts at 360 °C exposure temperature is as high as 430 °C.

When exiting the first heating section 1, the material passes to a second heating section 2 downstream of the first heating section 1. The second heating section 2 exposes the material containing long-chained hydrocarbons to a higher exposure temperature than the first heating section 1, namely a second exposure temperature. The second exposure temperature does not exceed a temperature of 50 °C above the temperature of the material containing long-chained hydrocarbons. In various embodiments the second exposure temperature does not exceed a temperature of 40 °C above the temperature of the material containing long-chained hydrocarbons. In various embodiments the second exposure temperature does not exceed a temperature of 25 °C above the temperature of the material containing long-chained hydrocarbons. In various embodiments the second exposure temperature is between 250 °C and 450 °C. In various embodiments the second exposure temperature is between 300 °C and 400 °C. The material containing long-chained hydrocarbons flows through the second heating section 2 and heats up towards the second exposure temperature.

In the embodiment of Fig. 1, the material containing long-chained hydrocarbons passes from the second heating section 2 to a third heating section 3 downstream of the second heating section 2. The third heating section 3 exposes the material to a third exposure temperature.

The third exposure temperature is higher than the second exposure temperature. The third exposure temperature does not exceed a temperature of 50 °C above the temperature of the material. In various embodiments the third exposure temperature does not exceed a temperature of 40 °C above the temperature of the material containing long-chained hydrocarbons. In various embodiments the third exposure temperature does not exceed a temperature of 25 °C above the temperature of the material containing long-chained hydrocarbons. The material containing long-chained hydrocarbons flows through the third heating section 3 and heats up towards the third exposure temperature.

From the third heating section 3 the material containing long-chained hydrocarbons passes to a fourth heating section 4 downstream of the third heating section 3. The fourth heating section 4 exposes the material to a fourth exposure temperature. The fourth exposure temperature does not exceed a temperature of 50 °C above the temperature of the material.

In various embodiments the fourth exposure temperature does not exceed a temperature of 40 °C above the temperature of the material containing long-chained hydrocarbons. In various embodiments the fourth exposure temperature does not exceed a temperature of 25 °C above the temperature of the material containing long-chained hydrocarbons. The fourth exposure temperature essentially determines the maximum temperature for the long-chained hydrocarbons leaving the heating zone. The material containing long-chained hydrocarbons flows through the fourth heating section 4 and heats up towards the fourth exposure temperature.

While the material containing long-chained hydrocarbons flows through the fourth heating section 4, some of the long-chained hydrocarbons are cracked. In some embodiments, some of the long-chained hydrocarbons are cracked while the material flows through the third heating section 3. In some embodiments, some of the long-chained hydrocarbons are cracked while the material flows through the second heating section 2. In some embodiments, some of the long-chained hydrocarbons are cracked while the material flows through the first heating section 1. Principally the hotter a heating section is, the more cracking takes place. Once substantial amounts of long-chained hydrocarbons are being cracked, the heating section limits the exposure temperature to a maximum of 50 °C above the temperature of the material. The material containing long-chained hydrocarbons thus also contains cracked hydrocarbons. That is, a share of the hydrocarbons with shorter chain lengths is increased as compared to the material before entering the heating zone. The material exiting the fourth heating section 4 is passed to the separation structure 12.

In various embodiments the heating sections are comprised of identical structures such that only one type of heating section can be used for each position in the chain of heating sections. In various embodiments the heating sections are designed for heating up to a temperature of 450 °C. In various embodiments the heating sections are designed for operational pressures between O bar and 150 bar. In further embodiments the heating sections are designed for operational pressures between 0 bar and 80 bar, preferably for operational pressures between 0 bar and 40 bar. In various embodiments the heating sections are supplied with a liquid as a heating medium. In various embodiments the heating sections are supplied with a thermal oil as a heating medium. In various embodiments the thermal oil is selected to have a boiling point above the operating temperatures of the heating sections at operating pressures and/or a solidification temperature below 40 °C.

In further embodiments the throughput of the material containing long-chained hydrocarbons is adjusted to ensure that the material exiting the first to fourth heating sections has reached a certain respective temperature. For the first to third heating sections that certain temperature is less than 50 °C below the exposure temperature of the respective following heating section. In various embodiments the certain temperature is less than 40 ° below the exposure temperature of the respective following heating section. In various embodiments the certain temperature is less than 25 °C below the exposure temperature of the respective following heating section. For the fourth heating section 4 the certain temperature is a predetermined maximum temperature.

For a heating structure having more or less heating sections the above applies correspondingly.

In some embodiments there is a back pressure control element 5a, 5b downstream of the heating zone 1, 2, 3, 4. The back pressure control element 5a, 5b is arranged to adjust a pressure of the material containing long-chained hydrocarbons in the heating zone. In various embodiments the back pressure control element controls a throughput of the material through the heating zone. The back pressure control element is arranged between the heating zone and the separation structure 12. The material containing long-chained hydrocarbons exiting the back pressure control element 5a, Sb passes to the separation structure 12. In some embodiments the back pressure control element comprises an adjustable valve 5a and a pressure sensor 5b. The pressure sensor 5b is configured to detect a pressure of the material in the heating zone. The adjustable valve 5a is configured to release the material as long as the pressure sensor 5b detects a pressure in a specific range. In some embodiments the specific range is between O bar and 150 bar. In further embodiments the specific range is between 0 bar and 80 bar, preferably between 0 bar and 40 bar. In some embodiments the specific range is at around 20 bar. If the material in the heating zone has a pressure outside the range, the valve 5a controls a throughput of material. For example, if the pressure in the heating zone drops below a lower boundary of the pressure range, the valve 5a reduces a throughput until pressure in the heating zone builds up. If the pressure in the heating zone exceeds an upper boundary, the valve 5a allows for an increased throughput until the pressure drops. In some embodiments the valve 5a has a structure of a pressure relief valve, that is, the valve 5a is kept closed by a preloaded spring and opens towards the following separation structure 12 once a predetermined pressure is exceeded, while it closes once the pressure drops below a predetermined pressure. In further embodiments the valve 5a is a gate valve opening and closing to adjust a throughput and thereby the pressure as detected by the pressure sensor 5b. In some embodiments the valve 5a is arranged to allow a small throughput at all times, said differently, the valve 5a is arranged to not be fully closed. In some embodiments, the valve 5a is actuated by a motor such as an electric, pneumatic, or hydraulic motor.

Further aspects of the separation structure 12 and of the method and structure for breaking down long-chained hydrocarbons are set forth in WO 2021/053139 A1.

The pressure in the heating zone is selected to maintain more of the cracked material in the liquid phase. This is to avoid material in the gas phase, as material in the gas phase impedes heat transfer through the material. Further, material changing from the liquid phase to the gas phase substantially increases in volume. Maintaining more of the cracked material in the liquid phase avoids that liquid material is driven through the material flow tubes at a velocity preventing the material from heating as intended.

Once the material has passed the back pressure control element, the pressure in the material drops. Particularly more of the shorter chained hydrocarbons resulting from cracking evaporate into a gas phase resulting in more hydrocarbons in a gas phase and some or all of any suppressed gas bubbles expand.

Fig. 2 shows an embodiment of the heating structure 11 in more detail. In this embodiment, the heating structure 11 comprises a first heating section 1 and a second heating section 2.

The first heating section 1 comprises a first material flow tube 101 with a first heating section inlet 102 and a first heating section outlet 103. The first material flow tube 101 extends from the first heating section inlet 102 to the first heating section outlet 103 and provides a flow path for molten long-chained hydrocarbons from the first heating section inlet 102 to the first heating section outlet 103. The first heating section 1 further comprises a first heating appliance 113. The first heating appliance 113 is configured to emit thermal energy to the molten long-chained hydrocarbons in the first material flow tube 101. In some embodiments the first heating appliance 113 is an electrical heater. In further embodiments the first heating appliance 113 is a shell of a shell and tube heat exchanger having a fluid heating medium flow through the shell at or around the first material flow tube 101. In some embodiments, the fluid heating medium enters the shell at a first heating medium entry 111 adjacent to the first heating section outlet 103, and the fluid heating medium exits the shell at a first heating medium exit 112. In some embodiments, the shell comprises baffles directing the flow of the heating medium inside the shell. The first heating section 1 further comprises a first distribution volume 110 upstream of the first material flow tube 101 and a first disengagement volume 120 downstream of the first material flow tube 101. If the first heating section 1 comprises a further material flow tube in addition to the first material flow tube 101, the flow path for molten long-chained hydrocarbons splits in the first distribution volume 110 into the material flow tubes of the first heating section 1 and is joined at the first disengagement volume 120.

In operation, long-chained hydrocarbons are heated to a molten state and enter the first heating section 1 at a first heating section entry 104. The molten long-chained hydrocarbons then pass through the first distribution volume 110 and through the first heating section inlet 102 into the first material flow tube 101. The heating appliance 113 further heats the molten long-chained hydrocarbons inside the first material flow tube 101 as explained further above with respect to the first heating section 1. The molten long-chained hydrocarbons then pass through the first heating section outlet 103 into the first disengagement volume 120. As likewise explained above, some of the molten long-chained hydrocarbons may start cracking inside the first material flow tube 101 and will thus have an evaporation temperature in the range of the operation temperature inside the first material flow tube 101. Consequently, hydrocarbons in the gas phase form gas bubbles 1000 in the molten long-chained hydrocarbons. In the disengagement volume 120 the gas bubbles 1000 disengage from long-chained hydrocarbons in the liquid phase 1001 and rise such that the long-chained hydrocarbons in the liquid phase 1001 will assume a lower portion of the first disengagement volume 120 and hydrocarbons in the gas phase 1002 will assume a higher portion of the first disengagement volume 120.

The second heating section 2 comprises a second material flow tube 202 with a second heating section inlet 212 and a second heating section outlet 213, and a third material flow tube 203 with a third heating section inlet 222 and a third heating section outlet 223. The second material flow tube 202 extends from the second heating section inlet 212 to the second heating section outlet 213. The third material flow tube 203 extends from the third heating section inlet 222 to the third heating section outlet 223. The second heating section 2 further comprises a second distribution volume 210 upstream of the second and third material flow tubes 202, 203 and a second disengagement volume 220 downstream of the second and third material flow tubes 202, 203. A flow path for hydrocarbons along the second heating section 2 splits in the second distribution volume 210 into the second and third material flow tubes 202, 203 of the first heating section 1 and is joined at the second disengagement volume 220. The second heating section inlet 212 is arranged at a higher level than the third heating section inlet 222. In some embodiments also the second material flow tube 202 is essentially arranged at a higher level than the third material flow tube 203.

The second heating section 2 comprises a second heating appliance 233. The second heating appliance 233 is configured to emit thermal energy to the molten long-chained hydrocarbons in at least one of the second and third material flow tubes 202, 203. The second heating appliance 233 corresponds principally to the first heating appliance 113 but provides higher temperatures to the molten long-chained hydrocarbons as explained further above with respect to the second heating section 2 and Fig. 1. In some embodiments, the second heating appliance 233 comprises a second heating medium entry 231 adjacent to the second and third heating section outlets 213, 223 and a second heating medium exit 232 adjacent to the second and third heating section inlets 212, 222. In operation, heating medium circulates from the second heating medium entry 231 to the second heating medium exit 232. In further embodiments, the heating medium has a negligible temperature drop, such that the circulation direction is less relevant. In such embodiments, the heating medium may circulate in the opposite direction, thus effectively from the second heating medium exit 232 to the second heating medium entry 231.

In various embodiments, the heating structure 11 further comprises a connecting tube 150.

In various embodiments, the connecting tube 150 has a circular inner cross-section. The connecting tube 150 connects the first and second heating sections 1, 2 particularly for transfer of long-chained hydrocarbons in the liquid phase 1001 and hydrocarbons in the gas phase 1002 from the first to the second heating sections 1, 2. Mare specifically, in operation long-chained hydrocarbons in the liquid phase 1001 and hydrocarbons in the gas phase 1002 exit the first disengagement volume 120 and pass the connecting tube 150 into the second distribution volume 210. In various embodiments, the connecting tube 150 extends essentially horizontally between first and second heating sections 1, 2. In further embodiments, the connecting tube 150 extends at an angle of 0° to 45° to a horizontal plane, preferably 0° to 35° to a horizontal plane, preferably 0° to 25° to a horizontal plane, preferably 0° to 15° to a horizontal plane, preferably at an angle of 0° to 10° to a horizontal plane, with the downstream end of the connecting tube 150 being higher than the upstream end.

In the second distribution volume 210 the long-chained hydrocarbons in the liquid phase 1001 and the hydrocarbons in the gas phase 1002 are split to pass either through the second heating section inlet 212 into the second material flow tube 202 or through the third heating section inlet 222 into the third material flow tube 203. As the second heating section inlet 212 is arranged at a higher level than the third heating section inlet 222, the hydrocarbons in the gas phase 1002 rather pass through the second heating section inlet 212 into the second material flow tube 202, and the long-chained hydrocarbons in the liquid phase 1001 rather pass through the third heating section inlet 222 into the third material flow tube 203. In this way, the second material flow tube 202 contains a higher share of hydrocarbons in the gas phase 1002, while the third material flow tube 203 contains a higher share of long-chained hydrocarbons in the liquid phase 1001. Thus, as a portion of the hydrocarbons in the gas phase 1002 have been removed from the long-chained hydrocarbons in the liquid phase 1001 in the third material flow tube 203, the long-chained hydrocarbons in the liquid phase 1001 in the third material flow tube 203 can further be heated more effectively. The hydrocarbons in the gas phase 1002 in the second material flow tube 202 bypass the long-chained hydrocarbons in the liquid phase 1001 and sooner reach a second heating section exit 205.

The second heating appliance 233 further heats the long-chained hydrocarbons inside the third material flow tube 203 as explained further above with respect to the second heating section 2. The molten long-chained hydrocarbons then pass primarily through the third heating section outlet 223 into the second disengagement volume 220. As likewise explained above, some of the long-chained hydrocarbons may start cracking inside the third material flow tube 203 and will thus have an evaporation temperature in the range of the operation temperature inside the third material flow tube 203. Consequently, hydrocarbons in the gas phase form further gas bubbles 1000 in the long-chained hydrocarbons in the liquid phase 1001. In the disengagement volume 220 the gas bubbles 1000 rise such that long- chained hydrocarbons in the liquid phase 1001 assume a lower portion of the disengagement volume 220 and gas bubbles 1000 from the third material flow tube 203 merge with the hydrocarbons in the gas phase 1002 from second material flow tube 202.

The hydrocarbons in the gas phase 1002 assume a higher portion of the second disengagement volume 220. Likewise, in the disengagement volume 220 long-chained hydrocarbons in the liquid phase 1001 from the second material flow tube 203 merge with the long-chained hydrocarbons in the liquid phase 1001 from the third material flow tube 208.

The long-chained hydrocarbons in the liquid phase 1001 and the hydrocarbons in the gas phase 1002 exit the second disengagement volume 220 and thus the second heating section 2 through the second heating section exit 205. In an embodiment, the second heating section exit 205 is connected to the third heating section 3 and one or more further heating sections. In another embodiment, the back pressure control element 5a, 5b and/or the separation structure 12 further downstream follow immediately the second heating section exit 205.

The embodiment of Fig. 2 further shows that the first heating section 1 is generally lower than the second heating section 2. Particularly the first heating section entry 104 is essentially flush and/or on a level with a lower portion or bottom of the first distribution volume 110, a top portion of the disengagement volume 120 is essentially flush and/or on a level with the connecting tube 150 and the connecting tube 150 is essentially flush and/or on a level with a lower portion or bottom of the second distribution volume 210. Further, the second heating section exit 205 is essentially flush and/or on a level with a top portion of the second disengagement volume 220. The connecting tube 150 extends preferably horizontally or at an angle between 0° and 45°, preferably Q° to 35° to a horizontal plane, preferably 0° to 25° to a horizontal plane, preferably 0° to 15° to a horizontal plane, preferably at an angle between 0° and 10° with the downstream end of the connecting tube 150 being higher than the upstream end. Likewise the first, second and third material flow tubes 101, 202, 203 extend preferably horizontally or at an angle between 0° and 10° with the downstream ends being higher than the respective upstream ends. Therefore, the hydrocarbons in the gas phase 1002 tend to rise through the first and second heating sections 1, 2 from the first heating section entry 104 to the second heating section exit 205 and preferably further to the back pressure control element 5a, 5b and/or to the separation structure 12 further downstream. If so required, the long-chained hydrocarbons in the liquid phase 1001 by contrast can be drained through the first heating section entry 104. In further embodiments, each following heating section connects to the respective preceding connecting tube with the bottom portion of the respective distribution volume and to the following connecting tube with the top portion of the respective disengagement volume.

It has been found that a separation of the hydrocarbons in the gas phase 1002 from the long-chained hydrocarbons in the liquid phase 1001 is advantageous as it allows the hydrocarbons in the gas phase 1002 to quickly pass the second heating section 2, while the long-chained hydrocarbons in the liquid phase 1001 have a better heating exposure from the second heating appliance 233 as the hydrocarbons in the gas phase 1002 interfere to a lesser degree with heat transfer into and through the long-chained hydrocarbons in the liquid phase 1001.

In various embodiments, the heating structure 11 is configured to maintain the separation of the hydrocarbons in the gas phase 1002 from the long-chained hydrocarbons in the liquid phase 1001 in the first disengagement volume 120, the connecting tube 150 and the second distribution volume 210. Particularly, the first disengagement volume 120, the connecting tube 150 and the second distribution volume 210 are configured to avoid intermixing of the hydrocarbons in the gas phase 1002 from the long-chained hydrocarbons in the liquid phase 1001.

In various embodiments, the connecting tube 150 has a circular cross-section with a diameter that is smaller than the diameter of the first disengagement volume 120, and/or the cross-sectional area of the connecting tube 150 is smaller than the cross-sectional area of the first disengagement volume 120. Due to the smaller cross-section at the connecting tube 150 at essentially constant mass flow across both, the first disengagement volume 120 and the connecting tube 150, the flow velocity of the hydrocarbons in the gas phase 1002 and the long-chained hydrocarbons in the liquid phase 1001 have a considerably higher velocity when passing through the connecting tube 150. In this way, the hydrocarbons in the gas phase 1002 and the long-chained hydrocarbons in the liquid phase 1001 stay inside the connecting tube 150 for a shorter period of time. Accordingly, the hydrocarbons in the gas phase 1002 and the long-chained hydrocarbons in the liquid phase 1001 cool down less during their passage through the connecting tube 150.

In some embodiments, the first and second heating sections 1, 2 are configured in a u- shape, such that the first heating section 1 has the flow of hydrocarbons along the first material flow tube 101 in a first direction and the second heating section 2 has the flow of hydrocarbons along the second and third material flow tubes 202, 203 in a second direction essentially in parallel to the first direction but opposite thereto. The advantage of this configuration is that the first heating section entry 104 is adjacent to the second heating section exit 205. Thus, a support structure for the first heating section entry 104 and the second heating section exit 205 can be arranged to be stationary, while the respective opposite ends of the first and second heating sections 1, 2 with the first disengagement volume 120, the connecting tube 150 and the second distribution volume 210 can move more freely under thermal expansion and contraction. The connecting tube 150 will however likewise extend and contract under thermal influence. In various embodiments, the connecting tube 150 has a diameter that is significantly smaller than each of the diameters of the first disengagement volume 120 and the second distribution volume 210. This renders the connecting tube 150 less stiff and the connecting tube 150 can bend more and will have a lower tendency to bend the first and second heating sections 1, 2. The lower limit of the diameter of the connecting tube however is determined by the minimum inner diameter required to maintain the gas and liquid phases separate as discussed further above. In further embodiments any number of heating sections is arranged with any two neighboring heating sections essentially in parallel with opposite flow directions in their respective material flow tubes.

The connecting tube 150 in various embodiments comprises an electric heating element.

The electric heating element allows, in some embodiments, to heat the hydrocarbons in the gas phase 1002 and the long-chained hydrocarbons in the liquid phase 1001 should the heating sections stand still for some time such that little newly heated material follows and the material inside the connecting tube 150 solidifies. In various embodiments the electrical heating element is configured to maintain the hydrocarbons in the gas phase 1002 and the long-chained hydrocarbons in the liquid phase 1001 to not solidify. The electric heating thus allows to maintain the hydrocarbons in the gas phase 1002 and the long-chained hydrocarbons in the liquid phase 1001 to remain in processable condition. In further embodiments a thermal oil is used to heat the connecting tube 150. In various embodiments this allows maintaining the hydrocarbon temperatures and respective liquid and gas phases while fluid flow is stopped, e.g. during stand still for maintenance.

The long-chained hydrocarbons in the liquid phase 1001 and the hydrocarbons in the gas phase 1002 remain separated even when flowing in a common tube as long as the flow pattern of the gas phase and the liquid phase is in one of bubble, plug, stratified, wavy or slug patterns. These patterns are also explained in “PERRY'S CHEMICAL ENGINEERS’

HANDBOOK”, seventh edition, Fig. 6-24. To maintain the gas phase and the liquid phase separate, the assembly for cracking long-chained hydrocarbons should be configured accordingly. Particularly, the connecting tube should extend at least partially horizontally or at an angle between 0° and 45° to a horizontal plane, preferably 0° to 35° to a horizontal plane, preferably O° to 25° to a horizontal plane, preferably 0° to 15° to a horizontal plane, preferably, between 0° and 10° to a horizontal plane. The connecting tube 150 should have a certain minimum inner diameter. Alternatively or additionally, at least one of the mass flow of the molten long-chained hydrocarbons entering the first heating section entry 104, the long-chained hydrocarbons in the liquid phase 1001 and the hydrocarbons in the gas phase 1002 should not exceed certain limits. Alternatively or additionally, the pressure of the material in the heating zone is adjustable accordingly. The pressure of the material in the heating zone influences the share of hydrocarbons in the gas phase 1002, as an evaporation temperature increases if the pressure increases. That is, at higher pressures, less of the hydrocarbons transition into the gas phase. As an example assuming a temperature between 250°C and 450°C, for a mass flow ranging from 1000 kg/h to 20000 kg/h, a gas content from 1% to 50% by mass, and at pressures between 100 kPa and 8100 kPa, the connecting tube 150 should have an inner diameter of at least 50 mm. In various embodiments the connecting tube 150 provides a circular inner cross section having a diameter in a range between 50 and 500 mm, preferably between 50 and 80 mm. However, itis also possible that the inner diameter of the connecting tube is predetermined by other factors, such as heat expansion characteristics, and one or more of the other parameters, i.e. feedstock composition and particle size, temperature, mass flow, gas content or pressure are adapted accordingly.

If the assembly for cracking long-chained hydrocarbons is configured with one or more of these parameters outside of these ranges, the flow pattern may become spray, thus forming an aerosol, or annular, that is, a liquid stream essentially surrounded by a gas flow. These flow patterns will impede disengagement of the long-chained hydrocarbons in the liquid phase 1001 and the hydrocarbons in the gas phase 1002, such that more of the long- chained hydrocarbons in the liquid phase 1001 will end up in a higher following material flow tube, such as the second material flow tube 202, and more of the hydrocarbons in the gas phase 1002 in a lower following material flow tube, such as the third material flow tube 203.

Fig. 3 shows a further embodiment of the heating structure 11. In this embodiment, the heating structure 11 comprises a first heating section 1 and a second heating section 2 communicatively coupled to each other by a connecting tube 150. In various embodiments, the connecting tube 150 extends essentially horizontally between first and second heating sections 1, 2. In further embodiments, the connecting tube 150 extends at an angle of 0° to 45° to a horizontal plane, preferably 0° to 35° to a horizontal plane, preferably 0° to 25° to a horizontal plane, preferably 0° to 15° to a horizontal plane, preferably at an angle of 0° to 10° to a horizontal plane, with the downstream end of the connecting tube 150 being higher than the upstream end. Corresponding to the configuration of the embodiment of Fig. 2, the first and second heating sections 1, 2 each comprise first and second distribution volumes 110, 210, respectively, and first and second disengagement volumes 120, 220, respectively. In the embodiment depicted in Fig. 3, the first heating section 1 comprises at least two first material flow tubes 101a. The first material flow tubes 101a extend and provide a flow path from the first distribution volume 110 to the first disengagement volume 120.

It has been found that the material containing long-chained hydrocarbons entering the heating section 1 from the feeding device 7 may contain gas, such as hydrocarbons in the gas phase 1002, depending particularly on the material, pressure and temperature in the feeding device 7. In further embodiments, the first material flow tubes 101a comprise at least an upper first material flow tube with an upper first heating section inlet and an upper first heating section outlet, and a lower first material flow tube with a lower first heating section inlet and a lower first heating section outlet. The upper material flow tube extends from the upper first heating section inlet to the upper first heating section outlet. The lower first material flow tube extends from the lower first heating section inlet to the lower first heating section outlet. In these further embodiments the upper first heating section inlet is above the lower first heating section inlet, such that the gas entering the heating section 1 rather passes the first heating section 1 through the upper first material flow tube into the first disengagement volume 120, and the long-chained hydrocarbons in the liquid phase 1001 rather pass the first heating section 1 through the lower first material flow tube into the first disengagement volume 120. In some embodiments also the upper first material flow tube is essentially arranged at a higher level than the lower first material flow tube.

In various embodiments the first heating section 1 of Fig. 3 comprises a plurality of first material flow tubes 101a. Some of the plurality of first material flow tubes 101a are arranged at a different level than other of the plurality of first material flow tubes 101a.

Corresponding to the embodiment of Fig. 2, the first heating section 1 comprises a first heating appliance 113 configured to emit thermal energy to the molten long-chained hydrocarbons in the first material flow tube 101. In some embodiments the heating appliance 113 is configured such that fluid heating medium enters the heating appliance 113 at a first heating medium entry 111 adjacent to the first disengagement volume 120, and the fluid heating medium exits the heating appliance 113 at a first heating medium exit 112 adjacent to the first distribution volume 110. In various embodiments, aspects not discussed with respect to Fig. 3 may usually be assumed to essentially correspond to Fig. 2.

Inthe embodiment of Fig. 3, the second heating section 2 further comprises a plurality of second and third material flow tubes 201. The second and third material flow tubes 201 comprise second and third heating section inlets 201a, 201b, respectively. The second and third material flow tubes 201 extend from the second and third heating section inlets 201a, 201b at the second distribution volume 210 to second and third heating section outlets 201c at the second disengagement volume 220. In various embodiments the second heating section inlets 201a are arranged in the vicinity of a top portion of the distribution volume 210.

In various embodiments the third heating section inlets are arranged lower than the second heating section inlets 201a and/or in the vicinity of a bottom portion of the second distribution volume 210.

The second heating section 2 comprises a second heating appliance 233. The second heating appliance 233 is configured to emit thermal energy to the molten long-chained hydrocarbons in at least one of the second and third material flow tubes 201. The second heating appliance 233 corresponds principally to the first heating appliance 113 but provides higher temperatures to the molten long-chained hydrocarbons as explained further above. In some embodiments, the second heating appliance 233 comprises a second heating medium entry 231 and a second heating medium exit 232 similar to the configuration discussed for the embodiment of Fig. 2.

In operation, molten long-chained hydrocarbons enter the first heating section 1 at a first heating section entry 104 into the first distribution volume 110. In the first distribution volume 110, the molten long-chained hydrocarbons split into the at least two first material flow tubes 101a to pass towards the first disengagement volume 120. Molten long-chained hydrocarbons which have heated to their respective cracking temperatures start cracking and evaporating. Evaporated hydrocarbons will form gas bubbles 1000 in the at least two first material flow tubes 101a. The molten long-chained hydrocarbons and the gas bubbles 1000 pass into the first disengagement volume 120. In the disengagement volume 120 the gas bubbles 1000 will rise such that long-chained hydrocarbons in the liquid phase 1001 will assume a lower portion of the first disengagement volume 120 and hydrocarbons in the gas phase 1002 will assume a higher portion of the first disengagement volume 120. In various embodiments the connecting tube 150 is configured to maintain separation of the hydrocarbons in the liquid phase 1001 and hydrocarbons in the gas phase 1002 within the designated process parameter ranges, such as temperature, mass flow, gas content and/or pressure of the hydrocarbons inside the heating structure 11. The hydrocarbons in the liquid phase 1001 and hydrocarbons in the gas phase 1002 pass from the connecting tube 150 into the second distribution volume 210 where they split into the second and third heating section inlets 201a, 201b. In various embodiments the hydrocarbons in the liquid phase

1001 pass through a lower or bottom portion of the second distribution volume 210, and hydrocarbons in the gas phase 1002 pass through a higher or top portion of the second distribution volume 210. In various embodiments the second heating section inlets 201a are arranged to primarily receive hydrocarbons in the gas phase 1002 and the third heating section inlets 201b are primarily arranged to receive hydrocarbons in the liquid phase 1001.

The hydrocarbons in the gas phase 1002 thus primarily pass from the second heating section inlets 201a through the second material flow tubes 201 and through second heating section outlets 201c towards the second disengagement volume 220. In various embodiments the second heating section outlets 201c are arranged to output the hydrocarbons in the gas phase 1002 towards an upper portion of the second disengagement volume 220 to avoid that the hydrocarbons in the gas phase 1002 mix with hydrocarbons in the liquid phase 1001 in a lower portion of the second disengagement volume 220.

The hydrocarbons in the liquid phase 1001 primarily pass from the third heating section inlets 201b through the third material flow tubes 201 and through the third heating section outlets 201c towards the second disengagement volume 220. In various embodiments the third heating section outlets 201c are arranged to output the hydrocarbons in the liquid phase 1001 towards a lower portion of the second disengagement volume 220 to avoid that the hydrocarbons in the liquid phase 1001 mix with hydrocarbons in the gas phase 1002 in an upper portion of the second disengagement volume 220. As explained further above, the second heating section 2 operates at higher temperatures than the first heating section 1.

Accordingly, further long-chained hydrocarbons in the liquid phase 1001 reach temperatures at which they tend to crack such that their evaporation temperature drops. As the second heating section 2 has a higher temperature, additional long-chained hydrocarbons in the liquid phase 1001 evaporate and transition into the gas phase. The additional evaporated hydrocarbons thus form further bubbles 1000 passing with the long-chained hydrocarbons in the liquid phase 1001 towards the second disengagement volume 220. In the second disengagement volume 220 the gas bubbles 1000 disengage from the long-chained hydrocarbons in the liquid phase 1001 and rise such that the long-chained hydrocarbons in the liquid phase 1001 will assume a lower portion of the second disengagement volume 220 and the gas bubbles 1000 merge with the hydrocarbons in the gas phase 1002 coming from the second material flow tubes 201 and assume a higher portion of the second disengagement volume 220. Consequently, the share of the hydrocarbons in the gas phase 1002 increases by mass, while the share of the long-chained hydrocarbons in the liquid phase 1001 decreases by mass.

As previously explained, the long-chained hydrocarbons in the liquid phase 1001 and the hydrocarbons in the gas phase 1002 exit the second disengagement volume 220 and thus the second heating section 2 through the second heating section exit 205. In an embodiment, the second heating section exit 205 is connected to the third heating section 3 and one or more further heating sections. In another embodiment, the back pressure control element 5a, 5b and/or to the separation structure 12 further downstream follow immediately the second heating section exit 205.

Fig. 4 shows a further embodiment of the heating structure 11. In this embodiment, the heating structure 11 comprises a first heating section 1, a second heating section 2 and a third heating section 3. The first and second heating sections 1, 2 are communicatively coupled to each other by an upper first connecting tube 151 and a lower first connecting tube 152. The second and third heating sections 2, 3 are communicatively coupled to each other by an upper second connecting tube 251 and a lower second connecting tube 252.

Corresponding to the configuration of the embodiments of Figs. 2 and 3, the first, second and third heating sections 1, 2, 3 each comprise first, second and third distribution volumes 110, 210, 310, respectively, and first, second and third disengagement volumes 120, 220, 320 respectively.

In the embodiment depicted in Fig. 4, the first heating section 1 comprises at least two first material flow tubes 101a. In various embodiments the first heating section 1 of Fig. 4 comprises a plurality of first material flow tubes 101a. The first material flow tubes 101a extend and provide a flow path from the first distribution volume 110 to the first disengagement volume 120. The first heating section 1 comprises a first heating medium entry 111 and a first heating medium exit 112 for circulating a heating medium to emit thermal energy to the molten long-chained hydrocarbons in at least one of the at least two first material flow tubes 101a. In further embodiments, the at least two first material flow tubes 101a are heated electrically.

In the embodiment of Fig. 4, the second heating section 2 further comprises a plurality of second and third material flow tubes 201. The structure of the plurality of second and third material flow tubes 201 of Fig. 4 essentially corresponds to the structure of the plurality of second and third material flow tubes 201 of Fig. 3, such that some details are omitted at this point.

The second and third material flow tubes 201 extend and provide a flow path from the second distribution volume 210 to the second disengagement volume 220. In various embodiments the second material flow tubes 201 extend and provide a flow path from a top portion of the second distribution volume 210 to a top portion of the second disengagement volume 220. In various embodiments the third material flow tubes 201 extend and provide a flow path from a bottom portion of the second distribution volume 210 to a bottom portion of the second disengagement volume 220. The second heating section 2 comprises a second heating medium entry 231 and a second heating medium exit 232 for circulating a heating medium to emit thermal energy to the molten long-chained hydrocarbons in at least one of the second and third material flow tubes 201. In further embodiments, at least one of the second and third material flow tubes 201 are heated electrically. Heating of the second and third material flow tubes 201 corresponds principally to heating of the first material flow tubes

101a, but provides higher temperatures to the long-chained hydrocarbons in the liquid phase 1001 and/or the hydrocarbons in the gas phase 1002 as explained further above.

In the embodiment of Fig. 4, the third heating section 3 further comprises a plurality of forth material flow tubes 301. The fourth material flow tubes 301 extend and provide a flow path from the third distribution volume 310 to the third disengagement volume 320. In various embodiments a portion of the fourth material flow tubes 301 extends and provides a flow path from a top portion of the third distribution volume 310 to a top portion of the third disengagement volume 320. In various embodiments a portion of the fourth material flow tubes 301 extends and provides a flow path from a bottom portion of the third distribution volume 310 to a bottom portion of the third disengagement volume 320. The structure of the plurality of forth material flow tubes 301 of the third heating section 3 essentially corresponds to the structure of the plurality of second and third material flow tubes 201 of the second heating section 2, such that details are omitted at this point. Differences will be explained in the following.

The third heating section 3 comprises a third heating medium entry 331 and a third heating medium exit 332 for circulating a heating medium to emit thermal energy to the molten long- chained hydrocarbons in at least some of the fourth material flow tubes 301. In further embodiments, at least some of the fourth material flow tubes 301 are heated electrically.

Heating of the fourth material flow tubes 301 corresponds principally to heating of the second and third material flow tubes 201, but provides higher temperatures to the long- chained hydrocarbons in the liquid phase 1001 and/or the hydrocarbons in the gas phase 1002 as explained further above.

In the embodiment of Fig. 4 the first disengagement volume 120 is in fluid communication with the second distribution volume 210 through the upper first connecting tube 151 and the lower first connecting tube 152. The upper first connecting tube 151 provides a fluid connection from the upper portion of the first disengagement volume 120 to the upper portion of the second distribution volume 210. The lower first connecting tube 152 provides a fluid connection from the lower portion of the first disengagement volume 120 to the lower portion of the second distribution volume 210.

In operation, molten long-chained hydrocarbons are heated in the first material flow tubes 1014 and, as previously explained, bubbles of cracked hydrocarbons in the gas phase are formed. In the disengagement volume 120 the gas bubbles 1000 disengage from long- chained hydrocarbons in the liquid phase 1001 and rise such that the long-chained hydrocarbons in the liquid phase 1001 will assume a lower portion of the first disengagement volume 120 and hydrocarbons in the gas phase 1002 will assume an upper portion of the first disengagement volume 120. The hydrocarbons in the gas phase 1002 thus pass from the upper portion of the first disengagement volume 120 through the upper first connecting tube 151 to the upper portion of the second distribution volume 210. The long-chained hydrocarbons in the liquid phase 1001 pass from the lower portion of the first disengagement volume 120 through the lower first connecting tube 152 to the lower portion of the second distribution volume 210. Accordingly, as the long-chained hydrocarbons in the liquid phase 1001 and the hydrocarbons in the gas phase 1002 pass separate tubes from the first heating section 1 to the second heating section 2, the separation of the liquid and gas phases can be maintained more easily, even if one or more of the parameters, such as temperature, mass flow, gas content, tube diameter or pressure is outside of the ranges discussed above. This particularly also allows for a higher mass flow or a smaller diameter or cross-section of the upper and lower first connecting tubes 151, 152.

Likewise, the second disengagement volume 220 is in fluid communication with the third distribution volume 310 through the upper second connecting tube 251 and the lower second connecting tube 252. The upper second connecting tube 251 provides a fluid connection from the upper portion of the second disengagement volume 220 to the upper portion of the third distribution volume 310. The lower second connecting tube 252 provides a fluid connection from the lower portion of the second disengagement volume 220 to the lower portion of the third distribution volume 310.

While mixing of the long-chained hydrocarbons in the liquid phase 1001 and the hydrocarbons in the gas phase 1002 is not desired during heating in the heating sections 1, 2, 3, 4, the long-chained hydrocarbons in the liquid phase 1001 and the hydrocarbons in the gas phase 1002 are preferably mixed before entering the separation structure 12. There is a significant pressure drop across the back pressure control element 5a, 5b. When passing the back pressure control element 5a, 5b downstream of the heating sections 1, 2, 3, 4, the pressure drop accelerates the flow of long-chained hydrocarbons in the liquid phase 1001 and the hydrocarbons in the gas phase 1002 to the order of the speed of sound in the gas phase. This leads to a significant mixing of the liquid and the gas phases. Preferably, a portion of the tube leading the hydrocarbons into the separation structure is arranged vertically and/or is narrow. Such vertical and/or narrow configuration likewise promotes mixing of the liquid and gas phases.

Waste plastic feedstock for the invention may preferably comprise polyethylene and/or polypropylene plastics. Preferably the sum of polyethylene and polypropylene in the feedstock is at least 50 wt.% by weight of the feedstock, more preferably at least 60 wt.%, still more preferably at least 75 wt.%, most preferably at least 90 wt.%. These materials represent a large portion of domestic plastic waste and are treatable by pyrolysis. The preferred plastic for the feedstock is polyethylene or polypropylene.

The feedstock may also comprise polyvinylchloride plastics, however, the level of PVC may preferably be limited to less than 10 wt.%, preferably less than 5 wt.%. PVC may be present at greater than 1 wt.%, more preferably greater than 5 wt.%. An effective absence of PVC in the feedstock may be preferred.

The feedstock may also comprise polyethylene terephthalate plastics, preferably greater than 3 wt.% of polyethylene terephthalate plastics, more preferably greater than 4 wt.%. The feedstock preferably comprises maximally 20 wt.% PET plastic. Preferably the content of polyethylene terephthalate plastics is maximally 10 wt.%, more preferably 5 wt. %.

The feedstock may comprise up to 100 wt.% polystyrene plastics. In embodiments, the feedstock may comprise at least 5 wt.%, more preferably 20 wt.%, more preferably 50wt% polystyrene.

Pyrolysis temperatures may vary within a limited range dependent upon factors such as feedstock makeup and operating pressures, preferably the plastics material is heated to a pyrolysis temperature of 360°C or more, about 390°C or more, more preferably about 400°C or more, up to about 450°C, although higher temperatures up to about 500°C or about 550°C may be implemented. The plastic pyrolysis may start from about 360°C, and so such temperatures may also be contemplated. Pyrolysis is, however, more significant at or above about 390°C, which may allow for a more economically attractive process.

The term “pyrolysis zone” as used herein refers to zones in which materials that are processed by the process or system (e.g. waste plastic or the derivates thereof generated by pyrolysis in the process or system) are at pyrolysis temperatures, for example at temperatures at or above 360°C, more preferably at temperatures at or above 390°C, still more preferably at or above 400°C. Pyrolysis zones are preferably those zones in the process or system in which the processed materials are at temperatures from about 360°C to about 550°C, more preferably from about 390°C to about 500°C, still more preferably from about 400°C to about 500°C. The process and system may comprise pyrolysis zones of different activity. For example, there may be primary pyrolysis zones in which the majority of pyrolysis occurs, which are preferably at temperatures above 390°C, and second pyrolysis zones in which the temperatures are above 360°C but below 390°C. Pyrolysis zones are zones in the system, process of apparatus why pyrolysis occurs, or conditions for pyrolysis are generated.

The pyrolysis is, as commonly understood, carried out in the absence of oxygen, most preferably under an inert atmosphere. Nitrogen gas may provide an inert atmosphers. Before start-up the system may purged with nitrogen gas to provide at least an initial inert atmosphere.

The invention preferably produces one or more hydrocarbon products, preferably wherein the hydrocarbon products include one or more of butane, propane, kerosene, diesel, fuel oil; light distillates, such as LPG, gasoline, naphtha, or mixtures thereof; middle distillates such as kerosene, jet fuel, diesel, or mixtures thereof; heavy distillates and residuum such as fuel oil, lubricating oils, paraffin, wax, asphalt, or mixtures thereof. Hydrocarbon products may be saturated, unsaturated, straight, cyclic or aromatic. Further product may include non- condensable gases, comprising methane, ethane, ethene and/or other small molecules. The products may be a source of feedstock for steam crackers of the manufacture of plastics.

The term “non-condensables” or “non-condensable gases” as variously referred to, identifies hydrocarbon fractions that are too volatile to condense in the distillation section, and that may, preferably will, exit the process as a gas. It is generally considered that non- condensable hydrocarbons in the pyrolysis process have from about 1 to about 7 carbon atoms. The non-condensables may include hydrocarbons that are saturated, unsaturated, straight, cyclic and/or aromatic.

The term “light hydrocarbons” or “LHC” as variously referred to, identifies hydrocarbon fractions that are condensable in the process and so obtainable as a liquid, yet which comprise short-chain molecules. It is generally considered that LHCs in the pyrolysis process have from about 3 to about 8 carbon atoms, possibly with some smaller portion of

C2 molecules and/or C10 molecules. The LHCs may include hydrocarbons that are saturated, unsaturated, straight, cyclic and/or aromatic.

The term “heavy hydrocarbons” or “HHC” as variously referred to, identifies hydrocarbon fractions that are condensable in the process and so obtainable as a liquid, with generally longer chain composition than LHCs. It is generally considered that HHCs in the pyrolysis process have at least about 7 carbon atoms (possibly with some smaller portion of C6 molecules), preferably up to about 35 carbon atoms. Preferred ranges may include low range products of about 7 to about 20 carbon atoms, possibly with some smaller portion of (C6 and/or C21 molecules. For the low range product, the final boiling point of the HHC may be about 430°C. Another preferred range may include medium range products of from about 8 to about 28 carbon atoms. For the medium range product, the final boiling point of the

HHC may be about 450°C. Another preferred range may include high range products from about 10 to about 35 carbon atoms. For the high range product, the final boiling point of the

HHC may be about 550°C. HHCs may include hydrocarbons that are saturated, unsaturated, straight, cyclic and/or aromatic.

It will be appreciated by the skilled reader dealing with petrochemicals, that there may be some variation in the boundary between non-condensables, LHC and HHC in a distillation process. Overlap and/or variation may be dependent, inter alia, upon chosen temperature, pressures and flow settings, and product specification may be adjusted to accommodate desired product qualities.

All documents cited in the Detailed Description of the Invention are, in relevant part, incorporated herein by reference; the citation of any document is not to be construed as an admission that it is prior art with respect to the present invention. To the extent that any meaning or definition of a term in this written document conflicts with any meaning or definition of the term in a document incorporated by reference, the meaning or definition assigned to the term in this written document shall govern.

While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

Claims

CONCLUSIONS

An apparatus for heating molten long chain hydrocarbons comprising: - a first heating section (1) having at least one first material flow tube (101, 101a) extending from a first heating section inlet (102) to a first heating section - outlet (103), wherein the first material flow tube (101, 1013) provides a flow path for the molten long chain hydrocarbons from the first heating section inlet (102) to the first heating section outlet (103), and a first heating structure (111, 112, 113) extending along at least a portion of the first material flow tube (101, 1013), wherein the first heating structure (111, 112, 113) is configured to transfer heat to the first material flow tube; and - a second heating section (2) with at least one second material flow tube (202) and at least one third material flow tube (203), the at least one second material flow tube (202) extending from a second heating section inlet (212) to a second heater section outlet (213), wherein the at least one third material flow tube (203) extends from a third heater section inlet (222) to a third heater section outlet (223), wherein the second and third material flow tubes (202, 203) providing flow paths for the molten long chain hydrocarbons from the second and third heater section inlets (212, 222) to the second and third heater section outlets (213, 223), respectively, wherein the second and third heater section inlets (212, 222) are configured to receive the molten long chain hydrocarbons from the first heating section outlet (103), and to split the flow path for the molten long chain hydrocarbons to the at least one second material flow tube (202) and the at least one third material flow tube (203); and wherein the second heating section inlet (212) and the third heating section inlet (222) are located at different heights.

The apparatus of claim 1, wherein the flow paths for the molten long chain hydrocarbons in the second and third material flow tubes converge adjacent to the second and third heating section outlets.

The apparatus of claim 1 or 2, wherein the first heating section has at least two material flow tubes that split the flow path for the molten long chain hydrocarbons adjacent the first heating section inlet and converge the flow path for the molten long chain hydrocarbons adjacent the first heating section outlet .

Device according to any of the preceding claims, wherein the second heating section has at least two second material flow tubes and/or at least two third material flow tubes.

5. Device according to any of the preceding claims, wherein an upper part of the first heating section is at the same height as a lower part of the second heating section.

An apparatus according to any one of the preceding claims, wherein the first and/or second heating section are configured such that the molten long-chain hydrocarbons can be cracked and decomposed into gas-phase hydrocarbons and liquid-phase long-chain hydrocarbons.

The apparatus of claim 6, further comprising a connecting portion between the first heating section and the second heating section, the connecting portion providing a flow path for the molten long chain hydrocarbons from the first heating section to the second heating section, and the apparatus being configured such that the separation between the hydrocarbons in the gas phase and the long chain hydrocarbons in the liquid phase as they pass through the connecting section is maintained.

Device according to claim 7, wherein the connecting portion is configured such that the flow path extends substantially horizontally or extends at an angle of 0° to 45° with respect to a horizontal plane, preferably at an angle of 0° to 10° ° with respect to a horizontal plane, with the downstream end of the flow path being higher than the upstream end.

An apparatus according to claim 7 or 8, wherein the connecting portion and/or a mass flow are adjusted to maintain the separation between the hydrocarbons in the gas phase and the long chain hydrocarbons in the liquid phase, wherein the flow pattern of the hydrocarbons in the gas phase and the long chain hydrocarbons in the liquid phase within the connecting section is preferably one of bubble, plug, layered, wavy or slug patterns.

A device according to any one of claims 7 to 9, wherein the connecting portion provides a single fluid channel with a round cross-section.

Device according to any one of claims 7 to 10, wherein the device is configured to, at the connecting part, have a temperature between 250°C and 450°C, a mass flow of 1000 kg/hour to 20,000 kg/hour, a gas content of the hydrocarbons in the gas phase from 1% by weight to 50% by weight, to provide a pressure between 100 kPa and 8100 kPa with respect to the ambient air pressure and wherein the connecting part has a circular cross-section with an internal diameter of at least 50 mm.

Device according to any one of the preceding claims, wherein, for solid material suspended in the molten long-chain hydrocarbons, at least one of the first, second or third material flow tubes has an internal cross-section adapted to convey the solid material with a predetermined maximum dimensions to pass.

The device according to any one of claims 7 to 12, wherein the connecting portion is equipped with an upper connecting tube and a lower connecting tube;

wherein the upper connecting tube is suitable for allowing the hydrocarbons to pass in the gas phase, and wherein the lower connecting tube is suitable for allowing the long-chain hydrocarbons to pass in the liquid phase.

An apparatus according to any one of the preceding claims, further comprising at least one third heating section, wherein each of the at least one third heating section has at least two fourth material flow tubes each extending from a respective fourth heating section inlet to a respective fourth heating section outlet, wherein the flow path is divided between the at least two fourth material flow tubes adjacent to the fourth heating section inlets and converges adjacent to the fourth heating section outlets, wherein the first and second heating sections and each of the at least one third heating section are configured such that material containing long chain hydrocarbons flows successively through each of them, and wherein at least one of the fourth material flow tubes preferably has an internal cross-section adapted to allow passage of solid material of a predetermined maximum size.

15. Method for heating plastic material to pyrolysis temperature, wherein the method comprises the following steps: - heating a mass of molten plastic-containing material in a first heating zone to obtain at least a first liquid phase and at least a first gas phase, wherein the first liquid phase and first gas phase are mixed together in the first heating zone; - allowing the first liquid phase and the first gas phase to separate to obtain a mass containing mainly the material in the first gas phase and a mass containing mainly the material in the first liquid phase; - transferring the material in the first liquid phase, and optionally the material in the first gas phase, to a second heating zone that has a higher temperature than the first heating zone, and heating to obtain at least one second liquid phase and at least one second gas phase, wherein the second liquid phase and the second gas phase are mixed together; - allowing the second liquid phase and second gas phase to separate to obtain a mass containing mainly the material in the second gas phase and a mass containing mainly the material in the second liquid phase; - optionally repeating the steps of heating, gas phase formation and gas phase separation one or more times in one or more other heating zones, with each subsequent heating zone increasing in temperature; and - transferring a liquid phase output from the heating zones, at a pyrolysis temperature, to a pyrolysis reactor and/or distillation apparatus.

18. Method according to claim 15, wherein the first, second and subsequent heating zones are heat exchangers, preferably tube heat exchangers.

Method according to claim 18, wherein the first, second and subsequent heating zones are heat exchangers that are distinguishable from each other.

A method according to any one of claims 15 to 17, wherein the body of molten plastics, gas phase and/or liquid phase, flows through the heating zones while they are heated.

A method according to any one of claims 15 to 18, wherein the separation of mixed liquid phase and gas phase takes place substantially downstream of each heating zone.

A method according to any one of claims 15 to 19, wherein the separation of mixed liquid phase and gas phase takes place under the influence of gravity, with a gas phase rising from the liquid phase.

A method according to any one of claims 15 to 20, wherein the plastic material is heated to a pyrolysis temperature of about 360°C to about 550°C, preferably from about 390°C to about 450°C prior to injection into the separation vessel.

A method according to any one of claims 15 to 21, wherein the successive heating zones are placed in series with phase separation volumes between at least one or more of the successive heating zones.

A method according to any one of claims 15 to 22, wherein the plurality of heating zones are placed in series and at least one or more downstream heating zones are placed higher than an upstream heating zone.

A method according to any one of claims 15 to 23, wherein there is a final heating zone before a pyrolysis reactor and wherein a liquid phase leaving the final heating zone has a temperature of from about 360°C to about 550°C, preferably from approximately 390°C to approximately 450°C.

A method according to any one of claims 15 to 24, wherein the first heating zone is fed with molten plastic-containing material through an extruder.

26. Method according to any one of claims 15 to 25, wherein the molten plastic-containing material comprises plastics of polyethylene and/or polypropylene, wherein the sum of polyethylene and polypropylene in the raw material is preferably at least 50% by weight of the raw material. , more preferably at least 60 wt. %.

A method according to any one of claims 15 to 26, wherein the molten plastic-containing material comprises polyvinyl chloride plastics, preferably more than 1 wt.% polyvinyl chloride plastics, more preferably more than 5 wt.% or wherein the raw material is less than 5% by weight of polyvinyl chloride plastics, more preferably less than 1% by weight. %.

A method according to any one of claims 15 to 27, wherein the molten plastic-containing material comprises polyethylene terephthalate plastics, preferably more than 3 wt.% polyethylene terephthalate plastics, more preferably more than 4 wt.% or wherein the raw material is less than 4% by weight of polyethylene terephthalate plastics, more preferably less than 3% by weight. %.

A method according to any one of claims 15 to 28, wherein the molten plastic-containing material comprises polystyrene plastics, preferably more than 1 wt.% polystyrene plastics, more preferably more than 5 wt.% or wherein the raw material is less than 20% by weight of polystyrene plastics, more preferably less than 5% by weight.

A method for the production of hydrocarbon material comprising the steps according to any one of the preceding claims 15 to 29 and comprising the further step of distilling gaseous hydrocarbons in a distillation apparatus to obtain the hydrocarbon product, preferably the hydrocarbon product being butane, propane , kerosene, diesel, fuel oil; light distillates, such as LPG, gasoline, naphtha or mixtures thereof; middle distillates such as kerosene, jet fuel, diesel or mixtures thereof; heavy distillates and residues such as fuel oil, lubricating oils, paraffin, wax, asphalt or mixtures thereof; or any mixture thereof; hydrocarbons that are saturated, unsaturated, unbranched, cyclic or aromatic; non-condensable gases including methane, ethane, ethylene and/or other small molecules; and mixtures thereof.

31. Device for pyrolyzing waste plastics into one or more hydrocarbon products, preferably at least one or more liquid hydrocarbon products, wherein the device comprises a device according to any one of claims 1 to 14 and downstream thereof at least one pyrolysis zone and at least one distillation - apparatus for distilling pyrolyzed material to obtain a hydrocarbon product, preferably the hydrocarbon product being butane, propane, kerosene, diesel, fuel oil; light distillates, such as LPG, gasoline, naphtha or mixtures thereof; middle distillates such as kerosene, jet fuel, diesel or mixtures thereof; heavy distillates and residues such as fuel oil, lubricants, paraffin, wax, asphalt or mixtures thereof; or any mixture thereof; hydrocarbons that are saturated, unsaturated, unbranched, cyclic or aromatic; non-condensable gases including methane, ethane, ethylene and/or other small molecules; and mixtures thereof.