Method and apparatus for converting wax to oil

Abstract

This invention relates to a method and apparatus for converting wax to oil in a pyrolysis process, wherein a feed containing plastic is supplied to a pyrolysis reactor, and the feed is pyrolyzed to form pyrolysis products. At least a wax fraction is separated from the pyrolysis products in a separation unit, and this wax fraction can be delivered to a bis-breaking unit where the wax fraction is cracked to form at least an oil product containing aliphatic compounds.

Description

Technical Field

[0001] This application relates to the method according to claim 1 and the apparatus according to claim 11 for converting wax into oil in a pyrolysis process.

Background Art

[0002] Pyrolysis products can be produced from different raw materials in a pyrolysis process. The raw materials can be pyrolyzed, for example, by using catalytic pyrolysis.

[0003] To generate positive economic value and reduce environmental pollution, waste plastics such as polyethylene and propylene can be converted into chemicals and fuels. As a promising versatile approach for converting waste plastics into chemicals and fuels, pyrolysis has become attractive to the scientific and industrial communities in recent years. However, the implementation of an efficient pyrolysis process with commercially viable production is a challenge. In addition, the technology of converting traditional plastics that require fossil fuel consumption into fuels is not an economical method and does not contribute to a circular economy of plastics. However, research on the technology of converting plastics into fuels has revealed that the conversion of waste plastics into naphtha or plastic monomers is a promising approach for manufacturing new plastics in a closed loop.

[0004] First-generation plastic pyrolysis has been carried out in stirring tank reactors (STRs) and screw reactors. Extensive research has been conducted to convert recycled waste plastics into oil, resulting in pilot plants working in STRs and screw reactors. In these types of reactors, the residence times of different plastic carbon chains are controlled, meaning that the smaller the compound formed, the faster it leaves the reactor (Scheirs, J., 2006, Overview of commercial pyrolysis processes for waste plastic, Feedstock Recycling and Pyrolysis of Waste Plastics, pp. 381-433).

[0005] Fluidized bed reactors can be a good option for scaling up processes. For example, companies like Anellotech (April 12, 2022, Plas-TCat® for mixed plastic recycling, Anellotech, Inc.) or BioBTX (BioBTX, nd, The BioBTX Technology) use catalytic pyrolysis to convert plastics into oil. The final products from current catalytic pyrolysis convert plastics into aromatics such as benzene, toluene, and xylene (BTX).

[0006] Traditional thermal pyrolysis in STR and screw reactors, which produces aliphatic monomers, has limitations in terms of scale-up. Fluidized bed pyrolysis is a good option for commercial-scale pyrolysis units. However, literature reviews and Valmet's experience have shown that fine-tuning the process efficiently and refining the final product are extremely difficult. Depending on the temperature, significant formation of highly viscous waxes, high-content non-condensable gas products, or trace amounts of undesirable aromatic compounds has been observed during thermal pyrolysis in different reactor technologies, particularly rise reactors.

[0007] A high content of wax or non-condensable gas compared to the required oil means a low process yield, reducing the plant's profitability. The formed wax or non-condensable gas cannot be easily transported to the refining plant. Furthermore, refineries are not interested in purchasing the produced wax.

[0008] One method for fine-tuning the products from pyrolysis is catalytic pyrolysis of waste PP / PE using zeolite catalysts. This process forms aromatic compounds with high BTX content from plastic pyrolysis, but it has only a niche market. This is due to the fact that petroleum refining companies are more interested in aliphatic hydrocarbons as feedstock for their hydrotreatment and steam cracking equipment. Aromatic compounds in oil result in high coking, high hydrogen consumption, and catalyst poisoning during oil reforming. Therefore, the general catalytic pyrolysis of plastics using zeolites is not a profitable route. [Prior art documents] [Non-patent literature]

[0009] [Non-Patent Document 1] Scheirs, J., 2006, Overview of commercial pyrolysis processes for waste plastic, Feedstock Recycling and Pyrolysis of Waste Plastics, pp. 381-433. [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] The object of this invention is to solve the above problems. Furthermore, the object is to disclose a new type of method and apparatus for processing pyrolysis products after pyrolysis. Furthermore, the object is to modify undesirable pyrolysis products after pyrolysis. Furthermore, the object is to convert the wax formed by pyrolysis into an oil product containing aliphatic compounds. [Means for solving the problem]

[0011] The method and apparatus are characterized by those presented in the claims.

[0012] A method for converting wax to oil in a pyrolysis process includes the steps of: feeding a feed containing plastic to a pyrolysis reactor; pyrolysis of the feed to form pyrolysis products; separating at least a wax fraction from the pyrolysis products in a separation unit; and supplying the wax fraction to a pyrolysis unit including a visbreaking unit and / or a pyrolysis reactor where the wax fraction is processed to form at least an oil product.

[0013] The apparatus may include a pyrolysis reactor for pyrolysis a feed containing plastic to form pyrolysis products, a feeder for supplying the feed to the pyrolysis reactor, a separation unit including at least one separation device for separating at least a wax fraction from the pyrolysis products, and a vis-breaking unit to which at least a wax fraction is delivered, processed, and to which at least an oil product is formed. [Brief explanation of the drawing]

[0014] To provide a further understanding of the present invention, the accompanying drawings, which are included and constitute part of this specification, illustrate several embodiments of the present invention and, together with the description, help to illustrate the principles of the present invention.

[0015] [Figure 1] Figure 1 is a flowchart of a process according to one embodiment. [Figure 2] Figure 2 is a flowchart of the process according to another embodiment. [Figure 3] Figure 3 is a flowchart of the process according to another embodiment. [Figure 4] Figure 4 is a flowchart of the process according to another embodiment. [Modes for carrying out the invention]

[0016] In a method for converting wax to oil in a pyrolysis process, a feed containing plastics is supplied to a pyrolysis reactor, where it is pyrolyzed to form pyrolysis products. At least a wax fraction is separated from the pyrolysis products in a separation unit, and at least a portion of the wax fraction is delivered to a bis-breaking unit where the wax fraction is cracked (broken down) to form at least an oil product containing aliphatic compounds. In one embodiment, the wax fraction or the entire wax fraction is delivered to the bis-breaking unit. The pyrolysis products can be delivered after the pyrolysis reactor to at least one condenser where the pyrolysis products are cooled. Non-condensable gases can be recycled from the separation unit to a combustor where the pyrolysis reactor, the bis-breaking unit, and / or the bed material of the pyrolysis reactor is processed.

[0017] An apparatus for converting wax to oil in a pyrolysis process includes a pyrolysis reactor for pyrolysis a feed containing plastics to form pyrolysis products, and a feeder for supplying the feed to the pyrolysis reactor. Furthermore, the apparatus includes a separation unit including at least one separation device for separating at least a wax fraction from the pyrolysis products, and a visbreaking unit including at least one visbreaker furnace to which at least a portion of the wax fraction is delivered and the wax fraction is cracked to form at least an oil product containing aliphatic compounds. Furthermore, the apparatus may include at least one condenser after the pyrolysis reactor to which the pyrolysis products are delivered and cooled. Furthermore, the apparatus may include at least one line for recirculating non-condensable gases from the separation unit to a combustor to which the pyrolysis reactor, the visbreaking unit, and / or the floor material of the pyrolysis reactor is processed.

[0018] In an embodiment of another method for converting wax in a pyrolysis process, a feed containing plastic is fed into a pyrolysis reactor, where the feed is pyrolyzed to form pyrolysis products. At least the wax fraction is separated from the pyrolysis products in a separation unit, and the wax fraction or at least a part of the wax fraction is delivered to a pyrolysis unit including the pyrolysis reactor, for example, a feeder (supply port, feed) of the pyrolysis reactor or the pyrolysis reactor. In one embodiment, the wax fraction is delivered to a pyrolysis unit and a bis-breaking unit where the wax fraction is cracked to form at least an oil product containing aliphatic compounds.

[0019] Some embodiments of the method and apparatus are shown in FIGS. 1, 2, 3, and 4.

[0020] In this context, a feed containing plastic means any feed or feed material containing at least plastic or a plastic material. Further, the feed can also contain materials other than plastic. The feed may contain one or more components. The plastic or plastic material may be a recycled material, a residual material, a waste material, or a virgin material or a combination thereof containing plastic, a polymer, or a mixture of these. In one embodiment, the feed is formed from recycled materials, waste materials, residual materials, and combinations thereof. In one embodiment, the plastic may include any plastic or polymer, for example, polyethylene, polypropylene, other polymers, or a combination thereof.

[0021] In this regard, pyrolysis products mean any pyrolysis products formed by pyrolysis, for example, by catalytic pyrolysis. In one embodiment, the pyrolysis products are in gaseous form. In one embodiment, the pyrolysis products are product vapors.

[0022] In this regard, the wax fraction means any fraction containing at least wax. Further, the wax fraction may contain tar and other impurities. In one embodiment, the wax fraction contains at least wax and tar. In one embodiment, the wax fraction contains wax, oil and tar.

[0023] In this regard, the oil product means any product containing at least aliphatic compounds. In one embodiment, the oil product is in vapor form, i.e., the oil product is oil product vapor.

[0024] The feed containing plastic is treated by pyrolysis in a pyrolysis reactor. Any suitable pyrolysis reactor can be used for this pyrolysis. In one embodiment, the pyrolysis reactor is a fluidized bed reactor. The feed may be treated by thermal pyrolysis. In one embodiment, the pyrolysis is carried out at a low temperature of 500 - 800 °C, and in one embodiment at a temperature of 550 - 700 °C. In one embodiment, the residence time may be 1 - 3 seconds in the pyrolysis reactor.

[0025] The feed containing plastic can be fed into the pyrolysis reactor using a feeder. Any suitable feeder can be used for the feeding. In one embodiment, the feeder is a screw feeder or an extruder.

[0026] The wax fraction is separated from the pyrolysis products in a separation unit. The separation unit includes at least one separation device. In one embodiment, the separation unit includes multiple separation devices. In one embodiment, a separation unit or separation device capable of separating a desired fraction or product based on its boiling point is used to separate the wax fraction. In one embodiment, the separation unit includes a distillation column, a scrubber, a condenser, a condenser, a quench, or other suitable separation device. Alternatively, any suitable separation unit or separation device can be used to separate the wax fraction from the pyrolysis products. In one embodiment, the separation unit includes at least a distillation column. In one embodiment, the separation unit includes at least a scrubber and a distillation column. In one embodiment, the separation unit includes at least a condenser or condenser. After separation, the wax fraction can be delivered to a vis-breaking unit.

[0027] In one embodiment, the method includes the step of delivering the pyrolysis products to at least one condenser or condenser from which the pyrolysis products are cooled. The pyrolysis products are cooled in the condenser or condenser, and a condensed flow containing wax and / or tar may be separated. In one embodiment, at least a wax fraction, and optionally a gas and / or oil fraction, are also separated in the condenser. In one embodiment, the apparatus includes at least one condenser or condenser for cooling the pyrolysis products. In one embodiment, the apparatus includes at least one condenser or condenser for cooling the pyrolysis products and separating a condensed flow containing wax and / or tar from the pyrolysis products. In one embodiment, the condenser is configured to separate at least a wax fraction and optionally a gas fraction and / or oil fraction. Any suitable condenser, condenser, etc., can be used for condensation. In one embodiment, a condenser is used as the separation device of a separation unit.

[0028] In one embodiment, the method includes the step of delivering the pyrolysis product to at least one scrubber in which the pyrolysis product is cooled. In one embodiment, the method includes the step of delivering the pyrolysis product to at least one scrubber in which the pyrolysis product is cooled and a condensed flow containing wax and / or tar is separated from the pyrolysis product to form a non-condensable pyrolysis product. In one embodiment, at least a wax fraction, and optionally a gas fraction and / or oil fraction, are also separated in one or more scrubbers. In one embodiment, the apparatus includes at least one scrubber for cooling the pyrolysis product. In one embodiment, the apparatus includes at least one scrubber for cooling the pyrolysis product and separating a condensed flow containing wax and / or tar from the pyrolysis product to form a non-condensable pyrolysis product. In one embodiment, one or more scrubbers are arranged to separate at least a wax fraction, and optionally a gas fraction and / or oil fraction. In one embodiment, the scrubber is used as a separation device in a separation unit. In one embodiment, the device includes at least two scrubbers or scrubber sections. In one embodiment, the device includes more than two scrubbers, for example, three, four, or five or more scrubbers. Any suitable scrubber, gas cleaning device, etc., can be used as a scrubber. In one embodiment, the scrubbers are arranged in series. In one embodiment, the temperature of the pyrolysis product is 500-600°C when supplied to the scrubber. In one embodiment, the temperature of the condensed flow is 70-200°C after one or more scrubbers, and in one embodiment, 100-150°C. In one embodiment, the flow temperature is 250-350°C after the first scrubber.

[0029] In one embodiment, the separation unit is a distillation unit comprising at least one distillation column from which at least a gas fraction, an oil fraction, and a wax fraction are separated. In one embodiment, the separation unit comprises a distillation column for separating fractions from the pyrolysis product. In one embodiment, the distillation column is used as a separation device of the separation unit for separating fractions from the pyrolysis product. The distillation column can fractionate the pyrolysis product into different fractions depending on the boiling point. Furthermore, the distillation column may incorporate packings and trays. In one embodiment, the gas fraction is recovered from the top of the distillation column, one or more oil fractions are recovered from the middle of the distillation column, and the wax fraction is recovered from the bottom of the distillation column. In one embodiment, the temperature of the wax fraction after the distillation column is 70-300°C, and in one embodiment, 100-200°C. In one embodiment, the temperature of the gas fraction after the distillation column is 20-30°C.

[0030] In one embodiment, a distillation column is used as a separation device for a separation unit to separate fractions from pyrolysis products, and the method includes the step of delivering non-condensable pyrolysis products from a scrubber to a distillation column from which at least gas fractions, oil fractions and wax fractions are separated. In one embodiment, the device includes at least one line for delivering non-condensable pyrolysis products from a scrubber to a distillation column from which at least gas fractions, oil fractions and wax fractions are separated. In one embodiment, a distillation column is used in the process having bottom boiling points and top boiling points of about 100-150°C and 20-30°C, respectively, and in one embodiment about 100°C and 25°C.

[0031] In one embodiment, the wax fraction or a portion of the wax fraction is delivered from the separation unit to a vis-breaking unit, for example, from a separation device, such as a distillation unit or distillation column, a scrubber, or a condenser. In one embodiment, the wax fraction or a portion of the wax fraction is delivered to a pyrolysis unit, for example, to a pyrolysis reactor or a feeder of a pyrolysis reactor.

[0032] In one embodiment, a wax fraction from a separation unit, such as a distillation unit, and / or a condensed flow from a scrubber are delivered to a vis-breaking unit. In one embodiment, the apparatus includes at least one line for delivering a wax fraction from a separation unit, such as a distillation column, and / or a condensed flow from a scrubber, to a vis-breaking unit.

[0033] In one embodiment, the wax fraction is recovered from the bottom of the separation unit or separation device and delivered to a screw breaking unit.

[0034] The wax fraction is processed in a bis-breaking unit and preferably cracked. In the bis-breaker furnace of the bis-breaking unit, the wax fraction is cracked in indirect thermal contact with the furnace to obtain a lighter product with a shorter carbon chain length. In one embodiment, the bis-breaking unit is based on a mild thermal cracking process. In one embodiment, the wax is cracked into a lighter compound at a temperature of 400-500°C. In one embodiment, the wax is cracked into a lighter compound in the bis-breaker furnace of the bis-breaking unit at a temperature of 400-500°C, preferably with a residence time of 30s-30min, i.e., 30 seconds-30 minutes, depending on the temperature. In one embodiment, the residence time is 1-10 minutes. In one embodiment, the residence time is less than 12 minutes, and in one embodiment, it is less than 10 minutes. Any suitable bis-breaker furnace can be used for bis-breaking. In one embodiment, the bis-breaking unit may include a coil furnace or a soaker furnace. In one embodiment, the temperature of the oil product after the bisbreaker furnace is 350-450°C.

[0035] In one embodiment, the oil product is recirculated from the vis-breaking unit to a separation unit, for example, to a separation device, such as a distillation column, condenser, or scrubber, or to a feeder of the separation device. In one embodiment, the oil product is recirculated from the vis-breaking unit to a separation unit or scrubber. In one embodiment, the oil product is recirculated from the vis-breaking unit to a separation device or scrubber of a separation unit, the scrubber of which may be located before the separation device of the separation unit. In one embodiment, the device includes at least one line for recirculating the oil product from the vis-breaking unit to a separation unit, for example, a separation device of the separation unit, or a scrubber, the scrubber of which may be located before the separation device of the separation unit.

[0036] In one embodiment, the bed material and / or char are separated from the pyrolysis products after the pyrolysis reactor. In one embodiment, the apparatus includes at least one cyclone for separating the bed material and / or char from the pyrolysis products after the pyrolysis reactor. In one embodiment, the apparatus further includes a combustor to which at least the bed material, e.g., sand, is delivered and the bed material of the pyrolysis reactor is heated. Any combustor, e.g., a fluidized bed combustor, may be used in the process. The heated bed material can be recycled from the combustor to the pyrolysis reactor.

[0037] In one embodiment, non-condensable gas from a separation unit, for example, from a separation device, is recirculated to a pyrolysis reactor, a vis-breaking unit, and / or a combustor that processes the floor material of the pyrolysis reactor. In one embodiment, the apparatus includes at least one line for recirculating the non-condensable gas from the separation unit to the pyrolysis reactor, the vis-breaking unit, and / or a combustor that processes the floor material of the pyrolysis reactor. Preferably, the vis-breaking unit, the pyrolysis reactor, and the combustor can obtain their energy from the non-condensable gas.

[0038] In one embodiment, at least a portion of the wax separated by a separation device, such as a condenser or scrubber, is recycled to a pyrolysis unit, for example, to a feeder of a pyrolysis reactor. In one embodiment, the device includes at least one line for recycling at least a portion of the wax separated by the separation device, such as a condenser or scrubber, to a feeder of a pyrolysis reactor. In one embodiment, a portion of warm wax, preferably a small portion of warm wax, is added to the feed to raise the feed temperature, in which case the work required in the feeder to heat the feed can be reduced. Furthermore, the viscosity of the feed may be reduced.

[0039] In one embodiment, the wax fraction is heated before the vis-breaking unit by using indirect contact with flue gas from the combustor where the floor material of the vis-breaking unit and / or pyrolysis reactor is processed. In one embodiment, the apparatus includes at least one heat exchanger for heating the wax fraction before the vis-breaking unit by using indirect contact with flue gas from the combustor where the floor material of the vis-breaking unit and / or pyrolysis reactor is processed. In one embodiment, the temperature of the flue gas is 600-800°C after the vis-breaking unit. In one embodiment, the temperature of the flue gas is 450-700°C after the heat exchange.

[0040] In one embodiment, the method and apparatus are based on a continuous process.

[0041] This invention makes it possible to convert wax and heavy tar formed by thermal decomposition into oil having a high content of aliphatic compounds. This increases the efficiency of the plant. Furthermore, if the wax is not cooled to room temperature but is transferred to the vis-breaking unit at a high temperature of about 100°C, energy can be saved. The wax can be heated using the flue gas of the vis-breaking unit, in which case the efficiency of the vis-breaking unit and the entire process can be increased. In addition, the feedstock for thermal decomposition can be heated by using the warm wax that is refluxed into the feeder.

[0042] The method and apparatus offer the possibility of easily, energy-efficiently, and cost-effectively converting a residue flow into a desired product in a pyrolysis process. This invention provides an industrially applicable, simple, and affordable method for producing a desired product from different raw materials. The method and apparatus are easy and simple to implement in relation to a manufacturing process. [Examples]

[0043] Figures 1, 2, 3, and 4 illustrate several embodiments of the process of converting wax to oil in a pyrolysis process.

[0044] The apparatus shown in Figures 1-4 includes a pyrolysis reactor (2), such as a fluidized bed pyrolysis reactor, for pyrolysis of a feed (1) containing plastic to form pyrolysis products (3), and a feeder for supplying the feed to the pyrolysis reactor. Furthermore, the apparatus includes a separation unit (10) including at least one separation device for separating at least a wax fraction (16), and a vis-breaking unit (13) including a vis-breaker furnace. The wax fraction (16) is delivered to the vis-breaking unit (13), where it is cracked to form at least an oil product (11) containing aliphatic compounds. Air (15) can be supplied to the vis-breaker furnace (13) via an air inlet.

[0045] The apparatus in Figure 1 includes a scrubber (8) for cooling the pyrolysis products (3), separating a condensed stream (18) containing wax and / or tar from the pyrolysis products, and forming non-condensable pyrolysis products (9). The scrubber (8) in Figure 2 includes two scrubbers, namely a first scrubber (8a) and a second scrubber (8b). The apparatus in Figure 4 includes more than two scrubbers, in this embodiment four scrubbers (8c, d, e, f) for cooling the pyrolysis products (3) and separating the wax fraction (16), oil fractions (14a, 14b), and gas fraction (12).

[0046] In the apparatus of Figure 4, the scrubber is used as a separation device for the separation unit. In one embodiment of Figure 4, the first scrubber (8c) may be optional, and / or any number of scrubbers may be used as third and fourth scrubbers (8e, f). In the apparatus of Figure 4, the wax fraction (16) is delivered via a line from the scrubber (8d) to the screw breaking unit (13).

[0047] In the apparatus shown in Figures 1 and 2, the separation apparatus of the separation unit (10) is a distillation column from which gas fractions (12), oil fractions (14a, 14b), and wax fractions (16) are separated. The apparatus includes lines for delivering non-condensable pyrolysis products (9) from scrubbers (8, 8b) to the distillation column (10). Furthermore, the apparatus includes lines for delivering the wax fraction (16) from the distillation column (10) and the condensed flow (18) from the scrubber (8) in Figure 1 or the second scrubber (8b) in Figure 2 to the vis-breaking unit (13). The wax fraction (16) is recovered from the bottom of the distillation column (10).

[0048] In the apparatus shown in Figure 3, the separation unit (10) is a condenser from which gas fractions (12), oil fractions (14a, 14b), and wax fraction (16) are separated. The apparatus includes a line for delivering the wax fraction (16) or a portion thereof from the condenser (10) to the suction breaking unit (13). The wax fraction (16) is recovered from the bottom of the condenser (10). Furthermore, the apparatus may include a line for delivering the wax fraction or a portion thereof from the condenser (10) to the feeder of the pyrolysis reactor (2), in which case the wax fraction or a portion thereof may be delivered from the condenser to the suction breaking unit and / or the pyrolysis unit.

[0049] Furthermore, the apparatus in Figures 2 and 4 includes a line for recirculating a portion of the wax (22) separated by the first scrubbers (8a, 8c) to the feeder of the pyrolysis reactor. In addition, the apparatus in Figures 1-4 includes a line for recirculating the non-condensable gas of the gas fraction (12) from a separation device (10) such as a distillation column or condenser, or from the scrubber (8f) to the pyrolysis reactor (2), vis-breaking unit (13), and / or combustor (6) where the floor material of the pyrolysis reactor is processed. The apparatus in Figures 1, 2, and 4 further includes a line for recirculating the oil product (11) from the vis-breaking unit (13) to the scrubber (8), and the apparatus in Figure 3 includes a line for recirculating the oil product (11) from the vis-breaking unit (13) to the feeder of the condenser.

[0050] Furthermore, the apparatus in the figure includes a cyclone (4) after the pyrolysis reactor (2) for separating the floor material and / or char from the pyrolysis products (3). The apparatus further includes a combustor (6) in which the floor material (5), such as sand, is heated. The heated floor material (7) is recirculated from the combustor to the pyrolysis reactor (2). Air (19) can be supplied to the combustor through an air inlet.

[0051] Furthermore, the apparatus in the figure includes a heat exchanger (20) for heating the wax fraction (16) in front of the screw-breaking unit (13) by using indirect contact with flue gas (17) from the screw-breaking unit (13). Alternatively, exhaust gas (21) from the combustor (6) is used to heat the wax fraction within the heat exchanger.

[0052] Example 1 In this process, the wax is converted into oil through the thermal decomposition process shown in Figures 1 and 2.

[0053] A plastic feed (1) containing waste PP / PE, which may have a chain length (C) of 4000 to 40000, is atomized and fed into a fluidized bed riser pyrolysis reactor (2), where the feed is pyrolyzed at a temperature of approximately 500 to 600°C with a residence time of 1 to 3 seconds to form pyrolysis product vapors (3). After the pyrolysis reactor, sand and / or char are separated from the pyrolysis products in a cyclone (4). The sand is treated in a combustor containing a fluidized bed so that the char burns and heats the sand. The hot sand is recycled back into the pyrolysis reactor. Air (19) can be supplied to the combustor (6).

[0054] From the cyclone (4), pyrolysis product vapor (3) at a temperature of approximately 500°C is delivered to the scrubber (8), where the pyrolysis product vapor is cooled and a condensed stream (18) containing wax and / or tar is separated from the pyrolysis products, forming non-condensable pyrolysis products (9). The temperature of the condensed stream (18) may be approximately 100°C after the scrubber. In the process according to Figure 2, the stream temperature may be approximately 300°C after the first scrubber (8a) and approximately 100°C after the second scrubber (8b). The non-condensable pyrolysis products (9) are delivered from the scrubber (8) or the last scrubber (8b) to the distillation column (10), where the gas fraction (12), oil fractions (14a, 14b) and wax fraction (16) are separated. The temperature of the wax fraction (16) is approximately 250°C after the distillation column.

[0055] The wax fraction (16) is delivered from the bottom of the distillation column to a bisbreaker furnace (13), where it is cracked to form an oil product containing aliphatic compounds. The wax fraction (16) contains at least wax and tar, and the chain length C may be less than 100-200. A condensed flow (18) from the scrubber can be combined with the flow of the wax fraction (16), and the combined flow can be delivered to the bisbreaker furnace. The wax fraction or the combined flow can be heated in a heat exchanger (20) before the bisbreaker furnace by using indirect contact with flue gas (17) from the bisbreaker furnace (13) and / or exhaust gas from the combustor (6). The temperature of the flue gas (17) may be about 700°C after the bisbreaker furnace and about 500°C after the heat exchanger. Inside the bisbreaker furnace, the wax fraction is cracked to form an oil product (11). The wax can be cracked into lighter compounds in a bisbreaker furnace at a temperature of 400-500°C with a residence time of 1-10 minutes. Air (15) can be supplied to the bisbreaking (13). The temperature of the oil product may be about 400°C after bisbreaking. The oil product (11) may be recycled from the bisbreaker furnace to a scrubber.

[0056] The non-condensable gas (12), such as a light gas, from the distillation column (10) may be recycled to the pyrolysis reactor (2), the bisbreaker furnace (13), and / or the combustor (6). The temperature of the non-condensable gas after the distillation column may be about 25°C.

[0057] In the process shown in Figure 2, a portion of the wax separated by the first scrubber (8a) can be recycled to the feeder of the pyrolysis reactor (2). In this case, the plastic feed (1) may be heated using warm wax, for example, at the start of the extruder.

[0058] The pyrolysis reactors, combustors, scrubbers, distillation columns, and bisbreaker furnaces used in Figures 1-4, as well as other process equipment and fixtures, are known in the art and therefore will not be described in further detail in this context.

[0059] The method and apparatus are suitable in various embodiments for producing desired products from different raw materials and for converting wax fractions of the products.

[0060] This invention is not limited to the examples described above. Rather, many modifications are possible within the scope of the idea of ​​this invention as defined by the claims.

Claims

1. A method for converting wax to oil in a thermal decomposition process, A process comprising supplying a feed (1) containing plastic to a pyrolysis reactor (2) containing flooring material, and pyrolyzing the feed to form pyrolysis products (3), A step of delivering the thermal decomposition product (3) to at least one condensation device (8, 8a, 8b) where the thermal decomposition product is cooled, The process includes separating at least the wax fraction (16) from the thermal decomposition product in the separation unit (10), A step of delivering at least a portion of the wax fraction (16) to a bisbreaker furnace of a bisbreaking unit (13) where the wax fraction is cracked and at least an oil product (11) containing an aliphatic compound is formed, A step of recirculating the non-condensable gas (12) from the separation unit (10) to the pyrolysis reactor (2), the screw breaking unit (13), and / or the combustor (6) in which the floor material (7) of the pyrolysis reactor is processed. A method characterized by including

2. The method according to claim 1, characterized in that it includes the step of delivering the pyrolysis product (3) to at least one scrubber (8) where the pyrolysis product is cooled, a condensed flow (18) containing wax and / or tar is separated from the pyrolysis product, and a non-condensable pyrolysis product (9) is formed.

3. The method according to claim 2, wherein a distillation column is used as the separation device of the separation unit (10) for separating fractions from the pyrolysis products, and the method includes the step of delivering the non-condensable pyrolysis products (9) from the scrubber (8) to the distillation column from which at least a gas fraction, an oil fraction and a wax fraction are separated.

4. The method according to claim 1 or 3, characterized in that the wax fraction (16) from the condenser, distillation column and / or scrubber, and / or the condensed flow (18) from the scrubber are delivered to the screw breaking unit (13).

5. The method according to any one of claims 1 to 4, characterized in that at least a portion of the wax separated by the separation device is recycled to the feeder of the pyrolysis reactor (2).

6. The method according to any one of claims 1 to 5, characterized in that the wax fraction (16) is recovered from the bottom of the separation unit (10) and delivered to the screw breaking unit (13).

7. The method according to any one of claims 1 to 6, characterized in that the flooring material and / or char (5) is separated from the pyrolysis product (3) after the pyrolysis reactor (2).

8. The method according to any one of claims 1 to 7, characterized in that the oil product (11) is recirculated from the screw breaking unit (13) to the separation unit (10) or scrubber (8).

9. The method according to any one of claims 1 to 8, characterized in that the wax fraction (16) is heated in front of the screw-breaking unit (13) by using indirect contact with flue gas (17) from the combustor in which the floor material of the screw-breaking unit and / or the pyrolysis reactor is processed.

10. The method according to any one of claims 1 to 9, characterized in that the wax is cracked into a lighter compound in the scisbreaker furnace of the scisbreaking unit (13) at a temperature of 400 to 500°C for a residence time of 30 seconds to 30 minutes.

11. A device for converting wax into oil in a thermal decomposition process, A pyrolysis reactor (2) containing floor material for pyrolysis of a feed (1) containing plastic to form pyrolysis products (3), and a feeder for supplying the feed to the pyrolysis reactor, The thermal decomposition product is delivered to and cooled by at least one condensation apparatus (8, 8a, 8b), A separation unit (10) including at least one separation device for separating at least the wax fraction (16) from the thermal decomposition product, A bisbreaking unit (13) includes at least one bisbreaker furnace to which at least a portion of the wax fraction (16) is delivered and the wax fraction is cracked to form at least an oil product (11) containing an aliphatic compound, At least one line for recirculating the non-condensable gas (12) from the separation unit (10) to the pyrolysis reactor (2), the screw breaking unit (13), and / or the combustor (6) where the floor material (7) of the pyrolysis reactor is processed. An apparatus characterized by including

12. The apparatus according to claim 11, characterized in that the separation unit (10) is a distillation unit including at least one distillation column from which at least a gas fraction, an oil fraction, and a wax fraction are separated.

13. The apparatus according to claim 11 or 12, further comprising at least one scrubber (8) for cooling the pyrolysis product (3), separating a condensed flow (18) containing wax and / or tar from the pyrolysis product, and forming a non-condensable pyrolysis product (9).

14. The apparatus according to claim 13, characterized in that it includes at least one line for delivering the non-condensable pyrolysis product (9) from the scrubber (8) to a distillation column from which at least a gas fraction, an oil fraction, and a wax fraction are separated.

15. The apparatus according to any one of claims 11 to 14, characterized in that it includes at least one line for delivering the wax fraction (16) from the separation device of the separation unit (10) and / or the condensed flow (18) from the scrubber to the screw breaking unit (13).

16. The apparatus according to any one of claims 11 to 15, characterized in that it includes at least one line for recirculating at least a portion of the wax separated by the separation device to the feeder of the pyrolysis reactor (2).

17. The apparatus according to any one of claims 11 to 16, further comprising at least one cyclone (4) for separating floor material and / or char (5) from the pyrolysis product (3) after the pyrolysis reactor (2).

18. The apparatus according to any one of claims 11 to 17, characterized in that it includes at least one line for recirculating the oil product (11) from the screw breaking unit (13) to the separation unit (10) or scrubber (8).

19. The apparatus according to any one of claims 11 to 18, further comprising at least one heat exchanger (20) for heating the wax fraction (16) in front of the screw breaking unit (13) by using indirect contact with flue gas from the combustor (6) in which the floor material of the pyrolysis reactor is processed.

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