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JP-3255780-U - Method and apparatus for converting wax to oil

JP3255780UJP 3255780 UJP3255780 UJP 3255780UJP-3255780-U

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. [Selection Diagram] Figure 1

Inventors

  • カズライエ トゥーラン
  • ナーリ トゥオマス
  • ライコ アンッティ

Assignees

  • バルメット テクノロジーズ オサケユキチュア

Dates

Publication Date
20260512
Application Date
20240508
Priority Date
20230510

Claims (19)

  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 method characterized by comprising the step of recirculating a 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.
  2. The method according to claim 1, characterized by comprising 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, characterized in that 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 gas fractions, oil fractions, and wax fractions 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 sprocket breaker furnace of the sprocket breaking 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, Apparatus comprising at least one line for recirculating a 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.
  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, characterized by comprising at least one scrubber (8) for cooling the pyrolysis product (3), separating the 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 by including at least one line for delivering the non-condensable pyrolysis product (9) from the scrubber (8) to a distillation column from which at least the gas fraction, oil fraction, and 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 by including 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, characterized by comprising at least one cyclone (4) for separating the 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 by including 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, characterized in that it includes at least one heat exchanger (20) for heating the wax fraction (16) in front of the sprocket 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.

Description

This application relates to the method according to claim 1 and the apparatus according to claim 11 for converting wax to oil in a pyrolysis process. Pyrolysis products can be generated from different raw materials in the pyrolysis process. These raw materials can be pyrolyzed, for example, by using catalytic pyrolysis. To generate positive economic value and reduce environmental pollution, waste plastics such as polyethylene and propylene can be converted into chemicals and fuels. Pyrolysis has become attractive to the scientific and industrial communities in recent years as a promising and versatile approach to converting waste plastics into chemicals and fuels. However, implementing efficient pyrolysis processes with commercially viable production remains a challenge. Furthermore, traditional plastic-to-fuel technologies, which require the consumption of fossil fuels, are not economically viable and do not contribute to a circular economy for plastics. Nevertheless, research into plastic-to-fuel technologies has revealed that the conversion of waste plastics into naphtha or plastic monomers is a promising approach for producing new plastics in a closed-loop system. 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 operating 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 Pyrolisis of Waste Plastics, pp. 381–433). 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). Traditional thermal decomposition in STR and screw reactors, which produces aliphatic monomers, has limitations in terms of scale-up. Fluidized bed decomposition is a good option for commercial-scale decomposition 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 decomposition in different reactor technologies, particularly rise reactors. 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. One method for fine-tuning the products from pyrolysis is catalytic pyrolysis of waste PP/PE using a zeolite catalyst. While this process produces aromatic compounds with high BTX content from plastic pyrolysis, 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 lead to high coking, high hydrogen consumption, and catalyst poisoning during oil reforming. Therefore, the general catalytic pyrolysis of plastics using zeolites is not a profitable pathway. Scheirs, J. , 2006, Overview of commercial pyrolysis processes for waste plastic, Feedstock Recycling and Pyrolysis of Waste Plastics, pp. 381-433 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. Figure 1 is a flowchart of a process according to one embodiment.Figure 2 is a flowchart of the process according to another embodiment.Figure 3 is a flowchart of the process according to another embodiment.Figure 4 is a flowchart of the process according to another embodiment. 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 the 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 oil products containing aliphatic compounds. In one embodiment, the wax fraction or the