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KR-20260062198-A - LIQUID FUEL PRODUCTION PROCESS FROM WASTE PLASTIC

KR20260062198AKR 20260062198 AKR20260062198 AKR 20260062198AKR-20260062198-A

Abstract

The present invention relates to a process for producing liquid fuel from waste plastics. A process for producing liquid fuel from waste plastics according to one embodiment of the present invention comprises: a step of preparing a catalyst; a step of stirring the catalyst, water, and waste plastic material in a stirrer to form a mixture; and a step of placing the mixture into a reactor and decomposing the waste plastics.

Inventors

  • 노인수
  • 권태은

Assignees

  • 서울과학기술대학교 산학협력단

Dates

Publication Date
20260507
Application Date
20241025

Claims (10)

  1. Step of preparing the catalyst; A step of forming a mixture by stirring the catalyst, water, and waste plastic material in a stirrer; and Step of placing the above mixture into a reactor and decomposing waste plastic; including, Process for producing liquid fuel from waste plastics.
  2. In paragraph 1, The step of preparing the above catalyst is, A step of forming a suspension by adding a stirring rod, a metal precursor, water, and a support in sequence and stirring in a stirrer at 100 rpm to 800 rpm for 60 minutes to 300 minutes; A step of evaporating water from the above suspension in a constant temperature water bath at a temperature range of 40 ℃ to 80 ℃; A step of drying the above-mentioned water-evaporated suspension in an oven at a temperature range of 80°C to 150°C for 6 to 24 hours; and A step of pre-treating the above dried suspension in a tube furnace under a 10% H₂ /Ar flow (50 mL/min) at a heating rate of 2 ℃/min to 10 ℃/min for 30 to 300 minutes to increase the temperature from room temperature to a range of 300 ℃ to 800 ℃, and maintaining it for 30 to 300 minutes to synthesize a catalyst; including, Process for producing liquid fuel from waste plastics.
  3. In paragraph 2, The above metal precursor is, Comprising at least one selected from the group consisting of ruthenium (Ru), platinum (Pt), iron (Fe), cobalt (Co), nickel (Ni), chromium (Cr), molybdenum (Mo), tungsten (W), rhodium (Rh), and palladium (Pd), Process for producing liquid fuel from waste plastics.
  4. In paragraph 2, The above support is a zeolite catalyst having Brønsted acid sites, Process for producing liquid fuel from waste plastics.
  5. In paragraph 4, The above zeolite catalyst comprises at least one selected from the group consisting of zeolite Y, zeolite Socony Mobil-5 (ZSM-5), beta zeolites (BEA), and mordenite zeolite (MOR). Process for producing liquid fuel from waste plastics.
  6. In paragraph 2, After the above preprocessing step, The above-mentioned synthesized catalyst is heated using a heating furnace under a 10% H₂ /Ar flow at a heating rate of 2 ℃/min to 10 ℃/min from room temperature to a temperature range of 200 ℃ to 600 ℃ for 30 minutes to 300 minutes, and then ex-situ reduction is performed at the said temperature for 30 minutes to 300 minutes. Process for producing liquid fuel from waste plastics.
  7. In paragraph 1, The above waste plastic comprises at least one selected from the group consisting of High Density Polyethylene (HDPE), Low Density Polyethylene (LDPE), Polypropylene (PP), Polyamide (PA), Polystyrene (PS), Polyvinyl Chloride (PVC), and Ethylene Vinyl Acetate (EVA). Process for producing liquid fuel from waste plastics.
  8. In paragraph 1, The step of forming the above mixture is, The above catalyst, water, and waste plastic material are sequentially placed into a stirrer and stirred to form a mixture. Process for producing liquid fuel from waste plastics.
  9. In paragraph 1, In the step of forming the above mixture, The mass ratio of the catalyst to water is 1:0.5 to 1:2, Process for producing liquid fuel from waste plastics.
  10. In paragraph 1, The step of decomposing the waste plastic is performed in a temperature range of 200 ℃ to 700 ℃ and a pressure range of 0.01 MPa to 10 MPa, Process for producing liquid fuel from waste plastics.

Description

Liquid Fuel Production Process from Waste Plastic The present invention relates to a process for producing liquid fuel from waste plastics. Global plastic production has surged over the past few years, increasing from 1.7 million tons in 1954 to 403 million tons in 2022. However, plastic waste management relies primarily on landfilling (~75%) or incineration (~14%), with the recycling rate remaining at only 11%. This trend exacerbates environmental pollution and highlights the urgent need for sustainable solutions in plastic waste management. In response to these challenges, innovative recycling technologies aimed at mitigating environmental risks are critically required. While mechanical recycling has traditionally been utilized, it often leads to the downcycling of plastics, damaging their mechanical properties. Chemical recycling methods, particularly catalytic recycling, are increasingly recognized as promising alternatives. Catalytic recycling can convert plastic waste into high-value chemicals and fuels at lower temperatures (250–400°C) compared to conventional chemical recycling methods (500–800°C). Furthermore, this facilitates the selective cleavage of C-C bonds in plastic waste, producing liquid fuel with a higher yield compared to conventional methods. These advantages reduce separation costs and energy input, providing an economical and environmentally friendly solution to the growing challenges associated with plastic waste management. There is an urgent need for technology that can selectively produce high-value-added liquid fuels from waste plastics through the catalytic cracking method (less than 0.1% of the total), which is considered a more advanced method among the chemical recycling technologies for waste plastics (less than 1% of the total). The aforementioned background technology is one that the inventor possessed or acquired in the process of deriving the disclosure of the present invention, and it cannot be considered as prior art disclosed to the general public prior to the filing of this application. FIGS. 1a to 1c are drawings showing the conversion rate under various reaction conditions and the results of reusability using 5% Ru/zeolite-Y according to an embodiment of the present invention. FIGS. 2a and 2b are diagrams showing the role of the acid site in LDPE depolymerization according to an embodiment of the present invention. FIGS. 3a to 3f are drawings showing the product distribution after the LDPE depolymerization reaction according to an embodiment of the present invention. FIGS. 4a to 4f are drawings showing the results of a depolymerization reaction using a substitute according to an embodiment of the present invention. FIGS. 5a to 5e are drawings showing the PE depolymerization results as a function of metal acid balance (MAB) according to an embodiment of the present invention. FIGS. 6a and 6b are diagrams illustrating an LDPE depolymerization mechanism according to an embodiment of the present invention. FIGS. 7a to 7d are drawings showing the results of a depolymerization reaction using various types of plastic according to an embodiment of the present invention. Hereinafter, embodiments are described in detail with reference to the attached drawings. However, various modifications may be made to the embodiments, and thus the scope of the patent application is not limited or restricted by these embodiments. It should be understood that all modifications, equivalents, and substitutions to the embodiments are included within the scope of the rights. The terms used in the embodiments are for illustrative purposes only and should not be interpreted as intended to be limiting. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "comprising" or "having" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof. Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the embodiments pertain. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application. In addition, when describing with reference to the attached drawings, identical components are assigned the same reference numeral regardless of drawing symbols, and redundant descriptions thereof are omitted. In describing the embodiments, if it is determined that a detailed description of related prior art could unnecessarily obscure the essence of