Poly(ethylene) terephthalate (PET) waste upcycling

The huge increase in the creation and incineration of post-consumer poly(ethylene terephthalate) (PET) waste have resulted in an urgent need of for efficient recycling processes such as chemical recycling. In this study, the depolymerization of pure and recycled poly(ethylene) terephthalate were car...

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Main Author: Mok, Darrel Sheng Yong
Other Authors: Hong Li
Format: Final Year Project
Language:English
Published: Nanyang Technological University 2022
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Online Access:https://hdl.handle.net/10356/159175
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Institution: Nanyang Technological University
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spelling sg-ntu-dr.10356-1591752023-03-04T20:13:29Z Poly(ethylene) terephthalate (PET) waste upcycling Mok, Darrel Sheng Yong Hong Li School of Mechanical and Aerospace Engineering ehongli@ntu.edu.sg Engineering::Mechanical engineering The huge increase in the creation and incineration of post-consumer poly(ethylene terephthalate) (PET) waste have resulted in an urgent need of for efficient recycling processes such as chemical recycling. In this study, the depolymerization of pure and recycled poly(ethylene) terephthalate were carried out in two types of alkaline hydrolysis. The first type of alkaline hydrolysis depolymerized ball milled pure (BMP) PET in a potassium hydroxide (KOH) solution, heated to 160°C using an oven for 60 mins. After the reactions, the residual solids were removed by centrifugation and weighted to form a characterization. The optimal BMP PET to achieve highest PET conversion of 73.4% occurs at KOH concentration of 3.47M and PET concentration of 13.33g/L. The byproducts of this reactions composed of ethylene glycol and terephthalic potassium salt were in liquid phase. They were electrolyzed using electrochemical impedance spectroscopy (EIS) to convert the ethylene glycol into formic acid, which were used to obtain terephthalate acid (TPA). The results of the reaction were analyzed using High Performance Liquid Chromatography (HPLC). The second type of alkaline hydrolysis depolymerized ball-milled or 5 mm flakes recycled PET in potassium or sodium hydroxide solution, heated to 60°C to 80°C for 6 hr. After the reactions, the residual solids were removed by centrifugation and weighted to form a characterization. The byproducts of this reactions composed of ethylene glycol and terephthalic potassium salt or terephthalic sodium salt in liquid phase. The optimal ball-milled recycled colorless (BMRC) PET concentration to achieve highest BMRC PET conversion of 100% in 3M NaOH is 95 g/L and the optimal hand cut recycled green (HCRG) PET concentration to achieve highest HCRG conversion rate of 100% in 9M NaOH is 36 g/L. Bachelor of Engineering (Mechanical Engineering) 2022-06-10T13:14:45Z 2022-06-10T13:14:45Z 2022 Final Year Project (FYP) Mok, D. S. Y. (2022). Poly(ethylene) terephthalate (PET) waste upcycling. Final Year Project (FYP), Nanyang Technological University, Singapore. https://hdl.handle.net/10356/159175 https://hdl.handle.net/10356/159175 en P-B040 application/pdf Nanyang Technological University
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Engineering::Mechanical engineering
spellingShingle Engineering::Mechanical engineering
Mok, Darrel Sheng Yong
Poly(ethylene) terephthalate (PET) waste upcycling
description The huge increase in the creation and incineration of post-consumer poly(ethylene terephthalate) (PET) waste have resulted in an urgent need of for efficient recycling processes such as chemical recycling. In this study, the depolymerization of pure and recycled poly(ethylene) terephthalate were carried out in two types of alkaline hydrolysis. The first type of alkaline hydrolysis depolymerized ball milled pure (BMP) PET in a potassium hydroxide (KOH) solution, heated to 160°C using an oven for 60 mins. After the reactions, the residual solids were removed by centrifugation and weighted to form a characterization. The optimal BMP PET to achieve highest PET conversion of 73.4% occurs at KOH concentration of 3.47M and PET concentration of 13.33g/L. The byproducts of this reactions composed of ethylene glycol and terephthalic potassium salt were in liquid phase. They were electrolyzed using electrochemical impedance spectroscopy (EIS) to convert the ethylene glycol into formic acid, which were used to obtain terephthalate acid (TPA). The results of the reaction were analyzed using High Performance Liquid Chromatography (HPLC). The second type of alkaline hydrolysis depolymerized ball-milled or 5 mm flakes recycled PET in potassium or sodium hydroxide solution, heated to 60°C to 80°C for 6 hr. After the reactions, the residual solids were removed by centrifugation and weighted to form a characterization. The byproducts of this reactions composed of ethylene glycol and terephthalic potassium salt or terephthalic sodium salt in liquid phase. The optimal ball-milled recycled colorless (BMRC) PET concentration to achieve highest BMRC PET conversion of 100% in 3M NaOH is 95 g/L and the optimal hand cut recycled green (HCRG) PET concentration to achieve highest HCRG conversion rate of 100% in 9M NaOH is 36 g/L.
author2 Hong Li
author_facet Hong Li
Mok, Darrel Sheng Yong
format Final Year Project
author Mok, Darrel Sheng Yong
author_sort Mok, Darrel Sheng Yong
title Poly(ethylene) terephthalate (PET) waste upcycling
title_short Poly(ethylene) terephthalate (PET) waste upcycling
title_full Poly(ethylene) terephthalate (PET) waste upcycling
title_fullStr Poly(ethylene) terephthalate (PET) waste upcycling
title_full_unstemmed Poly(ethylene) terephthalate (PET) waste upcycling
title_sort poly(ethylene) terephthalate (pet) waste upcycling
publisher Nanyang Technological University
publishDate 2022
url https://hdl.handle.net/10356/159175
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