Pyrolysis of Mixed Plastic Waste: I. Kinetic Study
Plastic wastes have become one of the biggest global environmental issues and thus recycling such massive quantities is targeted. Low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), and polystyrene (PS) are considered among the main types of plastic wastes. Since p...
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doaj-ce4190d3c3f94964b57ff6de88dc10cf2020-11-25T03:44:05ZengMDPI AGMaterials1996-19442020-10-01134912491210.3390/ma13214912Pyrolysis of Mixed Plastic Waste: I. Kinetic StudyIbrahim Dubdub0Mohammed Al-Yaari1Chemical Engineering Department, King Faisal University, P.O. Box 380, Al-Ahsa 31982, Saudi ArabiaChemical Engineering Department, King Faisal University, P.O. Box 380, Al-Ahsa 31982, Saudi ArabiaPlastic wastes have become one of the biggest global environmental issues and thus recycling such massive quantities is targeted. Low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), and polystyrene (PS) are considered among the main types of plastic wastes. Since pyrolysis is one of the most promising recycling techniques, this work aims to build knowledge on the co-pyrolysis of mixed polymers using two model-fitting (Criado and Coats–Redfern) methods. Seventeen co-pyrolysis tests using a thermogravimetric analyzer (TGA) at 60 K/min for different mixed compositions of LDPE, HDPE, PP, and PS were conducted. It was observed that the pyrolysis of the pure polymer samples occurs at different temperature ranges in the following order: PS < PP < LDPE < HDPE. However, compared to pure polymer samples, the co-pyrolysis of all-polymer mixtures was delayed. In addition, the synergistic effect on the co-pyrolysis of polymer blends was reported. The Master plot of the Criado model was used to determine the most suitable reaction mechanism. Then, the Coats–Redfern model was used to efficiently obtain the kinetic parameters (R<sup>2</sup> ≥ 97.83%) and the obtained values of the activation energy of different polymer blends were ranging from 104 to 260 kJ/mol. Furthermore, the most controlling reaction mechanisms were in the following orders: First order reaction (F1), Contracting sphere (R3), and then Contracting cylinder (R2).https://www.mdpi.com/1996-1944/13/21/4912mixed plastic wasterecyclingpyrolysiskineticsthermogravimetric analysis (TGA)Coats-Redfern model |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Ibrahim Dubdub Mohammed Al-Yaari |
spellingShingle |
Ibrahim Dubdub Mohammed Al-Yaari Pyrolysis of Mixed Plastic Waste: I. Kinetic Study Materials mixed plastic waste recycling pyrolysis kinetics thermogravimetric analysis (TGA) Coats-Redfern model |
author_facet |
Ibrahim Dubdub Mohammed Al-Yaari |
author_sort |
Ibrahim Dubdub |
title |
Pyrolysis of Mixed Plastic Waste: I. Kinetic Study |
title_short |
Pyrolysis of Mixed Plastic Waste: I. Kinetic Study |
title_full |
Pyrolysis of Mixed Plastic Waste: I. Kinetic Study |
title_fullStr |
Pyrolysis of Mixed Plastic Waste: I. Kinetic Study |
title_full_unstemmed |
Pyrolysis of Mixed Plastic Waste: I. Kinetic Study |
title_sort |
pyrolysis of mixed plastic waste: i. kinetic study |
publisher |
MDPI AG |
series |
Materials |
issn |
1996-1944 |
publishDate |
2020-10-01 |
description |
Plastic wastes have become one of the biggest global environmental issues and thus recycling such massive quantities is targeted. Low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), and polystyrene (PS) are considered among the main types of plastic wastes. Since pyrolysis is one of the most promising recycling techniques, this work aims to build knowledge on the co-pyrolysis of mixed polymers using two model-fitting (Criado and Coats–Redfern) methods. Seventeen co-pyrolysis tests using a thermogravimetric analyzer (TGA) at 60 K/min for different mixed compositions of LDPE, HDPE, PP, and PS were conducted. It was observed that the pyrolysis of the pure polymer samples occurs at different temperature ranges in the following order: PS < PP < LDPE < HDPE. However, compared to pure polymer samples, the co-pyrolysis of all-polymer mixtures was delayed. In addition, the synergistic effect on the co-pyrolysis of polymer blends was reported. The Master plot of the Criado model was used to determine the most suitable reaction mechanism. Then, the Coats–Redfern model was used to efficiently obtain the kinetic parameters (R<sup>2</sup> ≥ 97.83%) and the obtained values of the activation energy of different polymer blends were ranging from 104 to 260 kJ/mol. Furthermore, the most controlling reaction mechanisms were in the following orders: First order reaction (F1), Contracting sphere (R3), and then Contracting cylinder (R2). |
topic |
mixed plastic waste recycling pyrolysis kinetics thermogravimetric analysis (TGA) Coats-Redfern model |
url |
https://www.mdpi.com/1996-1944/13/21/4912 |
work_keys_str_mv |
AT ibrahimdubdub pyrolysisofmixedplasticwasteikineticstudy AT mohammedalyaari pyrolysisofmixedplasticwasteikineticstudy |
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