Sub- and supercritical water for chemical recycling of polyethylene terephthalate waste

2021 ◽  
Vol 233 ◽  
pp. 116389
Author(s):  
Maja Čolnik ◽  
Željko Knez ◽  
Mojca Škerget
Keyword(s):  
Polyethylene Terephthalate ◽  
Supercritical Water ◽  
Chemical Recycling

PENGGUNAAN AIR SUPER KRITIS PADA DEPOLIMERISASI NYLON-12 (BATCH PROCESS)

2018 ◽  
Vol 5 (3) ◽  
Author(s):  
Mohamad Yusman
Keyword(s):  
Supercritical Water ◽  
Scale Up ◽  
Experimental Studies ◽  
Reaction System ◽  
Batch Process ◽  
Chemical Recycling ◽  
Water Decomposition ◽  
Product Distributions ◽  
New Process ◽  
Nylon 12

Water at the supercritical state is a new process for the chemical recycling. At this thermodynamic state i.e. Pc = 218 atmospheres and Tc = 374oC , water behaves very differently from its everyday temperament and it is a very good solvent for organic components. Experimental studies show that supercritical water can decompose hydrocarbons/polymers and produce useful products like 2-Azacyclotridecanone /lactam-1 from Nylon-12 (batch process). The decomposition process itself was carried out in batch reaction system in order to get more information about product distributions, time dependence, and scale-up possibilities.Keywords: supercritical water, decomposition, batch, polymer, hydrocarbon

scholarly journals Engineering Microbes to Bio-Upcycle Polyethylene Terephthalate

2021 ◽  
Vol 9 ◽  
Author(s):  
Lakshika Dissanayake ◽  
Lahiru N. Jayakody
Keyword(s):  
Polyethylene Terephthalate ◽  
Metabolic Pathways ◽  
Aquatic Ecosystems ◽  
Value Added ◽  
Building Blocks ◽  
Chemical Recycling ◽  
Plastic Pollution ◽  
Microbial Cell Factories ◽  
Cell Factories ◽  
Value Added Products

Polyethylene terephthalate (PET) is globally the largest produced aromatic polyester with an annual production exceeding 50 million metric tons. PET can be mechanically and chemically recycled; however, the extra costs in chemical recycling are not justified when converting PET back to the original polymer, which leads to less than 30% of PET produced annually to be recycled. Hence, waste PET massively contributes to plastic pollution and damaging the terrestrial and aquatic ecosystems. The global energy and environmental concerns with PET highlight a clear need for technologies in PET “upcycling,” the creation of higher-value products from reclaimed PET. Several microbes that degrade PET and corresponding PET hydrolase enzymes have been successfully identified. The characterization and engineering of these enzymes to selectively depolymerize PET into original monomers such as terephthalic acid and ethylene glycol have been successful. Synthetic microbiology and metabolic engineering approaches enable the development of efficient microbial cell factories to convert PET-derived monomers into value-added products. In this mini-review, we present the recent progress of engineering microbes to produce higher-value chemical building blocks from waste PET using a wholly biological and a hybrid chemocatalytic–biological strategy. We also highlight the potent metabolic pathways to bio-upcycle PET into high-value biotransformed molecules. The new synthetic microbes will help establish the circular materials economy, alleviate the adverse energy and environmental impacts of PET, and provide market incentives for PET reclamation.

Experimental investigation on gasification characteristics of polyethylene terephthalate (PET) microplastics in supercritical water

Fuel ◽  
2020 ◽  
Vol 262 ◽  
pp. 116630 ◽  
Author(s):  
Bin Bai ◽  
Yigang Liu ◽  
Hua Zhang ◽  
Fayuan Zhou ◽  
Xiaodong Han ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Polyethylene Terephthalate ◽  
Supercritical Water

scholarly journals Safety Evaluation of Polyethylene Terephthalate Chemical Recycling Processes

2021 ◽  
Vol 13 (22) ◽  
pp. 12854
Author(s):  
Frank Welle
Keyword(s):  
Polyethylene Terephthalate ◽  
Evaluation Criteria ◽  
Safety Evaluation ◽  
Contamination Level ◽  
Chemical Recycling ◽  
Packaging Materials ◽  
Recycling Process ◽  
Mechanical Recycling ◽  
Lack Of Information ◽  
Food Input

Polyethylene terephthalate (PET) is one of the main packaging materials for beverage bottles. Even if this polymer is good to recycle, mechanical recycling processes need a well-sorted input fraction. For less-sorted PET packaging, or even non-food input sources, chemical recycling seems to be a solution to increase PET recycling. For post-consumer recyclates in packaging applications, it is essential that the safety of the recyclates is guaranteed, and the consumers’ health protected. For mechanical recycling processes, evaluation criteria are already established. For chemical recycling processes, however, such evaluation criteria are only roughly available. This study evaluated the safety of the chemical recycling process similar to the approach of the European Food Safety Authority (EFSA). However, due to the lack of information about the contamination level of the input materials for the chemical recycling process, the evaluation was adapted. In addition, the evaluation should be performed separately for the depolymerisation and for the repolymerisation steps. However, due to the high cleaning efficiencies of both steps, the evaluation can focus on the repolymerisation. This simplifies the assessment of the chemical recycling processes considerably.

scholarly journals Chemical Recycling of PET Wastes with Different Catalysts

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Mohammad Khoonkari ◽  
Amir Hossein Haghighi ◽  
Yahya Sefidbakht ◽  
Khadijeh Shekoohi ◽  
Abolfazl Ghaderian
Keyword(s):  
Ionic Liquids ◽  
Ethylene Glycol ◽  
Polyethylene Terephthalate ◽  
Chemical Processes ◽  
Metal Salts ◽  
Chemical Recycling ◽  
Sample Material ◽  
Pet Waste ◽  
The Subject ◽  
The One

Chemical recycling of polyethylene terephthalate, known as PET, has been the subject of increased interest as a valuable feedstock for different chemical processes. In this work, glycolysis of PET waste granules was carried out using excess ethylene glycol in the presence of different simple chemicals acting as catalysts, which are, namely, categorized in ionic liquids, metal salts, hydrotalcites, and enzymes. From every category, some materials as a sample were used, and the one which is going to bring the best result is noted. The effect of some parameters such as temperature, pressure, amount of sample, material ratio, and stirring rate was investigated. As a result we compared the best of each category with the others and final result is shown.

Current developments in chemical recycling of post-consumer polyethylene terephthalate wastes for new materials production: A review

2019 ◽  
Vol 225 ◽  
pp. 1052-1064 ◽  
Author(s):  
Ademola Bolanle Raheem ◽  
Zainura Zainon Noor ◽  
Azman Hassan ◽  
Mohd Kamaruddin Abd Hamid ◽  
Sani Amril Samsudin ◽  
...  
Keyword(s):  
Polyethylene Terephthalate ◽  
Chemical Recycling ◽  
New Materials

Subcritical and supercritical water for chemical recycling of plastic waste

2020 ◽  
Vol 25 ◽  
pp. 100364
Author(s):  
Alex Queiroz ◽  
Giovanni B. Pedroso ◽  
Sergio N. Kuriyama ◽  
Antonio A. Fidalgo-Neto
Keyword(s):  
Supercritical Water ◽  
Plastic Waste ◽  
Chemical Recycling

Supercritical Water Process for the Chemical Recycling of Waste Plastics

2010 ◽  
Author(s):  
Motonobu Goto ◽  
Fangming Jin ◽  
Qi Zhou ◽  
Bing Wu
Keyword(s):  
Supercritical Water ◽  
Chemical Recycling ◽  
Waste Plastics
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