Plastics and Priority during the Recycling

2017 ◽  
pp. 252-280
Author(s):  
Ljerka Kratofil Krehula ◽  
Zlata Hrnjak-Murgić ◽  
Zvonimir Katančić
Keyword(s):  
Natural Resources ◽  
Raw Materials ◽  
Chemical Recycling ◽  
High Quality ◽  
Plastics Recycling ◽  
General Overview ◽  
Poly Ethylene Terephthalate ◽  
Increasing Demand ◽  
Poly Ethylene ◽  
Legislative Measures

Increasing demand for post-consumer plastics recycling comes from growing environmental awareness and the need for sustainability as well as from legislative measures. Generally, the recycling of plastics is important in terms of natural resources preservation (oil, natural gas), energy conservation, saving of landfill spaces, reduction of greenhouse gas emissions, overall environmental protection, and economical benefits. The different types of plastics recycling result in valuable raw materials (mechanical and chemical recycling) or in a notable quantity of energy when plastic waste is used as a fuel (energy recovery). A priority during recycling is to create high quality pretreatment processes of post-consumer plastics in order to obtain the best possible product and to minimize recycling expenses. This chapter gives a general overview of plastics recycling, especially of pretreatment procedures, with an emphasis on poly(ethylene-terephthalate), polyethylene, and tire recycling processes. It reveals the main problems during these processes and states their analysis and possible solutions.

Plastics and Priority during the Recycling

2015 ◽  
pp. 257-284 ◽  
Author(s):  
Ljerka Kratofil Krehula ◽  
Zlata Hrnjak-Murgić ◽  
Zvonimir Katančić
Keyword(s):  
Natural Resources ◽  
Raw Materials ◽  
Chemical Recycling ◽  
High Quality ◽  
Plastics Recycling ◽  
General Overview ◽  
Poly Ethylene Terephthalate ◽  
Increasing Demand ◽  
Poly Ethylene ◽  
Legislative Measures

Increasing demand for post-consumer plastics recycling comes from growing environmental awareness and the need for sustainability as well as from legislative measures. Generally, the recycling of plastics is important in terms of natural resources preservation (oil, natural gas), energy conservation, saving of landfill spaces, reduction of greenhouse gas emissions, overall environmental protection, and economical benefits. The different types of plastics recycling result in valuable raw materials (mechanical and chemical recycling) or in a notable quantity of energy when plastic waste is used as a fuel (energy recovery). A priority during recycling is to create high quality pretreatment processes of post-consumer plastics in order to obtain the best possible product and to minimize recycling expenses. This chapter gives a general overview of plastics recycling, especially of pretreatment procedures, with an emphasis on poly(ethylene-terephthalate), polyethylene, and tire recycling processes. It reveals the main problems during these processes and states their analysis and possible solutions.

Synthesis and sizing performances of water-soluble polyester based on bis(2-hydroxyethyl) terephthalate derived from depolymerized waste poly(ethylene terephthalate) fabrics

2018 ◽  
Vol 89 (4) ◽  
pp. 572-579 ◽  
Author(s):  
Jing Lu ◽  
Mengjuan Li ◽  
Yanyan Li ◽  
Xiaoqiang Li ◽  
Qiang Gao ◽  
...  
Keyword(s):  
Surface Tension ◽  
Fourier Transform ◽  
Ethylene Terephthalate ◽  
Water Soluble ◽  
Chemical Recycling ◽  
Step Method ◽  
Pet Fabric ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
Viscosity Stability

This work aimed at effective chemical recycling of waste poly(ethylene terephthalate) (PET) fabrics into water-soluble polyester (WSP). For this, PET fabric waste was depolymerized using excess ethylene glycol (EG) in the presence of zinc acetate as catalyst. The glycolysis product of PET, bis(2-hydroxyethyl) terephthalate (BHET) was then used to synthesize WSP by a three-step method, that is, transesterification, esterification and polycondensation. The structures of BHET and WSP were identified by Fourier transform infrared spectra. Sizing performances of WSP were studied, and it was found that the surface tension of WSP size (57 mN/m, 22℃, 0.5% of weight) was lower than common sizes, the viscosity of WSP size was 1–2 mPa·S (95℃, 6% of weight) and the viscosity stability was larger than 90% at this temperature. The mixture of WSP and starch showed stronger adhesion to polyester–cotton roving and polyester roving than onefold starch. K/ S values of fibers before sizing and after desizing showed a slightly difference, which indicated that WSP would not influence the color of yarns when used as the sizing agent.

Chemical Recycling of Poly(Ethylene Terephthalate) Using a New Hybrid Process

2008 ◽  
Vol 41 (9) ◽  
pp. 923-928 ◽  
Author(s):  
Bo-kyung Kim ◽  
Dongpil Kim ◽  
Youngmin Cho ◽  
Myungwan Han
Keyword(s):  
Ethylene Terephthalate ◽  
Hybrid Process ◽  
Chemical Recycling ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

scholarly journals Chemical recycling of poly(ethylene terephthalate). Application to the synthesis of multiblock copolyesters

2014 ◽  
Vol 8 (8) ◽  
pp. 544-553 ◽  
Author(s):  
A. El Mejjatti ◽  
T. Harit ◽  
A. Riahi ◽  
R. Khiari ◽  
I. Bouabdallah ◽  
...  
Keyword(s):  
Ethylene Terephthalate ◽  
Chemical Recycling ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

scholarly journals Chemical and Electrochemical Recycling of End-Use Poly(ethylene terephthalate) (PET) Plastics in Batch, Microwave and Electrochemical Reactors

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2742
Author(s):  
Tessa H. T. Myren ◽  
Taylor A. Stinson ◽  
Zachary J. Mast ◽  
Chloe G. Huntzinger ◽  
Oana R. Luca
Keyword(s):  
Terephthalic Acid ◽  
Ethylene Terephthalate ◽  
Low Cost ◽  
Supporting Electrolyte ◽  
Chemical Recycling ◽  
High Concentration ◽  
Electrochemical Reactors ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
End Use

This work describes new methods for the chemical recycling of end-use poly(ethylene terephthalate) (PET) in batch, microwave and electrochemical reactors. The reactions are based on basic hydrolysis of the ester moieties in the polymer framework and occur under mild reaction conditions with low-cost reagents. We report end-use PET depolymerization in refluxing methanol with added NaOH with 75% yield of terephthalic acid in batch after 12 h, while yields up to 65% can be observed after only 40 min under microwave irradiation at 85 °C. Using basic conditions produced in the electrochemical reduction of protic solvents, electrolytic experiments have been shown to produce 17% terephthalic acid after 1 h of electrolysis at −2.2 V vs. Ag/AgCl in 50% water/methanol mixtures with NaCl as a supporting electrolyte. The latter method avoids the use of caustic solutions containing high-concentration NaOH at the outset, thus proving the concept for a novel, environmentally benign method for the electrochemical recycling of end-use PET based on low-cost solvents (water and methanol) and reagents (NaCl and electricity).

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