Analysis of recycled PET bottles products by pyrolysis-gas chromatography

Polyethylene terephthalate - I. Chemistry, thermodynamics and transport properties.

In the present study, thermal degradation of polyolefins (PP and LDPE) and PET in a tubular reactor in an inert atmosphere was conducted. Each polymer was subjected to pyrolysis at the temperatures of 673, 773, 873, and 973 K. Yields of tar, residual coke and gas, and conversion degrees were calculated. Tars which include valuable chemicals were characterized by GC–MS, 1H-NMR, FTIR, and GPC. Pyrolysis gases (C1 + C2, C3, C4, C5, and C6 + C7) were also analyzed by GC analysis. From the comparison of data, it can be said that pyrolysis of PP and LDPE leads to the formation of tar containing mainly paraffinic structures, while aromatic structures were produced by the pyrolysis of PET.

Comparative pyrolysis of polyolefins (PP and LDPE) and PET

Thermal degradation study of waste polyethylene terephthalate (PET) under inert and oxidative environments

The polyethylene terephthalate (PET) application has many challenges and potential due to its sustainability. The conventional PET degradation was developed for several technologies to get higher yield products of ethylene glycol, bis(2-hydroxyethyl terephthalate) and terephthalic acid. The chemical recycling of PET is reviewed, such as pyrolysis, hydrolysis, methanolysis, glycolysis, ionic-liquid, phase-transfer catalysis and combination of glycolysis–hydrolysis, glycolysis–methanolysis and methanolysis–hydrolysis. Furthermore, the reaction kinetics and reaction conditions were investigated both theoretically and experimentally. The recycling of PET is to solve environmental problems and find another source of raw material for petrochemical products and energy.

https://www.mdpi.com/2073-4360/13/9/1475/pdf

J.W. Lin

Papers

Kinetics of the thermal degradation of polyethylene terephthalate