Glycolysis of Postconsumer Polyethylene Terephthalate Waste

Abstract

Chemical recycling process of polyethylene terephthalate (PET) into bis-hydroxyethyl terephthalate
monomer (BHET) was investigated for that its bottle grade consumption is reaching high levels specially in
bottled water and soft drinks. Although the most commonly used recycling processes are in-plant and mechanical
methods, it was found that the benefits and opportunities offered by chemical recycling makes it one of the most
interesting processes to develop. Glycolysis of recycled polyethylene terephthalate (PET) from consumed bottled
water and soft- drink bottles was carried out with ethylene glycol (EG) for different weight ratios of PET to EG
using zinc acetate as catalyst at the boiling point of EG under nitrogenous atmosphere for a constant time of 3.5 h.
PET:EG ratio was studied to get information on the reaction behavior and yield results taking into account the
solvent excess influence. Monomer and oligomers were characterized using FTIR technique. The possibility of
improving the extraction process and the use of EG recovered from previous glycolysis reactions via distillation,
membranes or other separation method could lead to an ameliorated economic and environmental process.