Depolymerization of PET Bottle via Methanolysis and Hydrolysis

Polyethylene terephthalate (PET) bottle has been increasingly used in recent years and treatment of the postconsumer PET bottle poses economic and environmental problems. PET bottles can be recycled by chemically depolymerizing PET chain into its monomers or various valuable chemicals. Depending on the chemical agents used to break down the polyester chain, depolymerization route can be classified: glycolysis, methanolysis, hydrolysis, etc. Methanolysis can take a crucial role of depolymerizing low quality polyester bottles. Hydrolysis can produce terephthalic acid (TPA) and ethylene glycol (EG), i.e., the monomer from which PET is directly produced in a TPA-based PET production plant. Depolymerization kinetics of PET are indispensable for building a commercially viable depolymerization process. These PET degradation alternatives including various methanolysis and hydrolysis methods are reviewed.