Evaluation of Sodium/Protonated Titanate Nanotubes Catalysts in Virgin and Post Consumer PET Depolymerization

The high PET consume, mainly as bottles, associated with rapid disposal and high resistance to ambient conditions and biological degradation lead to accumulation in the enviromental, constituting a worrying scenario in world level. Chemical recycle PET by glycolysis is an important alternative, once bis(hydroxiethyl)terephthalate (BHET), high added value monomer, can be obtained. In this context, this study approaches the use of titanate nanotubes (i.e. sodium/protonated titanate nanotubes) as catalyst for PET glycolysis. Reactional conditions, the origin and granulometry of PET flakes were evaluated (at 196 °C). Best results (BHET yield > 80%) were obtained for both catalyst in 3 h of reaction. The protonated titanate nanotubes catalyst were more efficient than sodium titanate nanotubes due to greater concentration of Bronsted and Lewis acid sites, indicated by TPD analyzes.