Using waste to treat waste: Catalysts from spent alkaline batteries for glycolysis of PET waste

The recovery of Zn/ZnO nanoparticles from spent alkaline batteries was studied. This catalyst was employed for glycolysis of polyethylene terephthalate (PET) to produce bis(2-hydroxyethyl) terephthalate (BHET). The reaction temperature, catalyst/PET ratio and reaction time were investigated. Under the optimal conditions of 190 ℃ and 2 hours, with a catalyst/PET ratio of 2 %, the PET conversion rate and BHET yield of this process were 99 % and 81 %, respectively. The experimental results show that the catalyst exhibits high catalytic activity, is easy to separate, and has good reusability. In addition, this catalyst can deal effectively with impurities and dyes present in waste PET. Finally glycolysis kinetic studies were conducted on the reaction of PET degradation, and the activation energy of 118.8 kJ·mol −1 were obtained.