(385ao) Recycling of Post-Consumer Polyethylene Terephthalate (PET) Waste Via Glycolysis Using Ionic Liquid Catalyst

The mechanical recycling of complex polyethylene terephthalate (PET) waste, including multilayer packaging, colored plastics, and mixed plastic waste streams, presents significant challenges due to the presence of contaminants, and additives that can compromise the quality and properties of recycled material. In response, advanced chemical recycling methods such as glycolysis has emerged as a promising solution to address the limitations of mechanical recycling. This study focused on the glycolysis of post-consumer PET waste with using an ionic liquid (IL) catalyst containing 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and oxalic acid (OA). The research initially examined the impact of various reaction parameters, including temperature, time, catalyst dosage, and the ethylene glycol (EG) to PET ratio, on the conversion of PET and the yield of the monomer bis(2-hydroxyethyl) terephthalate (BHET). Under optimized conditions, the study evaluated the glycolysis performance of various PET waste, including textiles, bottle, and colored PET containers. Additionally, the study focused on separating additives and pigments from the reaction mixture to enhance the quality of resulting BHET for potential PET synthesis. The study also proposed a reaction mechanism to explain the glycolysis process. Furthermore, a techno-economic analysis was conducted to evaluate the feasibility and economic viability of scaling up the glycolysis process for industrial application.