Depolymerization of post-consumer poly (ethylene terephthalate) (PET) bottles and polyester based textiles waste using iron-based catalysts for efficient monomers recovery / Muhammad Aidel Ratno Hadiyono

Polyethylene terephthalate (PET) is a widely used polyester in our daily life and extensively used for beverages, personal care products and other liquid goods. This ubiquity comes at a significant environmental level where it has been contributing to the escalating plastic waste crisis. One of the most promising strategies to address this growing challenge is chemical recycling such as depolymerization, a process that breaks down PET into its constituent monomers align with circular economy approach. The environmental impacts of traditional depolymerization methods have issues related to the toxicity and non-renewable catalysts. Existing depolymerization techniques suffer with challenges such as inconsistent product quality, cost, increasing energy consumption, and complications in catalyst residue and monomers recovery management. This study demonstrates the acid- and base-free depolymerization of poly(ethylene terephthalate) (PET) with ethanol by FeCl3, FeBr3 (1.0-5.0 mol%) and the results showed that both catalysts gave diethyl terephthalate (DET) and ethylene glycol (EG) exclusively (98->99 %, 160-180 ºC), while FeCl3 showed better catalyst performance in terms of the activity. The utilization of the FeCl3 catalyst facilitated the exclusive and selective depolymerization of PET derived from textile waste, resulting in the production of DET along with the recovery of cotton waste. It strongly suggested the possibility of chemical recycling of cloth waste by the transesterification in this catalysis.