PET Recycling – Contributions of Crystallization to Sustainability

Polyethylene terephthalate (PET) is one of the most common thermoplastic polymers and its durability has become a major environmental concern. The current public debate on plastic debris also triggered the revision of PET recycling technologies. This Research Article focuses on the chemical recycling of PET by means of methanolysis. The process degrades PET into two main reaction products, dimethyl terephthalate (DMT) and ethylene glycol (EG). Subsequent separation by distillation combined with crystallization removes critical impurities and non‐PET components from co‐polymers, providing monomers of high purity needed for re‐polymerization purposes. This data on the methanolysis of PET has been presented at the ProcessNet Jahrestreffen 2019 der Fachgruppen ZER, KRI, and GFSP in Bamberg. They show that the reaction products, DMT and EG, can be easily recovered and purified by distillation. Further purification of DMT by melt crystallization achieves very high product purities (> 99.9 wt %).