Process Development and Optimization of Alkaline Hydrolysis for Depolymerization in Chemical Recycling of Poly(ethylene 2,5-furandicarboxylate) (PEF) Using Full Factorial Design

Abstract

This study explores the alkaline hydrolysis of poly(ethylene 2,5-furandicarboxylate) (PEF), a biobased alternative to PET, for the recovery of 2,5-furandicarboxylic acid (FDCA) through a systematic approach employing a full factorial design. The effects of reaction temperature, reaction time, and NaOH-to-PEF molar ratio on key outcomes: PEF conversion, FDCA yield, and FDCA assay, are evaluated. Statistical analysis, including ANOVA and contour plots, identified reaction temperature as the dominant factor for PEF conversion and FDCA yield, while FDCA assay was significantly influenced by the interaction between reaction time and NaOH-to-PEF molar ratio. Under optimal conditions (160 °C, 2 h, and NaOH-to-PEF ratio of 2.2:1), high PEF conversion (99.0%), FDCA yield (85.6%), and FDCA assay (98.7%) were achieved. This study demonstrated the feasibility of PEF depolymerization and paved the way for high-quality FDCA recovery through chemical recycling via alkaline hydrolysis, contributing to the advancement of sustainable recycling technologies.