This study explores a novel bio-solvolysis process for the chemical recycling of complex poly(ethylene terephthalate) (PET) waste using biobased monoethylene glycol (BioMEG) as a depolymerization agent. Five challenging PET waste streams, including multilayer trays, colored bottles, and post-consumer textiles, were selected for the study. The bio-solvolysis process was evaluated by monitoring the reaction over time, achieving a PET conversion of 91.3% to 97.1% and a bis(2-hydroxyethyl) terephthalate (BHT) monomer yield of 71.5% to 76.3%. A purification process using activated carbon (AC) was developed to remove color and reduce metal content in the BHT monomer. The purified BHT monomer showed a whiteness (L*) of over 95 and a Zn content of less than 2 mg/kg. The chemical structure of the purified monomers was analyzed using FTIR and DSC, and their composition was measured by 1H-NMR, demonstrating a high purity with a BHT content up to 99.5% mol. The study highlights the potential of using BioMEG in chemical recycling processes, offering a sustainable alternative to fossil-based ethylene glycol and contributing to the circular economy.This study explores a novel bio-solvolysis process for the chemical recycling of complex poly(ethylene terephthalate) (PET) waste using biobased monoethylene glycol (BioMEG) as a depolymerization agent. Five challenging PET waste streams, including multilayer trays, colored bottles, and post-consumer textiles, were selected for the study. The bio-solvolysis process was evaluated by monitoring the reaction over time, achieving a PET conversion of 91.3% to 97.1% and a bis(2-hydroxyethyl) terephthalate (BHT) monomer yield of 71.5% to 76.3%. A purification process using activated carbon (AC) was developed to remove color and reduce metal content in the BHT monomer. The purified BHT monomer showed a whiteness (L*) of over 95 and a Zn content of less than 2 mg/kg. The chemical structure of the purified monomers was analyzed using FTIR and DSC, and their composition was measured by 1H-NMR, demonstrating a high purity with a BHT content up to 99.5% mol. The study highlights the potential of using BioMEG in chemical recycling processes, offering a sustainable alternative to fossil-based ethylene glycol and contributing to the circular economy.