Abstract
Derived from renewable feedstocks, such as biomass, polylactic
acid (PLA) is considered a more environmentally friendly plastic than
conventional petroleum-based polyethylene terephthalate
(PET). However, PLA must still be recycled, and its growing popularity
and mixture with PET plastics at the disposal stage poses a
cross-contamination threat in existing recycling facilities and results
in low-value and low-quality recycled products. Hybrid upcycling has
been proposed as a promising sustainable solution for mixed plastic
waste, but its techno-economic and life cycle environmental performance
remain understudied. Here we propose a hybrid upcycling approach using a
biocompatible ionic liquid
(IL) to first chemically depolymerize plastics and then convert the
depolymerized stream via biological upgrading with no extra separation.
We show that over 95% of mixed PET/PLA was depolymerized into the
respective monomers, which then served as the sole carbon source for the growth of Pseudomonas putida,
enabling the conversion of the depolymerized plastics into
biodegradable polyhydroxyalkanoates (PHAs). In comparison to
conventional commercial PHAs, the estimated optimal production cost and
carbon footprint are reduced by 62% and 29%, respectively.
Original language | English |
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Journal | One Earth |
Volume | 6 |
Issue number | 11 |
Pages (from-to) | 1576-1590 |
ISSN | 2590-3330 |
DOIs | |
Publication status | Published - 2023 |