Leveling the cost and carbon footprint of circular polymers that are chemically recycled to monomer.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33837082.
- Also identified by DOI 10.1126/sciadv.abf0187 and PMC identifier 8034859.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Mechanical recycling of polymers downgrades them such that they are unusable after a few cycles. Alternatively, chemical recycling to monomer offers a means to recover the embodied chemical feedstocks for remanufacturing. However, only a limited number of commodity polymers may be chemically recycled, and the processes remain resource intensive. We use systems analysis to quantify the costs and life-cycle carbon footprints of virgin and chemically recycled polydiketoenamines (PDKs), next-generation polymers that depolymerize under ambient conditions in strong acid. The cost of producing virgin PDK resin using unoptimized processes is ~30-fold higher than recycling them, and the cost of recycled PDK resin ($1.5 kg<sup>-1</sup>) is on par with PET and HDPE, and below that of polyurethanes. Virgin resin production is carbon intensive (86 kg CO<sub>2</sub>e kg<sup>-1</sup>), while chemical recycling emits only 2 kg CO<sub>2</sub>e kg<sup>-1</sup> This cost and emissions disparity provides a strong incentive to recover and recycle future polymer waste.