Life cycle assessment of advanced grade PLA product with novel end-of-life treatment through depolymerization

Anna Schwarz; Špela Ferjan; Josse Kunst

doi:10.1016/j.scitotenv.2023.167020

Life cycle assessment of advanced grade PLA product with novel end-of-life treatment through depolymerization

Sci Total Environ. 2023 Dec 20:905:167020. doi: 10.1016/j.scitotenv.2023.167020. Epub 2023 Sep 13.

Authors

Anna Schwarz¹, Špela Ferjan², Josse Kunst³

Affiliations

¹ TNO, Climate, Air and Sustainability, P.O. Box 80015, NL-3508 TA Utrecht, the Netherlands. Electronic address: anna.schwarz@tno.nl.
² TNO, Climate, Air and Sustainability, P.O. Box 80015, NL-3508 TA Utrecht, the Netherlands.
³ Arapaha B.V, Sint Antoniuslaan 22C, 6221 XK Maastricht, the Netherlands.

PMID: 37714343
DOI: 10.1016/j.scitotenv.2023.167020

Abstract

Using biobased plastics has the potential to avoid fossil resource depletion and fossil CO₂ emissions. Polylactic acid (PLA) is a fast-growing bio-based plastic made from fermented sugars. Nowadays, PLA is used to replace fossil-based polymers in healthcare and single-use applications, such as for packaging applications. However, PLA offers a much broader application range with the targeted use of a combination of its stereoisomers; PL(L)A and PL(D)A. A variety of these advanced grades of PLA can be used for multiple purposes in durable consumer products such as furniture. Recycling complex, mixed material and advanced grades of PLA is currently limited, as mechanical recycling has limitations in recycling mixed PLA grades. Using a depolymerization technology, products of such advanced grades of PLA can be recycled to form high-quality recycled PLA. A cradle-to-grave life cycle assessment study was executed to evaluate the sustainability of high-end durable product (a rug) with mixtures of PLA grade and the novel depolymerization technology. The findings of the study showed a 70 % reduction in CO₂-eq. emissions compared to a conventionally designed rug. However, an increase is indicated in the following environmental impact categories: land use, eutrophication, and environmental toxicity. Sensitivity analyses for collection rates showcased that design for collection and recycling are key to obtaining a more sustainable biobased products. Additionally, scenario analysis supported depolymerization for PLA as recycling technology with low CO₂-eq. emissions. Based on the results of the LCA and additional scenario analysis, the use of PLA is encouraged to be used in more durable and lasting products, such as furniture, from an environmental perspective, provided that the products are designed for collection and high-quality recycling to ensure material circularity.

Keywords: Circular economy; Design for recycling; End-of-life; Life cycle assessment; Polylactic acid.