Cradle-to-grave life cycle assessment of single-use cups made from PLA, PP and PET

Christian Moretti,Lorie Hamelin,Line Geest Jakobsen,Martin H Junginger,Maria Magnea Steingrimsdottir,Linda Høibye,Li Shen

doi:10.1016/j.resconrec.2021.105508

Christian Moretti, Lorie Hamelin + Show 5 more

Open Access

https://doi.org/10.1016/j.resconrec.2021.105508

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Abstract

Polylactide (PLA) is both bio‐based and biodegradable and has therefore attracted increased attention for single-use plastics applications. Under the context of the recent EU Plastics and Bioeconomy strategies, this study uses life cycle assessment (LCA) to assess the environmental footprint of single-use drinking cups made from PLA, including 13 environmental impact categories. Land use changes (LUCs) were assessed based on a deterministic model. The manufacturing phase was modeled based on primary production data stemming directly from the industry. The end-of-life (EoL) impacts were assessed using the EASETECH. PLA cups were then compared with their petrochemical counterparts polyethylene terephthalate (PET) and polypropylene (PP) cups. Based on the available data quality of the petrochemical polymers, six impact categories were compared. For PLA cups, the process energy use in the conversion from biomass to PLA polymer was identified as the main environmental hotspot, followed by the electricity consumption of thermoforming of the cups. It was found that the biomass acquisition phase has a limited overall impact. LUCs contribute to a negligible impact in all impact categories except for climate change and photochemical ozone formation. Compared to PET cups, the current PLA cups offer environmental impact savings for climate change even including the impacts of LUC. Compared to both PET and PP cups, PLA cups offer savings for fossil fuels resource use but lead to higher impacts for photochemical ozone formation, acidification and terrestrial eutrophication.

Highlights

In 2015, the global plastic production amounted to approximately 380 Mt (Geyer et al, 2017), requiring approx. 6% of the global crude oil production (World Economic Forum, 2016) and generated an annual waste equivalent to the annual production due to the streams from previous years (Jambeck et al, 2015)
It is still to be questioned whether PLA is really a solution for the environmental issues caused by single-use plastics applications from a policy perspective (European Commission, 2019)
The targeted audience of this Life Cycle Assessment (LCA) is EU policy makers, who are interested in an environmental sustainability assessment of innovative single-use bio-based products to be used as the basis for possible future policy intervention (European Commission, 2019)

Summary

Introduction

In 2015, the global plastic production amounted to approximately 380 Mt (million metric tonnes) (Geyer et al, 2017), requiring approx. 6% of the global crude oil production (World Economic Forum, 2016) and generated an annual waste equivalent to the annual production due to the streams from previous years (Jambeck et al, 2015). The global demand for plastics is expected to double in the 20 years (European Commission, 2018a). To achieve such increased demand while combating climate change and plastics littering, novel polymers that are both bio-based and biodegradable, such as PLA (polylactic acid), have attracted much attention for single-use plastics applications. It is still to be questioned whether PLA is really a solution for the environmental issues caused by single-use plastics applications from a policy perspective (European Commission, 2019). To completely abandon the use of single-use cups is difficult in the short term, especially in the applications with stringent hygiene re quirements. The com mon key conclusions of these studies can be highlighted as follows: Study

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