Assessment of the environmental break-even point for deposit return systems through an LCA analysis of single-use and reusable cups

Abstract

The Circular Economy introduced new research challenges to be faced. Linear and circular supply chain comparisons require general methodologies to obtain significant and scalable results. A two-step methodology is here proposed to facilitate the interpretation of results during a Life Cycle Assessment (LCA). Firstly, an LCA analysis has been conducted on four single-use - Polypropylene (PP), Polylactic acid (PLA), Polyethylene terephthalate (PET), and Cardboard+Polyethylene coat - and reusable - PP, PLA, PET, and glass - cups. Secondly, the analyzed midpoint impact categories have been aggregated into the three main life cycle phases: production, use and End of Life (EoL). Then, they have been used to assess the environmental break-even point (BEP), i.e. the minimum number of uses necessary for a reusable cup to be preferable than a single-use cup, considering two EoL (energy recovery, and recycling) and three use phase strategies (onsite handwashing, onsite and offsite washing). Considering offsite washing - transport distance of 20km and industrial washing machines - and energy recovery, findings highlight that reusable plastic cups reach a break-even point for climate change and non-renewable energy use for n<150, while single-use PP cups are the best option in terms of acidification, eutrophication, and water scarcity indicator. With respect to PP single-use cups, for acidification, eutrophication, and water scarcity indicator, a BEP cannot be achieved, even in the case of infinite reuses. Results evidenced all the conditions for reaching a BEP, allowing to identify possible strategies to improve the efficiency of reusable products and to obtain an environmental benefit.