An environmental analysis of options for utilising wasted food and food residue

Abstract

The potential environmental impact of wasted food minimisation versus its utilisation in a circular bioeconomy is investigated based on a case study of Ireland. The amount of wasted food and food residue (WFFR) produced in 2010 was used for business-as-usual, (a) and four management options were assessed, (b) minimisation, (c) composting, (d) anaerobic digestion and (e) incineration. The environmental impacts Global Warming Potential (GWP), Acidification Potential (AP) and Eutrophication Potential (EP) were considered. A carbon return on investment (CRoI) was calculated for the three processing technologies (c-e). The results showed that a minimisation strategy for wasted food would result in the greatest reduction of all three impacts, -4.5 Mt CO₂-e (GWP), -11.4 kt PO₄³-e (EP) and -43.9 kt SO₂-e (AP) compared to business as usual. For WFFR utilisation in the circular bioeconomy, anaerobic digestion resulted in the lowest environmental impact and best CRoI of -0.84 kg CO₂-e per Euro. From an economic perspective, for minimisation to be beneficial, 0.15 kg of wasted food would need to be reduced per Euro spent.

Keywords: Carbon return on investment; Circular economy; Ireland; Life cycle assessment; Waste management; Waste reduction.