An environmental evaluation of food waste downstream management options: a hybrid LCA approach

Ramy Salemdeeb,Mohammad Bin Daina,Christian Reynolds,Abir Al-Tabbaa

doi:10.1007/s40093-018-0208-8

Abstract

PurposeFood waste treatment methods have been typically analysed using current energy generation conditions. To correctly evaluate treatment methods, they must be compared under existing and potential decarbonisation scenarios. This paper holistically quantifies the environmental impacts of three food waste downstream management options—incineration, composting, and anaerobic digestion (AD).MethodsThe assessment was carried out using a novel hybrid input–output-based life cycle assessment method (LCA), for 2014, and in a future decarbonised economy. The method introduces expanded system boundaries which reduced the level of incompleteness, a previous limitation of process-based LCA.ResultsUsing the 2014 UK energy mix, composting achieved the best score for seven of 14 environmental impacts, while AD scored second best for ten. Incineration had the highest environmental burdens in six impacts. Uncertainties in the LCA data made it difficult determine best treatment option. There was significant environmental impact from capital goods, meaning current treatment facilities should be used for their full lifespan. Hybrid IO LCA’s included additional processes and reduced truncation error increasing overall captured environmental impacts of composting, AD, and incineration by 26, 10 and 26%, respectively. Sensitivity and Monte Carlo analysis evaluate the methods robustness and illustrate the uncertainty of current LCA methods. Major implication: hybrid IO-LCA approaches must become the new norm for LCA.ConclusionThis study provided a deeper insight of the overall environmental performance of downstream food waste treatment options including ecological burdens associated with capital goods.

Highlights

In November 2016, 194 countries signed the world’s first comprehensive climate agreement in Paris
The environmental impacts of compost could be offset by its use as a substitute to synthetic fertiliser, the most significant being climate change (55%), freshwater eutrophication (95%), depletion of abiotic resources elements (48%)
The treatment of food waste contributes to the majority of environmental burdens associated with anaerobic digestion (AD)

Summary

Introduction

In November 2016, 194 countries signed the world’s first comprehensive climate agreement in Paris. This agreement has been adopted overwhelmingly to tackle climate change by introducing binding emissions targets In spite of various efforts to reduce food waste arisings per capita, quantities of food waste continue to increase due to population growth. As food waste is unlikely to be significantly reduced in the short term, greater efforts must be made to reduce its environmental impacts. This could be achieved by first quantifying environmental burdens associated with food waste treatment, identifying processes with the highest environmental impacts

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Conclusion