Anaerobic Digestion of food waste: Eliciting sustainable water-energy food nexus practices with Agent Based Modelling and visual analytics

Ruth Falconer, Ismail Haltas, Liz Varga, Paula Forbes, Mohamad Abdel-Aal, Nikolay Panayotov

Research output: Contribution to journalArticle

Abstract

Food waste is a problem for which solutions are recognised but not readily put into practice. What should
be the primary objective, reducing or eliminating surplus food production, requires great change within
social, cultural and economic structures. The secondary approach of redistributing surplus food to areas
of deficit (in terms of socio-economic groups and/or geographic regions) involves a significant logistical
burden, and suffers the same issues as with the elimination of waste. The least desirable, but perhaps
most practicable approach, is the use of food waste as a feedstock for Anaerobic Digestion (AD). The
strategic adoption of AD can therefore be seen as an important step towards mitigating food waste, but
the implementation of efficient AD systems on a large (county/region) scale involves significant
complexity. The optimal number, size and location of AD plants, and whether they are centralised versus
decentralised, may be determined by considering factors such as supply and proximity to feedstock,
transport links, emission hazards and social impact. Reaching balanced and objective decisions when
faced with such disparate criteria is inevitably very difficult. To address this problem we prototype and
evaluate a decision support tool for county-scale AD planning. Our approach is a hybridised Agent Based
Model (ABM) with a Multi Objective Optimisation. We capture the spatio-temporal dependencies that
exist in the water, energy and food systems associated with energy derived from food waste using Agent
Based Modelling (ABM). The use of Interactive Multi Criteria Analysis as visual analytics offers a means to
communicate the co-benefits and trade-offs that may emerge, as well as prioritise the AD strategies,
based on the prioritization of criteria. Specifically, the method supports exploration of the social, environmental and economic impact of different AD strategies and decisions, linked to current issues, namely
AD scale and adoption. The results highlight a trade-off between transport costs and social acceptability
for the AD centralised versus decentralised strategies. When low carbon options are weighted higher
then slow, steady and aggressive decentralised strategies are the best strategic adoption of AD.
Conversely, when Energy production is considered a priority, then aggressive scaling up in a centralised
approach is best with slow and steady approaches being further from the ideal. The framework has
demonstrated that it permits a space for dialogue and transparent prioritization of AD strategies based
on WEF nexus impacts.
Original languageEnglish
Article number120060
JournalJournal of Cleaner Production
Volume255
Early online date11 Jan 2020
DOIs
Publication statusE-pub ahead of print - 11 Jan 2020
Externally publishedYes

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