A Circular Economy Systems Engineering Framework for the Optimization of Food Supply Chains

Food supply chains rely heavily on the extraction of natural resources, including water, phosphorus, potassium, and fossil fuels. Population and welfare growth, along with the inflated standard of living increase the demand for food, leading to natural resource degradation, increased landfill wastes, water contamination, and greenhouse gas emissions. Circular Economy (CE) can be a solution for the transition of food supply chains to a more sustainable and regenerative future [1]. To achieve CE, we need to close material loops and connect different stages of the food supply chains that in a linear economy are discrete. These interconnections along with the multiple stakeholders connected with them make decision making for CE food supply chains very challenging. A holistic systems engineering approach is thus clearly needed to navigate the multi-scale, multi-faceted, and interconnected CE food supply chains, identify opportunities for synergistic benefits and systematically explore interactions and trade-offs [2].

In this work, we present the foundations of a systems engineering framework and decision-making tool for the analysis and trade-off optimization of interconnected CE food supply chains. The framework utilizes superstructure representations, along with mixed-integer modeling and optimization methods to establish the interconnections between different stages of the CE food supply chains. The analysis of the trade-offs is empowered by the introduction of composite metrics for CE that include waste, energy, and resource use minimization, as means to facilitate decision making and compare alternative processes, materials, resources, and technological options. To illustrate the applicability of the proposed framework we focus on the supply chain of coffee. A superstructure representation of the entire supply chain of coffee is presented, that involves alternative pathways for coffee harvesting and processing, waste utilization, product distribution, and new/alternative product introduction. Five different coffee-product demand scenarios are explored, showing that the production of instant coffee is the least energy and environmentally efficient scenario. On the contrary, the production of whole beans sets a hypothetical upper bound on the most circular coffee supply chain design and operation.

References:

[1] Ellen MacArthur Foundation, Intelligent assets: Unlocking the circular economy potential, 2016.

[2] Avraamidou, S., Baratsas, S.G., Tian, Y., Pistikopoulos, E.N., 2020. Circular economy - a challenge and an opportunity for process systems engineering. Computers & Chemical Engineering 133, 106629.