(325c) Circular Economy Systems Engineering

Natural resources play a critical role in the development and wealth of societies. They are vital for the provision of energy, food, shelter, transport and all basic functions of our societies. Population growth, welfare growth and the constant need of an increasing standard of living, means that more natural resources are used, leading to resource degradation, increased landfill wastes caused be the increased consumption, and negative environmental impact caused by the production and consumption of resources.

Circular Economy (CE) can be a solution to this resource challenge. CE is an economy that is restorative and regenerative by design and aims to keep products, components, and materials at their highest utility and value at all times [1]. CE operates at three levels, the micro-level (products, companies, consumers), meso-level (eco-industrial parks) and macro-level (city, region, nation and beyond) [2]. To achieve such an economy, four actions have been suggested: reuse, repair, remanufacturing, and recycling [3, 4]. These actions close loops and connect different stages of the supply chain of a product that in a linear economy are discreate. These interconnections along with the players and stakeholders connected with them make decision making for CE supply chains very challenging. A holistic systems engineering approach is thus clearly needed to navigate the multi-scale, multi-faceted and interconnected CE supply chain, identify opportunities for synergistic benefits and systematically explore interactions and trade-offs.

We present the foundations of a systems engineering framework and quantitative decision-making tools for the analysis and trade-off optimization of interconnected resource networks to achieve a CE. The framework combines data analytics and mixed-integer modelling & optimization methods to establish (i) the interconnections between different stages of the circular supply chain, (ii) the potentially competing interests amongst various stakeholders, and (iii) policy, regulation and societal issues. A multi-objective optimization strategy is followed for the analysis of the trade-offs 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 process, materials, resources and technological options. Links to multi-scale energy systems engineering and the Food-Energy-Water Nexus will also be discussed. The versatility, potential and applicability of the proposed framework will be demonstrated through representative case studies, including the (i) supply chain of coffee [5] and (ii) agricultural land allocation [6].

References:

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

[2] Kirchherr, D. Reike, M. Hekkert. Conceptualizing the circular economy: An analysis of 114 definitions, Resources, Conservation and Recycling, 127 (2017) 221-232.

[3] Lieder, A. Rashid. Towards circular economy implementation: a comprehensive review in context of manufacturing industry, Journal of Cleaner Production, 115 (2016) 36-51.

[4] De Angelis, M. Howard, J. Miemcyk. Supply Chain Management and the Circular Economy: towards the Circular Supply Chain, Production Planning and Control, 29 (2017) 425-437.

[5] A. Figueroa, T. Homann, H. M. Rawel. Coffee Production Wastes: Potentials and Perspectives, Austin Food Science, 1(3) (2016) 1014.

[6] Nie, Y.; Avraamidou, S.; Xiao, X.; Pistikopoulos, E. N.; Li, J.; Zeng, Y.; Song, F.; Yu, J.; Zhu, M. A Food-Energy-Water Nexus approach for land use optimization. Science of the Total Environment 659, (2019) 7-19.