Optimal Design of a Supply Chain for the Production of Starch-based Biopolymers by Waste Revalorization

Abstract

The management of waste from single-use fossil plastics is a challenge. This work presents a holistic multiscale analysis for the production of starch-based biopolymers by the valorisation of sewage sludge, lignocellulosic waste, and CO₂, promoting the technological substitution of fossil-based plastics and circular economy. An MILP (Mixed Integer Linear Programming) formulation is developed to design a supply chain for the production of biopolymers where economic, environmental, social issues, and budget limitation are considered. The analysis is focused on Spain. The base case aiming at minimizing production network costs shows that it is possible to replace 51% of the polyethylene by starch-based polymers with a total investment of 3100 M$. A multi-objective optimization maximizing the decarbonization and social benefit while minimizing the costs promoted by the production network, provides a substitution level of 43% for the same budget, reducing the avoided emissions by 18.7% but with a social improvement of 10.34% compared with the economic case.