Circularity assessment in a chemical company. Evaluation of mass-based vs. impact-based circularity

Abstract

Assessing the circularity of a chemical company can be challenging due to the lack of recorded data on chemical flows. This study evaluates the circularity of solvents in a Swiss chemical plant by analyzing material flows and environmental impacts. The recycling rate and retained environmental value are used as indicators. The company achieved a recycling rate of over 95 %, but the retained environmental value was only about 52 %. Maximizing circularity is not always enough to ensure environmental sustainability. Impact-based metrics are also necessary. This is evidenced by the fact that despite having extremely high mass-based circularity, the retained environmental value is remarkably lower. Since the mass-based circularity is already close to its maximum, additional measures such as using renewable energy for the distillation process or renewable feedstocks for solvent production would be required to further reduce the environmental impact.