WE.2.C || Benefits of Retaining Materials and Their Quality in a Circular Economy

Hummen, Torsten

Preserving material functionality for as long as possible is essential to ensure that the environment can provide natural resources of useful quality with instrumental value to humans. Unfortunately, however, the processing of materials usually changes their composition and thus their quality. This is especially true for recycling processes due to a high mix of different materials, which inevitably leads to material contamination and loss of the materials’ original functionality. To restore the quality of the material, those contaminants must be diluted, for example. Energy requirements for recycling can increase drastically at very high recycling rates due to the entropy law and may offset the environmental benefits gained by recovering secondary material. Closed-loop recycling, therefore, does not necessarly equate to greater sustainability and is one of the greatest challenges of the circular economy. While purely mass-based approaches such as material flow analysis (MFA) map the use of natural resources and quantify the recycling potential, they neither evaluate the resource effectiveness, nor the environmental benefits of closed material loops. However, measuring the effective preservation of material quality is key for a transition to a sustainable circular economy. It is discussed here based on a case study of materials embodied in residential heating appliances to derive general principles for product design that enable an improved recycling effectiveness.