MO.3.C || Circularity and Life Cycle Aspects of Recycling Technologies

Smuk, Lena; Berlin, Johanna; Evangelopoulos, Panagiotis

Chemical recycling is a key element for establishing a system for circular flow of polymers. All polymers, whether fossil- or bio-based, com¬plex, contaminated or pure, are subject to aging and therefore cannot be reused or mechanically recycled indefinitely. After certain service time/recycling cycle polymers require chemical recycling to be effectively used again. In waste hierarchy updated with circular thinking chemical recycling can be a sound alternative not only to incineration but sometimes even to mechanical recycling. In those cases when mechanical recycling involves high material losses, appearance of hazardous compounds, high risks of potentially toxic contamination etc., the priority of chemical recycling alternative over mechanical recycling can be justified. LCA-comparison of chemical recycling of plastics vs mechanical vs incineration is of great interest to the investors and policy makers, and new research results are published constantly. Recent studies, however, are rather focused on CO2 footprint, which is not enough to assess the full impact of chemical recycling. This paper presents preliminary results of the development of a holistic LCA methodology involving a wider range of indicators and taking into account the quality of the recyclate produced. The relevance of different indicators is discussed as well as a potential impact of chemical recycling on the achievement of environmental goals. What winnings can be achieved by implementation of chemical recycling if it causes 50% less CO2 emissions than incineration of the same plastic waste? What should be the balance between chemical and mechanical recycling if manufacturing of plastics via either pyrolysis or mechanical recycling results in similar CO2 emissions? These questions are analyzed along with the expected changes in the composition and volume of polymer flows and other parameters significant for assessing the environmental impact of chemical recycling in the future.