Life Cycle Assessment of Polymers and Their Recycling
Sabyasachi Das, Chao Liang, Jennifer B. Dunn
Abstract
Life cycle assessment (LCA) can be a powerful tool to compare options for reducing the environmental impacts of plastic. These options could include the use of different feedstocks, the application of different processing technologies, and the production of plastics from waste gases or recycled plastics. These options must be compared consistently and transparently to advance technology and policy development that will reduce the environmental effects of plastics compared to today’s baseline. Furthermore, LCA can be a useful decision-making tool for evaluating the energy and environmental effects of different polymer end-of-life options (e.g., recycling, conversion into fuels, technologies that degrade polymer waste into benign product), which are becoming prominent in the public debate concerning the large amounts of plastic waste society generates annually. In this chapter, we describe methodological aspects - functional unit, design of system boundary, available data sources, co-product handling technique, baseline or counterfactual scenarios, and choice of LCA indicators - of polymer and polymer recycling LCA that can have a pronounced effect on LCA results. We subsequently review the treatment of these methodological aspects of literature that examines LCA of biomass-derived polymers, polymers produced from waste CO2, and polymers at their end-of-life. We conclude with a discussion of remaining development needs for polymer LCA.