QUALITY ASSESSMENT AND ESTIMATION OF SUBSTITUTION RATIOS FOR RECYCLED PLASTIC

摘要

Owing to its versatility and specific properties, plastic has become an important material in the modern consumption-based society. Consequently, the global production of plastic has grown constantly throughout the last 50 years, and so has the generation of plastic waste. The political interest in plastic recycling has therefore increased over the last decades. While increasing separate collection of plastic has been the main focus so far, other parameters might significantly influence the environmental impact from a plastic recycling system. Using life cycle assessment (LCA) for environmental evaluation, system expansion is usually used to credit the secondary material, by subtracting the environmental impacts related to the production of virgin material which is substituted with recycled material. The amount of substitution is computed using a coefficient called substitution ratio (SR). Despite the fact that accounting for material quality is important for correct assessment, loss of quality has seldom been integrated in the SR in previous LCA studies, and no consensus presently exists with regards to how to account for it. The overall purpose of this study is to contribute to a more systematic assessment of resource quality and plastic recycling. The work involves preliminary results for selected plastic types in a European context.