Benefit of mechanical recycling, feedstock recycling and energy recovery from plastics waste

The comparison of the ecological benefit of different waste management and recycling strategies has to deal with the problem, that different strategies deliver different products. A new methodological approach, the so called "Utility Basket Method" is proposed. It takes into account that different recycling products are able to substitute different conventional products. This approach is applied to the comparison of 12 recycling/recovery options for post consumer plastics waste which are discussed in Germany. It results in a set of 12 systems which all process the same amount of waste and deliver all the same set of different products. For these systems 6 of 11 evaluated environmental criteria were found to be relevant for assessment. These criteria were deduced from complete mass and energy flux inventories which are established in the way of life cycle assessment (LCA) methodology is being operating as it is presently being subjected to standardization activities in the ISO. The resu lts are presented as the quantified reduction or enlargement of each environmental criterion versus conventional landfilling. It becomes obvious that the classification of recycling/recovery strategies in Mechanical Recycling, Feedstock Recycling and Energy Recovery gives no information about ecological advantages or disadvantages. The results depend on the specific boundary conditions of each recycling/recovery process.