The Circularity of Materials from the Perspective of the Product Life Cycle: A Case Study of Secondary Fence Board, Part 2 (Scenario Analysis)

Abstract

Recycling strategies demonstrate different life cycle environmental performance. In order to assess this performance, a life cycle assessment may be used. In such studies, the recycling should be linked with multifunctionality and allocation. This requires it to be modelled accordingly, especially in terms of environmental burdens and credits. The paper presents a case study of open-loop recycling. A flow of mixed post-consumer multi-material waste was reprocessed into another product with a new application—a fence board made of recycled material (secondary fence board). Although many allocation-related case studies are provided in the literature, no example of a comparison between different substitution scenarios for open-loop recycling has been found. In order to fill the gap, various hypothetical market-mix-based alternatives related to the virgin production and durability of products have been examined. The goal of the study is to assess the potential environmental impact of 1 m2 of secondary fence board modelled in different substitution scenarios. The paper is the second part of a two-part study. In Part 1, life cycle assessment results were presented for a baseline scenario (1A). Part 2 focuses strongly on allocation considerations. In order to ensure a consistency between the results of Part 1 and Part 2, the entire life cycle of the fence board has been taken into account in both calculations. The case study has shown that the results may be highly sensitive to the choice of substitutes and the choice of quality attributes impacting the reference flows (in our example, the durability of products).