Allocation Procedures for Generic Cascade Use Cases - An Evaluation Using Monte Carlo Analysis

Cascade use - a concept for increasing resource efficiency by multiple use of resources - gains in importance, in particular for bio-based materials. Allocation of environmental burdens and costs along the cascade chain plays a major role in deciding whether to establish a cascade or not. This highlights the need for a methodology for properly assessing different types of cascades. To provide guidance in terms of choice of allocation procedure available from life cycle assessment (LCA), Monte Carlo analysis is used. Especially hybrid, individually tailored allocation approaches can be evaluated in this way. The results show a high diversity of possible outcomes in terms of general allocation intensity (how much burden is shifted between steps of the cascade), rank reversals (exchange of positions inside the burden ranking) and variance of the overall results of the cascade allocation. Results are valuable for selecting an allocation procedure for cascade LCA and for further interpreting cascade models using specific allocation procedures.