Time and Life Cycle Assessment: How to Take Time into Account in the Inventory Step?

Abstract

Life cycle assessment is usually an assessment tool which only considers steady state processes: the temporal and spatial properties of extractions, usage and emissions are lost during the life cycle inventory step. This approach significantly reduces the environmental relevance of some results. As the development of dynamic impact methods is based on dynamic inventory data, it seems essential to develop a general methodology to achieve a temporal life cycle inventory. This study presents a method to select steps, in the whole network tree, for which dynamics have to be considered while the others are approximated by steady state representation. The selection procedure is based on the main contributors in term of impact. The approach is illustrated by the life cycle assessment of simplified rapeseed oil production as biofuel system.