The standard ISO 14044:2006 defines the hierarchical steps to follow when solving multifunctionality issues in life cycle assessment (LCA). However, the practical implementation of such a hierarchy has been debated for twenty-five years leading to different implementation practices from LCA practitioners. The first part of this study discussed the main steps where the ISO hierarchy has been implemented differently and explored current multifunctionality practices in peer-reviewed studies. A text-mining process was applied to quantitatively assess such practices in the 532 multifunctional case studies found in the literature. In the second part of the study, citation network analysis (CNA) was used to identify the major publications that influenced the development of the multifunctionality-debate in LCA, i.e., the key-route main path. The identified publications were then reviewed to detect the origins of the different practices and their underlying theories. Based on these insights, this study provided some “food for thought” on current practices to move towards consistent methodology. We believe that such an advancement is urgently needed for better positioning LCA as a tool for sustainability decision-making. In particular, consistent allocation practices could be especially beneficial in bioeconomy sectors, where production processes are usually multifunctional, and where current allocation practices are not harmonized yet.

Alternative fuel policies need accurate and transparent methods to find the embedded carbon intensity of individual refinery products. This study investigates different ways of allocating greenhouse gases emissions deriving from refining and upstream crude oil supply. Allocation methods based on mass, energy content, economic value and, innovatively, added-value, are compared with the marginal refining emissions calculated by CONCAWE’s linear-programming model to the average EU refinery, which has been adopted as reference in EU legislation. Beside the most important transportation fuels (gasoline, diesel, kerosene/jet fuel and heavy fuel oil), the analysis extends to petroleum coke and refinery hydrogen. Moreover, novel criteria, based on the implications due to hydrogen usage by each fuel pathway, have been introduced to test the consistency of the analysed approaches. It is found that only two economic-based allocation methods are consistent with the introduced criteria. These two methods also give negative refinery emissions for heavy products, which is coherent with the marginal emissions calculated through the CONCAWE refinery model. The recommended allocation methods are transparent and use only publicly available statistical data, so they may be useful not only for future EU legislation, but also in jurisdictions where a representative refinery model is not available.JRC.C.4-Sustainable Transpor