State of the Art on Allocation in LCA and Proposals for Changes in ISO 14044
Engineering and Protection of Environment
A literature review is presented in relation to the system expansion and the allocation of the environmental burdens in life cycle assessment (LCA). Many research centers in Europe and the world undertook subject of multi-functionality. Diversity of solutions and approaches is a barrier to an LCA practitioner who do not specializes in the subject related to multifunctionality and allocation. Wealth of literature and the progress made in the methodology create the need to systematize this
... ematize this issues. In the paper, various approaches and methodologies used in the life cycle analyses of multi-functional processes proposed in scientific papers, guides and manuals were compared. Recommendations related to the problem of multifunctionality of processes and systems which were identified in the literature were analyzed for compliance with the hierarchy of preferred solutions recommended in the ISO 14044, which arranges different solutions of multi-functionality from the most to the least recommended basing on the possibility of its implementation. Dependence of a choice of multifunctionality solution on approach to analysis: attributional analysis (ALCA) and consequential analysis (CLCA) was analyzed. Issues related to the use, advantages and disadvantages of an allocation on the basis of physical and economic relationships and of the system expansion (avoided emissions, substitution) were discussed closely. It is found on the basis of literature that in practice a procedure of solving multi-functionality mainly depends on context of analysis and the classification of the analyzed system. It has been shown that "Allocation procedure" of the ISO 14044 in relation to the literature is out of date and needs to be completed and changes. Finally, proposed changes and additions to the ISO 14044 resulting from the literature review were presented.