Methodological advancements in lca of waste management systems

Abstract

Waste management has been identified by the European Commission, the United States Environmental Protection Agency and the Organization for Economic Cooperation and Development, among other institutions, as a key issue for the achievement of a resource-efficient society and for achieving a sustainable economy. Waste management practices need to be improved in order to reinforce material recycling, closing essential material loops and also recovering energy from waste, while at the same time ensuring that toxic substances are not released to the environment. This essentially means moving from a linear extraction-use-throw away economy model to a more circular one. Life Cycle Assessment (LCA) has been gaining acceptance in recent years as the best tool to assist decision making for waste management policy and planning in Europe. It can provide a global and expanded view of the system, taking into account all the processes involved and its interactions with the economy (by means of reintroducing recycled materials or energy recovered from the waste management system), as well as accounting for a complete set of environmental effects (i.e. climate change, ozone layer depletion, acidification or eutrophication). During the last decades, some authors have identified methodological issues when performing LCA of Waste Management Systems (WMS) that may have a great influence on the final results of the analysis. These issues have been addressed in the last methodological guidelines about LCA and waste management developed by the Joint Research Centre of the European Union (published in 2011). However, according to the author, there are still some important issues when applying LCA to evaluate the environmental efficiency of WMS that merit special attention. In particular, the way in which collecting systems and credits due to material recovery have been historically modelled needs to be reviewed, especially if the focus of the analysis is the collection system itself and if we are performing an analysis of the system from an attributional LCA point of view. On the other hand, how resource depletion is assessed in LCA has been recently questioned in the literature, and needs also to be analysed. The work done in this thesis aims to identity these important issues and shed some light on how to address them. The outcomes of the thesis are (1) an alternative method to account for the credits of material recovery in LCA, more in line with the fundamental aim of the attributional approach in LCA; (2) a new predictive model for evaluating the environmental perfomance of waste collection, which produces more accurate results when compared with real collection routes than other existing models; and (3) a contribution to the ongoing discussion for the future development of a more robust method for evaluating Resource Scarcity impact category in LCA, by looking at synergies with Emergy Accounting methodology.

Date of Award	10 Apr 2015
Original language	English
Supervisor	Marco Raugei (Director), Pere Fullana i Palmer (Director) & Pedro Ysern Comas (Tutor)