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Int J Life Cycle Assess (2013) 18:102112 DOI 10.1007/s11367-012-0455-2
LCA OF WASTE MANAGEMENT SYSTEMS
Life cycle assessment of a waste lubricant oil management system
Ana Pires & Graa Martinho
Received: 20 May 2011 /Accepted: 6 June 2012 /Published online: 24 June 2012 # Springer-Verlag 2012
AbstractPurpose This paper compares 16 waste lubricant oil (WLO) systems (15 management alternatives and a system in use in Portugal) using a life cycle assessment (LCA). The alternatives tested use various mild processing techniques and recovery options: recycling during expanded clay production, recycling and electric energy production, re-refining, energy recovery during cement production, and energy recovery during expanded clay production.
Methods The proposed 15 alternatives and the actual present day situation were analyzed using LCA software UMBERTO 5.5, applied to eight environmental impact categories. The LCA included an expansion system to accommodate co-products.
Results The results show that mild processing with low liquid gas fuel consumption and re-refining is the best option to manage WLO with regard to abiotic depletion, eutrophication, global warming, and human toxicity environmental impacts. A further environmental option is to treat the WLO using the same mild processing technique, but then send it to expanded clay recycling to be used as a fuel in expanded clay production, as this is the best option regarding freshwater sedimental ecotoxicity, freshwater aquatic ecotoxicity, and acidification.
Conclusions It is recommended that there is a shift away from recycling and electric energy production. Although sensitivity analysis shows re-refining and energy recovery in expanded clay production are sensitive to unit location
and substituted products emission factors, the LCA analysis as a whole shows that both options are good recovery options; re-refining is the preferable option because it is closer to the New Waste Framework Directive waste hierarchy principle.
Keywords Energy recovery . Life cycle assessment . Re-refining . Waste lubricant oils
1 Introduction
The Waste Lubricant Oils (WLO) Directive 75/439/EEC (Council 1975) specifies a hierarchy of waste oils management that gives preference to regeneration or re-refining, and also accepts incineration under environmentally acceptable conditions. Portugal has not yet applied the hierarchical waste management principle as it has traditionally supported energy recovery. Portugal has transposed the WLO directive into national law, as well as the amendments contained in 87/101/EEC (Council 1986) via Law...