LCA OF WASTE MANAGEMENT SYSTEMS Life cycle assessment of a waste lubricant oil management system Ana Pires & Graça Martinho Received: 20 May 2011 / Accepted: 6 June 2012 / Published online: 24 June 2012 # Springer-Verlag 2012 Abstract Purpose 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 alter- natives tested use various mild processing techniques and recovery options: recycling during expanded clay produc- tion, recycling and electric energy production, re-refining, energy recovery during cement production, and energy re- covery during expanded clay production. Methods The proposed 15 alternatives and the actual pres- ent day situation were analyzed using LCA software UMBERTO 5.5, applied to eight environmental impact cat- egories. The LCA included an expansion system to accom- modate 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 envi- ronmental 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 hierar- chy 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 manage- ment that gives preference to regeneration or re-refining, and also accepts incineration under environmentally accept- able 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 Decree no. 153/2003 (MCOTA 2003). In 2006, this legal document imposed a minimum of 85 % WLO collection, 25 % re-refining, and 50 % recycling, and the creation of an integrated WLO management system through an extended producer respon- sibility (EPR) instrument. The entity created was SOGILUB (WLO management organization, in Portuguese Sociedade de Gestão Integrada de Óleos Lubrificantes Usados), which has an elaborate WLO management system, SIGOU (WLO management system, in Portuguese Sistema Integrado de Gestão de Óleos Usados, or SIGOU). So far, SOGILUB has achieved the national targets. However, under the New Waste Framework Directive 2008/98/EC (European Parliament and Council 2008), WLO management should focus on the waste hierarchy. In Responsible editor: Michael Z. Hauschild A. Pires (*) : G. Martinho Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica 2829-516, Portugal e-mail: alp11931@fct.unl.pt Int J Life Cycle Assess (2013) 18:102–112 DOI 10.1007/s11367-012-0455-2