Carbon Footprint Analysis for the Waste Oil Management System in Portugal
Ana Pires *
UNINOVA-Ca3, Caparica, Portugal and Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
Graça Martinho
Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
*Author to whom correspondence should be addressed.
Abstract
Aims: The study analyzes the carbon footprint of the waste oil management system operating in Portugal to ensure the sustainable operation in the future. The analysis was carried out in 2011for the system that is composed of a treatment procedure collecting the treated oil for re-refining, followed by the production of expanded clay and recycling for electricity production.
Methodology: Carbon footprint analysis was conducted by using the Umberto software 5.5 based on the concepts of life cycle assessment with respect to international standards (ISO). Within this context, the substances considered for such carbon footprint analysis are directly relevant to Intergovernmental Panel on Climate Change (IPCC, 2007).
Results: The results showed that managing waste oils may contribute to the reduction of carbon footprint due to the avoided emissions of greenhouse gas through the reuse of treated waste oils. The carbon dioxide equivalent emissions from collection and treatment of waste oils would not outweigh such benefit earned from the substitution of virgin lubricant oil even though the use of treated waste oils for producing expanded clay may end up some more carbon dioxide emissions.
Conclusion: The carbon footprint analysis in this study has shown the potential for improvements in the waste oil management system in Portugal. The most significant improvement that could be made is the increase of using treated waste oils for the expanded clay production. However, such a strategy would not be consistent with the waste hierarchy principle which dominates the current decision making in managing waste nationally.
Keywords: Waste oils, re-refining, expanded clay, electric energy, carbon footprint, waste hierarchy principle