The Contribution of Lube Additives to the Life Cycle Impacts of Fully Formulated Petroleum-Based Lubricants

Abstract

Problem statement: Previous applications of the Life Cycle Assessment (LCA) methodology to lubricants are not sufficiently detailed and comprehensive for R and D purposes and there are no LCAs of lube additives and fully formulated lubricants. The aim of this study is to integrate and expand previous LCAs of lubricants and to investigate on the contribution of lube additives to the environmental impacts of fully formulated lubricants. Approach: This study considers three base oils (mineral, poly-alpha olefins and hydrocracked) and a set of lubricating additives typically used in fully formulated engine oil. The LCA model was based on both industry and literature data. Results: The contribution of additives to the life cycle impacts of commercial lube oil was found to be remarkably high, particularly for land occupation and metal depletion (more than 50%) and for climate change (30%). Trends in the lubricants industry towards more sophisticated base oils correspond to remarkably higher environmental impacts per kg of product, but were likely to lead to reduce impacts per km. Conclusion: While the application of LCA to lubricants can be considered fully operational for general purposes outside the lubricants industry, this is not the case for R and D purposes within the industry. Additives can not be excluded from LCAs of modern lubricants, as their contribution in terms of environmental impact can be considerably high. As base oil is concerned, this study made the point on data availability and provided a contribution in order to integrate and expand previous LCAs of fully formulated lube oils.