Environmental and economic assessment of waste lubricant oil management in the EU

Of the 4.3 million tonnes lubricating oils placed on the EU28 market in 2017, 2 Mt (47 %) were potentially collectible. Of the 1.6 Mt collected, 61 % were regenerated and 39 % followed energy recovery pathways, such as conversion to fuel or combustion in industrial boilers, kilns and incinerators. Considering that energy recovery also offers important benefits, it is still unclear to which extent a further increase of regeneration would bring additional benefits. To answer this question, the present study applies life cycle assessment and costing methods to analyse the impacts of eight alternative pathways for the management of waste oil, including three regeneration pathways (hydro-treatment, solvent extraction and distillation) and five energy recovery pathways (two types of distillation into fuel oil, direct incineration in cement kilns, in hazardous waste incinerators and in industrial boilers). Whereas regeneration outperforms all energy recovery pathways from a climate change perspective, achieving savings of 344-537 kg CO2-eq t(-1) of waste oil regenerated, the results are more nuanced when considering the life cycle costs, where regeneration (achieving cost savings of 236-357 EUR t(- 1)) is robustly superior only to the different forms of direct incineration. A similar outcome is observed for the full environmental life cycle costs. In terms of policy implications, the findings suggest that current evidence would not justify a general preferential treatment and support of waste oil regeneration vis-a-vis the other treatment channels, especially conversion to fuel.