ABSTRACT
Coagulation phenomena can occur in certain types of waste lubricant oils (WLO) during regeneration processes involving alkaline treatments, causing plant shutdowns. In this context, the main objectives of this work were to study the effect of additives on the coagulation of WLO and to evaluate the possibility of removing the additives causing coagulation by solvent extraction. Calcium sulfonate, a detergent additive commonly used in engine oils was considered. It was observed that the presence of this additive at certain concentrations leads to the coagulation of WLO. Extraction tests were performed using 1-butanol. Results showed that it is possible to reverse the phenomena by removing the additives. However, when coagulation is due to the intrinsic nature of the base oil, as is the case of ester-based lubricants, it is not possible avoid coagulation. Therefore, in some case, a solvent extraction treatment can increase the regeneration potential of WLO.
