Avaliação e otimização do processo de recuperação de óleos lubrificantes automotivos usados

Abstract

Several recycling alternatives have been used around the world to recover the used lubricating oil. The process of solvent extraction is able to remove approximately 10-14% of contaminants, which corresponds approximately to the amount of additives and dross, typically found in used lubricating oil. This study had as objective to evaluate and optimize the recovery process of lubricating oils used in automotive diesel engines by polar solvent extraction (1-butanol, 2-propanol and methyl ethyl ketone) and clarification by natural clay, as well as characterizing physically and chemically the lubricating oil and clay samples, new, used, and recovered. The results allowed to conclude that the best extraction ranges are of 1: 6; 1: 4.7 and 1: 6 ratios for the IPP solvents, MEC and BUT respectively at the temperature of 30 ° C. The MEC solvent had a higher yield extraction (84%), followed by BUT (80%) and IPP (78%). The clarification process with natural clay by filtration column was efficient and allowed the recovery of clays, avoiding waste generation. Through the physical and chemical characterization of samples lubricant, there was a reduction and/or elimination of impurities and additives. The IR determinations allowed to monitor the oxidation products, additives and characteristic hydrocarbons in the whole process. The oxidative stability, PetroOXY method, indicated that the recovered samples are more stable compared the LUB0. The determination of metals showed that the clarification step was effective in the removal. The characterization by XRD, IR and TG, have suggested that there were not significant changes in the structures of clays. Thus, the process and re-refining using solvent and clay, afforded a product with quality that can be commercialized in the country, according to the current legislation, was possible further recovery of the agents involved, clays and solvents.