Re‐refining used oil using rosin: A new approach for recycling waste engine oil

Abstract In this study, used lubricant oil was recycled using sulfuric acid, soda ash, rosin, and potash alum. The study found that the physicochemical properties of the recovered oil were closely aligned with the properties of fresh oils, indicating that the recycling process via this modified method was effective. The quality of the recycled oil was assessed using various physio‐chemical tests, which included evaluating its viscosity, density, pour point, and aniline point. The analysis of the density of the used oil revealed a value of 863.54 kg/m 3 , whereas the density of the recovered oil sample showed a decrease to 850.26 kg/m 3 . This implies the treatment process was effective in eliminating the solid heavy impurities from the used oil. Additionally, the chemical composition of the recycled oil was analyzed using Fourier Transform Infrared Spectroscopy (FT‐IR) and UV–Visible spectra, which demonstrated that the composition of the recycled oil was similar to that of fresh oil. The FT‐IR analysis further revealed the presence of oxidized products in the used oil, which contributed to the oil's contamination. However, the UV analysis confirmed that the recycled oil was free from impurities post‐treatment, highlighting the effectiveness of the recycling process.