Reclamation of Used Transformer Oil by Adsorption

This study presents an evaluation of the removal of degradation products from used transformer oil using a commercial activated clay in batch experiments, at temperatures between 60° and 100°C. Experimental data were correlated by means of Total Acid Number Analysis, ASTM D 3339. As qualitative measurements of the efficiency of the treatment, ASTM color methodology and infrared spectroscopy analysis were employed. Equilibrium isotherms showed a type I behavior and were correlated by both Langmuir and Freundlich equations. Pore diffusion coefficients were also obtained in the order of 10−12 m2/s and showed typical Arrhenius dependence with temperature, Infrared spectroscopy indicated that carbonyl groups present in the used oil were not present after treatment with the clay, thus proving this to be an efficient method for recovery and possible commercial reutilization of used lubricant oils.