Modeling and simulation of waste engine oil treatment process using solvent extraction and carbonized-clay adsorption methods

There is the irresistible need to recover refined engine oil from waste engine oil through recycling procedures and treatment methods. To achieve this objective, waste engine oil samples were subjected to acid precipitation, carbonized-clay adsorption and solvent extraction methods. In it, 5000 ml of acid treated engine oil was recovered from the preliminary stage of treatment. Also, carbonized-clay adsorbent was produced from the admixture of activated charcoal from coconut husk and bentonite clay in specific ratios of 50, 100 and 200 %w/w. Actual waste engine oil treatments proceeded with the separate applications of carbonized-clay adsorption and solvent extraction methods on the basis of ratios of carbon-clay, adsorbent-oil and solvent-oil, while using experimental designs proposed by design expert version 7.0. Physicochemical property tests were conducted for waste and refined engine oil samples in order to check efficacies of treatments. The results showed increase in viscosity from 135cP to 185cP for waste engine oil to refined engine oil. Water and heavy metal contents in waste engine oil reduced after treatment, respectively from (1100 ppm, Cu (88.9 mg/l), Fe (322.8 mg/l) and Pb (12.4 mg/l)) to (40 ppm, Cu (8.5 mg/l), Fe (58.6 mg/l) and Pb (8.8 mg/l)). Optimal yields of refined engine oil were respectively 77.8 % and 76.5 %, for carbonized-clay adsorption and solvent extraction methods. Empirical models determined for the treatment processes also showed good correlation coefficients (R2) of 0.87 and 0.97, between experimental and predicted yields of refined engine oil for carbonized-clay adsorption and solvent extraction methods.