Optimization of the recycle used oil and its fuel quality characterization

Abstract

The optimization of recycling of used engine oil with clay sample has been studied using Response Surface Methodology. Acid concentration, activation temperature and time were the independent variables considered in optimizing the recycling of used oil and six responses evaluated. The surface characterization of the clay samples was performed using the Fourier Transform Infrared (FTIR) spectra and Brunauer Emmett Teller (BET) analyses. The relationship between independent variables and response was described by a second order polynomial equation. Statistical testing of the model was performed with F-test to obtain the correlation between the experimental data and predicted results for all responses. The adequacy of the model equations were evaluated by the Adjusted and Predicted R2 coefficients observed to be close to each other for all the six responses. Data obtained from recycling used oil using clay sample showed the optimum condition as; activation temperature of 106.80oC, acid concentration of 3M and activation time of 180 minutes. A yield of 66.28% was obtained at optimum condition and characterized fuel qualities found close to fresh oil used as standard in this work. The surface area and adsorption capacity of raw clay and activated clay samples was observed to have increase from 19.8m2/g to 437.83m2/g and 1.41 mg/g to 8.64 mg/g respectively. This difference adequately described the improvement of the adsorption phenomena of the activated clay over raw clay samples.