Study of sulphur removal in waste tyre pyrolysis oil using hybrid design

Abstract

Waste tyres are very difficult to dispose and there is a growing interest to produce fuel from waste tyres. However, the high sulphur content in the oil obtained from the pyrolysis of waste tyres is a potential obstacle to the utilisation of waste tyre pyrolysis oil in real combustion processes. The aim of this study was to investigate the interaction of parameters during the oxidative desulphurisation of waste tyre pyrolysis oil using a hybrid design approach. The parameters investigated were the temperature (48-62 °C), the amount of acetic acid (5.2-10.8 mL) and the amount of hydrogen peroxide (6-10.8 mL). The stirring speed and the reaction time were kept constant at 300 rpm and 50 minutes respectively. The acetonitrile to the oxidised tyre oil ratio used during all experiments was 1:2. The results showed that the sulphur content was significantly influenced by the three factors investigated during the study. The maximum sulphur reduction was 46 % while the minimum sulphur reduction was 33 %. The model obtained for the prediction of the sulphur removal was of the quadratic nature based on results of the statistical parameters. The high values of the coefficient of determination and the adjusted R2 was an indication of the accuracy and reliability of the model obtained. Moreover, the p-value of below 0.05 also indicated that the model had a high predictive power. Key words: waste tyre pyrolysis oil, hybrid design, interaction effect, model