Optimization of oil yield from isothermal pyrolysis of waste polystyrene over CuO/Kaolin

Isothermal pyrolysis of waste polystyrene over CuO/kaolin was investigated and optimized for maximum oil yield using Box-Behnken response surface design. The results revealed that the reaction variables affect the yields of the gaseous, liquid and char, respectively. Optimization of the reaction variables predicted an optimal yield of 96.07% at a residence time, heating rate, and catalyst loading of 45 min, 10 °C/min and 30%, respectively in agreement with the validation results of 95.56 ± 1.90%. The physicochemical properties of the oil conformed with petrodiesel properties and could be used as its substitute. The oil has a 84% dominance of benzene,1,1-(1-butenylidene)bis, and the mechanism through which it was formed has been proposed.