Experimental Studies on Conversion of Waste Polystyrene to Styrene and Liquid Fuel

Abstract

The degradation of waste polystyrene sample was carried out in the temperature range of 450-575 ‘c by both thermal degradation and by catalytic degradation using SILICA-ALUMINA as catalyst. It was found that liquid product yield increases with increasing temperature in both thermal as well as catalytic degradation till 550’c , afterwards liquid product yield starts decreasing with increasing temperature. In second stage to find out optimum polystyrene : silica-alumina ratio for maximum liquid product yield , catalytic degradation of polystyrene was carried out at 550’c in various proportion, i.e. 20:1 , 15:1 , 10:1 , 5:1 and 4:1. It was found that liquid product yield increases with increasing the ratio of catalyst upto 5:1 and afterwards increasing the catalyst ratio has resulted in decreasing the amount of liquid product. It was also found that styrene was the main constituents of liquid product ,about 86 % , in thermal degradation of polystyrene at 550’c while in catalytic pyrolysis done in 5:1 ratio at the same temperature has only 41 % styrene in the liquid product obtained. This study indicates that mechanism of degradation depends on the temperature of degradation as well as amount of catalyst used for degradation.