Cobalt-doped molecular sieve for efficient degradation of polypropylene into fuel oil: Kinetics and fuel properties of the oil

Abstract

The present research work is focused on thermogravimetric analysis of polypropylene over cobalt doped molecular sieve (Co/MS). The catalyst reduced the temperature of maximum degradation (Tmax) from 398.2 to 330 °C along with reduction in activation energy. Ozawa Flynn Waal (OFW), Coats Redfern (CR) and Tang Wanjun (TW) methods were applied for calculation of kinetic parameters. The activation energy values were determined in the range of 47.590–54.749, 40.708–60.525 and 41.276–50.283 kJ mol−1 using Ozawa Flynn Waal, Coats Redfern and Tang Wanjun methods respectively, which is relatively less as compared to the E values determined without catalyst using the same models. Furthermore, an effort was made to pyrolyze polypropylene in a salt bath using a glass vessel. The oil and gases recovered were studied through gas chromatography/mass spectrometry. It was concluded that, simple thermal degradation of polypropylene produced no oil; however, thermo-catalytic pyrolysis yielded more than 70% pyrolysis oil having a broad range of components from C4 to C21. Fuel characteristics of the oil determined were found comparable with fossil fuel oil and thus can be used as substitute for energy purpose.