Abstract
•Pyrolysis of polypropylene over cobalt doped molecular sieve was studied.•The catalyst reduced the temperature of maximum degradation and activation energy.•The oil and gases obtained were studied through gas chromatography/mass spectrometry.•Fuel properties of the oil were found comparable with fossil fuel oil.•The procedure has bright prospects for disposing of plastic waste.
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.