Investigation of synergetic, kinetics, thermodynamics, and batch studies of polypropylene-bakelite co-pyrolysis

Abstract

This study explores the co-pyrolysis recycling of the Polypropylene-Bakelite blend to improve the kinetics, thermodynamics, and conversion of thermal degradation of bakelite into useful products. The thermogravimetry analysis of the blend was conducted from ambient to 1000 °C at various heating rates in an N2 atmosphere. Thermogravimetric-Differential thermogravimetry curves revealed four steps of pyrolytic degradation, including two major weight loss steps (220–420 °C and 420–550 °C). The blending of polypropylene with Bakelite caused a shift in the pyrolytic degradation temperature zone and a synergetic effect. The pyrolytic degradation of the blended sample followed the F3 order-based mechanism with an average activation energy of 151 kJ/mol at 220–420 °C and the P3/2 nucleation mechanism with an average activation energy of 306 kJ/mol at 420–550 °C. The blend produced 47.66 % oil, 11.1 % wax, 15.1 % residue, and 26.14 % non-condensable gas during batch pyrolysis at 450 °C. The Gas Chromatography-Mass Spectrometry and Fourier Transform Infrared Spectroscopy analyses revealed that the oil contained 18.86 % saturated hydrocarbons (C8-54), 20.33 % unsaturated hydrocarbons (C7-19), and 60.81 % oxygenated compounds (C9-41) that could be used as transportation fuel.

Keywords

• Discarded bakelite
• Polypropylene
• Solid state kinetics
• Isoconversional methods
• Model fitting methods
• Synergetic effect