Characterization of SPW pyrolysis oils: Products spectra and opportunities

Pyrolysis is a promising technique for conversion of solid plastic waste (SPW) to fine chemicals and fuels both via thermal and catalytic cracking routes. The quality of the oil generated from pyrolysis of SPW largely depends upon on process operating parameters and feedstock characteristics. The contamination of pyrolysis oil with hetero-atom impurities like oxygen, nitrogen, sulfur, etc., is a growing concern because of its inability to be used for various applications. In order to identify the presence of possible contaminants and upgrade the pyrolysis oil produced from SPW, a detailed knowledge of their chemical composition is extremely vital. This knowledge can thus facilitate the process design required for upgrading pyrolysis oil obtained from SPW. The current chapter highlights the important techniques adopted for characterizing the plastic pyrolysis oil (PPO) from SPW. The various physicochemical properties discussed in this chapter include heating value, viscosity, density, water content, flash point, fire point, and pour point. Besides, the chemical composition of the pyrolysis oil obtained from thermal and catalytic processes analyzed using Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), one dimensional gas chromatography (1D-GC) and two-dimensional gas chromatography (GC × GC) coupled to different detectors is also presented.