The effect of thermal aging on the composition of pyrolysis oil fuel derived from typical waste plastics

This study reveals the influence of thermal aging on the pyrolysis oil fuel components of typical waste plastics, including polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC). Plastic samples were continuously heated in an aging oven at 100 °C to simulate thermal aging. The pyrolysis volatile compositions of fresh and aged plastic samples were comparatively studied by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) at 500 °C. The volatile composition analysis results showed that thermal aging changes the pyrolysis oil composition, and the influence strongly depends on the type of plastic. For PE and PP, which underwent random scission after thermal aging treatment, the influence of thermal aging on the heavy oil fraction was more obvious than that on the light oil and diesel oil fractions. For PVC samples, the thermal aging process caused structural defects and turned the color of the PVC light yellow. After 128-h thermal aging, the maximum weight loss rate decreased by 35.8%, and the fraction of C5-C9 components and aromatics first increased and then decreased. The maximum values were 80.21 ± 1.62% and 73.69 ± 0.73%, and the minimum values were 65.58 ± 2.63% and 63.98 ± 0.39%, respectively.