Degradation of Plastic Materials through Small-Scale Pyrolysis: Characterization of the Obtained Hydrocarbons and Life Cycle Analysis

Abstract

Plastic waste signifies a global predicament, aggravated by deficient management practices. Unearthing methods to repurpose energy from this waste is pivotal. This study delves into the pyrolytic degradation of low-density plastics to convert plastic waste into valuable products on a modest scale. A small-scale, low-CO2 emitting distiller was employed in the process. A zeolite was harnessed as a catalyst to augment the temperature and hasten the pyrolysis process. A comprehensive life cycle analysis was executed to assess the environmental impact of the process. In this scenario, zeolite-facilitated pyrolysis was more proficient compared to traditional thermal pyrolysis, generating a yield of 22.5% with the catalyst, contrasting with 18% without. A kinetic model was formulated, observing reaction mechanisms and temperature escalation and culminating in the extraction of aromatic oils. These oils were further distilled to produce liquid hydrocarbons, beginning the distillation at 60 °C with the catalyst. Characterization of the secured hydrocarbons was conducted using infrared, Raman spectroscopy, and gas chromatography, discovering compounds akin to gasoline, such as benzene, toluene, and xylenes. Additionally, the procedure exhibited a minimal environmental detriment, as validated by the life cycle analysis. This study concludes by highlighting the potential of small-scale, low-CO2 emitting pyrolytic degradation of low-density plastics for energy recovery from plastic waste, demonstrating the practical and environmental benefits of this avant-garde method.