(395c) Solvothermal Liquefaction of Mixed Waste Plastics: Effect of Solvents at Sub-and Supercritical Conditions

Plastics are being used widely in different applications these days due to their advantages such as corrosion resistance and also being light yet stable and having excellent insulating properties. These benefits have made plastics among the leading materials in different usage models. Despite all the aforementioned benefits, plastics are also blamed for a series of health and safety problems in addition to widespread pollution of the planet. Waste to liquid is one of the main solutions identified to overcome these devastating problems. This study aims to investigate the effects of different solvents such as ethanol, water, n-hexane, and toluene in subcritical and supercritical conditions to find the influence of polarity of solvents on depolymerization of plastics. Additionally, the effects of reaction parameters such as temperature (200, 275, and 350 °C) and time (60 -180 min) on the solvothermal liquefaction (STL) of mixed plastics combined from (polypropylene, low-density PE, polystyrene, and polyurethane) on the oil yield, composition, and quality of the bio-oil formed from STL are evaluated through ultimate analysis, proximate analysis, chemical composition, gas chromatography mass spectroscopy, proton nuclear magnetic resonance, thermogravimetric analysis, and Fourier-transform infrared spectroscopy of bio-oil. The reaction temperature was found to have a positive effect on biooil yield for the solvents; however, it is more significant for n-Hexane solvent in supercritical condition. This study was a step-forward towards investigating the effects of such solvents in order to figure out the influence of polarity of solvents on physicochemical properties and oil yield from mixed plastics.