Pyrolysis of Typical Ontario Raw Plastic Film Wastes

Plastic films are challenging to recycle due to contaminants and mixed polymer compositions. Uncatalyzed pyrolysis allows chemical recycling without expensive and complex purification steps. This study investigated heating municipal plastic film waste slowly (less than 5 °C/min during the reaction) to around 500 °C in a pyrolysis shaker reactor, modeling a rotary kiln or screw reactor, producing 72–87 wt % liquids and gases. Product liquid and gas compositions from various sources were similar, especially for film-only samples from which all paper, metal, and nonfilm plastic were manually removed. The presence of poly(ethylene terephthalate) (PET) in the waste stream reduced liquid yields and increased aromaticity, while paper did not affect yields. Energy requirements during the pyrolysis reaction were found to average between 1.0 and 1.2 kJ/g for the waste samples, which may be provided by renewable energy or the combustion of a fraction of the product gas.