Microwave assisted pyrolysis of corn derived plastic bags

Microwave assisted pyrolysis (MAP) of corn derived plastic bags (CDP) was performed to efficiently dispose waste or contaminated bio-plastic obtaining a liquid useful as source of chemicals and/or fuels. MAP was performed using different microwave (MW) power, MW absorbers (carbon or Fe), and apparatus obtaining a liquid, a char and a gas in amount depending on the pyrolysis conditions. Liquids were always separated in three phases: upper, medium, and bottom and deeply characterized. They contained large amount of aromatic acid, phthalates and their derivatives in the upper fractions. Medium fractions were mainly composed of water (70 wt%), acids, alcohols, anydrosugars and their pyrolysis products. Lower fractions showed close properties and composition than the upper fractions. The same classes of compounds were present in upper and bottom phases but in the last ones, these compounds were oligomers of those present in the upper fractions. Working with more drastic conditions lower fraction was reduced while char yield was increased. MAP converted a waste CDP, even contaminated, obtaining some chemicals or even fuel thus avoiding to send them to an anaerobic digestion for they transformation into carbon dioxide, water and a residue. This process may represent a green way to dispose CDP recovering a liquid useful as a source of chemicals or for production of fuels and avoiding to contaminate the residue of an anaerobic fermentation with plasticizers present in CDP.