TG/DTA-FTIR Study on Total Resource Recovery from Tetra Pak Waste by Pyrolysis under a CO 2 Environment

Pyrolysis of Tetra Pak waste under CO₂ was investigated using a thermogravimetric/differential thermal analyser coupled with a Fourier transform infrared spectrometer. Experimental results showed that cellulose was decomposed between 270 and 390 °C, leading to the formation of aldehydes, ketones, carboxylic acids and levoglucosan. Thermal cracking of polyethylene occurred between 440 and 530 °C and the main products were aliphatic hydrocarbons. CO can be produced by the gasification of pyrolytic char by CO₂ at temperatures ranging from 860–970 °C. Aluminium (Al) foil remained in a “thin layer shape” despite melting above 660 °C. CaO was generated from the decomposition of CaCO₃ used as a paper filler at 722 °C. The reaction between CaO and the CO₂ atmosphere during the cooling process led to the formation of new CaCO₃ which was the main component of ash after gasification and was easy to separate from Al foil.