(629b) Chemical Recycling of Agricultural Waste Plastic By Pyrolysis: Case of Study of Province of Buenos Aires, Argentina

This study addresses the use of pyrolysis as a way to carry out the chemical recycling of agricultural waste plastic (AWP) in the southwest region of Buenos Aires province in Argentina. Large containers of agrochemicals and silo bags are the main sources of AWP in this area of the country, and pyrolysis has been found as one acceptable treatment, as it allows obtaining energy, fuels or products of better added value than simply incinerating the residues. Pyrolysis also allows to reduce the carbon footprint when compared to other thermal treatments commonly used to dispose this kind of waste.

The liquid and gas products obtained by pyrolysis of AWP are characterized in the context of producing electric and thermal energy. Yields of liquid and gas productsa are 40 and 48% respectively. Besides, the solid co-product is studied.

The products, as well as the solid co-product, are characterized by thermal analysis (DSC/TGA), elemental analysis, lower heating value (LHV) measurements, X-ray diffraction and gas chromatographic analysis. Results indicate that gas and liquid show high LHV (49,6 and 46, 9 MJ/Kg respectively). Pyrolysis technology is compared to both mechanical recycling and incineration of plastic, considering CO₂ emissions. In addition, the energetic efficiency of the pyrolysis process of AWP is calculated, considering the liquid and gas products as alternatives to fuel-oil and natural gas respectively.

Conclusions

Pyrolysis of AWP has a significantly lower carbon footprint compared to incineration, while the process is adequate to recycle materials inapplicable for conventional recycling. The liquid is also considered as a potential material in the synthesis of circular economy plastics.