Degradación térmica de mezclas de polipropileno, poliestireno y polietilen tereftalato reciclados

Abstract

The objective of this study was to carry out the thermal degradation of recycled polypropylene (PP), polystyrene (PS) and polyethene terephthalate (PET) mixtures, to obtain a mixture of fuels, a batch reactor purged with nitrogen gas was used, generating an oxygen-free atmosphere, in turn, the reactor was connected to a condenser that operates through a cooling system at 10° C, for the collection of the condensable fractions. Tests were made in three types of mixtures at two temperatures 400° C and 450° C, each with three repetitions and a heating rate of 15 ° C min -1, thus it was possible to determine the influence of temperature on the fractions obtained. Initially, the reactor was filled with 100g of the mixture of PP, PS and PET, with which liquid, solid and gaseous fractions were obtained, the most interesting for this research is the liquid fraction obtained, which is characterized by GC-MS chromatography. The liquid fraction with the highest yield corresponds to sample 3 (PP = 25%, PET = 25% and PS = 50%), from which 55% of the liquid fraction was obtained at a temperature of 400 ° C and a residence time of 27 min. As a result of the thermal degradation, a hydrocarbon mixture was obtained with an API density of 22.5, mainly made up of aromatic compounds. Finally, the fuel mixture obtained by the thermal degradation of PP, PS and PET at 400 ° C can be fractionated to obtain refined hydrocarbon compounds, considering that the higher the degradation temperature will favour the generation of recoverable gases and heavy waxes.