Characterization of products obtained of waste polyethylene terephthalate by pyrolysis

Abstract

AbstractIn this study, waste polyethylene terephthalate (wPET) was converted to liquid fuel by the pyrolysis method. It was also investigated both effects of microwave pre‐treatment and catalyst (sodium borohydride) on total conversion and oil + gas yield. The reaction temperature of 375–425°C and the reaction time of 30 min are sufficient for the pyrolysis of waste plastic samples in a batch reactor. In the pyrolysis of wPETs, the highest oil + gas yield of 45% was obtained under the conditions of reaction temperature of 425°C and reaction time of 30 min. The highest total conversion was 62% of microwave pre‐treated wPETs under catalytic conditions. It can be argued that microwave pre‐treatment and NaBH4 influence the oil + gas yield in pyrolysis experiments. According to the gas chromatography–mass spectrometry (GC–MS) analysis results of the oil products, they consist of aromatic, mono and multi‐ring aromatic compounds and polyaromatic compounds. Higher heating values of the solid products obtained in pyrolysis are approximately 4000–6000 cal/g. According to X‐ray diffraction analysis (XRD) of the solid products, they consist largely of crystalline terephthalic acid (C8H6O4).