Potencial de produção de combustíveis através da pirólise rápida de resíduos cabos elétricos de alta tensão

Abstract

A challenge upon nowaday’s society is the reuse of electric wire and cable, which most of the efforts are directed in the recovery of the metal, while the polymeric fraction is incinerated. This method is, however, causing environmental issues, therefore, being necessary research for alternative ways of recycling. Cross-linked polyethylene (XLPE) is used as an insulator in high voltage electrical cables and wires and recycling it requires bigger efforts, once its thermoset nature precludes the utilization of traditional process. The present work aims to evaluate the efficiency of fast and catalytic pyrolysis as an alternative for XLPE conversion into fuel material with high energy density and economic value. Thereunto, it will be done characterization of XLPE, in order to determine its energetical potential by thermogravimetric analysis (TG), volatile content, ashes content and calorific value. Kaolin was used as catalyst and characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis, with the goal to study its application as a low-cost catalyst in the pyrolysis process. XLPE pyrolysis analysis were developed in a HP-R 5200 CDS Analytical micropyrolyzer linked to a gas chromatographer with mass spectrometer detector (GC-MS). XLPE characterizations assessed that this is a low ash (1,0%) and volatile (98,70%) content polymer, being, therefore, a good material capable of generating liquid products by pyrolysis. This process is important to raise energy density of this material, which was quantified in 44,58 MJ/kg, by converting its molecules into the ones contained in the most popular fuels for commercial use. The use of kaolin as a catalyst led to a decrease in the relative concentration of hydrocarbons in the range of diesel (C8-C24) from about 87% to 28%, and lubricating oils (C14-C50) from about 70% to 13%, in detriment of an increase in lighter hydrocarbons in the gasoline range (C8-C12) from around 28% to 87%. . Lastly, this process showed a great potential to transform the studied material into commercial use fuel and can be considered as a sustainable alternative for the management and reuse of this plastic waste.