It is noteworthy that these pyrolysis oils, which are obtained from the pyrolysis of PE/PP rich samples, are mainly composed of aromatics and do not show paraffins in their composition. The fact of the BIMU 8 is that the formation of aromatics strongly depends on the reactor design and the operating conditions used, and the generation of aromatic compounds even in the pyrolysis of pure polyolefins has been reported in the literature (e.g., ,  and ). The authors have also obtained oils with high contents of aromatics in the last years with the installation used for the pyrolysis of plastic mixtures (e.g., ,  and ), the same as the used for the production of the PO1 and PO2 samples. The installation used for the pyrolysis of plastic waste is not the same as the used for the experiments of the present paper, which is described in Section 2.2.
Table 4 shows the elemental composition and the HHV of the pyrolysis oils. Both samples are mainly composed of carbon and hydrogen, since they are at most hydrocarbon samples with few heteroatoms. Nevertheless, primary meristems must be pointed out that the chlorine content of both samples is quite high (0.8 wt.% and 0.9 wt.%), being the major disadvantage for the utilization of such pyrolysis oils. The H/C ratio of PO2 is lower than that of PO1, which is a consequence of the higher content of aromatics of PO2. HHV is very high for both samples, which clearly indicates their potential to be used as fuels provided that the rest of their properties allow it.