PAH presence in oils and tars from coal–tyre coprocessing

Gas chromatography–mass spectrometry (GC–MS) after fractionation into four chemical fractions using adsorption chromatography by open column has been used to identify and quantify Polycyclic Aromatic Hydrocarbons (PAH) in different conversion liquids: in two oils obtained at the same conditions from hydropyrolysis of coal–tyre (1:1) but in different reactors (tubing-bomb and autoclave reactors) and in a tar from hydropyrolysis of coal in a swept-fixed bed reactor. Structural identifications were based on a combination of chromatographic retention and mass spectral fragmentation data. Thin layer chromatography with flame ionization detector (TLC-FID) has been applied as well in order to see the influence of the analytical tool on the liquids nature. It can be concluded that the PAH formation and detection in the synthetic oils is not only a function of the reactor type but also is depending of the analytical technique and, within the same analytical technique, on the adsorbent used to fractionate them as well.