Performance comparison of tire pyrolysis oils in hydrotreating toward high-quality fuel

Hydrotreating is a process that uses existing refining facilities to upgrade waste tire pyrolysis oils, containing high amounts of bio-carbon, by reducing heteroatoms (e,g,. nitrogen, sulfur and oxygen) and aromatics content. A Ni − Mo/ γ − Al 2 O 3 catalyst was used to assess hydrotreating reactivity differences between three tire pyrolysis oils and a petroleum straight run vacuum gas oil in a semibatch reactor at 140 bar for four hours at three different temperatures ranging from 352 °C to 397 °C. Hydrodenitrogenation performance for tire pyrolysis oils is higher than their vacuum gas oil counterpart despite their larger content of nitrogen in the feed. Hydrodesulfurization conversion is similar for all the studied tire pyrolysis oils with temperature having a stronger effect on vacuum gas oil. For hydrodeoxygenation, residual oxygen was low ( < 0.1 wt%) for all tire pyrolysis oils. The conversion of aromatic carbon content for tire pyrolysis oils (10%–25%) is significantly reduced compared to vacuum gas oil (55 %). On a feedstock basis, vacuum gas oil, containing less light hydrocarbons (370 °C -), yields higher amounts of bottom residues (370 °C +). Meanwhile, tire pyrolysis oils produce more naphtha and kerosene products as temperatures increase. Hydrogen consumption calculation shows that TPOs require increased quantities of hydrogen compared to VGO. • Tire pyrolysis oils containing higher nitrogen compounds exhibit a higher hydrodenitrogenation conversion. • Similar performance in hydrodesulfurization of tire pyrolysis oil and fossil feed. • Tire pyrolysis oils have a lower aromatic ring hydrogenation than that of fossil feed. • In hydrodeoxygenation, the oxygen impurities in tire pyrolysis oils were successfully reduced while fossil feed was not studied due to its negligible oxygen content. • Tire pyrolysis oils produces more economically interesting lighter fractions (naphtha, kerosene and diesel) compared to fossil feed.