2018 Volume 61 Issue 6 Pages 323-331
Steam has good potential as a hydrogen source for upgrading of heavy oil. Catalytic cracking of petroleum residual oil with steam was examined using iron oxide-based catalysts containing zirconium and aluminum. After the lattice oxygen of iron oxide reacted with the heavy fractions, oxygen species were supplied to the iron oxide lattice from steam and reacted with heavy oil to produce light oil, residue, and carbon dioxide. Hydrogen species were also generated from steam and supplied to form light oil, preventing alkene generation. Sulfur compounds in the residual oil were reacted with the hydrogen species to form hydrogen sulfide. The compositions of iron, zirconium, and aluminum were not homogeneous in the catalyst. No coke was deposited in regions where the main component was iron oxide. Oxidative cracking of heavy fractions effectively occurred around such regions. Iron oxide-based catalyst containing zirconium and aluminum showed durable activity for the cracking of residual oil under a steam atmosphere.