No abstract

The behavior of a CeO 2 −ZrO 2 −Al 2 O 3 −FeO x catalyst typically employed during heavy oil decomposition was investigated in conjunction with the addition of H 2 O, as a means of improving the upgrading activity and suppressing coke formation on the catalyst. The upgrading of oil sand bitumen diluted with benzene was examined with this catalyst at various F H 2 O /F bitumen ratios [where F H 2 O is the water flow rate (g h −1 ) and F bitumen is the bitumen feedstock flow rate (g h −1 )] in a fixedbed flow-type reactor. Under optimal conditions (F H 2 O /F bitumen equal to approximately 20) and at a reaction temperature of 693 K, effective catalytic decomposition of the bitumen was observed with the lighter component (gas oil and vacuum gas oil) yield reaching 71 mol % C. In addition, the formation of coke on the catalyst was decreased to less than 14 mol % C. Analyses using quadrupole mass spectrometry determined that this catalyst upgrades the heavy oil through oxidation reactions, in which the lattice oxygen of the iron oxide is consumed and, subsequently, regenerated by the decomposition of water molecules over the catalyst.