Behaviors of metal compounds during hydrodemetallization of atmospheric residue

Behaviors of vanadium and nickel species during hydrodemetallization (HDM) were studied. A Kuwait atmospheric residue and its hydrodemetallized products from a pilot plant at mild and severe reaction conditions were characterized by using GPC coupled with ICP-MS and high temperature GC-AED after separation of them into saturates, aromatics, resins, and asphaltenes. It was found that the HDM reactivity of the vanadium species, especially those with lower molecular weight, was higher than that of Ni species, probably due to the higher polarity of the former than the latter. HDM of the vanadium species in the asphaltene was more difficult than that in the resin. The average molecular weight of metal species through higher temperature HDM was higher than that through the lower temperature HDM, although the metal removal at the higher temperature is higher. (C) 2016 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.