Petroleum residue upgrading with dispersed catalysts Part 2. Effect of operating conditions

The hydrotreatment of a petroleum residue in the presence of dispersed moly bdenite was carried out within a wide range of operating conditions and cat alyst loading. The effect of reaction severity as well as of molybdenum con centration on product distribution and quality was studied. Based on the ex perimental results, a simplified reaction scheme was proposed. The hydropro cessing of the residue was described in terms of the competition between tw o reactions: the direct conversion of the feedstock to distillate and coke, and the catalytic hydrogenation. Compared to thermal conditions, the prese nce of dispersed molybdenite controls very well coke formation; however, a trend of increasing formation of solids was observed at high catalyst conce ntrations. The overall upgrading of the feedstock requires significant amou nts of molybdenum as well as relatively high hydrogen pressure. (C) 2000 El sevier Science B.V. All rights reserved.