PETR 15 |
| Unsupported (Mo-W)S2 sulfide catalyst derived from (NH4)2 (Mox-W1-x) S4 (ATMW) bimetallic thiosalts precursors were prepared. The ATMW complexes were obtained from ammonium heptamolybdate and ammonium metatungstate in ammonia solutions in contact with flowing H2S gas. Bimetallic thiosalts with Mo/ (Mo+W) atomic ratios (R1) = 0.75, 0.85 and 0.95 (experimental values) were prepared. Activation of precursors as catalysts was made ex situ by treating the ATMW bimetallic precursor in 15% H2S/H2 gas mixtures at 400 °C four hours. The catalytic activity in the HDS of DBT was evaluated in a batch reactor at 623 K and 3.1 MPa. The (Mo-W)S2 bimetallic samples showed similar catalytic properties (5 - 5.8 x 10-7 mol/s.g) among them but higher activity and selectivity for hydrogenation than MoS2 (4 - 4.5 x 10-7 mol/s.g). Comparing these samples against the NiMoW trimetallic catalysts (23 x 10-7 mol/s.g), reported not long ago, we observed a lower activity but higher selectivity to hydrogenation. We conclude that a small synergistic effect due to addition of W in MoS2 occurred, however it is much smaller than the effect obtained when Ni is added as in the case of trimetallics. |
|
2nd International Symposium on Hydrotreating/Hydrocracking Technologies
1:30 PM-4:30 PM, Sunday, 10 September 2006 Palace -- Presidio Room, Oral
Division of Petroleum Chemistry |