Dibenzothiophene, HDS

In support of this suggestion, Kabe and co-workers have demonstrated that phenanthrene is a fairly strong inhibitor of the hydrogenation site in dibenzothiophene HDS (128). However, in gas oils other trace components such as nitrogen- and oxygen-containing materials can be even stronger... 

Figure 1 Plot of the rates of dibenzothiophene HDS as a function of the transition metal sulfide catalyst. (Reprinted from Ref 19. 1981, with permission from Elsevier)...

The activity and selectivity of 12.5% M0/AI2O3 nitrided at various temperatures for the hydrodesulfurization (HDS) of dibenzothiophene and the effect of re-treatment of NH3 on dibenzothiophene HDS were studied. The nitrided catalyst was significantly more active toward the scission of the C-S bond from dibenzothiophene with hydrogenation of dibenzothiophene. The sulfur species accumulated on the surface of the nitrided M0/AI2O3 catalysts by replacement of nitrogen species after reaction was analyzed by XPS measurement. The formation of molybdenum sulfide during the HDS dibenzothiophene led to a decrease in the activity of the nitrided catalyst, which approached that of the sulfided catalyst. 

The activities of nitrided catalysts for dibenzothiophene HDS versus time are shown in Fig. 1. The LTN catalyst was 1.5 and 1.6 times more active than MTN and HTN... 

The major product was biphenyl with a small amount of cyclohexylbenzene in dibenzothiophene HDS on the nitrided catalysts. In the scheme of the HDS of... 

The acid sites of iron-exchanged Y zeolite were studied using NH3-TPD and diffuse reflectance FTIR spectroscopy. The Bronsted acids of three iron-exchanged Y zeolites were correlated with the activity for dibenzothiophene HDS at 240 and 280°C and 10.1 MPa. The FTIR data on NH3 and NO adsorption showed that Fe ions on the zeolites was correlated with their activities during dibenzothiophene HDS. 

The effect of biphenyl addition on dibenzothiophene HDS on the MTN catalyst at the steady state was studied in order to determine whether biphenyl was hydrogenated to form... 

Fig. 4. The addition of (B) diethyl sulfide to dibenzothiophene HDS on LTN catalyst at 553 K. (A) No additioa...

Fig. 11. NEXAFS spectra at the C K-edge of an unsupported M0S2 sample treated under dibenzothiophene HDS conditions and a /S-Mo2C. Reprinted from Ref. (102). Copyright 2001, with permission from Elsevier...

Sulfur removal is accomplished directly by a hydrogenolysis mechanism or indirectly by prior hydrogenation. Figure 13.6 shows the two possible pathways for dibenzothiophene HDS. In the direct route, the S-atom is eliminated and replaced by hydrogen. The other mechanism requires saturation of one... 

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