Effects of Solvents in Deep Desulfurization of Benzothiophene and Dibenzothiophene

Abstract

Solvent effects on hydrodesulfurization of benzothiophene (BT) and dibenzothiophene (DBT) catalyzed by Co–Mo/Al2O3 were investigated under deep desulfurization conditions by using Langmuir-Hinshelwood (L–H) rate law. Solvents affected heats of adsorption of thiophenes rather than activation energy of HDS. Activation energies of HDS and heats of adsorption of thiophenes and solvents were estimated from the kinetic data.

Competitive hydrodesulfurization of 4,6-dimethyldibenzothiophene, hydrodenitrogenation of 2-methylpyridine, and hydrogenation of naphthalene over sulfided NiMo/γ-Al2O3

“…This indicates that the adsorption of toluene is much weaker than that of the S-containing molecules. The results reported by Kabe et al [33] indicate that the effects of the solvent are more pronounced below 300 • C. At 300 • C, there was hardly any difference between n-heptane and xylene, which are very similar to the solvents used in our study. Moreover, the effects of the solvent were more pronounced at 0.1 than at 1 wt% DBT in the feed [34].…”

“…Aromatic hydrocarbons in fuels have a detrimental effect on the catalyst activity [32]. In a series of papers Kabe and Ishihara and co-workers discussed the influence of solvents on the activity and selectivity of a sulfided CoMo/Al 2 O 3 catalyst in the HDS of benzothiophene (BT) and DBT [33][34][35]. They found that the catalytic activity decreased in the order toluene > decalin > n-pentadecane > 1-methylnaphthalene in the HDS of BT and in the order n-heptane > xylene > decalin > tetralin in the HDS of DBT.…”

Solvent extraction of aromatic components from petroleum derived fuels: a perspective review

“…The influence of aromatic compounds on the HDS of diesel fuel has been investigated by many researchers. [16][17][18][19][20][21][22][23][24][25][26] Literature reveals conflicting results regarding the inhibiting effect of aromatics on HDS. Farag et al 19 and Looij et al 21 studied the effects of naphthalene, tetraline, crysene and pyrene on deep HDS of diesel and found that these polynuclear aromatics have a negligible inhibitory effect on HDS.…”

“…Farag et al 19 and Looij et al 21 studied the effects of naphthalene, tetraline, crysene and pyrene on deep HDS of diesel and found that these polynuclear aromatics have a negligible inhibitory effect on HDS. On the other hand, Steiner, 18 Kabe et al, 26 Koltai et al, 27 Song et al, 28 Isoda et al, 29 Chen et al, 30 and Egorova and Prins 31 found a strong inhibitory effect of aromatic compounds on deep HDS and also reported that the adverse effect was more pronounced for 4,6-dimethyl dibenzothiophene (4,6-DMDBT) than for DBT. The competitive adsorption between the sulfur compounds and aromatics on the catalyst surface was the main reason for the decreased HDS efficiency.…”

Catalytic desulfurization of residual oil through partial oxidation in supercritical water

“…Despite the different postulates about inhibiting effects on HDS rate are made, the developed rate equations are similar. Ishihara and co-workers [17,18] reported that, for HDS the adsorption heat of sulfides was significantly af- fected by various solvents, whereas the activation energy did not change obviously. In this work, the existence of SCW affects the HDS rate due to the competitive adsorption with other reactants, but it is difficult to make clear whether SCW has influence on the HDS mechanism.…”