Effects of H2S on hydrodesulfurization of dibenzothiophene and 4,6-dimethyldibenzothiophene on alumina-supported NiMo and NiW catalysts

Citation
T. Kabe et al., Effects of H2S on hydrodesulfurization of dibenzothiophene and 4,6-dimethyldibenzothiophene on alumina-supported NiMo and NiW catalysts, APP CATAL A, 209(1-2), 2001, pp. 237-247
Citations number
26
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics","Chemical Engineering
Journal title
APPLIED CATALYSIS A-GENERAL
ISSN journal
0926-860X → ACNP
Volume
209
Issue
1-2
Year of publication
2001
Pages
237 - 247
Database
ISI
SICI code
0926-860X(20010228)209:1-2<237:EOHOHO>2.0.ZU;2-C
Abstract
Effects of the H2S partial pressure on the catalytic activity and product s electivity of the hydrodesulfurization (HDS) reactions of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) were investigated over t he sulfided NiMo/Al2O3 and NiW/Al2O3 catalysts under the deep desulfurizati on conditions (sulfur concentrations <0.05 wt.%). The inhibiting effects of H2S were observed in the HDS reactions of both DBT and 4,6-DMDBT. The HDS reaction of DBT was more strongly inhibited by H2S than that of 4,6-DMDBT o ver each catalyst. The formations of both biphenyls (BPs) and cyclohexylben zenes (CHBs) were inhibited by H2S, but the former were inhibited more stro ngly. The NiMo/Al2O3 catalyst was less susceptible to the inhibiting effect of H2S than the NiW/Al2O3 catalyst. The promotion of Ni on NiMo catalyst r educed the inhibiting effect of H2S on the HDS activity. The HDS reactions were expressed by the Langmuir-Hinshelwood rate equation to examine the mec hanisms of the inhibiting effects of H2S over the various catalysts. Over e ach catalyst, the heats of adsorption increased in the order DBT < 4,6-DMDB T < H2S. Since H2S was adsorbed on the catalyst more strongly than DBTs, th e HDS reactions of DBTs were inhibited. (C) 2001 Elsevier Science B.V. All rights reserved.