Hydrodesulfurization of sulfur heterocyclic compounds Reaction mechanisms

Singhal, Gopal H.; Espino, R.L.; Sobel, J.E.

doi:10.1016/0021-9517(81)90304-3

Cited by 61 publications

(11 citation statements)

References 17 publications

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“…Much attention has been focused on the deep desulfurization of light gas oil (LGO). In hydrodesulfurization (HDS) reactions, the importance of polyaromatic sulfur-containing compounds (PASC) such as benzothiophene (BT) and dibenzothiophene (DBT) has already been noted (Gates et al, 1979;Kilanowski and Gates, 1980;Broderick and Gates, 1981;Singhal et al, 1981;Vrinat and de Mourgues, 1982;Vriant, 1983;Girgis and Gates, 1991;Kabe et al, 1991Kabe et al, , 1992. Moreover, it has been reported that methyl-substituted BTs and DBTs are more difficult to desulfurize than nonsubstituted ones.…”

Section: Introductionmentioning

confidence: 99%

Deep Hydrodesulfurization of Light Gas Oil. 1. Kinetics and Mechanisms of Dibenzothiophene Hydrodesulfurization

Kabe

Akamatsu

Ishihara

et al. 1997

Ind. Eng. Chem. Res.

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Hydrodesulfurization (HDS) of light gas oil was investigated using sulfided Co-Mo/Al 2 O 3 catalyst. The behavior of dibenzothiophene, monomethyldibenzothiophenes (C1-DBTs) and dimethyldibenzothiophenes (C2-DBTs) in HDS was traced under the following conditions: temperature, 280-400 °C; LHSV, 2-10 h -1 ; and gas/oil, 1000 and 125 NL (L-(NTP))/L. The HDS of these compounds was treated as a pseudo-first-order reaction. The ratio of the rate constants of 4-methyldibenzothiophene (4-MDBT) and DBT to that of 4,6-dimethyldibenzothiophene (4,6-DMDBT) diminished relative to those of the model reactions. The activation energies of DBTs increased in the order DBT < 4-MDBT < 4,6-DMDBT, while the differences between values diminished relative to those of HDS reactions using a single component among DBT, 4-MDBT, and 4,6-DMDBT. The retarding effect of H 2 S on HDS decreased in the order DBT > 4-MDBT, and further, 4,6-DMDBT was not inhibited. The results indicated that the selectivity for biphenyls in the HDS of DBT was higher than in the HDS of 4-MDBT or 4,6-DMDBT and that DBT and 4-MDBT were adsorbed by the catalyst more weakly than 4,6-DMDBT. An aromatic hydrocarbon of larger ring number has a stronger retarding effect on the HDS rate. The addition of phenanthrene decreased the HDS rate of DBTs in the order DBT > 4-MDBT > 4,6-DMDBT, while 1-methylnaphthalene did not affect the HDS rate. The effect of phenanthrene on the HDS rate appeared to be related to the differences in the adsorption ability of DBTs. To the contrary, the addition of acridine decreased HDS rate in the order 4,6-DMDBT > 4-MDBT > DBT. The results indicate that the retarding effect of acridine is different from that of phenanthrene.

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Section: Introductionmentioning

confidence: 99%

Deep Hydrodesulfurization of Light Gas Oil. 1. Kinetics and Mechanisms of Dibenzothiophene Hydrodesulfurization

Kabe

Akamatsu

Ishihara

et al. 1997

Ind. Eng. Chem. Res.

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“…Besides, considerable quantities of other valuable products such as benzene, toluene and xylenes (BTX) are also witnessed. These products might originate from the decomposition of biphenyl, which is also observed as a product and widely reported in the direct desulfurization (DDS) pathway of the HDS process, indicating the presence of DDS reactions 24 . Other detectable products include benzene and biphenyl derivatives with various side chain substituents, which might be generated through alkylation reactions.…”

Section: Main Textmentioning

confidence: 59%

“…Other detectable products include benzene and biphenyl derivatives with various side chain substituents, which might be generated through alkylation reactions. However, typical products generated from the hydrogenation (HYD) pathway of the HDS process such as cyclohexylbenzene are not observed, con rming the absence of HYD reactions in the MDS process 24 . Besides, the presence of high boiling point soluble products con rmed by simulated distillation (Fig.…”

Section: Main Textmentioning

confidence: 98%

Methane-Assisted Catalytic Desulfurization in an Environmentally Benign Way

Song¹,

Xu²,

He³

et al. 2021

Preprint

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Petroleum is one of the most important natural resources for human beings, while the contained sulfur heteroatoms lead to a series of problems1. Therefore, a desulfurization process to reduce sulfur content is mandatory for clean petroleum utilization. Hydrodesulfurization is currently mature in industry, while this process is costly, energy intensive and environmentally unfriendly due to CO2 emission and H2S production2,3. Alternative cost-effective desulfurization process with environmentally benign sulfur-containing products remains unreported. Here we demonstrate that the desulfurization of a heavy oil model compound dibenzothiophene can be successfully achieved under methane environment over creatively designed dual catalyst system, generating a new sulfur-containing product CS2. Control experiments indicate that the presence of methane as well as catalyst components for direct desulfurization and methane activation are all required. The reaction process is better understood by extensive evidences from isotope labeling experiments, catalyst and product characterizations, density functional theory calculations and verification experiments, based on which a reasonable catalytic mechanism is proposed. It is found that methane-assisted desulfurization requires more stringent conditions, where sulfur vacancy abundance, methane activation capability and surface sulfur transfer are all indispensable. This study pioneers a transformational desulfurization route, which is more economically and environmentally attractive for petroleum processing industry.

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“…As to desulfurization, the results can be understood by the fact that sulfur atoms do not substantially exist in aromatic rings, and the active sites for desulfurization are different or separate from the ones for nuclear hydrogenation as many researchers have pointed out − multipoint adsorption …”

Section: Resultsmentioning

confidence: 99%

Heavy Oil Hydroprocessing with the Addition of Hydrogen-Donating Hydrocarbons Derived from Petroleum

Kubo

Higashi²,

Ohmoto³

et al. 1996

Energy Fuels

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The effects of the addition of hydrogen-donating hydrocarbons derived from petroleum were tested in a pilot plant (0.01 bbl/day) equipped with a downflow fixed bed reactor for the hydroprocessing of atmospheric residues, and the following results were obtained: (1) HHAP (partly hydrogenated product of a highly aromatic heavy fraction from petroleum) and HAP (highly aromatic heavy fraction prior to the hydrogenation to produce HHAP) were effective to reduce coke formation and hydrogen consumption. (2) A particular and effective mechanism resulting from the configurations of the additives was found to be initiated by the addition of these additives. (3) This mechanism was substantiated by detailed analyses of the products.

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Hydrodesulfurization of sulfur heterocyclic compounds Reaction mechanisms

Cited by 61 publications

References 17 publications

Deep Hydrodesulfurization of Light Gas Oil. 1. Kinetics and Mechanisms of Dibenzothiophene Hydrodesulfurization

Deep Hydrodesulfurization of Light Gas Oil. 1. Kinetics and Mechanisms of Dibenzothiophene Hydrodesulfurization

Methane-Assisted Catalytic Desulfurization in an Environmentally Benign Way

Heavy Oil Hydroprocessing with the Addition of Hydrogen-Donating Hydrocarbons Derived from Petroleum

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