Effects of Solvents on Deep Hydrodesulfurization of Benzothiophene and Dibenzothiophene

Ishihara, Atsushi; Itoh, Toshiyuki; Hino, Taro; Nomura, Masatoshi; Qi, Pengxu; Kabe, Toshiaki

doi:10.1006/jcat.1993.1077

Cited by 54 publications

(30 citation statements)

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“…Thus, in the absence of solvent, the P-free catalyst showed a higher HDS activity than NiMo/Al 2 O 3 reference catalyst being the most active catalyst modified with 1 wt.% of P. To see if we could improve the catalyst activity we conducted the DBT HDS test by using a mixture of DBT and solvent (n-hexadecane and p-xylene (90/10 %/%). Figure 6 [2,[47][48][49]. Taking into account that the solvent composition was 90% of n-hexadecane and only 10% of p-xylene, the inhibition of HDS reaction should be mainly due to n-hexadecane.…”

Section: Effects Of Solvent and Carbazole On The Dbt Hdsmentioning

confidence: 99%

Competitive HDS and HDN reactions over NiMoS/HMS-Al catalysts: Diminishing of the inhibition of HDS reaction by support modification with P

Zepeda¹,

Pawelec

Obeso–Estrella³

et al. 2016

Applied Catalysis B: Environmental

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Graphical abstract Abstract Individual and simultaneous hydrodesulfurization (HDS) of dibenzothiophene (DBT) and hydrodenitrogenation (HDN) of carbozole reactions have been studied in the presence of hydrogen (P=55 bar) at 310 ºC in a batch reactor over a series of sulfided NiMo/P/Al-HMS catalysts modified with phosphorus (0.5-2.0 wt.%). Both oxidic precursors and sulfide catalysts have been characterized by specific surface area, XRD, Raman, TPD-NH 3 , HRTEM, XPS and IR spectroscopy of adsorbed pyridine.Regardless of the reaction studied, all P-containing catalysts showed higher activity than that to the P-free one. The catalyst modified with optimized amount of P (1 wt.%) the best HDS activity and exhibited a lowest inhibition factor during simultaneous HDS and HDN, which was close to that of a commercial NiMo/Al 2 O 3 sulfide catalyst. This was linked with formation of irregular MoS 2 structures having high concentration of brim sites as well as with its largest total acidity.

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Section: Effects Of Solvent and Carbazole On The Dbt Hdsmentioning

confidence: 99%

Competitive HDS and HDN reactions over NiMoS/HMS-Al catalysts: Diminishing of the inhibition of HDS reaction by support modification with P

Zepeda¹,

Pawelec

Obeso–Estrella³

et al. 2016

Applied Catalysis B: Environmental

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“…HDS is the central process to remove sulphur from crude oils. There are several ways to prepare these catalysts, like comaceration [29], homogeneous sulphide precipitation [14], hydrothermal and solvothermal processes [30][31][32][33][34], solution reactions [35,36] and thiosalt decomposition [37][38][39]. With the decomposition of thiotungstates a high sulphur content can be achieved in the final WS 2 catalysts [40,41].…”

Section: Ws 2 Catalysts Are Promoted Mostly With Cobalt or Nickel Andmentioning

confidence: 99%

Thermal decomposition of ammonium tetrathiotungstate

Hunyadi

Ramos

Szilágyi

2015

J Therm Anal Calorim

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The thermal decomposition of ammonium tetrathiotungstate (ATT), (NH 4 ) 2 WS 4 was studied by SEM, FTIR, XRD, EDX and TG/DTA-MS. The decomposition of ATT involved three steps in inert atmosphere: (i) release of free water between 30-140 °C; (ii) formation of an amorphous WS 3 phase between 170-280 °C, from which (iii) a slightly crystalline WS 2 formed between 330-470 °C. As a difference compared to inert atmosphere, in air in the second step the ATT decomposed into directly WS 2 instead of WS 3 . This WS 2 phase was amorphous, and still contained traces of ATT. Between 260-2 500 °C from the WS 2 monoclinic tungsten oxide crystallized in two steps: at 302 °C a slightly crystalline m-WO 3 formed, which became more crystalline at 471 °C. During the investigation of the effect of the particle size, it was found that the thermal behaviour of ATT crystals was similar to ATT powder, with some shift in the decomposition temperature. The XRD results showed that the WS 2 formed from the ATT powder in N 2 had a higher level of crystallization, compared to the WS 2 obtained from ATT crystals.

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“…Laboratory-scale studies have been performed in pressurized flow [21] and batch reactors [22,23]. By using batch reactors, useful information such as HDS activity and selectivity (HYD/DDS) can be obtained by following the composition of the reaction mixture.…”

Section: Methodsmentioning

confidence: 99%

Synthesis, Characterization and HDS Activity of Carbon-Containing Ni–Mo Sulfide Nano-Spheres

et al. 2009

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Ni-promoted tetramethylammonium tetrathiomolybdate precursor was prepared by the aqueous solution precipitation method using (NH 4 ) 2 MoS 4 , (CH 3 ) 4 NBr and NiCl 2 .6H 2 O as raw materials. Carbon-containing Ni-Mo sulfide nanospheres, namely Ni/C 1 -MoS 2 , were obtained by ex situ thermal decomposition of the precursor under N 2 atmosphere. Energy dispersive X-ray spectroscopy (EDS), low temperature N 2 adsorption (BET method), X-ray diffraction (XRD), scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) techniques were employed to characterize these as-synthesized sulfide particles. The results showed that the average size of solid Ni-Mo sulfide nanospheres, with surface composition MoNi 0 . 40 S 0 . 73 C 1 . 43 , is 75 nm and the solid structure leads to low surface area of Ni/C 1 -MoS 2 . In addition, the introduction of methyl chain improved the dispersion of nickel phases and resulted in C/Mo ratio, 1.4. By comparison with catalytic performance of the Ni/MoS 2 catalyst counterpart, Ni/C 1 -MoS 2 revealed lower HDS activity but higher direct desulfurization (DDS) selectivity. Lower stacking number of MoS 2 slabs (5 layers) and shorter slabs length of MoS 2 slabs (6 nm) explained higher DDS selectivity satisfactorily. The formation of carboncontaining Ni-Mo sulfide nanospheres was possibly due to surfactant effect of tetramethylammonium cations and the potential measure to increase their surface area was discussed as well in this work.

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Effects of Solvents on Deep Hydrodesulfurization of Benzothiophene and Dibenzothiophene

Cited by 54 publications

References 0 publications

Competitive HDS and HDN reactions over NiMoS/HMS-Al catalysts: Diminishing of the inhibition of HDS reaction by support modification with P

Competitive HDS and HDN reactions over NiMoS/HMS-Al catalysts: Diminishing of the inhibition of HDS reaction by support modification with P

Thermal decomposition of ammonium tetrathiotungstate

Synthesis, Characterization and HDS Activity of Carbon-Containing Ni–Mo Sulfide Nano-Spheres

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