Effect of water on HDS of DBT over a dispersed Mo catalyst using in situ generated hydrogen

Lee, Roy Z.; Ng, Flora T. T.

doi:10.1016/j.cattod.2006.06.032

Cited by 27 publications

(8 citation statements)

References 8 publications

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“…Potential of H 2 O as free radicals scavenger in noncatalytic reactions (reactions {5} to {8} in Figure ) was indicated earlier. The overwhelming evidence for the presence of reforming and WGS reactions was clearly confirmed in several studies. − …”

Section: Hydroprocessing Mechanism In Aqueous Phasementioning

confidence: 73%

“…Even in the CO 2 + H 2 + SCW system, the rate of reaction was higher than in H 2 + SCW. When the feed was partially oxidized in situ in SCW to generate CO, the conversion of several reactants (e.g., DBT, carbazole, quinolin and naphthalene) involving the HYD route was higher than in H 2 + SCW. − ,− The involvement of H + ions during the HPR of residues in SCW, as part of ionic reactions (e.g., reactions {13} and {14}) was anticipated above. Under the conditions of conventional HPR, the final stages of HDO , and HDN, − that is, elimination of oxygen and nitrogen from the last intermediates, respectively were interpreted in terms of a proton transfer from catalyst to the intermediate.…”

Section: Hydroprocessing Mechanism In Aqueous Phasementioning

confidence: 93%

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Hydroprocessing in Aqueous Phase

Furimsky¹

2013

Ind. Eng. Chem. Res.

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A large consumption of H 2 affects the overall economy of conventional hydroprocessing. The costs can be decreased by using water as the source of active hydrogen. This can be achieved under subcritical and supercritical water conditions providing that an active and stable catalyst is developed. Hydroprocessing in aqueous phase has been studied for potential applications in upgrading of high oxygen content feeds and heavy petroleum feeds to liquid hydrocarbons. The feeds were tested at temperatures ranging from less than 200 to 500 °C and total pressure from 1 to 30 MPa. These conditions cover subcritical and supercritical regions of water. Water takes part in hydroprocessing reactions as a free radical scavenger and a hydrogen donor. Hydrogen generated in situ via partial reforming and water−gas shift reactions is more reactive than external hydrogen. Catalyst development for hydroprocessing in aqueous phase has been receiving much attention. High performance was observed over the catalysts containing noble metals (Pt, Pd, Ru, and Rh) supported on various supports; however, the information on a long-term stability of these catalysts is limited.

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Section: Hydroprocessing Mechanism In Aqueous Phasementioning

confidence: 73%

Section: Hydroprocessing Mechanism In Aqueous Phasementioning

confidence: 93%

Hydroprocessing in Aqueous Phase

Furimsky¹

2013

Ind. Eng. Chem. Res.

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“…Also, hosseipour et al [8] proposed that the water dissociation on the surface of a catalyst, in the case of SCW catalytic cracking, is another source for the creation of in-situ hydrogen. It is reported that this kind of hydrogen is more active than molecular hydrogen for hydrogenation of heavy oils in sub and supercritical water [9,10]. The oxygen required for oxidative cracking, CO production, and finally the formation of in-situ hydrogen can be supplied by air [11], hydrogen peroxide [12], or lattice oxygen of the catalyst in the case of catalytic cracking [8].…”

Section: Introductionmentioning

confidence: 99%

Catalytic cracking of heavy petroleum residue in supercritical water: Study on the effect of different metal oxide nanoparticles

Golmohammadi

Ahmadi

Towfighi

2016

The Journal of Supercritical Fluids

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Please cite this article as: Morteza Golmohammadi, Seyed Javad Ahmadi, Jafar Towfighi, Catalytic cracking of heavy petroleum residue in supercritical water: study on the effect of different metal oxide nanoparticles, The Journal of Supercritical Fluids http://dx. Highlights CeO 2 , Co 3 O 4 , and MnO 2 nanoparticles were synthesized in a batchwise SCW reactor. The ability of different nanocatalysts in upgrading of vacuum residue (VR) was examined. CeO 2 exhibited the best performance from the reaction yield as well as the catalytic stability point of view. Stability and catalytic activity of CeO 2 was evaluated after two successive experiment runs. Appropriate performance of CeO 2 can be ascribed to its redox property and high value of total OSC. AbstractCracking of heavy petroleum residue obtained from the vacuum distillation unit in supercritical water (SCW) was performed with and without catalysts. First, different nanoparticles, including CeO2, Co3O4, and MnO2 were synthesized in a batchwise SCW reactor; then, the abilities of aforementioned nanocatalysts to convert vacuum residue (VR) into the lighter fractions as well as their stability under severe condition of supercritical water were examined. The X-ray diffractometery (XRD) and transmission electron microscopy (TEM) images indicated that the obtained nanoparticles with a satisfactory size and morphology were synthesized under supercritical condition. VR cracking experiments were also conducted in a batchwise reactor under operating condition, namely temperature: 450 o C, reaction time: 60 min, catalyst/oil ratio (g/g): 1/5, and water/oil ratio (g/g): 80/3. The performance of different nanocatalysts was compared based on the yield of maltene, coke, and asphaltene obtained from VR cracking. As a result, it was determined that the efficiency of nanocatalysts in VR cracking diminishes in the order of CeO2> Co3O4> MnO2, while the non-catalytic cracking or SCW pyrolysis attained the lowest rank with a slight difference with the case of MnO2. Moreover, the XRD was utilized to investigate the stability of different catalysts. The results demonstrated that only CeO2 was stable, whereas the other catalysts were reduced to the lower oxidation states during the reaction.Nevertheless, the scanning electron microscopy (SEM) image and the Brunauer−Emmett−Teller (BET) surface area of spent CeO2 showed the agglomeration of nanoparticles after the reaction.

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“…Upon comparison of the hydrogen addition runs S2–S4, it is evident that the presence of water inhibits the desulfurization process. Water is known to inhibit desulfurization reactions during upgrading processes . The difference in the percent desulfurization of the two runs S2 (15%) and S4 (2%) shows a clear inhibition of the process by water.…”

Section: Resultsmentioning

confidence: 94%

“…Water is known to inhibit desulfurization reactions during upgrading processes. 44 The difference in the percent desulfurization of the two runs S2 (15%) and S4 (2%) shows a clear inhibition of the process by water. When a catalyst was used in the presence of water in run S5, the desulfurization was improved from 2% (S4) to 6% (S5).…”

Section: Industrial and Engineering Chemistry Researchmentioning

confidence: 96%

Novel Deep Eutectic Solvent-Dissolved Molybdenum Oxide Catalyst for the Upgrading of Heavy Crude Oil

Shuwa

Al‐Hajri

Jibril

et al. 2015

Ind. Eng. Chem. Res.

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A MoO 3 /deep eutectic solvent (DES) catalyst precursor solution was prepared by dissolving molybdenum trioxide in a DES based on choline chloride/urea. The catalyst precursor solution was characterized for its physical and chemical properties. The characterization results showed almost no change in the DES properties after the addition of MoO 3 . The solution was used in the catalytic upgrading reaction of heavy crude oil. The performance of the catalyst was analyzed by gas chromatography−mass spectrometry, Fourier transform infrared, and viscosity measurements of the heavy oil before and after the reaction. The use of the catalyst in the catalytic aquathermolysis showed an increase in the oil viscosity. In the presence of hydrogen and catalyst, the results showed a 43% reduction in the heavy oil viscosity, a 2.5°increase in the API gravity, and 32 wt % sulfur reduction.

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Effect of water on HDS of DBT over a dispersed Mo catalyst using in situ generated hydrogen

Cited by 27 publications

References 8 publications

Hydroprocessing in Aqueous Phase

Hydroprocessing in Aqueous Phase

Catalytic cracking of heavy petroleum residue in supercritical water: Study on the effect of different metal oxide nanoparticles

Novel Deep Eutectic Solvent-Dissolved Molybdenum Oxide Catalyst for the Upgrading of Heavy Crude Oil

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