An Active Carbon Catalyst Prevents Coke Formation from Asphaltenes during the Hydrocracking of Vacuum Residue

Fukuyama, Hidetsugu; Terai, Satoshi

doi:10.1080/10916460601054693

Cited by 21 publications

(11 citation statements)

References 8 publications

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“…Moreover, it has been suggested that an ACsupported catalyst limited the condensation reactions of asphaltenes that led to coke formation by providing adsorption sites to the free radicals, thus avoiding polymerisation reactions [49].…”

Section: >450°c and Asphaltene Conversionmentioning

confidence: 99%

Carbon nanofibres coated with Ni decorated MoS2 nanosheets as catalyst for vacuum residue hydroprocessing

Pinilla

Purón

Torres

et al. 2014

Applied Catalysis B: Environmental

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Catalysts based on functionalised carbon nanofibers (FCNF) coated with Ni-decorated MoS 2 nanosheets were obtained by direct decomposition of ammonium thiomolybdate and nickel nitrate impregnated on the FCNF under controlled temperature conditions in inert atmosphere. The catalysts were characterised by X-ray Diffraction (XRD), N 2 adsorption, Raman spectroscopy, temperature programmed reduction of sulfur species (TPR-S), NH 3 temperature programmed desorption (NH 3 -TPD) and transmission electron microscopy (TEM). Decomposition temperature was found to have a paramount importance in the formation of uniform MoS 2 slabs, as revealed by the TEM study: at 600 °C, non-uniform covering of the carbon nanofiber (CNF) was observed Higher asphaltene conversions were obtained for the CNF-supported catalysts prepared at 450 °C, which overperformed the Al 2 O 3 -supported benchmark catalyst. However, the catalytic performance in hydrodesulfurisation and hydrodemetallisation of the CNFbased catalysts was slightly lower than that of the benchmark catalyst.

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Section: >450°c and Asphaltene Conversionmentioning

confidence: 99%

Carbon nanofibres coated with Ni decorated MoS2 nanosheets as catalyst for vacuum residue hydroprocessing

Pinilla

Purón

Torres

et al. 2014

Applied Catalysis B: Environmental

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“…According to the literature, the activated carbon high surface area, variable pore structure, and surface functional groups are advantageous to prepare high quality products under mild conditions. 12,73,74 The upgrading of bitumens using activated carbon catalysts was investigated by Scott in hydrogen-rich solvents under supercritical states. 12 The solvents used are shown in Table 4.…”

Section: Current Progress Of the Research On Upgrading Using Catalystsmentioning

confidence: 99%

“…76 Besides, the free radicals initially generated from asphaltene pyrolysis can diffuse in the mesopores and can be adsorbed on the active sites to prevent condensation. 73…”

Section: Current Progress Of the Research On Upgrading Using Catalystsmentioning

confidence: 99%

A review of upgrading heavy oils with supercritical fluids

Yan

Wang

et al. 2015

RSC Adv.

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“…10 However, polycondensation and dehydrogenation of naphthenes are largely dependent upon the operating conditions and can be minimized by high hydrogen partial pressures and hydrogenation catalysts. 11,12 Recent advances in ultrahigh-resolution mass spectrometry have significantly improved our knowledge of the compositional characteristics of crude-oil-related materials, including asphaltenes. 13−17 Ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) enables the characterization of thousands of compounds present in these complex mixtures, giving the capability to identify compositional differences otherwise undetectable using conventional techniques.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Also, an increase in internal carbons in aromatic structures during hydrodemetallization experiments has been reported and can be attributed to aromatization of naphthenic ring systems as well as the condensation of hydrocarbon free radicals . However, polycondensation and dehydrogenation of naphthenes are largely dependent upon the operating conditions and can be minimized by high hydrogen partial pressures and hydrogenation catalysts. , …”

Section: Introductionmentioning

confidence: 99%

Asphaltene Characterization during Hydroprocessing by Ultrahigh-Resolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Rogel

Witt

2017

Energy Fuels

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Asphaltenes have a significant impact on the hydroprocessing of residues because they adversely affect the overall rate of hydroprocessing reactions. They also act as coke precursors, leading to catalyst deactivation. Understanding the changes of asphaltenes upon conversion can provide essential clues to the development and optimization of residue conversion processes. In this work, we use ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (positive-ion mode atmospheric pressure photoionization) to follow asphaltene changes during the hydroprocessing of a residue. Asphaltenes were extracted from the feed and from two different products sampled at various times during the run. Results indicate that intensities for hydrocarbon classes and N-containing classes increase for the processed asphaltenes, while the abundance of S classes decreases. Similar results are found when the number of peak assignments is compared. The average double-bond equivalent (DBE) increases as a function of time on stream, which is usually associated with cyclization and aromatization reactions. However, the disappearance of molecules with low DBE as well as molecules with large DBE points to preferential cracking/ hydrogenation of molecules in both regions. A small decrease in average molecular sizes is observed as a function of time on stream. In general, molecular size distributions for different DBEs are narrower for the products than for the feed. The distributions also point to the disappearance of the largest molecules from the products in accordance with the preferential cracking previously reported for large molecules under hydroprocessing conditions. Analyses of the more abundant classes revealed trends that vary depending upon the type of heteroatoms as well as their relative amount within the molecules.

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An Active Carbon Catalyst Prevents Coke Formation from Asphaltenes during the Hydrocracking of Vacuum Residue

Cited by 21 publications

References 8 publications

Carbon nanofibres coated with Ni decorated MoS2 nanosheets as catalyst for vacuum residue hydroprocessing

Carbon nanofibres coated with Ni decorated MoS2 nanosheets as catalyst for vacuum residue hydroprocessing

A review of upgrading heavy oils with supercritical fluids

Asphaltene Characterization during Hydroprocessing by Ultrahigh-Resolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

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