Asphaltene cracking in catalytic hydrotreating of heavy oils. 1. Processing of heavy oils by catalytic hydroprocessing and solvent deasphalting

Takeuchi, Chisato; Fukui, Yoshio; Nakamura, Munekazu; Shiroto, Yoshimi

doi:10.1021/i200021a012

Cited by 57 publications

(17 citation statements)

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“…Dolbear et al (1987) observed a linear correlation between demetallization and residue conversion in a fixed bed hydrotreating reactor, whereas sulfur conversion was not correlated. Asphaltene content was correlated with metals removal in a study using a proprietary catalyst by Takeuchi et al (1983), but the extent of demetallization did not correspond to either conversion of asphaltenes or to sulfur removal. A survey of studies of resid upgrading which used size-exclusion chromatography with elemental detectors, class fractionation, and NMR found that these methods were limited to diagnosing process performance rather than prediction (Reynolds, 1989).…”

mentioning

confidence: 97%

The relationship between chemical structure and reactivity of alberta bitumens and heavy oils

Gray¹,

Jokuty²,

Yeniova³

et al. 1991

Can J Chem Eng

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Long residues (424°C +) from Athabasca, Cold Lake, Lloydminster, and Peace River were hydrocracked over a commercial NilMo on y‐alumina catalyst at 430°C, 13.9 MPa (2000 psia). The conversion of residue fraction ranged from 55 to 68%, and was correlated with the concentration of carbon bound to aromatic rings in the feeds. Conversions of sulfur, Micro‐Carbon Residue, and metals were all highest for Peace River feed, following the same ranking as residue conversion. Estimates for the breakage of carbon‐carbon bonds and the uptake of hydrogen were diagnostic in interpreting the reactor performance.

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mentioning

confidence: 97%

The relationship between chemical structure and reactivity of alberta bitumens and heavy oils

Gray¹,

Jokuty²,

Yeniova³

et al. 1991

Can J Chem Eng

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“…In catalytic hydroprocessing studies, Takeuchi (20) showed that the average molecular weight of the aromatic sheets in the liquid product was hardly influenced* Consistent with the above model, this means that cracking takes place without attacking the individual aromatic sheets. It is further observed that the nitrogen left in the resulting product molecules is very refrac tory, another indication that the aromatic sheets and demetallized porphyrins have not been attacked.…”

Section: Basic Process Selection Considerationsmentioning

confidence: 59%

Modes of Operation in Hydrodemetallization

Dautzenberg

Deken

1987

ACS Symposium Series

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Some important chemical and engineering principles are examined in this paper to provide a basis for comparing various bottom-of-the-barrel process alternatives. The extent of how successfully the various hydroconversion approaches can cope with asphaltene conversion and metal removal is examined. Typical representative hydrogen-addition technologies are compared, including fixed-bed (FBR), back-mixed (BMR), and liquid-phase reactor approaches.The emphasis on catalysis for these approaches varies widely. Noncatalytic thermal (hydro-) demetallization appears to be the most attractive approach from an economic standpoint for stand-alone, grass-roots situations. BMR technology comes in second place, and FBR technology is third. Taking into account the sequence of historical developments and the apparent relation between economic attractiveness and the use of catalysis, the fundamental reasons for the observed trends are discussed.Some important chemical and engineering principles are examined in this paper to provide a basis for comparing various process alternatives for the conversion of the "bottom-of-the-barrel." Key economic issues are highlighted to facilitate the discussion.Coking is presently the most widely used primary upgrading process. In coking, a significant fraction of the feed, however, is converted to gas and coke. Hydroconversion offers the potential of complete or nearly complete recovery of the feed, including the asphaltene coke precursors. Hydroconversion using extended conventional technology has not become competitive with coking, however, mainly because of the presence of vanadium and nickel in the asphaltenes. In thermal hydroconversion, the removal of metals also plays an important role. The extent of how

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“…This finding is in agreement with previous reports that indicate that reaction rates of larger asphaltenes are more rapid than those of smaller asphaltenes. 33,34 Class Changes. A comparison of the principal classes of the feed and products can provide information about individual changes that occur in different classes and how those changes might compare to the behavior of the total of molecules described in the previous section.…”

Section: Energy and Fuelsmentioning

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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Asphaltene cracking in catalytic hydrotreating of heavy oils. 1. Processing of heavy oils by catalytic hydroprocessing and solvent deasphalting

Cited by 57 publications

References 0 publications

The relationship between chemical structure and reactivity of alberta bitumens and heavy oils

The relationship between chemical structure and reactivity of alberta bitumens and heavy oils

Modes of Operation in Hydrodemetallization

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

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