Basic studies of deactivation of hydrotreating catalysts with anthracene

Muegge, Brian; Massoth, F.E.

doi:10.1016/0378-3820(91)90014-4

Cited by 37 publications

(26 citation statements)

References 16 publications

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“…Massoth et al (309)(310)(311)(312)(313)(314) used IN as the model compound to study the effect of coke and metals on the overall HDN. The vacuum gas oil alone and spiked either with ACR or CAR was used to deposit from about 4% to 12% of coke on the sulfided CoMo/Al 2 O 3 catalyst (309).…”

Section: Vi18 Effect Of Catalyst Deactivation On Hdn Reactivitymentioning

confidence: 99%

“…The vacuum gas oil alone and spiked either with ACR or CAR was used to deposit from about 4% to 12% of coke on the sulfided CoMo/Al 2 O 3 catalyst (309). In another study, the HDN of IN was investigated at 648 K and H 2 pressure of 3.5 MPa over the sulfided NiMoP/Al 2 O 3 catalysts that were coked with anthracene (310). This appears to be a surprising observation that can be reconciled by assuming that N-compounds adsorbed preferentially on the inactive surface.…”

Section: Vi18 Effect Of Catalyst Deactivation On Hdn Reactivitymentioning

confidence: 99%

“…The studies of Gates et al (138 -140) and Massoth et al (309)(310)(311)(312)(313)(314) indicate that the mechanism and kinetics of HDN over the fresh catalysts differ from those over the deactivated catalysts. Consequently, the HDN reactivities of the N-compounds over the latter catalysts will be lower.…”

Section: Vi18 Effect Of Catalyst Deactivation On Hdn Reactivitymentioning

confidence: 99%

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Hydrodenitrogenation of Petroleum

Furimsky¹,

2005

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A high level of hydrodenitrogenation (HDN) is required to achieve a desirable conversion of other hydroprocessing reactions. This results from a strong adsorption of nitrogen-containing compounds on catalytic sites that slows down the hydrogen activation process and hinders the adsorption of other reactants. Studies on model compounds and real feeds indicate that less than 50 ppm of nitrogen in the feed can poison catalytic sites. Kinetic studies determined adsorption constants of various nitrogen-containing compounds and concluded that at least four different catalytic sites are required to interpret experimental observations in contrast with a dual site site ffi concept, which only considered two sites. The advancements in experimental techniques allowed identification of products formed during very early stages of hydrodenitrogenation. These results confirmed that the removal of the amino group from saturated amines, as the last step in hydrodenitrogenation, is governed by the type of carbon to which the amino group is attached rather than the number of hydrogen atoms attached to carbon in a and b position to nitrogen Performance of conventional Co(Ni)Mo(W)/Al 2 O 3 catalysts during hydrodenitrogenation was enhanced by combination with various additives and by replacing the traditionally used g-Al 2 O 3 support with novel supports. Catalytic functionalities could be modified by using different precursors of active metals and varying conditions during preparation. Progress has been made in the development of catalysts possessing a high selectivity for hydrodenitrogenation. In this case, the nonconventional catalysts based on the carbides and nitrides of transition metals exhibited high activity and selectivity. Noble metal sulfides alone or supported on different supports were active for HDN as well. Feedstocks used for catalyst evaluation included model compounds and mixtures of model compounds as well as real feeds. The challenges in the development of catalysts for hydrodenitrogenation of heavy feeds containing asphaltenes and metals have been identified.In general, compared to Q, conversions were little affected by a methyl (Me) on the aromatic ring, while being lower for Me on the N-ring, except for 2-MeQ. It is evident that Me substitution in the 2-position had little effect on HDN over the NiMoP/Al 2 O 3 catalyst, whereas it actually enhanced the HDN rate over the CoMo/Al 2 O 3 catalyst. For both catalysts the HDN rate was suppressed in 6-MeQ and particularly in 3-MeQ and 4-MeQ. The distribution of N-containing intermediates was influenced by the ring substitution and the type of catalyst. This suggests that several factors influence the overall HDN mechanism of Qs. This should be kept in mind while analyzing differences in the networks proposed by different authors.The preceding discussion on the HDN of Q mostly referred to conventional catalysts. A number of studies on the HDN of Q were conducted over unconventional catalysts. For example, 3-and 4-MeQs were more reactive than Q over the unsupported Zr,...

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Section: Vi18 Effect Of Catalyst Deactivation On Hdn Reactivitymentioning

confidence: 99%

Section: Vi18 Effect Of Catalyst Deactivation On Hdn Reactivitymentioning

confidence: 99%

Section: Vi18 Effect Of Catalyst Deactivation On Hdn Reactivitymentioning

confidence: 99%

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Hydrodenitrogenation of Petroleum

Furimsky¹,

2005

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“…Thus, intrapore diffusion can also be affected by catalyst deactivation. It has been observed that as coke content (Muegge and Massoth, 1991) or catalyst age (Guin et al, 1986;Zhang et al, 1995) increased, the effective diffusivity decreased. Guin et al (1986) studied intrapore diffusion in the catalysts used for hydrotreatment of coal derived liquid and observed substantial reductions, of up to 2 orders of magnitudes, in effective diffusivity.…”

Section: Do1mentioning

confidence: 99%

Configurational diffusion of asphaltenes in fresh and aged catalyst extrudates. Final technical report, September 20, 1991--September 30, 1996

Guin¹

1998

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“…In prior studies, the effect of coke derived from on the deactivation of anthracene (271) and from ,a vacuum gas a commercial NiMo/Al,O, hydrotreating catalyst was investigated.…”

Section: Introductionmentioning

confidence: 99%