Deactivation of hydroprocessing catalysts

Furimsky, Edward

doi:10.1016/s0920-5861(99)00096-6

Cited by 641 publications

(407 citation statements)

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“…Chlorine >> H2O ≈ H2S (17) In a broader context, H2S, H2O, CO, and NH3 are all inhibitors of sulfide catalysts as they compete for the active sites [23,46,59,65]. Badawi et al [23] found the following order of inhibition for HDO of guaiacol on MoS2 based on DFT calculations:…”

Section: Inhibition Strength Of H2s H2o and Chlorinementioning

confidence: 99%

“…Potassium should be removed prior to the HDO reactor as this is a source of severe and irreversible deactivation (see Figure 10). A guard bed prior to the hydrotreating reactor has been proposed to prevent metal deposition [65]. Here metals would be trapped in a porous material like alumina, bauxite, magnesium silicate, clays, or similar.…”

Section: Inhibition Strength Of H2s H2o and Chlorinementioning

confidence: 99%

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Deactivation of Ni-MoS2 by bio-oil impurities during hydrodeoxygenation of phenol and octanol

Mortensen

Gardini

Damsgaard

et al. 2016

Applied Catalysis A: General

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Deactivation of Ni-MoS2 by bio-oil impurities during hydrodeoxygenation of phenol and octanol, Applied Catalysis A, General http://dx.doi.org/10. 1016/j.apcata.2016.06.002 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Graphical abstractHighlights  Impurities as Cl, S, and K found in bio-oil will deactivate or inhibit MoS2-type catalyst by competing for the active sites  MoS2-based catalysts will produce sulfur containing hydrocarbons during HDO, but these can be removed again if a sufficiently high residence time is used enabling desulfurization of the product  Chlorine binds more strongly to the active sites of MoS2 based catalysts compared to H2O and H2S, while K irreversibly deactivates the catalyst 3 AbstractThe stability of Ni-MoS2/ZrO2 toward water, potassium, and chlorine containing compounds during hydrodeoxygenation (HDO) of a mixture of phenol and 1-octanol was investigated in a high pressure gas and liquid continuous flow fixed bed setup at 280°C and 100 bar. To maintain the stability of the catalyst, sufficient co-feeding of a sulfur source was necessary to avoid oxidation of the sulfide phase by oxygen replacement of the edge sulfur atoms in the MoS2 structure. However, the addition of sulfur to the feed gas resulted in the formation of sulfur containing compounds, mainly thiols, in the oil product if the residence time was too low. At a weight hourly space velocity (WHSV) of 4.9 h -1 the sulfur content in the liquid product was 980 ppm by weight, but this could be decreased to 5 ppm at a WHSV of 1.4 h -1 . A high co-feed of sulfur was needed when water was present in the feed and the H2O/H2S molar ratio should be below ca. 10 to maintain a decent stability of the catalyst. Chlorine containing compounds caused a reversible deactivation of the catalyst when co-fed to the reactor, where the catalytic activity could be completely regained when removing it from the feed. Commonly, chlorine, H2O, and H2S all inhibited the activity of the catalyst by competing for the active sites, with chlorine being by far the strongest inhibitor and H2S and H2O of roughly the same strength. Dissimilar, potassium was a severe poison and irreversibly deactivated the catalyst to <5% degree of deoxygenation when impregnated on the catalyst in a stoichiometric ratio relative to the active metal. This deactivation was a result of adsorption of potassium on the edge vacancy sites of the MoS2 slabs.

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Section: Inhibition Strength Of H2s H2o and Chlorinementioning

confidence: 99%

Section: Inhibition Strength Of H2s H2o and Chlorinementioning

confidence: 99%

Deactivation of Ni-MoS2 by bio-oil impurities during hydrodeoxygenation of phenol and octanol

Mortensen

Gardini

Damsgaard

et al. 2016

Applied Catalysis A: General

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“…Carbon on the catalyst is formed because many of the oxy compounds present in bio-oil can undergo polymerization and polycondensation reactions on the catalyst surface, forming polyaromatic species which can lead to the blocking of both the pore structure and the active sites of the catalyst. 23 As bio-oil is derived from biomass, it will contain traces of a range of inorganic compounds like alkali metals, transition metals, chlorine, sulfur, and phosphorus. 24 Especially, potassium, chlorine, and sulfur can be found in relatively high amounts in bio-oil with concentrations of up to 0.3 wt%, 0.6 wt%, and 0.8 wt%, respectively.…”

Section: Introductionmentioning

confidence: 99%

Stability and resistance of nickel catalysts for hydrodeoxygenation: carbon deposition and effects of sulfur, potassium, and chlorine in the feed

Mortensen

Gardini

Carvalho

et al. 2014

Catal. Sci. Technol.

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aThe long term stability and resistance toward carbon deposition, sulfur, chlorine, and potassium of Ni/ZrO 2 as a catalyst for the hydrodeoxygenation (HDO) of guaiacol in 1-octanol (as a model compound system for bio-oil) has been investigated at 250°C and 100 bar in a trickle bed reactor setup. Without impurities in the feed good stability of the Ni/ZrO 2 catalyst could be achieved over more than 100 h of operation, particularly for a sample prepared with small Ni particles, which minimized carbon deposition.Exposing the catalyst to 0.05 wt% sulfur in the feed resulted in rapid deactivation with complete loss of activity due to the formation of nickel sulfide. Exposing Ni/ZrO 2 to chlorine-containing compounds (at a concentration of 0.05 wt% Cl) on-stream led to a steady decrease in activity over 40 h of exposure.Removal of the chlorine species from the feed led to the regaining of activity. Analysis of the spent catalyst revealed that the adsorption of chlorine on the catalyst was completely reversible, but chlorine had caused sintering of nickel particles. In two experiments, potassium, as either KCl or KNO 3 , was impregnated on the catalyst prior to testing. In both cases deactivation was persistent over more than 20 h of testing and severely decreased the deoxygenation activity while the hydrogenation of guaiacol was unaffected. Overall, sulfur was found to be the worst poison, followed by potassium and then chlorine. Thus, removal/limitation of these species from bio-oil is a requirement before long term operation can be achieved with this catalyst.

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“…The future demand of transportation fuel can be fulfilled by upgrading unconventional reserves of heavy oil [1]. The amount of extra-heavy oil and bitumen is predicted to be around 5.4 trillion barrels.…”

Section: Introductionmentioning

confidence: 99%

Slurry Phase Hydrocracking of Residue by Phosphomolybdic and Phosphotungstic Acids

Prajapati¹,

Kohli²

2016

J Pet Environ Biotechnol

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Slurry phase hydrocracking of vacuum residue was studied on heteropoly acids and on super acid. In this regards, heteropoly acid of phosphomolybdic, phosphotungstic and superacid of molybdenum-antimony fluoride were used. Deep hydrocracking of residue was noticed even at moderate operating conditions for all acidic catalysts. Due to higher hydrogenating functionality of tungsten, the HDM activity of the phosphotungstic acid is higher than that of molybdenum containing acids. Even the residue hydrocracking activity of former catalyst is also high. It is also noticed from sulphur distribution of liquid product that thiophenic sulphur compounds are formed due to C-S bond cleavage at branching of condensed aromatic rings. Moreover, phosphotungstic acid gives high percentage of aromatic products whereas the considerable amount of saturate hydrocarbons is produced by phosphomolybdic acid. The coke produced by phosphotungstic acid catalyst is hard in nature indicating that extensive polymerization reaction occurs at reaction conditions. Higher H/C ratio indicates the deep hydrogenation of liquid products in presence of super acids. Instead of use superacid, tungsten based heteropoly acid can be effectively used for hydrocracking of residue.

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Deactivation of hydroprocessing catalysts

Cited by 641 publications

References 283 publications

Deactivation of Ni-MoS2 by bio-oil impurities during hydrodeoxygenation of phenol and octanol

Deactivation of Ni-MoS2 by bio-oil impurities during hydrodeoxygenation of phenol and octanol

Stability and resistance of nickel catalysts for hydrodeoxygenation: carbon deposition and effects of sulfur, potassium, and chlorine in the feed

Slurry Phase Hydrocracking of Residue by Phosphomolybdic and Phosphotungstic Acids

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