Regeneration of an n-decanethiol-poisoned nickel catalyst

Hassani, Hicham Oudghiri; Abatzoglou, Nicolas; Rakass, Souad; Rowntree, P.

doi:10.1016/j.jpowsour.2007.06.258

Cited by 10 publications

(7 citation statements)

References 43 publications

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“…Complete recuperation of reforming activity for bulk Ni catalysts was found by Oudghiri-Hassini et al using Ar/steam mixtures . Regenerated catalysts were characterized by means of XPS, indicating complete sulfur removal from the catalyst surface after the steam treatment.…”

Section: Strategies From Conventional Catalysismentioning

confidence: 69%

“…Complete recuperation of reforming activity for bulk Ni catalysts was found by Oudghiri-Hassini et al using Ar/steam mixtures. 465 above, Ni oxidation occurred and some oxidized Ni species were identified by infrared spectroscopy, underlining again the risk of altering the catalysts structure when an oxidative treatment is applied. Reducing atmospheres do not present the catalyst oxidation drawback observed when the spent samples are treated with steam or oxygen.…”

Section: Chemical Reviewsmentioning

confidence: 93%

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Strategies for Carbon and Sulfur Tolerant Solid Oxide Fuel Cell Materials, Incorporating Lessons from Heterogeneous Catalysis

et al. 2016

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Solid oxide fuel cells (SOFCs) are a rapidly emerging energy technology for a low carbon world, providing high efficiency, potential to use carbonaceous fuels, and compatibility with carbon capture and storage. However, current state-of-the-art materials have low tolerance to sulfur, a common contaminant of many fuels, and are vulnerable to deactivation due to carbon deposition when using carbon-containing compounds. In this review, we first study the theoretical basis behind carbon and sulfur poisoning, before examining the strategies toward carbon and sulfur tolerance used so far in the SOFC literature. We then study the more extensive relevant heterogeneous catalysis literature for strategies and materials which could be incorporated into carbon and sulfur tolerant fuel cells.

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Section: Strategies From Conventional Catalysismentioning

confidence: 69%

Section: Chemical Reviewsmentioning

confidence: 93%

Strategies for Carbon and Sulfur Tolerant Solid Oxide Fuel Cell Materials, Incorporating Lessons from Heterogeneous Catalysis

et al. 2016

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“…67,68 Removal of sulfur can be achieved to some extent by steaming of the catalyst, but this requires temperatures above 600-650 °C. 69,70 Thus, the catalyst appears to have little chance to avoid deactivation or to regain activity in the presence of sulfur species during HDO. Our results therefore do not confirm the observations by Song et al 26,27 that a high hydrogen pressure can retain Ni in an active state in HDO.…”

Section: Catalysis Science and Technology Papermentioning

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 deactivation of Ni catalysts by sulfur poisoning has been studied by many investigators and has been attributed to the formation of nickel sulfides (Ni x S y ) [22][23][24]. Both this work on Ni/Al 2 O 3 -type catalysts exposed to H 2 S and that of other authors indicate that a nickel sulfide (or, in general, a metal sulfide) can be regenerated with steam to form H 2 S and a metal oxide [25][26][27][28] followed by reduction in H 2 to recover the reduced metal as shown in Eqs. 1, 2, and 3.…”

Section: Introductionmentioning

confidence: 69%

“…They also found that oxidative treatment formed less active nickel aluminate with incomplete recovery of activity. Other work has shown that oxidative treatment restores most though not all reforming activity after exposure to sulfur [27] with nickel surface restructuring likely causing incomplete regeneration as nickel sulfur melts (alloys) have been found on catalysts used for hot syngas cleaning [24].…”

Section: Introductionmentioning

confidence: 99%

Bench- and Pilot-Scale Studies of Reaction and Regeneration of Ni–Mg–K/Al2O3 for Catalytic Conditioning of Biomass-Derived Syngas

Magrini‐Bair

Jablonski

Parent³

et al. 2012

Top Catal

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The National Renewable Energy Laboratory (NREL) is collaborating with both industrial and academic partners to develop technologies to help enable commercialization of biofuels produced from lignocellulosic biomass feedstocks. The focus of this paper is to report how various operating processes, utilized in-house and by collaborators, influence the catalytic activity during conditioning of biomass-derived syngas. Efficient cleaning and conditioning of biomass-derived syngas for use in fuel synthesis continues to be a significant technical barrier to commercialization. Multifunctional, fluidizable catalysts are being developed to reform undesired tars and light hydrocarbons, especially methane, to additional syngas, which can improve utilization of biomass carbon. This approach also eliminates both the need for downstream methane reforming and the production of an aqueous waste stream from tar scrubbing. This work was conducted with NiMgK/Al 2 O 3 catalysts. These catalysts were assessed for methane reforming performance in (i) fixed-bed, bench-scale tests with model syngas simulating that produced by oak gasification, and in pilot-scale, (ii) fluidized tests with actual oak-derived syngas, and (iii) recirculating/regenerating tests using model syngas. Bench-scale tests showed that the catalyst could be completely regenerated over several reforming reaction cycles. Pilot-scale tests using raw syngas showed that the catalyst lost activity from cycle to cycle when it was regenerated, though it was shown that bench-scale regeneration by steam oxidation and H 2 reduction did not cause this deactivation. Characterization by TPR indicates that the loss of a low temperature nickel oxide reduction feature is related to the catalyst deactivation, which is ascribed to nickel being incorporated into a spinel nickel aluminate that is not reduced with the given activation protocol. Results for 100 h time-on-stream using a recirculating/ regenerating reactor suggest that this type of process could be employed to keep a high level of steady-state reforming activity, without permanent deactivation of the catalyst. Additionally, the differences in catalyst performance using a simulated and real, biomass-derived syngas stream indicate that there are components present in the real stream that are not adequately modeled in the syngas stream. Heavy tars and polycyclic aromatics are known to be present in real syngas, and the use of benzene and naphthalene as surrogates may be insufficient. In addition, some inorganics found in biomass, which become concentrated in the ash following biomass gasification, may be transported to the reforming reactor where they can interact with catalysts. Therefore, in order to gain more representative results for how a catalyst would perform on an industrially-relevant scale, with real contaminants, appropriate small-scale biomass solids feeders or slipstreams of real process gas should be employed.

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Regeneration of an n-decanethiol-poisoned nickel catalyst

Cited by 10 publications

References 43 publications

Strategies for Carbon and Sulfur Tolerant Solid Oxide Fuel Cell Materials, Incorporating Lessons from Heterogeneous Catalysis

Strategies for Carbon and Sulfur Tolerant Solid Oxide Fuel Cell Materials, Incorporating Lessons from Heterogeneous Catalysis

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

Bench- and Pilot-Scale Studies of Reaction and Regeneration of Ni–Mg–K/Al2O3 for Catalytic Conditioning of Biomass-Derived Syngas

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