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Preferential adsorp...
Preferential adsorption of K species and the role of support during reforming of biomass derived producer gas over sulfur passivated Ni/MgAl2O4
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Hernandez, Asbel (författare)
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- Andersson, Klas J. (författare)
- Topsoe A/S
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- Engvall, Klas (författare)
- KTH,Kemiteknik
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visa fler...
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- Kantarelis, Efthymios, PhD, 1982- (författare)
- KTH,Processteknologi,Materialvetenskap
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visa färre...
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(creator_code:org_t)
- 2020
- 2020
- Engelska.
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Ingår i: Energy & Fuels. - 0887-0624 .- 1520-5029. ; 34:9, s. 11103-11111
- Relaterad länk:
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https://kth.diva-por... (primary) (Raw object)
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visa fler...
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https://urn.kb.se/re...
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Abstract
Ämnesord
Stäng
- Biomass gasification is a sustainable way to convert biomass residues into valuable fuels and chemicals via syngasproduction. However, several gas impurities need to be removed before thefinal synthesis. Understanding of the interactions andeffects of biomass-derived producer gas contaminants (S and K) on the performance of reforming catalysts is of great importancewhen it comes to process reliability and development. In the present study, the steam reforming activity at 800°C of a sulfur-equilibrated nickel catalyst during controlled exposure to alkali species (∼2 ppmv K) and in its absence was investigated using realproducer gas from a 5 kWthO2-blownfluidized-bed gasifier. Conversions of CH4,C2H4, and C10H8were used to evaluate theperformance of the Ni/MgAl2O4catalyst and MgAl2O4support. A significant and positive effect on the catalyst activity is observedwith addition of gas-phase KCl. This is assigned primarily to the observed K-induced reduction in sulfur coverage (θS)onNianeffect which is reversible. The catalytic contribution of the K-modified pure MgAl2O4support was found to be significant in theconversion of naphthalene but not for light hydrocarbons. The product and catalyst analyses provided evidence to elucidate thepreferential adsorption site for S and K on the catalyst as well as the role of the support. Whereas S, as expected, was found topreferentially adsorb on the surface of Ni particles, forming S-Ni sites, K was found to preferentially adsorb on the MgAl2O4support.A low but still significant K adsorption on S−Ni sites, or an effect on only the fraction of exposed Ni surface area near the metal−support interface, can, however, not be excluded. The result suggests that an improved Ni/MgAl2O4catalyst activity and anessentially carbon-free operation can be achieved in the presence of controlled amount of gas-phase potassium and high sulfurcoverages on Ni. Based on the results, a mechanism of the possible K−S interactions is proposed
Ämnesord
- TEKNIK OCH TEKNOLOGIER -- Kemiteknik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Chemical Engineering (hsv//eng)
- TEKNIK OCH TEKNOLOGIER -- Maskinteknik -- Energiteknik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Mechanical Engineering -- Energy Engineering (hsv//eng)
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