Endre søk
Link to record
Permanent link

Direct link
BETA
Publikasjoner (9 av 9) Visa alla publikasjoner
Garcilaso, V., Barrientos, J., Bobadilla, L. F., Laguna, O. H., Boutonnet, M., Centeno, M. A. & Odriozola, J. A. (2019). Promoting effect of CeO2, ZrO2 and Ce/Zr mixed oxides on Co/Γ-Al2O3 catalyst for Fischer-Tropsch synthesis. Renewable energy, 132, 1141-1150
Åpne denne publikasjonen i ny fane eller vindu >>Promoting effect of CeO2, ZrO2 and Ce/Zr mixed oxides on Co/Γ-Al2O3 catalyst for Fischer-Tropsch synthesis
Vise andre…
2019 (engelsk)Inngår i: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 132, s. 1141-1150Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

A series of cobalt-based catalysts have been synthesized using as support γ-Al2O3 promoted by ceria/zirconia mixed oxides with a variable Ce/Zr molar ratio. The obtained catalysts demonstrated oxide promotion results in the protection of the major textural properties, especially for Zr-rich solids. Reducibility of cobalt species was enhanced by the presence of mixed oxides. The chemical composition of the oxide promoter influenced not only physicochemical properties of final catalysts but also determined their performance during the reaction. In this sense, Zr-rich systems presented a superior catalytic performance both in total conversion and in selectivity towards long chain hydrocarbons. The observed Zr-promotion effect could be explained by two significant contributions: firstly, the partial inhibition of Co–Al spinel compound formation by the presence of Zr-rich phases which enhances the availability of Co actives site and secondly, Zr-associate acidic sites promote higher hydrocarbons selectivity.

sted, utgiver, år, opplag, sider
Elsevier Ltd, 2019
Emneord
Cobalt-based catalysts, GTL, Higher hydrocarbon selectivity, Oxide promoter, Support acidity, Zr–Ce oxides, Alumina, Aluminum oxide, Catalyst activity, Catalyst selectivity, Cobalt, Cobalt compounds, Fischer-Tropsch synthesis, Hydrocarbons, Zirconia, Catalytic performance, Chemical compositions, Higher hydrocarbons, Long chain hydrocarbons, Physicochemical property, Promotion effects, Textural properties, Cerium oxide, acidity, aluminum, catalyst, cerium, chemical composition, chemical reaction, hydrocarbon, oxide, zircon
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-236317 (URN)10.1016/j.renene.2018.08.080 (DOI)000449892900090 ()2-s2.0-85052734534 (Scopus ID)
Merknad

QC 20181116

Tilgjengelig fra: 2018-11-16 Laget: 2018-11-16 Sist oppdatert: 2018-12-07bibliografisk kontrollert
Barrientos, J., Gonzalez, N., Boutonnet, M. & Järås, S. (2017). Deactivation of Ni/gamma-Al2O3 Catalysts in CO Methanation: Effect of Zr, Mg, Ba and Ca Oxide Promoters. Paper presented at 17th Nordic Symposium on Catalysis, JUN 14-16, 2016, Lund Univ, Lund, Sweden. Topics in catalysis, 60(17-18), 1276-1284
Åpne denne publikasjonen i ny fane eller vindu >>Deactivation of Ni/gamma-Al2O3 Catalysts in CO Methanation: Effect of Zr, Mg, Ba and Ca Oxide Promoters
2017 (engelsk)Inngår i: Topics in catalysis, ISSN 1022-5528, E-ISSN 1572-9028, Vol. 60, nr 17-18, s. 1276-1284Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Catalyst deactivation is one of the major concerns in the production of substitute natural gas (SNG) via CO methanation. Catalysts in this application need to be active at low temperatures, resistant to polymeric carbon formation and stable at high temperatures and steam partial pressures. In the present work, a series of alumina-supported nickel catalysts promoted with Zr, Mg, Ba or Ca oxides were investigated. The catalysts were tested under low temperature CO methanation conditions in order to evaluate their resistance to carbon formation. The catalysts were also exposed to accelerated ageing conditions at high temperatures in order to study their thermal stability. The aged catalysts lost most of their activity mainly due to sintering of the support and the nickel crystallites. Apparently, none of these promoters had a satisfactory effect on the thermal resistance of the catalyst. Nevertheless, it was found that the presence of Zr can reduce the rate of polymeric carbon formation.

sted, utgiver, år, opplag, sider
Springer, 2017
Emneord
Nickel, Alumina, Promoters, Methanation, Deactivation, SNG
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-217745 (URN)10.1007/s11244-017-0812-2 (DOI)000413848700002 ()2-s2.0-85019736667 (Scopus ID)
Konferanse
17th Nordic Symposium on Catalysis, JUN 14-16, 2016, Lund Univ, Lund, Sweden
Forskningsfinansiär
EU, FP7, Seventh Framework Programme, 308733
Merknad

QC 20171122

Tilgjengelig fra: 2017-11-22 Laget: 2017-11-22 Sist oppdatert: 2018-02-28bibliografisk kontrollert
Barrientos, J., Garcilaso, V., Venezia, B., Aho, A., Antonio Odriozola, J., Boutonnet, M. & Järås, S. (2017). Fischer-Tropsch Synthesis Over Zr-Promoted Co/gamma-Al2O3 Catalysts. Paper presented at 17th Nordic Symposium on Catalysis, JUN 14-16, 2016, Lund Univ, Lund, SWEDEN. Topics in catalysis, 60(17-18), 1285-1298
Åpne denne publikasjonen i ny fane eller vindu >>Fischer-Tropsch Synthesis Over Zr-Promoted Co/gamma-Al2O3 Catalysts
Vise andre…
2017 (engelsk)Inngår i: Topics in catalysis, ISSN 1022-5528, E-ISSN 1572-9028, Vol. 60, nr 17-18, s. 1285-1298Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Two Zr-modified alumina supports were synthetized containing the same amount of Zr but a different distribution of this modifier over the alumina surface. These supports, together with the unmodified alumina carrier, were used to prepare three cobalt-based catalysts which were characterized and tested under relevant Fischer-Tropsch conditions. The three catalysts presented very similar porosity and cobalt dispersion. The addition of Zr nor its distribution enhanced the catalyst reducibility. The catalyst activity was superior when using a carrier consisting of large ZrO2 islands over the alumina surface. The use of a carrier with a homogeneous Zr distribution had however, a detrimental effect. Moreover, a faster initial deactivation rate was observed for the Zr-promoted catalysts, fact that may explain this contradictory effect of Zr on activity. Finally, the addition of Zr showed a clear enhancement of the selectivity to long chain hydrocarbons and ethylene, especially when Zr was well dispersed.

sted, utgiver, år, opplag, sider
SPRINGER/PLENUM PUBLISHERS, 2017
Emneord
Fischer-Tropsch synthesis, Co/Al2O3, Cobalt, Zr, Activity
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-217746 (URN)10.1007/s11244-017-0813-1 (DOI)000413848700003 ()2-s2.0-85020109653 (Scopus ID)
Konferanse
17th Nordic Symposium on Catalysis, JUN 14-16, 2016, Lund Univ, Lund, SWEDEN
Merknad

QC 20171122

Tilgjengelig fra: 2017-11-22 Laget: 2017-11-22 Sist oppdatert: 2017-11-22bibliografisk kontrollert
Barrientos, J., Montes, V., Boutonnet, M. & Järås, S. (2016). Further insights into the effect of sulfur on the activity and selectivity of cobalt-based Fischer–Tropsch catalysts. Catalysis Today, 275, 119-126
Åpne denne publikasjonen i ny fane eller vindu >>Further insights into the effect of sulfur on the activity and selectivity of cobalt-based Fischer–Tropsch catalysts
2016 (engelsk)Inngår i: Catalysis Today, ISSN 0920-5861, E-ISSN 1873-4308, Vol. 275, s. 119-126Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

 A sulfur poisoning study was performed by ex situ poisoning of a platinum-promoted cobalt/alumina catalyst with different sulfur amounts. The poisoned catalyst samples were tested at relevant Fischer–Tropsch reaction conditions and at the same CO conversion in order to evaluate the effect of sulfur on catalyst activity and product selectivity. It was found that the activity and the selectivity to long-chain hydrocarbons decrease with increasing sulfur content. Moreover, it was found that sulfur has no significant effect on the CO2 selectivity. It was also shown that sulfur significantly enhances olefin hydrogenation. Finally, a deactivation model relating the catalyst activity and the sulfur to cobalt active site ratio was proposed and used to describe the experimental results.

Emneord
Fischer–Tropsch, Sulfur, Cobalt, Deactivation, Selectivity
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-182347 (URN)10.1016/j.cattod.2015.10.039 (DOI)000382420300017 ()2-s2.0-84964998582 (Scopus ID)
Merknad

QC 20160926

Tilgjengelig fra: 2016-02-18 Laget: 2016-02-18 Sist oppdatert: 2017-11-30bibliografisk kontrollert
Suárez París, R., L’Abbate, M. E., Liotta, L. F., Montes, V., Barrientos, J., Regali, F., . . . Järås, S. (2016). Hydroconversion of paraffinic wax over platinum and palladium catalysts supported on silica–alumina. Catalysis Today, 275, 141-148
Åpne denne publikasjonen i ny fane eller vindu >>Hydroconversion of paraffinic wax over platinum and palladium catalysts supported on silica–alumina
Vise andre…
2016 (engelsk)Inngår i: Catalysis Today, ISSN 0920-5861, E-ISSN 1873-4308, Vol. 275, s. 141-148Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Two bifunctional catalysts consisting of platinum or palladium supported on amorphous silica–alumina were prepared and tested in hydrocracking/hydroisomerization of paraffinic wax. The performance of both noble metals was studied at the following reaction conditions: P = 35 bar; T = 300–330 °C; H2/wax = 0.1 wt/wt; WHSV = 1–4 h−1. The platinum sample was more active in hydrocracking of C22+ compounds and more selective to middle distillates. On the other hand, the palladium-based catalyst resulted in a higher isomerization degree of the products and lower amounts of methane and ethane. The higher production of light compounds over platinum is attributed to a monofunctional hydrogenolysis mechanism, in addition to the classical bifunctional route. Characterization studies showed that both catalysts had comparable metal and acid site distributions. These observations would indicate that the different catalyst performance is due to the different nature of platinum and palladium as hydrogenation/dehydrogenation function.

Emneord
Hydrocracking, Hydroisomerization, Wax, Fischer–Tropsch, Platinum, Palladium
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-182348 (URN)10.1016/j.cattod.2015.11.026 (DOI)000382420300020 ()2-s2.0-84982276972 (Scopus ID)
Merknad

QC 20160926

Tilgjengelig fra: 2016-02-18 Laget: 2016-02-18 Sist oppdatert: 2017-11-30bibliografisk kontrollert
Barrientos, J., González, N., Lualdi, M., Boutonnet, M. & Järås, S. (2016). The effect of catalyst pellet size on nickel carbonyl-induced particle sintering under low temperature CO methanation. Applied Catalysis A: General, 514, 91-102
Åpne denne publikasjonen i ny fane eller vindu >>The effect of catalyst pellet size on nickel carbonyl-induced particle sintering under low temperature CO methanation
Vise andre…
2016 (engelsk)Inngår i: Applied Catalysis A: General, ISSN 0926-860X, E-ISSN 1873-3875, Vol. 514, s. 91-102Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Abstract The present work aims to evaluate the effect of catalyst pellet size on deactivation due to nickel carbonyl-induced particle sintering. For that purpose, a γ-Al2O3-supported nickel catalyst was prepared and tested under low temperature and high CO partial pressure. A total of four different pellet sizes were employed in the present study. It was found that the deactivation rate decreases with increasing pellet size. A very severe deactivation was observed when using small pellets. Large pellets exhibited instead a more stable performance. This difference in catalyst stability was explained by X-ray diffraction analyses which revealed that the growth of the nickel particles was very severe when using small pellets. An evaluation of heat and mass transfer phenomena in these four pellets was also conducted. It was found that, under the present low temperature reaction conditions, the temperature at the catalyst external surface can greatly differ from that in the bulk gas when using sufficiently large pellets. It was also shown that, for large pellets, the major part of the interior of the catalyst is exposed to negligible CO partial pressures and high temperatures, fact that can reduce the potential for nickel carbonyl formation.

sted, utgiver, år, opplag, sider
Elsevier, 2016
Emneord
Methanation, Deactivation, Nickel carbonyl, Sintering, Heat and mass transfer, Alumina
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-182353 (URN)10.1016/j.apcata.2015.12.034 (DOI)000371551200010 ()2-s2.0-84955264386 (Scopus ID)
Forskningsfinansiär
EU, FP7, Seventh Framework Programme, 308733
Merknad

QC 20160330. QC 20160407

Tilgjengelig fra: 2016-02-18 Laget: 2016-02-18 Sist oppdatert: 2017-11-30bibliografisk kontrollert
Suárez París, R., Lopez Nina, L. G., Barrientos, J., Pardo, F., Boutonnet, M. & Järås, S. G. (2015). Catalytic conversion of biomass-derived synthesis gas to fuels. In: Catalysis. Volume 27: (pp. 62-143). Royal Society of Chemistry
Åpne denne publikasjonen i ny fane eller vindu >>Catalytic conversion of biomass-derived synthesis gas to fuels
Vise andre…
2015 (engelsk)Inngår i: Catalysis. Volume 27, Royal Society of Chemistry, 2015, s. 62-143Kapittel i bok, del av antologi (Fagfellevurdert)
Abstract [en]

Biomass-derived fuels constitute a promising alternative for diversifying the fuel supply and reducing the consumption of fossil fuels, leading to a reduction in greenhouse gas emissions and thus mitigating global warming. Biomass can be converted to synthesis gas, which can serve as a source for various liquid and gaseous fuels. Although significant progress has been achieved in the overall process, both economic and technical challenges still need to be overcome. Many pilot plants are already in operation and the first demonstration and semi-commercial installations are under construction or starting to operate. Catalysis is a key parameter in the conversion of synthesis gas to fuels. The aim of this work is to present the latest advances in the catalytic conversion of synthesis gas to Fischer-Tropsch gasoline and diesel, synthetic natural gas, ethanol and mixed alcohols. The syntheses of methanol and dimethyl ether are also briefly reviewed.

sted, utgiver, år, opplag, sider
Royal Society of Chemistry, 2015
Serie
Catalysis, ISSN 0140-0568 ; 27
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-167768 (URN)10.1039/9781782622697-00062 (DOI)2-s2.0-84926505246 (Scopus ID)978-1-78262-054-9 (ISBN)978-1-78262-269-7 (ISBN)
Forskningsfinansiär
Sida - Swedish International Development Cooperation AgencyEU, FP7, Seventh Framework Programme, FP7/2013
Merknad

QC 20161123

Tilgjengelig fra: 2015-05-27 Laget: 2015-05-22 Sist oppdatert: 2017-10-04bibliografisk kontrollert
Barrientos, J., Lualdi, M., Suarez Paris, R., Montes, V., Boutonnet, M. & Jaras, S. (2015). CO methanation over TiO2-supported nickel catalysts: A carbon formation study. Applied Catalysis A: General, 502, 276-286
Åpne denne publikasjonen i ny fane eller vindu >>CO methanation over TiO2-supported nickel catalysts: A carbon formation study
Vise andre…
2015 (engelsk)Inngår i: Applied Catalysis A: General, ISSN 0926-860X, E-ISSN 1873-3875, Vol. 502, s. 276-286Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

A systematic study on titania-supported nickel catalysts was performed in order to evaluate the effect of different process conditions on catalyst stability. Reaction tests and temperature-programmed-hydrogenation analyses were used in order to evaluate the effect of temperature, feed composition, water and reduction conditions on catalyst deactivation and carbon deposition. It was shown that high H-2/CO ratios and syngas partial pressures decrease the rate of carbon formation. Moreover, increasing temperature enhanced the formation of more stable carbon species and thus catalyst deactivation. The temperature-programmed hydrogenation analyses also revealed that water reduces the rate of carbon deposition. However, water enhanced catalyst deactivation when the catalysts were reduced at high temperatures. This negative effect of water is probably due to a progressive destruction of the strong-metal-support interaction characteristic of titania-supported nickel catalysts reduced at high temperatures. (C) 2015 Elsevier B.V. All rights reserved.

sted, utgiver, år, opplag, sider
Elsevier, 2015
Emneord
Methanation, Deactivation, Nickel, Titania, Carbon formation
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-174939 (URN)10.1016/j.apcata.2015.06.029 (DOI)000361162200033 ()2-s2.0-84934759326 (Scopus ID)
Forskningsfinansiär
Swedish Energy Agency
Merknad

QZ 20151019

Tilgjengelig fra: 2015-10-19 Laget: 2015-10-09 Sist oppdatert: 2017-12-01bibliografisk kontrollert
Barrientos, J., Lualdi, M., Boutonnet, M. & Järås, S. (2014). Deactivation of supported nickel catalysts during CO methanation. Applied Catalysis A: General, 486, 143-149
Åpne denne publikasjonen i ny fane eller vindu >>Deactivation of supported nickel catalysts during CO methanation
2014 (engelsk)Inngår i: Applied Catalysis A: General, ISSN 0926-860X, E-ISSN 1873-3875, Vol. 486, s. 143-149Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Deactivation of Ni-based catalysts was investigated during CO methanation over different supported catalysts. X-ray diffraction and temperature-programmed hydrogenation analyses were used to investigate nickel particle sintering and carbon formation during the first 24 h on stream. Titania-supported catalysts presented high resistance towards carbon deposition and nickel particle growth in comparison with the other tested catalysts. Particle size effects on these two deactivation causes were also evaluated. It was shown that carbon formation rates are higher on bigger crystal particles. However, it was found that titania-supported nickel catalysts reduced at high temperatures show the opposite effect. This difference is most probably due to a stronger interaction between nickel and TiOx (x < 2) species on smaller crystals which changes the CO dissociation properties and, in consequence, carbon formation rates.

Emneord
Methanation, Deactivation, Support, Titania, Carbon formation
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-157220 (URN)10.1016/j.apcata.2014.08.021 (DOI)000344439400016 ()2-s2.0-84908648449 (Scopus ID)
Forskningsfinansiär
EU, FP7, Seventh Framework Programme, 308733Swedish Energy Agency
Merknad

QC 20141209

Tilgjengelig fra: 2014-12-09 Laget: 2014-12-08 Sist oppdatert: 2017-12-05bibliografisk kontrollert
Organisasjoner
Identifikatorer
ORCID-id: ORCID iD iconorcid.org/0000-0003-3826-1858