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Enhanced investigation of CO methanation over Ni/Al2O3 catalysts for synthetic natural gas production / Dacheng Hu in Industrial & engineering chemistry research, Vol. 51 N° 13 (Avril 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4875–4886 Titre : Enhanced investigation of CO methanation over Ni/Al2O3 catalysts for synthetic natural gas production Type de document : texte imprimé Auteurs : Dacheng Hu, Auteur ; Jiajian Gao, Auteur ; Yuan Ping, Auteur Année de publication : 2012 Article en page(s) : pp. 4875–4886 Note générale : Chimie indutsrielle Langues : Anglais (eng) Mots-clés : Natural  gas Résumé : CO methanation reaction over the Ni/Al2O3 catalysts for synthetic natural gas production was systematically investigated by tuning a number of parameters, including using different commercial Al2O3 supports and varying NiO and MgO loading, calcination temperature, space velocity, H2/CO ratio, reaction pressure, and time, respectively. The catalytic performance was greatly influenced by the above-mentioned parameters. Briefly, a large surface area of the Al2O3 support, a moderate interaction between Ni and the support Al2O3, a proper Ni content (20 wt %), and a relatively low calcination temperature (400 °C) promoted the formation of small NiO particles and reducible β-type NiO species, which led to high catalytic activities and strong resistance to the carbon deposition, while addition of a small amount of MgO (2 wt %) could improve the catalyst stability by reducing the carbon deposition; other optimized conditions that enhanced the catalytic performance included high reaction pressure (3.0 MPa), high H2/CO ratio (≥3:1), low space velocity, and addition of quartz sand as the diluting agent in catalyst bed. The best catalyst combination was 20–40 wt % of NiO supported on a commercial Al2O3 (S4) with addition of 2–4 wt % of MgO, calcined at 400–500 °C and run at a reaction pressure of 3.0 MPa. On this catalyst, 100% of CO conversion could be achieved within a wide range of reaction temperature (300–550 °C), and the CH4 selectivity increased with increasing temperature and reached 96.5% at a relatively low temperature of 350 °C. These results will be very helpful to develop highly efficient Ni-based catalysts for the methanation reaction, to optimize the reaction process, and to better understand the above reaction. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300049f [article] Enhanced investigation of CO methanation over Ni/Al2O3 catalysts for synthetic natural gas production [texte imprimé] / Dacheng Hu, Auteur ; Jiajian Gao, Auteur ; Yuan Ping, Auteur . - 2012 . - pp. 4875–4886. Chimie indutsrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4875–4886 Mots-clés : Natural  gas Résumé : CO methanation reaction over the Ni/Al2O3 catalysts for synthetic natural gas production was systematically investigated by tuning a number of parameters, including using different commercial Al2O3 supports and varying NiO and MgO loading, calcination temperature, space velocity, H2/CO ratio, reaction pressure, and time, respectively. The catalytic performance was greatly influenced by the above-mentioned parameters. Briefly, a large surface area of the Al2O3 support, a moderate interaction between Ni and the support Al2O3, a proper Ni content (20 wt %), and a relatively low calcination temperature (400 °C) promoted the formation of small NiO particles and reducible β-type NiO species, which led to high catalytic activities and strong resistance to the carbon deposition, while addition of a small amount of MgO (2 wt %) could improve the catalyst stability by reducing the carbon deposition; other optimized conditions that enhanced the catalytic performance included high reaction pressure (3.0 MPa), high H2/CO ratio (≥3:1), low space velocity, and addition of quartz sand as the diluting agent in catalyst bed. The best catalyst combination was 20–40 wt % of NiO supported on a commercial Al2O3 (S4) with addition of 2–4 wt % of MgO, calcined at 400–500 °C and run at a reaction pressure of 3.0 MPa. On this catalyst, 100% of CO conversion could be achieved within a wide range of reaction temperature (300–550 °C), and the CH4 selectivity increased with increasing temperature and reached 96.5% at a relatively low temperature of 350 °C. These results will be very helpful to develop highly efficient Ni-based catalysts for the methanation reaction, to optimize the reaction process, and to better understand the above reaction. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300049f

Nickel catalysts supported on barium hexaaluminate for enhanced CO methanation / Jiajian Gao in Industrial & engineering chemistry research, Vol.51 N° 31 (Août 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol.51 N° 31 (Août 2012) . - pp. 10345-10353 Titre : Nickel catalysts supported on barium hexaaluminate for enhanced CO methanation Type de document : texte imprimé Auteurs : Jiajian Gao, Auteur ; Chunmiao Jia, Auteur ; Jing Li, Auteur Année de publication : 2012 Article en page(s) : pp. 10345-10353 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Methanation  Catalyst  support Résumé : We report the preparation and characterization of Ni nanoparticles supported on barium hexaaluminate (BHA) as CO methanation catalysts for the production of synthetic natural gas (SNG). BHA with a high thermal stability was synthesized by a coprecipitation method using aluminum nitrate, barium nitrate, and ammonium carbonate as the precursors. The Ni catalysts supported on the BHA support (Ni/BHA) were prepared by an impregnation method. X-ray diffraction, nitrogen adsorption, transmission electron microscopy, thermogravimetric analysis, H2 temperature-programmed reduction, O2 temperature-programmed oxidation, NH3 temperature-programmed desorption, and X-ray photoelectron spectroscopy are used to characterize the samples. The CO methanation reaction was carried out at pressures of 0.1 and 3.0 MPa, weight hourly space velocities (WHSVs) of 30 000, 120 000, and 240 000 mL·g–1·h–1, with a H2/CO feed ratio of 3, and in the temperature range 300–600 °C. The results show that although the BHA support has a relatively low surface area, Ni/BHA catalysts displayed much higher activity than Al2O3-supported Ni catalysts (Ni/Al2O3) with a similar level of NiO loading even after high temperature hydrothermal treatment. Nearly 100% CO conversion and 90% CH4 yield were achieved over Ni/BHA (NiO, 10 wt %) at 400 °C, 3.0 MPa, and a WHSV of 30 000 mL·g–1·h–1. Long time testing indicates that, compared to Ni/Al2O3 catalyst, Ni/BHA is more stable and is highly resistant to carbon deposition. The superior catalytic performance of the Ni/BHA catalyst is probably related to the relatively larger Ni particle size (20–40 nm), the high thermal stability of BHA support with nonacidic nature, and moderate Ni–BHA interaction. The work demonstrates BHA would be a promising alternative support for the efficient Ni catalysts to SNG production. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26234065 [article] Nickel catalysts supported on barium hexaaluminate for enhanced CO methanation [texte imprimé] / Jiajian Gao, Auteur ; Chunmiao Jia, Auteur ; Jing Li, Auteur . - 2012 . - pp. 10345-10353. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol.51 N° 31 (Août 2012) . - pp. 10345-10353 Mots-clés : Methanation  Catalyst  support Résumé : We report the preparation and characterization of Ni nanoparticles supported on barium hexaaluminate (BHA) as CO methanation catalysts for the production of synthetic natural gas (SNG). BHA with a high thermal stability was synthesized by a coprecipitation method using aluminum nitrate, barium nitrate, and ammonium carbonate as the precursors. The Ni catalysts supported on the BHA support (Ni/BHA) were prepared by an impregnation method. X-ray diffraction, nitrogen adsorption, transmission electron microscopy, thermogravimetric analysis, H2 temperature-programmed reduction, O2 temperature-programmed oxidation, NH3 temperature-programmed desorption, and X-ray photoelectron spectroscopy are used to characterize the samples. The CO methanation reaction was carried out at pressures of 0.1 and 3.0 MPa, weight hourly space velocities (WHSVs) of 30 000, 120 000, and 240 000 mL·g–1·h–1, with a H2/CO feed ratio of 3, and in the temperature range 300–600 °C. The results show that although the BHA support has a relatively low surface area, Ni/BHA catalysts displayed much higher activity than Al2O3-supported Ni catalysts (Ni/Al2O3) with a similar level of NiO loading even after high temperature hydrothermal treatment. Nearly 100% CO conversion and 90% CH4 yield were achieved over Ni/BHA (NiO, 10 wt %) at 400 °C, 3.0 MPa, and a WHSV of 30 000 mL·g–1·h–1. Long time testing indicates that, compared to Ni/Al2O3 catalyst, Ni/BHA is more stable and is highly resistant to carbon deposition. The superior catalytic performance of the Ni/BHA catalyst is probably related to the relatively larger Ni particle size (20–40 nm), the high thermal stability of BHA support with nonacidic nature, and moderate Ni–BHA interaction. The work demonstrates BHA would be a promising alternative support for the efficient Ni catalysts to SNG production. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26234065