Flame Spray Pyrolysis Synthesized Co and Co/Ru Based Catalysts for the Thermochemical GTL : Fischer Tropsch Process
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Data di Pubblicazione:
2015
Citazione:
Flame Spray Pyrolysis Synthesized Co and Co/Ru Based Catalysts for the Thermochemical GTL : Fischer Tropsch Process / A. Comazzi, C. Pirola, A. Di Michele, M. Compagnoni, F. Galli, S. Cane, F. Manenti, I. Rossetti, C.L. Bianchi. ((Intervento presentato al 23. convegno Topical conference about “Synthesis gas chemistry” tenutosi a Dresden nel 2015.
Abstract:
The Gas-to-Liquid Fischer-Tropsch process is an industrial process that converts syngas, a mixture of H2/CO characterized by a molar ratio equal to 2, into hydrocarbons in the range C1-C100 [1]. A monometallic 10%wtCo and bimetallic 10%wtCo - 0.1%wtRu based catalysts supported on silica were prepared by Flame Spray Pyrolysis (FSP), chatacterized by BET, SEM, TEM, TPR, XRD and tested at different temperature in a FT bench scale plant using a Packed Bed Reactor (PBR).
FSP technique allows to obtain single or mixed metal oxides with an high surface area and high thermal stability thanks to the dispersion, vaporization and flame-decomposition (pyrolysis) of the precursors solution [2]. The solution is composed of Co(CH3COO)2·4H2O (Fluka), Si(OC2H5)4 (Fluka) dissolved in a 1/1 mixture of CH3CH2COOH (Fluka)/C8H10 (Sigma Aldrich). The synthesis of the bimetallic catalyst starts with FSP followed by the addition of an impregnation step of Ru using Ru3(CO)12 (Sigma Aldrich) as a precursor.
Selectivity
T(ᵒC) %CO C2+ CO2 CH4 C7
Co 245
255
260 23.4
60.7
98.8 20.4
54.0
82.0 1
1
6 12
10
11 10
10
10 77
79
73
Co-Ru 225
230
245 55.8
73.2
94.5 50.2
65.1
77.5 1
2
6 9
9
12 18
17
14 72
72
68
The TPR profiles (Figure 1) of both samples show two different peaks; the first one at T= 320-360°C is related to the transition Co3O4CoO and the second at T= 700-800°C is attributable to the reduction step CoOCo [3]; Figure 1 also highlight that the insertion of Ru decrease both peaks temperatures of about 20°C.
The samples have been reduced in situ at T= 400°C and then tested at different temperature in the range T= 225-260°C at P= 2.0 MPa, H2/CO= 2 with sl/h/gcat= 3.0. The catalytic results summarized in Table 1 show that the bimetallic catalyst is more active in therms of CO conversion and C2+yeld if compared with the monometallic one, nevertheless the unpromoted catalyst shows selectivity to >C7 higher respect to the Ru-doped catalyst. Finally, the selectivity toward the reaction products is not largely influenced in the range of temperature tested.
Reference
[1] Q. Zhang, J. Kang, Wang Y, Chem. Cat. Chem. 2010, 2, 1030.
[2] H. Jang, C. Seong, Y. Suh, H. Kim, C. Lee C, Sci. and Tech. 2004, 38, 1027.
[3] C. Pirola, C.L. Bianchi, A. Di Michele, S. Vitali, V. Ragaini, Cat. Comm. 2009, 10, 823.
Tipologia IRIS:
14 - Intervento a convegno non pubblicato
Elenco autori:
A. Comazzi, C. Pirola, A. Di Michele, M. Compagnoni, F. Galli, S. Cane, F. Manenti, I. Rossetti, C.L. Bianchi
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