scholarly journals THE EFFECTS OF CERIUM PROMOTER ON THE PERFORMANCE OF COBALT-BASED CATALYSTS IN FISCHER TROPSCH SYNTHESIS FOR LIQUID FUEL PRODUCTION

2020 ◽  
Vol 21 (2) ◽  
pp. 1-11
Author(s):  
Ahmed Lateef Khalaf ◽  
Firas Khaleel Al-Zuhairi ◽  
Wafaa Abdul Kadhim ◽  
Mohd Hasbi Ab Rahim
Keyword(s):  
Space Velocity ◽  
Tropsch Synthesis ◽  
Feed Ratio ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Fuel Production ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Reaction Performance ◽  
Intensive Work

An intensive work of Fischer-Tropsch synthesis (FTS) on a cobalt-based catalyst supported with cerium as a promoter was presented. The influence of space velocity and inlet gas feed ratio on FTS reaction performance was studied for the synthesized catalysts. Incipient wetness impregnation method was utilized to synthesis both unpromoted (25%Co/?-Al2O3) and cerium promoted (1%Ce-25%Co/?-Al2O3) catalysts. The proposed catalysts were examined by N2 adsorption and temperature-programed reduction (TPR). The performance of Ce-promoted and unpromoted cobalt-based catalysts in FTS was assessed in terms of activity and selectivity to desired products (C5+). The obtained results revealed that the addition of cerium by impregnation notably favours the reducibility of cobalt oxides by reducing the reduction temperature. In addition, the promoted catalysts exhibited higher activity and selectivity toward desired products at low space velocity and high inlet gas feed ratio as compared with the unpromoted catalysts. In conclusion, a cerium based cobalt catalyst considered as a suitable candidate to be used in gas to the liquid conversion process. ABSTRAK: Kajian intensif sintesis Fischer-Tropsch (FTS) adalah tentang pemangkin berasas kobalt bersama penggalak cerium. Pengaruh tindak balas FTS pada halaju ruang dan nisbah suapan gas masuk dikaji menggunakan pemangkin yang disintesis. Kaedah impregnasi insipien basah telah digunakan bagi mensintesis pemangkin bukan penggalak (25%Co/?-Al2O3) dan penggalak cerium (1%Ce-25%Co/?-Al2O3). Pemangkin ini diuji dengan penjerapan N2 dan pengurangan suhu terprogram (TPR). Hasil tindak balas penggalak-Ce dan bukan penggalak berasas kobalt dalam FTS diperiksa dari segi aktiviti dan pemilihan hasil (C5+). Tindak balas menunjukkan dengan penambahan cerium melalui kaedah impregnasi dengan ketara mengurangkan kobalt oksida bersama pengurangan suhu. Di samping itu, pemangkin penggalak menunjukkan aktiviti dan pemilihan ke arah hasil pada halaju ruang dan nisbah suapan gas masuk yang tinggi berbanding dengan pemangkin bukan penggalak. Kesimpulan, pemangkin kobalt berasas cerium dianggap sesuai sebagai pemangkin sintesis bagi digunakan dalam proses penukaran gas ke cecair.

scholarly journals Significance of C3 Olefin to Paraffin Ratio in Cobalt Fischer–Tropsch Synthesis

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 967
Author(s):  
Erling Rytter ◽  
Jia Yang ◽  
Øyvind Borg ◽  
Anders Holmen
Keyword(s):  
Residence Time ◽  
Tropsch Synthesis ◽  
Cobalt Catalysts ◽  
Feed Ratio ◽  
Water Addition ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Metal Support Interaction ◽  
Metal Support ◽  
Added Water

The ratio between propene and propane (C3 o/p) during Fischer–Tropsch synthesis (FTS) has been analyzed based on both literature reports and experiments for five catalysts. The latter comprise four cobalt catalysts on γ-alumina with variations in pore sizes, and one catalyst on α-alumina. Overall variations include H2/CO feed ratio, residence time, water addition, transients between test conditions, CO conversion, cobalt particle size, promoter (Re), and support material. It was possible to rationalize all data based on secondary hydrogenation of olefins. In fact, it was deduced that olefins are dominating termination products in FTS, estimated to ca. 90% for C3, but that some paraffins most likely are also produced directly. Increased residence time and high H2/CO feed ratio favors olefin hydrogenation, while added water presumably displaces hydrogen on cobalt giving enhanced C3 o/p. High cobalt dispersion favors hydrogenation, as also promoted by Re. Effect of intraparticle diffusion is seen in transient periods; for example, as water is added or depleted. There is frequently positive correlation between C3 o/p and selectivity to longer chains; the latter expressed as C5+ selectivity, as both are sensitive to hydrogen activity. Some modifications, however, are needed due to the accepted volcano plot for C5+ selectivity with cobalt crystallite size. Titania as support shows unexpectedly low C3 o/p; probably due to SMSI (strong-metal-support-interaction).

Selective Fischer–Tropsch synthesis for jet fuel production over Y3+ modified Co/H-β catalysts

2020 ◽  
Vol 4 (7) ◽  
pp. 3528-3536
Author(s):  
Meng Yang ◽  
Lingjun Zhu ◽  
Yexin Zhuo ◽  
Jiacheng Liang ◽  
Shurong Wang
Keyword(s):  
Jet Fuel ◽  
Acid Strength ◽  
Tropsch Synthesis ◽  
Fuel Production ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Gaseous Hydrocarbons

Y3+, exchanged with the H protons in zeolites, decreased the acid strength of Co/Y-β-x (x = 1, 2, 3, 4) catalysts, which reduced the selectivity of gaseous hydrocarbons (C1–C4) and promoted the generation of JFRHs.

La-ZrO2 and Ru-ZrO2 Promoted Co/SiO2 Catalysts for Fischer-Tropsch Synthesis

2013 ◽  
Vol 634-638 ◽  
pp. 551-554
Author(s):  
Waritsara Bungmek ◽  
Passakorn Kongkinka ◽  
Siwaruk Chotiwan ◽  
Pinsuda Viravathana
Keyword(s):  
Catalytic Activity ◽  
Reaction Time ◽  
Cobalt Catalyst ◽  
Hydrocarbon Chain ◽  
Tropsch Synthesis ◽  
Incipient Wetness Impregnation ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Incipient Wetness ◽  
Co Precipitation

The performance of ZrO2-La promoted silica supported cobalt catalyst (100Co/15ZrO2/ 100Aerosil/0.66La) was compared to the ZrO2-Ru promoted one, 100Co/15ZrO2/100Aerosil/0.66Ru, in Fischer-Tropsch synthesis (FTS). These catalysts were prepared by co-precipitation and incipient wetness impregnation methods. The characterization by XRD confirmed the cobalt phase of Co3O4 in both catalysts. For their catalytic activity on FTS reaction, the results preliminarily showed the higher methane fraction (60-80%) and lower C2-C4(10-20%) and C5+(10-20%) fractions in ZrO2-La promoted catalyst compared to the fractions of methane (20-40%), C2-C4(20-50%), and C5+(10-60%) from the ZrO2-Ru promoted catalyst. During reaction, the maximum n-paraffin selectivity of 40% was at C3and the hydrocarbon chain was up to C6for the ZrO2-La promoted catalyst. For the ZrO2-Ru promoted catalyst, the result showed the maximum n-paraffin of C3at 30 min of reaction time. When the reaction time increased, the maximum n-paraffin selectivity shifted toward higher C number but levelled off (15%) and the hydrocarbon chain was up to C16.

scholarly journals Assessment of composition and calcination parameters in Fischer-Tropsch synthesis over Fe–Mn–Ce/γ-Al2O3 nanocatalyst

2021 ◽  
Vol 76 ◽  
pp. 11
Author(s):  
Reza Roknabadi ◽  
Ali Akbar Mirzaei ◽  
Hossein Atashi
Keyword(s):  
Fixed Bed ◽  
Chemical Properties ◽  
Tropsch Synthesis ◽  
Metal Species ◽  
Light Olefins ◽  
Incipient Wetness Impregnation ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Study Results ◽  
And Performance

The effects of nanocatalyst composition and calcination parameters on the performance of the Fe–Mn–Ce ternary nanocatalysts supported on alumina granules in a laboratory fixed bed microreactor have been evaluated. Nanocatalysts were synthesized by incipient wetness impregnation under vacuum method (simultaneous impregnation of metal species). The samples used for hydrogenation of carbon monoxide via Fischer-Tropsch synthesis. The optimum nanocatalyst composition for production of light olefins (C=2 – C=4) from synthesis gas is 75 wt%Fe–20 wt%Mn–5 wt%Ce. The calcination parameters (temperature, time and atmosphere) were investigated and their effects on the structure and performance of the nanocatalysts were determined. The maximum ratio of olefins/(methane + paraffin) and the best activity and selectivity belonged to the nanocatalyst which was calcined in static air at 500 °C for 7 h. The nanocatalyst precursors and calcined samples (fresh and used) were characterized by XRD, N2 physisorption, FE‒SEM, EDAX, MAP, TG, DSC, and H2–TPR. The present study results confirm that the structural, morphological and physic-chemical properties of the nanocatalyst have been impressed with metal species and calcination parameters.

scholarly journals Intrinsic Kinetics of Fischer–Tropsch Synthesis over Co/CNTs Catalysts: Effects of Support Interaction

2018 ◽  
Vol 43 (3-4) ◽  
pp. 262-273
Author(s):  
Behnam Hatami ◽  
Ahmad Tavasoli ◽  
Alireza Asghari ◽  
Yahya Zamani ◽  
Akbar Zamaniyan
Keyword(s):  
Carbon Nanotubes ◽  
Hydrogen Adsorption ◽  
Catalyst Support ◽  
Spillover Effect ◽  
Tropsch Synthesis ◽  
Cobalt Catalysts ◽  
High Dispersion ◽  
Impregnation Method ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis

The activities of cobalt catalysts prepared by the microemulsion impregnation method on carbon nanotubes (CNTs) and functionalised carbon nanotubes (FCNTs) supports were evaluated in the Fischer–Tropsch synthesis (FTS). The catalysts were characterised by transmission electron microscopy, X-ray diffraction and Brunauer–Emmett–Teller surface area methods. The results show that the cobalt particles in the FCNTs support are mostly located inside the tubes of the CNTs and show a narrower particle size distribution. The experimental results show that the cobalt catalyst supported on FCNTs leads to a higher CO conversion and FTS activity compared to that supported on normal CNTs. Calculated kinetic results show that the activation energies fall within the narrow range of 101.1–107.1 kJ mol−1 and the heat of hydrogen adsorption was calculated to be −40.2 and −26.2 kJ mol−1 for Co/CNTs and Co/FCNTs catalysts respectively. FCNTs, as a catalyst support of Co nanoparticles, maintain high dispersion which can be attributed to a hydrogen spillover effect of functional groups on the CNT surface.

PERFORMANCE OF Ce-INCORPORATED KIT-6 SUPPORTED COBALT CATALYSTS FOR FISCHER–TROPSCH SYNTHESIS

2011 ◽  
Vol 04 (04) ◽  
pp. 369-372 ◽  
Author(s):  
GUODONG TAN ◽  
JINLIN LI ◽  
KONGYONG LIEW
Keyword(s):  
Hydrothermal Process ◽  
Magic Angle Spinning ◽  
Tropsch Synthesis ◽  
Mesoporous Molecular Sieves ◽  
Magic Angle ◽  
Incipient Wetness Impregnation ◽  
Fischer Tropsch ◽  
Co Catalyst ◽  
Fischer Tropsch Synthesis ◽  
Temperature Programmed

A series of Ce -incorporated structure of cubic large mesoporous molecular sieves, KIT-6, with different Ce contents were synthesized by a direct hydrothermal process. A sample of Ce -loaded KIT-6 material was synthesised by incipent wetness impregnation. Similarly, catalysts with 15 wt.% Co loading on the above supports were also synthesized by incipient wetness impregnation. The supports and catalysts were characterized by X-ray diffraction, diffuse reflectance UV-vis, solid-state 29Si magic-angle spinning nuclear magnetic resonance, H2 -temperature programmed reduction, H2 -temperature programmed desorption and oxygen titration. The structure of the KIT-6 support was well retained after Ce incorporation. Small amounts of Ce in the Co catalyst were found to improve the activity and increase the selectivity to C5+ hydrocarbons for Fischer–Tropsch synthesis, while larger amounts of Ce had the reverse effect. Meanwhile, methane selectivity shows an opposite trend as compared with that of C5+ selectivity. Ce -loaded KIT-6 supported Co catalyst showed lower activity than KIT-6 supported Co catalyst.

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