Cobalt Catalysts Preparation and Characterization over Alumina Support for Fischer Tropsch Synthesis

2017 ◽  
Vol 2 (1) ◽  
pp. 51-61
Author(s):  
Nima Mohammadi Taher ◽  
Maedeh Mahmoudi ◽  
Seyyede Shahrzad Sajjadivand
Keyword(s):  
Surface Area ◽  
Cobalt Catalyst ◽  
Cobalt Content ◽  
Tropsch Synthesis ◽  
Cobalt Catalysts ◽  
Fischer Tropsch ◽  
Alumina Support ◽  
Fischer Tropsch Synthesis ◽  
X Ray ◽  
Temperature Programmed

Abstract An investigation was done to develop and characterize the alumina supported cobalt catalyst for Fischer-Tropsch Synthesis to produce biodiesel from biomass with the aim to produce alumina-supported cobalt catalysts containing 7 to 19 wt.% cobalt content. By using incipient wetness impregnation of γ-Al2O3 supports with cobalt nitrate hexahydrate with ethanol and distilled water solutions; the 14 wt.% cobalt content in catalyst was achieved. Nitrogen adsorption-desorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray fluorescence (XRF), H2temperature programmed reduction (H2-TPR), temperature programmed desorption (TPD), temperature programmed oxidation (TPO) and carbon monoxide chemisorption were used for the characterization of the catalysts to attain an appropriate cobalt catalyst. In order to investigate the effect of the impregnation on the crystalline size, surface area and cobalt content, three different impregnation methods with various durations were investigated. In addition, increasing the impregnation duration increased the cobalt content and its dispersion. Based on results, positive effect of the alumina support and impregnation duration on the crystallite size, surface area, and pore diameter, reducibility of the catalyst and cobalt dispersion were investigated. Thus, cobalt catalyst for using in fixed bed reactor to produce biodiesel from biomass through Fischer-Tropsch Synthesis was prepared and characterized.

scholarly journals The Effect of Cobalt Catalyst Loading at Very High Pressure Plasma-Catalysis in Fischer-Tropsch Synthesis

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1324
Author(s):  
Byron Bradley Govender ◽  
Samuel Ayodele Iwarere ◽  
Deresh Ramjugernath
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
Energy Consumption ◽  
Cobalt Catalyst ◽  
Tropsch Synthesis ◽  
Electrode Gap ◽  
Fischer Tropsch ◽  
Co Catalyst ◽  
Fischer Tropsch Synthesis ◽  
X Ray

The influence of different catalyst cobalt loadings on the C1-C3 hydrocarbon product yields and energy consumption in plasma-catalytic Fischer-Tropsch synthesis (FTS) was investigated from the standpoint of various reactor operating conditions: pressure (0.5 to 10 MPa), current (250 to 450 mA) and inter-electrode gap (0.5 to 2 mm). This was accomplished by introducing a mullite substrate, coated with 2 wt%-Co/5 wt%-Al2O3, 6 wt%-Co/5 wt%-Al2O3 or 0 wt%-Co/5 wt%-Al2O3 (blank catalyst), into a recently developed high pressure arc discharge reactor. The blank catalyst was ineffective in synthesizing hydrocarbons. Between the blank catalyst, 2 wt%, and the 6 wt% Co catalyst, the 6 wt% improved C1-C3 hydrocarbon production at all conditions, with higher yields and relatively lower energy consumption at (i) 10 MPa at 10 s, and 2 MPa at 60 s, for the pressure variation study; (ii) 250 mA for the current variation study; and (iii) 2 mm for the inter-electrode gap variation study. The inter-electrode gap of 2 mm, using the 6 wt% Co catalyst, led to the overall highest methane, ethane, ethylene, propane and propylene yields of 22 424, 517, 101, 79 and 19 ppm, respectively, compared to 40 ppm of methane and < 1 ppm of C1-C3 hydrocarbons for the blank catalyst, while consuming 660 times less energy for the production of a mole of methane. Furthermore, the 6 wt% Co catalyst produced carbon nanotubes (CNTs), detected via transmission electron microscopy (TEM). In addition, scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX) and x-ray diffraction (XRD) showed that the cobalt catalyst was modified by plasma treatment.

scholarly journals Cobalt Based Catalysts Supported on Two Kinds of Beta Zeolite for Application in Fischer-Tropsch Synthesis

Catalysts ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 497 ◽  
Author(s):  
Renata Sadek ◽  
Karolina A. Chalupka ◽  
Pawel Mierczynski ◽  
Jacek Rynkowski ◽  
Jacek Gurgul ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalytic Performance ◽  
Tropsch Synthesis ◽  
Zeolite Catalysts ◽  
Beta Zeolite ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
X Ray ◽  
Liquid Products ◽  
Temperature Programmed

Co-containing Beta zeolite catalysts prepared by a wet impregnation and two-step postsynthesis method were investigated. The activity of the catalysts was examined in Fischer-Tropsch synthesis (FTS), performed at 30 atm and 260 °C. The physicochemical properties of all systems were investigated by means of X-ray diffraction (XRD), in situ XRD, temperature programmed desorption of ammonia (NH3-TPD), X-ray Photoelectron Spectroscopy (XPS), temperature programmed reduction of hydrogen (TPR-H2), and transmission electron microscopy (TEM). Among the studied catalysts, the best results were obtained for the samples prepared by a two-step postsynthesis method, which achieved CO conversion of about 74%, and selectivity to liquid products of about 86%. The distribution of liquid products for Red-Me-Co20Beta was more diversified than for Red-Mi-Co20Beta. It was observed that significant influence of the zeolite dealumination of mesoporous zeolite on the catalytic performance in FTS. In contrast, for microporous catalysts, the dealumination did not play such a significant role and the relatively high activity is observed for both not dealuminated and dealuminated catalysts. The main liquid products of FTS on both mesoporous and microporous catalysts were C10-C14 isoalkanes and n-alkanes. The iso-/n-alkanes ratio for dealuminated zeolite catalysts was three times higher than that for not dealuminated ones, and was related to the presence of different kind of acidic sites in both zeolite catalysts.

Fischer–Tropsch synthesis over alumina-supported cobalt catalysts: effects of different spray temperature of aluminum slurry

2016 ◽  
Vol 94 (5) ◽  
pp. 515-522
Author(s):  
Yan Liu ◽  
Litao Jia ◽  
Bo Hou ◽  
Debao Li
Keyword(s):  
Cobalt Catalyst ◽  
Tropsch Synthesis ◽  
Cobalt Catalysts ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
High Conversion Rate ◽  
Supported Cobalt Catalysts ◽  
Aluminum Precursor ◽  
Excellent Stability ◽  
Aluminum Precursors

Aluminum slurry was obtained by precipitating Al(NO3)3·9H2O and ammonium carbonate, and the slurry was dried by adopting spray means. The effects of different spray temperature on the as-synthesised aluminum precursors, calcined alumina, and the supported cobalt catalysts were investigated by the characterizations of SEM, XRD, TG-DTA, H2-TPD, H2-TPR, etc., and the activity and stability of the as-prepared catalysts for Fischer–Tropsch synthesis were also studied. It indicated that the aluminum precursor spray dried at 250 °C exhibited homogeneous microspheres, the calcined alumina exhibited single-particle size distribution and monomodal pore distribution, and the corresponding supported cobalt catalyst possessed proper cobalt particles (6.4 nm), which was benefitial for acquiring a high conversion rate (the turnover frequency is 17.2 × 10−3/s) and excellent stability (the deactivation rate is 0.31%) for Fischer–Tropsch synthesis.

scholarly journals Fischer–Tropsch Synthesis: Effect of the Promoter’s Ionic Charge and Valence Level Energy on Activity

Reactions ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 408-426
Author(s):  
Mirtha Z. Leguizamón León Ribeiro ◽  
Joice C. Souza ◽  
Muthu Kumaran Gnanamani ◽  
Michela Martinelli ◽  
Gabriel F. Upton ◽  
...  
Keyword(s):  
Tropsch Synthesis ◽  
Orbital Energy ◽  
Level Energy ◽  
Ionic Charge ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
X Ray ◽  
Temperature Programmed ◽  
Similar Ionic Radius

In this contribution, we examine the effect of the promoter´s ionic charge and valence orbital energy on the catalytic activity of Fe-based catalysts, based on in situ synchrotron X-ray powder diffraction (SXRPD), temperature-programmed-based techniques (TPR, TPD, CO-TP carburization), and Fischer–Tropsch synthesis catalytic testing studies. We compared the promoting effects of K (a known promoter for longer-chained products) with Ba, which has a similar ionic radius but has double the ionic charge. Despite being partially “buried” in a crystalline BaCO3 phase, the carburization of the Ba-promoted catalyst was more effective than that of K; this was primarily due to its higher (2+) ionic charge. With Ba2+, higher selectivity to methane and lighter products were obtained compared to the K-promoted catalysts; this is likely due to Ba´s lesser capability of suppressing H adsorption on the catalyst surface. An explanation is provided in terms of a more limited mixing between electron-filled Ba2+ 5p and partially filled Fe 3d orbitals, which are expected to be important for the chemical promotion, as they are further apart in energy compared to the K+ 3p and Fe 3d orbitals.

scholarly journals Microwave Assisted Co/SiO2 preparation for Fischer-Tropsch synthesis

2020 ◽  
Vol 20 (2) ◽  
pp. 42-48
Author(s):  
TEUKU MUKHRIZA ◽  
KUI ZHANG ◽  
ANH N. PHAN
Keyword(s):  
Conventional Method ◽  
Cobalt Catalyst ◽  
Thermo Gravimetric Analysis ◽  
Cobalt Content ◽  
Tropsch Synthesis ◽  
Gravimetric Analysis ◽  
Fischer Tropsch ◽  
Porous Support ◽  
Fischer Tropsch Synthesis ◽  
Ft Synthesis

Cobalt catalyst has been widely used for Fischer-Tropsch (FT) Synthesis in Industry. The most common method to prepare cobalt catalyst is impregnations. Metal is deposited on porous support by contacting dry support with solution containing dissolved cobalt precursor. This step will follow by drying, calcination and reduction. The heating step used in this conventional method, however, may lead to the formation of metal silicate which is inactive site for catalysis.  In this study, author explore the use of microwave to prepare catalyst compared to conventional drying method. Cobalt catalyst with SiO2 support was prepared and characterized. Particle size, surface area, and cobalt content were investigated. Crystallite size of 3-8 nm was formed which was reported to be the optimum size for cobalt catalyst in FT Synthesis. Scanning Electron Microscope (SEM) and Transmission Electron Microscopy (TEM) image revealed that microwave catalyst showed better uniformity and cobalt dispersion on silica support. Thermo-Gravimetric Analysis (TGA) study also indicated that this catalyst has good stability at Low Temperature Fischer-Tropsch Synthesis. The catalysts were then applied plasma assisted FT process over a range of power plasma (20-60W) to investigate the effect on the conversion and selectivity. The results showed that microwave catalyst exhibit lower CO conversion at 42.06% compared to conventional method at 68.32%. However, microwave catalyst is more favourable for long chain hydrocarbon selectivity.

scholarly journals Fischer-Tropsch Synthesis: Cd, In and Sn Effects on a 15%Co/Al2O3 Catalyst

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 862 ◽  
Author(s):  
Wenping Ma ◽  
Gary Jacobs ◽  
Wilson D. Shafer ◽  
Yaying Ji ◽  
Jennifer L. S. Klettlinger ◽  
...  
Keyword(s):  
Active Sites ◽  
Catalyst Activity ◽  
Tropsch Synthesis ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
X Ray ◽  
H2 Chemisorption ◽  
Co Catalysts ◽  
Temperature Programmed ◽  
Al2o3 Catalyst

The effects of 1% of Cd, In and Sn additives on the physicochemical properties and Fischer-Tropsch synthesis (FTS) performance of a 15% Co/Al2O3 catalyst were investigated. The fresh and spent catalysts were characterized by BET, temperature programmed reduction (TPR), H2-chemisorption, NH3 temperature programmed desorption (TPD), X-ray absorption near edge spectroscopy (XANES), and X ray diffraction (XRD). The catalysts were tested in a 1 L continuously stirred tank reactor (CSTR) at 220 °C, 2.2 MPa, H2/CO = 2.1 and 20–55% CO conversion. Addition of 1% of Cd or In enhanced the reduction degree of 15%Co/Al2O3 by ~20%, while addition of 1% Sn slightly hindered it. All three additives adversely impacted Co dispersion by 22–32% by increasing apparent Co cluster size based on the H2-chemisorption measurements. However, the decreased Co active site density resulting from the additives did not result in a corresponding activity loss; instead, the additives decreased the activity of the Co catalysts to a much greater extent than expected, i.e., 82–93%. The additional detrimental effect on catalyst activity likely indicates that the Cd, In and Sn additives migrated to and covered active sites during reaction and/or provided an electronic effect. XANES results showed that oxides of the additives were present during the reaction, but that a fraction of metal was also likely present based on the TPR and reaction testing results. This is in contrast to typical promoters that become metallic at or below ~350 °C, such as noble metal promoters (e.g., Pt, Ru) and Group 11 promoters (e.g., Ag, Au) on Co catalysts in earlier studies. In the current work, all three additives remarkably increased CH4 and CO2 selectivities and decreased C5+ selectivity, with the Sn and In additives having a greater effect. Interestingly, the Cd, In, or Sn additives were found to influence hydrogenation and isomerization activities. At a similar conversion level (i.e., in the range of 40–50%), the additives significantly increased 2-C4 olefin content from 3.8 to 10.6% and n-C4 paraffin from 50 to 61% accompanied by decreases in 1-C4 olefin content from 48 to 30%. The Sn contributed the greatest impact on the secondary reactions of 1-olefins, followed by the In and Cd. NH3-TPD results suggest enhanced acid sites on cobalt catalysts resulting from the additives, which likely explains the change in selectivities for the different catalysts.

scholarly journals Ruthenium-Loaded Halloysite Nanotubes as Mesocatalysts for Fischer–Tropsch Synthesis

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1764 ◽  
Author(s):  
Anna Stavitskaya ◽  
Kristina Mazurova ◽  
Mikhail Kotelev ◽  
Oleg Eliseev ◽  
Pavel Gushchin ◽  
...  
Keyword(s):  
Ethylenediaminetetraacetic Acid ◽  
Halloysite Nanotubes ◽  
Tropsch Synthesis ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
X Ray ◽  
Ru Nanoparticles ◽  
Temperature Programmed ◽  
Major Factors ◽  
Acetone Azine

Halloysite aluminosilicate nanotubes loaded with ruthenium particles were used as reactors for Fischer–Tropsch synthesis. To load ruthenium inside clay, selective modification of the external surface with ethylenediaminetetraacetic acid, urea, or acetone azine was performed. Reduction of materials in a flow of hydrogen at 400 °C resulted in catalysts loaded with 2 wt.% of 3.5 nm Ru particles, densely packed inside the tubes. Catalysts were characterized by N2-adsorption, temperature-programmed desorption of ammonia, transmission electron microscopy, X-ray fluorescence, and X-ray diffraction analysis. We concluded that the total acidity and specific morphology of reactors were the major factors influencing activity and selectivity toward CH4, C2–4, and C5+ hydrocarbons in the Fischer–Tropsch process. Use of ethylenediaminetetraacetic acid for ruthenium binding gave a methanation catalyst with ca. 50% selectivity to methane and C2–4. Urea-modified halloysite resulted in the Ru-nanoreactors with high selectivity to valuable C5+ hydrocarbons containing few olefins and a high number of heavy fractions (α = 0.87). Modification with acetone azine gave the slightly higher CO conversion rate close to 19% and highest selectivity in C5+ products. Using a halloysite tube with a 10–20-nm lumen decreased the diffusion limitation and helped to produce high-molecular-weight hydrocarbons. The extremely small C2–C4 fraction obtained from the urea- and azine-modified sample was not reachable for non-templated Ru-nanoparticles. Dense packing of Ru nanoparticles increased the contact time of olefins and their reabsorption, producing higher amounts of C5+ hydrocarbons. Loading of Ru inside the nanoclay increased the particle stability and prevented their aggregation under reaction conditions.

XAS Study on Calcination Effect of Silica Supported Cobalt Catalysts for Fischer-Tropsch Synthesis

2012 ◽  
Vol 608-609 ◽  
pp. 1413-1418
Author(s):  
Siwaruk Chotiwan ◽  
Waritsara Bungmek ◽  
Sanya Prangsri-Aroon ◽  
Pinsuda Viravathana
Keyword(s):  
Performance Testing ◽  
Tropsch Synthesis ◽  
Cobalt Catalysts ◽  
Fischer Tropsch ◽  
Edge Structure ◽  
Fischer Tropsch Synthesis ◽  
X Ray ◽  
Supported Cobalt Catalysts ◽  
Methane Selectivity ◽  
X Ray Absorption

The precalcined and calcined silica supported cobalt catalysts at 15, 20, and 25%Co were investigated by X-ray Absorption Spectroscopy (XAS) including the X-ray absorption near edge structure (XANES) and the extended X-ray absorption fine structure (EXAFS). The results showed the phase of Co(NO3)2.6H2O in all precalcined catalysts, which corresponded to the XRD measurement. When increasing the amount of cobalt in the precalcined catalysts, there was the presence of ordered Co(NO3)2.6H2O phase. After calcination in Ar at 600°C for 6 h, the Co3O4phase was presented in all calcined catalysts. For the catalytic performance testing, the selected 20%Co/Aerosil_wi_calcined catalyst was reduced at 450°C in H2and operated at 190°C with a total pressure of 10 bar and H2/CO flow rate of 20:10 ml/min for Fischer-Tropsch synthesis. After reaction testing, the used 20%Co/Aerosil_wi catalyst showed the main phase of Co3O4. The result showed high methane selectivity at the beginning of reaction. By increasing of reaction time, the methane selectivity tended to decrease, whereas the C2-C4and C5+selectivity was increased.

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