scholarly journals Impact of Coordination Features of Co(II)-Glycine Complex on the Surface Sites of Co/SiO2 for Fischer–Tropsch Synthesis

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1295
Author(s):  
Qing-Qing Hao ◽  
Min Hu ◽  
Zhi-Xia Xie ◽  
Xiaoxun Ma ◽  
Wei Wang ◽  
...  
Keyword(s):  
Conventional Method ◽  
Specific Activity ◽  
Chelating Agent ◽  
Molar Ratio ◽  
Cobalt Hydroxide ◽  
Fischer Tropsch ◽  
Co Catalysts ◽  
Ft Synthesis ◽  
Improved Stability ◽  
Co Nanoparticles

To investigate the effect of coordination features of Co(II)-glycine complex on the performance of Co/SiO2 for Fischer–Tropsch (FT) synthesis, Co(II)-glycine complex precursors were prepared by the conventional method, i.e., simply adding glycine to the solution of Co nitrate and novel route, i.e., reaction of glycine with cobalt hydroxide. The SiO2-supported Co catalysts were prepared by using the different Co(II)-glycine complexes. It is found that glycine is an effective chelating agent for improving the dispersion of Co and the mass-specific activity in FT synthesis when the molar ratio of glycine/Co2+ = 3, which is independent to the preparation method in this study. Significantly, the surface Co properties were significantly influenced by the coordination features of the Co2+ and the molar ratio of glycine to Co2+ in the Co(II)-glycine complex. Specifically, the Co(3gly)/SiO2 catalyst prepared by the novel route exhibits smaller and homogenous Co nanoparticles, which result in improved stability compared to Co-3gly/SiO2 prepared by the conventional method. Thus, the newly developed method is more controllable and promising for the synthesis of Co-based catalysts for FT synthesis.

Investigation of the deactivation behavior of Co catalysts in Fischer–Tropsch synthesis using encapsulated Co nanoparticles with controlled SiO2 shell layer thickness

2020 ◽  
Vol 10 (4) ◽  
pp. 1182-1192 ◽  
Author(s):  
Jinglin Yang ◽  
Xuejin Fang ◽  
Yuebing Xu ◽  
Xiaohao Liu
Keyword(s):  
Layer Thickness ◽  
Tropsch Synthesis ◽  
Shell Layer ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Co Catalysts ◽  
Varying Thickness ◽  
Sio2 Shell ◽  
Co Nanoparticles

The deactivation behavior of Co catalysts was clearly elucidated using Co nanoparticles confined by a porous SiO2 shell layer with varying thickness and different reaction temperatures.

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.

Combining Fischer-Tropsch (FT) and Hydrocarbon Reactions under FT Reaction Conditions -- Catalyst and Reactor Studies with Co or Fe and Pt/ZSM-5

2007 ◽  
Vol 5 (1) ◽  
Author(s):  
Alba Mena Subiranas ◽  
Georg Schaub
Keyword(s):  
Catalyst Deactivation ◽  
Reaction Rates ◽  
Fischer Tropsch ◽  
Transportation Fuels ◽  
Co Catalysts ◽  
Ft Synthesis ◽  
Acidic Sites ◽  
Hydrocarbon Molecules ◽  
Methane Selectivity ◽  
Hydrocarbon Reactions

Fischer-Tropsch synthesis (FTS) offers the potential to produce high-value transportation fuels or petrochemicals from biomass (``2nd generation biofuels"). Primary synthesis products contain mainly n-alkanes and n-alkenes, ranging from methane to high molecular weight waxes. Bifunctional catalysts, as used in petroleum refining, are capable of modifying hydrocarbon molecules. They are characterized by the presence of acidic sites, which provide the hydrocracking and isomerization functions, as well as metal sites, which provide hydro-/dehydrogenation functions, and thus avoid the formation of carbon. The present study addresses the combination of FT synthesis (with Co or Fe catalysts) and hydrocarbon modification reactions. Experimental results obtained in a dual layer configuration with Fe and Co catalysts and Pt/ZSM-5 indicate i) an increase of branched hydrocarbons in the gasoline range (C5-C10), ii) a decrease of alkene and alcohol yields, iii) partial hydrocracking of long chain hydrocarbon molecules leading to higher yields of gasoline and distillates, iv) nearly constant methane selectivity in comparison with the FT catalyst alone, and v) no significant catalyst deactivation. In addition, studies with 1-octene as the model compound were carried out, being mixed with synthesis gas H2/CO or with H2/Ar. The presence of CO decreases reaction rates of hydrogenation and hydrocracking, although all reactions still occur to a significant extent. For the conditions used in this study (1 MPa, 200-300 °C, 4000 kg s/m3), a significant change of hydrocarbon product composition with hydroprocessing catalyst functions added can be observed.

A New Method for Plasminogen Standardization

1968 ◽  
Vol 20 (03/04) ◽  
pp. 548-554
Author(s):  
J Gajewski ◽  
G Markus
Keyword(s):  
Proteolytic Activity ◽  
Specific Activity ◽  
Molar Ratio ◽  
Sharp Transition ◽  
Equivalence Point ◽  
Constant Amount ◽  
Residual Level ◽  
Activity Measurements ◽  
Complete Saturation ◽  
Human Plasminogen

SummaryA method for the standardization of human plasminogen is proposed, based on the stoichiometric interaction between plasminogen and streptokinase, resulting in inhibition of proteolytic activity. Activation of a constant amount of plasminogen with increasing amounts of streptokinase yields linearly decreasing activities, as a function of streptokinase, with a sharp transition to a constant residual level. The point of transition corresponds to complete saturation of plasmin with streptokinase in a 1:1 molar ratio, and is therefore a measure of the amount of plasminogen present initially, in terms of streptokinase equivalents. The equivalence point is independent of the kind of protein substrate used, buffer, pH, length of digestion and, within limits, temperature. The method, therefore, is not subject to the variations commonly encountered in the usual determination based on specific activity measurements.

scholarly journals Preparation and High-Throughput Testing of TiO2-Supported Co Catalysts for Fischer‒Tropsch Synthesis

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 352
Author(s):  
Christian Schulz ◽  
Peter Kolb ◽  
Dennis Krupp ◽  
Lars Ritter ◽  
Alfred Haas ◽  
...  
Keyword(s):  
High Throughput ◽  
Anatase Phase ◽  
Rutile Phase ◽  
Tropsch Synthesis ◽  
Performance Tests ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Co Catalysts ◽  
Impregnation Technique ◽  
Co Conversion

A series of Co/TiO2 catalysts was tested in a parameters field study for Fischer‒Tropsch synthesis (FTS). All catalysts were prepared by the conventional impregnation technique to obtain an industrially relevant Co content of 10 wt % or 20 wt %, respectively. In summary, 10 different TiO2 of pure anatase phase, pure rutile phase, as well as mixed rutile and anatase phase were used as supports. Performance tests were conducted with a 32-fold high-throughput setup for accelerated catalyst benchmarking; thus, 48 experiments were completed within five weeks in a relevant operation parameters field (170 °C to 233.5 °C, H2/CO ratio 1 to 2.5, and 20 bar(g)). The most promising catalyst showed a CH4 selectivity of 5.3% at a relevant CO conversion of 60% and a C5+ productivity of 2.1 gC5+/(gCo h) at 207.5 °C. These TiO2-based materials were clearly differentiated with respect to the application as supports in Co-catalyzed FTS catalysis. The most prospective candidates are available for further FTS optimization at a commercial scale.

scholarly journals Ru-M (M = Fe or Co) Catalysts with high Ru surface concentration for Fischer-Tropsch synthesis

Fuel ◽  
2021 ◽  
Vol 293 ◽  
pp. 120435
Author(s):  
Dalia Liuzzi ◽  
Francisco J. Pérez-Alonso ◽  
Sergio Rojas
Keyword(s):  
Surface Concentration ◽  
Tropsch Synthesis ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Co Catalysts

Positive effects of a halloysite-supported Cu/Co catalyst fabricated by a urea-driven deposition precipitation method on the CO-SCR reaction and SO2 poisoning

2021 ◽  
Author(s):  
Wei-Jing Li ◽  
Shu Tsai ◽  
Ming-Yen Wey
Keyword(s):  
Co Oxidation ◽  
Catalytic Reduction ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Halloysite Nanotube ◽  
Co Catalyst ◽  
Reduction Of No ◽  
Co Catalysts ◽  
Positive Effects ◽  
So2 Poisoning

Cu/Co catalysts were prepared on halloysite nanotube supports by a urea-driven deposition-precipitation method for CO oxidation and the selective catalytic reduction of NO (CO-SCR). First, the Cu/NH3 molar ratio was...

scholarly journals In situ observation of phase changes of a silica-supported cobalt catalyst for the Fischer–Tropsch process by the development of a synchrotron-compatible in situ/operando powder X-ray diffraction cell

2018 ◽  
Vol 25 (6) ◽  
pp. 1673-1682 ◽  
Author(s):  
Adam S. Hoffman ◽  
Joseph A. Singh ◽  
Stacey F. Bent ◽  
Simon R. Bare
Keyword(s):  
High Pressure ◽  
Elevated Pressure ◽  
Phase Changes ◽  
In Situ Observation ◽  
X Ray Diffraction ◽  
Fischer Tropsch ◽  
X Ray ◽  
And Performance ◽  
Co Nanoparticles

In situ characterization of catalysts gives direct insight into the working state of the material. Here, the design and performance characteristics of a universal in situ synchrotron-compatible X-ray diffraction cell capable of operation at high temperature and high pressure, 1373 K, and 35 bar, respectively, are reported. Its performance is demonstrated by characterizing a cobalt-based catalyst used in a prototypical high-pressure catalytic reaction, the Fischer–Tropsch synthesis, using X-ray diffraction. Cobalt nanoparticles supported on silica were studied in situ during Fischer–Tropsch catalysis using syngas, H2 and CO, at 723 K and 20 bar. Post reaction, the Co nanoparticles were carburized at elevated pressure, demonstrating an increased rate of carburization compared with atmospheric studies.

Design Criteria and Optimization of Heat Recovery Steam Cycles for High-Efficiency, Coal-Fired, Fischer-Tropsch Plants

2012 ◽  
Author(s):  
Emanuele Martelli ◽  
Thomas G. Kreutz ◽  
Manuele Gatti ◽  
Paolo Chiesa ◽  
Stefano Consonni
Keyword(s):  
Heat Recovery ◽  
High Efficiency ◽  
Thermal Power ◽  
Combined Cycle ◽  
Synthesis Process ◽  
Integrated Gasification Combined Cycle ◽  
Fischer Tropsch ◽  
Ft Synthesis ◽  
Optimization Methodology ◽  
Integrated Gasification

In this work, the “HRSC Optimizer”, a recently developed optimization methodology for the design of Heat Recovery Steam Cycles (HRSCs), Steam Generators (HRSGs) and boilers, is applied to the design of steam cycles for three interesting coal fired, gasification based, plants with CO2 capture: a Fischer-Tropsch (FT) synthesis process with high recycle fraction of the unconverted FT gases (CTL-RC-CCS), a FT synthesis process with once-through reactor (CTL-OT-CCS), and an Integrated Gasification Combined Cycle (IGCC-CCS) based on the same technologies. The analysis reveals that designing efficient HRSCs for the IGCC and the once-through FT plant is relatively straightforward, while designing the HRSC for plant CTL-RC-CCS is very challenging because the recoverable thermal power is concentrated at low temperatures (i.e., below 260 °C) and only a small fraction can be used to superheat steam. As a consequence of the improved heat integration, the electric efficiency of the three plants is increased by about 2 percentage points with respect to the solutions previously published.

Fischer Tropsch synthesis: Deuterium isotopic study for the formation of oxygenates over CeO2 supported Pt–Co catalysts

2012 ◽  
Vol 25 ◽  
pp. 12-17 ◽  
Author(s):  
Muthu Kumaran Gnanamani ◽  
Gary Jacobs ◽  
Wilson D. Shafer ◽  
Mauro C. Ribeiro ◽  
Venkat Ramana Rao Pendyala ◽  
...  
Keyword(s):  
Tropsch Synthesis ◽  
Isotopic Study ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Co Catalysts
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