Effect of Temperature, Syngas Space Velocity and Catalyst Stability of Co-Mn/CNT Bimetallic Catalyst on Fischer Tropsch Synthesis Performance

The effect of reaction temperature, syngas space velocity, and catalyst stability on Fischer-Tropsch reaction was investigated using a fixed-bed microreactor. Cobalt and Manganese bimetallic catalysts on carbon nanotubes (CNT) support (Co-Mn/CNT) were synthesized via the strong electrostatic adsorption (SEA) method. For testing the performance of the catalyst, Co-Mn/CNT catalysts with four different manganese percentages (0, 5, 10, 15, and 20%) were synthesized. Synthesized catalysts were then analyzed by TEM, FESEM, atomic absorption spectrometry (AAS), and zeta potential sizer. In this study, the temperature was varied from 200 to 280 °C and syngas space velocity was varied from 0.5 to 4.5 L/g.h. Results showed an increasing reaction temperature from 200 °C to 280 °C with reaction pressure of 20 atm, the Space velocity of 2.5 L/h.g and H2/CO ratio of 2, lead to the rise of CO % conversion from 59.5% to 88.2% and an increase for C5+ selectivity from 83.2% to 85.8%. When compared to the other catalyst formulation, the catalyst sample with 95% cobalt and 5% manganese on CNT support (95Co5Mn/CNT) performed more stable for 48 h on stream.

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Effects of Cu and K Promoters on the Catalytic Performance of Iron-Based Nanocatalyst for Fischer-Tropsch Synthesis

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.832.15 ◽

2013 ◽

Vol 832 ◽

pp. 15-20 ◽

Cited By ~ 1

Author(s):

Sara Faiz Hanna Tasfy ◽

Noor Asmawati Mohd Zabidi ◽

Duvvuri Subbarao

Keyword(s):

Atmospheric Pressure ◽

Fixed Bed ◽

Space Velocity ◽

Catalytic Performance ◽

Reactant Ratio ◽

Impregnation Method ◽

Fischer Tropsch ◽

Heavy Hydrocarbons ◽

Co Conversion ◽

Iron Based

Iron-based nanocatalyst was prepared via impregnation method on SiO2 support. The effects of promoters, namely, K and Cu, on the physical properties and catalytic performance in FTS have been investigated. The FTS performance of the synthesized nanocatalysts was examined in a fixed-bed microreactor at temperature of 523K, atmospheric pressure, 1.5 reactant ratio (H2/CO) and space velocity of 3L/g-cat.h. In FTS reaction, Cu promoter resulted in a lower CO conversion and C5+ hydrocarbons selectivity but higher selectivity to the lighter hydrocarbons (C1-C4) comparedto those obtained using the K promoter. Higher CO conversion (28.9%) and C5+ hydrocarbons selectivity (54.4%) were obtained using K as a promoter compared to that of Cu promoter. However, the K-promoted nanocatalyst resulted in a lower CO conversion but higher selectivity of the heavy hydrocarbons (C5+) compared to those obtained using the un-promoted nanocatalyst.

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Effect of Pressure, H2/CO Ratio and Reduction Conditions on Co–Mn/CNT Bimetallic Catalyst Performance in Fischer–Tropsch Reaction

Symmetry ◽

10.3390/sym12050698 ◽

2020 ◽

Vol 12 (5) ◽

pp. 698

Author(s):

Omid Akbarzadeh ◽

Noor Asmawati Mohd Zabidi ◽

Guangxin Wang ◽

Amir Kordijazi ◽

Hamed Sadabadi ◽

...

Keyword(s):

Performance Test ◽

Bimetallic Catalyst ◽

Fixed Bed ◽

Tropsch Synthesis ◽

Process Conditions ◽

Gravimetric Analysis ◽

Product Analysis ◽

Fischer Tropsch ◽

Fischer Tropsch Synthesis ◽

Strong Electrostatic Adsorption

The effects of process conditions on Fischer–Tropsch Synthesis (FTS) product distributions were studied using a fixed-bed microreactor and a Co–Mn/CNT catalyst. Cobalt and Manganese, supported on Carbon Nanotubes (CNT) catalyst were prepared by a Strong Electrostatic Adsorption (SEA) method. CNT supports were initially acid and thermally treated in order to functionalize support to uptake more Co clusters. Catalyst samples were characterized by Transmitted Electron Microscope (TEM), particle size analyzer, and Thermal Gravimetric Analysis (TGA). TEM images showed catalyst metal particle intake on CNT support with different Co and Mn loading percentage. Performance test of Co–Mn/CNT in Fischer–Tropsch synthesis (FTS) was carried out in a fixed-bed micro-reactor at different pressures (from 1 atm to 25 atm), H2/CO ratio (0.5–2.5), and reduction temperature and duration. The reactor was connected to the online Gas Chromatograph (GC) for product analysis. It was found that the reaction conditions have the dominant effect on product selectivity. Cobalt catalyst supported on acid and thermal pre-treated CNT at optimum reaction condition resulted in CO conversion of 58.7% and C5+ selectivity of 59.1%.

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Effects of Cobalt Loading, Particle Size, and Calcination Condition on Co/CNT Catalyst Performance in Fischer–Tropsch Reactions

Symmetry ◽

10.3390/sym11010007 ◽

2018 ◽

Vol 11 (1) ◽

pp. 7 ◽

Cited By ~ 9

Author(s):

Omid Akbarzadeh ◽

Noor Mohd Zabidi ◽

Yasmin Abdul Wahab ◽

Nor Hamizi ◽

Zaira Chowdhury ◽

...

Keyword(s):

Particle Size ◽

Fixed Bed ◽

Xrd Analysis ◽

Bet Surface Area ◽

Fischer Tropsch ◽

Strong Electrostatic Adsorption ◽

Transmission Electron ◽

Co Conversion ◽

Cobalt Loading ◽

Temperature Programmed

The strong electrostatic adsorption (SEA) method was applied to the synthesis of a cobalt (Co) catalyst on a multi-walled carbon nanotube (CNT) support. In order to uptake more of the cobalt cluster with higher dispersion, the CNT was functionalized via acid and thermal treatment. The Co/CNT catalyst samples were characterized by a range of methods including the Brunauer–Emmet–Teller (BET) surface area analyzer, transmission electron microscopy (TEM), X-ray powder diffraction (XRD) analysis, atomic absorption spectroscopy (AAS), and H2-temperature programmed reduction (H2-TPR) analysis. The data from the TEM images revealed that the catalyst was highly dispersed over the external and internal walls of the CNT and that it demonstrated a narrow particle size of 6–8 nm. In addition, the data from the H2-TPR studies showed a lower reduction temperature (420 °C) for the pre-treated catalyst samples. Furthermore, a Fischer–Tropsch synthesis (FTS) reaction was chosen to evaluate the Co/CNT catalyst performance by using a fixed-bed microreactor at different parameters. Finally finding the optimum value of the cobalt loading percentage, particle size, and calcination conditions of Co/CNT catalyst resulted in a CO conversion and C5+ selectivity of 58.7% and 83.2%, respectively.

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Passivation of Co/Al2O3 Catalyst by Atomic Layer Deposition to Reduce Deactivation in the Fischer–Tropsch Synthesis

Catalysts ◽

10.3390/catal11060732 ◽

2021 ◽

Vol 11 (6) ◽

pp. 732

Author(s):

José Antonio Díaz-López ◽

Jordi Guilera ◽

Martí Biset-Peiró ◽

Dan Enache ◽

Gordon Kelly ◽

...

Keyword(s):

Atomic Layer Deposition ◽

Atomic Layer ◽

Tropsch Synthesis ◽

Catalyst Stability ◽

Fischer Tropsch ◽

Technical Feasibility ◽

Fischer Tropsch Synthesis ◽

Layer Deposition ◽

Co Conversion ◽

Al2o3 Catalyst

The present work explores the technical feasibility of passivating a Co/γ-Al2O3 catalyst by atomic layer deposition (ALD) to reduce deactivation rate during Fischer–Tropsch synthesis (FTS). Three samples of the reference catalyst were passivated using different numbers of ALD cycles (3, 6 and 10). Characterization results revealed that a shell of the passivating agent (Al2O3) grew around catalyst particles. This shell did not affect the properties of passivated samples below 10 cycles, in which catalyst reduction was hindered. Catalytic tests at 50% CO conversion evidenced that 3 and 6 ALD cycles increased catalyst stability without significantly affecting the catalytic performance, whereas 10 cycles caused blockage of the active phase that led to a strong decrease of catalytic activity. Catalyst deactivation modelling and tests at 60% CO conversion served to conclude that 3 to 6 ALD cycles reduced Co/γ-Al2O3 deactivation, so that the technical feasibility of this technique was proven in FTS.

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Effect of Cobalt Catalyst Confinement in Carbon Nanotubes Support on Fischer-Tropsch Synthesis Performance

Symmetry ◽

10.3390/sym10110572 ◽

2018 ◽

Vol 10 (11) ◽

pp. 572 ◽

Cited By ~ 13

Author(s):

Omid Akbarzadeh ◽

Noor Mohd Zabidi ◽

Yasmin Abdul Wahab ◽

Nor Hamizi ◽

Zaira Chowdhury ◽

...

Keyword(s):

Carbon Nanotubes ◽

Fixed Bed ◽

Tropsch Synthesis ◽

Fischer Tropsch ◽

Fischer Tropsch Synthesis ◽

Cobalt Oxide Nanoparticles ◽

Co Conversion ◽

Multi Walled Carbon Nanotubes ◽

Pre Treatment ◽

The Stability

Pre-treating the multi-walled carbon nanotubes (CNTs) support by refluxing in 35 vol% nitric acid followed by heating at the temperature of 600 to 900 °C resulted in the formation of defects on the CNTs. Increasing the temperature of the pre-treatment of the CNTs from 600 °C to 900 °C, enhanced the fraction of cobalt-oxide nanoparticles encapsulated in the channels of CNTs from 31% to 70%. The performance of Co/CNTs in Fischer-Tropsch synthesis (FTS) was evaluated in a fixed-bed micro-reactor at a temperature of 240 °C and a pressure of 2.0 MPa. The highest CO conversion obtained over Co/CNTs.A.900 was 59% and it dropped by ~3% after 130 h of time-on-stream. However, maximum CO conversion using Co/CNTs.A.600 catalysts was 28% and it decreased rapidly by about 54% after 130 h of time-on-stream. These findings show that the combined acid and thermal pre-treatment of CNTs support at 900 °C has improved the stability and activity of the Co/CNTs catalyst in FTS.

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Influence Factors of Denitration Study on Catalyst Mn-Ce/TiO2

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.634-638.526 ◽

2013 ◽

Vol 634-638 ◽

pp. 526-530

Author(s):

Chun Xiang Geng ◽

Qian Qian Chai ◽

Wei Yao ◽

Chen Long Wang

Keyword(s):

Reaction Temperature ◽

Catalytic Reduction ◽

Removal Rate ◽

Load Capacity ◽

Fixed Bed ◽

Influence Factors ◽

Space Velocity ◽

Molar Ratio ◽

Impregnation Method ◽

Ammonia Gas

Selective Catalytic Reduction (SCR) processes have been one of the most widely used denitration methods at present and the property of low tempreture catalyst becomes a hot research. The Mn-Ce/TiO2 catalyst was prepared by incipient impregnation method. The influence of load capacity, reaction temperature, O2 content, etc. on denitration were studied by a fixed bed catalyst reactor with ammonia gas. Results showed that catalyst with load capacity 18% performed high NO removal rate of 90% at conditions of reaction temperature 160°C, low space velocity, NH3/NO molar ratio 1: 1, O2 concentration 6%.

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Effect of CO Conversion on the Product Distribution of a Co/Al2O3 Fischer–Tropsch Synthesis Catalyst Using a Fixed Bed Reactor

Catalysis Letters ◽

10.1007/s10562-012-0908-z ◽

2012 ◽

Vol 142 (11) ◽

pp. 1382-1387 ◽

Cited By ~ 41

Author(s):

Dragomir B. Bukur ◽

Zhendong Pan ◽

Wenping Ma ◽

Gary Jacobs ◽

Burtron H. Davis

Keyword(s):

Fixed Bed ◽

Product Distribution ◽

Tropsch Synthesis ◽

Fixed Bed Reactor ◽

Fischer Tropsch ◽

Fischer Tropsch Synthesis ◽

Co Conversion

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On efficiency of vanadium-oxide promoter in cobalt Fischer – Tropsch catalysts

Kataliz v promyshlennosti ◽

10.18412/1816-0387-2021-1-2-15 ◽

2021 ◽

Vol 1 (1-2) ◽

pp. 15

Author(s):

Elham Yaghoobpour ◽

Yahya Zamani ◽

Saeed Zarrinpashne ◽

Akbar Zamaniyan

Keyword(s):

Vanadium Oxide ◽

Active Sites ◽

Fixed Bed ◽

Fixed Bed Reactor ◽

Bet Surface Area ◽

Incipient Wetness Impregnation ◽

Impregnation Method ◽

Fischer Tropsch ◽

Co Conversion ◽

Loading Amount

Promoters and their loading amount have crucial roles in cobalt Fischer – Tropsch catalysts. In this regard, the effects of vanadium oxide (V2O5) as a proposed promoter for Co catalyst supported on TiO2 have been investigated. Three catalysts with 0, 1, and 3 wt.% of V2O5 promoter loading are prepared by the incipient wetness impregnation method, and characterized by the BET surface area analyzer, XRD, H2-TPR, and TEM techniques. The fixed-bed reactor was employed for their evaluations. It was found that the catalyst containing 1 wt.% V2O5 has the best performance among the evaluated catalysts, demonstrating remarkable selectivity: 92 % C5+ and 5.7 % CH4, together with preserving the amount of CO conversion compared to the unpromoted catalyst. Furthermore, it is reported that the excess addition of V2O5 promoter (> 1 wt.%) in the introduced catalyst leads to the detrimental effect on the CO conversion and C5+ selectivity, mainly owing to diminished active sites by V2O5 loading.

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The Potential Use of Raw Iron Ore in Fischer-Tropsch Synthesis

International Journal of Petroleum Technology ◽

10.15377/2409-787x.2021.08.8 ◽

2021 ◽

Vol 8 ◽

pp. 99-115

Author(s):

Samuel Mubenesha ◽

Chike George Okoye-Chine ◽

Franscina Katuchero Ramutsindela ◽

Joshua Gorimbo ◽

Mahluli Moyo ◽

...

Keyword(s):

Iron Ore ◽

Iron Catalyst ◽

Fixed Bed ◽

Catalytic Performance ◽

Pilot Scale ◽

Manufacturing Cost ◽

Fischer Tropsch ◽

Ft Synthesis ◽

Co Conversion ◽

The Cost

Fischer-Tropsch (FT) synthesis has been studied in the literature as a greener pathway to cleaner and sustainable hydrocarbons production. However, the cost to upscale laboratory FT formulations to pilot scale is significantly expensive. This work proposes a cheaper and scalable low-temperature FT modified iron ore catalyst that is mechanically suited for fixed bed reactors. The mechanical strength reported in this investigation was three times more than commercial alumina spherical pellets and, therefore, suitable for pilot scale scenarios. A manufacturing cost analysis of iron ore was estimated to be US$38.45/kg using the CatCost model, and the conventionally prepared iron catalyst was US$71.44/kg using the same model. The manufacturing cost estimations of modified iron ore were found to be 46% cheaper than a conventional commercial iron catalyst. The catalytic performance of the modified iron ore catalyst showed a CO conversion of 72.1% ±4.24, with WGS and C5+ selectivity 48.6% ±1.96 and 83.2% ± 5.24, respectively. These findings were comparable (both in CO conversion and product selectivity) to the ones reported by other researchers.

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Mechanistic Insights for Dry Reforming of Methane on Cu/Ni Bimetallic Catalysts: DFT-Assisted Microkinetic Analysis for Coke Resistance

Catalysts ◽

10.3390/catal10091043 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1043

Author(s):

Ahmed Omran ◽

Sun Hee Yoon ◽

Murtaza Khan ◽

Minhaj Ghouri ◽

Anjaneyulu Chatla ◽

...

Keyword(s):

Energy Barrier ◽

Density Functional ◽

Carbon Deposition ◽

Bimetallic Catalyst ◽

Dry Reforming ◽

Coke Deposition ◽

Dry Reforming Of Methane ◽

Catalyst Stability ◽

Effect Of Temperature ◽

Elimination Mechanism

Density functional theory (DFT) calculations have been utilized to evaluate the complete reaction mechanism of methane dry reforming (DRM) over Ni2Cu (111) bimetallic catalyst. The detailed catalytic cycle on Ni2Cu (111) catalyst demonstrated superior coke resistance compared to pure Ni (111) and Ni2Fe (111) reported in the literature. Doping Cu in the Ni–Ni network enhanced the competitive CH oxidation by both atomic O and OH species with the latter having only 0.02 eV higher than the 1.06 eV energy barrier required for CH oxidation by atomic O. Among the C/CH oxidation pathways, C* + O* → CO (g) was the most favorable with an energy barrier of 0.72 eV. This was almost half of the energy barrier required for the rate-limiting step of CH decomposition (1.40 eV) and indicated enhanced coke deposition removal. Finally, we investigated the effect of temperature (800~1000 K) on the carbon deposition and elimination mechanism over Ni2Cu (111) catalyst. Under those realistic DRM conditions, the calculations showed a periodic cycle of simultaneous carbon deposition and elimination resulting in improved catalyst stability.

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