scholarly journals Fischer–Tropsch synthesis over Pd promoted cobalt based mesoporous supported catalyst

Author(s):  
Pavan Kumar Gupta ◽  
Abhishek Mahato ◽  
Goutam Kishore Gupta ◽  
Gajanan Sahu ◽  
Sudip Maity

The present study focuses on the catalytic conversion of syngas (CO + H2) through Fischer–Tropsch (FT) route using two identically prepared 0.1 wt.% palladium promoted Mesoporous Alumina (MA) and SBA–15 supported Co (15 wt.%) catalysts. The Fischer–Tropsch activity is performed in a fixed bed tubular reactor at temperature 220 °C and pressure 30 bar with H2/CO ratio ~2 having Gas Hourly Space Velocity (GHSV) of 500 h−1. Detail characterizations of the catalysts are carried out using different analytical techniques like N2 adsorption-desorption, Temperature-programmed reduction with hydrogen (H2-TPR), Temperature-programmed desorption with NH3 (NH3-TPD), X-Ray Diffraction (XRD), and Transmission Electron Microscopy (TEM). The results show that the SBA–15 supported catalyst exhibits higher C6–C12 selectivity (57.5%), and MA supported catalyst facilitates the formation of higher hydrocarbons (C13–C20) having a selectivity of 46.7%. This study attributes the use of both the support materials for the production of liquid hydrocarbons through FT synthesis.

2021 ◽  
Vol 1195 (1) ◽  
pp. 012009
Author(s):  
N H Berahim ◽  
A Abu Seman ◽  
N H Yasin ◽  
N S Abd Halim ◽  
N A Mohd Zabidi

Abstract Hydrogenation of CO2 into methanol is one of the most economical process to reduce CO2 concentration in the atmosphere. Since methanol is an industrial commodity used in chemical products as well as transportation fuel, this process has gained considerable interest, which enables the effective utilization of CO2. Nevertheless, the efficiency of direct CO2 hydrogenation to produce methanol is strongly reliant on the activity of the catalyst. In this regard, the present work highlights the synthesis of methanol, catalytic evaluation and characterization of catalysts Cu/ZnO supported on Al2O3 and SBA-15 pellets with the addition of group IV, V and VII metal oxides mixture as promoters. The catalysts were systematically prepared via impregnation technique with fixed Cu:Zn and promoter ratio from group VII:V:IV. The synthesized catalysts were characterized by H2-temperature-programmed reduction (H2-TPR), field emission scanning electron microscopy (FESEM), X-ray fluorescence (XRF), N2 adsorption-desorption and N2O pulse chemisorption method. The crushing strength of the pellets were also tested. Catalytic performances were evaluated for methanol synthesis from CO2 hydrogenation in a tubular, stainless steel fixed-bed reactor at 250 °C, 2 MPa, gas hourly space velocity (GHSV) 4000 ml/g.h and H2/CO2 ratio of 3:1. The tri-promoted Cu/ZnO supported on Al2O3 pellet resulted in CO2 conversion of 13.3 % compared to 11.61 % from that of SBA-15-supported catalyst. However, the catalyst supported on SBA-15 pellet exhibited 54.59% methanol selectivity, whereas Al2O3-supported catalyst only resulted in 46.73 % methanol selectivity.


Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 717 ◽  
Author(s):  
Marco Marchese ◽  
Niko Heikkinen ◽  
Emanuele Giglio ◽  
Andrea Lanzini ◽  
Juha Lehtonen ◽  
...  

A Co-Pt/γ-Al2O3 catalyst was manufactured and tested for Fischer–Tropsch applications. Catalyst kinetic experiments were performed using a tubular fixed-bed reactor system. The operative conditions were varied between 478 and 503 K, 15 and 30 bar, H2/CO molar ratio 1.06 and 2.11 at a carbon monoxide conversion level of about 10%. Several kinetic models were derived, and a carbide mechanism model was chosen, taking into account an increasing value of termination energy for α-olefins with increasing carbon numbers. In order to assess catalyst suitability for the determination of reaction kinetics and comparability to similar Fischer–Tropsch Synthesis (FTS) applications, the catalyst was characterized with gas sorption analysis, temperature-programmed reduction (TPR), and X-ray diffraction (XRD) techniques. The kinetic model developed is capable of describing the intrinsic behavior of the catalyst correctly. It accounts for the main deviations from the typical Anderson-Schulz-Flory distribution for Fischer–Tropsch products, with calculated activation energies and adsorption enthalpies in line with values available from the literature. The model suitably predicts the formation rates of methane and ethylene, as well as of the other α-olefins. Furthermore, it properly estimates high molecular weight n-paraffin formation up to carbon number C80.


2014 ◽  
Vol 875-877 ◽  
pp. 1534-1538
Author(s):  
Anita Ramli ◽  
Muhammad Farooq ◽  
Mas Fatiha Mohamad

In this paper the catalytic steam reforming of glycerol to H2 has been evaluated in the presence of Mo/γ-Al2O3 and Mo/γ-Al2O3-MgO in a fixed-bed microreactor at 700 oC. Physiochemical properties of the Mo catalysts were explored by various analytical techniques such as N2 adsorption–desorption (BET), X-ray diffraction (XRD), X-ray fluorescence spectrum (XRF), Temperature-programmed reduction (TPR) and Transmission Electron Microscopy (TEM). Mo/γ-Al2O3-MgO catalysts show promising results with higher H2 concentration produced as compared to Mo/γ-Al2O3 catalysts. The Mo was found to be uniformly distributed on the surface of γ-Al2O3-MgO support and addition of MgO contents into γ-Al2O3 improves the dispersion of Mo on the surface of the support.


2013 ◽  
Vol 832 ◽  
pp. 15-20 ◽  
Author(s):  
Sara Faiz Hanna Tasfy ◽  
Noor Asmawati Mohd Zabidi ◽  
Duvvuri Subbarao

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.


Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 872 ◽  
Author(s):  
Mohammad ◽  
Bepari ◽  
Aravamudhan ◽  
Kuila

Fischer–Tropsch (FT) synthesis was carried out in a 3D printed stainless steel (SS) microchannel microreactor using bimetallic Co-Ru catalysts on three different mesoporous silica supports. CoRu-MCM-41, CoRu-SBA-15, and CoRu-KIT-6 were synthesized using a one-pot hydrothermal method and characterized by Brunner–Emmett–Teller (BET), temperature programmed reduction (TPR), SEM-EDX, TEM, and X-ray photoelectron spectroscopy (XPS) techniques. The mesoporous catalysts show the long-range ordered structure as supported by BET and low-angle XRD studies. The TPR profiles of metal oxides with H2 varied significantly depending on the support. These catalysts were coated inside the microchannels using polyvinyl alcohol and kinetic performance was evaluated at three different temperatures, in the low-temperature FT regime (210–270 °C), at different Weight Hourly Space Velocity (WHSV) in the range of 3.15–25.2 kgcat.h/kmol using a syngas ratio of H2/CO = 2. The mesoporous supports have a significant effect on the FT kinetics and stability of the catalyst. The kinetic models (FT-3, FT-6), based on the Langmuir–Hinshelwood mechanism, were found to be statistically and physically relevant for FT synthesis using CoRu-MCM-41 and CoRu-KIT-6. The kinetic model equation (FT-2), derived using Eley–Rideal mechanism, is found to be relevant for CoRu-SBA-15 in the SS microchannel microreactor. CoRu-KIT-6 was found to be 2.5 times more active than Co-Ru-MCM-41 and slightly more active than CoRu-SBA-15, based on activation energy calculations. CoRu-KIT-6 was ~3 and ~1.5 times more stable than CoRu-SBA-15 and CoRu-MCM-41, respectively, based on CO conversion in the deactivation studies.


2021 ◽  
Vol 8 ◽  
pp. 99-115
Author(s):  
Samuel Mubenesha ◽  
Chike George Okoye-Chine ◽  
Franscina Katuchero Ramutsindela ◽  
Joshua Gorimbo ◽  
Mahluli Moyo ◽  
...  

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.


2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Teuku Mukhriza ◽  
Hartati Oktarina

Fischer-Tropsch (FT) Synthesis has been widely known for centuries as the process of converting syngas to liquid fuels. Several reactors including Slurry bubble column, fluidized-bed, and fixed bed reactors have been used for FTS on an industrial scale. Although science has seen remarkable development in technology for FT synthesis, the industry still faces challenges in optimizations of process parameters and achieved desired selectivity.  Extensive research has been continuously conducted to seek the best FT reactor offering heat uniformity and efficient heat transfer across the reactor to increase the catalytic activity and its lifetime. Dielectric Barrier Discharge (DBD) plasma has become one of the options to deal with these issues. This reactor work under low temperature delivers a synergistic effect between plasma and catalyst to break H2 and CO bond. DBD plasma is also suitable for feedstock with high H2/CO molar ratios. It is also found that FT catalyst such as cobalt catalyst used in DBD plasma was well dispersed on the support which in turn favour the selectivity toward liquid hydrocarbon.


Symmetry ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 7 ◽  
Author(s):  
Omid Akbarzadeh ◽  
Noor Mohd Zabidi ◽  
Yasmin Abdul Wahab ◽  
Nor Hamizi ◽  
Zaira Chowdhury ◽  
...  

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.


2012 ◽  
Vol 468-471 ◽  
pp. 87-92
Author(s):  
Mohammad Reza Hemmati Mahmoudi ◽  
Mohammad Kazemeini ◽  
Jamshid Zarkesh ◽  
Farhad Khorasheh

Samples of regular gamma and nano-structured alumina were prepared and their porosimetric properties evaluated by N2 porosimetry method. Moreover, cobalt based catalysts for Fischer-Tropsch (FT) Synthesis were prepared by loading cobalt under two calcinations using these alumina supports. Then the porosimetric properties of these materials as well as; their reactor behaviors assessed. Although the nano-structured favored the gamma alumina from pore volume and surface points of view, comparison of porosimetric properties of fresh alumina samples with corresponding catalysts prepared revealed that calcination effect in decreasing those factors was more pronounced for the nano-structured compared to gamma alumina. Also adsorption/desorption isotherms revealed that both materials were mesoporous. Catalytic activity assessment of both catalysts made by these supports showed that nano-structured alumina was more appropriate from activity and liquid hydrocarbon production points of view.


2013 ◽  
Vol 864-867 ◽  
pp. 366-372 ◽  
Author(s):  
Liang Yan Xia ◽  
Zhi Xiang Xia ◽  
Wei Tang ◽  
Hong Yan Wang ◽  
Meng Xiang Fang

MCM-41 supported nickel phosphide (Ni2P/MCM-41) was prepared by temperature-programmed reduction of the corresponding phosphate. The catalyst activity for hydrodeoxygenation (HDO), hydrodearomatization (HDA), hydrodenitrogenation (HDN) and hydrodesulfurization (HDS) was investigated in a fixed bed reactor. O-cresol HDO, 1-methylnaphthalene HDA, quinoline HDN, dibenzothiophene HDS and simultaneous HDO, HDA, HDN, HDS were respectively tested at different temperatures with constant pressure (6.0 MPa), liquid hourly space velocity (3.0 h-1), hydrogen-to-oil volume ratio (600:1). The results indicate that Ni2P /MCM-41 catalyst has great performance on HDO, HDA, HDN, HDS in single model compound reactions. O-cresol and DBT are almost completely transformed at 375°C, while 1-methylnaphthalene and quinoline reach the highest conversion at 300°C. In the simultaneous reactions, quinoline shows higher conversion by competitive adsorption on the catalyst hydrogenation sites, leading to conversion decrease of o-cresol, 1-methylnaphthalene and DBT.


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