Naproxen removal by CWPO with Fe3O4/multi-walled carbon nanotubes in a fixed-bed reactor

The effects of operating conditions on the higher alcohols synthesis reaction from synthesis gas were studied in a single-pass tubular downflow fixed-bed reactor, using sulfided K-promoted trimetallic Co-Rh-Mo catalyst supported on multi-walled carbon nanotubes (MWCNTs). The p CO conversion increased monotonically with increasing reaction temperature (from 275 to 350°C) and pressure (from 800 to 1400 psi), while decreasing monotonically with increasing GHSV (from 2.4 to 4.2 m3 (STP)/(kg of cat./h)). To maximize the ethanol STY and selectivity, the optimum operating conditions were determined as 330°C, 1320 psi, and 3.8 m3 (STP)/kg of cat./h). Maximum ethanol STY and selectivity were obtained using gas with H2 to CO molar ratio around 1.25.

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Continuous Fixed-Bed Column Studies of Textile Effluent Treatment using Multi-Walled Carbon Nanotubes Originated from Rosmarinus officinalis Oil

Journal of Environmental Nanotechnology ◽

10.13074/jent.2021.12.214444 ◽

2022 ◽

Vol 10 (4) ◽

pp. 22-30

Author(s):

S. Valliammai ◽

K. Gopal ◽

R. Nithya ◽

L. Rama Priya ◽

D. Kavitha

Keyword(s):

Electron Microscopy ◽

Carbon Nanotubes ◽

Service Time ◽

Fixed Bed ◽

Rosmarinus Officinalis ◽

Time Model ◽

Fixed Bed Column ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes ◽

Bed Depth Service Time

A continuous adsorption study in a fixed-bed column was carried out using Multi-walled Carbon Nanotubes derived from Rosmarinus officinalis oil as an adsorbent for removing the textile dye Acid blue 40 from an aqueous solution. The adsorbent, MWNTs were prepared from Rosmarinus officinalis oil as a precursor to Fe/Mo catalyst supported on silica at 650 ºC under N2 atmosphere by spray pyrolysis process characterized by scanning electron microscopy, Transmission Electron microscopy, and Raman spectroscopy. The effects of adsorbent bed height (2–6 cm), initial ion concentration (20– 60 mg/L), and flow rate (10–30 mL/min) on the column performance were analyzed. The breakthrough curve was analyzed using the mathematical models of Thomas, Yoon-Nelson, and bed depth service time. The Thomas model at different conditions defined the behaviors of the breakthrough curves. The bed depth service time model showed good agreement with the experimental data. The high values of correlation coefficients (R2 0.9875) obtained indicate the validity of the bed depth service time model for the present column system.

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Highly efficient as-synthesized and oxidized multi-walled carbon nanotubes for copper(II) and zinc(II) ion adsorption in a batch and fixed-bed process

Journal of Materials Research and Technology ◽

10.1016/j.jmrt.2021.09.094 ◽

2021 ◽

Vol 15 ◽

pp. 2848-2872

Author(s):

Titus Chinedu Egbosiuba ◽

Ambali Saka Abdulkareem

Keyword(s):

Carbon Nanotubes ◽

Fixed Bed ◽

Ion Adsorption ◽

Highly Efficient ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

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Adsorption of 2,4-dichlorophenoxyacetic acid using rice husk biochar, granular activated carbon, and multi-walled carbon nanotubes in a fixed bed column system

Water Science & Technology ◽

10.2166/wst.2018.467 ◽

2018 ◽

Vol 78 (8) ◽

pp. 1812-1821 ◽

Cited By ~ 8

Author(s):

Mehdi Bahrami ◽

Mohammad Javad Amiri ◽

Bahareh Beigzadeh

Keyword(s):

Carbon Nanotubes ◽

Activated Carbon ◽

Flow Rate ◽

Fixed Bed ◽

Dichlorophenoxyacetic Acid ◽

Fixed Bed Column ◽

Column System ◽

Multi Walled Carbon Nanotubes ◽

2,4 Dichlorophenoxyacetic Acid ◽

Walled Carbon Nanotubes

Abstract The 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide, as an aromatic hydrocarbon, is a dangerous and toxic organic pollutant among the agricultural pesticides. In this research, the performance of the biochar made from rice husk (BRH), granular activated carbon (GAC), and multi-walled carbon nanotubes (MWCNTs) was investigated for adsorption of 2,4-D in a fixed-bed column system. The influence of pH (2, 5, 7, 9), flow rate (0.5, 1, 1.5 mL min−1), bed depth (3, 6, 9 cm), and influent 2,4-D concentration (50, 100, 150, 300 mg L−1) on the adsorption process was evaluated. The resulting breakthrough curves indicated that the higher removal efficiency of 2,4-D took place at the lower flow rate, lower influent 2,4-D concentration, higher bed depth, and lower pH. While in most cases the removal ability of GAC was better than other adsorbents, generally, this study confirmed that the BRH, as a cheap and sustainable material, can be a viable alternative to GAC and MWCNTs for remediation and treatment scenarios, particularly in developing countries.

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Continuous adsorptive removal of glimepiride using multi-walled carbon nanotubes in fixed-bed column

Environmental Science and Pollution Research ◽

10.1007/s11356-020-11679-y ◽

2020 ◽

Author(s):

Ismail Badran ◽

Obada Qut ◽

Abdallah D. Manasrah ◽

Murad Abualhasan

Keyword(s):

Carbon Nanotubes ◽

Fixed Bed ◽

Fixed Bed Column ◽

Adsorptive Removal ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

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Growth of single-walled carbon nanotubes on a Co–Mo–MgO supported catalyst by the CVD of methane in a fixed bed reactor: Model setting and parameter estimation

Solid State Sciences ◽

10.1016/j.solidstatesciences.2011.03.016 ◽

2011 ◽

Vol 13 (6) ◽

pp. 1242-1250 ◽

Cited By ~ 9

Author(s):

Nosrat Izadi ◽

Ali Morad Rashidi ◽

Bahman Amini Horri ◽

Mohamad Reza Mosoudi ◽

Hamid Reza Bozorgzadeh ◽

...

Keyword(s):

Carbon Nanotubes ◽

Parameter Estimation ◽

Fixed Bed ◽

Supported Catalyst ◽

Single Walled Carbon Nanotubes ◽

Fixed Bed Reactor ◽

Reactor Model ◽

Single Walled Carbon ◽

Model Setting ◽

Walled Carbon Nanotubes

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Comparative Studies of Fischer-Tropsch Synthesis on Iron Catalysts Supported on Al2O3-Cr2O3 (2:1), Multi-Walled Carbon Nanotubes or BEA Zeolite Systems

Catalysts ◽

10.3390/catal9070605 ◽

2019 ◽

Vol 9 (7) ◽

pp. 605 ◽

Cited By ~ 3

Author(s):

Mierczynski ◽

Dawid ◽

Chalupka ◽

Maniukiewicz ◽

Witoska ◽

...

Keyword(s):

Carbon Nanotubes ◽

Physicochemical Properties ◽

Temperature Programmed Desorption ◽

Fixed Bed Reactor ◽

Iron Catalysts ◽

Fischer Tropsch ◽

Zeolite Β ◽

Multi Walled Carbon Nanotubes ◽

Temperature Programmed ◽

Walled Carbon Nanotubes

The main goal of the presented paper is to study the influence of a range of support materials, i.e., multi-walled carbon nanotubes (MWCNTs), Al2O3-Cr2O3 (2:1), zeolite β-H and zeolite β-Na on the physicochemical and catalytic properties in Fischer-Tropsch (F-T) synthesis. All tested Fe catalysts were synthesized using the impregnation method. Their physicochemical properties were extensively investigated using various characterization techniques such as the Temperature-Programmed Reduction of hydrogen (TPR-H2), X-ray diffraction, Temperature-Programmed Desorption of ammonia (TPD-NH3), Temperature-Programmed Desorption of carbon dioxide (TPD-CO2), Fourier transform infrared spectrometry (FTIR), Brunauer Emmett Teller method (BET) and Thermogravimetric Differential Analysis coupled with Mass Spectrometer (TG-DTA-MS). Activity tests were performed in F-T synthesis using a high-pressure fixed bed reactor and a gas mixture of H2 and CO (50% CO and 50% H2). The correlation between the physicochemical properties and reactivity in F-T synthesis was determined. The highest activity was from a 40%Fe/Al2O3-Cr2O3 (2:1) system which exhibited 89.9% of CO conversion and 66.6% selectivity toward liquid products. This catalyst also exhibited the lowest acidity, but the highest quantity of iron carbides on its surface. In addition, in the case of iron catalysts supported on MWCNTs or a binary oxide system, the smallest amount of carbon deposit formed on the surface of the catalyst during the F-T process was confirmed.

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Purification of single-walled carbon nanotubes using a fixed bed reactor packed with zirconia beads

Carbon ◽

10.1016/j.carbon.2007.11.013 ◽

2008 ◽

Vol 46 (2) ◽

pp. 245-254 ◽

Cited By ~ 15

Author(s):

Soon Huat Tan ◽

Jeung Choon Goak ◽

Sung Chul Hong ◽

Naesung Lee

Keyword(s):

Carbon Nanotubes ◽

Fixed Bed ◽

Single Walled Carbon Nanotubes ◽

Fixed Bed Reactor ◽

Single Walled Carbon ◽

Walled Carbon Nanotubes

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Study on Photocatalytic Desulfurization and Denitrification Performance of Cu- and Cr-Modified MWCNT

Processes ◽

10.3390/pr9101823 ◽

2021 ◽

Vol 9 (10) ◽

pp. 1823

Author(s):

Yi Sun ◽

Weiwei Jian ◽

Siqi Tong ◽

Danzhu Ma ◽

Bohan Zhuang ◽

...

Keyword(s):

Carbon Nanotubes ◽

Adsorption Capacity ◽

Adsorption Property ◽

Sol Gel ◽

Fixed Bed ◽

Space Velocity ◽

Fixed Bed Reactor ◽

Molar Ratio ◽

Multi Walled Carbon Nanotubes ◽

Electron Migration

Carbon nanotubes are a promising adsorbent for desulfurization and denitrification. In this paper, Cu- and Cr-doped TiO2 supported by multi-walled carbon nanotubes (MWCNTs/Cu-Cr-TiO2) were synthesized by the sol-gel method. Characterizations of the samples were performed by TEM, XPS, XRD, DRS, and BET. The experiments of simultaneous desulfurization and denitrification were conducted in a fixed-bed reactor. The results showed that the adsorbent with a Cu to Cr molar ratio of 3 displays excellent adsorption property. The SO2 and NO adsorption capacity of MWCNTs/Cu-Cr-TiO2 (Cu/Cr = 3) were 36.83 and 12.34 mg/g under the optimal experimental operating parameters (SO2 content: 1575 mg/m3, NO content 736 mg/m3, O2 content 8%, H2O content 5%, and space velocity 1003 h−1). The adsorption capacity of MWCNTs/Cu-Cr-TiO2 was significantly better than that of the adsorbent doped with Cu or Cr alone (MWCNTs/Cu-TiO2 and MWCNTs/Cr-TiO2). Compared with single metal doping, bimetallic multivalent states accelerate the electron migration and separation from holes, which increase the number of oxygen vacancies and enhance the adsorption of SO2 and NO. The kinetic models and the reaction mechanism of the desulfurization and denitrification were also analyzed in this work.

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