Separating the initial growth rate from the rate of deactivation in the growth kinetics of multi-walled carbon nanotubes from ethene over a cobalt-based bulk catalyst in a fixed-bed reactor

Carbon ◽  
2013 ◽  
Vol 58 ◽  
pp. 107-115 ◽  
Author(s):  
Michael J. Becker ◽  
Wei Xia ◽  
Kunpeng Xie ◽  
Arne Dittmer ◽  
Kristian Voelskow ◽  
...  
Author(s):  
Venkateswara Rao Surisetty ◽  
Janusz Kozinski ◽  
Ajay K. Dalai

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.


2021 ◽  
Vol 9 (2) ◽  
pp. 105110
Author(s):  
Y. Huaccallo-Aguilar ◽  
S. Álvarez-Torrellas ◽  
M. Larriba ◽  
V.I. Águeda ◽  
J.A. Delgado ◽  
...  

2022 ◽  
Vol 10 (4) ◽  
pp. 22-30
Author(s):  
S. Valliammai ◽  
K. Gopal ◽  
R. Nithya ◽  
L. Rama Priya ◽  
D. Kavitha

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.


2017 ◽  
Vol 4 (9) ◽  
pp. 1887-1899 ◽  
Author(s):  
Haiyun Zhang ◽  
Weixiao Chen ◽  
Xiaofang Shen ◽  
Meng Zhang ◽  
Yu Yang ◽  
...  

Carbonaceous nanomaterials differentially impact the bioaccumulation and elimination kinetics of phenanthrene in earthworms.


Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 798
Author(s):  
Ana T. S. C. Brandão ◽  
Liana Anicai ◽  
Oana Andreea Lazar ◽  
Sabrina Rosoiu ◽  
Aida Pantazi ◽  
...  

Nano carbons, such as graphene and carbon nanotubes, show very interesting electrochemical properties and are becoming a focus of interest in many areas, including electrodeposition of carbon–metal composites for battery application. The aim of this study was to incorporate carbon materials (namely oxidized multi-walled carbon nanotubes (ox-MWCNT), pristine multi-walled carbon nanotubes (P-MWCNT), and reduced graphene oxide (rGO)) into a metallic tin matrix. Formation of the carbon–tin composite materials was achieved by electrodeposition from a choline chloride-based ionic solvent. The different structures and treatments of the carbon materials will create metallic composites with different characteristics. The electrochemical characterization of Sn and Sn composites was performed using chronoamperometry, potentiometry, electrochemical impedance, and cyclic voltammetry. The initial growth stages of Sn and Sn composites were characterized by a glassy-carbon (GC) electrode surface. Nucleation studies were carried out, and the effect of the carbon materials was characterized using the Scharifker and Hills (SH) and Scharifker and Mostany (SM) models. Through a non-linear fitting method, it was shown that the nucleation of Sn and Sn composites on a GC surface occurred through a 3D instantaneous process with growth controlled by diffusion. According to Raman and XRD analysis, carbon materials were successfully incorporated at the Sn matrix. AFM and SEM images showed that the carbon incorporation influences the coverage of the surface as well as the size and shape of the agglomerate. From the analysis of the corrosion tests, it is possible to say that Sn-composite films exhibit a comparable or slightly better corrosion performance as compared to pure Sn films.


Sign in / Sign up

Export Citation Format

Share Document