Simple method for synthesis of carbon nanotubes over Ni-Mo/Al2O3 catalyst via pyrolysis of polyethylene waste using a two-stage process

Flame method is a new and simple method which may has the possibility of large-scale mass production for the synthesis of carbon nanotubes. It needs not the vacuum environment and carbon nanotubes can be captured at the normal atmospheric pressure. Synthesis of carbon nanotubes from the controllable flame is a new method. It can effectively avoid the defect of the traditional flame method. Experimental apparatus is mainly including controllable flame burner with its ancillary equipment, measuring instrument and catalyst preparation system, etc. The process of formation and growth for carbon nanotube is very complicated on account of the complexity of combustion and chemical reaction. It can be supposed that the formation and growth of carbon nanotubes from the controllable flame involves two steps in general.

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OPTIMIZING FLAME SYNTHESIS OF CARBON NANOTUBES: EXPERIMENTAL AND MODELLING PERSPECTIVES

Jurnal Teknologi ◽

10.11113/jt.v78.9595 ◽

2016 ◽

Vol 78 (8-4) ◽

Cited By ~ 2

Author(s):

Muhammad Thalhah Zainal ◽

Mohd Fairus Mohd Yasin ◽

Mazlan Abdul Wahid

Keyword(s):

Carbon Nanotubes ◽

Growth Rate ◽

Flame Temperature ◽

Chemical Vapour ◽

Optimization Techniques ◽

Scale Model ◽

Flame Synthesis ◽

Simple Method ◽

Experimental Findings ◽

Synthesis Of Carbon Nanotubes

Synthesis of carbon nanotubes in flames has become highly attractive due to its rapid, inexpensive, and simple method of production. The study of flame synthesis of carbon nanotubes revolves around the control of flame and catalyst parameters to increase the synthesis efficiency and to produce high quality nanotubes. The control parameters include flame temperature, concentration of carbon source species, catalyst type, equivalence ratio, and fuel type. Carbon nanotubes which are produced with rapid growth rate and possess high degree of purity and alignment are often desired. The present study reviews various optimization techniques from the advanced studies of chemical vapour deposition which are applicable for the synthesis of nanotubes in flames. The water-assisted and catalyst free synthesis are seen as possible candidates to improve the growth rate, alignment, and purity of the synthesized nanotubes. The state-of-the-art of the flame synthesis modelling at particle and flame scales are reviewed. Based on the thorough review of the recent experimental findings related to the catalytic growth of nanotube, possible refinement of the existing particle scale model is discussed. The possibility of two-way coupling between the two scales in computational fluid dynamics may be a major contribution towards the optimization of the flame synthesis.

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Impact of support calcination and competitive adsorbate in Fe/Mo-Al2O3 catalyst for synthesis of carbon nanotubes by V-flame

Materials Research Express ◽

10.1088/2053-1591/aac251 ◽

2018 ◽

Vol 5 (5) ◽

pp. 055024 ◽

Cited By ~ 1

Author(s):

Ya-Ping Sun ◽

Bao-Min Sun ◽

Gang Zhai ◽

Yong-Hong Guo ◽

Xiao-Wei Jia ◽

...

Keyword(s):

Carbon Nanotubes ◽

Synthesis Of Carbon Nanotubes ◽

Al2o3 Catalyst

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Synthesis of Carbon Nanotubes and Nanofibers on Silica and Cement Matrix Materials

Journal of Nanomaterials ◽

10.1155/2009/526128 ◽

2009 ◽

Vol 2009 ◽

pp. 1-4 ◽

Cited By ~ 25

Author(s):

Prasantha R. Mudimela ◽

Larisa I. Nasibulina ◽

Albert G. Nasibulin ◽

Andrzej Cwirzen ◽

Markus Valkeapää ◽

...

Keyword(s):

Carbon Nanotubes ◽

Matrix Material ◽

Cement Matrix ◽

Iron Salt ◽

Simple Method ◽

Model Object ◽

Physical Transformation ◽

20 Nm ◽

Synthesis Of Carbon Nanotubes ◽

Walled Cnts

In order to create strong composite materials, a good dispersion of carbon nanotubes (CNTs) and nanofibers (CNFs) in a matrix material must be obtained. We proposed a simple method of growing the desirable carbon nanomaterial directly on the surface of matrix particles. CNTs and CNFs were synthesised on the surface of model object, silica fume particles impregnated by iron salt, and directly on pristine cement particles, naturally containing iron oxide. Acetylene was successfully utilised as a carbon source in the temperature range from 550 to750∘C. 5–10 walled CNTs with diameters of 10–15 nm at600∘Cand 12–20 nm at 750∘Cwere synthesised on silica particles. In case of cement particles, mainly CNFs with a diameter of around 30 nm were grown. It was shown that high temperatures caused chemical and physical transformation of cement particles.

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Simulation of a Two-Stage Micro Trickle-Bed Hydrotreating Reactor using Athabasca Bitumen-Derived Heavy Gas Oil over Commercial NiMo/Al2O3 Catalyst: Effect of H2S on Hydrodesulfurization and Hydrodenitrogenation

International Journal of Chemical Reactor Engineering ◽

10.2202/1542-6580.1328 ◽

2006 ◽

Vol 4 (1) ◽

Cited By ~ 6

Author(s):

Christian Botchwey ◽

Ajay K Dalai ◽

John Adjaye

Keyword(s):

Hydrogen Sulfide ◽

Catalyst Loading ◽

Gas Oil ◽

Two Stage ◽

Sulfide Removal ◽

Hydrogen Sulfide Removal ◽

Heavy Gas Oil ◽

Stage Process ◽

Heavy Gas ◽

Al2o3 Catalyst

A two-stage, micro trickle-bed reactor (for studies of the effects of hydrogen sulfide on hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) of Athabasca bitumen-derived heavy gas oil over commercial NiMo/Al2O3 catalyst) has been simulated. One dimensional homogeneous mass transfer and a two dimensional heat transfer models were developed. The essence of the simulation was to enhance the understanding of the effects of hydrogen sulfide in the hydrotreating catalyst bed in a two-stage mode and also to predict the catalyst requirements for deep HDS and HDN processes. The kinetic model used in the simulation was based on the Langmuir-Hingshelwood method of rate determination. Adsorption constants were estimated by non-linear least squares method. The kinetic models were tested on independent set of data and found to predict the experimental data satisfactorily. The mass transfer simulation considered the effects of variables such as temperature and catalyst loading or liquid hourly space velocity (LHSV) on the trends of hydrogen sulfide generation and, sulfur and nitrogen conversions along the catalyst bed. The model was numerically solved using a fourth-order Runge-Kutta technique. The 1:3 wt/wt catalyst loading with inter-stage hydrogen sulfide removal was found to give the best HDN and HDS activities. Simulated results showed that doubling the present catalyst mass and operating at 653 °C with inter-stage hydrogen sulfide removal would give 6 and 179 ppm product sulfur and nitrogen, respectively. On the other hand, without hydrogen sulfide removal, only 49 and 302 ppm product sulfur and nitrogen could be attained, respectively. The heat transfer simulation compared temperature profiles in the two-stage process to a single stage process for the 1:3 wt/wt catalyst loading at 653 K. The temperature regime in Stage II was found to be more uniform unlike Stage I and the single stage. Crank Nicholson algorithm was used to solve the 2-D partial differential equations.

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Growth of Carbon Nanotubes Using MgO Supported Mo-Co Catalysts by Thermal Chemical Vapor Deposition Technique

Journal of Nano Research ◽

10.4028/www.scientific.net/jnanor.24.46 ◽

2013 ◽

Vol 24 ◽

pp. 46-57 ◽

Cited By ~ 1

Author(s):

C. Santhosh ◽

M. Saranya ◽

S. Felix ◽

R. Ramachandran ◽

N. Pradeep ◽

...

Keyword(s):

Carbon Nanotubes ◽

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Chemical Properties ◽

Chemical Vapor ◽

Simple Method ◽

Thermal Chemical Vapor Deposition ◽

Co Catalysts ◽

Vapor Deposition Technique ◽

Synthesis Of Carbon Nanotubes

A simple method is developed for the synthesis of carbon nanotubes (CNTs) using Mo-Co/MgO catalyst by a thermal chemical vapor deposition (CVD) technique. Acetylene was used as the source of carbon and nitrogen as carrier gas. A series of MgO supported Mo-Co catalysts were prepared by the combustion route using urea as the fuel at different stoichiometric ratios. It was found that a higher yield of carbon nanotubes was obtained by the developed catalysts. Also, the addition of molybdenum to Co/MgO catalysts could remarkably increase the yield and also improve the quality of CNTs from thermal CVD with acetylene as precursor gas. The morphology of the catalysts and CNTs obtained was studied by field emission scanning electron microscope (FE-SEM). Other techniques like Raman spectroscopy and XRD were also employed to know the physico-chemical properties of the samples.

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