A Review On Carbon Nanotubes Production Via Catalytic Methane Decomposition.

Methane decomposition is a promising approach to produce high purity, high yield and perfect orientation of carbon nanotubes and is viable for scaling up its production at a relatively low cost

The Synthesis And Applications Of Carbon Nanotubes From Natural Gas.

Carbon Nanotubes are newly discovered carbon: it is fullerene related structures but a fullerene's carbon form a sphere while a nanotube is cylindrical. According to theoretical predictions of carbon nanotubes. the tubular fullerene. may possess extraordinary physical and chemical properties. Due to its unique properties, carbon nanotubes have found a variety of potential applications in advance technologies; including nanoelectronics, biomedical, electromagnetics, electrochemical, composite. mass storage, etc. They provide an alternative to current technology to achieve better performance and smaller sizing in numerous applications. It brings technologies of all area to the edge and beyond expectation in the past. This paper will cover the outstanding properties of carbon nanotubes and the applications of carbon nanotubes

Review Of Carbon Nanotubes Growth And Synthesis.

Carbon nanotubes are tubular nanostructures derived from rolled graphene planes. Carbon nanotubes are fullerenes related structures but a fullerenes's carbon form a sphere; while a nanotubes are cylindrical. The growth mechanism of carbon nanotubes depend on the synthesis method

Rheological evaluation of the fabrication parameters of cellulose acetate butyrate membrane on CO2/N2 separation performance

The rise in emission of greenhouse gases (GHGs) mainly carbon dioxide (CO2) in recent years due to rapid development of modern civilisation, has been listed as the primary contributor to global warming. To address this global issue, membrane technology was applied and developed intensively because of its superior performance in terms of efficiency and economic advantages. In this study, the cellulose acetate butyrate (CAB) polymer was selected as the polymer matrix material since it exhibited excellent film-forming properties. In addition, the wet-phase inversion technique was adopted to synthesise the membrane based on different casting conditions. The optimum outcomes of the fabrication conditions were then characterised with the scanning electron micrograph (SEM) to determine the best CAB membrane for CO2/N2 separation. The results showed that CAB-70000 fabricated with 4 wt% of CAB polymer concentration, casting thickness of 250 µm, solvent evaporation time of 5 minutes, and 30 minutes of solvent exchange for isopropyl alcohol and n-hexane, exhibited the best gas separation performance. Further, CAB-70000 showed an average selectivity of 6.12 ± 0.09 and permeance up to 227.95 ± 0.39 GPU for CO2 and 37.28 ± 0.54 GPU for N2, respectively. In summary, this study is expected to show a detailed outline of the future direction and perspective of the novel CAB polymeric membrane that is suitable to be applied in the industry, and serves as an insight for researchers and manufacturers working in the related field of gas separation

Fuel Pyrolysis through Porous Media: Coke Formation and Coupled effect on Permeability

International audienceThe development of hypersonic vehicles (up to Mach 10) leads to an important heating of the whole structure. The fuel is thus used as a coolant. It presents an endothermic decomposition with possible coke formation. Its additional permeation through the porous structure involves internal convection. This implies very complex phenomena (heat and mass transfers with chemistry). In this paper, the n-dodecane pyrolysis is studied through stainless steel porous medium up to 820 K and 35 bar (supercritical state). The longitudinal profiles of chemical compositions inside the porous medium are given thanks to a specific sampling technique with off-line Gas Chromatograph and Mass Spectrometer analysis. By comparison with previous experiments under plug flow reactor, the conversion of dodecane is higher for the present experimental configuration. The pyrolysis produces preferentially light gaseous species, which results in a higher gasification rate for a similar pyrolysis rate. The effects of the residence time and of the contact surface area are demonstrated. The transient changes of Darcy's permeability are related to the coke formation thanks to previous experimental relationship with methane production. A time shift is observed between coke chemistry and permeability change. This work is quite unique to the author's knowledge because of the complex chemistry of heavy hydrocarbon fuels pyrolysis, particularly in porous medium