Kinetic modeling study of carbon nanotubes synthesis by fluidized bed chemical vapor deposition

Abstract

in Wiley InterScience (www.interscience.wiley.com).The kinetic and physical laws developed in the first part of the study have been implemented in a modified version of the bubbling bed Kato and Wen model to represent multiwalled carbon nanotubes (MWCNTs) synthesis by catalytic chemical vapor deposition from ethylene as carbon source and using an Fe/Al 2 O 3 catalyst. The absolute deviation for MWCNT productivity between experimental results of Part 1 and simulations is of 17.3% when only considering experiments for which the bed is mainly in bubbling regime. The influence of the main operating parameters on the evolutions with time of the species molar fractions, the weight of MWCNTs formed, and the bed characteristics has been numerically studied. Such capabilities can help designing new reactors. Finally, the model has been used for scale up purposes, by increasing the reactor diameter and catalyst weight. Simulations have shown that the process productivity could reach 74 tons/year of MWCNTs in a reactor 45 cm in diameter. 2008 American Institute of Chemical Engineers AIChE J, 55: [465][466][467][468][469][470][471][472][473][474] 2009

Reductively PEGylated carbon nanomaterials and their use to nucleate 3D protein crystals: a comparison of dimensionality

“…Starting materials were sourced from commercial suppliers: graphite (Graphexel natural crystalline flake graphite, grade: 2369, Graphexel Ltd., UK) for exfoliation to few layer graphite, graphite nanoplatelets, likely produced by exfoliation of graphite via acid intercalation 46 (XG Sciences), fluidized bed CVD-grown MWNTs (Arkema), 47 purified SWNTs (Thomas Swan Elicarb P925) synthesized by CVD on substrate 48 and carbon black (furnace black, Printex L6, Degussa). 49 The as-received materials were dried and reductively charged as described in detail in the ESI.…”

Carbon Nanotube Mass Production: Principles and Processes

“…[220] Simulation showed that the productivity of MWCNTs can reach 8 kg h À1 in a 45 cm diameter reactor operated under semi-batch conditions. [221] In the growth of aligned CNTs, the CNTs have similar lengths, and it is easy to design in situ methods to monitor the kinetics of aligned CNT growth. [222,223] The growth mark method was used to record the growth rate of aligned CNTs by adding marks during the growth process.…”

Simulation and modeling of carbon nanotube synthesis: current trends and investigations

“…Hence, the tight control over CNT array dimension was possible, which is essential in their incorporation into micro electro mechanical system (MEMS) and nano electro mechanical system (NEMS) devices. The modified version of the bubbling bed Kato and Wen model presented by Phillippe et al [10] includes additional advantages, as it succeeded in predicting the ethylene reaction rate by considering the axial convection and vertical diffusion in the fixed bed. However, in their model, it was assumed that the fluidized bed is isothermal, and that the bed is represented by a series of compartments whose heights are equal to the mean diameter of the bubbles at the corresponding level.…”

“…Phillippe et al [10] presented a modified version of the bubbling bed model by Kato and Wen to represent MWCNT synthesis through catalytic CVD in a fluidized bed. This model allowed predicting the relationships of the main operating parameters on the weight of CNTs, as shown in Figures 4 A, B and 3C.…”