Carbon Nanotube Mass Production: Principles and Processes

Abstract

Our society requires new materials for a sustainable future, and carbon nanotubes (CNTs) are among the most important advanced materials. This Review describes the state-of-the-art of CNT synthesis, with a focus on their mass-production in industry. At the nanoscale, the production of CNTs involves the self-assembly of carbon atoms into a one-dimensional tubular structure. We describe how this synthesis can be achieved on the macroscopic scale in processes akin to the continuous tonne-scale mass production of chemical products in the modern chemical industry. Our overview includes discussions on processing methods for high-purity CNTs, and the handling of heat and mass transfer problems. Manufacturing strategies for agglomerated and aligned single-/multiwalled CNTs are used as examples of the engineering science of CNT production, which includes an understanding of their growth mechanism, agglomeration mechanism, reactor design, and process intensification. We aim to provide guidelines for the production and commercialization of CNTs. Although CNTs can now be produced on the tonne scale, knowledge of the growth mechanism at the atomic scale, the relationship between CNT structure and application, and scale-up of the production of CNTs with specific chirality are still inadequate. A multidisciplinary approach is a prerequisite for the sustainable development of the CNT industry.

A review of the large-scale production of carbon nanotubes: The practice of nanoscale process engineering

“…Organic natural materials, such as coal, natural gas, liquefied petroleum gas [21], camphor, eucalyptus oil, turpentine oil, and city gas can serve as carbon sources for CNT synthesis [58]. Various process intensification technologies, such as advanced catalysis processing, multifunctional reactors (such as two-stage fluidized beds), coupledprocess development, and one-step synthesis routes for direct CNT applications have been proposed to efficiently produce CNTs [16]. However, exploring effective cheap feedstock to obtain CNTs with high purity, ideal structures, and high yields is still a challenge.…”

“…For MWCNT production, the producers are mainly located in China, Japan, the United States, Germany, and Korea. Based on the fluidized bed technologies developed at Tsinghua University, the commercial production of MWCNTs had been achieved by Cnano Technology located at Beijing in China with a capacity of 560 tons per year as of the middle of 2009 [16]. With regard to S/DWCNT production, both the CVD and the arc-discharge methods are used by industrial producers.…”

“…Many other articles have reviewed the growth of singleand multi-walled carbon nanotubes, using either arc discharge, laser ablation, or catalytic CVD techniques [4][5][6][7][8][9][10][11][12][13][14][15][16].…”

The Effect of Metal Loading on the Performance of Tri-metallic Supported Catalyst for Carbon Nanotubes Synthesis from Liquefied Petroleum Gas

“…Mo also acts as an inhibitor to prevent rapid deactivation of the catalyst (Dupuis, 2005;Ago et al, 2006). Mo also improves dispersion and prevents the sintering of Fe nanoparticles (Zhang et al, 2011). An advantage of using MgO as a catalyst support is that it increases the CNT yield and it can be separated easily from the CNT product (Tsoufis et al,Setyopratomo et al 121 2007) by a simple acid treatment, thereby facilitating the purification of CNT (Ago et al, 2006).…”

“…The size of metal nanoparticles dispersed on a catalyst support is affected by the level of metal loading, as a lower metal loading results in a smaller size of the metal nanoparticles. By contrast, increased metal loading may result in sintering of the metal particles (Zhang et al, 2011). The metal loading also substantially affects the extent of dispersion of the metal nanoparticles on the support .…”