Process for producing catalyst patricle diameter control type carbon nanostructure production, production apparatus therefor, and carbon nanostructure

Abstract

A process for producing a carbon nanostructure, comprising effecting contact of a raw gas with catalyst microparticles, while allowing them to flow, in a reactor furnace, wherein a high-pressure pulse gas is instantaneously blown to the catalyst microparticles to thereby float the same, then the floating of catalyst microparticles is discontinued so as to allow the catalyst microparticles to freely fall, and selection of particle diameter is carried out, and wherein catalyst microparticles having been selected in accordance with appropriate particle diameter control thus performed is transferred and fed into the reactor furnace. By this process, a carbon nanostructure can be continuously produced stably at low cost without being influenced by a dispersion of particle diameter inherent in catalyst raw materials. Further, there is provided a carbon nanostructure comprised of a curly carbon nanotube of 1 to 300 nm diameter, the curliness being one with a three-dimensional configuration having bending points irregularly incorporated therein.

Description

[0001] technology area [0002] The present invention relates to a method for producing carbon nanostructures such as carbon nanotubes and carbon nanocoils, a production device, and carbon nanostructures. Background technique [0003] Carbon nanostructures are nanoscale substances composed of carbon atoms, such as carbon nanotubes, carbon nanotubes with particles formed on carbon nanotubes, brush-like carbon nanotubes formed by a plurality of carbon nanotubes, Carbon nanotubes include twisted carbon nanohelixes (CarbonNanotwist), coil-shaped carbon nanocoils, spherical shell-shaped fullerenes, and the like. [0004] For example, in 1994, Amelinckx et al. (Amelinckx, X.B.Zhang, D.Bernaerts, X.F.Zhang, V.Ivanov and J.B.Nagy, SCIENCE, 265 (1994) 635 (Non-Patent Document 1)), using chemical vapor deposition (Chemical Vapor Deposition, hereinafter referred to as CVD method), synthesized carbon nanocoils for the first time. Furthermore, it was clarified that carbon nanocoils have ...

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Problems solved by technology

However, at the stage of purchasing from catalyst manufacturers, etc., or at the stage of refining in another catalyst process, the particle size distribution of catalyst fine particles varies.

And there is the following problem: even under the situation that the particle diameter of catalyst itself is neat, also can't avoid the coagulation between catalyst microparticles because of the impact of catalyst surface state, humidity in use environment etc., mixed in the catalyst can't be used for During the growth of carbon nanocoils, catalyst secondary particles with a large diameter of 1000nm or more, catalyst fine particles are excessively aggregated into agglomerates

Since carbon nanostructures such as carbon nanocoils grow on the surface of the catalyst particles, if the above-mentioned large-diameter particles are mixed with the catalyst particles introduced into the reaction furnace in a properly dispersed state, the following problems will arise. Carbon nanostructures with extremely thick wire diameters may reduce the yield of carbon nanostructures due to excessive agglomeration of catalysts, and lead to unstable yields

In addition, pre-selecting and preparing catalysts whose particle diameters fall within a predetermined range requires a treatment process, and there is a problem of increased production costs.

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