A continuous and efficient carbon nanotube fluidized bed preparation method

Abstract

The invention provides a continuous and efficient preparing method for a carbon-nanometer-tube fluidized bed. The continuous and efficient preparing method for the carbon-nanometer-tube fluidized bed includes the steps of catalyst reduction activation and carburizing reacting; a carbon-nanometer-tube growing reactor is a fluidized bed reactor divided into the upper section and the lower section, the carbon-nanometer-tube growing reacting process is carried out in the upper-section fluidized bed of a belt ring flow with the large inner diameter, the operating linear velocity is controlled to be the minimum fluidizing velocity larger than that of a catalyst and small carbon-nanometer-tube particles, and is controlled to be the minimum fluidizing velocity lower than that of large carbon-nanometer-tube aggregation particles, and therefore the large carbon-nanometer-tube aggregation particles are screened out of multi-scale particle flows of a carbon-nanometer-tube reactor and continue to enter the lower-section fluidized bed; the carbon-nanometer-tube fluidized bed serves as a collector of the large carbon-nanometer-tube aggregation particles, inert gas is used as a fluidizing medium, the large carbon-nanometer-tube aggregation particles are in the loosing state and convenient to move out of the reactor, and continuous preparing is really achieved.

Description

technical field [0001] The invention belongs to the technical field of carbon material preparation and relates to a continuous carbon nanotube fluidized bed preparation method. Background technique [0002] Carbon nanotubes are considered to be a new type of functional material and structural material with excellent performance, and have become a research hotspot in the past two decades. So far, there have been many methods for preparing carbon nanotubes, but there are only three main methods, namely arc method, laser ablation method and catalytic cracking method. The catalytic cracking method uses nano-scale iron, cobalt or silver as a catalyst, low-carbon short, carbon oxides or carbon monoxide as raw material gas, and a catalytic cracking reaction at high temperature to grow carbon nanotubes. The carbon nanotubes produced by this method have high purity, controllable specifications, and are easy to scale up industrially, and are considered to be the most promising method...

AI Technical Summary

Problems solved by technology

[0003] Among the catalytic cracking methods used in the production of carbon nanotubes at present, the existing technology is to use a fluidized bed reactor, but before the preparation of carbon nanotubes, the catalyst needs to be reduced and activated, because each batch of carbon nanotubes is prepared. The amount of catalyst required is small, and the reduction and activation conditions are special. It needs to be carried out in another separate reactor, and it is carried out in series with the carbonization reaction process. The process is cumbersome and complicated, and it cannot realize continuous production in the true sense.

At the same time, due to the temperature distribution characteristics and the endothermic characteristics of the pyrolysis reaction of hydrocarbon gas, the fluidized bed reactor cannot produce carbon nanotubes with high yield.

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