A device and method for single-stage continuous preparation of carbon nanotubes

Abstract

The invention provides a device for continuously preparing carbon nanotubes based on a fluidized bed reactor. The fluidized bed reactor has an annular variable diameter area, a raw gas inlet, a catalyst inlet, and a protective gas inlet. port and a pulse gas controller, the position of the annular variable diameter area is located at the top of the fluidized bed reactor from 1 / 4 from the bottom, and the pulse gas controller is arranged at the top of the circular arc of the annular variable diameter, The catalyst feed inlet is located at the top of the fluidized bed reactor, the feed gas inlet and protective gas inlet are located at the bottom of the fluidized bed reactor, and the device is also provided with a product outlet and a tail gas outlet. The device is simple in structure, low in cost, easy to operate, high in raw material utilization rate, can effectively control the problem of carbon deposition on the inner wall of the main reactor, and can prepare carbon nanotubes with high purity, which is suitable for large-scale industrial production.

Description

technical field [0001] The invention relates to a device and method for single-stage continuous preparation of carbon nanotubes. The device for continuously preparing carbon nanotubes of the present invention adopts a single-stage fluidized bed, has a simple structure, is easy to operate, can continuously and stably produce carbon nanotubes under normal pressure or high pressure, and has the advantages of improving the utilization rate of catalysts and raw materials and increasing carbon The advantages of the purity of nanotube products can save costs and are suitable for large-scale industrial production. Background technique [0002] As a one-dimensional nanomaterial, carbon nanotubes have excellent physical and mechanical properties. They are mainly coaxial circular tubes with several to dozens of layers composed of carbon atoms arranged in a hexagonal shape. It has a very large aspect ratio, the diameter is usually between 1-100nm, and the length is several microns to h...

AI Technical Summary

Problems solved by technology

The fixed fluidized bed process has simple equipment and flexible operation, and is only suitable for catalyst screening and the preparation of a small amount of carbon nanotubes; a fluidized fluidized bed can process a large amount of catalysts, and the yield of carbon nanotubes is also good, but the conversion rate of feed gas is low and the cost is high ; Floating fluidized beds are suitable for catalytic systems that are easy to gasify and decompose, and have high limitations; moving fluidized beds have problems with temperature gradients and moving speeds

In addition, for traditional fluidized beds, catalyst density and particle size have a great influence on reaction efficiency

If the density of the catalyst is low, the density of the prepared carbon nanotubes is small, and it is easy to be blown out of the reactor, and the residence time is short, resulting in low utilization of the catalyst

On the contrary, if the residence time in the reactor is increased, the carbon nanotubes will easily agglomerate, block the reactor, and easily cause fluidization difficulties in the production process, etc.

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