Method for producing carbon nanotubes by using semicoke-based catalyst prepared by micro-fluidized bed

The invention discloses a method for producing carbon nanotubes by using a semicoke-based catalyst prepared by a micro-fluidized bed. The method comprises the following steps: pyrolyzing pea coal in a pyrolyzing furnace; grinding and screening the coal semicoke particles to obtain powdery semicoke, washing the powdery semicoke with a hydrochloric acid or nitric acid solution, cleaning the powdery semicoke with deionized water, and drying the powdery semicoke to obtain semicoke powder for later use; feeding a proper amount of semicoke powder into a micro-fluidized bed reactor, continuously pumping the dipping solution into the micro-fluidized bed reactor, fully mixing, collecting the semicoke powder, washing, drying and baking; and activating the prepared semi-coke catalyst, putting the activated semi-coke catalyst into a fluidized bed reactor, introducing methane gas, and collecting the obtained carbon nanotubes. The coal pyrolysis semi-coke is adopted as a carrier, the catalyst is prepared by virtue of the m