Patent ID: 8911701

Claim:
An industrial process for fabricating carbon nanotubes (CNTs), comprising synthesis of the carbon nanotubes by decomposing a carbon source brought into contact, in a fluidized-bed reactor at a reaction temperature between 500° C. and 1500° C. with a catalyst in the form of substrate grains covered with a metal, the nanotubes produced being recovered, in which the carbon nanotubes synthesized in the reactor and fixed onto the grains of catalytic substrate in the form of an entangled three-dimensional network, forming agglomerates constituting the CNT powder, are recovered sequentially by discharging them while hot at the reaction temperature for synthesizing the CNTs, and discharge taking place beneath the reactor via an outlet of the reactor; wherein it comprises the following steps: 1) the temperature of the reactor is raised to the value desired for the synthesis, between 500° C. and 1500° C. for an initialization phase and this temperature is maintained with a carbon nanotube powder feedstock in the reactor; 2) a CNT synthesis phase for a defined time T 1 , consisting in: pulsingly injecting the catalyst into the reactor by means of an inert gas and continuously injecting reactive gases containing the carbon source into the reactor; and 3) a hot CNT recovery phase for a time T 2 , consisting in: stopping the injection of the catalyst when the reactor reaches a predetermined filling level, continuing to inject the reactive gases containing the carbon source, or stopping the injection after having maintained it for a defined time t r , discharging the CNT powder beneath the reactor in order to introduce it into a cooling container, stopping the discharge and recommencing a new phase 2).