Patent ID: 8092775

Claim:
A continuous method of purifying carbon nanotubes, comprising: a) feeding a carbon nanotube solution including carbon nanotube and solvent into a preheater while feeding an oxidizer into the preheater via a heat exchanger to produce a carbon nanotube mixture of the carbon nanotube solution and the oxidizer and then preheating the resultant carbon nanotube mixture at 100 to 370° C.; b) feeding the carbon nanotube mixture from the step (a) into a purifying reactor under subcritical water condition of 50 to 400 atm to obtain a purified product; c) reacting the purified product from step (b) with an acid solution to remove inorganic material; d) cooling down the purified product into 0 to 100° C. and depressurizing the purified product into 1 to 10 atm by feeding the purified product into a cooling down and depressurizing part via the heat exchanger of the step (a) while carrying out the process of step (a); and e) recovering the cooled down and depressurized product from the step (d).