Patent ID: 8771627

Claim:
A process for producing carbon nanotubes, comprising a) synthesizing alcohol(s) by fermentation of at least one vegetable matter and purifying the product obtained so as to obtain ethanol; b) dehydrating the ethanol obtained in a) to produce, in a first reactor, a mixture of ethylene and water and optionally purifying the product obtained; c) introducing, in a second reactor, a powdery catalyst at a temperature ranging from 500 to 700° C., the catalyst comprising iron supported by an inert solid substrate, the grains of catalyst having a d50 of less than 300 μm, wherein the powdery catalyst is produced by impregnating the solid substrate with an aqueous solution of iron then calcination of the solid substrate thus impregnated at a temperature of 200° C. to 400° C.; d) mixing ethylene with a flow of hydrogen and optionally with at least part of the water produced during the dehydrating of the ethanol in b) and then bringing said mixture into contact with the powdery catalyst of c), in a fluidized bed, to produce hydrogen and form carbon nanotubes on the surface of said catalyst by catalytic decomposition of ethylene; e) recovering the carbon nanotubes produced in d), wherein the hydrogen produced in d) is conveyed at least in part to a thermal oxidizer for combustion of the gases produced during stages a) to e).