Carbon nanostructures and process for the production of carbon-based nanotubes, nanofibres and nanostructures

A process for producing at least one carbon-based structure selected from nanotubes, nanofibers and nanostructures, comprising the steps of:

• a) generating a plasma with electrical energy;
• b) introducing a carbon precursor and optionally one or more catalysts and optionally a carrier plasma gas in a reaction zone of a high temperature resistant vessel;
• c) vaporizing the carbon precursor in the reaction zone at a very high temperature forming a vaporized carbon precursor;
• d) guiding at least a fraction of the vaporized carbon precursor through an opening in a nozzle having an inlet and an outlet wherein the opening narrows toward the outlet;
• e) guiding at least a fraction of the vaporized carbon precursor into a quenching zone for nucleation wherein the quenching zone has an upper part and a lower part;
• f) generating flow conditions by aerodynamic or electromagnetic forces to reduce flow of the carbon precursor, the vaporized carbon precursor, the one or more catalysts, and the carrier plasma gas from the quenching zone to the reaction zone;
• g) controlling the temperature of the upper part of the quenching zone at the very high temperature and the lower part of the quenching zone at a lower temperature to provide a quenching velocity between 103 K/s and 106 K/s;
• h) quenching the fraction of vaporized carbon precursor guided into the quenching zone;
• i) extracting at least one carbon-based structure from the quenching zone where the at least one carbon-based structure is selected from nanotubes, nanofibers, and nanostructures;
• and
• j) separating at least one carbon-based structure from at least one other reaction product.

A reactor for producing carbon-based nanotubes, nanofibers and nanostructures comprising:

• a) a head section comprising at least two electrodes;
• and
• optionally comprising at least one supply chosen from a carbon precursor supply, a catalyst supply, and a gas supply;
• b) a reaction zone characterized by having at least some gas temperatures during operation of 4000° C. or higher;
• c) at least one injector for injecting into the reaction zone an injected material chosen from a carbon precursor and a catalyst,
• d) a quenching zone where the gas temperature is controllable between 4000° C. in the upper part of this zone and 50° C. in the lower part of this zone, wherein the quenching zone is in fluid communication with the reaction zone;
• and
• e) a nozzle shaped choke, narrowing the open flow communication between the reaction zone and the quenching zone, wherein the nozzle shaped choke comprises a nozzle having an opening.