TH101992A - Process for carbon production Nanotubes from continuous raw materials - Google Patents

Abstract

DC60 (06/06/51) The subject of the invention is a process for the production of carbon nanotubes, which comprises the following stages: a) synthesis of alcohols by fermentation of at least one plant substance and selective purification of the resulting product; b) dehydration of the alcohol or the alcohols obtained in a) to produce, in the first stage reactor, a mixture of alkene and water and selective purification of the resulting product; c) insertion, specifically insertion into a fluidized bed, in the second stage reactor, of a powder catalyst at temperatures ranging from 450 to 850 °C, which is composed of at least one catalyst metal supported by an inert solid substrate, and the grains of the catalyst have a d50 less than 300 μm; d) selective contact of the alkene produced in b) with the powder catalyst of phase c), in a fluidized bed, to induce carbon nanotubes and hydrogen on the surface of such catalyst by catalytic decomposition of such alkene; e) recovery of the carbon nanotubes produced in d). The invention also concerns nanotubes that can be made by the above-mentioned process, which can be used advantageously in all known areas of carbon nanotube applications. The subject of the invention is a process for the production of carbon nanotubes, which comprises the following phases: a) synthesis of alcohol by fermentation of at least one plant substance and selective purification of the resulting product; b) dehydration of the alcohol or alcohol produced in a), to produce, in the first stage reactor, a mixture of alkene and water, and selective purification of the resulting product; c) Insertion, specifically insertion into a fluidized bed, in a second reactor, of a powdered catalyst at temperatures ranging from 450 to 850 °C, which comprises at least one catalytic metal supported by an inert solid substrate, with a catalyst grain size d50 less than 300 μm; d) Selective contact of the alkene produced in b) with the powdered catalyst of phase c), in the fluidized bed, to induce carbon nanotubes and hydrogen on the surface of such catalyst by catalytic decomposition of such alkene; e) Recovery of the carbon nanotubes produced in d). The fabrication also concerns nanotubes that can be made according to the above-mentioned methods, which can be used advantageously in all known areas of carbon nanotube applications.

Claims (18)

1. The procedure for producing carbon nanotubes consists of the following phases: a) Synthesis of alcohol by fermentation of at least one plant substance and selective purification of the resulting product; b) Dehydration of the alcohol or alcohol obtained in a) to produce, in the first stage reactor, a mixture of alkene and water and selective purification of the resulting product; c) Inoculation, specifically inoculation into a fluidized bed, in the second stage reactor, of a powder catalyst at temperatures ranging from 450 to 850 °C, which is composed of at least one catalytic metal supported by an inert solid substrate, with a grain size of d50 less than 300 μm; d) Selective contact of the alkene produced in b) with the powder catalyst of phase c), in the fluidized bed, to induce carbon nanotube formation and hydrogenation on the surface. The catalyst is activated by the catalytic decomposition of the alkene; e) the recovery of the carbon nanotubes produced in d) 2. The procedure under claim 1, characterized by phases c) to e), is carried out continuously and simultaneously in a second batch reactor. 3. Any one of the preceding claims, characterized by plant matter of choice from beets; sugarcane; cereals such as maize, wheat, barley and sorghum; potatoes; biomass; and sources of cellulose. 4. The process pursuant to claim 3, which is characterized by the grain being corn. 5. Any of the processes described in claims 1 through 4, which are characterized by the alcohol being ethanol. 6. Any of the preceding claims, characterized by phase b) being carried out using a (formula)-alumina-based catalyst. 7. Any of the procedures under the prior claims, characterized by phase c) being carried out at temperatures of 500°C to 700°C. 8. One of the preceding claims, characterized by the alkene being mixed in phase c) with a stream of hydrogen and/or at least the portion of water produced during the dehydration of the alcohol in b) 9. Any of the processes under the prior claim, characterized by the hydrogen produced in d) being recycled at least partially to a second batch reactor. 10. A process pursuant to one of the preceding claims, characterized by the presence of an iron catalyst. 11. One of the preceding claims, characterized by the production of a powdered catalyst by saturating a solid substrate with an aqueous solution of the reactive metal, and then calcining the saturated solid substrate to ash. 12. Any of the processes described in the prior claims, characterized by incineration to ash, are carried out at temperatures of 200°C to 400°C. 13. A process pursuant to one of the prior claims, characterized by a grain d50 of the powdered catalyst being less than 200 µm and preferably greater than 100 µm. 14. Carbon nanotubes that can be fabricated by any of the processes described in claims 1 through 13. 15. Carbon nanotubes pursuant to claim clause 14, which are characterized by the presence of at least 20% by mass, preferably at least 50% by mass, of continuously occurring carbon relative to the total mass of carbon. 16. Carbon nanotubes pursuant to claim clause 14, which are characterized by the presence of at least 0.2 x 10⁻¹⁰% by mass of 14C, preferably at least 0.6 x 10⁻¹⁰% by mass of 14C. 17. The use of carbon nanotubes under any of the claims 14 through 16 in composite materials to provide improved electrical and/or thermal conductivity and/or improved mechanical properties, especially resistance to tensile forces, to those materials. 18. The use of carbon nanotubes under any of the claims 14 through 16, in macromolecular mixtures intended for the packaging of electronic components or the manufacture of fuel tubes or anti-static coatings, or in thermistors or electrodes for supercapacitors.