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Title: Precursor soot synthesis of fullerenes and nanotubes without formation of carbonaceous soot

Abstract

The present invention is a method for the synthesis of fullerenes and/or nanotubes from precursor soot without the formation of carbonaceous soot. The method comprises the pyrolysis of a hydrocarbon fuel source by heating the fuel source at a sufficient temperature to transform the fuel source to a condensed hydrocarbon. The condensed hydrocarbon is a reaction medium comprising precursor soot wherein hydrogen exchange occurs within the reaction medium to form reactive radicals which cause continuous rearrangement of the carbon skeletal structure of the condensed hydrocarbon. Then, inducing dehydrogenation of the precursor soot to form fullerenes and/or nanotubes free from the formation of carbonaceous soot by continued heating at the sufficient temperature and by regulating the carbon to hydrogen ratio within the reaction medium. The dehydrogenation process produces hydrogen gas as a by-product. The method of the present invention in another embodiment is also a continuous synthesis process having a continuous supply of the fuel source. The method of the present invention can also be a continuous cyclic synthesis process wherein the reaction medium is fed back into the system as a fuel source after extraction of the fullerenes and/or nanotube products. The method of the present invention is also amore » method for producing precursor soot in bulk quantity, then forming fullerenes and/or nanotubes from the precursor bulk.« less

Inventors:
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1176152
Patent Number(s):
7,192,567
Application Number:
10/105,518
Assignee:
UT-Battelle LLC (Oak Ridge, TN) ORNL
DOE Contract Number:
AC05-00OR22725
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 54 ENVIRONMENTAL SCIENCES

Citation Formats

Reilly, Peter T. A. Precursor soot synthesis of fullerenes and nanotubes without formation of carbonaceous soot. United States: N. p., 2007. Web.
Reilly, Peter T. A. Precursor soot synthesis of fullerenes and nanotubes without formation of carbonaceous soot. United States.
Reilly, Peter T. A. Tue . "Precursor soot synthesis of fullerenes and nanotubes without formation of carbonaceous soot". United States. doi:. https://www.osti.gov/servlets/purl/1176152.
@article{osti_1176152,
title = {Precursor soot synthesis of fullerenes and nanotubes without formation of carbonaceous soot},
author = {Reilly, Peter T. A.},
abstractNote = {The present invention is a method for the synthesis of fullerenes and/or nanotubes from precursor soot without the formation of carbonaceous soot. The method comprises the pyrolysis of a hydrocarbon fuel source by heating the fuel source at a sufficient temperature to transform the fuel source to a condensed hydrocarbon. The condensed hydrocarbon is a reaction medium comprising precursor soot wherein hydrogen exchange occurs within the reaction medium to form reactive radicals which cause continuous rearrangement of the carbon skeletal structure of the condensed hydrocarbon. Then, inducing dehydrogenation of the precursor soot to form fullerenes and/or nanotubes free from the formation of carbonaceous soot by continued heating at the sufficient temperature and by regulating the carbon to hydrogen ratio within the reaction medium. The dehydrogenation process produces hydrogen gas as a by-product. The method of the present invention in another embodiment is also a continuous synthesis process having a continuous supply of the fuel source. The method of the present invention can also be a continuous cyclic synthesis process wherein the reaction medium is fed back into the system as a fuel source after extraction of the fullerenes and/or nanotube products. The method of the present invention is also a method for producing precursor soot in bulk quantity, then forming fullerenes and/or nanotubes from the precursor bulk.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Mar 20 00:00:00 EDT 2007},
month = {Tue Mar 20 00:00:00 EDT 2007}
}

Patent:

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  • The invention relates to methods for producing polycyclic aromatic hydrocarbons, fullerenes, and nanotubes, comprising: a. heating at least one carbon-containing material to form a condensed phase comprising at least one polycyclic aromatic hydrocarbon; b. collecting at least some of the condensed phase; c. reacting the condensed phase to form fullerenes and/or nanotubes.
  • Samples of soot precursor particles and carbonaceous soot from a nonsmoking ethene diffusion flame have been analyzed by means of laser microprobe mass spectrometry (LMMS). The mass spectra of soot precursor particles from the lower flame display many peaks in the 200--300-amu range that are characteristic of polycyclic aromatic hydrocarbons (PAHs). The most prominent of these are the masses 252, 276, and 300, which correspond to the isomers of C[sub 20]H[sub 12], C[sub 22]H[sub 12], and C[sub 24]H[sub 12], respectively. These masses are among those predicted by Stein and Fahr to be the most thermodynamically stable (stabilomers) under typical hydrocarbonmore » flame conditions, and they have been previously reported as components of soot collected from a variety of fuels and combustion configurations. Carbonaceous soot from the upper region of the flame yields mass spectra composed of carbon-hydrogen clusters, C[sub x]H[sub y] with x = 3 to 24 and y usually 0, 1, or 2. Smaller amounts of PAH-like species with masses in the 418 to 444 amu range are also found. These results suggest that the carbonization process observed in this flame is the dehydrogenation of the PAH species formed in the lower flame unaccompanied by polymeric growth. The LMMS technique provides a lower bound value of the hydrogen mole fraction X[sub H] of 0.36 (C/H = 1.8) for precursor particles from the lower diffusion flame and 0.15 (C/H = 5.6) for carbonaceous soot aggregates.« less
  • For the soot-free production of a fuel gas mixture containing carbon monoxide, hydrogen and gaseous hydrocarbons by partial oxidation of liquid hydrocarbons with air, with air numbers below 3 and temperatures between 600/sup 0/ and 800/sup 0/ C., a metal catalyst is employed according to the invention, which is prepared by forming shaped bodies composed of an aluminum alloy which contains 15 to 35 wt. % silicon. The shaped bodies are subjected for at least 10 hours at temperatures between about 600/sup 0/ and about 800/sup 0/ C. To an oxidizing atmosphere and for at least 10 hours at temperaturesmore » between about 600/sup 0/ and about 800/sup 0/ C. To gaseous or gasified hydrocarbons for the partial conversion of the aluminum in the shaped body to alpha -Al/sub 2/O/sub 3/ and for the partial conversion of the silicon in the shaped body to beta sic, respectively.« less