The invention provides improved burners, combustion apparatus, and methods
for carbon nanomaterial production. The burners of the invention provide
sooting flames of fuel and oxidizing gases. The condensable products of
combustion produced by the burners of this invention produce carbon
nanomaterials including without limitation, soot, fullerenic soot, and
fullerenes. The burners of the invention do not require premixing of the
fuel and oxidizing gases and are suitable for use with low vapor pressure
fuels such as those containing substantial amounts of polyaromatic
hydrocarbons. The burners of the invention can operate with a hot (e.g.,
uncooled) burner surface and require little, if any, cooling or other
forms of heat sinking. The burners of the invention comprise one or more
refractory elements forming the outlet of the burner at which a flame can
be established. The burners of the invention provide for improved flame
stability, can be employed with a wider range of fuel/oxidizer (e.g.,
air) ratios and a wider range of gas velocities, and are generally more
efficient than burners using water-cooled metal burner plates. The
burners of the invention can also be operated to reduce the formation of
undesirable soot deposits on the burner and on surfaces downstream of the
burner.