Abstract |
Improving NO Reduction Efficiency by
Acoustic Oscillations
S.Nemeth, S.V.Komarov, M.Hirasawa
(Institute of Multidisciplinary Research for Advanced Materials, Tohoku
University, Sendai, Japan)
e-mail:
nemeth@mail.iamp.tohoku.ac.jp
In
high temperature processes, one of the most harmful air pollutants is the
nitrogen oxide NO. The present study has been focused on a possibility for
improving NO reduction efficiency by application of powerful sound waves
(frequency 6.9~17.2 kHz, intensity 144~160 dB) that were produced by Hartmann
sound generators mounted on the top of a vertical reaction tube (height 1.8 m,
I.D. 105 mm). A graphite disc was positioned in the tube bottom part preheated
up to certain temperatures (873~1173 K). An Ar-NO synthetic gas mixture (NO
911~934 ppm) was injected onto the disc surface to perform reactions
2C+2NO=N2+2CO and C+2NO=N2+CO2. Without sound wave application NO content in
the flue gas was reduced to a level of 200-600 ppm. Exposing the disc surface
to sound waves resulted in the further decrease in NO concentration 50~250 ppm
values. The effect of NO reduction efficiency was found to be dependent on the
sound frequency, intensity, gas flow rate and temperature.
Section
: 11