Em. Vanveldhuizen et al., COMBINED EFFECTS OF PULSED DISCHARGE REMOVAL OF NO, SO2, AND NH3 FROMFLUE-GAS, Plasma chemistry and plasma processing, 18(1), 1998, pp. 91-111
Experiments have been performed using pulsed high-voltage discharges w
ith the aim of removing NO and SO2 from flue gas obtained from a metha
ne burner. It is found that the NO conversion is strongly increased by
the addition of SO2 or NH3. When both gases are added simultaneously
the increase almost disappears. The synergetic effect can be maintaine
d, as is shown, when NH3 is introduced much later than SO2. The SO2 re
moval is already 70% upon stoichiometric addition of NH3, but the elec
tric discharge improves this to >95% and reduces the NH3 leak to a few
ppm. This increase is probably related to aerosol production by the p
ulsed discharge which enhances the ammonium salt production. A so-call
ed ''history effect'' is observed, i.e., the removal of NO and SO2 dep
ends on the time that is taken to reach the required energization. It
appears that the discharge has to create favorable conditions for the
cleaning process. Using the synergetic and history effects the best cl
eaning result, at initial concentrations of 300 ppm, is 80% NO removal
and 95% SO2 removal with 3 ppm NH3 leak. In this case the energy cost
is 13 eV/NO (or a yield of 90 g NO and 200 g SO2 per kWh). Possibilit
ies for further improvement are indicated.