Ammonia → Ammonium bisulfate

Participants

Reaction Steps

Thus, in the present invention, the molar ratio of ammonia to sulfuric anhydride in the down flow gases after the reaction zone for the reduction of nitrogen oxides, i.e. at the inlet of the air preheater, is controlled within the range of O<NH3 /SO3 <2, preferably O<NH3 /SO3 <1.5, by which the ammonium salt of sulfuric acid is therein produced predominantly in the form of ammonium hydrogen sulfate (but not ammonium sulfate). Besides, the concentration of steam in the gases at the inlet of the air preheater is increased more than the concentration thereof in the usual boiler exhaust gases (e.g. 10 to 12% by volume), i.e. more than 12% by volume, preferably more than 15% by volume, by which the freezing point depression and the deliquescence of ammonium hydrogen sulfate are promoted.

Provenance & Evidence