Process for removing SO from a gaseous mixture (OP-3409)

A combination denitrogenation and desulfurization process which comprises the steps of:

• (a) contacting a gaseous mixture comprising nitrogen oxides and sulfur oxides in the presence of oxygen and in the absence of a catalyst, with ammonia in a molar amount equal to the sum of about 1.0 to about 3.0 times the moles of said nitrogen oxides plus about 0.01 to about 2.0 times the moles of said sulfur oxides to reduce said nitrogen oxides to nitrogen, at a temperature ranging from about 1300 to about 2200 degrees F.;
• (b) passing the gaseous product resulting from step (a) comprising nitrogen, said sulfur oxides and unreacted ammonia to an absorption zone maintained at absorption conditions to contact an aqueous composition comprising an ammonium salt selected from the group consisting of ammonium carbonate, ammonium bicarbonate, and mixtures thereof, in an amount such that the product of the partial pressures of said sulfur oxides and ammonia over said aqueous composition, measured at 140 degrees F., is not greater than about 5 (mm Hg).sup.2, in said absorption zone, to produce a gaseous effluent having a decreased amount of said sulfur oxides, and an ammonium salt of an acid of sulfur;
• and
• (c) recovering said ammonium salt of an acid of sulfur.