AN 1979 Bolme 4138470 Preventing escape of nitrogen oxides from an acqueous nitrate solution
Nitric oxide may be removed from gases which it is admixed by contacting the gases with aqueous solutions containing nitrate ions in sufficient concentration to oxidize the nitric oxide to nitrous acid and to retain it in the solution under stable conditions. Other oxides of nitrogen can also be absorbed producing nitrous acid which is retained in the aqueous solution in a similar manner. Thereafter, the scrubbing solution is regenerated under controlled conditions, producing a gas stream which contains the recovered nitrogen oxides in relatively high concentration and a scrubbing solution which can be recycled. The recovered nitrogen oxides may be used in the manufacture of nitric acid or other compounds or decomposed into harmless gases.