Removal of nitrogen oxides from industrial gases by use of oxidizing solutions in which nitrates are the oxidants

Abstract From the Canadian patent

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,a scrubbing solution which can be recycled. The recovered nitrogen oxides may be used in the manufacture of nitric acid or other …