The present invention relates to the removal of sulfur and nitrogen containing pollutants from waste gases. These pollutants are often present in the discharge gases of fossil fuel fired boilers or furnaces for industrial applications.
Previous methods for removing sulfur containing pollutants from gas streams have included such as scrubbing with large volumes of liquid solutions containing alkaline minerals, organic bases or alcohols. Such processes require substantial expenditures for large capacity scrubbing equipment and are of considerable disadvantage for use in combination with high temperature processes.
Other methods for removing sulfur oxides or hydrogen sulfide have included electrochemical separation as shown in U.S. Pat. No. 4,246,081, Jan. 20, 1981 to Winnick. The process requires the use of costly electric energy in an electrochemical apparatus to effect the separation.
U.S. Pat. Nos. 4,455,286, June 19, 1984 and 4,442,078, April 10, 1984 disclose methods for removing hydrogen sulfide and other sulfur containing gases from gas mixtures. These patents teach that copper oxide should be supported on a substrate such as zinc oxide when used to remove hydrogen sulfide from a hot fuel gas stream.