NO/NO x removal with C 2 H 2 as additive via dielectric barrier discharges

Effective reduction and removal of NO x from gas streams by dielectric barrier discharge (DBD) was studied. A laboratory‐scale experimental system was designed and constructed to evaluate the removal efficiency of NO and NO x . Particularly, C 2 H 2 was added as a reducing agent in the DeNO x plasma process via DBD. Experimental results indicated that the removal efficiency of NO/NO x increased with increasing applied voltage, gas temperature, and H 2 O (g) content. As the oxygen content in the gas stream is increased, more CH i radicals will be further oxidized to CO 2 , thus reducing the removal efficiency of NO x . When sufficient C 2 H 2 was added to the DBD process, as high as 91.2% of NO and 68.2% of NO x were removed at 140°C for the gas stream containing 500 ppm NO, 1,500 ppm C 2 H 2 , 3.2% H 2 O (g) , and 5% O 2 , with N 2 as the carrier gas. In addition to N 2 and H 2 O, the major products found in this process included NO 2 , N 2 O, HNO 3 , CO 2 , CO, and HCOOH, depending on H 2 O (g) and O 2 contents of the gas stream.