Abstract
A unique SNCR system using dissociated ammonia generated by an atmospheric plasma has been developed to remove NOx from combustors. However, the NOx removal mechanisms are not clear. In this paper, chemical compositions of dissociated ammonia at the plasma reactor exit were investigated. NH3 decomposition, hydrogen conversion, and nitrogen conversion were measured at various applied voltages and flow rates of ammonia gas. In the NOx removal technique, a temperature window enlargement of 150 °C was attained at the lower boundary of the temperature window. It found that dominant species causing the temperature window enlargement was molecular hydrogen formed by disassociation reaction of ammonia in the plasma.
