Flue Gas NOX Reduction Using Ammonia Radical Injection

Abstract

A novel technique has been developed for flue gas NOX reduction through the injection of plasma-treated ammonia and its decomposition products. Numerical investigation of the chemical kinetics shows nearly complete NO removal when ammonia radicals are injected into the flue gas. The feasibility of this new technique was experimentally explored on a small-scale laboratory combustor at Carnegie Mellon University and concurrently on a larger-scale combustor at the DOE Pittsburgh Energy Technology Center. Preliminary experimental results have shown that ammonia plasma-injection is more effective than simple ammonia-injection at low flue gas temperatures. NOX reduction of 85 to 90 percent was achieved at a low plasma power input. This technique is expected to provide additional opportunities for inexpensive and effective NOX reduction in stationary sources.