Rapid reduction of nitrogen oxides in exhaust gas streams

Abstract

Nitrogen oxides (NO_x) play a major role in the formation of photochemical smog and in acid rain production¹. Some progress has been made in reducing NO_x emissions through the use of combustion and exhaust control schemes, including three-way catalyst, staged combustion, and ammonia injection. Nevertheless, estimates indicate that the production of nitrogen oxides will continue to increase until the end of the century and beyond, if current trends continue². We describe here a new chemical process capable of completely removing NO_x from the products of combustion. The effectiveness of this process is established in flow tube experiments. Further, we demonstrate the practical feasibility of this method by eliminating NO_x from a portion of the exhaust from a single-cylinder diesel engine. Based on these results we conclude that this process for rapid reduction of nitrogen oxides could play a major role in controlling NO_x emissions from most combustion devices.