NOx Reduction from Stationary Combustion Sources via Plasma DeNOx

Stringent NOx control technologies, including selective catalytic reduction, are expensive and often require a high capital investment. In areas where ozone exceedances are infrequent or limited to a particular season, a NOx control technology with low capital costs but higher operating costs could be used during the ozone season only at potential cost savings over other capital intensive technologies. This paper discusses the development of a new technology, "plasma deNOx," for NOx control from stationary combustion sources. The technique, like selective catalytic and non-catalytic reduction, uses ammonia injection to reduce NOx in the combustion flue stream. However, by flrst dissociating the ammonia with a plasma device prior to injection into the flue gas stream, the plasma deNOx process does not require a narrow temperature window or expensive catalyst to achieve 90% NOx reduction. Laboratory experiments verifying the advantage of the plasma deNOx process over cold and hot ammonia injection processes, as well as larger scale experiments mapping key operating conditions of the plasma deNOx process, are described.