Reactions of oxides of nitrogen (NO{sub x}) leading to the formation of nitric acid (HNO{sub 3}) in non-thermal plasmas (NTPs). White paper for the Strategic Environmental Research and Development Program (SERDP) (Compliance Project CP-1038: Development of non-thermal plasma reactor technology for control of atmospheric emissions)

Abstract

SERDP Compliance Project CP-1038 (Development of Non-Thermal Plasma Reactor Technology for Control of Atmospheric Emissions) has been commissioned to evaluate and develop non-thermal plasma (NTP) reactor technology, a form of low-temperature plasma chemical processing, for Department of Defense (DoD) applications. The primary emphasis is on the control of emissions of oxides of nitrogen (NO{sub x}), with a secondary emphasis on hazardous air pollutant (HAP) emission control (primarily volatile organic compounds--VOCs). In this white paper, as a SERDP-requested deliverable, the authors will verify the NO{sub x} removal reactions in NTPs, especially those converging on nitric acid (HNO{sub 3}) as a primary reaction product. The benefit of making HNO{sub 3} as a primary terminal de-NO{sub x} product is that it can be easily neutralized by relatively simple caustic (base) scrubbers--although the economics of scrubber systems needs to be compared with the conversion to particles that can be filtered or precipitated. Jet engines also emit a significant amount of SO{sub x} in their exhaust; NTPs also remove SO{sub x} and actually do it more effectively in combination with NO{sub x}. This will not be dealt with in this particular white paper.