Production of nitric oxide using a pulsed arc discharge

Nitric monoxide (NO) is increasingly being used in medical applications. Currently, a gas cylinder of N₂ mixed with a high concentration of NO is used. This arrangement is potentially risky due to the possibility of accidental leak of NO from the cylinder. The presence of NO in air leads to the formation of nitric dioxide (NO₂), which is toxic to the lungs. Therefore, an on-site generation of NO would be very desirable for patients with acute respiratory distress syndrome and other related illnesses. We have recently reported on the production of NO using a pulsed arc discharge. In the present work, the discharge reactor was made simpler and smaller. NO was generated using a pulsed arc discharge in dry air and in mixtures of oxygen and nitrogen. The composition of the gas mixture after treatment with an arc discharge followed by exposure to heated molybdenum was 540 ppm of NO, 48 ppm of NO₂, and the balance dry air at 0.1 MPa and 300 ± 3 K. No ozone was detected at the outlet of the system by UV absorption. The density of the brass particles emitted from the electrodes, which had diameters over 0.3 μm, was less than 1.39 μg/L. A filter could readily capture and thus remove the brass particles.