Production of nitric monoxide using pulsed discharges for a medical application

Nitric monoxide (NO) is widely used in medical treatment of acute respiratory distress syndrome (ARDS). The production of NO is of interest to the medical community. In the present work, NO is generated by pulsed discharges between two rod electrodes in a mixture of nitrogen and oxygen. An are discharge having a temperature of about 10 000 K was produced, which was sufficient to generate NO. Some of the important parameters affecting the production of NO have been investigated. These include the percentage of O-2 (6-94%) in the mixture of N-2 and O-2, the energy of the discharge (0.5-12 J/pulse), the pulse repetition rate (0.5-4.5 pps) and the flow rate (1.35-5.4 l/min) of the gas mixture. NO2 produced in the discharge was successfully changed to NO using a heated molybdenum tube. NO2 must be extracted from the gas before clinical inhalation. The concentration of ozone was completely eliminated by bubbling the gas mixture through water. A maximum of NO and a minimum of NO2 concentrations were generated when the proportion of O-2 in the gas mixture was in the range of 20-27%. The concentrations of NO and NO2 increased with increasing pulse repetition rate and with decreasing flow rate of the mixture. In all cases, NO2 was effectively removed using a heated molybdenum tube.