Formation of NO x from Air and N 2 /O 2 Mixtures Using a Nonthermal Microwave Plasma System

We present an experimental study of NO x (NO and NO 2 ) formation from air and N 2 /O 2 /NO x mixtures using a nonthermal microwave plasma device. The tests were performed considering the energy consumed to generate plasma gas and the flow rate of air. The results demonstrated that NO x production was proportional to input power and the inverse of air flow rate. In the experiments that used N 2 and O 2 mixtures instead of air, the maximum NO x concentration produced at equilibrium was 16.02 ×10 16 molecules/J (0.66 ×10 16 NO molecules/J and 15.36 ×10 16 NO 2 molecules/J). Under the condition of the source gases consisting of NO and NO 2 of 970 ppm in the N 2 and O 2 mixture with a ratio of 79/21, the concentrations of NO x generated were 5,571 and 5,320 ppm.