Isotope separation and yield calculations for vibrationally enhanced oxidation of nitrogen

The separation of nitrogen isotopes by low temperature reaction of vibrationally excited nitrogen gas with oxygen has been studied, in which the formation of 15NO is theoretically favored. The potential yield and isotope separation coefficient β for this process were examined using a numerical simulation of the kinetic processes, which incorporated a steady-state isothermal model of the 14N2 and 14N15N vibrational distribution functions coupled with a non-steady-state kinetic model of the chemical system including N*2, O*2, N, O, and their reaction products. In the absence of O2, the vibrationally enhanced rate coefficient for the reaction N*2+O → NO+N was observed to be inversely proportional to the concentration of O atoms, due to VT loading of the N*2 distribution function. O2 was also found to greatly reduce the rate coefficient due to efficient depletion of the highly excited species via the reaction N2(v)+O2(0) → N2(v−1) +O2(1). Computed reaction yield increases dramatically if both the O*2 and N*2 vibrational temperatures are elevated, but only at the expense of greatly reduced β. The effective separative work for this process was estimated.