The effect of gas pressure on NO conversion energy efficiency in nonthermal nitrogen plasma

This work explores the effect of gas pressure on the rate of electron collision reactions and energy consumption for NO conversion in N 2 in a pulsed corona discharge reactor. A previous study showed that the rate constant of electron collision reactions, multiplied by the electron concentration, can be expressed as k [ e ] = β α - 0.5 P - 0.5 W 0.75 exp ( - α P / W ) . The model parameter α remains constant with increasing gas pressure, which verifies the previous assumption that the electron temperature is inversely proportional to gas pressure. However, the model parameter β decreases with increasing gas pressure, which indicates that the rate constant of electron collision reactions decreases with increasing gas pressure. The new expression for the rate constant of electron collision reactions, k [ e ] = B α - 0.5 P - 1.4 W 0.75 exp ( - α P / W ) , is more general because it explicitly accounts for the effect of gas pressure that was previously contained in the parameter β . The electron mean energy decreases with increasing gas pressure, which results in thermal dissipation of a larger fraction of the energy input to the reactor that heats the gas instead of producing plasma chemical reactions. Therefore, energy efficiency for NO conversion in N 2 decreases with increasing gas pressure.