Effect of CO₂ on Nonthermal-Plasma Reactions of Nitrogen Oxides in N₂. 2. Percent-Level Concentrations

Abstract

Both NO x conversion and CO 2 conversion decrease with increasing percent-level CO 2 concentration in nonthermal nitrogen plasma. The rate constants of electron collision reactions of both N 2 and CO 2 decrease with increasing CO 2 concentration because electronegative CO 2 reduces electron concentrations in the reactor due to the electron attachment process. The rate constant of CO 2 dissociation through electron collision is 1-2 orders of magnitude higher than that of N 2 dissociation because of low dissociation energy of CO 2 . Model data for reactor outlet NO x and CO x concentrations agree well with experimental data. The effect of CO 2 on NO, NO 2 , N 2 O, and CO concentrations can be explained on the basis of the proposed reaction mechanism and kinetic modeling.

Effect of reactor configuration on nitric oxide conversion in nitrogen plasma

“…Actual combustion exhaust streams contain percent levels of electronegative gases, such as O 2 , CO 2 and H 2 O, which have high electron affinities. Their presence can affect the electronic discharge because of electron attachment processes, which change the reaction chemistry dramatically, as reported by Zhao et al29–31 Therefore, further work is needed to examine the effect of reactor configuration on NO x conversion at more representative feed compositions.…”

Catalytic nonthermal plasma assisted co-processing of methane and nitrous oxide for methanol production

“…Free radical mechanism in NTP is widely accepted [33,38,40,41]. NTP generates energetic electrons and excited species that react with CH 4 and N 2 O to generate free radicals or neutrals, positive ions, negative ions, and excited molecules.…”

“…NTP generates energetic electrons and excited species that react with CH 4 and N 2 O to generate free radicals or neutrals, positive ions, negative ions, and excited molecules. The collisions of CH 4 molecules with energetic electrons lead to the formation of active species such as CH 3 * , CH 2 * , CH * and C 2 H * [41][42][43][44].…”

Methane conversion in pulsed corona discharge reactors

“…Mechanical, bimetallic thermometers placed in the reactor outlet stream proved to be relatively unresponsive and displayed near ambient temperatures, despite the fact that the reactor external support casing (a 0.05 m diameter stainless steel tube concentric to the reactor cathode) was hot to the touch (>350 K) near the reactor outlet. Therefore, the hydrogen switch based reactor (used for NO x conversion in our previous work [22,25,28,[32][33][34][35][36][37]) with the same reactor geometry as the thyratron-based reactor (tube length, 0.914 m; tube diameter, 0.024 m; wire diameter, 1 mm) was used during methane conversion to estimate the temperatures in the thyratron-based reactor. Fig.…”