NO synthesis stimulated by vibrational excitation

Elementary Reaction of NO Synthesis Stimulated by Vibrational Excitation... 

ELEMENTARY REACTION OF NO SYNTHESIS STIMULATED BY VIBRATIONAL EXCITATION OF MOLECULAR NITROGEN... 

The formula can be applied in the case of IXeEaT /hcoTo < 1, where hco and Xe are the vibrational quantum and anharmonicity coefficient of N2 molecules. Compare the rate coefficient (6-34) for NO synthesis stimulated by vibrational excitation with that of CO2 dissociation (see Section 5.2). Because NO synthesis represents the slow reaction, the rate coefficient (6-34) includes detailed characteristics of the elementary process in contrast to the case of fast reaction in plasma-chemical CO2 dissociation. For calculations of the rate coefficient using equation (6-34) at typical non-equilibrium plasma conditions (T 3000 K, To < 1000 K), one can take the pre-exponential factor Ao = 10 -10 cm°/s. 

The equation of N2 vibrational energy balance can be applied to illustrate the qualitative features of non-equilibrium plasma-chemical NO synthesis stimulated by vibrational excitation ... 

Plasma-Chemical NO Synthesis from Air Outside of the Active Discharge Zone (in Passive Zone). NO synthesis stimulated by vibrational excitation continues outside of the active discharge zone, using previously accumulated vibrational energy. The effective chemical process continues in the passive zone during a time interval Tp until the vibrational temperature from an initial value decreases to the critical value Based on (6-45), derive relation (6-46) for tp. 

Calculate the vibrational energy losses related to non-resonance VV exchange and VT relaxation from highly vibrationally excited N2 molecules during NO synthesis stimulated by vibrational excitation of nitrogen molecules in non-thermal air plasma. Demonstrate that these losses can be attributed to a single act of chemical reaction of synthesis and, therefore, can be included in the chemical factor. 

Electronically Adiabatic Channel of NO Synthesis O - - N2 NO - - N Stimulated by Vibrational Excitation of Molecular Nitrogen... 

The thermal NO synthesis from air follows the Zeldovich mechanism, which is stimulated by vibrational excitation of N2 molecules even at quasi-equihbrium, and the energy in thermal systems is distributed over all degrees of freedom, including those not effective in the synthesis. 

Total energy efficiency q) of the non-equihbrium plasma synthesis of NO from air or N2-O2 mixtures, stimulated by vibrational excitation, can be subdivided into three factors the excitation factor q x), the relaxation factor ( rei), and the chemical factor (/jchem, to be considered in the next section) ... 

Non-Adiabatic Channel of Elementary Reaction of Vibrationally Excited Nitrogen with Atomie Oxygen Limiting Zeldovich Mechanism of NO Synthesis. Compare probabilities (6-32) and (6-15) of non-adiabatic and adiabatic channels of the reaction O -I- N2 NO -f N, stimulated by vibrational excitation. Calculate the critical gas temperature To when the contributions of the channels in kinetics of NO synthesis are similar. How does the critical temperature depend on N2 vibrational energy ... 

The most eneigy-efifective mechanism of NO synthesis in plasma is related to stimulation of the process under non-equilibrium conditions by vibrational excitation of N2 molecules. The kinetics of this process is controlled by the Zeldovich mechanism (see Section 6.1.2) and is limited by the elementary endothermic reaction (6-2) of a vibrationally excited N2 molecule. Thus, elementary reaction (6-2) plays a key role in the entire plasma-chemical NO synthesis. This elementary reaction is limited not by W relaxation and formation of molecules with sufficient energy (as in the case of CO2 dissociation see Section 5.3), but by the elementary process of the chemical reaction itself. That is why the elementary process (6-2) should be considered to describe the Zeldovich kinetics of NO synthesis in non-equilibrium plasma. 

KINETICS AND ENERGY BALANCE OF PLASMA-CHEMICAL NO SYNTHESIS STIMULATED IN AIR AND O2-N2 MIXTURES BY VIBRATIONAL EXCITATION... 

Vibrationally excited molecules are very effective in the stimulation of endothermic chemical reactions. But the exothermic reactions with activation barriers are not stimulated by molecular vibrations (see Section 2.7), which slows down the whole process. In this case the hot atoms can make a difference by accelerating exothermic processes. This effect will be illustrated in Section 6.3.7 in the discussion of NO synthesis in non-equilibrium plasma. 

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