The effect of the oxidizing gas N2 on the conversion reaction under the action of plasma:
Influence of energy density Ed (kJ/mol) on CH4 conversion reaction: CH4 conversion and C2 hydrocarbon yield gradually increased with the increase of energy density, which means increasing plasma injection power and decreasing feedstock in flow reactor The air flow is beneficial to improve the conversion rate of CH4 and the yield of C2. When the energy density is 2000 kJ/mol, the CH4 conversion and C2 hydrocarbon yield can reach 52.7% and 40.9%, respectively. The relationship between energy density and CH4 conversion and C2 hydrocarbon yield is approximately logarithmic. When the energy density is lower than 1000kJ/mol, the CH4 conversion rate and C2 hydrocarbon yield increase rapidly with the increase of energy density; when the energy density exceeds 1000kJ/mol, the CH4 conversion rate and C2 hydrocarbon yield increase rapidly with the increase of energy density slow. It shows that in this reaction, the increase of energy density does not mean that the energy efficiency increases, on the contrary, there is a downward trend. Therefore, from the perspective of energy efficiency, an appropriate energy density should be selected.

The effect of N2 addition on the CH conversion reaction of plasma plasma: With the increase of N2 concentration in the feed gas, the CH4 conversion rate increases, indicating that the inert gas N2 has. Conducive to CH4 conversion. The yield of C2 hydrocarbons increased slightly with the increase of N2 addition amount, and the carbon deposition on the reactor wall decreased slightly with the increase of N2 addition amount. However, compared with the effect of H2 on the methane dehydrogenation coupling reaction, under the same experimental conditions, the yield of C2 hydrocarbons is lower and the amount of carbon deposition is higher.
From the emission spectrum of CH-N2 plasma, it can be found that the characteristic peak of N2 and the spectral peak of CH at 431 nm are in the wavelength range of 400-440 nm. Since the cleavage energy of the N-N bond of nitrogen molecules is as high as 9.76 eV, the possibility of forming N atoms in pulsed corona plasma is relatively small, so the active particles in the CH4-N2 plasma system are excited to free molecules and methyl groups. Based on the main.
The effect of O2 addition on methane plasma conversion reaction under the plasma energy density of 629 kJ/mol: Methane conversion increases with the increase of O2 addition, but the yield of C2 hydrocarbons (mainly C2H2) increases with the increase of O2 addition. gradually decreased. The research on adding gas to the methane plasma system shows that the addition of H2 or N2 not only promotes the conversion of methane, but also helps to improve the yield of C2 hydrocarbon products. The addition of O2 can effectively promote methane conversion, but the yield of C2 hydrocarbon products decreases.