Study On A Novel Plasma Discharge Reactor Under Atmospheric Pressure And Its Application For Methane Coupling

With the increasingly decreased reserves of usable petroleum resource, rational use of natural gas was involved in not only utilization and allotment of future resources but also environmental conservation which was a matter of significance. Due to the high dissociation energy of the C-H bond of methane and the thermodynamically unfavorable reactions, no great progress had been made in the research of conventionally catalytic coupling of methane, and more attention had been paid to the study of new methods. Plasma was an efficient and green chemical processing for methane activation. In recent years, more and more attention and evaluation had been focused on plasma catalysis of methane conversion.The glow discharge at atmospheric pressure can generate no-equilibrium plasma which has high electronic energy. And it adapted to industrialization for its using without vacuum system. The experiments of glow discharge plasma conversion of methane to C₂ hydrocarbons were conducted by a novel reactor with rotary electrode at room temperature and atmospheric pressure. The results showed that CH4 conversion, single pass yield and selectivity of C₂ hydrocarbons were advanced. And the optical emission spectroscopy diagnosis of CH4-H2 conversion reaction using rotary electrode was conducted for the first time.The content and results of this paper was as following:(1) At the ambient temperature and pressure, an even glow discharge plasma was used as a new method for the coupling of methane with developed rotary multidentate helix electrode. The reaction efficiency using helix electrode was high than that of three discs electrode. The using of the reactor with rotary helix electrode improved the uniformity of the electric fields and CH₄ was treated uniformly. Also, the exhaust of heat in helix electrode was easier than that in three-disc electrode and the selectivity of C₂ rose accordingly. Besides the factors which led to uniform electric fields discussed above, the axial ununiformity of electric fields was overcome and the discharge and reaction zone was extended. Further more, the mixing of helix electrode improved the intensity of turbulent flow and the uniformity of gas mixture was enhanced correspondingly.(2) Results of the technics experiment: The result of copper electrode was better than that of stainless steel electrode and the structure of helix was superior to that of three discs. The maximum conversion of methane, the single pass yield and the selectivity of C₂ hydrocarbons using three discs electrode were 66.45%, 63.62% and 95.75%, and those using helix electrode...