Study On Carbon Dioxide Reforming Of Methane To Syngas Via Non-equilibrium Plasma

Since global warming is getting worse, the research on utilization of carbon dioxide, which is the major greenhouse gas, has attracted more and more attention. Meanwhile, more attention has also been paid on the utilization of natural gas for the continuous decrease of petroleum resource. However, conventional carbon dioxide reforming of methane has a lot of shortages, such as high activation temperature and easy deactivation of catalyst. Non-equilibrium plasma, which has a unique non-equilibrium character, was applied to methane and carbon dioxide conversion, and attracted increasing interests.Carbon dioxide reforming of methane via two types of non-equilibrium plasma, the rotating multi-edge electrode glow discharge reactor and dielectric barrier discharge reactor, had been studied in this thesis. The effects of different parameters on the reforming reaction in those two types of reactors had been investigated, and compared to each other.In the rotating multi-edge electrode glow discharge reactor, the effects of mole ratio of CH₄/CO₂, total gas flow rate, parameters of high voltage generator (HVG), parameters of reactor and additive gas on the reforming reaction had been investigated. The results showed that the methane conversion and carbon monoxide selectivity were decreased by increasing the mole ratio of CH₄/CO₂, while the carbon dioxide conversion and hydrogen selectivity were increased; both the methane and carbon dioxide conversion were decreased by increasing the total flow rate; the influence of HVG parameters on reforming was come down to the influence of input current; the distance of discharge gap had big impact on both conversion and selectivity; different additive gases had only effect on products selectivity.In dielectric barrier discharge reactor, the effects of inner electrode material, distance of discharge gap, thickness of barrier and additive gas on the reforming reaction had been investigated. The results showed that additive gas and distance of discharge gap had more influence on reforming reaction than inner electrode material; the thickness of barrier showed its effects only at high total flow rate.Compare to the rotating multi-edge electrode glow discharge reactor, the carbon dioxide reforming of methane in dielectric barrier discharge reactor had lower conversion, syngas selectivity and wider products distribution, and the mole ratio of H₂/CO in the glow discharge reactor was closer to 1; the energy consumption per syngas production in dielectric barrier discharge reactor was far more than in the rotating multi-edge electrode glow discharge reactor.