Study On CH₄-CO₂ Reforming To Syngas By Plasma

With the continuous decrease of petroleum resources, more and more attention has been focused on the exploitation of natural gas that is high effectiveness, cleanness and abundant worldwide. CH₄ is a major constituent of natural gas. Both CO₂ and CH₄ are also major greenhouse gases. Therefore, conversion of CH₄ and CO₂ is concerned not only to resource disposition in the future, but also to protection of the environment. This paper studies that CH₄ and CO₂ produce synthetic gas by arc plasma.Based on different mole ratio of CH₄/CO₂, using the Gibbs minimization free energy method the C-H-O heterogeneous equilibrium system was analyzed. The results indicated that mole ratio of CH₄/CO₂ has a large of effect on products. The maximal equilibrium gaseous concentration of CO and H₂ were discovered during 1500K～2000K. CO and H₂ were just found as CH₄/CO₂=1/4,2/3,1/1, and as CH₄/CO₂=3/2,4/1 , C₂H₂ was found above 3000K except CO and H₂.The effects of mole ratio of CH₄/CO₂, input power, gas flow rate and its feed-in way on conversions of CH₄ and CO₂, selectivities of product have been investigated. The experimental results indicated that arc plasma played an important role to convert CH₄ and CO₂ into CO, H₂, C₂H₂, C₂H₄, C₃H₆ and C₃H₈. With decreasing on the CH₄/CO₂ mole ratio, the conversions of CH₄ increased obviously. the conversions of CO₂ showed a trend of first decrease then increase and selectivities of CO and H₂ were increased. With increasing in the input power, both conversions of CH₄ and CO₂ and selectivity of CO increased. The feed-in way from anode was more effective to excite the feed gas, and made increase in selectivity of CO. Also the conversions of CH₄ and CO₂ were affected by the flow rate of feed gas.