Study On Plasma Synthesis Of Methane And Carbon Dioxide At Environmental Benign

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. Following the key NSFC Project "Studies on Method and Application of Ionizing Gas Molecules with Strong Electric Field at High Pressure", this paper studies CH₄ and CO₂ plasma synthesis by strong dielectric barrier discharge at room temperature andatmospheric pressure without catalyst.Using the extreme physical method of electrons accelerated and gas moleculesexcitated in the strong ionization discharge, the gas discharge of strong electric field can be formed. The electric field intensity, the average energy and density of electron are respectively more than 400Td, 10eV and 10¹⁵ /cm³ in the discharging gap. Methane and carbon dioxide molecules are activated, ionized and dissociated into active particles such as CH₃, CH₂, CH, H OH, O and CO, by nonelastic collision with high energy electrons. The particles react each other in the reactor to synthesize chemically products including gaseous hydrocarbons, syngas, and oxygenates without any pollution. By changing the physical parameters such as discharge power per area, voltage, frequency and discharge gap and technical parameters such as total flow, volume ratio and reactor temperature, we study how these parameters affect methane and carbon dioxide plasma synthesis. Gas chromatograph is used to detect the productions in the experiments. The methane conversion attains 60 percent. The conversion of methane is increased in the presence of N₂ and CO₂. The optimum CH₄/CO₂ feed ratio is 3/1. High quality syngas is attained in 75 the volume percent of methane. And main components in liquid products are mathanal, ethanol, formic acid, acetic acid, and waiter.The experiments use CH₄ and CO₂ as stuff, which are very abundant in the nature, realize plasma synthesis at normal temperature and pressure without catalyst and absorbent direct conversion of methane and carbon dioxide to valuable products. It isimportant for providing a new source of chemical engineering raw material, reducing greehouse gases exhaust, realizing the strategy of continuable development.