Synthesis of oxygenates and higher hydrocarbons directly from methane and carbon dioxide using dielectric-barrier discharges: Product distribution

In this work, a direct conversion of methane in the presence of carbon dioxide using dielectric-barrier discharge plasmas has been conducted. The product includes syngas (H-2 and CO), gaseous hydrocarbons (C-2 to C-5), liquid hydrocarbons (C-5 to C11+), and oxygenates. The liquid hydrocarbons are highly branched, representing a high octane number, while the oxygenates mainly consist of series of alcohols and acids. A detailed analysis of product distribution has been performed under variable feed conditions with different reactor configurations. At the high CH4/CO2 feed ratio, the wider discharge gap (1.8 mm) is more favored for the formation of methanol and ethanol. For the production of acetic acid, the narrower discharge gap (1.1 mm) is better, especially, with the existence of after-glow zones. Conditions favored for the production of acetic acid are also good for the production of liquid fuels.