Methane dimerization via microwave plasmas

Methane can be converted to ethane and ethylene in a microwave plasma reactor at pressures from 10 to 100 mm Hg. The total methane conversion has a linear correlation with power ? (45 + pressure)/flow and can be as high as 90%. The conversion of methane to ethylene varies from 0 to 11%. It reaches a maximum at a value of Power ? (45 + Pressure)/Flow of 2200 W?mm Hg?s/mL. The energy efficiency of driving this thermodynamically unfavourable reaction is 2%.