Carbon dioxide reforming of methane in kilohertz spark‐discharge plasma at atmospheric pressure

The spark‐discharge plasma, generated between tubular and rotary‐disc electrodes using a sine‐wave high voltage with 5 kHz frequency, was explored for CO 2 reforming of CH 4 . Based upon the investigation on the effects of specific energy input and CO 2 /CH 4 ratio, the energy costs (EC) and fuel‐production efficiencies (η) at various CO 2 /CH 4 ratios ( r ) in the same conversion range were compared and accordingly their sequences were given: EC   CH   4( r = 0.5) and EC   CO   2( r = 3) are the lowest; η( r = 0.5) is the highest. Compared with other nonthermal discharge techniques, the kilohertz spark discharge exhibits low EC and high fuel‐production efficiency, especially at high total‐carbon conversions. Preliminary investigation on partial oxidation and CO 2 mixed reforming at (O 2 + CO 2 )/CH 4 = 0.5 exhibited high H 2 /CO ratio (nearly 2) and low total‐carbon EC (0.59–0.96 MJ/mol, 58–77% of total‐carbon conversion, and O 2 /(CO 2 + O 2 ) = 0.8). © 2010 American Institute of Chemical Engineers AIChE J, 2011