Renewable and high-concentration syngas production from oxidative reforming of simulated biogas with low energy cost in a plasma shade

Abstract

A novel plasma shade with large reactive space generated by rotating spark channels was used for the first time for oxidative reforming of simulated biogas (CH4:CO2:O2=3:2:2) to produce high-concentration syngas (CO+H2) with low energy cost. This unique plasma exhibited rapid- and slow-zones where the conversion of O2, CH4 and CO2 and dry-basis concentration of syngas (CCO+H2dry) changed at two significantly different paces with specific energy input (SEI). With increasing SEI, the conversion and CCO+H2dry first increased rapidly at SEI<84kJ/mol, while the conversion and CCO+H2dry increased at a much slower pace at SEI>84kJ/mol. Moreover, V-shape profile of syngas energy cost (ECCO+H2) versus SEI was observed. Thereby, the optimal SEI was found at which the lowest ECCO+H2 (1.0eV/molecule) and a very high CCO+H2dry (73%) were simultaneously achieved. The good stability of the plasma reaction at the optimal SEI was verified over an 8-hour test.