Steam Reforming of Dimethyl Ether by AC Corona Discharge Plasma with Various Waveforms

Abstract

Dimethyl ether (DME) is an ideal resource for hydrogen energy. In the present work, steam reforming of DME using AC corona discharge plasma has been investigated. The effects of H2O/DME feed ratio and input frequency and waveforms have been discussed. Steam reforming can inhibit the formation of undesired carbon deposits, improve the rate of H2 production, and decrease the energy consumption, compared to the decomposition of DME (to H2 and CO). The formation of carbon deposits is completely avoided when the H2O/DME ratio increases to 1.35, with which the H2 production rate is 1.8 times higher and the energy efficiency is 2.0 times higher than those of the decomposition reaction. AC plasma was found to be more efficient than DC plasma, and the optimum frequency is 2 kHz. The order of desired waveforms is sinusoid > sinusoid triangular > ramp > square. Steam plasma can eliminate the already formed carbon deposits, and the elimination rate is in linear proportion with the conversion rate of H2O. The plasma reaction pathway is analyzed according to the radical mechanism.