Development and testing of a self-triggered spark reactor for plasma driven dry reforming of methane

Abstract

A versatile reactor was developed for plasma induced dry reforming of methane at atmospheric pressure and room temperature. Among different types of electrical discharges tested, low-power self-triggered pulsed spark discharges give the best results in terms of CH4 and CO2 conversion, H2 and CO yield and selectivity, and energy efficiency. Moreover, undesired carbon deposits are not formed, certainly due to the low temperature but also to the short but strong current pulses between the electrodes, the surfaces of which are kept "clean" by the discharge itself. Optical emission spectroscopy was also used to investigate the plasma emitting species and to determine the average electron density. Dry reforming to convert greenhouse gases into syngas, a most versatile feedstock, is performed at atmospheric pressure and low temperature in a new plasma reactor energized by a low-power self-triggered pulsed spark discharge. In negative polarity with a power input of 20 W, a flow rate of 50 mL min-1 and a CO 2:CH4 ratio of 1:1, high conversions (78 and 73% for CH4 and CO2, respectively) and yields (65 and 72% for H2 and CO, respectively) are obtained. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.