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The performance of methane dry reforming in a self‐triggered spark discharge reactor is evaluated in terms of conversion of reagents, yield and selectivity of desired products (syngas), and energy efficiency. The effects of feed gas composition (CO2:CH4 ratio), flow rate and input electrical power were investigated. The process performance is very good: under the best experimental conditions (CO2:CH4 of 1:1 at 100 mL · min−1, input power of 20 W) conversion (71% for CH4 and 65% for CO2), selectivity (78% for H2 and 86% for CO), and energy efficiency (2.3–2.4 mmol · kJ−1) are all quite high. The formation of ethane, ethylene, and acetylene was also detected and analyzed as a function of the CO2:CH4 ratio. As the CO2:CH4 ratio is decreased below 1, the conversion of both CH4 and CO2 slightly increases, but the yield in syngas decreases favoring the formation of C2 hydrocarbons and the appearance of carbon deposits. Increasing the CO2:CH4 ratio from 0.5 to 1.5 has virtually no effect on the reagents conversion and on H2 production but promotes the formation of CO and reduces that of C2 hydrocarbons. The best CO2:CH4 was determined to be 1.0 considering also the lowest formation of water as byproduct and the optimal discharge stability.

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 CH 4 and CO 2 conversion, H 2 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

Using phenol as a model organic pollutant we studied and characterized an innovative advanced oxidation process in water using a prototype dielectric barrier discharge (DBD) reactor in which electric discharges are produced in the air above the water surface. Phenol is decomposed quite efficiently in this reactor operated at room temperature and atmospheric pressure. The process selectivity to form CO 2 is, however, to be improved since a large fraction of the treated organic carbon is unaccounted for. The rate of phenol conversion increases linearly with the reciprocal of the pollutant initial concentration, suggesting the operation of a mechanism of inhibition by products as found earlier for oxidation of volatile organic pollutants in air plasmas.

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