Alumina and quartz as dielectrics in a dielectric barrier discharges DBD system for CO₂ hydrogenation

In this work was studied the CO₂ carbon dioxide treatment, which is a pollutant gas and the main cause of global warming. For this aim, plasma was generated, through dielectric barrier discharges DBD, using hydrogen H₂ together with the CO₂ as reaction gases. There were used as dielectrics, alumina and quartz tubes of identical geometry. It was studied the CO₂ conversion in function of mixture composition CO₂+H₂, of the electrical power and the operation frequency, for three different gas flows. In all cases it was achieved better conversion levels with the alumina; this is because the alumina has a relative dielectric permittivity coefficient higher than the quartz. As products of CO₂ conversion in the chemical reactions, water H₂O and methane gas CH₄ were identified. The CO₂ conversion percentage to fixed work conditions was higher with the decrease the quantity of this gas in the mixture, with increase the active electrical power, and with decrease the operation electrical frequency. (paper)