Burst mode in a cooled packed-bed dielectric barrier discharge reactor for CO2 splitting

The so called ‘burst mode’, a rapidly pulsed power regime for dielectric barrier discharges (DBDs) has previously been reported to greatly improve the performance of an uncooled and unpacked DBD reactor for CO2 splitting. Here we explore the interaction between a DBD in burst mode and each of active cooling and a dielectric packing material (1.0–1.2 mm glass beads) in a coaxial, metal-dielectric DBD reactor for CO2 splitting. The effect of burst mode on CO2 conversion and energy efficiency under different combinations of cooling and packing were investigated and compared with those under continuous wave mode operation. The burst mode operation showed similar CO2 conversion and energy efficiency to continuous wave mode in the unpacked and uncooled configuration under the conditions investigated in this study. However, burst mode significantly outperformed continuous wave mode in the packed and uncooled configuration. When active cooling was employed, burst mode was found to provide only minor benefit or no benefit, depending on specific energy input (SEI), compared to continuous wave mode for each the packed and unpacked configurations. Maximum conversion and energy efficiency were achieved with both packing and active cooling across all SEI examined, and performance in this configuration was found to be relatively insensitive to the power delivery mode.