Improving the Conversion and Energy Efficiency of Carbon Dioxide Splitting in a Zirconia‐Packed Dielectric Barrier Discharge Reactor

Abstract

The use of plasma technology for CO2 splitting is gaining increasing interest, but one of the major obstacles to date for industrial implementation is the considerable energy cost. We demonstrate that the introduction of a packing of dielectric zirconia (ZrO2) beads into a dielectric barrier discharge (DBD) plasma reactor can enhance the CO2 conversion and energy efficiency up to a factor 1.9 and 2.2, respectively, compared to that in a normal (unpacked) DBD reactor. We obtained a maximum conversion of 42 % and a maximum energy efficiency of 9.6 %. However, it is the ability of the packing to almost double both the conversion and the energy efficiency simultaneously at certain input parameters that makes it very promising. The improved conversion and energy efficiency can be explained by the higher values of the local electric field and electron energy near the contact points of the beads and the lower breakdown voltage, demonstrated by 2 D fluid modeling.

Gliding Arc Plasmatron: Providing an Alternative Method for Carbon Dioxide Conversion

“…We also plot in Figure the results obtained in a DBD, which is very often used for CO 2 conversion. It is clear that the energy efficiency of the studies conducted with DBD are much lower than our results. This is again due to the non‐ideal operating conditions, as the SEI and electron temperature are typically higher than 1 eV molec −1 and 1 eV, respectively.…”

“…Due to its increasing interest, many researchers are investigating the splitting of CO 2 into CO and O 2 by plasma, both in pure CO 2 as well as in a mixture with other gases like CH 4 , H 2 , or H 2 O . When CO 2 is mixed with such a hydrogen source, value‐added chemicals can be produced, such as syngas, methanol, formaldehyde and formic acid.…”

“…When CO 2 is mixed with such a hydrogen source, value‐added chemicals can be produced, such as syngas, methanol, formaldehyde and formic acid. Most research on plasma‐based CO 2 conversion is done with one of the following types of plasmas: dielectric barrier discharges (DBD), microwave (MW) plasmas, nanosecond‐pulsed plasmas (NSP), spark discharges, and gliding arc discharges . A lot of research goes into improving the energy efficiency of the process.…”

The Quest for Value‐Added Products from Carbon Dioxide and Water in a Dielectric Barrier Discharge: A Chemical Kinetics Study

“…In most cases, the catalyst is added as beads or pellets in a DBD reactor to yield a so‐called packed‐bed DBD; this gives rise to electric field enhancements near the contact points of the beads or pellets and leads to higher electron energies and, thus, more pronounced electron impact dissociation of the gas molecules for the same applied power, which results in better energy efficiency. The latter was indeed demonstrated in several papers for pure CO 2 splitting, and we believe that similar improvements in energy efficiency would also be possible for combined CO 2 /H 2 O conversion.…”

Influence of Gap Size and Dielectric Constant of the Packing Material on the Plasma Behaviour in a Packed Bed DBD Reactor: A Fluid Modelling Study

“…Packed bed dielectric barrier discharge (DBD) reactors have received a lot of attention in recent years for environmental applications, such as for gaseous pollutant removal (e.g. NOx, VOC, …) or for gas conversion . Indeed, introducing a packing in a DBD reactor was found to enhance the energy efficiency of the process, or, if the packing is catalytically active, even to steer the process towards a certain preferred end product, in so‐called plasma catalysis .…”