Influence of Particle Distribution on CO₂ Dissociation and Discharge Behavior in a Fluidized-Bed DBD Reactor

Dielectric barrier discharge (DBD) plasma offers a promising, scalable non-thermal route for CO₂ dissociation and chemical production under ambient conditions. In this work, a plasma fluidized-bed DBD reactor was designed for direct CO₂ dissociation. A systematic study was conducted to investigate the influence of particle distribution on discharge activity, discharge power, CO₂ conversion, CO yield, and process energy efficiency. The inclusion of activated carbon particles modified the discharge by reducing the effective gap, lowering the breakdown voltage, and promoting more stable and intensified microdischarges. This change in discharge behavior enabled a 1. 4-fold increase in discharge power, a 2. 7-fold increase in CO₂ conversion and a peak energy efficiency of 28. 5 % at a low particle loading of 2. 5 g compared to an empty reactor. This represents more than a two-fold enhancement over typical efficiencies reported for other DBD reactors operating under comparable experimental conditions. At higher particle loadings, the reactor performance declined due to discharge damping, evidenced by a decrease in discharge power from 0. 32 kW at 2. 5 g to 0. 22 kW at 60 g. These findings establish that controlling the fluidized particle distribution density is key to modulating discharge behavior and optimizing the performance of scalable plasma fluidized bed DBD reactors.