Plasma-enhanced Carbon Capture and Utilization in CO₂ Methanation

To realize a carbon neutral society, methanation of CO₂ can be used to convert exhausted CO₂ into renewable methane using CO₂-free energy source such as renewable electricity. This study focuses on nonthermal plasma effect on CO₂ methanation over Ru based multi-metallic catalyst. To this end, CO₂ conversion behaviors in a packed-bed dielectric barrier discharge (PB-DBD) reactor at 30 kPa were investigated. The low-temperature CO₂ methanation can be improved by applying DBD to the reaction because nonthermal plasma would contribute to activating CO₂ into vibrational states. Besides, Ruthenium plays a significant role in plasma-enhanced reaction performance while no promotion by plasma was found out on the catalyst without Ru. In addition, increasing discharge frequency at constant power can further improve methanation performance because high-frequency operation enhances generation of vibrationally excited CO₂, further accelerating carbonate formation. To better understand reaction mechanism in DBD environment, in situ Fourier-transform infrared spectroscopy (FTIR) was employed.