CO2 Splitting in a Pulsed Corona Discharge Reactor

Carbon dioxide mitigation technologies have garnered increasing attention over the past decade to prevent further detrimental effect to the environment and increased global warming. Non-thermal plasma technology, specifically corona discharge, is a technology that is capable of reducing CO2 to CO which can then be utilised as a feedstock for various chemical feedstocks. As there is no existing work on this specific discharge type, a new reactor and experimental method was developed in order to assess its viability as a CO2 splitting technology. Additionally, a numerical model was built to validate the experimental results.
This thesis investigates pulsed power corona discharges for the splitting of CO2 and its ad-mixtures with argon and nitrogen. Special attention is paid to the conversion percentage and the energy efficiency of this process. Few previous works have examined the use of pulsed power in plasma applications and thus there is little understanding of the mechanisms and kinetically pathway of CO2 reduction in this type of system. this thesis aims to propose what they may be and how it differs from other plasma technology.
The results indicate that pulsed power corona discharges offer superior energy efficiency compared to other technologies however, the conversion is somewhat lower than other reported works. It is theorised that the input voltage waveform plays a significant role in determining the kinetical pathway of CO2 reduction and future work should revolve around optimising the voltage waveform to maximise both the conversion and energy efficiency.
Argon and nitrogen both have a positive effect on CO2 conversion and efficiency, up to a point, yet further addition sees more energy directed towards reactions and energy transfer to these species instead of the desired reaction of CO2 to CO.