Kinetic modeling of nanosecond repetitively pulsed discharges in CO2: Insights for reactor design
Researchers in the Aerospace Plasma Group use modeling to investigate how pulsed plasmas can efficiently convert carbon dioxide into usable products, a technology with applications ranging from terrestrial carbon recycling to producing essential consumables for Mars exploration.
Authors: Lanie McKinney, Tiago Silva, Vasco Guerra, and Carmen Guerra-Garcia
Citation: Journal of Physics D: Applied Physics, November 2025
Abstract:
Plasma-based CO2 conversion is an emerging power-to-X technology, with the potential to recycle carbon emissions on Earth and produce fuel and life- support consumables in-situ for the human exploration of Mars. In this work, we present a 0D chemical kinetic modeling framework using ZDPlasKin to simulate nanosecond repetitively pulsed (NRP) discharges in pure CO2, enabling systematic exploration of reactor performance across pressure, temperature, and pulse repetition frequency conditions relevant for integrated systems. A reduced chemical mechanism tailored for NRP discharges enabled long-timescale simulations (1–10 s) while still capturing key vibrational energy exchanges.
The results of the simulations link the temporal dynamics between pulse and interpulse chemistry to the overall reactor performance. At atmospheric pressure, increasing the pulse repetition frequency reduces CO recombination between pulses and improves conversion without an energy efficiency penalty. Conversion reaches saturation when the overall rate of CO production during the pulse is equal to the rate of CO recombination between pulses. Higher temperatures, which may be required for membrane-based oxygen separation, increase recombination rates and result in lower saturation values of conversion compared to lower temperatures. Additionally, small changes in the maximum reduced electric field strength, influencing total energy coupling, have a strong influence on conversion and efficiency. At low pressures, recombination is negligible, and conversion scales linearly with frequency. These results inform strategies for co-optimizing plasma operating conditions, supporting the engineering and design of CO2 plasma reactors for both terrestrial and space-based applications.
