Germany: Power-to-X Technology Renewable Energies: CO2 Splitting by Microwave Plasma
Among the pool of Power-to-X technologies, plasmas show high potential for the efficient use of intermittent renewable energies. New research shows that ultrafast pulsation of microwaves allow significant improvements of energy efficiencies during CO2 splitting at atmospheric pressure.
Karlsruhe/Germany — To mitigate the effects of climate change, we must not only reduce carbon dioxide (CO2) emissions, but also remove existing CO2 from the atmosphere. With power-to-X technologies and renewable energies, CO2 can be split into carbon monoxide and oxygen and converted into synthetic materials such as fuels. In the process, plasmas under low pressures achieve record efficiencies in CO2 splitting. Researchers at the Karlsruhe Institute of Technology (KIT) have shown that efficient CO2 splitting is possible even at atmospheric pressure using plasmas with ultrashort microwave pulses. Their results are published in the journal ACS Energy Letters.
The goal was to extend the potential benefits of microwave-assisted plasmas to the atmospheric pressure regime. The scientists succeeded in significantly improving CO2 splitting in plasma by using extremely short microwave pulses. The researchers were able to experimentally demonstrate non-equilibrium states in atmospheric CO2 microwave plasmas for the first time, which can be tuned thanks to the ultrashort pulses, allowing them to increase efficiencies.
Previous methods for CO2 splitting using plasma worked in vacuum to create non-equilibrium states due to the low pressure, allowing more efficient energy use. However, this approach in vacuum systems would not be suitable for industrial use due to high equipment requirements and high energy costs, says Alexander Navarrete from the Institute of Micro Process Engineering.