GHG-R Flagship Destination
Free Radical Breakthrough
Pioneering atmospheric methane removal
Team: Arun Majumdar, Rob Jackson
Atmospheric Methane Removal using Free Radicals - Atmospheric methane (CH4) concentrations have more than doubled from pre-industrial levels to above 1.9 parts per million (ppm) in 2024. Methane, the second most concentrated greenhouse gas in the atmosphere, has a high global warming potential, 120 times larger than CO2 at the time of emission and 28 times larger after 100 years. The short-term impacts of CH4 therefore constitute a serious issue in climate change.
The Global Methane Pledge, signed to date by more than 150 nations, promises to reduce CH4 emissions 30 percent over the next decade. Because CH4 is a symmetric, inert molecule with no dipole and high activation energy, it is not easily captured or separated. However, it may be possible to oxidize methane to CO2, reducing its 100-year global warming impact by 97 percent. Most methane is emitted at concentrations between 1,000 ppm. However, no technologies exist to oxidize these concentrations, let alone remove methane in the atmosphere.
The goal of this project is to develop room temperature photochemical strategies to remove atmospheric CH4 using free radicals generated by light. This includes the design and integration of a flow reactor system, the optimization of materials, and the quantification of the reaction rate for the atmospheric CH4 removal. We aim to explore the effects of CH4 concentration, operation temperature, and co-fed gases on photochemical CH4 removal. These experimental results are expected to guide the deployment of photochemical strategies to mitigate the climate impacts of CH4 as well as technical economic analyses of possible technologies.