Methane is a powerful greenhouse gas, much stronger than carbon dioxide over short timescales. While cutting methane emissions at their source is essential, some natural and hard-to-control human emissions cannot be fully mitigated. Technologies to remove methane from the atmosphere are still limited, especially since most emissions occur at very low concentrations, close to background levels.

Two types of methane removal have been explored. Reactor-based systems treat methane in enclosed chambers, allowing precise control and easy measurement of how much methane is destroyed. However, they become inefficient and very large at low methane concentrations. The most advanced reactor tested so far removes methane from barn ventilation air using UV light and chlorine, but energy use rises steeply below 20 ppm.

Open-air approaches could scale more quickly and cheaply, using chemicals like chlorine to speed up natural methane breakdown. But they are hard to monitor, can have unintended effects such as ozone loss, and their climate benefit is uncertain.

We propose plume-based methods that operate near emission sources, offering better control and easier monitoring. This approach combines the scalability of open-air systems with more reliable measurement, reporting, and verification (MRV), using existing commercial technologies.