Greenhouse gases are not seen as healthy for the environment, but researchers at Stanford University believe the type of gas released would still be an improvement. According to a study published in Nature Sustainability, a process has been developed to convert methane into carbon dioxide. The latter is considered a considerably less potent agent of global warming.
The study’s authors maintain that swapping methane for carbon dioxide could benefit the environment, by reducing the methane present in the atmosphere to pre-industrial concentrations, according to lead author Rob Jackson, the Michelle and Kevin Douglas Provostial Professor in Earth System Science in Stanford’s School of Earth, Energy & Environmental Sciences.
“An alternative is to offset these emissions via methane removal, so there is no net effect on warming the atmosphere,” study coauthor Chris Field, the Perry L. McCarty Director of the Stanford Woods Institute for the Environment, adds.
According to the study, the amount of methane in the atmosphere reached concentrations two and a half times greater than pre-industrial levels. Although the carbon dioxide present in the atmosphere is much greater, methane is 84 times more potent in terms of warming the climate system over the first 20 years after its release, the study adds.
The scientists note that capturing methane from the atmosphere is challenging because it is usually present in trace amounts, compared to carbon dioxide. The authors add, however, that zeolite, a crystalline material comprised primarily of aluminum, silicon, and oxygen, could work like a sponge to soak up methane. “The porous molecular structure, relatively large surface area and ability to host copper and iron in zeolites make them promising catalysts for capturing methane and other gases,” Ed Solomon, the Monroe E. Spaght Professor of Chemistry in the School of Humanities and Sciences, says.
While the process of collecting methane has not been established, scientists envision possibly using forced air systems in conjunction with chambers or reactors full of powdered or pelletized zeolites and other catalysts. The trapped methane could then be heated to form and release carbon dioxide, the authors suggest.
The study also suggests that energy policies could provide economic incentives to convert methane to carbon dioxide. As an example, if market prices for carbon offsets rise to $500 or more per ton this century, as assessment models predict, each ton of methane removed from the atmosphere could be worth more than $12,000.