EarthTalk – How to Reduce, Absorb, or Convert Atmospheric Methane?

Title card for the EarthTalk environmental column showing a green glass globe.

Roddy Scheer & Doug Moss

Dear EarthTalk:

What are some ways we can reduce, absorb or convert atmospheric methane to reduce its impact as a greenhouse gas?

William Jackman, Troy, NY

As global temperatures continue to rise at unprecedented levels, experts are searching for ways to reduce and remove methane, a climate-warming hydrocarbon that can remain in the atmosphere for up to 10 years. Mainly released from the agricultural sector or human-caused emissions, methane can trap the sun’s heat 85 times more than CO2, according to the World Resources Institute.

Scientists have developed multiple removal methods within the precise limitations of handling methane. “Traditional methane processing typically requires extremely high temperatures, which are costly to produce and harmful to the environment,” says Dr. Zhiliang Wang, a materials chemist at the University of Queensland. One removal method is called “ecosystem uptake enhancement” and fortifies soil with methane-absorbing minerals and microorganisms. Additionally, methane reactors are designed to break down or oxidize methane in air through ultraviolet light, and surface treatments coat large surface areas with metal that breaks down light-exposed methane. These strategies require specific conditions.

Hand drawing a line around the words "Climate Change" with surrounding words and images showing impacts — © iStock - tumsasedgars

There are promising, new methane removal strategies on the horizon. The Massachusetts Institute of Technology (MIT) has been working on a catalyst that converts methane into formaldehyde through a series of steps. Formaldehyde is a useful polymer in particle boards and textiles. “Other systems operate at high temperature and high pressure, and they use hydrogen peroxide, which is an expensive chemical, to drive the methane oxidation,” says Jimin Kim, a postdoc at MIT leading the study. “But our enzyme produces hydrogen peroxide from oxygen, so I think our system could be very cost-effective and scalable.” The clay-like zeolite and enzymes are combined to convert methane into methanol, which is then turned into formaldehyde. Moreover, engineers at University of Maryland are working on a membrane reactor that turns methane into chemicals for both large- and small-scale needs. “This is a major breakthrough in the conversion of natural gas to major commodity chemicals…in terms of the high yield achieved,” says Eric Washman, director of the Maryland Energy Innovation Institute.

There are challenges facing methane removal advancements. Government funding is being cut, so experts are less interested in investing limited resources into removing methane. Also, there is minimal government regulation regarding methane emissions and removal technology. The current legal framework would need to be enhanced in order to effectively maintain a clean atmosphere.