Environment

Can converting methane into CO2 lead to clean air?

In 2018, methane reached atmospheric concentrations two and a half times greater than pre-industrial levels

 
By DTE Staff
Published: Tuesday 21 May 2019
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Converting methane into carbon dioxide (CO2) could prove to be a counterintuitive solution for climate change and possibly help reduce greenhouse gases in the atmosphere to pre-industrial levels, according to a study.

About 60 per cent of methane is generated by humans and it is 84 times more potent in terms of warming the climate system over the first 20 years after its release. In 2018, methane reached atmospheric concentrations two and a half times greater than pre-industrial levels.

“If perfected, this technology could return the atmosphere to pre-industrial concentrations of methane and other gases,” Rob Jackson, a professor at Stanford University’s School of Earth, Energy and Environmental Sciences, said in a statement.

The study, published in the journal Nature Sustainability, showed that removing about 3.2 billion tons of methane from the atmosphere and converting it into an amount of CO2 equivalent to a few months of global industrial emissions, can help eliminate approximately one-sixth of all causes of global warming to date.

While the idea seems startling, swapping methane for CO2 could turn beneficial for the climate as some sources of methane emissions — such as from rice cultivation or cattle — may be very difficult or expensive to eliminate, says a release on the university’s website.

Though low concentration makes it challenging to capture methane from air, using a crystalline material called zeolite could help soak up the greenhouse gas. Zeolite consists primarily of aluminum, silicon and oxygen, the researchers said.

“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,” said Ed Solomon, professor of chemistry at the university's School of Humanities and Sciences.

Methane can be trapped using a giant contraption with electric fans, where air is forced through tumbling chambers or reactors full of powdered or pelletised zeolites and other catalysts. The trapped methane could then be heated to form and release CO2, the researchers said.

A zeolite array about the size of a football field could generate millions of dollars a year in income while removing harmful methane from the air. If market prices for carbon offsets rise to $500 or more per ton this century, each ton of methane removed from the atmosphere could be worth more than $12,000. This approach could also be applied to other greenhouse gases, they suggest.

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