Scientists say chemistry can convert a powerful greenhouse gas into plastic
Methane is often an overlooked supervillain of the Earth’s greenhouse gases.
The greenhouse gas is generated by cattle poop, burps and farts and oil and natural gas operations. It’s less abundant than carbon dioxide, but far more powerful, pound for pound, at heating up the planet.
Of all the warming of the planet from man-made greenhouse gas emissions, a third comes from methane. That includes producing and transporting coal, natural gas and oil, says the U.S. Environmental Protection Agency.
The EPA has proposed new standards to curb methane emissions. But researchers at Iowa State University have unlocked a way to break the powerful greenhouse gas down into safer chemicals — the kind of chemicals used to make everyday plastics like trash bags and milk containers — and keep it out of the atmosphere.
Methane is made up of one carbon atom bonded to four hydrogen atoms. The bond between the carbon and hydrogen is really strong and hard to break, said Yue Wu, an Iowa State University chemical engineering professor.
“Think about if you have a piece of wood, and the wood stick is very thin, you don’t need a lot of strength to break it,” Wu said. “But (if) it’s actually getting very thick, you probably have to use an ax to actually chop it.”
Wu and his research group put platinum onto a powdered carbide. They flowed methane through the surface. That quickly converted it into chemicals called ethylene and ethane.
Wu said the research shows chemistry can convert methane that’s normally burned and emitted directly into the atmosphere and “can actually harvest all that methane and convert it into ethylene and that can actually be something like really value-added chemicals.”
The research group is not the first to use platinum to try to convert methane into chemicals. But Wu says, typically, a gooey residue builds up on the platinum during the reaction. That didn’t happen for the researchers because they spread the platinum out into a really thin layer. The platinum continued to react, activate and break methane’s carbon-hydrogen bond for several days.
The technology has broader applications and could be used to capture and convert biowaste, like cow manure.
“We are not going to capture anything from a burp or a fart,” Wu said. “We are going to use the biowaste, the poop, anything from sewage, solid waste. Those things will decompose and generate methane.”
The Iowa State researchers worked with researchers from Purdue University and the U.S. Department of Energy. They recently published a paper in the journal Nature Catalysis.
The researchers are looking at how they can commercialize their technology.
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