Frontiers

From Greenhouse to Green

Daniel Mindiola is finding new ways to harness greenhouse gases.
November 2013

What if greenhouse gasses are not the problem but the solution? Presidential Term Professor of Chemistry Daniel Mindiola sees a greener future, in which we use gases like methane and ethane to produce energy and other products.

Mindiola admits that he got into this area of chemistry by “pure accident.” More than a decade ago, his lab was trying to generate catalysts via an oxidation reaction. Instead, they produced molecules that contained a reactive metal-carbon multiple bond. Now his research focuses on the role of metals in new transformations and catalytic processes, especially the conversion of potential waste into a catalyst or source of energy. “Chemistry is a slow process,” he says. “You know what you’re going for, but 99 percent of the time you’re never going to get there. But you’re going to discover something new and realize it’s even more important.”

He was lucky in the timing, as well: “We’re in the right time at the right place, now that the U.S. is delving into alternative energy forms.” Methane is a natural gas produced by bacteria and by petroleum extraction. Currently U.S. industries burn off about $32 billion worth of methane each year, because we can’t store it and don’t want to release it into the atmosphere. However, it could be a very clean source of fuel—if we can figure out how to keep it and control the release of its energy.

Mindiola’s lab is able to activate methane at room temperature. “Most people would say well, anybody can do that—all you do is grab methane and put a lighter to it,” he says. “But that’s uncontrolled. We can selectively convert methane to something more useful.” What they can’t do is convert it catalytically, so that the conversion will take place over and over again without wasting energy: “We’re not close to that yet.”

They’re closer to a system that can convert ethane to ethylene, an ingredient used to make polymers used in materials from plastic bottles to winter coats, reagents, solubles, alcohols, acids, and ethanol. Right now, ethane is used to make ethylene, by heating it to 800º C (1472º F) with high-velocity steam. The process is called stream cracking.  In past years gasoline was inexpensive enough that the energy required to produce that heat was not a problem. Now, though, “It’s more expensive to generate the ethylene than to sell it,” Mindiola says “So the price of ethylene, the price of propylene and other olefins, is going up.”

His lab can make the conversion at room temperature but not catalytically, “but we’re not that far away.” The metals used are also cheap and abundant, found even in enzymes and seawater. When they are able to convert it catalytically, he jokes, “That’s when we can start funding our own research and startup companies.”

Mindiola calls his current research very fundamental, trying to understand how chemical bonds are made and broken. “But I think we’re training the chemists of tomorrow in this area, who can say look, this is what I need to do. These are the molecules I need to make. So they get the best of both worlds.”