Ethanol's next breakthrough? Turning greenhouse gas into fuel.

Somewhere within the walls of a Tennessee lab, researchers stumbled upon an accidental finding that could potentially revolutionize the ethanol market hundreds of miles away in Iowa.

Scientists at Oak Ridge National Laboratory unintentionally uncovered a process that uses tiny bits of carbon and copper to convert the greenhouse gas carbon dioxide into ethanol fuel.

While the research remains in its preliminary phase, it could represent a breakthrough for renewable fuel operations in Iowa. By their nature, ethanol plants produce masses of excess carbon dioxide through the distillation process. If commercialized, the new process could allow ethanol producers to make even more ethanol fuel from the CO2 that's otherwise wasted.

"I think it could be very important. The idea that we could find a more useful and effective way to take care of excess carbon dioxide could be transformational," said Evan Saunders, a University of Iowa student who studied the financial viability of Oak Ridge's discovery. "This technology can potentially impact the world in a significant number of ways."

Saunders, who is studying for an MBA and a law degree, is among a group of four Iowa students investigating the economic potential of the discovery. While many factors remain uncertain, the initial results were encouraging, showing a potential market among ethanol producers. Plus, the process could prevent an untold amount of greenhouse gas from being released into the atmosphere.

That could be big news for Iowa, which leads the nation in ethanol production. In 2017, the state's 43 ethanol plants produced 4.2 billion gallons of ethanol, according to the Iowa Renewable Fuels Association.

And because the process of converting carbon dioxide to ethanol requires an infusion of electricity, experts believe it makes the most sense when paired with solar or wind power, which oftentimes produce more energy than the grid demands. Wind and solar energy are not easily stored or transported, so an electricity-to-ethanol pathway could provide a new way of moving and using renewable energy.

Iowa is a national leader in wind power, ranking in the top three, nationally, for capacity, power produced and number of turbines.

"We have some unique potential in the state because of the wind energy and ethanol production here," said Thomas Rietz, a University of Iowa finance professor who oversaw the students' research. "We’re rigged up already with the infrastructure to get the ethanol to the market. So it seems like a natural fit for the state."

How it works

Adam Rondinone, the senior scientist at Oak Ridge who led the study, said his team used a catalyst made of carbon, copper and nitrogen and applied voltage to trigger a chemical reaction. Researchers were surprised to find that the process transformed carbon dioxide into ethanol.

The process was replicated easily, he said, and the materials needed to perform it are relatively cheap and abundant.

Oak Ridge researchers are working on licensing the technology and hope to launch a large-scale demonstration project soon.

While the economics are still unproven, Rondinone said the technology could have major implications for the nation's energy market.

"If we can make gasoline from CO2 and electricity, that’s gasoline we don’t have to drill and bring up out of the ground," Rondinone said.

Likewise, if it's successful, the technology could reshape the national discussion on climate change.

"If we’re going to deal with this problem of climate change, we’re going to have to find substitutes for fossil carbon," he said. "And right now, we don’t have a lot of substitutes for fossil carbons in a lot of industries. ... Eventually, we have to reduce or eliminate all that CO2 we dig out of the ground."

'It's a remarkable discovery'

While Oak Ridge's research has not received widespread attention, the ethanol industry is following its progress closely, said Geoff Cooper, executive vice president of the Renewable Fuels Association.

"It’s a remarkable discovery," he said. "Whether it’s commercially feasible or not, we don’t know. But it's something that is definitely worth looking into."

Scientists already knew of complicated ways of converting carbon dioxide into ethanol, Cooper said. But Oak Ridge discovered a way to do it in a single step with only one catalyst.

"Obviously, when you’re removing steps and removing additional processes, you’re going to be able to do this more economically," he said. "So that’s why I think this is an important breakthrough with significant potential."

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Like any grain distillation process, ethanol production creates carbon dioxide waste. And in large amounts.

Cooper said about one-third of the incoming feedstock by weight ends up as CO2 waste. About 15 to 20 percent of the gas is captured and sold to other industries, like soda manufacturers. But much of it is released into the atmosphere, he said.

"If we’re taking CO2 and converting it into a usable liquid fuel rather than venting it into the atmosphere, that’s a solution for the environment and for fighting climate change that is also now producing a liquid fuel," he said.

While he stressed that the technology is not yet proven on any commercial scale, Cooper said it does represent a pivot in the discussion on how to store and transport renewable sources of power.

"It is different," he said. "There really is nobody thinking about storing excess power generation as anything other than electricity in a battery."

'If it works, it could be transformational'

While corn ethanol is considered a source of renewable energy, skeptics have pointed out that it comes with environmental costs, including the fertilizer used on corn fields, fuel for tractors and combines, and the emissions from ethanol plants.

Rondinone said his discovery may ultimately help the pro-ethanol camp's argument that the fuel is more environmentally responsible than the alternatives.

"The question of (whether) ethanol is carbon neutral is a very good one. I would say the skeptics have a very good point," Rondinone said. "I don’t have an opinion on whether it is or isn’t, but if we can take some of the CO2 that was going to be emitted anyways and put it to use it and minimize how much carbon we have to drill, in that sense, I would argue it would make corn ethanol more carbon neutral."

And the effects could go well beyond the ethanol market.

While ethanol plants release large amounts of carbon dioxide into the atmosphere, they are hardly alone. Carbon pollution is rampant across many industries, Rondinone said. And a new process of creating fuel from pollution could significantly curb the amount of greenhouse gas released into the atmosphere.

Eventually, Oak Ridge's technology could be deployed to factories across the globe, capturing their carbon emissions and turning them into storable, transportable fuel. Already, other researchers are looking into ways of capturing atmospheric carbon dioxide, Rondinone said.

"While this might be a drop in the bucket initially," he said, "the hope is, if it's successful, it will grow and it will contribute to a new type of energy economy where we will continuously recycle CO2 from the atmosphere rather than digging up CO2 from the ground."

Rondinone cautions that new technologies can succeed or fail for a variety of reasons. But for now, he remains optimistic.

"If we’re successful in getting this technology to market, I think it could be a significant development," he said. "If it works, it could be transformational."