A University of Oklahoma researcher is on the trail of a revolutionary advancement in the way we make fertilizer. If he’s successful, his work could spur enormous environmental benefits and put him on the ground floor of a billion-dollar industry.

But Kasun Gunasooriya isn’t talking much about commercial and environmental prizes right now. His hands are full searching for a golden needle in an infinite haystack of chemical possibilities. The assistant professor at OU’s School of Sustainable Chemical, Biological and Materials Engineering is looking for an inexpensive and environmentally friendly way to convert nitrates directly into ammonia, the key ingredient in fertilizer.

Gunasooriya is attempting to replace the Haber-Bosch process, a century-old industry standard that uses nitrogen and hydrogen to produce ammonia through the energy-intensive use of natural gas. The technology was considered one of the great advancements of the 20th century, opening the door to large-scale ammonia production and enabling a significant increase in global food production. Artificial intelligence, theoretical methods and advancements in chemical conversion technology have created opportunities for improving the ammonia production process. 

Much is at stake, Gunasooriya says. Such an advancement could prevent hundreds of millions of tons of carbon dioxide emissions annually and save enough energy annually to power California.

“Every year, we produce about 180 million metric tons of ammonia using the Haber-Bosch process worldwide. This process requires high temperature and pressure and consumes about 1% of the world’s annual energy output while generating 1.3% of global carbon dioxide emissions,” the researcher says.

Gunasooriya’s work recently was recognized with the prestigious Ralph E. Powe Junior Faculty Enhancement Award from Oak Ridge Associated Universities. The national award provides seed research grants to faculty approaching tenure.

For two years, Gunasooriya has been exploring the electrocatalytic nitrate conversion process, which is commonly used by municipalities to treat nitrate-polluted wastewater that can pose environmental harm if released into the watershed. The process is designed to convert nitrates to other less hazardous nitrogen-containing compounds, such as nitrogen dioxide and nitrogen monoxide.

But Gunasooriya is working to refine the process through selective conversion so it will only produce ammonia. If he and his team can achieve that, they will have found the holy grail of an industrial process that hasn’t been significantly modernized in more than a century.

“We don’t have a commercialized product yet because this research is still at very early stages,” he says. “There’s lots of work to do, but I think we are moving in the right direction.”

Gunasooriya is using AI and machine learning to comb through an endless field of possible chemical compounds for the right combination to create a catalyst that will facilitate the selective conversion of nitrates to ammonia.

“There aren’t many catalysts that can operate in a selective way. We’re trying to identify new materials that can give us close to 100% of ammonia formation through this reaction.”

The catalyst he’s looking for also must be durable and able to facilitate high-conversion activity with low energy demand. “We want this catalyst to last for at least a year or longer, so you need to get all three of these catalyst properties together,” he says. “That’s the challenge—we’re looking at activity, selectivity and durability. And it’s not an easy game.”

If successful, Gunasooriya says he will commercialize the technology he believes could fundamentally change the way ammonia is produced and delivered. Manufacturing facilities could be scaled down and operated in the same rural communities where farming takes place. Instead of burning natural gas, the electrocatalytic conversion process could be driven by voltage generated by wind or solar energy.

In the future, he hopes the technology could come full circle by helping to remediate nitrate pollution in drinking water, which is an ongoing public and environmental health issue in Oklahoma and other states with heavy agricultural activity. According to the Environmental Protection Agency, 12% of Oklahoma groundwater used for drinking has more than 10 milligrams of nitrate for every liter. That represents the highest percentage of nitrate concentrations in groundwater used for drinking among U.S. states.

Once nitrate pollution occurs, remediation is difficult, says Shellie Chard, water quality division director for the Oklahoma Department of Environmental Quality.

“There is not much that can be done to remove nitrogen and phosphorus from water bodies and groundwater after such nutrients have been introduced,” she says. “That is why Oklahoma’s source water protection programs are crucial to prevent nutrient pollution from occurring in the first place.”

 Mitigation is possible through reverse osmosis, ion exchange and biologically active filtration, Chard says.

But Gunasooriya sees a future where captured nitrates can be converted to ammonia more affordably and without harming the environment.

“According to the federal government, the highest concentrations per capita of nitrates are in Oklahoma, Kansas and Texas,” Gunasooriya says. “So that made us wonder, ‘What can we do? What kind of solutions can we find?’ Engineers love to come up with solutions for societal challenges.”  

Chip Minty is a Norman-based writer and the principal of Minty Communications, LLC. 

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