The Future of Fertilizer

By Robert Arnason, The Western Producer

When something is the “first in the world,” it’s usually a big deal. And when it’s a “first in the world” technology, it’s normally a big secret.

That’s not the case in Morris, a town with about 5,000 people in western Minnesota. The University of Minnesota researchers who developed the first in the world technology, at the West Central Research and Outreach Center (WCROC) in Morris, aren’t a secretive bunch.

Cory Marquart, the assistant scientist for renewable energy at WCROC, wore blue jeans and a golf shirt as he drove a Canadian visitor to the site of the unique technology — on a breezy, 23 C day in mid-June.

After a three-minute drive past a barn and next to a field with six-inch-high corn, Marquart stopped at the top of a hill, stepped out of the van and opened a chain-link gate to the first location in the world where wind power is used to make anhydrous ammonia fertilizer.

The location is scenic, on the eastern slope of a river valley, but the site is unassuming. There is a wind turbine, two small buildings (each about the size of a backyard shed), some electrical boxes and a white tank to store anhydrous ammonia. And that’s about it.

“In this building, we’re basically just making hydrogen and nitrogen,” Marquart said, while pointing at the equipment inside the first shed-like building.

The equipment in the second shed looks more complex, with two dozen gauges and a maze of blue steel pipes occupying 80 percent of the building.

“It’s a pump. Four heat exchangers, one more heat exchanger, electric heater and a rapid vessel,” Marquart said, rapidly listing the equipment in the building.

Using those devices, the blue pipes and a patented absorbent that captures ammonia, University of Minnesota scientists have devised a version of the Haber-Bosch process, combining hydrogen and nitrogen to produce NH3, or ammonia.

“This was the first one in the world to do all this at one site,” Marquart said. That is, use renewable electricity from a wind turbine and convert the energy into ammonia. As an added bonus, the process doesn’t emit greenhouse gases to the atmosphere.

The pilot plant, which can produce six pounds of ammonia per hour, isn’t new. It’s been operational since 2013, when the University of Minnesota officially opened the facility.

In the late 2000s and early 2020s, there was robust interest in producing nitrogen fertilizer from renewable energy like wind turbines. But that was a time of $7 per bushel corn and sky-high fertilizer prices.

When grain and fertilizer prices dropped back to earth in the mid-2010s, investors and the ag sector lost interest in “green ammonia.”

But now, with a renewed focus on curbing greenhouse gas emissions, countries and companies are shifting their attention back to the technology. The fertilizer industry is under pressure to cut emissions because the sector produces an immense amount of carbon dioxide.

“Typically, ammonia is produced using natural gas. You take natural gas through a process called steam-methane reforming, essentially to get to the hydrogen,” said Mike Reese, renewable energy director at WCROC and one of the speakers at the Midwest Farm Energy Conference, held June 15-16 in Morris.

“That’s performed (at) world-scale plants…. (and) one percent of global greenhouse gas emissions are attributable to ammonia nitrogen fertilizer production. I think it’s closer to two percent.”

The Royal Society of Britain says the process consumes “a lot of energy and produces around 1.8 percent of global carbon dioxide emissions.”

Reese and other speakers at the conference mentioned that numerous companies, including major players in the fertilizer industry, are investing huge sums into technology similar to the wind to ammonia plant in Morris.

In January, Yara, a Norwegian firm, announced it plans to build a green hydrogen plant in Norway to “demonstrate that ammonia produced using renewable energy can reduce the impact of carbon dioxide in fertilizer production.”

Much of the investment is going toward green ammonia and blue ammonia:

  • “Green” is hydrogen and ammonia produced with renewable energy.
  • “Blue” is hydrogen and ammonia produced from natural gas, but with carbon capture.

“Blue is when you’re producing via a more traditional route… (and) you’re capturing the carbon dioxide and storing it underground,” said Chris Mancinelli, a chemical engineer with Casale, a Swiss engineering company that designs ammonia plants.

“There’s a lot of projects that are going to move quickly on large-scale blue hydrogen.”

One of those is an Exxon-Mobil project on the Gulf of Mexico Coast, where the petroleum giant is building a world-scale, blue hydrogen/ammonia plant in Baytown, Texas.

The University of Minnesota wind-to-ammonia technology probably won’t lead to a world-scale fertilizer plant. Reese and other U of Minnesota scientists say the technology is a good fit for a regional plant producing ammonia to supply counties or municipalities.

“Rather than have these mega-scale plants, we plan to support commercial development of plants that use wind and solar power to electrolyze water,” Reese said. “So, we’re getting our hydrogen from water and pulling nitrogen from the air, and put it together to form anhydrous ammonia…. And it’s also used to produce other forms of nitrogen fertilizer, like urea.”

The question is whether small, green ammonia plants compete against world scale plants.

Matt Palys, from the chemical engineering department at the University of Minnesota, said local and regional ammonia plants could smooth out the highs and lows of fertilizer prices.

When grain and oilseed prices go up, nitrogen fertilizer prices also rise.

And when natural gas prices jump, fertilizer prices jump.

“We’ve talked about moving away from fossil fuels for sustainability reasons… but (renewable ammonia) could also give some price certainty and stability in the price of ammonia,” he said. “But the key question we need to ask, if we want renewable ammonia to be successful… is how much is this going to cost?”

That’s not an easy question to answer. A lot depends on the size of the plant and the cost of electricity to power the plant.

“Most of the power is consumed by electrolysis (separating hydrogen from water),” he said.

In his analysis, assuming a plant produces 10,000 tonnes of ammonia per year, it would cost about $700 per tonne to make the ammonia.

“This goes down to $565 (per tonne) at a 100,000 tonnes per year.”

At the current price for anhydrous, renewable or green ammonia could compete with large-scale plants.

But there is a major technical challenge with wind-to-ammonia plants.

What happens when the wind doesn’t blow? Would an operator need to shut down the plant on calm days and restart it when it was windy? Or would the facility need a back-up power supply, so the plant could be run continuously?

If the back-up supply of electricity comes from coal power, or another fossil fuel, then the ammonia from the plant may no longer be “green”.

There’s also the price tag for electrolyzers, used to separate hydrogen from water.

They are “extremely expensive,” Reese said.

The issue of intermittent power is a challenge, but green ammonia from small scale plants should have a transportation advantage because the fertilizer will be distributed to farms near the plant. Plus, much of Minnesota, North Dakota and the Prairies already has an infrastructure that supports ammonia, including pipelines, trucking and storage.

“U.S. nitrogen fertilizer could be supplied 100 percent by adding 50,000 (megawatts) of wind capacity.”

If the average wind turbine produces around two MW of power, it would require about 25,000 additional turbines, Reese added.

For now, he and his fellow scientists at WCROC are focusing on scaling up the pilot plant.

It only produces six lb. of ammonia per hour and they hope to increase the capacity to 90 lb. per hour.

“We got together with some other academic and commercial partners and we’re going to be installing a plant that’s about 15 times larger,” Reese said.

One of the partners is the Research Triangle Institute, a non-profit group from North Carolina.

Last year, the United States Dept. of Energy awarded $10 million to the Research Triangle Institute to produce ammonia from intermittent, renewable energy.

“We are excited to integrate advanced ammonia production and utilization technologies and demonstrate them under real-world conditions,” said Sameer Parvathikar, principal investigator at RTI.

In a Zoom presentation at the conference in Morris, Parvathikar said major players in the energy and fertilizer sectors are participating in the project, including Nutrien, Shell and General Electric.

“We are anticipating this to be about a three-year effort,” he said, to test and prove out the technology on a larger scale.

The wind-to-fertilizer technology may be a few years away from commercialization in Minnesota and across the northern Plains. But in the future, utilities could operate such plants to make use of “excess wind and solar power,” Reese said.

“(Or) farm co-operatives (could) partner with utilities… to produce ammonia.”

There are technical and economic obstacles in the way, so green ammonia may need support to realize its full potential.

“It’s an industry… that probably needs a little push to get going,” Reese said. “Much like the ethanol industry needed a push to get it going. When I say push, I mean potentially subsidies and incentives.”

It may require government help, but the idea of turning wind into fertilizer is tempting, especially in a region that has an abundance of wind, like Minnesota, the Dakotas, Montana and the Prairies, Reese said.

“If you can take wind energy that’s being produced from a farm field, use water, you can pull nitrogen from the air and produce nitrogen fertilizer, (then) you can use that product right under the wind turbine.”