Associated Press: Minnesota plant will produce fertilizer from wind

The winds sweeping across the Northern Plains could soon help farmers fertilize their crops of corn, wheat and sorghum.

Minnesota researchers have designed a $3.75 million carbon-free system that uses wind power from a turbine to produce anhydrous ammonia, a common nitrogen-based fertilizer.

A supply-and-demand match, the region has no shortage of wind and U.S. farmers use millions of tons of fertilizer, said Michael Reese, director of the University of Minnesota Renewable Energy Center.

It also would take advantage of the region's wind potential while skirting that industry's main hurdle of needing expensive transmission lines to ship electricity east to the urban areas that need it.

The system creates fertilizer by using an air separation unit to pull nitrogen from the air, while the turbine powers large electrolyzers that separate water into hydrogen and oxygen. The nitrogen and hydrogen are then synthesized into anhydrous ammonia using a century-old chemical process called Haber-Bosch.

Anhydrous ammonia is stored in pressurized tanks similar to propane, and it can be applied directly to fields or used as an ingredient in other nitrogen fertilizers. It's shipped to farmers through a network of pipelines, railcars and tanker trucks.

The U.S. is the largest importer of fertilizer in the world, with more than half its nitrogen coming from overseas, importing about $1.4 billion worth of anhydrous ammonia in 2009, or 6.1 million U.S. tons, according to the U.S. Department of Agriculture.

The question is whether a renewably produced fertilizer can compete in the market. At the current price of about $500 a ton, that would be difficult.

But if prices return to the near-$1,200-per-ton range seen a couple of years ago when natural gas prices spiked, "then sure, I believe it would work," Reese said.

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