System that turns manure into methane could boost Idaho’s vast dairy industry

A procedure converting cow manure to commercially-viable methane gas is an economically sweet-smelling opportunity that proponents say will revolutionize Idaho dairy lots.

By Dan Boyd – Journal Writer

http://www.journalnet.com/articles/2004/10/25/news/local/news07.txt

"There’s a long list of dairymen watching (the project)," said Brad Frazee, vice president of Biofuels, a division of Idaho Falls-based Intrepid Technology and Resources Inc. "We’ve got a lot riding on this."

The first Idaho prototype of an anaerobic digester, which takes bovine waste and transforms it into methane through a relatively simple bacterial process, is 95 percent complete.

Intrepid announced plans in January to build the digester facility near Rupert.

With little work remaining, Frazee said it should be completed and ready to go within the next two weeks.

Kent Hansen, a controls engineer at Idaho National Engineering and Environmental Laboratory and a candidate for the Idaho House of Representatives, has worked with Intrepid on the project and said the five-day process can be divided into several stages.

The anaerobic digester works by injecting manure, which is about 20 percent solid material, into a large tank.

A bacterial process breaks down the manure, and the moisture, carbon dioxide and hydrogen sulfite are settled and extracted from the mix.

"In order for this to work right, you have to have the right temperature in a very narrow proximity," Hansen said. "(The bacteria) is a living thing."

From there, the process isn’t complicated.

"What you have left is methane that is high enough quality that you can put it directly into a natural gas line," Hansen said.

He said a dairy with 4,000 cows will produce about 40,000 cubic feet of methane per day.

The only by-product, Hansen said, is a small amount of an odorless substance that looks like dirt and can be used as mulch.

Installation of an anaerobic digester costs less than $1 million, a fact that Hansen said has piqued the interest of numerous Idaho dairy owners and businessmen.

"This technology is cheaper than anything that’s around right now," he said. "As soon as it’s proven, there will be methane plants all over the Magic Valley."

Hansen touted the new technology as a potential economic boon to Idaho, as well as a way to alleviate some conflicts between dairy owners and adjacent homeowners.

"It’s not going to solve everyone’s problems with dairies but I think it might make some inroads," Frazee said.

He said it would take a herd of at least 2,000 cows to make the process economically viable.

Frazee said anaerobic digesters have been used in other states, including Utah, where the design for Intrepid’s model came from.

Though the process is expected to be largely confined to the Magic Valley in the near future, Frazee sees other parts of Idaho following suit.

"We certainly think there’s a lot of potential."

Dan Boyd covers higher education, politics and natural resource issues for the Journal. He can be reached at 239-3168 or by e-mail at [email protected].