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Nebraska Hog Producer Converts Waste into Watts

posted on January 6, 2012


The Environmental Protection Agency announced new rules this week aimed at reducing greenhouse gas emissions from power plants in 27 states.

The new standards are designed to address poor air quality in regions well downwind from the smokestacks in question, but critics called it another step by the Obama administration to crack down on the nation's 594 coal-fired power plants.

Utilities, however, aren't the only ones facing increased scrutiny. Agricultural producers, especially those raising livestock, are quick to point out that also must comply with a seemingly ever-increasing array of environmental regulations.

But one producer in Nebraska has found a way to generate his own electricity -- and enough for his neighbors -- while reducing emissions of a key greenhouse gas. Harvest Public Media's Perry Stoner explains how the innovative operation converts waste into watts.

Danny Kluthe runs a family hog operation in rural Dodge, Nebraska. Step inside one of the barns and you'll see and hear it's like many hog operations in the state.

Danny Kluthe, Dodge, Nebraska: " My job is to get them little pigs fat and get ‘em to market."

The little pigs weigh 12 pounds or so when they come to Kluthe's facility. Five or six months later, he's cared for them enough they are ready to go to market weighing 20 times more than when they arrived.

Danny Kluthe, Dodge, Nebraska: "These hogs are treated better than humans. I mean their diet is to a ‘T' for their age. Fresh water, fresh air. They sleep with a grin on their face."

With about 7500 hogs typically on hand, a lot goes into fattening them up. That means there's a lot that comes out of them too. It's manure and that's where Kluthe's operation becomes unlike any other in the state.

The waste of hogs and other farm animals creates high levels of the greenhouse gas methane. Methane can last more than a decade in the atmosphere – and is 20 times more powerful than carbon dioxide as a contributor to climate warming. But Kluthe is taking steps to make his farm an environmental game changer.

Danny Kluthe, Dodge, Nebraska: "I really call this thing a manure processing system with the byproduct being electricity."

Hogs create an average of more than a gallon of manure each day. All told, Kluthe's hogs generate over 9,000 gallons – enough to fill a gas tanker…every day of the year.

Down the hill from the hog barns is a pit. An underground pipe system uses gravity so the manure flows downhill. Manure collected in a pit is common at hog operations, but what happens in this pit is not. This 14-foot deep airtight tank is called a methane digester. There are about 150 of them on farms in the United States, but Kluthe's is the only one in Nebraska.

Danny Kluthe, Dodge, Nebraska: "The raw manure goes down to the digester where we've got bacteria-lots of bacteria-and what the bacteria does is actually breaks the manure down and it comes out liquid. Every day I feed about a quarter of a pit to the digester and every day the hogs replace it. That is renewable!"

The digester is heated to about 100 degrees. That's ideal for the bacteria to break down the manure and release methane gas... a process that takes about 3 weeks.

The pit traps the methane in its oxygen-free environment. Kluthe then uses the methane as a fuel to run farm utilities.

Danny Kluthe, Dodge, Nebraska: "From the breakdown of the raw manure is methane and that gets sucked up here to the 3306 Cat engine that's running a generator and it runs 24 hours a day, 7 days a week. I always say this Cat engine just purrs on this methane"

The caterpillar engine sits in its own small building. Designed to use either methane or propane as fuel, the engine produces electricity and it's put on the electrical grid, completing the manure to electricity process. Kluthe started dreaming of this facility in 2003, but wasn't producing electricity until more than two years later due mostly to the permitting process.

Nebraska Public Power now buys the energy from Kluthe's family energy company.

But generating electricity from hog manure isn't financially what it could be. Customer-generators in Nebraska like Kluthe can produce up to 25 kw. Above that amount they are paid what's called "avoided cost" from the utility. In simple terms, he's paid the utility's wholesale cost of electricity. The 25 kws allowed in Nebraska is among the lowest in the nation. In the end, the break even point for Kluthe's system is at least 15 years.

Danny Kluthe, Dodge, Nebraska: "We actually make enough electricity here to take care of about 45-50 homes a year. I would use about 20% of the production and export 80 or sell 80% so, you know, we're – for a byproduct we've actually got a lot of electricity here. Anybody in Cuming County that turns their lights on doesn't know the difference whether it's coming from Cooper Nuclear or Olean Energy."

Rick Stowell, Biological Systems Engineer, University of Nebraska - Lincoln "You're creating greenhouse gases and actually creating a very potent greenhouse gas, so you don't want that to escape and so it's really important to capture as much of that methane as you can."

For Biological Systems Engineers like Rick Stowell and Crystal Powers, finding ways to utilize what might otherwise be waste is a scientific process. That helps make agriculture more sustainable.

Crystal Powers, Biological Systems Engineer, University of Nebraska - Lincoln " In each step of the process from growing your forages and grains for your livestock to feed the animal to within the manure, 'how do we capture as much energy at each step?' And anaerobic digesters fit in there because we're figuring out how to get more energy out of the manure before it's ultimately used as fertilizer."

Livestock manure is used as fertilizer for crop agriculture. Methane-free manure is too and Kluthe says it's odorless. Some find livestock waste odor offensive and occasionally is the grounds for lawsuits. Ryan McGhee is with the USDA's Agricultural Research Service. In the lab, he's examining what's happening to the manure in the different stages of Kluthe's process.

Ryan McGhee, Biological Science Research Technician, USDA-ARS: "These samples are from the pit which are essentially green, raw manure, very little treatment, then the next step is after it's been digested through the anaerobic digester, and then the next sample is the basin, which is the basic flow of treatment at the Kluthe site. We are asking them to look at solids content, the organic matter, how that's breaking down that would tell us how well the digester's performing and then we are also very interested in what's the likelihood of gases coming off that would cause odors and the assumption is that the digester is going to break down those odorous gases and other undesirable gases coming off."

Livestock production can have another serious negative environmental impact: Water contamination.

Marty Link, Associate Director, Nebraska Department of Environmental Quality: "85% of our population in Nebraska relies on ground water for drinking water. If waste gets into water it's likely to cause a problem. That's the whole purpose of our Livestock Permitting Program is to keep livestock waste out of the waters of the state; the groundwater, the streams, the rivers, the lakes and the reservoirs."

Marty Link is Water Quality Associate Director with the Nebraska Department of Environmental Quality. She says harm to drinking water isn't the only concern if livestock waste gets in the water.

Marty Link, Associate Director, Nebraska Department of Environmental Quality: "When it runs off into a stream it can cause the algae to get all excited and it gets all this nutrients and it starts growing a lot and so there's an algae bloom. The algae bloom takes up a lot of oxygen. Oxygen is all depleted then from the water and the fish won't have the oxygen in order to breathe and they may die. That's a worse case scenario. Accidents happen but well managed waste should not make it into the stream and that's what everybody's goal is: to not let the waste make it into the stream."

Danny Kluthe, Dodge, Nebraska: "Now all the affluent that goes into the lagoon is odorless so really it's kind of nice pretty lake out there."

At Danny Kluthe's hog operation, he can still use the manure waste as fertilizer after capturing the methane to be a fuel source. He likes that the digester helps him be a good neighbor.

Danny Kluthe, Dodge, Nebraska: "We've got a track record and now we've got something that other producers can come and look at and say ‘wow'!"

It's a costly endeavor and Kluthe could only make happen with grants that totaled hundreds of thousands of dollars. That's one of the barriers in front of more livestock producers wanting to do what Kluthe has. But he's not done yet. Another grant will provide about one-fourth of the funding to install a scrubber that will remove methane impurities and leave propane. He estimates the additional use of the manure byproduct could eliminate his annual energy costs of $30,000.

Danny Kluthe, Dodge, Nebraska: "I'm excited about the fact that we'll be able to heat our barns, dry our corn, whatever we use propane for now, we're going to be using methane and will this solve our oil crisis? Probably not, but it's a piece of the puzzle."

For Market to Market, I'm Perry Stoner.

 


Tags: agriculture alternative energy animals biofuels Energy/Environment hog waste livestock manure methane Nebraska news pigs renewable fuels