Pig Project Fuels Alternative Energy
Anaerobic digester shows how hog farming can be more sustainable while supplying natural gas.
From a distance, the heavy, black plastic tarp looks like a huge bouncing pillow that kids love to jump on. But, upon closer inspection, you realize it covers a 3-plus-acre lagoon filled with waste from 8,000 pigs, along with the methane gas it creates. Surprisingly, you can stand right next to the lagoon and notice no decipherable odor.
The covered lagoon is part of a pilot project partnership between Smithfield Foods and Roeslein Alternative Energy (RAE). The joint venture -- Monarch Bioenergy -- converts manure collected from Smithfield farms, in northern Missouri, into renewable natural gas (RNG), while also providing ecological benefits for wildlife and natural habitats.
The anaerobic digester project fulfills a commitment to sustainability held by both parties. Smithfield's goal is to reduce its companywide greenhouse gas emissions 25% by 2025. Rudi Roeslein, RAE founder and president, plans to dovetail this project with an effort to increase plantings of prairie grasses. His long-term goal is to restore 30 million acres of land in the U.S. to native prairie plants over the next 30 years and use those plants to create biogas.
Roeslein is a self-made man. An engineer by trade, the company he and Fritz Dickmann founded in 1990, Roeslein and Associates, is a global leader in engineering, procurement, modular fabrication and construction of can-making and industrial plant facilities. He learned about anaerobic digestion technology in Europe and saw its potential application for the U.S.
Since 2012, Roeslein has invested $57 million of his own money to prove this technology could work on a large scale.
Converting methane to natural gas works by sucking the gas out of the lagoon into the gas purification system. Gas molecules are separated resulting in almost 99% pure methane. "Because we can't connect to a pipeline very easily from this farm, we set up a virtual pipeline," Roeslein says. The gas is compressed to 3600 pounds per square inch (psi) and moved by two trailers to a farm about 60 miles away. It's injected into the natural gas pipeline and sold through the Renewable Fuel Standard and to the carbon market in California.
"We approached Smithfield and asked for their pig manure, because that would give us an opportunity to prove the technology," he says. "As the project moved along, Smithfield saw the value and became a 50/50 partner in the venture.
"We are the first D3 renewable identification number [RIN] for swine manure renewable natural gas," Roeslein says. "We also have the lowest carbon intensity score in the country." EPA uses five RIN D-codes (D3, D4, D5, D6 and D7) to define biofuels under the Renewable Fuel Standard. D3 and D7 are for cellulosic biofuels with a greenhouse gas reduction requirement of 60%. The value of the gas is about $18- to $20-per-million BTUs.
Although it's not commercially ready for use on most farms yet, the pilot project showcases the capability of the technology and how it can potentially be incorporated in the future through partnerships and cost-share programs.
Smithfield owns nine finishing farms in northern Missouri that were previously part of the Premium Standard Farms system. Each farm consists of numerous "pods." The Locust Ridge farm has 14 pods with eight barns per pod. Each barn holds about 1,000 pigs, which arrive weighing about 50 pounds and leave when they're marketed around 250 to 280 pounds.
There is the annual potential to produce about 1.1 million dekatherms of energy from the 90 lagoons and 2 million pigs Smithfield has in this region of the state.
"This amount of energy is equivalent to offsetting approximately 5.7 million gallons of diesel fuel annually," says Brandon Butler, director of communications for RAE.
Kraig Westerbeek, senior director of Smithfield Renewables and hog production environmental affairs for Smithfield Foods, likes to explain the process as energy conversion.
"When you see a feed truck come onto the farm, it's delivering energy in the form of corn, soybean meal and other feedstuffs," Westerbeek says. When the animals consume feed, the energy can be tracked as feed conversion. But, pigs aren't 100% efficient. Some energy goes through the animal and ends up as manure that's scraped from the barn and piped to the lagoon digester.
"That energy is processed through anaerobic digestion: The solids break down, and methane gas is emitted -- that's the energy we're capturing," Westerbeek says. "Between what the animals have consumed, the energy they utilize to make body mass and the energy we're using to make natural gas, it's a very efficient process and a great recycling story."
The project is a big step toward Smithfield's goal of reducing carbon emissions, Westerbeek says.
"Forty percent of our carbon footprint comes from methane emissions -- from the crops used for feed all the way to the consumption of our product," he says. "To hit that 25% reduction, 90% of the finishing animals in the states of North Carolina, Virginia and Utah will be on biogas-based systems by the year 2028; and in northern Missouri, our goal is 100%."
Roeslein and Westerbeek believe their projects represent the future of agriculture. The wet weather experienced in much of the Midwest this year puts an exclamation point on the need to minimize erosion and runoff.
"When you look at the landscape, it can't absorb all the water," Roeslein says. "Native grasses have very deep roots that can sequester water and carbon that, through the process of transpiration and respiration, can help cool the atmosphere. We have 300 million acres of agriculture around the world that is not cooling our atmosphere for a good portion of the year because it's barren soil and acts as a passive solar collector."
Roeslein's working on another pilot project to convert 1,000 acres to native grasses for pollinators, wildlife and biogas production. Iowa State University has indicated the biomass potential is between 4 and 10 tons per acre.
"The next step is to find out what that biomass receives as a carbon intensity score, so we can give it a value. After that, we'll know what we can offer landowners to grow that commodity," he says.
HELPING THE ENVIRONMENT
The volume of gases under the lagoon-covered tarp is made up of about 65% methane, 30% carbon dioxide and the remainder hydrogen sulfide and other impurities. Methane is nearly 30% more destructive than carbon dioxide, Roeslein says, so keeping it under cover prevents it from being released into the atmosphere.
"It's a market-based solution that will allow farmers to grow something besides corn and beans while providing ecological and wildlife benefits in addition to renewable natural gas," Roeslein says. "We have a good market, and we have a good partner.
"Smithfield is committed to the environment, and that keeps me energized," he adds. "I could have taken my $57 million and bought a ranch next to Ted Turner somewhere and lived happily ever after. But, I've seen what's happened around the world [with environmental degradation]. I couldn't have slept thinking I was sitting on the sidelines doing nothing when there was this great opportunity to show the world there was a different way to do things."
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