Dung Power at U.S. Ethanol Plant
MEAD, Neb. -- The frosty-breathed cattle jostling for position at a feeding trough in rural Nebraska are not quite as typical as they appear: their manure is being captured in a new bid to quench America's thirst for ethanol.
Like other cows in the Midwestern landscape, the animals at the Mead plant, part of an experimental scheme dubbed "Genesis", churn out a steady supply of energy-rich excrement each day.
But these 27,000 cattle stand on slatted floors to deposit an estimated 1.6 million pounds (726,000 kg) of dung daily into deep pits, which are located adjacent to a new ethanol plant.
The pungent waste is then processed into methane gas, which powers the ethanol plant. Other byproducts of the manure include fertilizer for the surrounding corn fields. Corn is then fed back to the cattle or distilled into ethanol.
The operations all are contained in one 2,000-acre complex which produces about 24 million gallons of ethanol a year.
"This is the first of its kind to use this kind of closed loop system," said Ron Lamberty, a spokesman for the American Coalition for Ethanol (ACE), an industry lobbying organization.
"Most ethanol plants are powered with natural gas, but not quite that natural. It is very unique."
The United States currently counts 117 operational ethanol plants with the capacity to produce 5.3 billion gallons annually. More than 70 are under construction, according to ACE.
Traditional ethanol facilities use natural gas or coal to fuel the boilers that create steam and distil ethanol from corn or other plant-based sources.
But such operations are vulnerable to volatile natural gas prices, and critics say the pollution associated with coal-fired plants offset the benefits of substituting ethanol for gasoline.
The Mead plant offers a way round those problems and, because it removes cattle manure from the environment and recycles waste water, the project is environmentally friendly, according to its backers.
"It's win, win, win," said Brian Barber, director of project development for E3 BioFuels of Shawnee, Kansas, which owns the Mead facility.
PROTOTYPE FOR MORE
The Mead plant, which is slated to launch full operations Feb. 26, enters the market at a time when energy production is a key U.S. concern.
The Bush administration is proposing $1.6 billion in federal spending to promote ethanol and renewable fuels and Americans are expressing increasing interest in reducing their reliance on foreign oil.
A shift to fuels such as ethanol can help to slow global warming, blamed by scientists mainly on human use of fossil fuels in cars, factories and power plants.
Archer Daniels Midland Co. is the leading U.S. ethanol plant player, operating seven plants with annual capacity of 1.1 billion gallons, representing about 20 percent of the market.
In comparison, E3 BioFuels is tiny, with just one 24-million-gallon Mead plant in its ethanol portfolio. But E3 BioFuels chairman Dennis Langley said the $77 million venture is a prototype for at least 15 similar U.S. projects.
Development plans include three such complexes in Kansas, three in California, two in Nebraska and one in Iowa.
The new plants would also be teamed with feedlots or dairies and have a capacity of at least 50 million gallons a year. Langley, who formerly worked in natural gas pipeline operations, said he hopes to build about three a year over the next five years.
Langley also said his plants are more cost-efficient than competitors. A traditional ethanol plant requires about 1 British thermal unit (btu) to make 2 to 2.5 btus of ethanol, while Genesis will use 1 btu to make 46.67 btus of ethanol.
"It is just so much more energy-efficient," Langley said.
FRESH MANURE IS BEST
The Mead facility gets its manure from 300 pits laid under nine cattle buildings, which each hold about 3,000 cattle. The pits are pumped regularly because the fresher the manure, the more gas can be produced.
The closed-loop system includes two four-million-gallon anaerobic digesters -- special sealed containers -- that let bacteria break down the manure along with thin stillage, a by-product of the ethanol production process.
The biogas produced by the digesters powers the boilers in the ethanol plant instead of natural gas.
The ethanol production process also yields another by-product: wet distiller's grain, which is fed to the cattle as part of their ration. The cattle in turn produce manure which again begins the closed-loop cycle.
Langley said the projects have attracted venture capital funding and he has funding to proceed with new plants this year, though he declined to give details.
Back in Mead, start-up has been slowed by cold weather. "This concept is tremendous," said project development director Barber. "Now we have to show it works."