Soaring oil prices and government incentives are fueling increased interest in renewable energy sources such as cow manure.
And what better place to do manure research than in the Texas Panhandle, which holds the aromatic distinction of being the country’s biggest producer of cow pies in a state that leads the country in cattle production.
For years, researchers have studied manure as a fertilizer. Now, however, they are focusing on developing other uses for the abundant substance as the livestock industry grows and fertilizer’s role diminishes. State and federal energy bills also call for increasing renewable energy sources.
Cattle manure can be used as fuel instead of coal or natural gas to create steam to run turbines, which create electricity.
That’s how The Panda Group of Dallas plans to fuel a $120 million ethanol plant set to open next year in Hereford. The company said it
will realize an energy savings equivalent to 1,000 barrels of oil per day by turning manure and cotton-gin waste into clean-burning fuel to power the plant.
“I see it as a valuable tool in our tool box,” John Sweeten, resident director of the Texas Agricultural Experiment Station in Amarillo, said of cattle manure’s energy potential.
“Sixty-dollar-a-barrel oil recruits a lot of interest in biomass,” Sweeten said. “At $10-a-barrel oil, there’s not much interest.”
Biomass is renewable organic matter, such as manure and crops including corn, grain sorghum and soybeans, all of which can be processed into ethanol.
“Anything that’s renewable and is at least competitive with other prices, it’s better for everybody,” said Donald L. Klass of the Biomass Energy Research Association in Washington.
The potential for surplus manure stems from more cattle, dairy cows and hogs coming to the Panhandle, and farmers moving toward planting more dryland crops, which demand less fertilizer.
STUDYING THE PROCESS
Researchers at a feedlot are trying to figure out the best process and mix to create the most usable heat and energy.
A future research project will examine using manure from dairy cows, Sweeten said, which, like swine manure, requires a different process to capture the energy.
But cattle for meat outnumber other concentrated animal-feeding operations in the Panhandle. Nearly 5 million head of cattle come to about 100 Panhandle feedyards each year.
While there, they produce billions of pounds of manure.
“It’s almost too good not to use,” said David Parker, a professor of agriculture at West Texas A&M University.
The experiment station’s feedlot study involved taking cattle-manure samples from pens with different floors.
One set of pens was paved with fly ash, a by-product of the coal-fired power generating industry; the others had dirt floors.
In a sampling taken this summer, manure composted from the dirt-floor pens had more unusable material (59 percent) than that from the fly-ash-covered pens (20.2 percent). That means the pens paved with fly ash had more than twice the usable biomass from which to create energy.
But not many pens in commercial feedlots have fly-ash floors in pens.
“The trick is to recover the biodegradable and leave the dirt in the ground as it is,” Klass said.
BEST USED REGIONALLY
Sweeten said manure contains at best about a third to a quarter of the energy value as coal so “you don’t get as much bang for your buck, literally.”
That makes transporting manure far from where it’s produced impractical, so Sweeten said manure-generated energy would be used only regionally.
Large bulk samples from a composting manure pile from the fly-ash pens will be tested further in a small-scale combustion-testing project in College Station.
“I see it as something that can enhance our portfolio of renewable energy, but it can also help us on manure management,” Sweeten said.