U.S. Researchers Trying To Find New Uses for Cow Manure
DETROIT -- Home-buyers of tomorrow could find themselves walking across floors made from manure.
That is no cow pie-in-the-sky dream, according to researchers at Michigan State University and the U.S. Department of Agriculture.
They say fiber from processed and sterilized cow manure could take the place of sawdust in fiberboard, which is used to make everything from furniture to flooring to store shelves.
And the resulting product smells just fine.
The researchers hope it could be part of the solution to disposing of the 1.5 trillion to 2 trillion pounds of manure produced annually in the United States.
The concept has its skeptics.
"Is this something you're going to bring into the house?" asked Steve Fowler, an economist with the Composite Panel Association, a fiberboard-makers trade group based in Gaithersburg, Maryland.
Farmers traditionally use manure to fertilize their fields. But as the scale of farms has grown -- with more and more animals densely concentrated in a single location -- they can find themselves with too little land for the manure they produce.
"Farmers are having to put more and more money into dealing with manure," said Tim Zauche, a chemistry professor at the University of Wisconsin-Platteville who is working on the USDA research project.
A dairy farm can spend $200 (euro150) per cow per year to handle its manure, Zauche said. Those costs include onsite processing and spreading, as well as transportation for offsite disposal.
Environmental activists and regulators are paying increased attention to the contamination of streams and underground water sources from manure runoff. And people who move into what used to be rural areas often complain about manure's odor.
Under pressure from regulators and the public, more large livestock operations are installing expensive manure treatment systems known as anaerobic digesters.
The digesters use heat to deodorize and sterilize manure, while capturing and using the methane gas it produces to generate electricity. The systems also separate phosphorus-laden liquid fertilizer from semisolid plant residue.
The solids have some known uses, including animal bedding and potting soil, and agricultural scientists would like to find more.
"We really need to think outside the box on what uses for manure are," said Wendy Powers, a professor of agriculture at Michigan State University.
Scientists at Michigan State in East Lansing and at the USDA's Forest Products Laboratory in Madison, Wis., are conducting tests on various types of fiberboard made with the "digester solids."
As with the wood-based original, the manure-based product is made by combining fibers with a chemical resin, then subjecting the mixture to heat and pressure.
So far, fiberboard made with digester solids seems to match or beat the quality of wood-based products.
"It appears that the fibers interlock with each other better than wood," said Charles Gould at Michigan State's College of Agriculture and Natural Resources.
Gould and Laurent Matuana, a forestry professor at Michigan State, recently finished a pilot study of manure-based fiberboard, funded by a $5,000 (euro3,793) grant from the Michigan Biomass Energy Program.
A draft of the report concluded that fiberboard panels made with processed manure "performed very well in mechanical tests, in many cases meeting or exceeding the standard requirements for particleboard."
The USDA lab in Wisconsin recently began an 18-month, $30,000 (euro22,756) study to test the strength and endurance of the manure-based fiberboard and examine the economic practicality of using digested fiber to make building products.
One good thing about the manure-based fiber is cost, said Zauche. Farmers who currently pay to dispose of manure could soon be selling it.
Whether that is enough to overcome the public's squeamishness about using a manure byproduct as a building product remains to be seen, a plywood trade group representative said.
"If nobody in industry has an interest, it will die," said Craig Adair, spokesman for Tacoma, Wash.-based APA -- The Engineered Wood Association.
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Source: Associated Press