In Business, Creating Sustainable Enterprises & Communities

VALUE-ADDED CONSTRUCTION MATERIALS FROM A DIGESTER

In Business, November-December, Vol. 29, No. 6, p. 19

New uses for an old troublemaker known as manure fibers.

MICHIGAN STATE University Extension educator Charles Gould has a vision for new lines of composite materials that use a combination of plastic and manure fibers. His goal - explains an article in Resource for November 2007 by Laura Probyn - is to develop products for construction of everything from playground equipment to homes.
There are more than 40,000 dairy cattle in Michigan's Allegan, Ottawa and Kent counties. Rapid housing development has limited the acres available for manure utilization, writes Probyn of MSU's ANR Communications.
Gould read a report about how Iowa State University's biological composites lab successfully combined fibrous material from an anaerobic digester with plastic to create composite materials. Gould believed they could do this at MSU, and went to Laurent Matuana, an associate professor at the University's Department of Forestry. Together, they developed a project proposal that was then submitted to the Michigan Biomass Energy Program. They received a small grant and hired an undergraduate student to develop two prototype products - a digester fiber/plastic composite that could be used as decking, and a medium-density fiberboard. The products made with fiber from a digester worked very well, exceeding industry standards for strength, stiffness and internal bond.

TESTS SHOW VALUE
The digester fiber/plastic decking product performed better in tests against similar decking products made with wood/plastic. When two composite types were compared, the digester fiber/plastic decking product had properties that were superior to those of the wood product, including a darker color, which potentially could be more resistant to UV rays.
During the production process, the fibers intertwine and increase the strength of resulting composites. This offers an advantage in areas such as load-bearing capacity or material strength.
The properties of the medium-density fiberboard met or exceeded standard requirements. Matuana indicated that the work confirms that value-added products can be successfully manufactured from digester fibers.
“Everything being equal,” Matuana concludes, “the digester fibers are giving us much better properties than wood.”
There are numerous possibilities for construction materials containing the digester fibers. Because the chemicals used in the production of pressure-treated wood have been shown to be harmful to human health, the U.S. Environmental Protection Agency has outlawed use of pressure-treated wood in playground equipment. Fiber/plastic “lumber” could take its place. Other uses might include products for siding, furniture, or lake front sea walls.
Gould approached managers at two western Michigan home improvement retail chains to ascertain their feelings about carrying digester fiber/plastic decking or medium-density fiberboard made with the fibrous material from a digester. They indicated a willingness to purchase the product even though it was made out of fiber once found in manure, because they perceived the products to be green. The most common question asked was about odor. Neither the fiber/plastic decking nor the medium-density fiberboard emits an odor.

FURTHER TRIALS
Gould does not foresee any problems with pounding holes or drilling into the products at this point, but further testing is required. And, as always, more time and more money are required as well.
Matuana echos his colleague's sentiments. Properties related to nail-ability, screw-ability and humidity have not been investigated.
Gould and Matuana are planning to submit another funding proposal to the Michigan Biomass Energy Program and are looking to other funding sources, both through grants and the private sector. They also want to begin work on marketing plans.
Though the field of new, environmentally friendly materials could have positive economic impacts on the construction, nursery and possibly even the forestry industries, Gould is pondering the possibilities for his primary audience: farms and rural communities.
“There is a limited land base for manure application. Keeping Michigan's livestock industry strong and viable means we have to find a home for the manure generated by these farms,” Gould says. “Why not make products from manure that benefit society, add value to the farming operation, and at the same time, fit nicely into a sustainable management system? At the end of the day, it's really all about sustainability.”

Laura Probyn is the Communications Manager for ANR Communications, College of Agriculture and Natural Resources, Michigan State University Extension, East Lansing; probyn@anr.msu.edu.