Researchers have found that pig manure is fine for building
asphalt highways.
It’s a cheaper and environmentally-friendlier ingredient
than oil.
With funding from the National Science Foundation, the group
developed a process that turns the waste into a black crude – the sticky binder
that can be used to make asphalt. The cost to process the manure oil is US$0.56
a gallon, which is much cheaper and greener than current petroleum binders.
"It is different from petroleum refinery, which distills
crude oil to produce mainly fuel and leave the residue for asphalt," Ellie
Fini, lead researcher and assistant says professor of civil engineering.
"Here we produce bio-adhesive from breaking bio-mass
molecular structure and re-synthesizing the bio-adhesive structure.”
Hog-manure odours are filtered out during processing and the
dry matter byproduct can be used as fertilizer.
Pavement made with hog manure is being tested under traffic
conditions including a simulation of truck traffic making 20,000 passes over
it.
The tests have so far been successful, passing Department of
Transportation specifications, which led the group to form the company
Bio-Adhesives to scale up their research.
"We think it's scalable and cost-wise it's
profitable," says Fini.
"Our vision is to help the farmer and help the
construction industry, both sides. We see a win-win approach in the
solution."
"We generate 43 billion gallons of swine manure in the
world every year," says Daniel Oldham, graduate student researcher on the
project, who adds that China produces 10 times the amount of pig manure as the
U.S.
At the same time there are around 2.3 million miles of
asphalt paved roads in U.S., with the cost of paving an urban two-lane road
with traditional petroleum asphalt costing more than $800 per mile.
