Ethanol-Production Leftovers Worth More than the Fuel Itself
Mixing up a batch of ethanol from alfalfa or
switchgrass isn’t nearly as efficient as creating it from corn, but that
doesn’t mean growing grass crops for fuel won’t pay, says Paul
Weimer.
Mixing up a batch of ethanol from alfalfa or switchgrass isn’t nearly as efficient as creating it from corn, but that doesn’t mean growing grass crops for fuel won’t pay, says Paul Weimer.
Rather than dwelling on finding ways to squeeze extra ethanol out of biomass from crops such as switchgrass, Weimer is concentrating his research on the leftovers. He thinks that the large heap of fermentation residue from the ethanol-making process - what many people consider a byproduct - could be far more valuable than the ethanol itself.
“A lot of people want to do the same thing with biomass material that we’ve been doing with corn,” says Weimer… “They want to hit it with enzymes to break it down into sugars, and ferment those sugars into ethanol.
The problem with this, he explains, is that the enzymes needed to break down celluose biomass are very expensive, and they don’t work nearly as effectively as the enzymes used to convert starch. In fact, Weimer adds, both corn and cellulosic biomass must be subjected to costly pretreatment to maximize the ethanol yield.
Weimer says. “We think that the fermentation residue may actually be more valuable than the ethanol. And it may mean that we can do without pretreatment.”
Weimer was working on processes to separate a very sticky glue from fibers in the residue to come up with separate end uses for the fibers. Until he realized he could save energy, effort and expense by just leaving it alone — and using it all — as glue!
Specifically, they used it as wood glue. Weimer hopes to get the wood products industry interested in replacing half of the phenol formaldehyde (PF), a petroleum-based adhesive now used to make plywood, with the biomass-based adhesive.
“The PF that the fermentation process would partially replace sells for considerably more that ethanol, and the fermentation would still generate ethanol on the side,” he says.
Economic transference often includes byproducts from research that prove to be at least as valuable as the original focus. One of the really good reasons to support scientific investigations further afield than the mundane.
Posted: Thu - September 28, 2006 at 06:44 AM