[Gasification] Spokane WA gasifier

[Art Krenzel]

They will be attempting to gasify Kentucky Bluegrass straw.

Art Krenzel


2/1/08 - Capital Press
Grass straw gasifier ready to fire up

Farm-size demonstration project will turn straw into fuel



Scott A. Yates

Capital Press



SPOKANE - It's been a long time coming, but a million-dollar demonstration 
project intended to show that grass seed straw can be turned into fuel is 
due to start up this spring.



A project that received a $736,000 Department of Energy grant in 2002, with 
another $300,000 worth of in-kind services, the Farm Power gasifier was 
supposed to be online two years ago. Glitches, both technical and personal, 
slowed the project to a crawl. A lawsuit brought by the original contract 
director was settled with the stipulation that parties not discuss the 
decision.



Moving forward since then, the prototype farm-scale gasifier has been taking 
shape under a steel building on Larry Gady's farm south of Spokane. Looking 
like a stainless steel rocket, the gasifier is essentially a 
12-inch-diameter tube within a tube. It rises from near the concrete floor 
to within 4 feet of the roof's 31-foot peak.



This is the combustion chamber. Straw from a 20-ton storage unit next to the 
building will be fed into an opening near the top of the unit. The theory is 
as it drops down the length of the tube, sufficient time will elapse to 
allow the gasification process to occur.



Although it will initially be fired by propane, research shows the straw 
takes over the combustion process. Burning at 1,800 degrees F, the gasifier 
is designed to convert the carbon in the straw into a gas without gumming up 
the process with a lot of silica. The gas will run a diesel engine, which 
would generate electricity to return to the power grid.



Gary Banowetz, research leader for the USDA's Agricultural Research Service 
in Corvallis, Ore., said it remains to be seen just how much straw the 
gasifier can gobble up.



"We'd like to put 500 pounds to 2,000 pounds of straw in there per hour. The 
unknown is how fast can we put it through and effectively convert the 
carbon," he said.



Jack Zimmer is Farm Power's current contract director. He agreed the process 
has been slow, but explained that's because there is no such thing as an 
off-the-shelf gasifier sized for the farm.



Gasifier technology, however, isn't new. Researchers at the Western Research 
Institute near the University of Wyoming have been working on coal 
gasification for years.



Originally, the Farm Power team was going to use the cast-iron gasifier the 
Wyoming researchers had proven. Although it was shipped to the Northwest 
(pieces of it lie on the floor of the gasifier building), at 8,800 pounds it 
was deemed too heavy. A never-before-used stainless steel unit was 
commissioned, which weighs 2,000 pounds.



"Clearly, this is very much a work in progress. We anticipate the likelihood 
to tear it down and tweak it," Banowetz said.



A farm-size unit is the preferable size because the cost of transporting 
straw eats up more energy than it's worth.



"It's not like corn. We envision this being done on the farm or in a rural 
community where the haul is short," he said. "Straw is not very 
energy-dense."



The current project will have more than $1.3 million in it by the end, but 
Banowetz said the plan is to be able to build a second model for the cost of 
a fully equipped combine - about $350,000. If everything works as 
advertised, payback would take three years.



"I think all the competing uses will ultimately be based on the returns to 
the people producing the straw. The market will have to determine that," he 
said.



The second phase of the project is turning the gas from the straw 
gasification process into a liquid. Banowetz estimated 60 gallons of fuel 
might be synthesized from a ton of straw. At this point, he's not sure 
which - electricity or fuel - makes more sense to generate.



While the problem with silica should be reduced in the gasifier, there will 
still be 6 percent to 10 percent ash, or upwards of 1 ton of ash for every 
10 tons of straw burned. Banowetz said the leftovers contain potassium and 
phosphorus and can be applied to soil.



Staff writer Scott Yates is based in Spokane. 
E-mail:syates at capitalpress.com.