Researchers team up to develop pilot plant, advance biofuel technology

Iowa State University's Lysle Whitmer walked the length of the bio-oil production line – from the 55-gallon solvent tank to the twin-screw extruder with its mixing, chopping, heating and pressurizing functions to the reactor in the middle and then to the product separators and the solvent recycling system. 

"This is the culmination of everything we've learned about building pilot plants in the past 10 years," he said. "This is really a gem that represents everything we've learned thus far."

This latest pilot plant at Iowa State's BioCentury Research Farm is a joint project with Chevron U.S.A. University engineers are using the pilot plant to develop and demonstrate an advanced biorenewables technology called solvent liquefaction. The technology converts biomass such as quarter-inch d into a bio-oil that can be processed into fuels or chemicals and a biochar that can enrich soils.

The project is supported by a four-year, $3.5 million grant from the U.S. Department of Energy's Biomass Research and Development Initiative, obtained by Iowa State.

"This pilot plant is like a mini commercial system," said Robert C. Brown, the director of the Bioeconomy Institute and an Anson Marston Distinguished Professor in Engineering. "A good pilot plant has all of the unit operations that take biomass to a product. It's a big engineering challenge to tie all the steps together and have them operate in concert."

Whitmer said the engineers have now demonstrated the viability of every one of the pilot plant's operations. They're still working to efficiently and simultaneously run all the operations.

The pilot plant operates about once a week, Whitmer said. It can process about a pound of biomass every hour and typically runs for 15 to 18 hours at a time.