Process Lowers Costs of Converting Waste Cellulose

Biofine Inc. (Waltham, MA) has developed technology that more efficiently converts cellulose into levulinic acid, which can be used to produce a wide range of products, from alternative fuels to fertilizer.

The company has been developing the technology to increase the yield of levulinic acid from cellulose. (The yield from previous cellulose-conversion processes has been only about 25% levulinic acid—the remainder being tar.)

The patented Biofine process is said to reduce the time the cellulose remains in a processing vessel while "preferentially" producing levulinic acid—only 25% emerges as a coal-like tar.

A demonstration plant, funded by a $3-million grant from the U.S. Department of Energy and $1 million from the state of New York produces the acid at a cost of 4 cents to 32 cents per pound. This contrasts to the prevailing $5 to $10 per pound, according to the New York State Energy Research and Development Authority. This could drive the demand for levulinic acid up from its current worldwide level of 1 million pounds per year to as much as 1 trillion pounds.

As reported in the Mar. 1 issue of the Los Angeles Times, the South Glens Falls, NY, plant converts about a ton per day of waste sludge from a paper-processing plant into levulinic acid. The coal-like substance is burned to make steam and electricity for the process, which nets almost zero power use, according to Biofine's President Stephen Fitzpatrick, a chemical engineer.

Douglas C. Elliott, a chemist at the DOE's Pacific Northwest National Laboratory in Richland, WA believes the technology could lead to a new generation of alternative fuels.

Elliott and his co-workers have created what the lab calls "the first-ever multi-step catalytic process that converts levulinic acid into an alternative fuel component called methyltetrahydrofuran," or MTHF.

MTHF can be combined with natural-gas liquids to produce a clean-burning fuel for vehicles.

"Biofine has been able to refine levulinic acid production to the point that they can get a high enough yield to make it interesting economically," Elliott said. "And in the process, they remove all of the other contaminants that would hurt our catalyst and give us a clean product to work with."