Two-step chemical process turns raw biomass into biofuel

Feb 10, 2009 by Nicole Miller

(PhysOrg.com) -- Taking a chemical approach, researchers at the University of Wisconsin-Madison have developed a two-step method to convert the cellulose in raw biomass into a promising biofuel. The process, which is described in the Wednesday, Feb. 11 issue of the Journal of the American Chemical Society, is unprecedented in its use of untreated, inedible biomass as the starting material.

The key to the new process is the first step, in which cellulose is converted into the "platform" chemical 5-hydroxymethylfurfural (HMF), from which a variety of valuable commodity chemicals can be made. "Other groups have demonstrated some of the individual steps involved in converting biomass to HMF, starting with glucose or fructose," says Ronald Raines, a professor with appointments in the Department of Biochemistry and the Department of Chemistry. "What we did was show how to do the whole process in one step, starting with biomass itself."

Raines and graduate student Joseph Binder, a doctoral candidate in the chemistry department, developed a unique solvent system that makes this conversion possible. The special mix of solvents and additives, for which a patent is pending, has an extraordinary capacity to dissolve cellulose, the long chains of energy-rich sugar molecules found in plant material. Because cellulose is one of the most abundant organic substances on the planet, it is widely seen as a promising alternative to fossil fuels.

"This solvent system can dissolve cotton balls, which are pure cellulose," says Raines. "And it's a simple system-not corrosive, dangerous, expensive or stinky."

This approach simultaneously bypasses another vexing problem: lignin, the glue that holds plant cell walls together. Often described as intractable, lignin molecules act like a cage protecting the cellulose they surround. However, Raines and Binder used chemicals small enough to slip between the lignin molecules, where they work to dissolve the cellulose, cleave it into its component pieces and then convert those pieces into HMF.

In step two, Raines and Binder subsequently converted HMF into the promising biofuel 2,5-dimethylfuran (DMF). Taken together, the overall yield for this two-step biomass-to-biofuel process was 9 percent, meaning that 9 percent of the cellulose in their corn stover samples was ultimately converted into biofuel.

"The yield of DMF isn't fabulous yet, but that second step hasn't been optimized," says Raines, who is excited about DMF's prospects as a biofuel. DMF, he notes, has the same energy content as gasoline, doesn't mix with water and is compatible with the existing liquid transportation fuel infrastructure. It has already been used as a gasoline additive.

In addition to corn stover, Raines and Binder have tested their method using pine sawdust, and they're looking for more samples to try out. "Our process is so general I think we can make DMF or HMF out of any type of biomass," he says.

Provided by University of Wisconsin-Madison

Explore further: Researchers create materials that reproduce cephalopods' ability to quickly change colors and textures

add to favorites email to friend print save as pdf

Related Stories

NASA air campaigns focus on Arctic climate impacts

38 minutes ago

Over the past few decades, average global temperatures have been on the rise, and this warming is happening two to three times faster in the Arctic. As the region's summer comes to a close, NASA is hard at ...

Video: MAVEN set to slide into orbit around Mars

38 minutes ago

A NASA mission to Mars led by the University of Colorado Boulder is set to slide into orbit around the red planet this week after a 10-month, 442-million mile chase through the inner solar system. 

Global change: Trees continue to grow at a faster rate

38 minutes ago

Trees have been growing significantly faster since the 1960s. The typical development phases of trees and stands have barely changed, but they have accelerated—by as much as 70 percent. This was the outcome ...

Slimy fish and the origins of brain development

39 minutes ago

Lamprey—slimy, eel-like parasitic fish with tooth-riddled, jawless sucking mouths—are rather disgusting to look at, but thanks to their important position on the vertebrate family tree, they can offer ...

Recommended for you

Chemical biologists find new halogenation enzyme

Sep 15, 2014

Molecules containing carbon-halogen bonds are produced naturally across all kingdoms of life and constitute a large family of natural products with a broad range of biological activities. The presence of halogen substituents ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

E_L_Earnhardt
not rated yet Feb 10, 2009

GOOD WORK!
SDMike
not rated yet Feb 11, 2009
Oh NO! This discovery will simply increase the western world's exploitation of nature and slow the inevitable return of man to his natural place - a cave.