Monthly Archives: September 2015


Image Courtesy:

Biofuel prodcution involves removing Lignin from the biomass, in fact efficient removal so that Lignin and its by-products do not inhibit the enzymatic process that follows. But, what happens to the Lignin? Well, it can used in laying roads and thus creating bioasphalt.

Usually, after the sugars, cellulose, and other more useful materials have been extracted from plant matter to make biofuels or paper, the leftover lignin is tossed aside and burned. In principle, the economics are therefore promising: Paper companies could profit from what had been a waste product, and biofuel makers could similarly use the proceeds of selling lignin to bring down fuel production costs.

FYI, Lignin looks something like this.

Lignin. Image Courtesy: Wikimedia Commons

Lignin. Image Courtesy: Wikimedia Commons

Read more here
 R. Chris Williams, a materials engineer at the Iowa State University Institute for Transportation, has developed a way to turn lignin-rich stover, leftover from biofuel production, into bioasphalt. The Iowa team uses a process called fast pyrolysis that turns plant waste into a charcoal-like fertilizer, natural gas, and an oily mixture that can be made into bioasphalt.
If you live in Iowa, you could see the bioasphalt paved bike path in Des Moines as the article mentions.
Update: My friend Ethy, pointed out that the bike trail (~1 mile long) between University Avenue and Franklin Avenue, on the west side of Glendale Cemetery has this bioasphalt bike path. See map below. Link:
Google Maps

Google Maps
Bourzac, K. (2015). Inner Workings: Paving with plants Proceedings of the National Academy of Sciences, 112 (38), 11743-11744 DOI: 10.1073/pnas.1509010112