City to Test Bio-Based Asphalt from University, Startup

(Iowa State University)

A lab at Iowa State University in Ames has developed a potential green replacement for asphalt derived from petroleum, which will be put to a test in Iowa’s sometimes extreme winters and summers. The lab, in the Institute for Transportation’s Asphalt Materials and Pavements Program at Iowa State, developed the asphalt substitute, which will be part of a demonstration project in Des Moines, Iowa’s capital.

The lab is headed by Christopher Williams, associate professor of civil engineering, who adapted a thermochemical process called fast pyrolysis, which quickly heats farm and lumber wastes or other types of biomass without oxygen. The process produces a liquid bio-oil that can be used to manufacture fuels, chemicals, and asphalt, plus other environmentally friendly products. Three recent Iowa State grad students started a company, Avello Bioenergy Inc., that licensed the technology to develop and market products made from fast pyrolysis. Those products include Bioasphalt, derived from the work in Williams’s lab.

Bioasphalt will get a real-world test, thanks to the city of Des Moines that is using the material to pave part of the 10-foot wide Waveland Bicycle Trail on the city’s northwest side. The first test uses a 5 percent mix of bioasphalt. Williams says a successful demonstration would lead to more pavement tests containing higher percentages.