Petroleum-based polymers have been added to asphalt since the 1990s. Soft, rubbery polymer compounds improve asphalt by adding resilience and durability to the pavement. Iowa State University professor Chris Williams is confident the polymers in asphalt will someday be environmentally friendlier bio-polymers made from soybeans grown in Iowa and the Midwest.
The idea has taken a major step forward with the opening of the new $5.3 million Bio-Polymer Processing Facility, located west of Ames at Iowa State’s BioCentury Farm. The result of an ISU-industry partnership, the pilot plant-scale facility was built by Argo Genesis Chemical LLC, a sister company of Seneca Petroleum Co. Inc., of Crestwood, Illinois.
The facility is a sophisticated combination of pipes, hoses, electronics, and large tanks that will produce about 1,000 pounds of bio-polymers daily. The amount is a far cry from the few ounces that Williams and ISU chemical engineering associate professor Eric Cochran could make at a campus laboratory. In 2010 and 2011 the researchers developed a novel process to transform soybean oil into thermoplastics, which are polymers that can be melted and reshaped repeatedly.
The pilot plant’s production output is sufficient to provide enough bio-polymers for additional research and for companies to test the product. It is expected a handful of demonstration projects to evaluate the bio-polymers will be under way in Iowa and elsewhere by summer 2016, including asphalt sections at the National Center for Asphalt Technology test track in Auburn, Alabama.
“It is so exciting to see an ISU intellectual property taking the next step to commercialization with the pilot plant,” says Williams, the Gerald and Audrey Olson Professor of Civil Engineering and manager of the Asphalt Materials and Pavements Program at the ISU Institute for Transportation (InTrans).
The Midwest Transportation Center, which is located at InTrans, provided some matching funds for furthering the technology.
Williams explains that bio-polymers are an excellent replacement for petroleum-based polymers in asphalt. “The bio-polymer asphalt performs as well or even better than regular asphalt, it is cost effective, it reduces the carbon footprint by about 30 percent, and it is a safer material because it replaces the need for a more volatile and dangerous chemical in butadiene.
“All the way around, it’s a win-win situation.”
Williams and Cochran say their bio-polymers will also be evaluated in other products such as adhesives, coatings, and packing materials.
Because of Iowa’s huge soybean and corn crops, Williams says the state is a natural place to take cellulosic feedstocks and process them into higher-value materials. “We’re creating value-added products from Iowa agricultural commodities.”