Bio Buzzword: Biomass Materials Could be the Next Effective Asphalt Modifier

This article examines advancements made in fast pyrolysis, a thermal-chemical conversion process that converts biomass into three fractions made up of gases, similar to natural gas, solids and liquids. The liquid phase is called “bio-oil,” and researchers at Iowa State University have identified bio-oil fractions that can be used to supplement and possibly replace asphalt binders. Given the dwindling supply of funding available for highway improvements, the move away from dependence on foreign oil, and the shortages of asphalt, the ability to utilize bio-oil as asphalt binder is compelling. Challenges include the stabilization of upgraded bio-oil fractions, and the effect of temperature on the viscosity of bio-asphalt. Environmentally, the use of bio-oil could have environmental benefits, as it has lower production temperatures similar to warm-mix asphalt.