Rheological and chemical characterization of biobinders from different biomass resources

The increasing costs and strong worldwide demand for petroleum and the adverse environmental impact of the consumption of nonrenewable energy sources have encouraged the development of alternative sources of renewable energy. One source of renewable energy can be developed in biorefineries, where biomass feedstocks can be converted to biocrude oil through thermochemical processes. Biocrude oil can replace petroleumbased transportation fuels and can be used to build and maintain transportation infrastructure, which requires an energy-intensive process that consumes natural resources, including mineral aggregates, steel, cement, and petroleum-based binder. This study aimed to characterize biocrude oil as an alternative binder material, which is referred to here as biobinder. The hydrothermal liquefaction technique was used to produce biobinder from spirulina algae (microalgae), swine manure, and nanoalgae. A chemical analysis was performed with the saturates, aromatics, resins, and asphaltenes technique to characterize the percentage of different components present in the biobinder. A rheological characterization of biobinders was conducted to evaluate their feasibility for use in pavement construction and to predict their performance during the service life of a pavement. Surface free energy properties of biobinders also were determined with the use of a sessile drop device to characterize adhesion properties. The results indicated that biobinder had significantly different rheological and chemical properties than conventional asphalt binder. When blended with conventional binder, biobinder showed the potential to reduce the stiffness of original binder. As a result, it might be used to rejuvenate mixes with recycled asphalt materials or find an application under low-temperature conditions.