Biomass Valorization to Biochar: A Strategy for Volatile Organic Compound (VOC) Inhibition in Reactive Rejuvenated SBS-Modified Bitumen

To enable the application of biomass pyrolysis products in sustainable pavements and inhibit volatile organic compound (VOC) emissions from reactive rejuvenated SBS-modified bitumen (SMB), six different biomass feedstocks were used to prepare biochar. The effects of biochar on the pavement performance and VOC emissions of the reactive rejuvenated SMB were analyzed. Results show that the biochar diminishes VOC concentration as well as its environmental and health risks, and the inhibition effect intensifies with increasing biochar dosage. Under the same pyrolysis conditions, the bamboo biochar exhibits the strongest inhibition of both the VOC variety and concentration, followed by the rice husk biochar and the corncob biochar, whereas the rice straw biochar shows the weakest effect. The adsorption of VOC by bamboo biochar involves physical and chemical mechanisms, which arise from its abundant pore structure and surface polar functional groups. Besides, the 3 wt % biochar dosage is the optimal choice for reactive rejuvenated SMB.