Valorization of Spent Vetiver Roots for Biochar Generation.

Vetiver root is widely used to produce essential oils in the aromatherapy industry. After the extraction of oil, the roots are disposed of as waste. The central objective of this research was to explore the conversion of this waste into a resource using a circular economy framework. To generate biochar, vetiver roots were pyrolyzed at different temperatures (300, 500, and 700 °C) and residence times (30, 60, and 120 min). Analysis showed the root biochar generated at 500 °C and held for 60 min had the highest surface area of 308.15 m 2 /g and a yield of 53.76%, in addition to other favorable characteristics. Comparatively, the surface area and the yield of shoot biochar were significantly lower compared to those of the roots. Repurposing the spent root biomass for environmental and agronomic benefits, our circular economy concept prevents the plant tissue from entering landfills or the waste stream.