Green synthesis of high-performance activated carbon from biomass by coupling hydrothermal carbonization and pyrolysis self-activation

To address the issues of reliance on external activator in conventional biomass-derived activated carbon preparation and the requirement for pre-pulverization of feedstock, this study developed a coupled hydrothermal carbonization - pyrolysis self-activation process. Hydrothermal treatment was employed to produce a homogenized, carbon-enriched precursor. The endogenous H 2 O within this precursor and the CO 2 generated during pyrolysis served as activators, achieving self-activation of the carbon matrix. Following process optimization using response surface methodology, the resulting bamboo activated carbon exhibited a carbon yield of 13.1 % and a specific surface area of 1556 m 2 ·g −1 . Under conditions of 25 ℃ and 648.1 Pa, its equilibrium benzene adsorption capacity reached 141.6 mL·g −1 . The adsorption process was identified to be spontaneous, exothermic, and physically driven. This process provides a novel, green approach for the fabrication of biomass-derived activated carbon, demonstrating significant potential for industrial applications. • A novel method for green synthesis without the need for additional activators or pulverizing pretreatment. • The internal water of biomass and the pyrolysis-derived CO 2 contribute to efficient self-activation. • Comprehensively evaluated the preparation process parameters impact on pore structure and refined the process. • Adsorbent exhibits exceptional benzene adsorption and reveals the adsorption mechanism.