Mechanism of enhanced supercritical water gasification of anthracite via swelling pretreatment: Reaction kinetics and structural modifications

Benzene-induced swelling pretreatment markedly enhances the supercritical water gasification (SCWG) of anthracite by disrupting its hydrogen-bonding network and expanding the pore structure. Results demonstrate that this structural modification increases porosity by 33%, leading to a carbon gasification efficiency (CE) of 96.03 ± 0.47% under optimized conditions (750°C, 25 MPa)—a significant 15% enhancement over untreated coal (83.53 ± 0.62%). Hydrogen yield rose by 28% to 198.23 ± 2.15 mol/kg. Kinetic analysis revealed a 10—17% reduction in activation energy, supported by a multi-path reaction network model that highlights the synergy between enhanced mass transfer and free radical reactions. These findings underscore the potential of swelling pretreatment to overcome anthracite's inherent barriers, advancing scalable clean energy conversion strategies.