Reactivity and performance of steam gasification during biomass batch feeding

The steam gasification characteristics of poplar sawdust were investigated in a piston fed fixed-bed gasifier, reflecting the batch feeding process of fixed-bed gasifiers in industrial applications. The effects of operating conditions, including steam supply, the flow rate of inert gas, gasification temperature, and feeding rate, on gasification reactivity and performance were investigated online. The major gas product during pyrolysis was CO, followed by H₂, CH₄, and CO₂, and the gasification was greatly facilitated by the injection of steam to generate H₂. The gasification reactivity and performance were improved with increased steam supply and temperature. The maximum production rate of H₂ by char gasification was tripled and doubled, respectively, with an increase in steam supply from 50 to 400 mL/min and a temperature rise from 800 to 900 °C, and the time required for complete gasification was also halved. Compared to pyrolysis, the volume fraction of H₂ increased from 23% to 37%, and correspondingly, the H₂/CO ratio increased from 0.42 to 0.95.