Integrated sorption enhanced gasification and reforming for hydrogen-rich gas production from olive stones

This study explores the production of hydrogen-rich gas from olive stones via sorption enhanced gasification (SEG). A pilot-scale 30 kWth bubbling fluidized bed gasifier was integrated with a downstream gas cleaning and conditioning train consisting of two fixed-bed reactors, including chlorine, sulphur, and tar removal stages. Operating the gasifier at 660 °C under high steam-to-carbon conditions resulted in a hydrogen content of 80 vol% (dry basis) and a yield of 1 Nm 3 H 2 /kg biomass. Although this operating regime produced about 9 vol% CH 4 , subsequent tar reforming at 850 °C and 20000 h −1 space velocity enabled complete CH 4 and tar conversion, yielding a clean hydrogen-rich product gas. Tar levels were reduced to 2 g/Nm 3 (GC-MS) and 0.7 g/Nm 3 (gravimetric). These findings demonstrate that the integrated optimization of gasification and reforming processes enhances hydrogen yield and purity, highlighting the potential of SEG as a promising route toward renewable hydrogen-rich gas production from biomass. • Biomass-to-hydrogen via SEG using olive stones as feedstock. • Achieved 80% H 2 purity and 1 Nm 3 /kg at 660 °C under high S/C. • Full CH 4 reforming at 850 °C and 20000 h −1 ensured clean gas. • Tar reduced to 2 g/Nm 3 (GC-MS) and 0.7 g/Nm 3 (gravimetric). • SEG confirmed as a promising route for sustainable H 2 production.