Enhancing Hydrogen Production from Biomass Steam Gasification: The Role of Chemical Variability of Industrial Biomass Fly Ash Catalysts

This study examines the influence of industrial biomass fly ash (BFA) composition variability on its catalytic performance in biomass steam gasification, particularly regarding producer gas quality and hydrogen production. BFA samples, collected over two years from a bubbling fluidised bed combustion system, were granulated and calcined to remove CO2. Water-gas shift (WGS) reaction tests identified temperature as a key factor in H2 production, with BFA promoting CO conversion and increasing H2 yield by over 26-fold. Bench-scale gasification experiments confirmed BFA’s catalytic potential, with alkali and alkaline earth metals (AAEM) enhancing H2 yield up to two-fold and improving tar conversion. BFA-A granules, richest in CaO, achieved the highest H2 concentration (exceeding 50 % vol.dry and inert (N2, Ar) free gas). Despite slight variations, all BFA samples demonstrated strong catalytic performance, supporting their effective repurposing as waste-derived catalysts within industrial applications, aligning with circular economy principles.