Catalytic gasification of oil-extracted residue biomass of Botryococcus braunii

•Catalytic gasification of oil-extracted residue of Botryococcus braunii was performed.•Gas conversion of 91%-C without tar was attained at 1023 K by Ni–Fe/Mg/Al catalyst.•Composition of product gas with high contents of H2 and CO was suitable as syngas.•H2 yield of 74.7 mmol g-biomass−1 obtained was much higher than others reported.•The residue biomass can be a superior renewable source of syngas or hydrogen.

Catalytic gasification of the oil-extracted residue biomass of Botryococcus braunii was demonstrated in a laboratory-scale continuous feeding dual bed reactor. Steam gasification at 1023 K over Ni–Fe/Mg/Al catalyst can completely reform tar derived from pyrolysis of the residue biomass into C1 gases and hydrogen, and has achieved 91%-C conversion to gaseous product (CO + CO2 + CH4). Composition of product gas has higher contents of CO and H2 with their ratio (H2/CO) of around 2.4 which is slightly H2-rich syngas. Maximum hydrogen yield of 74.7 mmol g-biomass−1 obtained in this work is much higher than that from gasification of other algal biomass reported in literature. The residue biomass of B. braunii can be a superior renewable source of syngas or hydrogen.