Study on hydrogen-rich gas production by biomass catalytic pyrolysis assisted with magnetic field

•The biomass catalyst pyrolysis is assisted by a magnetic field.•10 wt.% Ni/CaO with magnetic property has the favorable catalytic ability.•The liquid yield is decreased and the gas yield is increased by magnetic field.•The H2 content and yield increased significantly to 62.2 vol.% and 469.22 mL/g.