Hydrogen-rich gas was produced from Citrullus-lanatus in a fixed-bed reactor using a novel Ni/dolomite/MgO/ γ − Al 2 O 3 with air-steam mixture as the gasifying agent. The feed and steam-air flow rates were 3 and 0.8 kg/h with fixed steam-air volume-concentration of 40% v/v. The results displayed a high cracking activity of the hydrocarbons/tar in the biomass by the catalyst with a resultant upgrade in the gas quality/H 2 yield. The highest H 2 yield was 66.1 g/kg biomass, a minimal tar concentration of 2 g/Nm3 with steam-to-biomass ratio of 2 at 1100 °C. The highest H 2 yield (57 vol%) was achieved at 0.28 equivalence ratio. [Display omitted] • Egusi melon seed shells were dehulled and gasified for hydrogen production. • A novel 2 wt% Ni/dolomite/MgO/ γ − Al 2 O 3 catalyst was employed in the gasification process. • The optimum hydrogen gas production was received for ER of 0.28 and a temperature of 1100 °C. • The highest quantity of hydrogen produced was 66.1 g H 2 /kg biomass.