The syngas that is produced from waste biomass often has high levels of CH4 and CO2, which are greenhouse gases. This investigation presents an integrated gasification and catalytic reforming process with a closed gas loop that can improve quality of syngas from corn straw and mitigate CH4 and CO2 emission. The effects of the support type, reforming temperature, steam-to-biomass (S/B) ratio, and catalyst-to-biomass ratio (C/B) ratio on gas yield and composition were experimentally examined with waste corn straw as the feedstock gasified at 850 degrees C in the proposed closed-loop apparatus. Reformation of syngas using Ni/gamma-Al2O3 at 850 degrees C, S/B = 1 and C/B = 0.5 yielded 1.16 m(3)/kg of syngas, which contained 48.5% H-2, 33.9% CO, 12.2% CO2 and 5.3% CH4, corresponding to 71.0% and 81.5% enhancements of the first two and -77.8% and -58.1% reductions of the last two components.