Abstract: The reforming of CO2, CH4, O2 and He mixture system to syngas was investigated in a continuous flowing fixed-bed reactor. The modified nickel catalysts supported on α-Al2O3 and γ-Al2O3, respectively were used in the reaction. It is found that the volume fraction of syngas obtained increased with the rise of temperature at 500 ℃ to 700 ℃, atmospheric pressure, and the 15% volume fraction of CO2 in feed gas. Compared with γ-Al2O3 supported catalyst, α-Al2O3 supported catalyst possesses a higher activity and selectivity. When α-Al2O3 supported catalyst was used, the presence of oxygen in feed gas promotes the production of syngas and the volume fractions of syngas increase as the volume fraction of O2 increases. Moreover, a lower volume ratio of CO2 to CH4 is conductive to the production of syngas and the conversion of CO2. α-Al2O3 supported catalyst possesses good regenerability. When the volume ratio of CO2 to CH4 is 3:：4 and the volume fraction of O2 is 2.5% in the feed gas, the volume fraction of syngas in product gas reaches 83.82% and the conversion of CO2 is up to 95.05% at atmospheric pressure and 700 ℃.

Key words: flue gas, carbon dioxide, methane, reforming, syngas