Patent ID: 8524119

Claim:
A method for preparing synthesis gas, comprising: carrying out a combined reforming process of steam and carbon dioxide reforming of natural gas, which reforms natural gas with steam and carbon dioxide simultaneously, on a catalyst obtained by reducing a catalyst for natural gas reforming which reforms natural gas with steam and carbon dioxide simultaneously with hydrogen gas at a temperature of 700-1000° C., under the conditions of a reaction temperature of 850-1000° C., reaction pressure of 0.5-20 atm, space velocity of 1,000-500,000 h −1 , and a molar ratio of CH 4 /H 2 O/CO 2 of 1/1.0-2.0/0.3-0.6, wherein the catalyst comprises Ce/MgAlO x or Ce-Zr/MgAlO x , as a carrier comprising 3-20 wt % based on the carrier of Ce or Ce-Zr, respectively, carried on the MgAlO x having the weight ratio of MgO/Al 2 O 3 within the range of 3/7 to 7/3; and Ni, as an active ingredient, supported on the Ce/MgAlO x or Ce-Zr/MgAlO x carrier in an amount of 5-20 wt % based on the carrier, and has a specific surface area of 80-200 m 2 /g after calcining at a temperature of 600-1000° C.; wherein the combined reforming process provides a CH 4 conversion and CO 2 conversion maintained at 80% or higher and 45% or higher, respectively, and a molar ratio of H 2 (2CO+3CO 2 ) is maintained at 0.85-1.15.