TECHNOLOGY FOCUS - CHEMICAL ENGINEERING - Preferred Method: The fuel is reformed at 300-800 degrees C in the autothermal reforming reactor, and the remaining unreacted fuel is subjected into steam reforming reaction at 600-800 degrees C in the steam reforming reactor. The first and second reformed gas can be further subjected into deoxygenation reaction at 100-500 degrees C using at least one deoxygenation reactor (131, 132) connected to the autothermal reforming reactor or steam reforming reactor to remove the oxygen content in the first and second reformed gas. The water-gas shift reaction can be performed at (i) 250-450 degrees C in the water-gas shift reaction unit comprising a noble metal catalyst containing platinum, rhenium and/or copper; and a catalyst carrier containing aluminum oxide, cerium oxide, cerium dioxide, zirconium oxide, and/or zirconium dioxide; or (ii) 200-450 degrees C in the water-gas shift reaction unit comprising a base metal catalyst and a catalyst carrier containing copper-zinc-aluminum oxide or iron-chromium-aluminum oxide. The selective oxidation reaction is performed at 100-200 degrees C. The oxygen gas-to-carbon (O2/C) mole ratio in the fuel supply is reduced when the temperature at the discharge port of the autothermal reforming catalyst reaches 550-650 degrees C. The heating unit provides heat by operating it with the burner for burning at least part of the fuel supply or the second output gas having carbon monoxide concentration of higher than 20 ppm, or by employing exothermic oxidation reaction with catalyst.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The fuel supply also includes water and air. The autothermal reforming reactor includes autothermal reforming catalyst comprising a noble metal catalyst containing rhodium and/or platinum; and a catalyst carrier containing aluminum oxide, cerium oxide, cerium dioxide, zirconium oxide and/or zirconium dioxide. The steam reforming reactor includes steam reforming catalyst comprising a noble metal catalyst containing ruthenium, palladium, rhodium, and/or platinum; and a catalyst carrier containing aluminum oxide, cerium oxide, cerium dioxide, zirconium oxide and/or zirconium dioxide. The deoxygenation reactor includes a noble metal catalyst containing palladium, rhodium, and/or platinum; and a catalyst carrier containing aluminum oxide, cerium oxide, cerium dioxide, zirconium oxide and/or zirconium dioxide. The selective oxidation reaction unit includes a noble metal catalyst containing platinum and/or ruthenium; and a catalyst carrier containing aluminum oxide, cerium oxide, cerium dioxide, zirconium oxide, zirconium dioxide, and/or zeolite. The concentration of carbon monoxide in the second output gas obtained from the selective oxidation reaction unit is less than 20 ppm.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The fuel supply includes a fuel mixture comprising fossil material such as natural gas, alcohol, liquefied petroleum gas, kerosene or diesel; or renewable resource such as methane produced from anaerobic reaction or alcohol fermented from biomass energy resources.