Patent ID: 8486167

Claim:
A reformed gas production method of using a reforming catalyst to reform a fuel that contains a plurality of types of hydrocarbons having at least two carbon atoms so as to produce a reformed gas that includes methane, hydrogen, and carbon monoxide, comprising: determining a thermal decomposition temperature of each of the hydrocarbon having at least two carbon atoms that makes up the fuel, the thermal decomposition temperature of the hydrocarbon serving as a temperature that rises as the concentration of the hydrocarbon is lowered; determining a thermal decomposition index temperature of the fuel which is a value of the lowest thermal decomposition temperature of the plurality of types of hydrocarbons that make up the fuel, the thermal decomposition index temperature being determined by the type and the concentration of the hydrocarbon; supplying a fluid that includes the fuel, at least one of a steam-containing gas and a carbon dioxide-containing gas, and an oxygen-containing gas, to a reforming reaction region, and supplying also a hydrogen gas to the reforming reaction region; bringing the hydrogen-containing gas and the oxygen-containing gas to the reforming reaction region for combustion of hydrogen until the temperature of the reforming reaction region reaches an appropriate operation temperature required for reforming of the fuel, so that resultant combustion heat of hydrogen causes the temperature of the reforming reaction region to rise to reach the appropriate operation temperature, thereby to effect a partial oxidization reaction in which the fuel and oxygen are brought into contact with the reforming catalyst to generate reaction heat, as well as a reforming reaction in which the fuel and at least one of the steam and the carbon dioxide-containing gas are brought into contact with the reforming catalyst; and detecting the temperature of the reforming reaction region and referring to the determined thermal decomposition index temperature; wherein if the determined reforming reaction region temperature exceeds said determined thermal decomposition index temperature of the fuel, the method effects a flow rate adjustment of each of said gasses for, increasing a supply ratio of at least one of said steam-containing gas and said carbon dioxide-containing gas relative to a current supply ratio thereof, or decreasing a supply ratio of said oxygen-containing gas relative to a current supply ratio thereof, or controlling a temperature adjusting mechanism to cool said reforming reaction region; thereby to produce the reformed gas under a condition of an upper limit temperature of the reforming reaction region reached by the reaction of heat from the partial oxidation reaction being kept below the terminal decomposition index temperature of the fuel.