Patent ID: 8758950

Claim:
A fuel cell system comprising: a reforming unit configured to subject a mixed gas containing a raw gas and steam to a reforming reaction by a reforming catalyst, thereby generating a reformed gas containing hydrogen; a carbon monoxide decreasing unit configured to allow the reformed gas generated by the reforming unit to contact a carbon monoxide decreasing catalyst, thereby decreasing carbon monoxide contained in the reformed gas; a fuel cell configured to generate electric power by hydrogen contained in the reformed gas passed through the carbon monoxide decreasing unit; a burner unit configured to burn at least one of an off-gas containing hydrogen not consumed in the fuel cell, the raw gas and the reformed gas using combustion air; a raw gas supply device configured to supply the raw gas to the reforming unit and the burner unit directly or through the reforming unit; a heating unit configured to perform a heating operation for at least one of the reforming catalyst and the carbon monoxide decreasing catalyst; and a control unit configured to control the heating unit at a start-up operation of the fuel cell system, so as to adjust an amount of a desorbed raw gas desorbed out of components of the raw gas adsorbed to at least one of the reforming catalyst and the carbon monoxide decreasing catalyst such that a ratio of an amount of the combustion air to an amount of the raw gas in the burner unit falls within a predetermined range.