Patent ID: 7713318

Claim:
A method of operating a hydrogen generator including: a reformer having a reforming catalyst configured to cause a source material and water to react with each other to generate a hydrogen-rich reformed gas; a reformer heater configured to heat said reformer; a carbon monoxide reducing portion having a carbon monoxide reducing catalyst configured to reduce carbon monoxide contained in the reformed gas; a carbon monoxide reduction heater configured to heat at least one of said carbon monoxide reducing portion, the carbon monoxide reducing catalyst and the reformed gas passing through said carbon monoxide reducing portion; and a reformer temperature sensor configured to detect a temperature of said reformer, said method comprising: in a stop operation period, stopping supply of the source material and water to the reformer; in a state in which the supply of the source material and the water to the reformer is stopped, heating said carbon monoxide reducing portion by operating said carbon monoxide reduction heater such that a temperature of said carbon monoxide reducing portion is kept higher than a first predetermined temperature which fails to allow steam present within said carbon monoxide reducing portion to condense; then supplying the source material to purge an interior of the hydrogen generator when the temperature detected by said reformer temperature sensor becomes a temperature which fails to allow carbon to be deposited on the reforming catalyst; and then stopping the supply of the source material and the operation of said carbon monoxide reduction heater.