(US5346779-A)      A raw material gas is reformed with steam to a fuel gas which is fed to a fuel electrode of a fuel cell for power generation. A main reformer is provided for reforming the raw material gas to the fuel gas. A fuel cell receives the fuel gas to cause the power generation and to produce steam. A second reformer is provided for reforming with the steam non-reformed raw material gas discharged from the fuel electrode. The second reformer includes a cylindrical or tubular main body. An entrance for the gas discharged from the fuel electrode is formed at one end of the main body, and an exit for the gas is formed at the other end of the main body. The reforming catalyst is placed in a space between the gas entrance and exit, and a lid is provided at one or both ends of the main body for loading and unloading of the reforming catalyst.    Alternatively, the reforming catalyst is divided into several blocks in the main body of the second reformer so that a block which is damaged by a carbonate is replaceable by new one. The second reformer may have a double-cylinder structure. The reforming catalyst is placed in an inner cylinder or in space between the inner and outer cylinders. The inner cylinder or the space which does not carry the reforming catalyst is used as a passage for discharging the gas from the second reformer, and one end of the inner cylinder is communicated with one end of the outer cylinder.    (EP575883-B1)      The reforming method involves feeding the raw material gas to a main reformer (1) to reform the gas to fuel gas (FG). Feeding the fuel gas to the fuel electrode (3) of the fuel cell (I). Introducing to a second reformer (5) non-reformed raw material gas contained in the gas discharged from the fuel electrode.    Reforming the gas with hydrogen produced by a reaction at the fuel electrode and a sensible heat of the gas discharged from the electrode, thereby reducing the amount of non-reformed raw material gas. The raw material gas is a hydrocarbon such as methane.    ADVANTAGE -   Reduces amount of non-reformed raw material gas in system and improves reforming conversion ratio of system as a whole.