An ejector receives steam at a primary inlet and natural gas at a secondary inlet. A computer responds to a signal indicating current in the load of a fuel cell as well as a signal indicating temperature of a steam reformer to move a linear actuator to control a needle that adjusts the size of the steam orifice. Reformate is fed to a separator scrubber which cools the reformate to its dew point indicated by a sensor. From that, a controller generates the fuel/carbon ratio for display and to bias a signal on a line regulating the amount of steam passing through an ejector to the inlet of the reformer. Alternatively, the reformate may be cooled to its dew point by a controllable heat exchanger in response to pressure and temperature signals.