Reformer and fuel cell system control and method of operation

A transient-capable steam reformer for producing hydrogen from a hydrogen-containing feedstock, comprising:

• at least one catalyst bed containing a catalyst in thermal communication with an least one burner for producing reformed gases containing hydrogen;
• means for measuring the temperature of at least one of the catalyst or catalyst bed, gases exiting or downstream of the catalyst bed, or gases exiting or downstream of the burner;
• an at least one feedstock delivery means;
• and
• a controller responsive to the measured temperature and configured to control the delivery of the feedstock such that the burner maintains the catalyst bed at a temperature sufficient to support transient operation of the reformer from a starting hydrogen output level of less than 20% of a maximum rated hydrogen output, to a requested hydrogen output rate which is over 75% of the maximum rated hydrogen output, where the requested hydrogen output rate is supplied over the duration of a transient period during which the requested hydrogen output rate increases.

A transient-capable steam reformer for producing hydrogen from a hydrogen-containing feedstock, comprising:

• at least one catalyst bed containing a catalyst in thermal communication with an least one burner, for producing reformed gases including hydrogen;
• means for measuring the temperature of at least one of the catalyst or catalyst bed, gases exiting or downstream of the catalyst bed, or gases exiting or downstream of the burner;
• means for separating hydrogen from the gases produced at the catalyst bed,
• an at least one feedstock delivery means;
• means for measuring the pressure of the hydrogen exiting the hydrogen separation means;
• and
• a controller responsive to the measured temperature and the measured hydrogen pressure, and configured to control the delivery of the feedstock such that the burner maintains the catalyst bed at a temperature sufficient to support transient operation of the reformer from a starting hydrogen output level of less than 20% of a maximum rated hydrogen output, to a requested hydrogen output rate which is over 75% of the maximum rated hydrogen output, where the requested hydrogen output rate is supplied over the duration of a transient period during which the requested hydrogen output rate increases, and the controller is further configured to maintain a feedstock delivery rate sufficient to maintain the pressure of the hydrogen exiting the hydrogen separation means above a minimum hydrogen output pressure during the transient period.