Patent ID: 7267899

Claim:
A method of improving the efficiency of an electrochemical fuel cell system of the type having a fuel supply for delivering a hydrogen rich fuel stream through a fuel supply conduit to a fuel cell stack, said method comprising the steps of: providing an impurity sensor carried by said fuel supply conduit communicating with said fuel stream passing therein for detecting impurities in said fuel stream; detecting the presence of impurities in said fuel stream passing through said fuel supply conduit; providing a pressure adjusting mechanism operatively associated with said fuel cell and communicating with said impurity sensor, wherein said pressure adjusting mechanism is operative to generate pressure within said fuel cell to raise said normal operating pressure of said fuel cell to an elevated operating pressure; and, activating said pressure adjusting mechanism in response to detecting said said impurities to raise the pressure of said fuel cell to said elevated operating pressure before said impurities enter said fuel cell; whereby, raising said normal operating pressure of said fuel cell to said elevated operating pressure before said impurities enter said fuel cell resists binding of said impurities within said fuel cell to maintain efficient electricity production.