Fuel cell system containing humidity sensor and method of operating thereof

A fuel cell system, comprising:

• a fuel cell stack that produces an anode exhaust stream;
• an anode recycle blower that receives the anode exhaust stream and outputs an anode recycle stream;
• a humidity sensor configured to measure a steam concentration of the anode recycle stream;
• a carbon dioxide removal system configured to remove carbon dioxide from the anode recycle stream;
• a bypass conduit which bypasses the carbon dioxide removal system;
• a plurality of valves for controlling a flow of the anode recycle stream through at least one of the carbon dioxide removal system and the bypass conduit;
• and
• a master controller configured to receive steam concentration measurement from the humidity sensor and control the operation of the anode recycle blower based on the steam concentration measurement, wherein the master controller is further configured to control the operation of the plurality of valves based on the steam concentration measurement.