Fuel cell system

DETAILED DESCRIPTION In accordance with the principles of the present invention, the above and other objectives are realized in an internally reforming fuel cell system of the above-described type wherein the gas exhausted from the anode section of the fuel cell of the system is applied to a gas separation means, and wherein the gas separation means acts to remove unused fuel process gas from the exhaust gas to the exclusion of other gas constituents.
The removed fuel process gas, no longer diluted by the other gas constituents, is then applied as input fuel process gas to the anode section of a fuel cell.
The fuel cell system thus experiences a higher overall utilization of its fuel process gas.
Removal of unused fuel process gas from the anode exhaust gas also reduces the dilution effects caused by the unused process gas on the other constituents contained in the exhaust gas.
This is extremely beneficial where the fuel cell system employs a molten carbonate fuel cell since the exhaust gas now contains substantial amounts of fuel-free, undiluted carbon dioxide which can be fed to the cathode section of the molten carbonate cell at a higher partial pressure.
In a further aspect of the invention, the separation means employed to separate the process gas is a gas transfer device.
A preferable, gas transfer device is an electrochemical cell such as, for example, a phosphoric acid fuel electrochemical cell.
In yet a further aspect of the invention, a shift reactor is placed forward of the separation means to increase the amount of available unused fuel process gas in the anode exhaust gas.