CO2 concentrations in a molten carbonate electrochemical cell

The molten carbonate fuel cell is now being investigated as a possible alternative to the aqueous alkaline fuel cell which has been successfully converted into a CO2 concentrator for use in a manned spacecraft. This high-temperature (above 500 C) device has the following potential advantages over the aqueous concentrator: any humidity from 0 to 100% can be tolerated, noble electrodes are not required, and higher current densities appear possible. During the tests of a laboratory-size cell, in both driven and hydrogen modes, high current efficiencies have been achieved, but removal efficiencies have been low. Increasing current improves the removal, but current efficiency drops, which is thought to be due to poor mass transfer characteristics inherent in the small cell. Water vapor in the cathode feed has no effect on electrical or electrochemical performance, and no CO is found in the cathode (cabin) gas stream, nor carbon in the anode