Reviewing the factors affecting regenerative molten carbonate fuel cells

Abstract

To evaluate the possibility to use molten carbonate fuel cell technology for high temperature electrolysis, the factors affecting the electrode reactions have been examined by surveying the published literature. The literature results showed that H2, CO2 and CO evolved as cathode off-gases and O2 as anode gas. At low polarisation, the discharge of oxide ions to O2 was the only anodic process; increasing polarisation and current densities, the discharge of carbonate ions contributed to the anodic reaction and CO2 was concurrently produced at the anode. Molten Li2CO3 at 850°C–900°C readily absorbed the produced CO2 (the CO2 concentration in the anode compartment was lower than 0.5%). In this condition, titanium cathode enhanced CO production. The co-production of CO represents a serious disadvantage to power a polymer electrolyte membrane fuel cell. On the other hand, the production of syngas could offer attractive applications such as synfuel production and carbon dioxide regeneration.