Tippawan P., Assabumrungrat S., Arpornwichanop A., 2014, Theoretical Study on the Ethanol-Fueled SOFC System Integrated with Dehumidifier, Chemical Engineering Transactions, 39, 1465-1470.
A solid oxide fuel cell (SOFC) fuelled by ethanol, an attractive green fuel that can be renewably produced from agricultural products, is regarded as a promising clean process to generate electricity with high efficiency. However, the direct feeding of ethanol to SOFC always causes a carbon formation problem. The use of an external steam reformer to convert ethanol into hydrogen for SOFC is another choice. In general, more steam is introduced to the reformer to obtain the hydrogen-rich gas product. This operational strategy may degrade the SOFC performance due to the dilution effect caused by the excess steam. In this study, the effect of removing steam from the reforming gas before it enters a cell stack on the electrical efficiency of SOFC is investigated. The minimization of total Gibbs free energy is employed to determine the equilibrium compositions of a hydrogen-rich gas from the ethanol steam reforming process. The electrical characteristics of the SOFC are evaluated by using the generalized, steady state electrochemical model taking all various voltage losses into account. An internal reforming of CH4 and CO in the SOFC stack is also considered. Performance of the steam reformer and SOFC integrated system with and without a dehumidifying unit is compared and analysed with respect to key operating parameters.
