Ping-Hsun Hsieh

Molten Carbonate Fuel Cells

Molten Carbonate Fuel Cells (MCFCs) are high-temperature fuel cells that stand at the end of more than 35 years of intensive development and are finding increased application in the field of high-efficiency, clean energy supply. Thanks to their operating principle, they can provide heat and power at overall efficiencies of 90%, and they could also be used in the incumbent large-scale application of carbon capture and sequestration (CCS). Despite continuous improvements in the technology, some crucial issues still call for focused research and development before the MCFC achieves full operational reliability, especially in conversion of waste-derived fuels. In addition, to gain experience and steepen the learning curve leading to market maturity, cost reduction of components and manufacturing processes are a priority.

A Corresponding States Method for the Prediction of Surface Tension of Molten Carbonate Mixtures

A methodology using the theory of corresponding states has been developed to predict the surface tension of molten alkali carbonate mixtures and alkali-alkaline-earth carbonate mixtures as a function of composition and temperature. To correlate the dimensionless surface tension, the parameters for pure components are determined. The potential parameters of pure salt are defined at the melting point with respect to a standard salt. A size-dependent mixing rule is proposed to predict properties of a mixture based on the heats of mixing of molten salts. Selected experimental data of binary mixtures at 40-60 mol % Li are used to fit key parameters. The correlations developed by this method provide very good accuracy for both binary and ternary alkali carbonate mixtures (within 1.5% deviation for ternary alkali carbonates). In alkali-alkaline-earth carbonate mixtures, a similar accuracy is only achieved in the low alkaline-earth fraction range.