Proposal and fundamental analysis of thermally regenerative fuel cell utilizing solar heat

Abstract

In Japan, it is difficult to obtain high-temperature heat continuously from the Sun. However, it is easy to obtain low-temperature solar thermal energy. In order to use such low-temperature solar energy, the authors propose the use of a thermally regenerative fuel cell operated by solar energy. It is a direct energy conversion process which consists of 2-propanol dehydrogenation at the negative electrode, acetone hydrogenation at the positive electrode and an electrolyte sandwiched by both electrodes. By means of a combination of chemical reactions and fuel cells, it can convert low temperature thermal energy (like solar thermal energy) into electrical energy directly. In order to make clear the characteristics of their proposed cell, the authors use molecular hydrogen as the proton source instead of 2-propanol. The activity of a ruthenium and platinum composite catalyst-supported carbon plate for acetone hydrogenation at 363 K is higher than that of a ruthenium or platinum mono-metallic catalyst-supported carbon plate. The activity of ruthenium and platinum composite catalyst-supported carbon felt or carbon cloth is much higher than carbon-plate-supported catalysts. The authors adopted a ruthenium and platinum composite catalyst supported carbon felt or cloth as electrodes of the cell and examined its characteristics.