Study on solar chemical heat pump system-basic experiment on falling film reaction of 2-propanol dehydrogenation

It is not easy to use solar energy because it has low energy density and is interrupted by passing clouds. Furthermore it is difficult to continuously get high-temperature thermal energy from the Sun under a poor solar condition such as in Japan. However it is easy to get low-temperature thermal energy. Therefore, the authors use a chemical heat pump, which uses endothermic and exothermic reactions, in order to upgrade low-temperature thermal energy obtained from the Sun. They adopted a 2-propanol/acetone/hydrogen system as the chemical reaction. In the endothermic process of this system, improvement of the heat utilization factor was one of the serious subjects to realize this system. In order to solve this problem, the authors made a new type of reactor called a falling-liquid film reactor (FFR) and experimented with the dehydrogenation reaction of 2-propanol. The major result was that the FFR provides four times the heat utilization factor of a conventional liquid-phase suspension reactor does. In this paper, the authors describe the detailed results obtained from the above experiments.