Masamitsu Takabatake

Development of a small temperature difference generator by using the dissociation and expansion characteristics of a CO 2 hydrate

The introduction of distributed generation systems using renewable energy has been advancing in Japan mainly driven by the influence of the Fukushima Daiichi nuclear accident. In this work, a distributed energy system which exploits the unique state-change property of a CO2 hydrate through a heat cycle is proposed. The proposed system is environmentally friendly because no fossil fuel is burnt and no carbon dioxide is emitted to the atmosphere. Furthermore, the inputs of heat energy are supplied by renewable sources such as the outdoor cold air and the geothermal heat, as cold and hot mediums, respectively. In this study, we determined the characteristics of the output of the proposed generation system by experiments performed in a prototype constructed in our laboratory. As a result, a maximum power output of 30W and a maximum efficiency of 2.15% were obtained.

Investigation of the heat cycleq of a CO2 hydrate using plate type heat exchangers

In cold climates, the high heat demand during winter calls for an especial attention on the development of new generation systems with low impact on the environment. Due to this, the development of a clean CO2 hydrate generation system which operates utilizing the expansion characteristics of the CO2 hydrate without burning any type of fossil fuels, and utilizing only the outdoor temperature of the cold district is being undertaken. To develop this type of clean generation systems, in this work, the basic characteristics of the thermal cycle of a CO2 hydrate is investigated by analyzing the pressure characteristics due to the internal temperature changes when the CO2 hydrate undergoes generation and dissociation processes by utilizing plate type heat exchangers for these processes.