- Research and Development
- 2020.09.27
Technology for reusing heat by using a chemical heat storage material
We have developed a material that stores heat by using a chemical technology without using complicated equipment. The technology makes it possible to use heat energy efficiently.


What is the technology for reusing heat by using a chemical heat storage material?
We have been developing technologies for reusing waste heat. Calcium oxide, which is a familiar desiccant for dried nori seaweed, is used as the heat storage material. Calcium oxide does not generate heat by itself and can be stored at normal temperature. However, it reacts violently with water and turns into calcium hydroxide by generating heat of 500°C (heat release). When calcium hydroxide is heated, it returns to calcium oxide due to dehydration (heat storage). We aim to achieve commercial applications by using the reversible characteristics.
Click/tap here to watch a video that shows the characteristics of the technology.

What are the key features of this technology?
Calcium oxide is a fine powder just like flour. When it is used on a large scale, it is very difficult to allow water, which is used for heat generation, to uniformly infiltrate into the entire powder. We have developed a technology to form the powder into granules. Many pores help water infiltrate to fully demonstrate the inherent heat generation potential. The forming technology was developed by applying the technology for designing silicate-based inorganic paints, which was refined over many years of operation. The condition of granules can be maintained even when the cycle of heat generation and heat storage is repeated.

Contribution to solving social issues
Fossil resources are burned 24 hours every day to obtain thermal energy required for our daily lives. No matter how the combustion efficiency is increased, carbon dioxide is emitted in proportion to the amount of energy produced. As the global energy demand has been increasing, environmentally friendly energy is required in large quantities. Most of such energy is used for heating, but humankind is not good at using energy efficiently. A large amount of high-temperature heat, which is still usable, is wasted. The chemical heat storage technology helps improve the heat utilization technology and thereby contributes to reducing the consumption of fossil fuels.