Development of Energy Storage Device by CO₂ Hybridization of CO₂ Heat Pump Cycle and CO₂ Hydrate Cycle

In recent years, the spread of power generation using renewable energies has been expanding toward carbon neutrality by 2050, with the introduction of solar power, wind power, and other forms of power generation[1]. However, renewable energy power generation is easily affected by weather conditions, and storage devices are needed to ensure a stable power supply. Therefore, the development of energy storage devices that are low-cost and have a small environmental impact is a very important issue [2] [3]. CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> hydrates are formed at around 0°C and dissociate at around 3~5 MPa at 10~20°C, making them a promising storage method for high-density, high-pressure CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> gas. In this study, CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> is compressed by a compressor using electricity generated by renewable energy sources such as solar power. The compressed CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> is then fed into a reaction vessel containing water to produce CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> hydrate. The heat source required in the process of the system is atmospheric heat or waste heat from factories. In this study, we manipulate temperature and pressure to conduct CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> hydrate generation experiments, aiming to elucidate the relationship between the amount of CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> hydrate generated and agitation through experimental methods.