Development of Co2 Injection Method “cosmos” for Co2 Ocean Storage

Ocean storage of CO2 was proposed by Marchetti as one of greenhouse gas control technologies, where CO2 is captured from flue gas of fossil fuels and injected into deep seafloor below the depth of 3500m to be sequestered from the atmosphere as shown in Fig. 1. In the last decade of the twenties century, there was a great progress in study on the ocean storage. Aya and his colleagues and Nishikawa and his colleagues 4 reported the stability of liquid CO2 drops covered with CO2 hydrate films under deep-sea conditions. Shindo and his colleagues 6 proposed a mechanism of formation of CO2 hydrate at the interface between liquid CO2 and water to simulate the effect of CO2 hydrate films on CO2 dissolution. Ohsumi and his colleagues simulated the dissolution of CO2 stored on deep seafloor. Hirai and his colleagues 9 and Teng and Yamasaki 11 reported dissolution rate of CO2 hydrate films in deep sea. Brewer and his colleagues 13 carried out small scale field experiments of liquid CO2 releasing to observe the behavior of released CO2 droplets and to measure pH change nearby CO2. Tamburri and his colleagues reported the influence of CO2 on deep-sea animals.