SIMULATING EXPERIMENTS OF CO_2 OCEAN STORAGE WITH A LARGE HIGH-PRESSURE TANK

摘要

The authors carried out simulating experiments of CO_2 ocean storage with a large high-pressure tank to investigate dissolution of CO_2 drops with CO_2 hydrate films, and compared the experimental results with those predicted with Ranz-Marshall's equation. In the experiments, the CO_2 drops were stored in fresh water pressurized at 30MPa in two temperature regions for two days to observe change of drop diameter and to measure pH change in ambient water around the drops. The diameter change in the experiments, where there was no artificial flow, was larger than that predicted under no-flow condition, which implies that the dissolution could be enhanced by slight disturbance around the drops. On the other hand, the pH measurement showed the lowering of pH during the experimental period, and the pH change was depressed at lower temperatures, which agrees with temperature dependency in the dissolution rate predicted.