Carbon dioxide solvents such as organochlorides. It is used by some dry cleaners for this reason (see green chemistry). It is used in the preparation of some aerogels because of the properties of supercritical carbon dioxide. Plants require carbon dioxide to conduct photosynthesis. The atmospheres of greenhouses may (if of large size, must) be enriched with additional to sustain and increase the rate of plant growth. At very high concentrations (100 times atmospheric concentration, or greater), carbon dioxide can be toxic to animal life, so raising the concentration to 10,000 ppm (1%) or higher for several hours will eliminate pests such as
Ocean storage of carbon dioxide injection, carbon dioxide hydrate is another popular method for storage. Hydrate formation takes place when the dissolved concentration of liquid carbon dioxide is around 30% and 400 meters below sea level. Hydrates form as an external layer around liquid carbon dioxide droplets or as a solid mass. The molecular composition is composed of carbon dioxide and water, carbon dioxide•nHO (n ≈ 5.75). The resulting density is denser than seawater by approximately 10%. Compared to liquid carbon dioxide, the hydrate form dissolves significantly slower in seawater, at about 0.2 cm/hr as well. Additionally, the hydrate remains immobile on the seafloor and