degasification changes carbon dioxide gas back into carbon in solid form.
degasification changes carbon dioxide gas back into carbon in solid form.
what changes carbon dioxide gas back into carbon in solid form?
degasification
atmospheric carbon dioxide plays an integral role in the earth's carbon cycle whereby carbon dioxide is removed from the atmosphere by some natural processes such as photosynthesis and deposition of carbonates, to form limestones for example, and added back to the atmosphere by other natural processes such as respiration and the acid dissolution of carbonate deposits. there are two broad carbon cycles on earth: the fast carbon cycle and the slow carbon cycle. the fast carbon cycle refers to movements of carbon between the environment and living things in the biosphere whereas the slow carbon cycle involves the movement of carbon between the atmosphere, oceans, soil, rocks, and volcanism. both carbon cycles are intrinsically interconnected and atmospheric gaseous carbon dioxide facilitates the carbon cycle.
carbon dioxide in earth's atmosphere
carbon dioxide ocean storage can occur through solid or solid hydrate of carbon dioxide. the solid state density of carbon dioxide is approximately 1.5 times greater than seawater and thus tends to sink to the ocean floor. the dissolving rate at the surface is about 0.2 cm/hr such that a small quantity of carbon dioxide can be completely dissolved before reaching the sea floor. in addition to solid 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 forms hydrate cap, forcing liquid carbon dioxide to only move laterally. the overall molecular stability relies on the temperature and pressure of the environment, and hydrates only dissociate when placed in direct contact with additional heat and water at concentrations below its equilibrium concentration. however, due to its crystalline structure, pure hydrate doesn't travel through pipes. given that 100% efficiency is extremely difficult to achieve, in reality, both laboratory and field experiments suggest that sinking reaction efficiency is approximately 15-25%. any kind of instability of hydrates is likely to cause dissolution and dispersion during the descending or injection process.
ocean storage of carbon dioxide