Supercritical carbon dioxide

A supercritical fluid is a substance at a temperature and pressure above its critical temperature and pressure. The critical point represents the highest temperature and pressure at which the substance can exist as a vapour and liquid in equilibrium. It has the unique ability to diffuse through solids like a gas, and dissolve materials like a liquid. Additionally, it can readily change in density upon minor changes in temperature or pressure. These properties make it suitable as a substitute for organic solvents.

Carbon dioxide usually behaves as a gas in air or as a solid called dry ice when frozen. Above its critical temperature and pressure, it behaves like a supercritical fluid and can adopt properties midway between a gas and a liquid.

Supercritical carbon dioxide is for instance used by coffee manufacturers as a decaffeinating solvent, because of its low toxicity and environmental impact..

Source: GreenFacts

Carbon dioxide (CO₂) - Supercritical & Ultra-supercritical technology

Español: Dióxido de carbono supercrítico
Français: Dioxyde de carbone supercritique
Nederlands: Superkritisch koolstofdioxide

CO2 Capture & Storage