What is a supercritical fluid?

Supercritical fluid is a substance that has been heated over its critical point. The critical point of the substance is the point where the critical pressure and the critical temperature coexist, allowing the substance to exist in its liquid and gaseous form in balance. As a result of the acceptance of the substance behind this point, the liquid, which has the dissolved properties of the liquid but the diffusion properties of the gas. This means that it can dissolve substances as a liquid and at the same time expand to fill the container like gas. These unique properties allow you to use in different industries. In order to become supercritical, one must know the critical temperature and critical pressure. Normally, the gas can be converted into a liquid at a high temperature with the addition of pressure and the liquid at high pressure can turn into gas with the addition of heat. A critical pressure is a pressure over which a substance cannot exist as a gas, despite how high the temperature is. Similarly, the critical temperature is a point over which the substance cannot be a liquid, although the pressure is high.

When a substance is heated above the critical temperature and is under pressure above critical pressure, an interesting phenomenon occurs. The substance cannot be either liquid or gas. Rather, it has the properties of both. The lines between the phases of the mass virtually disappear and the fluid changes the properties. The new supercritical fluid has the properties of liquid and gas.

One supercritical fluid that is often used is carbon dioxide. It is a good substance that turns into supercritical fluid because its critical temperature is 87.8 ° F (31 ° C) and its critical pressure is 73 atmosphere (about 55,480 mm Hg). For example, pressure manipulation may change which the substances dissolve in the liquid. Since carbon dioxide is a non -polar molecule, modifiers can be added to increase its ability to dissolve the polar molecules.

someThe supercritical fluid can be used to extract a larger amount of the required substance in a shorter period of time. These and other features allow them to use in a large range of industries. For example, the food and pharmaceutical industry can use fluid to extraction of certain food compounds. Using supercritical fluid, such as carbon dioxide, the scientist can extract fatty acids, oils and antioxidants without the chemical rest on the extract. Supercritical carbon dioxide also has a relatively low temperature, so it can be used in cases where chemicals cannot be exposed to high heat.