What Is a Super Critical Fluid?

What is a Super Critical Fluid?

As defined by several chemists around the world, a Super Critical Fluid is a substance that can either be a liquid or a gas that is determined by the state above its critical temperature and its critical pressure, where gases and liquids can coexist. It displays unique properties that are different from the standard conditions of other gases or liquids. The critical point of a super critical fluid represents the highest temperature and pressure at which the substance can exist as a vapor or a liquid in its equilibrium.

Most chemists refer to a diagram similar to this one when they are referring to super critical fluids, such as water and carbon dioxide. (See the Figure below).

Using spectroscopic techniques such as laser flash photolysis, pulse radiolysis and time-resolved fluorescence spectroscopy, chemists have measured the effects of temperature and pressure on a wide variety of reactions in supercritical carbon dioxide and super critical water. Through this process, the chemists found different types of reactions, such as hydrogen abstractions and esterifications that follow the similar mechanisms of liquids and they occur at reasonable rates of carbon dioxide. These chemists are trying to find several ways to stabilize the reactions and use it in soluble materials. (The University of Notre Dame Chemical Engineering testing).

A super critical fluid also has the gaseous property to penetrate anything and the liquid property of being able to dissolve materials into several different components. Also, the super critical fluids proposes the advantage of the ability to change density to a great extent in a continuous manner. Due to this fact, the use of carbon dioxide and water, two of the several types of super critical fluids, offers a form of an organic solvent substitute, which in turn is used in the food and health industry.

Super critical fluids like carbon dioxide and water are especially beneficial replacements for organic solvents containing various types of hazardous toxins. By changing the temperature and pressure while adding small amounts of co-solvents, these two environmentally friendly substances will create vast majorities of organic solvents that would be safely used in food and health industries.

In fact, supercritical carbon dioxide is used commercially for the decaffeination of coffee and tea. It is also used in a wide variety of natural oils, spices, flavors and fragrances. Super critical carbon dioxide and water not only is used for consumer purposes, these super critical fluids can be used in the specialty of extractions, such as the removal of metals from soils, the removal of uranium from the ore, the removal of sludge, and aqueous waste streams.

While super critical fluids are important to the world of chemistry, it is also very essential for the environment and the economy. Several harmful