Supercritical Fluids and Clean Separations

Gases at high pressures have been used in the chemical, oil and polymer industries for a long time. The production of low-density polyethylene is a good example of a reaction in a supercritical fluid. Ethylene (critical temperature 9 C) is used as both reactant and supercritical solvent 

The coruiection between supercritical fluids and clean separations is, however, more recent. It appears during the 1970s, when it was shown that supercritical carbon dioxide could become an important extraction solvent for food-related applications. Since then, the field has expanded enormously. A wide range of fundamental studies have been pubhshed and many patents submitted, with potential applications in separation processes, chemistry, and materials science. Many books and reviews have been pubhshed on different aspects of supercritical fluids. 

The scope of this section wiU be strictly Hmited to describing the recent advances in separation and chemical reaction plus separation using carbon dioxide as the main solvent, which, in the authors view, will set the trends in this area for the next few years. 

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