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Near the critical point, small changes in pressure or temperature result in large changes in density, allowing many properties of a supercritical fluid to be "fine-tuned". Supercritical fluids occur in the atmospheres of the gas giants Jupiter and Saturn, the terrestrial planet Venus, and probably in those of the ice giants Uranus and Neptune.
It is called supercritical fluid. The common textbook knowledge that all distinction between liquid and vapor disappears beyond the critical point has been challenged by Fisher and Widom, [8] who identified a p–T line that separates states with different asymptotic statistical properties (Fisher–Widom line).
More specifically, it behaves as a supercritical fluid above its critical temperature (304.128 K, 30.9780 °C, 87.7604 °F) [1] and critical pressure (7.3773 MPa, 72.808 atm, 1,070.0 psi, 73.773 bar), [1] expanding to fill its container like a gas but with a density like that of a liquid. Supercritical CO
Non ideal compressible fluid dynamics (NICFD), or non ideal gas dynamics, is a branch of fluid mechanics studying the dynamic behavior of fluids not obeying ideal-gas thermodynamics. It is for example the case of dense vapors , supercritical flows and compressible two-phase flows .
For any temperature below the critical point, the density of the gas will be less than that of the liquid. At the critical point, the density of the liquid and gas phases are identical and the compound becomes a supercritical fluid. [1]
This reflects the fact that, at extremely high temperatures and pressures, the liquid and gaseous phases become indistinguishable, [3] in what is known as a supercritical fluid. In water, the critical point occurs at around T c = 647.096 K (373.946 °C), p c = 22.064 MPa (217.75 atm) and ρ c = 356 kg/m 3 .
Supercritical water has a density between that of water vapor and liquid at standard conditions, and exhibits high gas-like diffusion rates along with high liquid-like collision rates. In addition, the behavior of water as a solvent is altered (in comparison to that of subcritical liquid water) - it behaves much less like a polar solvent.
The supercritical solvent is passed into a vessel at lower pressure than the extraction vessel. The density, and hence dissolving power, of supercritical fluids varies sharply with pressure, and hence the solubility in the lower density CO 2 is much lower, and the material precipitates for collection. It is possible to fractionate the dissolved ...