Patent ID: 6884911
Filing Date: 2005-04-26
Classification: B01D

Abstract:
1. A method for processing a solute comprising the steps of: (a) dissolving said solute, or a portion of said solute, in a liquid solvent that has an affinity for the solubilization of said solute, thereby forming a solvent/solute liquid phase; (b) dissolving a gaseous fluid in the solvent/solute liquid phase to form a solvent/solute/gaseous fluid liquid phase; (c) causing the solvent/solute/gaseous fluid liquid phase to expand through a retention medium comprising a filter that can retain unsolubilized solute particles; (d) causing the gaseous fluid to be dissolved to a concentration such that the solvent/solute/gaseous fluid liquid phase expands until it loses its affinity for the solubilization of said solute and said solute precipitates; (e) retaining precipitated solute on a retention medium comprising a filter, which retention medium is the same as the retention medium used in step (c) or is a different retention medium; (f) reducing the pressure in the liquid phase to a point where a substantial amount of the gaseous fluid is expelled so as to provide a resultant liquid phase having an affinity for the solubilization of said solute; and (g) optionally adding more solute to the liquid phase produced in step (f); and further comprising repeating steps (a) through (f) one or more times, or repeating steps (a) through (g) one or more times; and wherein the gaseous fluid is selected from carbon dioxide, nitrous oxide, trifluoromethane, ethane, ethylene, propane, sulfur hexafluoride, propylene, butane, isobutane, pentane, and mixtures thereof.