Recovery of fatty acids from dilute aqueous solutions

Claim 1

A PROCESS FOR SEPARATING AND DEHYDRATING A MIXTURE OF C2 THROUGH C4 FATTY ACIDS PRESENT IN A DILUTE AQUEOUS SOLUTION WHICH COMPRISES THE STEPS OF EXTRACTING THE ACIDS WITH A HIGH BOILING POLAR OXYGENATED ORGANIC SOLVENT AS THE EXTRACTANT, SAID HIGH BOILING POLAR OXYGENATED ORGANIC SOLVENT HAVING GOOD EXTRACTIVE CAPACITIES FOR C2 AND C3 FATTY ACIDS, LIMITED SOLUBILITY IN WATER AND A MINIMUM BOILING POINT OF 160*C.; RECOVERING THE POLAR ORGANIC SOLVENT EXTRACT PHASE CONTAINING POLAR ORGANIC SOLVENT, WATER, AND EXTRACTED ACIDS; FLASH HEATING THIS EXTRACT PHASE AT APPROXIMATELY ATMOSPHERIC PRESSURE TO VAPORIZE OFF A MAJOR PROPORTION OF THE WATER AND ONLY A MINOR PROPORTION OF THE POLAR ORGANIC SOLVENT AND ACIDS CONTAINED THEREIN; DISCHARGING THE PREDOMINANTLY ACID SOLVENT MIXTURE BOTTOMS FROM THE FIRST FLASH HEATING ZONE; SUBJECTING THE THUS DISCHARGED ACID SOLVENT MIXTURE TO A SECOND FLASH HEATING AT RDUCED PRESSURE TO VAPORIZE A SUBSTANTIAL QUANTITY OF THE RESIDUAL WATER CONTAINED THEREIN AND ONLY MINOR AMOUNTS OF ACIDS AND SOLVENTS; DISCHARGING THE RESULTANT MIXTURE OF FLASHED VAPOR AND LIQUID ACID-SOLVENT MIXTURE TO A DEHYDRATION DISTILLATION ZONE; DISTILLING THIS PREDOMINANTLY ACID-SOLVENT MIXTURE AT REDUCED PRESSURE IN THE DEHYDRATION ZONE; TAKING OVERHEAD A VAPOR MIXTURE COMPRISING WATER AND POLAR ORGANIC SOLVENT INCLUDING THE FLASHED VAPOR FROM THE SECOND FLASH HEATING STEP; DISCHARGING A SUBSTANTIALLY ANHYDROUS ACID SOLVENT MIXTURE BOTTOMS FROM THE DEHYDRATION ZONE; DISTILLING OFF THE ACIDS AT REDUCED PRESSSURE FROM THIS ACID SOLVENT MIXTURE.