| abstract |
A fluid extractant, and a process and apparatus for using the extractant to separate an organic liquid from an aqueous mixture. The extractant comprises a first fluid solvent which is a gas in its near-critical or supercritical state and a cosolvent. A preferred first fluid solvent is near-critical liquid carbon dioxide. Preferred cosolvents are 2-ethyl hexanol for ethanol extraction, and hexanoic acid for acetic acid extraction. Organic compounds such as monohydric alcohols, monoacids, ketones, ethers, aldehydes and esters can be recovered from dilute aqueous solutions more economically than possible by prior art processes of distillation. |