Patent ID: 8263814

Claim:
A method for extracting ethanol from an ethanol-water solution comprising: a) mixing an ethanol-water solution with a first solvent comprising an esterified fatty acid, wherein the esterified fatty acid comprises a hydroxylated fatty acid component and an alcohol component such that the alcohol component is a C 3-6 alcohol, wherein the distribution coefficient for ethanol in the mixture of the ethanol-water solution and the first solvent is at least 0.02 favoring the transfer of ethanol from the ethanol-water solution to the first solvent, thereby extracting the ethanol from the ethanol-water solution into the first solvent; b) separating the first solvent and the ethanol-water solution; c) contacting the first solvent with carbon dioxide, wherein the carbon dioxide is at a liquid or near supercritical phase, wherein the distribution coefficient for ethanol in a mixture of the first solvent and the carbon dioxide is at least 0.1 favoring the transfer of ethanol from the first solvent to the carbon dioxide, thereby extracting the ethanol from the first solvent into the carbon dioxide; and d) converting the carbon dioxide to vapor phase, thereby releasing the ethanol from the carbon dioxide, yielding a solution of greater ethanol concentration than the ethanol concentration in the starting ethanol-water solution.