Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 14, 2005
Publication Date: February 20, 2006
Citation: Offeman, R.D., Stephenson, S.K., Robertson, G.H., Orts, W.J. 2006. Solvent extraction of ethanol from aqueous solutions using biobased oils, alcohols and esters. Journal of the American Oil Chemists' Society. 83: 153-157. Interpretive Summary: Currently the energy required to distill a gallon of ethanol from a fermentor and dehydrate it is equivalent to 18-22% of the fuel value of a gallon of ethanol. Solvent extraction is a less energy-intensive alternative to distillation. This paper is the third in a series that searches for better solvents for recovering ethanol from aqueous solutions, and seeks to develop a better understanding of solvent molecular properties that enhance extraction. This paper examines the ethanol extraction performance of several vegetable oils and their derivatives. Improvements in extraction solvents could lead to reduction in energy required to produce ethanol from grain and biomass sources.
Technical Abstract: Distribution coefficients and separation factors were determined for the partitioning of ethanol and water from aqueous mixtures into several vegetable oils and their fatty alcohol and fatty ester derivatives. Castor oil, ricinoleyl alcohol and methyl ricinoleate all show higher ethanol distribution coefficients, and similar or reduced separation factors, relative to other oils and derivatives studied here or reported by others. Of particular interest, ricinoleyl alcohol has an ethanol distribution coefficient 50% higher than that of oleyl alcohol, a commonly studied solvent for ethanol extraction from fermentation broths.