Separation technologies for the recovery and dehydration of alcohols from fermentation broths

Multi-column distillation followed by molecular sieve adsorption is currently the standard method for producing fuel-grade ethanol from dilute fermentation broths in modern corn-to-ethanol facilities. As the liquid biofuels industry transitions to lignocellulosic feedstocks, expands the end-product portfolio to include other alcohols, and encounters more dilute alcohol concentrations, alternative separation technologies which are more energy efficient than the conventional approach will be in demand. In this review, alcohol recovery technology options and alcohol dehydration technology options for the production of ethanol and 1-butanol are reviewed and compared, with an emphasis on the energy footprint of each approach. Select hybrid technologies are also described. Published in 2008 by John Wiley & Sons, Ltd