Methods for recovery of at least one alcohol from dilute aqueous alcohol
feed streams are described. The methods include steps of a) providing a
source of a dilute aqueous alcohol feed stream including at least one
alcohol; b) substantially removing any solids from the dilute aqueous
alcohol feed stream to form a feed stream substantially devoid of solids;
c) circulating the feed stream substantially devoid of solids through a
liquid-liquid extraction system having multiple equilibrium stages; d)
recovering a raffinate phase substantially depleted in the at least one
alcohol and an extract phase substantially enriched in the at least one
alcohol; e) passing the extract phase to a recovery system wherein the
extract phase is subjected to microwave radiation; f) recovering the
volatilized product; and g) recycling the solvent to the liquid-liquid
extraction system. The microwave radiation substantially heats the
alcohol but not the solvent to form a volatilized product of
substantially pure alcohol. The methods further include optional steps of
removing any residual water from the substantially pure alcohol product
to form a fuel-grade alcohol. The liquid-liquid extraction system can be
a hydrophobic, microporous membrane extraction system having a plurality
of hollow fibers.