TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: During or after separation of the ionic liquid phase from the aqueous phase, production of the butanol product in the fermentation broth continues. The process is conducted in a vessel external to the fermentor. After separation of the aqueous phase from the ionic liquid phase, the aqueous phase or its portion is returned to the fermentor. After butanol recovery, the ionic liquid is recycled to the fermentation broth. The process further comprises mixing of the recovered butanol with a motor fuel. Preferred Components: At least one ionic liquid comprises a cation comprising 1-ethyl-3-methylimidazolium, 1-butyl-3-methylimidazolium , 1-(N,N,N-dimethyl(methylethoxy)aminoethyl)-5-methylpyrrolidin-2-one, 1-(N,N,N-dimethylpropylaminoethyl)-5-methylpyrrolidin-2-one, 1-(N,N,N-dimethyl(hydroxyethyl)aminoethyl)-5-methylpyrrolidin-2-one or 1-(N,N,N-dimethyl(ethylethoxy)aminoethyl)-5-methylpyrrolidin-2-one. At least one ionic liquid is 1-(N,N,N-dimethyl(ethylethoxy)aminoethyl)-5-methylpyrrolidin-2-one bis(trifluoromethane)sulfonamide, 1-(N,N,N-dimethylpropylaminoethyl)-5-methylpyrrolidin-2-one bis(trifluoromethane)sulfonamide, 1-(N,N,N-dimethyl(methylethoxy)aminoethyl)-5-methylpyrrolidin-2-one bis(trifluoromethane)sulfonamide, 1-(N,N,N-dimethyl(hydroxyethyl)aminoethyl)-5-methylpyrrolidin-2-one bis(trifluoromethane)sulfonamide (all preferred), 1-ethyl-3-methylimidazolium levulinate, 1-(N,N,N-dimethyl(ethylethoxy)aminoethyl)-5-methylpyrrolidin-2-one hexafluoropropane sulfonate, 1-(N,N,N-dimethyl(methylethoxy)aminoethyl)-5-methylpyrrolidin-2-one hexafluoropropane sulfonate or 1-butyl-3-methylimidazolium levulinate. EXAMPLE - Stock culture of Saccharomyces cerevisiae was grown by taking cells off an agar plate and placing them in a 15 ml sterile polypropylene test tube containing yeast extract peptone dextrose (YPD) medium (3 ml). The test tube was incubated at 30 degrees C at 175 rpm in an incubator. After 24 hours the test tube was removed and used immediately. Then the prepared stock culture portion (50 mu l) was inoculated into 15 ml sterile polypropylene culture tube containing fresh YPD medium (3 ml) and incubated for 4 hours at 30 degrees C at 175 rpm. After 4 hours, culture tube was inoculated with 1-ethyl-3-methylimidazolium levulinate (150 mu l). Then the culture tube was inoculated with an ionic liquid and continued for another 16 hours under same conditions. After 16 hours, sample was taken from culture tube by spinning at 28000 rpm and 20 degrees C for 10 minutes in a centrifuge to obtain butanol.